Version:  2.0.40 2.2.26 2.4.37 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 3.19 4.0

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                 /* Applications forget to leave groups before exiting */
399                 ip_mc_drop_socket(sk);
400 
401                 /* If linger is set, we don't return until the close
402                  * is complete.  Otherwise we return immediately. The
403                  * actually closing is done the same either way.
404                  *
405                  * If the close is due to the process exiting, we never
406                  * linger..
407                  */
408                 timeout = 0;
409                 if (sock_flag(sk, SOCK_LINGER) &&
410                     !(current->flags & PF_EXITING))
411                         timeout = sk->sk_lingertime;
412                 sock->sk = NULL;
413                 sk->sk_prot->close(sk, timeout);
414         }
415         return 0;
416 }
417 EXPORT_SYMBOL(inet_release);
418 
419 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
420 {
421         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
422         struct sock *sk = sock->sk;
423         struct inet_sock *inet = inet_sk(sk);
424         struct net *net = sock_net(sk);
425         unsigned short snum;
426         int chk_addr_ret;
427         int err;
428 
429         /* If the socket has its own bind function then use it. (RAW) */
430         if (sk->sk_prot->bind) {
431                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
432                 goto out;
433         }
434         err = -EINVAL;
435         if (addr_len < sizeof(struct sockaddr_in))
436                 goto out;
437 
438         if (addr->sin_family != AF_INET) {
439                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
440                  * only if s_addr is INADDR_ANY.
441                  */
442                 err = -EAFNOSUPPORT;
443                 if (addr->sin_family != AF_UNSPEC ||
444                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
445                         goto out;
446         }
447 
448         chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
449 
450         /* Not specified by any standard per-se, however it breaks too
451          * many applications when removed.  It is unfortunate since
452          * allowing applications to make a non-local bind solves
453          * several problems with systems using dynamic addressing.
454          * (ie. your servers still start up even if your ISDN link
455          *  is temporarily down)
456          */
457         err = -EADDRNOTAVAIL;
458         if (!net->ipv4.sysctl_ip_nonlocal_bind &&
459             !(inet->freebind || inet->transparent) &&
460             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
461             chk_addr_ret != RTN_LOCAL &&
462             chk_addr_ret != RTN_MULTICAST &&
463             chk_addr_ret != RTN_BROADCAST)
464                 goto out;
465 
466         snum = ntohs(addr->sin_port);
467         err = -EACCES;
468         if (snum && snum < PROT_SOCK &&
469             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
470                 goto out;
471 
472         /*      We keep a pair of addresses. rcv_saddr is the one
473          *      used by hash lookups, and saddr is used for transmit.
474          *
475          *      In the BSD API these are the same except where it
476          *      would be illegal to use them (multicast/broadcast) in
477          *      which case the sending device address is used.
478          */
479         lock_sock(sk);
480 
481         /* Check these errors (active socket, double bind). */
482         err = -EINVAL;
483         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
484                 goto out_release_sock;
485 
486         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
487         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
488                 inet->inet_saddr = 0;  /* Use device */
489 
490         /* Make sure we are allowed to bind here. */
491         if (sk->sk_prot->get_port(sk, snum)) {
492                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
493                 err = -EADDRINUSE;
494                 goto out_release_sock;
495         }
496 
497         if (inet->inet_rcv_saddr)
498                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
499         if (snum)
500                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
501         inet->inet_sport = htons(inet->inet_num);
502         inet->inet_daddr = 0;
503         inet->inet_dport = 0;
504         sk_dst_reset(sk);
505         err = 0;
506 out_release_sock:
507         release_sock(sk);
508 out:
509         return err;
510 }
511 EXPORT_SYMBOL(inet_bind);
512 
513 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
514                        int addr_len, int flags)
515 {
516         struct sock *sk = sock->sk;
517 
518         if (addr_len < sizeof(uaddr->sa_family))
519                 return -EINVAL;
520         if (uaddr->sa_family == AF_UNSPEC)
521                 return sk->sk_prot->disconnect(sk, flags);
522 
523         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
524                 return -EAGAIN;
525         return sk->sk_prot->connect(sk, uaddr, addr_len);
526 }
527 EXPORT_SYMBOL(inet_dgram_connect);
528 
529 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
530 {
531         DEFINE_WAIT(wait);
532 
533         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
534         sk->sk_write_pending += writebias;
535 
536         /* Basic assumption: if someone sets sk->sk_err, he _must_
537          * change state of the socket from TCP_SYN_*.
538          * Connect() does not allow to get error notifications
539          * without closing the socket.
540          */
541         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
542                 release_sock(sk);
543                 timeo = schedule_timeout(timeo);
544                 lock_sock(sk);
545                 if (signal_pending(current) || !timeo)
546                         break;
547                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
548         }
549         finish_wait(sk_sleep(sk), &wait);
550         sk->sk_write_pending -= writebias;
551         return timeo;
552 }
553 
554 /*
555  *      Connect to a remote host. There is regrettably still a little
556  *      TCP 'magic' in here.
557  */
558 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
559                           int addr_len, int flags)
560 {
561         struct sock *sk = sock->sk;
562         int err;
563         long timeo;
564 
565         if (addr_len < sizeof(uaddr->sa_family))
566                 return -EINVAL;
567 
568         if (uaddr->sa_family == AF_UNSPEC) {
569                 err = sk->sk_prot->disconnect(sk, flags);
570                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
571                 goto out;
572         }
573 
574         switch (sock->state) {
575         default:
576                 err = -EINVAL;
577                 goto out;
578         case SS_CONNECTED:
579                 err = -EISCONN;
580                 goto out;
581         case SS_CONNECTING:
582                 err = -EALREADY;
583                 /* Fall out of switch with err, set for this state */
584                 break;
585         case SS_UNCONNECTED:
586                 err = -EISCONN;
587                 if (sk->sk_state != TCP_CLOSE)
588                         goto out;
589 
590                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
591                 if (err < 0)
592                         goto out;
593 
594                 sock->state = SS_CONNECTING;
595 
596                 /* Just entered SS_CONNECTING state; the only
597                  * difference is that return value in non-blocking
598                  * case is EINPROGRESS, rather than EALREADY.
