Version:  2.0.40 2.2.26 2.4.37 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 4.7

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         .set_peek_off      = sk_set_peek_off,
952 #ifdef CONFIG_COMPAT
953         .compat_setsockopt = compat_sock_common_setsockopt,
954         .compat_getsockopt = compat_sock_common_getsockopt,
955         .compat_ioctl      = inet_compat_ioctl,
956 #endif
957 };
958 EXPORT_SYMBOL(inet_dgram_ops);
959 
960 /*
961  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
962  * udp_poll
963  */
964 static const struct proto_ops inet_sockraw_ops = {
965         .family            = PF_INET,
966         .owner             = THIS_MODULE,
967         .release           = inet_release,
968         .bind              = inet_bind,
969         .connect           = inet_dgram_connect,
970         .socketpair        = sock_no_socketpair,
971         .accept            = sock_no_accept,
972         .getname           = inet_getname,
973         .poll              = datagram_poll,
974         .ioctl             = inet_ioctl,
975         .listen            = sock_no_listen,
976         .shutdown          = inet_shutdown,
977         .setsockopt        = sock_common_setsockopt,
978         .getsockopt        = sock_common_getsockopt,
979         .sendmsg           = inet_sendmsg,
980         .recvmsg           = inet_recvmsg,
981         .mmap              = sock_no_mmap,
982         .sendpage          = inet_sendpage,
983 #ifdef CONFIG_COMPAT
984         .compat_setsockopt = compat_sock_common_setsockopt,
985         .compat_getsockopt = compat_sock_common_getsockopt,
986         .compat_ioctl      = inet_compat_ioctl,
987 #endif
988 };
989 
990 static const struct net_proto_family inet_family_ops = {
991         .family = PF_INET,
992         .create = inet_create,
993         .owner  = THIS_MODULE,
994 };
995 
996 /* Upon startup we insert all the elements in inetsw_array[] into
997  * the linked list inetsw.
998  */
999 static struct inet_protosw inetsw_array[] =
1000 {
1001         {
1002                 .type =       SOCK_STREAM,
1003                 .protocol =   IPPROTO_TCP,
1004                 .prot =       &tcp_prot,
1005                 .ops =        &inet_stream_ops,
1006                 .flags =      INET_PROTOSW_PERMANENT |
1007                               INET_PROTOSW_ICSK,
1008         },
1009 
1010         {
1011                 .type =       SOCK_DGRAM,
1012                 .protocol =   IPPROTO_UDP,
1013                 .prot =       &udp_prot,
1014                 .ops =        &inet_dgram_ops,
1015                 .flags =      INET_PROTOSW_PERMANENT,
1016        },
1017 
1018        {
1019                 .type =       SOCK_DGRAM,
1020                 .protocol =   IPPROTO_ICMP,
1021                 .prot =       &ping_prot,
1022                 .ops =        &inet_dgram_ops,
1023                 .flags =      INET_PROTOSW_REUSE,
1024        },
1025 
1026        {
1027                .type =       SOCK_RAW,
1028                .protocol =   IPPROTO_IP,        /* wild card */
1029                .prot =       &raw_prot,
1030                .ops =        &inet_sockraw_ops,
1031                .flags =      INET_PROTOSW_REUSE,
1032        }
1033 };
1034 
1035 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1036 
1037 void inet_register_protosw(struct inet_protosw *p)
1038 {
1039         struct list_head *lh;
1040         struct inet_protosw *answer;
1041         int protocol = p->protocol;
1042         struct list_head *last_perm;
1043 
1044         spin_lock_bh(&inetsw_lock);
1045 
1046         if (p->type >= SOCK_MAX)
1047                 goto out_illegal;
1048 
1049         /* If we are trying to override a permanent protocol, bail. */
1050         last_perm = &inetsw[p->type];
1051         list_for_each(lh, &inetsw[p->type]) {
1052                 answer = list_entry(lh, struct inet_protosw, list);
1053                 /* Check only the non-wild match. */
1054                 if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1055                         break;
1056                 if (protocol == answer->protocol)
1057                         goto out_permanent;
1058                 last_perm = lh;
1059         }
1060 
1061         /* Add the new entry after the last permanent entry if any, so that
1062          * the new entry does not override a permanent entry when matched with
1063          * a wild-card protocol. But it is allowed to override any existing
1064          * non-permanent entry.  This means that when we remove this entry, the
1065          * system automatically returns to the old behavior.
