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Linux/net/ipv4/ip_sockglue.c

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  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  4  *              operating system.  INET is implemented using the  BSD Socket
  5  *              interface as the means of communication with the user level.
  6  *
  7  *              The IP to API glue.
  8  *
  9  * Authors:     see ip.c
 10  *
 11  * Fixes:
 12  *              Many            :       Split from ip.c , see ip.c for history.
 13  *              Martin Mares    :       TOS setting fixed.
 14  *              Alan Cox        :       Fixed a couple of oopses in Martin's
 15  *                                      TOS tweaks.
 16  *              Mike McLagan    :       Routing by source
 17  */
 18 
 19 #include <linux/module.h>
 20 #include <linux/types.h>
 21 #include <linux/mm.h>
 22 #include <linux/skbuff.h>
 23 #include <linux/ip.h>
 24 #include <linux/icmp.h>
 25 #include <linux/inetdevice.h>
 26 #include <linux/netdevice.h>
 27 #include <linux/slab.h>
 28 #include <net/sock.h>
 29 #include <net/ip.h>
 30 #include <net/icmp.h>
 31 #include <net/tcp_states.h>
 32 #include <linux/udp.h>
 33 #include <linux/igmp.h>
 34 #include <linux/netfilter.h>
 35 #include <linux/route.h>
 36 #include <linux/mroute.h>
 37 #include <net/inet_ecn.h>
 38 #include <net/route.h>
 39 #include <net/xfrm.h>
 40 #include <net/compat.h>
 41 #include <net/checksum.h>
 42 #if IS_ENABLED(CONFIG_IPV6)
 43 #include <net/transp_v6.h>
 44 #endif
 45 #include <net/ip_fib.h>
 46 
 47 #include <linux/errqueue.h>
 48 #include <linux/uaccess.h>
 49 
 50 #include <linux/bpfilter.h>
 51 
 52 /*
 53  *      SOL_IP control messages.
 54  */
 55 
 56 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
 57 {
 58         struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
 59 
 60         info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
 61 
 62         put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
 63 }
 64 
 65 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
 66 {
 67         int ttl = ip_hdr(skb)->ttl;
 68         put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
 69 }
 70 
 71 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
 72 {
 73         put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
 74 }
 75 
 76 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
 77 {
 78         if (IPCB(skb)->opt.optlen == 0)
 79                 return;
 80 
 81         put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
 82                  ip_hdr(skb) + 1);
 83 }
 84 
 85 
 86 static void ip_cmsg_recv_retopts(struct net *net, struct msghdr *msg,
 87                                  struct sk_buff *skb)
 88 {
 89         unsigned char optbuf[sizeof(struct ip_options) + 40];
 90         struct ip_options *opt = (struct ip_options *)optbuf;
 91 
 92         if (IPCB(skb)->opt.optlen == 0)
 93                 return;
 94 
 95         if (ip_options_echo(net, opt, skb)) {
 96                 msg->msg_flags |= MSG_CTRUNC;
 97                 return;
 98         }
 99         ip_options_undo(opt);
100 
101         put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
102 }
103 
104 static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb)
105 {
106         int val;
107 
108         if (IPCB(skb)->frag_max_size == 0)
109                 return;
110 
111         val = IPCB(skb)->frag_max_size;
112         put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val);
113 }
114 
115 static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
116                                   int tlen, int offset)
117 {
118         __wsum csum = skb->csum;
119 
120         if (skb->ip_summed != CHECKSUM_COMPLETE)
121                 return;
122 
123         if (offset != 0) {
124                 int tend_off = skb_transport_offset(skb) + tlen;
125                 csum = csum_sub(csum, skb_checksum(skb, tend_off, offset, 0));
126         }
127 
128         put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum);
129 }
130 
131 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
132 {
133         char *secdata;
134         u32 seclen, secid;
135         int err;
136 
137         err = security_socket_getpeersec_dgram(NULL, skb, &secid);
138         if (err)
139                 return;
140 
141         err = security_secid_to_secctx(secid, &secdata, &seclen);
142         if (err)
143                 return;
144 
145         put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
146         security_release_secctx(secdata, seclen);
147 }
148 
149 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
150 {
151         __be16 _ports[2], *ports;
152         struct sockaddr_in sin;
153 
154         /* All current transport protocols have the port numbers in the
155          * first four bytes of the transport header and this function is
156          * written with this assumption in mind.
157          */
158         ports = skb_header_pointer(skb, skb_transport_offset(skb),
159                                    sizeof(_ports), &_ports);
160         if (!ports)
161                 return;
162 
163         sin.sin_family = AF_INET;
164         sin.sin_addr.s_addr = ip_hdr(skb)->daddr;
165         sin.sin_port = ports[1];
166         memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
167 
168         put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
169 }
170 
171 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
172                          struct sk_buff *skb, int tlen, int offset)
173 {
174         struct inet_sock *inet = inet_sk(sk);
175         unsigned int flags = inet->cmsg_flags;
176 
177         /* Ordered by supposed usage frequency */
178         if (flags & IP_CMSG_PKTINFO) {
179                 ip_cmsg_recv_pktinfo(msg, skb);
180 
181                 flags &= ~IP_CMSG_PKTINFO;
182                 if (!flags)
183                         return;
184         }
185 
186         if (flags & IP_CMSG_TTL) {
187                 ip_cmsg_recv_ttl(msg, skb);
188 
189                 flags &= ~IP_CMSG_TTL;
190                 if (!flags)
191                         return;
192         }
193 
194         if (flags & IP_CMSG_TOS) {
195                 ip_cmsg_recv_tos(msg, skb);
196 
197                 flags &= ~IP_CMSG_TOS;
198                 if (!flags)
199                         return;
200         }
201 
202         if (flags & IP_CMSG_RECVOPTS) {
203                 ip_cmsg_recv_opts(msg, skb);
204 
205                 flags &= ~IP_CMSG_RECVOPTS;
206                 if (!flags)
207                         return;
208         }
209 
210         if (flags & IP_CMSG_RETOPTS) {
211                 ip_cmsg_recv_retopts(sock_net(sk), msg, skb);
212 
213                 flags &= ~IP_CMSG_RETOPTS;
214                 if (!flags)
215                         return;
216         }
217 
218         if (flags & IP_CMSG_PASSSEC) {
219                 ip_cmsg_recv_security(msg, skb);
220 
221                 flags &= ~IP_CMSG_PASSSEC;
222                 if (!flags)
223                         return;
224         }
225 
226         if (flags & IP_CMSG_ORIGDSTADDR) {
227                 ip_cmsg_recv_dstaddr(msg, skb);
228 
229                 flags &= ~IP_CMSG_ORIGDSTADDR;
230                 if (!flags)
231                         return;
232         }
233 
234         if (flags & IP_CMSG_CHECKSUM)
235                 ip_cmsg_recv_checksum(msg, skb, tlen, offset);
236 
237         if (flags & IP_CMSG_RECVFRAGSIZE)
238                 ip_cmsg_recv_fragsize(msg, skb);
239 }
240 EXPORT_SYMBOL(ip_cmsg_recv_offset);
241 
242 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
243                  bool allow_ipv6)
244 {
245         int err, val;
246         struct cmsghdr *cmsg;
247         struct net *net = sock_net(sk);
248 
249         for_each_cmsghdr(cmsg, msg) {
250                 if (!CMSG_OK(msg, cmsg))
251                         return -EINVAL;
252 #if IS_ENABLED(CONFIG_IPV6)
253                 if (allow_ipv6 &&
254                     cmsg->cmsg_level == SOL_IPV6 &&
255                     cmsg->cmsg_type == IPV6_PKTINFO) {