599                  */
600                 err = -EINPROGRESS;
601                 break;
602         }
603 
604         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
605 
606         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
607                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
608                                 tcp_sk(sk)->fastopen_req &&
609                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
610 
611                 /* Error code is set above */
612                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
613                         goto out;
614 
615                 err = sock_intr_errno(timeo);
616                 if (signal_pending(current))
617                         goto out;
618         }
619 
620         /* Connection was closed by RST, timeout, ICMP error
621          * or another process disconnected us.
622          */
623         if (sk->sk_state == TCP_CLOSE)
624                 goto sock_error;
625 
626         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
627          * and error was received after socket entered established state.
628          * Hence, it is handled normally after connect() return successfully.
629          */
630 
631         sock->state = SS_CONNECTED;
632         err = 0;
633 out:
634         return err;
635 
636 sock_error:
637         err = sock_error(sk) ? : -ECONNABORTED;
638         sock->state = SS_UNCONNECTED;
639         if (sk->sk_prot->disconnect(sk, flags))
640                 sock->state = SS_DISCONNECTING;
641         goto out;
642 }
643 EXPORT_SYMBOL(__inet_stream_connect);
644 
645 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
646                         int addr_len, int flags)
647 {
648         int err;
649 
650         lock_sock(sock->sk);
651         err = __inet_stream_connect(sock, uaddr, addr_len, flags);
652         release_sock(sock->sk);
653         return err;
654 }
655 EXPORT_SYMBOL(inet_stream_connect);
656 
657 /*
658  *      Accept a pending connection. The TCP layer now gives BSD semantics.
659  */
660 
661 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
662 {
663         struct sock *sk1 = sock->sk;
664         int err = -EINVAL;
665         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
666 
667         if (!sk2)
668                 goto do_err;
669 
670         lock_sock(sk2);
671 
672         sock_rps_record_flow(sk2);
673         WARN_ON(!((1 << sk2->sk_state) &
674                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
675                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
676 
677         sock_graft(sk2, newsock);
678 
679         newsock->state = SS_CONNECTED;
680         err = 0;
681         release_sock(sk2);
682 do_err:
683         return err;
684 }
685 EXPORT_SYMBOL(inet_accept);
686 
687 
688 /*
689  *      This does both peername and sockname.
690  */
691 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
692                         int *uaddr_len, int peer)
693 {
694         struct sock *sk         = sock->sk;
695         struct inet_sock *inet  = inet_sk(sk);
696         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
697 
698         sin->sin_family = AF_INET;
699         if (peer) {
700                 if (!inet->inet_dport ||
701                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
702                      peer == 1))
703                         return -ENOTCONN;
704                 sin->sin_port = inet->inet_dport;
705                 sin->sin_addr.s_addr = inet->inet_daddr;
706         } else {
707                 __be32 addr = inet->inet_rcv_saddr;
708                 if (!addr)
709                         addr = inet->inet_saddr;
710                 sin->sin_port = inet->inet_sport;
711                 sin->sin_addr.s_addr = addr;
712         }
713         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
714         *uaddr_len = sizeof(*sin);
715         return 0;
716 }
717 EXPORT_SYMBOL(inet_getname);
718 
719 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
720                  size_t size)
721 {
722         struct sock *sk = sock->sk;
723 
724         sock_rps_record_flow(sk);
725 
726         /* We may need to bind the socket. */
727         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
728             inet_autobind(sk))
729                 return -EAGAIN;
730 
731         return sk->sk_prot->sendmsg(iocb, sk, msg, size);
732 }
733 EXPORT_SYMBOL(inet_sendmsg);
734 
735 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
736                       size_t size, int flags)
737 {
738         struct sock *sk = sock->sk;
739 
740         sock_rps_record_flow(sk);
741 
742         /* We may need to bind the socket. */
743         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
744             inet_autobind(sk))
745                 return -EAGAIN;
746 
747         if (sk->sk_prot->sendpage)
748                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
749         return sock_no_sendpage(sock, page, offset, size, flags);
750 }
751 EXPORT_SYMBOL(inet_sendpage);
752 
753 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
754                  size_t size, int flags)
755 {
756         struct sock *sk = sock->sk;
757         int addr_len = 0;
758         int err;
759 
760         sock_rps_record_flow(sk);
761 
762         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
763                                    flags & ~MSG_DONTWAIT, &addr_len);
764         if (err >= 0)
765                 msg->msg_namelen = addr_len;
766         return err;
767 }
768 EXPORT_SYMBOL(inet_recvmsg);
769 
770 int inet_shutdown(struct socket *sock, int how)
771 {
772         struct sock *sk = sock->sk;
773         int err = 0;
774 
775         /* This should really check to make sure
776          * the socket is a TCP socket. (WHY AC...)
777          */
778         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
779                        1->2 bit 2 snds.
780                        2->3 */
781         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
782                 return -EINVAL;
783 
784         lock_sock(sk);
785         if (sock->state == SS_CONNECTING) {
786                 if ((1 << sk->sk_state) &
787                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
788                         sock->state = SS_DISCONNECTING;
789                 else
790                         sock->state = SS_CONNECTED;
791         }
792 
793         switch (sk->sk_state) {
794         case TCP_CLOSE:
795                 err = -ENOTCONN;
796                 /* Hack to wake up other listeners, who can poll for
797                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
798         default:
799                 sk->sk_shutdown |= how;
800                 if (sk->sk_prot->shutdown)
801                         sk->sk_prot->shutdown(sk, how);
802                 break;
803 
804         /* Remaining two branches are temporary solution for missing
805          * close() in multithreaded environment. It is _not_ a good idea,
806          * but we have no choice until close() is repaired at VFS level.
