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[UDP]: Fix AF-specific references in AF-agnostic code.
[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 udp_hash_port(__u16 port)
122 {
123 return port;
124 }
125
126 static inline int __udp_lib_port_inuse(unsigned int hash, int port,
127 const struct sock *this_sk,
128 struct hlist_head udptable[],
129 const struct udp_get_port_ops *ops)
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 (this_sk) {
142 if (ops->saddr_cmp(sk, this_sk))
143 return 1;
144 } else if (ops->saddr_any(sk))
145 return 1;
146 }
147 return 0;
148 }
149
150 /**
151 * __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
152 *
153 * @sk: socket struct in question
154 * @snum: port number to look up
155 * @udptable: hash list table, must be of UDP_HTABLE_SIZE
156 * @port_rover: pointer to record of last unallocated port
157 * @ops: AF-dependent address operations
158 */
159 int __udp_lib_get_port(struct sock *sk, unsigned short snum,
160 struct hlist_head udptable[], int *port_rover,
161 const struct udp_get_port_ops *ops)
162 {
163 struct hlist_node *node;
164 struct hlist_head *head;
165 struct sock *sk2;
166 unsigned int hash;
167 int error = 1;
168
169 write_lock_bh(&udp_hash_lock);
170 if (snum == 0) {
171 int best_size_so_far, best, result, i;
172
173 if (*port_rover > sysctl_local_port_range[1] ||
174 *port_rover < sysctl_local_port_range[0])
175 *port_rover = sysctl_local_port_range[0];
176 best_size_so_far = 32767;
177 best = result = *port_rover;
178 for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
179 int size;
180
181 hash = ops->hash_port_and_rcv_saddr(result, sk);
182 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
183 if (hlist_empty(head)) {
184 if (result > sysctl_local_port_range[1])
185 result = sysctl_local_port_range[0] +
186 ((result - sysctl_local_port_range[0]) &
187 (UDP_HTABLE_SIZE - 1));
188 goto gotit;
189 }
190 size = 0;
191 sk_for_each(sk2, node, head) {
192 if (++size >= best_size_so_far)
193 goto next;
194 }
195 best_size_so_far = size;
196 best = result;
197 next:
198 ;
199 }
200 result = best;
201 for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE;
202 i++, result += UDP_HTABLE_SIZE) {
203 if (result > sysctl_local_port_range[1])
204 result = sysctl_local_port_range[0]
205 + ((result - sysctl_local_port_range[0]) &
206 (UDP_HTABLE_SIZE - 1));
207 hash = udp_hash_port(result);
208 if (__udp_lib_port_inuse(hash, result,
209 NULL, udptable, ops))
210 continue;
211 if (ops->saddr_any(sk))
212 break;
213
214 hash = ops->hash_port_and_rcv_saddr(result, sk);
215 if (! __udp_lib_port_inuse(hash, result,
216 sk, udptable, ops))
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 = udp_hash_port(snum);
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 ops->saddr_cmp(sk, sk2))
235 goto fail;
236
237 if (!ops->saddr_any(sk)) {
238 hash = ops->hash_port_and_rcv_saddr(snum, sk);
239 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
240
241 sk_for_each(sk2, node, head)
242 if (sk2->sk_hash == hash &&
243 sk2 != sk &&
244 inet_sk(sk2)->num == snum &&
245 (!sk2->sk_reuse || !sk->sk_reuse) &&
246 (!sk2->sk_bound_dev_if ||
247 !sk->sk_bound_dev_if ||
248 sk2->sk_bound_dev_if ==
249 sk->sk_bound_dev_if) &&
250 ops->saddr_cmp(sk, sk2))
251 goto fail;
252 }
253 }
254 inet_sk(sk)->num = snum;
255 sk->sk_hash = hash;
256 if (sk_unhashed(sk)) {
257 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
258 sk_add_node(sk, head);
259 sock_prot_inc_use(sk->sk_prot);
260 }
261 error = 0;
262 fail:
263 write_unlock_bh(&udp_hash_lock);
264 return error;
265 }
266
267 int udp_get_port(struct sock *sk, unsigned short snum,
268 const struct udp_get_port_ops *ops)
269 {
270 return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, ops);
271 }
272
273 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
274 {
275 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
276
277 return ( !ipv6_only_sock(sk2) &&
278 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
279 inet1->rcv_saddr == inet2->rcv_saddr ));
280 }
281
282 static int ipv4_rcv_saddr_any(const struct sock *sk)
283 {
284 return !inet_sk(sk)->rcv_saddr;
285 }
286
287 static inline unsigned int ipv4_hash_port_and_addr(__u16 port, __be32 addr)
288 {
289 addr ^= addr >> 16;
290 addr ^= addr >> 8;
291 return port ^ addr;
292 }
293
294 static unsigned int ipv4_hash_port_and_rcv_saddr(__u16 port,
295 const struct sock *sk)
296 {
297 return ipv4_hash_port_and_addr(port, inet_sk(sk)->rcv_saddr);
298 }
299
300 const struct udp_get_port_ops udp_ipv4_ops = {
301 .saddr_cmp = ipv4_rcv_saddr_equal,
302 .saddr_any = ipv4_rcv_saddr_any,
303 .hash_port_and_rcv_saddr = ipv4_hash_port_and_rcv_saddr,
304 };
305
306 static inline int udp_v4_get_port(struct sock *sk, unsigned short snum)
307 {
308 return udp_get_port(sk, snum, &udp_ipv4_ops);
309 }
310
311 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
312 * harder than this. -DaveM
313 */
314 static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
315 __be32 daddr, __be16 dport,
316 int dif, struct hlist_head udptable[])
317 {
318 struct sock *sk, *result = NULL;
319 struct hlist_node *node;
320 unsigned int hash, hashwild;
321 int score, best = -1, hport = ntohs(dport);
322
323 hash = ipv4_hash_port_and_addr(hport, daddr);
324 hashwild = udp_hash_port(hport);
325
326 read_lock(&udp_hash_lock);
327
328 lookup:
329
330 sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
331 struct inet_sock *inet = inet_sk(sk);
332
333 if (sk->sk_hash != hash || ipv6_only_sock(sk) ||
334 inet->num != hport)
335 continue;
336
337 score = (sk->sk_family == PF_INET ? 1 : 0);
338 if (inet->rcv_saddr) {
339 if (inet->rcv_saddr != daddr)
340 continue;
341 score+=2;
342 }
343 if (inet->daddr) {
344 if (inet->daddr != saddr)
345 continue;
346 score+=2;
347 }
348 if (inet->dport) {
349 if (inet->dport != sport)
350 continue;
351 score+=2;
352 }
353 if (sk->sk_bound_dev_if) {
354 if (sk->sk_bound_dev_if != dif)
355 continue;
356 score+=2;
357 }
358 if (score == 9) {
359 result = sk;
360 goto found;
361 } else if (score > best) {
362 result = sk;
363 best = score;
364 }
365 }
366
367 if (hash != hashwild) {
368 hash = hashwild;
369 goto lookup;
370 }
371 found:
372 if (result)
373 sock_hold(result);
374 read_unlock(&udp_hash_lock);
375 return result;
376 }
377
378 static inline struct sock *udp_v4_mcast_next(struct sock *sk, unsigned int hnum,
379 int hport, __be32 loc_addr,
380 __be16 rmt_port, __be32 rmt_addr,
381 int dif)
382 {
383 struct hlist_node *node;
384 struct sock *s = sk;
385
386 sk_for_each_from(s, node) {
387 struct inet_sock *inet = inet_sk(s);
388
389 if (s->sk_hash != hnum ||
390 inet->num != hport ||
391 (inet->daddr && inet->daddr != rmt_addr) ||
392 (inet->dport != rmt_port && inet->dport) ||
393 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
394 ipv6_only_sock(s) ||
395 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
396 continue;
397 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
398 continue;
399 goto found;
400 }
401 s = NULL;
402 found:
403 return s;
404 }
405
406 /*
407 * This routine is called by the ICMP module when it gets some
408 * sort of error condition. If err < 0 then the socket should
409 * be closed and the error returned to the user. If err > 0
410 * it's just the icmp type << 8 | icmp code.
