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fuse: no abort on interrupt
[linux-2.6/openmoko-kernel/knife-kernel.git] / net / ipv4 / udp.c
blobcb9fc58efb2f1da00ad4789370be1d1ac07f1fcd
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 * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
13 * Alan Cox, <Alan.Cox@linux.org>
14 * Hirokazu Takahashi, <taka@valinux.co.jp>
15 *
16 * Fixes:
17 * Alan Cox : verify_area() calls
18 * Alan Cox : stopped close while in use off icmp
19 * messages. Not a fix but a botch that
20 * for udp at least is 'valid'.
21 * Alan Cox : Fixed icmp handling properly
22 * Alan Cox : Correct error for oversized datagrams
23 * Alan Cox : Tidied select() semantics.
24 * Alan Cox : udp_err() fixed properly, also now
25 * select and read wake correctly on errors
26 * Alan Cox : udp_send verify_area moved to avoid mem leak
27 * Alan Cox : UDP can count its memory
28 * Alan Cox : send to an unknown connection causes
29 * an ECONNREFUSED off the icmp, but
30 * does NOT close.
31 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
32 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
33 * bug no longer crashes it.
34 * Fred Van Kempen : Net2e support for sk->broadcast.
35 * Alan Cox : Uses skb_free_datagram
36 * Alan Cox : Added get/set sockopt support.
37 * Alan Cox : Broadcasting without option set returns EACCES.
38 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
39 * Alan Cox : Use ip_tos and ip_ttl
40 * Alan Cox : SNMP Mibs
41 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
42 * Matt Dillon : UDP length checks.
43 * Alan Cox : Smarter af_inet used properly.
44 * Alan Cox : Use new kernel side addressing.
45 * Alan Cox : Incorrect return on truncated datagram receive.
46 * Arnt Gulbrandsen : New udp_send and stuff
47 * Alan Cox : Cache last socket
48 * Alan Cox : Route cache
49 * Jon Peatfield : Minor efficiency fix to sendto().
50 * Mike Shaver : RFC1122 checks.
51 * Alan Cox : Nonblocking error fix.
52 * Willy Konynenberg : Transparent proxying support.
53 * Mike McLagan : Routing by source
54 * David S. Miller : New socket lookup architecture.
55 * Last socket cache retained as it
56 * does have a high hit rate.
57 * Olaf Kirch : Don't linearise iovec on sendmsg.
58 * Andi Kleen : Some cleanups, cache destination entry
59 * for connect.
60 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
61 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
62 * return ENOTCONN for unconnected sockets (POSIX)
63 * Janos Farkas : don't deliver multi/broadcasts to a different
64 * bound-to-device socket
65 * Hirokazu Takahashi : HW checksumming for outgoing UDP
66 * datagrams.
67 * Hirokazu Takahashi : sendfile() on UDP works now.
68 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
69 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
70 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
71 * a single port at the same time.
72 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
73 * James Chapman : Add L2TP encapsulation type.
74 *
75 *
76 * This program is free software; you can redistribute it and/or
77 * modify it under the terms of the GNU General Public License
78 * as published by the Free Software Foundation; either version
79 * 2 of the License, or (at your option) any later version.
80 */
81
82 #include <asm/system.h>
83 #include <asm/uaccess.h>
84 #include <asm/ioctls.h>
85 #include <linux/types.h>
86 #include <linux/fcntl.h>
87 #include <linux/module.h>
88 #include <linux/socket.h>
89 #include <linux/sockios.h>
90 #include <linux/igmp.h>
91 #include <linux/in.h>
92 #include <linux/errno.h>
93 #include <linux/timer.h>
94 #include <linux/mm.h>
95 #include <linux/inet.h>
96 #include <linux/netdevice.h>
97 #include <net/tcp_states.h>
98 #include <linux/skbuff.h>
99 #include <linux/proc_fs.h>
100 #include <linux/seq_file.h>
101 #include <net/net_namespace.h>
102 #include <net/icmp.h>
103 #include <net/route.h>
104 #include <net/checksum.h>
105 #include <net/xfrm.h>
106 #include "udp_impl.h"
107
108 /*
109 * Snmp MIB for the UDP layer
110 */
111
112 DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly;
113
114 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
115 DEFINE_RWLOCK(udp_hash_lock);
116
117 static inline int __udp_lib_lport_inuse(__u16 num,
118 const struct hlist_head udptable[])
119 {
120 struct sock *sk;
121 struct hlist_node *node;
122
123 sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
124 if (sk->sk_hash == num)
125 return 1;
126 return 0;
127 }
128
129 /**
130 * __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
131 *
132 * @sk: socket struct in question
133 * @snum: port number to look up
134 * @udptable: hash list table, must be of UDP_HTABLE_SIZE
135 * @saddr_comp: AF-dependent comparison of bound local IP addresses
136 */
137 int __udp_lib_get_port(struct sock *sk, unsigned short snum,
138 struct hlist_head udptable[],
139 int (*saddr_comp)(const struct sock *sk1,
140 const struct sock *sk2 ) )
141 {
142 struct hlist_node *node;
143 struct hlist_head *head;
144 struct sock *sk2;
145 int error = 1;
146
147 write_lock_bh(&udp_hash_lock);
148
149 if (!snum) {
150 int i, low, high;
151 unsigned rover, best, best_size_so_far;
152
153 inet_get_local_port_range(&low, &high);
154
155 best_size_so_far = UINT_MAX;
156 best = rover = net_random() % (high - low) + low;
157
158 /* 1st pass: look for empty (or shortest) hash chain */
159 for (i = 0; i < UDP_HTABLE_SIZE; i++) {
160 int size = 0;
161
162 head = &udptable[rover & (UDP_HTABLE_SIZE - 1)];
163 if (hlist_empty(head))
164 goto gotit;
165
166 sk_for_each(sk2, node, head) {
167 if (++size >= best_size_so_far)
168 goto next;
169 }
170 best_size_so_far = size;
171 best = rover;
172 next:
173 /* fold back if end of range */
174 if (++rover > high)
175 rover = low + ((rover - low)
176 & (UDP_HTABLE_SIZE - 1));
177
178
179 }
180
181 /* 2nd pass: find hole in shortest hash chain */
