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TOMOYO Linux Cross Reference
Linux/net/core/filter.c

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Linux Socket Filter - Kernel level socket filtering
  3  *
  4  * Based on the design of the Berkeley Packet Filter. The new
  5  * internal format has been designed by PLUMgrid:
  6  *
  7  *      Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
  8  *
  9  * Authors:
 10  *
 11  *      Jay Schulist <jschlst@samba.org>
 12  *      Alexei Starovoitov <ast@plumgrid.com>
 13  *      Daniel Borkmann <dborkman@redhat.com>
 14  *
 15  * This program is free software; you can redistribute it and/or
 16  * modify it under the terms of the GNU General Public License
 17  * as published by the Free Software Foundation; either version
 18  * 2 of the License, or (at your option) any later version.
 19  *
 20  * Andi Kleen - Fix a few bad bugs and races.
 21  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
 22  */
 23 
 24 #include <linux/module.h>
 25 #include <linux/types.h>
 26 #include <linux/mm.h>
 27 #include <linux/fcntl.h>
 28 #include <linux/socket.h>
 29 #include <linux/sock_diag.h>
 30 #include <linux/in.h>
 31 #include <linux/inet.h>
 32 #include <linux/netdevice.h>
 33 #include <linux/if_packet.h>
 34 #include <linux/if_arp.h>
 35 #include <linux/gfp.h>
 36 #include <net/ip.h>
 37 #include <net/protocol.h>
 38 #include <net/netlink.h>
 39 #include <linux/skbuff.h>
 40 #include <net/sock.h>
 41 #include <net/flow_dissector.h>
 42 #include <linux/errno.h>
 43 #include <linux/timer.h>
 44 #include <linux/uaccess.h>
 45 #include <asm/unaligned.h>
 46 #include <linux/filter.h>
 47 #include <linux/ratelimit.h>
 48 #include <linux/seccomp.h>
 49 #include <linux/if_vlan.h>
 50 #include <linux/bpf.h>
 51 #include <net/sch_generic.h>
 52 #include <net/cls_cgroup.h>
 53 #include <net/dst_metadata.h>
 54 #include <net/dst.h>
 55 #include <net/sock_reuseport.h>
 56 #include <net/busy_poll.h>
 57 
 58 /**
 59  *      sk_filter_trim_cap - run a packet through a socket filter
 60  *      @sk: sock associated with &sk_buff
 61  *      @skb: buffer to filter
 62  *      @cap: limit on how short the eBPF program may trim the packet
 63  *
 64  * Run the eBPF program and then cut skb->data to correct size returned by
 65  * the program. If pkt_len is 0 we toss packet. If skb->len is smaller
 66  * than pkt_len we keep whole skb->data. This is the socket level
 67  * wrapper to BPF_PROG_RUN. It returns 0 if the packet should
 68  * be accepted or -EPERM if the packet should be tossed.
 69  *
 70  */
 71 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap)
 72 {
 73         int err;
 74         struct sk_filter *filter;
 75 
 76         /*
 77          * If the skb was allocated from pfmemalloc reserves, only
 78          * allow SOCK_MEMALLOC sockets to use it as this socket is
 79          * helping free memory
 80          */
 81         if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) {
 82                 NET_INC_STATS(sock_net(sk), LINUX_MIB_PFMEMALLOCDROP);
 83                 return -ENOMEM;
 84         }
 85         err = BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb);
 86         if (err)
 87                 return err;
 88 
 89         err = security_sock_rcv_skb(sk, skb);
 90         if (err)
 91                 return err;
 92 
 93         rcu_read_lock();
 94         filter = rcu_dereference(sk->sk_filter);
 95         if (filter) {
 96                 struct sock *save_sk = skb->sk;
 97                 unsigned int pkt_len;
 98 
 99                 skb->sk = sk;
100                 pkt_len = bpf_prog_run_save_cb(filter->prog, skb);
101                 skb->sk = save_sk;
102                 err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM;
103         }
104         rcu_read_unlock();
105 
106         return err;
107 }
108 EXPORT_SYMBOL(sk_filter_trim_cap);
109 
110 BPF_CALL_1(__skb_get_pay_offset, struct sk_buff *, skb)
111 {
112         return skb_get_poff(skb);
113 }
114 
115 BPF_CALL_3(__skb_get_nlattr, struct sk_buff *, skb, u32, a, u32, x)
116 {
117         struct nlattr *nla;
118 
119         if (skb_is_nonlinear(skb))
120                 return 0;
121 
122         if (skb->len < sizeof(struct nlattr))
123                 return 0;
124 
125         if (a > skb->len - sizeof(struct nlattr))
126                 return 0;
127 
128         nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x);
129         if (nla)
130                 return (void *) nla - (void *) skb->data;
131 
132         return 0;
133 }
134 
135 BPF_CALL_3(__skb_get_nlattr_nest, struct sk_buff *, skb, u32, a, u32, x)
136 {
137         struct nlattr *nla;
138 
139         if (skb_is_nonlinear(skb))
140                 return 0;
141 
142         if (skb->len < sizeof(struct nlattr))
143                 return 0;
144 
145         if (a > skb->len - sizeof(struct nlattr))
146                 return 0;
147 
148         nla = (struct nlattr *) &skb->data[a];
149         if (nla->nla_len > skb->len - a)
150                 return 0;
151 
152         nla = nla_find_nested(nla, x);
153         if (nla)
154                 return (void *) nla - (void *) skb->data;
155 
156         return 0;
157 }
158 
159 BPF_CALL_0(__get_raw_cpu_id)
160 {
161         return raw_smp_processor_id();
162 }
163 
164 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
165         .func           = __get_raw_cpu_id,
166         .gpl_only       = false,
167         .ret_type       = RET_INTEGER,
168 };
169 
170 static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
171                               struct bpf_insn *insn_buf)
172 {
173         struct bpf_insn *insn = insn_buf;
174 
175         switch (skb_field) {
176         case SKF_AD_MARK:
177                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
178 
179                 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
180                                       offsetof(struct sk_buff, mark));
181                 break;
182 
183         case SKF_AD_PKTTYPE:
184                 *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_TYPE_OFFSET());
185                 *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, PKT_TYPE_MAX);
186 #ifdef __BIG_ENDIAN_BITFIELD
187                 *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 5);
188 #endif
189                 break;
190 
191         case SKF_AD_QUEUE:
192                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
193 
194                 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
195                                       offsetof(struct sk_buff, queue_mapping));
196                 break;
197 
198         case SKF_AD_VLAN_TAG:
199         case SKF_AD_VLAN_TAG_PRESENT:
200                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
201                 BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
202 
203                 /* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */
204                 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
205                                       offsetof(struct sk_buff, vlan_tci));
206                 if (skb_field == SKF_AD_VLAN_TAG) {
207                         *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg,
208                                                 ~VLAN_TAG_PRESENT);
209                 } else {
210                         /* dst_reg >>= 12 */
211                         *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12);
212                         /* dst_reg &= 1 */
213                         *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1);
214                 }
215                 break;
216         }
217 
218         return insn - insn_buf;
219 }
220 
221 static bool convert_bpf_extensions(struct sock_filter *fp,
222                                    struct bpf_insn **insnp)
223 {
224         struct bpf_insn *insn = *insnp;
225         u32 cnt;
226 
227         switch (fp->k) {
228         case SKF_AD_OFF + SKF_AD_PROTOCOL:
229                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
230 
231                 /* A = *(u16 *) (CTX + offsetof(protocol)) */
232                 *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX,
233                                       offsetof(struct sk_buff, protocol));
234                 /* A = ntohs(A) [emitting a nop or swap16] */
235                 *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16);
236                 break;
237 
238         case SKF_AD_OFF + SKF_AD_PKTTYPE:
239                 cnt = convert_skb_access(SKF_AD_PKTTYPE, BPF_REG_A, BPF_REG_CTX, insn);
240                 insn += cnt - 1;
241                 break;
242 
243         case SKF_AD_OFF + SKF_AD_IFINDEX:
244         case SKF_AD_OFF + SKF_AD_HATYPE:
245                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
246                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
247 
248                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
249                                       BPF_REG_TMP, BPF_REG_CTX,
250                                       offsetof(struct sk_buff, dev));
251                 /* if (tmp != 0) goto pc + 1 */
252                 *insn++ = BPF_JMP_IMM(BPF_JNE, BPF_REG_TMP, 0, 1);
253                 *insn++ = BPF_EXIT_INSN();
254                 if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX)
255                         *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_TMP,
256                                             offsetof(struct net_device, ifindex));
257                 else
258                         *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_TMP,
259                                             offsetof(struct net_device, type));
260                 break;
261 
262         case SKF_AD_OFF + SKF_AD_MARK:
263                 cnt = convert_skb_access(SKF_AD_MARK, BPF_REG_A, BPF_REG_CTX, insn);
264                 insn += cnt - 1;
265                 break;
266 
267         case SKF_AD_OFF + SKF_AD_RXHASH:
268                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
269 
270                 *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX,
271                                     offsetof(struct sk_buff, hash));
272                 break;
273 
274         case SKF_AD_OFF + SKF_AD_QUEUE:
275                 cnt = convert_skb_access(SKF_AD_QUEUE, BPF_REG_A, BPF_REG_CTX, insn);
276                 insn += cnt - 1;
277                 break;
278 
279         case SKF_AD_OFF + SKF_AD_VLAN_TAG:
280                 cnt = convert_skb_access(SKF_AD_VLAN_TAG,
281                                          BPF_REG_A, BPF_REG_CTX, insn);
282                 insn += cnt - 1;
283                 break;
284 
285         case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT:
286                 cnt = convert_skb_access(SKF_AD_VLAN_TAG_PRESENT,
287                                          BPF_REG_A, BPF_REG_CTX, insn);
288                 insn += cnt - 1;
289                 break;
290 
291         case SKF_AD_OFF + SKF_AD_VLAN_TPID:
292                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2);
293 
294                 /* A = *(u16 *) (CTX + offsetof(vlan_proto)) */
295                 *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX,
296                                       offsetof(struct sk_buff, vlan_proto));
297                 /* A = ntohs(A) [emitting a nop or swap16] */
298                 *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16);
299                 break;
300 
301         case SKF_AD_OFF + SKF_AD_PAY_OFFSET:
302         case SKF_AD_OFF + SKF_AD_NLATTR:
303         case SKF_AD_OFF + SKF_AD_NLATTR_NEST:
304         case SKF_AD_OFF + SKF_AD_CPU:
305         case SKF_AD_OFF + SKF_AD_RANDOM:
306                 /* arg1 = CTX */
307                 *insn++ = BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX);
308                 /* arg2 = A */
309                 *insn++ = BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_A);
310                 /* arg3 = X */
311                 *insn++ = BPF_MOV64_REG(BPF_REG_ARG3, BPF_REG_X);
312                 /* Emit call(arg1=CTX, arg2=A, arg3=X) */
313                 switch (fp->k) {
314                 case SKF_AD_OFF + SKF_AD_PAY_OFFSET:
315                         *insn = BPF_EMIT_CALL(__skb_get_pay_offset);
316                         break;
317                 case SKF_AD_OFF + SKF_AD_NLATTR:
318                         *insn = BPF_EMIT_CALL(__skb_get_nlattr);
319                         break;
320                 case SKF_AD_OFF + SKF_AD_NLATTR_NEST:
321                         *insn = BPF_EMIT_CALL(__skb_get_nlattr_nest);
322                         break;
323                 case SKF_AD_OFF + SKF_AD_CPU:
324                         *insn = BPF_EMIT_CALL(__get_raw_cpu_id);
325                         break;
326                 case SKF_AD_OFF + SKF_AD_RANDOM:
327                         *insn = BPF_EMIT_CALL(bpf_user_rnd_u32);
328                         bpf_user_rnd_init_once();
329                         break;
330                 }
331                 break;
332 
333         case SKF_AD_OFF + SKF_AD_ALU_XOR_X:
334                 /* A ^= X */
335                 *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X);
336                 break;
337 
338         default:
339                 /* This is just a dummy call to avoid letting the compiler
340                  * evict __bpf_call_base() as an optimization. Placed here
341                  * where no-one bothers.
342                  */
343                 BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0);
344                 return false;
345         }
346 
347         *insnp = insn;
348         return true;
349 }
350 
351 /**
352  *      bpf_convert_filter - convert filter program
353  *      @prog: the user passed filter program
354  *      @len: the length of the user passed filter program
355  *      @new_prog: buffer where converted program will be stored
356  *      @new_len: pointer to store length of converted program
357  *
358  * Remap 'sock_filter' style classic BPF (cBPF) instruction set to 'bpf_insn'
359  * style extended BPF (eBPF).
360  * Conversion workflow:
361  *
362  * 1) First pass for calculating the new program length:
363  *   bpf_convert_filter(old_prog, old_len, NULL, &new_len)
364  *
365  * 2) 2nd pass to remap in two passes: 1st pass finds new
366  *    jump offsets, 2nd pass remapping:
367  *   new_prog = kmalloc(sizeof(struct bpf_insn) * new_len);
368  *   bpf_convert_filter(old_prog, old_len, new_prog, &new_len);
369  */
370 static int bpf_convert_filter(struct sock_filter *prog, int len,
371                               struct bpf_insn *new_prog, int *new_len)
372 {
373         int new_flen = 0, pass = 0, target, i;
374         struct bpf_insn *new_insn;
375         struct sock_filter *fp;
376         int *addrs = NULL;
377         u8 bpf_src;
378 
379         BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK);
380         BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
381 
382         if (len <= 0 || len > BPF_MAXINSNS)
383                 return -EINVAL;
384 
385         if (new_prog) {
386                 addrs = kcalloc(len, sizeof(*addrs),
387                                 GFP_KERNEL | __GFP_NOWARN);
388                 if (!addrs)
389                         return -ENOMEM;
390         }
391 
392 do_pass:
393         new_insn = new_prog;
394         fp = prog;
395 
396         /* Classic BPF related prologue emission. */
397         if (new_insn) {
398                 /* Classic BPF expects A and X to be reset first. These need
399                  * to be guaranteed to be the first two instructions.
400                  */
401                 *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_A, BPF_REG_A);
402                 *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_X, BPF_REG_X);
403 
404                 /* All programs must keep CTX in callee saved BPF_REG_CTX.
405                  * In eBPF case it's done by the compiler, here we need to
406                  * do this ourself. Initial CTX is present in BPF_REG_ARG1.
407                  */
408                 *new_insn++ = BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1);
409         } else {
410                 new_insn += 3;
411         }
412 
413         for (i = 0; i < len; fp++, i++) {
414                 struct bpf_insn tmp_insns[6] = { };
415                 struct bpf_insn *insn = tmp_insns;
416 
417                 if (addrs)
418                         addrs[i] = new_insn - new_prog;
419 
420                 switch (fp->code) {
421                 /* All arithmetic insns and skb loads map as-is. */
422                 case BPF_ALU | BPF_ADD | BPF_X:
423                 case BPF_ALU | BPF_ADD | BPF_K:
424                 case BPF_ALU | BPF_SUB | BPF_X:
425                 case BPF_ALU | BPF_SUB | BPF_K:
426                 case BPF_ALU | BPF_AND | BPF_X:
427                 case BPF_ALU | BPF_AND | BPF_K:
428                 case BPF_ALU | BPF_OR | BPF_X:
429                 case BPF_ALU | BPF_OR | BPF_K:
430                 case BPF_ALU | BPF_LSH | BPF_X:
431                 case BPF_ALU | BPF_LSH | BPF_K:
432                 case BPF_ALU | BPF_RSH | BPF_X:
433                 case BPF_ALU | BPF_RSH | BPF_K:
434                 case BPF_ALU | BPF_XOR | BPF_X:
435                 case BPF_ALU | BPF_XOR | BPF_K:
436                 case BPF_ALU | BPF_MUL | BPF_X:
437                 case BPF_ALU | BPF_MUL | BPF_K:
438                 case BPF_ALU | BPF_DIV | BPF_X:
439                 case BPF_ALU | BPF_DIV | BPF_K:
440                 case BPF_ALU | BPF_MOD | BPF_X:
441                 case BPF_ALU | BPF_MOD | BPF_K:
442                 case BPF_ALU | BPF_NEG:
443                 case BPF_LD | BPF_ABS | BPF_W:
444                 case BPF_LD | BPF_ABS | BPF_H:
445                 case BPF_LD | BPF_ABS | BPF_B:
446                 case BPF_LD | BPF_IND | BPF_W:
447                 case BPF_LD | BPF_IND | BPF_H:
448                 case BPF_LD | BPF_IND | BPF_B:
449                         /* Check for overloaded BPF extension and
450                          * directly convert it if found, otherwise
451                          * just move on with mapping.