411 * Header points to the ip header of the error packet. We move
412 * on past this. Then (as it used to claim before adjustment)
413 * header points to the first 8 bytes of the udp header. We need
414 * to find the appropriate port.
415 */
416
417 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
418 {
419 struct inet_sock *inet;
420 struct iphdr *iph = (struct iphdr*)skb->data;
421 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
422 const int type = icmp_hdr(skb)->type;
423 const int code = icmp_hdr(skb)->code;
424 struct sock *sk;
425 int harderr;
426 int err;
427
428 sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
429 skb->dev->ifindex, udptable );
430 if (sk == NULL) {
431 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
432 return; /* No socket for error */
433 }
434
435 err = 0;
436 harderr = 0;
437 inet = inet_sk(sk);
438
439 switch (type) {
440 default:
441 case ICMP_TIME_EXCEEDED:
442 err = EHOSTUNREACH;
443 break;
444 case ICMP_SOURCE_QUENCH:
445 goto out;
446 case ICMP_PARAMETERPROB:
447 err = EPROTO;
448 harderr = 1;
449 break;
450 case ICMP_DEST_UNREACH:
451 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
452 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
453 err = EMSGSIZE;
454 harderr = 1;
455 break;
456 }
457 goto out;
458 }
459 err = EHOSTUNREACH;
460 if (code <= NR_ICMP_UNREACH) {
461 harderr = icmp_err_convert[code].fatal;
462 err = icmp_err_convert[code].errno;
463 }
464 break;
465 }
466
467 /*
468 * RFC1122: OK. Passes ICMP errors back to application, as per
469 * 4.1.3.3.
470 */
471 if (!inet->recverr) {
472 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
473 goto out;
474 } else {
475 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
476 }
477 sk->sk_err = err;
478 sk->sk_error_report(sk);
479 out:
480 sock_put(sk);
481 }
482
483 void udp_err(struct sk_buff *skb, u32 info)
484 {
485 return __udp4_lib_err(skb, info, udp_hash);
486 }
487
488 /*
489 * Throw away all pending data and cancel the corking. Socket is locked.
490 */
491 static void udp_flush_pending_frames(struct sock *sk)
492 {
493 struct udp_sock *up = udp_sk(sk);
494
495 if (up->pending) {
496 up->len = 0;
497 up->pending = 0;
498 ip_flush_pending_frames(sk);
499 }
500 }
501
502 /**
503 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
504 * @sk: socket we are sending on
505 * @skb: sk_buff containing the filled-in UDP header
506 * (checksum field must be zeroed out)
507 */
508 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
509 __be32 src, __be32 dst, int len )
510 {
511 unsigned int offset;
512 struct udphdr *uh = udp_hdr(skb);
513 __wsum csum = 0;
514
515 if (skb_queue_len(&sk->sk_write_queue) == 1) {
516 /*
517 * Only one fragment on the socket.
518 */
519 skb->csum_start = skb_transport_header(skb) - skb->head;
520 skb->csum_offset = offsetof(struct udphdr, check);
521 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
522 } else {
523 /*
524 * HW-checksum won't work as there are two or more
525 * fragments on the socket so that all csums of sk_buffs
526 * should be together
527 */
528 offset = skb_transport_offset(skb);
529 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
530
531 skb->ip_summed = CHECKSUM_NONE;
532
533 skb_queue_walk(&sk->sk_write_queue, skb) {
534 csum = csum_add(csum, skb->csum);
535 }
536
537 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
538 if (uh->check == 0)
539 uh->check = CSUM_MANGLED_0;
540 }
541 }
542
543 /*
544 * Push out all pending data as one UDP datagram. Socket is locked.
