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

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  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/in.h>
 30 #include <linux/inet.h>
 31 #include <linux/netdevice.h>
 32 #include <linux/if_packet.h>
 33 #include <linux/gfp.h>
 34 #include <net/ip.h>
 35 #include <net/protocol.h>
 36 #include <net/netlink.h>
 37 #include <linux/skbuff.h>
 38 #include <net/sock.h>
 39 #include <net/flow_dissector.h>
 40 #include <linux/errno.h>
 41 #include <linux/timer.h>
 42 #include <asm/uaccess.h>
 43 #include <asm/unaligned.h>
 44 #include <linux/filter.h>
 45 #include <linux/ratelimit.h>
 46 #include <linux/seccomp.h>
 47 #include <linux/if_vlan.h>
 48 #include <linux/bpf.h>
 49 #include <net/sch_generic.h>
 50 #include <net/cls_cgroup.h>
 51 #include <net/dst_metadata.h>
 52 #include <net/dst.h>
 53 #include <net/sock_reuseport.h>
 54 
 55 /**
 56  *      sk_filter_trim_cap - run a packet through a socket filter
 57  *      @sk: sock associated with &sk_buff
 58  *      @skb: buffer to filter
 59  *      @cap: limit on how short the eBPF program may trim the packet
 60  *
 61  * Run the eBPF program and then cut skb->data to correct size returned by
 62  * the program. If pkt_len is 0 we toss packet. If skb->len is smaller
 63  * than pkt_len we keep whole skb->data. This is the socket level
 64  * wrapper to BPF_PROG_RUN. It returns 0 if the packet should
 65  * be accepted or -EPERM if the packet should be tossed.
 66  *
 67  */
 68 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap)
 69 {
 70         int err;
 71         struct sk_filter *filter;
 72 
 73         /*
 74          * If the skb was allocated from pfmemalloc reserves, only
 75          * allow SOCK_MEMALLOC sockets to use it as this socket is
 76          * helping free memory
 77          */
 78         if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
 79                 return -ENOMEM;
 80 
 81         err = security_sock_rcv_skb(sk, skb);
 82         if (err)
 83                 return err;
 84 
 85         rcu_read_lock();
 86         filter = rcu_dereference(sk->sk_filter);
 87         if (filter) {
 88                 unsigned int pkt_len = bpf_prog_run_save_cb(filter->prog, skb);
 89                 err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM;
 90         }
 91         rcu_read_unlock();
 92 
 93         return err;
 94 }
 95 EXPORT_SYMBOL(sk_filter_trim_cap);
 96 
 97 static u64 __skb_get_pay_offset(u64 ctx, u64 a, u64 x, u64 r4, u64 r5)
 98 {
 99         return skb_get_poff((struct sk_buff *)(unsigned long) ctx);
100 }
101 
102 static u64 __skb_get_nlattr(u64 ctx, u64 a, u64 x, u64 r4, u64 r5)
103 {
104         struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx;
105         struct nlattr *nla;
106 
107         if (skb_is_nonlinear(skb))
108                 return 0;
109 
110         if (skb->len < sizeof(struct nlattr))
111                 return 0;
112 
113         if (a > skb->len - sizeof(struct nlattr))
114                 return 0;
115 
116         nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x);
117         if (nla)
118                 return (void *) nla - (void *) skb->data;
119 
120         return 0;
121 }
122 
123 static u64 __skb_get_nlattr_nest(u64 ctx, u64 a, u64 x, u64 r4, u64 r5)
124 {
125         struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx;
126         struct nlattr *nla;
127 
128         if (skb_is_nonlinear(skb))
129                 return 0;
130 
131         if (skb->len < sizeof(struct nlattr))
132                 return 0;
133 
134         if (a > skb->len - sizeof(struct nlattr))
135                 return 0;
136 
137         nla = (struct nlattr *) &skb->data[a];
138         if (nla->nla_len > skb->len - a)
139                 return 0;
140 
141         nla = nla_find_nested(nla, x);
142         if (nla)
143                 return (void *) nla - (void *) skb->data;
144 
145         return 0;
146 }
147 
148 static u64 __get_raw_cpu_id(u64 ctx, u64 a, u64 x, u64 r4, u64 r5)
149 {
150         return raw_smp_processor_id();
151 }
152 
153 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
154         .func           = __get_raw_cpu_id,
155         .gpl_only       = false,
156         .ret_type       = RET_INTEGER,
157 };
158 
159 static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
160                               struct bpf_insn *insn_buf)
161 {
162         struct bpf_insn *insn = insn_buf;
163 
164         switch (skb_field) {
165         case SKF_AD_MARK:
166                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
167 
168                 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
169                                       offsetof(struct sk_buff, mark));
170                 break;
171 
172         case SKF_AD_PKTTYPE:
173                 *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_TYPE_OFFSET());
174                 *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, PKT_TYPE_MAX);
175 #ifdef __BIG_ENDIAN_BITFIELD
176                 *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 5);
177 #endif
178                 break;
179 
180         case SKF_AD_QUEUE:
181                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
182 
183                 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
184                                       offsetof(struct sk_buff, queue_mapping));
185                 break;
186 
187         case SKF_AD_VLAN_TAG:
188         case SKF_AD_VLAN_TAG_PRESENT:
189                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
190                 BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
191 
192                 /* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */
193                 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
194                                       offsetof(struct sk_buff, vlan_tci));
195                 if (skb_field == SKF_AD_VLAN_TAG) {
196                         *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg,
197                                                 ~VLAN_TAG_PRESENT);
198                 } else {
199                         /* dst_reg >>= 12 */
200                         *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12);
201                         /* dst_reg &= 1 */
202                         *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1);
203                 }
204                 break;
205         }
206 
207         return insn - insn_buf;
208 }
209 
210 static bool convert_bpf_extensions(struct sock_filter *fp,
211                                    struct bpf_insn **insnp)
212 {
213         struct bpf_insn *insn = *insnp;
214         u32 cnt;
215 
216         switch (fp->k) {
217         case SKF_AD_OFF + SKF_AD_PROTOCOL:
218                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
219 
220                 /* A = *(u16 *) (CTX + offsetof(protocol)) */
221                 *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX,
222                                       offsetof(struct sk_buff, protocol));
223                 /* A = ntohs(A) [emitting a nop or swap16] */
224                 *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16);
225                 break;
226 
227         case SKF_AD_OFF + SKF_AD_PKTTYPE:
228                 cnt = convert_skb_access(SKF_AD_PKTTYPE, BPF_REG_A, BPF_REG_CTX, insn);
229                 insn += cnt - 1;
230                 break;
231 
232         case SKF_AD_OFF + SKF_AD_IFINDEX:
233         case SKF_AD_OFF + SKF_AD_HATYPE:
234                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
235                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
236                 BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)) < 0);
237 
238                 *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)),
239                                       BPF_REG_TMP, BPF_REG_CTX,
240                                       offsetof(struct sk_buff, dev));
241                 /* if (tmp != 0) goto pc + 1 */
242                 *insn++ = BPF_JMP_IMM(BPF_JNE, BPF_REG_TMP, 0, 1);
243                 *insn++ = BPF_EXIT_INSN();
244                 if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX)
245                         *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_TMP,
246                                             offsetof(struct net_device, ifindex));
247                 else
248                         *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_TMP,
249                                             offsetof(struct net_device, type));
250                 break;
251 
252         case SKF_AD_OFF + SKF_AD_MARK:
253                 cnt = convert_skb_access(SKF_AD_MARK, BPF_REG_A, BPF_REG_CTX, insn);
254                 insn += cnt - 1;
255                 break;
256 
257         case SKF_AD_OFF + SKF_AD_RXHASH:
258                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
259 
260                 *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX,
261                                     offsetof(struct sk_buff, hash));
262                 break;
263 
264         case SKF_AD_OFF + SKF_AD_QUEUE:
265                 cnt = convert_skb_access(SKF_AD_QUEUE, BPF_REG_A, BPF_REG_CTX, insn);
266                 insn += cnt - 1;
267                 break;
268 
269         case SKF_AD_OFF + SKF_AD_VLAN_TAG:
270                 cnt = convert_skb_access(SKF_AD_VLAN_TAG,
271                                          BPF_REG_A, BPF_REG_CTX, insn);
272                 insn += cnt - 1;
273                 break;
274 
275         case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT:
276                 cnt = convert_skb_access(SKF_AD_VLAN_TAG_PRESENT,
277                                          BPF_REG_A, BPF_REG_CTX, insn);
278                 insn += cnt - 1;
279                 break;
280 
281         case SKF_AD_OFF + SKF_AD_VLAN_TPID:
282                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2);
283 
284                 /* A = *(u16 *) (CTX + offsetof(vlan_proto)) */
285                 *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX,
286                                       offsetof(struct sk_buff, vlan_proto));
287                 /* A = ntohs(A) [emitting a nop or swap16] */
288                 *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16);
289                 break;
290 
291         case SKF_AD_OFF + SKF_AD_PAY_OFFSET:
292         case SKF_AD_OFF + SKF_AD_NLATTR:
293         case SKF_AD_OFF + SKF_AD_NLATTR_NEST:
294         case SKF_AD_OFF + SKF_AD_CPU:
295         case SKF_AD_OFF + SKF_AD_RANDOM:
296                 /* arg1 = CTX */
297                 *insn++ = BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX);
298                 /* arg2 = A */
299                 *insn++ = BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_A);
300                 /* arg3 = X */
301                 *insn++ = BPF_MOV64_REG(BPF_REG_ARG3, BPF_REG_X);
302                 /* Emit call(arg1=CTX, arg2=A, arg3=X) */
303                 switch (fp->k) {
304                 case SKF_AD_OFF + SKF_AD_PAY_OFFSET:
305                         *insn = BPF_EMIT_CALL(__skb_get_pay_offset);
306                         break;
307                 case SKF_AD_OFF + SKF_AD_NLATTR:
308                         *insn = BPF_EMIT_CALL(__skb_get_nlattr);
309                         break;
310                 case SKF_AD_OFF + SKF_AD_NLATTR_NEST:
311                         *insn = BPF_EMIT_CALL(__skb_get_nlattr_nest);
312                         break;
313                 case SKF_AD_OFF + SKF_AD_CPU:
314                         *insn = BPF_EMIT_CALL(__get_raw_cpu_id);
315                         break;
316                 case SKF_AD_OFF + SKF_AD_RANDOM:
317                         *insn = BPF_EMIT_CALL(bpf_user_rnd_u32);
318                         bpf_user_rnd_init_once();
319                         break;
320                 }
321                 break;
322 
323         case SKF_AD_OFF + SKF_AD_ALU_XOR_X:
324                 /* A ^= X */
325                 *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X);
326                 break;
327 
328         default:
329                 /* This is just a dummy call to avoid letting the compiler
330                  * evict __bpf_call_base() as an optimization. Placed here
331                  * where no-one bothers.
332                  */
333                 BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0);
334                 return false;
335         }
336 
337         *insnp = insn;
338         return true;
339 }
340 
341 /**
342  *      bpf_convert_filter - convert filter program
343  *      @prog: the user passed filter program
344  *      @len: the length of the user passed filter program
345  *      @new_prog: buffer where converted program will be stored
346  *      @new_len: pointer to store length of converted program
347  *
348  * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style.
349  * Conversion workflow:
350  *
351  * 1) First pass for calculating the new program length:
352  *   bpf_convert_filter(old_prog, old_len, NULL, &new_len)
353  *
354  * 2) 2nd pass to remap in two passes: 1st pass finds new
355  *    jump offsets, 2nd pass remapping:
356  *   new_prog = kmalloc(sizeof(struct bpf_insn) * new_len);
357  *   bpf_convert_filter(old_prog, old_len, new_prog, &new_len);
358  */
359 static int bpf_convert_filter(struct sock_filter *prog, int len,
360                               struct bpf_insn *new_prog, int *new_len)
361 {
362         int new_flen = 0, pass = 0, target, i;
363         struct bpf_insn *new_insn;
364         struct sock_filter *fp;
365         int *addrs = NULL;
366         u8 bpf_src;
367 
368         BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK);
369         BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
370 
371         if (len <= 0 || len > BPF_MAXINSNS)
372                 return -EINVAL;
373 
374         if (new_prog) {
375                 addrs = kcalloc(len, sizeof(*addrs),
376                                 GFP_KERNEL | __GFP_NOWARN);
377                 if (!addrs)
378                         return -ENOMEM;
379         }
380 
381 do_pass:
382         new_insn = new_prog;
383         fp = prog;
384 
385         /* Classic BPF related prologue emission. */
386         if (new_insn) {
387                 /* Classic BPF expects A and X to be reset first. These need
388                  * to be guaranteed to be the first two instructions.
