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
ip_cmsg_recv_pktinfo(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_ttl(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_tos(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_opts(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_retopts(struct net * net,struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_fragsize(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_checksum(struct msghdr * msg,struct sk_buff * skb,int tlen,int offset)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
ip_cmsg_recv_security(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_dstaddr(struct msghdr * msg,struct sk_buff * skb)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
ip_cmsg_recv_offset(struct msghdr * msg,struct sock * sk,struct sk_buff * skb,int tlen,int offset)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
ip_cmsg_send(struct sock * sk,struct msghdr * msg,struct ipcm_cookie * ipc,bool allow_ipv6)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,
284 KERNEL_SOCKPTR(CMSG_DATA(cmsg)),
285 err < 40 ? err : 40);
286 if (err)
287 return err;
288 break;
289 case IP_PKTINFO:
290 {
291 struct in_pktinfo *info;
292 if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
293 return -EINVAL;
294 info = (struct in_pktinfo *)CMSG_DATA(cmsg);
295 if (info->ipi_ifindex)
296 ipc->oif = info->ipi_ifindex;
297 ipc->addr = info->ipi_spec_dst.s_addr;
298 break;
299 }
300 case IP_TTL:
301 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
302 return -EINVAL;
303 val = *(int *)CMSG_DATA(cmsg);
304 if (val < 1 || val > 255)
305 return -EINVAL;
306 ipc->ttl = val;
307 break;
308 case IP_TOS:
309 if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
310 val = *(int *)CMSG_DATA(cmsg);
311 else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
312 val = *(u8 *)CMSG_DATA(cmsg);
313 else
314 return -EINVAL;
315 if (val < 0 || val > 255)
316 return -EINVAL;
317 ipc->tos = val;
318 ipc->priority = rt_tos2priority(ipc->tos);
319 break;
320
321 default:
322 return -EINVAL;
323 }
324 }
325 return 0;
326 }
327
ip_ra_destroy_rcu(struct rcu_head * head)328 static void ip_ra_destroy_rcu(struct rcu_head *head)
329 {
330 struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
331
332 sock_put(ra->saved_sk);
333 kfree(ra);
334 }
335
ip_ra_control(struct sock * sk,unsigned char on,void (* destructor)(struct sock *))336 int ip_ra_control(struct sock *sk, unsigned char on,
337 void (*destructor)(struct sock *))
338 {
339 struct ip_ra_chain *ra, *new_ra;
340 struct ip_ra_chain __rcu **rap;
341 struct net *net = sock_net(sk);
342
343 if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
344 return -EINVAL;
345
346 new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
347 if (on && !new_ra)
348 return -ENOMEM;
349
350 mutex_lock(&net->ipv4.ra_mutex);
351 for (rap = &net->ipv4.ra_chain;
352 (ra = rcu_dereference_protected(*rap,
353 lockdep_is_held(&net->ipv4.ra_mutex))) != NULL;
354 rap = &ra->next) {
355 if (ra->sk == sk) {
356 if (on) {
357 mutex_unlock(&net->ipv4.ra_mutex);
358 kfree(new_ra);
359 return -EADDRINUSE;
360 }
361 /* dont let ip_call_ra_chain() use sk again */
362 ra->sk = NULL;
363 RCU_INIT_POINTER(*rap, ra->next);
364 mutex_unlock(&net->ipv4.ra_mutex);
365
366 if (ra->destructor)
367 ra->destructor(sk);
368 /*
369 * Delay sock_put(sk) and kfree(ra) after one rcu grace
370 * period. This guarantee ip_call_ra_chain() dont need
371 * to mess with socket refcounts.
372 */
373 ra->saved_sk = sk;
374 call_rcu(&ra->rcu, ip_ra_destroy_rcu);
375 return 0;
376 }
377 }
378 if (!new_ra) {
379 mutex_unlock(&net->ipv4.ra_mutex);
380 return -ENOBUFS;
381 }
382 new_ra->sk = sk;
383 new_ra->destructor = destructor;
384
385 RCU_INIT_POINTER(new_ra->next, ra);
386 rcu_assign_pointer(*rap, new_ra);
387 sock_hold(sk);
388 mutex_unlock(&net->ipv4.ra_mutex);
389
390 return 0;
391 }
392
ipv4_icmp_error_rfc4884(const struct sk_buff * skb,struct sock_ee_data_rfc4884 * out)393 static void ipv4_icmp_error_rfc4884(const struct sk_buff *skb,
394 struct sock_ee_data_rfc4884 *out)
395 {
396 switch (icmp_hdr(skb)->type) {
397 case ICMP_DEST_UNREACH:
398 case ICMP_TIME_EXCEEDED:
399 case ICMP_PARAMETERPROB:
400 ip_icmp_error_rfc4884(skb, out, sizeof(struct icmphdr),
401 icmp_hdr(skb)->un.reserved[1] * 4);
402 }
403 }
404
ip_icmp_error(struct sock * sk,struct sk_buff * skb,int err,__be16 port,u32 info,u8 * payload)405 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
406 __be16 port, u32 info, u8 *payload)
407 {
408 struct sock_exterr_skb *serr;
409
410 skb = skb_clone(skb, GFP_ATOMIC);
411 if (!skb)
412 return;
413
414 serr = SKB_EXT_ERR(skb);
415 serr->ee.ee_errno = err;
416 serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
417 serr->ee.ee_type = icmp_hdr(skb)->type;
418 serr->ee.ee_code = icmp_hdr(skb)->code;
419 serr->ee.ee_pad = 0;
420 serr->ee.ee_info = info;
421 serr->ee.ee_data = 0;
422 serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
423 skb_network_header(skb);
424 serr->port = port;
425
426 if (skb_pull(skb, payload - skb->data)) {
427 if (inet_sk(sk)->recverr_rfc4884)
428 ipv4_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
429
430 skb_reset_transport_header(skb);
431 if (sock_queue_err_skb(sk, skb) == 0)
432 return;
433 }
434 kfree_skb(skb);
435 }
436
ip_local_error(struct sock * sk,int err,__be32 daddr,__be16 port,u32 info)437 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
438 {
439 struct inet_sock *inet = inet_sk(sk);
440 struct sock_exterr_skb *serr;
441 struct iphdr *iph;
442 struct sk_buff *skb;
443
444 if (!inet->recverr)
445 return;
446
447 skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
448 if (!skb)
449 return;
450
451 skb_put(skb, sizeof(struct iphdr));
452 skb_reset_network_header(skb);
453 iph = ip_hdr(skb);
454 iph->daddr = daddr;
455
456 serr = SKB_EXT_ERR(skb);
457 serr->ee.ee_errno = err;
458 serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
459 serr->ee.ee_type = 0;
460 serr->ee.ee_code = 0;
461 serr->ee.ee_pad = 0;
462 serr->ee.ee_info = info;
463 serr->ee.ee_data = 0;
464 serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
465 serr->port = port;
466
467 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
468 skb_reset_transport_header(skb);
469
470 if (sock_queue_err_skb(sk, skb))
471 kfree_skb(skb);
472 }
473
474 /* For some errors we have valid addr_offset even with zero payload and
475 * zero port. Also, addr_offset should be supported if port is set.
