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kernel-wide: replace USHORT_MAX, SHORT_MAX and SHORT_MIN with USHRT_MAX, SHRT_MAX...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / udp.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * The User Datagram Protocol (UDP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
12 * Hirokazu Takahashi, <taka@valinux.co.jp>
13 *
14 * Fixes:
15 * Alan Cox : verify_area() calls
16 * Alan Cox : stopped close while in use off icmp
17 * messages. Not a fix but a botch that
18 * for udp at least is 'valid'.
19 * Alan Cox : Fixed icmp handling properly
20 * Alan Cox : Correct error for oversized datagrams
21 * Alan Cox : Tidied select() semantics.
22 * Alan Cox : udp_err() fixed properly, also now
23 * select and read wake correctly on errors
24 * Alan Cox : udp_send verify_area moved to avoid mem leak
25 * Alan Cox : UDP can count its memory
26 * Alan Cox : send to an unknown connection causes
27 * an ECONNREFUSED off the icmp, but
28 * does NOT close.
29 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
31 * bug no longer crashes it.
32 * Fred Van Kempen : Net2e support for sk->broadcast.
33 * Alan Cox : Uses skb_free_datagram
34 * Alan Cox : Added get/set sockopt support.
35 * Alan Cox : Broadcasting without option set returns EACCES.
36 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
37 * Alan Cox : Use ip_tos and ip_ttl
38 * Alan Cox : SNMP Mibs
39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
40 * Matt Dillon : UDP length checks.
41 * Alan Cox : Smarter af_inet used properly.
42 * Alan Cox : Use new kernel side addressing.
43 * Alan Cox : Incorrect return on truncated datagram receive.
44 * Arnt Gulbrandsen : New udp_send and stuff
45 * Alan Cox : Cache last socket
46 * Alan Cox : Route cache
47 * Jon Peatfield : Minor efficiency fix to sendto().
48 * Mike Shaver : RFC1122 checks.
49 * Alan Cox : Nonblocking error fix.
50 * Willy Konynenberg : Transparent proxying support.
51 * Mike McLagan : Routing by source
52 * David S. Miller : New socket lookup architecture.
53 * Last socket cache retained as it
54 * does have a high hit rate.
55 * Olaf Kirch : Don't linearise iovec on sendmsg.
56 * Andi Kleen : Some cleanups, cache destination entry
57 * for connect.
58 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
59 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
60 * return ENOTCONN for unconnected sockets (POSIX)
61 * Janos Farkas : don't deliver multi/broadcasts to a different
62 * bound-to-device socket
63 * Hirokazu Takahashi : HW checksumming for outgoing UDP
64 * datagrams.
65 * Hirokazu Takahashi : sendfile() on UDP works now.
66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
69 * a single port at the same time.
70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71 * James Chapman : Add L2TP encapsulation type.
72 *
73 *
74 * This program is free software; you can redistribute it and/or
75 * modify it under the terms of the GNU General Public License
76 * as published by the Free Software Foundation; either version
77 * 2 of the License, or (at your option) any later version.
78 */
79
80 #include <asm/system.h>
81 #include <asm/uaccess.h>
82 #include <asm/ioctls.h>
83 #include <linux/bootmem.h>
84 #include <linux/highmem.h>
85 #include <linux/swap.h>
86 #include <linux/types.h>
87 #include <linux/fcntl.h>
88 #include <linux/module.h>
89 #include <linux/socket.h>
90 #include <linux/sockios.h>
91 #include <linux/igmp.h>
92 #include <linux/in.h>
93 #include <linux/errno.h>
94 #include <linux/timer.h>
95 #include <linux/mm.h>
96 #include <linux/inet.h>
97 #include <linux/netdevice.h>
98 #include <linux/slab.h>
99 #include <net/tcp_states.h>
100 #include <linux/skbuff.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <net/net_namespace.h>
104 #include <net/icmp.h>
105 #include <net/route.h>
106 #include <net/checksum.h>
107 #include <net/xfrm.h>
108 #include "udp_impl.h"
109
110 struct udp_table udp_table __read_mostly;
111 EXPORT_SYMBOL(udp_table);
112
113 int sysctl_udp_mem[3] __read_mostly;
114 EXPORT_SYMBOL(sysctl_udp_mem);
115
116 int sysctl_udp_rmem_min __read_mostly;
117 EXPORT_SYMBOL(sysctl_udp_rmem_min);
118
119 int sysctl_udp_wmem_min __read_mostly;
120 EXPORT_SYMBOL(sysctl_udp_wmem_min);
121
122 atomic_t udp_memory_allocated;
123 EXPORT_SYMBOL(udp_memory_allocated);
124
125 #define MAX_UDP_PORTS 65536
126 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
127
128 static int udp_lib_lport_inuse(struct net *net, __u16 num,
129 const struct udp_hslot *hslot,
130 unsigned long *bitmap,
131 struct sock *sk,
132 int (*saddr_comp)(const struct sock *sk1,
133 const struct sock *sk2),
134 unsigned int log)
135 {
136 struct sock *sk2;
137 struct hlist_nulls_node *node;
138
139 sk_nulls_for_each(sk2, node, &hslot->head)
140 if (net_eq(sock_net(sk2), net) &&
141 sk2 != sk &&
142 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
143 (!sk2->sk_reuse || !sk->sk_reuse) &&
144 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
145 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
146 (*saddr_comp)(sk, sk2)) {
147 if (bitmap)
148 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
149 bitmap);
150 else
151 return 1;
152 }
153 return 0;
154 }
155
156 /*
157 * Note: we still hold spinlock of primary hash chain, so no other writer
158 * can insert/delete a socket with local_port == num
159 */
160 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
161 struct udp_hslot *hslot2,
162 struct sock *sk,
163 int (*saddr_comp)(const struct sock *sk1,
164 const struct sock *sk2))
165 {
166 struct sock *sk2;
167 struct hlist_nulls_node *node;
168 int res = 0;
169
170 spin_lock(&hslot2->lock);
171 udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
172 if (net_eq(sock_net(sk2), net) &&
173 sk2 != sk &&
174 (udp_sk(sk2)->udp_port_hash == num) &&
175 (!sk2->sk_reuse || !sk->sk_reuse) &&
176 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
177 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
178 (*saddr_comp)(sk, sk2)) {
179 res = 1;
180 break;
181 }
182 spin_unlock(&hslot2->lock);
183 return res;
184 }
185
186 /**
187 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
188 *
189 * @sk: socket struct in question
190 * @snum: port number to look up
191 * @saddr_comp: AF-dependent comparison of bound local IP addresses
192 * @hash2_nulladdr: AF-dependant hash value in secondary hash chains,
193 * with NULL address
194 */
195 int udp_lib_get_port(struct sock *sk, unsigned short snum,
196 int (*saddr_comp)(const struct sock *sk1,
197 const struct sock *sk2),
198 unsigned int hash2_nulladdr)
199 {
200 struct udp_hslot *hslot, *hslot2;
201 struct udp_table *udptable = sk->sk_prot->h.udp_table;
202 int error = 1;
203 struct net *net = sock_net(sk);
204
205 if (!snum) {
206 int low, high, remaining;
207 unsigned rand;
208 unsigned short first, last;
209 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
210
211 inet_get_local_port_range(&low, &high);
212 remaining = (high - low) + 1;
213
214 rand = net_random();
215 first = (((u64)rand * remaining) >> 32) + low;
216 /*
217 * force rand to be an odd multiple of UDP_HTABLE_SIZE
218 */
219 rand = (rand | 1) * (udptable->mask + 1);
220 last = first + udptable->mask + 1;
221 do {
222 hslot = udp_hashslot(udptable, net, first);
223 bitmap_zero(bitmap, PORTS_PER_CHAIN);
224 spin_lock_bh(&hslot->lock);
225 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
226 saddr_comp, udptable->log);
227
228 snum = first;
229 /*
230 * Iterate on all possible values of snum for this hash.
231 * Using steps of an odd multiple of UDP_HTABLE_SIZE
232 * give us randomization and full range coverage.