452                          */
453                         if (BPF_CLASS(fp->code) == BPF_LD &&
454                             BPF_MODE(fp->code) == BPF_ABS &&
455                             convert_bpf_extensions(fp, &insn))
456                                 break;
457 
458                         *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k);
459                         break;
460 
461                 /* Jump transformation cannot use BPF block macros
462                  * everywhere as offset calculation and target updates
463                  * require a bit more work than the rest, i.e. jump
464                  * opcodes map as-is, but offsets need adjustment.
465                  */
466 
467 #define BPF_EMIT_JMP                                                    \
468         do {                                                            \
469                 if (target >= len || target < 0)                        \
470                         goto err;                                       \
471                 insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0;   \
472                 /* Adjust pc relative offset for 2nd or 3rd insn. */    \
473                 insn->off -= insn - tmp_insns;                          \
474         } while (0)
475 
476                 case BPF_JMP | BPF_JA:
477                         target = i + fp->k + 1;
478                         insn->code = fp->code;
479                         BPF_EMIT_JMP;
480                         break;
481 
482                 case BPF_JMP | BPF_JEQ | BPF_K:
483                 case BPF_JMP | BPF_JEQ | BPF_X:
484                 case BPF_JMP | BPF_JSET | BPF_K:
485                 case BPF_JMP | BPF_JSET | BPF_X:
486                 case BPF_JMP | BPF_JGT | BPF_K:
487                 case BPF_JMP | BPF_JGT | BPF_X:
488                 case BPF_JMP | BPF_JGE | BPF_K:
489                 case BPF_JMP | BPF_JGE | BPF_X:
490                         if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) {
491                                 /* BPF immediates are signed, zero extend
492                                  * immediate into tmp register and use it
493                                  * in compare insn.
494                                  */
495                                 *insn++ = BPF_MOV32_IMM(BPF_REG_TMP, fp->k);
496 
497                                 insn->dst_reg = BPF_REG_A;
498                                 insn->src_reg = BPF_REG_TMP;
499                                 bpf_src = BPF_X;
500                         } else {
501                                 insn->dst_reg = BPF_REG_A;
502                                 insn->imm = fp->k;
503                                 bpf_src = BPF_SRC(fp->code);
504                                 insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0;
505                         }
506 
507                         /* Common case where 'jump_false' is next insn. */
508                         if (fp->jf == 0) {
509                                 insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src;
510                                 target = i + fp->jt + 1;
511                                 BPF_EMIT_JMP;
512                                 break;
513                         }
514 
515                         /* Convert JEQ into JNE when 'jump_true' is next insn. */
516                         if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) {
517                                 insn->code = BPF_JMP | BPF_JNE | bpf_src;
518                                 target = i + fp->jf + 1;
519                                 BPF_EMIT_JMP;
520                                 break;
521                         }
522 
523                         /* Other jumps are mapped into two insns: Jxx and JA. */
524                         target = i + fp->jt + 1;
525                         insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src;
526                         BPF_EMIT_JMP;
527                         insn++;
528 
529                         insn->code = BPF_JMP | BPF_JA;
530                         target = i + fp->jf + 1;
531                         BPF_EMIT_JMP;
532                         break;
533 
534                 /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */
535                 case BPF_LDX | BPF_MSH | BPF_B:
536                         /* tmp = A */
537                         *insn++ = BPF_MOV64_REG(BPF_REG_TMP, BPF_REG_A);
538                         /* A = BPF_R0 = *(u8 *) (skb->data + K) */
539                         *insn++ = BPF_LD_ABS(BPF_B, fp->k);
540                         /* A &= 0xf */
541                         *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf);
542                         /* A <<= 2 */
543                         *insn++ = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2);
544                         /* X = A */
545                         *insn++ = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A);
546                         /* A = tmp */
547                         *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_TMP);
548                         break;
549 
550                 /* RET_K is remaped into 2 insns. RET_A case doesn't need an
551                  * extra mov as BPF_REG_0 is already mapped into BPF_REG_A.
552                  */
553                 case BPF_RET | BPF_A:
554                 case BPF_RET | BPF_K:
555                         if (BPF_RVAL(fp->code) == BPF_K)
556                                 *insn++ = BPF_MOV32_RAW(BPF_K, BPF_REG_0,
557                                                         0, fp->k);
558                         *insn = BPF_EXIT_INSN();
559                         break;
560 
561                 /* Store to stack. */
562                 case BPF_ST:
563                 case BPF_STX:
564                         *insn = BPF_STX_MEM(BPF_W, BPF_REG_FP, BPF_CLASS(fp->code) ==
565                                             BPF_ST ? BPF_REG_A : BPF_REG_X,
566                                             -(BPF_MEMWORDS - fp->k) * 4);
567                         break;
568 
569                 /* Load from stack. */
570                 case BPF_LD | BPF_MEM:
571                 case BPF_LDX | BPF_MEM:
572                         *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD  ?
573                                             BPF_REG_A : BPF_REG_X, BPF_REG_FP,
574                                             -(BPF_MEMWORDS - fp->k) * 4);
575                         break;
576 
577                 /* A = K or X = K */
578                 case BPF_LD | BPF_IMM:
579                 case BPF_LDX | BPF_IMM:
580                         *insn = BPF_MOV32_IMM(BPF_CLASS(fp->code) == BPF_LD ?
581                                               BPF_REG_A : BPF_REG_X, fp->k);
582                         break;
583 
584                 /* X = A */
585                 case BPF_MISC | BPF_TAX:
586                         *insn = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A);
587                         break;
588 
589                 /* A = X */
590                 case BPF_MISC | BPF_TXA:
591                         *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_X);
592                         break;
593 
594                 /* A = skb->len or X = skb->len */
595                 case BPF_LD | BPF_W | BPF_LEN:
596                 case BPF_LDX | BPF_W | BPF_LEN:
597                         *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ?
598                                             BPF_REG_A : BPF_REG_X, BPF_REG_CTX,
599                                             offsetof(struct sk_buff, len));
600                         break;
601 
602                 /* Access seccomp_data fields. */
603                 case BPF_LDX | BPF_ABS | BPF_W:
604                         /* A = *(u32 *) (ctx + K) */
605                         *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, fp->k);
606                         break;
607 
608                 /* Unknown instruction. */
609                 default:
610                         goto err;
611                 }
612 
613                 insn++;
614                 if (new_prog)
615                         memcpy(new_insn, tmp_insns,
616                                sizeof(*insn) * (insn - tmp_insns));
617                 new_insn += insn - tmp_insns;
618         }
619 
620         if (!new_prog) {
621                 /* Only calculating new length. */
622                 *new_len = new_insn - new_prog;
623                 return 0;
624         }
625 
626         pass++;
627         if (new_flen != new_insn - new_prog) {
628                 new_flen = new_insn - new_prog;
629                 if (pass > 2)
630                         goto err;
631                 goto do_pass;
632         }
633 
634         kfree(addrs);
635         BUG_ON(*new_len != new_flen);
636         return 0;
637 err:
638         kfree(addrs);
639         return -EINVAL;
640 }
641 
642 /* Security:
643  *
644  * As we dont want to clear mem[] array for each packet going through
645  * __bpf_prog_run(), we check that filter loaded by user never try to read
646  * a cell if not previously written, and we check all branches to be sure
647  * a malicious user doesn't try to abuse us.
648  */
649 static int check_load_and_stores(const struct sock_filter *filter, int flen)
650 {
651         u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */
652         int pc, ret = 0;
653 
654         BUILD_BUG_ON(BPF_MEMWORDS > 16);
655 
656         masks = kmalloc_array(flen, sizeof(*masks), GFP_KERNEL);
657         if (!masks)
658                 return -ENOMEM;
659 
660         memset(masks, 0xff, flen * sizeof(*masks));
661 
662         for (pc = 0; pc < flen; pc++) {
663                 memvalid &= masks[pc];
664 
665                 switch (filter[pc].code) {
666                 case BPF_ST:
667                 case BPF_STX:
668                         memvalid |= (1 << filter[pc].k);
669                         break;
670                 case BPF_LD | BPF_MEM:
671                 case BPF_LDX | BPF_MEM:
672                         if (!(memvalid & (1 << filter[pc].k))) {
673                                 ret = -EINVAL;
674                                 goto error;
675                         }
676                         break;
677                 case BPF_JMP | BPF_JA:
678                         /* A jump must set masks on target */
679                         masks[pc + 1 + filter[pc].k] &= memvalid;
680                         memvalid = ~0;
681                         break;
682                 case BPF_JMP | BPF_JEQ | BPF_K:
683                 case BPF_JMP | BPF_JEQ | BPF_X:
684                 case BPF_JMP | BPF_JGE | BPF_K:
685                 case BPF_JMP | BPF_JGE | BPF_X:
686                 case BPF_JMP | BPF_JGT | BPF_K:
687                 case BPF_JMP | BPF_JGT | BPF_X:
688                 case BPF_JMP | BPF_JSET | BPF_K:
689                 case BPF_JMP | BPF_JSET | BPF_X:
690                         /* A jump must set masks on targets */
691                         masks[pc + 1 + filter[pc].jt] &= memvalid;
692                         masks[pc + 1 + filter[pc].jf] &= memvalid;
693                         memvalid = ~0;
694                         break;
695                 }
696         }
697 error:
698         kfree(masks);
699         return ret;
700 }
701 
702 static bool chk_code_allowed(u16 code_to_probe)
703 {
704         static const bool codes[] = {
705                 /* 32 bit ALU operations */
706                 [BPF_ALU | BPF_ADD | BPF_K] = true,
707                 [BPF_ALU | BPF_ADD | BPF_X] = true,
708                 [BPF_ALU | BPF_SUB | BPF_K] = true,
709                 [BPF_ALU | BPF_SUB | BPF_X] = true,
710                 [BPF_ALU | BPF_MUL | BPF_K] = true,
711                 [BPF_ALU | BPF_MUL | BPF_X] = true,
712                 [BPF_ALU | BPF_DIV | BPF_K] = true,
713                 [BPF_ALU | BPF_DIV | BPF_X] = true,
714                 [BPF_ALU | BPF_MOD | BPF_K] = true,
715                 [BPF_ALU | BPF_MOD | BPF_X] = true,
716                 [BPF_ALU | BPF_AND | BPF_K] = true,
717                 [BPF_ALU | BPF_AND | BPF_X] = true,
718                 [BPF_ALU | BPF_OR | BPF_K] = true,
719                 [BPF_ALU | BPF_OR | BPF_X] = true,
720                 [BPF_ALU | BPF_XOR | BPF_K] = true,
721                 [BPF_ALU | BPF_XOR | BPF_X] = true,
722                 [BPF_ALU | BPF_LSH | BPF_K] = true,
723                 [BPF_ALU | BPF_LSH | BPF_X] = true,
724                 [BPF_ALU | BPF_RSH | BPF_K] = true,
725                 [BPF_ALU | BPF_RSH | BPF_X] = true,
726                 [BPF_ALU | BPF_NEG] = true,
727                 /* Load instructions */
728                 [BPF_LD | BPF_W | BPF_ABS] = true,
729                 [BPF_LD | BPF_H | BPF_ABS] = true,
730                 [BPF_LD | BPF_B | BPF_ABS] = true,
731                 [BPF_LD | BPF_W | BPF_LEN] = true,
732                 [BPF_LD | BPF_W | BPF_IND] = true,
733                 [BPF_LD | BPF_H | BPF_IND] = true,
734                 [BPF_LD | BPF_B | BPF_IND] = true,
735                 [BPF_LD | BPF_IMM] = true,
736                 [BPF_LD | BPF_MEM] = true,
737                 [BPF_LDX | BPF_W | BPF_LEN] = true,
738                 [BPF_LDX | BPF_B | BPF_MSH] = true,
739                 [BPF_LDX | BPF_IMM] = true,
740                 [BPF_LDX | BPF_MEM] = true,
741                 /* Store instructions */
742                 [BPF_ST] = true,
743                 [BPF_STX] = true,
744                 /* Misc instructions */
745                 [BPF_MISC | BPF_TAX] = true,
746                 [BPF_MISC | BPF_TXA] = true,
747                 /* Return instructions */
748                 [BPF_RET | BPF_K] = true,
749                 [BPF_RET | BPF_A] = true,
750                 /* Jump instructions */
751                 [BPF_JMP | BPF_JA] = true,
752                 [BPF_JMP | BPF_JEQ | BPF_K] = true,
753                 [BPF_JMP | BPF_JEQ | BPF_X] = true,
754                 [BPF_JMP | BPF_JGE | BPF_K] = true,
755                 [BPF_JMP | BPF_JGE | BPF_X] = true,
756                 [BPF_JMP | BPF_JGT | BPF_K] = true,
757                 [BPF_JMP | BPF_JGT | BPF_X] = true,
758                 [BPF_JMP | BPF_JSET | BPF_K] = true,
759                 [BPF_JMP | BPF_JSET | BPF_X] = true,
760         };
761 
762         if (code_to_probe >= ARRAY_SIZE(codes))
763                 return false;
764 
765         return codes[code_to_probe];
766 }
767 
768 static bool bpf_check_basics_ok(const struct sock_filter *filter,
769                                 unsigned int flen)
770 {
771         if (filter == NULL)
772                 return false;
773         if (flen == 0 || flen > BPF_MAXINSNS)
774                 return false;
775 
776         return true;
777 }
778 
779 /**
780  *      bpf_check_classic - verify socket filter code
781  *      @filter: filter to verify
782  *      @flen: length of filter
783  *
784  * Check the user's filter code. If we let some ugly
785  * filter code slip through kaboom! The filter must contain
786  * no references or jumps that are out of range, no illegal
787  * instructions, and must end with a RET instruction.
788  *
789  * All jumps are forward as they are not signed.
790  *
791  * Returns 0 if the rule set is legal or -EINVAL if not.
792  */
793 static int bpf_check_classic(const struct sock_filter *filter,
794                              unsigned int flen)
795 {
796         bool anc_found;
797         int pc;
798 
799         /* Check the filter code now */
800         for (pc = 0; pc < flen; pc++) {
801                 const struct sock_filter *ftest = &filter[pc];
802 
803                 /* May we actually operate on this code? */
804                 if (!chk_code_allowed(ftest->code))
805                         return -EINVAL;
806 
807                 /* Some instructions need special checks */
808                 switch (ftest->code) {
809                 case BPF_ALU | BPF_DIV | BPF_K:
810                 case BPF_ALU | BPF_MOD | BPF_K:
811                         /* Check for division by zero */
812                         if (ftest->k == 0)
813                                 return -EINVAL;
814                         break;
815                 case BPF_ALU | BPF_LSH | BPF_K:
816                 case BPF_ALU | BPF_RSH | BPF_K:
817                         if (ftest->k >= 32)
818                                 return -EINVAL;
819                         break;
820                 case BPF_LD | BPF_MEM:
821                 case BPF_LDX | BPF_MEM:
822                 case BPF_ST:
823                 case BPF_STX:
824                         /* Check for invalid memory addresses */
825                         if (ftest->k >= BPF_MEMWORDS)
826                                 return -EINVAL;
827                         break;
828                 case BPF_JMP | BPF_JA:
829                         /* Note, the large ftest->k might cause loops.