476 */
ipv4_datagram_support_addr(struct sock_exterr_skb * serr)477 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
478 {
479 return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
480 serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
481 }
482
483 /* IPv4 supports cmsg on all imcp errors and some timestamps
484 *
485 * Timestamp code paths do not initialize the fields expected by cmsg:
486 * the PKTINFO fields in skb->cb[]. Fill those in here.
487 */
ipv4_datagram_support_cmsg(const struct sock * sk,struct sk_buff * skb,int ee_origin)488 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
489 struct sk_buff *skb,
490 int ee_origin)
491 {
492 struct in_pktinfo *info;
493
494 if (ee_origin == SO_EE_ORIGIN_ICMP)
495 return true;
496
497 if (ee_origin == SO_EE_ORIGIN_LOCAL)
498 return false;
499
500 /* Support IP_PKTINFO on tstamp packets if requested, to correlate
501 * timestamp with egress dev. Not possible for packets without iif
502 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
503 */
504 info = PKTINFO_SKB_CB(skb);
505 if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
506 !info->ipi_ifindex)
507 return false;
508
509 info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
510 return true;
511 }
512
513 /*
514 * Handle MSG_ERRQUEUE
515 */
ip_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)516 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
517 {
518 struct sock_exterr_skb *serr;
519 struct sk_buff *skb;
520 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
521 struct {
522 struct sock_extended_err ee;
523 struct sockaddr_in offender;
524 } errhdr;
525 int err;
526 int copied;
527
528 err = -EAGAIN;
529 skb = sock_dequeue_err_skb(sk);
530 if (!skb)
531 goto out;
532
533 copied = skb->len;
534 if (copied > len) {
535 msg->msg_flags |= MSG_TRUNC;
536 copied = len;
537 }
538 err = skb_copy_datagram_msg(skb, 0, msg, copied);
539 if (unlikely(err)) {
540 kfree_skb(skb);
541 return err;
542 }
543 sock_recv_timestamp(msg, sk, skb);
544
545 serr = SKB_EXT_ERR(skb);
546
547 if (sin && ipv4_datagram_support_addr(serr)) {
548 sin->sin_family = AF_INET;
549 sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
550 serr->addr_offset);
551 sin->sin_port = serr->port;
552 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
553 *addr_len = sizeof(*sin);
554 }
555
556 memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
557 sin = &errhdr.offender;
558 memset(sin, 0, sizeof(*sin));
559
560 if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
561 sin->sin_family = AF_INET;
562 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
563 if (inet_sk(sk)->cmsg_flags)
564 ip_cmsg_recv(msg, skb);
565 }
566
567 put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
568
569 /* Now we could try to dump offended packet options */
570
571 msg->msg_flags |= MSG_ERRQUEUE;
572 err = copied;
573
574 consume_skb(skb);
575 out:
576 return err;
577 }
578
__ip_sock_set_tos(struct sock * sk,int val)579 void __ip_sock_set_tos(struct sock *sk, int val)
580 {
581 if (sk->sk_type == SOCK_STREAM) {
582 val &= ~INET_ECN_MASK;
583 val |= inet_sk(sk)->tos & INET_ECN_MASK;
584 }
585 if (inet_sk(sk)->tos != val) {
586 inet_sk(sk)->tos = val;
587 sk->sk_priority = rt_tos2priority(val);
588 sk_dst_reset(sk);
589 }
590 }
591
ip_sock_set_tos(struct sock * sk,int val)592 void ip_sock_set_tos(struct sock *sk, int val)
593 {
594 lock_sock(sk);
595 __ip_sock_set_tos(sk, val);
596 release_sock(sk);
597 }
598 EXPORT_SYMBOL(ip_sock_set_tos);
599
ip_sock_set_freebind(struct sock * sk)600 void ip_sock_set_freebind(struct sock *sk)
601 {
602 lock_sock(sk);
603 inet_sk(sk)->freebind = true;
604 release_sock(sk);
605 }
606 EXPORT_SYMBOL(ip_sock_set_freebind);
607
ip_sock_set_recverr(struct sock * sk)608 void ip_sock_set_recverr(struct sock *sk)
609 {
610 lock_sock(sk);
611 inet_sk(sk)->recverr = true;
612 release_sock(sk);
613 }
614 EXPORT_SYMBOL(ip_sock_set_recverr);
615
ip_sock_set_mtu_discover(struct sock * sk,int val)616 int ip_sock_set_mtu_discover(struct sock *sk, int val)
617 {
618 if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
619 return -EINVAL;
620 lock_sock(sk);
621 inet_sk(sk)->pmtudisc = val;
622 release_sock(sk);
623 return 0;
624 }
625 EXPORT_SYMBOL(ip_sock_set_mtu_discover);
626
ip_sock_set_pktinfo(struct sock * sk)627 void ip_sock_set_pktinfo(struct sock *sk)
628 {
629 lock_sock(sk);
630 inet_sk(sk)->cmsg_flags |= IP_CMSG_PKTINFO;
631 release_sock(sk);
632 }
633 EXPORT_SYMBOL(ip_sock_set_pktinfo);
634
635 /*
636 * Socket option code for IP. This is the end of the line after any
637 * TCP,UDP etc options on an IP socket.