389                  */
390                 *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_A, BPF_REG_A);
391                 *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_X, BPF_REG_X);
392 
393                 /* All programs must keep CTX in callee saved BPF_REG_CTX.
394                  * In eBPF case it's done by the compiler, here we need to
395                  * do this ourself. Initial CTX is present in BPF_REG_ARG1.
396                  */
397                 *new_insn++ = BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1);
398         } else {
399                 new_insn += 3;
400         }
401 
402         for (i = 0; i < len; fp++, i++) {
403                 struct bpf_insn tmp_insns[6] = { };
404                 struct bpf_insn *insn = tmp_insns;
405 
406                 if (addrs)
407                         addrs[i] = new_insn - new_prog;
408 
409                 switch (fp->code) {
410                 /* All arithmetic insns and skb loads map as-is. */
411                 case BPF_ALU | BPF_ADD | BPF_X:
412                 case BPF_ALU | BPF_ADD | BPF_K:
413                 case BPF_ALU | BPF_SUB | BPF_X:
414                 case BPF_ALU | BPF_SUB | BPF_K:
415                 case BPF_ALU | BPF_AND | BPF_X:
416                 case BPF_ALU | BPF_AND | BPF_K:
417                 case BPF_ALU | BPF_OR | BPF_X:
418                 case BPF_ALU | BPF_OR | BPF_K:
419                 case BPF_ALU | BPF_LSH | BPF_X:
420                 case BPF_ALU | BPF_LSH | BPF_K:
421                 case BPF_ALU | BPF_RSH | BPF_X:
422                 case BPF_ALU | BPF_RSH | BPF_K:
423                 case BPF_ALU | BPF_XOR | BPF_X:
424                 case BPF_ALU | BPF_XOR | BPF_K:
425                 case BPF_ALU | BPF_MUL | BPF_X:
426                 case BPF_ALU | BPF_MUL | BPF_K:
427                 case BPF_ALU | BPF_DIV | BPF_X:
428                 case BPF_ALU | BPF_DIV | BPF_K:
429                 case BPF_ALU | BPF_MOD | BPF_X:
430                 case BPF_ALU | BPF_MOD | BPF_K:
431                 case BPF_ALU | BPF_NEG:
432                 case BPF_LD | BPF_ABS | BPF_W:
433                 case BPF_LD | BPF_ABS | BPF_H:
434                 case BPF_LD | BPF_ABS | BPF_B:
435                 case BPF_LD | BPF_IND | BPF_W:
436                 case BPF_LD | BPF_IND | BPF_H:
437                 case BPF_LD | BPF_IND | BPF_B:
438                         /* Check for overloaded BPF extension and
439                          * directly convert it if found, otherwise
440                          * just move on with mapping.
441                          */
442                         if (BPF_CLASS(fp->code) == BPF_LD &&
443                             BPF_MODE(fp->code) == BPF_ABS &&
444                             convert_bpf_extensions(fp, &insn))
445                                 break;
446 
447                         *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k);
448                         break;
449 
450                 /* Jump transformation cannot use BPF block macros
451                  * everywhere as offset calculation and target updates
452                  * require a bit more work than the rest, i.e. jump
453                  * opcodes map as-is, but offsets need adjustment.
454                  */
455 
456 #define BPF_EMIT_JMP                                                    \
457         do {                                                            \
458                 if (target >= len || target < 0)                        \
459                         goto err;                                       \
460                 insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0;   \
461                 /* Adjust pc relative offset for 2nd or 3rd insn. */    \
462                 insn->off -= insn - tmp_insns;                          \
463         } while (0)
464 
465                 case BPF_JMP | BPF_JA:
466                         target = i + fp->k + 1;
467                         insn->code = fp->code;
468                         BPF_EMIT_JMP;
469                         break;
470 
471                 case BPF_JMP | BPF_JEQ | BPF_K:
472                 case BPF_JMP | BPF_JEQ | BPF_X:
473                 case BPF_JMP | BPF_JSET | BPF_K:
474                 case BPF_JMP | BPF_JSET | BPF_X:
475                 case BPF_JMP | BPF_JGT | BPF_K:
476                 case BPF_JMP | BPF_JGT | BPF_X:
477                 case BPF_JMP | BPF_JGE | BPF_K:
478                 case BPF_JMP | BPF_JGE | BPF_X:
479                         if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) {
480                                 /* BPF immediates are signed, zero extend
481                                  * immediate into tmp register and use it
482                                  * in compare insn.
483                                  */
484                                 *insn++ = BPF_MOV32_IMM(BPF_REG_TMP, fp->k);
485 
486                                 insn->dst_reg = BPF_REG_A;
487                                 insn->src_reg = BPF_REG_TMP;
488                                 bpf_src = BPF_X;
489                         } else {
490                                 insn->dst_reg = BPF_REG_A;
491                                 insn->imm = fp->k;
492                                 bpf_src = BPF_SRC(fp->code);
493                                 insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0;
494                         }
495 
496                         /* Common case where 'jump_false' is next insn. */
497                         if (fp->jf == 0) {
498                                 insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src;
499                                 target = i + fp->jt + 1;
500                                 BPF_EMIT_JMP;
501                                 break;
502                         }
503 
504                         /* Convert JEQ into JNE when 'jump_true' is next insn. */
505                         if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) {
506                                 insn->code = BPF_JMP | BPF_JNE | bpf_src;
507                                 target = i + fp->jf + 1;
508                                 BPF_EMIT_JMP;
509                                 break;
510                         }
511 
512                         /* Other jumps are mapped into two insns: Jxx and JA. */
513                         target = i + fp->jt + 1;
514                         insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src;
515                         BPF_EMIT_JMP;
516                         insn++;
517 
518                         insn->code = BPF_JMP | BPF_JA;
519                         target = i + fp->jf + 1;
520                         BPF_EMIT_JMP;
521                         break;
522 
523                 /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */
524                 case BPF_LDX | BPF_MSH | BPF_B:
525                         /* tmp = A */
526                         *insn++ = BPF_MOV64_REG(BPF_REG_TMP, BPF_REG_A);
527                         /* A = BPF_R0 = *(u8 *) (skb->data + K) */
528                         *insn++ = BPF_LD_ABS(BPF_B, fp->k);
529                         /* A &= 0xf */
530                         *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf);
531                         /* A <<= 2 */
532                         *insn++ = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2);
533                         /* X = A */
534                         *insn++ = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A);
535                         /* A = tmp */
536                         *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_TMP);
537                         break;
538 
539                 /* RET_K is remaped into 2 insns. RET_A case doesn't need an
540                  * extra mov as BPF_REG_0 is already mapped into BPF_REG_A.
541                  */
542                 case BPF_RET | BPF_A:
543                 case BPF_RET | BPF_K:
544                         if (BPF_RVAL(fp->code) == BPF_K)
545                                 *insn++ = BPF_MOV32_RAW(BPF_K, BPF_REG_0,
546                                                         0, fp->k);
547                         *insn = BPF_EXIT_INSN();
548                         break;
549 
550                 /* Store to stack. */
551                 case BPF_ST:
552                 case BPF_STX:
553                         *insn = BPF_STX_MEM(BPF_W, BPF_REG_FP, BPF_CLASS(fp->code) ==
554                                             BPF_ST ? BPF_REG_A : BPF_REG_X,
555                                             -(BPF_MEMWORDS - fp->k) * 4);
556                         break;
557 
558                 /* Load from stack. */
559                 case BPF_LD | BPF_MEM:
560                 case BPF_LDX | BPF_MEM:
561                         *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD  ?
562                                             BPF_REG_A : BPF_REG_X, BPF_REG_FP,
563                                             -(BPF_MEMWORDS - fp->k) * 4);
564                         break;
565 
566                 /* A = K or X = K */
567                 case BPF_LD | BPF_IMM:
568                 case BPF_LDX | BPF_IMM:
569                         *insn = BPF_MOV32_IMM(BPF_CLASS(fp->code) == BPF_LD ?
570                                               BPF_REG_A : BPF_REG_X, fp->k);
571                         break;
572 
573                 /* X = A */
574                 case BPF_MISC | BPF_TAX:
575                         *insn = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A);
576                         break;
577 
578                 /* A = X */
579                 case BPF_MISC | BPF_TXA:
580                         *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_X);
581                         break;
582 
583                 /* A = skb->len or X = skb->len */
584                 case BPF_LD | BPF_W | BPF_LEN:
585                 case BPF_LDX | BPF_W | BPF_LEN:
586                         *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ?
587                                             BPF_REG_A : BPF_REG_X, BPF_REG_CTX,
588                                             offsetof(struct sk_buff, len));
589                         break;
590 
591                 /* Access seccomp_data fields. */
592                 case BPF_LDX | BPF_ABS | BPF_W:
593                         /* A = *(u32 *) (ctx + K) */
594                         *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, fp->k);
595                         break;
596 
597                 /* Unknown instruction. */
598                 default:
599                         goto err;
600                 }
601 
602                 insn++;
603                 if (new_prog)
604                         memcpy(new_insn, tmp_insns,
605                                sizeof(*insn) * (insn - tmp_insns));
606                 new_insn += insn - tmp_insns;
607         }
608 
609         if (!new_prog) {
610                 /* Only calculating new length. */
611                 *new_len = new_insn - new_prog;
612                 return 0;
613         }
614 
615         pass++;
616         if (new_flen != new_insn - new_prog) {
617                 new_flen = new_insn - new_prog;
618                 if (pass > 2)
619                         goto err;
620                 goto do_pass;
621         }
622 
623         kfree(addrs);
624         BUG_ON(*new_len != new_flen);
625         return 0;
626 err:
627         kfree(addrs);
628         return -EINVAL;
629 }
630 
631 /* Security:
632  *
633  * As we dont want to clear mem[] array for each packet going through
634  * __bpf_prog_run(), we check that filter loaded by user never try to read
635  * a cell if not previously written, and we check all branches to be sure
636  * a malicious user doesn't try to abuse us.