233 */
234 do {
235 if (low <= snum && snum <= high &&
236 !test_bit(snum >> udptable->log, bitmap) &&
237 !inet_is_reserved_local_port(snum))
238 goto found;
239 snum += rand;
240 } while (snum != first);
241 spin_unlock_bh(&hslot->lock);
242 } while (++first != last);
243 goto fail;
244 } else {
245 hslot = udp_hashslot(udptable, net, snum);
246 spin_lock_bh(&hslot->lock);
247 if (hslot->count > 10) {
248 int exist;
249 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
250
251 slot2 &= udptable->mask;
252 hash2_nulladdr &= udptable->mask;
253
254 hslot2 = udp_hashslot2(udptable, slot2);
255 if (hslot->count < hslot2->count)
256 goto scan_primary_hash;
257
258 exist = udp_lib_lport_inuse2(net, snum, hslot2,
259 sk, saddr_comp);
260 if (!exist && (hash2_nulladdr != slot2)) {
261 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
262 exist = udp_lib_lport_inuse2(net, snum, hslot2,
263 sk, saddr_comp);
264 }
265 if (exist)
266 goto fail_unlock;
267 else
268 goto found;
269 }
270 scan_primary_hash:
271 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
272 saddr_comp, 0))
273 goto fail_unlock;
274 }
275 found:
276 inet_sk(sk)->inet_num = snum;
277 udp_sk(sk)->udp_port_hash = snum;
278 udp_sk(sk)->udp_portaddr_hash ^= snum;
279 if (sk_unhashed(sk)) {
280 sk_nulls_add_node_rcu(sk, &hslot->head);
281 hslot->count++;
282 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
283
284 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
285 spin_lock(&hslot2->lock);
286 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
287 &hslot2->head);
288 hslot2->count++;
289 spin_unlock(&hslot2->lock);
290 }
291 error = 0;
292 fail_unlock:
293 spin_unlock_bh(&hslot->lock);
294 fail:
295 return error;
296 }
297 EXPORT_SYMBOL(udp_lib_get_port);
298
299 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
300 {
301 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
302
303 return (!ipv6_only_sock(sk2) &&
304 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
305 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
306 }
307
308 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
309 unsigned int port)
310 {
311 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
312 }
313
314 int udp_v4_get_port(struct sock *sk, unsigned short snum)
315 {
316 unsigned int hash2_nulladdr =
317 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
318 unsigned int hash2_partial =
319 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
320
321 /* precompute partial secondary hash */
322 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
323 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
324 }
325
326 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
327 unsigned short hnum,
328 __be16 sport, __be32 daddr, __be16 dport, int dif)
329 {
330 int score = -1;
331
332 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
333 !ipv6_only_sock(sk)) {
334 struct inet_sock *inet = inet_sk(sk);
335
336 score = (sk->sk_family == PF_INET ? 1 : 0);
337 if (inet->inet_rcv_saddr) {
338 if (inet->inet_rcv_saddr != daddr)
339 return -1;
340 score += 2;
341 }
342 if (inet->inet_daddr) {
343 if (inet->inet_daddr != saddr)
344 return -1;
345 score += 2;
346 }
347 if (inet->inet_dport) {
348 if (inet->inet_dport != sport)
349 return -1;
350 score += 2;
351 }
352 if (sk->sk_bound_dev_if) {
353 if (sk->sk_bound_dev_if != dif)
354 return -1;
355 score += 2;
356 }
357 }
358 return score;
359 }
360
361 /*
362 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
363 */
364 #define SCORE2_MAX (1 + 2 + 2 + 2)
365 static inline int compute_score2(struct sock *sk, struct net *net,
366 __be32 saddr, __be16 sport,
367 __be32 daddr, unsigned int hnum, int dif)
368 {
369 int score = -1;
370
371 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) {
372 struct inet_sock *inet = inet_sk(sk);
373
374 if (inet->inet_rcv_saddr != daddr)
375 return -1;
376 if (inet->inet_num != hnum)
377 return -1;
378
379 score = (sk->sk_family == PF_INET ? 1 : 0);
380 if (inet->inet_daddr) {
381 if (inet->inet_daddr != saddr)
382 return -1;
383 score += 2;
384 }
385 if (inet->inet_dport) {
386 if (inet->inet_dport != sport)
387 return -1;
388 score += 2;
389 }
390 if (sk->sk_bound_dev_if) {
391 if (sk->sk_bound_dev_if != dif)
392 return -1;
393 score += 2;
394 }
395 }
396 return score;
397 }
398
399
400 /* called with read_rcu_lock() */
401 static struct sock *udp4_lib_lookup2(struct net *net,
402 __be32 saddr, __be16 sport,
403 __be32 daddr, unsigned int hnum, int dif,
404 struct udp_hslot *hslot2, unsigned int slot2)
405 {
406 struct sock *sk, *result;
407 struct hlist_nulls_node *node;
408 int score, badness;
409
410 begin:
411 result = NULL;
412 badness = -1;
413 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
414 score = compute_score2(sk, net, saddr, sport,
415 daddr, hnum, dif);
416 if (score > badness) {
417 result = sk;
418 badness = score;
419 if (score == SCORE2_MAX)
420 goto exact_match;
421 }
422 }
423 /*
424 * if the nulls value we got at the end of this lookup is
425 * not the expected one, we must restart lookup.
426 * We probably met an item that was moved to another chain.
427 */
428 if (get_nulls_value(node) != slot2)
429 goto begin;
430
431 if (result) {
432 exact_match:
433 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
434 result = NULL;
435 else if (unlikely(compute_score2(result, net, saddr, sport,
436 daddr, hnum, dif) < badness)) {
437 sock_put(result);
438 goto begin;
439 }
440 }
441 return result;
442 }
443
444 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
445 * harder than this. -DaveM
446 */
447 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
448 __be16 sport, __be32 daddr, __be16 dport,
449 int dif, struct udp_table *udptable)
450 {
451 struct sock *sk, *result;
452 struct hlist_nulls_node *node;
453 unsigned short hnum = ntohs(dport);
454 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
455 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
456 int score, badness;
457
458 rcu_read_lock();
459 if (hslot->count > 10) {
460 hash2 = udp4_portaddr_hash(net, daddr, hnum);
461 slot2 = hash2 & udptable->mask;
462 hslot2 = &udptable->hash2[slot2];
463 if (hslot->count < hslot2->count)
464 goto begin;
465
466 result = udp4_lib_lookup2(net, saddr, sport,
467 daddr, hnum, dif,
468 hslot2, slot2);
469 if (!result) {
470 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
471 slot2 = hash2 & udptable->mask;
472 hslot2 = &udptable->hash2[slot2];
473 if (hslot->count < hslot2->count)
474 goto begin;
475
476 result = udp4_lib_lookup2(net, saddr, sport,
477 htonl(INADDR_ANY), hnum, dif,
478 hslot2, slot2);
479 }
480 rcu_read_unlock();
481 return result;
482 }
483 begin:
484 result = NULL;
485 badness = -1;
486 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
487 score = compute_score(sk, net, saddr, hnum, sport,
488 daddr, dport, dif);
489 if (score > badness) {
490 result = sk;
491 badness = score;
492 }
493 }
494 /*
495 * if the nulls value we got at the end of this lookup is
496 * not the expected one, we must restart lookup.
497 * We probably met an item that was moved to another chain.
498 */
499 if (get_nulls_value(node) != slot)
500 goto begin;
501
502 if (result) {
503 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
504 result = NULL;
505 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
506 daddr, dport, dif) < badness)) {
507 sock_put(result);
508 goto begin;
509 }
510 }
511 rcu_read_unlock();
512 return result;
513 }
514
515 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
516 __be16 sport, __be16 dport,
517 struct udp_table *udptable)
518 {
519 struct sock *sk;
520 const struct iphdr *iph = ip_hdr(skb);
521
522 if (unlikely(sk = skb_steal_sock(skb)))
523 return sk;
524 else
525 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
526 iph->daddr, dport, inet_iif(skb),
527 udptable);
528 }
529
530 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
531 __be32 daddr, __be16 dport, int dif)
532 {
533 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
534 }
535 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
536
537 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
538 __be16 loc_port, __be32 loc_addr,
539 __be16 rmt_port, __be32 rmt_addr,
540 int dif)
541 {
542 struct hlist_nulls_node *node;
543 struct sock *s = sk;
544 unsigned short hnum = ntohs(loc_port);
545
546 sk_nulls_for_each_from(s, node) {
547 struct inet_sock *inet = inet_sk(s);
548
549 if (!net_eq(sock_net(s), net) ||
550 udp_sk(s)->udp_port_hash != hnum ||
551 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
552 (inet->inet_dport != rmt_port && inet->inet_dport) ||
553 (inet->inet_rcv_saddr &&
554 inet->inet_rcv_saddr != loc_addr) ||
555 ipv6_only_sock(s) ||
556 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
557 continue;
558 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
559 continue;
560 goto found;
561 }
562 s = NULL;
563 found:
564 return s;
565 }
566
567 /*
568 * This routine is called by the ICMP module when it gets some
569 * sort of error condition. If err < 0 then the socket should
570 * be closed and the error returned to the user. If err > 0
571 * it's just the icmp type << 8 | icmp code.
