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Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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 __read_mostly;
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 MAX_UDP_PORTS 65536
125 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
126
127 static int udp_lib_lport_inuse(struct net *net, __u16 num,
128 const struct udp_hslot *hslot,
129 unsigned long *bitmap,
130 struct sock *sk,
131 int (*saddr_comp)(const struct sock *sk1,
132 const struct sock *sk2),
133 unsigned int log)
134 {
135 struct sock *sk2;
136 struct hlist_nulls_node *node;
137
138 sk_nulls_for_each(sk2, node, &hslot->head)
139 if (net_eq(sock_net(sk2), net) &&
140 sk2 != sk &&
141 (bitmap || sk2->sk_hash == num) &&
142 (!sk2->sk_reuse || !sk->sk_reuse) &&
143 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
144 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
145 (*saddr_comp)(sk, sk2)) {
146 if (bitmap)
147 __set_bit(sk2->sk_hash >> log, bitmap);
148 else
149 return 1;
150 }
151 return 0;
152 }
153
154 /**
155 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
156 *
157 * @sk: socket struct in question
158 * @snum: port number to look up
159 * @saddr_comp: AF-dependent comparison of bound local IP addresses
160 */
161 int udp_lib_get_port(struct sock *sk, unsigned short snum,
162 int (*saddr_comp)(const struct sock *sk1,
163 const struct sock *sk2))
164 {
165 struct udp_hslot *hslot;
166 struct udp_table *udptable = sk->sk_prot->h.udp_table;
167 int error = 1;
168 struct net *net = sock_net(sk);
169
170 if (!snum) {
171 int low, high, remaining;
172 unsigned rand;
173 unsigned short first, last;
174 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
175
176 inet_get_local_port_range(&low, &high);
177 remaining = (high - low) + 1;
178
179 rand = net_random();
180 first = (((u64)rand * remaining) >> 32) + low;
181 /*
182 * force rand to be an odd multiple of UDP_HTABLE_SIZE
183 */
184 rand = (rand | 1) * (udptable->mask + 1);
185 for (last = first + udptable->mask + 1;
186 first != last;
187 first++) {
188 hslot = udp_hashslot(udptable, net, first);
189 bitmap_zero(bitmap, PORTS_PER_CHAIN);
190 spin_lock_bh(&hslot->lock);
191 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
192 saddr_comp, udptable->log);
193
194 snum = first;
195 /*
196 * Iterate on all possible values of snum for this hash.
197 * Using steps of an odd multiple of UDP_HTABLE_SIZE
198 * give us randomization and full range coverage.
199 */
200 do {
201 if (low <= snum && snum <= high &&
202 !test_bit(snum >> udptable->log, bitmap))
203 goto found;
204 snum += rand;
205 } while (snum != first);
206 spin_unlock_bh(&hslot->lock);
207 }
208 goto fail;
209 } else {
210 hslot = udp_hashslot(udptable, net, snum);
211 spin_lock_bh(&hslot->lock);
212 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
213 saddr_comp, 0))
214 goto fail_unlock;
215 }
216 found:
217 inet_sk(sk)->inet_num = snum;
218 sk->sk_hash = snum;
219 if (sk_unhashed(sk)) {
220 sk_nulls_add_node_rcu(sk, &hslot->head);
221 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
222 }
223 error = 0;
224 fail_unlock:
225 spin_unlock_bh(&hslot->lock);
226 fail:
227 return error;
228 }
229 EXPORT_SYMBOL(udp_lib_get_port);
230
231 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
232 {
233 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
234
235 return (!ipv6_only_sock(sk2) &&
236 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
237 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
238 }
239
240 int udp_v4_get_port(struct sock *sk, unsigned short snum)
241 {
242 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
243 }
244
245 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
246 unsigned short hnum,
247 __be16 sport, __be32 daddr, __be16 dport, int dif)
248 {
249 int score = -1;
250
251 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
252 !ipv6_only_sock(sk)) {
253 struct inet_sock *inet = inet_sk(sk);
254
255 score = (sk->sk_family == PF_INET ? 1 : 0);
256 if (inet->inet_rcv_saddr) {
257 if (inet->inet_rcv_saddr != daddr)
258 return -1;
259 score += 2;
260 }
261 if (inet->inet_daddr) {
262 if (inet->inet_daddr != saddr)
263 return -1;
264 score += 2;
265 }
266 if (inet->inet_dport) {
267 if (inet->inet_dport != sport)
268 return -1;
269 score += 2;
270 }
271 if (sk->sk_bound_dev_if) {
272 if (sk->sk_bound_dev_if != dif)
273 return -1;
274 score += 2;
275 }
276 }
277 return score;
278 }
279
280 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
281 * harder than this. -DaveM
282 */
283 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
284 __be16 sport, __be32 daddr, __be16 dport,
285 int dif, struct udp_table *udptable)
286 {
287 struct sock *sk, *result;
288 struct hlist_nulls_node *node;
289 unsigned short hnum = ntohs(dport);
290 unsigned int hash = udp_hashfn(net, hnum, udptable->mask);
291 struct udp_hslot *hslot = &udptable->hash[hash];
292 int score, badness;
293
294 rcu_read_lock();
295 begin:
296 result = NULL;
297 badness = -1;
298 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
299 score = compute_score(sk, net, saddr, hnum, sport,
300 daddr, dport, dif);
301 if (score > badness) {
302 result = sk;
303 badness = score;
304 }
305 }
306 /*
307 * if the nulls value we got at the end of this lookup is
308 * not the expected one, we must restart lookup.
309 * We probably met an item that was moved to another chain.
310 */
311 if (get_nulls_value(node) != hash)
312 goto begin;
313
314 if (result) {
315 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
316 result = NULL;
317 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
318 daddr, dport, dif) < badness)) {
319 sock_put(result);
320 goto begin;
321 }
322 }
323 rcu_read_unlock();
324 return result;
325 }
326
327 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
328 __be16 sport, __be16 dport,
329 struct udp_table *udptable)
330 {
331 struct sock *sk;
332 const struct iphdr *iph = ip_hdr(skb);
333
334 if (unlikely(sk = skb_steal_sock(skb)))
335 return sk;
336 else
337 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
338 iph->daddr, dport, inet_iif(skb),
339 udptable);
340 }
341
342 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
343 __be32 daddr, __be16 dport, int dif)
344 {
345 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
346 }
347 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
348
349 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
350 __be16 loc_port, __be32 loc_addr,
351 __be16 rmt_port, __be32 rmt_addr,
352 int dif)
353 {
354 struct hlist_nulls_node *node;
355 struct sock *s = sk;
356 unsigned short hnum = ntohs(loc_port);
357
358 sk_nulls_for_each_from(s, node) {
359 struct inet_sock *inet = inet_sk(s);
360
361 if (!net_eq(sock_net(s), net) ||
362 s->sk_hash != hnum ||
363 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
364 (inet->inet_dport != rmt_port && inet->inet_dport) ||
365 (inet->inet_rcv_saddr &&
366 inet->inet_rcv_saddr != loc_addr) ||
367 ipv6_only_sock(s) ||
368 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
369 continue;
370 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
371 continue;
372 goto found;
373 }
374 s = NULL;
375 found:
376 return s;
377 }
378
379 /*
380 * This routine is called by the ICMP module when it gets some
381 * sort of error condition. If err < 0 then the socket should
382 * be closed and the error returned to the user. If err > 0
383 * it's just the icmp type << 8 | icmp code.