638 */
setsockopt_needs_rtnl(int optname)639 static bool setsockopt_needs_rtnl(int optname)
640 {
641 switch (optname) {
642 case IP_ADD_MEMBERSHIP:
643 case IP_ADD_SOURCE_MEMBERSHIP:
644 case IP_BLOCK_SOURCE:
645 case IP_DROP_MEMBERSHIP:
646 case IP_DROP_SOURCE_MEMBERSHIP:
647 case IP_MSFILTER:
648 case IP_UNBLOCK_SOURCE:
649 case MCAST_BLOCK_SOURCE:
650 case MCAST_MSFILTER:
651 case MCAST_JOIN_GROUP:
652 case MCAST_JOIN_SOURCE_GROUP:
653 case MCAST_LEAVE_GROUP:
654 case MCAST_LEAVE_SOURCE_GROUP:
655 case MCAST_UNBLOCK_SOURCE:
656 return true;
657 }
658 return false;
659 }
660
set_mcast_msfilter(struct sock * sk,int ifindex,int numsrc,int fmode,struct sockaddr_storage * group,struct sockaddr_storage * list)661 static int set_mcast_msfilter(struct sock *sk, int ifindex,
662 int numsrc, int fmode,
663 struct sockaddr_storage *group,
664 struct sockaddr_storage *list)
665 {
666 struct ip_msfilter *msf;
667 struct sockaddr_in *psin;
668 int err, i;
669
670 msf = kmalloc(IP_MSFILTER_SIZE(numsrc), GFP_KERNEL);
671 if (!msf)
672 return -ENOBUFS;
673
674 psin = (struct sockaddr_in *)group;
675 if (psin->sin_family != AF_INET)
676 goto Eaddrnotavail;
677 msf->imsf_multiaddr = psin->sin_addr.s_addr;
678 msf->imsf_interface = 0;
679 msf->imsf_fmode = fmode;
680 msf->imsf_numsrc = numsrc;
681 for (i = 0; i < numsrc; ++i) {
682 psin = (struct sockaddr_in *)&list[i];
683
684 if (psin->sin_family != AF_INET)
685 goto Eaddrnotavail;
686 msf->imsf_slist_flex[i] = psin->sin_addr.s_addr;
687 }
688 err = ip_mc_msfilter(sk, msf, ifindex);
689 kfree(msf);
690 return err;
691
692 Eaddrnotavail:
693 kfree(msf);
694 return -EADDRNOTAVAIL;
695 }
696
copy_group_source_from_sockptr(struct group_source_req * greqs,sockptr_t optval,int optlen)697 static int copy_group_source_from_sockptr(struct group_source_req *greqs,
698 sockptr_t optval, int optlen)
699 {
700 if (in_compat_syscall()) {
701 struct compat_group_source_req gr32;
702
703 if (optlen != sizeof(gr32))
704 return -EINVAL;
705 if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
706 return -EFAULT;
707 greqs->gsr_interface = gr32.gsr_interface;
708 greqs->gsr_group = gr32.gsr_group;
709 greqs->gsr_source = gr32.gsr_source;
710 } else {
711 if (optlen != sizeof(*greqs))
712 return -EINVAL;
713 if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))
714 return -EFAULT;
715 }
716
717 return 0;
718 }
719
do_mcast_group_source(struct sock * sk,int optname,sockptr_t optval,int optlen)720 static int do_mcast_group_source(struct sock *sk, int optname,
721 sockptr_t optval, int optlen)
722 {
723 struct group_source_req greqs;
724 struct ip_mreq_source mreqs;
725 struct sockaddr_in *psin;
726 int omode, add, err;
727
728 err = copy_group_source_from_sockptr(&greqs, optval, optlen);
729 if (err)
730 return err;
731
732 if (greqs.gsr_group.ss_family != AF_INET ||
733 greqs.gsr_source.ss_family != AF_INET)
734 return -EADDRNOTAVAIL;
735
736 psin = (struct sockaddr_in *)&greqs.gsr_group;
737 mreqs.imr_multiaddr = psin->sin_addr.s_addr;
738 psin = (struct sockaddr_in *)&greqs.gsr_source;
739 mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
740 mreqs.imr_interface = 0; /* use index for mc_source */
741
742 if (optname == MCAST_BLOCK_SOURCE) {
743 omode = MCAST_EXCLUDE;
744 add = 1;
745 } else if (optname == MCAST_UNBLOCK_SOURCE) {
746 omode = MCAST_EXCLUDE;
747 add = 0;
748 } else if (optname == MCAST_JOIN_SOURCE_GROUP) {
749 struct ip_mreqn mreq;
750
751 psin = (struct sockaddr_in *)&greqs.gsr_group;
752 mreq.imr_multiaddr = psin->sin_addr;
753 mreq.imr_address.s_addr = 0;
754 mreq.imr_ifindex = greqs.gsr_interface;
755 err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
756 if (err && err != -EADDRINUSE)
757 return err;
758 greqs.gsr_interface = mreq.imr_ifindex;
759 omode = MCAST_INCLUDE;
760 add = 1;
761 } else /* MCAST_LEAVE_SOURCE_GROUP */ {
762 omode = MCAST_INCLUDE;
763 add = 0;
764 }
765 return ip_mc_source(add, omode, sk, &mreqs, greqs.gsr_interface);
766 }
767
ip_set_mcast_msfilter(struct sock * sk,sockptr_t optval,int optlen)768 static int ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval, int optlen)
769 {
770 struct group_filter *gsf = NULL;
771 int err;
772
773 if (optlen < GROUP_FILTER_SIZE(0))
774 return -EINVAL;
775 if (optlen > READ_ONCE(sysctl_optmem_max))
776 return -ENOBUFS;
777
778 gsf = memdup_sockptr(optval, optlen);
779 if (IS_ERR(gsf))
780 return PTR_ERR(gsf);
781
782 /* numsrc >= (4G-140)/128 overflow in 32 bits */
783 err = -ENOBUFS;
784 if (gsf->gf_numsrc >= 0x1ffffff ||
785 gsf->gf_numsrc > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf))
786 goto out_free_gsf;
787
788 err = -EINVAL;
789 if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
790 goto out_free_gsf;
791
792 err = set_mcast_msfilter(sk, gsf->gf_interface, gsf->gf_numsrc,
793 gsf->gf_fmode, &gsf->gf_group,
794 gsf->gf_slist_flex);
795 out_free_gsf:
796 kfree(gsf);
797 return err;
798 }
799
compat_ip_set_mcast_msfilter(struct sock * sk,sockptr_t optval,int optlen)800 static int compat_ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
801 int optlen)
802 {
803 const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
804 struct compat_group_filter *gf32;
805 unsigned int n;
806 void *p;
807 int err;
808
809 if (optlen < size0)
810 return -EINVAL;
