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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[deliverable/linux.git] / net / ipv4 / udp.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 * The User Datagram Protocol (UDP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
12 * Hirokazu Takahashi, <taka@valinux.co.jp>
13 *
14 * Fixes:
15 * Alan Cox : verify_area() calls
16 * Alan Cox : stopped close while in use off icmp
17 * messages. Not a fix but a botch that
18 * for udp at least is 'valid'.
19 * Alan Cox : Fixed icmp handling properly
20 * Alan Cox : Correct error for oversized datagrams
21 * Alan Cox : Tidied select() semantics.
22 * Alan Cox : udp_err() fixed properly, also now
23 * select and read wake correctly on errors
24 * Alan Cox : udp_send verify_area moved to avoid mem leak
25 * Alan Cox : UDP can count its memory
26 * Alan Cox : send to an unknown connection causes
27 * an ECONNREFUSED off the icmp, but
28 * does NOT close.
29 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
31 * bug no longer crashes it.
32 * Fred Van Kempen : Net2e support for sk->broadcast.
33 * Alan Cox : Uses skb_free_datagram
34 * Alan Cox : Added get/set sockopt support.
35 * Alan Cox : Broadcasting without option set returns EACCES.
36 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
37 * Alan Cox : Use ip_tos and ip_ttl
38 * Alan Cox : SNMP Mibs
39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
40 * Matt Dillon : UDP length checks.
41 * Alan Cox : Smarter af_inet used properly.
42 * Alan Cox : Use new kernel side addressing.
43 * Alan Cox : Incorrect return on truncated datagram receive.
44 * Arnt Gulbrandsen : New udp_send and stuff
45 * Alan Cox : Cache last socket
46 * Alan Cox : Route cache
47 * Jon Peatfield : Minor efficiency fix to sendto().
48 * Mike Shaver : RFC1122 checks.
49 * Alan Cox : Nonblocking error fix.
50 * Willy Konynenberg : Transparent proxying support.
51 * Mike McLagan : Routing by source
52 * David S. Miller : New socket lookup architecture.
53 * Last socket cache retained as it
54 * does have a high hit rate.
55 * Olaf Kirch : Don't linearise iovec on sendmsg.
56 * Andi Kleen : Some cleanups, cache destination entry
57 * for connect.
58 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
59 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
60 * return ENOTCONN for unconnected sockets (POSIX)
61 * Janos Farkas : don't deliver multi/broadcasts to a different
62 * bound-to-device socket
63 * Hirokazu Takahashi : HW checksumming for outgoing UDP
64 * datagrams.
65 * Hirokazu Takahashi : sendfile() on UDP works now.
66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
69 * a single port at the same time.
70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71 * James Chapman : Add L2TP encapsulation type.
72 *
73 *
74 * This program is free software; you can redistribute it and/or
75 * modify it under the terms of the GNU General Public License
76 * as published by the Free Software Foundation; either version
77 * 2 of the License, or (at your option) any later version.
78 */
79
80 #include <asm/system.h>
81 #include <asm/uaccess.h>
82 #include <asm/ioctls.h>
83 #include <linux/bootmem.h>
84 #include <linux/highmem.h>
85 #include <linux/swap.h>
86 #include <linux/types.h>
87 #include <linux/fcntl.h>
88 #include <linux/module.h>
89 #include <linux/socket.h>
90 #include <linux/sockios.h>
91 #include <linux/igmp.h>
92 #include <linux/in.h>
93 #include <linux/errno.h>
94 #include <linux/timer.h>
95 #include <linux/mm.h>
96 #include <linux/inet.h>
97 #include <linux/netdevice.h>
98 #include <net/tcp_states.h>
99 #include <linux/skbuff.h>
100 #include <linux/proc_fs.h>
101 #include <linux/seq_file.h>
102 #include <net/net_namespace.h>
103 #include <net/icmp.h>
104 #include <net/route.h>
105 #include <net/checksum.h>
106 #include <net/xfrm.h>
107 #include "udp_impl.h"
108
109 struct udp_table udp_table;
110 EXPORT_SYMBOL(udp_table);
111
112 int sysctl_udp_mem[3] __read_mostly;
113 EXPORT_SYMBOL(sysctl_udp_mem);
114
115 int sysctl_udp_rmem_min __read_mostly;
116 EXPORT_SYMBOL(sysctl_udp_rmem_min);
117
118 int sysctl_udp_wmem_min __read_mostly;
119 EXPORT_SYMBOL(sysctl_udp_wmem_min);
120
121 atomic_t udp_memory_allocated;
122 EXPORT_SYMBOL(udp_memory_allocated);
123
124 #define PORTS_PER_CHAIN (65536 / UDP_HTABLE_SIZE)
125
126 static int udp_lib_lport_inuse(struct net *net, __u16 num,
127 const struct udp_hslot *hslot,
128 unsigned long *bitmap,
129 struct sock *sk,
130 int (*saddr_comp)(const struct sock *sk1,
131 const struct sock *sk2))
132 {
133 struct sock *sk2;
134 struct hlist_nulls_node *node;
135
136 sk_nulls_for_each(sk2, node, &hslot->head)
137 if (net_eq(sock_net(sk2), net) &&
138 sk2 != sk &&
139 (bitmap || sk2->sk_hash == num) &&
140 (!sk2->sk_reuse || !sk->sk_reuse) &&
141 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
142 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
143 (*saddr_comp)(sk, sk2)) {
144 if (bitmap)
145 __set_bit(sk2->sk_hash / UDP_HTABLE_SIZE,
146 bitmap);
147 else
148 return 1;
149 }
150 return 0;
151 }
152
153 /**
154 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
155 *
156 * @sk: socket struct in question
157 * @snum: port number to look up
158 * @saddr_comp: AF-dependent comparison of bound local IP addresses
159 */
160 int udp_lib_get_port(struct sock *sk, unsigned short snum,
161 int (*saddr_comp)(const struct sock *sk1,
162 const struct sock *sk2))
163 {
164 struct udp_hslot *hslot;
165 struct udp_table *udptable = sk->sk_prot->h.udp_table;
166 int error = 1;
167 struct net *net = sock_net(sk);
168
169 if (!snum) {
170 int low, high, remaining;
171 unsigned rand;
172 unsigned short first, last;
173 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
174
175 inet_get_local_port_range(&low, &high);
176 remaining = (high - low) + 1;
177
178 rand = net_random();
179 first = (((u64)rand * remaining) >> 32) + low;
180 /*
181 * force rand to be an odd multiple of UDP_HTABLE_SIZE
182 */
183 rand = (rand | 1) * UDP_HTABLE_SIZE;
184 for (last = first + UDP_HTABLE_SIZE; first != last; first++) {
185 hslot = &udptable->hash[udp_hashfn(net, first)];
186 bitmap_zero(bitmap, PORTS_PER_CHAIN);
187 spin_lock_bh(&hslot->lock);
188 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
189 saddr_comp);
190
191 snum = first;
192 /*
193 * Iterate on all possible values of snum for this hash.
194 * Using steps of an odd multiple of UDP_HTABLE_SIZE
195 * give us randomization and full range coverage.