384 * Header points to the ip header of the error packet. We move
385 * on past this. Then (as it used to claim before adjustment)
386 * header points to the first 8 bytes of the udp header. We need
387 * to find the appropriate port.
388 */
389
390 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
391 {
392 struct inet_sock *inet;
393 struct iphdr *iph = (struct iphdr *)skb->data;
394 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
395 const int type = icmp_hdr(skb)->type;
396 const int code = icmp_hdr(skb)->code;
397 struct sock *sk;
398 int harderr;
399 int err;
400 struct net *net = dev_net(skb->dev);
401
402 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
403 iph->saddr, uh->source, skb->dev->ifindex, udptable);
404 if (sk == NULL) {
405 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
406 return; /* No socket for error */
407 }
408
409 err = 0;
410 harderr = 0;
411 inet = inet_sk(sk);
412
413 switch (type) {
414 default:
415 case ICMP_TIME_EXCEEDED:
416 err = EHOSTUNREACH;
417 break;
418 case ICMP_SOURCE_QUENCH:
419 goto out;
420 case ICMP_PARAMETERPROB:
421 err = EPROTO;
422 harderr = 1;
423 break;
424 case ICMP_DEST_UNREACH:
425 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
426 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
427 err = EMSGSIZE;
428 harderr = 1;
429 break;
430 }
431 goto out;
432 }
433 err = EHOSTUNREACH;
434 if (code <= NR_ICMP_UNREACH) {
435 harderr = icmp_err_convert[code].fatal;
436 err = icmp_err_convert[code].errno;
437 }
438 break;
439 }
440
441 /*
442 * RFC1122: OK. Passes ICMP errors back to application, as per
443 * 4.1.3.3.
444 */
445 if (!inet->recverr) {
446 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
447 goto out;
448 } else {
449 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
450 }
451 sk->sk_err = err;
452 sk->sk_error_report(sk);
453 out:
454 sock_put(sk);
455 }
456
457 void udp_err(struct sk_buff *skb, u32 info)
458 {
459 __udp4_lib_err(skb, info, &udp_table);
460 }
461
462 /*
463 * Throw away all pending data and cancel the corking. Socket is locked.
464 */
465 void udp_flush_pending_frames(struct sock *sk)
466 {
467 struct udp_sock *up = udp_sk(sk);
468
469 if (up->pending) {
470 up->len = 0;
471 up->pending = 0;
472 ip_flush_pending_frames(sk);
473 }
474 }
475 EXPORT_SYMBOL(udp_flush_pending_frames);
476
477 /**
478 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
479 * @sk: socket we are sending on
480 * @skb: sk_buff containing the filled-in UDP header
481 * (checksum field must be zeroed out)
482 */
483 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
484 __be32 src, __be32 dst, int len)
485 {
486 unsigned int offset;
487 struct udphdr *uh = udp_hdr(skb);
488 __wsum csum = 0;
489
490 if (skb_queue_len(&sk->sk_write_queue) == 1) {
491 /*
492 * Only one fragment on the socket.
493 */
494 skb->csum_start = skb_transport_header(skb) - skb->head;
495 skb->csum_offset = offsetof(struct udphdr, check);
496 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
497 } else {
498 /*
499 * HW-checksum won't work as there are two or more
500 * fragments on the socket so that all csums of sk_buffs
501 * should be together
502 */
503 offset = skb_transport_offset(skb);
504 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
505
506 skb->ip_summed = CHECKSUM_NONE;
507
508 skb_queue_walk(&sk->sk_write_queue, skb) {
509 csum = csum_add(csum, skb->csum);
510 }
511
512 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
513 if (uh->check == 0)
514 uh->check = CSUM_MANGLED_0;
515 }
516 }
517
518 /*
519 * Push out all pending data as one UDP datagram. Socket is locked.
520 */
521 static int udp_push_pending_frames(struct sock *sk)
522 {
523 struct udp_sock *up = udp_sk(sk);
524 struct inet_sock *inet = inet_sk(sk);
525 struct flowi *fl = &inet->cork.fl;
526 struct sk_buff *skb;
527 struct udphdr *uh;
528 int err = 0;
529 int is_udplite = IS_UDPLITE(sk);
530 __wsum csum = 0;
531
532 /* Grab the skbuff where UDP header space exists. */
533 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
534 goto out;
535
536 /*
537 * Create a UDP header
538 */
539 uh = udp_hdr(skb);
540 uh->source = fl->fl_ip_sport;
541 uh->dest = fl->fl_ip_dport;
542 uh->len = htons(up->len);
543 uh->check = 0;
544
545 if (is_udplite) /* UDP-Lite */
546 csum = udplite_csum_outgoing(sk, skb);
547
548 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
549
550 skb->ip_summed = CHECKSUM_NONE;
551 goto send;
552
553 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
554
555 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
556 goto send;
557
558 } else /* `normal' UDP */
559 csum = udp_csum_outgoing(sk, skb);
560
561 /* add protocol-dependent pseudo-header */
562 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
563 sk->sk_protocol, csum);
564 if (uh->check == 0)
565 uh->check = CSUM_MANGLED_0;
566
567 send:
568 err = ip_push_pending_frames(sk);
569 if (err) {
570 if (err == -ENOBUFS && !inet->recverr) {
571 UDP_INC_STATS_USER(sock_net(sk),
572 UDP_MIB_SNDBUFERRORS, is_udplite);
573 err = 0;
574 }
575 } else
576 UDP_INC_STATS_USER(sock_net(sk),
577 UDP_MIB_OUTDATAGRAMS, is_udplite);
578 out:
579 up->len = 0;
580 up->pending = 0;
581 return err;
582 }
583
584 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
585 size_t len)
586 {
587 struct inet_sock *inet = inet_sk(sk);
588 struct udp_sock *up = udp_sk(sk);
589 int ulen = len;
590 struct ipcm_cookie ipc;
591 struct rtable *rt = NULL;
592 int free = 0;
593 int connected = 0;
594 __be32 daddr, faddr, saddr;
595 __be16 dport;
596 u8 tos;
597 int err, is_udplite = IS_UDPLITE(sk);
598 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
599 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
600
601 if (len > 0xFFFF)
602 return -EMSGSIZE;
603
604 /*
605 * Check the flags.