1066          */
1067         list_add_rcu(&p->list, last_perm);
1068 out:
1069         spin_unlock_bh(&inetsw_lock);
1070 
1071         return;
1072 
1073 out_permanent:
1074         pr_err("Attempt to override permanent protocol %d\n", protocol);
1075         goto out;
1076 
1077 out_illegal:
1078         pr_err("Ignoring attempt to register invalid socket type %d\n",
1079                p->type);
1080         goto out;
1081 }
1082 EXPORT_SYMBOL(inet_register_protosw);
1083 
1084 void inet_unregister_protosw(struct inet_protosw *p)
1085 {
1086         if (INET_PROTOSW_PERMANENT & p->flags) {
1087                 pr_err("Attempt to unregister permanent protocol %d\n",
1088                        p->protocol);
1089         } else {
1090                 spin_lock_bh(&inetsw_lock);
1091                 list_del_rcu(&p->list);
1092                 spin_unlock_bh(&inetsw_lock);
1093 
1094                 synchronize_net();
1095         }
1096 }
1097 EXPORT_SYMBOL(inet_unregister_protosw);
1098 
1099 static int inet_sk_reselect_saddr(struct sock *sk)
1100 {
1101         struct inet_sock *inet = inet_sk(sk);
1102         __be32 old_saddr = inet->inet_saddr;
1103         __be32 daddr = inet->inet_daddr;
1104         struct flowi4 *fl4;
1105         struct rtable *rt;
1106         __be32 new_saddr;
1107         struct ip_options_rcu *inet_opt;
1108 
1109         inet_opt = rcu_dereference_protected(inet->inet_opt,
1110                                              lockdep_sock_is_held(sk));
1111         if (inet_opt && inet_opt->opt.srr)
1112                 daddr = inet_opt->opt.faddr;
1113 
1114         /* Query new route. */
1115         fl4 = &inet->cork.fl.u.ip4;
1116         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1117                               sk->sk_bound_dev_if, sk->sk_protocol,
1118                               inet->inet_sport, inet->inet_dport, sk);
1119         if (IS_ERR(rt))
1120                 return PTR_ERR(rt);
1121 
1122         sk_setup_caps(sk, &rt->dst);
1123 
1124         new_saddr = fl4->saddr;
1125 
1126         if (new_saddr == old_saddr)
1127                 return 0;
1128 
1129         if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1130                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1131                         __func__, &old_saddr, &new_saddr);
1132         }
1133 
1134         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1135 
1136         /*
1137          * XXX The only one ugly spot where we need to
1138          * XXX really change the sockets identity after
1139          * XXX it has entered the hashes. -DaveM
1140          *
1141          * Besides that, it does not check for connection
1142          * uniqueness. Wait for troubles.