637  */
638 static int check_load_and_stores(const struct sock_filter *filter, int flen)
639 {
640         u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */
641         int pc, ret = 0;
642 
643         BUILD_BUG_ON(BPF_MEMWORDS > 16);
644 
645         masks = kmalloc_array(flen, sizeof(*masks), GFP_KERNEL);
646         if (!masks)
647                 return -ENOMEM;
648 
649         memset(masks, 0xff, flen * sizeof(*masks));
650 
651         for (pc = 0; pc < flen; pc++) {
652                 memvalid &= masks[pc];
653 
654                 switch (filter[pc].code) {
655                 case BPF_ST:
656                 case BPF_STX:
657                         memvalid |= (1 << filter[pc].k);
658                         break;
659                 case BPF_LD | BPF_MEM:
660                 case BPF_LDX | BPF_MEM:
661                         if (!(memvalid & (1 << filter[pc].k))) {
662                                 ret = -EINVAL;
663                                 goto error;
664                         }
665                         break;
666                 case BPF_JMP | BPF_JA:
667                         /* A jump must set masks on target */
668                         masks[pc + 1 + filter[pc].k] &= memvalid;
669                         memvalid = ~0;
670                         break;
671                 case BPF_JMP | BPF_JEQ | BPF_K:
672                 case BPF_JMP | BPF_JEQ | BPF_X:
673                 case BPF_JMP | BPF_JGE | BPF_K:
674                 case BPF_JMP | BPF_JGE | BPF_X:
675                 case BPF_JMP | BPF_JGT | BPF_K:
676                 case BPF_JMP | BPF_JGT | BPF_X:
677                 case BPF_JMP | BPF_JSET | BPF_K:
678                 case BPF_JMP | BPF_JSET | BPF_X:
679                         /* A jump must set masks on targets */
680                         masks[pc + 1 + filter[pc].jt] &= memvalid;
681                         masks[pc + 1 + filter[pc].jf] &= memvalid;
682                         memvalid = ~0;
683                         break;
684                 }
685         }
686 error:
687         kfree(masks);
688         return ret;
689 }
690 
691 static bool chk_code_allowed(u16 code_to_probe)
692 {
693         static const bool codes[] = {
694                 /* 32 bit ALU operations */
695                 [BPF_ALU | BPF_ADD | BPF_K] = true,
696                 [BPF_ALU | BPF_ADD | BPF_X] = true,
697                 [BPF_ALU | BPF_SUB | BPF_K] = true,
698                 [BPF_ALU | BPF_SUB | BPF_X] = true,
699                 [BPF_ALU | BPF_MUL | BPF_K] = true,
700                 [BPF_ALU | BPF_MUL | BPF_X] = true,
701                 [BPF_ALU | BPF_DIV | BPF_K] = true,
702                 [BPF_ALU | BPF_DIV | BPF_X] = true,
703                 [BPF_ALU | BPF_MOD | BPF_K] = true,
704                 [BPF_ALU | BPF_MOD | BPF_X] = true,
705                 [BPF_ALU | BPF_AND | BPF_K] = true,
706                 [BPF_ALU | BPF_AND | BPF_X] = true,
707                 [BPF_ALU | BPF_OR | BPF_K] = true,
708                 [BPF_ALU | BPF_OR | BPF_X] = true,
709                 [BPF_ALU | BPF_XOR | BPF_K] = true,
710                 [BPF_ALU | BPF_XOR | BPF_X] = true,
711                 [BPF_ALU | BPF_LSH | BPF_K] = true,
712                 [BPF_ALU | BPF_LSH | BPF_X] = true,
713                 [BPF_ALU | BPF_RSH | BPF_K] = true,
714                 [BPF_ALU | BPF_RSH | BPF_X] = true,
715                 [BPF_ALU | BPF_NEG] = true,
716                 /* Load instructions */
717                 [BPF_LD | BPF_W | BPF_ABS] = true,
718                 [BPF_LD | BPF_H | BPF_ABS] = true,
719                 [BPF_LD | BPF_B | BPF_ABS] = true,
720                 [BPF_LD | BPF_W | BPF_LEN] = true,
721                 [BPF_LD | BPF_W | BPF_IND] = true,
722                 [BPF_LD | BPF_H | BPF_IND] = true,
723                 [BPF_LD | BPF_B | BPF_IND] = true,
724                 [BPF_LD | BPF_IMM] = true,
725                 [BPF_LD | BPF_MEM] = true,
726                 [BPF_LDX | BPF_W | BPF_LEN] = true,
727                 [BPF_LDX | BPF_B | BPF_MSH] = true,
728                 [BPF_LDX | BPF_IMM] = true,
729                 [BPF_LDX | BPF_MEM] = true,
730                 /* Store instructions */
731                 [BPF_ST] = true,
732                 [BPF_STX] = true,
733                 /* Misc instructions */
734                 [BPF_MISC | BPF_TAX] = true,
735                 [BPF_MISC | BPF_TXA] = true,
736                 /* Return instructions */
737                 [BPF_RET | BPF_K] = true,
738                 [BPF_RET | BPF_A] = true,
739                 /* Jump instructions */
740                 [BPF_JMP | BPF_JA] = true,
741                 [BPF_JMP | BPF_JEQ | BPF_K] = true,
742                 [BPF_JMP | BPF_JEQ | BPF_X] = true,
743                 [BPF_JMP | BPF_JGE | BPF_K] = true,
744                 [BPF_JMP | BPF_JGE | BPF_X] = true,
745                 [BPF_JMP | BPF_JGT | BPF_K] = true,
746                 [BPF_JMP | BPF_JGT | BPF_X] = true,
747                 [BPF_JMP | BPF_JSET | BPF_K] = true,
748                 [BPF_JMP | BPF_JSET | BPF_X] = true,
749         };
750 
751         if (code_to_probe >= ARRAY_SIZE(codes))
752                 return false;
753 
754         return codes[code_to_probe];
755 }
756 
757 static bool bpf_check_basics_ok(const struct sock_filter *filter,
758                                 unsigned int flen)
759 {
760         if (filter == NULL)
761                 return false;
762         if (flen == 0 || flen > BPF_MAXINSNS)
763                 return false;
764 
765         return true;
766 }
767 
768 /**
769  *      bpf_check_classic - verify socket filter code
770  *      @filter: filter to verify
771  *      @flen: length of filter
772  *
773  * Check the user's filter code. If we let some ugly
774  * filter code slip through kaboom! The filter must contain
775  * no references or jumps that are out of range, no illegal
776  * instructions, and must end with a RET instruction.
777  *
778  * All jumps are forward as they are not signed.
779  *
780  * Returns 0 if the rule set is legal or -EINVAL if not.
781  */
782 static int bpf_check_classic(const struct sock_filter *filter,
783                              unsigned int flen)
784 {
785         bool anc_found;
786         int pc;
787 
788         /* Check the filter code now */
789         for (pc = 0; pc < flen; pc++) {
790                 const struct sock_filter *ftest = &filter[pc];
791 
792                 /* May we actually operate on this code? */
793                 if (!chk_code_allowed(ftest->code))
794                         return -EINVAL;
795 
796                 /* Some instructions need special checks */
797                 switch (ftest->code) {
798                 case BPF_ALU | BPF_DIV | BPF_K:
799                 case BPF_ALU | BPF_MOD | BPF_K:
800                         /* Check for division by zero */
801                         if (ftest->k == 0)
802                                 return -EINVAL;
803                         break;
804                 case BPF_ALU | BPF_LSH | BPF_K:
805                 case BPF_ALU | BPF_RSH | BPF_K:
806                         if (ftest->k >= 32)
807                                 return -EINVAL;
808                         break;
809                 case BPF_LD | BPF_MEM:
810                 case BPF_LDX | BPF_MEM:
811                 case BPF_ST:
812                 case BPF_STX:
813                         /* Check for invalid memory addresses */
814                         if (ftest->k >= BPF_MEMWORDS)
815                                 return -EINVAL;
816                         break;
817                 case BPF_JMP | BPF_JA:
818                         /* Note, the large ftest->k might cause loops.
819                          * Compare this with conditional jumps below,
820                          * where offsets are limited. --ANK (981016)
821                          */
822                         if (ftest->k >= (unsigned int)(flen - pc - 1))
823                                 return -EINVAL;
824                         break;
825                 case BPF_JMP | BPF_JEQ | BPF_K:
826                 case BPF_JMP | BPF_JEQ | BPF_X:
827                 case BPF_JMP | BPF_JGE | BPF_K:
828                 case BPF_JMP | BPF_JGE | BPF_X:
829                 case BPF_JMP | BPF_JGT | BPF_K:
830                 case BPF_JMP | BPF_JGT | BPF_X:
831                 case BPF_JMP | BPF_JSET | BPF_K:
832                 case BPF_JMP | BPF_JSET | BPF_X:
833                         /* Both conditionals must be safe */
834                         if (pc + ftest->jt + 1 >= flen ||
835                             pc + ftest->jf + 1 >= flen)
836                                 return -EINVAL;
837                         break;
838                 case BPF_LD | BPF_W | BPF_ABS:
839                 case BPF_LD | BPF_H | BPF_ABS:
840                 case BPF_LD | BPF_B | BPF_ABS:
841                         anc_found = false;
842                         if (bpf_anc_helper(ftest) & BPF_ANC)
843                                 anc_found = true;
844                         /* Ancillary operation unknown or unsupported */
845                         if (anc_found == false && ftest->k >= SKF_AD_OFF)
846                                 return -EINVAL;
847                 }
848         }
849 
850         /* Last instruction must be a RET code */
851         switch (filter[flen - 1].code) {
852         case BPF_RET | BPF_K:
853         case BPF_RET | BPF_A:
854                 return check_load_and_stores(filter, flen);
855         }
856 
857         return -EINVAL;
858 }
859 
860 static int bpf_prog_store_orig_filter(struct bpf_prog *fp,
861                                       const struct sock_fprog *fprog)
862 {
863         unsigned int fsize = bpf_classic_proglen(fprog);
864         struct sock_fprog_kern *fkprog;
865 
866         fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL);
867         if (!fp->orig_prog)
868                 return -ENOMEM;
869 
870         fkprog = fp->orig_prog;
871         fkprog->len = fprog->len;
872 
873         fkprog->filter = kmemdup(fp->insns, fsize,
874                                  GFP_KERNEL | __GFP_NOWARN);
875         if (!fkprog->filter) {
876                 kfree(fp->orig_prog);
877                 return -ENOMEM;
878         }
879 
880         return 0;
881 }
882 
883 static void bpf_release_orig_filter(struct bpf_prog *fp)
884 {
885         struct sock_fprog_kern *fprog = fp->orig_prog;
886 
887         if (fprog) {
888                 kfree(fprog->filter);
889                 kfree(fprog);
890         }
891 }
892 
893 static void __bpf_prog_release(struct bpf_prog *prog)
894 {
895         if (prog->type == BPF_PROG_TYPE_SOCKET_FILTER) {
896                 bpf_prog_put(prog);
897         } else {
898                 bpf_release_orig_filter(prog);
899                 bpf_prog_free(prog);
900         }
901 }
902 
903 static void __sk_filter_release(struct sk_filter *fp)
904 {
905         __bpf_prog_release(fp->prog);
906         kfree(fp);
907 }
908 
909 /**
910  *      sk_filter_release_rcu - Release a socket filter by rcu_head
911  *      @rcu: rcu_head that contains the sk_filter to free
912  */
913 static void sk_filter_release_rcu(struct rcu_head *rcu)
914 {
915         struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
916 
917         __sk_filter_release(fp);
918 }
919 
920 /**
921  *      sk_filter_release - release a socket filter
922  *      @fp: filter to remove
923  *
924  *      Remove a filter from a socket and release its resources.
925  */
926 static void sk_filter_release(struct sk_filter *fp)
927 {
928         if (atomic_dec_and_test(&fp->refcnt))
929                 call_rcu(&fp->rcu, sk_filter_release_rcu);
930 }
931 
932 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
933 {
934         u32 filter_size = bpf_prog_size(fp->prog->len);
935 
936         atomic_sub(filter_size, &sk->sk_omem_alloc);
937         sk_filter_release(fp);
938 }
939 
940 /* try to charge the socket memory if there is space available
941  * return true on success
942  */
943 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp)
944 {
945         u32 filter_size = bpf_prog_size(fp->prog->len);
946 
947         /* same check as in sock_kmalloc() */
948         if (filter_size <= sysctl_optmem_max &&
949             atomic_read(&sk->sk_omem_alloc) + filter_size < sysctl_optmem_max) {
950                 atomic_inc(&fp->refcnt);
951                 atomic_add(filter_size, &sk->sk_omem_alloc);
952                 return true;
953         }
954         return false;
955 }
956 
957 static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp)
958 {
959         struct sock_filter *old_prog;
960         struct bpf_prog *old_fp;
961         int err, new_len, old_len = fp->len;
962 
963         /* We are free to overwrite insns et al right here as it
964          * won't be used at this point in time anymore internally
965          * after the migration to the internal BPF instruction
966          * representation.
967          */
968         BUILD_BUG_ON(sizeof(struct sock_filter) !=
969                      sizeof(struct bpf_insn));
970 
971         /* Conversion cannot happen on overlapping memory areas,
972          * so we need to keep the user BPF around until the 2nd
973          * pass. At this time, the user BPF is stored in fp->insns.
974          */
975         old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter),
976                            GFP_KERNEL | __GFP_NOWARN);
977         if (!old_prog) {
978                 err = -ENOMEM;
979                 goto out_err;
980         }
981 
982         /* 1st pass: calculate the new program length. */
983         err = bpf_convert_filter(old_prog, old_len, NULL, &new_len);
984         if (err)
985                 goto out_err_free;
986 
987         /* Expand fp for appending the new filter representation. */
988         old_fp = fp;
989         fp = bpf_prog_realloc(old_fp, bpf_prog_size(new_len), 0);
990         if (!fp) {
991                 /* The old_fp is still around in case we couldn't
992                  * allocate new memory, so uncharge on that one.
993                  */
994                 fp = old_fp;
995                 err = -ENOMEM;
996                 goto out_err_free;
997         }
998 
999         fp->len = new_len;
1000 
1001         /* 2nd pass: remap sock_filter insns into bpf_insn insns. */
1002         err = bpf_convert_filter(old_prog, old_len, fp->insnsi, &new_len);
1003         if (err)
1004                 /* 2nd bpf_convert_filter() can fail only if it fails
1005                  * to allocate memory, remapping must succeed. Note,
1006                  * that at this time old_fp has already been released
1007                  * by krealloc().
1008                  */
1009                 goto out_err_free;
1010 
1011         /* We are guaranteed to never error here with cBPF to eBPF
1012          * transitions, since there's no issue with type compatibility
1013          * checks on program arrays.
1014          */
1015         fp = bpf_prog_select_runtime(fp, &err);
1016 
1017         kfree(old_prog);
1018         return fp;
1019 
1020 out_err_free:
1021         kfree(old_prog);
1022 out_err:
1023         __bpf_prog_release(fp);
1024         return ERR_PTR(err);
1025 }
1026 
1027 static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp,
1028                                            bpf_aux_classic_check_t trans)
1029 {
1030         int err;
1031 
1032         fp->bpf_func = NULL;
1033         fp->jited = 0;
1034 
1035         err = bpf_check_classic(fp->insns, fp->len);
1036         if (err) {
1037                 __bpf_prog_release(fp);
1038                 return ERR_PTR(err);
1039         }
1040 
1041         /* There might be additional checks and transformations
1042          * needed on classic filters, f.e. in case of seccomp.