545 */
546 static int udp_push_pending_frames(struct sock *sk)
547 {
548 struct udp_sock *up = udp_sk(sk);
549 struct inet_sock *inet = inet_sk(sk);
550 struct flowi *fl = &inet->cork.fl;
551 struct sk_buff *skb;
552 struct udphdr *uh;
553 int err = 0;
554 __wsum csum = 0;
555
556 /* Grab the skbuff where UDP header space exists. */
557 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
558 goto out;
559
560 /*
561 * Create a UDP header
562 */
563 uh = udp_hdr(skb);
564 uh->source = fl->fl_ip_sport;
565 uh->dest = fl->fl_ip_dport;
566 uh->len = htons(up->len);
567 uh->check = 0;
568
569 if (up->pcflag) /* UDP-Lite */
570 csum = udplite_csum_outgoing(sk, skb);
571
572 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
573
574 skb->ip_summed = CHECKSUM_NONE;
575 goto send;
576
577 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
578
579 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
580 goto send;
581
582 } else /* `normal' UDP */
583 csum = udp_csum_outgoing(sk, skb);
584
585 /* add protocol-dependent pseudo-header */
586 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
587 sk->sk_protocol, csum );
588 if (uh->check == 0)
589 uh->check = CSUM_MANGLED_0;
590
591 send:
592 err = ip_push_pending_frames(sk);
593 out:
594 up->len = 0;
595 up->pending = 0;
596 return err;
597 }
598
599 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
600 size_t len)
601 {
602 struct inet_sock *inet = inet_sk(sk);
603 struct udp_sock *up = udp_sk(sk);
604 int ulen = len;
605 struct ipcm_cookie ipc;
606 struct rtable *rt = NULL;
607 int free = 0;
608 int connected = 0;
609 __be32 daddr, faddr, saddr;
610 __be16 dport;
611 u8 tos;
612 int err, is_udplite = up->pcflag;
613 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
614 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
615
616 if (len > 0xFFFF)
617 return -EMSGSIZE;
618
619 /*
620 * Check the flags.
621 */
622
623 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */
624 return -EOPNOTSUPP;
625
626 ipc.opt = NULL;
627
628 if (up->pending) {
629 /*
630 * There are pending frames.
631 * The socket lock must be held while it's corked.
632 */
633 lock_sock(sk);
634 if (likely(up->pending)) {
635 if (unlikely(up->pending != AF_INET)) {
636 release_sock(sk);
637 return -EINVAL;
638 }
639 goto do_append_data;
640 }
641 release_sock(sk);
642 }
643 ulen += sizeof(struct udphdr);
644
645 /*
646 * Get and verify the address.
647 */
648 if (msg->msg_name) {
649 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
650 if (msg->msg_namelen < sizeof(*usin))
651 return -EINVAL;
652 if (usin->sin_family != AF_INET) {
653 if (usin->sin_family != AF_UNSPEC)
654 return -EAFNOSUPPORT;
655 }
656
657 daddr = usin->sin_addr.s_addr;
658 dport = usin->sin_port;
659 if (dport == 0)
660 return -EINVAL;
661 } else {
662 if (sk->sk_state != TCP_ESTABLISHED)
663 return -EDESTADDRREQ;
664 daddr = inet->daddr;
665 dport = inet->dport;
666 /* Open fast path for connected socket.
667 Route will not be used, if at least one option is set.
668 */
669 connected = 1;
670 }
671 ipc.addr = inet->saddr;
672
673 ipc.oif = sk->sk_bound_dev_if;
674 if (msg->msg_controllen) {
675 err = ip_cmsg_send(msg, &ipc);
676 if (err)
677 return err;
678 if (ipc.opt)
679 free = 1;
680 connected = 0;
681 }
682 if (!ipc.opt)
683 ipc.opt = inet->opt;
684
685 saddr = ipc.addr;
686 ipc.addr = faddr = daddr;
687
688 if (ipc.opt && ipc.opt->srr) {
689 if (!daddr)
690 return -EINVAL;
691 faddr = ipc.opt->faddr;
692 connected = 0;
693 }
694 tos = RT_TOS(inet->tos);
695 if (sock_flag(sk, SOCK_LOCALROUTE) ||
696 (msg->msg_flags & MSG_DONTROUTE) ||
697 (ipc.opt && ipc.opt->is_strictroute)) {
698 tos |= RTO_ONLINK;
699 connected = 0;
700 }
701
702 if (MULTICAST(daddr)) {
703 if (!ipc.oif)
704 ipc.oif = inet->mc_index;
705 if (!saddr)
706 saddr = inet->mc_addr;
707 connected = 0;
708 }
709
710 if (connected)
711 rt = (struct rtable*)sk_dst_check(sk, 0);
712
713 if (rt == NULL) {
714 struct flowi fl = { .oif = ipc.oif,
715 .nl_u = { .ip4_u =
716 { .daddr = faddr,
717 .saddr = saddr,
718 .tos = tos } },
719 .proto = sk->sk_protocol,
720 .uli_u = { .ports =
721 { .sport = inet->sport,
722 .dport = dport } } };
723 security_sk_classify_flow(sk, &fl);
724 err = ip_route_output_flow(&rt, &fl, sk, 1);
725 if (err)
726 goto out;
727
728 err = -EACCES;
729 if ((rt->rt_flags & RTCF_BROADCAST) &&
730 !sock_flag(sk, SOCK_BROADCAST))
731 goto out;
732 if (connected)
733 sk_dst_set(sk, dst_clone(&rt->u.dst));
734 }
735
736 if (msg->msg_flags&MSG_CONFIRM)
737 goto do_confirm;
738 back_from_confirm:
739
740 saddr = rt->rt_src;
741 if (!ipc.addr)
742 daddr = ipc.addr = rt->rt_dst;
743
744 lock_sock(sk);
745 if (unlikely(up->pending)) {
746 /* The socket is already corked while preparing it. */
747 /* ... which is an evident application bug. --ANK */
748 release_sock(sk);
749
750 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
751 err = -EINVAL;
752 goto out;
753 }
754 /*
755 * Now cork the socket to pend data.
756 */
757 inet->cork.fl.fl4_dst = daddr;
758 inet->cork.fl.fl_ip_dport = dport;
759 inet->cork.fl.fl4_src = saddr;
760 inet->cork.fl.fl_ip_sport = inet->sport;
761 up->pending = AF_INET;
762
763 do_append_data:
764 up->len += ulen;
765 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
766 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
767 sizeof(struct udphdr), &ipc, rt,
768 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
769 if (err)
770 udp_flush_pending_frames(sk);
771 else if (!corkreq)
772 err = udp_push_pending_frames(sk);
773 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
774 up->pending = 0;
775 release_sock(sk);
776
777 out:
778 ip_rt_put(rt);
779 if (free)
780 kfree(ipc.opt);
781 if (!err) {
782 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
783 return len;
784 }
785 /*
786 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
787 * ENOBUFS might not be good (it's not tunable per se), but otherwise
788 * we don't have a good statistic (IpOutDiscards but it can be too many
789 * things). We could add another new stat but at least for now that
790 * seems like overkill.