572 * Header points to the ip header of the error packet. We move
573 * on past this. Then (as it used to claim before adjustment)
574 * header points to the first 8 bytes of the udp header. We need
575 * to find the appropriate port.
576 */
577
578 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
579 {
580 struct inet_sock *inet;
581 struct iphdr *iph = (struct iphdr *)skb->data;
582 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
583 const int type = icmp_hdr(skb)->type;
584 const int code = icmp_hdr(skb)->code;
585 struct sock *sk;
586 int harderr;
587 int err;
588 struct net *net = dev_net(skb->dev);
589
590 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
591 iph->saddr, uh->source, skb->dev->ifindex, udptable);
592 if (sk == NULL) {
593 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
594 return; /* No socket for error */
595 }
596
597 err = 0;
598 harderr = 0;
599 inet = inet_sk(sk);
600
601 switch (type) {
602 default:
603 case ICMP_TIME_EXCEEDED:
604 err = EHOSTUNREACH;
605 break;
606 case ICMP_SOURCE_QUENCH:
607 goto out;
608 case ICMP_PARAMETERPROB:
609 err = EPROTO;
610 harderr = 1;
611 break;
612 case ICMP_DEST_UNREACH:
613 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
614 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
615 err = EMSGSIZE;
616 harderr = 1;
617 break;
618 }
619 goto out;
620 }
621 err = EHOSTUNREACH;
622 if (code <= NR_ICMP_UNREACH) {
623 harderr = icmp_err_convert[code].fatal;
624 err = icmp_err_convert[code].errno;
625 }
626 break;
627 }
628
629 /*
630 * RFC1122: OK. Passes ICMP errors back to application, as per
631 * 4.1.3.3.
632 */
633 if (!inet->recverr) {
634 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
635 goto out;
636 } else {
637 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
638 }
639 sk->sk_err = err;
640 sk->sk_error_report(sk);
641 out:
642 sock_put(sk);
643 }
644
645 void udp_err(struct sk_buff *skb, u32 info)
646 {
647 __udp4_lib_err(skb, info, &udp_table);
648 }
649
650 /*
651 * Throw away all pending data and cancel the corking. Socket is locked.
652 */
653 void udp_flush_pending_frames(struct sock *sk)
654 {
655 struct udp_sock *up = udp_sk(sk);
656
657 if (up->pending) {
658 up->len = 0;
659 up->pending = 0;
660 ip_flush_pending_frames(sk);
661 }
662 }
663 EXPORT_SYMBOL(udp_flush_pending_frames);
664
665 /**
666 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
667 * @sk: socket we are sending on
668 * @skb: sk_buff containing the filled-in UDP header
669 * (checksum field must be zeroed out)
670 */
671 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
672 __be32 src, __be32 dst, int len)
673 {
674 unsigned int offset;
675 struct udphdr *uh = udp_hdr(skb);
676 __wsum csum = 0;
677
678 if (skb_queue_len(&sk->sk_write_queue) == 1) {
679 /*
680 * Only one fragment on the socket.
681 */
682 skb->csum_start = skb_transport_header(skb) - skb->head;
683 skb->csum_offset = offsetof(struct udphdr, check);
684 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
685 } else {
686 /*
687 * HW-checksum won't work as there are two or more
688 * fragments on the socket so that all csums of sk_buffs
689 * should be together
690 */
691 offset = skb_transport_offset(skb);
692 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
693
694 skb->ip_summed = CHECKSUM_NONE;
695
696 skb_queue_walk(&sk->sk_write_queue, skb) {
697 csum = csum_add(csum, skb->csum);
698 }
699
700 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
701 if (uh->check == 0)
702 uh->check = CSUM_MANGLED_0;
703 }
704 }
705
706 /*
707 * Push out all pending data as one UDP datagram. Socket is locked.
708 */
709 static int udp_push_pending_frames(struct sock *sk)
710 {
711 struct udp_sock *up = udp_sk(sk);
712 struct inet_sock *inet = inet_sk(sk);
713 struct flowi *fl = &inet->cork.fl;
714 struct sk_buff *skb;
715 struct udphdr *uh;
716 int err = 0;
717 int is_udplite = IS_UDPLITE(sk);
718 __wsum csum = 0;
719
720 /* Grab the skbuff where UDP header space exists. */
721 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
722 goto out;
723
724 /*
725 * Create a UDP header
726 */
727 uh = udp_hdr(skb);
728 uh->source = fl->fl_ip_sport;
729 uh->dest = fl->fl_ip_dport;
730 uh->len = htons(up->len);
731 uh->check = 0;
732
733 if (is_udplite) /* UDP-Lite */
734 csum = udplite_csum_outgoing(sk, skb);
735
736 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
737
738 skb->ip_summed = CHECKSUM_NONE;
739 goto send;
740
741 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
742
743 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
744 goto send;
745
746 } else /* `normal' UDP */
747 csum = udp_csum_outgoing(sk, skb);
748
749 /* add protocol-dependent pseudo-header */
750 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
751 sk->sk_protocol, csum);
752 if (uh->check == 0)
753 uh->check = CSUM_MANGLED_0;
754
755 send:
756 err = ip_push_pending_frames(sk);
757 if (err) {
758 if (err == -ENOBUFS && !inet->recverr) {
759 UDP_INC_STATS_USER(sock_net(sk),
760 UDP_MIB_SNDBUFERRORS, is_udplite);
761 err = 0;
762 }
763 } else
764 UDP_INC_STATS_USER(sock_net(sk),
765 UDP_MIB_OUTDATAGRAMS, is_udplite);
766 out:
767 up->len = 0;
768 up->pending = 0;
769 return err;
770 }
771
772 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
773 size_t len)
774 {
775 struct inet_sock *inet = inet_sk(sk);
776 struct udp_sock *up = udp_sk(sk);
777 int ulen = len;
778 struct ipcm_cookie ipc;
779 struct rtable *rt = NULL;
780 int free = 0;
781 int connected = 0;
782 __be32 daddr, faddr, saddr;
783 __be16 dport;
784 u8 tos;
785 int err, is_udplite = IS_UDPLITE(sk);
786 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
787 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
788
789 if (len > 0xFFFF)
790 return -EMSGSIZE;
791
792 /*
793 * Check the flags.
794 */
795
796 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
797 return -EOPNOTSUPP;
798
799 ipc.opt = NULL;
800 ipc.shtx.flags = 0;
801
802 if (up->pending) {
803 /*
804 * There are pending frames.
805 * The socket lock must be held while it's corked.
806 */
807 lock_sock(sk);
808 if (likely(up->pending)) {
809 if (unlikely(up->pending != AF_INET)) {
810 release_sock(sk);
811 return -EINVAL;
812 }
813 goto do_append_data;
814 }
815 release_sock(sk);
816 }
817 ulen += sizeof(struct udphdr);
818
819 /*
820 * Get and verify the address.
821 */
822 if (msg->msg_name) {
823 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
824 if (msg->msg_namelen < sizeof(*usin))
825 return -EINVAL;
826 if (usin->sin_family != AF_INET) {
827 if (usin->sin_family != AF_UNSPEC)
828 return -EAFNOSUPPORT;
829 }
830
831 daddr = usin->sin_addr.s_addr;
832 dport = usin->sin_port;
833 if (dport == 0)
834 return -EINVAL;
835 } else {
836 if (sk->sk_state != TCP_ESTABLISHED)
837 return -EDESTADDRREQ;
838 daddr = inet->inet_daddr;
839 dport = inet->inet_dport;
840 /* Open fast path for connected socket.