1143          */
1144         return __sk_prot_rehash(sk);
1145 }
1146 
1147 int inet_sk_rebuild_header(struct sock *sk)
1148 {
1149         struct inet_sock *inet = inet_sk(sk);
1150         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1151         __be32 daddr;
1152         struct ip_options_rcu *inet_opt;
1153         struct flowi4 *fl4;
1154         int err;
1155 
1156         /* Route is OK, nothing to do. */
1157         if (rt)
1158                 return 0;
1159 
1160         /* Reroute. */
1161         rcu_read_lock();
1162         inet_opt = rcu_dereference(inet->inet_opt);
1163         daddr = inet->inet_daddr;
1164         if (inet_opt && inet_opt->opt.srr)
1165                 daddr = inet_opt->opt.faddr;
1166         rcu_read_unlock();
1167         fl4 = &inet->cork.fl.u.ip4;
1168         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1169                                    inet->inet_dport, inet->inet_sport,
1170                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1171                                    sk->sk_bound_dev_if);
1172         if (!IS_ERR(rt)) {
1173                 err = 0;
1174                 sk_setup_caps(sk, &rt->dst);
1175         } else {
1176                 err = PTR_ERR(rt);
1177 
1178                 /* Routing failed... */
1179                 sk->sk_route_caps = 0;
1180                 /*
1181                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1182                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1183                  */
1184                 if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1185                     sk->sk_state != TCP_SYN_SENT ||
1186                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1187                     (err = inet_sk_reselect_saddr(sk)) != 0)
1188                         sk->sk_err_soft = -err;
1189         }
1190 
1191         return err;
1192 }
1193 EXPORT_SYMBOL(inet_sk_rebuild_header);
1194 
1195 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1196                                  netdev_features_t features)
1197 {
1198         bool udpfrag = false, fixedid = false, encap;
1199         struct sk_buff *segs = ERR_PTR(-EINVAL);
1200         const struct net_offload *ops;
1201         unsigned int offset = 0;
1202         struct iphdr *iph;
1203         int proto, tot_len;
1204         int nhoff;
1205         int ihl;
1206         int id;
1207 
1208         skb_reset_network_header(skb);
1209         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1210         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1211                 goto out;
1212 
1213         iph = ip_hdr(skb);
1214         ihl = iph->ihl * 4;
1215         if (ihl < sizeof(*iph))
1216                 goto out;
1217 
1218         id = ntohs(iph->id);
1219         proto = iph->protocol;
1220 
1221         /* Warning: after this point, iph might be no longer valid */
1222         if (unlikely(!pskb_may_pull(skb, ihl)))
1223                 goto out;
1224         __skb_pull(skb, ihl);
1225 
1226         encap = SKB_GSO_CB(skb)->encap_level > 0;
1227         if (encap)
1228                 features &= skb->dev->hw_enc_features;
1229         SKB_GSO_CB(skb)->encap_level += ihl;
1230 
1231         skb_reset_transport_header(skb);
1232 
1233         segs = ERR_PTR(-EPROTONOSUPPORT);
1234 
1235         if (!skb->encapsulation || encap) {
1236                 udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1237                 fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1238 
1239                 /* fixed ID is invalid if DF bit is not set */
1240                 if (fixedid && !(iph->frag_off & htons(IP_DF)))
1241                         goto out;
1242         }
1243 
1244         ops = rcu_dereference(inet_offloads[proto]);
1245         if (likely(ops && ops->callbacks.gso_segment))
1246                 segs = ops->callbacks.gso_segment(skb, features);
1247 
1248         if (IS_ERR_OR_NULL(segs))
1249                 goto out;
1250 
1251         skb = segs;
1252         do {
1253                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1254                 if (udpfrag) {
1255                         iph->frag_off = htons(offset >> 3);
1256                         if (skb->next)
1257                                 iph->frag_off |= htons(IP_MF);
1258                         offset += skb->len - nhoff - ihl;
1259                         tot_len = skb->len - nhoff;
1260                 } else if (skb_is_gso(skb)) {
1261                         if (!fixedid) {
1262                                 iph->id = htons(id);
1263                                 id += skb_shinfo(skb)->gso_segs;
1264                         }
1265                         tot_len = skb_shinfo(skb)->gso_size +
1266                                   SKB_GSO_CB(skb)->data_offset +
