Version:  2.0.40 2.2.26 2.4.37 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6

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/ip_tunnels.h>
116 #include <net/xfrm.h>
117 #include <net/net_namespace.h>
118 #include <net/secure_seq.h>
119 #ifdef CONFIG_IP_MROUTE
120 #include <linux/mroute.h>
121 #endif
122 #include <net/l3mdev.h>
123 
124 
125 /* The inetsw table contains everything that inet_create needs to
126  * build a new socket.
127  */
128 static struct list_head inetsw[SOCK_MAX];
129 static DEFINE_SPINLOCK(inetsw_lock);
130 
131 /* New destruction routine */
132 
133 void inet_sock_destruct(struct sock *sk)
134 {
135         struct inet_sock *inet = inet_sk(sk);
136 
137         __skb_queue_purge(&sk->sk_receive_queue);
138         __skb_queue_purge(&sk->sk_error_queue);
139 
140         sk_mem_reclaim(sk);
141 
142         if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
143                 pr_err("Attempt to release TCP socket in state %d %p\n",
144                        sk->sk_state, sk);
145                 return;
146         }
147         if (!sock_flag(sk, SOCK_DEAD)) {
148                 pr_err("Attempt to release alive inet socket %p\n", sk);
149                 return;
150         }
151 
152         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
153         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
154         WARN_ON(sk->sk_wmem_queued);
155         WARN_ON(sk->sk_forward_alloc);
156 
157         kfree(rcu_dereference_protected(inet->inet_opt, 1));
158         dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
159         dst_release(sk->sk_rx_dst);
160         sk_refcnt_debug_dec(sk);
161 }
162 EXPORT_SYMBOL(inet_sock_destruct);
163 
164 /*
165  *      The routines beyond this point handle the behaviour of an AF_INET
166  *      socket object. Mostly it punts to the subprotocols of IP to do
167  *      the work.
168  */
169 
170 /*
171  *      Automatically bind an unbound socket.
172  */
173 
174 static int inet_autobind(struct sock *sk)
175 {
176         struct inet_sock *inet;
177         /* We may need to bind the socket. */
178         lock_sock(sk);
179         inet = inet_sk(sk);
180         if (!inet->inet_num) {
181                 if (sk->sk_prot->get_port(sk, 0)) {
182                         release_sock(sk);
183                         return -EAGAIN;
184                 }
185                 inet->inet_sport = htons(inet->inet_num);
186         }
187         release_sock(sk);
188         return 0;
189 }
190 
191 /*
192  *      Move a socket into listening state.
193  */
194 int inet_listen(struct socket *sock, int backlog)
195 {
196         struct sock *sk = sock->sk;
197         unsigned char old_state;
198         int err;
199 
200         lock_sock(sk);
201 
202         err = -EINVAL;
203         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
204                 goto out;
205 
206         old_state = sk->sk_state;
207         if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
208                 goto out;
209 
210         /* Really, if the socket is already in listen state
211          * we can only allow the backlog to be adjusted.
212          */
213         if (old_state != TCP_LISTEN) {
214                 /* Check special setups for testing purpose to enable TFO w/o
215                  * requiring TCP_FASTOPEN sockopt.
216                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
217                  * Also fastopenq may already been allocated because this
218                  * socket was in TCP_LISTEN state previously but was
219                  * shutdown() (rather than close()).
220                  */
221                 if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
222                     !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
223                         if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
224                                 fastopen_queue_tune(sk, backlog);
225                         else if ((sysctl_tcp_fastopen &
226                                   TFO_SERVER_WO_SOCKOPT2) != 0)
227                                 fastopen_queue_tune(sk,
228                                     ((uint)sysctl_tcp_fastopen) >> 16);
229 
230                         tcp_fastopen_init_key_once(true);
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         if (protocol < 0 || protocol >= IPPROTO_MAX)
261                 return -EINVAL;
262 
263         sock->state = SS_UNCONNECTED;
264 
265         /* Look for the requested type/protocol pair. */
266 lookup_protocol:
267         err = -ESOCKTNOSUPPORT;
268         rcu_read_lock();
269         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
270 
271                 err = 0;
272                 /* Check the non-wild match. */
273                 if (protocol == answer->protocol) {
274                         if (protocol != IPPROTO_IP)
275                                 break;
276                 } else {
277                         /* Check for the two wild cases. */
278                         if (IPPROTO_IP == protocol) {
279                                 protocol = answer->protocol;
280                                 break;
281                         }
282                         if (IPPROTO_IP == answer->protocol)
283                                 break;
284                 }
285                 err = -EPROTONOSUPPORT;
286         }
287 
288         if (unlikely(err)) {
289                 if (try_loading_module < 2) {
290                         rcu_read_unlock();
291                         /*
292                          * Be more specific, e.g. net-pf-2-proto-132-type-1
293                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
294                          */
295                         if (++try_loading_module == 1)
296                                 request_module("net-pf-%d-proto-%d-type-%d",
297                                                PF_INET, protocol, sock->type);
298                         /*
299                          * Fall back to generic, e.g. net-pf-2-proto-132
300                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
301                          */
302                         else
303                                 request_module("net-pf-%d-proto-%d",
304                                                PF_INET, protocol);
305                         goto lookup_protocol;
306                 } else
307                         goto out_rcu_unlock;
308         }
309 
310         err = -EPERM;
311         if (sock->type == SOCK_RAW && !kern &&
312             !ns_capable(net->user_ns, CAP_NET_RAW))
313                 goto out_rcu_unlock;
314 
315         sock->ops = answer->ops;
316         answer_prot = answer->prot;
317         answer_flags = answer->flags;
318         rcu_read_unlock();
319 
320         WARN_ON(!answer_prot->slab);
321 
322         err = -ENOBUFS;
323         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
324         if (!sk)
325                 goto out;
326 
327         err = 0;
328         if (INET_PROTOSW_REUSE & answer_flags)
329                 sk->sk_reuse = SK_CAN_REUSE;
330 
331         inet = inet_sk(sk);
332         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
333 
334         inet->nodefrag = 0;
335 
336         if (SOCK_RAW == sock->type) {
337                 inet->inet_num = protocol;
338                 if (IPPROTO_RAW == protocol)
339                         inet->hdrincl = 1;
340         }
341 
342         if (net->ipv4.sysctl_ip_no_pmtu_disc)
343                 inet->pmtudisc = IP_PMTUDISC_DONT;
344         else
345                 inet->pmtudisc = IP_PMTUDISC_WANT;
346 
347         inet->inet_id = 0;
348 
349         sock_init_data(sock, sk);
350 
351         sk->sk_destruct    = inet_sock_destruct;
352         sk->sk_protocol    = protocol;
353         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
354 
355         inet->uc_ttl    = -1;
356         inet->mc_loop   = 1;
357         inet->mc_ttl    = 1;
358         inet->mc_all    = 1;
359         inet->mc_index  = 0;
360         inet->mc_list   = NULL;
361         inet->rcv_tos   = 0;
362 
363         sk_refcnt_debug_inc(sk);
364 
365         if (inet->inet_num) {
366                 /* It assumes that any protocol which allows
367                  * the user to assign a number at socket
368                  * creation time automatically
369                  * shares.