841 Route will not be used, if at least one option is set.
842 */
843 connected = 1;
844 }
845 ipc.addr = inet->inet_saddr;
846
847 ipc.oif = sk->sk_bound_dev_if;
848 err = sock_tx_timestamp(msg, sk, &ipc.shtx);
849 if (err)
850 return err;
851 if (msg->msg_controllen) {
852 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
853 if (err)
854 return err;
855 if (ipc.opt)
856 free = 1;
857 connected = 0;
858 }
859 if (!ipc.opt)
860 ipc.opt = inet->opt;
861
862 saddr = ipc.addr;
863 ipc.addr = faddr = daddr;
864
865 if (ipc.opt && ipc.opt->srr) {
866 if (!daddr)
867 return -EINVAL;
868 faddr = ipc.opt->faddr;
869 connected = 0;
870 }
871 tos = RT_TOS(inet->tos);
872 if (sock_flag(sk, SOCK_LOCALROUTE) ||
873 (msg->msg_flags & MSG_DONTROUTE) ||
874 (ipc.opt && ipc.opt->is_strictroute)) {
875 tos |= RTO_ONLINK;
876 connected = 0;
877 }
878
879 if (ipv4_is_multicast(daddr)) {
880 if (!ipc.oif)
881 ipc.oif = inet->mc_index;
882 if (!saddr)
883 saddr = inet->mc_addr;
884 connected = 0;
885 }
886
887 if (connected)
888 rt = (struct rtable *)sk_dst_check(sk, 0);
889
890 if (rt == NULL) {
891 struct flowi fl = { .oif = ipc.oif,
892 .mark = sk->sk_mark,
893 .nl_u = { .ip4_u =
894 { .daddr = faddr,
895 .saddr = saddr,
896 .tos = tos } },
897 .proto = sk->sk_protocol,
898 .flags = inet_sk_flowi_flags(sk),
899 .uli_u = { .ports =
900 { .sport = inet->inet_sport,
901 .dport = dport } } };
902 struct net *net = sock_net(sk);
903
904 security_sk_classify_flow(sk, &fl);
905 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
906 if (err) {
907 if (err == -ENETUNREACH)
908 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
909 goto out;
910 }
911
912 err = -EACCES;
913 if ((rt->rt_flags & RTCF_BROADCAST) &&
914 !sock_flag(sk, SOCK_BROADCAST))
915 goto out;
916 if (connected)
917 sk_dst_set(sk, dst_clone(&rt->u.dst));
918 }
919
920 if (msg->msg_flags&MSG_CONFIRM)
921 goto do_confirm;
922 back_from_confirm:
923
924 saddr = rt->rt_src;
925 if (!ipc.addr)
926 daddr = ipc.addr = rt->rt_dst;
927
928 lock_sock(sk);
929 if (unlikely(up->pending)) {
930 /* The socket is already corked while preparing it. */
931 /* ... which is an evident application bug. --ANK */
932 release_sock(sk);
933
934 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
935 err = -EINVAL;
936 goto out;
937 }
938 /*
939 * Now cork the socket to pend data.
940 */
941 inet->cork.fl.fl4_dst = daddr;
942 inet->cork.fl.fl_ip_dport = dport;
943 inet->cork.fl.fl4_src = saddr;
944 inet->cork.fl.fl_ip_sport = inet->inet_sport;
945 up->pending = AF_INET;
946
947 do_append_data:
948 up->len += ulen;
949 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
950 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
951 sizeof(struct udphdr), &ipc, &rt,
952 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
953 if (err)
954 udp_flush_pending_frames(sk);
955 else if (!corkreq)
956 err = udp_push_pending_frames(sk);
957 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
958 up->pending = 0;
959 release_sock(sk);
960
961 out:
962 ip_rt_put(rt);
963 if (free)
964 kfree(ipc.opt);
965 if (!err)
966 return len;
967 /*
968 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
969 * ENOBUFS might not be good (it's not tunable per se), but otherwise
970 * we don't have a good statistic (IpOutDiscards but it can be too many
971 * things). We could add another new stat but at least for now that
972 * seems like overkill.
973 */
974 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
975 UDP_INC_STATS_USER(sock_net(sk),
976 UDP_MIB_SNDBUFERRORS, is_udplite);
977 }
978 return err;
979
980 do_confirm:
981 dst_confirm(&rt->u.dst);
982 if (!(msg->msg_flags&MSG_PROBE) || len)
983 goto back_from_confirm;
984 err = 0;
985 goto out;
986 }
987 EXPORT_SYMBOL(udp_sendmsg);
988
989 int udp_sendpage(struct sock *sk, struct page *page, int offset,
990 size_t size, int flags)
991 {
992 struct udp_sock *up = udp_sk(sk);
993 int ret;
994
995 if (!up->pending) {
996 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
997
998 /* Call udp_sendmsg to specify destination address which
999 * sendpage interface can't pass.
1000 * This will succeed only when the socket is connected.
1001 */
1002 ret = udp_sendmsg(NULL, sk, &msg, 0);
1003 if (ret < 0)
1004 return ret;
1005 }
1006
1007 lock_sock(sk);
1008
1009 if (unlikely(!up->pending)) {
1010 release_sock(sk);
1011
1012 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
1013 return -EINVAL;
1014 }
1015
1016 ret = ip_append_page(sk, page, offset, size, flags);
1017 if (ret == -EOPNOTSUPP) {
1018 release_sock(sk);
1019 return sock_no_sendpage(sk->sk_socket, page, offset,
1020 size, flags);
1021 }
1022 if (ret < 0) {
1023 udp_flush_pending_frames(sk);
1024 goto out;
1025 }
1026
1027 up->len += size;
1028 if (!(up->corkflag || (flags&MSG_MORE)))
1029 ret = udp_push_pending_frames(sk);
1030 if (!ret)
1031 ret = size;
1032 out:
1033 release_sock(sk);
1034 return ret;
1035 }
1036
1037
1038 /**
1039 * first_packet_length - return length of first packet in receive queue
1040 * @sk: socket
1041 *
1042 * Drops all bad checksum frames, until a valid one is found.
1043 * Returns the length of found skb, or 0 if none is found.
1044 */
1045 static unsigned int first_packet_length(struct sock *sk)
1046 {
1047 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
1048 struct sk_buff *skb;
1049 unsigned int res;
1050
1051 __skb_queue_head_init(&list_kill);
1052
1053 spin_lock_bh(&rcvq->lock);
1054 while ((skb = skb_peek(rcvq)) != NULL &&
1055 udp_lib_checksum_complete(skb)) {
1056 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1057 IS_UDPLITE(sk));
1058 atomic_inc(&sk->sk_drops);
1059 __skb_unlink(skb, rcvq);
1060 __skb_queue_tail(&list_kill, skb);
1061 }
1062 res = skb ? skb->len : 0;
1063 spin_unlock_bh(&rcvq->lock);
1064
1065 if (!skb_queue_empty(&list_kill)) {
1066 lock_sock_bh(sk);
1067 __skb_queue_purge(&list_kill);
1068 sk_mem_reclaim_partial(sk);
1069 unlock_sock_bh(sk);
1070 }
1071 return res;
1072 }
1073
1074 /*
1075 * IOCTL requests applicable to the UDP protocol
1076 */
1077
1078 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1079 {
1080 switch (cmd) {
1081 case SIOCOUTQ:
1082 {
1083 int amount = sk_wmem_alloc_get(sk);
1084
1085 return put_user(amount, (int __user *)arg);
1086 }
1087
1088 case SIOCINQ:
1089 {
1090 unsigned int amount = first_packet_length(sk);
1091
1092 if (amount)
1093 /*
1094 * We will only return the amount
1095 * of this packet since that is all
1096 * that will be read.
1097 */
1098 amount -= sizeof(struct udphdr);
1099
1100 return put_user(amount, (int __user *)arg);
1101 }
1102
1103 default:
1104 return -ENOIOCTLCMD;
1105 }
1106
1107 return 0;
1108 }
1109 EXPORT_SYMBOL(udp_ioctl);
1110
1111 /*
1112 * This should be easy, if there is something there we
1113 * return it, otherwise we block.