1267                                   skb->head - (unsigned char *)iph;
1268                 } else {
1269                         if (!fixedid)
1270                                 iph->id = htons(id++);
1271                         tot_len = skb->len - nhoff;
1272                 }
1273                 iph->tot_len = htons(tot_len);
1274                 ip_send_check(iph);
1275                 if (encap)
1276                         skb_reset_inner_headers(skb);
1277                 skb->network_header = (u8 *)iph - skb->head;
1278         } while ((skb = skb->next));
1279 
1280 out:
1281         return segs;
1282 }
1283 EXPORT_SYMBOL(inet_gso_segment);
1284 
1285 struct sk_buff **inet_gro_receive(struct sk_buff **head, struct sk_buff *skb)
1286 {
1287         const struct net_offload *ops;
1288         struct sk_buff **pp = NULL;
1289         struct sk_buff *p;
1290         const struct iphdr *iph;
1291         unsigned int hlen;
1292         unsigned int off;
1293         unsigned int id;
1294         int flush = 1;
1295         int proto;
1296 
1297         off = skb_gro_offset(skb);
1298         hlen = off + sizeof(*iph);
1299         iph = skb_gro_header_fast(skb, off);
1300         if (skb_gro_header_hard(skb, hlen)) {
1301                 iph = skb_gro_header_slow(skb, hlen, off);
1302                 if (unlikely(!iph))
1303                         goto out;
1304         }
1305 
1306         proto = iph->protocol;
1307 
1308         rcu_read_lock();
1309         ops = rcu_dereference(inet_offloads[proto]);
1310         if (!ops || !ops->callbacks.gro_receive)
1311                 goto out_unlock;
1312 
1313         if (*(u8 *)iph != 0x45)
1314                 goto out_unlock;
1315 
1316         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1317                 goto out_unlock;
1318 
1319         id = ntohl(*(__be32 *)&iph->id);
1320         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1321         id >>= 16;
1322 
1323         for (p = *head; p; p = p->next) {
1324                 struct iphdr *iph2;
1325                 u16 flush_id;
1326 
1327                 if (!NAPI_GRO_CB(p)->same_flow)
1328                         continue;
1329 
1330                 iph2 = (struct iphdr *)(p->data + off);
1331                 /* The above works because, with the exception of the top
1332                  * (inner most) layer, we only aggregate pkts with the same
1333                  * hdr length so all the hdrs we'll need to verify will start
1334                  * at the same offset.
1335                  */
1336                 if ((iph->protocol ^ iph2->protocol) |
1337                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1338                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1339                         NAPI_GRO_CB(p)->same_flow = 0;
1340                         continue;
1341                 }
1342 
1343                 /* All fields must match except length and checksum. */
1344                 NAPI_GRO_CB(p)->flush |=
1345                         (iph->ttl ^ iph2->ttl) |
1346                         (iph->tos ^ iph2->tos) |
1347                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1348 
1349                 NAPI_GRO_CB(p)->flush |= flush;
1350 
1351                 /* We need to store of the IP ID check to be included later
1352                  * when we can verify that this packet does in fact belong
1353                  * to a given flow.
1354                  */
1355                 flush_id = (u16)(id - ntohs(iph2->id));
1356 
1357                 /* This bit of code makes it much easier for us to identify
1358                  * the cases where we are doing atomic vs non-atomic IP ID
1359                  * checks.  Specifically an atomic check can return IP ID
1360                  * values 0 - 0xFFFF, while a non-atomic check can only
1361                  * return 0 or 0xFFFF.
1362                  */
1363                 if (!NAPI_GRO_CB(p)->is_atomic ||
1364                     !(iph->frag_off & htons(IP_DF))) {
1365                         flush_id ^= NAPI_GRO_CB(p)->count;
1366                         flush_id = flush_id ? 0xFFFF : 0;
1367                 }
1368 
1369                 /* If the previous IP ID value was based on an atomic
1370                  * datagram we can overwrite the value and ignore it.
1371                  */
1372                 if (NAPI_GRO_CB(skb)->is_atomic)
1373                         NAPI_GRO_CB(p)->flush_id = flush_id;
1374                 else
1375                         NAPI_GRO_CB(p)->flush_id |= flush_id;
1376         }
1377 
1378         NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1379         NAPI_GRO_CB(skb)->flush |= flush;
1380         skb_set_network_header(skb, off);
1381         /* The above will be needed by the transport layer if there is one
1382          * immediately following this IP hdr.