1043          */
1044         if (trans) {
1045                 err = trans(fp->insns, fp->len);
1046                 if (err) {
1047                         __bpf_prog_release(fp);
1048                         return ERR_PTR(err);
1049                 }
1050         }
1051 
1052         /* Probe if we can JIT compile the filter and if so, do
1053          * the compilation of the filter.
1054          */
1055         bpf_jit_compile(fp);
1056 
1057         /* JIT compiler couldn't process this filter, so do the
1058          * internal BPF translation for the optimized interpreter.
1059          */
1060         if (!fp->jited)
1061                 fp = bpf_migrate_filter(fp);
1062 
1063         return fp;
1064 }
1065 
1066 /**
1067  *      bpf_prog_create - create an unattached filter
1068  *      @pfp: the unattached filter that is created
1069  *      @fprog: the filter program
1070  *
1071  * Create a filter independent of any socket. We first run some
1072  * sanity checks on it to make sure it does not explode on us later.
1073  * If an error occurs or there is insufficient memory for the filter
1074  * a negative errno code is returned. On success the return is zero.
1075  */
1076 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog)
1077 {
1078         unsigned int fsize = bpf_classic_proglen(fprog);
1079         struct bpf_prog *fp;
1080 
1081         /* Make sure new filter is there and in the right amounts. */
1082         if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1083                 return -EINVAL;
1084 
1085         fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1086         if (!fp)
1087                 return -ENOMEM;
1088 
1089         memcpy(fp->insns, fprog->filter, fsize);
1090 
1091         fp->len = fprog->len;
1092         /* Since unattached filters are not copied back to user
1093          * space through sk_get_filter(), we do not need to hold
1094          * a copy here, and can spare us the work.
1095          */
1096         fp->orig_prog = NULL;
1097 
1098         /* bpf_prepare_filter() already takes care of freeing
1099          * memory in case something goes wrong.
1100          */
1101         fp = bpf_prepare_filter(fp, NULL);
1102         if (IS_ERR(fp))
1103                 return PTR_ERR(fp);
1104 
1105         *pfp = fp;
1106         return 0;
1107 }
1108 EXPORT_SYMBOL_GPL(bpf_prog_create);
1109 
1110 /**
1111  *      bpf_prog_create_from_user - create an unattached filter from user buffer
1112  *      @pfp: the unattached filter that is created
1113  *      @fprog: the filter program
1114  *      @trans: post-classic verifier transformation handler
1115  *      @save_orig: save classic BPF program
1116  *
1117  * This function effectively does the same as bpf_prog_create(), only
1118  * that it builds up its insns buffer from user space provided buffer.
1119  * It also allows for passing a bpf_aux_classic_check_t handler.
1120  */
1121 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
1122                               bpf_aux_classic_check_t trans, bool save_orig)
1123 {
1124         unsigned int fsize = bpf_classic_proglen(fprog);
1125         struct bpf_prog *fp;
1126         int err;
1127 
1128         /* Make sure new filter is there and in the right amounts. */
1129         if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1130                 return -EINVAL;
1131 
1132         fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1133         if (!fp)
1134                 return -ENOMEM;
1135 
1136         if (copy_from_user(fp->insns, fprog->filter, fsize)) {
1137                 __bpf_prog_free(fp);
1138                 return -EFAULT;
1139         }
1140 
1141         fp->len = fprog->len;
1142         fp->orig_prog = NULL;
1143 
1144         if (save_orig) {
1145                 err = bpf_prog_store_orig_filter(fp, fprog);
1146                 if (err) {
1147                         __bpf_prog_free(fp);
1148                         return -ENOMEM;
1149                 }
1150         }
1151 
1152         /* bpf_prepare_filter() already takes care of freeing
1153          * memory in case something goes wrong.
1154          */
1155         fp = bpf_prepare_filter(fp, trans);
1156         if (IS_ERR(fp))
1157                 return PTR_ERR(fp);
1158 
1159         *pfp = fp;
1160         return 0;
1161 }
1162 EXPORT_SYMBOL_GPL(bpf_prog_create_from_user);
1163 
1164 void bpf_prog_destroy(struct bpf_prog *fp)
1165 {
1166         __bpf_prog_release(fp);
1167 }
1168 EXPORT_SYMBOL_GPL(bpf_prog_destroy);
1169 
1170 static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk)
1171 {
1172         struct sk_filter *fp, *old_fp;
1173 
1174         fp = kmalloc(sizeof(*fp), GFP_KERNEL);
1175         if (!fp)
1176                 return -ENOMEM;
1177 
1178         fp->prog = prog;
1179         atomic_set(&fp->refcnt, 0);
1180 
1181         if (!sk_filter_charge(sk, fp)) {
1182                 kfree(fp);
1183                 return -ENOMEM;
1184         }
1185 
1186         old_fp = rcu_dereference_protected(sk->sk_filter,
1187                                            lockdep_sock_is_held(sk));
1188         rcu_assign_pointer(sk->sk_filter, fp);
1189 
1190         if (old_fp)
1191                 sk_filter_uncharge(sk, old_fp);
1192 
1193         return 0;
1194 }
1195 
1196 static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk)
1197 {
1198         struct bpf_prog *old_prog;
1199         int err;
1200 
1201         if (bpf_prog_size(prog->len) > sysctl_optmem_max)
1202                 return -ENOMEM;
1203 
1204         if (sk_unhashed(sk) && sk->sk_reuseport) {
1205                 err = reuseport_alloc(sk);
1206                 if (err)
1207                         return err;
1208         } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) {
1209                 /* The socket wasn't bound with SO_REUSEPORT */
1210                 return -EINVAL;
1211         }
1212 
1213         old_prog = reuseport_attach_prog(sk, prog);
1214         if (old_prog)
1215                 bpf_prog_destroy(old_prog);
1216 
1217         return 0;
1218 }
1219 
1220 static
1221 struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk)
1222 {
1223         unsigned int fsize = bpf_classic_proglen(fprog);
1224         struct bpf_prog *prog;
1225         int err;
1226 
1227         if (sock_flag(sk, SOCK_FILTER_LOCKED))
1228                 return ERR_PTR(-EPERM);
1229 
1230         /* Make sure new filter is there and in the right amounts. */
1231         if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1232                 return ERR_PTR(-EINVAL);
1233 
1234         prog = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1235         if (!prog)
1236                 return ERR_PTR(-ENOMEM);
1237 
1238         if (copy_from_user(prog->insns, fprog->filter, fsize)) {
1239                 __bpf_prog_free(prog);
1240                 return ERR_PTR(-EFAULT);
1241         }
1242 
1243         prog->len = fprog->len;
1244 
1245         err = bpf_prog_store_orig_filter(prog, fprog);
1246         if (err) {
1247                 __bpf_prog_free(prog);
1248                 return ERR_PTR(-ENOMEM);
1249         }
1250 
1251         /* bpf_prepare_filter() already takes care of freeing
1252          * memory in case something goes wrong.
1253          */
1254         return bpf_prepare_filter(prog, NULL);
1255 }
1256 
1257 /**
1258  *      sk_attach_filter - attach a socket filter
1259  *      @fprog: the filter program
1260  *      @sk: the socket to use
1261  *
1262  * Attach the user's filter code. We first run some sanity checks on
1263  * it to make sure it does not explode on us later. If an error
1264  * occurs or there is insufficient memory for the filter a negative
1265  * errno code is returned. On success the return is zero.
1266  */
1267 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
1268 {
1269         struct bpf_prog *prog = __get_filter(fprog, sk);
1270         int err;
1271 
1272         if (IS_ERR(prog))
1273                 return PTR_ERR(prog);
1274 
1275         err = __sk_attach_prog(prog, sk);
1276         if (err < 0) {
1277                 __bpf_prog_release(prog);
1278                 return err;
1279         }
1280 
1281         return 0;
1282 }
1283 EXPORT_SYMBOL_GPL(sk_attach_filter);
1284 
1285 int sk_reuseport_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 = __reuseport_attach_prog(prog, sk);
1294         if (err < 0) {
1295                 __bpf_prog_release(prog);
1296                 return err;
1297         }
1298 
1299         return 0;
1300 }
1301 
1302 static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk)
1303 {
1304         if (sock_flag(sk, SOCK_FILTER_LOCKED))
1305                 return ERR_PTR(-EPERM);
1306 
1307         return bpf_prog_get_type(ufd, BPF_PROG_TYPE_SOCKET_FILTER);
1308 }
1309 
1310 int sk_attach_bpf(u32 ufd, struct sock *sk)
1311 {
1312         struct bpf_prog *prog = __get_bpf(ufd, sk);
1313         int err;
1314 
1315         if (IS_ERR(prog))
1316                 return PTR_ERR(prog);
1317 
1318         err = __sk_attach_prog(prog, sk);
1319         if (err < 0) {
1320                 bpf_prog_put(prog);
1321                 return err;
1322         }
1323 
1324         return 0;
1325 }
1326 
1327 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk)
1328 {
1329         struct bpf_prog *prog = __get_bpf(ufd, sk);
1330         int err;
1331 
1332         if (IS_ERR(prog))
1333                 return PTR_ERR(prog);
1334 
1335         err = __reuseport_attach_prog(prog, sk);
1336         if (err < 0) {
1337                 bpf_prog_put(prog);
1338                 return err;
1339         }
1340 
1341         return 0;
1342 }
1343 
1344 struct bpf_scratchpad {
1345         union {
1346                 __be32 diff[MAX_BPF_STACK / sizeof(__be32)];
1347                 u8     buff[MAX_BPF_STACK];
1348         };
1349 };
1350 
1351 static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp);
1352 
1353 static inline int bpf_try_make_writable(struct sk_buff *skb,
1354                                         unsigned int write_len)
1355 {
1356         int err;
1357 
1358         err = skb_ensure_writable(skb, write_len);
1359         bpf_compute_data_end(skb);
1360 
1361         return err;
1362 }
1363 
1364 static inline void bpf_push_mac_rcsum(struct sk_buff *skb)
1365 {
1366         if (skb_at_tc_ingress(skb))
1367                 skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len);
1368 }
1369 
1370 static inline void bpf_pull_mac_rcsum(struct sk_buff *skb)
1371 {
1372         if (skb_at_tc_ingress(skb))
1373                 skb_postpull_rcsum(skb, skb_mac_header(skb), skb->mac_len);
1374 }
1375 
1376 static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags)
1377 {
1378         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1379         unsigned int offset = (unsigned int) r2;
1380         void *from = (void *) (long) r3;
1381         unsigned int len = (unsigned int) r4;
1382         void *ptr;
1383 
1384         if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM | BPF_F_INVALIDATE_HASH)))
1385                 return -EINVAL;
1386         if (unlikely(offset > 0xffff))
1387                 return -EFAULT;
1388         if (unlikely(bpf_try_make_writable(skb, offset + len)))
1389                 return -EFAULT;
1390 
1391         ptr = skb->data + offset;
1392         if (flags & BPF_F_RECOMPUTE_CSUM)
1393                 __skb_postpull_rcsum(skb, ptr, len, offset);
1394 
1395         memcpy(ptr, from, len);
1396 
1397         if (flags & BPF_F_RECOMPUTE_CSUM)
1398                 __skb_postpush_rcsum(skb, ptr, len, offset);
1399         if (flags & BPF_F_INVALIDATE_HASH)
1400                 skb_clear_hash(skb);
1401 
1402         return 0;
1403 }
1404 
1405 static const struct bpf_func_proto bpf_skb_store_bytes_proto = {
1406         .func           = bpf_skb_store_bytes,
1407         .gpl_only       = false,
1408         .ret_type       = RET_INTEGER,
1409         .arg1_type      = ARG_PTR_TO_CTX,
1410         .arg2_type      = ARG_ANYTHING,
1411         .arg3_type      = ARG_PTR_TO_STACK,
1412         .arg4_type      = ARG_CONST_STACK_SIZE,
1413         .arg5_type      = ARG_ANYTHING,
1414 };
1415 
1416 static u64 bpf_skb_load_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1417 {
1418         const struct sk_buff *skb = (const struct sk_buff *)(unsigned long) r1;
1419         unsigned int offset = (unsigned int) r2;
1420         void *to = (void *)(unsigned long) r3;
1421         unsigned int len = (unsigned int) r4;
1422         void *ptr;
1423 
1424         if (unlikely(offset > 0xffff))
1425                 goto err_clear;
1426 
1427         ptr = skb_header_pointer(skb, offset, len, to);
1428         if (unlikely(!ptr))
