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Merge master.kernel.org:/pub/scm/linux/kernel/git/bart/ide-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 * 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 *
74 *
75 * This program is free software; you can redistribute it and/or
76 * modify it under the terms of the GNU General Public License
77 * as published by the Free Software Foundation; either version
78 * 2 of the License, or (at your option) any later version.
79 */
80
81 #include <asm/system.h>
82 #include <asm/uaccess.h>
83 #include <asm/ioctls.h>
84 #include <linux/types.h>
85 #include <linux/fcntl.h>
86 #include <linux/module.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
89 #include <linux/igmp.h>
90 #include <linux/in.h>
91 #include <linux/errno.h>
92 #include <linux/timer.h>
93 #include <linux/mm.h>
94 #include <linux/inet.h>
95 #include <linux/netdevice.h>
96 #include <net/tcp_states.h>
97 #include <linux/skbuff.h>
98 #include <linux/proc_fs.h>
99 #include <linux/seq_file.h>
100 #include <net/icmp.h>
101 #include <net/route.h>
102 #include <net/checksum.h>
103 #include <net/xfrm.h>
104 #include "udp_impl.h"
105
106 /*
107 * Snmp MIB for the UDP layer
108 */
109
110 DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly;
111
112 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
113 DEFINE_RWLOCK(udp_hash_lock);
114
115 static int udp_port_rover;
116
117 /*
118 * Note about this hash function :
119 * Typical use is probably daddr = 0, only dport is going to vary hash
120 */
121 static inline unsigned int hash_port_and_addr(__u16 port, __be32 addr)
122 {
123 addr ^= addr >> 16;
124 addr ^= addr >> 8;
125 return port ^ addr;
126 }
127
128 static inline int __udp_lib_port_inuse(unsigned int hash, int port,
129 __be32 daddr, struct hlist_head udptable[])
130 {
131 struct sock *sk;
132 struct hlist_node *node;
133 struct inet_sock *inet;
134
135 sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
136 if (sk->sk_hash != hash)
137 continue;
138 inet = inet_sk(sk);
139 if (inet->num != port)
140 continue;
141 if (inet->rcv_saddr == daddr)
142 return 1;
143 }
144 return 0;
145 }
146
147 /**
148 * __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
149 *
150 * @sk: socket struct in question
151 * @snum: port number to look up
152 * @udptable: hash list table, must be of UDP_HTABLE_SIZE
153 * @port_rover: pointer to record of last unallocated port
154 * @saddr_comp: AF-dependent comparison of bound local IP addresses
155 */
156 int __udp_lib_get_port(struct sock *sk, unsigned short snum,
157 struct hlist_head udptable[], int *port_rover,
158 int (*saddr_comp)(const struct sock *sk1,
159 const struct sock *sk2 ) )
160 {
161 struct hlist_node *node;
162 struct hlist_head *head;
163 struct sock *sk2;
164 unsigned int hash;
165 int error = 1;
166
167 write_lock_bh(&udp_hash_lock);
168 if (snum == 0) {
169 int best_size_so_far, best, result, i;
170
171 if (*port_rover > sysctl_local_port_range[1] ||
172 *port_rover < sysctl_local_port_range[0])
173 *port_rover = sysctl_local_port_range[0];
174 best_size_so_far = 32767;
175 best = result = *port_rover;
176 for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
177 int size;
178
179 hash = hash_port_and_addr(result,
180 inet_sk(sk)->rcv_saddr);
181 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
182 if (hlist_empty(head)) {
183 if (result > sysctl_local_port_range[1])
184 result = sysctl_local_port_range[0] +
185 ((result - sysctl_local_port_range[0]) &
186 (UDP_HTABLE_SIZE - 1));
187 goto gotit;
188 }
189 size = 0;
190 sk_for_each(sk2, node, head) {
191 if (++size >= best_size_so_far)
192 goto next;
193 }
194 best_size_so_far = size;
195 best = result;
196 next:
197 ;
198 }
199 result = best;
200 for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE;
201 i++, result += UDP_HTABLE_SIZE) {
202 if (result > sysctl_local_port_range[1])
203 result = sysctl_local_port_range[0]
204 + ((result - sysctl_local_port_range[0]) &
205 (UDP_HTABLE_SIZE - 1));
206 hash = hash_port_and_addr(result, 0);
207 if (__udp_lib_port_inuse(hash, result,
208 0, udptable))
209 continue;
210 if (!inet_sk(sk)->rcv_saddr)
211 break;
212
213 hash = hash_port_and_addr(result,
214 inet_sk(sk)->rcv_saddr);
215 if (! __udp_lib_port_inuse(hash, result,
216 inet_sk(sk)->rcv_saddr, udptable))
217 break;
218 }
219 if (i >= (1 << 16) / UDP_HTABLE_SIZE)
220 goto fail;
221 gotit:
222 *port_rover = snum = result;
223 } else {
224 hash = hash_port_and_addr(snum, 0);
225 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
226
227 sk_for_each(sk2, node, head)
228 if (sk2->sk_hash == hash &&
229 sk2 != sk &&
230 inet_sk(sk2)->num == snum &&
231 (!sk2->sk_reuse || !sk->sk_reuse) &&
232 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
233 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
234 (*saddr_comp)(sk, sk2))
235 goto fail;
236
237 if (inet_sk(sk)->rcv_saddr) {
238 hash = hash_port_and_addr(snum,
239 inet_sk(sk)->rcv_saddr);
240 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
241
242 sk_for_each(sk2, node, head)
243 if (sk2->sk_hash == hash &&
244 sk2 != sk &&
245 inet_sk(sk2)->num == snum &&
246 (!sk2->sk_reuse || !sk->sk_reuse) &&
247 (!sk2->sk_bound_dev_if ||
248 !sk->sk_bound_dev_if ||
249 sk2->sk_bound_dev_if ==
250 sk->sk_bound_dev_if) &&
251 (*saddr_comp)(sk, sk2))
252 goto fail;
253 }
254 }
255 inet_sk(sk)->num = snum;
256 sk->sk_hash = hash;
257 if (sk_unhashed(sk)) {
258 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
259 sk_add_node(sk, head);
260 sock_prot_inc_use(sk->sk_prot);
261 }
262 error = 0;
263 fail:
264 write_unlock_bh(&udp_hash_lock);
265 return error;
266 }
267
268 int udp_get_port(struct sock *sk, unsigned short snum,
269 int (*scmp)(const struct sock *, const struct sock *))
270 {
271 return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp);
272 }
273
274 int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
275 {
276 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
277
278 return ( !ipv6_only_sock(sk2) &&
279 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
280 inet1->rcv_saddr == inet2->rcv_saddr ));
281 }
282