256                         struct in6_pktinfo *src_info;
257 
258                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
259                                 return -EINVAL;
260                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
261                         if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
262                                 return -EINVAL;
263                         if (src_info->ipi6_ifindex)
264                                 ipc->oif = src_info->ipi6_ifindex;
265                         ipc->addr = src_info->ipi6_addr.s6_addr32[3];
266                         continue;
267                 }
268 #endif
269                 if (cmsg->cmsg_level == SOL_SOCKET) {
270                         err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc);
271                         if (err)
272                                 return err;
273                         continue;
274                 }
275 
276                 if (cmsg->cmsg_level != SOL_IP)
277                         continue;
278                 switch (cmsg->cmsg_type) {
279                 case IP_RETOPTS:
280                         err = cmsg->cmsg_len - sizeof(struct cmsghdr);
281 
282                         /* Our caller is responsible for freeing ipc->opt */
283                         err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
284                                              err < 40 ? err : 40);
285                         if (err)
286                                 return err;
287                         break;
288                 case IP_PKTINFO:
289                 {
290                         struct in_pktinfo *info;
291                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
292                                 return -EINVAL;
293                         info = (struct in_pktinfo *)CMSG_DATA(cmsg);
294                         if (info->ipi_ifindex)
295                                 ipc->oif = info->ipi_ifindex;
296                         ipc->addr = info->ipi_spec_dst.s_addr;
297                         break;
298                 }
299                 case IP_TTL:
300                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
301                                 return -EINVAL;
302                         val = *(int *)CMSG_DATA(cmsg);
303                         if (val < 1 || val > 255)
304                                 return -EINVAL;
305                         ipc->ttl = val;
306                         break;
307                 case IP_TOS:
308                         if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
309                                 val = *(int *)CMSG_DATA(cmsg);
310                         else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
311                                 val = *(u8 *)CMSG_DATA(cmsg);
312                         else
313                                 return -EINVAL;
314                         if (val < 0 || val > 255)
315                                 return -EINVAL;
316                         ipc->tos = val;
317                         ipc->priority = rt_tos2priority(ipc->tos);
318                         break;
319 
320                 default:
321                         return -EINVAL;
322                 }
323         }
324         return 0;
325 }
326 
327 static void ip_ra_destroy_rcu(struct rcu_head *head)
328 {
329         struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
330 
331         sock_put(ra->saved_sk);
332         kfree(ra);
333 }
334 
335 int ip_ra_control(struct sock *sk, unsigned char on,
336                   void (*destructor)(struct sock *))
337 {
338         struct ip_ra_chain *ra, *new_ra;
339         struct ip_ra_chain __rcu **rap;
340         struct net *net = sock_net(sk);
341 
342         if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
343                 return -EINVAL;
344 
345         new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
346         if (on && !new_ra)
347                 return -ENOMEM;
348 
349         mutex_lock(&net->ipv4.ra_mutex);
350         for (rap = &net->ipv4.ra_chain;
351              (ra = rcu_dereference_protected(*rap,
352                         lockdep_is_held(&net->ipv4.ra_mutex))) != NULL;
353              rap = &ra->next) {
354                 if (ra->sk == sk) {
355                         if (on) {
356                                 mutex_unlock(&net->ipv4.ra_mutex);
357                                 kfree(new_ra);
358                                 return -EADDRINUSE;
359                         }
360                         /* dont let ip_call_ra_chain() use sk again */
361                         ra->sk = NULL;
362                         RCU_INIT_POINTER(*rap, ra->next);
363                         mutex_unlock(&net->ipv4.ra_mutex);
364 
365                         if (ra->destructor)
366                                 ra->destructor(sk);
367                         /*
368                          * Delay sock_put(sk) and kfree(ra) after one rcu grace
369                          * period. This guarantee ip_call_ra_chain() dont need
370                          * to mess with socket refcounts.
371                          */
372                         ra->saved_sk = sk;
373                         call_rcu(&ra->rcu, ip_ra_destroy_rcu);
374                         return 0;
375                 }
376         }
377         if (!new_ra) {
378                 mutex_unlock(&net->ipv4.ra_mutex);
379                 return -ENOBUFS;
380         }
381         new_ra->sk = sk;
382         new_ra->destructor = destructor;
383 
384         RCU_INIT_POINTER(new_ra->next, ra);
385         rcu_assign_pointer(*rap, new_ra);
386         sock_hold(sk);
387         mutex_unlock(&net->ipv4.ra_mutex);
388 
389         return 0;
390 }
391 
392 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
393                    __be16 port, u32 info, u8 *payload)
394 {
395         struct sock_exterr_skb *serr;
396 
397         skb = skb_clone(skb, GFP_ATOMIC);
398         if (!skb)
399                 return;
400 
401         serr = SKB_EXT_ERR(skb);
402         serr->ee.ee_errno = err;
403         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
404         serr->ee.ee_type = icmp_hdr(skb)->type;
405         serr->ee.ee_code = icmp_hdr(skb)->code;
406         serr->ee.ee_pad = 0;
407         serr->ee.ee_info = info;
408         serr->ee.ee_data = 0;
409         serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
410                                    skb_network_header(skb);
411         serr->port = port;
412 
413         if (skb_pull(skb, payload - skb->data)) {
414                 skb_reset_transport_header(skb);
415                 if (sock_queue_err_skb(sk, skb) == 0)
416                         return;
417         }
418         kfree_skb(skb);
419 }
420 
421 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
422 {
423         struct inet_sock *inet = inet_sk(sk);
424         struct sock_exterr_skb *serr;
425         struct iphdr *iph;
426         struct sk_buff *skb;
427 
428         if (!inet->recverr)
429                 return;
430 
431         skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
432         if (!skb)
433                 return;
434 
435         skb_put(skb, sizeof(struct iphdr));
436         skb_reset_network_header(skb);
437         iph = ip_hdr(skb);
438         iph->daddr = daddr;
439 
440         serr = SKB_EXT_ERR(skb);
441         serr->ee.ee_errno = err;
442         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
443         serr->ee.ee_type = 0;
444         serr->ee.ee_code = 0;
445         serr->ee.ee_pad = 0;
446         serr->ee.ee_info = info;
447         serr->ee.ee_data = 0;
448         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
449         serr->port = port;
450 
451         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
452         skb_reset_transport_header(skb);
453 
454         if (sock_queue_err_skb(sk, skb))
455                 kfree_skb(skb);
456 }
457 
458 /* For some errors we have valid addr_offset even with zero payload and
459  * zero port. Also, addr_offset should be supported if port is set.