606 */
607
608 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
609 return -EOPNOTSUPP;
610
611 ipc.opt = NULL;
612 ipc.shtx.flags = 0;
613
614 if (up->pending) {
615 /*
616 * There are pending frames.
617 * The socket lock must be held while it's corked.
618 */
619 lock_sock(sk);
620 if (likely(up->pending)) {
621 if (unlikely(up->pending != AF_INET)) {
622 release_sock(sk);
623 return -EINVAL;
624 }
625 goto do_append_data;
626 }
627 release_sock(sk);
628 }
629 ulen += sizeof(struct udphdr);
630
631 /*
632 * Get and verify the address.
633 */
634 if (msg->msg_name) {
635 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
636 if (msg->msg_namelen < sizeof(*usin))
637 return -EINVAL;
638 if (usin->sin_family != AF_INET) {
639 if (usin->sin_family != AF_UNSPEC)
640 return -EAFNOSUPPORT;
641 }
642
643 daddr = usin->sin_addr.s_addr;
644 dport = usin->sin_port;
645 if (dport == 0)
646 return -EINVAL;
647 } else {
648 if (sk->sk_state != TCP_ESTABLISHED)
649 return -EDESTADDRREQ;
650 daddr = inet->inet_daddr;
651 dport = inet->inet_dport;
652 /* Open fast path for connected socket.
653 Route will not be used, if at least one option is set.
654 */
655 connected = 1;
656 }
657 ipc.addr = inet->inet_saddr;
658
659 ipc.oif = sk->sk_bound_dev_if;
660 err = sock_tx_timestamp(msg, sk, &ipc.shtx);
661 if (err)
662 return err;
663 if (msg->msg_controllen) {
664 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
665 if (err)
666 return err;
667 if (ipc.opt)
668 free = 1;
669 connected = 0;
670 }
671 if (!ipc.opt)
672 ipc.opt = inet->opt;
673
674 saddr = ipc.addr;
675 ipc.addr = faddr = daddr;
676
677 if (ipc.opt && ipc.opt->srr) {
678 if (!daddr)
679 return -EINVAL;
680 faddr = ipc.opt->faddr;
681 connected = 0;
682 }
683 tos = RT_TOS(inet->tos);
684 if (sock_flag(sk, SOCK_LOCALROUTE) ||
685 (msg->msg_flags & MSG_DONTROUTE) ||
686 (ipc.opt && ipc.opt->is_strictroute)) {
687 tos |= RTO_ONLINK;
688 connected = 0;
689 }
690
691 if (ipv4_is_multicast(daddr)) {
692 if (!ipc.oif)
693 ipc.oif = inet->mc_index;
694 if (!saddr)
695 saddr = inet->mc_addr;
696 connected = 0;
697 }
698
699 if (connected)
700 rt = (struct rtable *)sk_dst_check(sk, 0);
701
702 if (rt == NULL) {
703 struct flowi fl = { .oif = ipc.oif,
704 .mark = sk->sk_mark,
705 .nl_u = { .ip4_u =
706 { .daddr = faddr,
707 .saddr = saddr,
708 .tos = tos } },
709 .proto = sk->sk_protocol,
710 .flags = inet_sk_flowi_flags(sk),
711 .uli_u = { .ports =
712 { .sport = inet->inet_sport,
713 .dport = dport } } };
714 struct net *net = sock_net(sk);
715
716 security_sk_classify_flow(sk, &fl);
717 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
718 if (err) {
719 if (err == -ENETUNREACH)
720 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
721 goto out;
722 }
723
724 err = -EACCES;
725 if ((rt->rt_flags & RTCF_BROADCAST) &&
726 !sock_flag(sk, SOCK_BROADCAST))
727 goto out;
728 if (connected)
729 sk_dst_set(sk, dst_clone(&rt->u.dst));
730 }
731
732 if (msg->msg_flags&MSG_CONFIRM)
733 goto do_confirm;
734 back_from_confirm:
735
736 saddr = rt->rt_src;
737 if (!ipc.addr)
738 daddr = ipc.addr = rt->rt_dst;
739
740 lock_sock(sk);
741 if (unlikely(up->pending)) {
742 /* The socket is already corked while preparing it. */
743 /* ... which is an evident application bug. --ANK */
744 release_sock(sk);
745
746 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
747 err = -EINVAL;
748 goto out;
749 }
750 /*
751 * Now cork the socket to pend data.
752 */
753 inet->cork.fl.fl4_dst = daddr;
754 inet->cork.fl.fl_ip_dport = dport;
755 inet->cork.fl.fl4_src = saddr;
756 inet->cork.fl.fl_ip_sport = inet->inet_sport;
757 up->pending = AF_INET;
758
759 do_append_data:
760 up->len += ulen;
761 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
762 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
763 sizeof(struct udphdr), &ipc, &rt,
764 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
765 if (err)
766 udp_flush_pending_frames(sk);
767 else if (!corkreq)
768 err = udp_push_pending_frames(sk);
769 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
770 up->pending = 0;
771 release_sock(sk);
772
773 out:
774 ip_rt_put(rt);
775 if (free)
776 kfree(ipc.opt);
777 if (!err)
778 return len;
779 /*
780 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
781 * ENOBUFS might not be good (it's not tunable per se), but otherwise
782 * we don't have a good statistic (IpOutDiscards but it can be too many
783 * things). We could add another new stat but at least for now that
784 * seems like overkill.
785 */
786 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
787 UDP_INC_STATS_USER(sock_net(sk),
788 UDP_MIB_SNDBUFERRORS, is_udplite);
789 }
790 return err;
791
792 do_confirm:
793 dst_confirm(&rt->u.dst);
794 if (!(msg->msg_flags&MSG_PROBE) || len)
795 goto back_from_confirm;
796 err = 0;
797 goto out;
798 }
799 EXPORT_SYMBOL(udp_sendmsg);
800
801 int udp_sendpage(struct sock *sk, struct page *page, int offset,
802 size_t size, int flags)
803 {
804 struct udp_sock *up = udp_sk(sk);
805 int ret;
806
807 if (!up->pending) {
808 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
809
810 /* Call udp_sendmsg to specify destination address which
811 * sendpage interface can't pass.
812 * This will succeed only when the socket is connected.
