Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/net/ipv4/af_inet.c

  1 /*
  2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  3  *              operating system.  INET is implemented using the  BSD Socket
  4  *              interface as the means of communication with the user level.
  5  *
  6  *              PF_INET protocol family socket handler.
  7  *
  8  * Authors:     Ross Biro
  9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 10  *              Florian La Roche, <flla@stud.uni-sb.de>
 11  *              Alan Cox, <A.Cox@swansea.ac.uk>
 12  *
 13  * Changes (see also sock.c)
 14  *
 15  *              piggy,
 16  *              Karl Knutson    :       Socket protocol table
 17  *              A.N.Kuznetsov   :       Socket death error in accept().
 18  *              John Richardson :       Fix non blocking error in connect()
 19  *                                      so sockets that fail to connect
 20  *                                      don't return -EINPROGRESS.
 21  *              Alan Cox        :       Asynchronous I/O support
 22  *              Alan Cox        :       Keep correct socket pointer on sock
 23  *                                      structures
 24  *                                      when accept() ed
 25  *              Alan Cox        :       Semantics of SO_LINGER aren't state
 26  *                                      moved to close when you look carefully.
 27  *                                      With this fixed and the accept bug fixed
 28  *                                      some RPC stuff seems happier.
 29  *              Niibe Yutaka    :       4.4BSD style write async I/O
 30  *              Alan Cox,
 31  *              Tony Gale       :       Fixed reuse semantics.
 32  *              Alan Cox        :       bind() shouldn't abort existing but dead
 33  *                                      sockets. Stops FTP netin:.. I hope.
 34  *              Alan Cox        :       bind() works correctly for RAW sockets.
 35  *                                      Note that FreeBSD at least was broken
 36  *                                      in this respect so be careful with
 37  *                                      compatibility tests...
 38  *              Alan Cox        :       routing cache support
 39  *              Alan Cox        :       memzero the socket structure for
 40  *                                      compactness.
 41  *              Matt Day        :       nonblock connect error handler
 42  *              Alan Cox        :       Allow large numbers of pending sockets
 43  *                                      (eg for big web sites), but only if
 44  *                                      specifically application requested.
 45  *              Alan Cox        :       New buffering throughout IP. Used
 46  *                                      dumbly.
 47  *              Alan Cox        :       New buffering now used smartly.
 48  *              Alan Cox        :       BSD rather than common sense
 49  *                                      interpretation of listen.
 50  *              Germano Caronni :       Assorted small races.
 51  *              Alan Cox        :       sendmsg/recvmsg basic support.
 52  *              Alan Cox        :       Only sendmsg/recvmsg now supported.
 53  *              Alan Cox        :       Locked down bind (see security list).
 54  *              Alan Cox        :       Loosened bind a little.
 55  *              Mike McLagan    :       ADD/DEL DLCI Ioctls
 56  *      Willy Konynenberg       :       Transparent proxying support.
 57  *              David S. Miller :       New socket lookup architecture.
 58  *                                      Some other random speedups.
 59  *              Cyrus Durgin    :       Cleaned up file for kmod hacks.
 60  *              Andi Kleen      :       Fix inet_stream_connect TCP race.
 61  *
 62  *              This program is free software; you can redistribute it and/or
 63  *              modify it under the terms of the GNU General Public License
 64  *              as published by the Free Software Foundation; either version
 65  *              2 of the License, or (at your option) any later version.
 66  */
 67 
 68 #define pr_fmt(fmt) "IPv4: " fmt
 69 
 70 #include <linux/err.h>
 71 #include <linux/errno.h>
 72 #include <linux/types.h>
 73 #include <linux/socket.h>
 74 #include <linux/in.h>
 75 #include <linux/kernel.h>
 76 #include <linux/module.h>
 77 #include <linux/sched.h>
 78 #include <linux/timer.h>
 79 #include <linux/string.h>
 80 #include <linux/sockios.h>
 81 #include <linux/net.h>
 82 #include <linux/capability.h>
 83 #include <linux/fcntl.h>
 84 #include <linux/mm.h>
 85 #include <linux/interrupt.h>
 86 #include <linux/stat.h>
 87 #include <linux/init.h>
 88 #include <linux/poll.h>
 89 #include <linux/netfilter_ipv4.h>
 90 #include <linux/random.h>
 91 #include <linux/slab.h>
 92 
 93 #include <asm/uaccess.h>
 94 
 95 #include <linux/inet.h>
 96 #include <linux/igmp.h>
 97 #include <linux/inetdevice.h>
 98 #include <linux/netdevice.h>
 99 #include <net/checksum.h>
100 #include <net/ip.h>
101 #include <net/protocol.h>
102 #include <net/arp.h>
103 #include <net/route.h>
104 #include <net/ip_fib.h>
105 #include <net/inet_connection_sock.h>
106 #include <net/tcp.h>
107 #include <net/udp.h>
108 #include <net/udplite.h>
109 #include <net/ping.h>
110 #include <linux/skbuff.h>
111 #include <net/sock.h>
112 #include <net/raw.h>
113 #include <net/icmp.h>
114 #include <net/inet_common.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #include <net/secure_seq.h>
118 #ifdef CONFIG_IP_MROUTE
119 #include <linux/mroute.h>
120 #endif
121 
122 
123 /* The inetsw table contains everything that inet_create needs to
124  * build a new socket.
125  */
126 static struct list_head inetsw[SOCK_MAX];
127 static DEFINE_SPINLOCK(inetsw_lock);
128 
129 /* New destruction routine */
130 
131 void inet_sock_destruct(struct sock *sk)
132 {
133         struct inet_sock *inet = inet_sk(sk);
134 
135         __skb_queue_purge(&sk->sk_receive_queue);
136         __skb_queue_purge(&sk->sk_error_queue);
137 
138         sk_mem_reclaim(sk);
139 
140         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
141                 pr_err("Attempt to release TCP socket in state %d %p\n",
142                        sk->sk_state, sk);
143                 return;
144         }
145         if (!sock_flag(sk, SOCK_DEAD)) {
146                 pr_err("Attempt to release alive inet socket %p\n", sk);
147                 return;
148         }
149 
150         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
151         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
152         WARN_ON(sk->sk_wmem_queued);
153         WARN_ON(sk->sk_forward_alloc);
154 
155         kfree(rcu_dereference_protected(inet->inet_opt, 1));
156         dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
157         dst_release(sk->sk_rx_dst);
158         sk_refcnt_debug_dec(sk);
159 }
160 EXPORT_SYMBOL(inet_sock_destruct);
161 
162 /*
163  *      The routines beyond this point handle the behaviour of an AF_INET
164  *      socket object. Mostly it punts to the subprotocols of IP to do
165  *      the work.
166  */
167 
168 /*
169  *      Automatically bind an unbound socket.
170  */
171 
172 static int inet_autobind(struct sock *sk)
173 {
174         struct inet_sock *inet;
175         /* We may need to bind the socket. */
176         lock_sock(sk);
177         inet = inet_sk(sk);
178         if (!inet->inet_num) {
179                 if (sk->sk_prot->get_port(sk, 0)) {
180                         release_sock(sk);
181                         return -EAGAIN;
182                 }
183                 inet->inet_sport = htons(inet->inet_num);
184         }
185         release_sock(sk);
186         return 0;
187 }
188 
189 /*
190  *      Move a socket into listening state.