791 */
792 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
793 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
794 }
795 return err;
796
797 do_confirm:
798 dst_confirm(&rt->u.dst);
799 if (!(msg->msg_flags&MSG_PROBE) || len)
800 goto back_from_confirm;
801 err = 0;
802 goto out;
803 }
804
805 int udp_sendpage(struct sock *sk, struct page *page, int offset,
806 size_t size, int flags)
807 {
808 struct udp_sock *up = udp_sk(sk);
809 int ret;
810
811 if (!up->pending) {
812 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
813
814 /* Call udp_sendmsg to specify destination address which
815 * sendpage interface can't pass.
816 * This will succeed only when the socket is connected.
817 */
818 ret = udp_sendmsg(NULL, sk, &msg, 0);
819 if (ret < 0)
820 return ret;
821 }
822
823 lock_sock(sk);
824
825 if (unlikely(!up->pending)) {
826 release_sock(sk);
827
828 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
829 return -EINVAL;
830 }
831
832 ret = ip_append_page(sk, page, offset, size, flags);
833 if (ret == -EOPNOTSUPP) {
834 release_sock(sk);
835 return sock_no_sendpage(sk->sk_socket, page, offset,
836 size, flags);
837 }
838 if (ret < 0) {
839 udp_flush_pending_frames(sk);
840 goto out;
841 }
842
843 up->len += size;
844 if (!(up->corkflag || (flags&MSG_MORE)))
845 ret = udp_push_pending_frames(sk);
846 if (!ret)
847 ret = size;
848 out:
849 release_sock(sk);
850 return ret;
851 }
852
853 /*
854 * IOCTL requests applicable to the UDP protocol
855 */
856
857 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
858 {
859 switch (cmd) {
860 case SIOCOUTQ:
861 {
862 int amount = atomic_read(&sk->sk_wmem_alloc);
863 return put_user(amount, (int __user *)arg);
864 }
865
866 case SIOCINQ:
867 {
868 struct sk_buff *skb;
869 unsigned long amount;
870
871 amount = 0;
872 spin_lock_bh(&sk->sk_receive_queue.lock);
873 skb = skb_peek(&sk->sk_receive_queue);
874 if (skb != NULL) {
875 /*
876 * We will only return the amount
877 * of this packet since that is all
878 * that will be read.
879 */
880 amount = skb->len - sizeof(struct udphdr);
881 }
882 spin_unlock_bh(&sk->sk_receive_queue.lock);
883 return put_user(amount, (int __user *)arg);
884 }
885
886 default:
887 return -ENOIOCTLCMD;
888 }
889
890 return 0;
891 }
892
893 /*
894 * This should be easy, if there is something there we
895 * return it, otherwise we block.
896 */
897
898 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
899 size_t len, int noblock, int flags, int *addr_len)
900 {
901 struct inet_sock *inet = inet_sk(sk);
902 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
903 struct sk_buff *skb;
904 unsigned int ulen, copied;
905 int err;
906 int is_udplite = IS_UDPLITE(sk);
907
908 /*
909 * Check any passed addresses
910 */
911 if (addr_len)
912 *addr_len=sizeof(*sin);
913
914 if (flags & MSG_ERRQUEUE)
915 return ip_recv_error(sk, msg, len);
916
917 try_again:
918 skb = skb_recv_datagram(sk, flags, noblock, &err);
919 if (!skb)
920 goto out;
921
922 ulen = skb->len - sizeof(struct udphdr);
923 copied = len;
924 if (copied > ulen)
925 copied = ulen;
926 else if (copied < ulen)
927 msg->msg_flags |= MSG_TRUNC;
928
929 /*
930 * If checksum is needed at all, try to do it while copying the
931 * data. If the data is truncated, or if we only want a partial
932 * coverage checksum (UDP-Lite), do it before the copy.
933 */
934
935 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
936 if (udp_lib_checksum_complete(skb))
937 goto csum_copy_err;
938 }
939
940 if (skb_csum_unnecessary(skb))
941 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
942 msg->msg_iov, copied );
943 else {
944 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
945
946 if (err == -EINVAL)
947 goto csum_copy_err;
948 }
949
950 if (err)
951 goto out_free;
952
953 sock_recv_timestamp(msg, sk, skb);
954
955 /* Copy the address. */
956 if (sin)
957 {
958 sin->sin_family = AF_INET;
959 sin->sin_port = udp_hdr(skb)->source;
960 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
961 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
962 }
963 if (inet->cmsg_flags)
964 ip_cmsg_recv(msg, skb);
965
966 err = copied;
967 if (flags & MSG_TRUNC)
968 err = ulen;
969
970 out_free:
971 skb_free_datagram(sk, skb);
972 out:
973 return err;
974
975 csum_copy_err:
976 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
977
978 skb_kill_datagram(sk, skb, flags);
979
980 if (noblock)
981 return -EAGAIN;
982 goto try_again;
983 }
984
985
986 int udp_disconnect(struct sock *sk, int flags)
987 {
988 struct inet_sock *inet = inet_sk(sk);
989 /*
990 * 1003.1g - break association.
991 */
992
993 sk->sk_state = TCP_CLOSE;
994 inet->daddr = 0;
995 inet->dport = 0;
996 sk->sk_bound_dev_if = 0;
997 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
998 inet_reset_saddr(sk);
999
1000 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1001 sk->sk_prot->unhash(sk);
1002 inet->sport = 0;
1003 }
1004 sk_dst_reset(sk);
1005 return 0;
1006 }
1007
1008 /* return:
1009 * 1 if the UDP system should process it
1010 * 0 if we should drop this packet
1011 * -1 if it should get processed by xfrm4_rcv_encap
1012 */
1013 static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
1014 {
1015 #ifndef CONFIG_XFRM
1016 return 1;
1017 #else
1018 struct udp_sock *up = udp_sk(sk);
1019 struct udphdr *uh;
1020 struct iphdr *iph;
1021 int iphlen, len;
1022
1023 __u8 *udpdata;
1024 __be32 *udpdata32;
1025 __u16 encap_type = up->encap_type;
1026
1027 /* if we're overly short, let UDP handle it */
1028 len = skb->len - sizeof(struct udphdr);
1029 if (len <= 0)
1030 return 1;
1031
1032 /* if this is not encapsulated socket, then just return now */
1033 if (!encap_type)
1034 return 1;
1035
1036 /* If this is a paged skb, make sure we pull up
1037 * whatever data we need to look at. */
1038 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
1039 return 1;
1040
1041 /* Now we can get the pointers */
1042 uh = udp_hdr(skb);
1043 udpdata = (__u8 *)uh + sizeof(struct udphdr);
1044 udpdata32 = (__be32 *)udpdata;
1045
1046 switch (encap_type) {
1047 default:
1048 case UDP_ENCAP_ESPINUDP:
1049 /* Check if this is a keepalive packet. If so, eat it. */
1050 if (len == 1 && udpdata[0] == 0xff) {
1051 return 0;
1052 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
1053 /* ESP Packet without Non-ESP header */
1054 len = sizeof(struct udphdr);
1055 } else
1056 /* Must be an IKE packet.. pass it through */
1057 return 1;
1058 break;
1059 case UDP_ENCAP_ESPINUDP_NON_IKE:
1060 /* Check if this is a keepalive packet. If so, eat it. */
1061 if (len == 1 && udpdata[0] == 0xff) {
1062 return 0;
1063 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
1064 udpdata32[0] == 0 && udpdata32[1] == 0) {
1065
1066 /* ESP Packet with Non-IKE marker */
1067 len = sizeof(struct udphdr) + 2 * sizeof(u32);
1068 } else
1069 /* Must be an IKE packet.. pass it through */
1070 return 1;
1071 break;
1072 }
1073
1074 /* At this point we are sure that this is an ESPinUDP packet,
1075 * so we need to remove 'len' bytes from the packet (the UDP
1076 * header and optional ESP marker bytes) and then modify the
1077 * protocol to ESP, and then call into the transform receiver.