813 */
814 ret = udp_sendmsg(NULL, sk, &msg, 0);
815 if (ret < 0)
816 return ret;
817 }
818
819 lock_sock(sk);
820
821 if (unlikely(!up->pending)) {
822 release_sock(sk);
823
824 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
825 return -EINVAL;
826 }
827
828 ret = ip_append_page(sk, page, offset, size, flags);
829 if (ret == -EOPNOTSUPP) {
830 release_sock(sk);
831 return sock_no_sendpage(sk->sk_socket, page, offset,
832 size, flags);
833 }
834 if (ret < 0) {
835 udp_flush_pending_frames(sk);
836 goto out;
837 }
838
839 up->len += size;
840 if (!(up->corkflag || (flags&MSG_MORE)))
841 ret = udp_push_pending_frames(sk);
842 if (!ret)
843 ret = size;
844 out:
845 release_sock(sk);
846 return ret;
847 }
848
849
850 /**
851 * first_packet_length - return length of first packet in receive queue
852 * @sk: socket
853 *
854 * Drops all bad checksum frames, until a valid one is found.
855 * Returns the length of found skb, or 0 if none is found.
856 */
857 static unsigned int first_packet_length(struct sock *sk)
858 {
859 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
860 struct sk_buff *skb;
861 unsigned int res;
862
863 __skb_queue_head_init(&list_kill);
864
865 spin_lock_bh(&rcvq->lock);
866 while ((skb = skb_peek(rcvq)) != NULL &&
867 udp_lib_checksum_complete(skb)) {
868 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
869 IS_UDPLITE(sk));
870 atomic_inc(&sk->sk_drops);
871 __skb_unlink(skb, rcvq);
872 __skb_queue_tail(&list_kill, skb);
873 }
874 res = skb ? skb->len : 0;
875 spin_unlock_bh(&rcvq->lock);
876
877 if (!skb_queue_empty(&list_kill)) {
878 lock_sock(sk);
879 __skb_queue_purge(&list_kill);
880 sk_mem_reclaim_partial(sk);
881 release_sock(sk);
882 }
883 return res;
884 }
885
886 /*
887 * IOCTL requests applicable to the UDP protocol
888 */
889
890 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
891 {
892 switch (cmd) {
893 case SIOCOUTQ:
894 {
895 int amount = sk_wmem_alloc_get(sk);
896
897 return put_user(amount, (int __user *)arg);
898 }
899
900 case SIOCINQ:
901 {
902 unsigned int amount = first_packet_length(sk);
903
904 if (amount)
905 /*
906 * We will only return the amount
907 * of this packet since that is all
908 * that will be read.
909 */
910 amount -= sizeof(struct udphdr);
911
912 return put_user(amount, (int __user *)arg);
913 }
914
915 default:
916 return -ENOIOCTLCMD;
917 }
918
919 return 0;
920 }
921 EXPORT_SYMBOL(udp_ioctl);
922
923 /*
924 * This should be easy, if there is something there we
925 * return it, otherwise we block.
926 */
927
928 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
929 size_t len, int noblock, int flags, int *addr_len)
930 {
931 struct inet_sock *inet = inet_sk(sk);
932 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
933 struct sk_buff *skb;
934 unsigned int ulen, copied;
935 int peeked;
936 int err;
937 int is_udplite = IS_UDPLITE(sk);
938
939 /*
940 * Check any passed addresses
941 */
942 if (addr_len)
943 *addr_len = sizeof(*sin);
944
945 if (flags & MSG_ERRQUEUE)
946 return ip_recv_error(sk, msg, len);
947
948 try_again:
949 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
950 &peeked, &err);
951 if (!skb)
952 goto out;
953
954 ulen = skb->len - sizeof(struct udphdr);
955 copied = len;
956 if (copied > ulen)
957 copied = ulen;
958 else if (copied < ulen)
959 msg->msg_flags |= MSG_TRUNC;
960
961 /*
962 * If checksum is needed at all, try to do it while copying the
963 * data. If the data is truncated, or if we only want a partial
964 * coverage checksum (UDP-Lite), do it before the copy.
965 */
966
967 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
968 if (udp_lib_checksum_complete(skb))
969 goto csum_copy_err;
970 }
971
972 if (skb_csum_unnecessary(skb))
973 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
974 msg->msg_iov, copied);
975 else {
976 err = skb_copy_and_csum_datagram_iovec(skb,
977 sizeof(struct udphdr),
978 msg->msg_iov);
979
980 if (err == -EINVAL)
981 goto csum_copy_err;
982 }
983
984 if (err)
985 goto out_free;
986
987 if (!peeked)
988 UDP_INC_STATS_USER(sock_net(sk),
989 UDP_MIB_INDATAGRAMS, is_udplite);
990
991 sock_recv_ts_and_drops(msg, sk, skb);
992
993 /* Copy the address. */
994 if (sin) {
995 sin->sin_family = AF_INET;
996 sin->sin_port = udp_hdr(skb)->source;
997 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
998 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
999 }
1000 if (inet->cmsg_flags)
1001 ip_cmsg_recv(msg, skb);
1002
1003 err = copied;
1004 if (flags & MSG_TRUNC)
1005 err = ulen;
1006
1007 out_free:
1008 skb_free_datagram_locked(sk, skb);
1009 out:
1010 return err;
1011
1012 csum_copy_err:
1013 lock_sock(sk);
1014 if (!skb_kill_datagram(sk, skb, flags))
1015 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1016 release_sock(sk);
1017
1018 if (noblock)
1019 return -EAGAIN;
1020 goto try_again;
1021 }
1022
1023
1024 int udp_disconnect(struct sock *sk, int flags)
1025 {
1026 struct inet_sock *inet = inet_sk(sk);
1027 /*
1028 * 1003.1g - break association.
1029 */
1030
1031 sk->sk_state = TCP_CLOSE;
1032 inet->inet_daddr = 0;
1033 inet->inet_dport = 0;
1034 sk->sk_bound_dev_if = 0;
1035 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1036 inet_reset_saddr(sk);
1037
1038 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1039 sk->sk_prot->unhash(sk);
1040 inet->inet_sport = 0;
1041 }
1042 sk_dst_reset(sk);
1043 return 0;
1044 }
1045 EXPORT_SYMBOL(udp_disconnect);
1046
1047 void udp_lib_unhash(struct sock *sk)
1048 {
1049 if (sk_hashed(sk)) {
1050 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1051 struct udp_hslot *hslot = udp_hashslot(udptable, sock_net(sk),
1052 sk->sk_hash);
1053
1054 spin_lock_bh(&hslot->lock);
1055 if (sk_nulls_del_node_init_rcu(sk)) {
1056 inet_sk(sk)->inet_num = 0;
1057 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1058 }
1059 spin_unlock_bh(&hslot->lock);
1060 }
1061 }
1062 EXPORT_SYMBOL(udp_lib_unhash);
1063
1064 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1065 {
1066 int rc = sock_queue_rcv_skb(sk, skb);
1067
1068 if (rc < 0) {
1069 int is_udplite = IS_UDPLITE(sk);
1070
1071 /* Note that an ENOMEM error is charged twice */
1072 if (rc == -ENOMEM)
1073 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1074 is_udplite);
1075 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1076 kfree_skb(skb);
1077 return -1;
1078 }
1079
1080 return 0;
1081
1082 }
1083
1084 /* returns:
1085 * -1: error
1086 * 0: success
1087 * >0: "udp encap" protocol resubmission
1088 *
1089 * Note that in the success and error cases, the skb is assumed to
1090 * have either been requeued or freed.