182 rover = best;
183 for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) {
184 if (! __udp_lib_lport_inuse(rover, udptable))
185 goto gotit;
186 rover += UDP_HTABLE_SIZE;
187 if (rover > high)
188 rover = low + ((rover - low)
189 & (UDP_HTABLE_SIZE - 1));
190 }
191
192
193 /* All ports in use! */
194 goto fail;
195
196 gotit:
197 snum = rover;
198 } else {
199 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
200
201 sk_for_each(sk2, node, head)
202 if (sk2->sk_hash == snum &&
203 sk2 != sk &&
204 (!sk2->sk_reuse || !sk->sk_reuse) &&
205 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
206 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
207 (*saddr_comp)(sk, sk2) )
208 goto fail;
209 }
210
211 inet_sk(sk)->num = snum;
212 sk->sk_hash = snum;
213 if (sk_unhashed(sk)) {
214 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
215 sk_add_node(sk, head);
216 sock_prot_inc_use(sk->sk_prot);
217 }
218 error = 0;
219 fail:
220 write_unlock_bh(&udp_hash_lock);
221 return error;
222 }
223
224 int udp_get_port(struct sock *sk, unsigned short snum,
225 int (*scmp)(const struct sock *, const struct sock *))
226 {
227 return __udp_lib_get_port(sk, snum, udp_hash, scmp);
228 }
229
230 int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
231 {
232 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
233
234 return ( !ipv6_only_sock(sk2) &&
235 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
236 inet1->rcv_saddr == inet2->rcv_saddr ));
237 }
238
239 static inline int udp_v4_get_port(struct sock *sk, unsigned short snum)
240 {
241 return udp_get_port(sk, snum, ipv4_rcv_saddr_equal);
242 }
243
244 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
245 * harder than this. -DaveM
246 */
247 static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
248 __be32 daddr, __be16 dport,
249 int dif, struct hlist_head udptable[])
250 {
251 struct sock *sk, *result = NULL;
252 struct hlist_node *node;
253 unsigned short hnum = ntohs(dport);
254 int badness = -1;
255
256 read_lock(&udp_hash_lock);
257 sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
258 struct inet_sock *inet = inet_sk(sk);
259
260 if (sk->sk_hash == hnum && !ipv6_only_sock(sk)) {
261 int score = (sk->sk_family == PF_INET ? 1 : 0);
262 if (inet->rcv_saddr) {
263 if (inet->rcv_saddr != daddr)
264 continue;
265 score+=2;
266 }
267 if (inet->daddr) {
268 if (inet->daddr != saddr)
269 continue;
270 score+=2;
271 }
272 if (inet->dport) {
273 if (inet->dport != sport)
274 continue;
275 score+=2;
276 }
277 if (sk->sk_bound_dev_if) {
278 if (sk->sk_bound_dev_if != dif)
279 continue;
280 score+=2;
281 }
282 if (score == 9) {
283 result = sk;
284 break;
285 } else if (score > badness) {
286 result = sk;
287 badness = score;
288 }
289 }
290 }
291 if (result)
292 sock_hold(result);
293 read_unlock(&udp_hash_lock);
294 return result;
295 }
296
297 static inline struct sock *udp_v4_mcast_next(struct sock *sk,
298 __be16 loc_port, __be32 loc_addr,
299 __be16 rmt_port, __be32 rmt_addr,
300 int dif)
301 {
302 struct hlist_node *node;
303 struct sock *s = sk;
304 unsigned short hnum = ntohs(loc_port);
305
306 sk_for_each_from(s, node) {
307 struct inet_sock *inet = inet_sk(s);
308
309 if (s->sk_hash != hnum ||
310 (inet->daddr && inet->daddr != rmt_addr) ||
311 (inet->dport != rmt_port && inet->dport) ||
312 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
313 ipv6_only_sock(s) ||
314 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
315 continue;
316 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
317 continue;
318 goto found;
319 }
320 s = NULL;
321 found:
322 return s;
323 }
324
325 /*
326 * This routine is called by the ICMP module when it gets some
327 * sort of error condition. If err < 0 then the socket should
328 * be closed and the error returned to the user. If err > 0
329 * it's just the icmp type << 8 | icmp code.
330 * Header points to the ip header of the error packet. We move
331 * on past this. Then (as it used to claim before adjustment)
332 * header points to the first 8 bytes of the udp header. We need
333 * to find the appropriate port.
334 */
335
336 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
337 {
338 struct inet_sock *inet;
339 struct iphdr *iph = (struct iphdr*)skb->data;
340 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
341 const int type = icmp_hdr(skb)->type;
342 const int code = icmp_hdr(skb)->code;
343 struct sock *sk;
344 int harderr;
345 int err;
346
347 sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
348 skb->dev->ifindex, udptable );
349 if (sk == NULL) {
350 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
351 return; /* No socket for error */
352 }
353
354 err = 0;
355 harderr = 0;
356 inet = inet_sk(sk);
357
358 switch (type) {
359 default:
360 case ICMP_TIME_EXCEEDED:
361 err = EHOSTUNREACH;
362 break;
363 case ICMP_SOURCE_QUENCH:
364 goto out;
365 case ICMP_PARAMETERPROB:
366 err = EPROTO;
367 harderr = 1;
368 break;
369 case ICMP_DEST_UNREACH:
370 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
371 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
372 err = EMSGSIZE;
373 harderr = 1;
374 break;
375 }
376 goto out;
377 }
378 err = EHOSTUNREACH;
379 if (code <= NR_ICMP_UNREACH) {
380 harderr = icmp_err_convert[code].fatal;
381 err = icmp_err_convert[code].errno;
382 }
383 break;
384 }
385
386 /*
387 * RFC1122: OK. Passes ICMP errors back to application, as per
388 * 4.1.3.3.
389 */
390 if (!inet->recverr) {
391 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
392 goto out;
393 } else {
394 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
395 }
396 sk->sk_err = err;
397 sk->sk_error_report(sk);
398 out:
399 sock_put(sk);
400 }
401
402 void udp_err(struct sk_buff *skb, u32 info)
403 {
404 return __udp4_lib_err(skb, info, udp_hash);
405 }
406
407 /*
408 * Throw away all pending data and cancel the corking. Socket is locked.