283 static inline int udp_v4_get_port(struct sock *sk, unsigned short snum)
284 {
285 return udp_get_port(sk, snum, ipv4_rcv_saddr_equal);
286 }
287
288 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
289 * harder than this. -DaveM
290 */
291 static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
292 __be32 daddr, __be16 dport,
293 int dif, struct hlist_head udptable[])
294 {
295 struct sock *sk, *result = NULL;
296 struct hlist_node *node;
297 unsigned int hash, hashwild;
298 int score, best = -1, hport = ntohs(dport);
299
300 hash = hash_port_and_addr(hport, daddr);
301 hashwild = hash_port_and_addr(hport, 0);
302
303 read_lock(&udp_hash_lock);
304
305 lookup:
306
307 sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
308 struct inet_sock *inet = inet_sk(sk);
309
310 if (sk->sk_hash != hash || ipv6_only_sock(sk) ||
311 inet->num != hport)
312 continue;
313
314 score = (sk->sk_family == PF_INET ? 1 : 0);
315 if (inet->rcv_saddr) {
316 if (inet->rcv_saddr != daddr)
317 continue;
318 score+=2;
319 }
320 if (inet->daddr) {
321 if (inet->daddr != saddr)
322 continue;
323 score+=2;
324 }
325 if (inet->dport) {
326 if (inet->dport != sport)
327 continue;
328 score+=2;
329 }
330 if (sk->sk_bound_dev_if) {
331 if (sk->sk_bound_dev_if != dif)
332 continue;
333 score+=2;
334 }
335 if (score == 9) {
336 result = sk;
337 goto found;
338 } else if (score > best) {
339 result = sk;
340 best = score;
341 }
342 }
343
344 if (hash != hashwild) {
345 hash = hashwild;
346 goto lookup;
347 }
348 found:
349 if (result)
350 sock_hold(result);
351 read_unlock(&udp_hash_lock);
352 return result;
353 }
354
355 static inline struct sock *udp_v4_mcast_next(struct sock *sk, unsigned int hnum,
356 int hport, __be32 loc_addr,
357 __be16 rmt_port, __be32 rmt_addr,
358 int dif)
359 {
360 struct hlist_node *node;
361 struct sock *s = sk;
362
363 sk_for_each_from(s, node) {
364 struct inet_sock *inet = inet_sk(s);
365
366 if (s->sk_hash != hnum ||
367 inet->num != hport ||
368 (inet->daddr && inet->daddr != rmt_addr) ||
369 (inet->dport != rmt_port && inet->dport) ||
370 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
371 ipv6_only_sock(s) ||
372 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
373 continue;
374 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
375 continue;
376 goto found;
377 }
378 s = NULL;
379 found:
380 return s;
381 }
382
383 /*
384 * This routine is called by the ICMP module when it gets some
385 * sort of error condition. If err < 0 then the socket should
386 * be closed and the error returned to the user. If err > 0
387 * it's just the icmp type << 8 | icmp code.
388 * Header points to the ip header of the error packet. We move
389 * on past this. Then (as it used to claim before adjustment)
390 * header points to the first 8 bytes of the udp header. We need
391 * to find the appropriate port.
392 */
393
394 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
395 {
396 struct inet_sock *inet;
397 struct iphdr *iph = (struct iphdr*)skb->data;
398 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
399 const int type = icmp_hdr(skb)->type;
400 const int code = icmp_hdr(skb)->code;
401 struct sock *sk;
402 int harderr;
403 int err;
404
405 sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
406 skb->dev->ifindex, udptable );
407 if (sk == NULL) {
408 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
409 return; /* No socket for error */
410 }
411
412 err = 0;
413 harderr = 0;
414 inet = inet_sk(sk);
415
416 switch (type) {
417 default:
418 case ICMP_TIME_EXCEEDED:
419 err = EHOSTUNREACH;
420 break;
421 case ICMP_SOURCE_QUENCH:
422 goto out;
423 case ICMP_PARAMETERPROB:
424 err = EPROTO;
425 harderr = 1;
426 break;
427 case ICMP_DEST_UNREACH:
428 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
429 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
430 err = EMSGSIZE;
431 harderr = 1;
432 break;
433 }
434 goto out;
435 }
436 err = EHOSTUNREACH;
437 if (code <= NR_ICMP_UNREACH) {
438 harderr = icmp_err_convert[code].fatal;
439 err = icmp_err_convert[code].errno;
440 }
441 break;
442 }
443
444 /*
445 * RFC1122: OK. Passes ICMP errors back to application, as per
446 * 4.1.3.3.
447 */
448 if (!inet->recverr) {
449 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
450 goto out;
451 } else {
452 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
453 }
454 sk->sk_err = err;
455 sk->sk_error_report(sk);
456 out:
457 sock_put(sk);
458 }
459
460 void udp_err(struct sk_buff *skb, u32 info)
461 {
462 return __udp4_lib_err(skb, info, udp_hash);
463 }
464
465 /*
466 * Throw away all pending data and cancel the corking. Socket is locked.
467 */
468 static void udp_flush_pending_frames(struct sock *sk)
469 {
470 struct udp_sock *up = udp_sk(sk);
471
472 if (up->pending) {
473 up->len = 0;
474 up->pending = 0;
475 ip_flush_pending_frames(sk);
476 }
477 }
478
479 /**
480 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
481 * @sk: socket we are sending on
482 * @skb: sk_buff containing the filled-in UDP header
483 * (checksum field must be zeroed out)
484 */
485 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
486 __be32 src, __be32 dst, int len )
487 {
488 unsigned int offset;
489 struct udphdr *uh = udp_hdr(skb);
490 __wsum csum = 0;
491
492 if (skb_queue_len(&sk->sk_write_queue) == 1) {
493 /*
494 * Only one fragment on the socket.
495 */
496 skb->csum_start = skb_transport_header(skb) - skb->head;
497 skb->csum_offset = offsetof(struct udphdr, check);
498 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
499 } else {
500 /*
501 * HW-checksum won't work as there are two or more
502 * fragments on the socket so that all csums of sk_buffs
503 * should be together
504 */
505 offset = skb_transport_offset(skb);
506 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
507
508 skb->ip_summed = CHECKSUM_NONE;
509
510 skb_queue_walk(&sk->sk_write_queue, skb) {
511 csum = csum_add(csum, skb->csum);
512 }
513
514 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
515 if (uh->check == 0)
516 uh->check = CSUM_MANGLED_0;
517 }
518 }
519
520 /*
521 * Push out all pending data as one UDP datagram. Socket is locked.