1429                 goto err_clear;
1430         if (ptr != to)
1431                 memcpy(to, ptr, len);
1432 
1433         return 0;
1434 err_clear:
1435         memset(to, 0, len);
1436         return -EFAULT;
1437 }
1438 
1439 static const struct bpf_func_proto bpf_skb_load_bytes_proto = {
1440         .func           = bpf_skb_load_bytes,
1441         .gpl_only       = false,
1442         .ret_type       = RET_INTEGER,
1443         .arg1_type      = ARG_PTR_TO_CTX,
1444         .arg2_type      = ARG_ANYTHING,
1445         .arg3_type      = ARG_PTR_TO_RAW_STACK,
1446         .arg4_type      = ARG_CONST_STACK_SIZE,
1447 };
1448 
1449 static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
1450 {
1451         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1452         unsigned int offset = (unsigned int) r2;
1453         __sum16 *ptr;
1454 
1455         if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK)))
1456                 return -EINVAL;
1457         if (unlikely(offset > 0xffff || offset & 1))
1458                 return -EFAULT;
1459         if (unlikely(bpf_try_make_writable(skb, offset + sizeof(*ptr))))
1460                 return -EFAULT;
1461 
1462         ptr = (__sum16 *)(skb->data + offset);
1463         switch (flags & BPF_F_HDR_FIELD_MASK) {
1464         case 0:
1465                 if (unlikely(from != 0))
1466                         return -EINVAL;
1467 
1468                 csum_replace_by_diff(ptr, to);
1469                 break;
1470         case 2:
1471                 csum_replace2(ptr, from, to);
1472                 break;
1473         case 4:
1474                 csum_replace4(ptr, from, to);
1475                 break;
1476         default:
1477                 return -EINVAL;
1478         }
1479 
1480         return 0;
1481 }
1482 
1483 static const struct bpf_func_proto bpf_l3_csum_replace_proto = {
1484         .func           = bpf_l3_csum_replace,
1485         .gpl_only       = false,
1486         .ret_type       = RET_INTEGER,
1487         .arg1_type      = ARG_PTR_TO_CTX,
1488         .arg2_type      = ARG_ANYTHING,
1489         .arg3_type      = ARG_ANYTHING,
1490         .arg4_type      = ARG_ANYTHING,
1491         .arg5_type      = ARG_ANYTHING,
1492 };
1493 
1494 static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
1495 {
1496         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1497         bool is_pseudo = flags & BPF_F_PSEUDO_HDR;
1498         bool is_mmzero = flags & BPF_F_MARK_MANGLED_0;
1499         unsigned int offset = (unsigned int) r2;
1500         __sum16 *ptr;
1501 
1502         if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_PSEUDO_HDR |
1503                                BPF_F_HDR_FIELD_MASK)))
1504                 return -EINVAL;
1505         if (unlikely(offset > 0xffff || offset & 1))
1506                 return -EFAULT;
1507         if (unlikely(bpf_try_make_writable(skb, offset + sizeof(*ptr))))
1508                 return -EFAULT;
1509 
1510         ptr = (__sum16 *)(skb->data + offset);
1511         if (is_mmzero && !*ptr)
1512                 return 0;
1513 
1514         switch (flags & BPF_F_HDR_FIELD_MASK) {
1515         case 0:
1516                 if (unlikely(from != 0))
1517                         return -EINVAL;
1518 
1519                 inet_proto_csum_replace_by_diff(ptr, skb, to, is_pseudo);
1520                 break;
1521         case 2:
1522                 inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo);
1523                 break;
1524         case 4:
1525                 inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo);
1526                 break;
1527         default:
1528                 return -EINVAL;
1529         }
1530 
1531         if (is_mmzero && !*ptr)
1532                 *ptr = CSUM_MANGLED_0;
1533         return 0;
1534 }
1535 
1536 static const struct bpf_func_proto bpf_l4_csum_replace_proto = {
1537         .func           = bpf_l4_csum_replace,
1538         .gpl_only       = false,
1539         .ret_type       = RET_INTEGER,
1540         .arg1_type      = ARG_PTR_TO_CTX,
1541         .arg2_type      = ARG_ANYTHING,
1542         .arg3_type      = ARG_ANYTHING,
1543         .arg4_type      = ARG_ANYTHING,
1544         .arg5_type      = ARG_ANYTHING,
1545 };
1546 
1547 static u64 bpf_csum_diff(u64 r1, u64 from_size, u64 r3, u64 to_size, u64 seed)
1548 {
1549         struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp);
1550         u64 diff_size = from_size + to_size;
1551         __be32 *from = (__be32 *) (long) r1;
1552         __be32 *to   = (__be32 *) (long) r3;
1553         int i, j = 0;
1554 
1555         /* This is quite flexible, some examples:
1556          *
1557          * from_size == 0, to_size > 0,  seed := csum --> pushing data
1558          * from_size > 0,  to_size == 0, seed := csum --> pulling data
1559          * from_size > 0,  to_size > 0,  seed := 0    --> diffing data
1560          *
1561          * Even for diffing, from_size and to_size don't need to be equal.
1562          */
1563         if (unlikely(((from_size | to_size) & (sizeof(__be32) - 1)) ||
1564                      diff_size > sizeof(sp->diff)))
1565                 return -EINVAL;
1566 
1567         for (i = 0; i < from_size / sizeof(__be32); i++, j++)
1568                 sp->diff[j] = ~from[i];
1569         for (i = 0; i <   to_size / sizeof(__be32); i++, j++)
1570                 sp->diff[j] = to[i];
1571 
1572         return csum_partial(sp->diff, diff_size, seed);
1573 }
1574 
1575 static const struct bpf_func_proto bpf_csum_diff_proto = {
1576         .func           = bpf_csum_diff,
1577         .gpl_only       = false,
1578         .ret_type       = RET_INTEGER,
1579         .arg1_type      = ARG_PTR_TO_STACK,
1580         .arg2_type      = ARG_CONST_STACK_SIZE_OR_ZERO,
1581         .arg3_type      = ARG_PTR_TO_STACK,
1582         .arg4_type      = ARG_CONST_STACK_SIZE_OR_ZERO,
1583         .arg5_type      = ARG_ANYTHING,
1584 };
1585 
1586 static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb)
1587 {
1588         return dev_forward_skb(dev, skb);
1589 }
1590 
1591 static inline int __bpf_tx_skb(struct net_device *dev, struct sk_buff *skb)
1592 {
1593         int ret;
1594 
1595         if (unlikely(__this_cpu_read(xmit_recursion) > XMIT_RECURSION_LIMIT)) {
1596                 net_crit_ratelimited("bpf: recursion limit reached on datapath, buggy bpf program?\n");
1597                 kfree_skb(skb);
1598                 return -ENETDOWN;
1599         }
1600 
1601         skb->dev = dev;
1602 
1603         __this_cpu_inc(xmit_recursion);
1604         ret = dev_queue_xmit(skb);
1605         __this_cpu_dec(xmit_recursion);
1606 
1607         return ret;
1608 }
1609 
1610 static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5)
1611 {
1612         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1613         struct net_device *dev;
1614 
1615         if (unlikely(flags & ~(BPF_F_INGRESS)))
1616                 return -EINVAL;
1617 
1618         dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex);
1619         if (unlikely(!dev))
1620                 return -EINVAL;
1621 
1622         skb = skb_clone(skb, GFP_ATOMIC);
1623         if (unlikely(!skb))
1624                 return -ENOMEM;
1625 
1626         bpf_push_mac_rcsum(skb);
1627 
1628         return flags & BPF_F_INGRESS ?
1629                __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);
1630 }
1631 
1632 static const struct bpf_func_proto bpf_clone_redirect_proto = {
1633         .func           = bpf_clone_redirect,
1634         .gpl_only       = false,
1635         .ret_type       = RET_INTEGER,
1636         .arg1_type      = ARG_PTR_TO_CTX,
1637         .arg2_type      = ARG_ANYTHING,
1638         .arg3_type      = ARG_ANYTHING,
1639 };
1640 
1641 struct redirect_info {
1642         u32 ifindex;
1643         u32 flags;
1644 };
1645 
1646 static DEFINE_PER_CPU(struct redirect_info, redirect_info);
1647 
1648 static u64 bpf_redirect(u64 ifindex, u64 flags, u64 r3, u64 r4, u64 r5)
1649 {
1650         struct redirect_info *ri = this_cpu_ptr(&redirect_info);
1651 
1652         if (unlikely(flags & ~(BPF_F_INGRESS)))
1653                 return TC_ACT_SHOT;
1654 
1655         ri->ifindex = ifindex;
1656         ri->flags = flags;
1657 
1658         return TC_ACT_REDIRECT;
1659 }
1660 
1661 int skb_do_redirect(struct sk_buff *skb)
1662 {
1663         struct redirect_info *ri = this_cpu_ptr(&redirect_info);
1664         struct net_device *dev;
1665 
1666         dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->ifindex);
1667         ri->ifindex = 0;
1668         if (unlikely(!dev)) {
1669                 kfree_skb(skb);
1670                 return -EINVAL;
1671         }
1672 
1673         bpf_push_mac_rcsum(skb);
1674 
1675         return ri->flags & BPF_F_INGRESS ?
1676                __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);
1677 }
1678 
1679 static const struct bpf_func_proto bpf_redirect_proto = {
1680         .func           = bpf_redirect,
1681         .gpl_only       = false,
1682         .ret_type       = RET_INTEGER,
1683         .arg1_type      = ARG_ANYTHING,
1684         .arg2_type      = ARG_ANYTHING,
1685 };
1686 
1687 static u64 bpf_get_cgroup_classid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1688 {
1689         return task_get_classid((struct sk_buff *) (unsigned long) r1);
1690 }
1691 
1692 static const struct bpf_func_proto bpf_get_cgroup_classid_proto = {
1693         .func           = bpf_get_cgroup_classid,
1694         .gpl_only       = false,
1695         .ret_type       = RET_INTEGER,
1696         .arg1_type      = ARG_PTR_TO_CTX,
1697 };
1698 
1699 static u64 bpf_get_route_realm(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1700 {
1701         return dst_tclassid((struct sk_buff *) (unsigned long) r1);
1702 }
1703 
1704 static const struct bpf_func_proto bpf_get_route_realm_proto = {
1705         .func           = bpf_get_route_realm,
1706         .gpl_only       = false,
1707         .ret_type       = RET_INTEGER,
1708         .arg1_type      = ARG_PTR_TO_CTX,
1709 };
1710 
1711 static u64 bpf_get_hash_recalc(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1712 {
1713         /* If skb_clear_hash() was called due to mangling, we can
1714          * trigger SW recalculation here. Later access to hash
1715          * can then use the inline skb->hash via context directly
1716          * instead of calling this helper again.
1717          */
1718         return skb_get_hash((struct sk_buff *) (unsigned long) r1);
1719 }
1720 
1721 static const struct bpf_func_proto bpf_get_hash_recalc_proto = {
1722         .func           = bpf_get_hash_recalc,
1723         .gpl_only       = false,
1724         .ret_type       = RET_INTEGER,
1725         .arg1_type      = ARG_PTR_TO_CTX,
1726 };
1727 
1728 static u64 bpf_skb_vlan_push(u64 r1, u64 r2, u64 vlan_tci, u64 r4, u64 r5)
1729 {
1730         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1731         __be16 vlan_proto = (__force __be16) r2;
1732         int ret;
1733 
1734         if (unlikely(vlan_proto != htons(ETH_P_8021Q) &&
1735                      vlan_proto != htons(ETH_P_8021AD)))
1736                 vlan_proto = htons(ETH_P_8021Q);
1737 
1738         bpf_push_mac_rcsum(skb);
1739         ret = skb_vlan_push(skb, vlan_proto, vlan_tci);
1740         bpf_pull_mac_rcsum(skb);
1741 
1742         bpf_compute_data_end(skb);
1743         return ret;
1744 }
1745 
1746 const struct bpf_func_proto bpf_skb_vlan_push_proto = {
1747         .func           = bpf_skb_vlan_push,
1748         .gpl_only       = false,
1749         .ret_type       = RET_INTEGER,
1750         .arg1_type      = ARG_PTR_TO_CTX,
1751         .arg2_type      = ARG_ANYTHING,
1752         .arg3_type      = ARG_ANYTHING,
1753 };
1754 EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto);
1755 
1756 static u64 bpf_skb_vlan_pop(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1757 {
1758         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1759         int ret;
1760 
1761         bpf_push_mac_rcsum(skb);
1762         ret = skb_vlan_pop(skb);
1763         bpf_pull_mac_rcsum(skb);
1764 
1765         bpf_compute_data_end(skb);
1766         return ret;
1767 }
1768 
1769 const struct bpf_func_proto bpf_skb_vlan_pop_proto = {
1770         .func           = bpf_skb_vlan_pop,
1771         .gpl_only       = false,
1772         .ret_type       = RET_INTEGER,
1773         .arg1_type      = ARG_PTR_TO_CTX,
1774 };
1775 EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto);
1776 
1777 static int bpf_skb_generic_push(struct sk_buff *skb, u32 off, u32 len)
1778 {
1779         /* Caller already did skb_cow() with len as headroom,
1780          * so no need to do it here.