196 */
197 do {
198 if (low <= snum && snum <= high &&
199 !test_bit(snum / UDP_HTABLE_SIZE, bitmap))
200 goto found;
201 snum += rand;
202 } while (snum != first);
203 spin_unlock_bh(&hslot->lock);
204 }
205 goto fail;
206 } else {
207 hslot = &udptable->hash[udp_hashfn(net, snum)];
208 spin_lock_bh(&hslot->lock);
209 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, saddr_comp))
210 goto fail_unlock;
211 }
212 found:
213 inet_sk(sk)->num = snum;
214 sk->sk_hash = snum;
215 if (sk_unhashed(sk)) {
216 sk_nulls_add_node_rcu(sk, &hslot->head);
217 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
218 }
219 error = 0;
220 fail_unlock:
221 spin_unlock_bh(&hslot->lock);
222 fail:
223 return error;
224 }
225 EXPORT_SYMBOL(udp_lib_get_port);
226
227 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
228 {
229 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
230
231 return (!ipv6_only_sock(sk2) &&
232 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
233 inet1->rcv_saddr == inet2->rcv_saddr));
234 }
235
236 int udp_v4_get_port(struct sock *sk, unsigned short snum)
237 {
238 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
239 }
240
241 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
242 unsigned short hnum,
243 __be16 sport, __be32 daddr, __be16 dport, int dif)
244 {
245 int score = -1;
246
247 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
248 !ipv6_only_sock(sk)) {
249 struct inet_sock *inet = inet_sk(sk);
250
251 score = (sk->sk_family == PF_INET ? 1 : 0);
252 if (inet->rcv_saddr) {
253 if (inet->rcv_saddr != daddr)
254 return -1;
255 score += 2;
256 }
257 if (inet->daddr) {
258 if (inet->daddr != saddr)
259 return -1;
260 score += 2;
261 }
262 if (inet->dport) {
263 if (inet->dport != sport)
264 return -1;
265 score += 2;
266 }
267 if (sk->sk_bound_dev_if) {
268 if (sk->sk_bound_dev_if != dif)
269 return -1;
270 score += 2;
271 }
272 }
273 return score;
274 }
275
276 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
277 * harder than this. -DaveM
278 */
279 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
280 __be16 sport, __be32 daddr, __be16 dport,
281 int dif, struct udp_table *udptable)
282 {
283 struct sock *sk, *result;
284 struct hlist_nulls_node *node;
285 unsigned short hnum = ntohs(dport);
286 unsigned int hash = udp_hashfn(net, hnum);
287 struct udp_hslot *hslot = &udptable->hash[hash];
288 int score, badness;
289
290 rcu_read_lock();
291 begin:
292 result = NULL;
293 badness = -1;
294 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
295 score = compute_score(sk, net, saddr, hnum, sport,
296 daddr, dport, dif);
297 if (score > badness) {
298 result = sk;
299 badness = score;
300 }
301 }
302 /*
303 * if the nulls value we got at the end of this lookup is
304 * not the expected one, we must restart lookup.
305 * We probably met an item that was moved to another chain.
306 */
307 if (get_nulls_value(node) != hash)
308 goto begin;
309
310 if (result) {
311 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
312 result = NULL;
313 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
314 daddr, dport, dif) < badness)) {
315 sock_put(result);
316 goto begin;
317 }
318 }
319 rcu_read_unlock();
320 return result;
321 }
322
323 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
324 __be16 sport, __be16 dport,
325 struct udp_table *udptable)
326 {
327 struct sock *sk;
328 const struct iphdr *iph = ip_hdr(skb);
329
330 if (unlikely(sk = skb_steal_sock(skb)))
331 return sk;
332 else
333 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
334 iph->daddr, dport, inet_iif(skb),
335 udptable);
336 }
337
338 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
339 __be32 daddr, __be16 dport, int dif)
340 {
341 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
342 }
343 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
344
345 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
346 __be16 loc_port, __be32 loc_addr,
347 __be16 rmt_port, __be32 rmt_addr,
348 int dif)
349 {
350 struct hlist_nulls_node *node;
351 struct sock *s = sk;
352 unsigned short hnum = ntohs(loc_port);
353
354 sk_nulls_for_each_from(s, node) {
355 struct inet_sock *inet = inet_sk(s);
356
357 if (!net_eq(sock_net(s), net) ||
358 s->sk_hash != hnum ||
359 (inet->daddr && inet->daddr != rmt_addr) ||
360 (inet->dport != rmt_port && inet->dport) ||
361 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
362 ipv6_only_sock(s) ||
363 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
364 continue;
365 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
366 continue;
367 goto found;
368 }
369 s = NULL;
370 found:
371 return s;
372 }
373
374 /*
375 * This routine is called by the ICMP module when it gets some
376 * sort of error condition. If err < 0 then the socket should
377 * be closed and the error returned to the user. If err > 0
378 * it's just the icmp type << 8 | icmp code.
379 * Header points to the ip header of the error packet. We move
380 * on past this. Then (as it used to claim before adjustment)
381 * header points to the first 8 bytes of the udp header. We need
382 * to find the appropriate port.
383 */
384
385 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
386 {
387 struct inet_sock *inet;
388 struct iphdr *iph = (struct iphdr *)skb->data;
389 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
390 const int type = icmp_hdr(skb)->type;
391 const int code = icmp_hdr(skb)->code;
392 struct sock *sk;
393 int harderr;
394 int err;
395 struct net *net = dev_net(skb->dev);
396
397 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
398 iph->saddr, uh->source, skb->dev->ifindex, udptable);
399 if (sk == NULL) {
400 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
401 return; /* No socket for error */
402 }
403
404 err = 0;
405 harderr = 0;
406 inet = inet_sk(sk);
407
408 switch (type) {
409 default:
410 case ICMP_TIME_EXCEEDED:
411 err = EHOSTUNREACH;
412 break;
413 case ICMP_SOURCE_QUENCH:
414 goto out;
415 case ICMP_PARAMETERPROB:
416 err = EPROTO;
417 harderr = 1;
418 break;
419 case ICMP_DEST_UNREACH:
420 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
421 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
422 err = EMSGSIZE;
423 harderr = 1;
424 break;
425 }
426 goto out;
427 }
428 err = EHOSTUNREACH;
429 if (code <= NR_ICMP_UNREACH) {
430 harderr = icmp_err_convert[code].fatal;
431 err = icmp_err_convert[code].errno;
432 }
433 break;
434 }
435
436 /*
437 * RFC1122: OK. Passes ICMP errors back to application, as per
438 * 4.1.3.3.
439 */
440 if (!inet->recverr) {
441 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
442 goto out;
443 } else {
444 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
445 }
446 sk->sk_err = err;
447 sk->sk_error_report(sk);
448 out:
449 sock_put(sk);
450 }
451
452 void udp_err(struct sk_buff *skb, u32 info)
453 {
454 __udp4_lib_err(skb, info, &udp_table);
455 }
456
457 /*
458 * Throw away all pending data and cancel the corking. Socket is locked.