811 if (optlen > READ_ONCE(sysctl_optmem_max) - 4)
812 return -ENOBUFS;
813
814 p = kmalloc(optlen + 4, GFP_KERNEL);
815 if (!p)
816 return -ENOMEM;
817 gf32 = p + 4; /* we want ->gf_group and ->gf_slist_flex aligned */
818
819 err = -EFAULT;
820 if (copy_from_sockptr(gf32, optval, optlen))
821 goto out_free_gsf;
822
823 /* numsrc >= (4G-140)/128 overflow in 32 bits */
824 n = gf32->gf_numsrc;
825 err = -ENOBUFS;
826 if (n >= 0x1ffffff)
827 goto out_free_gsf;
828
829 err = -EINVAL;
830 if (offsetof(struct compat_group_filter, gf_slist_flex[n]) > optlen)
831 goto out_free_gsf;
832
833 /* numsrc >= (4G-140)/128 overflow in 32 bits */
834 err = -ENOBUFS;
835 if (n > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf))
836 goto out_free_gsf;
837 err = set_mcast_msfilter(sk, gf32->gf_interface, n, gf32->gf_fmode,
838 &gf32->gf_group, gf32->gf_slist_flex);
839 out_free_gsf:
840 kfree(p);
841 return err;
842 }
843
ip_mcast_join_leave(struct sock * sk,int optname,sockptr_t optval,int optlen)844 static int ip_mcast_join_leave(struct sock *sk, int optname,
845 sockptr_t optval, int optlen)
846 {
847 struct ip_mreqn mreq = { };
848 struct sockaddr_in *psin;
849 struct group_req greq;
850
851 if (optlen < sizeof(struct group_req))
852 return -EINVAL;
853 if (copy_from_sockptr(&greq, optval, sizeof(greq)))
854 return -EFAULT;
855
856 psin = (struct sockaddr_in *)&greq.gr_group;
857 if (psin->sin_family != AF_INET)
858 return -EINVAL;
859 mreq.imr_multiaddr = psin->sin_addr;
860 mreq.imr_ifindex = greq.gr_interface;
861 if (optname == MCAST_JOIN_GROUP)
862 return ip_mc_join_group(sk, &mreq);
863 return ip_mc_leave_group(sk, &mreq);
864 }
865
compat_ip_mcast_join_leave(struct sock * sk,int optname,sockptr_t optval,int optlen)866 static int compat_ip_mcast_join_leave(struct sock *sk, int optname,
867 sockptr_t optval, int optlen)
868 {
869 struct compat_group_req greq;
870 struct ip_mreqn mreq = { };
871 struct sockaddr_in *psin;
872
873 if (optlen < sizeof(struct compat_group_req))
874 return -EINVAL;
875 if (copy_from_sockptr(&greq, optval, sizeof(greq)))
876 return -EFAULT;
877
878 psin = (struct sockaddr_in *)&greq.gr_group;
879 if (psin->sin_family != AF_INET)
880 return -EINVAL;
881 mreq.imr_multiaddr = psin->sin_addr;
882 mreq.imr_ifindex = greq.gr_interface;
883
884 if (optname == MCAST_JOIN_GROUP)
885 return ip_mc_join_group(sk, &mreq);
886 return ip_mc_leave_group(sk, &mreq);
887 }
888
889 DEFINE_STATIC_KEY_FALSE(ip4_min_ttl);
890
do_ip_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)891 int do_ip_setsockopt(struct sock *sk, int level, int optname,
892 sockptr_t optval, unsigned int optlen)
893 {
894 struct inet_sock *inet = inet_sk(sk);
895 struct net *net = sock_net(sk);
896 int val = 0, err;
897 bool needs_rtnl = setsockopt_needs_rtnl(optname);
898
899 switch (optname) {
900 case IP_PKTINFO:
901 case IP_RECVTTL:
902 case IP_RECVOPTS:
903 case IP_RECVTOS:
904 case IP_RETOPTS:
905 case IP_TOS:
906 case IP_TTL:
907 case IP_HDRINCL:
908 case IP_MTU_DISCOVER:
909 case IP_RECVERR:
910 case IP_ROUTER_ALERT:
911 case IP_FREEBIND:
912 case IP_PASSSEC:
913 case IP_TRANSPARENT:
914 case IP_MINTTL:
915 case IP_NODEFRAG:
916 case IP_BIND_ADDRESS_NO_PORT:
917 case IP_UNICAST_IF:
918 case IP_MULTICAST_TTL:
919 case IP_MULTICAST_ALL:
920 case IP_MULTICAST_LOOP:
921 case IP_RECVORIGDSTADDR:
922 case IP_CHECKSUM:
923 case IP_RECVFRAGSIZE:
924 case IP_RECVERR_RFC4884:
925 if (optlen >= sizeof(int)) {
926 if (copy_from_sockptr(&val, optval, sizeof(val)))
927 return -EFAULT;
928 } else if (optlen >= sizeof(char)) {
929 unsigned char ucval;
930
931 if (copy_from_sockptr(&ucval, optval, sizeof(ucval)))
932 return -EFAULT;
933 val = (int) ucval;
934 }
935 }
936
937 /* If optlen==0, it is equivalent to val == 0 */
938
939 if (optname == IP_ROUTER_ALERT)
940 return ip_ra_control(sk, val ? 1 : 0, NULL);
941 if (ip_mroute_opt(optname))
942 return ip_mroute_setsockopt(sk, optname, optval, optlen);
943
944 err = 0;
945 if (needs_rtnl)
946 rtnl_lock();
947 sockopt_lock_sock(sk);
948
949 switch (optname) {
950 case IP_OPTIONS:
951 {
952 struct ip_options_rcu *old, *opt = NULL;
953
954 if (optlen > 40)
955 goto e_inval;
956 err = ip_options_get(sock_net(sk), &opt, optval, optlen);
957 if (err)
958 break;
959 old = rcu_dereference_protected(inet->inet_opt,
960 lockdep_sock_is_held(sk));
961 if (inet->is_icsk) {
962 struct inet_connection_sock *icsk = inet_csk(sk);
963 #if IS_ENABLED(CONFIG_IPV6)
964 if (sk->sk_family == PF_INET ||
965 (!((1 << sk->sk_state) &
966 (TCPF_LISTEN | TCPF_CLOSE)) &&
967 inet->inet_daddr != LOOPBACK4_IPV6)) {
968 #endif
969 if (old)
970 icsk->icsk_ext_hdr_len -= old->opt.optlen;
971 if (opt)
972 icsk->icsk_ext_hdr_len += opt->opt.optlen;
973 icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
974 #if IS_ENABLED(CONFIG_IPV6)
975 }
976 #endif
977 }
978 rcu_assign_pointer(inet->inet_opt, opt);
979 if (old)
980 kfree_rcu(old, rcu);
981 break;
982 }
983 case IP_PKTINFO:
984 if (val)
985 inet->cmsg_flags |= IP_CMSG_PKTINFO;
986 else
987 inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
988 break;
989 case IP_RECVTTL:
990 if (val)
991 inet->cmsg_flags |= IP_CMSG_TTL;
992 else
993 inet->cmsg_flags &= ~IP_CMSG_TTL;
994 break;
995 case IP_RECVTOS:
996 if (val)
997 inet->cmsg_flags |= IP_CMSG_TOS;
998 else