807          */
808         case TCP_LISTEN:
809                 if (!(how & RCV_SHUTDOWN))
810                         break;
811                 /* Fall through */
812         case TCP_SYN_SENT:
813                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
814                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
815                 break;
816         }
817 
818         /* Wake up anyone sleeping in poll. */
819         sk->sk_state_change(sk);
820         release_sock(sk);
821         return err;
822 }
823 EXPORT_SYMBOL(inet_shutdown);
824 
825 /*
826  *      ioctl() calls you can issue on an INET socket. Most of these are
827  *      device configuration and stuff and very rarely used. Some ioctls
828  *      pass on to the socket itself.
829  *
830  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
831  *      loads the devconfigure module does its configuring and unloads it.
832  *      There's a good 20K of config code hanging around the kernel.
833  */
834 
835 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
836 {
837         struct sock *sk = sock->sk;
838         int err = 0;
839         struct net *net = sock_net(sk);
840 
841         switch (cmd) {
842         case SIOCGSTAMP:
843                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
844                 break;
845         case SIOCGSTAMPNS:
846                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
847                 break;
848         case SIOCADDRT:
849         case SIOCDELRT:
850         case SIOCRTMSG:
851                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
852                 break;
853         case SIOCDARP:
854         case SIOCGARP:
855         case SIOCSARP:
856                 err = arp_ioctl(net, cmd, (void __user *)arg);
857                 break;
858         case SIOCGIFADDR:
859         case SIOCSIFADDR:
860         case SIOCGIFBRDADDR:
861         case SIOCSIFBRDADDR:
862         case SIOCGIFNETMASK:
863         case SIOCSIFNETMASK:
864         case SIOCGIFDSTADDR:
865         case SIOCSIFDSTADDR:
866         case SIOCSIFPFLAGS:
867         case SIOCGIFPFLAGS:
868         case SIOCSIFFLAGS:
869                 err = devinet_ioctl(net, cmd, (void __user *)arg);
870                 break;
871         default:
872                 if (sk->sk_prot->ioctl)
873                         err = sk->sk_prot->ioctl(sk, cmd, arg);
874                 else
875                         err = -ENOIOCTLCMD;
876                 break;
877         }
878         return err;
879 }
880 EXPORT_SYMBOL(inet_ioctl);
881 
882 #ifdef CONFIG_COMPAT
883 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
884 {
885         struct sock *sk = sock->sk;
886         int err = -ENOIOCTLCMD;
887 
888         if (sk->sk_prot->compat_ioctl)
889                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
890 
891         return err;
892 }
893 #endif
894 
895 const struct proto_ops inet_stream_ops = {
896         .family            = PF_INET,
897         .owner             = THIS_MODULE,
898         .release           = inet_release,
899         .bind              = inet_bind,
900         .connect           = inet_stream_connect,
901         .socketpair        = sock_no_socketpair,
902         .accept            = inet_accept,
903         .getname           = inet_getname,
904         .poll              = tcp_poll,
905         .ioctl             = inet_ioctl,
906         .listen            = inet_listen,
907         .shutdown          = inet_shutdown,
908         .setsockopt        = sock_common_setsockopt,
909         .getsockopt        = sock_common_getsockopt,
910         .sendmsg           = inet_sendmsg,
911         .recvmsg           = inet_recvmsg,
912         .mmap              = sock_no_mmap,
913         .sendpage          = inet_sendpage,
914         .splice_read       = tcp_splice_read,
915 #ifdef CONFIG_COMPAT
916         .compat_setsockopt = compat_sock_common_setsockopt,
917         .compat_getsockopt = compat_sock_common_getsockopt,
918         .compat_ioctl      = inet_compat_ioctl,
919 #endif
920 };
921 EXPORT_SYMBOL(inet_stream_ops);
922 
923 const struct proto_ops inet_dgram_ops = {
924         .family            = PF_INET,
925         .owner             = THIS_MODULE,
926         .release           = inet_release,
927         .bind              = inet_bind,
928         .connect           = inet_dgram_connect,
929         .socketpair        = sock_no_socketpair,
930         .accept            = sock_no_accept,
931         .getname           = inet_getname,
932         .poll              = udp_poll,
933         .ioctl             = inet_ioctl,
934         .listen            = sock_no_listen,
935         .shutdown          = inet_shutdown,
936         .setsockopt        = sock_common_setsockopt,
937         .getsockopt        = sock_common_getsockopt,
938         .sendmsg           = inet_sendmsg,
939         .recvmsg           = inet_recvmsg,
940         .mmap              = sock_no_mmap,
941         .sendpage          = inet_sendpage,
942 #ifdef CONFIG_COMPAT
943         .compat_setsockopt = compat_sock_common_setsockopt,
944         .compat_getsockopt = compat_sock_common_getsockopt,
945         .compat_ioctl      = inet_compat_ioctl,
946 #endif
947 };
948 EXPORT_SYMBOL(inet_dgram_ops);
949 
950 /*
951  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
952  * udp_poll
953  */
954 static const struct proto_ops inet_sockraw_ops = {
955         .family            = PF_INET,
956         .owner             = THIS_MODULE,
957         .release           = inet_release,
958         .bind              = inet_bind,
959         .connect           = inet_dgram_connect,
960         .socketpair        = sock_no_socketpair,
961         .accept            = sock_no_accept,
962         .getname           = inet_getname,
963         .poll              = datagram_poll,
964         .ioctl             = inet_ioctl,
965         .listen            = sock_no_listen,
966         .shutdown          = inet_shutdown,
967         .setsockopt        = sock_common_setsockopt,
968         .getsockopt        = sock_common_getsockopt,
969         .sendmsg           = inet_sendmsg,
970         .recvmsg           = inet_recvmsg,
971         .mmap              = sock_no_mmap,
972         .sendpage          = inet_sendpage,
973 #ifdef CONFIG_COMPAT
974         .compat_setsockopt = compat_sock_common_setsockopt,
975         .compat_getsockopt = compat_sock_common_getsockopt,
976         .compat_ioctl      = inet_compat_ioctl,
977 #endif
978 };
979 
980 static const struct net_proto_family inet_family_ops = {
981         .family = PF_INET,
982         .create = inet_create,
983         .owner  = THIS_MODULE,
984 };
985 
986 /* Upon startup we insert all the elements in inetsw_array[] into
987  * the linked list inetsw.