191  */
192 int inet_listen(struct socket *sock, int backlog)
193 {
194         struct sock *sk = sock->sk;
195         unsigned char old_state;
196         int err;
197 
198         lock_sock(sk);
199 
200         err = -EINVAL;
201         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
202                 goto out;
203 
204         old_state = sk->sk_state;
205         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
206                 goto out;
207 
208         /* Really, if the socket is already in listen state
209          * we can only allow the backlog to be adjusted.
210          */
211         if (old_state != TCP_LISTEN) {
212                 /* Check special setups for testing purpose to enable TFO w/o
213                  * requiring TCP_FASTOPEN sockopt.
214                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
215                  * Also fastopenq may already been allocated because this
216                  * socket was in TCP_LISTEN state previously but was
217                  * shutdown() (rather than close()).
218                  */
219                 if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
220                     inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
221                         if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
222                                 err = fastopen_init_queue(sk, backlog);
223                         else if ((sysctl_tcp_fastopen &
224                                   TFO_SERVER_WO_SOCKOPT2) != 0)
225                                 err = fastopen_init_queue(sk,
226                                     ((uint)sysctl_tcp_fastopen) >> 16);
227                         else
228                                 err = 0;
229                         if (err)
230                                 goto out;
231                 }
232                 err = inet_csk_listen_start(sk, backlog);
233                 if (err)
234                         goto out;
235         }
236         sk->sk_max_ack_backlog = backlog;
237         err = 0;
238 
239 out:
240         release_sock(sk);
241         return err;
242 }
243 EXPORT_SYMBOL(inet_listen);
244 
245 /*
246  *      Create an inet socket.
247  */
248 
249 static int inet_create(struct net *net, struct socket *sock, int protocol,
250                        int kern)
251 {
252         struct sock *sk;
253         struct inet_protosw *answer;
254         struct inet_sock *inet;
255         struct proto *answer_prot;
256         unsigned char answer_flags;
257         int try_loading_module = 0;
258         int err;
259 
260         sock->state = SS_UNCONNECTED;
261 
262         /* Look for the requested type/protocol pair. */
263 lookup_protocol:
264         err = -ESOCKTNOSUPPORT;
265         rcu_read_lock();
266         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
267 
268                 err = 0;
269                 /* Check the non-wild match. */
270                 if (protocol == answer->protocol) {
271                         if (protocol != IPPROTO_IP)
272                                 break;
273                 } else {
274                         /* Check for the two wild cases. */
275                         if (IPPROTO_IP == protocol) {
276                                 protocol = answer->protocol;
277                                 break;
278                         }
279                         if (IPPROTO_IP == answer->protocol)
280                                 break;
281                 }
282                 err = -EPROTONOSUPPORT;
283         }
284 
285         if (unlikely(err)) {
286                 if (try_loading_module < 2) {
287                         rcu_read_unlock();
288                         /*
289                          * Be more specific, e.g. net-pf-2-proto-132-type-1
290                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
291                          */
292                         if (++try_loading_module == 1)
293                                 request_module("net-pf-%d-proto-%d-type-%d",
294                                                PF_INET, protocol, sock->type);
295                         /*
296                          * Fall back to generic, e.g. net-pf-2-proto-132
297                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
298                          */
299                         else
300                                 request_module("net-pf-%d-proto-%d",
301                                                PF_INET, protocol);
302                         goto lookup_protocol;
303                 } else
304                         goto out_rcu_unlock;
305         }
306 
307         err = -EPERM;
308         if (sock->type == SOCK_RAW && !kern &&
309             !ns_capable(net->user_ns, CAP_NET_RAW))
310                 goto out_rcu_unlock;
311 
312         sock->ops = answer->ops;
313         answer_prot = answer->prot;
314         answer_flags = answer->flags;
315         rcu_read_unlock();
316 
317         WARN_ON(answer_prot->slab == NULL);
318 
319         err = -ENOBUFS;
320         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
321         if (sk == NULL)
322                 goto out;
323 
324         err = 0;
325         if (INET_PROTOSW_REUSE & answer_flags)
326                 sk->sk_reuse = SK_CAN_REUSE;
327 
328         inet = inet_sk(sk);
329         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
330 
331         inet->nodefrag = 0;
332 
333         if (SOCK_RAW == sock->type) {
334                 inet->inet_num = protocol;
335                 if (IPPROTO_RAW == protocol)
336                         inet->hdrincl = 1;
337         }
338 
339         if (net->ipv4.sysctl_ip_no_pmtu_disc)
340                 inet->pmtudisc = IP_PMTUDISC_DONT;
341         else
342                 inet->pmtudisc = IP_PMTUDISC_WANT;
343 
344         inet->inet_id = 0;
345 
346         sock_init_data(sock, sk);
347 
348         sk->sk_destruct    = inet_sock_destruct;
349         sk->sk_protocol    = protocol;
350         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
351 
352         inet->uc_ttl    = -1;
353         inet->mc_loop   = 1;
354         inet->mc_ttl    = 1;
355         inet->mc_all    = 1;
356         inet->mc_index  = 0;
357         inet->mc_list   = NULL;
358         inet->rcv_tos   = 0;
359 
360         sk_refcnt_debug_inc(sk);
361 
362         if (inet->inet_num) {
363                 /* It assumes that any protocol which allows
364                  * the user to assign a number at socket
365                  * creation time automatically
366                  * shares.
367                  */
368                 inet->inet_sport = htons(inet->inet_num);
369                 /* Add to protocol hash chains. */
370                 sk->sk_prot->hash(sk);
371         }
372 
373         if (sk->sk_prot->init) {
374                 err = sk->sk_prot->init(sk);
375                 if (err)
376                         sk_common_release(sk);
377         }
378 out:
379         return err;
380 out_rcu_unlock:
381         rcu_read_unlock();
382         goto out;
383 }
384 
385 
386 /*
387  *      The peer socket should always be NULL (or else). When we call this
388  *      function we are destroying the object and from then on nobody
389  *      should refer to it.
390  */
391 int inet_release(struct socket *sock)
392 {
393         struct sock *sk = sock->sk;
394 
395         if (sk) {
396                 long timeout;
397 
398                 sock_rps_reset_flow(sk);
399 
400                 /* Applications forget to leave groups before exiting */
401                 ip_mc_drop_socket(sk);
402 
403                 /* If linger is set, we don't return until the close
404                  * is complete.  Otherwise we return immediately. The
405                  * actually closing is done the same either way.
406                  *
407                  * If the close is due to the process exiting, we never
408                  * linger..
409                  */
410                 timeout = 0;
411                 if (sock_flag(sk, SOCK_LINGER) &&
412                     !(current->flags & PF_EXITING))
413                         timeout = sk->sk_lingertime;
414                 sock->sk = NULL;
415                 sk->sk_prot->close(sk, timeout);
416         }
417         return 0;
418 }
419 EXPORT_SYMBOL(inet_release);
420 
421 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
422 {
423         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
424         struct sock *sk = sock->sk;
425         struct inet_sock *inet = inet_sk(sk);
426         struct net *net = sock_net(sk);
427         unsigned short snum;
428         int chk_addr_ret;
429         int err;
430 
431         /* If the socket has its own bind function then use it. (RAW) */
432         if (sk->sk_prot->bind) {
433                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
434                 goto out;
435         }
436         err = -EINVAL;
437         if (addr_len < sizeof(struct sockaddr_in))
438                 goto out;
439 
440         if (addr->sin_family != AF_INET) {
441                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
442                  * only if s_addr is INADDR_ANY.