522 */
523 static int udp_push_pending_frames(struct sock *sk)
524 {
525 struct udp_sock *up = udp_sk(sk);
526 struct inet_sock *inet = inet_sk(sk);
527 struct flowi *fl = &inet->cork.fl;
528 struct sk_buff *skb;
529 struct udphdr *uh;
530 int err = 0;
531 __wsum csum = 0;
532
533 /* Grab the skbuff where UDP header space exists. */
534 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
535 goto out;
536
537 /*
538 * Create a UDP header
539 */
540 uh = udp_hdr(skb);
541 uh->source = fl->fl_ip_sport;
542 uh->dest = fl->fl_ip_dport;
543 uh->len = htons(up->len);
544 uh->check = 0;
545
546 if (up->pcflag) /* UDP-Lite */
547 csum = udplite_csum_outgoing(sk, skb);
548
549 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
550
551 skb->ip_summed = CHECKSUM_NONE;
552 goto send;
553
554 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
555
556 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
557 goto send;
558
559 } else /* `normal' UDP */
560 csum = udp_csum_outgoing(sk, skb);
561
562 /* add protocol-dependent pseudo-header */
563 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
564 sk->sk_protocol, csum );
565 if (uh->check == 0)
566 uh->check = CSUM_MANGLED_0;
567
568 send:
569 err = ip_push_pending_frames(sk);
570 out:
571 up->len = 0;
572 up->pending = 0;
573 return err;
574 }
575
576 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
577 size_t len)
578 {
579 struct inet_sock *inet = inet_sk(sk);
580 struct udp_sock *up = udp_sk(sk);
581 int ulen = len;
582 struct ipcm_cookie ipc;
583 struct rtable *rt = NULL;
584 int free = 0;
585 int connected = 0;
586 __be32 daddr, faddr, saddr;
587 __be16 dport;
588 u8 tos;
589 int err, is_udplite = up->pcflag;
590 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
591 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
592
593 if (len > 0xFFFF)
594 return -EMSGSIZE;
595
596 /*
597 * Check the flags.
598 */
599
600 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */
601 return -EOPNOTSUPP;
602
603 ipc.opt = NULL;
604
605 if (up->pending) {
606 /*
607 * There are pending frames.
608 * The socket lock must be held while it's corked.
609 */
610 lock_sock(sk);
611 if (likely(up->pending)) {
612 if (unlikely(up->pending != AF_INET)) {
613 release_sock(sk);
614 return -EINVAL;
615 }
616 goto do_append_data;
617 }
618 release_sock(sk);
619 }
620 ulen += sizeof(struct udphdr);
621
622 /*
623 * Get and verify the address.
624 */
625 if (msg->msg_name) {
626 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
627 if (msg->msg_namelen < sizeof(*usin))
628 return -EINVAL;
629 if (usin->sin_family != AF_INET) {
630 if (usin->sin_family != AF_UNSPEC)
631 return -EAFNOSUPPORT;
632 }
633
634 daddr = usin->sin_addr.s_addr;
635 dport = usin->sin_port;
636 if (dport == 0)
637 return -EINVAL;
638 } else {
639 if (sk->sk_state != TCP_ESTABLISHED)
640 return -EDESTADDRREQ;
641 daddr = inet->daddr;
642 dport = inet->dport;
643 /* Open fast path for connected socket.
644 Route will not be used, if at least one option is set.
645 */
646 connected = 1;
647 }
648 ipc.addr = inet->saddr;
649
650 ipc.oif = sk->sk_bound_dev_if;
651 if (msg->msg_controllen) {
652 err = ip_cmsg_send(msg, &ipc);
653 if (err)
654 return err;
655 if (ipc.opt)
656 free = 1;
657 connected = 0;
658 }
659 if (!ipc.opt)
660 ipc.opt = inet->opt;
661
662 saddr = ipc.addr;
663 ipc.addr = faddr = daddr;
664
665 if (ipc.opt && ipc.opt->srr) {
666 if (!daddr)
667 return -EINVAL;
668 faddr = ipc.opt->faddr;
669 connected = 0;
670 }
671 tos = RT_TOS(inet->tos);
672 if (sock_flag(sk, SOCK_LOCALROUTE) ||
673 (msg->msg_flags & MSG_DONTROUTE) ||
674 (ipc.opt && ipc.opt->is_strictroute)) {
675 tos |= RTO_ONLINK;
676 connected = 0;
677 }
678
679 if (MULTICAST(daddr)) {
680 if (!ipc.oif)
681 ipc.oif = inet->mc_index;
682 if (!saddr)
683 saddr = inet->mc_addr;
684 connected = 0;
685 }
686
687 if (connected)
688 rt = (struct rtable*)sk_dst_check(sk, 0);
689
690 if (rt == NULL) {
691 struct flowi fl = { .oif = ipc.oif,
692 .nl_u = { .ip4_u =
693 { .daddr = faddr,
694 .saddr = saddr,
695 .tos = tos } },
696 .proto = sk->sk_protocol,
697 .uli_u = { .ports =
698 { .sport = inet->sport,
699 .dport = dport } } };
700 security_sk_classify_flow(sk, &fl);
701 err = ip_route_output_flow(&rt, &fl, sk, 1);
702 if (err)
703 goto out;
704
705 err = -EACCES;
706 if ((rt->rt_flags & RTCF_BROADCAST) &&
707 !sock_flag(sk, SOCK_BROADCAST))
708 goto out;
709 if (connected)
710 sk_dst_set(sk, dst_clone(&rt->u.dst));
711 }
712
713 if (msg->msg_flags&MSG_CONFIRM)
714 goto do_confirm;
715 back_from_confirm:
716
717 saddr = rt->rt_src;
718 if (!ipc.addr)
719 daddr = ipc.addr = rt->rt_dst;
720
721 lock_sock(sk);
722 if (unlikely(up->pending)) {
723 /* The socket is already corked while preparing it. */
724 /* ... which is an evident application bug. --ANK */
725 release_sock(sk);
726
727 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
728 err = -EINVAL;
729 goto out;
730 }
731 /*
732 * Now cork the socket to pend data.
