Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * INET An implementation of the TCP/IP protocol suite for the LINUX
4 : * operating system. INET is implemented using the BSD Socket
5 : * interface as the means of communication with the user level.
6 : *
7 : * The User Datagram Protocol (UDP).
8 : *
9 : * Authors: Ross Biro
10 : * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 : * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
12 : * Alan Cox, <alan@lxorguk.ukuu.org.uk>
13 : * Hirokazu Takahashi, <taka@valinux.co.jp>
14 : *
15 : * Fixes:
16 : * Alan Cox : verify_area() calls
17 : * Alan Cox : stopped close while in use off icmp
18 : * messages. Not a fix but a botch that
19 : * for udp at least is 'valid'.
20 : * Alan Cox : Fixed icmp handling properly
21 : * Alan Cox : Correct error for oversized datagrams
22 : * Alan Cox : Tidied select() semantics.
23 : * Alan Cox : udp_err() fixed properly, also now
24 : * select and read wake correctly on errors
25 : * Alan Cox : udp_send verify_area moved to avoid mem leak
26 : * Alan Cox : UDP can count its memory
27 : * Alan Cox : send to an unknown connection causes
28 : * an ECONNREFUSED off the icmp, but
29 : * does NOT close.
30 : * Alan Cox : Switched to new sk_buff handlers. No more backlog!
31 : * Alan Cox : Using generic datagram code. Even smaller and the PEEK
32 : * bug no longer crashes it.
33 : * Fred Van Kempen : Net2e support for sk->broadcast.
34 : * Alan Cox : Uses skb_free_datagram
35 : * Alan Cox : Added get/set sockopt support.
36 : * Alan Cox : Broadcasting without option set returns EACCES.
37 : * Alan Cox : No wakeup calls. Instead we now use the callbacks.
38 : * Alan Cox : Use ip_tos and ip_ttl
39 : * Alan Cox : SNMP Mibs
40 : * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
41 : * Matt Dillon : UDP length checks.
42 : * Alan Cox : Smarter af_inet used properly.
43 : * Alan Cox : Use new kernel side addressing.
44 : * Alan Cox : Incorrect return on truncated datagram receive.
45 : * Arnt Gulbrandsen : New udp_send and stuff
46 : * Alan Cox : Cache last socket
47 : * Alan Cox : Route cache
48 : * Jon Peatfield : Minor efficiency fix to sendto().
49 : * Mike Shaver : RFC1122 checks.
50 : * Alan Cox : Nonblocking error fix.
51 : * Willy Konynenberg : Transparent proxying support.
52 : * Mike McLagan : Routing by source
53 : * David S. Miller : New socket lookup architecture.
54 : * Last socket cache retained as it
55 : * does have a high hit rate.
56 : * Olaf Kirch : Don't linearise iovec on sendmsg.
57 : * Andi Kleen : Some cleanups, cache destination entry
58 : * for connect.
59 : * Vitaly E. Lavrov : Transparent proxy revived after year coma.
60 : * Melvin Smith : Check msg_name not msg_namelen in sendto(),
61 : * return ENOTCONN for unconnected sockets (POSIX)
62 : * Janos Farkas : don't deliver multi/broadcasts to a different
63 : * bound-to-device socket
64 : * Hirokazu Takahashi : HW checksumming for outgoing UDP
65 : * datagrams.
66 : * Hirokazu Takahashi : sendfile() on UDP works now.
67 : * Arnaldo C. Melo : convert /proc/net/udp to seq_file
68 : * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
69 : * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
70 : * a single port at the same time.
71 : * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
72 : * James Chapman : Add L2TP encapsulation type.