459 */
460 void udp_flush_pending_frames(struct sock *sk)
461 {
462 struct udp_sock *up = udp_sk(sk);
463
464 if (up->pending) {
465 up->len = 0;
466 up->pending = 0;
467 ip_flush_pending_frames(sk);
468 }
469 }
470 EXPORT_SYMBOL(udp_flush_pending_frames);
471
472 /**
473 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
474 * @sk: socket we are sending on
475 * @skb: sk_buff containing the filled-in UDP header
476 * (checksum field must be zeroed out)
477 */
478 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
479 __be32 src, __be32 dst, int len)
480 {
481 unsigned int offset;
482 struct udphdr *uh = udp_hdr(skb);
483 __wsum csum = 0;
484
485 if (skb_queue_len(&sk->sk_write_queue) == 1) {
486 /*
487 * Only one fragment on the socket.
488 */
489 skb->csum_start = skb_transport_header(skb) - skb->head;
490 skb->csum_offset = offsetof(struct udphdr, check);
491 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
492 } else {
493 /*
494 * HW-checksum won't work as there are two or more
495 * fragments on the socket so that all csums of sk_buffs
496 * should be together
497 */
498 offset = skb_transport_offset(skb);
499 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
500
501 skb->ip_summed = CHECKSUM_NONE;
502
503 skb_queue_walk(&sk->sk_write_queue, skb) {
504 csum = csum_add(csum, skb->csum);
505 }
506
507 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
508 if (uh->check == 0)
509 uh->check = CSUM_MANGLED_0;
510 }
511 }
512
513 /*
514 * Push out all pending data as one UDP datagram. Socket is locked.
515 */
516 static int udp_push_pending_frames(struct sock *sk)
517 {
518 struct udp_sock *up = udp_sk(sk);
519 struct inet_sock *inet = inet_sk(sk);
520 struct flowi *fl = &inet->cork.fl;
521 struct sk_buff *skb;
522 struct udphdr *uh;
523 int err = 0;
524 int is_udplite = IS_UDPLITE(sk);
525 __wsum csum = 0;
526
527 /* Grab the skbuff where UDP header space exists. */
528 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
529 goto out;
530
531 /*
532 * Create a UDP header
533 */
534 uh = udp_hdr(skb);
535 uh->source = fl->fl_ip_sport;
536 uh->dest = fl->fl_ip_dport;
537 uh->len = htons(up->len);
538 uh->check = 0;
539
540 if (is_udplite) /* UDP-Lite */
541 csum = udplite_csum_outgoing(sk, skb);
542
543 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
544
545 skb->ip_summed = CHECKSUM_NONE;
546 goto send;
547
548 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
549
550 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
551 goto send;
552
553 } else /* `normal' UDP */
554 csum = udp_csum_outgoing(sk, skb);
555
556 /* add protocol-dependent pseudo-header */
557 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
558 sk->sk_protocol, csum);
559 if (uh->check == 0)
560 uh->check = CSUM_MANGLED_0;
561
562 send:
563 err = ip_push_pending_frames(sk);
564 if (err) {
565 if (err == -ENOBUFS && !inet->recverr) {
566 UDP_INC_STATS_USER(sock_net(sk),
567 UDP_MIB_SNDBUFERRORS, is_udplite);
568 err = 0;
569 }
570 } else
571 UDP_INC_STATS_USER(sock_net(sk),
572 UDP_MIB_OUTDATAGRAMS, is_udplite);
573 out:
574 up->len = 0;
575 up->pending = 0;
576 return err;
577 }
578
579 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
580 size_t len)
581 {
582 struct inet_sock *inet = inet_sk(sk);
583 struct udp_sock *up = udp_sk(sk);
584 int ulen = len;
585 struct ipcm_cookie ipc;
586 struct rtable *rt = NULL;
587 int free = 0;
588 int connected = 0;
589 __be32 daddr, faddr, saddr;
590 __be16 dport;
591 u8 tos;
592 int err, is_udplite = IS_UDPLITE(sk);
593 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
594 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
595
596 if (len > 0xFFFF)
597 return -EMSGSIZE;
598
599 /*
600 * Check the flags.
601 */
602
603 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
604 return -EOPNOTSUPP;
605
606 ipc.opt = NULL;
607 ipc.shtx.flags = 0;
608
609 if (up->pending) {
610 /*
611 * There are pending frames.
612 * The socket lock must be held while it's corked.
613 */
614 lock_sock(sk);
615 if (likely(up->pending)) {
616 if (unlikely(up->pending != AF_INET)) {
617 release_sock(sk);
618 return -EINVAL;
619 }
620 goto do_append_data;
621 }
622 release_sock(sk);
623 }
624 ulen += sizeof(struct udphdr);
625
626 /*
627 * Get and verify the address.
628 */
629 if (msg->msg_name) {
630 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
631 if (msg->msg_namelen < sizeof(*usin))
632 return -EINVAL;
633 if (usin->sin_family != AF_INET) {
634 if (usin->sin_family != AF_UNSPEC)
635 return -EAFNOSUPPORT;
636 }
637
638 daddr = usin->sin_addr.s_addr;
639 dport = usin->sin_port;
640 if (dport == 0)
641 return -EINVAL;
642 } else {
643 if (sk->sk_state != TCP_ESTABLISHED)
644 return -EDESTADDRREQ;
645 daddr = inet->daddr;
646 dport = inet->dport;
647 /* Open fast path for connected socket.
648 Route will not be used, if at least one option is set.
649 */
650 connected = 1;
651 }
652 ipc.addr = inet->saddr;
653
654 ipc.oif = sk->sk_bound_dev_if;
655 err = sock_tx_timestamp(msg, sk, &ipc.shtx);
656 if (err)
657 return err;
658 if (msg->msg_controllen) {
659 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
660 if (err)
661 return err;
662 if (ipc.opt)
663 free = 1;
664 connected = 0;
665 }
666 if (!ipc.opt)
667 ipc.opt = inet->opt;
668
669 saddr = ipc.addr;
670 ipc.addr = faddr = daddr;
671
672 if (ipc.opt && ipc.opt->srr) {
673 if (!daddr)
674 return -EINVAL;
675 faddr = ipc.opt->faddr;
676 connected = 0;
677 }
678 tos = RT_TOS(inet->tos);
679 if (sock_flag(sk, SOCK_LOCALROUTE) ||
680 (msg->msg_flags & MSG_DONTROUTE) ||
681 (ipc.opt && ipc.opt->is_strictroute)) {
682 tos |= RTO_ONLINK;
683 connected = 0;
684 }
685
686 if (ipv4_is_multicast(daddr)) {
687 if (!ipc.oif)
688 ipc.oif = inet->mc_index;
689 if (!saddr)
690 saddr = inet->mc_addr;
691 connected = 0;
692 }
693
694 if (connected)
695 rt = (struct rtable *)sk_dst_check(sk, 0);
696
697 if (rt == NULL) {
698 struct flowi fl = { .oif = ipc.oif,
699 .mark = sk->sk_mark,
700 .nl_u = { .ip4_u =
701 { .daddr = faddr,
702 .saddr = saddr,
703 .tos = tos } },
704 .proto = sk->sk_protocol,
705 .flags = inet_sk_flowi_flags(sk),
706 .uli_u = { .ports =
707 { .sport = inet->sport,
708 .dport = dport } } };
709 struct net *net = sock_net(sk);
710
711 security_sk_classify_flow(sk, &fl);
712 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
713 if (err) {
714 if (err == -ENETUNREACH)
715 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
716 goto out;
717 }
718
719 err = -EACCES;
720 if ((rt->rt_flags & RTCF_BROADCAST) &&
721 !sock_flag(sk, SOCK_BROADCAST))
722 goto out;
723 if (connected)
724 sk_dst_set(sk, dst_clone(&rt->u.dst));
725 }
726
727 if (msg->msg_flags&MSG_CONFIRM)
728 goto do_confirm;
729 back_from_confirm:
730
731 saddr = rt->rt_src;
732 if (!ipc.addr)
733 daddr = ipc.addr = rt->rt_dst;
734
735 lock_sock(sk);
736 if (unlikely(up->pending)) {
737 /* The socket is already corked while preparing it. */
738 /* ... which is an evident application bug. --ANK */
739 release_sock(sk);
740
741 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
742 err = -EINVAL;
743 goto out;
744 }
745 /*
746 * Now cork the socket to pend data.