409 */
410 static void udp_flush_pending_frames(struct sock *sk)
411 {
412 struct udp_sock *up = udp_sk(sk);
413
414 if (up->pending) {
415 up->len = 0;
416 up->pending = 0;
417 ip_flush_pending_frames(sk);
418 }
419 }
420
421 /**
422 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
423 * @sk: socket we are sending on
424 * @skb: sk_buff containing the filled-in UDP header
425 * (checksum field must be zeroed out)
426 */
427 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
428 __be32 src, __be32 dst, int len )
429 {
430 unsigned int offset;
431 struct udphdr *uh = udp_hdr(skb);
432 __wsum csum = 0;
433
434 if (skb_queue_len(&sk->sk_write_queue) == 1) {
435 /*
436 * Only one fragment on the socket.
437 */
438 skb->csum_start = skb_transport_header(skb) - skb->head;
439 skb->csum_offset = offsetof(struct udphdr, check);
440 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
441 } else {
442 /*
443 * HW-checksum won't work as there are two or more
444 * fragments on the socket so that all csums of sk_buffs
445 * should be together
446 */
447 offset = skb_transport_offset(skb);
448 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
449
450 skb->ip_summed = CHECKSUM_NONE;
451
452 skb_queue_walk(&sk->sk_write_queue, skb) {
453 csum = csum_add(csum, skb->csum);
454 }
455
456 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
457 if (uh->check == 0)
458 uh->check = CSUM_MANGLED_0;
459 }
460 }
461
462 /*
463 * Push out all pending data as one UDP datagram. Socket is locked.
464 */
465 static int udp_push_pending_frames(struct sock *sk)
466 {
467 struct udp_sock *up = udp_sk(sk);
468 struct inet_sock *inet = inet_sk(sk);
469 struct flowi *fl = &inet->cork.fl;
470 struct sk_buff *skb;
471 struct udphdr *uh;
472 int err = 0;
473 __wsum csum = 0;
474
475 /* Grab the skbuff where UDP header space exists. */
476 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
477 goto out;
478
479 /*
480 * Create a UDP header
481 */
482 uh = udp_hdr(skb);
483 uh->source = fl->fl_ip_sport;
484 uh->dest = fl->fl_ip_dport;
485 uh->len = htons(up->len);
486 uh->check = 0;
487
488 if (up->pcflag) /* UDP-Lite */
489 csum = udplite_csum_outgoing(sk, skb);
490
491 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
492
493 skb->ip_summed = CHECKSUM_NONE;
494 goto send;
495
496 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
497
498 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
499 goto send;
500
501 } else /* `normal' UDP */
502 csum = udp_csum_outgoing(sk, skb);
503
504 /* add protocol-dependent pseudo-header */
505 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
506 sk->sk_protocol, csum );
507 if (uh->check == 0)
508 uh->check = CSUM_MANGLED_0;
509
510 send:
511 err = ip_push_pending_frames(sk);
512 out:
513 up->len = 0;
514 up->pending = 0;
515 if (!err)
516 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, up->pcflag);
517 return err;
518 }
519
520 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
521 size_t len)
522 {
523 struct inet_sock *inet = inet_sk(sk);
524 struct udp_sock *up = udp_sk(sk);
525 int ulen = len;
526 struct ipcm_cookie ipc;
527 struct rtable *rt = NULL;
528 int free = 0;
529 int connected = 0;
530 __be32 daddr, faddr, saddr;
531 __be16 dport;
532 u8 tos;
533 int err, is_udplite = up->pcflag;
534 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
535 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
536
537 if (len > 0xFFFF)
538 return -EMSGSIZE;
539
540 /*
541 * Check the flags.
542 */
543
544 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */
545 return -EOPNOTSUPP;
546
547 ipc.opt = NULL;
548
549 if (up->pending) {
550 /*
551 * There are pending frames.
552 * The socket lock must be held while it's corked.
553 */
554 lock_sock(sk);
555 if (likely(up->pending)) {
556 if (unlikely(up->pending != AF_INET)) {
557 release_sock(sk);
558 return -EINVAL;
559 }
560 goto do_append_data;
561 }
562 release_sock(sk);
563 }
564 ulen += sizeof(struct udphdr);
565
566 /*
567 * Get and verify the address.
568 */
569 if (msg->msg_name) {
570 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
571 if (msg->msg_namelen < sizeof(*usin))
572 return -EINVAL;
573 if (usin->sin_family != AF_INET) {
574 if (usin->sin_family != AF_UNSPEC)
575 return -EAFNOSUPPORT;
576 }
577
578 daddr = usin->sin_addr.s_addr;
579 dport = usin->sin_port;
580 if (dport == 0)
581 return -EINVAL;
582 } else {
583 if (sk->sk_state != TCP_ESTABLISHED)
584 return -EDESTADDRREQ;
585 daddr = inet->daddr;
586 dport = inet->dport;
587 /* Open fast path for connected socket.