1383          */
1384 
1385         /* Note : No need to call skb_gro_postpull_rcsum() here,
1386          * as we already checked checksum over ipv4 header was 0
1387          */
1388         skb_gro_pull(skb, sizeof(*iph));
1389         skb_set_transport_header(skb, skb_gro_offset(skb));
1390 
1391         pp = ops->callbacks.gro_receive(head, skb);
1392 
1393 out_unlock:
1394         rcu_read_unlock();
1395 
1396 out:
1397         NAPI_GRO_CB(skb)->flush |= flush;
1398 
1399         return pp;
1400 }
1401 EXPORT_SYMBOL(inet_gro_receive);
1402 
1403 static struct sk_buff **ipip_gro_receive(struct sk_buff **head,
1404                                          struct sk_buff *skb)
1405 {
1406         if (NAPI_GRO_CB(skb)->encap_mark) {
1407                 NAPI_GRO_CB(skb)->flush = 1;
1408                 return NULL;
1409         }
1410 
1411         NAPI_GRO_CB(skb)->encap_mark = 1;
1412 
1413         return inet_gro_receive(head, skb);
1414 }
1415 
1416 #define SECONDS_PER_DAY 86400
1417 
1418 /* inet_current_timestamp - Return IP network timestamp
1419  *
1420  * Return milliseconds since midnight in network byte order.
1421  */
1422 __be32 inet_current_timestamp(void)
1423 {
1424         u32 secs;
1425         u32 msecs;
1426         struct timespec64 ts;
1427 
1428         ktime_get_real_ts64(&ts);
1429 
1430         /* Get secs since midnight. */
1431         (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1432         /* Convert to msecs. */
1433         msecs = secs * MSEC_PER_SEC;
1434         /* Convert nsec to msec. */
1435         msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1436 
1437         /* Convert to network byte order. */
1438         return htonl(msecs);
1439 }
1440 EXPORT_SYMBOL(inet_current_timestamp);
1441 
1442 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1443 {
1444         if (sk->sk_family == AF_INET)
1445                 return ip_recv_error(sk, msg, len, addr_len);
1446 #if IS_ENABLED(CONFIG_IPV6)
1447         if (sk->sk_family == AF_INET6)
1448                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1449 #endif
1450         return -EINVAL;
1451 }
1452 
1453 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1454 {
1455         __be16 newlen = htons(skb->len - nhoff);
1456         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1457         const struct net_offload *ops;
1458         int proto = iph->protocol;
1459         int err = -ENOSYS;
1460 
1461         if (skb->encapsulation)
1462                 skb_set_inner_network_header(skb, nhoff);
1463 
1464         csum_replace2(&iph->check, iph->tot_len, newlen);
1465         iph->tot_len = newlen;
1466 
1467         rcu_read_lock();
1468         ops = rcu_dereference(inet_offloads[proto]);
1469         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1470                 goto out_unlock;
1471 
1472         /* Only need to add sizeof(*iph) to get to the next hdr below
1473          * because any hdr with option will have been flushed in
1474          * inet_gro_receive().
1475          */
1476         err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1477 
1478 out_unlock:
1479         rcu_read_unlock();
1480 
1481         return err;
1482 }
1483 EXPORT_SYMBOL(inet_gro_complete);
1484 
1485 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1486 {
1487         skb->encapsulation = 1;
1488         skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1489         return inet_gro_complete(skb, nhoff);
1490 }
1491 
1492 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1493                          unsigned short type, unsigned char protocol,
1494                          struct net *net)
1495 {
1496         struct socket *sock;
1497         int rc = sock_create_kern(net, family, type, protocol, &sock);
1498 
1499         if (rc == 0) {
1500                 *sk = sock->sk;
1501                 (*sk)->sk_allocation = GFP_ATOMIC;
1502                 /*
1503                  * Unhash it so that IP input processing does not even see it,
1504                  * we do not wish this socket to see incoming packets.