370                  */
371                 inet->inet_sport = htons(inet->inet_num);
372                 /* Add to protocol hash chains. */
373                 err = sk->sk_prot->hash(sk);
374                 if (err) {
375                         sk_common_release(sk);
376                         goto out;
377                 }
378         }
379 
380         if (sk->sk_prot->init) {
381                 err = sk->sk_prot->init(sk);
382                 if (err)
383                         sk_common_release(sk);
384         }
385 out:
386         return err;
387 out_rcu_unlock:
388         rcu_read_unlock();
389         goto out;
390 }
391 
392 
393 /*
394  *      The peer socket should always be NULL (or else). When we call this
395  *      function we are destroying the object and from then on nobody
396  *      should refer to it.
397  */
398 int inet_release(struct socket *sock)
399 {
400         struct sock *sk = sock->sk;
401 
402         if (sk) {
403                 long timeout;
404 
405                 /* Applications forget to leave groups before exiting */
406                 ip_mc_drop_socket(sk);
407 
408                 /* If linger is set, we don't return until the close
409                  * is complete.  Otherwise we return immediately. The
410                  * actually closing is done the same either way.
411                  *
412                  * If the close is due to the process exiting, we never
413                  * linger..
414                  */
415                 timeout = 0;
416                 if (sock_flag(sk, SOCK_LINGER) &&
417                     !(current->flags & PF_EXITING))
418                         timeout = sk->sk_lingertime;
419                 sock->sk = NULL;
420                 sk->sk_prot->close(sk, timeout);
421         }
422         return 0;
423 }
424 EXPORT_SYMBOL(inet_release);
425 
426 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
427 {
428         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
429         struct sock *sk = sock->sk;
430         struct inet_sock *inet = inet_sk(sk);
431         struct net *net = sock_net(sk);
432         unsigned short snum;
433         int chk_addr_ret;
434         u32 tb_id = RT_TABLE_LOCAL;
435         int err;
436 
437         /* If the socket has its own bind function then use it. (RAW) */
438         if (sk->sk_prot->bind) {
439                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
440                 goto out;
441         }
442         err = -EINVAL;
443         if (addr_len < sizeof(struct sockaddr_in))
444                 goto out;
445 
446         if (addr->sin_family != AF_INET) {
447                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
448                  * only if s_addr is INADDR_ANY.
449                  */
450                 err = -EAFNOSUPPORT;
451                 if (addr->sin_family != AF_UNSPEC ||
452                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
453                         goto out;
454         }
455 
456         tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
457         chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
458 
459         /* Not specified by any standard per-se, however it breaks too
460          * many applications when removed.  It is unfortunate since
461          * allowing applications to make a non-local bind solves
462          * several problems with systems using dynamic addressing.
463          * (ie. your servers still start up even if your ISDN link
464          *  is temporarily down)
465          */
466         err = -EADDRNOTAVAIL;
467         if (!net->ipv4.sysctl_ip_nonlocal_bind &&
468             !(inet->freebind || inet->transparent) &&
469             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
470             chk_addr_ret != RTN_LOCAL &&
471             chk_addr_ret != RTN_MULTICAST &&
472             chk_addr_ret != RTN_BROADCAST)
473                 goto out;
474 
475         snum = ntohs(addr->sin_port);
476         err = -EACCES;
477         if (snum && snum < PROT_SOCK &&
478             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
479                 goto out;
480 
481         /*      We keep a pair of addresses. rcv_saddr is the one
482          *      used by hash lookups, and saddr is used for transmit.
483          *
484          *      In the BSD API these are the same except where it
485          *      would be illegal to use them (multicast/broadcast) in
486          *      which case the sending device address is used.
487          */
488         lock_sock(sk);
489 
490         /* Check these errors (active socket, double bind). */
491         err = -EINVAL;
492         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
493                 goto out_release_sock;
494 
495         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
496         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
497                 inet->inet_saddr = 0;  /* Use device */
498 
499         /* Make sure we are allowed to bind here. */
500         if ((snum || !inet->bind_address_no_port) &&
501             sk->sk_prot->get_port(sk, snum)) {
502                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
503                 err = -EADDRINUSE;
504                 goto out_release_sock;
505         }
506 
507         if (inet->inet_rcv_saddr)
508                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
509         if (snum)
510                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
511         inet->inet_sport = htons(inet->inet_num);
512         inet->inet_daddr = 0;
513         inet->inet_dport = 0;
514         sk_dst_reset(sk);
515         err = 0;
516 out_release_sock:
517         release_sock(sk);
518 out:
519         return err;
520 }
521 EXPORT_SYMBOL(inet_bind);
522 
523 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
524                        int addr_len, int flags)
525 {
526         struct sock *sk = sock->sk;
527 
528         if (addr_len < sizeof(uaddr->sa_family))
529                 return -EINVAL;
530         if (uaddr->sa_family == AF_UNSPEC)
531                 return sk->sk_prot->disconnect(sk, flags);
532 
533         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
534                 return -EAGAIN;
535         return sk->sk_prot->connect(sk, uaddr, addr_len);
536 }
537 EXPORT_SYMBOL(inet_dgram_connect);
538 
539 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
540 {
541         DEFINE_WAIT(wait);
542 
543         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
544         sk->sk_write_pending += writebias;
545 
546         /* Basic assumption: if someone sets sk->sk_err, he _must_
547          * change state of the socket from TCP_SYN_*.
548          * Connect() does not allow to get error notifications
549          * without closing the socket.
550          */
551         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
552                 release_sock(sk);
553                 timeo = schedule_timeout(timeo);
554                 lock_sock(sk);
555                 if (signal_pending(current) || !timeo)
556                         break;
557                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
558         }
559         finish_wait(sk_sleep(sk), &wait);
560         sk->sk_write_pending -= writebias;
561         return timeo;
562 }
563 
564 /*
565  *      Connect to a remote host. There is regrettably still a little
566  *      TCP 'magic' in here.