588 Route will not be used, if at least one option is set.
589 */
590 connected = 1;
591 }
592 ipc.addr = inet->saddr;
593
594 ipc.oif = sk->sk_bound_dev_if;
595 if (msg->msg_controllen) {
596 err = ip_cmsg_send(msg, &ipc);
597 if (err)
598 return err;
599 if (ipc.opt)
600 free = 1;
601 connected = 0;
602 }
603 if (!ipc.opt)
604 ipc.opt = inet->opt;
605
606 saddr = ipc.addr;
607 ipc.addr = faddr = daddr;
608
609 if (ipc.opt && ipc.opt->srr) {
610 if (!daddr)
611 return -EINVAL;
612 faddr = ipc.opt->faddr;
613 connected = 0;
614 }
615 tos = RT_TOS(inet->tos);
616 if (sock_flag(sk, SOCK_LOCALROUTE) ||
617 (msg->msg_flags & MSG_DONTROUTE) ||
618 (ipc.opt && ipc.opt->is_strictroute)) {
619 tos |= RTO_ONLINK;
620 connected = 0;
621 }
622
623 if (MULTICAST(daddr)) {
624 if (!ipc.oif)
625 ipc.oif = inet->mc_index;
626 if (!saddr)
627 saddr = inet->mc_addr;
628 connected = 0;
629 }
630
631 if (connected)
632 rt = (struct rtable*)sk_dst_check(sk, 0);
633
634 if (rt == NULL) {
635 struct flowi fl = { .oif = ipc.oif,
636 .nl_u = { .ip4_u =
637 { .daddr = faddr,
638 .saddr = saddr,
639 .tos = tos } },
640 .proto = sk->sk_protocol,
641 .uli_u = { .ports =
642 { .sport = inet->sport,
643 .dport = dport } } };
644 security_sk_classify_flow(sk, &fl);
645 err = ip_route_output_flow(&rt, &fl, sk, 1);
646 if (err) {
647 if (err == -ENETUNREACH)
648 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
649 goto out;
650 }
651
652 err = -EACCES;
653 if ((rt->rt_flags & RTCF_BROADCAST) &&
654 !sock_flag(sk, SOCK_BROADCAST))
655 goto out;
656 if (connected)
657 sk_dst_set(sk, dst_clone(&rt->u.dst));
658 }
659
660 if (msg->msg_flags&MSG_CONFIRM)
661 goto do_confirm;
662 back_from_confirm:
663
664 saddr = rt->rt_src;
665 if (!ipc.addr)
666 daddr = ipc.addr = rt->rt_dst;
667
668 lock_sock(sk);
669 if (unlikely(up->pending)) {
670 /* The socket is already corked while preparing it. */
671 /* ... which is an evident application bug. --ANK */
672 release_sock(sk);
673
674 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
675 err = -EINVAL;
676 goto out;
677 }
678 /*
679 * Now cork the socket to pend data.
680 */
681 inet->cork.fl.fl4_dst = daddr;
682 inet->cork.fl.fl_ip_dport = dport;
683 inet->cork.fl.fl4_src = saddr;
684 inet->cork.fl.fl_ip_sport = inet->sport;
685 up->pending = AF_INET;
686
687 do_append_data:
688 up->len += ulen;
689 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
690 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
691 sizeof(struct udphdr), &ipc, rt,
692 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
693 if (err)
694 udp_flush_pending_frames(sk);
695 else if (!corkreq)
696 err = udp_push_pending_frames(sk);
697 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
698 up->pending = 0;
699 release_sock(sk);
700
701 out:
702 ip_rt_put(rt);
703 if (free)
704 kfree(ipc.opt);
705 if (!err)
706 return len;
707 /*
708 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
709 * ENOBUFS might not be good (it's not tunable per se), but otherwise
710 * we don't have a good statistic (IpOutDiscards but it can be too many
711 * things). We could add another new stat but at least for now that
712 * seems like overkill.
713 */
714 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
715 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
716 }
717 return err;
718
719 do_confirm:
720 dst_confirm(&rt->u.dst);
721 if (!(msg->msg_flags&MSG_PROBE) || len)
722 goto back_from_confirm;
723 err = 0;
724 goto out;
725 }
726
727 int udp_sendpage(struct sock *sk, struct page *page, int offset,
728 size_t size, int flags)
729 {
730 struct udp_sock *up = udp_sk(sk);
731 int ret;
732
733 if (!up->pending) {
734 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
735
736 /* Call udp_sendmsg to specify destination address which
737 * sendpage interface can't pass.
738 * This will succeed only when the socket is connected.
739 */
740 ret = udp_sendmsg(NULL, sk, &msg, 0);
741 if (ret < 0)
742 return ret;
743 }
744
745 lock_sock(sk);
746
747 if (unlikely(!up->pending)) {
748 release_sock(sk);
749
750 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
751 return -EINVAL;
752 }
753
754 ret = ip_append_page(sk, page, offset, size, flags);
755 if (ret == -EOPNOTSUPP) {
756 release_sock(sk);
757 return sock_no_sendpage(sk->sk_socket, page, offset,
758 size, flags);
759 }
760 if (ret < 0) {
761 udp_flush_pending_frames(sk);
762 goto out;
763 }
764
765 up->len += size;
766 if (!(up->corkflag || (flags&MSG_MORE)))
767 ret = udp_push_pending_frames(sk);
768 if (!ret)
769 ret = size;
770 out:
771 release_sock(sk);
772 return ret;
773 }
774
775 /*
776 * IOCTL requests applicable to the UDP protocol
777 */
778
779 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
780 {
781 switch (cmd) {
782 case SIOCOUTQ:
783 {
784 int amount = atomic_read(&sk->sk_wmem_alloc);
785 return put_user(amount, (int __user *)arg);
786 }
787
788 case SIOCINQ:
789 {
790 struct sk_buff *skb;
791 unsigned long amount;
792
793 amount = 0;
794 spin_lock_bh(&sk->sk_receive_queue.lock);
795 skb = skb_peek(&sk->sk_receive_queue);
796 if (skb != NULL) {
797 /*
798 * We will only return the amount
799 * of this packet since that is all
800 * that will be read.
801 */
802 amount = skb->len - sizeof(struct udphdr);
803 }
804 spin_unlock_bh(&sk->sk_receive_queue.lock);
805 return put_user(amount, (int __user *)arg);
806 }
807
808 default:
809 return -ENOIOCTLCMD;
810 }
811
812 return 0;
813 }
814
815 /*
816 * This should be easy, if there is something there we
817 * return it, otherwise we block.
818 */
819
820 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
821 size_t len, int noblock, int flags, int *addr_len)
822 {
823 struct inet_sock *inet = inet_sk(sk);
824 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
825 struct sk_buff *skb;
826 unsigned int ulen, copied;
827 int err;
828 int is_udplite = IS_UDPLITE(sk);
829
830 /*
831 * Check any passed addresses
832 */
833 if (addr_len)
834 *addr_len=sizeof(*sin);
835
836 if (flags & MSG_ERRQUEUE)
837 return ip_recv_error(sk, msg, len);
838
839 try_again:
840 skb = skb_recv_datagram(sk, flags, noblock, &err);
841 if (!skb)
842 goto out;
843
844 ulen = skb->len - sizeof(struct udphdr);
845 copied = len;
846 if (copied > ulen)
847 copied = ulen;
848 else if (copied < ulen)
849 msg->msg_flags |= MSG_TRUNC;
850
851 /*
852 * If checksum is needed at all, try to do it while copying the
853 * data. If the data is truncated, or if we only want a partial
854 * coverage checksum (UDP-Lite), do it before the copy.