988  */
989 static struct inet_protosw inetsw_array[] =
990 {
991         {
992                 .type =       SOCK_STREAM,
993                 .protocol =   IPPROTO_TCP,
994                 .prot =       &tcp_prot,
995                 .ops =        &inet_stream_ops,
996                 .flags =      INET_PROTOSW_PERMANENT |
997                               INET_PROTOSW_ICSK,
998         },
999 
1000         {
1001                 .type =       SOCK_DGRAM,
1002                 .protocol =   IPPROTO_UDP,
1003                 .prot =       &udp_prot,
1004                 .ops =        &inet_dgram_ops,
1005                 .flags =      INET_PROTOSW_PERMANENT,
1006        },
1007 
1008        {
1009                 .type =       SOCK_DGRAM,
1010                 .protocol =   IPPROTO_ICMP,
1011                 .prot =       &ping_prot,
1012                 .ops =        &inet_dgram_ops,
1013                 .flags =      INET_PROTOSW_REUSE,
1014        },
1015 
1016        {
1017                .type =       SOCK_RAW,
1018                .protocol =   IPPROTO_IP,        /* wild card */
1019                .prot =       &raw_prot,
1020                .ops =        &inet_sockraw_ops,
1021                .flags =      INET_PROTOSW_REUSE,
1022        }
1023 };
1024 
1025 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1026 
1027 void inet_register_protosw(struct inet_protosw *p)
1028 {
1029         struct list_head *lh;
1030         struct inet_protosw *answer;
1031         int protocol = p->protocol;
1032         struct list_head *last_perm;
1033 
1034         spin_lock_bh(&inetsw_lock);
1035 
1036         if (p->type >= SOCK_MAX)
1037                 goto out_illegal;
1038 
1039         /* If we are trying to override a permanent protocol, bail. */
1040         answer = NULL;
1041         last_perm = &inetsw[p->type];
1042         list_for_each(lh, &inetsw[p->type]) {
1043                 answer = list_entry(lh, struct inet_protosw, list);
1044 
1045                 /* Check only the non-wild match. */
1046                 if (INET_PROTOSW_PERMANENT & answer->flags) {
1047                         if (protocol == answer->protocol)
1048                                 break;
1049                         last_perm = lh;
1050                 }
1051 
1052                 answer = NULL;
1053         }
1054         if (answer)
1055                 goto out_permanent;
1056 
1057         /* Add the new entry after the last permanent entry if any, so that
1058          * the new entry does not override a permanent entry when matched with
1059          * a wild-card protocol. But it is allowed to override any existing
1060          * non-permanent entry.  This means that when we remove this entry, the
1061          * system automatically returns to the old behavior.
1062          */
1063         list_add_rcu(&p->list, last_perm);
1064 out:
1065         spin_unlock_bh(&inetsw_lock);
1066 
1067         return;
1068 
1069 out_permanent:
1070         pr_err("Attempt to override permanent protocol %d\n", protocol);
1071         goto out;
1072 
1073 out_illegal:
1074         pr_err("Ignoring attempt to register invalid socket type %d\n",
1075                p->type);
1076         goto out;
1077 }
1078 EXPORT_SYMBOL(inet_register_protosw);
1079 
1080 void inet_unregister_protosw(struct inet_protosw *p)
1081 {
1082         if (INET_PROTOSW_PERMANENT & p->flags) {
1083                 pr_err("Attempt to unregister permanent protocol %d\n",
1084                        p->protocol);
1085         } else {
1086                 spin_lock_bh(&inetsw_lock);
1087                 list_del_rcu(&p->list);
1088                 spin_unlock_bh(&inetsw_lock);
1089 
1090                 synchronize_net();
1091         }
1092 }
1093 EXPORT_SYMBOL(inet_unregister_protosw);
1094 
1095 /*
1096  *      Shall we try to damage output packets if routing dev changes?
