Version:  2.0.40 2.2.26 2.4.37 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 4.8 4.9 4.10

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/kmod.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 <linux/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                 /* Enable TFO w/o requiring TCP_FASTOPEN socket option.
215                  * Note that only TCP sockets (SOCK_STREAM) will reach here.
216                  * Also fastopen backlog may already been set via the option
217                  * because the socket was in TCP_LISTEN state previously but
218                  * was shutdown() rather than close().
219                  */
220                 if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
221                     (sysctl_tcp_fastopen & TFO_SERVER_ENABLE) &&
222                     !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
223                         fastopen_queue_tune(sk, backlog);
224                         tcp_fastopen_init_key_once(true);
225                 }
226 
227                 err = inet_csk_listen_start(sk, backlog);
228                 if (err)
229                         goto out;
230         }
231         sk->sk_max_ack_backlog = backlog;
232         err = 0;
233 
234 out:
235         release_sock(sk);
236         return err;
237 }
238 EXPORT_SYMBOL(inet_listen);
239 
240 /*
241  *      Create an inet socket.
242  */
243 
244 static int inet_create(struct net *net, struct socket *sock, int protocol,
245                        int kern)
246 {
247         struct sock *sk;
248         struct inet_protosw *answer;
249         struct inet_sock *inet;
250         struct proto *answer_prot;
251         unsigned char answer_flags;
252         int try_loading_module = 0;
253         int err;
254 
255         if (protocol < 0 || protocol >= IPPROTO_MAX)
256                 return -EINVAL;
257 
258         sock->state = SS_UNCONNECTED;
259 
260         /* Look for the requested type/protocol pair. */
261 lookup_protocol:
262         err = -ESOCKTNOSUPPORT;
263         rcu_read_lock();
264         list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
265 
266                 err = 0;
267                 /* Check the non-wild match. */
268                 if (protocol == answer->protocol) {
269                         if (protocol != IPPROTO_IP)
270                                 break;
271                 } else {
272                         /* Check for the two wild cases. */
273                         if (IPPROTO_IP == protocol) {
274                                 protocol = answer->protocol;
275                                 break;
276                         }
277                         if (IPPROTO_IP == answer->protocol)
278                                 break;
279                 }
280                 err = -EPROTONOSUPPORT;
281         }
282 
283         if (unlikely(err)) {
284                 if (try_loading_module < 2) {
285                         rcu_read_unlock();
286                         /*
287                          * Be more specific, e.g. net-pf-2-proto-132-type-1
288                          * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
289                          */
290                         if (++try_loading_module == 1)
291                                 request_module("net-pf-%d-proto-%d-type-%d",
292                                                PF_INET, protocol, sock->type);
293                         /*
294                          * Fall back to generic, e.g. net-pf-2-proto-132
295                          * (net-pf-PF_INET-proto-IPPROTO_SCTP)
296                          */
297                         else
298                                 request_module("net-pf-%d-proto-%d",
299                                                PF_INET, protocol);
300                         goto lookup_protocol;
301                 } else
302                         goto out_rcu_unlock;
303         }
304 
305         err = -EPERM;
306         if (sock->type == SOCK_RAW && !kern &&
307             !ns_capable(net->user_ns, CAP_NET_RAW))
308                 goto out_rcu_unlock;
309 
310         sock->ops = answer->ops;
311         answer_prot = answer->prot;
312         answer_flags = answer->flags;
313         rcu_read_unlock();
314 
315         WARN_ON(!answer_prot->slab);
316 
317         err = -ENOBUFS;
318         sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
319         if (!sk)
320                 goto out;
321 
322         err = 0;
323         if (INET_PROTOSW_REUSE & answer_flags)
324                 sk->sk_reuse = SK_CAN_REUSE;
325 
326         inet = inet_sk(sk);
327         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
328 
329         inet->nodefrag = 0;
330 
331         if (SOCK_RAW == sock->type) {
332                 inet->inet_num = protocol;
333                 if (IPPROTO_RAW == protocol)
334                         inet->hdrincl = 1;
335         }
336 
337         if (net->ipv4.sysctl_ip_no_pmtu_disc)
338                 inet->pmtudisc = IP_PMTUDISC_DONT;
339         else
340                 inet->pmtudisc = IP_PMTUDISC_WANT;
341 
342         inet->inet_id = 0;
343 
344         sock_init_data(sock, sk);
345 
346         sk->sk_destruct    = inet_sock_destruct;
347         sk->sk_protocol    = protocol;
348         sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
349 
350         inet->uc_ttl    = -1;
351         inet->mc_loop   = 1;
352         inet->mc_ttl    = 1;
353         inet->mc_all    = 1;
354         inet->mc_index  = 0;
355         inet->mc_list   = NULL;
356         inet->rcv_tos   = 0;
357 
358         sk_refcnt_debug_inc(sk);
359 
360         if (inet->inet_num) {
361                 /* It assumes that any protocol which allows
362                  * the user to assign a number at socket
363                  * creation time automatically
364                  * shares.
365                  */
366                 inet->inet_sport = htons(inet->inet_num);
367                 /* Add to protocol hash chains. */
368                 err = sk->sk_prot->hash(sk);
369                 if (err) {
370                         sk_common_release(sk);
371                         goto out;
372                 }
373         }
374 
375         if (sk->sk_prot->init) {
376                 err = sk->sk_prot->init(sk);
377                 if (err) {
378                         sk_common_release(sk);
379                         goto out;
380                 }
381         }
382 
383         if (!kern) {
384                 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
385                 if (err) {
386                         sk_common_release(sk);
387                         goto out;
388                 }
389         }
390 out:
391         return err;
392 out_rcu_unlock:
393         rcu_read_unlock();
394         goto out;
395 }
396 
397 
398 /*
399  *      The peer socket should always be NULL (or else). When we call this
400  *      function we are destroying the object and from then on nobody
401  *      should refer to it.
402  */
403 int inet_release(struct socket *sock)
404 {
405         struct sock *sk = sock->sk;
406 
407         if (sk) {
408                 long timeout;
409 
410                 /* Applications forget to leave groups before exiting */
411                 ip_mc_drop_socket(sk);
412 
413                 /* If linger is set, we don't return until the close
414                  * is complete.  Otherwise we return immediately. The
415                  * actually closing is done the same either way.
416                  *
417                  * If the close is due to the process exiting, we never
418                  * linger..
419                  */
420                 timeout = 0;
421                 if (sock_flag(sk, SOCK_LINGER) &&
422                     !(current->flags & PF_EXITING))
423                         timeout = sk->sk_lingertime;
424                 sock->sk = NULL;
425                 sk->sk_prot->close(sk, timeout);
426         }
427         return 0;
428 }
429 EXPORT_SYMBOL(inet_release);
430 
431 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
432 {
433         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
434         struct sock *sk = sock->sk;
435         struct inet_sock *inet = inet_sk(sk);
436         struct net *net = sock_net(sk);
437         unsigned short snum;
438         int chk_addr_ret;
439         u32 tb_id = RT_TABLE_LOCAL;
440         int err;
441 
442         /* If the socket has its own bind function then use it. (RAW) */
443         if (sk->sk_prot->bind) {
444                 err = sk->sk_prot->bind(sk, uaddr, addr_len);
445                 goto out;
446         }
447         err = -EINVAL;
448         if (addr_len < sizeof(struct sockaddr_in))
449                 goto out;
450 
451         if (addr->sin_family != AF_INET) {
452                 /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
453                  * only if s_addr is INADDR_ANY.