747 */
748 inet->cork.fl.fl4_dst = daddr;
749 inet->cork.fl.fl_ip_dport = dport;
750 inet->cork.fl.fl4_src = saddr;
751 inet->cork.fl.fl_ip_sport = inet->sport;
752 up->pending = AF_INET;
753
754 do_append_data:
755 up->len += ulen;
756 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
757 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
758 sizeof(struct udphdr), &ipc, &rt,
759 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
760 if (err)
761 udp_flush_pending_frames(sk);
762 else if (!corkreq)
763 err = udp_push_pending_frames(sk);
764 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
765 up->pending = 0;
766 release_sock(sk);
767
768 out:
769 ip_rt_put(rt);
770 if (free)
771 kfree(ipc.opt);
772 if (!err)
773 return len;
774 /*
775 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
776 * ENOBUFS might not be good (it's not tunable per se), but otherwise
777 * we don't have a good statistic (IpOutDiscards but it can be too many
778 * things). We could add another new stat but at least for now that
779 * seems like overkill.
780 */
781 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
782 UDP_INC_STATS_USER(sock_net(sk),
783 UDP_MIB_SNDBUFERRORS, is_udplite);
784 }
785 return err;
786
787 do_confirm:
788 dst_confirm(&rt->u.dst);
789 if (!(msg->msg_flags&MSG_PROBE) || len)
790 goto back_from_confirm;
791 err = 0;
792 goto out;
793 }
794 EXPORT_SYMBOL(udp_sendmsg);
795
796 int udp_sendpage(struct sock *sk, struct page *page, int offset,
797 size_t size, int flags)
798 {
799 struct udp_sock *up = udp_sk(sk);
800 int ret;
801
802 if (!up->pending) {
803 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
804
805 /* Call udp_sendmsg to specify destination address which
806 * sendpage interface can't pass.
807 * This will succeed only when the socket is connected.
808 */
809 ret = udp_sendmsg(NULL, sk, &msg, 0);
810 if (ret < 0)
811 return ret;
812 }
813
814 lock_sock(sk);
815
816 if (unlikely(!up->pending)) {
817 release_sock(sk);
818
819 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
820 return -EINVAL;
821 }
822
823 ret = ip_append_page(sk, page, offset, size, flags);
824 if (ret == -EOPNOTSUPP) {
825 release_sock(sk);
826 return sock_no_sendpage(sk->sk_socket, page, offset,
827 size, flags);
828 }
829 if (ret < 0) {
830 udp_flush_pending_frames(sk);
831 goto out;
832 }
833
834 up->len += size;
835 if (!(up->corkflag || (flags&MSG_MORE)))
836 ret = udp_push_pending_frames(sk);
837 if (!ret)
838 ret = size;
839 out:
840 release_sock(sk);
841 return ret;
842 }
843
844
845 /**
846 * first_packet_length - return length of first packet in receive queue
847 * @sk: socket
848 *
849 * Drops all bad checksum frames, until a valid one is found.
850 * Returns the length of found skb, or 0 if none is found.
851 */
852 static unsigned int first_packet_length(struct sock *sk)
853 {
854 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
855 struct sk_buff *skb;
856 unsigned int res;
857
858 __skb_queue_head_init(&list_kill);
859
860 spin_lock_bh(&rcvq->lock);
861 while ((skb = skb_peek(rcvq)) != NULL &&
862 udp_lib_checksum_complete(skb)) {
863 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
864 IS_UDPLITE(sk));
865 __skb_unlink(skb, rcvq);
866 __skb_queue_tail(&list_kill, skb);
867 }
868 res = skb ? skb->len : 0;
869 spin_unlock_bh(&rcvq->lock);
870
871 if (!skb_queue_empty(&list_kill)) {
872 lock_sock(sk);
873 __skb_queue_purge(&list_kill);
874 sk_mem_reclaim_partial(sk);
875 release_sock(sk);
876 }
877 return res;
878 }
879
880 /*
881 * IOCTL requests applicable to the UDP protocol
882 */
883
884 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
885 {
886 switch (cmd) {
887 case SIOCOUTQ:
888 {
889 int amount = sk_wmem_alloc_get(sk);
890
891 return put_user(amount, (int __user *)arg);
892 }
893
894 case SIOCINQ:
895 {
896 unsigned int amount = first_packet_length(sk);
897
898 if (amount)
899 /*
900 * We will only return the amount
901 * of this packet since that is all
902 * that will be read.
903 */
904 amount -= sizeof(struct udphdr);
905
906 return put_user(amount, (int __user *)arg);
907 }
908
909 default:
910 return -ENOIOCTLCMD;
911 }
912
913 return 0;
914 }
915 EXPORT_SYMBOL(udp_ioctl);
916
917 /*
918 * This should be easy, if there is something there we
919 * return it, otherwise we block.
920 */
921
922 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
923 size_t len, int noblock, int flags, int *addr_len)
924 {
925 struct inet_sock *inet = inet_sk(sk);
926 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
927 struct sk_buff *skb;
928 unsigned int ulen, copied;
929 int peeked;
930 int err;
931 int is_udplite = IS_UDPLITE(sk);
932
933 /*
934 * Check any passed addresses
935 */
936 if (addr_len)
937 *addr_len = sizeof(*sin);
938
939 if (flags & MSG_ERRQUEUE)
940 return ip_recv_error(sk, msg, len);
941
942 try_again:
943 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
944 &peeked, &err);
945 if (!skb)
946 goto out;
947
948 ulen = skb->len - sizeof(struct udphdr);
949 copied = len;
950 if (copied > ulen)
951 copied = ulen;
952 else if (copied < ulen)
953 msg->msg_flags |= MSG_TRUNC;
954
955 /*
956 * If checksum is needed at all, try to do it while copying the
957 * data. If the data is truncated, or if we only want a partial
958 * coverage checksum (UDP-Lite), do it before the copy.