733 */
734 inet->cork.fl.fl4_dst = daddr;
735 inet->cork.fl.fl_ip_dport = dport;
736 inet->cork.fl.fl4_src = saddr;
737 inet->cork.fl.fl_ip_sport = inet->sport;
738 up->pending = AF_INET;
739
740 do_append_data:
741 up->len += ulen;
742 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
743 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
744 sizeof(struct udphdr), &ipc, rt,
745 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
746 if (err)
747 udp_flush_pending_frames(sk);
748 else if (!corkreq)
749 err = udp_push_pending_frames(sk);
750 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
751 up->pending = 0;
752 release_sock(sk);
753
754 out:
755 ip_rt_put(rt);
756 if (free)
757 kfree(ipc.opt);
758 if (!err) {
759 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
760 return len;
761 }
762 /*
763 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
764 * ENOBUFS might not be good (it's not tunable per se), but otherwise
765 * we don't have a good statistic (IpOutDiscards but it can be too many
766 * things). We could add another new stat but at least for now that
767 * seems like overkill.
768 */
769 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
770 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
771 }
772 return err;
773
774 do_confirm:
775 dst_confirm(&rt->u.dst);
776 if (!(msg->msg_flags&MSG_PROBE) || len)
777 goto back_from_confirm;
778 err = 0;
779 goto out;
780 }
781
782 int udp_sendpage(struct sock *sk, struct page *page, int offset,
783 size_t size, int flags)
784 {
785 struct udp_sock *up = udp_sk(sk);
786 int ret;
787
788 if (!up->pending) {
789 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
790
791 /* Call udp_sendmsg to specify destination address which
792 * sendpage interface can't pass.
793 * This will succeed only when the socket is connected.
794 */
795 ret = udp_sendmsg(NULL, sk, &msg, 0);
796 if (ret < 0)
797 return ret;
798 }
799
800 lock_sock(sk);
801
802 if (unlikely(!up->pending)) {
803 release_sock(sk);
804
805 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
806 return -EINVAL;
807 }
808
809 ret = ip_append_page(sk, page, offset, size, flags);
810 if (ret == -EOPNOTSUPP) {
811 release_sock(sk);
812 return sock_no_sendpage(sk->sk_socket, page, offset,
813 size, flags);
814 }
815 if (ret < 0) {
816 udp_flush_pending_frames(sk);
817 goto out;
818 }
819
820 up->len += size;
821 if (!(up->corkflag || (flags&MSG_MORE)))
822 ret = udp_push_pending_frames(sk);
823 if (!ret)
824 ret = size;
825 out:
826 release_sock(sk);
827 return ret;
828 }
829
830 /*
831 * IOCTL requests applicable to the UDP protocol
832 */
833
834 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
835 {
836 switch (cmd) {
837 case SIOCOUTQ:
838 {
839 int amount = atomic_read(&sk->sk_wmem_alloc);
840 return put_user(amount, (int __user *)arg);
841 }
842
843 case SIOCINQ:
844 {
845 struct sk_buff *skb;
846 unsigned long amount;
847
848 amount = 0;
849 spin_lock_bh(&sk->sk_receive_queue.lock);
850 skb = skb_peek(&sk->sk_receive_queue);
851 if (skb != NULL) {
852 /*
853 * We will only return the amount
854 * of this packet since that is all
855 * that will be read.
856 */
857 amount = skb->len - sizeof(struct udphdr);
858 }
859 spin_unlock_bh(&sk->sk_receive_queue.lock);
860 return put_user(amount, (int __user *)arg);
861 }
862
863 default:
864 return -ENOIOCTLCMD;
865 }
866
867 return 0;
868 }
869
870 /*
871 * This should be easy, if there is something there we
872 * return it, otherwise we block.
873 */
874
875 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
876 size_t len, int noblock, int flags, int *addr_len)
877 {
878 struct inet_sock *inet = inet_sk(sk);
879 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
880 struct sk_buff *skb;
881 unsigned int ulen, copied;
882 int err;
883 int is_udplite = IS_UDPLITE(sk);
884
885 /*
886 * Check any passed addresses
887 */
888 if (addr_len)
889 *addr_len=sizeof(*sin);
890
891 if (flags & MSG_ERRQUEUE)
892 return ip_recv_error(sk, msg, len);
893
894 try_again:
895 skb = skb_recv_datagram(sk, flags, noblock, &err);
896 if (!skb)
897 goto out;
898
899 ulen = skb->len - sizeof(struct udphdr);
900 copied = len;
901 if (copied > ulen)
902 copied = ulen;
903 else if (copied < ulen)
904 msg->msg_flags |= MSG_TRUNC;
905
906 /*
907 * If checksum is needed at all, try to do it while copying the
908 * data. If the data is truncated, or if we only want a partial
909 * coverage checksum (UDP-Lite), do it before the copy.
910 */
911
912 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
913 if (udp_lib_checksum_complete(skb))
914 goto csum_copy_err;
915 }
916
917 if (skb_csum_unnecessary(skb))
918 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
919 msg->msg_iov, copied );
920 else {
921 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
922
923 if (err == -EINVAL)
924 goto csum_copy_err;
925 }
926
927 if (err)
928 goto out_free;
929
930 sock_recv_timestamp(msg, sk, skb);
931
932 /* Copy the address. */
933 if (sin)
934 {
935 sin->sin_family = AF_INET;
936 sin->sin_port = udp_hdr(skb)->source;
937 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
938 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
939 }
940 if (inet->cmsg_flags)
941 ip_cmsg_recv(msg, skb);
942
943 err = copied;
944 if (flags & MSG_TRUNC)
945 err = ulen;
946
947 out_free:
948 skb_free_datagram(sk, skb);
949 out:
950 return err;
951
952 csum_copy_err:
953 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
954
955 skb_kill_datagram(sk, skb, flags);
956
957 if (noblock)
958 return -EAGAIN;
959 goto try_again;
960 }
961
962
963 int udp_disconnect(struct sock *sk, int flags)
964 {
965 struct inet_sock *inet = inet_sk(sk);
966 /*
967 * 1003.1g - break association.