567  */
568 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
569                           int addr_len, int flags)
570 {
571         struct sock *sk = sock->sk;
572         int err;
573         long timeo;
574 
575         if (addr_len < sizeof(uaddr->sa_family))
576                 return -EINVAL;
577 
578         if (uaddr->sa_family == AF_UNSPEC) {
579                 err = sk->sk_prot->disconnect(sk, flags);
580                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
581                 goto out;
582         }
583 
584         switch (sock->state) {
585         default:
586                 err = -EINVAL;
587                 goto out;
588         case SS_CONNECTED:
589                 err = -EISCONN;
590                 goto out;
591         case SS_CONNECTING:
592                 err = -EALREADY;
593                 /* Fall out of switch with err, set for this state */
594                 break;
595         case SS_UNCONNECTED:
596                 err = -EISCONN;
597                 if (sk->sk_state != TCP_CLOSE)
598                         goto out;
599 
600                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
601                 if (err < 0)
602                         goto out;
603 
604                 sock->state = SS_CONNECTING;
605 
606                 /* Just entered SS_CONNECTING state; the only
607                  * difference is that return value in non-blocking
608                  * case is EINPROGRESS, rather than EALREADY.
609                  */
610                 err = -EINPROGRESS;
611                 break;
612         }
613 
614         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
615 
616         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
617                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
618                                 tcp_sk(sk)->fastopen_req &&
619                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
620 
621                 /* Error code is set above */
622                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
623                         goto out;
624 
625                 err = sock_intr_errno(timeo);
626                 if (signal_pending(current))
627                         goto out;
628         }
629 
630         /* Connection was closed by RST, timeout, ICMP error
631          * or another process disconnected us.
632          */
633         if (sk->sk_state == TCP_CLOSE)
634                 goto sock_error;
635 
636         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
637          * and error was received after socket entered established state.
638          * Hence, it is handled normally after connect() return successfully.
639          */
640 
641         sock->state = SS_CONNECTED;
642         err = 0;
643 out:
644         return err;
645 
646 sock_error:
647         err = sock_error(sk) ? : -ECONNABORTED;
648         sock->state = SS_UNCONNECTED;
649         if (sk->sk_prot->disconnect(sk, flags))
650                 sock->state = SS_DISCONNECTING;
651         goto out;
652 }
653 EXPORT_SYMBOL(__inet_stream_connect);
654 
655 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
656                         int addr_len, int flags)
657 {
658         int err;
659 
660         lock_sock(sock->sk);
661         err = __inet_stream_connect(sock, uaddr, addr_len, flags);
662         release_sock(sock->sk);
663         return err;
664 }
665 EXPORT_SYMBOL(inet_stream_connect);
666 
667 /*
668  *      Accept a pending connection. The TCP layer now gives BSD semantics.
669  */
670 
671 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
672 {
673         struct sock *sk1 = sock->sk;
674         int err = -EINVAL;
675         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
676 
677         if (!sk2)
678                 goto do_err;
679 
680         lock_sock(sk2);
681 
682         sock_rps_record_flow(sk2);
683         WARN_ON(!((1 << sk2->sk_state) &
684                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
685                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
686 
687         sock_graft(sk2, newsock);
688 
689         newsock->state = SS_CONNECTED;
690         err = 0;
691         release_sock(sk2);
692 do_err:
693         return err;
694 }
695 EXPORT_SYMBOL(inet_accept);
696 
697 
698 /*
699  *      This does both peername and sockname.
700  */
701 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
702                         int *uaddr_len, int peer)
703 {
704         struct sock *sk         = sock->sk;
705         struct inet_sock *inet  = inet_sk(sk);
706         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
707 
708         sin->sin_family = AF_INET;
709         if (peer) {
710                 if (!inet->inet_dport ||
711                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
712                      peer == 1))
713                         return -ENOTCONN;
714                 sin->sin_port = inet->inet_dport;
715                 sin->sin_addr.s_addr = inet->inet_daddr;
716         } else {
717                 __be32 addr = inet->inet_rcv_saddr;
718                 if (!addr)
719                         addr = inet->inet_saddr;
720                 sin->sin_port = inet->inet_sport;
721                 sin->sin_addr.s_addr = addr;
722         }
723         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
724         *uaddr_len = sizeof(*sin);
725         return 0;
726 }
727 EXPORT_SYMBOL(inet_getname);
728 
729 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
730 {
731         struct sock *sk = sock->sk;
732 
733         sock_rps_record_flow(sk);
734 
735         /* We may need to bind the socket. */
736         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
737             inet_autobind(sk))
738                 return -EAGAIN;
739 
740         return sk->sk_prot->sendmsg(sk, msg, size);
741 }
742 EXPORT_SYMBOL(inet_sendmsg);
743 
744 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
745                       size_t size, int flags)
746 {
747         struct sock *sk = sock->sk;
748 
749         sock_rps_record_flow(sk);
750 
751         /* We may need to bind the socket. */
752         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
753             inet_autobind(sk))
754                 return -EAGAIN;
755 
756         if (sk->sk_prot->sendpage)
757                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
758         return sock_no_sendpage(sock, page, offset, size, flags);
759 }
760 EXPORT_SYMBOL(inet_sendpage);
761 
762 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
763                  int flags)
764 {
765         struct sock *sk = sock->sk;
766         int addr_len = 0;
767         int err;
768 
769         sock_rps_record_flow(sk);
770 
771         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
772                                    flags & ~MSG_DONTWAIT, &addr_len);
773         if (err >= 0)
774                 msg->msg_namelen = addr_len;
775         return err;
776 }
777 EXPORT_SYMBOL(inet_recvmsg);
778 
779 int inet_shutdown(struct socket *sock, int how)
780 {
781         struct sock *sk = sock->sk;
782         int err = 0;
783 
784         /* This should really check to make sure
785          * the socket is a TCP socket. (WHY AC...)
786          */
787         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
788                        1->2 bit 2 snds.
789                        2->3 */
790         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
791                 return -EINVAL;
792 
793         lock_sock(sk);
794         if (sock->state == SS_CONNECTING) {
795                 if ((1 << sk->sk_state) &
796                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
797                         sock->state = SS_DISCONNECTING;
798                 else
799                         sock->state = SS_CONNECTED;
800         }
801 
802         switch (sk->sk_state) {
803         case TCP_CLOSE:
804                 err = -ENOTCONN;
805                 /* Hack to wake up other listeners, who can poll for
806                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
807         default:
808                 sk->sk_shutdown |= how;
809                 if (sk->sk_prot->shutdown)
810                         sk->sk_prot->shutdown(sk, how);
811                 break;
812 
813         /* Remaining two branches are temporary solution for missing
814          * close() in multithreaded environment. It is _not_ a good idea,
815          * but we have no choice until close() is repaired at VFS level.
816          */
817         case TCP_LISTEN:
818                 if (!(how & RCV_SHUTDOWN))
819                         break;
820                 /* Fall through */
821         case TCP_SYN_SENT:
822                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
823                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
824                 break;
825         }
826 
827         /* Wake up anyone sleeping in poll. */
828         sk->sk_state_change(sk);
829         release_sock(sk);
830         return err;
831 }
832 EXPORT_SYMBOL(inet_shutdown);
833 
834 /*
835  *      ioctl() calls you can issue on an INET socket. Most of these are
836  *      device configuration and stuff and very rarely used. Some ioctls
837  *      pass on to the socket itself.
