31a20f17c854c46f67c3e585e63115ec52816545
[linux-2.6.git] / net / ipv6 / datagram.c
1 /*
2  *      common UDP/RAW code
3  *      Linux INET6 implementation
4  *
5  *      Authors:
6  *      Pedro Roque             <roque@di.fc.ul.pt>
7  *
8  *      $Id: datagram.c,v 1.24 2002/02/01 22:01:04 davem Exp $
9  *
10  *      This program is free software; you can redistribute it and/or
11  *      modify it under the terms of the GNU General Public License
12  *      as published by the Free Software Foundation; either version
13  *      2 of the License, or (at your option) any later version.
14  */
15
16 #include <linux/capability.h>
17 #include <linux/errno.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/interrupt.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in6.h>
24 #include <linux/ipv6.h>
25 #include <linux/route.h>
26
27 #include <net/ipv6.h>
28 #include <net/ndisc.h>
29 #include <net/addrconf.h>
30 #include <net/transp_v6.h>
31 #include <net/ip6_route.h>
32 #include <net/tcp_states.h>
33
34 #include <linux/errqueue.h>
35 #include <asm/uaccess.h>
36
37 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
38 {
39         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
40         struct inet_sock        *inet = inet_sk(sk);
41         struct ipv6_pinfo       *np = inet6_sk(sk);
42         struct in6_addr         *daddr, *final_p = NULL, final;
43         struct dst_entry        *dst;
44         struct flowi            fl;
45         struct ip6_flowlabel    *flowlabel = NULL;
46         int                     addr_type;
47         int                     err;
48
49         if (usin->sin6_family == AF_INET) {
50                 if (__ipv6_only_sock(sk))
51                         return -EAFNOSUPPORT;
52                 err = ip4_datagram_connect(sk, uaddr, addr_len);
53                 goto ipv4_connected;
54         }
55
56         if (addr_len < SIN6_LEN_RFC2133)
57                 return -EINVAL;
58
59         if (usin->sin6_family != AF_INET6)
60                 return -EAFNOSUPPORT;
61
62         memset(&fl, 0, sizeof(fl));
63         if (np->sndflow) {
64                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
65                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
66                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
67                         if (flowlabel == NULL)
68                                 return -EINVAL;
69                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
70                 }
71         }
72
73         addr_type = ipv6_addr_type(&usin->sin6_addr);
74
75         if (addr_type == IPV6_ADDR_ANY) {
76                 /*
77                  *      connect to self
78                  */
79                 usin->sin6_addr.s6_addr[15] = 0x01;
80         }
81
82         daddr = &usin->sin6_addr;
83
84         if (addr_type == IPV6_ADDR_MAPPED) {
85                 struct sockaddr_in sin;
86
87                 if (__ipv6_only_sock(sk)) {
88                         err = -ENETUNREACH;
89                         goto out;
90                 }
91                 sin.sin_family = AF_INET;
92                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
93                 sin.sin_port = usin->sin6_port;
94
95                 err = ip4_datagram_connect(sk,
96                                            (struct sockaddr*) &sin,
97                                            sizeof(sin));
98
99 ipv4_connected:
100                 if (err)
101                         goto out;
102
103                 ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
104
105                 if (ipv6_addr_any(&np->saddr)) {
106                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
107                                       inet->saddr);
108                 }
109
110                 if (ipv6_addr_any(&np->rcv_saddr)) {
111                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
112                                       inet->rcv_saddr);
113                 }
114                 goto out;
115         }
116
117         if (addr_type&IPV6_ADDR_LINKLOCAL) {
118                 if (addr_len >= sizeof(struct sockaddr_in6) &&
119                     usin->sin6_scope_id) {
120                         if (sk->sk_bound_dev_if &&
121                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
122                                 err = -EINVAL;
123                                 goto out;
124                         }
125                         sk->sk_bound_dev_if = usin->sin6_scope_id;
126                         if (!sk->sk_bound_dev_if &&
127                             (addr_type & IPV6_ADDR_MULTICAST))
128                                 fl.oif = np->mcast_oif;
129                 }
130
131                 /* Connect to link-local address requires an interface */
132                 if (!sk->sk_bound_dev_if) {
133                         err = -EINVAL;
134                         goto out;
135                 }
136         }
137
138         ipv6_addr_copy(&np->daddr, daddr);
139         np->flow_label = fl.fl6_flowlabel;
140
141         inet->dport = usin->sin6_port;
142
143         /*
144          *      Check for a route to destination an obtain the
145          *      destination cache for it.