968 */
969
970 sk->sk_state = TCP_CLOSE;
971 inet->daddr = 0;
972 inet->dport = 0;
973 sk->sk_bound_dev_if = 0;
974 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
975 inet_reset_saddr(sk);
976
977 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
978 sk->sk_prot->unhash(sk);
979 inet->sport = 0;
980 }
981 sk_dst_reset(sk);
982 return 0;
983 }
984
985 /* return:
986 * 1 if the UDP system should process it
987 * 0 if we should drop this packet
988 * -1 if it should get processed by xfrm4_rcv_encap
989 */
990 static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
991 {
992 #ifndef CONFIG_XFRM
993 return 1;
994 #else
995 struct udp_sock *up = udp_sk(sk);
996 struct udphdr *uh;
997 struct iphdr *iph;
998 int iphlen, len;
999
1000 __u8 *udpdata;
1001 __be32 *udpdata32;
1002 __u16 encap_type = up->encap_type;
1003
1004 /* if we're overly short, let UDP handle it */
1005 len = skb->len - sizeof(struct udphdr);
1006 if (len <= 0)
1007 return 1;
1008
1009 /* if this is not encapsulated socket, then just return now */
1010 if (!encap_type)
1011 return 1;
1012
1013 /* If this is a paged skb, make sure we pull up
1014 * whatever data we need to look at. */
1015 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
1016 return 1;
1017
1018 /* Now we can get the pointers */
1019 uh = udp_hdr(skb);
1020 udpdata = (__u8 *)uh + sizeof(struct udphdr);
1021 udpdata32 = (__be32 *)udpdata;
1022
1023 switch (encap_type) {
1024 default:
1025 case UDP_ENCAP_ESPINUDP:
1026 /* Check if this is a keepalive packet. If so, eat it. */
1027 if (len == 1 && udpdata[0] == 0xff) {
1028 return 0;
1029 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
1030 /* ESP Packet without Non-ESP header */
1031 len = sizeof(struct udphdr);
1032 } else
1033 /* Must be an IKE packet.. pass it through */
1034 return 1;
1035 break;
1036 case UDP_ENCAP_ESPINUDP_NON_IKE:
1037 /* Check if this is a keepalive packet. If so, eat it. */
1038 if (len == 1 && udpdata[0] == 0xff) {
1039 return 0;
1040 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
1041 udpdata32[0] == 0 && udpdata32[1] == 0) {
1042
1043 /* ESP Packet with Non-IKE marker */
1044 len = sizeof(struct udphdr) + 2 * sizeof(u32);
1045 } else
1046 /* Must be an IKE packet.. pass it through */
1047 return 1;
1048 break;
1049 }
1050
1051 /* At this point we are sure that this is an ESPinUDP packet,
1052 * so we need to remove 'len' bytes from the packet (the UDP
1053 * header and optional ESP marker bytes) and then modify the
1054 * protocol to ESP, and then call into the transform receiver.
1055 */
1056 if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1057 return 0;
1058
1059 /* Now we can update and verify the packet length... */
1060 iph = ip_hdr(skb);
1061 iphlen = iph->ihl << 2;
1062 iph->tot_len = htons(ntohs(iph->tot_len) - len);
1063 if (skb->len < iphlen + len) {
1064 /* packet is too small!?! */
1065 return 0;
1066 }
1067
1068 /* pull the data buffer up to the ESP header and set the
1069 * transport header to point to ESP. Keep UDP on the stack
1070 * for later.
1071 */
1072 __skb_pull(skb, len);
1073 skb_reset_transport_header(skb);
1074
1075 /* modify the protocol (it's ESP!) */
1076 iph->protocol = IPPROTO_ESP;
1077
1078 /* and let the caller know to send this into the ESP processor... */
1079 return -1;
1080 #endif
1081 }
1082
1083 /* returns:
1084 * -1: error
1085 * 0: success
1086 * >0: "udp encap" protocol resubmission
1087 *
1088 * Note that in the success and error cases, the skb is assumed to
1089 * have either been requeued or freed.
1090 */
1091 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
1092 {
1093 struct udp_sock *up = udp_sk(sk);
1094 int rc;
1095
1096 /*
1097 * Charge it to the socket, dropping if the queue is full.
1098 */
1099 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1100 goto drop;
1101 nf_reset(skb);
1102
1103 if (up->encap_type) {
1104 /*
1105 * This is an encapsulation socket, so let's see if this is
1106 * an encapsulated packet.
1107 * If it's a keepalive packet, then just eat it.
1108 * If it's an encapsulateed packet, then pass it to the
1109 * IPsec xfrm input and return the response
1110 * appropriately. Otherwise, just fall through and
1111 * pass this up the UDP socket.
1112 */
1113 int ret;
1114
1115 ret = udp_encap_rcv(sk, skb);
1116 if (ret == 0) {
1117 /* Eat the packet .. */
1118 kfree_skb(skb);
1119 return 0;
1120 }
1121 if (ret < 0) {
1122 /* process the ESP packet */
1123 ret = xfrm4_rcv_encap(skb, up->encap_type);
1124 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
1125 return -ret;
1126 }
1127 /* FALLTHROUGH -- it's a UDP Packet */
1128 }
1129
1130 /*
1131 * UDP-Lite specific tests, ignored on UDP sockets
1132 */
1133 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1134
1135 /*
1136 * MIB statistics other than incrementing the error count are
1137 * disabled for the following two types of errors: these depend
1138 * on the application settings, not on the functioning of the
1139 * protocol stack as such.
1140 *
1141 * RFC 3828 here recommends (sec 3.3): "There should also be a
1142 * way ... to ... at least let the receiving application block
1143 * delivery of packets with coverage values less than a value
1144 * provided by the application."
1145 */
1146 if (up->pcrlen == 0) { /* full coverage was set */
1147 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1148 "%d while full coverage %d requested\n",
1149 UDP_SKB_CB(skb)->cscov, skb->len);
1150 goto drop;
1151 }
1152 /* The next case involves violating the min. coverage requested
1153 * by the receiver. This is subtle: if receiver wants x and x is
1154 * greater than the buffersize/MTU then receiver will complain
1155 * that it wants x while sender emits packets of smaller size y.
1156 * Therefore the above ...()->partial_cov statement is essential.
1157 */
1158 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1159 LIMIT_NETDEBUG(KERN_WARNING
1160 "UDPLITE: coverage %d too small, need min %d\n",
1161 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1162 goto drop;
1163 }
1164 }
1165
1166 if (sk->sk_filter) {
1167 if (udp_lib_checksum_complete(skb))
1168 goto drop;
1169 }
1170
1171 if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
1172 /* Note that an ENOMEM error is charged twice */
1173 if (rc == -ENOMEM)
1174 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
1175 goto drop;
1176 }
1177
1178 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
1179 return 0;
1180
1181 drop:
1182 UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
1183 kfree_skb(skb);
1184 return -1;
1185 }
1186
1187 /*
1188 * Multicasts and broadcasts go to each listener.
1189 *
1190 * Note: called only from the BH handler context,
1191 * so we don't need to lock the hashes.