460  */
461 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
462 {
463         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
464                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
465 }
466 
467 /* IPv4 supports cmsg on all imcp errors and some timestamps
468  *
469  * Timestamp code paths do not initialize the fields expected by cmsg:
470  * the PKTINFO fields in skb->cb[]. Fill those in here.
471  */
472 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
473                                        struct sk_buff *skb,
474                                        int ee_origin)
475 {
476         struct in_pktinfo *info;
477 
478         if (ee_origin == SO_EE_ORIGIN_ICMP)
479                 return true;
480 
481         if (ee_origin == SO_EE_ORIGIN_LOCAL)
482                 return false;
483 
484         /* Support IP_PKTINFO on tstamp packets if requested, to correlate
485          * timestamp with egress dev. Not possible for packets without iif
486          * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
487          */
488         info = PKTINFO_SKB_CB(skb);
489         if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
490             !info->ipi_ifindex)
491                 return false;
492 
493         info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
494         return true;
495 }
496 
497 /*
498  *      Handle MSG_ERRQUEUE
499  */
500 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
501 {
502         struct sock_exterr_skb *serr;
503         struct sk_buff *skb;
504         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
505         struct {
506                 struct sock_extended_err ee;
507                 struct sockaddr_in       offender;
508         } errhdr;
509         int err;
510         int copied;
511 
512         err = -EAGAIN;
513         skb = sock_dequeue_err_skb(sk);
514         if (!skb)
515                 goto out;
516 
517         copied = skb->len;
518         if (copied > len) {
519                 msg->msg_flags |= MSG_TRUNC;
520                 copied = len;
521         }
522         err = skb_copy_datagram_msg(skb, 0, msg, copied);
523         if (unlikely(err)) {
524                 kfree_skb(skb);
525                 return err;
526         }
527         sock_recv_timestamp(msg, sk, skb);
528 
529         serr = SKB_EXT_ERR(skb);
530 
531         if (sin && ipv4_datagram_support_addr(serr)) {
532                 sin->sin_family = AF_INET;
533                 sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
534                                                    serr->addr_offset);
535                 sin->sin_port = serr->port;
536                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
537                 *addr_len = sizeof(*sin);
538         }
539 
540         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
541         sin = &errhdr.offender;
542         memset(sin, 0, sizeof(*sin));
543 
544         if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
545                 sin->sin_family = AF_INET;
546                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
547                 if (inet_sk(sk)->cmsg_flags)
548                         ip_cmsg_recv(msg, skb);
549         }
550 
551         put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
552 
553         /* Now we could try to dump offended packet options */
554 
555         msg->msg_flags |= MSG_ERRQUEUE;
556         err = copied;
557 
558         consume_skb(skb);
559 out:
560         return err;
561 }
562 
563 
564 /*
565  *      Socket option code for IP. This is the end of the line after any
566  *      TCP,UDP etc options on an IP socket.
567  */
568 static bool setsockopt_needs_rtnl(int optname)
569 {
570         switch (optname) {
571         case IP_ADD_MEMBERSHIP:
572         case IP_ADD_SOURCE_MEMBERSHIP:
573         case IP_BLOCK_SOURCE:
574         case IP_DROP_MEMBERSHIP:
575         case IP_DROP_SOURCE_MEMBERSHIP:
576         case IP_MSFILTER:
577         case IP_UNBLOCK_SOURCE:
578         case MCAST_BLOCK_SOURCE:
579         case MCAST_MSFILTER:
580         case MCAST_JOIN_GROUP:
581         case MCAST_JOIN_SOURCE_GROUP:
582         case MCAST_LEAVE_GROUP:
583         case MCAST_LEAVE_SOURCE_GROUP:
584         case MCAST_UNBLOCK_SOURCE:
585                 return true;
586         }
587         return false;
588 }
589 
590 static int do_ip_setsockopt(struct sock *sk, int level,
591                             int optname, char __user *optval, unsigned int optlen)
592 {
593         struct inet_sock *inet = inet_sk(sk);
594         struct net *net = sock_net(sk);
595         int val = 0, err;
596         bool needs_rtnl = setsockopt_needs_rtnl(optname);
597 
598         switch (optname) {
599         case IP_PKTINFO:
600         case IP_RECVTTL:
601         case IP_RECVOPTS:
602         case IP_RECVTOS:
603         case IP_RETOPTS:
604         case IP_TOS:
605         case IP_TTL:
606         case IP_HDRINCL:
607         case IP_MTU_DISCOVER:
608         case IP_RECVERR:
609         case IP_ROUTER_ALERT:
610         case IP_FREEBIND:
611         case IP_PASSSEC:
612         case IP_TRANSPARENT:
613         case IP_MINTTL:
614         case IP_NODEFRAG:
615         case IP_BIND_ADDRESS_NO_PORT:
616         case IP_UNICAST_IF:
617         case IP_MULTICAST_TTL:
618         case IP_MULTICAST_ALL:
619         case IP_MULTICAST_LOOP:
620         case IP_RECVORIGDSTADDR:
621         case IP_CHECKSUM:
622         case IP_RECVFRAGSIZE:
623                 if (optlen >= sizeof(int)) {
624                         if (get_user(val, (int __user *) optval))
625                                 return -EFAULT;
626                 } else if (optlen >= sizeof(char)) {
627                         unsigned char ucval;
628 
629                         if (get_user(ucval, (unsigned char __user *) optval))
630                                 return -EFAULT;
631                         val = (int) ucval;
632                 }
633         }
634 
635         /* If optlen==0, it is equivalent to val == 0 */
636 
637         if (optname == IP_ROUTER_ALERT)
638                 return ip_ra_control(sk, val ? 1 : 0, NULL);
639         if (ip_mroute_opt(optname))
640                 return ip_mroute_setsockopt(sk, optname, optval, optlen);
641 
642         err = 0;
643         if (needs_rtnl)
644                 rtnl_lock();
645         lock_sock(sk);
646 
647         switch (optname) {
648         case IP_OPTIONS:
649         {
650                 struct ip_options_rcu *old, *opt = NULL;
651 
652                 if (optlen > 40)
653                         goto e_inval;
654                 err = ip_options_get_from_user(sock_net(sk), &opt,
655                                                optval, optlen);
656                 if (err)
657                         break;
658                 old = rcu_dereference_protected(inet->inet_opt,
659                                                 lockdep_sock_is_held(sk));
660                 if (inet->is_icsk) {
661                         struct inet_connection_sock *icsk = inet_csk(sk);
662 #if IS_ENABLED(CONFIG_IPV6)
663                         if (sk->sk_family == PF_INET ||
664                             (!((1 << sk->sk_state) &
665                                (TCPF_LISTEN | TCPF_CLOSE)) &&
666                              inet->inet_daddr != LOOPBACK4_IPV6)) {
667 #endif