443                  */
444                 err = -EAFNOSUPPORT;
445                 if (addr->sin_family != AF_UNSPEC ||
446                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
447                         goto out;
448         }
449 
450         chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
451 
452         /* Not specified by any standard per-se, however it breaks too
453          * many applications when removed.  It is unfortunate since
454          * allowing applications to make a non-local bind solves
455          * several problems with systems using dynamic addressing.
456          * (ie. your servers still start up even if your ISDN link
457          *  is temporarily down)
458          */
459         err = -EADDRNOTAVAIL;
460         if (!net->ipv4.sysctl_ip_nonlocal_bind &&
461             !(inet->freebind || inet->transparent) &&
462             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
463             chk_addr_ret != RTN_LOCAL &&
464             chk_addr_ret != RTN_MULTICAST &&
465             chk_addr_ret != RTN_BROADCAST)
466                 goto out;
467 
468         snum = ntohs(addr->sin_port);
469         err = -EACCES;
470         if (snum && snum < PROT_SOCK &&
471             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
472                 goto out;
473 
474         /*      We keep a pair of addresses. rcv_saddr is the one
475          *      used by hash lookups, and saddr is used for transmit.
476          *
477          *      In the BSD API these are the same except where it
478          *      would be illegal to use them (multicast/broadcast) in
479          *      which case the sending device address is used.
480          */
481         lock_sock(sk);
482 
483         /* Check these errors (active socket, double bind). */
484         err = -EINVAL;
485         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
486                 goto out_release_sock;
487 
488         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
489         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
490                 inet->inet_saddr = 0;  /* Use device */
491 
492         /* Make sure we are allowed to bind here. */
493         if (sk->sk_prot->get_port(sk, snum)) {
494                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
495                 err = -EADDRINUSE;
496                 goto out_release_sock;
497         }
498 
499         if (inet->inet_rcv_saddr)
500                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
501         if (snum)
502                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
503         inet->inet_sport = htons(inet->inet_num);
504         inet->inet_daddr = 0;
505         inet->inet_dport = 0;
506         sk_dst_reset(sk);
507         err = 0;
508 out_release_sock:
509         release_sock(sk);
510 out:
511         return err;
512 }
513 EXPORT_SYMBOL(inet_bind);
514 
515 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
516                        int addr_len, int flags)
517 {
518         struct sock *sk = sock->sk;
519 
520         if (addr_len < sizeof(uaddr->sa_family))
521                 return -EINVAL;
522         if (uaddr->sa_family == AF_UNSPEC)
523                 return sk->sk_prot->disconnect(sk, flags);
524 
525         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
526                 return -EAGAIN;
527         return sk->sk_prot->connect(sk, uaddr, addr_len);
528 }
529 EXPORT_SYMBOL(inet_dgram_connect);
530 
531 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
532 {
533         DEFINE_WAIT(wait);
534 
535         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
536         sk->sk_write_pending += writebias;
537 
538         /* Basic assumption: if someone sets sk->sk_err, he _must_
539          * change state of the socket from TCP_SYN_*.
540          * Connect() does not allow to get error notifications
541          * without closing the socket.
542          */
543         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
544                 release_sock(sk);
545                 timeo = schedule_timeout(timeo);
546                 lock_sock(sk);
547                 if (signal_pending(current) || !timeo)
548                         break;
549                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
550         }
551         finish_wait(sk_sleep(sk), &wait);
552         sk->sk_write_pending -= writebias;
553         return timeo;
554 }
555 
556 /*
557  *      Connect to a remote host. There is regrettably still a little
558  *      TCP 'magic' in here.
559  */
560 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
561                           int addr_len, int flags)
562 {
563         struct sock *sk = sock->sk;
564         int err;
565         long timeo;
566 
567         if (addr_len < sizeof(uaddr->sa_family))
568                 return -EINVAL;
569 
570         if (uaddr->sa_family == AF_UNSPEC) {
571                 err = sk->sk_prot->disconnect(sk, flags);
572                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
573                 goto out;
574         }
575 
576         switch (sock->state) {
577         default:
578                 err = -EINVAL;
579                 goto out;
580         case SS_CONNECTED:
581                 err = -EISCONN;
582                 goto out;
583         case SS_CONNECTING:
584                 err = -EALREADY;
585                 /* Fall out of switch with err, set for this state */
586                 break;
587         case SS_UNCONNECTED:
588                 err = -EISCONN;
589                 if (sk->sk_state != TCP_CLOSE)
590                         goto out;
591 
592                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
593                 if (err < 0)
594                         goto out;
595 
596                 sock->state = SS_CONNECTING;
597 
598                 /* Just entered SS_CONNECTING state; the only
599                  * difference is that return value in non-blocking
600                  * case is EINPROGRESS, rather than EALREADY.
601                  */
602                 err = -EINPROGRESS;
603                 break;
604         }
605 
606         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
607 
608         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
609                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
610                                 tcp_sk(sk)->fastopen_req &&
611                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
612 
613                 /* Error code is set above */
614                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
615                         goto out;
616 
617                 err = sock_intr_errno(timeo);
618                 if (signal_pending(current))
619                         goto out;
620         }
621 
622         /* Connection was closed by RST, timeout, ICMP error
623          * or another process disconnected us.
624          */
625         if (sk->sk_state == TCP_CLOSE)
626                 goto sock_error;
627 
628         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
629          * and error was received after socket entered established state.
630          * Hence, it is handled normally after connect() return successfully.
631          */
632 
633         sock->state = SS_CONNECTED;
634         err = 0;
635 out:
636         return err;
637 
638 sock_error:
639         err = sock_error(sk) ? : -ECONNABORTED;
640         sock->state = SS_UNCONNECTED;
641         if (sk->sk_prot->disconnect(sk, flags))
642                 sock->state = SS_DISCONNECTING;
643         goto out;
644 }
645 EXPORT_SYMBOL(__inet_stream_connect);
646 
647 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
648                         int addr_len, int flags)
649 {
650         int err;
651 
652         lock_sock(sock->sk);
653         err = __inet_stream_connect(sock, uaddr, addr_len, flags);
654         release_sock(sock->sk);
655         return err;
656 }
657 EXPORT_SYMBOL(inet_stream_connect);
658 
659 /*
660  *      Accept a pending connection. The TCP layer now gives BSD semantics.
661  */
662 
663 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
664 {
665         struct sock *sk1 = sock->sk;
666         int err = -EINVAL;
667         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
668 
669         if (!sk2)
670                 goto do_err;
671 
672         lock_sock(sk2);
673 
674         sock_rps_record_flow(sk2);
675         WARN_ON(!((1 << sk2->sk_state) &
676                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
677                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
678 
679         sock_graft(sk2, newsock);
680 
681         newsock->state = SS_CONNECTED;
682         err = 0;
683         release_sock(sk2);
684 do_err:
685         return err;
686 }
687 EXPORT_SYMBOL(inet_accept);
688 
689 
690 /*
691  *      This does both peername and sockname.