1192 */
1193 static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
1194 struct udphdr *uh,
1195 __be32 saddr, __be32 daddr,
1196 struct hlist_head udptable[])
1197 {
1198 struct sock *sk, *skw, *sknext;
1199 int dif;
1200 int hport = ntohs(uh->dest);
1201 unsigned int hash = hash_port_and_addr(hport, daddr);
1202 unsigned int hashwild = hash_port_and_addr(hport, 0);
1203
1204 dif = skb->dev->ifindex;
1205
1206 read_lock(&udp_hash_lock);
1207
1208 sk = sk_head(&udptable[hash & (UDP_HTABLE_SIZE - 1)]);
1209 skw = sk_head(&udptable[hashwild & (UDP_HTABLE_SIZE - 1)]);
1210
1211 sk = udp_v4_mcast_next(sk, hash, hport, daddr, uh->source, saddr, dif);
1212 if (!sk) {
1213 hash = hashwild;
1214 sk = udp_v4_mcast_next(skw, hash, hport, daddr, uh->source,
1215 saddr, dif);
1216 }
1217 if (sk) {
1218 do {
1219 struct sk_buff *skb1 = skb;
1220 sknext = udp_v4_mcast_next(sk_next(sk), hash, hport,
1221 daddr, uh->source, saddr, dif);
1222 if (!sknext && hash != hashwild) {
1223 hash = hashwild;
1224 sknext = udp_v4_mcast_next(skw, hash, hport,
1225 daddr, uh->source, saddr, dif);
1226 }
1227 if (sknext)
1228 skb1 = skb_clone(skb, GFP_ATOMIC);
1229
1230 if (skb1) {
1231 int ret = udp_queue_rcv_skb(sk, skb1);
1232 if (ret > 0)
1233 /*
1234 * we should probably re-process
1235 * instead of dropping packets here.
1236 */
1237 kfree_skb(skb1);
1238 }
1239 sk = sknext;
1240 } while (sknext);
1241 } else
1242 kfree_skb(skb);
1243 read_unlock(&udp_hash_lock);
1244 return 0;
1245 }
1246
1247 /* Initialize UDP checksum. If exited with zero value (success),
1248 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1249 * Otherwise, csum completion requires chacksumming packet body,
1250 * including udp header and folding it to skb->csum.
1251 */
1252 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1253 int proto)
1254 {
1255 const struct iphdr *iph;
1256 int err;
1257
1258 UDP_SKB_CB(skb)->partial_cov = 0;
1259 UDP_SKB_CB(skb)->cscov = skb->len;
1260
1261 if (proto == IPPROTO_UDPLITE) {
1262 err = udplite_checksum_init(skb, uh);
1263 if (err)
1264 return err;
1265 }
1266
1267 iph = ip_hdr(skb);
1268 if (uh->check == 0) {
1269 skb->ip_summed = CHECKSUM_UNNECESSARY;
1270 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1271 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1272 proto, skb->csum))
1273 skb->ip_summed = CHECKSUM_UNNECESSARY;
1274 }
1275 if (!skb_csum_unnecessary(skb))
1276 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1277 skb->len, proto, 0);
1278 /* Probably, we should checksum udp header (it should be in cache
1279 * in any case) and data in tiny packets (< rx copybreak).
1280 */
1281
1282 return 0;
1283 }
1284
1285 /*
1286 * All we need to do is get the socket, and then do a checksum.
1287 */
1288
1289 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
1290 int proto)
1291 {
1292 struct sock *sk;
1293 struct udphdr *uh = udp_hdr(skb);
1294 unsigned short ulen;
1295 struct rtable *rt = (struct rtable*)skb->dst;
1296 __be32 saddr = ip_hdr(skb)->saddr;
1297 __be32 daddr = ip_hdr(skb)->daddr;
1298
1299 /*
1300 * Validate the packet.
1301 */
1302 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1303 goto drop; /* No space for header. */
1304
1305 ulen = ntohs(uh->len);
1306 if (ulen > skb->len)
1307 goto short_packet;
1308
1309 if (proto == IPPROTO_UDP) {
1310 /* UDP validates ulen. */
1311 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1312 goto short_packet;
1313 uh = udp_hdr(skb);
1314 }
1315
1316 if (udp4_csum_init(skb, uh, proto))
1317 goto csum_error;
1318
1319 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1320 return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
1321
1322 sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
1323 skb->dev->ifindex, udptable);
1324
1325 if (sk != NULL) {
1326 int ret = udp_queue_rcv_skb(sk, skb);
1327 sock_put(sk);
1328
1329 /* a return value > 0 means to resubmit the input, but
1330 * it wants the return to be -protocol, or 0
1331 */
1332 if (ret > 0)
1333 return -ret;
1334 return 0;
1335 }
1336
1337 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1338 goto drop;
1339 nf_reset(skb);
1340
1341 /* No socket. Drop packet silently, if checksum is wrong */
1342 if (udp_lib_checksum_complete(skb))
1343 goto csum_error;
1344
1345 UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1346 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1347
1348 /*
1349 * Hmm. We got an UDP packet to a port to which we
1350 * don't wanna listen. Ignore it.
1351 */
1352 kfree_skb(skb);
1353 return 0;
1354
1355 short_packet:
1356 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
1357 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1358 NIPQUAD(saddr),
1359 ntohs(uh->source),
1360 ulen,
1361 skb->len,
1362 NIPQUAD(daddr),
1363 ntohs(uh->dest));
1364 goto drop;
1365
1366 csum_error:
1367 /*
1368 * RFC1122: OK. Discards the bad packet silently (as far as
1369 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1370 */
1371 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
1372 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1373 NIPQUAD(saddr),
1374 ntohs(uh->source),
1375 NIPQUAD(daddr),
1376 ntohs(uh->dest),
1377 ulen);
1378 drop:
1379 UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1380 kfree_skb(skb);
1381 return 0;
1382 }
1383
1384 int udp_rcv(struct sk_buff *skb)
1385 {
1386 return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
1387 }
1388
1389 int udp_destroy_sock(struct sock *sk)
1390 {
1391 lock_sock(sk);
1392 udp_flush_pending_frames(sk);
1393 release_sock(sk);
1394 return 0;
1395 }
1396
1397 /*
1398 * Socket option code for UDP
1399 */
1400 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1401 char __user *optval, int optlen,
1402 int (*push_pending_frames)(struct sock *))
1403 {
1404 struct udp_sock *up = udp_sk(sk);
1405 int val;
1406 int err = 0;
1407
1408 if (optlen<sizeof(int))
1409 return -EINVAL;
1410
1411 if (get_user(val, (int __user *)optval))
1412 return -EFAULT;
1413
1414 switch (optname) {
1415 case UDP_CORK:
1416 if (val != 0) {
1417 up->corkflag = 1;
1418 } else {
1419 up->corkflag = 0;
1420 lock_sock(sk);
1421 (*push_pending_frames)(sk);
1422 release_sock(sk);
1423 }
1424 break;
1425
1426 case UDP_ENCAP:
1427 switch (val) {
1428 case 0:
1429 case UDP_ENCAP_ESPINUDP:
1430 case UDP_ENCAP_ESPINUDP_NON_IKE:
1431 up->encap_type = val;
1432 break;
1433 default:
1434 err = -ENOPROTOOPT;
1435 break;
1436 }
1437 break;
1438
1439 /*
1440 * UDP-Lite's partial checksum coverage (RFC 3828).