1097  */
1098 
1099 int sysctl_ip_dynaddr __read_mostly;
1100 
1101 static int inet_sk_reselect_saddr(struct sock *sk)
1102 {
1103         struct inet_sock *inet = inet_sk(sk);
1104         __be32 old_saddr = inet->inet_saddr;
1105         __be32 daddr = inet->inet_daddr;
1106         struct flowi4 *fl4;
1107         struct rtable *rt;
1108         __be32 new_saddr;
1109         struct ip_options_rcu *inet_opt;
1110 
1111         inet_opt = rcu_dereference_protected(inet->inet_opt,
1112                                              sock_owned_by_user(sk));
1113         if (inet_opt && inet_opt->opt.srr)
1114                 daddr = inet_opt->opt.faddr;
1115 
1116         /* Query new route. */
1117         fl4 = &inet->cork.fl.u.ip4;
1118         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1119                               sk->sk_bound_dev_if, sk->sk_protocol,
1120                               inet->inet_sport, inet->inet_dport, sk);
1121         if (IS_ERR(rt))
1122                 return PTR_ERR(rt);
1123 
1124         sk_setup_caps(sk, &rt->dst);
1125 
1126         new_saddr = fl4->saddr;
1127 
1128         if (new_saddr == old_saddr)
1129                 return 0;
1130 
1131         if (sysctl_ip_dynaddr > 1) {
1132                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1133                         __func__, &old_saddr, &new_saddr);
1134         }
1135 
1136         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1137 
1138         /*
1139          * XXX The only one ugly spot where we need to
1140          * XXX really change the sockets identity after
1141          * XXX it has entered the hashes. -DaveM
1142          *
1143          * Besides that, it does not check for connection
1144          * uniqueness. Wait for troubles.
1145          */
1146         __sk_prot_rehash(sk);
1147         return 0;
1148 }
1149 
1150 int inet_sk_rebuild_header(struct sock *sk)
1151 {
1152         struct inet_sock *inet = inet_sk(sk);
1153         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1154         __be32 daddr;
1155         struct ip_options_rcu *inet_opt;
1156         struct flowi4 *fl4;
1157         int err;
1158 
1159         /* Route is OK, nothing to do. */
1160         if (rt)
1161                 return 0;
1162 
1163         /* Reroute. */
1164         rcu_read_lock();
1165         inet_opt = rcu_dereference(inet->inet_opt);
1166         daddr = inet->inet_daddr;
1167         if (inet_opt && inet_opt->opt.srr)
1168                 daddr = inet_opt->opt.faddr;
1169         rcu_read_unlock();
1170         fl4 = &inet->cork.fl.u.ip4;
1171         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1172                                    inet->inet_dport, inet->inet_sport,
1173                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1174                                    sk->sk_bound_dev_if);
1175         if (!IS_ERR(rt)) {
1176                 err = 0;
1177                 sk_setup_caps(sk, &rt->dst);
1178         } else {
1179                 err = PTR_ERR(rt);
1180 
1181                 /* Routing failed... */
1182                 sk->sk_route_caps = 0;
1183                 /*
1184                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1185                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1186                  */
1187                 if (!sysctl_ip_dynaddr ||
1188                     sk->sk_state != TCP_SYN_SENT ||
1189                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1190                     (err = inet_sk_reselect_saddr(sk)) != 0)
1191                         sk->sk_err_soft = -err;
1192         }
1193 
1194         return err;
1195 }
1196 EXPORT_SYMBOL(inet_sk_rebuild_header);
1197 
1198 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1199                                         netdev_features_t features)
1200 {
1201         struct sk_buff *segs = ERR_PTR(-EINVAL);
1202         const struct net_offload *ops;
1203         unsigned int offset = 0;
1204         bool udpfrag, encap;
1205         struct iphdr *iph;
1206         int proto;
1207         int nhoff;
1208         int ihl;
1209         int id;
1210 
1211         if (unlikely(skb_shinfo(skb)->gso_type &
1212                      ~(SKB_GSO_TCPV4 |
1213                        SKB_GSO_UDP |
1214                        SKB_GSO_DODGY |
1215                        SKB_GSO_TCP_ECN |
1216                        SKB_GSO_GRE |
1217                        SKB_GSO_GRE_CSUM |
1218                        SKB_GSO_IPIP |
1219                        SKB_GSO_SIT |
1220                        SKB_GSO_TCPV6 |
1221                        SKB_GSO_UDP_TUNNEL |
1222                        SKB_GSO_UDP_TUNNEL_CSUM |
1223                        SKB_GSO_TUNNEL_REMCSUM |
1224                        0)))
1225                 goto out;
1226 
1227         skb_reset_network_header(skb);
1228         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1229         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1230                 goto out;
1231 
1232         iph = ip_hdr(skb);
1233         ihl = iph->ihl * 4;
1234         if (ihl < sizeof(*iph))
1235                 goto out;
1236 
1237         id = ntohs(iph->id);
1238         proto = iph->protocol;
1239 
1240         /* Warning: after this point, iph might be no longer valid */
1241         if (unlikely(!pskb_may_pull(skb, ihl)))
1242                 goto out;
1243         __skb_pull(skb, ihl);
1244 
1245         encap = SKB_GSO_CB(skb)->encap_level > 0;
1246         if (encap)
1247                 features &= skb->dev->hw_enc_features;
1248         SKB_GSO_CB(skb)->encap_level += ihl;
1249 
1250         skb_reset_transport_header(skb);
1251 
1252         segs = ERR_PTR(-EPROTONOSUPPORT);
1253 
1254         if (skb->encapsulation &&
1255             skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
1256                 udpfrag = proto == IPPROTO_UDP && encap;
1257         else
1258                 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
1259 
1260         ops = rcu_dereference(inet_offloads[proto]);
1261         if (likely(ops && ops->callbacks.gso_segment))
1262                 segs = ops->callbacks.gso_segment(skb, features);
1263 
1264         if (IS_ERR_OR_NULL(segs))
1265                 goto out;
1266 
1267         skb = segs;
1268         do {
1269                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1270                 if (udpfrag) {
1271                         iph->id = htons(id);
1272                         iph->frag_off = htons(offset >> 3);