668                                 if (old)
669                                         icsk->icsk_ext_hdr_len -= old->opt.optlen;
670                                 if (opt)
671                                         icsk->icsk_ext_hdr_len += opt->opt.optlen;
672                                 icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
673 #if IS_ENABLED(CONFIG_IPV6)
674                         }
675 #endif
676                 }
677                 rcu_assign_pointer(inet->inet_opt, opt);
678                 if (old)
679                         kfree_rcu(old, rcu);
680                 break;
681         }
682         case IP_PKTINFO:
683                 if (val)
684                         inet->cmsg_flags |= IP_CMSG_PKTINFO;
685                 else
686                         inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
687                 break;
688         case IP_RECVTTL:
689                 if (val)
690                         inet->cmsg_flags |=  IP_CMSG_TTL;
691                 else
692                         inet->cmsg_flags &= ~IP_CMSG_TTL;
693                 break;
694         case IP_RECVTOS:
695                 if (val)
696                         inet->cmsg_flags |=  IP_CMSG_TOS;
697                 else
698                         inet->cmsg_flags &= ~IP_CMSG_TOS;
699                 break;
700         case IP_RECVOPTS:
701                 if (val)
702                         inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
703                 else
704                         inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
705                 break;
706         case IP_RETOPTS:
707                 if (val)
708                         inet->cmsg_flags |= IP_CMSG_RETOPTS;
709                 else
710                         inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
711                 break;
712         case IP_PASSSEC:
713                 if (val)
714                         inet->cmsg_flags |= IP_CMSG_PASSSEC;
715                 else
716                         inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
717                 break;
718         case IP_RECVORIGDSTADDR:
719                 if (val)
720                         inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
721                 else
722                         inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
723                 break;
724         case IP_CHECKSUM:
725                 if (val) {
726                         if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
727                                 inet_inc_convert_csum(sk);
728                                 inet->cmsg_flags |= IP_CMSG_CHECKSUM;
729                         }
730                 } else {
731                         if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
732                                 inet_dec_convert_csum(sk);
733                                 inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
734                         }
735                 }
736                 break;
737         case IP_RECVFRAGSIZE:
738                 if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
739                         goto e_inval;
740                 if (val)
741                         inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
742                 else
743                         inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
744                 break;
745         case IP_TOS:    /* This sets both TOS and Precedence */
746                 if (sk->sk_type == SOCK_STREAM) {
747                         val &= ~INET_ECN_MASK;
748                         val |= inet->tos & INET_ECN_MASK;
749                 }
750                 if (inet->tos != val) {
751                         inet->tos = val;
752                         sk->sk_priority = rt_tos2priority(val);
753                         sk_dst_reset(sk);
754                 }
755                 break;
756         case IP_TTL:
757                 if (optlen < 1)
758                         goto e_inval;
759                 if (val != -1 && (val < 1 || val > 255))
760                         goto e_inval;
761                 inet->uc_ttl = val;
762                 break;
763         case IP_HDRINCL:
764                 if (sk->sk_type != SOCK_RAW) {
765                         err = -ENOPROTOOPT;
766                         break;
767                 }
768                 inet->hdrincl = val ? 1 : 0;
769                 break;
770         case IP_NODEFRAG:
771                 if (sk->sk_type != SOCK_RAW) {
772                         err = -ENOPROTOOPT;
773                         break;
774                 }
775                 inet->nodefrag = val ? 1 : 0;
776                 break;
777         case IP_BIND_ADDRESS_NO_PORT:
778                 inet->bind_address_no_port = val ? 1 : 0;
779                 break;
780         case IP_MTU_DISCOVER:
781                 if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
782                         goto e_inval;
783                 inet->pmtudisc = val;
784                 break;
785         case IP_RECVERR:
786                 inet->recverr = !!val;
787                 if (!val)
788                         skb_queue_purge(&sk->sk_error_queue);
789                 break;
790         case IP_MULTICAST_TTL:
791                 if (sk->sk_type == SOCK_STREAM)
792                         goto e_inval;
793                 if (optlen < 1)
794                         goto e_inval;
795                 if (val == -1)
796                         val = 1;
797                 if (val < 0 || val > 255)
798                         goto e_inval;
799                 inet->mc_ttl = val;
800                 break;
801         case IP_MULTICAST_LOOP:
802                 if (optlen < 1)
803                         goto e_inval;
804                 inet->mc_loop = !!val;
805                 break;
806         case IP_UNICAST_IF:
807         {
808                 struct net_device *dev = NULL;
809                 int ifindex;
810                 int midx;
811 
812                 if (optlen != sizeof(int))
813                         goto e_inval;
814 
815                 ifindex = (__force int)ntohl((__force __be32)val);
816                 if (ifindex == 0) {
817                         inet->uc_index = 0;
818                         err = 0;
819                         break;
820                 }
821 
822                 dev = dev_get_by_index(sock_net(sk), ifindex);
823                 err = -EADDRNOTAVAIL;
824                 if (!dev)
825                         break;
826 
827                 midx = l3mdev_master_ifindex(dev);
828                 dev_put(dev);
829 
830                 err = -EINVAL;
831                 if (sk->sk_bound_dev_if &&
832                     (!midx || midx != sk->sk_bound_dev_if))
833                         break;
834 
835                 inet->uc_index = ifindex;
836                 err = 0;
837                 break;
838         }
839         case IP_MULTICAST_IF:
840         {
841                 struct ip_mreqn mreq;
842                 struct net_device *dev = NULL;
843                 int midx;
844 
845                 if (sk->sk_type == SOCK_STREAM)
846                         goto e_inval;
847                 /*
848                  *      Check the arguments are allowable
849                  */
850 