959 */
960
961 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
962 if (udp_lib_checksum_complete(skb))
963 goto csum_copy_err;
964 }
965
966 if (skb_csum_unnecessary(skb))
967 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
968 msg->msg_iov, copied);
969 else {
970 err = skb_copy_and_csum_datagram_iovec(skb,
971 sizeof(struct udphdr),
972 msg->msg_iov);
973
974 if (err == -EINVAL)
975 goto csum_copy_err;
976 }
977
978 if (err)
979 goto out_free;
980
981 if (!peeked)
982 UDP_INC_STATS_USER(sock_net(sk),
983 UDP_MIB_INDATAGRAMS, is_udplite);
984
985 sock_recv_timestamp(msg, sk, skb);
986
987 /* Copy the address. */
988 if (sin) {
989 sin->sin_family = AF_INET;
990 sin->sin_port = udp_hdr(skb)->source;
991 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
992 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
993 }
994 if (inet->cmsg_flags)
995 ip_cmsg_recv(msg, skb);
996
997 err = copied;
998 if (flags & MSG_TRUNC)
999 err = ulen;
1000
1001 out_free:
1002 skb_free_datagram_locked(sk, skb);
1003 out:
1004 return err;
1005
1006 csum_copy_err:
1007 lock_sock(sk);
1008 if (!skb_kill_datagram(sk, skb, flags))
1009 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1010 release_sock(sk);
1011
1012 if (noblock)
1013 return -EAGAIN;
1014 goto try_again;
1015 }
1016
1017
1018 int udp_disconnect(struct sock *sk, int flags)
1019 {
1020 struct inet_sock *inet = inet_sk(sk);
1021 /*
1022 * 1003.1g - break association.
1023 */
1024
1025 sk->sk_state = TCP_CLOSE;
1026 inet->daddr = 0;
1027 inet->dport = 0;
1028 sk->sk_bound_dev_if = 0;
1029 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1030 inet_reset_saddr(sk);
1031
1032 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1033 sk->sk_prot->unhash(sk);
1034 inet->sport = 0;
1035 }
1036 sk_dst_reset(sk);
1037 return 0;
1038 }
1039 EXPORT_SYMBOL(udp_disconnect);
1040
1041 void udp_lib_unhash(struct sock *sk)
1042 {
1043 if (sk_hashed(sk)) {
1044 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1045 unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash);
1046 struct udp_hslot *hslot = &udptable->hash[hash];
1047
1048 spin_lock_bh(&hslot->lock);
1049 if (sk_nulls_del_node_init_rcu(sk)) {
1050 inet_sk(sk)->num = 0;
1051 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1052 }
1053 spin_unlock_bh(&hslot->lock);
1054 }
1055 }
1056 EXPORT_SYMBOL(udp_lib_unhash);
1057
1058 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1059 {
1060 int is_udplite = IS_UDPLITE(sk);
1061 int rc;
1062
1063 if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
1064 /* Note that an ENOMEM error is charged twice */
1065 if (rc == -ENOMEM) {
1066 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1067 is_udplite);
1068 atomic_inc(&sk->sk_drops);
1069 }
1070 goto drop;
1071 }
1072
1073 return 0;
1074
1075 drop:
1076 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1077 kfree_skb(skb);
1078 return -1;
1079 }
1080
1081 /* returns:
1082 * -1: error
1083 * 0: success
1084 * >0: "udp encap" protocol resubmission
1085 *
1086 * Note that in the success and error cases, the skb is assumed to
1087 * have either been requeued or freed.
1088 */
1089 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1090 {
1091 struct udp_sock *up = udp_sk(sk);
1092 int rc;
1093 int is_udplite = IS_UDPLITE(sk);
1094
1095 /*
1096 * Charge it to the socket, dropping if the queue is full.
1097 */
1098 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1099 goto drop;
1100 nf_reset(skb);
1101
1102 if (up->encap_type) {
1103 /*
1104 * This is an encapsulation socket so pass the skb to
1105 * the socket's udp_encap_rcv() hook. Otherwise, just
1106 * fall through and pass this up the UDP socket.
1107 * up->encap_rcv() returns the following value:
1108 * =0 if skb was successfully passed to the encap
1109 * handler or was discarded by it.
1110 * >0 if skb should be passed on to UDP.
1111 * <0 if skb should be resubmitted as proto -N
1112 */
1113
1114 /* if we're overly short, let UDP handle it */
1115 if (skb->len > sizeof(struct udphdr) &&
1116 up->encap_rcv != NULL) {
1117 int ret;
1118
1119 ret = (*up->encap_rcv)(sk, skb);
1120 if (ret <= 0) {
1121 UDP_INC_STATS_BH(sock_net(sk),
1122 UDP_MIB_INDATAGRAMS,
1123 is_udplite);
1124 return -ret;
1125 }
1126 }
1127
1128 /* FALLTHROUGH -- it's a UDP Packet */
1129 }
1130
1131 /*
1132 * UDP-Lite specific tests, ignored on UDP sockets
1133 */
1134 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1135
1136 /*
1137 * MIB statistics other than incrementing the error count are
1138 * disabled for the following two types of errors: these depend
1139 * on the application settings, not on the functioning of the
1140 * protocol stack as such.
1141 *
1142 * RFC 3828 here recommends (sec 3.3): "There should also be a
1143 * way ... to ... at least let the receiving application block
1144 * delivery of packets with coverage values less than a value
1145 * provided by the application."
1146 */
1147 if (up->pcrlen == 0) { /* full coverage was set */
1148 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1149 "%d while full coverage %d requested\n",
1150 UDP_SKB_CB(skb)->cscov, skb->len);
1151 goto drop;
1152 }
1153 /* The next case involves violating the min. coverage requested
1154 * by the receiver. This is subtle: if receiver wants x and x is
1155 * greater than the buffersize/MTU then receiver will complain
1156 * that it wants x while sender emits packets of smaller size y.
1157 * Therefore the above ...()->partial_cov statement is essential.
1158 */
1159 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1160 LIMIT_NETDEBUG(KERN_WARNING
1161 "UDPLITE: coverage %d too small, need min %d\n",
1162 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1163 goto drop;
1164 }
1165 }
1166
1167 if (sk->sk_filter) {
1168 if (udp_lib_checksum_complete(skb))
1169 goto drop;
1170 }
1171
1172 rc = 0;
1173
1174 bh_lock_sock(sk);
1175 if (!sock_owned_by_user(sk))
1176 rc = __udp_queue_rcv_skb(sk, skb);
1177 else
1178 sk_add_backlog(sk, skb);
1179 bh_unlock_sock(sk);
1180
1181 return rc;
1182
1183 drop:
1184 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1185 kfree_skb(skb);
1186 return -1;
1187 }
1188
1189 /*
1190 * Multicasts and broadcasts go to each listener.
1191 *
1192 * Note: called only from the BH handler context,
1193 * so we don't need to lock the hashes.