1091 */
1092 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1093 {
1094 struct udp_sock *up = udp_sk(sk);
1095 int rc;
1096 int is_udplite = IS_UDPLITE(sk);
1097
1098 /*
1099 * Charge it to the socket, dropping if the queue is full.
1100 */
1101 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1102 goto drop;
1103 nf_reset(skb);
1104
1105 if (up->encap_type) {
1106 /*
1107 * This is an encapsulation socket so pass the skb to
1108 * the socket's udp_encap_rcv() hook. Otherwise, just
1109 * fall through and pass this up the UDP socket.
1110 * up->encap_rcv() returns the following value:
1111 * =0 if skb was successfully passed to the encap
1112 * handler or was discarded by it.
1113 * >0 if skb should be passed on to UDP.
1114 * <0 if skb should be resubmitted as proto -N
1115 */
1116
1117 /* if we're overly short, let UDP handle it */
1118 if (skb->len > sizeof(struct udphdr) &&
1119 up->encap_rcv != NULL) {
1120 int ret;
1121
1122 ret = (*up->encap_rcv)(sk, skb);
1123 if (ret <= 0) {
1124 UDP_INC_STATS_BH(sock_net(sk),
1125 UDP_MIB_INDATAGRAMS,
1126 is_udplite);
1127 return -ret;
1128 }
1129 }
1130
1131 /* FALLTHROUGH -- it's a UDP Packet */
1132 }
1133
1134 /*
1135 * UDP-Lite specific tests, ignored on UDP sockets
1136 */
1137 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1138
1139 /*
1140 * MIB statistics other than incrementing the error count are
1141 * disabled for the following two types of errors: these depend
1142 * on the application settings, not on the functioning of the
1143 * protocol stack as such.
1144 *
1145 * RFC 3828 here recommends (sec 3.3): "There should also be a
1146 * way ... to ... at least let the receiving application block
1147 * delivery of packets with coverage values less than a value
1148 * provided by the application."
1149 */
1150 if (up->pcrlen == 0) { /* full coverage was set */
1151 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1152 "%d while full coverage %d requested\n",
1153 UDP_SKB_CB(skb)->cscov, skb->len);
1154 goto drop;
1155 }
1156 /* The next case involves violating the min. coverage requested
1157 * by the receiver. This is subtle: if receiver wants x and x is
1158 * greater than the buffersize/MTU then receiver will complain
1159 * that it wants x while sender emits packets of smaller size y.
1160 * Therefore the above ...()->partial_cov statement is essential.
1161 */
1162 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1163 LIMIT_NETDEBUG(KERN_WARNING
1164 "UDPLITE: coverage %d too small, need min %d\n",
1165 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1166 goto drop;
1167 }
1168 }
1169
1170 if (sk->sk_filter) {
1171 if (udp_lib_checksum_complete(skb))
1172 goto drop;
1173 }
1174
1175 rc = 0;
1176
1177 bh_lock_sock(sk);
1178 if (!sock_owned_by_user(sk))
1179 rc = __udp_queue_rcv_skb(sk, skb);
1180 else
1181 sk_add_backlog(sk, skb);
1182 bh_unlock_sock(sk);
1183
1184 return rc;
1185
1186 drop:
1187 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1188 atomic_inc(&sk->sk_drops);
1189 kfree_skb(skb);
1190 return -1;
1191 }
1192
1193 /*
1194 * Multicasts and broadcasts go to each listener.
1195 *
1196 * Note: called only from the BH handler context,
1197 * so we don't need to lock the hashes.
1198 */
1199 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1200 struct udphdr *uh,
1201 __be32 saddr, __be32 daddr,
1202 struct udp_table *udptable)
1203 {
1204 struct sock *sk;
1205 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1206 int dif;
1207
1208 spin_lock(&hslot->lock);
1209 sk = sk_nulls_head(&hslot->head);
1210 dif = skb->dev->ifindex;
1211 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1212 if (sk) {
1213 struct sock *sknext = NULL;
1214
1215 do {
1216 struct sk_buff *skb1 = skb;
1217
1218 sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1219 daddr, uh->source, saddr,
1220 dif);
1221 if (sknext)
1222 skb1 = skb_clone(skb, GFP_ATOMIC);
1223
1224 if (skb1) {
1225 int ret = udp_queue_rcv_skb(sk, skb1);
1226 if (ret > 0)
1227 /* we should probably re-process instead
1228 * of dropping packets here. */
1229 kfree_skb(skb1);
1230 }
1231 sk = sknext;
1232 } while (sknext);
1233 } else
1234 consume_skb(skb);
1235 spin_unlock(&hslot->lock);
1236 return 0;
1237 }
1238
1239 /* Initialize UDP checksum. If exited with zero value (success),
1240 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1241 * Otherwise, csum completion requires chacksumming packet body,
1242 * including udp header and folding it to skb->csum.
1243 */
1244 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1245 int proto)
1246 {
1247 const struct iphdr *iph;
1248 int err;
1249
1250 UDP_SKB_CB(skb)->partial_cov = 0;
1251 UDP_SKB_CB(skb)->cscov = skb->len;
1252
1253 if (proto == IPPROTO_UDPLITE) {
1254 err = udplite_checksum_init(skb, uh);
1255 if (err)
1256 return err;
1257 }
1258
1259 iph = ip_hdr(skb);
1260 if (uh->check == 0) {
1261 skb->ip_summed = CHECKSUM_UNNECESSARY;
1262 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1263 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1264 proto, skb->csum))
1265 skb->ip_summed = CHECKSUM_UNNECESSARY;
1266 }
1267 if (!skb_csum_unnecessary(skb))
1268 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1269 skb->len, proto, 0);
1270 /* Probably, we should checksum udp header (it should be in cache
1271 * in any case) and data in tiny packets (< rx copybreak).
1272 */
1273
1274 return 0;
1275 }
1276
1277 /*
1278 * All we need to do is get the socket, and then do a checksum.
1279 */
1280
1281 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1282 int proto)
1283 {
1284 struct sock *sk;
1285 struct udphdr *uh;
1286 unsigned short ulen;
1287 struct rtable *rt = skb_rtable(skb);
1288 __be32 saddr, daddr;
1289 struct net *net = dev_net(skb->dev);
1290
1291 /*
1292 * Validate the packet.