1078 */
1079 if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1080 return 0;
1081
1082 /* Now we can update and verify the packet length... */
1083 iph = ip_hdr(skb);
1084 iphlen = iph->ihl << 2;
1085 iph->tot_len = htons(ntohs(iph->tot_len) - len);
1086 if (skb->len < iphlen + len) {
1087 /* packet is too small!?! */
1088 return 0;
1089 }
1090
1091 /* pull the data buffer up to the ESP header and set the
1092 * transport header to point to ESP. Keep UDP on the stack
1093 * for later.
1094 */
1095 __skb_pull(skb, len);
1096 skb_reset_transport_header(skb);
1097
1098 /* modify the protocol (it's ESP!) */
1099 iph->protocol = IPPROTO_ESP;
1100
1101 /* and let the caller know to send this into the ESP processor... */
1102 return -1;
1103 #endif
1104 }
1105
1106 /* returns:
1107 * -1: error
1108 * 0: success
1109 * >0: "udp encap" protocol resubmission
1110 *
1111 * Note that in the success and error cases, the skb is assumed to
1112 * have either been requeued or freed.
1113 */
1114 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
1115 {
1116 struct udp_sock *up = udp_sk(sk);
1117 int rc;
1118
1119 /*
1120 * Charge it to the socket, dropping if the queue is full.
1121 */
1122 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1123 goto drop;
1124 nf_reset(skb);
1125
1126 if (up->encap_type) {
1127 /*
1128 * This is an encapsulation socket, so let's see if this is
1129 * an encapsulated packet.
1130 * If it's a keepalive packet, then just eat it.
1131 * If it's an encapsulateed packet, then pass it to the
1132 * IPsec xfrm input and return the response
1133 * appropriately. Otherwise, just fall through and
1134 * pass this up the UDP socket.
1135 */
1136 int ret;
1137
1138 ret = udp_encap_rcv(sk, skb);
1139 if (ret == 0) {
1140 /* Eat the packet .. */
1141 kfree_skb(skb);
1142 return 0;
1143 }
1144 if (ret < 0) {
1145 /* process the ESP packet */
1146 ret = xfrm4_rcv_encap(skb, up->encap_type);
1147 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
1148 return -ret;
1149 }
1150 /* FALLTHROUGH -- it's a UDP Packet */
1151 }
1152
1153 /*
1154 * UDP-Lite specific tests, ignored on UDP sockets
1155 */
1156 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1157
1158 /*
1159 * MIB statistics other than incrementing the error count are
1160 * disabled for the following two types of errors: these depend
1161 * on the application settings, not on the functioning of the
1162 * protocol stack as such.
1163 *
1164 * RFC 3828 here recommends (sec 3.3): "There should also be a
1165 * way ... to ... at least let the receiving application block
1166 * delivery of packets with coverage values less than a value
1167 * provided by the application."
1168 */
1169 if (up->pcrlen == 0) { /* full coverage was set */
1170 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1171 "%d while full coverage %d requested\n",
1172 UDP_SKB_CB(skb)->cscov, skb->len);
1173 goto drop;
1174 }
1175 /* The next case involves violating the min. coverage requested
1176 * by the receiver. This is subtle: if receiver wants x and x is
1177 * greater than the buffersize/MTU then receiver will complain
1178 * that it wants x while sender emits packets of smaller size y.
1179 * Therefore the above ...()->partial_cov statement is essential.
1180 */
1181 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1182 LIMIT_NETDEBUG(KERN_WARNING
1183 "UDPLITE: coverage %d too small, need min %d\n",
1184 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1185 goto drop;
1186 }
1187 }
1188
1189 if (sk->sk_filter) {
1190 if (udp_lib_checksum_complete(skb))
1191 goto drop;
1192 }
1193
1194 if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
1195 /* Note that an ENOMEM error is charged twice */
1196 if (rc == -ENOMEM)
1197 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
1198 goto drop;
1199 }
1200
1201 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
1202 return 0;
1203
1204 drop:
1205 UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
1206 kfree_skb(skb);
1207 return -1;
1208 }
1209
1210 /*
1211 * Multicasts and broadcasts go to each listener.
1212 *
1213 * Note: called only from the BH handler context,
1214 * so we don't need to lock the hashes.