851                 if (optlen < sizeof(struct in_addr))
852                         goto e_inval;
853 
854                 err = -EFAULT;
855                 if (optlen >= sizeof(struct ip_mreqn)) {
856                         if (copy_from_user(&mreq, optval, sizeof(mreq)))
857                                 break;
858                 } else {
859                         memset(&mreq, 0, sizeof(mreq));
860                         if (optlen >= sizeof(struct ip_mreq)) {
861                                 if (copy_from_user(&mreq, optval,
862                                                    sizeof(struct ip_mreq)))
863                                         break;
864                         } else if (optlen >= sizeof(struct in_addr)) {
865                                 if (copy_from_user(&mreq.imr_address, optval,
866                                                    sizeof(struct in_addr)))
867                                         break;
868                         }
869                 }
870 
871                 if (!mreq.imr_ifindex) {
872                         if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
873                                 inet->mc_index = 0;
874                                 inet->mc_addr  = 0;
875                                 err = 0;
876                                 break;
877                         }
878                         dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
879                         if (dev)
880                                 mreq.imr_ifindex = dev->ifindex;
881                 } else
882                         dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
883 
884 
885                 err = -EADDRNOTAVAIL;
886                 if (!dev)
887                         break;
888 
889                 midx = l3mdev_master_ifindex(dev);
890 
891                 dev_put(dev);
892 
893                 err = -EINVAL;
894                 if (sk->sk_bound_dev_if &&
895                     mreq.imr_ifindex != sk->sk_bound_dev_if &&
896                     (!midx || midx != sk->sk_bound_dev_if))
897                         break;
898 
899                 inet->mc_index = mreq.imr_ifindex;
900                 inet->mc_addr  = mreq.imr_address.s_addr;
901                 err = 0;
902                 break;
903         }
904 
905         case IP_ADD_MEMBERSHIP:
906         case IP_DROP_MEMBERSHIP:
907         {
908                 struct ip_mreqn mreq;
909 
910                 err = -EPROTO;
911                 if (inet_sk(sk)->is_icsk)
912                         break;
913 
914                 if (optlen < sizeof(struct ip_mreq))
915                         goto e_inval;
916                 err = -EFAULT;
917                 if (optlen >= sizeof(struct ip_mreqn)) {
918                         if (copy_from_user(&mreq, optval, sizeof(mreq)))
919                                 break;
920                 } else {
921                         memset(&mreq, 0, sizeof(mreq));
922                         if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
923                                 break;
924                 }
925 
926                 if (optname == IP_ADD_MEMBERSHIP)
927                         err = ip_mc_join_group(sk, &mreq);
928                 else
929                         err = ip_mc_leave_group(sk, &mreq);
930                 break;
931         }
932         case IP_MSFILTER:
933         {
934                 struct ip_msfilter *msf;
935 
936                 if (optlen < IP_MSFILTER_SIZE(0))
937                         goto e_inval;
938                 if (optlen > sysctl_optmem_max) {
939                         err = -ENOBUFS;
940                         break;
941                 }
942                 msf = memdup_user(optval, optlen);
943                 if (IS_ERR(msf)) {
944                         err = PTR_ERR(msf);
945                         break;
946                 }
947                 /* numsrc >= (1G-4) overflow in 32 bits */
948                 if (msf->imsf_numsrc >= 0x3ffffffcU ||
949                     msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
950                         kfree(msf);
951                         err = -ENOBUFS;
952                         break;
953                 }
954                 if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
955                         kfree(msf);
956                         err = -EINVAL;
957                         break;
958                 }
959                 err = ip_mc_msfilter(sk, msf, 0);
960                 kfree(msf);
961                 break;
962         }
963         case IP_BLOCK_SOURCE:
964         case IP_UNBLOCK_SOURCE:
965         case IP_ADD_SOURCE_MEMBERSHIP:
966         case IP_DROP_SOURCE_MEMBERSHIP:
967         {
968                 struct ip_mreq_source mreqs;
969                 int omode, add;
970 
971                 if (optlen != sizeof(struct ip_mreq_source))
972                         goto e_inval;
973                 if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
974                         err = -EFAULT;
975                         break;
976                 }
977                 if (optname == IP_BLOCK_SOURCE) {
978                         omode = MCAST_EXCLUDE;
979                         add = 1;
980                 } else if (optname == IP_UNBLOCK_SOURCE) {
981                         omode = MCAST_EXCLUDE;
982                         add = 0;
983                 } else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
984                         struct ip_mreqn mreq;
985 
986                         mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
987                         mreq.imr_address.s_addr = mreqs.imr_interface;
988                         mreq.imr_ifindex = 0;
989                         err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
990                         if (err && err != -EADDRINUSE)
991                                 break;
992                         omode = MCAST_INCLUDE;
993                         add = 1;
994                 } else /* IP_DROP_SOURCE_MEMBERSHIP */ {
995                         omode = MCAST_INCLUDE;
996                         add = 0;
997                 }
998                 err = ip_mc_source(add, omode, sk, &mreqs, 0);
999                 break;
1000         }
1001         case MCAST_JOIN_GROUP:
1002         case MCAST_LEAVE_GROUP:
1003         {
1004                 struct group_req greq;
1005                 struct sockaddr_in *psin;
1006                 struct ip_mreqn mreq;
1007 
1008                 if (optlen < sizeof(struct group_req))
1009                         goto e_inval;
1010                 err = -EFAULT;
1011                 if (copy_from_user(&greq, optval, sizeof(greq)))
1012                         break;
1013                 psin = (struct sockaddr_in *)&greq.gr_group;
1014                 if (psin->sin_family != AF_INET)
1015                         goto e_inval;
1016                 memset(&mreq, 0, sizeof(mreq));
1017                 mreq.imr_multiaddr = psin->sin_addr;
1018                 mreq.imr_ifindex = greq.gr_interface;
1019 
1020                 if (optname == MCAST_JOIN_GROUP)
1021                         err = ip_mc_join_group(sk, &mreq);
1022                 else
1023                         err = ip_mc_leave_group(sk, &mreq);
1024                 break;
1025         }