830                          * Compare this with conditional jumps below,
831                          * where offsets are limited. --ANK (981016)
832                          */
833                         if (ftest->k >= (unsigned int)(flen - pc - 1))
834                                 return -EINVAL;
835                         break;
836                 case BPF_JMP | BPF_JEQ | BPF_K:
837                 case BPF_JMP | BPF_JEQ | BPF_X:
838                 case BPF_JMP | BPF_JGE | BPF_K:
839                 case BPF_JMP | BPF_JGE | BPF_X:
840                 case BPF_JMP | BPF_JGT | BPF_K:
841                 case BPF_JMP | BPF_JGT | BPF_X:
842                 case BPF_JMP | BPF_JSET | BPF_K:
843                 case BPF_JMP | BPF_JSET | BPF_X:
844                         /* Both conditionals must be safe */
845                         if (pc + ftest->jt + 1 >= flen ||
846                             pc + ftest->jf + 1 >= flen)
847                                 return -EINVAL;
848                         break;
849                 case BPF_LD | BPF_W | BPF_ABS:
850                 case BPF_LD | BPF_H | BPF_ABS:
851                 case BPF_LD | BPF_B | BPF_ABS:
852                         anc_found = false;
853                         if (bpf_anc_helper(ftest) & BPF_ANC)
854                                 anc_found = true;
855                         /* Ancillary operation unknown or unsupported */
856                         if (anc_found == false && ftest->k >= SKF_AD_OFF)
857                                 return -EINVAL;
858                 }
859         }
860 
861         /* Last instruction must be a RET code */
862         switch (filter[flen - 1].code) {
863         case BPF_RET | BPF_K:
864         case BPF_RET | BPF_A:
865                 return check_load_and_stores(filter, flen);
866         }
867 
868         return -EINVAL;
869 }
870 
871 static int bpf_prog_store_orig_filter(struct bpf_prog *fp,
872                                       const struct sock_fprog *fprog)
873 {
874         unsigned int fsize = bpf_classic_proglen(fprog);
875         struct sock_fprog_kern *fkprog;
876 
877         fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL);
878         if (!fp->orig_prog)
879                 return -ENOMEM;
880 
881         fkprog = fp->orig_prog;
882         fkprog->len = fprog->len;
883 
884         fkprog->filter = kmemdup(fp->insns, fsize,
885                                  GFP_KERNEL | __GFP_NOWARN);
886         if (!fkprog->filter) {
887                 kfree(fp->orig_prog);
888                 return -ENOMEM;
889         }
890 
891         return 0;
892 }
893 
894 static void bpf_release_orig_filter(struct bpf_prog *fp)
895 {
896         struct sock_fprog_kern *fprog = fp->orig_prog;
897 
898         if (fprog) {
899                 kfree(fprog->filter);
900                 kfree(fprog);
901         }
902 }
903 
904 static void __bpf_prog_release(struct bpf_prog *prog)
905 {
906         if (prog->type == BPF_PROG_TYPE_SOCKET_FILTER) {
907                 bpf_prog_put(prog);
908         } else {
909                 bpf_release_orig_filter(prog);
910                 bpf_prog_free(prog);
911         }
912 }
913 
914 static void __sk_filter_release(struct sk_filter *fp)
915 {
916         __bpf_prog_release(fp->prog);
917         kfree(fp);
918 }
919 
920 /**
921  *      sk_filter_release_rcu - Release a socket filter by rcu_head
922  *      @rcu: rcu_head that contains the sk_filter to free
923  */
924 static void sk_filter_release_rcu(struct rcu_head *rcu)
925 {
926         struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
927 
928         __sk_filter_release(fp);
929 }
930 
931 /**
932  *      sk_filter_release - release a socket filter
933  *      @fp: filter to remove
934  *
935  *      Remove a filter from a socket and release its resources.
936  */
937 static void sk_filter_release(struct sk_filter *fp)
938 {
939         if (refcount_dec_and_test(&fp->refcnt))
940                 call_rcu(&fp->rcu, sk_filter_release_rcu);
941 }
942 
943 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
944 {
945         u32 filter_size = bpf_prog_size(fp->prog->len);
946 
947         atomic_sub(filter_size, &sk->sk_omem_alloc);
948         sk_filter_release(fp);
949 }
950 
951 /* try to charge the socket memory if there is space available
952  * return true on success
953  */
954 static bool __sk_filter_charge(struct sock *sk, struct sk_filter *fp)
955 {
956         u32 filter_size = bpf_prog_size(fp->prog->len);
957 
958         /* same check as in sock_kmalloc() */
959         if (filter_size <= sysctl_optmem_max &&
960             atomic_read(&sk->sk_omem_alloc) + filter_size < sysctl_optmem_max) {
961                 atomic_add(filter_size, &sk->sk_omem_alloc);
962                 return true;
963         }
964         return false;
965 }
966 
967 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp)
968 {
969         bool ret = __sk_filter_charge(sk, fp);
970         if (ret)
971                 refcount_inc(&fp->refcnt);
972         return ret;
973 }
974 
975 static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp)
976 {
977         struct sock_filter *old_prog;
978         struct bpf_prog *old_fp;
979         int err, new_len, old_len = fp->len;
980 
981         /* We are free to overwrite insns et al right here as it
982          * won't be used at this point in time anymore internally
983          * after the migration to the internal BPF instruction
984          * representation.
985          */
986         BUILD_BUG_ON(sizeof(struct sock_filter) !=
987                      sizeof(struct bpf_insn));
988 
989         /* Conversion cannot happen on overlapping memory areas,
990          * so we need to keep the user BPF around until the 2nd
991          * pass. At this time, the user BPF is stored in fp->insns.
992          */
993         old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter),
994                            GFP_KERNEL | __GFP_NOWARN);
995         if (!old_prog) {
996                 err = -ENOMEM;
997                 goto out_err;
998         }
999 
1000         /* 1st pass: calculate the new program length. */
1001         err = bpf_convert_filter(old_prog, old_len, NULL, &new_len);
1002         if (err)
1003                 goto out_err_free;
1004 
1005         /* Expand fp for appending the new filter representation. */
1006         old_fp = fp;
1007         fp = bpf_prog_realloc(old_fp, bpf_prog_size(new_len), 0);
1008         if (!fp) {
1009                 /* The old_fp is still around in case we couldn't
1010                  * allocate new memory, so uncharge on that one.
1011                  */
1012                 fp = old_fp;
1013                 err = -ENOMEM;
1014                 goto out_err_free;
1015         }
1016 
1017         fp->len = new_len;
1018 
1019         /* 2nd pass: remap sock_filter insns into bpf_insn insns. */
1020         err = bpf_convert_filter(old_prog, old_len, fp->insnsi, &new_len);
1021         if (err)
1022                 /* 2nd bpf_convert_filter() can fail only if it fails
1023                  * to allocate memory, remapping must succeed. Note,
1024                  * that at this time old_fp has already been released
1025                  * by krealloc().
1026                  */
1027                 goto out_err_free;
1028 
1029         /* We are guaranteed to never error here with cBPF to eBPF
1030          * transitions, since there's no issue with type compatibility
1031          * checks on program arrays.
1032          */
1033         fp = bpf_prog_select_runtime(fp, &err);
1034 
1035         kfree(old_prog);
1036         return fp;
1037 
1038 out_err_free:
1039         kfree(old_prog);
1040 out_err:
1041         __bpf_prog_release(fp);
1042         return ERR_PTR(err);
1043 }
1044 
1045 static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp,
1046                                            bpf_aux_classic_check_t trans)
1047 {
1048         int err;
1049 
1050         fp->bpf_func = NULL;
1051         fp->jited = 0;
1052 
1053         err = bpf_check_classic(fp->insns, fp->len);
1054         if (err) {
1055                 __bpf_prog_release(fp);
1056                 return ERR_PTR(err);
1057         }
1058 
1059         /* There might be additional checks and transformations
1060          * needed on classic filters, f.e. in case of seccomp.
1061          */
1062         if (trans) {
1063                 err = trans(fp->insns, fp->len);
1064                 if (err) {
1065                         __bpf_prog_release(fp);
1066                         return ERR_PTR(err);
1067                 }
1068         }
1069 
1070         /* Probe if we can JIT compile the filter and if so, do
1071          * the compilation of the filter.
1072          */
1073         bpf_jit_compile(fp);
1074 
1075         /* JIT compiler couldn't process this filter, so do the
1076          * internal BPF translation for the optimized interpreter.
1077          */
1078         if (!fp->jited)
1079                 fp = bpf_migrate_filter(fp);
1080 
1081         return fp;
1082 }
1083 
1084 /**
1085  *      bpf_prog_create - create an unattached filter
1086  *      @pfp: the unattached filter that is created
1087  *      @fprog: the filter program
1088  *
1089  * Create a filter independent of any socket. We first run some
1090  * sanity checks on it to make sure it does not explode on us later.
1091  * If an error occurs or there is insufficient memory for the filter
1092  * a negative errno code is returned. On success the return is zero.
1093  */
1094 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog)
1095 {
1096         unsigned int fsize = bpf_classic_proglen(fprog);
1097         struct bpf_prog *fp;
1098 
1099         /* Make sure new filter is there and in the right amounts. */
1100         if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1101                 return -EINVAL;
1102 
1103         fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1104         if (!fp)
1105                 return -ENOMEM;
1106 
1107         memcpy(fp->insns, fprog->filter, fsize);
1108 
1109         fp->len = fprog->len;
1110         /* Since unattached filters are not copied back to user
1111          * space through sk_get_filter(), we do not need to hold
1112          * a copy here, and can spare us the work.
1113          */
1114         fp->orig_prog = NULL;
1115 
1116         /* bpf_prepare_filter() already takes care of freeing
1117          * memory in case something goes wrong.
1118          */
1119         fp = bpf_prepare_filter(fp, NULL);
1120         if (IS_ERR(fp))
1121                 return PTR_ERR(fp);
1122 
1123         *pfp = fp;
1124         return 0;
1125 }
1126 EXPORT_SYMBOL_GPL(bpf_prog_create);
1127 
1128 /**
1129  *      bpf_prog_create_from_user - create an unattached filter from user buffer
1130  *      @pfp: the unattached filter that is created
1131  *      @fprog: the filter program
1132  *      @trans: post-classic verifier transformation handler
1133  *      @save_orig: save classic BPF program
1134  *
1135  * This function effectively does the same as bpf_prog_create(), only
1136  * that it builds up its insns buffer from user space provided buffer.
1137  * It also allows for passing a bpf_aux_classic_check_t handler.
1138  */
1139 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
1140                               bpf_aux_classic_check_t trans, bool save_orig)
1141 {
1142         unsigned int fsize = bpf_classic_proglen(fprog);
1143         struct bpf_prog *fp;
1144         int err;
1145 
1146         /* Make sure new filter is there and in the right amounts. */
1147         if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1148                 return -EINVAL;
1149 
1150         fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1151         if (!fp)
1152                 return -ENOMEM;
1153 
1154         if (copy_from_user(fp->insns, fprog->filter, fsize)) {
1155                 __bpf_prog_free(fp);
1156                 return -EFAULT;
1157         }
1158 
1159         fp->len = fprog->len;
1160         fp->orig_prog = NULL;
1161 
1162         if (save_orig) {
1163                 err = bpf_prog_store_orig_filter(fp, fprog);
1164                 if (err) {
1165                         __bpf_prog_free(fp);
1166                         return -ENOMEM;
1167                 }
1168         }
1169 
1170         /* bpf_prepare_filter() already takes care of freeing
1171          * memory in case something goes wrong.
1172          */
1173         fp = bpf_prepare_filter(fp, trans);
1174         if (IS_ERR(fp))
1175                 return PTR_ERR(fp);
1176 
1177         *pfp = fp;
1178         return 0;
1179 }
1180 EXPORT_SYMBOL_GPL(bpf_prog_create_from_user);
1181 
1182 void bpf_prog_destroy(struct bpf_prog *fp)
1183 {
1184         __bpf_prog_release(fp);
1185 }
1186 EXPORT_SYMBOL_GPL(bpf_prog_destroy);
1187 
1188 static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk)
1189 {
1190         struct sk_filter *fp, *old_fp;
1191 
1192         fp = kmalloc(sizeof(*fp), GFP_KERNEL);
1193         if (!fp)
1194                 return -ENOMEM;
1195 
1196         fp->prog = prog;
1197 
1198         if (!__sk_filter_charge(sk, fp)) {
1199                 kfree(fp);
1200                 return -ENOMEM;
1201         }
1202         refcount_set(&fp->refcnt, 1);
1203 
1204         old_fp = rcu_dereference_protected(sk->sk_filter,
1205                                            lockdep_sock_is_held(sk));
1206         rcu_assign_pointer(sk->sk_filter, fp);
1207 
1208         if (old_fp)
1209                 sk_filter_uncharge(sk, old_fp);
1210 
1211         return 0;
1212 }
1213 
1214 static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk)
1215 {
1216         struct bpf_prog *old_prog;
1217         int err;
1218 
1219         if (bpf_prog_size(prog->len) > sysctl_optmem_max)
1220                 return -ENOMEM;
1221 
1222         if (sk_unhashed(sk) && sk->sk_reuseport) {
1223                 err = reuseport_alloc(sk);
1224                 if (err)
1225                         return err;
1226         } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) {
1227                 /* The socket wasn't bound with SO_REUSEPORT */
1228                 return -EINVAL;
1229         }
1230 
1231         old_prog = reuseport_attach_prog(sk, prog);
1232         if (old_prog)
1233                 bpf_prog_destroy(old_prog);
1234 
1235         return 0;
1236 }
1237 
1238 static
1239 struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk)
1240 {
1241         unsigned int fsize = bpf_classic_proglen(fprog);
1242         struct bpf_prog *prog;
1243         int err;
1244 
1245         if (sock_flag(sk, SOCK_FILTER_LOCKED))
1246                 return ERR_PTR(-EPERM);
1247 
1248         /* Make sure new filter is there and in the right amounts. */
1249         if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1250                 return ERR_PTR(-EINVAL);
1251 
1252         prog = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1253         if (!prog)
1254                 return ERR_PTR(-ENOMEM);
1255 
1256         if (copy_from_user(prog->insns, fprog->filter, fsize)) {
1257                 __bpf_prog_free(prog);
1258                 return ERR_PTR(-EFAULT);
1259         }
1260 
1261         prog->len = fprog->len;
1262 
1263         err = bpf_prog_store_orig_filter(prog, fprog);
1264         if (err) {
1265                 __bpf_prog_free(prog);
1266                 return ERR_PTR(-ENOMEM);
1267         }
1268 
1269         /* bpf_prepare_filter() already takes care of freeing
1270          * memory in case something goes wrong.
1271          */
1272         return bpf_prepare_filter(prog, NULL);
1273 }
1274 
1275 /**
1276  *      sk_attach_filter - attach a socket filter
1277  *      @fprog: the filter program
1278  *      @sk: the socket to use
1279  *
1280  * Attach the user's filter code. We first run some sanity checks on
1281  * it to make sure it does not explode on us later. If an error
1282  * occurs or there is insufficient memory for the filter a negative
1283  * errno code is returned. On success the return is zero.