1293 */
1294 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1295 goto drop; /* No space for header. */
1296
1297 uh = udp_hdr(skb);
1298 ulen = ntohs(uh->len);
1299 if (ulen > skb->len)
1300 goto short_packet;
1301
1302 if (proto == IPPROTO_UDP) {
1303 /* UDP validates ulen. */
1304 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1305 goto short_packet;
1306 uh = udp_hdr(skb);
1307 }
1308
1309 if (udp4_csum_init(skb, uh, proto))
1310 goto csum_error;
1311
1312 saddr = ip_hdr(skb)->saddr;
1313 daddr = ip_hdr(skb)->daddr;
1314
1315 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1316 return __udp4_lib_mcast_deliver(net, skb, uh,
1317 saddr, daddr, udptable);
1318
1319 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1320
1321 if (sk != NULL) {
1322 int ret = udp_queue_rcv_skb(sk, skb);
1323 sock_put(sk);
1324
1325 /* a return value > 0 means to resubmit the input, but
1326 * it wants the return to be -protocol, or 0
1327 */
1328 if (ret > 0)
1329 return -ret;
1330 return 0;
1331 }
1332
1333 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1334 goto drop;
1335 nf_reset(skb);
1336
1337 /* No socket. Drop packet silently, if checksum is wrong */
1338 if (udp_lib_checksum_complete(skb))
1339 goto csum_error;
1340
1341 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1342 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1343
1344 /*
1345 * Hmm. We got an UDP packet to a port to which we
1346 * don't wanna listen. Ignore it.
1347 */
1348 kfree_skb(skb);
1349 return 0;
1350
1351 short_packet:
1352 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1353 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1354 &saddr,
1355 ntohs(uh->source),
1356 ulen,
1357 skb->len,
1358 &daddr,
1359 ntohs(uh->dest));
1360 goto drop;
1361
1362 csum_error:
1363 /*
1364 * RFC1122: OK. Discards the bad packet silently (as far as
1365 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1366 */
1367 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1368 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1369 &saddr,
1370 ntohs(uh->source),
1371 &daddr,
1372 ntohs(uh->dest),
1373 ulen);
1374 drop:
1375 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1376 kfree_skb(skb);
1377 return 0;
1378 }
1379
1380 int udp_rcv(struct sk_buff *skb)
1381 {
1382 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1383 }
1384
1385 void udp_destroy_sock(struct sock *sk)
1386 {
1387 lock_sock(sk);
1388 udp_flush_pending_frames(sk);
1389 release_sock(sk);
1390 }
1391
1392 /*
1393 * Socket option code for UDP
1394 */
1395 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1396 char __user *optval, unsigned int optlen,
1397 int (*push_pending_frames)(struct sock *))
1398 {
1399 struct udp_sock *up = udp_sk(sk);
1400 int val;
1401 int err = 0;
1402 int is_udplite = IS_UDPLITE(sk);
1403
1404 if (optlen < sizeof(int))
1405 return -EINVAL;
1406
1407 if (get_user(val, (int __user *)optval))
1408 return -EFAULT;
1409
1410 switch (optname) {
1411 case UDP_CORK:
1412 if (val != 0) {
1413 up->corkflag = 1;
1414 } else {
1415 up->corkflag = 0;
1416 lock_sock(sk);
1417 (*push_pending_frames)(sk);
1418 release_sock(sk);
1419 }
1420 break;
1421
1422 case UDP_ENCAP:
1423 switch (val) {
1424 case 0:
1425 case UDP_ENCAP_ESPINUDP:
1426 case UDP_ENCAP_ESPINUDP_NON_IKE:
1427 up->encap_rcv = xfrm4_udp_encap_rcv;
1428 /* FALLTHROUGH */
1429 case UDP_ENCAP_L2TPINUDP:
1430 up->encap_type = val;
1431 break;
1432 default:
1433 err = -ENOPROTOOPT;
1434 break;
1435 }
1436 break;
1437
1438 /*
1439 * UDP-Lite's partial checksum coverage (RFC 3828).
1440 */
1441 /* The sender sets actual checksum coverage length via this option.
1442 * The case coverage > packet length is handled by send module. */
1443 case UDPLITE_SEND_CSCOV:
1444 if (!is_udplite) /* Disable the option on UDP sockets */
1445 return -ENOPROTOOPT;
1446 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1447 val = 8;
1448 else if (val > USHORT_MAX)
1449 val = USHORT_MAX;
1450 up->pcslen = val;
1451 up->pcflag |= UDPLITE_SEND_CC;
1452 break;
1453
1454 /* The receiver specifies a minimum checksum coverage value. To make
1455 * sense, this should be set to at least 8 (as done below). If zero is
1456 * used, this again means full checksum coverage. */
1457 case UDPLITE_RECV_CSCOV:
1458 if (!is_udplite) /* Disable the option on UDP sockets */
1459 return -ENOPROTOOPT;
1460 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1461 val = 8;
1462 else if (val > USHORT_MAX)
1463 val = USHORT_MAX;
1464 up->pcrlen = val;
1465 up->pcflag |= UDPLITE_RECV_CC;
1466 break;
1467
1468 default:
1469 err = -ENOPROTOOPT;
1470 break;
1471 }
1472
1473 return err;
1474 }
1475 EXPORT_SYMBOL(udp_lib_setsockopt);
1476
1477 int udp_setsockopt(struct sock *sk, int level, int optname,
1478 char __user *optval, unsigned int optlen)
1479 {
1480 if (level == SOL_UDP || level == SOL_UDPLITE)
1481 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1482 udp_push_pending_frames);
1483 return ip_setsockopt(sk, level, optname, optval, optlen);
1484 }
1485
1486 #ifdef CONFIG_COMPAT
1487 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1488 char __user *optval, unsigned int optlen)
1489 {
1490 if (level == SOL_UDP || level == SOL_UDPLITE)
1491 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1492 udp_push_pending_frames);
1493 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1494 }
1495 #endif
1496
1497 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1498 char __user *optval, int __user *optlen)
1499 {
1500 struct udp_sock *up = udp_sk(sk);
1501 int val, len;
1502
1503 if (get_user(len, optlen))
1504 return -EFAULT;
1505
1506 len = min_t(unsigned int, len, sizeof(int));
1507
1508 if (len < 0)
1509 return -EINVAL;
1510
1511 switch (optname) {
1512 case UDP_CORK:
1513 val = up->corkflag;
1514 break;
1515
1516 case UDP_ENCAP:
1517 val = up->encap_type;
1518 break;
1519
1520 /* The following two cannot be changed on UDP sockets, the return is
1521 * always 0 (which corresponds to the full checksum coverage of UDP). */
1522 case UDPLITE_SEND_CSCOV:
1523 val = up->pcslen;
1524 break;
1525
1526 case UDPLITE_RECV_CSCOV:
1527 val = up->pcrlen;
1528 break;
1529
1530 default:
1531 return -ENOPROTOOPT;
1532 }
1533
1534 if (put_user(len, optlen))
1535 return -EFAULT;
1536 if (copy_to_user(optval, &val, len))
1537 return -EFAULT;
1538 return 0;
1539 }
1540 EXPORT_SYMBOL(udp_lib_getsockopt);
1541
1542 int udp_getsockopt(struct sock *sk, int level, int optname,
1543 char __user *optval, int __user *optlen)
1544 {
1545 if (level == SOL_UDP || level == SOL_UDPLITE)
1546 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1547 return ip_getsockopt(sk, level, optname, optval, optlen);
1548 }
1549
1550 #ifdef CONFIG_COMPAT
1551 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1552 char __user *optval, int __user *optlen)
1553 {
1554 if (level == SOL_UDP || level == SOL_UDPLITE)
1555 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1556 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1557 }
1558 #endif
1559 /**
1560 * udp_poll - wait for a UDP event.