1026         case MCAST_JOIN_SOURCE_GROUP:
1027         case MCAST_LEAVE_SOURCE_GROUP:
1028         case MCAST_BLOCK_SOURCE:
1029         case MCAST_UNBLOCK_SOURCE:
1030         {
1031                 struct group_source_req greqs;
1032                 struct ip_mreq_source mreqs;
1033                 struct sockaddr_in *psin;
1034                 int omode, add;
1035 
1036                 if (optlen != sizeof(struct group_source_req))
1037                         goto e_inval;
1038                 if (copy_from_user(&greqs, optval, sizeof(greqs))) {
1039                         err = -EFAULT;
1040                         break;
1041                 }
1042                 if (greqs.gsr_group.ss_family != AF_INET ||
1043                     greqs.gsr_source.ss_family != AF_INET) {
1044                         err = -EADDRNOTAVAIL;
1045                         break;
1046                 }
1047                 psin = (struct sockaddr_in *)&greqs.gsr_group;
1048                 mreqs.imr_multiaddr = psin->sin_addr.s_addr;
1049                 psin = (struct sockaddr_in *)&greqs.gsr_source;
1050                 mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
1051                 mreqs.imr_interface = 0; /* use index for mc_source */
1052 
1053                 if (optname == MCAST_BLOCK_SOURCE) {
1054                         omode = MCAST_EXCLUDE;
1055                         add = 1;
1056                 } else if (optname == MCAST_UNBLOCK_SOURCE) {
1057                         omode = MCAST_EXCLUDE;
1058                         add = 0;
1059                 } else if (optname == MCAST_JOIN_SOURCE_GROUP) {
1060                         struct ip_mreqn mreq;
1061 
1062                         psin = (struct sockaddr_in *)&greqs.gsr_group;
1063                         mreq.imr_multiaddr = psin->sin_addr;
1064                         mreq.imr_address.s_addr = 0;
1065                         mreq.imr_ifindex = greqs.gsr_interface;
1066                         err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
1067                         if (err && err != -EADDRINUSE)
1068                                 break;
1069                         greqs.gsr_interface = mreq.imr_ifindex;
1070                         omode = MCAST_INCLUDE;
1071                         add = 1;
1072                 } else /* MCAST_LEAVE_SOURCE_GROUP */ {
1073                         omode = MCAST_INCLUDE;
1074                         add = 0;
1075                 }
1076                 err = ip_mc_source(add, omode, sk, &mreqs,
1077                                    greqs.gsr_interface);
1078                 break;
1079         }
1080         case MCAST_MSFILTER:
1081         {
1082                 struct sockaddr_in *psin;
1083                 struct ip_msfilter *msf = NULL;
1084                 struct group_filter *gsf = NULL;
1085                 int msize, i, ifindex;
1086 
1087                 if (optlen < GROUP_FILTER_SIZE(0))
1088                         goto e_inval;
1089                 if (optlen > sysctl_optmem_max) {
1090                         err = -ENOBUFS;
1091                         break;
1092                 }
1093                 gsf = memdup_user(optval, optlen);
1094                 if (IS_ERR(gsf)) {
1095                         err = PTR_ERR(gsf);
1096                         break;
1097                 }
1098 
1099                 /* numsrc >= (4G-140)/128 overflow in 32 bits */
1100                 if (gsf->gf_numsrc >= 0x1ffffff ||
1101                     gsf->gf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1102                         err = -ENOBUFS;
1103                         goto mc_msf_out;
1104                 }
1105                 if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1106                         err = -EINVAL;
1107                         goto mc_msf_out;
1108                 }
1109                 msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
1110                 msf = kmalloc(msize, GFP_KERNEL);
1111                 if (!msf) {
1112                         err = -ENOBUFS;
1113                         goto mc_msf_out;
1114                 }
1115                 ifindex = gsf->gf_interface;
1116                 psin = (struct sockaddr_in *)&gsf->gf_group;
1117                 if (psin->sin_family != AF_INET) {
1118                         err = -EADDRNOTAVAIL;
1119                         goto mc_msf_out;
1120                 }
1121                 msf->imsf_multiaddr = psin->sin_addr.s_addr;
1122                 msf->imsf_interface = 0;
1123                 msf->imsf_fmode = gsf->gf_fmode;
1124                 msf->imsf_numsrc = gsf->gf_numsrc;
1125                 err = -EADDRNOTAVAIL;
1126                 for (i = 0; i < gsf->gf_numsrc; ++i) {
1127                         psin = (struct sockaddr_in *)&gsf->gf_slist[i];
1128 
1129                         if (psin->sin_family != AF_INET)
1130                                 goto mc_msf_out;
1131                         msf->imsf_slist[i] = psin->sin_addr.s_addr;
1132                 }
1133                 kfree(gsf);
1134                 gsf = NULL;
1135 
1136                 err = ip_mc_msfilter(sk, msf, ifindex);
1137 mc_msf_out:
1138                 kfree(msf);
1139                 kfree(gsf);
1140                 break;
1141         }
1142         case IP_MULTICAST_ALL:
1143                 if (optlen < 1)
1144                         goto e_inval;
1145                 if (val != 0 && val != 1)
1146                         goto e_inval;
1147                 inet->mc_all = val;
1148                 break;
1149 
1150         case IP_FREEBIND:
1151                 if (optlen < 1)
1152                         goto e_inval;
1153                 inet->freebind = !!val;
1154                 break;
1155 
1156         case IP_IPSEC_POLICY:
1157         case IP_XFRM_POLICY:
1158                 err = -EPERM;
1159                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1160                         break;
1161                 err = xfrm_user_policy(sk, optname, optval, optlen);
1162                 break;
1163 
1164         case IP_TRANSPARENT:
1165                 if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1166                     !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1167                         err = -EPERM;
1168                         break;
1169                 }
1170                 if (optlen < 1)
1171                         goto e_inval;
1172                 inet->transparent = !!val;
1173                 break;
1174 
1175         case IP_MINTTL:
1176                 if (optlen < 1)
1177                         goto e_inval;
1178                 if (val < 0 || val > 255)
1179                         goto e_inval;
1180                 inet->min_ttl = val;
1181                 break;
1182 
1183         default:
1184                 err = -ENOPROTOOPT;
1185                 break;
1186         }
1187         release_sock(sk);
1188         if (needs_rtnl)
1189                 rtnl_unlock();
1190         return err;
1191 
1192 e_inval:
1193         release_sock(sk);
1194         if (needs_rtnl)
1195                 rtnl_unlock();
1196         return -EINVAL;
1197 }
1198 
1199 /**
1200  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1201  * @sk: socket
1202  * @skb: buffer
1203  *
1204  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1205  * destination in skb->cb[] before dst drop.