1505                  */
1506                 (*sk)->sk_prot->unhash(*sk);
1507         }
1508         return rc;
1509 }
1510 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1511 
1512 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1513 {
1514         return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1515 }
1516 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1517 
1518 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1519 {
1520         unsigned long res = 0;
1521         int i;
1522 
1523         for_each_possible_cpu(i)
1524                 res += snmp_get_cpu_field(mib, i, offt);
1525         return res;
1526 }
1527 EXPORT_SYMBOL_GPL(snmp_fold_field);
1528 
1529 #if BITS_PER_LONG==32
1530 
1531 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1532                          size_t syncp_offset)
1533 {
1534         void *bhptr;
1535         struct u64_stats_sync *syncp;
1536         u64 v;
1537         unsigned int start;
1538 
1539         bhptr = per_cpu_ptr(mib, cpu);
1540         syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1541         do {
1542                 start = u64_stats_fetch_begin_irq(syncp);
1543                 v = *(((u64 *)bhptr) + offt);
1544         } while (u64_stats_fetch_retry_irq(syncp, start));
1545 
1546         return v;
1547 }
1548 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1549 
1550 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1551 {
1552         u64 res = 0;
1553         int cpu;
1554 
1555         for_each_possible_cpu(cpu) {
1556                 res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1557         }
1558         return res;
1559 }
1560 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1561 #endif
1562 
1563 #ifdef CONFIG_IP_MULTICAST
1564 static const struct net_protocol igmp_protocol = {
1565         .handler =      igmp_rcv,
1566         .netns_ok =     1,
1567 };
1568 #endif
1569 
1570 static const struct net_protocol tcp_protocol = {
1571         .early_demux    =       tcp_v4_early_demux,
1572         .handler        =       tcp_v4_rcv,
1573         .err_handler    =       tcp_v4_err,
1574         .no_policy      =       1,
1575         .netns_ok       =       1,
1576         .icmp_strict_tag_validation = 1,
1577 };
1578 
1579 static const struct net_protocol udp_protocol = {
1580         .early_demux =  udp_v4_early_demux,
1581         .handler =      udp_rcv,
1582         .err_handler =  udp_err,
1583         .no_policy =    1,
1584         .netns_ok =     1,
1585 };
1586 
1587 static const struct net_protocol icmp_protocol = {
1588         .handler =      icmp_rcv,
1589         .err_handler =  icmp_err,
1590         .no_policy =    1,
1591         .netns_ok =     1,
1592 };
1593 
1594 static __net_init int ipv4_mib_init_net(struct net *net)
1595 {
1596         int i;
1597 
1598         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1599         if (!net->mib.tcp_statistics)
1600                 goto err_tcp_mib;
1601         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1602         if (!net->mib.ip_statistics)
1603                 goto err_ip_mib;
1604 
1605         for_each_possible_cpu(i) {
1606                 struct ipstats_mib *af_inet_stats;
1607                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1608                 u64_stats_init(&af_inet_stats->syncp);
1609         }
1610 
1611         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1612         if (!net->mib.net_statistics)
1613                 goto err_net_mib;
1614         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1615         if (!net->mib.udp_statistics)
1616                 goto err_udp_mib;
1617         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1618         if (!net->mib.udplite_statistics)
1619                 goto err_udplite_mib;
1620         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1621         if (!net->mib.icmp_statistics)
1622                 goto err_icmp_mib;
1623         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1624                                               GFP_KERNEL);
1625         if (!net->mib.icmpmsg_statistics)
1626                 goto err_icmpmsg_mib;
1627 
1628         tcp_mib_init(net);
1629         return 0;
1630 
1631 err_icmpmsg_mib:
1632         free_percpu(net->mib.icmp_statistics);
1633 err_icmp_mib:
1634         free_percpu(net->mib.udplite_statistics);
1635 err_udplite_mib:
1636         free_percpu(net->mib.udp_statistics);
1637 err_udp_mib:
1638         free_percpu(net->mib.net_statistics);