1215 */
1216 static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
1217 struct udphdr *uh,
1218 __be32 saddr, __be32 daddr,
1219 struct hlist_head udptable[])
1220 {
1221 struct sock *sk, *skw, *sknext;
1222 int dif;
1223 int hport = ntohs(uh->dest);
1224 unsigned int hash = ipv4_hash_port_and_addr(hport, daddr);
1225 unsigned int hashwild = udp_hash_port(hport);
1226
1227 dif = skb->dev->ifindex;
1228
1229 read_lock(&udp_hash_lock);
1230
1231 sk = sk_head(&udptable[hash & (UDP_HTABLE_SIZE - 1)]);
1232 skw = sk_head(&udptable[hashwild & (UDP_HTABLE_SIZE - 1)]);
1233
1234 sk = udp_v4_mcast_next(sk, hash, hport, daddr, uh->source, saddr, dif);
1235 if (!sk) {
1236 hash = hashwild;
1237 sk = udp_v4_mcast_next(skw, hash, hport, daddr, uh->source,
1238 saddr, dif);
1239 }
1240 if (sk) {
1241 do {
1242 struct sk_buff *skb1 = skb;
1243 sknext = udp_v4_mcast_next(sk_next(sk), hash, hport,
1244 daddr, uh->source, saddr, dif);
1245 if (!sknext && hash != hashwild) {
1246 hash = hashwild;
1247 sknext = udp_v4_mcast_next(skw, hash, hport,
1248 daddr, uh->source, saddr, dif);
1249 }
1250 if (sknext)
1251 skb1 = skb_clone(skb, GFP_ATOMIC);
1252
1253 if (skb1) {
1254 int ret = udp_queue_rcv_skb(sk, skb1);
1255 if (ret > 0)
1256 /*
1257 * we should probably re-process
1258 * instead of dropping packets here.
1259 */
1260 kfree_skb(skb1);
1261 }
1262 sk = sknext;
1263 } while (sknext);
1264 } else
1265 kfree_skb(skb);
1266 read_unlock(&udp_hash_lock);
1267 return 0;
1268 }
1269
1270 /* Initialize UDP checksum. If exited with zero value (success),
1271 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1272 * Otherwise, csum completion requires chacksumming packet body,
1273 * including udp header and folding it to skb->csum.
1274 */
1275 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1276 int proto)
1277 {
1278 const struct iphdr *iph;
1279 int err;
1280
1281 UDP_SKB_CB(skb)->partial_cov = 0;
1282 UDP_SKB_CB(skb)->cscov = skb->len;
1283
1284 if (proto == IPPROTO_UDPLITE) {
1285 err = udplite_checksum_init(skb, uh);
1286 if (err)
1287 return err;
1288 }
1289
1290 iph = ip_hdr(skb);
1291 if (uh->check == 0) {
1292 skb->ip_summed = CHECKSUM_UNNECESSARY;
1293 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1294 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1295 proto, skb->csum))
1296 skb->ip_summed = CHECKSUM_UNNECESSARY;
1297 }
1298 if (!skb_csum_unnecessary(skb))
1299 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1300 skb->len, proto, 0);
1301 /* Probably, we should checksum udp header (it should be in cache
1302 * in any case) and data in tiny packets (< rx copybreak).
1303 */
1304
1305 return 0;
1306 }
1307
1308 /*
1309 * All we need to do is get the socket, and then do a checksum.
1310 */
1311
1312 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
1313 int proto)
1314 {
1315 struct sock *sk;
1316 struct udphdr *uh = udp_hdr(skb);
1317 unsigned short ulen;
1318 struct rtable *rt = (struct rtable*)skb->dst;
1319 __be32 saddr = ip_hdr(skb)->saddr;
1320 __be32 daddr = ip_hdr(skb)->daddr;
1321
1322 /*
1323 * Validate the packet.
1324 */
1325 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1326 goto drop; /* No space for header. */
1327
1328 ulen = ntohs(uh->len);
1329 if (ulen > skb->len)
1330 goto short_packet;
1331
1332 if (proto == IPPROTO_UDP) {
1333 /* UDP validates ulen. */
1334 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1335 goto short_packet;
1336 uh = udp_hdr(skb);
1337 }
1338
1339 if (udp4_csum_init(skb, uh, proto))
1340 goto csum_error;
1341
1342 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1343 return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
1344
1345 sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
1346 skb->dev->ifindex, udptable);
1347
1348 if (sk != NULL) {
1349 int ret = udp_queue_rcv_skb(sk, skb);
1350 sock_put(sk);
1351
1352 /* a return value > 0 means to resubmit the input, but
1353 * it wants the return to be -protocol, or 0
1354 */
1355 if (ret > 0)
1356 return -ret;
1357 return 0;
1358 }
1359
1360 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1361 goto drop;
1362 nf_reset(skb);
1363
1364 /* No socket. Drop packet silently, if checksum is wrong */
1365 if (udp_lib_checksum_complete(skb))
1366 goto csum_error;
1367
1368 UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1369 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1370
1371 /*
1372 * Hmm. We got an UDP packet to a port to which we
1373 * don't wanna listen. Ignore it.
1374 */
1375 kfree_skb(skb);
1376 return 0;
1377
1378 short_packet:
1379 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
1380 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1381 NIPQUAD(saddr),
1382 ntohs(uh->source),
1383 ulen,
1384 skb->len,
1385 NIPQUAD(daddr),
1386 ntohs(uh->dest));
1387 goto drop;
1388
1389 csum_error:
1390 /*
1391 * RFC1122: OK. Discards the bad packet silently (as far as
1392 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1393 */
1394 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
1395 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1396 NIPQUAD(saddr),
1397 ntohs(uh->source),
1398 NIPQUAD(daddr),
1399 ntohs(uh->dest),
1400 ulen);
1401 drop:
1402 UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1403 kfree_skb(skb);
1404 return 0;
1405 }
1406
1407 int udp_rcv(struct sk_buff *skb)
1408 {
1409 return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
1410 }
1411
1412 int udp_destroy_sock(struct sock *sk)
1413 {
1414 lock_sock(sk);
1415 udp_flush_pending_frames(sk);
1416 release_sock(sk);
1417 return 0;
1418 }
1419
1420 /*
1421 * Socket option code for UDP
1422 */
1423 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1424 char __user *optval, int optlen,
1425 int (*push_pending_frames)(struct sock *))
1426 {
1427 struct udp_sock *up = udp_sk(sk);
1428 int val;
1429 int err = 0;
1430
1431 if (optlen<sizeof(int))
1432 return -EINVAL;
1433
1434 if (get_user(val, (int __user *)optval))
1435 return -EFAULT;
1436
1437 switch (optname) {
1438 case UDP_CORK:
1439 if (val != 0) {
1440 up->corkflag = 1;
1441 } else {
1442 up->corkflag = 0;
1443 lock_sock(sk);
1444 (*push_pending_frames)(sk);
1445 release_sock(sk);
1446 }
1447 break;
1448
1449 case UDP_ENCAP:
1450 switch (val) {
1451 case 0:
1452 case UDP_ENCAP_ESPINUDP:
1453 case UDP_ENCAP_ESPINUDP_NON_IKE:
1454 up->encap_type = val;
1455 break;
1456 default:
1457 err = -ENOPROTOOPT;
1458 break;
1459 }
1460 break;
1461
1462 /*
1463 * UDP-Lite's partial checksum coverage (RFC 3828).