1114 */
1115
1116 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1117 size_t len, int noblock, int flags, int *addr_len)
1118 {
1119 struct inet_sock *inet = inet_sk(sk);
1120 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
1121 struct sk_buff *skb;
1122 unsigned int ulen;
1123 int peeked;
1124 int err;
1125 int is_udplite = IS_UDPLITE(sk);
1126
1127 /*
1128 * Check any passed addresses
1129 */
1130 if (addr_len)
1131 *addr_len = sizeof(*sin);
1132
1133 if (flags & MSG_ERRQUEUE)
1134 return ip_recv_error(sk, msg, len);
1135
1136 try_again:
1137 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1138 &peeked, &err);
1139 if (!skb)
1140 goto out;
1141
1142 ulen = skb->len - sizeof(struct udphdr);
1143 if (len > ulen)
1144 len = ulen;
1145 else if (len < ulen)
1146 msg->msg_flags |= MSG_TRUNC;
1147
1148 /*
1149 * If checksum is needed at all, try to do it while copying the
1150 * data. If the data is truncated, or if we only want a partial
1151 * coverage checksum (UDP-Lite), do it before the copy.
1152 */
1153
1154 if (len < ulen || UDP_SKB_CB(skb)->partial_cov) {
1155 if (udp_lib_checksum_complete(skb))
1156 goto csum_copy_err;
1157 }
1158
1159 if (skb_csum_unnecessary(skb))
1160 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1161 msg->msg_iov, len);
1162 else {
1163 err = skb_copy_and_csum_datagram_iovec(skb,
1164 sizeof(struct udphdr),
1165 msg->msg_iov);
1166
1167 if (err == -EINVAL)
1168 goto csum_copy_err;
1169 }
1170
1171 if (err)
1172 goto out_free;
1173
1174 if (!peeked)
1175 UDP_INC_STATS_USER(sock_net(sk),
1176 UDP_MIB_INDATAGRAMS, is_udplite);
1177
1178 sock_recv_ts_and_drops(msg, sk, skb);
1179
1180 /* Copy the address. */
1181 if (sin) {
1182 sin->sin_family = AF_INET;
1183 sin->sin_port = udp_hdr(skb)->source;
1184 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1185 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1186 }
1187 if (inet->cmsg_flags)
1188 ip_cmsg_recv(msg, skb);
1189
1190 err = len;
1191 if (flags & MSG_TRUNC)
1192 err = ulen;
1193
1194 out_free:
1195 skb_free_datagram_locked(sk, skb);
1196 out:
1197 return err;
1198
1199 csum_copy_err:
1200 lock_sock_bh(sk);
1201 if (!skb_kill_datagram(sk, skb, flags))
1202 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1203 unlock_sock_bh(sk);
1204
1205 if (noblock)
1206 return -EAGAIN;
1207 goto try_again;
1208 }
1209
1210
1211 int udp_disconnect(struct sock *sk, int flags)
1212 {
1213 struct inet_sock *inet = inet_sk(sk);
1214 /*
1215 * 1003.1g - break association.
1216 */
1217
1218 sk->sk_state = TCP_CLOSE;
1219 inet->inet_daddr = 0;
1220 inet->inet_dport = 0;
1221 sock_rps_save_rxhash(sk, 0);
1222 sk->sk_bound_dev_if = 0;
1223 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1224 inet_reset_saddr(sk);
1225
1226 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1227 sk->sk_prot->unhash(sk);
1228 inet->inet_sport = 0;
1229 }
1230 sk_dst_reset(sk);
1231 return 0;
1232 }
1233 EXPORT_SYMBOL(udp_disconnect);
1234
1235 void udp_lib_unhash(struct sock *sk)
1236 {
1237 if (sk_hashed(sk)) {
1238 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1239 struct udp_hslot *hslot, *hslot2;
1240
1241 hslot = udp_hashslot(udptable, sock_net(sk),
1242 udp_sk(sk)->udp_port_hash);
1243 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1244
1245 spin_lock_bh(&hslot->lock);
1246 if (sk_nulls_del_node_init_rcu(sk)) {
1247 hslot->count--;
1248 inet_sk(sk)->inet_num = 0;
1249 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1250
1251 spin_lock(&hslot2->lock);
1252 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1253 hslot2->count--;
1254 spin_unlock(&hslot2->lock);
1255 }
1256 spin_unlock_bh(&hslot->lock);
1257 }
1258 }
1259 EXPORT_SYMBOL(udp_lib_unhash);
1260
1261 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1262 {
1263 int rc;
1264
1265 if (inet_sk(sk)->inet_daddr)
1266 sock_rps_save_rxhash(sk, skb->rxhash);
1267
1268 rc = ip_queue_rcv_skb(sk, skb);
1269 if (rc < 0) {
1270 int is_udplite = IS_UDPLITE(sk);
1271
1272 /* Note that an ENOMEM error is charged twice */
1273 if (rc == -ENOMEM)
1274 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1275 is_udplite);
1276 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1277 kfree_skb(skb);
1278 return -1;
1279 }
1280
1281 return 0;
1282
1283 }
1284
1285 /* returns:
1286 * -1: error
1287 * 0: success
1288 * >0: "udp encap" protocol resubmission
1289 *
1290 * Note that in the success and error cases, the skb is assumed to
1291 * have either been requeued or freed.
1292 */
1293 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1294 {
1295 struct udp_sock *up = udp_sk(sk);
1296 int rc;
1297 int is_udplite = IS_UDPLITE(sk);
1298
1299 /*
1300 * Charge it to the socket, dropping if the queue is full.
1301 */
1302 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1303 goto drop;
1304 nf_reset(skb);
1305
1306 if (up->encap_type) {
1307 /*
1308 * This is an encapsulation socket so pass the skb to
1309 * the socket's udp_encap_rcv() hook. Otherwise, just
1310 * fall through and pass this up the UDP socket.
1311 * up->encap_rcv() returns the following value:
1312 * =0 if skb was successfully passed to the encap
1313 * handler or was discarded by it.
1314 * >0 if skb should be passed on to UDP.
1315 * <0 if skb should be resubmitted as proto -N
1316 */
1317
1318 /* if we're overly short, let UDP handle it */
1319 if (skb->len > sizeof(struct udphdr) &&
1320 up->encap_rcv != NULL) {
1321 int ret;
1322
1323 ret = (*up->encap_rcv)(sk, skb);
1324 if (ret <= 0) {
1325 UDP_INC_STATS_BH(sock_net(sk),
1326 UDP_MIB_INDATAGRAMS,
1327 is_udplite);
1328 return -ret;
1329 }
1330 }
1331
1332 /* FALLTHROUGH -- it's a UDP Packet */
1333 }
1334
1335 /*
1336 * UDP-Lite specific tests, ignored on UDP sockets
1337 */
1338 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1339
1340 /*
1341 * MIB statistics other than incrementing the error count are
1342 * disabled for the following two types of errors: these depend
1343 * on the application settings, not on the functioning of the
1344 * protocol stack as such.
1345 *
1346 * RFC 3828 here recommends (sec 3.3): "There should also be a
1347 * way ... to ... at least let the receiving application block
1348 * delivery of packets with coverage values less than a value
1349 * provided by the application."
1350 */
1351 if (up->pcrlen == 0) { /* full coverage was set */
1352 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1353 "%d while full coverage %d requested\n",
1354 UDP_SKB_CB(skb)->cscov, skb->len);
1355 goto drop;
1356 }
1357 /* The next case involves violating the min. coverage requested
1358 * by the receiver. This is subtle: if receiver wants x and x is
1359 * greater than the buffersize/MTU then receiver will complain
1360 * that it wants x while sender emits packets of smaller size y.
1361 * Therefore the above ...()->partial_cov statement is essential.