1441 */
1442 /* The sender sets actual checksum coverage length via this option.
1443 * The case coverage > packet length is handled by send module. */
1444 case UDPLITE_SEND_CSCOV:
1445 if (!up->pcflag) /* Disable the option on UDP sockets */
1446 return -ENOPROTOOPT;
1447 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1448 val = 8;
1449 up->pcslen = val;
1450 up->pcflag |= UDPLITE_SEND_CC;
1451 break;
1452
1453 /* The receiver specifies a minimum checksum coverage value. To make
1454 * sense, this should be set to at least 8 (as done below). If zero is
1455 * used, this again means full checksum coverage. */
1456 case UDPLITE_RECV_CSCOV:
1457 if (!up->pcflag) /* Disable the option on UDP sockets */
1458 return -ENOPROTOOPT;
1459 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1460 val = 8;
1461 up->pcrlen = val;
1462 up->pcflag |= UDPLITE_RECV_CC;
1463 break;
1464
1465 default:
1466 err = -ENOPROTOOPT;
1467 break;
1468 }
1469
1470 return err;
1471 }
1472
1473 int udp_setsockopt(struct sock *sk, int level, int optname,
1474 char __user *optval, int optlen)
1475 {
1476 if (level == SOL_UDP || level == SOL_UDPLITE)
1477 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1478 udp_push_pending_frames);
1479 return ip_setsockopt(sk, level, optname, optval, optlen);
1480 }
1481
1482 #ifdef CONFIG_COMPAT
1483 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1484 char __user *optval, int optlen)
1485 {
1486 if (level == SOL_UDP || level == SOL_UDPLITE)
1487 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1488 udp_push_pending_frames);
1489 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1490 }
1491 #endif
1492
1493 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1494 char __user *optval, int __user *optlen)
1495 {
1496 struct udp_sock *up = udp_sk(sk);
1497 int val, len;
1498
1499 if (get_user(len,optlen))
1500 return -EFAULT;
1501
1502 len = min_t(unsigned int, len, sizeof(int));
1503
1504 if (len < 0)
1505 return -EINVAL;
1506
1507 switch (optname) {
1508 case UDP_CORK:
1509 val = up->corkflag;
1510 break;
1511
1512 case UDP_ENCAP:
1513 val = up->encap_type;
1514 break;
1515
1516 /* The following two cannot be changed on UDP sockets, the return is
1517 * always 0 (which corresponds to the full checksum coverage of UDP). */
1518 case UDPLITE_SEND_CSCOV:
1519 val = up->pcslen;
1520 break;
1521
1522 case UDPLITE_RECV_CSCOV:
1523 val = up->pcrlen;
1524 break;
1525
1526 default:
1527 return -ENOPROTOOPT;
1528 }
1529
1530 if (put_user(len, optlen))
1531 return -EFAULT;
1532 if (copy_to_user(optval, &val,len))
1533 return -EFAULT;
1534 return 0;
1535 }
1536
1537 int udp_getsockopt(struct sock *sk, int level, int optname,
1538 char __user *optval, int __user *optlen)
1539 {
1540 if (level == SOL_UDP || level == SOL_UDPLITE)
1541 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1542 return ip_getsockopt(sk, level, optname, optval, optlen);
1543 }
1544
1545 #ifdef CONFIG_COMPAT
1546 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1547 char __user *optval, int __user *optlen)
1548 {
1549 if (level == SOL_UDP || level == SOL_UDPLITE)
1550 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1551 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1552 }
1553 #endif
1554 /**
1555 * udp_poll - wait for a UDP event.
1556 * @file - file struct
1557 * @sock - socket
1558 * @wait - poll table
1559 *
1560 * This is same as datagram poll, except for the special case of
1561 * blocking sockets. If application is using a blocking fd
1562 * and a packet with checksum error is in the queue;
1563 * then it could get return from select indicating data available
1564 * but then block when reading it. Add special case code
1565 * to work around these arguably broken applications.
1566 */
1567 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1568 {
1569 unsigned int mask = datagram_poll(file, sock, wait);
1570 struct sock *sk = sock->sk;
1571 int is_lite = IS_UDPLITE(sk);
1572
1573 /* Check for false positives due to checksum errors */
1574 if ( (mask & POLLRDNORM) &&
1575 !(file->f_flags & O_NONBLOCK) &&
1576 !(sk->sk_shutdown & RCV_SHUTDOWN)){
1577 struct sk_buff_head *rcvq = &sk->sk_receive_queue;
1578 struct sk_buff *skb;
1579
1580 spin_lock_bh(&rcvq->lock);
1581 while ((skb = skb_peek(rcvq)) != NULL &&
1582 udp_lib_checksum_complete(skb)) {
1583 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
1584 __skb_unlink(skb, rcvq);
1585 kfree_skb(skb);
1586 }
1587 spin_unlock_bh(&rcvq->lock);
1588
1589 /* nothing to see, move along */
1590 if (skb == NULL)
1591 mask &= ~(POLLIN | POLLRDNORM);
1592 }
1593
1594 return mask;
1595
1596 }
1597
1598 struct proto udp_prot = {
1599 .name = "UDP",
1600 .owner = THIS_MODULE,
1601 .close = udp_lib_close,
1602 .connect = ip4_datagram_connect,
1603 .disconnect = udp_disconnect,
1604 .ioctl = udp_ioctl,
1605 .destroy = udp_destroy_sock,
1606 .setsockopt = udp_setsockopt,
1607 .getsockopt = udp_getsockopt,
1608 .sendmsg = udp_sendmsg,
1609 .recvmsg = udp_recvmsg,
1610 .sendpage = udp_sendpage,
1611 .backlog_rcv = udp_queue_rcv_skb,
1612 .hash = udp_lib_hash,
1613 .unhash = udp_lib_unhash,
1614 .get_port = udp_v4_get_port,
1615 .obj_size = sizeof(struct udp_sock),
1616 #ifdef CONFIG_COMPAT
1617 .compat_setsockopt = compat_udp_setsockopt,
1618 .compat_getsockopt = compat_udp_getsockopt,
1619 #endif
1620 };
1621
1622 /* ------------------------------------------------------------------------ */
1623 #ifdef CONFIG_PROC_FS