1194 */
1195 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1196 struct udphdr *uh,
1197 __be32 saddr, __be32 daddr,
1198 struct udp_table *udptable)
1199 {
1200 struct sock *sk;
1201 struct udp_hslot *hslot = &udptable->hash[udp_hashfn(net, ntohs(uh->dest))];
1202 int dif;
1203
1204 spin_lock(&hslot->lock);
1205 sk = sk_nulls_head(&hslot->head);
1206 dif = skb->dev->ifindex;
1207 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1208 if (sk) {
1209 struct sock *sknext = NULL;
1210
1211 do {
1212 struct sk_buff *skb1 = skb;
1213
1214 sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1215 daddr, uh->source, saddr,
1216 dif);
1217 if (sknext)
1218 skb1 = skb_clone(skb, GFP_ATOMIC);
1219
1220 if (skb1) {
1221 int ret = udp_queue_rcv_skb(sk, skb1);
1222 if (ret > 0)
1223 /* we should probably re-process instead
1224 * of dropping packets here. */
1225 kfree_skb(skb1);
1226 }
1227 sk = sknext;
1228 } while (sknext);
1229 } else
1230 consume_skb(skb);
1231 spin_unlock(&hslot->lock);
1232 return 0;
1233 }
1234
1235 /* Initialize UDP checksum. If exited with zero value (success),
1236 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1237 * Otherwise, csum completion requires chacksumming packet body,
1238 * including udp header and folding it to skb->csum.
1239 */
1240 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1241 int proto)
1242 {
1243 const struct iphdr *iph;
1244 int err;
1245
1246 UDP_SKB_CB(skb)->partial_cov = 0;
1247 UDP_SKB_CB(skb)->cscov = skb->len;
1248
1249 if (proto == IPPROTO_UDPLITE) {
1250 err = udplite_checksum_init(skb, uh);
1251 if (err)
1252 return err;
1253 }
1254
1255 iph = ip_hdr(skb);
1256 if (uh->check == 0) {
1257 skb->ip_summed = CHECKSUM_UNNECESSARY;
1258 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1259 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1260 proto, skb->csum))
1261 skb->ip_summed = CHECKSUM_UNNECESSARY;
1262 }
1263 if (!skb_csum_unnecessary(skb))
1264 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1265 skb->len, proto, 0);
1266 /* Probably, we should checksum udp header (it should be in cache
1267 * in any case) and data in tiny packets (< rx copybreak).
1268 */
1269
1270 return 0;
1271 }
1272
1273 /*
1274 * All we need to do is get the socket, and then do a checksum.
1275 */
1276
1277 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1278 int proto)
1279 {
1280 struct sock *sk;
1281 struct udphdr *uh;
1282 unsigned short ulen;
1283 struct rtable *rt = skb_rtable(skb);
1284 __be32 saddr, daddr;
1285 struct net *net = dev_net(skb->dev);
1286
1287 /*
1288 * Validate the packet.
1289 */
1290 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1291 goto drop; /* No space for header. */
1292
1293 uh = udp_hdr(skb);
1294 ulen = ntohs(uh->len);
1295 if (ulen > skb->len)
1296 goto short_packet;
1297
1298 if (proto == IPPROTO_UDP) {
1299 /* UDP validates ulen. */
1300 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1301 goto short_packet;
1302 uh = udp_hdr(skb);
1303 }
1304
1305 if (udp4_csum_init(skb, uh, proto))
1306 goto csum_error;
1307
1308 saddr = ip_hdr(skb)->saddr;
1309 daddr = ip_hdr(skb)->daddr;
1310
1311 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1312 return __udp4_lib_mcast_deliver(net, skb, uh,
1313 saddr, daddr, udptable);
1314
1315 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1316
1317 if (sk != NULL) {
1318 int ret = udp_queue_rcv_skb(sk, skb);
1319 sock_put(sk);
1320
1321 /* a return value > 0 means to resubmit the input, but
1322 * it wants the return to be -protocol, or 0
1323 */
1324 if (ret > 0)
1325 return -ret;
1326 return 0;
1327 }
1328
1329 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1330 goto drop;
1331 nf_reset(skb);
1332
1333 /* No socket. Drop packet silently, if checksum is wrong */
1334 if (udp_lib_checksum_complete(skb))
1335 goto csum_error;
1336
1337 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1338 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1339
1340 /*
1341 * Hmm. We got an UDP packet to a port to which we
1342 * don't wanna listen. Ignore it.
1343 */
1344 kfree_skb(skb);
1345 return 0;
1346
1347 short_packet:
1348 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1349 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1350 &saddr,
1351 ntohs(uh->source),
1352 ulen,
1353 skb->len,
1354 &daddr,
1355 ntohs(uh->dest));
1356 goto drop;
1357
1358 csum_error:
1359 /*
1360 * RFC1122: OK. Discards the bad packet silently (as far as
1361 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1362 */
1363 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1364 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1365 &saddr,
1366 ntohs(uh->source),
1367 &daddr,
1368 ntohs(uh->dest),
1369 ulen);
1370 drop:
1371 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1372 kfree_skb(skb);
1373 return 0;
1374 }
1375
1376 int udp_rcv(struct sk_buff *skb)
1377 {
1378 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1379 }
1380
1381 void udp_destroy_sock(struct sock *sk)
1382 {
1383 lock_sock(sk);
1384 udp_flush_pending_frames(sk);
1385 release_sock(sk);
1386 }
1387
1388 /*
1389 * Socket option code for UDP
1390 */
1391 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1392 char __user *optval, unsigned int optlen,
1393 int (*push_pending_frames)(struct sock *))
1394 {
1395 struct udp_sock *up = udp_sk(sk);
1396 int val;
1397 int err = 0;
1398 int is_udplite = IS_UDPLITE(sk);
1399
1400 if (optlen < sizeof(int))
1401 return -EINVAL;
1402
1403 if (get_user(val, (int __user *)optval))
1404 return -EFAULT;
1405
1406 switch (optname) {
1407 case UDP_CORK:
1408 if (val != 0) {
1409 up->corkflag = 1;
1410 } else {
1411 up->corkflag = 0;
1412 lock_sock(sk);
1413 (*push_pending_frames)(sk);
1414 release_sock(sk);
1415 }
1416 break;
1417
1418 case UDP_ENCAP:
1419 switch (val) {
1420 case 0:
1421 case UDP_ENCAP_ESPINUDP:
1422 case UDP_ENCAP_ESPINUDP_NON_IKE:
1423 up->encap_rcv = xfrm4_udp_encap_rcv;
1424 /* FALLTHROUGH */
1425 case UDP_ENCAP_L2TPINUDP:
1426 up->encap_type = val;
1427 break;
1428 default:
1429 err = -ENOPROTOOPT;
1430 break;
1431 }
1432 break;
1433
1434 /*
1435 * UDP-Lite's partial checksum coverage (RFC 3828).
1436 */
1437 /* The sender sets actual checksum coverage length via this option.