454                  */
455                 err = -EAFNOSUPPORT;
456                 if (addr->sin_family != AF_UNSPEC ||
457                     addr->sin_addr.s_addr != htonl(INADDR_ANY))
458                         goto out;
459         }
460 
461         tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
462         chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
463 
464         /* Not specified by any standard per-se, however it breaks too
465          * many applications when removed.  It is unfortunate since
466          * allowing applications to make a non-local bind solves
467          * several problems with systems using dynamic addressing.
468          * (ie. your servers still start up even if your ISDN link
469          *  is temporarily down)
470          */
471         err = -EADDRNOTAVAIL;
472         if (!net->ipv4.sysctl_ip_nonlocal_bind &&
473             !(inet->freebind || inet->transparent) &&
474             addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
475             chk_addr_ret != RTN_LOCAL &&
476             chk_addr_ret != RTN_MULTICAST &&
477             chk_addr_ret != RTN_BROADCAST)
478                 goto out;
479 
480         snum = ntohs(addr->sin_port);
481         err = -EACCES;
482         if (snum && snum < PROT_SOCK &&
483             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
484                 goto out;
485 
486         /*      We keep a pair of addresses. rcv_saddr is the one
487          *      used by hash lookups, and saddr is used for transmit.
488          *
489          *      In the BSD API these are the same except where it
490          *      would be illegal to use them (multicast/broadcast) in
491          *      which case the sending device address is used.
492          */
493         lock_sock(sk);
494 
495         /* Check these errors (active socket, double bind). */
496         err = -EINVAL;
497         if (sk->sk_state != TCP_CLOSE || inet->inet_num)
498                 goto out_release_sock;
499 
500         inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
501         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
502                 inet->inet_saddr = 0;  /* Use device */
503 
504         /* Make sure we are allowed to bind here. */
505         if ((snum || !inet->bind_address_no_port) &&
506             sk->sk_prot->get_port(sk, snum)) {
507                 inet->inet_saddr = inet->inet_rcv_saddr = 0;
508                 err = -EADDRINUSE;
509                 goto out_release_sock;
510         }
511 
512         if (inet->inet_rcv_saddr)
513                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
514         if (snum)
515                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
516         inet->inet_sport = htons(inet->inet_num);
517         inet->inet_daddr = 0;
518         inet->inet_dport = 0;
519         sk_dst_reset(sk);
520         err = 0;
521 out_release_sock:
522         release_sock(sk);
523 out:
524         return err;
525 }
526 EXPORT_SYMBOL(inet_bind);
527 
528 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
529                        int addr_len, int flags)
530 {
531         struct sock *sk = sock->sk;
532 
533         if (addr_len < sizeof(uaddr->sa_family))
534                 return -EINVAL;
535         if (uaddr->sa_family == AF_UNSPEC)
536                 return sk->sk_prot->disconnect(sk, flags);
537 
538         if (!inet_sk(sk)->inet_num && inet_autobind(sk))
539                 return -EAGAIN;
540         return sk->sk_prot->connect(sk, uaddr, addr_len);
541 }
542 EXPORT_SYMBOL(inet_dgram_connect);
543 
544 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
545 {
546         DEFINE_WAIT_FUNC(wait, woken_wake_function);
547 
548         add_wait_queue(sk_sleep(sk), &wait);
549         sk->sk_write_pending += writebias;
550 
551         /* Basic assumption: if someone sets sk->sk_err, he _must_
552          * change state of the socket from TCP_SYN_*.
553          * Connect() does not allow to get error notifications
554          * without closing the socket.
555          */
556         while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
557                 release_sock(sk);
558                 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
559                 lock_sock(sk);
560                 if (signal_pending(current) || !timeo)
561                         break;
562         }
563         remove_wait_queue(sk_sleep(sk), &wait);
564         sk->sk_write_pending -= writebias;
565         return timeo;
566 }
567 
568 /*
569  *      Connect to a remote host. There is regrettably still a little
570  *      TCP 'magic' in here.
571  */
572 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
573                           int addr_len, int flags)
574 {
575         struct sock *sk = sock->sk;
576         int err;
577         long timeo;
578 
579         if (addr_len < sizeof(uaddr->sa_family))
580                 return -EINVAL;
581 
582         if (uaddr->sa_family == AF_UNSPEC) {
583                 err = sk->sk_prot->disconnect(sk, flags);
584                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
585                 goto out;
586         }
587 
588         switch (sock->state) {
589         default:
590                 err = -EINVAL;
591                 goto out;
592         case SS_CONNECTED:
593                 err = -EISCONN;
594                 goto out;
595         case SS_CONNECTING:
596                 err = -EALREADY;
597                 /* Fall out of switch with err, set for this state */
598                 break;
599         case SS_UNCONNECTED:
600                 err = -EISCONN;
601                 if (sk->sk_state != TCP_CLOSE)
602                         goto out;
603 
604                 err = sk->sk_prot->connect(sk, uaddr, addr_len);
605                 if (err < 0)
606                         goto out;
607 
608                 sock->state = SS_CONNECTING;
609 
610                 /* Just entered SS_CONNECTING state; the only
611                  * difference is that return value in non-blocking
612                  * case is EINPROGRESS, rather than EALREADY.
613                  */
614                 err = -EINPROGRESS;
615                 break;
616         }
617 
618         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
619 
620         if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
621                 int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
622                                 tcp_sk(sk)->fastopen_req &&
623                                 tcp_sk(sk)->fastopen_req->data ? 1 : 0;
624 
625                 /* Error code is set above */
626                 if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
627                         goto out;
628 
629                 err = sock_intr_errno(timeo);
630                 if (signal_pending(current))
631                         goto out;
632         }
633 
634         /* Connection was closed by RST, timeout, ICMP error
635          * or another process disconnected us.
636          */
637         if (sk->sk_state == TCP_CLOSE)
638                 goto sock_error;
639 
640         /* sk->sk_err may be not zero now, if RECVERR was ordered by user
641          * and error was received after socket entered established state.
642          * Hence, it is handled normally after connect() return successfully.