692  */
693 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
694                         int *uaddr_len, int peer)
695 {
696         struct sock *sk         = sock->sk;
697         struct inet_sock *inet  = inet_sk(sk);
698         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
699 
700         sin->sin_family = AF_INET;
701         if (peer) {
702                 if (!inet->inet_dport ||
703                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
704                      peer == 1))
705                         return -ENOTCONN;
706                 sin->sin_port = inet->inet_dport;
707                 sin->sin_addr.s_addr = inet->inet_daddr;
708         } else {
709                 __be32 addr = inet->inet_rcv_saddr;
710                 if (!addr)
711                         addr = inet->inet_saddr;
712                 sin->sin_port = inet->inet_sport;
713                 sin->sin_addr.s_addr = addr;
714         }
715         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
716         *uaddr_len = sizeof(*sin);
717         return 0;
718 }
719 EXPORT_SYMBOL(inet_getname);
720 
721 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
722                  size_t size)
723 {
724         struct sock *sk = sock->sk;
725 
726         sock_rps_record_flow(sk);
727 
728         /* We may need to bind the socket. */
729         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
730             inet_autobind(sk))
731                 return -EAGAIN;
732 
733         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
734 }
735 EXPORT_SYMBOL(inet_sendmsg);
736 
737 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
738                       size_t size, int flags)
739 {
740         struct sock *sk = sock->sk;
741 
742         sock_rps_record_flow(sk);
743 
744         /* We may need to bind the socket. */
745         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
746             inet_autobind(sk))
747                 return -EAGAIN;
748 
749         if (sk->sk_prot->sendpage)
750                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
751         return sock_no_sendpage(sock, page, offset, size, flags);
752 }
753 EXPORT_SYMBOL(inet_sendpage);
754 
755 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
756                  size_t size, int flags)
757 {
758         struct sock *sk = sock->sk;
759         int addr_len = 0;
760         int err;
761 
762         sock_rps_record_flow(sk);
763 
764         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
765                                    flags & ~MSG_DONTWAIT, &addr_len);
766         if (err >= 0)
767                 msg->msg_namelen = addr_len;
768         return err;
769 }
770 EXPORT_SYMBOL(inet_recvmsg);
771 
772 int inet_shutdown(struct socket *sock, int how)
773 {
774         struct sock *sk = sock->sk;
775         int err = 0;
776 
777         /* This should really check to make sure
778          * the socket is a TCP socket. (WHY AC...)
779          */
780         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
781                        1->2 bit 2 snds.
782                        2->3 */
783         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
784                 return -EINVAL;
785 
786         lock_sock(sk);
787         if (sock->state == SS_CONNECTING) {
788                 if ((1 << sk->sk_state) &
789                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
790                         sock->state = SS_DISCONNECTING;
791                 else
792                         sock->state = SS_CONNECTED;
793         }
794 
795         switch (sk->sk_state) {
796         case TCP_CLOSE:
797                 err = -ENOTCONN;
798                 /* Hack to wake up other listeners, who can poll for
799                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
800         default:
801                 sk->sk_shutdown |= how;
802                 if (sk->sk_prot->shutdown)
803                         sk->sk_prot->shutdown(sk, how);
804                 break;
805 
806         /* Remaining two branches are temporary solution for missing
807          * close() in multithreaded environment. It is _not_ a good idea,
808          * but we have no choice until close() is repaired at VFS level.
809          */
810         case TCP_LISTEN:
811                 if (!(how & RCV_SHUTDOWN))
812                         break;
813                 /* Fall through */
814         case TCP_SYN_SENT:
815                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
816                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
817                 break;
818         }
819 
820         /* Wake up anyone sleeping in poll. */
821         sk->sk_state_change(sk);
822         release_sock(sk);
823         return err;
824 }
825 EXPORT_SYMBOL(inet_shutdown);
826 
827 /*
828  *      ioctl() calls you can issue on an INET socket. Most of these are
829  *      device configuration and stuff and very rarely used. Some ioctls
830  *      pass on to the socket itself.
831  *
832  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
833  *      loads the devconfigure module does its configuring and unloads it.
834  *      There's a good 20K of config code hanging around the kernel.
835  */
836 
837 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
838 {
839         struct sock *sk = sock->sk;
840         int err = 0;
841         struct net *net = sock_net(sk);
842 
843         switch (cmd) {
844         case SIOCGSTAMP:
845                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
846                 break;
847         case SIOCGSTAMPNS:
848                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
849                 break;
850         case SIOCADDRT:
851         case SIOCDELRT:
852         case SIOCRTMSG:
853                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
854                 break;
855         case SIOCDARP:
856         case SIOCGARP:
857         case SIOCSARP:
858                 err = arp_ioctl(net, cmd, (void __user *)arg);
859                 break;
860         case SIOCGIFADDR:
861         case SIOCSIFADDR:
862         case SIOCGIFBRDADDR:
863         case SIOCSIFBRDADDR:
864         case SIOCGIFNETMASK:
865         case SIOCSIFNETMASK:
866         case SIOCGIFDSTADDR:
867         case SIOCSIFDSTADDR:
868         case SIOCSIFPFLAGS:
869         case SIOCGIFPFLAGS:
870         case SIOCSIFFLAGS:
871                 err = devinet_ioctl(net, cmd, (void __user *)arg);
872                 break;
873         default:
874                 if (sk->sk_prot->ioctl)
875                         err = sk->sk_prot->ioctl(sk, cmd, arg);
876                 else
877                         err = -ENOIOCTLCMD;
878                 break;
879         }
880         return err;
881 }
882 EXPORT_SYMBOL(inet_ioctl);
883 
884 #ifdef CONFIG_COMPAT
885 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
886 {
887         struct sock *sk = sock->sk;
888         int err = -ENOIOCTLCMD;
889 
890         if (sk->sk_prot->compat_ioctl)
891                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
892 
893         return err;
894 }
895 #endif
896 
897 const struct proto_ops inet_stream_ops = {
898         .family            = PF_INET,
899         .owner             = THIS_MODULE,
900         .release           = inet_release,
901         .bind              = inet_bind,
902         .connect           = inet_stream_connect,
903         .socketpair        = sock_no_socketpair,
904         .accept            = inet_accept,
905         .getname           = inet_getname,
906         .poll              = tcp_poll,
907         .ioctl             = inet_ioctl,
908         .listen            = inet_listen,
909         .shutdown          = inet_shutdown,
910         .setsockopt        = sock_common_setsockopt,
911         .getsockopt        = sock_common_getsockopt,
912         .sendmsg           = inet_sendmsg,
913         .recvmsg           = inet_recvmsg,
914         .mmap              = sock_no_mmap,
915         .sendpage          = inet_sendpage,
916         .splice_read       = tcp_splice_read,
917 #ifdef CONFIG_COMPAT
918         .compat_setsockopt = compat_sock_common_setsockopt,
919         .compat_getsockopt = compat_sock_common_getsockopt,
920         .compat_ioctl      = inet_compat_ioctl,
921 #endif
922 };
923 EXPORT_SYMBOL(inet_stream_ops);
924 
925 const struct proto_ops inet_dgram_ops = {
926         .family            = PF_INET,
927         .owner             = THIS_MODULE,
928         .release           = inet_release,
929         .bind              = inet_bind,
930         .connect           = inet_dgram_connect,
931         .socketpair        = sock_no_socketpair,
932         .accept            = sock_no_accept,
933         .getname           = inet_getname,
934         .poll              = udp_poll,
935         .ioctl             = inet_ioctl,
936         .listen            = sock_no_listen,
937         .shutdown          = inet_shutdown,
938         .setsockopt        = sock_common_setsockopt,
939         .getsockopt        = sock_common_getsockopt,
940         .sendmsg           = inet_sendmsg,
941         .recvmsg           = inet_recvmsg,
942         .mmap              = sock_no_mmap,
943         .sendpage          = inet_sendpage,
944 #ifdef CONFIG_COMPAT
945         .compat_setsockopt = compat_sock_common_setsockopt,
946         .compat_getsockopt = compat_sock_common_getsockopt,
947         .compat_ioctl      = inet_compat_ioctl,
948 #endif
949 };
950 EXPORT_SYMBOL(inet_dgram_ops);
951 
952 /*
953  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
954  * udp_poll
955  */
956 static const struct proto_ops inet_sockraw_ops = {
957         .family            = PF_INET,
958         .owner             = THIS_MODULE,
959         .release           = inet_release,
960         .bind              = inet_bind,
961         .connect           = inet_dgram_connect,
962         .socketpair        = sock_no_socketpair,
963         .accept            = sock_no_accept,
964         .getname           = inet_getname,
965         .poll              = datagram_poll,
966         .ioctl             = inet_ioctl,
967         .listen            = sock_no_listen,
968         .shutdown          = inet_shutdown,
969         .setsockopt        = sock_common_setsockopt,
970         .getsockopt        = sock_common_getsockopt,
971         .sendmsg           = inet_sendmsg,
972         .recvmsg           = inet_recvmsg,
973         .mmap              = sock_no_mmap,
974         .sendpage          = inet_sendpage,
975 #ifdef CONFIG_COMPAT
976         .compat_setsockopt = compat_sock_common_setsockopt,
977         .compat_getsockopt = compat_sock_common_getsockopt,
978         .compat_ioctl      = inet_compat_ioctl,
979 #endif
980 };
981 
982 static const struct net_proto_family inet_family_ops = {
983         .family = PF_INET,
984         .create = inet_create,
985         .owner  = THIS_MODULE,
986 };
987 
988 /* Upon startup we insert all the elements in inetsw_array[] into
989  * the linked list inetsw.