1362 */
1363 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1364 LIMIT_NETDEBUG(KERN_WARNING
1365 "UDPLITE: coverage %d too small, need min %d\n",
1366 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1367 goto drop;
1368 }
1369 }
1370
1371 if (sk->sk_filter) {
1372 if (udp_lib_checksum_complete(skb))
1373 goto drop;
1374 }
1375
1376
1377 if (sk_rcvqueues_full(sk, skb))
1378 goto drop;
1379
1380 rc = 0;
1381
1382 bh_lock_sock(sk);
1383 if (!sock_owned_by_user(sk))
1384 rc = __udp_queue_rcv_skb(sk, skb);
1385 else if (sk_add_backlog(sk, skb)) {
1386 bh_unlock_sock(sk);
1387 goto drop;
1388 }
1389 bh_unlock_sock(sk);
1390
1391 return rc;
1392
1393 drop:
1394 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1395 atomic_inc(&sk->sk_drops);
1396 kfree_skb(skb);
1397 return -1;
1398 }
1399
1400
1401 static void flush_stack(struct sock **stack, unsigned int count,
1402 struct sk_buff *skb, unsigned int final)
1403 {
1404 unsigned int i;
1405 struct sk_buff *skb1 = NULL;
1406 struct sock *sk;
1407
1408 for (i = 0; i < count; i++) {
1409 sk = stack[i];
1410 if (likely(skb1 == NULL))
1411 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
1412
1413 if (!skb1) {
1414 atomic_inc(&sk->sk_drops);
1415 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1416 IS_UDPLITE(sk));
1417 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1418 IS_UDPLITE(sk));
1419 }
1420
1421 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1422 skb1 = NULL;
1423 }
1424 if (unlikely(skb1))
1425 kfree_skb(skb1);
1426 }
1427
1428 /*
1429 * Multicasts and broadcasts go to each listener.
1430 *
1431 * Note: called only from the BH handler context.
1432 */
1433 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1434 struct udphdr *uh,
1435 __be32 saddr, __be32 daddr,
1436 struct udp_table *udptable)
1437 {
1438 struct sock *sk, *stack[256 / sizeof(struct sock *)];
1439 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1440 int dif;
1441 unsigned int i, count = 0;
1442
1443 spin_lock(&hslot->lock);
1444 sk = sk_nulls_head(&hslot->head);
1445 dif = skb->dev->ifindex;
1446 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1447 while (sk) {
1448 stack[count++] = sk;
1449 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1450 daddr, uh->source, saddr, dif);
1451 if (unlikely(count == ARRAY_SIZE(stack))) {
1452 if (!sk)
1453 break;
1454 flush_stack(stack, count, skb, ~0);
1455 count = 0;
1456 }
1457 }
1458 /*
1459 * before releasing chain lock, we must take a reference on sockets
1460 */
1461 for (i = 0; i < count; i++)
1462 sock_hold(stack[i]);
1463
1464 spin_unlock(&hslot->lock);
1465
1466 /*
1467 * do the slow work with no lock held
1468 */
1469 if (count) {
1470 flush_stack(stack, count, skb, count - 1);
1471
1472 for (i = 0; i < count; i++)
1473 sock_put(stack[i]);
1474 } else {
1475 kfree_skb(skb);
1476 }
1477 return 0;
1478 }
1479
1480 /* Initialize UDP checksum. If exited with zero value (success),
1481 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1482 * Otherwise, csum completion requires chacksumming packet body,
1483 * including udp header and folding it to skb->csum.
1484 */
1485 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1486 int proto)
1487 {
1488 const struct iphdr *iph;
1489 int err;
1490
1491 UDP_SKB_CB(skb)->partial_cov = 0;
1492 UDP_SKB_CB(skb)->cscov = skb->len;
1493
1494 if (proto == IPPROTO_UDPLITE) {
1495 err = udplite_checksum_init(skb, uh);
1496 if (err)
1497 return err;
1498 }
1499
1500 iph = ip_hdr(skb);
1501 if (uh->check == 0) {
1502 skb->ip_summed = CHECKSUM_UNNECESSARY;
1503 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1504 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1505 proto, skb->csum))
1506 skb->ip_summed = CHECKSUM_UNNECESSARY;
1507 }
1508 if (!skb_csum_unnecessary(skb))
1509 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1510 skb->len, proto, 0);
1511 /* Probably, we should checksum udp header (it should be in cache
1512 * in any case) and data in tiny packets (< rx copybreak).
1513 */
1514
1515 return 0;
1516 }
1517
1518 /*
1519 * All we need to do is get the socket, and then do a checksum.
1520 */
1521
1522 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1523 int proto)
1524 {
1525 struct sock *sk;
1526 struct udphdr *uh;
1527 unsigned short ulen;
1528 struct rtable *rt = skb_rtable(skb);
1529 __be32 saddr, daddr;
1530 struct net *net = dev_net(skb->dev);
1531
1532 /*
1533 * Validate the packet.
1534 */
1535 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1536 goto drop; /* No space for header. */
1537
1538 uh = udp_hdr(skb);
1539 ulen = ntohs(uh->len);
1540 saddr = ip_hdr(skb)->saddr;
1541 daddr = ip_hdr(skb)->daddr;
1542
1543 if (ulen > skb->len)
1544 goto short_packet;
1545
1546 if (proto == IPPROTO_UDP) {
1547 /* UDP validates ulen. */
1548 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1549 goto short_packet;
1550 uh = udp_hdr(skb);
1551 }
1552
1553 if (udp4_csum_init(skb, uh, proto))
1554 goto csum_error;
1555
1556 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1557 return __udp4_lib_mcast_deliver(net, skb, uh,
1558 saddr, daddr, udptable);
1559
1560 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1561
1562 if (sk != NULL) {
1563 int ret = udp_queue_rcv_skb(sk, skb);
1564 sock_put(sk);
1565
1566 /* a return value > 0 means to resubmit the input, but
1567 * it wants the return to be -protocol, or 0
1568 */
1569 if (ret > 0)
1570 return -ret;
1571 return 0;
1572 }
1573
1574 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1575 goto drop;
1576 nf_reset(skb);
1577
1578 /* No socket. Drop packet silently, if checksum is wrong */
1579 if (udp_lib_checksum_complete(skb))
1580 goto csum_error;
1581
1582 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1583 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1584
1585 /*
1586 * Hmm. We got an UDP packet to a port to which we
1587 * don't wanna listen. Ignore it.
1588 */
1589 kfree_skb(skb);
1590 return 0;
1591
1592 short_packet:
1593 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1594 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1595 &saddr,
1596 ntohs(uh->source),
1597 ulen,
1598 skb->len,
1599 &daddr,
1600 ntohs(uh->dest));
1601 goto drop;
1602
1603 csum_error:
1604 /*
1605 * RFC1122: OK. Discards the bad packet silently (as far as
1606 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1607 */
1608 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1609 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1610 &saddr,
1611 ntohs(uh->source),
1612 &daddr,
1613 ntohs(uh->dest),
1614 ulen);
1615 drop:
1616 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1617 kfree_skb(skb);
1618 return 0;
1619 }
1620
1621 int udp_rcv(struct sk_buff *skb)
1622 {
1623 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1624 }
1625
1626 void udp_destroy_sock(struct sock *sk)
1627 {
1628 lock_sock_bh(sk);
1629 udp_flush_pending_frames(sk);
1630 unlock_sock_bh(sk);
1631 }
1632
1633 /*
1634 * Socket option code for UDP
1635 */
1636 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1637 char __user *optval, unsigned int optlen,
1638 int (*push_pending_frames)(struct sock *))
1639 {
1640 struct udp_sock *up = udp_sk(sk);
1641 int val;
1642 int err = 0;
1643 int is_udplite = IS_UDPLITE(sk);
1644
1645 if (optlen < sizeof(int))
1646 return -EINVAL;
1647
1648 if (get_user(val, (int __user *)optval))
1649 return -EFAULT;
1650
1651 switch (optname) {
1652 case UDP_CORK:
1653 if (val != 0) {
1654 up->corkflag = 1;
1655 } else {
1656 up->corkflag = 0;
1657 lock_sock(sk);
1658 (*push_pending_frames)(sk);
1659 release_sock(sk);
1660 }
1661 break;
1662
1663 case UDP_ENCAP:
1664 switch (val) {
1665 case 0:
1666 case UDP_ENCAP_ESPINUDP:
1667 case UDP_ENCAP_ESPINUDP_NON_IKE:
1668 up->encap_rcv = xfrm4_udp_encap_rcv;
1669 /* FALLTHROUGH */
1670 case UDP_ENCAP_L2TPINUDP:
1671 up->encap_type = val;
1672 break;
1673 default:
1674 err = -ENOPROTOOPT;
1675 break;
1676 }
1677 break;
1678
1679 /*
1680 * UDP-Lite's partial checksum coverage (RFC 3828).
1681 */
1682 /* The sender sets actual checksum coverage length via this option.