146          */
147
148         fl.proto = sk->sk_protocol;
149         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
150         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
151         fl.oif = sk->sk_bound_dev_if;
152         fl.fl_ip_dport = inet->dport;
153         fl.fl_ip_sport = inet->sport;
154
155         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
156                 fl.oif = np->mcast_oif;
157
158         security_sk_classify_flow(sk, &fl);
159
160         if (flowlabel) {
161                 if (flowlabel->opt && flowlabel->opt->srcrt) {
162                         struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
163                         ipv6_addr_copy(&final, &fl.fl6_dst);
164                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
165                         final_p = &final;
166                 }
167         } else if (np->opt && np->opt->srcrt) {
168                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
169                 ipv6_addr_copy(&final, &fl.fl6_dst);
170                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
171                 final_p = &final;
172         }
173
174         err = ip6_dst_lookup(sk, &dst, &fl);
175         if (err)
176                 goto out;
177         if (final_p)
178                 ipv6_addr_copy(&fl.fl6_dst, final_p);
179
180         if ((err = xfrm_lookup(&dst, &fl, sk, 1)) < 0)
181                 goto out;
182
183         /* source address lookup done in ip6_dst_lookup */
184
185         if (ipv6_addr_any(&np->saddr))
186                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
187
188         if (ipv6_addr_any(&np->rcv_saddr)) {
189                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
190                 inet->rcv_saddr = LOOPBACK4_IPV6;
191         }
192
193         ip6_dst_store(sk, dst,
194                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
195                       &np->daddr : NULL,
196 #ifdef CONFIG_IPV6_SUBTREES
197                       ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
198                       &np->saddr :
199 #endif
200                       NULL);
201
202         sk->sk_state = TCP_ESTABLISHED;
203 out:
204         fl6_sock_release(flowlabel);
205         return err;
206 }
207
208 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
209                      __be16 port, u32 info, u8 *payload)
210 {
211         struct ipv6_pinfo *np  = inet6_sk(sk);
212         struct icmp6hdr *icmph = (struct icmp6hdr *)skb->h.raw;
213         struct sock_exterr_skb *serr;
214
215         if (!np->recverr)
216                 return;
217
218         skb = skb_clone(skb, GFP_ATOMIC);
219         if (!skb)
220                 return;
221
222         serr = SKB_EXT_ERR(skb);
223         serr->ee.ee_errno = err;
224         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
225         serr->ee.ee_type = icmph->icmp6_type;
226         serr->ee.ee_code = icmph->icmp6_code;
227         serr->ee.ee_pad = 0;
228         serr->ee.ee_info = info;
229         serr->ee.ee_data = 0;
230         serr->addr_offset = (u8*)&(((struct ipv6hdr*)(icmph+1))->daddr) - skb->nh.raw;
231         serr->port = port;
232
233         skb->h.raw = payload;
234         __skb_pull(skb, payload - skb->data);
235
236         if (sock_queue_err_skb(sk, skb))
237                 kfree_skb(skb);
238 }
239
240 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
241 {
242         struct ipv6_pinfo *np = inet6_sk(sk);
243         struct sock_exterr_skb *serr;
244         struct ipv6hdr *iph;
245         struct sk_buff *skb;
246
247         if (!np->recverr)
248                 return;
249
250         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
251         if (!skb)
252                 return;
253
254         skb_put(skb, sizeof(struct ipv6hdr));
255         skb_reset_network_header(skb);
256         iph = skb->nh.ipv6h;
257         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
258
259         serr = SKB_EXT_ERR(skb);
260         serr->ee.ee_errno = err;
261         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
262         serr->ee.ee_type = 0;
263         serr->ee.ee_code = 0;
264         serr->ee.ee_pad = 0;
265         serr->ee.ee_info = info;
266         serr->ee.ee_data = 0;
267         serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
268         serr->port = fl->fl_ip_dport;
269
270         skb->h.raw = skb->tail;
271         __skb_pull(skb, skb->tail - skb->data);
272
273         if (sock_queue_err_skb(sk, skb))
274                 kfree_skb(skb);
275 }
276
277 /*
278  *      Handle MSG_ERRQUEUE
279  */
280 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
281 {
282         struct ipv6_pinfo *np = inet6_sk(sk);
283         struct sock_exterr_skb *serr;
284         struct sk_buff *skb, *skb2;
285         struct sockaddr_in6 *sin;
286         struct {
287                 struct sock_extended_err ee;
288                 struct sockaddr_in6      offender;
289         } errhdr;
290         int err;
291         int copied;
292
293         err = -EAGAIN;
294         skb = skb_dequeue(&sk->sk_error_queue);
295         if (skb == NULL)