990  */
991 static struct inet_protosw inetsw_array[] =
992 {
993         {
994                 .type =       SOCK_STREAM,
995                 .protocol =   IPPROTO_TCP,
996                 .prot =       &tcp_prot,
997                 .ops =        &inet_stream_ops,
998                 .flags =      INET_PROTOSW_PERMANENT |
999                               INET_PROTOSW_ICSK,
1000         },
1001 
1002         {
1003                 .type =       SOCK_DGRAM,
1004                 .protocol =   IPPROTO_UDP,
1005                 .prot =       &udp_prot,
1006                 .ops =        &inet_dgram_ops,
1007                 .flags =      INET_PROTOSW_PERMANENT,
1008        },
1009 
1010        {
1011                 .type =       SOCK_DGRAM,
1012                 .protocol =   IPPROTO_ICMP,
1013                 .prot =       &ping_prot,
1014                 .ops =        &inet_dgram_ops,
1015                 .flags =      INET_PROTOSW_REUSE,
1016        },
1017 
1018        {
1019                .type =       SOCK_RAW,
1020                .protocol =   IPPROTO_IP,        /* wild card */
1021                .prot =       &raw_prot,
1022                .ops =        &inet_sockraw_ops,
1023                .flags =      INET_PROTOSW_REUSE,
1024        }
1025 };
1026 
1027 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1028 
1029 void inet_register_protosw(struct inet_protosw *p)
1030 {
1031         struct list_head *lh;
1032         struct inet_protosw *answer;
1033         int protocol = p->protocol;
1034         struct list_head *last_perm;
1035 
1036         spin_lock_bh(&inetsw_lock);
1037 
1038         if (p->type >= SOCK_MAX)
1039                 goto out_illegal;
1040 
1041         /* If we are trying to override a permanent protocol, bail. */
1042         answer = NULL;
1043         last_perm = &inetsw[p->type];
1044         list_for_each(lh, &inetsw[p->type]) {
1045                 answer = list_entry(lh, struct inet_protosw, list);
1046 
1047                 /* Check only the non-wild match. */
1048                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1049                         if (protocol == answer->protocol)
1050                                 break;
1051                         last_perm = lh;
1052                 }
1053 
1054                 answer = NULL;
1055         }
1056         if (answer)
1057                 goto out_permanent;
1058 
1059         /* Add the new entry after the last permanent entry if any, so that
1060          * the new entry does not override a permanent entry when matched with
1061          * a wild-card protocol. But it is allowed to override any existing
1062          * non-permanent entry.  This means that when we remove this entry, the
1063          * system automatically returns to the old behavior.
1064          */
1065         list_add_rcu(&p->list, last_perm);
1066 out:
1067         spin_unlock_bh(&inetsw_lock);
1068 
1069         return;
1070 
1071 out_permanent:
1072         pr_err("Attempt to override permanent protocol %d\n", protocol);
1073         goto out;
1074 
1075 out_illegal:
1076         pr_err("Ignoring attempt to register invalid socket type %d\n",
1077                p->type);
1078         goto out;
1079 }
1080 EXPORT_SYMBOL(inet_register_protosw);
1081 
1082 void inet_unregister_protosw(struct inet_protosw *p)
1083 {
1084         if (INET_PROTOSW_PERMANENT & p->flags) {
1085                 pr_err("Attempt to unregister permanent protocol %d\n",
1086                        p->protocol);
1087         } else {
1088                 spin_lock_bh(&inetsw_lock);
1089                 list_del_rcu(&p->list);
1090                 spin_unlock_bh(&inetsw_lock);
1091 
1092                 synchronize_net();
1093         }
1094 }
1095 EXPORT_SYMBOL(inet_unregister_protosw);
1096 
1097 /*
1098  *      Shall we try to damage output packets if routing dev changes?
1099  */
1100 
1101 int sysctl_ip_dynaddr __read_mostly;
1102 
1103 static int inet_sk_reselect_saddr(struct sock *sk)
1104 {
1105         struct inet_sock *inet = inet_sk(sk);
1106         __be32 old_saddr = inet->inet_saddr;
1107         __be32 daddr = inet->inet_daddr;
1108         struct flowi4 *fl4;
1109         struct rtable *rt;
1110         __be32 new_saddr;
1111         struct ip_options_rcu *inet_opt;
1112 
1113         inet_opt = rcu_dereference_protected(inet->inet_opt,
1114                                              sock_owned_by_user(sk));
1115         if (inet_opt && inet_opt->opt.srr)
1116                 daddr = inet_opt->opt.faddr;
1117 
1118         /* Query new route. */
1119         fl4 = &inet->cork.fl.u.ip4;
1120         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1121                               sk->sk_bound_dev_if, sk->sk_protocol,
1122                               inet->inet_sport, inet->inet_dport, sk);
1123         if (IS_ERR(rt))
1124                 return PTR_ERR(rt);
1125 
1126         sk_setup_caps(sk, &rt->dst);
1127 
1128         new_saddr = fl4->saddr;
1129 
1130         if (new_saddr == old_saddr)
1131                 return 0;
1132 
1133         if (sysctl_ip_dynaddr > 1) {
1134                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1135                         __func__, &old_saddr, &new_saddr);
1136         }
1137 
1138         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1139 
1140         /*
1141          * XXX The only one ugly spot where we need to
1142          * XXX really change the sockets identity after
1143          * XXX it has entered the hashes. -DaveM
1144          *
1145          * Besides that, it does not check for connection
1146          * uniqueness. Wait for troubles.