1683 * The case coverage > packet length is handled by send module. */
1684 case UDPLITE_SEND_CSCOV:
1685 if (!is_udplite) /* Disable the option on UDP sockets */
1686 return -ENOPROTOOPT;
1687 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1688 val = 8;
1689 else if (val > USHRT_MAX)
1690 val = USHRT_MAX;
1691 up->pcslen = val;
1692 up->pcflag |= UDPLITE_SEND_CC;
1693 break;
1694
1695 /* The receiver specifies a minimum checksum coverage value. To make
1696 * sense, this should be set to at least 8 (as done below). If zero is
1697 * used, this again means full checksum coverage. */
1698 case UDPLITE_RECV_CSCOV:
1699 if (!is_udplite) /* Disable the option on UDP sockets */
1700 return -ENOPROTOOPT;
1701 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1702 val = 8;
1703 else if (val > USHRT_MAX)
1704 val = USHRT_MAX;
1705 up->pcrlen = val;
1706 up->pcflag |= UDPLITE_RECV_CC;
1707 break;
1708
1709 default:
1710 err = -ENOPROTOOPT;
1711 break;
1712 }
1713
1714 return err;
1715 }
1716 EXPORT_SYMBOL(udp_lib_setsockopt);
1717
1718 int udp_setsockopt(struct sock *sk, int level, int optname,
1719 char __user *optval, unsigned int optlen)
1720 {
1721 if (level == SOL_UDP || level == SOL_UDPLITE)
1722 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1723 udp_push_pending_frames);
1724 return ip_setsockopt(sk, level, optname, optval, optlen);
1725 }
1726
1727 #ifdef CONFIG_COMPAT
1728 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1729 char __user *optval, unsigned int optlen)
1730 {
1731 if (level == SOL_UDP || level == SOL_UDPLITE)
1732 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1733 udp_push_pending_frames);
1734 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1735 }
1736 #endif
1737
1738 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1739 char __user *optval, int __user *optlen)
1740 {
1741 struct udp_sock *up = udp_sk(sk);
1742 int val, len;
1743
1744 if (get_user(len, optlen))
1745 return -EFAULT;
1746
1747 len = min_t(unsigned int, len, sizeof(int));
1748
1749 if (len < 0)
1750 return -EINVAL;
1751
1752 switch (optname) {
1753 case UDP_CORK:
1754 val = up->corkflag;
1755 break;
1756
1757 case UDP_ENCAP:
1758 val = up->encap_type;
1759 break;
1760
1761 /* The following two cannot be changed on UDP sockets, the return is
1762 * always 0 (which corresponds to the full checksum coverage of UDP). */
1763 case UDPLITE_SEND_CSCOV:
1764 val = up->pcslen;
1765 break;
1766
1767 case UDPLITE_RECV_CSCOV:
1768 val = up->pcrlen;
1769 break;
1770
1771 default:
1772 return -ENOPROTOOPT;
1773 }
1774
1775 if (put_user(len, optlen))
1776 return -EFAULT;
1777 if (copy_to_user(optval, &val, len))
1778 return -EFAULT;
1779 return 0;
1780 }
1781 EXPORT_SYMBOL(udp_lib_getsockopt);
1782
1783 int udp_getsockopt(struct sock *sk, int level, int optname,
1784 char __user *optval, int __user *optlen)
1785 {
1786 if (level == SOL_UDP || level == SOL_UDPLITE)
1787 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1788 return ip_getsockopt(sk, level, optname, optval, optlen);
1789 }
1790
1791 #ifdef CONFIG_COMPAT
1792 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1793 char __user *optval, int __user *optlen)
1794 {
1795 if (level == SOL_UDP || level == SOL_UDPLITE)
1796 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1797 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1798 }
1799 #endif
1800 /**
1801 * udp_poll - wait for a UDP event.
1802 * @file - file struct
1803 * @sock - socket
1804 * @wait - poll table
1805 *
1806 * This is same as datagram poll, except for the special case of
1807 * blocking sockets. If application is using a blocking fd
1808 * and a packet with checksum error is in the queue;
1809 * then it could get return from select indicating data available
1810 * but then block when reading it. Add special case code
1811 * to work around these arguably broken applications.
1812 */
1813 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1814 {
1815 unsigned int mask = datagram_poll(file, sock, wait);
1816 struct sock *sk = sock->sk;
1817
1818 /* Check for false positives due to checksum errors */
1819 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1820 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1821 mask &= ~(POLLIN | POLLRDNORM);
1822
1823 return mask;
1824
1825 }
1826 EXPORT_SYMBOL(udp_poll);
1827
1828 struct proto udp_prot = {
1829 .name = "UDP",
1830 .owner = THIS_MODULE,
1831 .close = udp_lib_close,
1832 .connect = ip4_datagram_connect,
1833 .disconnect = udp_disconnect,
1834 .ioctl = udp_ioctl,
1835 .destroy = udp_destroy_sock,
1836 .setsockopt = udp_setsockopt,
1837 .getsockopt = udp_getsockopt,
1838 .sendmsg = udp_sendmsg,
1839 .recvmsg = udp_recvmsg,
1840 .sendpage = udp_sendpage,
1841 .backlog_rcv = __udp_queue_rcv_skb,
1842 .hash = udp_lib_hash,
1843 .unhash = udp_lib_unhash,
1844 .get_port = udp_v4_get_port,
1845 .memory_allocated = &udp_memory_allocated,
1846 .sysctl_mem = sysctl_udp_mem,
1847 .sysctl_wmem = &sysctl_udp_wmem_min,
1848 .sysctl_rmem = &sysctl_udp_rmem_min,
1849 .obj_size = sizeof(struct udp_sock),
1850 .slab_flags = SLAB_DESTROY_BY_RCU,
1851 .h.udp_table = &udp_table,
1852 #ifdef CONFIG_COMPAT
1853 .compat_setsockopt = compat_udp_setsockopt,
1854 .compat_getsockopt = compat_udp_getsockopt,
1855 #endif
1856 };
1857 EXPORT_SYMBOL(udp_prot);
1858
1859 /* ------------------------------------------------------------------------ */
1860 #ifdef CONFIG_PROC_FS
1861
1862 static struct sock *udp_get_first(struct seq_file *seq, int start)
1863 {
1864 struct sock *sk;
1865 struct udp_iter_state *state = seq->private;
1866 struct net *net = seq_file_net(seq);
1867
1868 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1869 ++state->bucket) {
1870 struct hlist_nulls_node *node;
1871 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1872
1873 if (hlist_nulls_empty(&hslot->head))
1874 continue;
1875
1876 spin_lock_bh(&hslot->lock);
1877 sk_nulls_for_each(sk, node, &hslot->head) {
1878 if (!net_eq(sock_net(sk), net))
1879 continue;
1880 if (sk->sk_family == state->family)
1881 goto found;
1882 }
1883 spin_unlock_bh(&hslot->lock);
1884 }
1885 sk = NULL;
1886 found:
1887 return sk;
1888 }
1889
1890 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1891 {
1892 struct udp_iter_state *state = seq->private;
1893 struct net *net = seq_file_net(seq);
1894
1895 do {
1896 sk = sk_nulls_next(sk);
1897 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1898
1899 if (!sk) {
1900 if (state->bucket <= state->udp_table->mask)
1901 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1902 return udp_get_first(seq, state->bucket + 1);
1903 }
1904 return sk;
1905 }
1906
1907 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1908 {
1909 struct sock *sk = udp_get_first(seq, 0);
1910
1911 if (sk)
1912 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1913 --pos;
1914 return pos ? NULL : sk;
1915 }
1916
1917 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1918 {
1919 struct udp_iter_state *state = seq->private;
1920 state->bucket = MAX_UDP_PORTS;
1921
1922 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1923 }
1924
1925 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1926 {
1927 struct sock *sk;
1928
1929 if (v == SEQ_START_TOKEN)
1930 sk = udp_get_idx(seq, 0);
1931 else
1932 sk = udp_get_next(seq, v);
1933
1934 ++*pos;
1935 return sk;
1936 }
1937
1938 static void udp_seq_stop(struct seq_file *seq, void *v)
1939 {
1940 struct udp_iter_state *state = seq->private;
1941
1942 if (state->bucket <= state->udp_table->mask)
1943 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1944 }
1945