838  *
839  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
840  *      loads the devconfigure module does its configuring and unloads it.
841  *      There's a good 20K of config code hanging around the kernel.
842  */
843 
844 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
845 {
846         struct sock *sk = sock->sk;
847         int err = 0;
848         struct net *net = sock_net(sk);
849 
850         switch (cmd) {
851         case SIOCGSTAMP:
852                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
853                 break;
854         case SIOCGSTAMPNS:
855                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
856                 break;
857         case SIOCADDRT:
858         case SIOCDELRT:
859         case SIOCRTMSG:
860                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
861                 break;
862         case SIOCDARP:
863         case SIOCGARP:
864         case SIOCSARP:
865                 err = arp_ioctl(net, cmd, (void __user *)arg);
866                 break;
867         case SIOCGIFADDR:
868         case SIOCSIFADDR:
869         case SIOCGIFBRDADDR:
870         case SIOCSIFBRDADDR:
871         case SIOCGIFNETMASK:
872         case SIOCSIFNETMASK:
873         case SIOCGIFDSTADDR:
874         case SIOCSIFDSTADDR:
875         case SIOCSIFPFLAGS:
876         case SIOCGIFPFLAGS:
877         case SIOCSIFFLAGS:
878                 err = devinet_ioctl(net, cmd, (void __user *)arg);
879                 break;
880         default:
881                 if (sk->sk_prot->ioctl)
882                         err = sk->sk_prot->ioctl(sk, cmd, arg);
883                 else
884                         err = -ENOIOCTLCMD;
885                 break;
886         }
887         return err;
888 }
889 EXPORT_SYMBOL(inet_ioctl);
890 
891 #ifdef CONFIG_COMPAT
892 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
893 {
894         struct sock *sk = sock->sk;
895         int err = -ENOIOCTLCMD;
896 
897         if (sk->sk_prot->compat_ioctl)
898                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
899 
900         return err;
901 }
902 #endif
903 
904 const struct proto_ops inet_stream_ops = {
905         .family            = PF_INET,
906         .owner             = THIS_MODULE,
907         .release           = inet_release,
908         .bind              = inet_bind,
909         .connect           = inet_stream_connect,
910         .socketpair        = sock_no_socketpair,
911         .accept            = inet_accept,
912         .getname           = inet_getname,
913         .poll              = tcp_poll,
914         .ioctl             = inet_ioctl,
915         .listen            = inet_listen,
916         .shutdown          = inet_shutdown,
917         .setsockopt        = sock_common_setsockopt,
918         .getsockopt        = sock_common_getsockopt,
919         .sendmsg           = inet_sendmsg,
920         .recvmsg           = inet_recvmsg,
921         .mmap              = sock_no_mmap,
922         .sendpage          = inet_sendpage,
923         .splice_read       = tcp_splice_read,
924 #ifdef CONFIG_COMPAT
925         .compat_setsockopt = compat_sock_common_setsockopt,
926         .compat_getsockopt = compat_sock_common_getsockopt,
927         .compat_ioctl      = inet_compat_ioctl,
928 #endif
929 };
930 EXPORT_SYMBOL(inet_stream_ops);
931 
932 const struct proto_ops inet_dgram_ops = {
933         .family            = PF_INET,
934         .owner             = THIS_MODULE,
935         .release           = inet_release,
936         .bind              = inet_bind,
937         .connect           = inet_dgram_connect,
938         .socketpair        = sock_no_socketpair,
939         .accept            = sock_no_accept,
940         .getname           = inet_getname,
941         .poll              = udp_poll,
942         .ioctl             = inet_ioctl,
943         .listen            = sock_no_listen,
944         .shutdown          = inet_shutdown,
945         .setsockopt        = sock_common_setsockopt,
946         .getsockopt        = sock_common_getsockopt,
947         .sendmsg           = inet_sendmsg,
948         .recvmsg           = inet_recvmsg,
949         .mmap              = sock_no_mmap,
950         .sendpage          = inet_sendpage,
951 #ifdef CONFIG_COMPAT
952         .compat_setsockopt = compat_sock_common_setsockopt,
953         .compat_getsockopt = compat_sock_common_getsockopt,
954         .compat_ioctl      = inet_compat_ioctl,
955 #endif
956 };
957 EXPORT_SYMBOL(inet_dgram_ops);
958 
959 /*
960  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
961  * udp_poll
962  */
963 static const struct proto_ops inet_sockraw_ops = {
964         .family            = PF_INET,
965         .owner             = THIS_MODULE,
966         .release           = inet_release,
967         .bind              = inet_bind,
968         .connect           = inet_dgram_connect,
969         .socketpair        = sock_no_socketpair,
970         .accept            = sock_no_accept,
971         .getname           = inet_getname,
972         .poll              = datagram_poll,
973         .ioctl             = inet_ioctl,
974         .listen            = sock_no_listen,
975         .shutdown          = inet_shutdown,
976         .setsockopt        = sock_common_setsockopt,
977         .getsockopt        = sock_common_getsockopt,
978         .sendmsg           = inet_sendmsg,
979         .recvmsg           = inet_recvmsg,
980         .mmap              = sock_no_mmap,
981         .sendpage          = inet_sendpage,
982 #ifdef CONFIG_COMPAT
983         .compat_setsockopt = compat_sock_common_setsockopt,
984         .compat_getsockopt = compat_sock_common_getsockopt,
985         .compat_ioctl      = inet_compat_ioctl,
986 #endif
987 };
988 
989 static const struct net_proto_family inet_family_ops = {
990         .family = PF_INET,
991         .create = inet_create,
992         .owner  = THIS_MODULE,
993 };
994 
995 /* Upon startup we insert all the elements in inetsw_array[] into
996  * the linked list inetsw.