1147          */
1148         __sk_prot_rehash(sk);
1149         return 0;
1150 }
1151 
1152 int inet_sk_rebuild_header(struct sock *sk)
1153 {
1154         struct inet_sock *inet = inet_sk(sk);
1155         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1156         __be32 daddr;
1157         struct ip_options_rcu *inet_opt;
1158         struct flowi4 *fl4;
1159         int err;
1160 
1161         /* Route is OK, nothing to do. */
1162         if (rt)
1163                 return 0;
1164 
1165         /* Reroute. */
1166         rcu_read_lock();
1167         inet_opt = rcu_dereference(inet->inet_opt);
1168         daddr = inet->inet_daddr;
1169         if (inet_opt && inet_opt->opt.srr)
1170                 daddr = inet_opt->opt.faddr;
1171         rcu_read_unlock();
1172         fl4 = &inet->cork.fl.u.ip4;
1173         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1174                                    inet->inet_dport, inet->inet_sport,
1175                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1176                                    sk->sk_bound_dev_if);
1177         if (!IS_ERR(rt)) {
1178                 err = 0;
1179                 sk_setup_caps(sk, &rt->dst);
1180         } else {
1181                 err = PTR_ERR(rt);
1182 
1183                 /* Routing failed... */
1184                 sk->sk_route_caps = 0;
1185                 /*
1186                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1187                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1188                  */
1189                 if (!sysctl_ip_dynaddr ||
1190                     sk->sk_state != TCP_SYN_SENT ||
1191                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1192                     (err = inet_sk_reselect_saddr(sk)) != 0)
1193                         sk->sk_err_soft = -err;
1194         }
1195 
1196         return err;
1197 }
1198 EXPORT_SYMBOL(inet_sk_rebuild_header);
1199 
1200 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1201                                         netdev_features_t features)
1202 {
1203         struct sk_buff *segs = ERR_PTR(-EINVAL);
1204         const struct net_offload *ops;
1205         unsigned int offset = 0;
1206         bool udpfrag, encap;
1207         struct iphdr *iph;
1208         int proto;
1209         int nhoff;
1210         int ihl;
1211         int id;
1212 
1213         if (unlikely(skb_shinfo(skb)->gso_type &
1214                      ~(SKB_GSO_TCPV4 |
1215                        SKB_GSO_UDP |
1216                        SKB_GSO_DODGY |
1217                        SKB_GSO_TCP_ECN |
1218                        SKB_GSO_GRE |
1219                        SKB_GSO_GRE_CSUM |
1220                        SKB_GSO_IPIP |
1221                        SKB_GSO_SIT |
1222                        SKB_GSO_TCPV6 |
1223                        SKB_GSO_UDP_TUNNEL |
1224                        SKB_GSO_UDP_TUNNEL_CSUM |
1225                        SKB_GSO_MPLS |
1226                        0)))
1227                 goto out;
1228 
1229         skb_reset_network_header(skb);
1230         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1231         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1232                 goto out;
1233 
1234         iph = ip_hdr(skb);
1235         ihl = iph->ihl * 4;
1236         if (ihl < sizeof(*iph))
1237                 goto out;
1238 
1239         id = ntohs(iph->id);
1240         proto = iph->protocol;
1241 
1242         /* Warning: after this point, iph might be no longer valid */
1243         if (unlikely(!pskb_may_pull(skb, ihl)))
1244                 goto out;
1245         __skb_pull(skb, ihl);
1246 
1247         encap = SKB_GSO_CB(skb)->encap_level > 0;
1248         if (encap)
1249                 features &= skb->dev->hw_enc_features;
1250         SKB_GSO_CB(skb)->encap_level += ihl;
1251 
1252         skb_reset_transport_header(skb);
1253 
1254         segs = ERR_PTR(-EPROTONOSUPPORT);
1255 
1256         if (skb->encapsulation &&
1257             skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
1258                 udpfrag = proto == IPPROTO_UDP && encap;
1259         else
1260                 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
1261 
1262         ops = rcu_dereference(inet_offloads[proto]);
1263         if (likely(ops && ops->callbacks.gso_segment))
1264                 segs = ops->callbacks.gso_segment(skb, features);
1265 
1266         if (IS_ERR_OR_NULL(segs))
1267                 goto out;
1268 
1269         skb = segs;
1270         do {
1271                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1272                 if (udpfrag) {
1273                         iph->id = htons(id);
1274                         iph->frag_off = htons(offset >> 3);
1275                         if (skb->next != NULL)
1276                                 iph->frag_off |= htons(IP_MF);
1277                         offset += skb->len - nhoff - ihl;
1278                 } else {
1279                         iph->id = htons(id++);
1280                 }
1281                 iph->tot_len = htons(skb->len - nhoff);
1282                 ip_send_check(iph);
1283                 if (encap)
1284                         skb_reset_inner_headers(skb);
1285                 skb->network_header = (u8 *)iph - skb->head;
1286         } while ((skb = skb->next));
1287 
1288 out:
1289         return segs;
1290 }
1291 
1292 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1293                                          struct sk_buff *skb)
1294 {
1295         const struct net_offload *ops;
1296         struct sk_buff **pp = NULL;
1297         struct sk_buff *p;
1298         const struct iphdr *iph;
1299         unsigned int hlen;
1300         unsigned int off;
1301         unsigned int id;
1302         int flush = 1;
1303         int proto;
1304 
1305         off = skb_gro_offset(skb);
1306         hlen = off + sizeof(*iph);
1307         iph = skb_gro_header_fast(skb, off);
1308         if (skb_gro_header_hard(skb, hlen)) {
1309                 iph = skb_gro_header_slow(skb, hlen, off);
1310                 if (unlikely(!iph))
1311                         goto out;
1312         }
1313 
1314         proto = iph->protocol;
1315 
1316         rcu_read_lock();
1317         ops = rcu_dereference(inet_offloads[proto]);
1318         if (!ops || !ops->callbacks.gro_receive)
1319                 goto out_unlock;
1320 
1321         if (*(u8 *)iph != 0x45)
1322                 goto out_unlock;
1323 
1324         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1325                 goto out_unlock;
1326 
1327         id = ntohl(*(__be32 *)&iph->id);
1328         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1329         id >>= 16;
1330 
1331         for (p = *head; p; p = p->next) {
1332                 struct iphdr *iph2;
1333 
1334                 if (!NAPI_GRO_CB(p)->same_flow)
1335                         continue;
1336 
1337                 iph2 = (struct iphdr *)(p->data + off);
1338                 /* The above works because, with the exception of the top
1339                  * (inner most) layer, we only aggregate pkts with the same
1340                  * hdr length so all the hdrs we'll need to verify will start
1341                  * at the same offset.
1342                  */
1343                 if ((iph->protocol ^ iph2->protocol) |
1344                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1345                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1346                         NAPI_GRO_CB(p)->same_flow = 0;
1347                         continue;
1348                 }
1349 
1350                 /* All fields must match except length and checksum. */
1351                 NAPI_GRO_CB(p)->flush |=
1352                         (iph->ttl ^ iph2->ttl) |
1353                         (iph->tos ^ iph2->tos) |
1354                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1355 
1356                 /* Save the IP ID check to be included later when we get to
1357                  * the transport layer so only the inner most IP ID is checked.