296                 goto out;
297
298         copied = skb->len;
299         if (copied > len) {
300                 msg->msg_flags |= MSG_TRUNC;
301                 copied = len;
302         }
303         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
304         if (err)
305                 goto out_free_skb;
306
307         sock_recv_timestamp(msg, sk, skb);
308
309         serr = SKB_EXT_ERR(skb);
310
311         sin = (struct sockaddr_in6 *)msg->msg_name;
312         if (sin) {
313                 sin->sin6_family = AF_INET6;
314                 sin->sin6_flowinfo = 0;
315                 sin->sin6_port = serr->port;
316                 sin->sin6_scope_id = 0;
317                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
318                         ipv6_addr_copy(&sin->sin6_addr,
319                           (struct in6_addr *)(skb->nh.raw + serr->addr_offset));
320                         if (np->sndflow)
321                                 sin->sin6_flowinfo = *(__be32*)(skb->nh.raw + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK;
322                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
323                                 sin->sin6_scope_id = IP6CB(skb)->iif;
324                 } else {
325                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
326                                       htonl(0xffff),
327                                       *(__be32*)(skb->nh.raw + serr->addr_offset));
328                 }
329         }
330
331         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
332         sin = &errhdr.offender;
333         sin->sin6_family = AF_UNSPEC;
334         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
335                 sin->sin6_family = AF_INET6;
336                 sin->sin6_flowinfo = 0;
337                 sin->sin6_scope_id = 0;
338                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
339                         ipv6_addr_copy(&sin->sin6_addr, &skb->nh.ipv6h->saddr);
340                         if (np->rxopt.all)
341                                 datagram_recv_ctl(sk, msg, skb);
342                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
343                                 sin->sin6_scope_id = IP6CB(skb)->iif;
344                 } else {
345                         struct inet_sock *inet = inet_sk(sk);
346
347                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
348                                       htonl(0xffff),
349                                       skb->nh.iph->saddr);
350                         if (inet->cmsg_flags)
351                                 ip_cmsg_recv(msg, skb);
352                 }
353         }
354
355         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
356
357         /* Now we could try to dump offended packet options */
358
359         msg->msg_flags |= MSG_ERRQUEUE;
360         err = copied;
361
362         /* Reset and regenerate socket error */
363         spin_lock_bh(&sk->sk_error_queue.lock);
364         sk->sk_err = 0;
365         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
366                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
367                 spin_unlock_bh(&sk->sk_error_queue.lock);
368                 sk->sk_error_report(sk);
369         } else {
370                 spin_unlock_bh(&sk->sk_error_queue.lock);
371         }
372
373 out_free_skb:
374         kfree_skb(skb);
375 out:
376         return err;
377 }
378
379
380
381 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
382 {
383         struct ipv6_pinfo *np = inet6_sk(sk);
384         struct inet6_skb_parm *opt = IP6CB(skb);
385
386         if (np->rxopt.bits.rxinfo) {
387                 struct in6_pktinfo src_info;
388
389                 src_info.ipi6_ifindex = opt->iif;
390                 ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
391                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
392         }
393
394         if (np->rxopt.bits.rxhlim) {
395                 int hlim = skb->nh.ipv6h->hop_limit;
396                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
397         }
398
399         if (np->rxopt.bits.rxtclass) {
400                 int tclass = (ntohl(*(__be32 *)skb->nh.ipv6h) >> 20) & 0xff;
401                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
402         }
403
404         if (np->rxopt.bits.rxflow && (*(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK)) {
405                 __be32 flowinfo = *(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK;
406                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
407         }
408
409         /* HbH is allowed only once */
410         if (np->rxopt.bits.hopopts && opt->hop) {
411                 u8 *ptr = skb->nh.raw + opt->hop;
412                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
413         }
414
415         if (opt->lastopt &&
416             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
417                 /*
418                  * Silly enough, but we need to reparse in order to
419                  * report extension headers (except for HbH)
420                  * in order.