1284  */
1285 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
1286 {
1287         struct bpf_prog *prog = __get_filter(fprog, sk);
1288         int err;
1289 
1290         if (IS_ERR(prog))
1291                 return PTR_ERR(prog);
1292 
1293         err = __sk_attach_prog(prog, sk);
1294         if (err < 0) {
1295                 __bpf_prog_release(prog);
1296                 return err;
1297         }
1298 
1299         return 0;
1300 }
1301 EXPORT_SYMBOL_GPL(sk_attach_filter);
1302 
1303 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk)
1304 {
1305         struct bpf_prog *prog = __get_filter(fprog, sk);
1306         int err;
1307 
1308         if (IS_ERR(prog))
1309                 return PTR_ERR(prog);
1310 
1311         err = __reuseport_attach_prog(prog, sk);
1312         if (err < 0) {
1313                 __bpf_prog_release(prog);
1314                 return err;
1315         }
1316 
1317         return 0;
1318 }
1319 
1320 static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk)
1321 {
1322         if (sock_flag(sk, SOCK_FILTER_LOCKED))
1323                 return ERR_PTR(-EPERM);
1324 
1325         return bpf_prog_get_type(ufd, BPF_PROG_TYPE_SOCKET_FILTER);
1326 }
1327 
1328 int sk_attach_bpf(u32 ufd, struct sock *sk)
1329 {
1330         struct bpf_prog *prog = __get_bpf(ufd, sk);
1331         int err;
1332 
1333         if (IS_ERR(prog))
1334                 return PTR_ERR(prog);
1335 
1336         err = __sk_attach_prog(prog, sk);
1337         if (err < 0) {
1338                 bpf_prog_put(prog);
1339                 return err;
1340         }
1341 
1342         return 0;
1343 }
1344 
1345 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk)
1346 {
1347         struct bpf_prog *prog = __get_bpf(ufd, sk);
1348         int err;
1349 
1350         if (IS_ERR(prog))
1351                 return PTR_ERR(prog);
1352 
1353         err = __reuseport_attach_prog(prog, sk);
1354         if (err < 0) {
1355                 bpf_prog_put(prog);
1356                 return err;
1357         }
1358 
1359         return 0;
1360 }
1361 
1362 struct bpf_scratchpad {
1363         union {
1364                 __be32 diff[MAX_BPF_STACK / sizeof(__be32)];
1365                 u8     buff[MAX_BPF_STACK];
1366         };
1367 };
1368 
1369 static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp);
1370 
1371 static inline int __bpf_try_make_writable(struct sk_buff *skb,
1372                                           unsigned int write_len)
1373 {
1374         return skb_ensure_writable(skb, write_len);
1375 }
1376 
1377 static inline int bpf_try_make_writable(struct sk_buff *skb,
1378                                         unsigned int write_len)
1379 {
1380         int err = __bpf_try_make_writable(skb, write_len);
1381 
1382         bpf_compute_data_end(skb);
1383         return err;
1384 }
1385 
1386 static int bpf_try_make_head_writable(struct sk_buff *skb)
1387 {
1388         return bpf_try_make_writable(skb, skb_headlen(skb));
1389 }
1390 
1391 static inline void bpf_push_mac_rcsum(struct sk_buff *skb)
1392 {
1393         if (skb_at_tc_ingress(skb))
1394                 skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len);
1395 }
1396 
1397 static inline void bpf_pull_mac_rcsum(struct sk_buff *skb)
1398 {
1399         if (skb_at_tc_ingress(skb))
1400                 skb_postpull_rcsum(skb, skb_mac_header(skb), skb->mac_len);
1401 }
1402 
1403 BPF_CALL_5(bpf_skb_store_bytes, struct sk_buff *, skb, u32, offset,
1404            const void *, from, u32, len, u64, flags)
1405 {
1406         void *ptr;
1407 
1408         if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM | BPF_F_INVALIDATE_HASH)))
1409                 return -EINVAL;
1410         if (unlikely(offset > 0xffff))
1411                 return -EFAULT;
1412         if (unlikely(bpf_try_make_writable(skb, offset + len)))
1413                 return -EFAULT;
1414 
1415         ptr = skb->data + offset;
1416         if (flags & BPF_F_RECOMPUTE_CSUM)
1417                 __skb_postpull_rcsum(skb, ptr, len, offset);
1418 
1419         memcpy(ptr, from, len);
1420 
1421         if (flags & BPF_F_RECOMPUTE_CSUM)
1422                 __skb_postpush_rcsum(skb, ptr, len, offset);
1423         if (flags & BPF_F_INVALIDATE_HASH)
1424                 skb_clear_hash(skb);
1425 
1426         return 0;
1427 }
1428 
1429 static const struct bpf_func_proto bpf_skb_store_bytes_proto = {
1430         .func           = bpf_skb_store_bytes,
1431         .gpl_only       = false,
1432         .ret_type       = RET_INTEGER,
1433         .arg1_type      = ARG_PTR_TO_CTX,
1434         .arg2_type      = ARG_ANYTHING,
1435         .arg3_type      = ARG_PTR_TO_MEM,
1436         .arg4_type      = ARG_CONST_SIZE,
1437         .arg5_type      = ARG_ANYTHING,
1438 };
1439 
1440 BPF_CALL_4(bpf_skb_load_bytes, const struct sk_buff *, skb, u32, offset,
1441            void *, to, u32, len)
1442 {
1443         void *ptr;
1444 
1445         if (unlikely(offset > 0xffff))
1446                 goto err_clear;
1447 
1448         ptr = skb_header_pointer(skb, offset, len, to);
1449         if (unlikely(!ptr))
1450                 goto err_clear;
1451         if (ptr != to)
1452                 memcpy(to, ptr, len);
1453 
1454         return 0;
1455 err_clear:
1456         memset(to, 0, len);
1457         return -EFAULT;
1458 }
1459 
1460 static const struct bpf_func_proto bpf_skb_load_bytes_proto = {
1461         .func           = bpf_skb_load_bytes,
1462         .gpl_only       = false,
1463         .ret_type       = RET_INTEGER,
1464         .arg1_type      = ARG_PTR_TO_CTX,
1465         .arg2_type      = ARG_ANYTHING,
1466         .arg3_type      = ARG_PTR_TO_UNINIT_MEM,
1467         .arg4_type      = ARG_CONST_SIZE,
1468 };
1469 
1470 BPF_CALL_2(bpf_skb_pull_data, struct sk_buff *, skb, u32, len)
1471 {
1472         /* Idea is the following: should the needed direct read/write
1473          * test fail during runtime, we can pull in more data and redo
1474          * again, since implicitly, we invalidate previous checks here.
1475          *
1476          * Or, since we know how much we need to make read/writeable,
1477          * this can be done once at the program beginning for direct
1478          * access case. By this we overcome limitations of only current
1479          * headroom being accessible.
1480          */
1481         return bpf_try_make_writable(skb, len ? : skb_headlen(skb));
1482 }
1483 
1484 static const struct bpf_func_proto bpf_skb_pull_data_proto = {
1485         .func           = bpf_skb_pull_data,
1486         .gpl_only       = false,
1487         .ret_type       = RET_INTEGER,
1488         .arg1_type      = ARG_PTR_TO_CTX,
1489         .arg2_type      = ARG_ANYTHING,
1490 };
1491 
1492 BPF_CALL_5(bpf_l3_csum_replace, struct sk_buff *, skb, u32, offset,
1493            u64, from, u64, to, u64, flags)
1494 {
1495         __sum16 *ptr;
1496 
1497         if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK)))
1498                 return -EINVAL;
1499         if (unlikely(offset > 0xffff || offset & 1))
1500                 return -EFAULT;
1501         if (unlikely(bpf_try_make_writable(skb, offset + sizeof(*ptr))))
1502                 return -EFAULT;
1503 
1504         ptr = (__sum16 *)(skb->data + offset);
1505         switch (flags & BPF_F_HDR_FIELD_MASK) {
1506         case 0:
1507                 if (unlikely(from != 0))
1508                         return -EINVAL;
1509 
1510                 csum_replace_by_diff(ptr, to);
1511                 break;
1512         case 2:
1513                 csum_replace2(ptr, from, to);
1514                 break;
1515         case 4:
1516                 csum_replace4(ptr, from, to);
1517                 break;
1518         default:
1519                 return -EINVAL;
1520         }
1521 
1522         return 0;
1523 }
1524 
1525 static const struct bpf_func_proto bpf_l3_csum_replace_proto = {
1526         .func           = bpf_l3_csum_replace,
1527         .gpl_only       = false,
1528         .ret_type       = RET_INTEGER,
1529         .arg1_type      = ARG_PTR_TO_CTX,
1530         .arg2_type      = ARG_ANYTHING,
1531         .arg3_type      = ARG_ANYTHING,
1532         .arg4_type      = ARG_ANYTHING,
1533         .arg5_type      = ARG_ANYTHING,
1534 };
1535 
1536 BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset,
1537            u64, from, u64, to, u64, flags)
1538 {
1539         bool is_pseudo = flags & BPF_F_PSEUDO_HDR;
1540         bool is_mmzero = flags & BPF_F_MARK_MANGLED_0;
1541         bool do_mforce = flags & BPF_F_MARK_ENFORCE;
1542         __sum16 *ptr;
1543 
1544         if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_MARK_ENFORCE |
1545                                BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK)))
1546                 return -EINVAL;
1547         if (unlikely(offset > 0xffff || offset & 1))
1548                 return -EFAULT;
1549         if (unlikely(bpf_try_make_writable(skb, offset + sizeof(*ptr))))
1550                 return -EFAULT;
1551 
1552         ptr = (__sum16 *)(skb->data + offset);
1553         if (is_mmzero && !do_mforce && !*ptr)
1554                 return 0;
1555 
1556         switch (flags & BPF_F_HDR_FIELD_MASK) {
1557         case 0:
1558                 if (unlikely(from != 0))
1559                         return -EINVAL;
1560 
1561                 inet_proto_csum_replace_by_diff(ptr, skb, to, is_pseudo);
1562                 break;
1563         case 2:
1564                 inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo);
1565                 break;
1566         case 4:
1567                 inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo);
1568                 break;
1569         default:
1570                 return -EINVAL;
1571         }
1572 
1573         if (is_mmzero && !*ptr)
1574                 *ptr = CSUM_MANGLED_0;
1575         return 0;
1576 }
1577 
1578 static const struct bpf_func_proto bpf_l4_csum_replace_proto = {
1579         .func           = bpf_l4_csum_replace,
1580         .gpl_only       = false,
1581         .ret_type       = RET_INTEGER,
1582         .arg1_type      = ARG_PTR_TO_CTX,
1583         .arg2_type      = ARG_ANYTHING,
1584         .arg3_type      = ARG_ANYTHING,
1585         .arg4_type      = ARG_ANYTHING,
1586         .arg5_type      = ARG_ANYTHING,
1587 };
1588 
1589 BPF_CALL_5(bpf_csum_diff, __be32 *, from, u32, from_size,
1590            __be32 *, to, u32, to_size, __wsum, seed)
1591 {
1592         struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp);
1593         u32 diff_size = from_size + to_size;
1594         int i, j = 0;
1595 
1596         /* This is quite flexible, some examples:
1597          *
1598          * from_size == 0, to_size > 0,  seed := csum --> pushing data
1599          * from_size > 0,  to_size == 0, seed := csum --> pulling data
1600          * from_size > 0,  to_size > 0,  seed := 0    --> diffing data
1601          *
1602          * Even for diffing, from_size and to_size don't need to be equal.
1603          */
1604         if (unlikely(((from_size | to_size) & (sizeof(__be32) - 1)) ||
1605                      diff_size > sizeof(sp->diff)))
1606                 return -EINVAL;
1607 
1608         for (i = 0; i < from_size / sizeof(__be32); i++, j++)
1609                 sp->diff[j] = ~from[i];
1610         for (i = 0; i <   to_size / sizeof(__be32); i++, j++)
1611                 sp->diff[j] = to[i];
1612 
1613         return csum_partial(sp->diff, diff_size, seed);
1614 }
1615 
1616 static const struct bpf_func_proto bpf_csum_diff_proto = {
1617         .func           = bpf_csum_diff,
1618         .gpl_only       = false,
1619         .pkt_access     = true,
1620         .ret_type       = RET_INTEGER,
1621         .arg1_type      = ARG_PTR_TO_MEM,
1622         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
1623         .arg3_type      = ARG_PTR_TO_MEM,
1624         .arg4_type      = ARG_CONST_SIZE_OR_ZERO,
1625         .arg5_type      = ARG_ANYTHING,
1626 };
1627 
1628 BPF_CALL_2(bpf_csum_update, struct sk_buff *, skb, __wsum, csum)
1629 {
1630         /* The interface is to be used in combination with bpf_csum_diff()
1631          * for direct packet writes. csum rotation for alignment as well
1632          * as emulating csum_sub() can be done from the eBPF program.
1633          */
1634         if (skb->ip_summed == CHECKSUM_COMPLETE)
1635                 return (skb->csum = csum_add(skb->csum, csum));
1636 
1637         return -ENOTSUPP;
1638 }
1639 
1640 static const struct bpf_func_proto bpf_csum_update_proto = {
1641         .func           = bpf_csum_update,
1642         .gpl_only       = false,
1643         .ret_type       = RET_INTEGER,
1644         .arg1_type      = ARG_PTR_TO_CTX,
1645         .arg2_type      = ARG_ANYTHING,
1646 };
1647 
1648 static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb)
1649 {
1650         return dev_forward_skb(dev, skb);
1651 }
1652 
1653 static inline int __bpf_rx_skb_no_mac(struct net_device *dev,
1654                                       struct sk_buff *skb)
1655 {
1656         int ret = ____dev_forward_skb(dev, skb);
1657 
1658         if (likely(!ret)) {
1659                 skb->dev = dev;
1660                 ret = netif_rx(skb);
1661         }
1662 
1663         return ret;
1664 }
1665 
1666 static inline int __bpf_tx_skb(struct net_device *dev, struct sk_buff *skb)
1667 {
1668         int ret;
1669 
1670         if (unlikely(__this_cpu_read(xmit_recursion) > XMIT_RECURSION_LIMIT)) {
1671                 net_crit_ratelimited("bpf: recursion limit reached on datapath, buggy bpf program?\n");
1672                 kfree_skb(skb);
1673                 return -ENETDOWN;
1674         }
1675 
1676         skb->dev = dev;
1677 
1678         __this_cpu_inc(xmit_recursion);
1679         ret = dev_queue_xmit(skb);
1680         __this_cpu_dec(xmit_recursion);
1681 
1682         return ret;
1683 }
1684 
1685 static int __bpf_redirect_no_mac(struct sk_buff *skb, struct net_device *dev,
1686                                  u32 flags)
1687 {
1688         /* skb->mac_len is not set on normal egress */
1689         unsigned int mlen = skb->network_header - skb->mac_header;
1690 
1691         __skb_pull(skb, mlen);
1692 
1693         /* At ingress, the mac header has already been pulled once.
1694          * At egress, skb_pospull_rcsum has to be done in case that
1695          * the skb is originated from ingress (i.e. a forwarded skb)
1696          * to ensure that rcsum starts at net header.
1697          */
1698         if (!skb_at_tc_ingress(skb))
1699                 skb_postpull_rcsum(skb, skb_mac_header(skb), mlen);
1700         skb_pop_mac_header(skb);
1701         skb_reset_mac_len(skb);
1702         return flags & BPF_F_INGRESS ?
1703                __bpf_rx_skb_no_mac(dev, skb) : __bpf_tx_skb(dev, skb);
1704 }
1705 
1706 static int __bpf_redirect_common(struct sk_buff *skb, struct net_device *dev,
1707                                  u32 flags)
1708 {
1709         /* Verify that a link layer header is carried */
1710         if (unlikely(skb->mac_header >= skb->network_header)) {
1711                 kfree_skb(skb);
1712                 return -ERANGE;
1713         }
1714 
1715         bpf_push_mac_rcsum(skb);
1716         return flags & BPF_F_INGRESS ?
1717                __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);
1718 }
1719 
1720 static int __bpf_redirect(struct sk_buff *skb, struct net_device *dev,
1721                           u32 flags)
1722 {
1723         if (dev_is_mac_header_xmit(dev))
1724                 return __bpf_redirect_common(skb, dev, flags);
1725         else
1726                 return __bpf_redirect_no_mac(skb, dev, flags);
1727 }
1728 
1729 BPF_CALL_3(bpf_clone_redirect, struct sk_buff *, skb, u32, ifindex, u64, flags)
1730 {
1731         struct net_device *dev;
1732         struct sk_buff *clone;
1733         int ret;
1734 
1735         if (unlikely(flags & ~(BPF_F_INGRESS)))
1736                 return -EINVAL;
1737 
1738         dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex);
1739         if (unlikely(!dev))
1740                 return -EINVAL;
1741 
1742         clone = skb_clone(skb, GFP_ATOMIC);
1743         if (unlikely(!clone))
1744                 return -ENOMEM;
1745 
1746         /* For direct write, we need to keep the invariant that the skbs
1747          * we're dealing with need to be uncloned. Should uncloning fail
1748          * here, we need to free the just generated clone to unclone once
1749          * again.