1358                  * This is because some GSO/TSO implementations do not
1359                  * correctly increment the IP ID for the outer hdrs.
1360                  */
1361                 NAPI_GRO_CB(p)->flush_id =
1362                             ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1363                 NAPI_GRO_CB(p)->flush |= flush;
1364         }
1365 
1366         NAPI_GRO_CB(skb)->flush |= flush;
1367         skb_set_network_header(skb, off);
1368         /* The above will be needed by the transport layer if there is one
1369          * immediately following this IP hdr.
1370          */
1371 
1372         /* Note : No need to call skb_gro_postpull_rcsum() here,
1373          * as we already checked checksum over ipv4 header was 0
1374          */
1375         skb_gro_pull(skb, sizeof(*iph));
1376         skb_set_transport_header(skb, skb_gro_offset(skb));
1377 
1378         pp = ops->callbacks.gro_receive(head, skb);
1379 
1380 out_unlock:
1381         rcu_read_unlock();
1382 
1383 out:
1384         NAPI_GRO_CB(skb)->flush |= flush;
1385 
1386         return pp;
1387 }
1388 
1389 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1390 {
1391         if (sk->sk_family == AF_INET)
1392                 return ip_recv_error(sk, msg, len, addr_len);
1393 #if IS_ENABLED(CONFIG_IPV6)
1394         if (sk->sk_family == AF_INET6)
1395                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1396 #endif
1397         return -EINVAL;
1398 }
1399 
1400 static int inet_gro_complete(struct sk_buff *skb, int nhoff)
1401 {
1402         __be16 newlen = htons(skb->len - nhoff);
1403         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1404         const struct net_offload *ops;
1405         int proto = iph->protocol;
1406         int err = -ENOSYS;
1407 
1408         if (skb->encapsulation)
1409                 skb_set_inner_network_header(skb, nhoff);
1410 
1411         csum_replace2(&iph->check, iph->tot_len, newlen);
1412         iph->tot_len = newlen;
1413 
1414         rcu_read_lock();
1415         ops = rcu_dereference(inet_offloads[proto]);
1416         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1417                 goto out_unlock;
1418 
1419         /* Only need to add sizeof(*iph) to get to the next hdr below
1420          * because any hdr with option will have been flushed in
1421          * inet_gro_receive().
1422          */
1423         err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1424 
1425 out_unlock:
1426         rcu_read_unlock();
1427 
1428         return err;
1429 }
1430 
1431 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1432                          unsigned short type, unsigned char protocol,
1433                          struct net *net)
1434 {
1435         struct socket *sock;
1436         int rc = sock_create_kern(family, type, protocol, &sock);
1437 
1438         if (rc == 0) {
1439                 *sk = sock->sk;
1440                 (*sk)->sk_allocation = GFP_ATOMIC;
1441                 /*
1442                  * Unhash it so that IP input processing does not even see it,
1443                  * we do not wish this socket to see incoming packets.
1444                  */
1445                 (*sk)->sk_prot->unhash(*sk);
1446 
1447                 sk_change_net(*sk, net);
1448         }
1449         return rc;
1450 }
1451 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1452 
1453 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1454 {
1455         unsigned long res = 0;
1456         int i;
1457 
1458         for_each_possible_cpu(i)
1459                 res += *(((unsigned long *) per_cpu_ptr(mib, i)) + offt);
1460         return res;
1461 }
1462 EXPORT_SYMBOL_GPL(snmp_fold_field);
1463 
1464 #if BITS_PER_LONG==32
1465 
1466 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1467 {
1468         u64 res = 0;
1469         int cpu;
1470 
1471         for_each_possible_cpu(cpu) {
1472                 void *bhptr;
1473                 struct u64_stats_sync *syncp;
1474                 u64 v;
1475                 unsigned int start;
1476 
1477                 bhptr = per_cpu_ptr(mib, cpu);
1478                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1479                 do {
1480                         start = u64_stats_fetch_begin_irq(syncp);
1481                         v = *(((u64 *) bhptr) + offt);
1482                 } while (u64_stats_fetch_retry_irq(syncp, start));
1483 
1484                 res += v;
1485         }
1486         return res;
1487 }
1488 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1489 #endif
1490 
1491 #ifdef CONFIG_IP_MULTICAST
1492 static const struct net_protocol igmp_protocol = {
1493         .handler =      igmp_rcv,
1494         .netns_ok =     1,
1495 };
1496 #endif
1497 
1498 static const struct net_protocol tcp_protocol = {
1499         .early_demux    =       tcp_v4_early_demux,
1500         .handler        =       tcp_v4_rcv,
1501         .err_handler    =       tcp_v4_err,
1502         .no_policy      =       1,
1503         .netns_ok       =       1,
1504         .icmp_strict_tag_validation = 1,
1505 };
1506 
1507 static const struct net_protocol udp_protocol = {
1508         .early_demux =  udp_v4_early_demux,
1509         .handler =      udp_rcv,
1510         .err_handler =  udp_err,
1511         .no_policy =    1,
1512         .netns_ok =     1,
1513 };
1514 
1515 static const struct net_protocol icmp_protocol = {
1516         .handler =      icmp_rcv,
1517         .err_handler =  icmp_err,
1518         .no_policy =    1,
1519         .netns_ok =     1,
1520 };
1521 
1522 static __net_init int ipv4_mib_init_net(struct net *net)
1523 {
1524         int i;
1525 
1526         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1527         if (!net->mib.tcp_statistics)
1528                 goto err_tcp_mib;
1529         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1530         if (!net->mib.ip_statistics)
1531                 goto err_ip_mib;
1532 
1533         for_each_possible_cpu(i) {
1534                 struct ipstats_mib *af_inet_stats;
1535                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1536                 u64_stats_init(&af_inet_stats->syncp);
1537         }
1538 
1539         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1540         if (!net->mib.net_statistics)
1541                 goto err_net_mib;
1542         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1543         if (!net->mib.udp_statistics)
1544                 goto err_udp_mib;
1545         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1546         if (!net->mib.udplite_statistics)
1547                 goto err_udplite_mib;
1548         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1549         if (!net->mib.icmp_statistics)
1550                 goto err_icmp_mib;
1551         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1552                                               GFP_KERNEL);
1553         if (!net->mib.icmpmsg_statistics)
1554                 goto err_icmpmsg_mib;
1555 
1556         tcp_mib_init(net);
1557         return 0;
1558 
1559 err_icmpmsg_mib:
1560         free_percpu(net->mib.icmp_statistics);
1561 err_icmp_mib:
1562         free_percpu(net->mib.udplite_statistics);
1563 err_udplite_mib:
1564         free_percpu(net->mib.udp_statistics);
1565 err_udp_mib:
1566         free_percpu(net->mib.net_statistics);
1567 err_net_mib:
1568         free_percpu(net->mib.ip_statistics);
1569 err_ip_mib:
1570         free_percpu(net->mib.tcp_statistics);
1571 err_tcp_mib:
1572         return -ENOMEM;
1573 }
1574 
1575 static __net_exit void ipv4_mib_exit_net(struct net *net)
1576 {
1577         kfree(net->mib.icmpmsg_statistics);
1578         free_percpu(net->mib.icmp_statistics);
1579         free_percpu(net->mib.udplite_statistics);
1580         free_percpu(net->mib.udp_statistics);
1581         free_percpu(net->mib.net_statistics);
1582         free_percpu(net->mib.ip_statistics);
1583         free_percpu(net->mib.tcp_statistics);
1584 }
1585 
1586 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1587         .init = ipv4_mib_init_net,
1588         .exit = ipv4_mib_exit_net,
1589 };
1590 
1591 static int __init init_ipv4_mibs(void)
1592 {
1593         return register_pernet_subsys(&ipv4_mib_ops);
1594 }
1595 
1596 static __net_init int inet_init_net(struct net *net)
1597 {
1598         /*
1599          * Set defaults for local port range
1600          */
1601         seqlock_init(&net->ipv4.ip_local_ports.lock);
1602         net->ipv4.ip_local_ports.range[0] =  32768;
1603         net->ipv4.ip_local_ports.range[1] =  61000;
1604 
1605         seqlock_init(&net->ipv4.ping_group_range.lock);
1606         /*
1607          * Sane defaults - nobody may create ping sockets.