1781          */
1782         skb_push(skb, len);
1783         memmove(skb->data, skb->data + len, off);
1784         memset(skb->data + off, 0, len);
1785 
1786         /* No skb_postpush_rcsum(skb, skb->data + off, len)
1787          * needed here as it does not change the skb->csum
1788          * result for checksum complete when summing over
1789          * zeroed blocks.
1790          */
1791         return 0;
1792 }
1793 
1794 static int bpf_skb_generic_pop(struct sk_buff *skb, u32 off, u32 len)
1795 {
1796         /* skb_ensure_writable() is not needed here, as we're
1797          * already working on an uncloned skb.
1798          */
1799         if (unlikely(!pskb_may_pull(skb, off + len)))
1800                 return -ENOMEM;
1801 
1802         skb_postpull_rcsum(skb, skb->data + off, len);
1803         memmove(skb->data + len, skb->data, off);
1804         __skb_pull(skb, len);
1805 
1806         return 0;
1807 }
1808 
1809 static int bpf_skb_net_hdr_push(struct sk_buff *skb, u32 off, u32 len)
1810 {
1811         bool trans_same = skb->transport_header == skb->network_header;
1812         int ret;
1813 
1814         /* There's no need for __skb_push()/__skb_pull() pair to
1815          * get to the start of the mac header as we're guaranteed
1816          * to always start from here under eBPF.
1817          */
1818         ret = bpf_skb_generic_push(skb, off, len);
1819         if (likely(!ret)) {
1820                 skb->mac_header -= len;
1821                 skb->network_header -= len;
1822                 if (trans_same)
1823                         skb->transport_header = skb->network_header;
1824         }
1825 
1826         return ret;
1827 }
1828 
1829 static int bpf_skb_net_hdr_pop(struct sk_buff *skb, u32 off, u32 len)
1830 {
1831         bool trans_same = skb->transport_header == skb->network_header;
1832         int ret;
1833 
1834         /* Same here, __skb_push()/__skb_pull() pair not needed. */
1835         ret = bpf_skb_generic_pop(skb, off, len);
1836         if (likely(!ret)) {
1837                 skb->mac_header += len;
1838                 skb->network_header += len;
1839                 if (trans_same)
1840                         skb->transport_header = skb->network_header;
1841         }
1842 
1843         return ret;
1844 }
1845 
1846 static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
1847 {
1848         const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr);
1849         u32 off = skb->network_header - skb->mac_header;
1850         int ret;
1851 
1852         ret = skb_cow(skb, len_diff);
1853         if (unlikely(ret < 0))
1854                 return ret;
1855 
1856         ret = bpf_skb_net_hdr_push(skb, off, len_diff);
1857         if (unlikely(ret < 0))
1858                 return ret;
1859 
1860         if (skb_is_gso(skb)) {
1861                 /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV4 needs to
1862                  * be changed into SKB_GSO_TCPV6.
1863                  */
1864                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
1865                         skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV4;
1866                         skb_shinfo(skb)->gso_type |=  SKB_GSO_TCPV6;
1867                 }
1868 
1869                 /* Due to IPv6 header, MSS needs to be downgraded. */
1870                 skb_shinfo(skb)->gso_size -= len_diff;
1871                 /* Header must be checked, and gso_segs recomputed. */
1872                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1873                 skb_shinfo(skb)->gso_segs = 0;
1874         }
1875 
1876         skb->protocol = htons(ETH_P_IPV6);
1877         skb_clear_hash(skb);
1878 
1879         return 0;
1880 }
1881 
1882 static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
1883 {
1884         const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr);
1885         u32 off = skb->network_header - skb->mac_header;
1886         int ret;
1887 
1888         ret = skb_unclone(skb, GFP_ATOMIC);
1889         if (unlikely(ret < 0))
1890                 return ret;
1891 
1892         ret = bpf_skb_net_hdr_pop(skb, off, len_diff);
1893         if (unlikely(ret < 0))
1894                 return ret;
1895 
1896         if (skb_is_gso(skb)) {
1897                 /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV6 needs to
1898                  * be changed into SKB_GSO_TCPV4.
1899                  */
1900                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
1901                         skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV6;
1902                         skb_shinfo(skb)->gso_type |=  SKB_GSO_TCPV4;
1903                 }
1904 
1905                 /* Due to IPv4 header, MSS can be upgraded. */
1906                 skb_shinfo(skb)->gso_size += len_diff;
1907                 /* Header must be checked, and gso_segs recomputed. */
1908                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1909                 skb_shinfo(skb)->gso_segs = 0;
1910         }
1911 
1912         skb->protocol = htons(ETH_P_IP);
1913         skb_clear_hash(skb);
1914 
1915         return 0;
1916 }
1917 
1918 static int bpf_skb_proto_xlat(struct sk_buff *skb, __be16 to_proto)
1919 {
1920         __be16 from_proto = skb->protocol;
1921 
1922         if (from_proto == htons(ETH_P_IP) &&
1923               to_proto == htons(ETH_P_IPV6))
1924                 return bpf_skb_proto_4_to_6(skb);
1925 
1926         if (from_proto == htons(ETH_P_IPV6) &&
1927               to_proto == htons(ETH_P_IP))
1928                 return bpf_skb_proto_6_to_4(skb);
1929 
1930         return -ENOTSUPP;
1931 }
1932 
1933 static u64 bpf_skb_change_proto(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5)
1934 {
1935         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1936         __be16 proto = (__force __be16) r2;
1937         int ret;
1938 
1939         if (unlikely(flags))
1940                 return -EINVAL;
1941 
1942         /* General idea is that this helper does the basic groundwork
1943          * needed for changing the protocol, and eBPF program fills the
1944          * rest through bpf_skb_store_bytes(), bpf_lX_csum_replace()
1945          * and other helpers, rather than passing a raw buffer here.
1946          *
1947          * The rationale is to keep this minimal and without a need to
1948          * deal with raw packet data. F.e. even if we would pass buffers
1949          * here, the program still needs to call the bpf_lX_csum_replace()
1950          * helpers anyway. Plus, this way we keep also separation of
1951          * concerns, since f.e. bpf_skb_store_bytes() should only take
1952          * care of stores.
1953          *
1954          * Currently, additional options and extension header space are
1955          * not supported, but flags register is reserved so we can adapt
1956          * that. For offloads, we mark packet as dodgy, so that headers
1957          * need to be verified first.
1958          */
1959         ret = bpf_skb_proto_xlat(skb, proto);
1960         bpf_compute_data_end(skb);
1961         return ret;
1962 }
1963 
1964 static const struct bpf_func_proto bpf_skb_change_proto_proto = {
1965         .func           = bpf_skb_change_proto,
1966         .gpl_only       = false,
1967         .ret_type       = RET_INTEGER,
1968         .arg1_type      = ARG_PTR_TO_CTX,
1969         .arg2_type      = ARG_ANYTHING,
1970         .arg3_type      = ARG_ANYTHING,
1971 };
1972 
1973 static u64 bpf_skb_change_type(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1974 {
1975         struct sk_buff *skb = (struct sk_buff *) (long) r1;
1976         u32 pkt_type = r2;
1977 
1978         /* We only allow a restricted subset to be changed for now. */
1979         if (unlikely(skb->pkt_type > PACKET_OTHERHOST ||
1980                      pkt_type > PACKET_OTHERHOST))
1981                 return -EINVAL;
1982 
1983         skb->pkt_type = pkt_type;
1984         return 0;
1985 }
1986 
1987 static const struct bpf_func_proto bpf_skb_change_type_proto = {
1988         .func           = bpf_skb_change_type,
1989         .gpl_only       = false,
1990         .ret_type       = RET_INTEGER,
1991         .arg1_type      = ARG_PTR_TO_CTX,
1992         .arg2_type      = ARG_ANYTHING,
1993 };
1994 
1995 bool bpf_helper_changes_skb_data(void *func)
1996 {
1997         if (func == bpf_skb_vlan_push)
1998                 return true;
1999         if (func == bpf_skb_vlan_pop)
2000                 return true;
2001         if (func == bpf_skb_store_bytes)
2002                 return true;
2003         if (func == bpf_skb_change_proto)
2004                 return true;
2005         if (func == bpf_l3_csum_replace)
2006                 return true;
2007         if (func == bpf_l4_csum_replace)
2008                 return true;
2009 
2010         return false;
2011 }
2012 
2013 static unsigned long bpf_skb_copy(void *dst_buff, const void *skb,
2014                                   unsigned long off, unsigned long len)
2015 {
2016         void *ptr = skb_header_pointer(skb, off, len, dst_buff);
2017 
2018         if (unlikely(!ptr))
2019                 return len;
2020         if (ptr != dst_buff)
2021                 memcpy(dst_buff, ptr, len);
2022 
2023         return 0;
2024 }
2025 
2026 static u64 bpf_skb_event_output(u64 r1, u64 r2, u64 flags, u64 r4,
2027                                 u64 meta_size)
2028 {
2029         struct sk_buff *skb = (struct sk_buff *)(long) r1;
2030         struct bpf_map *map = (struct bpf_map *)(long) r2;
2031         u64 skb_size = (flags & BPF_F_CTXLEN_MASK) >> 32;
2032         void *meta = (void *)(long) r4;
2033 
2034         if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
2035                 return -EINVAL;
2036         if (unlikely(skb_size > skb->len))
2037                 return -EFAULT;
2038 
2039         return bpf_event_output(map, flags, meta, meta_size, skb, skb_size,
2040                                 bpf_skb_copy);
2041 }
2042 
2043 static const struct bpf_func_proto bpf_skb_event_output_proto = {
2044         .func           = bpf_skb_event_output,
2045         .gpl_only       = true,
2046         .ret_type       = RET_INTEGER,
2047         .arg1_type      = ARG_PTR_TO_CTX,
2048         .arg2_type      = ARG_CONST_MAP_PTR,
2049         .arg3_type      = ARG_ANYTHING,
2050         .arg4_type      = ARG_PTR_TO_STACK,
2051         .arg5_type      = ARG_CONST_STACK_SIZE,
2052 };
2053 
2054 static unsigned short bpf_tunnel_key_af(u64 flags)
2055 {
2056         return flags & BPF_F_TUNINFO_IPV6 ? AF_INET6 : AF_INET;
2057 }
2058 
2059 static u64 bpf_skb_get_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5)
2060 {
2061         struct sk_buff *skb = (struct sk_buff *) (long) r1;
2062         struct bpf_tunnel_key *to = (struct bpf_tunnel_key *) (long) r2;
2063         const struct ip_tunnel_info *info = skb_tunnel_info(skb);
2064         u8 compat[sizeof(struct bpf_tunnel_key)];
2065         void *to_orig = to;
2066         int err;
2067 
2068         if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) {
2069                 err = -EINVAL;
2070                 goto err_clear;
2071         }
2072         if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) {
2073                 err = -EPROTO;
2074                 goto err_clear;
2075         }
2076         if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
2077                 err = -EINVAL;
2078                 switch (size) {
2079                 case offsetof(struct bpf_tunnel_key, tunnel_label):
2080                 case offsetof(struct bpf_tunnel_key, tunnel_ext):
2081                         goto set_compat;
2082                 case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
2083                         /* Fixup deprecated structure layouts here, so we have
2084                          * a common path later on.