999 inet->cmsg_flags &= ~IP_CMSG_TOS;
1000 break;
1001 case IP_RECVOPTS:
1002 if (val)
1003 inet->cmsg_flags |= IP_CMSG_RECVOPTS;
1004 else
1005 inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
1006 break;
1007 case IP_RETOPTS:
1008 if (val)
1009 inet->cmsg_flags |= IP_CMSG_RETOPTS;
1010 else
1011 inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
1012 break;
1013 case IP_PASSSEC:
1014 if (val)
1015 inet->cmsg_flags |= IP_CMSG_PASSSEC;
1016 else
1017 inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
1018 break;
1019 case IP_RECVORIGDSTADDR:
1020 if (val)
1021 inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
1022 else
1023 inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
1024 break;
1025 case IP_CHECKSUM:
1026 if (val) {
1027 if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
1028 inet_inc_convert_csum(sk);
1029 inet->cmsg_flags |= IP_CMSG_CHECKSUM;
1030 }
1031 } else {
1032 if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
1033 inet_dec_convert_csum(sk);
1034 inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
1035 }
1036 }
1037 break;
1038 case IP_RECVFRAGSIZE:
1039 if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
1040 goto e_inval;
1041 if (val)
1042 inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
1043 else
1044 inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
1045 break;
1046 case IP_TOS: /* This sets both TOS and Precedence */
1047 __ip_sock_set_tos(sk, val);
1048 break;
1049 case IP_TTL:
1050 if (optlen < 1)
1051 goto e_inval;
1052 if (val != -1 && (val < 1 || val > 255))
1053 goto e_inval;
1054 inet->uc_ttl = val;
1055 break;
1056 case IP_HDRINCL:
1057 if (sk->sk_type != SOCK_RAW) {
1058 err = -ENOPROTOOPT;
1059 break;
1060 }
1061 inet->hdrincl = val ? 1 : 0;
1062 break;
1063 case IP_NODEFRAG:
1064 if (sk->sk_type != SOCK_RAW) {
1065 err = -ENOPROTOOPT;
1066 break;
1067 }
1068 inet->nodefrag = val ? 1 : 0;
1069 break;
1070 case IP_BIND_ADDRESS_NO_PORT:
1071 inet->bind_address_no_port = val ? 1 : 0;
1072 break;
1073 case IP_MTU_DISCOVER:
1074 if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
1075 goto e_inval;
1076 inet->pmtudisc = val;
1077 break;
1078 case IP_RECVERR:
1079 inet->recverr = !!val;
1080 if (!val)
1081 skb_queue_purge(&sk->sk_error_queue);
1082 break;
1083 case IP_RECVERR_RFC4884:
1084 if (val < 0 || val > 1)
1085 goto e_inval;
1086 inet->recverr_rfc4884 = !!val;
1087 break;
1088 case IP_MULTICAST_TTL:
1089 if (sk->sk_type == SOCK_STREAM)
1090 goto e_inval;
1091 if (optlen < 1)
1092 goto e_inval;
1093 if (val == -1)
1094 val = 1;
1095 if (val < 0 || val > 255)
1096 goto e_inval;
1097 inet->mc_ttl = val;
1098 break;
1099 case IP_MULTICAST_LOOP:
1100 if (optlen < 1)
1101 goto e_inval;
1102 inet->mc_loop = !!val;
1103 break;
1104 case IP_UNICAST_IF:
1105 {
1106 struct net_device *dev = NULL;
1107 int ifindex;
1108 int midx;
1109
1110 if (optlen != sizeof(int))
1111 goto e_inval;
1112
1113 ifindex = (__force int)ntohl((__force __be32)val);
1114 if (ifindex == 0) {
1115 inet->uc_index = 0;
1116 err = 0;
1117 break;
1118 }
1119
1120 dev = dev_get_by_index(sock_net(sk), ifindex);
1121 err = -EADDRNOTAVAIL;
1122 if (!dev)
1123 break;
1124
1125 midx = l3mdev_master_ifindex(dev);
1126 dev_put(dev);
1127
1128 err = -EINVAL;
1129 if (sk->sk_bound_dev_if && midx != sk->sk_bound_dev_if)
1130 break;
1131
1132 inet->uc_index = ifindex;
1133 err = 0;
1134 break;
1135 }
1136 case IP_MULTICAST_IF:
1137 {
1138 struct ip_mreqn mreq;
1139 struct net_device *dev = NULL;
1140 int midx;
1141
1142 if (sk->sk_type == SOCK_STREAM)
1143 goto e_inval;
1144 /*
1145 * Check the arguments are allowable
1146 */
1147
1148 if (optlen < sizeof(struct in_addr))
1149 goto e_inval;
1150
1151 err = -EFAULT;
1152 if (optlen >= sizeof(struct ip_mreqn)) {
1153 if (copy_from_sockptr(&mreq, optval, sizeof(mreq)))
1154 break;
1155 } else {
1156 memset(&mreq, 0, sizeof(mreq));
1157 if (optlen >= sizeof(struct ip_mreq)) {
1158 if (copy_from_sockptr(&mreq, optval,
1159 sizeof(struct ip_mreq)))
1160 break;
1161 } else if (optlen >= sizeof(struct in_addr)) {
1162 if (copy_from_sockptr(&mreq.imr_address, optval,
1163 sizeof(struct in_addr)))
1164 break;
1165 }
1166 }
1167
1168 if (!mreq.imr_ifindex) {
1169 if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
1170 inet->mc_index = 0;
1171 inet->mc_addr = 0;
1172 err = 0;
1173 break;
1174 }
1175 dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
1176 if (dev)
1177 mreq.imr_ifindex = dev->ifindex;
1178 } else
1179 dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
1180
1181
1182 err = -EADDRNOTAVAIL;
1183 if (!dev)
1184 break;
1185
1186 midx = l3mdev_master_ifindex(dev);
1187
1188 dev_put(dev);
1189
1190 err = -EINVAL;
1191 if (sk->sk_bound_dev_if &&
1192 mreq.imr_ifindex != sk->sk_bound_dev_if &&
1193 midx != sk->sk_bound_dev_if)
1194 break;
1195
1196 inet->mc_index = mreq.imr_ifindex;
1197 inet->mc_addr = mreq.imr_address.s_addr;
1198 err = 0;
1199 break;
1200 }
1201
1202 case IP_ADD_MEMBERSHIP:
1203 case IP_DROP_MEMBERSHIP:
1204 {
1205 struct ip_mreqn mreq;
1206
1207 err = -EPROTO;
1208 if (inet_sk(sk)->is_icsk)
1209 break;
1210
1211 if (optlen < sizeof(struct ip_mreq))
1212 goto e_inval;
1213 err = -EFAULT;
1214 if (optlen >= sizeof(struct ip_mreqn)) {
1215 if (copy_from_sockptr(&mreq, optval, sizeof(mreq)))