1608          * Boot scripts should set this to distro-specific group.
1609          */
1610         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1611         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1612         return 0;
1613 }
1614 
1615 static __net_exit void inet_exit_net(struct net *net)
1616 {
1617 }
1618 
1619 static __net_initdata struct pernet_operations af_inet_ops = {
1620         .init = inet_init_net,
1621         .exit = inet_exit_net,
1622 };
1623 
1624 static int __init init_inet_pernet_ops(void)
1625 {
1626         return register_pernet_subsys(&af_inet_ops);
1627 }
1628 
1629 static int ipv4_proc_init(void);
1630 
1631 /*
1632  *      IP protocol layer initialiser
1633  */
1634 
1635 static struct packet_offload ip_packet_offload __read_mostly = {
1636         .type = cpu_to_be16(ETH_P_IP),
1637         .callbacks = {
1638                 .gso_segment = inet_gso_segment,
1639                 .gro_receive = inet_gro_receive,
1640                 .gro_complete = inet_gro_complete,
1641         },
1642 };
1643 
1644 static const struct net_offload ipip_offload = {
1645         .callbacks = {
1646                 .gso_segment    = inet_gso_segment,
1647                 .gro_receive    = inet_gro_receive,
1648                 .gro_complete   = inet_gro_complete,
1649         },
1650 };
1651 
1652 static int __init ipv4_offload_init(void)
1653 {
1654         /*
1655          * Add offloads
1656          */
1657         if (udpv4_offload_init() < 0)
1658                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1659         if (tcpv4_offload_init() < 0)
1660                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1661 
1662         dev_add_offload(&ip_packet_offload);
1663         inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1664         return 0;
1665 }
1666 
1667 fs_initcall(ipv4_offload_init);
1668 
1669 static struct packet_type ip_packet_type __read_mostly = {
1670         .type = cpu_to_be16(ETH_P_IP),
1671         .func = ip_rcv,
1672 };
1673 
1674 static int __init inet_init(void)
1675 {
1676         struct inet_protosw *q;
1677         struct list_head *r;
1678         int rc = -EINVAL;
1679 
1680         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1681 
1682         rc = proto_register(&tcp_prot, 1);
1683         if (rc)
1684                 goto out;
1685 
1686         rc = proto_register(&udp_prot, 1);
1687         if (rc)
1688                 goto out_unregister_tcp_proto;
1689 
1690         rc = proto_register(&raw_prot, 1);
1691         if (rc)
1692                 goto out_unregister_udp_proto;
1693 
1694         rc = proto_register(&ping_prot, 1);
1695         if (rc)
1696                 goto out_unregister_raw_proto;
1697 
1698         /*
1699          *      Tell SOCKET that we are alive...
1700          */
1701 
1702         (void)sock_register(&inet_family_ops);
1703 
1704 #ifdef CONFIG_SYSCTL
1705         ip_static_sysctl_init();
1706 #endif
1707 
1708         /*
1709          *      Add all the base protocols.
1710          */
1711 
1712         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1713                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1714         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1715                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1716         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1717                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1718 #ifdef CONFIG_IP_MULTICAST
1719         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1720                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1721 #endif
1722 
1723         /* Register the socket-side information for inet_create. */
1724         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1725                 INIT_LIST_HEAD(r);
1726 
1727         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1728                 inet_register_protosw(q);
1729 
1730         /*
1731          *      Set the ARP module up
1732          */
1733 
1734         arp_init();
1735 
1736         /*
1737          *      Set the IP module up
1738          */
1739 
1740         ip_init();
1741 
1742         tcp_v4_init();
1743 
1744         /* Setup TCP slab cache for open requests. */
1745         tcp_init();
1746 
1747         /* Setup UDP memory threshold */
1748         udp_init();
1749 
1750         /* Add UDP-Lite (RFC 3828) */
1751         udplite4_register();
1752 
1753         ping_init();
1754 
1755         /*
1756          *      Set the ICMP layer up
1757          */
1758 
1759         if (icmp_init() < 0)
1760                 panic("Failed to create the ICMP control socket.\n");
1761 
1762         /*
1763          *      Initialise the multicast router
1764          */
1765 #if defined(CONFIG_IP_MROUTE)
1766         if (ip_mr_init())
1767                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1768 #endif
1769 
1770         if (init_inet_pernet_ops())
1771                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1772         /*
1773          *      Initialise per-cpu ipv4 mibs
1774          */
1775 
1776         if (init_ipv4_mibs())
1777                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1778 
1779         ipv4_proc_init();
1780 
1781         ipfrag_init();
1782 
1783         dev_add_pack(&ip_packet_type);
1784 
1785         rc = 0;
1786 out:
1787         return rc;
1788 out_unregister_raw_proto:
1789         proto_unregister(&raw_prot);
1790 out_unregister_udp_proto:
1791         proto_unregister(&udp_prot);
1792 out_unregister_tcp_proto:
1793         proto_unregister(&tcp_prot);
1794         goto out;
1795 }
1796 
1797 fs_initcall(inet_init);
1798 
1799 /* ------------------------------------------------------------------------ */
1800 
1801 #ifdef CONFIG_PROC_FS
1802 static int __init ipv4_proc_init(void)
1803 {
1804         int rc = 0;
1805 
1806         if (raw_proc_init())
1807                 goto out_raw;
1808         if (tcp4_proc_init())
1809                 goto out_tcp;
1810         if (udp4_proc_init())
1811                 goto out_udp;
1812         if (ping_proc_init())
1813                 goto out_ping;
1814         if (ip_misc_proc_init())
1815                 goto out_misc;
1816 out:
1817         return rc;
1818 out_misc:
1819         ping_proc_exit();
1820 out_ping:
1821         udp4_proc_exit();
1822 out_udp:
1823         tcp4_proc_exit();
1824 out_tcp:
1825         raw_proc_exit();
1826 out_raw:
1827         rc = -ENOMEM;
1828         goto out;
1829 }
1830 
1831 #else /* CONFIG_PROC_FS */
1832 static int __init ipv4_proc_init(void)
1833 {
1834         return 0;
1835 }
1836 #endif /* CONFIG_PROC_FS */
1837 
1838 MODULE_ALIAS_NETPROTO(PF_INET);
1839 
1840 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us