997  */
998 static struct inet_protosw inetsw_array[] =
999 {
1000         {
1001                 .type =       SOCK_STREAM,
1002                 .protocol =   IPPROTO_TCP,
1003                 .prot =       &tcp_prot,
1004                 .ops =        &inet_stream_ops,
1005                 .flags =      INET_PROTOSW_PERMANENT |
1006                               INET_PROTOSW_ICSK,
1007         },
1008 
1009         {
1010                 .type =       SOCK_DGRAM,
1011                 .protocol =   IPPROTO_UDP,
1012                 .prot =       &udp_prot,
1013                 .ops =        &inet_dgram_ops,
1014                 .flags =      INET_PROTOSW_PERMANENT,
1015        },
1016 
1017        {
1018                 .type =       SOCK_DGRAM,
1019                 .protocol =   IPPROTO_ICMP,
1020                 .prot =       &ping_prot,
1021                 .ops =        &inet_dgram_ops,
1022                 .flags =      INET_PROTOSW_REUSE,
1023        },
1024 
1025        {
1026                .type =       SOCK_RAW,
1027                .protocol =   IPPROTO_IP,        /* wild card */
1028                .prot =       &raw_prot,
1029                .ops =        &inet_sockraw_ops,
1030                .flags =      INET_PROTOSW_REUSE,
1031        }
1032 };
1033 
1034 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1035 
1036 void inet_register_protosw(struct inet_protosw *p)
1037 {
1038         struct list_head *lh;
1039         struct inet_protosw *answer;
1040         int protocol = p->protocol;
1041         struct list_head *last_perm;
1042 
1043         spin_lock_bh(&inetsw_lock);
1044 
1045         if (p->type >= SOCK_MAX)
1046                 goto out_illegal;
1047 
1048         /* If we are trying to override a permanent protocol, bail. */
1049         last_perm = &inetsw[p->type];
1050         list_for_each(lh, &inetsw[p->type]) {
1051                 answer = list_entry(lh, struct inet_protosw, list);
1052                 /* Check only the non-wild match. */
1053                 if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1054                         break;
1055                 if (protocol == answer->protocol)
1056                         goto out_permanent;
1057                 last_perm = lh;
1058         }
1059 
1060         /* Add the new entry after the last permanent entry if any, so that
1061          * the new entry does not override a permanent entry when matched with
1062          * a wild-card protocol. But it is allowed to override any existing
1063          * non-permanent entry.  This means that when we remove this entry, the
1064          * system automatically returns to the old behavior.
1065          */
1066         list_add_rcu(&p->list, last_perm);
1067 out:
1068         spin_unlock_bh(&inetsw_lock);
1069 
1070         return;
1071 
1072 out_permanent:
1073         pr_err("Attempt to override permanent protocol %d\n", protocol);
1074         goto out;
1075 
1076 out_illegal:
1077         pr_err("Ignoring attempt to register invalid socket type %d\n",
1078                p->type);
1079         goto out;
1080 }
1081 EXPORT_SYMBOL(inet_register_protosw);
1082 
1083 void inet_unregister_protosw(struct inet_protosw *p)
1084 {
1085         if (INET_PROTOSW_PERMANENT & p->flags) {
1086                 pr_err("Attempt to unregister permanent protocol %d\n",
1087                        p->protocol);
1088         } else {
1089                 spin_lock_bh(&inetsw_lock);
1090                 list_del_rcu(&p->list);
1091                 spin_unlock_bh(&inetsw_lock);
1092 
1093                 synchronize_net();
1094         }
1095 }
1096 EXPORT_SYMBOL(inet_unregister_protosw);
1097 
1098 static int inet_sk_reselect_saddr(struct sock *sk)
1099 {
1100         struct inet_sock *inet = inet_sk(sk);
1101         __be32 old_saddr = inet->inet_saddr;
1102         __be32 daddr = inet->inet_daddr;
1103         struct flowi4 *fl4;
1104         struct rtable *rt;
1105         __be32 new_saddr;
1106         struct ip_options_rcu *inet_opt;
1107 
1108         inet_opt = rcu_dereference_protected(inet->inet_opt,
1109                                              sock_owned_by_user(sk));
1110         if (inet_opt && inet_opt->opt.srr)
1111                 daddr = inet_opt->opt.faddr;
1112 
1113         /* Query new route. */
1114         fl4 = &inet->cork.fl.u.ip4;
1115         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1116                               sk->sk_bound_dev_if, sk->sk_protocol,
1117                               inet->inet_sport, inet->inet_dport, sk);
1118         if (IS_ERR(rt))
1119                 return PTR_ERR(rt);
1120 
1121         sk_setup_caps(sk, &rt->dst);
1122 
1123         new_saddr = fl4->saddr;
1124 
1125         if (new_saddr == old_saddr)
1126                 return 0;
1127 
1128         if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1129                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1130                         __func__, &old_saddr, &new_saddr);
1131         }
1132 
1133         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1134 
1135         /*
1136          * XXX The only one ugly spot where we need to
1137          * XXX really change the sockets identity after
1138          * XXX it has entered the hashes. -DaveM
1139          *
1140          * Besides that, it does not check for connection
1141          * uniqueness. Wait for troubles.
1142          */
1143         return __sk_prot_rehash(sk);
1144 }
1145 
1146 int inet_sk_rebuild_header(struct sock *sk)
1147 {
1148         struct inet_sock *inet = inet_sk(sk);
1149         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1150         __be32 daddr;
1151         struct ip_options_rcu *inet_opt;
1152         struct flowi4 *fl4;
1153         int err;
1154 
1155         /* Route is OK, nothing to do. */
1156         if (rt)
1157                 return 0;
1158 
1159         /* Reroute. */
1160         rcu_read_lock();
1161         inet_opt = rcu_dereference(inet->inet_opt);
1162         daddr = inet->inet_daddr;
1163         if (inet_opt && inet_opt->opt.srr)
1164                 daddr = inet_opt->opt.faddr;
1165         rcu_read_unlock();
1166         fl4 = &inet->cork.fl.u.ip4;
1167         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1168                                    inet->inet_dport, inet->inet_sport,
1169                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1170                                    sk->sk_bound_dev_if);
1171         if (!IS_ERR(rt)) {
1172                 err = 0;
1173                 sk_setup_caps(sk, &rt->dst);
1174         } else {
1175                 err = PTR_ERR(rt);
1176 
1177                 /* Routing failed... */
1178                 sk->sk_route_caps = 0;
1179                 /*
1180                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1181                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1182                  */
1183                 if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1184                     sk->sk_state != TCP_SYN_SENT ||
1185                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1186                     (err = inet_sk_reselect_saddr(sk)) != 0)
1187                         sk->sk_err_soft = -err;
1188         }
1189 
1190         return err;
1191 }
1192 EXPORT_SYMBOL(inet_sk_rebuild_header);
1193 
1194 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1195                                         netdev_features_t features)
1196 {
1197         struct sk_buff *segs = ERR_PTR(-EINVAL);
1198         const struct net_offload *ops;