643          */
644 
645         sock->state = SS_CONNECTED;
646         err = 0;
647 out:
648         return err;
649 
650 sock_error:
651         err = sock_error(sk) ? : -ECONNABORTED;
652         sock->state = SS_UNCONNECTED;
653         if (sk->sk_prot->disconnect(sk, flags))
654                 sock->state = SS_DISCONNECTING;
655         goto out;
656 }
657 EXPORT_SYMBOL(__inet_stream_connect);
658 
659 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
660                         int addr_len, int flags)
661 {
662         int err;
663 
664         lock_sock(sock->sk);
665         err = __inet_stream_connect(sock, uaddr, addr_len, flags);
666         release_sock(sock->sk);
667         return err;
668 }
669 EXPORT_SYMBOL(inet_stream_connect);
670 
671 /*
672  *      Accept a pending connection. The TCP layer now gives BSD semantics.
673  */
674 
675 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
676 {
677         struct sock *sk1 = sock->sk;
678         int err = -EINVAL;
679         struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
680 
681         if (!sk2)
682                 goto do_err;
683 
684         lock_sock(sk2);
685 
686         sock_rps_record_flow(sk2);
687         WARN_ON(!((1 << sk2->sk_state) &
688                   (TCPF_ESTABLISHED | TCPF_SYN_RECV |
689                   TCPF_CLOSE_WAIT | TCPF_CLOSE)));
690 
691         sock_graft(sk2, newsock);
692 
693         newsock->state = SS_CONNECTED;
694         err = 0;
695         release_sock(sk2);
696 do_err:
697         return err;
698 }
699 EXPORT_SYMBOL(inet_accept);
700 
701 
702 /*
703  *      This does both peername and sockname.
704  */
705 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
706                         int *uaddr_len, int peer)
707 {
708         struct sock *sk         = sock->sk;
709         struct inet_sock *inet  = inet_sk(sk);
710         DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
711 
712         sin->sin_family = AF_INET;
713         if (peer) {
714                 if (!inet->inet_dport ||
715                     (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
716                      peer == 1))
717                         return -ENOTCONN;
718                 sin->sin_port = inet->inet_dport;
719                 sin->sin_addr.s_addr = inet->inet_daddr;
720         } else {
721                 __be32 addr = inet->inet_rcv_saddr;
722                 if (!addr)
723                         addr = inet->inet_saddr;
724                 sin->sin_port = inet->inet_sport;
725                 sin->sin_addr.s_addr = addr;
726         }
727         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
728         *uaddr_len = sizeof(*sin);
729         return 0;
730 }
731 EXPORT_SYMBOL(inet_getname);
732 
733 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
734 {
735         struct sock *sk = sock->sk;
736 
737         sock_rps_record_flow(sk);
738 
739         /* We may need to bind the socket. */
740         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
741             inet_autobind(sk))
742                 return -EAGAIN;
743 
744         return sk->sk_prot->sendmsg(sk, msg, size);
745 }
746 EXPORT_SYMBOL(inet_sendmsg);
747 
748 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
749                       size_t size, int flags)
750 {
751         struct sock *sk = sock->sk;
752 
753         sock_rps_record_flow(sk);
754 
755         /* We may need to bind the socket. */
756         if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
757             inet_autobind(sk))
758                 return -EAGAIN;
759 
760         if (sk->sk_prot->sendpage)
761                 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
762         return sock_no_sendpage(sock, page, offset, size, flags);
763 }
764 EXPORT_SYMBOL(inet_sendpage);
765 
766 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
767                  int flags)
768 {
769         struct sock *sk = sock->sk;
770         int addr_len = 0;
771         int err;
772 
773         sock_rps_record_flow(sk);
774 
775         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
776                                    flags & ~MSG_DONTWAIT, &addr_len);
777         if (err >= 0)
778                 msg->msg_namelen = addr_len;
779         return err;
780 }
781 EXPORT_SYMBOL(inet_recvmsg);
782 
783 int inet_shutdown(struct socket *sock, int how)
784 {
785         struct sock *sk = sock->sk;
786         int err = 0;
787 
788         /* This should really check to make sure
789          * the socket is a TCP socket. (WHY AC...)
790          */
791         how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
792                        1->2 bit 2 snds.
793                        2->3 */
794         if ((how & ~SHUTDOWN_MASK) || !how)     /* MAXINT->0 */
795                 return -EINVAL;
796 
797         lock_sock(sk);
798         if (sock->state == SS_CONNECTING) {
799                 if ((1 << sk->sk_state) &
800                     (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
801                         sock->state = SS_DISCONNECTING;
802                 else
803                         sock->state = SS_CONNECTED;
804         }
805 
806         switch (sk->sk_state) {
807         case TCP_CLOSE:
808                 err = -ENOTCONN;
809                 /* Hack to wake up other listeners, who can poll for
810                    POLLHUP, even on eg. unconnected UDP sockets -- RR */
811         default:
812                 sk->sk_shutdown |= how;
813                 if (sk->sk_prot->shutdown)
814                         sk->sk_prot->shutdown(sk, how);
815                 break;
816 
817         /* Remaining two branches are temporary solution for missing
818          * close() in multithreaded environment. It is _not_ a good idea,
819          * but we have no choice until close() is repaired at VFS level.
820          */
821         case TCP_LISTEN:
822                 if (!(how & RCV_SHUTDOWN))
823                         break;
824                 /* Fall through */
825         case TCP_SYN_SENT:
826                 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
827                 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
828                 break;
829         }
830 
831         /* Wake up anyone sleeping in poll. */
832         sk->sk_state_change(sk);
833         release_sock(sk);
834         return err;
835 }
836 EXPORT_SYMBOL(inet_shutdown);
837 
838 /*
839  *      ioctl() calls you can issue on an INET socket. Most of these are
840  *      device configuration and stuff and very rarely used. Some ioctls
841  *      pass on to the socket itself.
842  *
843  *      NOTE: I like the idea of a module for the config stuff. ie ifconfig
844  *      loads the devconfigure module does its configuring and unloads it.
845  *      There's a good 20K of config code hanging around the kernel.