2085                          */
2086                         if (ip_tunnel_info_af(info) != AF_INET)
2087                                 goto err_clear;
2088 set_compat:
2089                         to = (struct bpf_tunnel_key *)compat;
2090                         break;
2091                 default:
2092                         goto err_clear;
2093                 }
2094         }
2095 
2096         to->tunnel_id = be64_to_cpu(info->key.tun_id);
2097         to->tunnel_tos = info->key.tos;
2098         to->tunnel_ttl = info->key.ttl;
2099 
2100         if (flags & BPF_F_TUNINFO_IPV6) {
2101                 memcpy(to->remote_ipv6, &info->key.u.ipv6.src,
2102                        sizeof(to->remote_ipv6));
2103                 to->tunnel_label = be32_to_cpu(info->key.label);
2104         } else {
2105                 to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
2106         }
2107 
2108         if (unlikely(size != sizeof(struct bpf_tunnel_key)))
2109                 memcpy(to_orig, to, size);
2110 
2111         return 0;
2112 err_clear:
2113         memset(to_orig, 0, size);
2114         return err;
2115 }
2116 
2117 static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = {
2118         .func           = bpf_skb_get_tunnel_key,
2119         .gpl_only       = false,
2120         .ret_type       = RET_INTEGER,
2121         .arg1_type      = ARG_PTR_TO_CTX,
2122         .arg2_type      = ARG_PTR_TO_RAW_STACK,
2123         .arg3_type      = ARG_CONST_STACK_SIZE,
2124         .arg4_type      = ARG_ANYTHING,
2125 };
2126 
2127 static u64 bpf_skb_get_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5)
2128 {
2129         struct sk_buff *skb = (struct sk_buff *) (long) r1;
2130         u8 *to = (u8 *) (long) r2;
2131         const struct ip_tunnel_info *info = skb_tunnel_info(skb);
2132         int err;
2133 
2134         if (unlikely(!info ||
2135                      !(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))) {
2136                 err = -ENOENT;
2137                 goto err_clear;
2138         }
2139         if (unlikely(size < info->options_len)) {
2140                 err = -ENOMEM;
2141                 goto err_clear;
2142         }
2143 
2144         ip_tunnel_info_opts_get(to, info);
2145         if (size > info->options_len)
2146                 memset(to + info->options_len, 0, size - info->options_len);
2147 
2148         return info->options_len;
2149 err_clear:
2150         memset(to, 0, size);
2151         return err;
2152 }
2153 
2154 static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto = {
2155         .func           = bpf_skb_get_tunnel_opt,
2156         .gpl_only       = false,
2157         .ret_type       = RET_INTEGER,
2158         .arg1_type      = ARG_PTR_TO_CTX,
2159         .arg2_type      = ARG_PTR_TO_RAW_STACK,
2160         .arg3_type      = ARG_CONST_STACK_SIZE,
2161 };
2162 
2163 static struct metadata_dst __percpu *md_dst;
2164 
2165 static u64 bpf_skb_set_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5)
2166 {
2167         struct sk_buff *skb = (struct sk_buff *) (long) r1;
2168         struct bpf_tunnel_key *from = (struct bpf_tunnel_key *) (long) r2;
2169         struct metadata_dst *md = this_cpu_ptr(md_dst);
2170         u8 compat[sizeof(struct bpf_tunnel_key)];
2171         struct ip_tunnel_info *info;
2172 
2173         if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6 | BPF_F_ZERO_CSUM_TX |
2174                                BPF_F_DONT_FRAGMENT)))
2175                 return -EINVAL;
2176         if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
2177                 switch (size) {
2178                 case offsetof(struct bpf_tunnel_key, tunnel_label):
2179                 case offsetof(struct bpf_tunnel_key, tunnel_ext):
2180                 case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
2181                         /* Fixup deprecated structure layouts here, so we have
2182                          * a common path later on.
2183                          */
2184                         memcpy(compat, from, size);
2185                         memset(compat + size, 0, sizeof(compat) - size);
2186                         from = (struct bpf_tunnel_key *)compat;
2187                         break;
2188                 default:
2189                         return -EINVAL;
2190                 }
2191         }
2192         if (unlikely((!(flags & BPF_F_TUNINFO_IPV6) && from->tunnel_label) ||
2193                      from->tunnel_ext))
2194                 return -EINVAL;
2195 
2196         skb_dst_drop(skb);
2197         dst_hold((struct dst_entry *) md);
2198         skb_dst_set(skb, (struct dst_entry *) md);
2199 
2200         info = &md->u.tun_info;
2201         info->mode = IP_TUNNEL_INFO_TX;
2202 
2203         info->key.tun_flags = TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_NOCACHE;
2204         if (flags & BPF_F_DONT_FRAGMENT)
2205                 info->key.tun_flags |= TUNNEL_DONT_FRAGMENT;
2206 
2207         info->key.tun_id = cpu_to_be64(from->tunnel_id);
2208         info->key.tos = from->tunnel_tos;
2209         info->key.ttl = from->tunnel_ttl;
2210 
2211         if (flags & BPF_F_TUNINFO_IPV6) {
2212                 info->mode |= IP_TUNNEL_INFO_IPV6;
2213                 memcpy(&info->key.u.ipv6.dst, from->remote_ipv6,
2214                        sizeof(from->remote_ipv6));
2215                 info->key.label = cpu_to_be32(from->tunnel_label) &
2216                                   IPV6_FLOWLABEL_MASK;
2217         } else {
2218                 info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
2219                 if (flags & BPF_F_ZERO_CSUM_TX)
2220                         info->key.tun_flags &= ~TUNNEL_CSUM;
2221         }
2222 
2223         return 0;
2224 }
2225 
2226 static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = {
2227         .func           = bpf_skb_set_tunnel_key,
2228         .gpl_only       = false,
2229         .ret_type       = RET_INTEGER,
2230         .arg1_type      = ARG_PTR_TO_CTX,
2231         .arg2_type      = ARG_PTR_TO_STACK,
2232         .arg3_type      = ARG_CONST_STACK_SIZE,
2233         .arg4_type      = ARG_ANYTHING,
2234 };
2235 
2236 static u64 bpf_skb_set_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5)
2237 {
2238         struct sk_buff *skb = (struct sk_buff *) (long) r1;
2239         u8 *from = (u8 *) (long) r2;
2240         struct ip_tunnel_info *info = skb_tunnel_info(skb);
2241         const struct metadata_dst *md = this_cpu_ptr(md_dst);
2242 
2243         if (unlikely(info != &md->u.tun_info || (size & (sizeof(u32) - 1))))
2244                 return -EINVAL;
2245         if (unlikely(size > IP_TUNNEL_OPTS_MAX))
2246                 return -ENOMEM;
2247 
2248         ip_tunnel_info_opts_set(info, from, size);
2249 
2250         return 0;
2251 }
2252 
2253 static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = {
2254         .func           = bpf_skb_set_tunnel_opt,
2255         .gpl_only       = false,
2256         .ret_type       = RET_INTEGER,
2257         .arg1_type      = ARG_PTR_TO_CTX,
2258         .arg2_type      = ARG_PTR_TO_STACK,
2259         .arg3_type      = ARG_CONST_STACK_SIZE,
2260 };
2261 
2262 static const struct bpf_func_proto *
2263 bpf_get_skb_set_tunnel_proto(enum bpf_func_id which)
2264 {
2265         if (!md_dst) {
2266                 /* Race is not possible, since it's called from verifier
2267                  * that is holding verifier mutex.
2268                  */
2269                 md_dst = metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX,
2270                                                    GFP_KERNEL);
2271                 if (!md_dst)
2272                         return NULL;
2273         }
2274 
2275         switch (which) {
2276         case BPF_FUNC_skb_set_tunnel_key:
2277                 return &bpf_skb_set_tunnel_key_proto;
2278         case BPF_FUNC_skb_set_tunnel_opt:
2279                 return &bpf_skb_set_tunnel_opt_proto;
2280         default:
2281                 return NULL;
2282         }
2283 }
2284 
2285 #ifdef CONFIG_SOCK_CGROUP_DATA
2286 static u64 bpf_skb_under_cgroup(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
2287 {
2288         struct sk_buff *skb = (struct sk_buff *)(long)r1;
2289         struct bpf_map *map = (struct bpf_map *)(long)r2;
2290         struct bpf_array *array = container_of(map, struct bpf_array, map);
2291         struct cgroup *cgrp;
2292         struct sock *sk;
2293         u32 i = (u32)r3;
2294 
2295         sk = skb->sk;
2296         if (!sk || !sk_fullsock(sk))
2297                 return -ENOENT;
2298 
2299         if (unlikely(i >= array->map.max_entries))
2300                 return -E2BIG;
2301 
2302         cgrp = READ_ONCE(array->ptrs[i]);
2303         if (unlikely(!cgrp))
2304                 return -EAGAIN;
2305 
2306         return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data), cgrp);
2307 }
2308 
2309 static const struct bpf_func_proto bpf_skb_under_cgroup_proto = {
2310         .func           = bpf_skb_under_cgroup,
2311         .gpl_only       = false,
2312         .ret_type       = RET_INTEGER,
2313         .arg1_type      = ARG_PTR_TO_CTX,
2314         .arg2_type      = ARG_CONST_MAP_PTR,
2315         .arg3_type      = ARG_ANYTHING,
2316 };
2317 #endif
2318 
2319 static const struct bpf_func_proto *
2320 sk_filter_func_proto(enum bpf_func_id func_id)
2321 {
2322         switch (func_id) {
2323         case BPF_FUNC_map_lookup_elem:
2324                 return &bpf_map_lookup_elem_proto;
2325         case BPF_FUNC_map_update_elem:
2326                 return &bpf_map_update_elem_proto;
2327         case BPF_FUNC_map_delete_elem:
2328                 return &bpf_map_delete_elem_proto;
2329         case BPF_FUNC_get_prandom_u32:
2330                 return &bpf_get_prandom_u32_proto;
2331         case BPF_FUNC_get_smp_processor_id:
2332                 return &bpf_get_raw_smp_processor_id_proto;
2333         case BPF_FUNC_tail_call:
2334                 return &bpf_tail_call_proto;
2335         case BPF_FUNC_ktime_get_ns:
2336                 return &bpf_ktime_get_ns_proto;
2337         case BPF_FUNC_trace_printk:
2338                 if (capable(CAP_SYS_ADMIN))
2339                         return bpf_get_trace_printk_proto();
2340         default:
2341                 return NULL;
2342         }
2343 }
2344 
2345 static const struct bpf_func_proto *
2346 tc_cls_act_func_proto(enum bpf_func_id func_id)
2347 {
2348         switch (func_id) {
2349         case BPF_FUNC_skb_store_bytes:
2350                 return &bpf_skb_store_bytes_proto;
2351         case BPF_FUNC_skb_load_bytes:
2352                 return &bpf_skb_load_bytes_proto;
2353         case BPF_FUNC_csum_diff:
2354                 return &bpf_csum_diff_proto;
2355         case BPF_FUNC_l3_csum_replace:
2356                 return &bpf_l3_csum_replace_proto;
2357         case BPF_FUNC_l4_csum_replace:
2358                 return &bpf_l4_csum_replace_proto;
2359         case BPF_FUNC_clone_redirect:
2360                 return &bpf_clone_redirect_proto;
2361         case BPF_FUNC_get_cgroup_classid:
2362                 return &bpf_get_cgroup_classid_proto;
2363         case BPF_FUNC_skb_vlan_push:
2364                 return &bpf_skb_vlan_push_proto;
2365         case BPF_FUNC_skb_vlan_pop:
2366                 return &bpf_skb_vlan_pop_proto;
2367         case BPF_FUNC_skb_change_proto:
2368                 return &bpf_skb_change_proto_proto;
2369         case BPF_FUNC_skb_change_type:
2370                 return &bpf_skb_change_type_proto;
2371         case BPF_FUNC_skb_get_tunnel_key:
2372                 return &bpf_skb_get_tunnel_key_proto;
2373         case BPF_FUNC_skb_set_tunnel_key:
2374                 return bpf_get_skb_set_tunnel_proto(func_id);
2375         case BPF_FUNC_skb_get_tunnel_opt:
2376                 return &bpf_skb_get_tunnel_opt_proto;
2377         case BPF_FUNC_skb_set_tunnel_opt:
2378                 return bpf_get_skb_set_tunnel_proto(func_id);
2379         case BPF_FUNC_redirect:
2380                 return &bpf_redirect_proto;
2381         case BPF_FUNC_get_route_realm:
2382                 return &bpf_get_route_realm_proto;
2383         case BPF_FUNC_get_hash_recalc:
2384                 return &bpf_get_hash_recalc_proto;
2385         case BPF_FUNC_perf_event_output:
2386                 return &bpf_skb_event_output_proto;
2387         case BPF_FUNC_get_smp_processor_id:
2388                 return &bpf_get_smp_processor_id_proto;
2389 #ifdef CONFIG_SOCK_CGROUP_DATA
2390         case BPF_FUNC_skb_under_cgroup:
2391                 return &bpf_skb_under_cgroup_proto;
2392 #endif
2393         default:
2394                 return sk_filter_func_proto(func_id);
2395         }
2396 }
2397 
2398 static const struct bpf_func_proto *
2399 xdp_func_proto(enum bpf_func_id func_id)
2400 {
2401         return sk_filter_func_proto(func_id);
2402 }
2403 
2404 static bool __is_valid_access(int off, int size, enum bpf_access_type type)
2405 {
2406         if (off < 0 || off >= sizeof(struct __sk_buff))
2407                 return false;
2408         /* The verifier guarantees that size > 0. */
2409         if (off % size != 0)
2410                 return false;
2411         if (size != sizeof(__u32))
2412                 return false;
2413 
2414         return true;
2415 }
2416 
2417 static bool sk_filter_is_valid_access(int off, int size,
2418                                       enum bpf_access_type type,
2419                                       enum bpf_reg_type *reg_type)
2420 {
2421         switch (off) {
2422         case offsetof(struct __sk_buff, tc_classid):
2423         case offsetof(struct __sk_buff, data):
2424         case offsetof(struct __sk_buff, data_end):
2425                 return false;
2426         }
2427 
2428         if (type == BPF_WRITE) {
2429                 switch (off) {
2430                 case offsetof(struct __sk_buff, cb[0]) ...