1639 err_net_mib:
1640         free_percpu(net->mib.ip_statistics);
1641 err_ip_mib:
1642         free_percpu(net->mib.tcp_statistics);
1643 err_tcp_mib:
1644         return -ENOMEM;
1645 }
1646 
1647 static __net_exit void ipv4_mib_exit_net(struct net *net)
1648 {
1649         kfree(net->mib.icmpmsg_statistics);
1650         free_percpu(net->mib.icmp_statistics);
1651         free_percpu(net->mib.udplite_statistics);
1652         free_percpu(net->mib.udp_statistics);
1653         free_percpu(net->mib.net_statistics);
1654         free_percpu(net->mib.ip_statistics);
1655         free_percpu(net->mib.tcp_statistics);
1656 }
1657 
1658 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1659         .init = ipv4_mib_init_net,
1660         .exit = ipv4_mib_exit_net,
1661 };
1662 
1663 static int __init init_ipv4_mibs(void)
1664 {
1665         return register_pernet_subsys(&ipv4_mib_ops);
1666 }
1667 
1668 static __net_init int inet_init_net(struct net *net)
1669 {
1670         /*
1671          * Set defaults for local port range
1672          */
1673         seqlock_init(&net->ipv4.ip_local_ports.lock);
1674         net->ipv4.ip_local_ports.range[0] =  32768;
1675         net->ipv4.ip_local_ports.range[1] =  60999;
1676 
1677         seqlock_init(&net->ipv4.ping_group_range.lock);
1678         /*
1679          * Sane defaults - nobody may create ping sockets.
1680          * Boot scripts should set this to distro-specific group.
1681          */
1682         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1683         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1684 
1685         /* Default values for sysctl-controlled parameters.
1686          * We set them here, in case sysctl is not compiled.
1687          */
1688         net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1689         net->ipv4.sysctl_ip_dynaddr = 0;
1690         net->ipv4.sysctl_ip_early_demux = 1;
1691 
1692         return 0;
1693 }
1694 
1695 static __net_exit void inet_exit_net(struct net *net)
1696 {
1697 }
1698 
1699 static __net_initdata struct pernet_operations af_inet_ops = {
1700         .init = inet_init_net,
1701         .exit = inet_exit_net,
1702 };
1703 
1704 static int __init init_inet_pernet_ops(void)
1705 {
1706         return register_pernet_subsys(&af_inet_ops);
1707 }
1708 
1709 static int ipv4_proc_init(void);
1710 
1711 /*
1712  *      IP protocol layer initialiser
1713  */
1714 
1715 static struct packet_offload ip_packet_offload __read_mostly = {
1716         .type = cpu_to_be16(ETH_P_IP),
1717         .callbacks = {
1718                 .gso_segment = inet_gso_segment,
1719                 .gro_receive = inet_gro_receive,
1720                 .gro_complete = inet_gro_complete,
1721         },
1722 };
1723 
1724 static const struct net_offload ipip_offload = {
1725         .callbacks = {
1726                 .gso_segment    = inet_gso_segment,
1727                 .gro_receive    = ipip_gro_receive,
1728                 .gro_complete   = ipip_gro_complete,
1729         },
1730 };
1731 
1732 static int __init ipv4_offload_init(void)
1733 {
1734         /*
1735          * Add offloads
1736          */
1737         if (udpv4_offload_init() < 0)
1738                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1739         if (tcpv4_offload_init() < 0)
1740                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1741 
1742         dev_add_offload(&ip_packet_offload);
1743         inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1744         return 0;
1745 }
1746 
1747 fs_initcall(ipv4_offload_init);
1748 
1749 static struct packet_type ip_packet_type __read_mostly = {
1750         .type = cpu_to_be16(ETH_P_IP),
1751         .func = ip_rcv,
1752 };
1753 
1754 static int __init inet_init(void)
1755 {
1756         struct inet_protosw *q;
1757         struct list_head *r;
1758         int rc = -EINVAL;
1759 
1760         sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1761 
1762         rc = proto_register(&tcp_prot, 1);
1763         if (rc)
1764                 goto out;
1765 
1766         rc = proto_register(&udp_prot, 1);
1767         if (rc)
1768                 goto out_unregister_tcp_proto;
1769 
1770         rc = proto_register(&raw_prot, 1);
1771         if (rc)
1772                 goto out_unregister_udp_proto;
1773 
1774         rc = proto_register(&ping_prot, 1);
1775         if (rc)
1776                 goto out_unregister_raw_proto;
1777 
1778         /*
1779          *      Tell SOCKET that we are alive...