1750          */
1751         ret = bpf_try_make_head_writable(skb);
1752         if (unlikely(ret)) {
1753                 kfree_skb(clone);
1754                 return -ENOMEM;
1755         }
1756 
1757         return __bpf_redirect(clone, dev, flags);
1758 }
1759 
1760 static const struct bpf_func_proto bpf_clone_redirect_proto = {
1761         .func           = bpf_clone_redirect,
1762         .gpl_only       = false,
1763         .ret_type       = RET_INTEGER,
1764         .arg1_type      = ARG_PTR_TO_CTX,
1765         .arg2_type      = ARG_ANYTHING,
1766         .arg3_type      = ARG_ANYTHING,
1767 };
1768 
1769 struct redirect_info {
1770         u32 ifindex;
1771         u32 flags;
1772 };
1773 
1774 static DEFINE_PER_CPU(struct redirect_info, redirect_info);
1775 
1776 BPF_CALL_2(bpf_redirect, u32, ifindex, u64, flags)
1777 {
1778         struct redirect_info *ri = this_cpu_ptr(&redirect_info);
1779 
1780         if (unlikely(flags & ~(BPF_F_INGRESS)))
1781                 return TC_ACT_SHOT;
1782 
1783         ri->ifindex = ifindex;
1784         ri->flags = flags;
1785 
1786         return TC_ACT_REDIRECT;
1787 }
1788 
1789 int skb_do_redirect(struct sk_buff *skb)
1790 {
1791         struct redirect_info *ri = this_cpu_ptr(&redirect_info);
1792         struct net_device *dev;
1793 
1794         dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->ifindex);
1795         ri->ifindex = 0;
1796         if (unlikely(!dev)) {
1797                 kfree_skb(skb);
1798                 return -EINVAL;
1799         }
1800 
1801         return __bpf_redirect(skb, dev, ri->flags);
1802 }
1803 
1804 static const struct bpf_func_proto bpf_redirect_proto = {
1805         .func           = bpf_redirect,
1806         .gpl_only       = false,
1807         .ret_type       = RET_INTEGER,
1808         .arg1_type      = ARG_ANYTHING,
1809         .arg2_type      = ARG_ANYTHING,
1810 };
1811 
1812 BPF_CALL_1(bpf_get_cgroup_classid, const struct sk_buff *, skb)
1813 {
1814         return task_get_classid(skb);
1815 }
1816 
1817 static const struct bpf_func_proto bpf_get_cgroup_classid_proto = {
1818         .func           = bpf_get_cgroup_classid,
1819         .gpl_only       = false,
1820         .ret_type       = RET_INTEGER,
1821         .arg1_type      = ARG_PTR_TO_CTX,
1822 };
1823 
1824 BPF_CALL_1(bpf_get_route_realm, const struct sk_buff *, skb)
1825 {
1826         return dst_tclassid(skb);
1827 }
1828 
1829 static const struct bpf_func_proto bpf_get_route_realm_proto = {
1830         .func           = bpf_get_route_realm,
1831         .gpl_only       = false,
1832         .ret_type       = RET_INTEGER,
1833         .arg1_type      = ARG_PTR_TO_CTX,
1834 };
1835 
1836 BPF_CALL_1(bpf_get_hash_recalc, struct sk_buff *, skb)
1837 {
1838         /* If skb_clear_hash() was called due to mangling, we can
1839          * trigger SW recalculation here. Later access to hash
1840          * can then use the inline skb->hash via context directly
1841          * instead of calling this helper again.
1842          */
1843         return skb_get_hash(skb);
1844 }
1845 
1846 static const struct bpf_func_proto bpf_get_hash_recalc_proto = {
1847         .func           = bpf_get_hash_recalc,
1848         .gpl_only       = false,
1849         .ret_type       = RET_INTEGER,
1850         .arg1_type      = ARG_PTR_TO_CTX,
1851 };
1852 
1853 BPF_CALL_1(bpf_set_hash_invalid, struct sk_buff *, skb)
1854 {
1855         /* After all direct packet write, this can be used once for
1856          * triggering a lazy recalc on next skb_get_hash() invocation.
1857          */
1858         skb_clear_hash(skb);
1859         return 0;
1860 }
1861 
1862 static const struct bpf_func_proto bpf_set_hash_invalid_proto = {
1863         .func           = bpf_set_hash_invalid,
1864         .gpl_only       = false,
1865         .ret_type       = RET_INTEGER,
1866         .arg1_type      = ARG_PTR_TO_CTX,
1867 };
1868 
1869 BPF_CALL_3(bpf_skb_vlan_push, struct sk_buff *, skb, __be16, vlan_proto,
1870            u16, vlan_tci)
1871 {
1872         int ret;
1873 
1874         if (unlikely(vlan_proto != htons(ETH_P_8021Q) &&
1875                      vlan_proto != htons(ETH_P_8021AD)))
1876                 vlan_proto = htons(ETH_P_8021Q);
1877 
1878         bpf_push_mac_rcsum(skb);
1879         ret = skb_vlan_push(skb, vlan_proto, vlan_tci);
1880         bpf_pull_mac_rcsum(skb);
1881 
1882         bpf_compute_data_end(skb);
1883         return ret;
1884 }
1885 
1886 const struct bpf_func_proto bpf_skb_vlan_push_proto = {
1887         .func           = bpf_skb_vlan_push,
1888         .gpl_only       = false,
1889         .ret_type       = RET_INTEGER,
1890         .arg1_type      = ARG_PTR_TO_CTX,
1891         .arg2_type      = ARG_ANYTHING,
1892         .arg3_type      = ARG_ANYTHING,
1893 };
1894 EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto);
1895 
1896 BPF_CALL_1(bpf_skb_vlan_pop, struct sk_buff *, skb)
1897 {
1898         int ret;
1899 
1900         bpf_push_mac_rcsum(skb);
1901         ret = skb_vlan_pop(skb);
1902         bpf_pull_mac_rcsum(skb);
1903 
1904         bpf_compute_data_end(skb);
1905         return ret;
1906 }
1907 
1908 const struct bpf_func_proto bpf_skb_vlan_pop_proto = {
1909         .func           = bpf_skb_vlan_pop,
1910         .gpl_only       = false,
1911         .ret_type       = RET_INTEGER,
1912         .arg1_type      = ARG_PTR_TO_CTX,
1913 };
1914 EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto);
1915 
1916 static int bpf_skb_generic_push(struct sk_buff *skb, u32 off, u32 len)
1917 {
1918         /* Caller already did skb_cow() with len as headroom,
1919          * so no need to do it here.
1920          */
1921         skb_push(skb, len);
1922         memmove(skb->data, skb->data + len, off);
1923         memset(skb->data + off, 0, len);
1924 
1925         /* No skb_postpush_rcsum(skb, skb->data + off, len)
1926          * needed here as it does not change the skb->csum
1927          * result for checksum complete when summing over
1928          * zeroed blocks.
1929          */
1930         return 0;
1931 }
1932 
1933 static int bpf_skb_generic_pop(struct sk_buff *skb, u32 off, u32 len)
1934 {
1935         /* skb_ensure_writable() is not needed here, as we're
1936          * already working on an uncloned skb.
1937          */
1938         if (unlikely(!pskb_may_pull(skb, off + len)))
1939                 return -ENOMEM;
1940 
1941         skb_postpull_rcsum(skb, skb->data + off, len);
1942         memmove(skb->data + len, skb->data, off);
1943         __skb_pull(skb, len);
1944 
1945         return 0;
1946 }
1947 
1948 static int bpf_skb_net_hdr_push(struct sk_buff *skb, u32 off, u32 len)
1949 {
1950         bool trans_same = skb->transport_header == skb->network_header;
1951         int ret;
1952 
1953         /* There's no need for __skb_push()/__skb_pull() pair to
1954          * get to the start of the mac header as we're guaranteed
1955          * to always start from here under eBPF.
1956          */
1957         ret = bpf_skb_generic_push(skb, off, len);
1958         if (likely(!ret)) {
1959                 skb->mac_header -= len;
1960                 skb->network_header -= len;
1961                 if (trans_same)
1962                         skb->transport_header = skb->network_header;
1963         }
1964 
1965         return ret;
1966 }
1967 
1968 static int bpf_skb_net_hdr_pop(struct sk_buff *skb, u32 off, u32 len)
1969 {
1970         bool trans_same = skb->transport_header == skb->network_header;
1971         int ret;
1972 
1973         /* Same here, __skb_push()/__skb_pull() pair not needed. */
1974         ret = bpf_skb_generic_pop(skb, off, len);
1975         if (likely(!ret)) {
1976                 skb->mac_header += len;
1977                 skb->network_header += len;
1978                 if (trans_same)
1979                         skb->transport_header = skb->network_header;
1980         }
1981 
1982         return ret;
1983 }
1984 
1985 static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
1986 {
1987         const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr);
1988         u32 off = skb->network_header - skb->mac_header;
1989         int ret;
1990 
1991         ret = skb_cow(skb, len_diff);
1992         if (unlikely(ret < 0))
1993                 return ret;
1994 
1995         ret = bpf_skb_net_hdr_push(skb, off, len_diff);
1996         if (unlikely(ret < 0))
1997                 return ret;
1998 
1999         if (skb_is_gso(skb)) {
2000                 /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV4 needs to
2001                  * be changed into SKB_GSO_TCPV6.
2002                  */
2003                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
2004                         skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV4;
2005                         skb_shinfo(skb)->gso_type |=  SKB_GSO_TCPV6;
2006                 }
2007 
2008                 /* Due to IPv6 header, MSS needs to be downgraded. */
2009                 skb_shinfo(skb)->gso_size -= len_diff;
2010                 /* Header must be checked, and gso_segs recomputed. */
2011                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2012                 skb_shinfo(skb)->gso_segs = 0;
2013         }
2014 
2015         skb->protocol = htons(ETH_P_IPV6);
2016         skb_clear_hash(skb);
2017 
2018         return 0;
2019 }
2020 
2021 static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
2022 {
2023         const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr);
2024         u32 off = skb->network_header - skb->mac_header;
2025         int ret;
2026 
2027         ret = skb_unclone(skb, GFP_ATOMIC);
2028         if (unlikely(ret < 0))
2029                 return ret;
2030 
2031         ret = bpf_skb_net_hdr_pop(skb, off, len_diff);
2032         if (unlikely(ret < 0))
2033                 return ret;
2034 
2035         if (skb_is_gso(skb)) {
2036                 /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV6 needs to
2037                  * be changed into SKB_GSO_TCPV4.
2038                  */
2039                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
2040                         skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV6;
2041                         skb_shinfo(skb)->gso_type |=  SKB_GSO_TCPV4;
2042                 }
2043 
2044                 /* Due to IPv4 header, MSS can be upgraded. */
2045                 skb_shinfo(skb)->gso_size += len_diff;
2046                 /* Header must be checked, and gso_segs recomputed. */
2047                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2048                 skb_shinfo(skb)->gso_segs = 0;
2049         }
2050 
2051         skb->protocol = htons(ETH_P_IP);
2052         skb_clear_hash(skb);
2053 
2054         return 0;
2055 }
2056 
2057 static int bpf_skb_proto_xlat(struct sk_buff *skb, __be16 to_proto)
2058 {
2059         __be16 from_proto = skb->protocol;
2060 
2061         if (from_proto == htons(ETH_P_IP) &&
2062               to_proto == htons(ETH_P_IPV6))
2063                 return bpf_skb_proto_4_to_6(skb);
2064 
2065         if (from_proto == htons(ETH_P_IPV6) &&
2066               to_proto == htons(ETH_P_IP))
2067                 return bpf_skb_proto_6_to_4(skb);
2068 
2069         return -ENOTSUPP;
2070 }
2071 
2072 BPF_CALL_3(bpf_skb_change_proto, struct sk_buff *, skb, __be16, proto,
2073            u64, flags)
2074 {
2075         int ret;
2076 
2077         if (unlikely(flags))
2078                 return -EINVAL;
2079 
2080         /* General idea is that this helper does the basic groundwork
2081          * needed for changing the protocol, and eBPF program fills the
2082          * rest through bpf_skb_store_bytes(), bpf_lX_csum_replace()
2083          * and other helpers, rather than passing a raw buffer here.
2084          *
2085          * The rationale is to keep this minimal and without a need to
2086          * deal with raw packet data. F.e. even if we would pass buffers
2087          * here, the program still needs to call the bpf_lX_csum_replace()
2088          * helpers anyway. Plus, this way we keep also separation of
2089          * concerns, since f.e. bpf_skb_store_bytes() should only take
2090          * care of stores.
2091          *
2092          * Currently, additional options and extension header space are
2093          * not supported, but flags register is reserved so we can adapt
2094          * that. For offloads, we mark packet as dodgy, so that headers
2095          * need to be verified first.
2096          */
2097         ret = bpf_skb_proto_xlat(skb, proto);
2098         bpf_compute_data_end(skb);
2099         return ret;
2100 }
2101 
2102 static const struct bpf_func_proto bpf_skb_change_proto_proto = {
2103         .func           = bpf_skb_change_proto,
2104         .gpl_only       = false,
2105         .ret_type       = RET_INTEGER,
2106         .arg1_type      = ARG_PTR_TO_CTX,
2107         .arg2_type      = ARG_ANYTHING,
2108         .arg3_type      = ARG_ANYTHING,
2109 };
2110 
2111 BPF_CALL_2(bpf_skb_change_type, struct sk_buff *, skb, u32, pkt_type)
2112 {
2113         /* We only allow a restricted subset to be changed for now. */
2114         if (unlikely(!skb_pkt_type_ok(skb->pkt_type) ||
2115                      !skb_pkt_type_ok(pkt_type)))
2116                 return -EINVAL;
2117 
2118         skb->pkt_type = pkt_type;
2119         return 0;
2120 }
2121 
2122 static const struct bpf_func_proto bpf_skb_change_type_proto = {
2123         .func           = bpf_skb_change_type,
2124         .gpl_only       = false,
2125         .ret_type       = RET_INTEGER,
2126         .arg1_type      = ARG_PTR_TO_CTX,
2127         .arg2_type      = ARG_ANYTHING,
2128 };
2129 
2130 static u32 __bpf_skb_min_len(const struct sk_buff *skb)
2131 {
2132         u32 min_len = skb_network_offset(skb);
2133 
2134         if (skb_transport_header_was_set(skb))
2135                 min_len = skb_transport_offset(skb);
2136         if (skb->ip_summed == CHECKSUM_PARTIAL)
2137                 min_len = skb_checksum_start_offset(skb) +
2138                           skb->csum_offset + sizeof(__sum16);
2139         return min_len;
2140 }
2141 
2142 static u32 __bpf_skb_max_len(const struct sk_buff *skb)
2143 {
2144         return skb->dev->mtu + skb->dev->hard_header_len;
2145 }
2146 
2147 static int bpf_skb_grow_rcsum(struct sk_buff *skb, unsigned int new_len)
2148 {
2149         unsigned int old_len = skb->len;
2150         int ret;
2151 
2152         ret = __skb_grow_rcsum(skb, new_len);
2153         if (!ret)
2154                 memset(skb->data + old_len, 0, new_len - old_len);
2155         return ret;
2156 }
2157 
2158 static int bpf_skb_trim_rcsum(struct sk_buff *skb, unsigned int new_len)
2159 {
2160         return __skb_trim_rcsum(skb, new_len);
2161 }
2162 
2163 BPF_CALL_3(bpf_skb_change_tail, struct sk_buff *, skb, u32, new_len,
2164            u64, flags)
2165 {
2166         u32 max_len = __bpf_skb_max_len(skb);
2167         u32 min_len = __bpf_skb_min_len(skb);
2168         int ret;
2169 
2170         if (unlikely(flags || new_len > max_len || new_len < min_len))
2171                 return -EINVAL;
2172         if (skb->encapsulation)
2173                 return -ENOTSUPP;
2174 
2175         /* The basic idea of this helper is that it's performing the
2176          * needed work to either grow or trim an skb, and eBPF program
2177          * rewrites the rest via helpers like bpf_skb_store_bytes(),
2178          * bpf_lX_csum_replace() and others rather than passing a raw
2179          * buffer here. This one is a slow path helper and intended
2180          * for replies with control messages.