1199         unsigned int offset = 0;
1200         bool udpfrag, encap;
1201         struct iphdr *iph;
1202         int proto;
1203         int nhoff;
1204         int ihl;
1205         int id;
1206 
1207         if (unlikely(skb_shinfo(skb)->gso_type &
1208                      ~(SKB_GSO_TCPV4 |
1209                        SKB_GSO_UDP |
1210                        SKB_GSO_DODGY |
1211                        SKB_GSO_TCP_ECN |
1212                        SKB_GSO_GRE |
1213                        SKB_GSO_GRE_CSUM |
1214                        SKB_GSO_IPIP |
1215                        SKB_GSO_SIT |
1216                        SKB_GSO_TCPV6 |
1217                        SKB_GSO_UDP_TUNNEL |
1218                        SKB_GSO_UDP_TUNNEL_CSUM |
1219                        SKB_GSO_TUNNEL_REMCSUM |
1220                        0)))
1221                 goto out;
1222 
1223         skb_reset_network_header(skb);
1224         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1225         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1226                 goto out;
1227 
1228         iph = ip_hdr(skb);
1229         ihl = iph->ihl * 4;
1230         if (ihl < sizeof(*iph))
1231                 goto out;
1232 
1233         id = ntohs(iph->id);
1234         proto = iph->protocol;
1235 
1236         /* Warning: after this point, iph might be no longer valid */
1237         if (unlikely(!pskb_may_pull(skb, ihl)))
1238                 goto out;
1239         __skb_pull(skb, ihl);
1240 
1241         encap = SKB_GSO_CB(skb)->encap_level > 0;
1242         if (encap)
1243                 features &= skb->dev->hw_enc_features;
1244         SKB_GSO_CB(skb)->encap_level += ihl;
1245 
1246         skb_reset_transport_header(skb);
1247 
1248         segs = ERR_PTR(-EPROTONOSUPPORT);
1249 
1250         if (skb->encapsulation &&
1251             skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
1252                 udpfrag = proto == IPPROTO_UDP && encap;
1253         else
1254                 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
1255 
1256         ops = rcu_dereference(inet_offloads[proto]);
1257         if (likely(ops && ops->callbacks.gso_segment))
1258                 segs = ops->callbacks.gso_segment(skb, features);
1259 
1260         if (IS_ERR_OR_NULL(segs))
1261                 goto out;
1262 
1263         skb = segs;
1264         do {
1265                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1266                 if (udpfrag) {
1267                         iph->id = htons(id);
1268                         iph->frag_off = htons(offset >> 3);
1269                         if (skb->next)
1270                                 iph->frag_off |= htons(IP_MF);
1271                         offset += skb->len - nhoff - ihl;
1272                 } else {
1273                         iph->id = htons(id++);
1274                 }
1275                 iph->tot_len = htons(skb->len - nhoff);
1276                 ip_send_check(iph);
1277                 if (encap)
1278                         skb_reset_inner_headers(skb);
1279                 skb->network_header = (u8 *)iph - skb->head;
1280         } while ((skb = skb->next));
1281 
1282 out:
1283         return segs;
1284 }
1285 
1286 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1287                                          struct sk_buff *skb)
1288 {
1289         const struct net_offload *ops;
1290         struct sk_buff **pp = NULL;
1291         struct sk_buff *p;
1292         const struct iphdr *iph;
1293         unsigned int hlen;
1294         unsigned int off;
1295         unsigned int id;
1296         int flush = 1;
1297         int proto;
1298 
1299         off = skb_gro_offset(skb);
1300         hlen = off + sizeof(*iph);
1301         iph = skb_gro_header_fast(skb, off);
1302         if (skb_gro_header_hard(skb, hlen)) {
1303                 iph = skb_gro_header_slow(skb, hlen, off);
1304                 if (unlikely(!iph))
1305                         goto out;
1306         }
1307 
1308         proto = iph->protocol;
1309 
1310         rcu_read_lock();
1311         ops = rcu_dereference(inet_offloads[proto]);
1312         if (!ops || !ops->callbacks.gro_receive)
1313                 goto out_unlock;
1314 
1315         if (*(u8 *)iph != 0x45)
1316                 goto out_unlock;
1317 
1318         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1319                 goto out_unlock;
1320 
1321         id = ntohl(*(__be32 *)&iph->id);
1322         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1323         id >>= 16;
1324 
1325         for (p = *head; p; p = p->next) {
1326                 struct iphdr *iph2;
1327 
1328                 if (!NAPI_GRO_CB(p)->same_flow)
1329                         continue;
1330 
1331                 iph2 = (struct iphdr *)(p->data + off);
1332                 /* The above works because, with the exception of the top
1333                  * (inner most) layer, we only aggregate pkts with the same
1334                  * hdr length so all the hdrs we'll need to verify will start
1335                  * at the same offset.
1336                  */
1337                 if ((iph->protocol ^ iph2->protocol) |
1338                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1339                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1340                         NAPI_GRO_CB(p)->same_flow = 0;
1341                         continue;
1342                 }
1343 
1344                 /* All fields must match except length and checksum. */
1345                 NAPI_GRO_CB(p)->flush |=
1346                         (iph->ttl ^ iph2->ttl) |
1347                         (iph->tos ^ iph2->tos) |
1348                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1349 
1350                 /* Save the IP ID check to be included later when we get to
1351                  * the transport layer so only the inner most IP ID is checked.
1352                  * This is because some GSO/TSO implementations do not
1353                  * correctly increment the IP ID for the outer hdrs.
1354                  */
1355                 NAPI_GRO_CB(p)->flush_id =
1356                             ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1357                 NAPI_GRO_CB(p)->flush |= flush;
1358         }
1359 
1360         NAPI_GRO_CB(skb)->flush |= flush;
1361         skb_set_network_header(skb, off);
1362         /* The above will be needed by the transport layer if there is one
1363          * immediately following this IP hdr.
1364          */
1365 
1366         /* Note : No need to call skb_gro_postpull_rcsum() here,
1367          * as we already checked checksum over ipv4 header was 0
1368          */
1369         skb_gro_pull(skb, sizeof(*iph));
1370         skb_set_transport_header(skb, skb_gro_offset(skb));
1371 
1372         pp = ops->callbacks.gro_receive(head, skb);
1373 
1374 out_unlock:
1375         rcu_read_unlock();
1376 
1377 out:
1378         NAPI_GRO_CB(skb)->flush |= flush;
1379 
1380         return pp;
1381 }
1382 
1383 static struct sk_buff **ipip_gro_receive(struct sk_buff **head,
1384                                          struct sk_buff *skb)
1385 {
1386         if (NAPI_GRO_CB(skb)->encap_mark) {
1387                 NAPI_GRO_CB(skb)->flush = 1;
1388                 return NULL;
1389         }
1390 
1391         NAPI_GRO_CB(skb)->encap_mark = 1;
1392 
1393         return inet_gro_receive(head, skb);
1394 }
1395 
1396 #define SECONDS_PER_DAY 86400
1397 
1398 /* inet_current_timestamp - Return IP network timestamp
1399  *
1400  * Return milliseconds since midnight in network byte order.