855 */
856
857 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
858 if (udp_lib_checksum_complete(skb))
859 goto csum_copy_err;
860 }
861
862 if (skb_csum_unnecessary(skb))
863 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
864 msg->msg_iov, copied );
865 else {
866 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
867
868 if (err == -EINVAL)
869 goto csum_copy_err;
870 }
871
872 if (err)
873 goto out_free;
874
875 sock_recv_timestamp(msg, sk, skb);
876
877 /* Copy the address. */
878 if (sin)
879 {
880 sin->sin_family = AF_INET;
881 sin->sin_port = udp_hdr(skb)->source;
882 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
883 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
884 }
885 if (inet->cmsg_flags)
886 ip_cmsg_recv(msg, skb);
887
888 err = copied;
889 if (flags & MSG_TRUNC)
890 err = ulen;
891
892 out_free:
893 skb_free_datagram(sk, skb);
894 out:
895 return err;
896
897 csum_copy_err:
898 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
899
900 skb_kill_datagram(sk, skb, flags);
901
902 if (noblock)
903 return -EAGAIN;
904 goto try_again;
905 }
906
907
908 int udp_disconnect(struct sock *sk, int flags)
909 {
910 struct inet_sock *inet = inet_sk(sk);
911 /*
912 * 1003.1g - break association.
913 */
914
915 sk->sk_state = TCP_CLOSE;
916 inet->daddr = 0;
917 inet->dport = 0;
918 sk->sk_bound_dev_if = 0;
919 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
920 inet_reset_saddr(sk);
921
922 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
923 sk->sk_prot->unhash(sk);
924 inet->sport = 0;
925 }
926 sk_dst_reset(sk);
927 return 0;
928 }
929
930 /* returns:
931 * -1: error
932 * 0: success
933 * >0: "udp encap" protocol resubmission
934 *
935 * Note that in the success and error cases, the skb is assumed to
936 * have either been requeued or freed.
937 */
938 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
939 {
940 struct udp_sock *up = udp_sk(sk);
941 int rc;
942
943 /*
944 * Charge it to the socket, dropping if the queue is full.
945 */
946 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
947 goto drop;
948 nf_reset(skb);
949
950 if (up->encap_type) {
951 /*
952 * This is an encapsulation socket so pass the skb to
953 * the socket's udp_encap_rcv() hook. Otherwise, just
954 * fall through and pass this up the UDP socket.
955 * up->encap_rcv() returns the following value:
956 * =0 if skb was successfully passed to the encap
957 * handler or was discarded by it.
958 * >0 if skb should be passed on to UDP.
959 * <0 if skb should be resubmitted as proto -N
960 */
961
962 /* if we're overly short, let UDP handle it */
963 if (skb->len > sizeof(struct udphdr) &&
964 up->encap_rcv != NULL) {
965 int ret;
966
967 ret = (*up->encap_rcv)(sk, skb);
968 if (ret <= 0) {
969 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
970 return -ret;
971 }
972 }
973
974 /* FALLTHROUGH -- it's a UDP Packet */
975 }
976
977 /*
978 * UDP-Lite specific tests, ignored on UDP sockets
979 */
980 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
981
982 /*
983 * MIB statistics other than incrementing the error count are
984 * disabled for the following two types of errors: these depend
985 * on the application settings, not on the functioning of the
986 * protocol stack as such.
987 *
988 * RFC 3828 here recommends (sec 3.3): "There should also be a
989 * way ... to ... at least let the receiving application block
990 * delivery of packets with coverage values less than a value
991 * provided by the application."
992 */
993 if (up->pcrlen == 0) { /* full coverage was set */
994 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
995 "%d while full coverage %d requested\n",
996 UDP_SKB_CB(skb)->cscov, skb->len);
997 goto drop;
998 }
999 /* The next case involves violating the min. coverage requested
1000 * by the receiver. This is subtle: if receiver wants x and x is
1001 * greater than the buffersize/MTU then receiver will complain
1002 * that it wants x while sender emits packets of smaller size y.
1003 * Therefore the above ...()->partial_cov statement is essential.
1004 */
1005 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1006 LIMIT_NETDEBUG(KERN_WARNING
1007 "UDPLITE: coverage %d too small, need min %d\n",
1008 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1009 goto drop;
1010 }
1011 }
1012
1013 if (sk->sk_filter) {
1014 if (udp_lib_checksum_complete(skb))
1015 goto drop;
1016 }
1017
1018 if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
1019 /* Note that an ENOMEM error is charged twice */
1020 if (rc == -ENOMEM)
1021 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
1022 goto drop;
1023 }
1024
1025 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
1026 return 0;
1027
1028 drop:
1029 UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
1030 kfree_skb(skb);
1031 return -1;
1032 }
1033
1034 /*
1035 * Multicasts and broadcasts go to each listener.
1036 *
1037 * Note: called only from the BH handler context,
1038 * so we don't need to lock the hashes.
1039 */
1040 static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
1041 struct udphdr *uh,
1042 __be32 saddr, __be32 daddr,
1043 struct hlist_head udptable[])
1044 {
1045 struct sock *sk;
1046 int dif;
1047
1048 read_lock(&udp_hash_lock);
1049 sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
1050 dif = skb->dev->ifindex;
1051 sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
1052 if (sk) {
1053 struct sock *sknext = NULL;
1054
1055 do {
1056 struct sk_buff *skb1 = skb;
1057
1058 sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr,
1059 uh->source, saddr, dif);
1060 if (sknext)
1061 skb1 = skb_clone(skb, GFP_ATOMIC);
1062
1063 if (skb1) {
1064 int ret = udp_queue_rcv_skb(sk, skb1);
1065 if (ret > 0)
1066 /* we should probably re-process instead
1067 * of dropping packets here. */
1068 kfree_skb(skb1);
1069 }
1070 sk = sknext;
1071 } while (sknext);
1072 } else
1073 kfree_skb(skb);
1074 read_unlock(&udp_hash_lock);
1075 return 0;
1076 }
1077
1078 /* Initialize UDP checksum. If exited with zero value (success),
1079 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1080 * Otherwise, csum completion requires chacksumming packet body,
1081 * including udp header and folding it to skb->csum.