1464 */
1465 /* The sender sets actual checksum coverage length via this option.
1466 * The case coverage > packet length is handled by send module. */
1467 case UDPLITE_SEND_CSCOV:
1468 if (!up->pcflag) /* Disable the option on UDP sockets */
1469 return -ENOPROTOOPT;
1470 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1471 val = 8;
1472 up->pcslen = val;
1473 up->pcflag |= UDPLITE_SEND_CC;
1474 break;
1475
1476 /* The receiver specifies a minimum checksum coverage value. To make
1477 * sense, this should be set to at least 8 (as done below). If zero is
1478 * used, this again means full checksum coverage. */
1479 case UDPLITE_RECV_CSCOV:
1480 if (!up->pcflag) /* Disable the option on UDP sockets */
1481 return -ENOPROTOOPT;
1482 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1483 val = 8;
1484 up->pcrlen = val;
1485 up->pcflag |= UDPLITE_RECV_CC;
1486 break;
1487
1488 default:
1489 err = -ENOPROTOOPT;
1490 break;
1491 }
1492
1493 return err;
1494 }
1495
1496 int udp_setsockopt(struct sock *sk, int level, int optname,
1497 char __user *optval, int optlen)
1498 {
1499 if (level == SOL_UDP || level == SOL_UDPLITE)
1500 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1501 udp_push_pending_frames);
1502 return ip_setsockopt(sk, level, optname, optval, optlen);
1503 }
1504
1505 #ifdef CONFIG_COMPAT
1506 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1507 char __user *optval, int optlen)
1508 {
1509 if (level == SOL_UDP || level == SOL_UDPLITE)
1510 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1511 udp_push_pending_frames);
1512 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1513 }
1514 #endif
1515
1516 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1517 char __user *optval, int __user *optlen)
1518 {
1519 struct udp_sock *up = udp_sk(sk);
1520 int val, len;
1521
1522 if (get_user(len,optlen))
1523 return -EFAULT;
1524
1525 len = min_t(unsigned int, len, sizeof(int));
1526
1527 if (len < 0)
1528 return -EINVAL;
1529
1530 switch (optname) {
1531 case UDP_CORK:
1532 val = up->corkflag;
1533 break;
1534
1535 case UDP_ENCAP:
1536 val = up->encap_type;
1537 break;
1538
1539 /* The following two cannot be changed on UDP sockets, the return is
1540 * always 0 (which corresponds to the full checksum coverage of UDP). */
1541 case UDPLITE_SEND_CSCOV:
1542 val = up->pcslen;
1543 break;
1544
1545 case UDPLITE_RECV_CSCOV:
1546 val = up->pcrlen;
1547 break;
1548
1549 default:
1550 return -ENOPROTOOPT;
1551 }
1552
1553 if (put_user(len, optlen))
1554 return -EFAULT;
1555 if (copy_to_user(optval, &val,len))
1556 return -EFAULT;
1557 return 0;
1558 }
1559
1560 int udp_getsockopt(struct sock *sk, int level, int optname,
1561 char __user *optval, int __user *optlen)
1562 {
1563 if (level == SOL_UDP || level == SOL_UDPLITE)
1564 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1565 return ip_getsockopt(sk, level, optname, optval, optlen);
1566 }
1567
1568 #ifdef CONFIG_COMPAT
1569 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1570 char __user *optval, int __user *optlen)
1571 {
1572 if (level == SOL_UDP || level == SOL_UDPLITE)
1573 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1574 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1575 }
1576 #endif
1577 /**
1578 * udp_poll - wait for a UDP event.
1579 * @file - file struct
1580 * @sock - socket
1581 * @wait - poll table
1582 *
1583 * This is same as datagram poll, except for the special case of
1584 * blocking sockets. If application is using a blocking fd
1585 * and a packet with checksum error is in the queue;
1586 * then it could get return from select indicating data available
1587 * but then block when reading it. Add special case code
1588 * to work around these arguably broken applications.
1589 */
1590 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1591 {
1592 unsigned int mask = datagram_poll(file, sock, wait);
1593 struct sock *sk = sock->sk;
1594 int is_lite = IS_UDPLITE(sk);
1595
1596 /* Check for false positives due to checksum errors */
1597 if ( (mask & POLLRDNORM) &&
1598 !(file->f_flags & O_NONBLOCK) &&
1599 !(sk->sk_shutdown & RCV_SHUTDOWN)){
1600 struct sk_buff_head *rcvq = &sk->sk_receive_queue;
1601 struct sk_buff *skb;
1602
1603 spin_lock_bh(&rcvq->lock);
1604 while ((skb = skb_peek(rcvq)) != NULL &&
1605 udp_lib_checksum_complete(skb)) {
1606 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
1607 __skb_unlink(skb, rcvq);
1608 kfree_skb(skb);
1609 }
1610 spin_unlock_bh(&rcvq->lock);
1611
1612 /* nothing to see, move along */
1613 if (skb == NULL)
1614 mask &= ~(POLLIN | POLLRDNORM);
1615 }
1616
1617 return mask;
1618
1619 }
1620
1621 struct proto udp_prot = {
1622 .name = "UDP",
1623 .owner = THIS_MODULE,
1624 .close = udp_lib_close,
1625 .connect = ip4_datagram_connect,
1626 .disconnect = udp_disconnect,
1627 .ioctl = udp_ioctl,
1628 .destroy = udp_destroy_sock,
1629 .setsockopt = udp_setsockopt,
1630 .getsockopt = udp_getsockopt,
1631 .sendmsg = udp_sendmsg,
1632 .recvmsg = udp_recvmsg,
1633 .sendpage = udp_sendpage,
1634 .backlog_rcv = udp_queue_rcv_skb,
1635 .hash = udp_lib_hash,
1636 .unhash = udp_lib_unhash,
1637 .get_port = udp_v4_get_port,
1638 .obj_size = sizeof(struct udp_sock),
1639 #ifdef CONFIG_COMPAT
1640 .compat_setsockopt = compat_udp_setsockopt,
1641 .compat_getsockopt = compat_udp_getsockopt,
1642 #endif
1643 };
1644
1645 /* ------------------------------------------------------------------------ */
1646 #ifdef CONFIG_PROC_FS