846  */
847 
848 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
849 {
850         struct sock *sk = sock->sk;
851         int err = 0;
852         struct net *net = sock_net(sk);
853 
854         switch (cmd) {
855         case SIOCGSTAMP:
856                 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
857                 break;
858         case SIOCGSTAMPNS:
859                 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
860                 break;
861         case SIOCADDRT:
862         case SIOCDELRT:
863         case SIOCRTMSG:
864                 err = ip_rt_ioctl(net, cmd, (void __user *)arg);
865                 break;
866         case SIOCDARP:
867         case SIOCGARP:
868         case SIOCSARP:
869                 err = arp_ioctl(net, cmd, (void __user *)arg);
870                 break;
871         case SIOCGIFADDR:
872         case SIOCSIFADDR:
873         case SIOCGIFBRDADDR:
874         case SIOCSIFBRDADDR:
875         case SIOCGIFNETMASK:
876         case SIOCSIFNETMASK:
877         case SIOCGIFDSTADDR:
878         case SIOCSIFDSTADDR:
879         case SIOCSIFPFLAGS:
880         case SIOCGIFPFLAGS:
881         case SIOCSIFFLAGS:
882                 err = devinet_ioctl(net, cmd, (void __user *)arg);
883                 break;
884         default:
885                 if (sk->sk_prot->ioctl)
886                         err = sk->sk_prot->ioctl(sk, cmd, arg);
887                 else
888                         err = -ENOIOCTLCMD;
889                 break;
890         }
891         return err;
892 }
893 EXPORT_SYMBOL(inet_ioctl);
894 
895 #ifdef CONFIG_COMPAT
896 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
897 {
898         struct sock *sk = sock->sk;
899         int err = -ENOIOCTLCMD;
900 
901         if (sk->sk_prot->compat_ioctl)
902                 err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
903 
904         return err;
905 }
906 #endif
907 
908 const struct proto_ops inet_stream_ops = {
909         .family            = PF_INET,
910         .owner             = THIS_MODULE,
911         .release           = inet_release,
912         .bind              = inet_bind,
913         .connect           = inet_stream_connect,
914         .socketpair        = sock_no_socketpair,
915         .accept            = inet_accept,
916         .getname           = inet_getname,
917         .poll              = tcp_poll,
918         .ioctl             = inet_ioctl,
919         .listen            = inet_listen,
920         .shutdown          = inet_shutdown,
921         .setsockopt        = sock_common_setsockopt,
922         .getsockopt        = sock_common_getsockopt,
923         .sendmsg           = inet_sendmsg,
924         .recvmsg           = inet_recvmsg,
925         .mmap              = sock_no_mmap,
926         .sendpage          = inet_sendpage,
927         .splice_read       = tcp_splice_read,
928         .read_sock         = tcp_read_sock,
929         .peek_len          = tcp_peek_len,
930 #ifdef CONFIG_COMPAT
931         .compat_setsockopt = compat_sock_common_setsockopt,
932         .compat_getsockopt = compat_sock_common_getsockopt,
933         .compat_ioctl      = inet_compat_ioctl,
934 #endif
935 };
936 EXPORT_SYMBOL(inet_stream_ops);
937 
938 const struct proto_ops inet_dgram_ops = {
939         .family            = PF_INET,
940         .owner             = THIS_MODULE,
941         .release           = inet_release,
942         .bind              = inet_bind,
943         .connect           = inet_dgram_connect,
944         .socketpair        = sock_no_socketpair,
945         .accept            = sock_no_accept,
946         .getname           = inet_getname,
947         .poll              = udp_poll,
948         .ioctl             = inet_ioctl,
949         .listen            = sock_no_listen,
950         .shutdown          = inet_shutdown,
951         .setsockopt        = sock_common_setsockopt,
952         .getsockopt        = sock_common_getsockopt,
953         .sendmsg           = inet_sendmsg,
954         .recvmsg           = inet_recvmsg,
955         .mmap              = sock_no_mmap,
956         .sendpage          = inet_sendpage,
957         .set_peek_off      = sk_set_peek_off,
958 #ifdef CONFIG_COMPAT
959         .compat_setsockopt = compat_sock_common_setsockopt,
960         .compat_getsockopt = compat_sock_common_getsockopt,
961         .compat_ioctl      = inet_compat_ioctl,
962 #endif
963 };
964 EXPORT_SYMBOL(inet_dgram_ops);
965 
966 /*
967  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
968  * udp_poll
969  */
970 static const struct proto_ops inet_sockraw_ops = {
971         .family            = PF_INET,
972         .owner             = THIS_MODULE,
973         .release           = inet_release,
974         .bind              = inet_bind,
975         .connect           = inet_dgram_connect,
976         .socketpair        = sock_no_socketpair,
977         .accept            = sock_no_accept,
978         .getname           = inet_getname,
979         .poll              = datagram_poll,
980         .ioctl             = inet_ioctl,
981         .listen            = sock_no_listen,
982         .shutdown          = inet_shutdown,
983         .setsockopt        = sock_common_setsockopt,
984         .getsockopt        = sock_common_getsockopt,
985         .sendmsg           = inet_sendmsg,
986         .recvmsg           = inet_recvmsg,
987         .mmap              = sock_no_mmap,
988         .sendpage          = inet_sendpage,
989 #ifdef CONFIG_COMPAT
990         .compat_setsockopt = compat_sock_common_setsockopt,
991         .compat_getsockopt = compat_sock_common_getsockopt,
992         .compat_ioctl      = inet_compat_ioctl,
993 #endif
994 };
995 
996 static const struct net_proto_family inet_family_ops = {
997         .family = PF_INET,
998         .create = inet_create,
999         .owner  = THIS_MODULE,
1000 };
1001 
1002 /* Upon startup we insert all the elements in inetsw_array[] into
1003  * the linked list inetsw.
1004  */
1005 static struct inet_protosw inetsw_array[] =
1006 {
1007         {
1008                 .type =       SOCK_STREAM,
1009                 .protocol =   IPPROTO_TCP,
1010                 .prot =       &tcp_prot,
1011                 .ops =        &inet_stream_ops,
1012                 .flags =      INET_PROTOSW_PERMANENT |
1013                               INET_PROTOSW_ICSK,
1014         },
1015 
1016         {
1017                 .type =       SOCK_DGRAM,
1018                 .protocol =   IPPROTO_UDP,
1019                 .prot =       &udp_prot,
1020                 .ops =        &inet_dgram_ops,
1021                 .flags =      INET_PROTOSW_PERMANENT,
1022        },
1023 
1024        {
1025                 .type =       SOCK_DGRAM,
1026                 .protocol =   IPPROTO_ICMP,
1027                 .prot =       &ping_prot,
1028                 .ops =        &inet_dgram_ops,
1029                 .flags =      INET_PROTOSW_REUSE,
1030        },
1031 
1032        {
1033                .type =       SOCK_RAW,
1034                .protocol =   IPPROTO_IP,        /* wild card */
1035                .prot =       &raw_prot,
1036                .ops =        &inet_sockraw_ops,
1037                .flags =      INET_PROTOSW_REUSE,
1038        }
1039 };
1040 
1041 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1042 
1043 void inet_register_protosw(struct inet_protosw *p)
1044 {
1045         struct list_head *lh;
1046         struct inet_protosw *answer;
1047         int protocol = p->protocol;
1048         struct list_head *last_perm;
1049 
1050         spin_lock_bh(&inetsw_lock);
1051 
1052         if (p->type >= SOCK_MAX)
1053                 goto out_illegal;
1054 
1055         /* If we are trying to override a permanent protocol, bail. */
1056         last_perm = &inetsw[p->type];
1057         list_for_each(lh, &inetsw[p->type]) {
1058                 answer = list_entry(lh, struct inet_protosw, list);
1059                 /* Check only the non-wild match. */
1060                 if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1061                         break;
1062                 if (protocol == answer->protocol)
1063                         goto out_permanent;
1064                 last_perm = lh;
1065         }
1066 
1067         /* Add the new entry after the last permanent entry if any, so that
1068          * the new entry does not override a permanent entry when matched with
1069          * a wild-card protocol. But it is allowed to override any existing
1070          * non-permanent entry.  This means that when we remove this entry, the
1071          * system automatically returns to the old behavior.