1216 break;
1217 } else {
1218 memset(&mreq, 0, sizeof(mreq));
1219 if (copy_from_sockptr(&mreq, optval,
1220 sizeof(struct ip_mreq)))
1221 break;
1222 }
1223
1224 if (optname == IP_ADD_MEMBERSHIP)
1225 err = ip_mc_join_group(sk, &mreq);
1226 else
1227 err = ip_mc_leave_group(sk, &mreq);
1228 break;
1229 }
1230 case IP_MSFILTER:
1231 {
1232 struct ip_msfilter *msf;
1233
1234 if (optlen < IP_MSFILTER_SIZE(0))
1235 goto e_inval;
1236 if (optlen > READ_ONCE(sysctl_optmem_max)) {
1237 err = -ENOBUFS;
1238 break;
1239 }
1240 msf = memdup_sockptr(optval, optlen);
1241 if (IS_ERR(msf)) {
1242 err = PTR_ERR(msf);
1243 break;
1244 }
1245 /* numsrc >= (1G-4) overflow in 32 bits */
1246 if (msf->imsf_numsrc >= 0x3ffffffcU ||
1247 msf->imsf_numsrc > READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) {
1248 kfree(msf);
1249 err = -ENOBUFS;
1250 break;
1251 }
1252 if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
1253 kfree(msf);
1254 err = -EINVAL;
1255 break;
1256 }
1257 err = ip_mc_msfilter(sk, msf, 0);
1258 kfree(msf);
1259 break;
1260 }
1261 case IP_BLOCK_SOURCE:
1262 case IP_UNBLOCK_SOURCE:
1263 case IP_ADD_SOURCE_MEMBERSHIP:
1264 case IP_DROP_SOURCE_MEMBERSHIP:
1265 {
1266 struct ip_mreq_source mreqs;
1267 int omode, add;
1268
1269 if (optlen != sizeof(struct ip_mreq_source))
1270 goto e_inval;
1271 if (copy_from_sockptr(&mreqs, optval, sizeof(mreqs))) {
1272 err = -EFAULT;
1273 break;
1274 }
1275 if (optname == IP_BLOCK_SOURCE) {
1276 omode = MCAST_EXCLUDE;
1277 add = 1;
1278 } else if (optname == IP_UNBLOCK_SOURCE) {
1279 omode = MCAST_EXCLUDE;
1280 add = 0;
1281 } else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
1282 struct ip_mreqn mreq;
1283
1284 mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
1285 mreq.imr_address.s_addr = mreqs.imr_interface;
1286 mreq.imr_ifindex = 0;
1287 err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
1288 if (err && err != -EADDRINUSE)
1289 break;
1290 omode = MCAST_INCLUDE;
1291 add = 1;
1292 } else /* IP_DROP_SOURCE_MEMBERSHIP */ {
1293 omode = MCAST_INCLUDE;
1294 add = 0;
1295 }
1296 err = ip_mc_source(add, omode, sk, &mreqs, 0);
1297 break;
1298 }
1299 case MCAST_JOIN_GROUP:
1300 case MCAST_LEAVE_GROUP:
1301 if (in_compat_syscall())
1302 err = compat_ip_mcast_join_leave(sk, optname, optval,
1303 optlen);
1304 else
1305 err = ip_mcast_join_leave(sk, optname, optval, optlen);
1306 break;
1307 case MCAST_JOIN_SOURCE_GROUP:
1308 case MCAST_LEAVE_SOURCE_GROUP:
1309 case MCAST_BLOCK_SOURCE:
1310 case MCAST_UNBLOCK_SOURCE:
1311 err = do_mcast_group_source(sk, optname, optval, optlen);
1312 break;
1313 case MCAST_MSFILTER:
1314 if (in_compat_syscall())
1315 err = compat_ip_set_mcast_msfilter(sk, optval, optlen);
1316 else
1317 err = ip_set_mcast_msfilter(sk, optval, optlen);
1318 break;
1319 case IP_MULTICAST_ALL:
1320 if (optlen < 1)
1321 goto e_inval;
1322 if (val != 0 && val != 1)
1323 goto e_inval;
1324 inet->mc_all = val;
1325 break;
1326
1327 case IP_FREEBIND:
1328 if (optlen < 1)
1329 goto e_inval;
1330 inet->freebind = !!val;
1331 break;
1332
1333 case IP_IPSEC_POLICY:
1334 case IP_XFRM_POLICY:
1335 err = -EPERM;
1336 if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1337 break;
1338 err = xfrm_user_policy(sk, optname, optval, optlen);
1339 break;
1340
1341 case IP_TRANSPARENT:
1342 if (!!val && !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1343 !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1344 err = -EPERM;
1345 break;
1346 }
1347 if (optlen < 1)
1348 goto e_inval;
1349 inet->transparent = !!val;
1350 break;
1351
1352 case IP_MINTTL:
1353 if (optlen < 1)
1354 goto e_inval;
1355 if (val < 0 || val > 255)
1356 goto e_inval;
1357
1358 if (val)
1359 static_branch_enable(&ip4_min_ttl);
1360
1361 /* tcp_v4_err() and tcp_v4_rcv() might read min_ttl
1362 * while we are changint it.
1363 */
1364 WRITE_ONCE(inet->min_ttl, val);
1365 break;
1366
1367 default:
1368 err = -ENOPROTOOPT;
1369 break;
1370 }
1371 sockopt_release_sock(sk);
1372 if (needs_rtnl)
1373 rtnl_unlock();
1374 return err;
1375
1376 e_inval:
1377 sockopt_release_sock(sk);
1378 if (needs_rtnl)
1379 rtnl_unlock();
1380 return -EINVAL;
1381 }
1382
1383 /**
1384 * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1385 * @sk: socket
1386 * @skb: buffer
1387 *
1388 * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1389 * destination in skb->cb[] before dst drop.
1390 * This way, receiver doesn't make cache line misses to read rtable.
1391 */
ipv4_pktinfo_prepare(const struct sock * sk,struct sk_buff * skb)1392 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1393 {
1394 struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1395 bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1396 ipv6_sk_rxinfo(sk);
1397
1398 if (prepare && skb_rtable(skb)) {
1399 /* skb->cb is overloaded: prior to this point it is IP{6}CB
1400 * which has interface index (iif) as the first member of the
1401 * underlying inet{6}_skb_parm struct. This code then overlays
1402 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1403 * element so the iif is picked up from the prior IPCB. If iif
1404 * is the loopback interface, then return the sending interface
1405 * (e.g., process binds socket to eth0 for Tx which is
1406 * redirected to loopback in the rtable/dst).