1438 * The case coverage > packet length is handled by send module. */
1439 case UDPLITE_SEND_CSCOV:
1440 if (!is_udplite) /* Disable the option on UDP sockets */
1441 return -ENOPROTOOPT;
1442 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1443 val = 8;
1444 else if (val > USHORT_MAX)
1445 val = USHORT_MAX;
1446 up->pcslen = val;
1447 up->pcflag |= UDPLITE_SEND_CC;
1448 break;
1449
1450 /* The receiver specifies a minimum checksum coverage value. To make
1451 * sense, this should be set to at least 8 (as done below). If zero is
1452 * used, this again means full checksum coverage. */
1453 case UDPLITE_RECV_CSCOV:
1454 if (!is_udplite) /* Disable the option on UDP sockets */
1455 return -ENOPROTOOPT;
1456 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1457 val = 8;
1458 else if (val > USHORT_MAX)
1459 val = USHORT_MAX;
1460 up->pcrlen = val;
1461 up->pcflag |= UDPLITE_RECV_CC;
1462 break;
1463
1464 default:
1465 err = -ENOPROTOOPT;
1466 break;
1467 }
1468
1469 return err;
1470 }
1471 EXPORT_SYMBOL(udp_lib_setsockopt);
1472
1473 int udp_setsockopt(struct sock *sk, int level, int optname,
1474 char __user *optval, unsigned int optlen)
1475 {
1476 if (level == SOL_UDP || level == SOL_UDPLITE)
1477 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1478 udp_push_pending_frames);
1479 return ip_setsockopt(sk, level, optname, optval, optlen);
1480 }
1481
1482 #ifdef CONFIG_COMPAT
1483 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1484 char __user *optval, unsigned int optlen)
1485 {
1486 if (level == SOL_UDP || level == SOL_UDPLITE)
1487 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1488 udp_push_pending_frames);
1489 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1490 }
1491 #endif
1492
1493 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1494 char __user *optval, int __user *optlen)
1495 {
1496 struct udp_sock *up = udp_sk(sk);
1497 int val, len;
1498
1499 if (get_user(len, optlen))
1500 return -EFAULT;
1501
1502 len = min_t(unsigned int, len, sizeof(int));
1503
1504 if (len < 0)
1505 return -EINVAL;
1506
1507 switch (optname) {
1508 case UDP_CORK:
1509 val = up->corkflag;
1510 break;
1511
1512 case UDP_ENCAP:
1513 val = up->encap_type;
1514 break;
1515
1516 /* The following two cannot be changed on UDP sockets, the return is
1517 * always 0 (which corresponds to the full checksum coverage of UDP). */
1518 case UDPLITE_SEND_CSCOV:
1519 val = up->pcslen;
1520 break;
1521
1522 case UDPLITE_RECV_CSCOV:
1523 val = up->pcrlen;
1524 break;
1525
1526 default:
1527 return -ENOPROTOOPT;
1528 }
1529
1530 if (put_user(len, optlen))
1531 return -EFAULT;
1532 if (copy_to_user(optval, &val, len))
1533 return -EFAULT;
1534 return 0;
1535 }
1536 EXPORT_SYMBOL(udp_lib_getsockopt);
1537
1538 int udp_getsockopt(struct sock *sk, int level, int optname,
1539 char __user *optval, int __user *optlen)
1540 {
1541 if (level == SOL_UDP || level == SOL_UDPLITE)
1542 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1543 return ip_getsockopt(sk, level, optname, optval, optlen);
1544 }
1545
1546 #ifdef CONFIG_COMPAT
1547 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1548 char __user *optval, int __user *optlen)
1549 {
1550 if (level == SOL_UDP || level == SOL_UDPLITE)
1551 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1552 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1553 }
1554 #endif
1555 /**
1556 * udp_poll - wait for a UDP event.
1557 * @file - file struct
1558 * @sock - socket
1559 * @wait - poll table
1560 *
1561 * This is same as datagram poll, except for the special case of
1562 * blocking sockets. If application is using a blocking fd
1563 * and a packet with checksum error is in the queue;
1564 * then it could get return from select indicating data available
1565 * but then block when reading it. Add special case code
1566 * to work around these arguably broken applications.
1567 */
1568 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1569 {
1570 unsigned int mask = datagram_poll(file, sock, wait);
1571 struct sock *sk = sock->sk;
1572
1573 /* Check for false positives due to checksum errors */
1574 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1575 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1576 mask &= ~(POLLIN | POLLRDNORM);
1577
1578 return mask;
1579
1580 }
1581 EXPORT_SYMBOL(udp_poll);
1582
1583 struct proto udp_prot = {
1584 .name = "UDP",
1585 .owner = THIS_MODULE,
1586 .close = udp_lib_close,
1587 .connect = ip4_datagram_connect,
1588 .disconnect = udp_disconnect,
1589 .ioctl = udp_ioctl,
1590 .destroy = udp_destroy_sock,
1591 .setsockopt = udp_setsockopt,
1592 .getsockopt = udp_getsockopt,
1593 .sendmsg = udp_sendmsg,
1594 .recvmsg = udp_recvmsg,
1595 .sendpage = udp_sendpage,
1596 .backlog_rcv = __udp_queue_rcv_skb,
1597 .hash = udp_lib_hash,
1598 .unhash = udp_lib_unhash,
1599 .get_port = udp_v4_get_port,
1600 .memory_allocated = &udp_memory_allocated,
1601 .sysctl_mem = sysctl_udp_mem,
1602 .sysctl_wmem = &sysctl_udp_wmem_min,
1603 .sysctl_rmem = &sysctl_udp_rmem_min,
1604 .obj_size = sizeof(struct udp_sock),
1605 .slab_flags = SLAB_DESTROY_BY_RCU,
1606 .h.udp_table = &udp_table,
1607 #ifdef CONFIG_COMPAT
1608 .compat_setsockopt = compat_udp_setsockopt,
1609 .compat_getsockopt = compat_udp_getsockopt,
1610 #endif
1611 };
1612 EXPORT_SYMBOL(udp_prot);
1613
1614 /* ------------------------------------------------------------------------ */
1615 #ifdef CONFIG_PROC_FS
1616
1617 static struct sock *udp_get_first(struct seq_file *seq, int start)
1618 {
1619 struct sock *sk;
1620 struct udp_iter_state *state = seq->private;
1621 struct net *net = seq_file_net(seq);
1622
1623 for (state->bucket = start; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1624 struct hlist_nulls_node *node;
1625 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1626 spin_lock_bh(&hslot->lock);
1627 sk_nulls_for_each(sk, node, &hslot->head) {
1628 if (!net_eq(sock_net(sk), net))
1629 continue;
1630 if (sk->sk_family == state->family)
1631 goto found;
1632 }
1633 spin_unlock_bh(&hslot->lock);
1634 }
1635 sk = NULL;
1636 found:
1637 return sk;
1638 }
1639
1640 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1641 {
1642 struct udp_iter_state *state = seq->private;
1643 struct net *net = seq_file_net(seq);
1644
1645 do {
1646 sk = sk_nulls_next(sk);
1647 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1648
1649 if (!sk) {
1650 if (state->bucket < UDP_HTABLE_SIZE)
1651 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1652 return udp_get_first(seq, state->bucket + 1);
1653 }
1654 return sk;
1655 }
1656
1657 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1658 {
1659 struct sock *sk = udp_get_first(seq, 0);
1660
1661 if (sk)
1662 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1663 --pos;
1664 return pos ? NULL : sk;
1665 }
1666
1667 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1668 {
1669 struct udp_iter_state *state = seq->private;