1072          */
1073         list_add_rcu(&p->list, last_perm);
1074 out:
1075         spin_unlock_bh(&inetsw_lock);
1076 
1077         return;
1078 
1079 out_permanent:
1080         pr_err("Attempt to override permanent protocol %d\n", protocol);
1081         goto out;
1082 
1083 out_illegal:
1084         pr_err("Ignoring attempt to register invalid socket type %d\n",
1085                p->type);
1086         goto out;
1087 }
1088 EXPORT_SYMBOL(inet_register_protosw);
1089 
1090 void inet_unregister_protosw(struct inet_protosw *p)
1091 {
1092         if (INET_PROTOSW_PERMANENT & p->flags) {
1093                 pr_err("Attempt to unregister permanent protocol %d\n",
1094                        p->protocol);
1095         } else {
1096                 spin_lock_bh(&inetsw_lock);
1097                 list_del_rcu(&p->list);
1098                 spin_unlock_bh(&inetsw_lock);
1099 
1100                 synchronize_net();
1101         }
1102 }
1103 EXPORT_SYMBOL(inet_unregister_protosw);
1104 
1105 static int inet_sk_reselect_saddr(struct sock *sk)
1106 {
1107         struct inet_sock *inet = inet_sk(sk);
1108         __be32 old_saddr = inet->inet_saddr;
1109         __be32 daddr = inet->inet_daddr;
1110         struct flowi4 *fl4;
1111         struct rtable *rt;
1112         __be32 new_saddr;
1113         struct ip_options_rcu *inet_opt;
1114 
1115         inet_opt = rcu_dereference_protected(inet->inet_opt,
1116                                              lockdep_sock_is_held(sk));
1117         if (inet_opt && inet_opt->opt.srr)
1118                 daddr = inet_opt->opt.faddr;
1119 
1120         /* Query new route. */
1121         fl4 = &inet->cork.fl.u.ip4;
1122         rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1123                               sk->sk_bound_dev_if, sk->sk_protocol,
1124                               inet->inet_sport, inet->inet_dport, sk);
1125         if (IS_ERR(rt))
1126                 return PTR_ERR(rt);
1127 
1128         sk_setup_caps(sk, &rt->dst);
1129 
1130         new_saddr = fl4->saddr;
1131 
1132         if (new_saddr == old_saddr)
1133                 return 0;
1134 
1135         if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1136                 pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1137                         __func__, &old_saddr, &new_saddr);
1138         }
1139 
1140         inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1141 
1142         /*
1143          * XXX The only one ugly spot where we need to
1144          * XXX really change the sockets identity after
1145          * XXX it has entered the hashes. -DaveM
1146          *
1147          * Besides that, it does not check for connection
1148          * uniqueness. Wait for troubles.
1149          */
1150         return __sk_prot_rehash(sk);
1151 }
1152 
1153 int inet_sk_rebuild_header(struct sock *sk)
1154 {
1155         struct inet_sock *inet = inet_sk(sk);
1156         struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1157         __be32 daddr;
1158         struct ip_options_rcu *inet_opt;
1159         struct flowi4 *fl4;
1160         int err;
1161 
1162         /* Route is OK, nothing to do. */
1163         if (rt)
1164                 return 0;
1165 
1166         /* Reroute. */
1167         rcu_read_lock();
1168         inet_opt = rcu_dereference(inet->inet_opt);
1169         daddr = inet->inet_daddr;
1170         if (inet_opt && inet_opt->opt.srr)
1171                 daddr = inet_opt->opt.faddr;
1172         rcu_read_unlock();
1173         fl4 = &inet->cork.fl.u.ip4;
1174         rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1175                                    inet->inet_dport, inet->inet_sport,
1176                                    sk->sk_protocol, RT_CONN_FLAGS(sk),
1177                                    sk->sk_bound_dev_if);
1178         if (!IS_ERR(rt)) {
1179                 err = 0;
1180                 sk_setup_caps(sk, &rt->dst);
1181         } else {
1182                 err = PTR_ERR(rt);
1183 
1184                 /* Routing failed... */
1185                 sk->sk_route_caps = 0;
1186                 /*
1187                  * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1188                  * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1189                  */
1190                 if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1191                     sk->sk_state != TCP_SYN_SENT ||
1192                     (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1193                     (err = inet_sk_reselect_saddr(sk)) != 0)
1194                         sk->sk_err_soft = -err;
1195         }
1196 
1197         return err;
1198 }
1199 EXPORT_SYMBOL(inet_sk_rebuild_header);
1200 
1201 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1202                                  netdev_features_t features)
1203 {
1204         bool udpfrag = false, fixedid = false, gso_partial, encap;
1205         struct sk_buff *segs = ERR_PTR(-EINVAL);
1206         const struct net_offload *ops;
1207         unsigned int offset = 0;
1208         struct iphdr *iph;
1209         int proto, tot_len;
1210         int nhoff;
1211         int ihl;
1212         int id;
1213 
1214         skb_reset_network_header(skb);
1215         nhoff = skb_network_header(skb) - skb_mac_header(skb);
1216         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1217                 goto out;
1218 
1219         iph = ip_hdr(skb);
1220         ihl = iph->ihl * 4;
1221         if (ihl < sizeof(*iph))
1222                 goto out;
1223 
1224         id = ntohs(iph->id);
1225         proto = iph->protocol;
1226 
1227         /* Warning: after this point, iph might be no longer valid */
1228         if (unlikely(!pskb_may_pull(skb, ihl)))
1229                 goto out;
1230         __skb_pull(skb, ihl);
1231 
1232         encap = SKB_GSO_CB(skb)->encap_level > 0;
1233         if (encap)
1234                 features &= skb->dev->hw_enc_features;
1235         SKB_GSO_CB(skb)->encap_level += ihl;
1236 
1237         skb_reset_transport_header(skb);
1238 
1239         segs = ERR_PTR(-EPROTONOSUPPORT);
1240 
1241         if (!skb->encapsulation || encap) {
1242                 udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1243                 fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1244 
1245                 /* fixed ID is invalid if DF bit is not set */
1246                 if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1247                         goto out;
1248         }
1249 
1250         ops = rcu_dereference(inet_offloads[proto]);
1251         if (likely(ops && ops->callbacks.gso_segment))
1252                 segs = ops->callbacks.gso_segment(skb, features);
1253 
1254         if (IS_ERR_OR_NULL(segs))
1255                 goto out;
1256 
1257         gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1258 
1259         skb = segs;
1260         do {
1261                 iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1262                 if (udpfrag) {
1263                         iph->frag_off = htons(offset >> 3);
1264                         if (skb->next)
1265                                 iph->frag_off |= htons(IP_MF);
1266                         offset += skb->len - nhoff - ihl;
1267                         tot_len = skb->len - nhoff;
1268                 } else if (skb_is_gso(skb)) {
1269                         if (!fixedid) {
1270                                 iph->id = htons(id);
1271                                 id += skb_shinfo(skb)->gso_segs;
1272                         }
1273 
1274                         if (gso_partial)
1275                                 tot_len = skb_shinfo(skb)->gso_size +
1276                                           SKB_GSO_CB(skb)->data_offset +
1277                                           skb->head - (unsigned char *)iph;
1278                         else
1279                                 tot_len = skb->len - nhoff;