1780          */
1781 
1782         (void)sock_register(&inet_family_ops);
1783 
1784 #ifdef CONFIG_SYSCTL
1785         ip_static_sysctl_init();
1786 #endif
1787 
1788         /*
1789          *      Add all the base protocols.
1790          */
1791 
1792         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1793                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1794         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1795                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1796         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1797                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1798 #ifdef CONFIG_IP_MULTICAST
1799         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1800                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1801 #endif
1802 
1803         /* Register the socket-side information for inet_create. */
1804         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1805                 INIT_LIST_HEAD(r);
1806 
1807         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1808                 inet_register_protosw(q);
1809 
1810         /*
1811          *      Set the ARP module up
1812          */
1813 
1814         arp_init();
1815 
1816         /*
1817          *      Set the IP module up
1818          */
1819 
1820         ip_init();
1821 
1822         tcp_v4_init();
1823 
1824         /* Setup TCP slab cache for open requests. */
1825         tcp_init();
1826 
1827         /* Setup UDP memory threshold */
1828         udp_init();
1829 
1830         /* Add UDP-Lite (RFC 3828) */
1831         udplite4_register();
1832 
1833         ping_init();
1834 
1835         /*
1836          *      Set the ICMP layer up
1837          */
1838 
1839         if (icmp_init() < 0)
1840                 panic("Failed to create the ICMP control socket.\n");
1841 
1842         /*
1843          *      Initialise the multicast router
1844          */
1845 #if defined(CONFIG_IP_MROUTE)
1846         if (ip_mr_init())
1847                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1848 #endif
1849 
1850         if (init_inet_pernet_ops())
1851                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1852         /*
1853          *      Initialise per-cpu ipv4 mibs
1854          */
1855 
1856         if (init_ipv4_mibs())
1857                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1858 
1859         ipv4_proc_init();
1860 
1861         ipfrag_init();
1862 
1863         dev_add_pack(&ip_packet_type);
1864 
1865         ip_tunnel_core_init();
1866 
1867         rc = 0;
1868 out:
1869         return rc;
1870 out_unregister_raw_proto:
1871         proto_unregister(&raw_prot);
1872 out_unregister_udp_proto:
1873         proto_unregister(&udp_prot);
1874 out_unregister_tcp_proto:
1875         proto_unregister(&tcp_prot);
1876         goto out;
1877 }
1878 
1879 fs_initcall(inet_init);
1880 
1881 /* ------------------------------------------------------------------------ */
1882 
1883 #ifdef CONFIG_PROC_FS
1884 static int __init ipv4_proc_init(void)
1885 {
1886         int rc = 0;
1887 
1888         if (raw_proc_init())
1889                 goto out_raw;
1890         if (tcp4_proc_init())
1891                 goto out_tcp;
1892         if (udp4_proc_init())
1893                 goto out_udp;
1894         if (ping_proc_init())
1895                 goto out_ping;
1896         if (ip_misc_proc_init())
1897                 goto out_misc;
1898 out:
1899         return rc;
1900 out_misc:
1901         ping_proc_exit();
1902 out_ping:
1903         udp4_proc_exit();
1904 out_udp:
1905         tcp4_proc_exit();
1906 out_tcp:
1907         raw_proc_exit();
1908 out_raw:
1909         rc = -ENOMEM;
1910         goto out;
1911 }
1912 
1913 #else /* CONFIG_PROC_FS */
1914 static int __init ipv4_proc_init(void)
1915 {
1916         return 0;
1917 }
1918 #endif /* CONFIG_PROC_FS */
1919 
1920 MODULE_ALIAS_NETPROTO(PF_INET);
1921 
1922 

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