1273                         if (skb->next != NULL)
1274                                 iph->frag_off |= htons(IP_MF);
1275                         offset += skb->len - nhoff - ihl;
1276                 } else {
1277                         iph->id = htons(id++);
1278                 }
1279                 iph->tot_len = htons(skb->len - nhoff);
1280                 ip_send_check(iph);
1281                 if (encap)
1282                         skb_reset_inner_headers(skb);
1283                 skb->network_header = (u8 *)iph - skb->head;
1284         } while ((skb = skb->next));
1285 
1286 out:
1287         return segs;
1288 }
1289 
1290 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1291                                          struct sk_buff *skb)
1292 {
1293         const struct net_offload *ops;
1294         struct sk_buff **pp = NULL;
1295         struct sk_buff *p;
1296         const struct iphdr *iph;
1297         unsigned int hlen;
1298         unsigned int off;
1299         unsigned int id;
1300         int flush = 1;
1301         int proto;
1302 
1303         off = skb_gro_offset(skb);
1304         hlen = off + sizeof(*iph);
1305         iph = skb_gro_header_fast(skb, off);
1306         if (skb_gro_header_hard(skb, hlen)) {
1307                 iph = skb_gro_header_slow(skb, hlen, off);
1308                 if (unlikely(!iph))
1309                         goto out;
1310         }
1311 
1312         proto = iph->protocol;
1313 
1314         rcu_read_lock();
1315         ops = rcu_dereference(inet_offloads[proto]);
1316         if (!ops || !ops->callbacks.gro_receive)
1317                 goto out_unlock;
1318 
1319         if (*(u8 *)iph != 0x45)
1320                 goto out_unlock;
1321 
1322         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1323                 goto out_unlock;
1324 
1325         id = ntohl(*(__be32 *)&iph->id);
1326         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1327         id >>= 16;
1328 
1329         for (p = *head; p; p = p->next) {
1330                 struct iphdr *iph2;
1331 
1332                 if (!NAPI_GRO_CB(p)->same_flow)
1333                         continue;
1334 
1335                 iph2 = (struct iphdr *)(p->data + off);
1336                 /* The above works because, with the exception of the top
1337                  * (inner most) layer, we only aggregate pkts with the same
1338                  * hdr length so all the hdrs we'll need to verify will start
1339                  * at the same offset.
1340                  */
1341                 if ((iph->protocol ^ iph2->protocol) |
1342                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1343                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1344                         NAPI_GRO_CB(p)->same_flow = 0;
1345                         continue;
1346                 }
1347 
1348                 /* All fields must match except length and checksum. */
1349                 NAPI_GRO_CB(p)->flush |=
1350                         (iph->ttl ^ iph2->ttl) |
1351                         (iph->tos ^ iph2->tos) |
1352                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1353 
1354                 /* Save the IP ID check to be included later when we get to
1355                  * the transport layer so only the inner most IP ID is checked.
1356                  * This is because some GSO/TSO implementations do not
1357                  * correctly increment the IP ID for the outer hdrs.
1358                  */
1359                 NAPI_GRO_CB(p)->flush_id =
1360                             ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1361                 NAPI_GRO_CB(p)->flush |= flush;
1362         }
1363 
1364         NAPI_GRO_CB(skb)->flush |= flush;
1365         skb_set_network_header(skb, off);
1366         /* The above will be needed by the transport layer if there is one
1367          * immediately following this IP hdr.
1368          */
1369 
1370         /* Note : No need to call skb_gro_postpull_rcsum() here,
1371          * as we already checked checksum over ipv4 header was 0
1372          */
1373         skb_gro_pull(skb, sizeof(*iph));
1374         skb_set_transport_header(skb, skb_gro_offset(skb));
1375 
1376         pp = ops->callbacks.gro_receive(head, skb);
1377 
1378 out_unlock:
1379         rcu_read_unlock();
1380 
1381 out:
1382         NAPI_GRO_CB(skb)->flush |= flush;
1383 
1384         return pp;
1385 }
1386 
1387 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1388 {
1389         if (sk->sk_family == AF_INET)
1390                 return ip_recv_error(sk, msg, len, addr_len);
1391 #if IS_ENABLED(CONFIG_IPV6)
1392         if (sk->sk_family == AF_INET6)
1393                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1394 #endif
1395         return -EINVAL;
1396 }
1397 
1398 static int inet_gro_complete(struct sk_buff *skb, int nhoff)
1399 {
1400         __be16 newlen = htons(skb->len - nhoff);
1401         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1402         const struct net_offload *ops;
1403         int proto = iph->protocol;
1404         int err = -ENOSYS;
1405 
1406         if (skb->encapsulation)
1407                 skb_set_inner_network_header(skb, nhoff);
1408 
1409         csum_replace2(&iph->check, iph->tot_len, newlen);
1410         iph->tot_len = newlen;
1411 
1412         rcu_read_lock();
1413         ops = rcu_dereference(inet_offloads[proto]);
1414         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1415                 goto out_unlock;
1416 
1417         /* Only need to add sizeof(*iph) to get to the next hdr below
1418          * because any hdr with option will have been flushed in
1419          * inet_gro_receive().
1420          */
1421         err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1422 
1423 out_unlock:
1424         rcu_read_unlock();
1425 
1426         return err;
1427 }
1428 
1429 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1430                          unsigned short type, unsigned char protocol,
1431                          struct net *net)
1432 {
1433         struct socket *sock;
1434         int rc = sock_create_kern(family, type, protocol, &sock);
1435 
1436         if (rc == 0) {
1437                 *sk = sock->sk;
1438                 (*sk)->sk_allocation = GFP_ATOMIC;
1439                 /*
1440                  * Unhash it so that IP input processing does not even see it,
1441                  * we do not wish this socket to see incoming packets.