2181          *
2182          * Like in bpf_skb_change_proto(), we want to keep this rather
2183          * minimal and without protocol specifics so that we are able
2184          * to separate concerns as in bpf_skb_store_bytes() should only
2185          * be the one responsible for writing buffers.
2186          *
2187          * It's really expected to be a slow path operation here for
2188          * control message replies, so we're implicitly linearizing,
2189          * uncloning and drop offloads from the skb by this.
2190          */
2191         ret = __bpf_try_make_writable(skb, skb->len);
2192         if (!ret) {
2193                 if (new_len > skb->len)
2194                         ret = bpf_skb_grow_rcsum(skb, new_len);
2195                 else if (new_len < skb->len)
2196                         ret = bpf_skb_trim_rcsum(skb, new_len);
2197                 if (!ret && skb_is_gso(skb))
2198                         skb_gso_reset(skb);
2199         }
2200 
2201         bpf_compute_data_end(skb);
2202         return ret;
2203 }
2204 
2205 static const struct bpf_func_proto bpf_skb_change_tail_proto = {
2206         .func           = bpf_skb_change_tail,
2207         .gpl_only       = false,
2208         .ret_type       = RET_INTEGER,
2209         .arg1_type      = ARG_PTR_TO_CTX,
2210         .arg2_type      = ARG_ANYTHING,
2211         .arg3_type      = ARG_ANYTHING,
2212 };
2213 
2214 BPF_CALL_3(bpf_skb_change_head, struct sk_buff *, skb, u32, head_room,
2215            u64, flags)
2216 {
2217         u32 max_len = __bpf_skb_max_len(skb);
2218         u32 new_len = skb->len + head_room;
2219         int ret;
2220 
2221         if (unlikely(flags || (!skb_is_gso(skb) && new_len > max_len) ||
2222                      new_len < skb->len))
2223                 return -EINVAL;
2224 
2225         ret = skb_cow(skb, head_room);
2226         if (likely(!ret)) {
2227                 /* Idea for this helper is that we currently only
2228                  * allow to expand on mac header. This means that
2229                  * skb->protocol network header, etc, stay as is.
2230                  * Compared to bpf_skb_change_tail(), we're more
2231                  * flexible due to not needing to linearize or
2232                  * reset GSO. Intention for this helper is to be
2233                  * used by an L3 skb that needs to push mac header
2234                  * for redirection into L2 device.
2235                  */
2236                 __skb_push(skb, head_room);
2237                 memset(skb->data, 0, head_room);
2238                 skb_reset_mac_header(skb);
2239         }
2240 
2241         bpf_compute_data_end(skb);
2242         return 0;
2243 }
2244 
2245 static const struct bpf_func_proto bpf_skb_change_head_proto = {
2246         .func           = bpf_skb_change_head,
2247         .gpl_only       = false,
2248         .ret_type       = RET_INTEGER,
2249         .arg1_type      = ARG_PTR_TO_CTX,
2250         .arg2_type      = ARG_ANYTHING,
2251         .arg3_type      = ARG_ANYTHING,
2252 };
2253 
2254 BPF_CALL_2(bpf_xdp_adjust_head, struct xdp_buff *, xdp, int, offset)
2255 {
2256         void *data = xdp->data + offset;
2257 
2258         if (unlikely(data < xdp->data_hard_start ||
2259                      data > xdp->data_end - ETH_HLEN))
2260                 return -EINVAL;
2261 
2262         xdp->data = data;
2263 
2264         return 0;
2265 }
2266 
2267 static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
2268         .func           = bpf_xdp_adjust_head,
2269         .gpl_only       = false,
2270         .ret_type       = RET_INTEGER,
2271         .arg1_type      = ARG_PTR_TO_CTX,
2272         .arg2_type      = ARG_ANYTHING,
2273 };
2274 
2275 bool bpf_helper_changes_pkt_data(void *func)
2276 {
2277         if (func == bpf_skb_vlan_push ||
2278             func == bpf_skb_vlan_pop ||
2279             func == bpf_skb_store_bytes ||
2280             func == bpf_skb_change_proto ||
2281             func == bpf_skb_change_head ||
2282             func == bpf_skb_change_tail ||
2283             func == bpf_skb_pull_data ||
2284             func == bpf_clone_redirect ||
2285             func == bpf_l3_csum_replace ||
2286             func == bpf_l4_csum_replace ||
2287             func == bpf_xdp_adjust_head)
2288                 return true;
2289 
2290         return false;
2291 }
2292 
2293 static unsigned long bpf_skb_copy(void *dst_buff, const void *skb,
2294                                   unsigned long off, unsigned long len)
2295 {
2296         void *ptr = skb_header_pointer(skb, off, len, dst_buff);
2297 
2298         if (unlikely(!ptr))
2299                 return len;
2300         if (ptr != dst_buff)
2301                 memcpy(dst_buff, ptr, len);
2302 
2303         return 0;
2304 }
2305 
2306 BPF_CALL_5(bpf_skb_event_output, struct sk_buff *, skb, struct bpf_map *, map,
2307            u64, flags, void *, meta, u64, meta_size)
2308 {
2309         u64 skb_size = (flags & BPF_F_CTXLEN_MASK) >> 32;
2310 
2311         if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
2312                 return -EINVAL;
2313         if (unlikely(skb_size > skb->len))
2314                 return -EFAULT;
2315 
2316         return bpf_event_output(map, flags, meta, meta_size, skb, skb_size,
2317                                 bpf_skb_copy);
2318 }
2319 
2320 static const struct bpf_func_proto bpf_skb_event_output_proto = {
2321         .func           = bpf_skb_event_output,
2322         .gpl_only       = true,
2323         .ret_type       = RET_INTEGER,
2324         .arg1_type      = ARG_PTR_TO_CTX,
2325         .arg2_type      = ARG_CONST_MAP_PTR,
2326         .arg3_type      = ARG_ANYTHING,
2327         .arg4_type      = ARG_PTR_TO_MEM,
2328         .arg5_type      = ARG_CONST_SIZE,
2329 };
2330 
2331 static unsigned short bpf_tunnel_key_af(u64 flags)
2332 {
2333         return flags & BPF_F_TUNINFO_IPV6 ? AF_INET6 : AF_INET;
2334 }
2335 
2336 BPF_CALL_4(bpf_skb_get_tunnel_key, struct sk_buff *, skb, struct bpf_tunnel_key *, to,
2337            u32, size, u64, flags)
2338 {
2339         const struct ip_tunnel_info *info = skb_tunnel_info(skb);
2340         u8 compat[sizeof(struct bpf_tunnel_key)];
2341         void *to_orig = to;
2342         int err;
2343 
2344         if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) {
2345                 err = -EINVAL;
2346                 goto err_clear;
2347         }
2348         if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) {
2349                 err = -EPROTO;
2350                 goto err_clear;
2351         }
2352         if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
2353                 err = -EINVAL;
2354                 switch (size) {
2355                 case offsetof(struct bpf_tunnel_key, tunnel_label):
2356                 case offsetof(struct bpf_tunnel_key, tunnel_ext):
2357                         goto set_compat;
2358                 case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
2359                         /* Fixup deprecated structure layouts here, so we have
2360                          * a common path later on.
2361                          */
2362                         if (ip_tunnel_info_af(info) != AF_INET)
2363                                 goto err_clear;
2364 set_compat:
2365                         to = (struct bpf_tunnel_key *)compat;
2366                         break;
2367                 default:
2368                         goto err_clear;
2369                 }
2370         }
2371 
2372         to->tunnel_id = be64_to_cpu(info->key.tun_id);
2373         to->tunnel_tos = info->key.tos;
2374         to->tunnel_ttl = info->key.ttl;
2375 
2376         if (flags & BPF_F_TUNINFO_IPV6) {
2377                 memcpy(to->remote_ipv6, &info->key.u.ipv6.src,
2378                        sizeof(to->remote_ipv6));
2379                 to->tunnel_label = be32_to_cpu(info->key.label);
2380         } else {
2381                 to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
2382         }
2383 
2384         if (unlikely(size != sizeof(struct bpf_tunnel_key)))
2385                 memcpy(to_orig, to, size);
2386 
2387         return 0;
2388 err_clear:
2389         memset(to_orig, 0, size);
2390         return err;
2391 }
2392 
2393 static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = {
2394         .func           = bpf_skb_get_tunnel_key,
2395         .gpl_only       = false,
2396         .ret_type       = RET_INTEGER,
2397         .arg1_type      = ARG_PTR_TO_CTX,
2398         .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
2399         .arg3_type      = ARG_CONST_SIZE,
2400         .arg4_type      = ARG_ANYTHING,
2401 };
2402 
2403 BPF_CALL_3(bpf_skb_get_tunnel_opt, struct sk_buff *, skb, u8 *, to, u32, size)
2404 {
2405         const struct ip_tunnel_info *info = skb_tunnel_info(skb);
2406         int err;
2407 
2408         if (unlikely(!info ||
2409                      !(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))) {
2410                 err = -ENOENT;
2411                 goto err_clear;
2412         }
2413         if (unlikely(size < info->options_len)) {
2414                 err = -ENOMEM;
2415                 goto err_clear;
2416         }
2417 
2418         ip_tunnel_info_opts_get(to, info);
2419         if (size > info->options_len)
2420                 memset(to + info->options_len, 0, size - info->options_len);
2421 
2422         return info->options_len;
2423 err_clear:
2424         memset(to, 0, size);
2425         return err;
2426 }
2427 
2428 static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto = {
2429         .func           = bpf_skb_get_tunnel_opt,
2430         .gpl_only       = false,
2431         .ret_type       = RET_INTEGER,
2432         .arg1_type      = ARG_PTR_TO_CTX,
2433         .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
2434         .arg3_type      = ARG_CONST_SIZE,
2435 };
2436 
2437 static struct metadata_dst __percpu *md_dst;
2438 
2439 BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *, skb,
2440            const struct bpf_tunnel_key *, from, u32, size, u64, flags)
2441 {
2442         struct metadata_dst *md = this_cpu_ptr(md_dst);
2443         u8 compat[sizeof(struct bpf_tunnel_key)];
2444         struct ip_tunnel_info *info;
2445 
2446         if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6 | BPF_F_ZERO_CSUM_TX |
2447                                BPF_F_DONT_FRAGMENT)))
2448                 return -EINVAL;
2449         if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
2450                 switch (size) {
2451                 case offsetof(struct bpf_tunnel_key, tunnel_label):
2452                 case offsetof(struct bpf_tunnel_key, tunnel_ext):
2453                 case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
2454                         /* Fixup deprecated structure layouts here, so we have
2455                          * a common path later on.
2456                          */
2457                         memcpy(compat, from, size);
2458                         memset(compat + size, 0, sizeof(compat) - size);
2459                         from = (const struct bpf_tunnel_key *) compat;
2460                         break;
2461                 default:
2462                         return -EINVAL;
2463                 }
2464         }
2465         if (unlikely((!(flags & BPF_F_TUNINFO_IPV6) && from->tunnel_label) ||
2466                      from->tunnel_ext))
2467                 return -EINVAL;
2468 
2469         skb_dst_drop(skb);
2470         dst_hold((struct dst_entry *) md);
2471         skb_dst_set(skb, (struct dst_entry *) md);
2472 
2473         info = &md->u.tun_info;
2474         info->mode = IP_TUNNEL_INFO_TX;
2475 
2476         info->key.tun_flags = TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_NOCACHE;
2477         if (flags & BPF_F_DONT_FRAGMENT)
2478                 info->key.tun_flags |= TUNNEL_DONT_FRAGMENT;
2479 
2480         info->key.tun_id = cpu_to_be64(from->tunnel_id);
2481         info->key.tos = from->tunnel_tos;
2482         info->key.ttl = from->tunnel_ttl;
2483 
2484         if (flags & BPF_F_TUNINFO_IPV6) {
2485                 info->mode |= IP_TUNNEL_INFO_IPV6;
2486                 memcpy(&info->key.u.ipv6.dst, from->remote_ipv6,
2487                        sizeof(from->remote_ipv6));
2488                 info->key.label = cpu_to_be32(from->tunnel_label) &
2489                                   IPV6_FLOWLABEL_MASK;
2490         } else {
2491                 info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
2492                 if (flags & BPF_F_ZERO_CSUM_TX)
2493                         info->key.tun_flags &= ~TUNNEL_CSUM;
2494         }
2495 
2496         return 0;
2497 }
2498 
2499 static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = {
2500         .func           = bpf_skb_set_tunnel_key,
2501         .gpl_only       = false,
2502         .ret_type       = RET_INTEGER,
2503         .arg1_type      = ARG_PTR_TO_CTX,
2504         .arg2_type      = ARG_PTR_TO_MEM,
2505         .arg3_type      = ARG_CONST_SIZE,
2506         .arg4_type      = ARG_ANYTHING,
2507 };
2508 
2509 BPF_CALL_3(bpf_skb_set_tunnel_opt, struct sk_buff *, skb,
2510            const u8 *, from, u32, size)
2511 {
2512         struct ip_tunnel_info *info = skb_tunnel_info(skb);
2513         const struct metadata_dst *md = this_cpu_ptr(md_dst);
2514 
2515         if (unlikely(info != &md->u.tun_info || (size & (sizeof(u32) - 1))))
2516                 return -EINVAL;
2517         if (unlikely(size > IP_TUNNEL_OPTS_MAX))
2518                 return -ENOMEM;
2519 
2520         ip_tunnel_info_opts_set(info, from, size);
2521 
2522         return 0;
2523 }
2524 
2525 static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = {
2526         .func           = bpf_skb_set_tunnel_opt,
2527         .gpl_only       = false,
2528         .ret_type       = RET_INTEGER,
2529         .arg1_type      = ARG_PTR_TO_CTX,
2530         .arg2_type      = ARG_PTR_TO_MEM,
2531         .arg3_type      = ARG_CONST_SIZE,
2532 };
2533 
2534 static const struct bpf_func_proto *
2535 bpf_get_skb_set_tunnel_proto(enum bpf_func_id which)
2536 {
2537         if (!md_dst) {
2538                 /* Race is not possible, since it's called from verifier
2539                  * that is holding verifier mutex.