2431                      offsetof(struct __sk_buff, cb[4]):
2432                         break;
2433                 default:
2434                         return false;
2435                 }
2436         }
2437 
2438         return __is_valid_access(off, size, type);
2439 }
2440 
2441 static bool tc_cls_act_is_valid_access(int off, int size,
2442                                        enum bpf_access_type type,
2443                                        enum bpf_reg_type *reg_type)
2444 {
2445         if (type == BPF_WRITE) {
2446                 switch (off) {
2447                 case offsetof(struct __sk_buff, mark):
2448                 case offsetof(struct __sk_buff, tc_index):
2449                 case offsetof(struct __sk_buff, priority):
2450                 case offsetof(struct __sk_buff, cb[0]) ...
2451                      offsetof(struct __sk_buff, cb[4]):
2452                 case offsetof(struct __sk_buff, tc_classid):
2453                         break;
2454                 default:
2455                         return false;
2456                 }
2457         }
2458 
2459         switch (off) {
2460         case offsetof(struct __sk_buff, data):
2461                 *reg_type = PTR_TO_PACKET;
2462                 break;
2463         case offsetof(struct __sk_buff, data_end):
2464                 *reg_type = PTR_TO_PACKET_END;
2465                 break;
2466         }
2467 
2468         return __is_valid_access(off, size, type);
2469 }
2470 
2471 static bool __is_valid_xdp_access(int off, int size,
2472                                   enum bpf_access_type type)
2473 {
2474         if (off < 0 || off >= sizeof(struct xdp_md))
2475                 return false;
2476         if (off % size != 0)
2477                 return false;
2478         if (size != 4)
2479                 return false;
2480 
2481         return true;
2482 }
2483 
2484 static bool xdp_is_valid_access(int off, int size,
2485                                 enum bpf_access_type type,
2486                                 enum bpf_reg_type *reg_type)
2487 {
2488         if (type == BPF_WRITE)
2489                 return false;
2490 
2491         switch (off) {
2492         case offsetof(struct xdp_md, data):
2493                 *reg_type = PTR_TO_PACKET;
2494                 break;
2495         case offsetof(struct xdp_md, data_end):
2496                 *reg_type = PTR_TO_PACKET_END;
2497                 break;
2498         }
2499 
2500         return __is_valid_xdp_access(off, size, type);
2501 }
2502 
2503 void bpf_warn_invalid_xdp_action(u32 act)
2504 {
2505         WARN_ONCE(1, "Illegal XDP return value %u, expect packet loss\n", act);
2506 }
2507 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
2508 
2509 static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
2510                                       int src_reg, int ctx_off,
2511                                       struct bpf_insn *insn_buf,
2512                                       struct bpf_prog *prog)
2513 {
2514         struct bpf_insn *insn = insn_buf;
2515 
2516         switch (ctx_off) {
2517         case offsetof(struct __sk_buff, len):
2518                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
2519 
2520                 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
2521                                       offsetof(struct sk_buff, len));
2522                 break;
2523 
2524         case offsetof(struct __sk_buff, protocol):
2525                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
2526 
2527                 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
2528                                       offsetof(struct sk_buff, protocol));
2529                 break;
2530 
2531         case offsetof(struct __sk_buff, vlan_proto):
2532                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2);
2533 
2534                 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
2535                                       offsetof(struct sk_buff, vlan_proto));
2536                 break;
2537 
2538         case offsetof(struct __sk_buff, priority):
2539                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4);
2540 
2541                 if (type == BPF_WRITE)
2542                         *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg,
2543                                               offsetof(struct sk_buff, priority));
2544                 else
2545                         *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
2546                                               offsetof(struct sk_buff, priority));
2547                 break;
2548 
2549         case offsetof(struct __sk_buff, ingress_ifindex):
2550                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, skb_iif) != 4);
2551 
2552                 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
2553                                       offsetof(struct sk_buff, skb_iif));
2554                 break;
2555 
2556         case offsetof(struct __sk_buff, ifindex):
2557                 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
2558 
2559                 *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)),
2560                                       dst_reg, src_reg,
2561                                       offsetof(struct sk_buff, dev));
2562                 *insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1);
2563                 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, dst_reg,
2564                                       offsetof(struct net_device, ifindex));
2565                 break;
2566 
2567         case offsetof(struct __sk_buff, hash):
2568                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
2569 
2570                 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
2571                                       offsetof(struct sk_buff, hash));
2572                 break;
2573 
2574         case offsetof(struct __sk_buff, mark):
2575                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
2576 
2577                 if (type == BPF_WRITE)
2578                         *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg,
2579                                               offsetof(struct sk_buff, mark));
2580                 else
2581                         *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
2582                                               offsetof(struct sk_buff, mark));
2583                 break;
2584 
2585         case offsetof(struct __sk_buff, pkt_type):
2586                 return convert_skb_access(SKF_AD_PKTTYPE, dst_reg, src_reg, insn);
2587 
2588         case offsetof(struct __sk_buff, queue_mapping):
2589                 return convert_skb_access(SKF_AD_QUEUE, dst_reg, src_reg, insn);
2590 
2591         case offsetof(struct __sk_buff, vlan_present):
2592                 return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT,
2593                                           dst_reg, src_reg, insn);
2594 
2595         case offsetof(struct __sk_buff, vlan_tci):
2596                 return convert_skb_access(SKF_AD_VLAN_TAG,
2597                                           dst_reg, src_reg, insn);
2598 
2599         case offsetof(struct __sk_buff, cb[0]) ...
2600                 offsetof(struct __sk_buff, cb[4]):
2601                 BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20);
2602 
2603                 prog->cb_access = 1;
2604                 ctx_off -= offsetof(struct __sk_buff, cb[0]);
2605                 ctx_off += offsetof(struct sk_buff, cb);
2606                 ctx_off += offsetof(struct qdisc_skb_cb, data);
2607                 if (type == BPF_WRITE)
2608                         *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, ctx_off);
2609                 else
2610                         *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, ctx_off);
2611                 break;
2612 
2613         case offsetof(struct __sk_buff, tc_classid):
2614                 ctx_off -= offsetof(struct __sk_buff, tc_classid);
2615                 ctx_off += offsetof(struct sk_buff, cb);
2616                 ctx_off += offsetof(struct qdisc_skb_cb, tc_classid);
2617                 if (type == BPF_WRITE)
2618                         *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, ctx_off);
2619                 else
2620                         *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, ctx_off);
2621                 break;
2622 
2623         case offsetof(struct __sk_buff, data):
2624                 *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, data)),
2625                                       dst_reg, src_reg,
2626                                       offsetof(struct sk_buff, data));
2627                 break;
2628 
2629         case offsetof(struct __sk_buff, data_end):
2630                 ctx_off -= offsetof(struct __sk_buff, data_end);
2631                 ctx_off += offsetof(struct sk_buff, cb);
2632                 ctx_off += offsetof(struct bpf_skb_data_end, data_end);
2633                 *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(void *)),
2634                                       dst_reg, src_reg, ctx_off);
2635                 break;
2636 
2637         case offsetof(struct __sk_buff, tc_index):
2638 #ifdef CONFIG_NET_SCHED
2639                 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, tc_index) != 2);
2640 
2641                 if (type == BPF_WRITE)
2642                         *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg,
2643                                               offsetof(struct sk_buff, tc_index));
2644                 else
2645                         *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
2646                                               offsetof(struct sk_buff, tc_index));
2647                 break;
2648 #else
2649                 if (type == BPF_WRITE)
2650                         *insn++ = BPF_MOV64_REG(dst_reg, dst_reg);
2651                 else
2652                         *insn++ = BPF_MOV64_IMM(dst_reg, 0);
2653                 break;
2654 #endif
2655         }
2656 
2657         return insn - insn_buf;
2658 }
2659 
2660 static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg,
2661                                   int src_reg, int ctx_off,
2662                                   struct bpf_insn *insn_buf,
2663                                   struct bpf_prog *prog)
2664 {
2665         struct bpf_insn *insn = insn_buf;
2666 
2667         switch (ctx_off) {
2668         case offsetof(struct xdp_md, data):
2669                 *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data)),
2670                                       dst_reg, src_reg,
2671                                       offsetof(struct xdp_buff, data));
2672                 break;
2673         case offsetof(struct xdp_md, data_end):
2674                 *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data_end)),
2675                                       dst_reg, src_reg,
2676                                       offsetof(struct xdp_buff, data_end));
2677                 break;
2678         }
2679 
2680         return insn - insn_buf;
2681 }
2682 
2683 static const struct bpf_verifier_ops sk_filter_ops = {
2684         .get_func_proto         = sk_filter_func_proto,
2685         .is_valid_access        = sk_filter_is_valid_access,
2686         .convert_ctx_access     = bpf_net_convert_ctx_access,
2687 };
2688 
2689 static const struct bpf_verifier_ops tc_cls_act_ops = {
2690         .get_func_proto         = tc_cls_act_func_proto,
2691         .is_valid_access        = tc_cls_act_is_valid_access,
2692         .convert_ctx_access     = bpf_net_convert_ctx_access,
2693 };
2694 
2695 static const struct bpf_verifier_ops xdp_ops = {
2696         .get_func_proto         = xdp_func_proto,
2697         .is_valid_access        = xdp_is_valid_access,
2698         .convert_ctx_access     = xdp_convert_ctx_access,
2699 };
2700 
2701 static struct bpf_prog_type_list sk_filter_type __read_mostly = {
2702         .ops    = &sk_filter_ops,
2703         .type   = BPF_PROG_TYPE_SOCKET_FILTER,
2704 };
2705 
2706 static struct bpf_prog_type_list sched_cls_type __read_mostly = {
2707         .ops    = &tc_cls_act_ops,
2708         .type   = BPF_PROG_TYPE_SCHED_CLS,
2709 };
2710 
2711 static struct bpf_prog_type_list sched_act_type __read_mostly = {
2712         .ops    = &tc_cls_act_ops,
2713         .type   = BPF_PROG_TYPE_SCHED_ACT,
2714 };
2715 
2716 static struct bpf_prog_type_list xdp_type __read_mostly = {
2717         .ops    = &xdp_ops,
2718         .type   = BPF_PROG_TYPE_XDP,
2719 };
2720 
2721 static int __init register_sk_filter_ops(void)
2722 {
2723         bpf_register_prog_type(&sk_filter_type);
2724         bpf_register_prog_type(&sched_cls_type);
2725         bpf_register_prog_type(&sched_act_type);
2726         bpf_register_prog_type(&xdp_type);
2727 
2728         return 0;
2729 }
2730 late_initcall(register_sk_filter_ops);
2731 
2732 int sk_detach_filter(struct sock *sk)
2733 {
2734         int ret = -ENOENT;
2735         struct sk_filter *filter;
2736 
2737         if (sock_flag(sk, SOCK_FILTER_LOCKED))
2738                 return -EPERM;
2739 
2740         filter = rcu_dereference_protected(sk->sk_filter,
2741                                            lockdep_sock_is_held(sk));
2742         if (filter) {
2743                 RCU_INIT_POINTER(sk->sk_filter, NULL);
2744                 sk_filter_uncharge(sk, filter);
2745                 ret = 0;
2746         }
2747 
2748         return ret;
2749 }
2750 EXPORT_SYMBOL_GPL(sk_detach_filter);
2751 
2752 int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf,
2753                   unsigned int len)
2754 {
2755         struct sock_fprog_kern *fprog;
2756         struct sk_filter *filter;
2757         int ret = 0;
2758 
2759         lock_sock(sk);
2760         filter = rcu_dereference_protected(sk->sk_filter,
2761                                            lockdep_sock_is_held(sk));
2762         if (!filter)
2763                 goto out;
2764 
2765         /* We're copying the filter that has been originally attached,
2766          * so no conversion/decode needed anymore. eBPF programs that
2767          * have no original program cannot be dumped through this.
2768          */
2769         ret = -EACCES;
2770         fprog = filter->prog->orig_prog;
2771         if (!fprog)
2772                 goto out;
2773 
2774         ret = fprog->len;
2775         if (!len)
2776                 /* User space only enquires number of filter blocks. */
2777                 goto out;
2778 
2779         ret = -EINVAL;
2780         if (len < fprog->len)
2781                 goto out;
2782 
2783         ret = -EFAULT;
2784         if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog)))
2785                 goto out;
2786 
2787         /* Instead of bytes, the API requests to return the number
2788          * of filter blocks.
2789          */
2790         ret = fprog->len;
2791 out:
2792         release_sock(sk);
2793         return ret;
2794 }
2795 

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