1280                 } else {
1281                         if (!fixedid)
1282                                 iph->id = htons(id++);
1283                         tot_len = skb->len - nhoff;
1284                 }
1285                 iph->tot_len = htons(tot_len);
1286                 ip_send_check(iph);
1287                 if (encap)
1288                         skb_reset_inner_headers(skb);
1289                 skb->network_header = (u8 *)iph - skb->head;
1290         } while ((skb = skb->next));
1291 
1292 out:
1293         return segs;
1294 }
1295 EXPORT_SYMBOL(inet_gso_segment);
1296 
1297 struct sk_buff **inet_gro_receive(struct sk_buff **head, struct sk_buff *skb)
1298 {
1299         const struct net_offload *ops;
1300         struct sk_buff **pp = NULL;
1301         struct sk_buff *p;
1302         const struct iphdr *iph;
1303         unsigned int hlen;
1304         unsigned int off;
1305         unsigned int id;
1306         int flush = 1;
1307         int proto;
1308 
1309         off = skb_gro_offset(skb);
1310         hlen = off + sizeof(*iph);
1311         iph = skb_gro_header_fast(skb, off);
1312         if (skb_gro_header_hard(skb, hlen)) {
1313                 iph = skb_gro_header_slow(skb, hlen, off);
1314                 if (unlikely(!iph))
1315                         goto out;
1316         }
1317 
1318         proto = iph->protocol;
1319 
1320         rcu_read_lock();
1321         ops = rcu_dereference(inet_offloads[proto]);
1322         if (!ops || !ops->callbacks.gro_receive)
1323                 goto out_unlock;
1324 
1325         if (*(u8 *)iph != 0x45)
1326                 goto out_unlock;
1327 
1328         if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1329                 goto out_unlock;
1330 
1331         id = ntohl(*(__be32 *)&iph->id);
1332         flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1333         id >>= 16;
1334 
1335         for (p = *head; p; p = p->next) {
1336                 struct iphdr *iph2;
1337                 u16 flush_id;
1338 
1339                 if (!NAPI_GRO_CB(p)->same_flow)
1340                         continue;
1341 
1342                 iph2 = (struct iphdr *)(p->data + off);
1343                 /* The above works because, with the exception of the top
1344                  * (inner most) layer, we only aggregate pkts with the same
1345                  * hdr length so all the hdrs we'll need to verify will start
1346                  * at the same offset.
1347                  */
1348                 if ((iph->protocol ^ iph2->protocol) |
1349                     ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1350                     ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1351                         NAPI_GRO_CB(p)->same_flow = 0;
1352                         continue;
1353                 }
1354 
1355                 /* All fields must match except length and checksum. */
1356                 NAPI_GRO_CB(p)->flush |=
1357                         (iph->ttl ^ iph2->ttl) |
1358                         (iph->tos ^ iph2->tos) |
1359                         ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1360 
1361                 NAPI_GRO_CB(p)->flush |= flush;
1362 
1363                 /* We need to store of the IP ID check to be included later
1364                  * when we can verify that this packet does in fact belong
1365                  * to a given flow.
1366                  */
1367                 flush_id = (u16)(id - ntohs(iph2->id));
1368 
1369                 /* This bit of code makes it much easier for us to identify
1370                  * the cases where we are doing atomic vs non-atomic IP ID
1371                  * checks.  Specifically an atomic check can return IP ID
1372                  * values 0 - 0xFFFF, while a non-atomic check can only
1373                  * return 0 or 0xFFFF.
1374                  */
1375                 if (!NAPI_GRO_CB(p)->is_atomic ||
1376                     !(iph->frag_off & htons(IP_DF))) {
1377                         flush_id ^= NAPI_GRO_CB(p)->count;
1378                         flush_id = flush_id ? 0xFFFF : 0;
1379                 }
1380 
1381                 /* If the previous IP ID value was based on an atomic
1382                  * datagram we can overwrite the value and ignore it.
1383                  */
1384                 if (NAPI_GRO_CB(skb)->is_atomic)
1385                         NAPI_GRO_CB(p)->flush_id = flush_id;
1386                 else
1387                         NAPI_GRO_CB(p)->flush_id |= flush_id;
1388         }
1389 
1390         NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1391         NAPI_GRO_CB(skb)->flush |= flush;
1392         skb_set_network_header(skb, off);
1393         /* The above will be needed by the transport layer if there is one
1394          * immediately following this IP hdr.
1395          */
1396 
1397         /* Note : No need to call skb_gro_postpull_rcsum() here,
1398          * as we already checked checksum over ipv4 header was 0
1399          */
1400         skb_gro_pull(skb, sizeof(*iph));
1401         skb_set_transport_header(skb, skb_gro_offset(skb));
1402 
1403         pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
1404 
1405 out_unlock:
1406         rcu_read_unlock();
1407 
1408 out:
1409         NAPI_GRO_CB(skb)->flush |= flush;
1410 
1411         return pp;
1412 }
1413 EXPORT_SYMBOL(inet_gro_receive);
1414 
1415 static struct sk_buff **ipip_gro_receive(struct sk_buff **head,
1416                                          struct sk_buff *skb)
1417 {
1418         if (NAPI_GRO_CB(skb)->encap_mark) {
1419                 NAPI_GRO_CB(skb)->flush = 1;
1420                 return NULL;
1421         }
1422 
1423         NAPI_GRO_CB(skb)->encap_mark = 1;
1424 
1425         return inet_gro_receive(head, skb);
1426 }
1427 
1428 #define SECONDS_PER_DAY 86400
1429 
1430 /* inet_current_timestamp - Return IP network timestamp
1431  *
1432  * Return milliseconds since midnight in network byte order.
1433  */
1434 __be32 inet_current_timestamp(void)
1435 {
1436         u32 secs;
1437         u32 msecs;
1438         struct timespec64 ts;
1439 
1440         ktime_get_real_ts64(&ts);
1441 
1442         /* Get secs since midnight. */
1443         (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1444         /* Convert to msecs. */
1445         msecs = secs * MSEC_PER_SEC;
1446         /* Convert nsec to msec. */
1447         msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1448 
1449         /* Convert to network byte order. */
1450         return htonl(msecs);
1451 }
1452 EXPORT_SYMBOL(inet_current_timestamp);
1453 
1454 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1455 {
1456         if (sk->sk_family == AF_INET)
1457                 return ip_recv_error(sk, msg, len, addr_len);
1458 #if IS_ENABLED(CONFIG_IPV6)
1459         if (sk->sk_family == AF_INET6)
1460                 return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1461 #endif
1462         return -EINVAL;
1463 }
1464 
1465 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1466 {
1467         __be16 newlen = htons(skb->len - nhoff);
1468         struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1469         const struct net_offload *ops;
1470         int proto = iph->protocol;
1471         int err = -ENOSYS;
1472 
1473         if (skb->encapsulation)
1474                 skb_set_inner_network_header(skb, nhoff);
1475 
1476         csum_replace2(&iph->check, iph->tot_len, newlen);
1477         iph->tot_len = newlen;
1478 
1479         rcu_read_lock();
1480         ops = rcu_dereference(inet_offloads[proto]);
1481         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1482                 goto out_unlock;
1483 
1484         /* Only need to add sizeof(*iph) to get to the next hdr below
1485          * because any hdr with option will have been flushed in
1486          * inet_gro_receive().