1624
1625 static struct sock *udp_get_first(struct seq_file *seq)
1626 {
1627 struct sock *sk;
1628 struct udp_iter_state *state = seq->private;
1629
1630 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1631 struct hlist_node *node;
1632 sk_for_each(sk, node, state->hashtable + state->bucket) {
1633 if (sk->sk_family == state->family)
1634 goto found;
1635 }
1636 }
1637 sk = NULL;
1638 found:
1639 return sk;
1640 }
1641
1642 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1643 {
1644 struct udp_iter_state *state = seq->private;
1645
1646 do {
1647 sk = sk_next(sk);
1648 try_again:
1649 ;
1650 } while (sk && sk->sk_family != state->family);
1651
1652 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
1653 sk = sk_head(state->hashtable + state->bucket);
1654 goto try_again;
1655 }
1656 return sk;
1657 }
1658
1659 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1660 {
1661 struct sock *sk = udp_get_first(seq);
1662
1663 if (sk)
1664 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1665 --pos;
1666 return pos ? NULL : sk;
1667 }
1668
1669 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1670 {
1671 read_lock(&udp_hash_lock);
1672 return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
1673 }
1674
1675 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1676 {
1677 struct sock *sk;
1678
1679 if (v == (void *)1)
1680 sk = udp_get_idx(seq, 0);
1681 else
1682 sk = udp_get_next(seq, v);
1683
1684 ++*pos;
1685 return sk;
1686 }
1687
1688 static void udp_seq_stop(struct seq_file *seq, void *v)
1689 {
1690 read_unlock(&udp_hash_lock);
1691 }
1692
1693 static int udp_seq_open(struct inode *inode, struct file *file)
1694 {
1695 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1696 struct seq_file *seq;
1697 int rc = -ENOMEM;
1698 struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
1699
1700 if (!s)
1701 goto out;
1702 s->family = afinfo->family;
1703 s->hashtable = afinfo->hashtable;
1704 s->seq_ops.start = udp_seq_start;
1705 s->seq_ops.next = udp_seq_next;
1706 s->seq_ops.show = afinfo->seq_show;
1707 s->seq_ops.stop = udp_seq_stop;
1708
1709 rc = seq_open(file, &s->seq_ops);
1710 if (rc)
1711 goto out_kfree;
1712
1713 seq = file->private_data;
1714 seq->private = s;
1715 out:
1716 return rc;
1717 out_kfree:
1718 kfree(s);
1719 goto out;
1720 }
1721
1722 /* ------------------------------------------------------------------------ */
1723 int udp_proc_register(struct udp_seq_afinfo *afinfo)
1724 {
1725 struct proc_dir_entry *p;
1726 int rc = 0;
1727
1728 if (!afinfo)
1729 return -EINVAL;
1730 afinfo->seq_fops->owner = afinfo->owner;
1731 afinfo->seq_fops->open = udp_seq_open;
1732 afinfo->seq_fops->read = seq_read;
1733 afinfo->seq_fops->llseek = seq_lseek;
1734 afinfo->seq_fops->release = seq_release_private;
1735
1736 p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
1737 if (p)
1738 p->data = afinfo;
1739 else
1740 rc = -ENOMEM;
1741 return rc;
1742 }
1743
1744 void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
1745 {
1746 if (!afinfo)
1747 return;
1748 proc_net_remove(afinfo->name);
1749 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
1750 }
1751
1752 /* ------------------------------------------------------------------------ */
1753 static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
1754 {
1755 struct inet_sock *inet = inet_sk(sp);
1756 __be32 dest = inet->daddr;
1757 __be32 src = inet->rcv_saddr;
1758 __u16 destp = ntohs(inet->dport);
1759 __u16 srcp = ntohs(inet->sport);
1760
1761 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
1762 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
1763 bucket, src, srcp, dest, destp, sp->sk_state,
1764 atomic_read(&sp->sk_wmem_alloc),
1765 atomic_read(&sp->sk_rmem_alloc),
1766 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1767 atomic_read(&sp->sk_refcnt), sp);
1768 }
1769
1770 int udp4_seq_show(struct seq_file *seq, void *v)
1771 {
1772 if (v == SEQ_START_TOKEN)
1773 seq_printf(seq, "%-127s\n",
1774 " sl local_address rem_address st tx_queue "
1775 "rx_queue tr tm->when retrnsmt uid timeout "
1776 "inode");
1777 else {
1778 char tmpbuf[129];
1779 struct udp_iter_state *state = seq->private;
1780
1781 udp4_format_sock(v, tmpbuf, state->bucket);
1782 seq_printf(seq, "%-127s\n", tmpbuf);
1783 }
1784 return 0;
1785 }
1786
1787 /* ------------------------------------------------------------------------ */
1788 static struct file_operations udp4_seq_fops;
1789 static struct udp_seq_afinfo udp4_seq_afinfo = {
1790 .owner = THIS_MODULE,
1791 .name = "udp",
1792 .family = AF_INET,
1793 .hashtable = udp_hash,
1794 .seq_show = udp4_seq_show,
1795 .seq_fops = &udp4_seq_fops,
1796 };
1797
1798 int __init udp4_proc_init(void)
1799 {
1800 return udp_proc_register(&udp4_seq_afinfo);
1801 }
1802
1803 void udp4_proc_exit(void)
1804 {
1805 udp_proc_unregister(&udp4_seq_afinfo);
1806 }
1807 #endif /* CONFIG_PROC_FS */
1808
1809 EXPORT_SYMBOL(udp_disconnect);
1810 EXPORT_SYMBOL(udp_hash);
1811 EXPORT_SYMBOL(udp_hash_lock);
1812 EXPORT_SYMBOL(udp_ioctl);
1813 EXPORT_SYMBOL(udp_get_port);
1814 EXPORT_SYMBOL(udp_prot);
1815 EXPORT_SYMBOL(udp_sendmsg);
1816 EXPORT_SYMBOL(udp_lib_getsockopt);
1817 EXPORT_SYMBOL(udp_lib_setsockopt);
1818 EXPORT_SYMBOL(udp_poll);
1819
1820 #ifdef CONFIG_PROC_FS
1821 EXPORT_SYMBOL(udp_proc_register);
1822 EXPORT_SYMBOL(udp_proc_unregister);
1823 #endif
Linux kernel - Deliverables
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