1561 * @file - file struct
1562 * @sock - socket
1563 * @wait - poll table
1564 *
1565 * This is same as datagram poll, except for the special case of
1566 * blocking sockets. If application is using a blocking fd
1567 * and a packet with checksum error is in the queue;
1568 * then it could get return from select indicating data available
1569 * but then block when reading it. Add special case code
1570 * to work around these arguably broken applications.
1571 */
1572 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1573 {
1574 unsigned int mask = datagram_poll(file, sock, wait);
1575 struct sock *sk = sock->sk;
1576
1577 /* Check for false positives due to checksum errors */
1578 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1579 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1580 mask &= ~(POLLIN | POLLRDNORM);
1581
1582 return mask;
1583
1584 }
1585 EXPORT_SYMBOL(udp_poll);
1586
1587 struct proto udp_prot = {
1588 .name = "UDP",
1589 .owner = THIS_MODULE,
1590 .close = udp_lib_close,
1591 .connect = ip4_datagram_connect,
1592 .disconnect = udp_disconnect,
1593 .ioctl = udp_ioctl,
1594 .destroy = udp_destroy_sock,
1595 .setsockopt = udp_setsockopt,
1596 .getsockopt = udp_getsockopt,
1597 .sendmsg = udp_sendmsg,
1598 .recvmsg = udp_recvmsg,
1599 .sendpage = udp_sendpage,
1600 .backlog_rcv = __udp_queue_rcv_skb,
1601 .hash = udp_lib_hash,
1602 .unhash = udp_lib_unhash,
1603 .get_port = udp_v4_get_port,
1604 .memory_allocated = &udp_memory_allocated,
1605 .sysctl_mem = sysctl_udp_mem,
1606 .sysctl_wmem = &sysctl_udp_wmem_min,
1607 .sysctl_rmem = &sysctl_udp_rmem_min,
1608 .obj_size = sizeof(struct udp_sock),
1609 .slab_flags = SLAB_DESTROY_BY_RCU,
1610 .h.udp_table = &udp_table,
1611 #ifdef CONFIG_COMPAT
1612 .compat_setsockopt = compat_udp_setsockopt,
1613 .compat_getsockopt = compat_udp_getsockopt,
1614 #endif
1615 };
1616 EXPORT_SYMBOL(udp_prot);
1617
1618 /* ------------------------------------------------------------------------ */
1619 #ifdef CONFIG_PROC_FS
1620
1621 static struct sock *udp_get_first(struct seq_file *seq, int start)
1622 {
1623 struct sock *sk;
1624 struct udp_iter_state *state = seq->private;
1625 struct net *net = seq_file_net(seq);
1626
1627 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1628 ++state->bucket) {
1629 struct hlist_nulls_node *node;
1630 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1631
1632 if (hlist_nulls_empty(&hslot->head))
1633 continue;
1634
1635 spin_lock_bh(&hslot->lock);
1636 sk_nulls_for_each(sk, node, &hslot->head) {
1637 if (!net_eq(sock_net(sk), net))
1638 continue;
1639 if (sk->sk_family == state->family)
1640 goto found;
1641 }
1642 spin_unlock_bh(&hslot->lock);
1643 }
1644 sk = NULL;
1645 found:
1646 return sk;
1647 }
1648
1649 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1650 {
1651 struct udp_iter_state *state = seq->private;
1652 struct net *net = seq_file_net(seq);
1653
1654 do {
1655 sk = sk_nulls_next(sk);
1656 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1657
1658 if (!sk) {
1659 if (state->bucket <= state->udp_table->mask)
1660 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1661 return udp_get_first(seq, state->bucket + 1);
1662 }
1663 return sk;
1664 }
1665
1666 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1667 {
1668 struct sock *sk = udp_get_first(seq, 0);
1669
1670 if (sk)
1671 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1672 --pos;
1673 return pos ? NULL : sk;
1674 }
1675
1676 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1677 {
1678 struct udp_iter_state *state = seq->private;
1679 state->bucket = MAX_UDP_PORTS;
1680
1681 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1682 }
1683
1684 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1685 {
1686 struct sock *sk;
1687
1688 if (v == SEQ_START_TOKEN)
1689 sk = udp_get_idx(seq, 0);
1690 else
1691 sk = udp_get_next(seq, v);
1692
1693 ++*pos;
1694 return sk;
1695 }
1696
1697 static void udp_seq_stop(struct seq_file *seq, void *v)
1698 {
1699 struct udp_iter_state *state = seq->private;
1700
1701 if (state->bucket <= state->udp_table->mask)
1702 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1703 }
1704
1705 static int udp_seq_open(struct inode *inode, struct file *file)
1706 {
1707 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1708 struct udp_iter_state *s;
1709 int err;
1710
1711 err = seq_open_net(inode, file, &afinfo->seq_ops,
1712 sizeof(struct udp_iter_state));
1713 if (err < 0)
1714 return err;
1715
1716 s = ((struct seq_file *)file->private_data)->private;
1717 s->family = afinfo->family;
1718 s->udp_table = afinfo->udp_table;
1719 return err;
1720 }
1721
1722 /* ------------------------------------------------------------------------ */
1723 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1724 {
1725 struct proc_dir_entry *p;
1726 int rc = 0;
1727
1728 afinfo->seq_fops.open = udp_seq_open;
1729 afinfo->seq_fops.read = seq_read;
1730 afinfo->seq_fops.llseek = seq_lseek;
1731 afinfo->seq_fops.release = seq_release_net;
1732
1733 afinfo->seq_ops.start = udp_seq_start;
1734 afinfo->seq_ops.next = udp_seq_next;
1735 afinfo->seq_ops.stop = udp_seq_stop;
1736
1737 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1738 &afinfo->seq_fops, afinfo);
1739 if (!p)
1740 rc = -ENOMEM;
1741 return rc;
1742 }
1743 EXPORT_SYMBOL(udp_proc_register);
1744
1745 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1746 {
1747 proc_net_remove(net, afinfo->name);
1748 }
1749 EXPORT_SYMBOL(udp_proc_unregister);
1750
1751 /* ------------------------------------------------------------------------ */
1752 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1753 int bucket, int *len)
1754 {
1755 struct inet_sock *inet = inet_sk(sp);
1756 __be32 dest = inet->inet_daddr;