2540                  */
2541                 md_dst = metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX,
2542                                                    GFP_KERNEL);
2543                 if (!md_dst)
2544                         return NULL;
2545         }
2546 
2547         switch (which) {
2548         case BPF_FUNC_skb_set_tunnel_key:
2549                 return &bpf_skb_set_tunnel_key_proto;
2550         case BPF_FUNC_skb_set_tunnel_opt:
2551                 return &bpf_skb_set_tunnel_opt_proto;
2552         default:
2553                 return NULL;
2554         }
2555 }
2556 
2557 BPF_CALL_3(bpf_skb_under_cgroup, struct sk_buff *, skb, struct bpf_map *, map,
2558            u32, idx)
2559 {
2560         struct bpf_array *array = container_of(map, struct bpf_array, map);
2561         struct cgroup *cgrp;
2562         struct sock *sk;
2563 
2564         sk = skb_to_full_sk(skb);
2565         if (!sk || !sk_fullsock(sk))
2566                 return -ENOENT;
2567         if (unlikely(idx >= array->map.max_entries))
2568                 return -E2BIG;
2569 
2570         cgrp = READ_ONCE(array->ptrs[idx]);
2571         if (unlikely(!cgrp))
2572                 return -EAGAIN;
2573 
2574         return sk_under_cgroup_hierarchy(sk, cgrp);
2575 }
2576 
2577 static const struct bpf_func_proto bpf_skb_under_cgroup_proto = {
2578         .func           = bpf_skb_under_cgroup,
2579         .gpl_only       = false,
2580         .ret_type       = RET_INTEGER,
2581         .arg1_type      = ARG_PTR_TO_CTX,
2582         .arg2_type      = ARG_CONST_MAP_PTR,
2583         .arg3_type      = ARG_ANYTHING,
2584 };
2585 
2586 static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
2587                                   unsigned long off, unsigned long len)
2588 {
2589         memcpy(dst_buff, src_buff + off, len);
2590         return 0;
2591 }
2592 
2593 BPF_CALL_5(bpf_xdp_event_output, struct xdp_buff *, xdp, struct bpf_map *, map,
2594            u64, flags, void *, meta, u64, meta_size)
2595 {
2596         u64 xdp_size = (flags & BPF_F_CTXLEN_MASK) >> 32;
2597 
2598         if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
2599                 return -EINVAL;
2600         if (unlikely(xdp_size > (unsigned long)(xdp->data_end - xdp->data)))
2601                 return -EFAULT;
2602 
2603         return bpf_event_output(map, flags, meta, meta_size, xdp->data,
2604                                 xdp_size, bpf_xdp_copy);
2605 }
2606 
2607 static const struct bpf_func_proto bpf_xdp_event_output_proto = {
2608         .func           = bpf_xdp_event_output,
2609         .gpl_only       = true,
2610         .ret_type       = RET_INTEGER,
2611         .arg1_type      = ARG_PTR_TO_CTX,
2612         .arg2_type      = ARG_CONST_MAP_PTR,
2613         .arg3_type      = ARG_ANYTHING,
2614         .arg4_type      = ARG_PTR_TO_MEM,
2615         .arg5_type      = ARG_CONST_SIZE,
2616 };
2617 
2618 BPF_CALL_1(bpf_get_socket_cookie, struct sk_buff *, skb)
2619 {
2620         return skb->sk ? sock_gen_cookie(skb->sk) : 0;
2621 }
2622 
2623 static const struct bpf_func_proto bpf_get_socket_cookie_proto = {
2624         .func           = bpf_get_socket_cookie,
2625         .gpl_only       = false,
2626         .ret_type       = RET_INTEGER,
2627         .arg1_type      = ARG_PTR_TO_CTX,
2628 };
2629 
2630 BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb)
2631 {
2632         struct sock *sk = sk_to_full_sk(skb->sk);
2633         kuid_t kuid;
2634 
2635         if (!sk || !sk_fullsock(sk))
2636                 return overflowuid;
2637         kuid = sock_net_uid(sock_net(sk), sk);
2638         return from_kuid_munged(sock_net(sk)->user_ns, kuid);
2639 }
2640 
2641 static const struct bpf_func_proto bpf_get_socket_uid_proto = {
2642         .func           = bpf_get_socket_uid,
2643         .gpl_only       = false,
2644         .ret_type       = RET_INTEGER,
2645         .arg1_type      = ARG_PTR_TO_CTX,
2646 };
2647 
2648 static const struct bpf_func_proto *
2649 bpf_base_func_proto(enum bpf_func_id func_id)
2650 {
2651         switch (func_id) {
2652         case BPF_FUNC_map_lookup_elem:
2653                 return &bpf_map_lookup_elem_proto;
2654         case BPF_FUNC_map_update_elem:
2655                 return &bpf_map_update_elem_proto;
2656         case BPF_FUNC_map_delete_elem:
2657                 return &bpf_map_delete_elem_proto;
2658         case BPF_FUNC_get_prandom_u32:
2659                 return &bpf_get_prandom_u32_proto;
2660         case BPF_FUNC_get_smp_processor_id:
2661                 return &bpf_get_raw_smp_processor_id_proto;
2662         case BPF_FUNC_get_numa_node_id:
2663                 return &bpf_get_numa_node_id_proto;
2664         case BPF_FUNC_tail_call:
2665                 return &bpf_tail_call_proto;
2666         case BPF_FUNC_ktime_get_ns:
2667                 return &bpf_ktime_get_ns_proto;
2668         case BPF_FUNC_trace_printk:
2669                 if (capable(CAP_SYS_ADMIN))
2670                         return bpf_get_trace_printk_proto();
2671         default:
2672                 return NULL;
2673         }
2674 }
2675 
2676 static const struct bpf_func_proto *
2677 sk_filter_func_proto(enum bpf_func_id func_id)
2678 {
2679         switch (func_id) {
2680         case BPF_FUNC_skb_load_bytes:
2681                 return &bpf_skb_load_bytes_proto;
2682         case BPF_FUNC_get_socket_cookie:
2683                 return &bpf_get_socket_cookie_proto;
2684         case BPF_FUNC_get_socket_uid:
2685                 return &bpf_get_socket_uid_proto;
2686         default:
2687                 return bpf_base_func_proto(func_id);
2688         }
2689 }
2690 
2691 static const struct bpf_func_proto *
2692 tc_cls_act_func_proto(enum bpf_func_id func_id)
2693 {
2694         switch (func_id) {
2695         case BPF_FUNC_skb_store_bytes:
2696                 return &bpf_skb_store_bytes_proto;
2697         case BPF_FUNC_skb_load_bytes:
2698                 return &bpf_skb_load_bytes_proto;
2699         case BPF_FUNC_skb_pull_data:
2700                 return &bpf_skb_pull_data_proto;
2701         case BPF_FUNC_csum_diff:
2702                 return &bpf_csum_diff_proto;
2703         case BPF_FUNC_csum_update:
2704                 return &bpf_csum_update_proto;
2705         case BPF_FUNC_l3_csum_replace:
2706                 return &bpf_l3_csum_replace_proto;
2707         case BPF_FUNC_l4_csum_replace:
2708                 return &bpf_l4_csum_replace_proto;
2709         case BPF_FUNC_clone_redirect:
2710                 return &bpf_clone_redirect_proto;
2711         case BPF_FUNC_get_cgroup_classid:
2712                 return &bpf_get_cgroup_classid_proto;
2713         case BPF_FUNC_skb_vlan_push:
2714                 return &bpf_skb_vlan_push_proto;
2715         case BPF_FUNC_skb_vlan_pop:
2716                 return &bpf_skb_vlan_pop_proto;
2717         case BPF_FUNC_skb_change_proto:
2718                 return &bpf_skb_change_proto_proto;
2719         case BPF_FUNC_skb_change_type:
2720                 return &bpf_skb_change_type_proto;
2721         case BPF_FUNC_skb_change_tail:
2722                 return &bpf_skb_change_tail_proto;
2723         case BPF_FUNC_skb_get_tunnel_key:
2724                 return &bpf_skb_get_tunnel_key_proto;
2725         case BPF_FUNC_skb_set_tunnel_key:
2726                 return bpf_get_skb_set_tunnel_proto(func_id);
2727         case BPF_FUNC_skb_get_tunnel_opt:
2728                 return &bpf_skb_get_tunnel_opt_proto;
2729         case BPF_FUNC_skb_set_tunnel_opt:
2730                 return bpf_get_skb_set_tunnel_proto(func_id);
2731         case BPF_FUNC_redirect:
2732                 return &bpf_redirect_proto;
2733         case BPF_FUNC_get_route_realm:
2734                 return &bpf_get_route_realm_proto;
2735         case BPF_FUNC_get_hash_recalc:
2736                 return &bpf_get_hash_recalc_proto;
2737         case BPF_FUNC_set_hash_invalid:
2738                 return &bpf_set_hash_invalid_proto;
2739         case BPF_FUNC_perf_event_output:
2740                 return &bpf_skb_event_output_proto;
2741         case BPF_FUNC_get_smp_processor_id:
2742                 return &bpf_get_smp_processor_id_proto;
2743         case BPF_FUNC_skb_under_cgroup:
2744                 return &bpf_skb_under_cgroup_proto;
2745         case BPF_FUNC_get_socket_cookie:
2746                 return &bpf_get_socket_cookie_proto;
2747         case BPF_FUNC_get_socket_uid:
2748                 return &bpf_get_socket_uid_proto;
2749         default:
2750                 return bpf_base_func_proto(func_id);
2751         }
2752 }
2753 
2754 static const struct bpf_func_proto *
2755 xdp_func_proto(enum bpf_func_id func_id)
2756 {
2757         switch (func_id) {
2758         case BPF_FUNC_perf_event_output:
2759                 return &bpf_xdp_event_output_proto;
2760         case BPF_FUNC_get_smp_processor_id:
2761                 return &bpf_get_smp_processor_id_proto;
2762         case BPF_FUNC_xdp_adjust_head:
2763                 return &bpf_xdp_adjust_head_proto;
2764         default:
2765                 return bpf_base_func_proto(func_id);
2766         }
2767 }
2768 
2769 static const struct bpf_func_proto *
2770 cg_skb_func_proto(enum bpf_func_id func_id)
2771 {
2772         return sk_filter_func_proto(func_id);
2773 }
2774 
2775 static const struct bpf_func_proto *
2776 lwt_inout_func_proto(enum bpf_func_id func_id)
2777 {
2778         switch (func_id) {
2779         case BPF_FUNC_skb_load_bytes:
2780                 return &bpf_skb_load_bytes_proto;
2781         case BPF_FUNC_skb_pull_data:
2782                 return &bpf_skb_pull_data_proto;
2783         case BPF_FUNC_csum_diff:
2784                 return &bpf_csum_diff_proto;
2785         case BPF_FUNC_get_cgroup_classid:
2786                 return &bpf_get_cgroup_classid_proto;
2787         case BPF_FUNC_get_route_realm:
2788                 return &bpf_get_route_realm_proto;
2789         case BPF_FUNC_get_hash_recalc:
2790                 return &bpf_get_hash_recalc_proto;
2791         case BPF_FUNC_perf_event_output:
2792                 return &bpf_skb_event_output_proto;
2793         case BPF_FUNC_get_smp_processor_id:
2794                 return &bpf_get_smp_processor_id_proto;
2795         case BPF_FUNC_skb_under_cgroup:
2796                 return &bpf_skb_under_cgroup_proto;
2797         default:
2798                 return bpf_base_func_proto(func_id);
2799         }
2800 }
2801 
2802 static const struct bpf_func_proto *
2803 lwt_xmit_func_proto(enum bpf_func_id func_id)
2804 {
2805         switch (func_id) {
2806         case BPF_FUNC_skb_get_tunnel_key:
2807                 return &bpf_skb_get_tunnel_key_proto;
2808         case BPF_FUNC_skb_set_tunnel_key:
2809                 return bpf_get_skb_set_tunnel_proto(func_id);
2810         case BPF_FUNC_skb_get_tunnel_opt:
2811                 return &bpf_skb_get_tunnel_opt_proto;
2812         case BPF_FUNC_skb_set_tunnel_opt:
2813                 return bpf_get_skb_set_tunnel_proto(func_id);
2814         case BPF_FUNC_redirect:
2815                 return &bpf_redirect_proto;
2816         case BPF_FUNC_clone_redirect:
2817                 return &bpf_clone_redirect_proto;
2818         case BPF_FUNC_skb_change_tail:
2819                 return &bpf_skb_change_tail_proto;
2820         case BPF_FUNC_skb_change_head:
2821                 return &bpf_skb_change_head_proto;
2822         case BPF_FUNC_skb_store_bytes:
2823                 return &bpf_skb_store_bytes_proto;
2824         case BPF_FUNC_csum_update:
2825                 return &bpf_csum_update_proto;
2826         case BPF_FUNC_l3_csum_replace:
2827                 return &bpf_l3_csum_replace_proto;
2828         case BPF_FUNC_l4_csum_replace:
2829                 return &bpf_l4_csum_replace_proto;
2830         case BPF_FUNC_set_hash_invalid:
2831                 return &bpf_set_hash_invalid_proto;
2832         default:
2833                 return lwt_inout_func_proto(func_id);
2834         }
2835 }
2836 
2837 static bool __is_valid_access(int off, int size)
2838 {
2839         if (off < 0 || off >= sizeof(struct __sk_buff))
2840                 return false;
2841 
2842         /* The verifier guarantees that size > 0. */
2843         if (off % size != 0)
2844                 return false;
2845 
2846         switch (off) {
2847         case offsetof(struct __sk_buff, cb[0]) ...
2848              offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2849                 if (off + size >
2850                     offsetof(struct __sk_buff, cb[4]) + sizeof(__u32))
2851                         return false;
2852                 break;
2853         default:
2854                 if (size != sizeof(__u32))
2855                         return false;
2856         }
2857 
2858         return true;
2859 }
2860 
2861 static bool sk_filter_is_valid_access(int off, int size,
2862                                       enum bpf_access_type type,
2863                                       enum bpf_reg_type *reg_type)
2864 {
2865         switch (off) {
2866         case offsetof(struct __sk_buff, tc_classid):
2867         case offsetof(struct __sk_buff, data):
2868         case offsetof(struct __sk_buff, data_end):
2869                 return false;
2870         }
2871 
2872         if (type == BPF_WRITE) {
2873                 switch (off) {
2874                 case offsetof(struct __sk_buff, cb[0]) ...
2875                      offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2876                         break;
2877                 default:
2878                         return false;
2879                 }
2880         }
2881 
2882         return __is_valid_access(off, size);
2883 }
2884 
2885 static bool lwt_is_valid_access(int off, int size,
2886                                 enum bpf_access_type type,
2887                                 enum bpf_reg_type *reg_type)
2888 {
2889         switch (off) {
2890         case offsetof(struct __sk_buff, tc_classid):
2891                 return false;
2892         }
2893 
2894         if (type == BPF_WRITE) {
2895                 switch (off) {
2896                 case offsetof(struct __sk_buff, mark):
2897                 case offsetof(struct __sk_buff, priority):
2898                 case offsetof(struct __sk_buff, cb[0]) ...
2899                      offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2900                         break;
2901                 default:
2902                         return false;
2903                 }
2904         }
2905 
2906         switch (off) {
2907         case offsetof(struct __sk_buff, data):
2908                 *reg_type = PTR_TO_PACKET;
2909                 break;
2910         case offsetof(struct __sk_buff, data_end):
2911                 *reg_type = PTR_TO_PACKET_END;
2912                 break;
2913         }
2914 
2915         return __is_valid_access(off, size);
2916 }
2917 
2918 static bool sock_filter_is_valid_access(int off, int size,
2919                                         enum bpf_access_type type,
2920                                         enum bpf_reg_type *reg_type)
2921 {
2922         if (type == BPF_WRITE) {
2923                 switch (off) {
2924                 case offsetof(struct bpf_sock, bound_dev_if):
2925                         break;
2926                 default:
2927                         return false;
2928                 }
2929         }
2930 
2931         if (off < 0 || off + size > sizeof(struct bpf_sock))
2932                 return false;
2933         /* The verifier guarantees that size > 0. */
2934         if (off % size != 0)
2935                 return false;
2936         if (size != sizeof(__u32))
2937                 return false;
2938 
2939         return true;
2940 }
2941 
2942 static int tc_cls_act_prologue(struct bpf_insn *insn_buf, bool direct_write,
2943                                const struct bpf_prog *prog)
2944 {
2945         struct bpf_insn *insn = insn_buf;
2946 
2947         if (!direct_write)
2948                 return 0;
2949 
2950         /* if (!skb->cloned)
2951          *       goto start;
2952          *
2953          * (Fast-path, otherwise approximation that we might be
2954          *  a clone, do the rest in helper.)
2955          */
2956         *insn++ = BPF_LDX_MEM(BPF_B, BPF_REG_6, BPF_REG_1, CLONED_OFFSET());
2957         *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_6, CLONED_MASK);
2958         *insn++ = BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 7);
2959 
2960         /* ret = bpf_skb_pull_data(skb, 0); */
2961         *insn++ = BPF_MOV64_REG(BPF_REG_6, BPF_REG_1);
2962         *insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_2, BPF_REG_2);
2963         *insn++ = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
2964                                BPF_FUNC_skb_pull_data);
2965         /* if (!ret)
2966          *      goto restore;
2967          * return TC_ACT_SHOT;
2968          */
2969         *insn++ = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2);
2970         *insn++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_0, TC_ACT_SHOT);
2971         *insn++ = BPF_EXIT_INSN();
2972 
2973         /* restore: */
2974         *insn++ = BPF_MOV64_REG(BPF_REG_1, BPF_REG_6);
2975         /* start: */
2976         *insn++ = prog->insnsi[0];
2977 
2978         return insn - insn_buf;
2979 }
2980 
2981 static bool tc_cls_act_is_valid_access(int off, int size,
2982                                        enum bpf_access_type type,
2983                                        enum bpf_reg_type *reg_type)
2984 {
2985         if (type == BPF_WRITE) {
2986                 switch (off) {
2987                 case offsetof(struct __sk_buff, mark):
2988                 case offsetof(struct __sk_buff, tc_index):
2989                 case offsetof(struct __sk_buff, priority):
2990                 case offsetof(struct __sk_buff, cb[0]) ...