1082 */
1083 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1084 int proto)
1085 {
1086 const struct iphdr *iph;
1087 int err;
1088
1089 UDP_SKB_CB(skb)->partial_cov = 0;
1090 UDP_SKB_CB(skb)->cscov = skb->len;
1091
1092 if (proto == IPPROTO_UDPLITE) {
1093 err = udplite_checksum_init(skb, uh);
1094 if (err)
1095 return err;
1096 }
1097
1098 iph = ip_hdr(skb);
1099 if (uh->check == 0) {
1100 skb->ip_summed = CHECKSUM_UNNECESSARY;
1101 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1102 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1103 proto, skb->csum))
1104 skb->ip_summed = CHECKSUM_UNNECESSARY;
1105 }
1106 if (!skb_csum_unnecessary(skb))
1107 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1108 skb->len, proto, 0);
1109 /* Probably, we should checksum udp header (it should be in cache
1110 * in any case) and data in tiny packets (< rx copybreak).
1111 */
1112
1113 return 0;
1114 }
1115
1116 /*
1117 * All we need to do is get the socket, and then do a checksum.
1118 */
1119
1120 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
1121 int proto)
1122 {
1123 struct sock *sk;
1124 struct udphdr *uh = udp_hdr(skb);
1125 unsigned short ulen;
1126 struct rtable *rt = (struct rtable*)skb->dst;
1127 __be32 saddr = ip_hdr(skb)->saddr;
1128 __be32 daddr = ip_hdr(skb)->daddr;
1129
1130 /*
1131 * Validate the packet.
1132 */
1133 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1134 goto drop; /* No space for header. */
1135
1136 ulen = ntohs(uh->len);
1137 if (ulen > skb->len)
1138 goto short_packet;
1139
1140 if (proto == IPPROTO_UDP) {
1141 /* UDP validates ulen. */
1142 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1143 goto short_packet;
1144 uh = udp_hdr(skb);
1145 }
1146
1147 if (udp4_csum_init(skb, uh, proto))
1148 goto csum_error;
1149
1150 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1151 return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
1152
1153 sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
1154 skb->dev->ifindex, udptable );
1155
1156 if (sk != NULL) {
1157 int ret = udp_queue_rcv_skb(sk, skb);
1158 sock_put(sk);
1159
1160 /* a return value > 0 means to resubmit the input, but
1161 * it wants the return to be -protocol, or 0
1162 */
1163 if (ret > 0)
1164 return -ret;
1165 return 0;
1166 }
1167
1168 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1169 goto drop;
1170 nf_reset(skb);
1171
1172 /* No socket. Drop packet silently, if checksum is wrong */
1173 if (udp_lib_checksum_complete(skb))
1174 goto csum_error;
1175
1176 UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1177 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1178
1179 /*
1180 * Hmm. We got an UDP packet to a port to which we
1181 * don't wanna listen. Ignore it.
1182 */
1183 kfree_skb(skb);
1184 return 0;
1185
1186 short_packet:
1187 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
1188 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1189 NIPQUAD(saddr),
1190 ntohs(uh->source),
1191 ulen,
1192 skb->len,
1193 NIPQUAD(daddr),
1194 ntohs(uh->dest));
1195 goto drop;
1196
1197 csum_error:
1198 /*
1199 * RFC1122: OK. Discards the bad packet silently (as far as
1200 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1201 */
1202 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
1203 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1204 NIPQUAD(saddr),
1205 ntohs(uh->source),
1206 NIPQUAD(daddr),
1207 ntohs(uh->dest),
1208 ulen);
1209 drop:
1210 UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1211 kfree_skb(skb);
1212 return 0;
1213 }
1214
1215 int udp_rcv(struct sk_buff *skb)
1216 {
1217 return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
1218 }
1219
1220 int udp_destroy_sock(struct sock *sk)
1221 {
1222 lock_sock(sk);
1223 udp_flush_pending_frames(sk);
1224 release_sock(sk);
1225 return 0;
1226 }
1227
1228 /*
1229 * Socket option code for UDP
1230 */
1231 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1232 char __user *optval, int optlen,
1233 int (*push_pending_frames)(struct sock *))
1234 {
1235 struct udp_sock *up = udp_sk(sk);
1236 int val;
1237 int err = 0;
1238
1239 if (optlen<sizeof(int))
1240 return -EINVAL;
1241
1242 if (get_user(val, (int __user *)optval))
1243 return -EFAULT;
1244
1245 switch (optname) {
1246 case UDP_CORK:
1247 if (val != 0) {
1248 up->corkflag = 1;
1249 } else {
1250 up->corkflag = 0;
1251 lock_sock(sk);
1252 (*push_pending_frames)(sk);
1253 release_sock(sk);
1254 }
1255 break;
1256
1257 case UDP_ENCAP:
1258 switch (val) {
1259 case 0:
1260 case UDP_ENCAP_ESPINUDP:
1261 case UDP_ENCAP_ESPINUDP_NON_IKE:
1262 up->encap_rcv = xfrm4_udp_encap_rcv;
1263 /* FALLTHROUGH */
1264 case UDP_ENCAP_L2TPINUDP:
1265 up->encap_type = val;
1266 break;
1267 default:
1268 err = -ENOPROTOOPT;
1269 break;
1270 }
1271 break;
1272
1273 /*
1274 * UDP-Lite's partial checksum coverage (RFC 3828).
1275 */
1276 /* The sender sets actual checksum coverage length via this option.