1442                  */
1443                 (*sk)->sk_prot->unhash(*sk);
1444 
1445                 sk_change_net(*sk, net);
1446         }
1447         return rc;
1448 }
1449 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1450 
1451 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1452 {
1453         unsigned long res = 0;
1454         int i;
1455 
1456         for_each_possible_cpu(i)
1457                 res += *(((unsigned long *) per_cpu_ptr(mib, i)) + offt);
1458         return res;
1459 }
1460 EXPORT_SYMBOL_GPL(snmp_fold_field);
1461 
1462 #if BITS_PER_LONG==32
1463 
1464 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1465 {
1466         u64 res = 0;
1467         int cpu;
1468 
1469         for_each_possible_cpu(cpu) {
1470                 void *bhptr;
1471                 struct u64_stats_sync *syncp;
1472                 u64 v;
1473                 unsigned int start;
1474 
1475                 bhptr = per_cpu_ptr(mib, cpu);
1476                 syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1477                 do {
1478                         start = u64_stats_fetch_begin_irq(syncp);
1479                         v = *(((u64 *) bhptr) + offt);
1480                 } while (u64_stats_fetch_retry_irq(syncp, start));
1481 
1482                 res += v;
1483         }
1484         return res;
1485 }
1486 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1487 #endif
1488 
1489 #ifdef CONFIG_IP_MULTICAST
1490 static const struct net_protocol igmp_protocol = {
1491         .handler =      igmp_rcv,
1492         .netns_ok =     1,
1493 };
1494 #endif
1495 
1496 static const struct net_protocol tcp_protocol = {
1497         .early_demux    =       tcp_v4_early_demux,
1498         .handler        =       tcp_v4_rcv,
1499         .err_handler    =       tcp_v4_err,
1500         .no_policy      =       1,
1501         .netns_ok       =       1,
1502         .icmp_strict_tag_validation = 1,
1503 };
1504 
1505 static const struct net_protocol udp_protocol = {
1506         .early_demux =  udp_v4_early_demux,
1507         .handler =      udp_rcv,
1508         .err_handler =  udp_err,
1509         .no_policy =    1,
1510         .netns_ok =     1,
1511 };
1512 
1513 static const struct net_protocol icmp_protocol = {
1514         .handler =      icmp_rcv,
1515         .err_handler =  icmp_err,
1516         .no_policy =    1,
1517         .netns_ok =     1,
1518 };
1519 
1520 static __net_init int ipv4_mib_init_net(struct net *net)
1521 {
1522         int i;
1523 
1524         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1525         if (!net->mib.tcp_statistics)
1526                 goto err_tcp_mib;
1527         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1528         if (!net->mib.ip_statistics)
1529                 goto err_ip_mib;
1530 
1531         for_each_possible_cpu(i) {
1532                 struct ipstats_mib *af_inet_stats;
1533                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1534                 u64_stats_init(&af_inet_stats->syncp);
1535         }
1536 
1537         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1538         if (!net->mib.net_statistics)
1539                 goto err_net_mib;
1540         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1541         if (!net->mib.udp_statistics)
1542                 goto err_udp_mib;
1543         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1544         if (!net->mib.udplite_statistics)
1545                 goto err_udplite_mib;
1546         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1547         if (!net->mib.icmp_statistics)
1548                 goto err_icmp_mib;
1549         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1550                                               GFP_KERNEL);
1551         if (!net->mib.icmpmsg_statistics)
1552                 goto err_icmpmsg_mib;
1553 
1554         tcp_mib_init(net);
1555         return 0;
1556 
1557 err_icmpmsg_mib:
1558         free_percpu(net->mib.icmp_statistics);
1559 err_icmp_mib:
1560         free_percpu(net->mib.udplite_statistics);
1561 err_udplite_mib:
1562         free_percpu(net->mib.udp_statistics);
1563 err_udp_mib:
1564         free_percpu(net->mib.net_statistics);
1565 err_net_mib:
1566         free_percpu(net->mib.ip_statistics);
1567 err_ip_mib:
1568         free_percpu(net->mib.tcp_statistics);
1569 err_tcp_mib:
1570         return -ENOMEM;
1571 }
1572 
1573 static __net_exit void ipv4_mib_exit_net(struct net *net)
1574 {
1575         kfree(net->mib.icmpmsg_statistics);
1576         free_percpu(net->mib.icmp_statistics);
1577         free_percpu(net->mib.udplite_statistics);
1578         free_percpu(net->mib.udp_statistics);
1579         free_percpu(net->mib.net_statistics);
1580         free_percpu(net->mib.ip_statistics);
1581         free_percpu(net->mib.tcp_statistics);
1582 }
1583 
1584 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1585         .init = ipv4_mib_init_net,
1586         .exit = ipv4_mib_exit_net,
1587 };
1588 
1589 static int __init init_ipv4_mibs(void)
1590 {
1591         return register_pernet_subsys(&ipv4_mib_ops);
1592 }
1593 
1594 static __net_init int inet_init_net(struct net *net)
1595 {
1596         /*
1597          * Set defaults for local port range
1598          */
1599         seqlock_init(&net->ipv4.ip_local_ports.lock);
1600         net->ipv4.ip_local_ports.range[0] =  32768;
1601         net->ipv4.ip_local_ports.range[1] =  61000;
1602 
1603         seqlock_init(&net->ipv4.ping_group_range.lock);
1604         /*
1605          * Sane defaults - nobody may create ping sockets.
1606          * Boot scripts should set this to distro-specific group.