1401  */
1402 __be32 inet_current_timestamp(void)
1403 {
1404         u32 secs;
1405         u32 msecs;
1406         struct timespec64 ts;
1407 
1408         ktime_get_real_ts64(&ts);
1409 
1410         /* Get secs since midnight. */
1411         (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1412         /* Convert to msecs. */
1413         msecs = secs * MSEC_PER_SEC;
1414         /* Convert nsec to msec. */
1415         msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1416 
1417         /* Convert to network byte order. */
1418         return htonl(msecs);
1419 }
1420 EXPORT_SYMBOL(inet_current_timestamp);
1421 
1422 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1423 {
1424         if (sk->sk_family == AF_INET)
1425                 return ip_recv_error(sk, msg, len, addr_len);
1426 #if IS_ENABLED(CONFIG_IPV6)
1427         if (sk->sk_family == AF_INET6)
1428                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1429 #endif
1430         return -EINVAL;
1431 }
1432 
1433 static int inet_gro_complete(struct sk_buff *skb, int nhoff)
1434 {
1435         __be16 newlen = htons(skb->len - nhoff);
1436         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1437         const struct net_offload *ops;
1438         int proto = iph->protocol;
1439         int err = -ENOSYS;
1440 
1441         if (skb->encapsulation)
1442                 skb_set_inner_network_header(skb, nhoff);
1443 
1444         csum_replace2(&iph->check, iph->tot_len, newlen);
1445         iph->tot_len = newlen;
1446 
1447         rcu_read_lock();
1448         ops = rcu_dereference(inet_offloads[proto]);
1449         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1450                 goto out_unlock;
1451 
1452         /* Only need to add sizeof(*iph) to get to the next hdr below
1453          * because any hdr with option will have been flushed in
1454          * inet_gro_receive().
1455          */
1456         err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1457 
1458 out_unlock:
1459         rcu_read_unlock();
1460 
1461         return err;
1462 }
1463 
1464 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1465 {
1466         skb->encapsulation = 1;
1467         skb_shinfo(skb)->gso_type |= SKB_GSO_IPIP;
1468         return inet_gro_complete(skb, nhoff);
1469 }
1470 
1471 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1472                          unsigned short type, unsigned char protocol,
1473                          struct net *net)
1474 {
1475         struct socket *sock;
1476         int rc = sock_create_kern(net, family, type, protocol, &sock);
1477 
1478         if (rc == 0) {
1479                 *sk = sock->sk;
1480                 (*sk)->sk_allocation = GFP_ATOMIC;
1481                 /*
1482                  * Unhash it so that IP input processing does not even see it,
1483                  * we do not wish this socket to see incoming packets.
1484                  */
1485                 (*sk)->sk_prot->unhash(*sk);
1486         }
1487         return rc;
1488 }
1489 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1490 
1491 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1492 {
1493         return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1494 }
1495 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1496 
1497 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1498 {
1499         unsigned long res = 0;
1500         int i;
1501 
1502         for_each_possible_cpu(i)
1503                 res += snmp_get_cpu_field(mib, i, offt);
1504         return res;
1505 }
1506 EXPORT_SYMBOL_GPL(snmp_fold_field);
1507 
1508 #if BITS_PER_LONG==32
1509 
1510 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1511                          size_t syncp_offset)
1512 {
1513         void *bhptr;
1514         struct u64_stats_sync *syncp;
1515         u64 v;
1516         unsigned int start;
1517 
1518         bhptr = per_cpu_ptr(mib, cpu);
1519         syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1520         do {
1521                 start = u64_stats_fetch_begin_irq(syncp);
1522                 v = *(((u64 *)bhptr) + offt);
1523         } while (u64_stats_fetch_retry_irq(syncp, start));
1524 
1525         return v;
1526 }
1527 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1528 
1529 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1530 {
1531         u64 res = 0;
1532         int cpu;
1533 
1534         for_each_possible_cpu(cpu) {
1535                 res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1536         }
1537         return res;
1538 }
1539 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1540 #endif
1541 
1542 #ifdef CONFIG_IP_MULTICAST
1543 static const struct net_protocol igmp_protocol = {
1544         .handler =      igmp_rcv,
1545         .netns_ok =     1,
1546 };
1547 #endif
1548 
1549 static const struct net_protocol tcp_protocol = {
1550         .early_demux    =       tcp_v4_early_demux,
1551         .handler        =       tcp_v4_rcv,
1552         .err_handler    =       tcp_v4_err,
1553         .no_policy      =       1,
1554         .netns_ok       =       1,
1555         .icmp_strict_tag_validation = 1,
1556 };
1557 
1558 static const struct net_protocol udp_protocol = {
1559         .early_demux =  udp_v4_early_demux,
1560         .handler =      udp_rcv,
1561         .err_handler =  udp_err,
1562         .no_policy =    1,
1563         .netns_ok =     1,
1564 };
1565 
1566 static const struct net_protocol icmp_protocol = {
1567         .handler =      icmp_rcv,
1568         .err_handler =  icmp_err,
1569         .no_policy =    1,
1570         .netns_ok =     1,
1571 };
1572 
1573 static __net_init int ipv4_mib_init_net(struct net *net)
1574 {
1575         int i;
1576 
1577         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1578         if (!net->mib.tcp_statistics)
1579                 goto err_tcp_mib;
1580         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1581         if (!net->mib.ip_statistics)
1582                 goto err_ip_mib;
1583 
1584         for_each_possible_cpu(i) {
1585                 struct ipstats_mib *af_inet_stats;
1586                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1587                 u64_stats_init(&af_inet_stats->syncp);
1588         }
1589 
1590         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1591         if (!net->mib.net_statistics)
1592                 goto err_net_mib;
1593         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1594         if (!net->mib.udp_statistics)
1595                 goto err_udp_mib;
1596         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1597         if (!net->mib.udplite_statistics)
1598                 goto err_udplite_mib;
1599         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1600         if (!net->mib.icmp_statistics)
1601                 goto err_icmp_mib;
1602         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1603                                               GFP_KERNEL);
1604         if (!net->mib.icmpmsg_statistics)
1605                 goto err_icmpmsg_mib;
1606 
1607         tcp_mib_init(net);
1608         return 0;
1609 
1610 err_icmpmsg_mib:
1611         free_percpu(net->mib.icmp_statistics);
1612 err_icmp_mib:
1613         free_percpu(net->mib.udplite_statistics);
1614 err_udplite_mib:
1615         free_percpu(net->mib.udp_statistics);
1616 err_udp_mib:
1617         free_percpu(net->mib.net_statistics);
1618 err_net_mib:
1619         free_percpu(net->mib.ip_statistics);
1620 err_ip_mib:
1621         free_percpu(net->mib.tcp_statistics);
1622 err_tcp_mib:
1623         return -ENOMEM;
1624 }
1625 
1626 static __net_exit void ipv4_mib_exit_net(struct net *net)
1627 {
1628         kfree(net->mib.icmpmsg_statistics);
1629         free_percpu(net->mib.icmp_statistics);
1630         free_percpu(net->mib.udplite_statistics);
1631         free_percpu(net->mib.udp_statistics);
1632         free_percpu(net->mib.net_statistics);
1633         free_percpu(net->mib.ip_statistics);
1634         free_percpu(net->mib.tcp_statistics);
1635 }
1636 
1637 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1638         .init = ipv4_mib_init_net,
1639         .exit = ipv4_mib_exit_net,
1640 };
1641 
1642 static int __init init_ipv4_mibs(void)
1643 {
1644         return register_pernet_subsys(&ipv4_mib_ops);
1645 }
1646 
1647 static __net_init int inet_init_net(struct net *net)
1648 {
1649         /*
1650          * Set defaults for local port range
1651          */
1652         seqlock_init(&net->ipv4.ip_local_ports.lock);
1653         net->ipv4.ip_local_ports.range[0] =  32768;
1654         net->ipv4.ip_local_ports.range[1] =  60999;
1655 
1656         seqlock_init(&net->ipv4.ping_group_range.lock);
1657         /*
1658          * Sane defaults - nobody may create ping sockets.