1277 * The case coverage > packet length is handled by send module. */
1278 case UDPLITE_SEND_CSCOV:
1279 if (!up->pcflag) /* Disable the option on UDP sockets */
1280 return -ENOPROTOOPT;
1281 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1282 val = 8;
1283 up->pcslen = val;
1284 up->pcflag |= UDPLITE_SEND_CC;
1285 break;
1286
1287 /* The receiver specifies a minimum checksum coverage value. To make
1288 * sense, this should be set to at least 8 (as done below). If zero is
1289 * used, this again means full checksum coverage. */
1290 case UDPLITE_RECV_CSCOV:
1291 if (!up->pcflag) /* Disable the option on UDP sockets */
1292 return -ENOPROTOOPT;
1293 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1294 val = 8;
1295 up->pcrlen = val;
1296 up->pcflag |= UDPLITE_RECV_CC;
1297 break;
1298
1299 default:
1300 err = -ENOPROTOOPT;
1301 break;
1302 }
1303
1304 return err;
1305 }
1306
1307 int udp_setsockopt(struct sock *sk, int level, int optname,
1308 char __user *optval, int optlen)
1309 {
1310 if (level == SOL_UDP || level == SOL_UDPLITE)
1311 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1312 udp_push_pending_frames);
1313 return ip_setsockopt(sk, level, optname, optval, optlen);
1314 }
1315
1316 #ifdef CONFIG_COMPAT
1317 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1318 char __user *optval, int optlen)
1319 {
1320 if (level == SOL_UDP || level == SOL_UDPLITE)
1321 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1322 udp_push_pending_frames);
1323 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1324 }
1325 #endif
1326
1327 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1328 char __user *optval, int __user *optlen)
1329 {
1330 struct udp_sock *up = udp_sk(sk);
1331 int val, len;
1332
1333 if (get_user(len,optlen))
1334 return -EFAULT;
1335
1336 len = min_t(unsigned int, len, sizeof(int));
1337
1338 if (len < 0)
1339 return -EINVAL;
1340
1341 switch (optname) {
1342 case UDP_CORK:
1343 val = up->corkflag;
1344 break;
1345
1346 case UDP_ENCAP:
1347 val = up->encap_type;
1348 break;
1349
1350 /* The following two cannot be changed on UDP sockets, the return is
1351 * always 0 (which corresponds to the full checksum coverage of UDP). */
1352 case UDPLITE_SEND_CSCOV:
1353 val = up->pcslen;
1354 break;
1355
1356 case UDPLITE_RECV_CSCOV:
1357 val = up->pcrlen;
1358 break;
1359
1360 default:
1361 return -ENOPROTOOPT;
1362 }
1363
1364 if (put_user(len, optlen))
1365 return -EFAULT;
1366 if (copy_to_user(optval, &val,len))
1367 return -EFAULT;
1368 return 0;
1369 }
1370
1371 int udp_getsockopt(struct sock *sk, int level, int optname,
1372 char __user *optval, int __user *optlen)
1373 {
1374 if (level == SOL_UDP || level == SOL_UDPLITE)
1375 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1376 return ip_getsockopt(sk, level, optname, optval, optlen);
1377 }
1378
1379 #ifdef CONFIG_COMPAT
1380 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1381 char __user *optval, int __user *optlen)
1382 {
1383 if (level == SOL_UDP || level == SOL_UDPLITE)
1384 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1385 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1386 }
1387 #endif
1388 /**
1389 * udp_poll - wait for a UDP event.
1390 * @file - file struct
1391 * @sock - socket
1392 * @wait - poll table
1393 *
1394 * This is same as datagram poll, except for the special case of
1395 * blocking sockets. If application is using a blocking fd
1396 * and a packet with checksum error is in the queue;
1397 * then it could get return from select indicating data available
1398 * but then block when reading it. Add special case code
1399 * to work around these arguably broken applications.
1400 */
1401 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1402 {
1403 unsigned int mask = datagram_poll(file, sock, wait);
1404 struct sock *sk = sock->sk;
1405 int is_lite = IS_UDPLITE(sk);
1406
1407 /* Check for false positives due to checksum errors */
1408 if ( (mask & POLLRDNORM) &&
1409 !(file->f_flags & O_NONBLOCK) &&
1410 !(sk->sk_shutdown & RCV_SHUTDOWN)){
1411 struct sk_buff_head *rcvq = &sk->sk_receive_queue;
1412 struct sk_buff *skb;
1413
1414 spin_lock_bh(&rcvq->lock);
1415 while ((skb = skb_peek(rcvq)) != NULL &&
1416 udp_lib_checksum_complete(skb)) {
1417 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
1418 __skb_unlink(skb, rcvq);
1419 kfree_skb(skb);
1420 }
1421 spin_unlock_bh(&rcvq->lock);
1422
1423 /* nothing to see, move along */
1424 if (skb == NULL)
1425 mask &= ~(POLLIN | POLLRDNORM);
1426 }
1427
1428 return mask;
1429
1430 }
1431
1432 struct proto udp_prot = {
1433 .name = "UDP",
1434 .owner = THIS_MODULE,
1435 .close = udp_lib_close,
1436 .connect = ip4_datagram_connect,
1437 .disconnect = udp_disconnect,
1438 .ioctl = udp_ioctl,
1439 .destroy = udp_destroy_sock,
1440 .setsockopt = udp_setsockopt,
1441 .getsockopt = udp_getsockopt,
1442 .sendmsg = udp_sendmsg,
1443 .recvmsg = udp_recvmsg,
1444 .sendpage = udp_sendpage,
1445 .backlog_rcv = udp_queue_rcv_skb,
1446 .hash = udp_lib_hash,
1447 .unhash = udp_lib_unhash,
1448 .get_port = udp_v4_get_port,
1449 .obj_size = sizeof(struct udp_sock),
1450 #ifdef CONFIG_COMPAT
1451 .compat_setsockopt = compat_udp_setsockopt,
1452 .compat_getsockopt = compat_udp_getsockopt,
1453 #endif
1454 };
1455
1456 /* ------------------------------------------------------------------------ */
1457 #ifdef CONFIG_PROC_FS
1458