1206  * This way, receiver doesn't make cache line misses to read rtable.
1207  */
1208 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1209 {
1210         struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1211         bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1212                        ipv6_sk_rxinfo(sk);
1213 
1214         if (prepare && skb_rtable(skb)) {
1215                 /* skb->cb is overloaded: prior to this point it is IP{6}CB
1216                  * which has interface index (iif) as the first member of the
1217                  * underlying inet{6}_skb_parm struct. This code then overlays
1218                  * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1219                  * element so the iif is picked up from the prior IPCB. If iif
1220                  * is the loopback interface, then return the sending interface
1221                  * (e.g., process binds socket to eth0 for Tx which is
1222                  * redirected to loopback in the rtable/dst).
1223                  */
1224                 struct rtable *rt = skb_rtable(skb);
1225                 bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1226 
1227                 if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1228                         pktinfo->ipi_ifindex = inet_iif(skb);
1229                 else if (l3slave && rt && rt->rt_iif)
1230                         pktinfo->ipi_ifindex = rt->rt_iif;
1231 
1232                 pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1233         } else {
1234                 pktinfo->ipi_ifindex = 0;
1235                 pktinfo->ipi_spec_dst.s_addr = 0;
1236         }
1237         skb_dst_drop(skb);
1238 }
1239 
1240 int ip_setsockopt(struct sock *sk, int level,
1241                 int optname, char __user *optval, unsigned int optlen)
1242 {
1243         int err;
1244 
1245         if (level != SOL_IP)
1246                 return -ENOPROTOOPT;
1247 
1248         err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1249 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1250         if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
1251             optname < BPFILTER_IPT_SET_MAX)
1252                 err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen);
1253 #endif
1254 #ifdef CONFIG_NETFILTER
1255         /* we need to exclude all possible ENOPROTOOPTs except default case */
1256         if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1257                         optname != IP_IPSEC_POLICY &&
1258                         optname != IP_XFRM_POLICY &&
1259                         !ip_mroute_opt(optname))
1260                 err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1261 #endif
1262         return err;
1263 }
1264 EXPORT_SYMBOL(ip_setsockopt);
1265 
1266 #ifdef CONFIG_COMPAT
1267 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1268                          char __user *optval, unsigned int optlen)
1269 {
1270         int err;
1271 
1272         if (level != SOL_IP)
1273                 return -ENOPROTOOPT;
1274 
1275         if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1276                 return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1277                         ip_setsockopt);
1278 
1279         err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1280 #ifdef CONFIG_NETFILTER
1281         /* we need to exclude all possible ENOPROTOOPTs except default case */
1282         if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1283                         optname != IP_IPSEC_POLICY &&
1284                         optname != IP_XFRM_POLICY &&
1285                         !ip_mroute_opt(optname))
1286                 err = compat_nf_setsockopt(sk, PF_INET, optname, optval,
1287                                            optlen);
1288 #endif
1289         return err;
1290 }
1291 EXPORT_SYMBOL(compat_ip_setsockopt);
1292 #endif
1293 
1294 /*
1295  *      Get the options. Note for future reference. The GET of IP options gets
1296  *      the _received_ ones. The set sets the _sent_ ones.
1297  */
1298 
1299 static bool getsockopt_needs_rtnl(int optname)
1300 {
1301         switch (optname) {
1302         case IP_MSFILTER:
1303         case MCAST_MSFILTER:
1304                 return true;
1305         }
1306         return false;
1307 }
1308 
1309 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1310                             char __user *optval, int __user *optlen, unsigned int flags)
1311 {
1312         struct inet_sock *inet = inet_sk(sk);
1313         bool needs_rtnl = getsockopt_needs_rtnl(optname);
1314         int val, err = 0;
1315         int len;
1316 
1317         if (level != SOL_IP)
1318                 return -EOPNOTSUPP;
1319 
1320         if (ip_mroute_opt(optname))
1321                 return ip_mroute_getsockopt(sk, optname, optval, optlen);
1322 
1323         if (get_user(len, optlen))
1324                 return -EFAULT;
1325         if (len < 0)
1326                 return -EINVAL;
1327 
1328         if (needs_rtnl)
1329                 rtnl_lock();
1330         lock_sock(sk);
1331 
1332         switch (optname) {
1333         case IP_OPTIONS:
1334         {
1335                 unsigned char optbuf[sizeof(struct ip_options)+40];
1336                 struct ip_options *opt = (struct ip_options *)optbuf;
1337                 struct ip_options_rcu *inet_opt;
1338 
1339                 inet_opt = rcu_dereference_protected(inet->inet_opt,
1340                                                      lockdep_sock_is_held(sk));
1341                 opt->optlen = 0;
1342                 if (inet_opt)
1343                         memcpy(optbuf, &inet_opt->opt,
1344                                sizeof(struct ip_options) +
1345                                inet_opt->opt.optlen);
1346                 release_sock(sk);
1347 
1348                 if (opt->optlen == 0)
1349                         return put_user(0, optlen);
1350 
1351                 ip_options_undo(opt);
1352 
1353                 len = min_t(unsigned int, len, opt->optlen);
1354                 if (put_user(len, optlen))
1355                         return -EFAULT;
1356                 if (copy_to_user(optval, opt->__data, len))
1357                         return -EFAULT;
1358                 return 0;
1359         }
1360         case IP_PKTINFO:
1361                 val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1362                 break;
1363         case IP_RECVTTL:
1364                 val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1365                 break;
1366         case IP_RECVTOS:
1367                 val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1368                 break;
1369         case IP_RECVOPTS:
1370                 val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1371                 break;
1372         case IP_RETOPTS:
1373                 val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1374                 break;
1375         case IP_PASSSEC:
1376                 val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1377                 break;
1378         case IP_RECVORIGDSTADDR:
1379                 val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1380                 break;
1381         case IP_CHECKSUM:
1382                 val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1383                 break;
1384         case IP_RECVFRAGSIZE:
1385                 val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1386                 break;
1387         case IP_TOS:
1388                 val = inet->tos;
1389                 break;
1390         case IP_TTL:
1391         {
1392                 struct net *net = sock_net(sk);
1393                 val = (inet->uc_ttl == -1 ?