421                  *
422                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
423                  * (and WILL NOT be) defined because
424                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
425                  */
426                 unsigned int off = sizeof(struct ipv6hdr);
427                 u8 nexthdr = skb->nh.ipv6h->nexthdr;
428
429                 while (off <= opt->lastopt) {
430                         unsigned len;
431                         u8 *ptr = skb->nh.raw + off;
432
433                         switch(nexthdr) {
434                         case IPPROTO_DSTOPTS:
435                                 nexthdr = ptr[0];
436                                 len = (ptr[1] + 1) << 3;
437                                 if (np->rxopt.bits.dstopts)
438                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
439                                 break;
440                         case IPPROTO_ROUTING:
441                                 nexthdr = ptr[0];
442                                 len = (ptr[1] + 1) << 3;
443                                 if (np->rxopt.bits.srcrt)
444                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
445                                 break;
446                         case IPPROTO_AH:
447                                 nexthdr = ptr[0];
448                                 len = (ptr[1] + 2) << 2;
449                                 break;
450                         default:
451                                 nexthdr = ptr[0];
452                                 len = (ptr[1] + 1) << 3;
453                                 break;
454                         }
455
456                         off += len;
457                 }
458         }
459
460         /* socket options in old style */
461         if (np->rxopt.bits.rxoinfo) {
462                 struct in6_pktinfo src_info;
463
464                 src_info.ipi6_ifindex = opt->iif;
465                 ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
466                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
467         }
468         if (np->rxopt.bits.rxohlim) {
469                 int hlim = skb->nh.ipv6h->hop_limit;
470                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
471         }
472         if (np->rxopt.bits.ohopopts && opt->hop) {
473                 u8 *ptr = skb->nh.raw + opt->hop;
474                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
475         }
476         if (np->rxopt.bits.odstopts && opt->dst0) {
477                 u8 *ptr = skb->nh.raw + opt->dst0;
478                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
479         }
480         if (np->rxopt.bits.osrcrt && opt->srcrt) {
481                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(skb->nh.raw + opt->srcrt);
482                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
483         }
484         if (np->rxopt.bits.odstopts && opt->dst1) {
485                 u8 *ptr = skb->nh.raw + opt->dst1;
486                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
487         }
488         return 0;
489 }
490
491 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
492                       struct ipv6_txoptions *opt,
493                       int *hlimit, int *tclass)
494 {
495         struct in6_pktinfo *src_info;
496         struct cmsghdr *cmsg;
497         struct ipv6_rt_hdr *rthdr;
498         struct ipv6_opt_hdr *hdr;
499         int len;
500         int err = 0;
501
502         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
503                 int addr_type;
504                 struct net_device *dev = NULL;
505
506                 if (!CMSG_OK(msg, cmsg)) {
507                         err = -EINVAL;
508                         goto exit_f;
509                 }
510
511                 if (cmsg->cmsg_level != SOL_IPV6)
512                         continue;
513
514                 switch (cmsg->cmsg_type) {
515                 case IPV6_PKTINFO:
516                 case IPV6_2292PKTINFO:
517                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
518                                 err = -EINVAL;
519                                 goto exit_f;
520                         }
521
522                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
523
524                         if (src_info->ipi6_ifindex) {
525                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
526                                         return -EINVAL;
527                                 fl->oif = src_info->ipi6_ifindex;
528                         }
529
530                         addr_type = ipv6_addr_type(&src_info->ipi6_addr);
531
532                         if (addr_type == IPV6_ADDR_ANY)
533                                 break;
534
535                         if (addr_type & IPV6_ADDR_LINKLOCAL) {
536                                 if (!src_info->ipi6_ifindex)
537                                         return -EINVAL;
538                                 else {
539                                         dev = dev_get_by_index(src_info->ipi6_ifindex);
540                                         if (!dev)
541                                                 return -ENODEV;
542                                 }
543                         }
544                         if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) {
545                                 if (dev)
546                                         dev_put(dev);
547                                 err = -EINVAL;
548                                 goto exit_f;
549                         }
550                         if (dev)
551                                 dev_put(dev);
552
553                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
554                         break;
555
556                 case IPV6_FLOWINFO:
557                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
558                                 err = -EINVAL;
559                                 goto exit_f;
560                         }
561
562                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
563                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
564                                         err = -EINVAL;
565                                         goto exit_f;
566                                 }
567                         }
568                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