1459 static struct sock *udp_get_first(struct seq_file *seq)
1460 {
1461 struct sock *sk;
1462 struct udp_iter_state *state = seq->private;
1463
1464 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1465 struct hlist_node *node;
1466 sk_for_each(sk, node, state->hashtable + state->bucket) {
1467 if (sk->sk_family == state->family)
1468 goto found;
1469 }
1470 }
1471 sk = NULL;
1472 found:
1473 return sk;
1474 }
1475
1476 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1477 {
1478 struct udp_iter_state *state = seq->private;
1479
1480 do {
1481 sk = sk_next(sk);
1482 try_again:
1483 ;
1484 } while (sk && sk->sk_family != state->family);
1485
1486 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
1487 sk = sk_head(state->hashtable + state->bucket);
1488 goto try_again;
1489 }
1490 return sk;
1491 }
1492
1493 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1494 {
1495 struct sock *sk = udp_get_first(seq);
1496
1497 if (sk)
1498 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1499 --pos;
1500 return pos ? NULL : sk;
1501 }
1502
1503 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1504 {
1505 read_lock(&udp_hash_lock);
1506 return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
1507 }
1508
1509 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1510 {
1511 struct sock *sk;
1512
1513 if (v == (void *)1)
1514 sk = udp_get_idx(seq, 0);
1515 else
1516 sk = udp_get_next(seq, v);
1517
1518 ++*pos;
1519 return sk;
1520 }
1521
1522 static void udp_seq_stop(struct seq_file *seq, void *v)
1523 {
1524 read_unlock(&udp_hash_lock);
1525 }
1526
1527 static int udp_seq_open(struct inode *inode, struct file *file)
1528 {
1529 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1530 struct seq_file *seq;
1531 int rc = -ENOMEM;
1532 struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
1533
1534 if (!s)
1535 goto out;
1536 s->family = afinfo->family;
1537 s->hashtable = afinfo->hashtable;
1538 s->seq_ops.start = udp_seq_start;
1539 s->seq_ops.next = udp_seq_next;
1540 s->seq_ops.show = afinfo->seq_show;
1541 s->seq_ops.stop = udp_seq_stop;
1542
1543 rc = seq_open(file, &s->seq_ops);
1544 if (rc)
1545 goto out_kfree;
1546
1547 seq = file->private_data;
1548 seq->private = s;
1549 out:
1550 return rc;
1551 out_kfree:
1552 kfree(s);
1553 goto out;
1554 }
1555
1556 /* ------------------------------------------------------------------------ */
1557 int udp_proc_register(struct udp_seq_afinfo *afinfo)
1558 {
1559 struct proc_dir_entry *p;
1560 int rc = 0;
1561
1562 if (!afinfo)
1563 return -EINVAL;
1564 afinfo->seq_fops->owner = afinfo->owner;
1565 afinfo->seq_fops->open = udp_seq_open;
1566 afinfo->seq_fops->read = seq_read;
1567 afinfo->seq_fops->llseek = seq_lseek;
1568 afinfo->seq_fops->release = seq_release_private;
1569
1570 p = proc_net_fops_create(&init_net, afinfo->name, S_IRUGO, afinfo->seq_fops);
1571 if (p)
1572 p->data = afinfo;
1573 else
1574 rc = -ENOMEM;
1575 return rc;
1576 }
1577
1578 void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
1579 {
1580 if (!afinfo)
1581 return;
1582 proc_net_remove(&init_net, afinfo->name);
1583 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
1584 }
1585
1586 /* ------------------------------------------------------------------------ */
1587 static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
1588 {
1589 struct inet_sock *inet = inet_sk(sp);
1590 __be32 dest = inet->daddr;
1591 __be32 src = inet->rcv_saddr;
1592 __u16 destp = ntohs(inet->dport);
1593 __u16 srcp = ntohs(inet->sport);
1594
1595 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
1596 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
1597 bucket, src, srcp, dest, destp, sp->sk_state,
1598 atomic_read(&sp->sk_wmem_alloc),
1599 atomic_read(&sp->sk_rmem_alloc),
1600 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1601 atomic_read(&sp->sk_refcnt), sp);
1602 }
1603
1604 int udp4_seq_show(struct seq_file *seq, void *v)
1605 {
1606 if (v == SEQ_START_TOKEN)
1607 seq_printf(seq, "%-127s\n",
1608 " sl local_address rem_address st tx_queue "
1609 "rx_queue tr tm->when retrnsmt uid timeout "
1610 "inode");
1611 else {
1612 char tmpbuf[129];
1613 struct udp_iter_state *state = seq->private;
1614
1615 udp4_format_sock(v, tmpbuf, state->bucket);
1616 seq_printf(seq, "%-127s\n", tmpbuf);
1617 }
1618 return 0;
1619 }
1620
1621 /* ------------------------------------------------------------------------ */
1622 static struct file_operations udp4_seq_fops;
1623 static struct udp_seq_afinfo udp4_seq_afinfo = {
1624 .owner = THIS_MODULE,
1625 .name = "udp",
1626 .family = AF_INET,
1627 .hashtable = udp_hash,
1628 .seq_show = udp4_seq_show,
1629 .seq_fops = &udp4_seq_fops,
1630 };
1631
1632 int __init udp4_proc_init(void)
1633 {
1634 return udp_proc_register(&udp4_seq_afinfo);
1635 }
1636
1637 void udp4_proc_exit(void)
1638 {
1639 udp_proc_unregister(&udp4_seq_afinfo);
1640 }
1641 #endif /* CONFIG_PROC_FS */
1642
1643 EXPORT_SYMBOL(udp_disconnect);
1644 EXPORT_SYMBOL(udp_hash);
1645 EXPORT_SYMBOL(udp_hash_lock);
1646 EXPORT_SYMBOL(udp_ioctl);
1647 EXPORT_SYMBOL(udp_get_port);
1648 EXPORT_SYMBOL(udp_prot);
1649 EXPORT_SYMBOL(udp_sendmsg);
1650 EXPORT_SYMBOL(udp_lib_getsockopt);
1651 EXPORT_SYMBOL(udp_lib_setsockopt);
1652 EXPORT_SYMBOL(udp_poll);
1653
1654 #ifdef CONFIG_PROC_FS
1655 EXPORT_SYMBOL(udp_proc_register);
1656 EXPORT_SYMBOL(udp_proc_unregister);
1657 #endif
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