1487          */
1488         err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1489 
1490 out_unlock:
1491         rcu_read_unlock();
1492 
1493         return err;
1494 }
1495 EXPORT_SYMBOL(inet_gro_complete);
1496 
1497 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1498 {
1499         skb->encapsulation = 1;
1500         skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1501         return inet_gro_complete(skb, nhoff);
1502 }
1503 
1504 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1505                          unsigned short type, unsigned char protocol,
1506                          struct net *net)
1507 {
1508         struct socket *sock;
1509         int rc = sock_create_kern(net, family, type, protocol, &sock);
1510 
1511         if (rc == 0) {
1512                 *sk = sock->sk;
1513                 (*sk)->sk_allocation = GFP_ATOMIC;
1514                 /*
1515                  * Unhash it so that IP input processing does not even see it,
1516                  * we do not wish this socket to see incoming packets.
1517                  */
1518                 (*sk)->sk_prot->unhash(*sk);
1519         }
1520         return rc;
1521 }
1522 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1523 
1524 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1525 {
1526         return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1527 }
1528 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1529 
1530 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1531 {
1532         unsigned long res = 0;
1533         int i;
1534 
1535         for_each_possible_cpu(i)
1536                 res += snmp_get_cpu_field(mib, i, offt);
1537         return res;
1538 }
1539 EXPORT_SYMBOL_GPL(snmp_fold_field);
1540 
1541 #if BITS_PER_LONG==32
1542 
1543 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1544                          size_t syncp_offset)
1545 {
1546         void *bhptr;
1547         struct u64_stats_sync *syncp;
1548         u64 v;
1549         unsigned int start;
1550 
1551         bhptr = per_cpu_ptr(mib, cpu);
1552         syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1553         do {
1554                 start = u64_stats_fetch_begin_irq(syncp);
1555                 v = *(((u64 *)bhptr) + offt);
1556         } while (u64_stats_fetch_retry_irq(syncp, start));
1557 
1558         return v;
1559 }
1560 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1561 
1562 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1563 {
1564         u64 res = 0;
1565         int cpu;
1566 
1567         for_each_possible_cpu(cpu) {
1568                 res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1569         }
1570         return res;
1571 }
1572 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1573 #endif
1574 
1575 #ifdef CONFIG_IP_MULTICAST
1576 static const struct net_protocol igmp_protocol = {
1577         .handler =      igmp_rcv,
1578         .netns_ok =     1,
1579 };
1580 #endif
1581 
1582 static const struct net_protocol tcp_protocol = {
1583         .early_demux    =       tcp_v4_early_demux,
1584         .handler        =       tcp_v4_rcv,
1585         .err_handler    =       tcp_v4_err,
1586         .no_policy      =       1,
1587         .netns_ok       =       1,
1588         .icmp_strict_tag_validation = 1,
1589 };
1590 
1591 static const struct net_protocol udp_protocol = {
1592         .early_demux =  udp_v4_early_demux,
1593         .handler =      udp_rcv,
1594         .err_handler =  udp_err,
1595         .no_policy =    1,
1596         .netns_ok =     1,
1597 };
1598 
1599 static const struct net_protocol icmp_protocol = {
1600         .handler =      icmp_rcv,
1601         .err_handler =  icmp_err,
1602         .no_policy =    1,
1603         .netns_ok =     1,
1604 };
1605 
1606 static __net_init int ipv4_mib_init_net(struct net *net)
1607 {
1608         int i;
1609 
1610         net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1611         if (!net->mib.tcp_statistics)
1612                 goto err_tcp_mib;
1613         net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1614         if (!net->mib.ip_statistics)
1615                 goto err_ip_mib;
1616 
1617         for_each_possible_cpu(i) {
1618                 struct ipstats_mib *af_inet_stats;
1619                 af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1620                 u64_stats_init(&af_inet_stats->syncp);
1621         }
1622 
1623         net->mib.net_statistics = alloc_percpu(struct linux_mib);
1624         if (!net->mib.net_statistics)
1625                 goto err_net_mib;
1626         net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1627         if (!net->mib.udp_statistics)
1628                 goto err_udp_mib;
1629         net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1630         if (!net->mib.udplite_statistics)
1631                 goto err_udplite_mib;
1632         net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1633         if (!net->mib.icmp_statistics)
1634                 goto err_icmp_mib;
1635         net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1636                                               GFP_KERNEL);
1637         if (!net->mib.icmpmsg_statistics)
1638                 goto err_icmpmsg_mib;
1639 
1640         tcp_mib_init(net);
1641         return 0;
1642 
1643 err_icmpmsg_mib:
1644         free_percpu(net->mib.icmp_statistics);
1645 err_icmp_mib:
1646         free_percpu(net->mib.udplite_statistics);
1647 err_udplite_mib:
1648         free_percpu(net->mib.udp_statistics);
1649 err_udp_mib:
1650         free_percpu(net->mib.net_statistics);
1651 err_net_mib:
1652         free_percpu(net->mib.ip_statistics);
1653 err_ip_mib:
1654         free_percpu(net->mib.tcp_statistics);
1655 err_tcp_mib:
1656         return -ENOMEM;
1657 }
1658 
1659 static __net_exit void ipv4_mib_exit_net(struct net *net)
1660 {
1661         kfree(net->mib.icmpmsg_statistics);
1662         free_percpu(net->mib.icmp_statistics);
1663         free_percpu(net->mib.udplite_statistics);
1664         free_percpu(net->mib.udp_statistics);
1665         free_percpu(net->mib.net_statistics);
1666         free_percpu(net->mib.ip_statistics);
1667         free_percpu(net->mib.tcp_statistics);
1668 }
1669 
1670 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1671         .init = ipv4_mib_init_net,
1672         .exit = ipv4_mib_exit_net,
1673 };
1674 
1675 static int __init init_ipv4_mibs(void)
1676 {
1677         return register_pernet_subsys(&ipv4_mib_ops);
1678 }
1679 
1680 static __net_init int inet_init_net(struct net *net)
1681 {
1682         /*
1683          * Set defaults for local port range
1684          */
1685         seqlock_init(&net->ipv4.ip_local_ports.lock);
1686         net->ipv4.ip_local_ports.range[0] =  32768;
1687         net->ipv4.ip_local_ports.range[1] =  60999;
1688 
1689         seqlock_init(&net->ipv4.ping_group_range.lock);
1690         /*
1691          * Sane defaults - nobody may create ping sockets.