1407 */
1408 struct rtable *rt = skb_rtable(skb);
1409 bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1410
1411 if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1412 pktinfo->ipi_ifindex = inet_iif(skb);
1413 else if (l3slave && rt && rt->rt_iif)
1414 pktinfo->ipi_ifindex = rt->rt_iif;
1415
1416 pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1417 } else {
1418 pktinfo->ipi_ifindex = 0;
1419 pktinfo->ipi_spec_dst.s_addr = 0;
1420 }
1421 skb_dst_drop(skb);
1422 }
1423
ip_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1424 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1425 unsigned int optlen)
1426 {
1427 int err;
1428
1429 if (level != SOL_IP)
1430 return -ENOPROTOOPT;
1431
1432 err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1433 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1434 if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
1435 optname < BPFILTER_IPT_SET_MAX)
1436 err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen);
1437 #endif
1438 #ifdef CONFIG_NETFILTER
1439 /* we need to exclude all possible ENOPROTOOPTs except default case */
1440 if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1441 optname != IP_IPSEC_POLICY &&
1442 optname != IP_XFRM_POLICY &&
1443 !ip_mroute_opt(optname))
1444 err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1445 #endif
1446 return err;
1447 }
1448 EXPORT_SYMBOL(ip_setsockopt);
1449
1450 /*
1451 * Get the options. Note for future reference. The GET of IP options gets
1452 * the _received_ ones. The set sets the _sent_ ones.
1453 */
1454
getsockopt_needs_rtnl(int optname)1455 static bool getsockopt_needs_rtnl(int optname)
1456 {
1457 switch (optname) {
1458 case IP_MSFILTER:
1459 case MCAST_MSFILTER:
1460 return true;
1461 }
1462 return false;
1463 }
1464
ip_get_mcast_msfilter(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)1465 static int ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
1466 sockptr_t optlen, int len)
1467 {
1468 const int size0 = offsetof(struct group_filter, gf_slist_flex);
1469 struct group_filter gsf;
1470 int num, gsf_size;
1471 int err;
1472
1473 if (len < size0)
1474 return -EINVAL;
1475 if (copy_from_sockptr(&gsf, optval, size0))
1476 return -EFAULT;
1477
1478 num = gsf.gf_numsrc;
1479 err = ip_mc_gsfget(sk, &gsf, optval,
1480 offsetof(struct group_filter, gf_slist_flex));
1481 if (err)
1482 return err;
1483 if (gsf.gf_numsrc < num)
1484 num = gsf.gf_numsrc;
1485 gsf_size = GROUP_FILTER_SIZE(num);
1486 if (copy_to_sockptr(optlen, &gsf_size, sizeof(int)) ||
1487 copy_to_sockptr(optval, &gsf, size0))
1488 return -EFAULT;
1489 return 0;
1490 }
1491
compat_ip_get_mcast_msfilter(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)1492 static int compat_ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
1493 sockptr_t optlen, int len)
1494 {
1495 const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1496 struct compat_group_filter gf32;
1497 struct group_filter gf;
1498 int num;
1499 int err;
1500
1501 if (len < size0)
1502 return -EINVAL;
1503 if (copy_from_sockptr(&gf32, optval, size0))
1504 return -EFAULT;
1505
1506 gf.gf_interface = gf32.gf_interface;
1507 gf.gf_fmode = gf32.gf_fmode;
1508 num = gf.gf_numsrc = gf32.gf_numsrc;
1509 gf.gf_group = gf32.gf_group;
1510
1511 err = ip_mc_gsfget(sk, &gf, optval,
1512 offsetof(struct compat_group_filter, gf_slist_flex));
1513 if (err)
1514 return err;
1515 if (gf.gf_numsrc < num)
1516 num = gf.gf_numsrc;
1517 len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
1518 if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1519 copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
1520 &gf.gf_fmode, sizeof(gf.gf_fmode)) ||
1521 copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
1522 &gf.gf_numsrc, sizeof(gf.gf_numsrc)))
1523 return -EFAULT;
1524 return 0;
1525 }
1526
do_ip_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1527 int do_ip_getsockopt(struct sock *sk, int level, int optname,
1528 sockptr_t optval, sockptr_t optlen)
1529 {
1530 struct inet_sock *inet = inet_sk(sk);
1531 bool needs_rtnl = getsockopt_needs_rtnl(optname);
1532 int val, err = 0;
1533 int len;
1534
1535 if (level != SOL_IP)
1536 return -EOPNOTSUPP;
1537
1538 if (ip_mroute_opt(optname))
1539 return ip_mroute_getsockopt(sk, optname, optval, optlen);
1540
1541 if (copy_from_sockptr(&len, optlen, sizeof(int)))
1542 return -EFAULT;
1543 if (len < 0)
1544 return -EINVAL;
1545
1546 if (needs_rtnl)
1547 rtnl_lock();
1548 sockopt_lock_sock(sk);
1549
1550 switch (optname) {
1551 case IP_OPTIONS:
1552 {
1553 unsigned char optbuf[sizeof(struct ip_options)+40];
1554 struct ip_options *opt = (struct ip_options *)optbuf;
1555 struct ip_options_rcu *inet_opt;
1556
1557 inet_opt = rcu_dereference_protected(inet->inet_opt,
1558 lockdep_sock_is_held(sk));
1559 opt->optlen = 0;
1560 if (inet_opt)
1561 memcpy(optbuf, &inet_opt->opt,
1562 sizeof(struct ip_options) +
1563 inet_opt->opt.optlen);
1564 sockopt_release_sock(sk);
1565
1566 if (opt->optlen == 0) {
1567 len = 0;
1568 return copy_to_sockptr(optlen, &len, sizeof(int));
1569 }
1570
1571 ip_options_undo(opt);
1572
1573 len = min_t(unsigned int, len, opt->optlen);
1574 if (copy_to_sockptr(optlen, &len, sizeof(int)))
1575 return -EFAULT;
1576 if (copy_to_sockptr(optval, opt->__data, len))
1577 return -EFAULT;
1578 return 0;
1579 }
1580 case IP_PKTINFO:
1581 val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1582 break;
1583 case IP_RECVTTL:
1584 val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1585 break;
1586 case IP_RECVTOS:
1587 val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1588 break;
1589 case IP_RECVOPTS:
1590 val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1591 break;
1592 case IP_RETOPTS:
1593 val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1594 break;
1595 case IP_PASSSEC:
1596 val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1597 break;
1598 case IP_RECVORIGDSTADDR:
1599 val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1600 break;
1601 case IP_CHECKSUM:
1602 val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1603 break;
1604 case IP_RECVFRAGSIZE:
1605 val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1606 break;
1607 case IP_TOS:
1608 val = inet->tos;
1609 break;
1610 case IP_TTL:
1611 {
1612 struct net *net = sock_net(sk);
1613 val = (inet->uc_ttl == -1 ?