1607          */
1608         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1609         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1610         return 0;
1611 }
1612 
1613 static __net_exit void inet_exit_net(struct net *net)
1614 {
1615 }
1616 
1617 static __net_initdata struct pernet_operations af_inet_ops = {
1618         .init = inet_init_net,
1619         .exit = inet_exit_net,
1620 };
1621 
1622 static int __init init_inet_pernet_ops(void)
1623 {
1624         return register_pernet_subsys(&af_inet_ops);
1625 }
1626 
1627 static int ipv4_proc_init(void);
1628 
1629 /*
1630  *      IP protocol layer initialiser
1631  */
1632 
1633 static struct packet_offload ip_packet_offload __read_mostly = {
1634         .type = cpu_to_be16(ETH_P_IP),
1635         .callbacks = {
1636                 .gso_segment = inet_gso_segment,
1637                 .gro_receive = inet_gro_receive,
1638                 .gro_complete = inet_gro_complete,
1639         },
1640 };
1641 
1642 static const struct net_offload ipip_offload = {
1643         .callbacks = {
1644                 .gso_segment    = inet_gso_segment,
1645                 .gro_receive    = inet_gro_receive,
1646                 .gro_complete   = inet_gro_complete,
1647         },
1648 };
1649 
1650 static int __init ipv4_offload_init(void)
1651 {
1652         /*
1653          * Add offloads
1654          */
1655         if (udpv4_offload_init() < 0)
1656                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1657         if (tcpv4_offload_init() < 0)
1658                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1659 
1660         dev_add_offload(&ip_packet_offload);
1661         inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1662         return 0;
1663 }
1664 
1665 fs_initcall(ipv4_offload_init);
1666 
1667 static struct packet_type ip_packet_type __read_mostly = {
1668         .type = cpu_to_be16(ETH_P_IP),
1669         .func = ip_rcv,
1670 };
1671 
1672 static int __init inet_init(void)
1673 {
1674         struct inet_protosw *q;
1675         struct list_head *r;
1676         int rc = -EINVAL;
1677 
1678         BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1679 
1680         rc = proto_register(&tcp_prot, 1);
1681         if (rc)
1682                 goto out;
1683 
1684         rc = proto_register(&udp_prot, 1);
1685         if (rc)
1686                 goto out_unregister_tcp_proto;
1687 
1688         rc = proto_register(&raw_prot, 1);
1689         if (rc)
1690                 goto out_unregister_udp_proto;
1691 
1692         rc = proto_register(&ping_prot, 1);
1693         if (rc)
1694                 goto out_unregister_raw_proto;
1695 
1696         /*
1697          *      Tell SOCKET that we are alive...
1698          */
1699 
1700         (void)sock_register(&inet_family_ops);
1701 
1702 #ifdef CONFIG_SYSCTL
1703         ip_static_sysctl_init();
1704 #endif
1705 
1706         /*
1707          *      Add all the base protocols.
1708          */
1709 
1710         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1711                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1712         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1713                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1714         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1715                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1716 #ifdef CONFIG_IP_MULTICAST
1717         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1718                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1719 #endif
1720 
1721         /* Register the socket-side information for inet_create. */
1722         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1723                 INIT_LIST_HEAD(r);
1724 
1725         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1726                 inet_register_protosw(q);
1727 
1728         /*
1729          *      Set the ARP module up
1730          */
1731 
1732         arp_init();
1733 
1734         /*
1735          *      Set the IP module up
1736          */
1737 
1738         ip_init();
1739 
1740         tcp_v4_init();
1741 
1742         /* Setup TCP slab cache for open requests. */
1743         tcp_init();
1744 
1745         /* Setup UDP memory threshold */
1746         udp_init();
1747 
1748         /* Add UDP-Lite (RFC 3828) */
1749         udplite4_register();
1750 
1751         ping_init();
1752 
1753         /*
1754          *      Set the ICMP layer up
1755          */
1756 
1757         if (icmp_init() < 0)
1758                 panic("Failed to create the ICMP control socket.\n");
1759 
1760         /*
1761          *      Initialise the multicast router
1762          */
1763 #if defined(CONFIG_IP_MROUTE)
1764         if (ip_mr_init())
1765                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1766 #endif
1767 
1768         if (init_inet_pernet_ops())
1769                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1770         /*
1771          *      Initialise per-cpu ipv4 mibs
1772          */
1773 
1774         if (init_ipv4_mibs())
1775                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1776 
1777         ipv4_proc_init();
1778 
1779         ipfrag_init();
1780 
1781         dev_add_pack(&ip_packet_type);
1782 
1783         rc = 0;
1784 out:
1785         return rc;
1786 out_unregister_raw_proto:
1787         proto_unregister(&raw_prot);
1788 out_unregister_udp_proto:
1789         proto_unregister(&udp_prot);
1790 out_unregister_tcp_proto:
1791         proto_unregister(&tcp_prot);
1792         goto out;
1793 }
1794 
1795 fs_initcall(inet_init);
1796 
1797 /* ------------------------------------------------------------------------ */
1798 
1799 #ifdef CONFIG_PROC_FS
1800 static int __init ipv4_proc_init(void)
1801 {
1802         int rc = 0;
1803 
1804         if (raw_proc_init())
1805                 goto out_raw;
1806         if (tcp4_proc_init())
1807                 goto out_tcp;
1808         if (udp4_proc_init())
1809                 goto out_udp;
1810         if (ping_proc_init())
1811                 goto out_ping;
1812         if (ip_misc_proc_init())
1813                 goto out_misc;
1814 out:
1815         return rc;
1816 out_misc:
1817         ping_proc_exit();
1818 out_ping:
1819         udp4_proc_exit();
1820 out_udp:
1821         tcp4_proc_exit();
1822 out_tcp:
1823         raw_proc_exit();
1824 out_raw:
1825         rc = -ENOMEM;
1826         goto out;
1827 }
1828 
1829 #else /* CONFIG_PROC_FS */
1830 static int __init ipv4_proc_init(void)
1831 {
1832         return 0;
1833 }
1834 #endif /* CONFIG_PROC_FS */
1835 
1836 MODULE_ALIAS_NETPROTO(PF_INET);
1837 
1838 

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