1394                        net->ipv4.sysctl_ip_default_ttl :
1395                        inet->uc_ttl);
1396                 break;
1397         }
1398         case IP_HDRINCL:
1399                 val = inet->hdrincl;
1400                 break;
1401         case IP_NODEFRAG:
1402                 val = inet->nodefrag;
1403                 break;
1404         case IP_BIND_ADDRESS_NO_PORT:
1405                 val = inet->bind_address_no_port;
1406                 break;
1407         case IP_MTU_DISCOVER:
1408                 val = inet->pmtudisc;
1409                 break;
1410         case IP_MTU:
1411         {
1412                 struct dst_entry *dst;
1413                 val = 0;
1414                 dst = sk_dst_get(sk);
1415                 if (dst) {
1416                         val = dst_mtu(dst);
1417                         dst_release(dst);
1418                 }
1419                 if (!val) {
1420                         release_sock(sk);
1421                         return -ENOTCONN;
1422                 }
1423                 break;
1424         }
1425         case IP_RECVERR:
1426                 val = inet->recverr;
1427                 break;
1428         case IP_MULTICAST_TTL:
1429                 val = inet->mc_ttl;
1430                 break;
1431         case IP_MULTICAST_LOOP:
1432                 val = inet->mc_loop;
1433                 break;
1434         case IP_UNICAST_IF:
1435                 val = (__force int)htonl((__u32) inet->uc_index);
1436                 break;
1437         case IP_MULTICAST_IF:
1438         {
1439                 struct in_addr addr;
1440                 len = min_t(unsigned int, len, sizeof(struct in_addr));
1441                 addr.s_addr = inet->mc_addr;
1442                 release_sock(sk);
1443 
1444                 if (put_user(len, optlen))
1445                         return -EFAULT;
1446                 if (copy_to_user(optval, &addr, len))
1447                         return -EFAULT;
1448                 return 0;
1449         }
1450         case IP_MSFILTER:
1451         {
1452                 struct ip_msfilter msf;
1453 
1454                 if (len < IP_MSFILTER_SIZE(0)) {
1455                         err = -EINVAL;
1456                         goto out;
1457                 }
1458                 if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1459                         err = -EFAULT;
1460                         goto out;
1461                 }
1462                 err = ip_mc_msfget(sk, &msf,
1463                                    (struct ip_msfilter __user *)optval, optlen);
1464                 goto out;
1465         }
1466         case MCAST_MSFILTER:
1467         {
1468                 struct group_filter gsf;
1469 
1470                 if (len < GROUP_FILTER_SIZE(0)) {
1471                         err = -EINVAL;
1472                         goto out;
1473                 }
1474                 if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1475                         err = -EFAULT;
1476                         goto out;
1477                 }
1478                 err = ip_mc_gsfget(sk, &gsf,
1479                                    (struct group_filter __user *)optval,
1480                                    optlen);
1481                 goto out;
1482         }
1483         case IP_MULTICAST_ALL:
1484                 val = inet->mc_all;
1485                 break;
1486         case IP_PKTOPTIONS:
1487         {
1488                 struct msghdr msg;
1489 
1490                 release_sock(sk);
1491 
1492                 if (sk->sk_type != SOCK_STREAM)
1493                         return -ENOPROTOOPT;
1494 
1495                 msg.msg_control = (__force void *) optval;
1496                 msg.msg_controllen = len;
1497                 msg.msg_flags = flags;
1498 
1499                 if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1500                         struct in_pktinfo info;
1501 
1502                         info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1503                         info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1504                         info.ipi_ifindex = inet->mc_index;
1505                         put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1506                 }
1507                 if (inet->cmsg_flags & IP_CMSG_TTL) {
1508                         int hlim = inet->mc_ttl;
1509                         put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1510                 }
1511                 if (inet->cmsg_flags & IP_CMSG_TOS) {
1512                         int tos = inet->rcv_tos;
1513                         put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1514                 }
1515                 len -= msg.msg_controllen;
1516                 return put_user(len, optlen);
1517         }
1518         case IP_FREEBIND:
1519                 val = inet->freebind;
1520                 break;
1521         case IP_TRANSPARENT:
1522                 val = inet->transparent;
1523                 break;
1524         case IP_MINTTL:
1525                 val = inet->min_ttl;
1526                 break;
1527         default:
1528                 release_sock(sk);
1529                 return -ENOPROTOOPT;
1530         }
1531         release_sock(sk);
1532 
1533         if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1534                 unsigned char ucval = (unsigned char)val;
1535                 len = 1;
1536                 if (put_user(len, optlen))
1537                         return -EFAULT;
1538                 if (copy_to_user(optval, &ucval, 1))
1539                         return -EFAULT;
1540         } else {
1541                 len = min_t(unsigned int, sizeof(int), len);
1542                 if (put_user(len, optlen))
1543                         return -EFAULT;
1544                 if (copy_to_user(optval, &val, len))
1545                         return -EFAULT;
1546         }
1547         return 0;
1548 
1549 out:
1550         release_sock(sk);
1551         if (needs_rtnl)
1552                 rtnl_unlock();
1553         return err;
1554 }
1555 
1556 int ip_getsockopt(struct sock *sk, int level,
1557                   int optname, char __user *optval, int __user *optlen)
1558 {
1559         int err;
1560 
1561         err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1562 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1563         if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1564             optname < BPFILTER_IPT_GET_MAX)
1565                 err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1566 #endif
1567 #ifdef CONFIG_NETFILTER
1568         /* we need to exclude all possible ENOPROTOOPTs except default case */
1569         if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1570                         !ip_mroute_opt(optname)) {
1571                 int len;
1572 
1573                 if (get_user(len, optlen))
1574                         return -EFAULT;
1575 
1576                 err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
1577                 if (err >= 0)
1578                         err = put_user(len, optlen);
1579                 return err;
1580         }
1581 #endif
1582         return err;
1583 }
1584 EXPORT_SYMBOL(ip_getsockopt);
1585 
1586 #ifdef CONFIG_COMPAT
1587 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1588                          char __user *optval, int __user *optlen)
1589 {
1590         int err;
1591 
1592         if (optname == MCAST_MSFILTER)
1593                 return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1594                         ip_getsockopt);
1595 
1596         err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1597                 MSG_CMSG_COMPAT);
1598 
1599 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1600         if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1601             optname < BPFILTER_IPT_GET_MAX)
1602                 err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1603 #endif
1604 #ifdef CONFIG_NETFILTER
1605         /* we need to exclude all possible ENOPROTOOPTs except default case */
1606         if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1607                         !ip_mroute_opt(optname)) {
1608                 int len;
1609 
1610                 if (get_user(len, optlen))
1611                         return -EFAULT;
1612 
1613                 err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1614                 if (err >= 0)
1615                         err = put_user(len, optlen);
1616                 return err;
1617         }
1618 #endif
1619         return err;
1620 }
1621 EXPORT_SYMBOL(compat_ip_getsockopt);
1622 #endif
1623 

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