1614 READ_ONCE(net->ipv4.sysctl_ip_default_ttl) :
1615 inet->uc_ttl);
1616 break;
1617 }
1618 case IP_HDRINCL:
1619 val = inet->hdrincl;
1620 break;
1621 case IP_NODEFRAG:
1622 val = inet->nodefrag;
1623 break;
1624 case IP_BIND_ADDRESS_NO_PORT:
1625 val = inet->bind_address_no_port;
1626 break;
1627 case IP_MTU_DISCOVER:
1628 val = inet->pmtudisc;
1629 break;
1630 case IP_MTU:
1631 {
1632 struct dst_entry *dst;
1633 val = 0;
1634 dst = sk_dst_get(sk);
1635 if (dst) {
1636 val = dst_mtu(dst);
1637 dst_release(dst);
1638 }
1639 if (!val) {
1640 sockopt_release_sock(sk);
1641 return -ENOTCONN;
1642 }
1643 break;
1644 }
1645 case IP_RECVERR:
1646 val = inet->recverr;
1647 break;
1648 case IP_RECVERR_RFC4884:
1649 val = inet->recverr_rfc4884;
1650 break;
1651 case IP_MULTICAST_TTL:
1652 val = inet->mc_ttl;
1653 break;
1654 case IP_MULTICAST_LOOP:
1655 val = inet->mc_loop;
1656 break;
1657 case IP_UNICAST_IF:
1658 val = (__force int)htonl((__u32) inet->uc_index);
1659 break;
1660 case IP_MULTICAST_IF:
1661 {
1662 struct in_addr addr;
1663 len = min_t(unsigned int, len, sizeof(struct in_addr));
1664 addr.s_addr = inet->mc_addr;
1665 sockopt_release_sock(sk);
1666
1667 if (copy_to_sockptr(optlen, &len, sizeof(int)))
1668 return -EFAULT;
1669 if (copy_to_sockptr(optval, &addr, len))
1670 return -EFAULT;
1671 return 0;
1672 }
1673 case IP_MSFILTER:
1674 {
1675 struct ip_msfilter msf;
1676
1677 if (len < IP_MSFILTER_SIZE(0)) {
1678 err = -EINVAL;
1679 goto out;
1680 }
1681 if (copy_from_sockptr(&msf, optval, IP_MSFILTER_SIZE(0))) {
1682 err = -EFAULT;
1683 goto out;
1684 }
1685 err = ip_mc_msfget(sk, &msf, optval, optlen);
1686 goto out;
1687 }
1688 case MCAST_MSFILTER:
1689 if (in_compat_syscall())
1690 err = compat_ip_get_mcast_msfilter(sk, optval, optlen,
1691 len);
1692 else
1693 err = ip_get_mcast_msfilter(sk, optval, optlen, len);
1694 goto out;
1695 case IP_MULTICAST_ALL:
1696 val = inet->mc_all;
1697 break;
1698 case IP_PKTOPTIONS:
1699 {
1700 struct msghdr msg;
1701
1702 sockopt_release_sock(sk);
1703
1704 if (sk->sk_type != SOCK_STREAM)
1705 return -ENOPROTOOPT;
1706
1707 if (optval.is_kernel) {
1708 msg.msg_control_is_user = false;
1709 msg.msg_control = optval.kernel;
1710 } else {
1711 msg.msg_control_is_user = true;
1712 msg.msg_control_user = optval.user;
1713 }
1714 msg.msg_controllen = len;
1715 msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;
1716
1717 if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1718 struct in_pktinfo info;
1719
1720 info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1721 info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1722 info.ipi_ifindex = inet->mc_index;
1723 put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1724 }
1725 if (inet->cmsg_flags & IP_CMSG_TTL) {
1726 int hlim = inet->mc_ttl;
1727 put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1728 }
1729 if (inet->cmsg_flags & IP_CMSG_TOS) {
1730 int tos = inet->rcv_tos;
1731 put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1732 }
1733 len -= msg.msg_controllen;
1734 return copy_to_sockptr(optlen, &len, sizeof(int));
1735 }
1736 case IP_FREEBIND:
1737 val = inet->freebind;
1738 break;
1739 case IP_TRANSPARENT:
1740 val = inet->transparent;
1741 break;
1742 case IP_MINTTL:
1743 val = inet->min_ttl;
1744 break;
1745 default:
1746 sockopt_release_sock(sk);
1747 return -ENOPROTOOPT;
1748 }
1749 sockopt_release_sock(sk);
1750
1751 if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1752 unsigned char ucval = (unsigned char)val;
1753 len = 1;
1754 if (copy_to_sockptr(optlen, &len, sizeof(int)))
1755 return -EFAULT;
1756 if (copy_to_sockptr(optval, &ucval, 1))
1757 return -EFAULT;
1758 } else {
1759 len = min_t(unsigned int, sizeof(int), len);
1760 if (copy_to_sockptr(optlen, &len, sizeof(int)))
1761 return -EFAULT;
1762 if (copy_to_sockptr(optval, &val, len))
1763 return -EFAULT;
1764 }
1765 return 0;
1766
1767 out:
1768 sockopt_release_sock(sk);
1769 if (needs_rtnl)
1770 rtnl_unlock();
1771 return err;
1772 }
1773
ip_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1774 int ip_getsockopt(struct sock *sk, int level,
1775 int optname, char __user *optval, int __user *optlen)
1776 {
1777 int err;
1778
1779 err = do_ip_getsockopt(sk, level, optname,
1780 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
1781
1782 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1783 if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1784 optname < BPFILTER_IPT_GET_MAX)
1785 err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1786 #endif
1787 #ifdef CONFIG_NETFILTER
1788 /* we need to exclude all possible ENOPROTOOPTs except default case */
1789 if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1790 !ip_mroute_opt(optname)) {
1791 int len;
1792
1793 if (get_user(len, optlen))
1794 return -EFAULT;
1795
1796 err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
1797 if (err >= 0)
1798 err = put_user(len, optlen);
1799 return err;
1800 }
1801 #endif
1802 return err;
1803 }
1804 EXPORT_SYMBOL(ip_getsockopt);
1805