1757 __be32 src = inet->inet_rcv_saddr;
1758 __u16 destp = ntohs(inet->inet_dport);
1759 __u16 srcp = ntohs(inet->inet_sport);
1760
1761 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1762 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1763 bucket, src, srcp, dest, destp, sp->sk_state,
1764 sk_wmem_alloc_get(sp),
1765 sk_rmem_alloc_get(sp),
1766 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1767 atomic_read(&sp->sk_refcnt), sp,
1768 atomic_read(&sp->sk_drops), len);
1769 }
1770
1771 int udp4_seq_show(struct seq_file *seq, void *v)
1772 {
1773 if (v == SEQ_START_TOKEN)
1774 seq_printf(seq, "%-127s\n",
1775 " sl local_address rem_address st tx_queue "
1776 "rx_queue tr tm->when retrnsmt uid timeout "
1777 "inode ref pointer drops");
1778 else {
1779 struct udp_iter_state *state = seq->private;
1780 int len;
1781
1782 udp4_format_sock(v, seq, state->bucket, &len);
1783 seq_printf(seq, "%*s\n", 127 - len, "");
1784 }
1785 return 0;
1786 }
1787
1788 /* ------------------------------------------------------------------------ */
1789 static struct udp_seq_afinfo udp4_seq_afinfo = {
1790 .name = "udp",
1791 .family = AF_INET,
1792 .udp_table = &udp_table,
1793 .seq_fops = {
1794 .owner = THIS_MODULE,
1795 },
1796 .seq_ops = {
1797 .show = udp4_seq_show,
1798 },
1799 };
1800
1801 static int udp4_proc_init_net(struct net *net)
1802 {
1803 return udp_proc_register(net, &udp4_seq_afinfo);
1804 }
1805
1806 static void udp4_proc_exit_net(struct net *net)
1807 {
1808 udp_proc_unregister(net, &udp4_seq_afinfo);
1809 }
1810
1811 static struct pernet_operations udp4_net_ops = {
1812 .init = udp4_proc_init_net,
1813 .exit = udp4_proc_exit_net,
1814 };
1815
1816 int __init udp4_proc_init(void)
1817 {
1818 return register_pernet_subsys(&udp4_net_ops);
1819 }
1820
1821 void udp4_proc_exit(void)
1822 {
1823 unregister_pernet_subsys(&udp4_net_ops);
1824 }
1825 #endif /* CONFIG_PROC_FS */
1826
1827 static __initdata unsigned long uhash_entries;
1828 static int __init set_uhash_entries(char *str)
1829 {
1830 if (!str)
1831 return 0;
1832 uhash_entries = simple_strtoul(str, &str, 0);
1833 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
1834 uhash_entries = UDP_HTABLE_SIZE_MIN;
1835 return 1;
1836 }
1837 __setup("uhash_entries=", set_uhash_entries);
1838
1839 void __init udp_table_init(struct udp_table *table, const char *name)
1840 {
1841 unsigned int i;
1842
1843 if (!CONFIG_BASE_SMALL)
1844 table->hash = alloc_large_system_hash(name,
1845 sizeof(struct udp_hslot),
1846 uhash_entries,
1847 21, /* one slot per 2 MB */
1848 0,
1849 &table->log,
1850 &table->mask,
1851 64 * 1024);
1852 /*
1853 * Make sure hash table has the minimum size
1854 */
1855 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
1856 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
1857 sizeof(struct udp_hslot), GFP_KERNEL);
1858 if (!table->hash)
1859 panic(name);
1860 table->log = ilog2(UDP_HTABLE_SIZE_MIN);
1861 table->mask = UDP_HTABLE_SIZE_MIN - 1;
1862 }
1863 for (i = 0; i <= table->mask; i++) {
1864 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
1865 spin_lock_init(&table->hash[i].lock);
1866 }
1867 }
1868
1869 void __init udp_init(void)
1870 {
1871 unsigned long nr_pages, limit;
1872
1873 udp_table_init(&udp_table, "UDP");
1874 /* Set the pressure threshold up by the same strategy of TCP. It is a
1875 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1876 * toward zero with the amount of memory, with a floor of 128 pages.
1877 */
1878 nr_pages = totalram_pages - totalhigh_pages;
1879 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1880 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1881 limit = max(limit, 128UL);
1882 sysctl_udp_mem[0] = limit / 4 * 3;
1883 sysctl_udp_mem[1] = limit;
1884 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1885
1886 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1887 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1888 }
1889
1890 int udp4_ufo_send_check(struct sk_buff *skb)
1891 {
1892 const struct iphdr *iph;
1893 struct udphdr *uh;
1894
1895 if (!pskb_may_pull(skb, sizeof(*uh)))
1896 return -EINVAL;
1897
1898 iph = ip_hdr(skb);
1899 uh = udp_hdr(skb);
1900
1901 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1902 IPPROTO_UDP, 0);
1903 skb->csum_start = skb_transport_header(skb) - skb->head;
1904 skb->csum_offset = offsetof(struct udphdr, check);
1905 skb->ip_summed = CHECKSUM_PARTIAL;
1906 return 0;
1907 }
1908
1909 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
1910 {
1911 struct sk_buff *segs = ERR_PTR(-EINVAL);
1912 unsigned int mss;
1913 int offset;
1914 __wsum csum;
1915
1916 mss = skb_shinfo(skb)->gso_size;
1917 if (unlikely(skb->len <= mss))
1918 goto out;
1919
1920 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1921 /* Packet is from an untrusted source, reset gso_segs. */
1922 int type = skb_shinfo(skb)->gso_type;
1923
1924 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1925 !(type & (SKB_GSO_UDP))))
1926 goto out;
1927
1928 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1929
1930 segs = NULL;
1931 goto out;
1932 }
1933
1934 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1935 * do checksum of UDP packets sent as multiple IP fragments.
1936 */
1937 offset = skb->csum_start - skb_headroom(skb);
1938 csum = skb_checksum(skb, offset, skb->len - offset, 0);
1939 offset += skb->csum_offset;
1940 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
1941 skb->ip_summed = CHECKSUM_NONE;
1942
1943 /* Fragment the skb. IP headers of the fragments are updated in
1944 * inet_gso_segment()
1945 */
1946 segs = skb_segment(skb, features);
1947 out:
1948 return segs;
1949 }
1950
Linux kernel - Deliverables
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