1670 state->bucket = UDP_HTABLE_SIZE;
1671
1672 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1673 }
1674
1675 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1676 {
1677 struct sock *sk;
1678
1679 if (v == SEQ_START_TOKEN)
1680 sk = udp_get_idx(seq, 0);
1681 else
1682 sk = udp_get_next(seq, v);
1683
1684 ++*pos;
1685 return sk;
1686 }
1687
1688 static void udp_seq_stop(struct seq_file *seq, void *v)
1689 {
1690 struct udp_iter_state *state = seq->private;
1691
1692 if (state->bucket < UDP_HTABLE_SIZE)
1693 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1694 }
1695
1696 static int udp_seq_open(struct inode *inode, struct file *file)
1697 {
1698 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1699 struct udp_iter_state *s;
1700 int err;
1701
1702 err = seq_open_net(inode, file, &afinfo->seq_ops,
1703 sizeof(struct udp_iter_state));
1704 if (err < 0)
1705 return err;
1706
1707 s = ((struct seq_file *)file->private_data)->private;
1708 s->family = afinfo->family;
1709 s->udp_table = afinfo->udp_table;
1710 return err;
1711 }
1712
1713 /* ------------------------------------------------------------------------ */
1714 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1715 {
1716 struct proc_dir_entry *p;
1717 int rc = 0;
1718
1719 afinfo->seq_fops.open = udp_seq_open;
1720 afinfo->seq_fops.read = seq_read;
1721 afinfo->seq_fops.llseek = seq_lseek;
1722 afinfo->seq_fops.release = seq_release_net;
1723
1724 afinfo->seq_ops.start = udp_seq_start;
1725 afinfo->seq_ops.next = udp_seq_next;
1726 afinfo->seq_ops.stop = udp_seq_stop;
1727
1728 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1729 &afinfo->seq_fops, afinfo);
1730 if (!p)
1731 rc = -ENOMEM;
1732 return rc;
1733 }
1734 EXPORT_SYMBOL(udp_proc_register);
1735
1736 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1737 {
1738 proc_net_remove(net, afinfo->name);
1739 }
1740 EXPORT_SYMBOL(udp_proc_unregister);
1741
1742 /* ------------------------------------------------------------------------ */
1743 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1744 int bucket, int *len)
1745 {
1746 struct inet_sock *inet = inet_sk(sp);
1747 __be32 dest = inet->daddr;
1748 __be32 src = inet->rcv_saddr;
1749 __u16 destp = ntohs(inet->dport);
1750 __u16 srcp = ntohs(inet->sport);
1751
1752 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
1753 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1754 bucket, src, srcp, dest, destp, sp->sk_state,
1755 sk_wmem_alloc_get(sp),
1756 sk_rmem_alloc_get(sp),
1757 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1758 atomic_read(&sp->sk_refcnt), sp,
1759 atomic_read(&sp->sk_drops), len);
1760 }
1761
1762 int udp4_seq_show(struct seq_file *seq, void *v)
1763 {
1764 if (v == SEQ_START_TOKEN)
1765 seq_printf(seq, "%-127s\n",
1766 " sl local_address rem_address st tx_queue "
1767 "rx_queue tr tm->when retrnsmt uid timeout "
1768 "inode ref pointer drops");
1769 else {
1770 struct udp_iter_state *state = seq->private;
1771 int len;
1772
1773 udp4_format_sock(v, seq, state->bucket, &len);
1774 seq_printf(seq, "%*s\n", 127 - len, "");
1775 }
1776 return 0;
1777 }
1778
1779 /* ------------------------------------------------------------------------ */
1780 static struct udp_seq_afinfo udp4_seq_afinfo = {
1781 .name = "udp",
1782 .family = AF_INET,
1783 .udp_table = &udp_table,
1784 .seq_fops = {
1785 .owner = THIS_MODULE,
1786 },
1787 .seq_ops = {
1788 .show = udp4_seq_show,
1789 },
1790 };
1791
1792 static int udp4_proc_init_net(struct net *net)
1793 {
1794 return udp_proc_register(net, &udp4_seq_afinfo);
1795 }
1796
1797 static void udp4_proc_exit_net(struct net *net)
1798 {
1799 udp_proc_unregister(net, &udp4_seq_afinfo);
1800 }
1801
1802 static struct pernet_operations udp4_net_ops = {
1803 .init = udp4_proc_init_net,
1804 .exit = udp4_proc_exit_net,
1805 };
1806
1807 int __init udp4_proc_init(void)
1808 {
1809 return register_pernet_subsys(&udp4_net_ops);
1810 }
1811
1812 void udp4_proc_exit(void)
1813 {
1814 unregister_pernet_subsys(&udp4_net_ops);
1815 }
1816 #endif /* CONFIG_PROC_FS */
1817
1818 void __init udp_table_init(struct udp_table *table)
1819 {
1820 int i;
1821
1822 for (i = 0; i < UDP_HTABLE_SIZE; i++) {
1823 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
1824 spin_lock_init(&table->hash[i].lock);
1825 }
1826 }
1827
1828 void __init udp_init(void)
1829 {
1830 unsigned long nr_pages, limit;
1831
1832 udp_table_init(&udp_table);
1833 /* Set the pressure threshold up by the same strategy of TCP. It is a
1834 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1835 * toward zero with the amount of memory, with a floor of 128 pages.
1836 */
1837 nr_pages = totalram_pages - totalhigh_pages;
1838 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1839 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1840 limit = max(limit, 128UL);
1841 sysctl_udp_mem[0] = limit / 4 * 3;
1842 sysctl_udp_mem[1] = limit;
1843 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1844
1845 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1846 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1847 }
1848
1849 int udp4_ufo_send_check(struct sk_buff *skb)
1850 {
1851 const struct iphdr *iph;
1852 struct udphdr *uh;
1853
1854 if (!pskb_may_pull(skb, sizeof(*uh)))
1855 return -EINVAL;
1856
1857 iph = ip_hdr(skb);
1858 uh = udp_hdr(skb);
1859
1860 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1861 IPPROTO_UDP, 0);
1862 skb->csum_start = skb_transport_header(skb) - skb->head;
1863 skb->csum_offset = offsetof(struct udphdr, check);
1864 skb->ip_summed = CHECKSUM_PARTIAL;
1865 return 0;
1866 }
1867
1868 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
1869 {
1870 struct sk_buff *segs = ERR_PTR(-EINVAL);
1871 unsigned int mss;
1872 int offset;
1873 __wsum csum;
1874
1875 mss = skb_shinfo(skb)->gso_size;
1876 if (unlikely(skb->len <= mss))
1877 goto out;
1878
1879 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1880 /* Packet is from an untrusted source, reset gso_segs. */
1881 int type = skb_shinfo(skb)->gso_type;
1882
1883 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1884 !(type & (SKB_GSO_UDP))))
1885 goto out;
1886
1887 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1888
1889 segs = NULL;
1890 goto out;
1891 }
1892
1893 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1894 * do checksum of UDP packets sent as multiple IP fragments.
1895 */
1896 offset = skb->csum_start - skb_headroom(skb);
1897 csum = skb_checksum(skb, offset, skb->len - offset, 0);
1898 offset += skb->csum_offset;
1899 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
1900 skb->ip_summed = CHECKSUM_NONE;
1901
1902 /* Fragment the skb. IP headers of the fragments are updated in
1903 * inet_gso_segment()
1904 */
1905 segs = skb_segment(skb, features);
1906 out:
1907 return segs;
1908 }
1909
Linux kernel - Deliverables
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