569                         break;
570
571                 case IPV6_2292HOPOPTS:
572                 case IPV6_HOPOPTS:
573                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
574                                 err = -EINVAL;
575                                 goto exit_f;
576                         }
577
578                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
579                         len = ((hdr->hdrlen + 1) << 3);
580                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
581                                 err = -EINVAL;
582                                 goto exit_f;
583                         }
584                         if (!capable(CAP_NET_RAW)) {
585                                 err = -EPERM;
586                                 goto exit_f;
587                         }
588                         opt->opt_nflen += len;
589                         opt->hopopt = hdr;
590                         break;
591
592                 case IPV6_2292DSTOPTS:
593                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
594                                 err = -EINVAL;
595                                 goto exit_f;
596                         }
597
598                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
599                         len = ((hdr->hdrlen + 1) << 3);
600                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
601                                 err = -EINVAL;
602                                 goto exit_f;
603                         }
604                         if (!capable(CAP_NET_RAW)) {
605                                 err = -EPERM;
606                                 goto exit_f;
607                         }
608                         if (opt->dst1opt) {
609                                 err = -EINVAL;
610                                 goto exit_f;
611                         }
612                         opt->opt_flen += len;
613                         opt->dst1opt = hdr;
614                         break;
615
616                 case IPV6_DSTOPTS:
617                 case IPV6_RTHDRDSTOPTS:
618                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
619                                 err = -EINVAL;
620                                 goto exit_f;
621                         }
622
623                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
624                         len = ((hdr->hdrlen + 1) << 3);
625                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
626                                 err = -EINVAL;
627                                 goto exit_f;
628                         }
629                         if (!capable(CAP_NET_RAW)) {
630                                 err = -EPERM;
631                                 goto exit_f;
632                         }
633                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
634                                 opt->opt_flen += len;
635                                 opt->dst1opt = hdr;
636                         } else {
637                                 opt->opt_nflen += len;
638                                 opt->dst0opt = hdr;
639                         }
640                         break;
641
642                 case IPV6_2292RTHDR:
643                 case IPV6_RTHDR:
644                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
645                                 err = -EINVAL;
646                                 goto exit_f;
647                         }
648
649                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
650
651                         switch (rthdr->type) {
652                         case IPV6_SRCRT_TYPE_0:
653 #ifdef CONFIG_IPV6_MIP6
654                         case IPV6_SRCRT_TYPE_2:
655 #endif
656                                 break;
657                         default:
658                                 err = -EINVAL;
659                                 goto exit_f;
660                         }
661
662                         len = ((rthdr->hdrlen + 1) << 3);
663
664                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
665                                 err = -EINVAL;
666                                 goto exit_f;
667                         }
668
669                         /* segments left must also match */
670                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
671                                 err = -EINVAL;
672                                 goto exit_f;
673                         }
674
675                         opt->opt_nflen += len;
676                         opt->srcrt = rthdr;
677
678                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
679                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
680
681                                 opt->opt_nflen += dsthdrlen;
682                                 opt->dst0opt = opt->dst1opt;
683                                 opt->dst1opt = NULL;
684                                 opt->opt_flen -= dsthdrlen;
685                         }
686
687                         break;
688
689                 case IPV6_2292HOPLIMIT:
690                 case IPV6_HOPLIMIT:
691                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
692                                 err = -EINVAL;
693                                 goto exit_f;
694                         }
695
696                         *hlimit = *(int *)CMSG_DATA(cmsg);
697                         break;
698
699                 case IPV6_TCLASS:
700                     {
701                         int tc;
702
703                         err = -EINVAL;
704                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
705                                 goto exit_f;
706                         }
707
708                         tc = *(int *)CMSG_DATA(cmsg);
709                         if (tc < -1 || tc > 0xff)
710                                 goto exit_f;
711
712                         err = 0;
713                         *tclass = tc;
714
715                         break;
716                     }
717                 default:
718                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
719                                        cmsg->cmsg_type);
720                         err = -EINVAL;
721                         break;
722                 };
723         }
724
725 exit_f:
726         return err;
727 }