1659          * Boot scripts should set this to distro-specific group.
1660          */
1661         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1662         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1663         return 0;
1664 }
1665 
1666 static __net_exit void inet_exit_net(struct net *net)
1667 {
1668 }
1669 
1670 static __net_initdata struct pernet_operations af_inet_ops = {
1671         .init = inet_init_net,
1672         .exit = inet_exit_net,
1673 };
1674 
1675 static int __init init_inet_pernet_ops(void)
1676 {
1677         return register_pernet_subsys(&af_inet_ops);
1678 }
1679 
1680 static int ipv4_proc_init(void);
1681 
1682 /*
1683  *      IP protocol layer initialiser
1684  */
1685 
1686 static struct packet_offload ip_packet_offload __read_mostly = {
1687         .type = cpu_to_be16(ETH_P_IP),
1688         .callbacks = {
1689                 .gso_segment = inet_gso_segment,
1690                 .gro_receive = inet_gro_receive,
1691                 .gro_complete = inet_gro_complete,
1692         },
1693 };
1694 
1695 static const struct net_offload ipip_offload = {
1696         .callbacks = {
1697                 .gso_segment    = inet_gso_segment,
1698                 .gro_receive    = ipip_gro_receive,
1699                 .gro_complete   = ipip_gro_complete,
1700         },
1701 };
1702 
1703 static int __init ipv4_offload_init(void)
1704 {
1705         /*
1706          * Add offloads
1707          */
1708         if (udpv4_offload_init() < 0)
1709                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1710         if (tcpv4_offload_init() < 0)
1711                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1712 
1713         dev_add_offload(&ip_packet_offload);
1714         inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1715         return 0;
1716 }
1717 
1718 fs_initcall(ipv4_offload_init);
1719 
1720 static struct packet_type ip_packet_type __read_mostly = {
1721         .type = cpu_to_be16(ETH_P_IP),
1722         .func = ip_rcv,
1723 };
1724 
1725 static int __init inet_init(void)
1726 {
1727         struct inet_protosw *q;
1728         struct list_head *r;
1729         int rc = -EINVAL;
1730 
1731         sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1732 
1733         rc = proto_register(&tcp_prot, 1);
1734         if (rc)
1735                 goto out;
1736 
1737         rc = proto_register(&udp_prot, 1);
1738         if (rc)
1739                 goto out_unregister_tcp_proto;
1740 
1741         rc = proto_register(&raw_prot, 1);
1742         if (rc)
1743                 goto out_unregister_udp_proto;
1744 
1745         rc = proto_register(&ping_prot, 1);
1746         if (rc)
1747                 goto out_unregister_raw_proto;
1748 
1749         /*
1750          *      Tell SOCKET that we are alive...
1751          */
1752 
1753         (void)sock_register(&inet_family_ops);
1754 
1755 #ifdef CONFIG_SYSCTL
1756         ip_static_sysctl_init();
1757 #endif
1758 
1759         /*
1760          *      Add all the base protocols.
1761          */
1762 
1763         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1764                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1765         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1766                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1767         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1768                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1769 #ifdef CONFIG_IP_MULTICAST
1770         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1771                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1772 #endif
1773 
1774         /* Register the socket-side information for inet_create. */
1775         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1776                 INIT_LIST_HEAD(r);
1777 
1778         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1779                 inet_register_protosw(q);
1780 
1781         /*
1782          *      Set the ARP module up
1783          */
1784 
1785         arp_init();
1786 
1787         /*
1788          *      Set the IP module up
1789          */
1790 
1791         ip_init();
1792 
1793         tcp_v4_init();
1794 
1795         /* Setup TCP slab cache for open requests. */
1796         tcp_init();
1797 
1798         /* Setup UDP memory threshold */
1799         udp_init();
1800 
1801         /* Add UDP-Lite (RFC 3828) */
1802         udplite4_register();
1803 
1804         ping_init();
1805 
1806         /*
1807          *      Set the ICMP layer up
1808          */
1809 
1810         if (icmp_init() < 0)
1811                 panic("Failed to create the ICMP control socket.\n");
1812 
1813         /*
1814          *      Initialise the multicast router
1815          */
1816 #if defined(CONFIG_IP_MROUTE)
1817         if (ip_mr_init())
1818                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1819 #endif
1820 
1821         if (init_inet_pernet_ops())
1822                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1823         /*
1824          *      Initialise per-cpu ipv4 mibs
1825          */
1826 
1827         if (init_ipv4_mibs())
1828                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1829 
1830         ipv4_proc_init();
1831 
1832         ipfrag_init();
1833 
1834         dev_add_pack(&ip_packet_type);
1835 
1836         ip_tunnel_core_init();
1837 
1838         rc = 0;
1839 out:
1840         return rc;
1841 out_unregister_raw_proto:
1842         proto_unregister(&raw_prot);
1843 out_unregister_udp_proto:
1844         proto_unregister(&udp_prot);
1845 out_unregister_tcp_proto:
1846         proto_unregister(&tcp_prot);
1847         goto out;
1848 }
1849 
1850 fs_initcall(inet_init);
1851 
1852 /* ------------------------------------------------------------------------ */
1853 
1854 #ifdef CONFIG_PROC_FS
1855 static int __init ipv4_proc_init(void)
1856 {
1857         int rc = 0;
1858 
1859         if (raw_proc_init())
1860                 goto out_raw;
1861         if (tcp4_proc_init())
1862                 goto out_tcp;
1863         if (udp4_proc_init())
1864                 goto out_udp;
1865         if (ping_proc_init())
1866                 goto out_ping;
1867         if (ip_misc_proc_init())
1868                 goto out_misc;
1869 out:
1870         return rc;
1871 out_misc:
1872         ping_proc_exit();
1873 out_ping:
1874         udp4_proc_exit();
1875 out_udp:
1876         tcp4_proc_exit();
1877 out_tcp:
1878         raw_proc_exit();
1879 out_raw:
1880         rc = -ENOMEM;
1881         goto out;
1882 }
1883 
1884 #else /* CONFIG_PROC_FS */
1885 static int __init ipv4_proc_init(void)
1886 {
1887         return 0;
1888 }
1889 #endif /* CONFIG_PROC_FS */
1890 
1891 MODULE_ALIAS_NETPROTO(PF_INET);
1892 
1893 

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