2991                      offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2992                 case offsetof(struct __sk_buff, tc_classid):
2993                         break;
2994                 default:
2995                         return false;
2996                 }
2997         }
2998 
2999         switch (off) {
3000         case offsetof(struct __sk_buff, data):
3001                 *reg_type = PTR_TO_PACKET;
3002                 break;
3003         case offsetof(struct __sk_buff, data_end):
3004                 *reg_type = PTR_TO_PACKET_END;
3005                 break;
3006         }
3007 
3008         return __is_valid_access(off, size);
3009 }
3010 
3011 static bool __is_valid_xdp_access(int off, int size)
3012 {
3013         if (off < 0 || off >= sizeof(struct xdp_md))
3014                 return false;
3015         if (off % size != 0)
3016                 return false;
3017         if (size != sizeof(__u32))
3018                 return false;
3019 
3020         return true;
3021 }
3022 
3023 static bool xdp_is_valid_access(int off, int size,
3024                                 enum bpf_access_type type,
3025                                 enum bpf_reg_type *reg_type)
3026 {
3027         if (type == BPF_WRITE)
3028                 return false;
3029 
3030         switch (off) {
3031         case offsetof(struct xdp_md, data):
3032                 *reg_type = PTR_TO_PACKET;
3033                 break;
3034         case offsetof(struct xdp_md, data_end):
3035                 *reg_type = PTR_TO_PACKET_END;
3036                 break;
3037         }
3038 
3039         return __is_valid_xdp_access(off, size);
3040 }
3041 
3042 void bpf_warn_invalid_xdp_action(u32 act)
3043 {
3044         WARN_ONCE(1, "Illegal XDP return value %u, expect packet loss\n", act);
3045 }
3046 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
3047 
3048 static u32 bpf_convert_ctx_access(enum bpf_access_type type,
3049                                   const struct bpf_insn *si,
3050                                   struct bpf_insn *insn_buf,
3051                                   struct bpf_prog *prog)
3052 {
3053         struct bpf_insn *insn = insn_buf;
3054         int off;
3055 
3056         switch (si->off) {
3057         case offsetof(struct __sk_buff, len):
3058                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
3059 
3060                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3061                                       offsetof(struct sk_buff, len));
3062                 break;
3063 
3064         case offsetof(struct __sk_buff, protocol):
3065                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
3066 
3067                 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3068                                       offsetof(struct sk_buff, protocol));
3069                 break;
3070 
3071         case offsetof(struct __sk_buff, vlan_proto):
3072                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2);
3073 
3074                 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3075                                       offsetof(struct sk_buff, vlan_proto));
3076                 break;
3077 
3078         case offsetof(struct __sk_buff, priority):
3079                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4);
3080 
3081                 if (type == BPF_WRITE)
3082                         *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
3083                                               offsetof(struct sk_buff, priority));
3084                 else
3085                         *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3086                                               offsetof(struct sk_buff, priority));
3087                 break;
3088 
3089         case offsetof(struct __sk_buff, ingress_ifindex):
3090                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, skb_iif) != 4);
3091 
3092                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3093                                       offsetof(struct sk_buff, skb_iif));
3094                 break;
3095 
3096         case offsetof(struct __sk_buff, ifindex):
3097                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
3098 
3099                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
3100                                       si->dst_reg, si->src_reg,
3101                                       offsetof(struct sk_buff, dev));
3102                 *insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 1);
3103                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
3104                                       offsetof(struct net_device, ifindex));
3105                 break;
3106 
3107         case offsetof(struct __sk_buff, hash):
3108                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
3109 
3110                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3111                                       offsetof(struct sk_buff, hash));
3112                 break;
3113 
3114         case offsetof(struct __sk_buff, mark):
3115                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
3116 
3117                 if (type == BPF_WRITE)
3118                         *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
3119                                               offsetof(struct sk_buff, mark));
3120                 else
3121                         *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3122                                               offsetof(struct sk_buff, mark));
3123                 break;
3124 
3125         case offsetof(struct __sk_buff, pkt_type):
3126                 return convert_skb_access(SKF_AD_PKTTYPE, si->dst_reg,
3127                                           si->src_reg, insn);
3128 
3129         case offsetof(struct __sk_buff, queue_mapping):
3130                 return convert_skb_access(SKF_AD_QUEUE, si->dst_reg,
3131                                           si->src_reg, insn);
3132 
3133         case offsetof(struct __sk_buff, vlan_present):
3134                 return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT,
3135                                           si->dst_reg, si->src_reg, insn);
3136 
3137         case offsetof(struct __sk_buff, vlan_tci):
3138                 return convert_skb_access(SKF_AD_VLAN_TAG,
3139                                           si->dst_reg, si->src_reg, insn);
3140 
3141         case offsetof(struct __sk_buff, cb[0]) ...
3142              offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
3143                 BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20);
3144                 BUILD_BUG_ON((offsetof(struct sk_buff, cb) +
3145                               offsetof(struct qdisc_skb_cb, data)) %
3146                              sizeof(__u64));
3147 
3148                 prog->cb_access = 1;
3149                 off  = si->off;
3150                 off -= offsetof(struct __sk_buff, cb[0]);
3151                 off += offsetof(struct sk_buff, cb);
3152                 off += offsetof(struct qdisc_skb_cb, data);
3153                 if (type == BPF_WRITE)
3154                         *insn++ = BPF_STX_MEM(BPF_SIZE(si->code), si->dst_reg,
3155                                               si->src_reg, off);
3156                 else
3157                         *insn++ = BPF_LDX_MEM(BPF_SIZE(si->code), si->dst_reg,
3158                                               si->src_reg, off);
3159                 break;
3160 
3161         case offsetof(struct __sk_buff, tc_classid):
3162                 BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, tc_classid) != 2);
3163 
3164                 off  = si->off;
3165                 off -= offsetof(struct __sk_buff, tc_classid);
3166                 off += offsetof(struct sk_buff, cb);
3167                 off += offsetof(struct qdisc_skb_cb, tc_classid);
3168                 if (type == BPF_WRITE)
3169                         *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg,
3170                                               si->src_reg, off);
3171                 else
3172                         *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg,
3173                                               si->src_reg, off);
3174                 break;
3175 
3176         case offsetof(struct __sk_buff, data):
3177                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, data),
3178                                       si->dst_reg, si->src_reg,
3179                                       offsetof(struct sk_buff, data));
3180                 break;
3181 
3182         case offsetof(struct __sk_buff, data_end):
3183                 off  = si->off;
3184                 off -= offsetof(struct __sk_buff, data_end);
3185                 off += offsetof(struct sk_buff, cb);
3186                 off += offsetof(struct bpf_skb_data_end, data_end);
3187                 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(void *), si->dst_reg,
3188                                       si->src_reg, off);
3189                 break;
3190 
3191         case offsetof(struct __sk_buff, tc_index):
3192 #ifdef CONFIG_NET_SCHED
3193                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, tc_index) != 2);
3194 
3195                 if (type == BPF_WRITE)
3196                         *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg, si->src_reg,
3197                                               offsetof(struct sk_buff, tc_index));
3198                 else
3199                         *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3200                                               offsetof(struct sk_buff, tc_index));
3201 #else
3202                 if (type == BPF_WRITE)
3203                         *insn++ = BPF_MOV64_REG(si->dst_reg, si->dst_reg);
3204                 else
3205                         *insn++ = BPF_MOV64_IMM(si->dst_reg, 0);
3206 #endif
3207                 break;
3208 
3209         case offsetof(struct __sk_buff, napi_id):
3210 #if defined(CONFIG_NET_RX_BUSY_POLL)
3211                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, napi_id) != 4);
3212 
3213                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3214                                       offsetof(struct sk_buff, napi_id));
3215                 *insn++ = BPF_JMP_IMM(BPF_JGE, si->dst_reg, MIN_NAPI_ID, 1);
3216                 *insn++ = BPF_MOV64_IMM(si->dst_reg, 0);
3217 #else
3218                 *insn++ = BPF_MOV64_IMM(si->dst_reg, 0);
3219 #endif
3220                 break;
3221         }
3222 
3223         return insn - insn_buf;
3224 }
3225 
3226 static u32 sock_filter_convert_ctx_access(enum bpf_access_type type,
3227                                           const struct bpf_insn *si,
3228                                           struct bpf_insn *insn_buf,
3229                                           struct bpf_prog *prog)
3230 {
3231         struct bpf_insn *insn = insn_buf;
3232 
3233         switch (si->off) {
3234         case offsetof(struct bpf_sock, bound_dev_if):
3235                 BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_bound_dev_if) != 4);
3236 
3237                 if (type == BPF_WRITE)
3238                         *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
3239                                         offsetof(struct sock, sk_bound_dev_if));
3240                 else
3241                         *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3242                                       offsetof(struct sock, sk_bound_dev_if));
3243                 break;
3244 
3245         case offsetof(struct bpf_sock, family):
3246                 BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_family) != 2);
3247 
3248                 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3249                                       offsetof(struct sock, sk_family));
3250                 break;
3251 
3252         case offsetof(struct bpf_sock, type):
3253                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3254                                       offsetof(struct sock, __sk_flags_offset));
3255                 *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_TYPE_MASK);
3256                 *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_TYPE_SHIFT);
3257                 break;
3258 
3259         case offsetof(struct bpf_sock, protocol):
3260                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3261                                       offsetof(struct sock, __sk_flags_offset));
3262                 *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK);
3263                 *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_PROTO_SHIFT);
3264                 break;
3265         }
3266 
3267         return insn - insn_buf;
3268 }
3269 
3270 static u32 tc_cls_act_convert_ctx_access(enum bpf_access_type type,
3271                                          const struct bpf_insn *si,
3272                                          struct bpf_insn *insn_buf,
3273                                          struct bpf_prog *prog)
3274 {
3275         struct bpf_insn *insn = insn_buf;
3276 
3277         switch (si->off) {
3278         case offsetof(struct __sk_buff, ifindex):
3279                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
3280 
3281                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
3282                                       si->dst_reg, si->src_reg,
3283                                       offsetof(struct sk_buff, dev));
3284                 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
3285                                       offsetof(struct net_device, ifindex));
3286                 break;
3287         default:
3288                 return bpf_convert_ctx_access(type, si, insn_buf, prog);
3289         }
3290 
3291         return insn - insn_buf;
3292 }
3293 
3294 static u32 xdp_convert_ctx_access(enum bpf_access_type type,
3295                                   const struct bpf_insn *si,
3296                                   struct bpf_insn *insn_buf,
3297                                   struct bpf_prog *prog)
3298 {
3299         struct bpf_insn *insn = insn_buf;
3300 
3301         switch (si->off) {
3302         case offsetof(struct xdp_md, data):
3303                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data),
3304                                       si->dst_reg, si->src_reg,
3305                                       offsetof(struct xdp_buff, data));
3306                 break;
3307         case offsetof(struct xdp_md, data_end):
3308                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data_end),
3309                                       si->dst_reg, si->src_reg,
3310                                       offsetof(struct xdp_buff, data_end));
3311                 break;
3312         }
3313 
3314         return insn - insn_buf;
3315 }
3316 
3317 const struct bpf_verifier_ops sk_filter_prog_ops = {
3318         .get_func_proto         = sk_filter_func_proto,
3319         .is_valid_access        = sk_filter_is_valid_access,
3320         .convert_ctx_access     = bpf_convert_ctx_access,
3321 };
3322 
3323 const struct bpf_verifier_ops tc_cls_act_prog_ops = {
3324         .get_func_proto         = tc_cls_act_func_proto,
3325         .is_valid_access        = tc_cls_act_is_valid_access,
3326         .convert_ctx_access     = tc_cls_act_convert_ctx_access,
3327         .gen_prologue           = tc_cls_act_prologue,
3328         .test_run               = bpf_prog_test_run_skb,
3329 };
3330 
3331 const struct bpf_verifier_ops xdp_prog_ops = {
3332         .get_func_proto         = xdp_func_proto,
3333         .is_valid_access        = xdp_is_valid_access,
3334         .convert_ctx_access     = xdp_convert_ctx_access,
3335         .test_run               = bpf_prog_test_run_xdp,
3336 };
3337 
3338 const struct bpf_verifier_ops cg_skb_prog_ops = {
3339         .get_func_proto         = cg_skb_func_proto,
3340         .is_valid_access        = sk_filter_is_valid_access,
3341         .convert_ctx_access     = bpf_convert_ctx_access,
3342         .test_run               = bpf_prog_test_run_skb,
3343 };
3344 
3345 const struct bpf_verifier_ops lwt_inout_prog_ops = {
3346         .get_func_proto         = lwt_inout_func_proto,
3347         .is_valid_access        = lwt_is_valid_access,
3348         .convert_ctx_access     = bpf_convert_ctx_access,
3349         .test_run               = bpf_prog_test_run_skb,
3350 };
3351 
3352 const struct bpf_verifier_ops lwt_xmit_prog_ops = {
3353         .get_func_proto         = lwt_xmit_func_proto,
3354         .is_valid_access        = lwt_is_valid_access,
3355         .convert_ctx_access     = bpf_convert_ctx_access,
3356         .gen_prologue           = tc_cls_act_prologue,
3357         .test_run               = bpf_prog_test_run_skb,
3358 };
3359 
3360 const struct bpf_verifier_ops cg_sock_prog_ops = {
3361         .get_func_proto         = bpf_base_func_proto,
3362         .is_valid_access        = sock_filter_is_valid_access,
3363         .convert_ctx_access     = sock_filter_convert_ctx_access,
3364 };
3365 
3366 int sk_detach_filter(struct sock *sk)
3367 {
3368         int ret = -ENOENT;
3369         struct sk_filter *filter;
3370 
3371         if (sock_flag(sk, SOCK_FILTER_LOCKED))
3372                 return -EPERM;
3373 
3374         filter = rcu_dereference_protected(sk->sk_filter,
3375                                            lockdep_sock_is_held(sk));
3376         if (filter) {
3377                 RCU_INIT_POINTER(sk->sk_filter, NULL);
3378                 sk_filter_uncharge(sk, filter);
3379                 ret = 0;
3380         }
3381 
3382         return ret;
3383 }
3384 EXPORT_SYMBOL_GPL(sk_detach_filter);
3385 
3386 int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf,
3387                   unsigned int len)
3388 {
3389         struct sock_fprog_kern *fprog;
3390         struct sk_filter *filter;
3391         int ret = 0;
3392 
3393         lock_sock(sk);
3394         filter = rcu_dereference_protected(sk->sk_filter,
3395                                            lockdep_sock_is_held(sk));
3396         if (!filter)
3397                 goto out;
3398 
3399         /* We're copying the filter that has been originally attached,
3400          * so no conversion/decode needed anymore. eBPF programs that
3401          * have no original program cannot be dumped through this.
3402          */
3403         ret = -EACCES;
3404         fprog = filter->prog->orig_prog;
3405         if (!fprog)
3406                 goto out;
3407 
3408         ret = fprog->len;
3409         if (!len)
3410                 /* User space only enquires number of filter blocks. */
3411                 goto out;
3412 
3413         ret = -EINVAL;
3414         if (len < fprog->len)
3415                 goto out;
3416 
3417         ret = -EFAULT;
3418         if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog)))
3419                 goto out;
3420 
3421         /* Instead of bytes, the API requests to return the number
3422          * of filter blocks.
3423          */
3424         ret = fprog->len;
3425 out:
3426         release_sock(sk);
3427         return ret;
3428 }
3429 

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