1946 static int udp_seq_open(struct inode *inode, struct file *file)
1947 {
1948 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1949 struct udp_iter_state *s;
1950 int err;
1951
1952 err = seq_open_net(inode, file, &afinfo->seq_ops,
1953 sizeof(struct udp_iter_state));
1954 if (err < 0)
1955 return err;
1956
1957 s = ((struct seq_file *)file->private_data)->private;
1958 s->family = afinfo->family;
1959 s->udp_table = afinfo->udp_table;
1960 return err;
1961 }
1962
1963 /* ------------------------------------------------------------------------ */
1964 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1965 {
1966 struct proc_dir_entry *p;
1967 int rc = 0;
1968
1969 afinfo->seq_fops.open = udp_seq_open;
1970 afinfo->seq_fops.read = seq_read;
1971 afinfo->seq_fops.llseek = seq_lseek;
1972 afinfo->seq_fops.release = seq_release_net;
1973
1974 afinfo->seq_ops.start = udp_seq_start;
1975 afinfo->seq_ops.next = udp_seq_next;
1976 afinfo->seq_ops.stop = udp_seq_stop;
1977
1978 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1979 &afinfo->seq_fops, afinfo);
1980 if (!p)
1981 rc = -ENOMEM;
1982 return rc;
1983 }
1984 EXPORT_SYMBOL(udp_proc_register);
1985
1986 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1987 {
1988 proc_net_remove(net, afinfo->name);
1989 }
1990 EXPORT_SYMBOL(udp_proc_unregister);
1991
1992 /* ------------------------------------------------------------------------ */
1993 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1994 int bucket, int *len)
1995 {
1996 struct inet_sock *inet = inet_sk(sp);
1997 __be32 dest = inet->inet_daddr;
1998 __be32 src = inet->inet_rcv_saddr;
1999 __u16 destp = ntohs(inet->inet_dport);
2000 __u16 srcp = ntohs(inet->inet_sport);
2001
2002 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2003 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
2004 bucket, src, srcp, dest, destp, sp->sk_state,
2005 sk_wmem_alloc_get(sp),
2006 sk_rmem_alloc_get(sp),
2007 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
2008 atomic_read(&sp->sk_refcnt), sp,
2009 atomic_read(&sp->sk_drops), len);
2010 }
2011
2012 int udp4_seq_show(struct seq_file *seq, void *v)
2013 {
2014 if (v == SEQ_START_TOKEN)
2015 seq_printf(seq, "%-127s\n",
2016 " sl local_address rem_address st tx_queue "
2017 "rx_queue tr tm->when retrnsmt uid timeout "
2018 "inode ref pointer drops");
2019 else {
2020 struct udp_iter_state *state = seq->private;
2021 int len;
2022
2023 udp4_format_sock(v, seq, state->bucket, &len);
2024 seq_printf(seq, "%*s\n", 127 - len, "");
2025 }
2026 return 0;
2027 }
2028
2029 /* ------------------------------------------------------------------------ */
2030 static struct udp_seq_afinfo udp4_seq_afinfo = {
2031 .name = "udp",
2032 .family = AF_INET,
2033 .udp_table = &udp_table,
2034 .seq_fops = {
2035 .owner = THIS_MODULE,
2036 },
2037 .seq_ops = {
2038 .show = udp4_seq_show,
2039 },
2040 };
2041
2042 static int __net_init udp4_proc_init_net(struct net *net)
2043 {
2044 return udp_proc_register(net, &udp4_seq_afinfo);
2045 }
2046
2047 static void __net_exit udp4_proc_exit_net(struct net *net)
2048 {
2049 udp_proc_unregister(net, &udp4_seq_afinfo);
2050 }
2051
2052 static struct pernet_operations udp4_net_ops = {
2053 .init = udp4_proc_init_net,
2054 .exit = udp4_proc_exit_net,
2055 };
2056
2057 int __init udp4_proc_init(void)
2058 {
2059 return register_pernet_subsys(&udp4_net_ops);
2060 }
2061
2062 void udp4_proc_exit(void)
2063 {
2064 unregister_pernet_subsys(&udp4_net_ops);
2065 }
2066 #endif /* CONFIG_PROC_FS */
2067
2068 static __initdata unsigned long uhash_entries;
2069 static int __init set_uhash_entries(char *str)
2070 {
2071 if (!str)
2072 return 0;
2073 uhash_entries = simple_strtoul(str, &str, 0);
2074 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2075 uhash_entries = UDP_HTABLE_SIZE_MIN;
2076 return 1;
2077 }
2078 __setup("uhash_entries=", set_uhash_entries);
2079
2080 void __init udp_table_init(struct udp_table *table, const char *name)
2081 {
2082 unsigned int i;
2083
2084 if (!CONFIG_BASE_SMALL)
2085 table->hash = alloc_large_system_hash(name,
2086 2 * sizeof(struct udp_hslot),
2087 uhash_entries,
2088 21, /* one slot per 2 MB */
2089 0,
2090 &table->log,
2091 &table->mask,
2092 64 * 1024);
2093 /*
2094 * Make sure hash table has the minimum size
2095 */
2096 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
2097 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
2098 2 * sizeof(struct udp_hslot), GFP_KERNEL);
2099 if (!table->hash)
2100 panic(name);
2101 table->log = ilog2(UDP_HTABLE_SIZE_MIN);
2102 table->mask = UDP_HTABLE_SIZE_MIN - 1;
2103 }
2104 table->hash2 = table->hash + (table->mask + 1);
2105 for (i = 0; i <= table->mask; i++) {
2106 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
2107 table->hash[i].count = 0;
2108 spin_lock_init(&table->hash[i].lock);
2109 }
2110 for (i = 0; i <= table->mask; i++) {
2111 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
2112 table->hash2[i].count = 0;
2113 spin_lock_init(&table->hash2[i].lock);
2114 }
2115 }
2116
2117 void __init udp_init(void)
2118 {
2119 unsigned long nr_pages, limit;
2120
2121 udp_table_init(&udp_table, "UDP");
2122 /* Set the pressure threshold up by the same strategy of TCP. It is a
2123 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
2124 * toward zero with the amount of memory, with a floor of 128 pages.
2125 */
2126 nr_pages = totalram_pages - totalhigh_pages;
2127 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2128 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
2129 limit = max(limit, 128UL);
2130 sysctl_udp_mem[0] = limit / 4 * 3;
2131 sysctl_udp_mem[1] = limit;
2132 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2133
2134 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2135 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2136 }
2137
2138 int udp4_ufo_send_check(struct sk_buff *skb)
2139 {
2140 const struct iphdr *iph;
2141 struct udphdr *uh;
2142
2143 if (!pskb_may_pull(skb, sizeof(*uh)))
2144 return -EINVAL;
2145
2146 iph = ip_hdr(skb);
2147 uh = udp_hdr(skb);
2148
2149 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
2150 IPPROTO_UDP, 0);
2151 skb->csum_start = skb_transport_header(skb) - skb->head;
2152 skb->csum_offset = offsetof(struct udphdr, check);
2153 skb->ip_summed = CHECKSUM_PARTIAL;
2154 return 0;
2155 }
2156
2157 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
2158 {
2159 struct sk_buff *segs = ERR_PTR(-EINVAL);
2160 unsigned int mss;
2161 int offset;
2162 __wsum csum;
2163
2164 mss = skb_shinfo(skb)->gso_size;
2165 if (unlikely(skb->len <= mss))
2166 goto out;
2167
2168 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2169 /* Packet is from an untrusted source, reset gso_segs. */
2170 int type = skb_shinfo(skb)->gso_type;
2171
2172 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
2173 !(type & (SKB_GSO_UDP))))
2174 goto out;
2175
2176 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2177
2178 segs = NULL;
2179 goto out;
2180 }
2181
2182 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
2183 * do checksum of UDP packets sent as multiple IP fragments.
2184 */
2185 offset = skb->csum_start - skb_headroom(skb);
2186 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2187 offset += skb->csum_offset;
2188 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2189 skb->ip_summed = CHECKSUM_NONE;
2190
2191 /* Fragment the skb. IP headers of the fragments are updated in
2192 * inet_gso_segment()
2193 */
2194 segs = skb_segment(skb, features);
2195 out:
2196 return segs;
2197 }
2198
kernel source for telekom puls (alcatel/mediatek)