1647
1648 static struct sock *udp_get_first(struct seq_file *seq)
1649 {
1650 struct sock *sk;
1651 struct udp_iter_state *state = seq->private;
1652
1653 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1654 struct hlist_node *node;
1655 sk_for_each(sk, node, state->hashtable + state->bucket) {
1656 if (sk->sk_family == state->family)
1657 goto found;
1658 }
1659 }
1660 sk = NULL;
1661 found:
1662 return sk;
1663 }
1664
1665 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1666 {
1667 struct udp_iter_state *state = seq->private;
1668
1669 do {
1670 sk = sk_next(sk);
1671 try_again:
1672 ;
1673 } while (sk && sk->sk_family != state->family);
1674
1675 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
1676 sk = sk_head(state->hashtable + state->bucket);
1677 goto try_again;
1678 }
1679 return sk;
1680 }
1681
1682 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1683 {
1684 struct sock *sk = udp_get_first(seq);
1685
1686 if (sk)
1687 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1688 --pos;
1689 return pos ? NULL : sk;
1690 }
1691
1692 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1693 {
1694 read_lock(&udp_hash_lock);
1695 return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
1696 }
1697
1698 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1699 {
1700 struct sock *sk;
1701
1702 if (v == (void *)1)
1703 sk = udp_get_idx(seq, 0);
1704 else
1705 sk = udp_get_next(seq, v);
1706
1707 ++*pos;
1708 return sk;
1709 }
1710
1711 static void udp_seq_stop(struct seq_file *seq, void *v)
1712 {
1713 read_unlock(&udp_hash_lock);
1714 }
1715
1716 static int udp_seq_open(struct inode *inode, struct file *file)
1717 {
1718 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1719 struct seq_file *seq;
1720 int rc = -ENOMEM;
1721 struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
1722
1723 if (!s)
1724 goto out;
1725 s->family = afinfo->family;
1726 s->hashtable = afinfo->hashtable;
1727 s->seq_ops.start = udp_seq_start;
1728 s->seq_ops.next = udp_seq_next;
1729 s->seq_ops.show = afinfo->seq_show;
1730 s->seq_ops.stop = udp_seq_stop;
1731
1732 rc = seq_open(file, &s->seq_ops);
1733 if (rc)
1734 goto out_kfree;
1735
1736 seq = file->private_data;
1737 seq->private = s;
1738 out:
1739 return rc;
1740 out_kfree:
1741 kfree(s);
1742 goto out;
1743 }
1744
1745 /* ------------------------------------------------------------------------ */
1746 int udp_proc_register(struct udp_seq_afinfo *afinfo)
1747 {
1748 struct proc_dir_entry *p;
1749 int rc = 0;
1750
1751 if (!afinfo)
1752 return -EINVAL;
1753 afinfo->seq_fops->owner = afinfo->owner;
1754 afinfo->seq_fops->open = udp_seq_open;
1755 afinfo->seq_fops->read = seq_read;
1756 afinfo->seq_fops->llseek = seq_lseek;
1757 afinfo->seq_fops->release = seq_release_private;
1758
1759 p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
1760 if (p)
1761 p->data = afinfo;
1762 else
1763 rc = -ENOMEM;
1764 return rc;
1765 }
1766
1767 void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
1768 {
1769 if (!afinfo)
1770 return;
1771 proc_net_remove(afinfo->name);
1772 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
1773 }
1774
1775 /* ------------------------------------------------------------------------ */
1776 static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
1777 {
1778 struct inet_sock *inet = inet_sk(sp);
1779 __be32 dest = inet->daddr;
1780 __be32 src = inet->rcv_saddr;
1781 __u16 destp = ntohs(inet->dport);
1782 __u16 srcp = ntohs(inet->sport);
1783
1784 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
1785 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
1786 bucket, src, srcp, dest, destp, sp->sk_state,
1787 atomic_read(&sp->sk_wmem_alloc),
1788 atomic_read(&sp->sk_rmem_alloc),
1789 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1790 atomic_read(&sp->sk_refcnt), sp);
1791 }
1792
1793 int udp4_seq_show(struct seq_file *seq, void *v)
1794 {
1795 if (v == SEQ_START_TOKEN)
1796 seq_printf(seq, "%-127s\n",
1797 " sl local_address rem_address st tx_queue "
1798 "rx_queue tr tm->when retrnsmt uid timeout "
1799 "inode");
1800 else {
1801 char tmpbuf[129];
1802 struct udp_iter_state *state = seq->private;
1803
1804 udp4_format_sock(v, tmpbuf, state->bucket);
1805 seq_printf(seq, "%-127s\n", tmpbuf);
1806 }
1807 return 0;
1808 }
1809
1810 /* ------------------------------------------------------------------------ */
1811 static struct file_operations udp4_seq_fops;
1812 static struct udp_seq_afinfo udp4_seq_afinfo = {
1813 .owner = THIS_MODULE,
1814 .name = "udp",
1815 .family = AF_INET,
1816 .hashtable = udp_hash,
1817 .seq_show = udp4_seq_show,
1818 .seq_fops = &udp4_seq_fops,
1819 };
1820
1821 int __init udp4_proc_init(void)
1822 {
1823 return udp_proc_register(&udp4_seq_afinfo);
1824 }
1825
1826 void udp4_proc_exit(void)
1827 {
1828 udp_proc_unregister(&udp4_seq_afinfo);
1829 }
1830 #endif /* CONFIG_PROC_FS */
1831
1832 EXPORT_SYMBOL(udp_disconnect);
1833 EXPORT_SYMBOL(udp_hash);
1834 EXPORT_SYMBOL(udp_hash_lock);
1835 EXPORT_SYMBOL(udp_ioctl);
1836 EXPORT_SYMBOL(udp_get_port);
1837 EXPORT_SYMBOL(udp_prot);
1838 EXPORT_SYMBOL(udp_sendmsg);
1839 EXPORT_SYMBOL(udp_lib_getsockopt);
1840 EXPORT_SYMBOL(udp_lib_setsockopt);
1841 EXPORT_SYMBOL(udp_poll);
1842
1843 #ifdef CONFIG_PROC_FS
1844 EXPORT_SYMBOL(udp_proc_register);
1845 EXPORT_SYMBOL(udp_proc_unregister);
1846 #endif
Linux kernel - Deliverables
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