1692          * Boot scripts should set this to distro-specific group.
1693          */
1694         net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1695         net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1696 
1697         /* Default values for sysctl-controlled parameters.
1698          * We set them here, in case sysctl is not compiled.
1699          */
1700         net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1701         net->ipv4.sysctl_ip_dynaddr = 0;
1702         net->ipv4.sysctl_ip_early_demux = 1;
1703 
1704         return 0;
1705 }
1706 
1707 static __net_exit void inet_exit_net(struct net *net)
1708 {
1709 }
1710 
1711 static __net_initdata struct pernet_operations af_inet_ops = {
1712         .init = inet_init_net,
1713         .exit = inet_exit_net,
1714 };
1715 
1716 static int __init init_inet_pernet_ops(void)
1717 {
1718         return register_pernet_subsys(&af_inet_ops);
1719 }
1720 
1721 static int ipv4_proc_init(void);
1722 
1723 /*
1724  *      IP protocol layer initialiser
1725  */
1726 
1727 static struct packet_offload ip_packet_offload __read_mostly = {
1728         .type = cpu_to_be16(ETH_P_IP),
1729         .callbacks = {
1730                 .gso_segment = inet_gso_segment,
1731                 .gro_receive = inet_gro_receive,
1732                 .gro_complete = inet_gro_complete,
1733         },
1734 };
1735 
1736 static const struct net_offload ipip_offload = {
1737         .callbacks = {
1738                 .gso_segment    = inet_gso_segment,
1739                 .gro_receive    = ipip_gro_receive,
1740                 .gro_complete   = ipip_gro_complete,
1741         },
1742 };
1743 
1744 static int __init ipv4_offload_init(void)
1745 {
1746         /*
1747          * Add offloads
1748          */
1749         if (udpv4_offload_init() < 0)
1750                 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1751         if (tcpv4_offload_init() < 0)
1752                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1753 
1754         dev_add_offload(&ip_packet_offload);
1755         inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1756         return 0;
1757 }
1758 
1759 fs_initcall(ipv4_offload_init);
1760 
1761 static struct packet_type ip_packet_type __read_mostly = {
1762         .type = cpu_to_be16(ETH_P_IP),
1763         .func = ip_rcv,
1764 };
1765 
1766 static int __init inet_init(void)
1767 {
1768         struct inet_protosw *q;
1769         struct list_head *r;
1770         int rc = -EINVAL;
1771 
1772         sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1773 
1774         rc = proto_register(&tcp_prot, 1);
1775         if (rc)
1776                 goto out;
1777 
1778         rc = proto_register(&udp_prot, 1);
1779         if (rc)
1780                 goto out_unregister_tcp_proto;
1781 
1782         rc = proto_register(&raw_prot, 1);
1783         if (rc)
1784                 goto out_unregister_udp_proto;
1785 
1786         rc = proto_register(&ping_prot, 1);
1787         if (rc)
1788                 goto out_unregister_raw_proto;
1789 
1790         /*
1791          *      Tell SOCKET that we are alive...
1792          */
1793 
1794         (void)sock_register(&inet_family_ops);
1795 
1796 #ifdef CONFIG_SYSCTL
1797         ip_static_sysctl_init();
1798 #endif
1799 
1800         /*
1801          *      Add all the base protocols.
1802          */
1803 
1804         if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1805                 pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1806         if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1807                 pr_crit("%s: Cannot add UDP protocol\n", __func__);
1808         if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1809                 pr_crit("%s: Cannot add TCP protocol\n", __func__);
1810 #ifdef CONFIG_IP_MULTICAST
1811         if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1812                 pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1813 #endif
1814 
1815         /* Register the socket-side information for inet_create. */
1816         for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1817                 INIT_LIST_HEAD(r);
1818 
1819         for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1820                 inet_register_protosw(q);
1821 
1822         /*
1823          *      Set the ARP module up
1824          */
1825 
1826         arp_init();
1827 
1828         /*
1829          *      Set the IP module up
1830          */
1831 
1832         ip_init();
1833 
1834         tcp_v4_init();
1835 
1836         /* Setup TCP slab cache for open requests. */
1837         tcp_init();
1838 
1839         /* Setup UDP memory threshold */
1840         udp_init();
1841 
1842         /* Add UDP-Lite (RFC 3828) */
1843         udplite4_register();
1844 
1845         ping_init();
1846 
1847         /*
1848          *      Set the ICMP layer up
1849          */
1850 
1851         if (icmp_init() < 0)
1852                 panic("Failed to create the ICMP control socket.\n");
1853 
1854         /*
1855          *      Initialise the multicast router
1856          */
1857 #if defined(CONFIG_IP_MROUTE)
1858         if (ip_mr_init())
1859                 pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1860 #endif
1861 
1862         if (init_inet_pernet_ops())
1863                 pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1864         /*
1865          *      Initialise per-cpu ipv4 mibs
1866          */
1867 
1868         if (init_ipv4_mibs())
1869                 pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1870 
1871         ipv4_proc_init();
1872 
1873         ipfrag_init();
1874 
1875         dev_add_pack(&ip_packet_type);
1876 
1877         ip_tunnel_core_init();
1878 
1879         rc = 0;
1880 out:
1881         return rc;
1882 out_unregister_raw_proto:
1883         proto_unregister(&raw_prot);
1884 out_unregister_udp_proto:
1885         proto_unregister(&udp_prot);
1886 out_unregister_tcp_proto:
1887         proto_unregister(&tcp_prot);
1888         goto out;
1889 }
1890 
1891 fs_initcall(inet_init);
1892 
1893 /* ------------------------------------------------------------------------ */
1894 
1895 #ifdef CONFIG_PROC_FS
1896 static int __init ipv4_proc_init(void)
1897 {
1898         int rc = 0;
1899 
1900         if (raw_proc_init())
1901                 goto out_raw;
1902         if (tcp4_proc_init())
1903                 goto out_tcp;
1904         if (udp4_proc_init())
1905                 goto out_udp;
1906         if (ping_proc_init())
1907                 goto out_ping;
1908         if (ip_misc_proc_init())
1909                 goto out_misc;
1910 out:
1911         return rc;
1912 out_misc:
1913         ping_proc_exit();
1914 out_ping:
1915         udp4_proc_exit();
1916 out_udp:
1917         tcp4_proc_exit();
1918 out_tcp:
1919         raw_proc_exit();
1920 out_raw:
1921         rc = -ENOMEM;
1922         goto out;
1923 }
1924 
1925 #else /* CONFIG_PROC_FS */
1926 static int __init ipv4_proc_init(void)
1927 {
1928         return 0;
1929 }
1930 #endif /* CONFIG_PROC_FS */
1931 

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