73 : */
74 :
75 : #define pr_fmt(fmt) "UDP: " fmt
76 :
77 : #include <linux/uaccess.h>
78 : #include <asm/ioctls.h>
79 : #include <linux/memblock.h>
80 : #include <linux/highmem.h>
81 : #include <linux/swap.h>
82 : #include <linux/types.h>
83 : #include <linux/fcntl.h>
84 : #include <linux/module.h>
85 : #include <linux/socket.h>
86 : #include <linux/sockios.h>
87 : #include <linux/igmp.h>
88 : #include <linux/inetdevice.h>
89 : #include <linux/in.h>
90 : #include <linux/errno.h>
91 : #include <linux/timer.h>
92 : #include <linux/mm.h>
93 : #include <linux/inet.h>
94 : #include <linux/netdevice.h>
95 : #include <linux/slab.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/net_namespace.h>
101 : #include <net/icmp.h>
102 : #include <net/inet_hashtables.h>
103 : #include <net/ip_tunnels.h>
104 : #include <net/route.h>
105 : #include <net/checksum.h>
106 : #include <net/xfrm.h>
107 : #include <trace/events/udp.h>
108 : #include <linux/static_key.h>
109 : #include <linux/btf_ids.h>
110 : #include <trace/events/skb.h>
111 : #include <net/busy_poll.h>
112 : #include "udp_impl.h"
113 : #include <net/sock_reuseport.h>
114 : #include <net/addrconf.h>
115 : #include <net/udp_tunnel.h>
116 : #if IS_ENABLED(CONFIG_IPV6)
117 : #include <net/ipv6_stubs.h>
118 : #endif
119 :
120 : struct udp_table udp_table __read_mostly;
121 : EXPORT_SYMBOL(udp_table);
122 :
123 : long sysctl_udp_mem[3] __read_mostly;
124 : EXPORT_SYMBOL(sysctl_udp_mem);
125 :
126 : atomic_long_t udp_memory_allocated;
127 : EXPORT_SYMBOL(udp_memory_allocated);
128 :
129 : #define MAX_UDP_PORTS 65536
130 : #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
131 :
132 35 : static int udp_lib_lport_inuse(struct net *net, __u16 num,
133 : const struct udp_hslot *hslot,
134 : unsigned long *bitmap,
135 : struct sock *sk, unsigned int log)
136 : {
137 35 : struct sock *sk2;
138 35 : kuid_t uid = sock_i_uid(sk);
139 :
140 70 : sk_for_each(sk2, &hslot->head) {
141 0 : if (net_eq(sock_net(sk2), net) &&
142 0 : sk2 != sk &&
143 0 : (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
144 0 : (!sk2->sk_reuse || !sk->sk_reuse) &&
145 0 : (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
146 0 : sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
147 0 : inet_rcv_saddr_equal(sk, sk2, true)) {
148 0 : if (sk2->sk_reuseport && sk->sk_reuseport &&
149 0 : !rcu_access_pointer(sk->sk_reuseport_cb) &&
150 0 : uid_eq(uid, sock_i_uid(sk2))) {
151 0 : if (!bitmap)
152 : return 0;
153 : } else {
154 0 : if (!bitmap)
155 : return 1;
156 0 : __set_bit(udp_sk(sk2)->udp_port_hash >> log,
157 : bitmap);
158 : }
159 : }
160 : }
161 : return 0;
162 : }
163 :
164 : /*
165 : * Note: we still hold spinlock of primary hash chain, so no other writer
166 : * can insert/delete a socket with local_port == num
167 : */
168 0 : static int udp_lib_lport_inuse2(struct net *net, __u16 num,
169 : struct udp_hslot *hslot2,
170 : struct sock *sk)
171 : {
172 0 : struct sock *sk2;
173 0 : kuid_t uid = sock_i_uid(sk);
174 0 : int res = 0;
175 :
176 0 : spin_lock(&hslot2->lock);
177 0 : udp_portaddr_for_each_entry(sk2, &hslot2->head) {
178 0 : if (net_eq(sock_net(sk2), net) &&
179 0 : sk2 != sk &&
180 0 : (udp_sk(sk2)->udp_port_hash == num) &&
181 0 : (!sk2->sk_reuse || !sk->sk_reuse) &&
182 0 : (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
183 0 : sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
184 0 : inet_rcv_saddr_equal(sk, sk2, true)) {
185 0 : if (sk2->sk_reuseport && sk->sk_reuseport &&
186 0 : !rcu_access_pointer(sk->sk_reuseport_cb) &&
187 0 : uid_eq(uid, sock_i_uid(sk2))) {
188 : res = 0;
189 : } else {
190 : res = 1;
191 : }
192 : break;
193 : }
194 : }
195 0 : spin_unlock(&hslot2->lock);
196 0 : return res;
197 : }
198 :
199 0 : static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
200 : {
201 0 : struct net *net = sock_net(sk);
202 0 : kuid_t uid = sock_i_uid(sk);
203 0 : struct sock *sk2;
204 :
205 0 : sk_for_each(sk2, &hslot->head) {
206 0 : if (net_eq(sock_net(sk2), net) &&
207 0 : sk2 != sk &&
208 0 : sk2->sk_family == sk->sk_family &&
209 0 : ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
210 0 : (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
211 0 : (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
212 0 : sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
213 0 : inet_rcv_saddr_equal(sk, sk2, false)) {
214 0 : return reuseport_add_sock(sk, sk2,
215 0 : inet_rcv_saddr_any(sk));
216 : }
217 : }
218 :
219 0 : return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
220 : }
221 :
222 : /**
223 : * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
224 : *
225 : * @sk: socket struct in question
226 : * @snum: port number to look up
227 : * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
228 : * with NULL address
229 : */
230 35 : int udp_lib_get_port(struct sock *sk, unsigned short snum,
231 : unsigned int hash2_nulladdr)
232 : {
233 35 : struct udp_hslot *hslot, *hslot2;
234 35 : struct udp_table *udptable = sk->sk_prot->h.udp_table;
235 35 : int error = 1;
236 35 : struct net *net = sock_net(sk);
237 :
238 35 : if (!snum) {
239 33 : int low, high, remaining;
240 33 : unsigned int rand;
241 33 : unsigned short first, last;
242 33 : DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
243 :
244 33 : inet_get_local_port_range(net, &low, &high);
245 33 : remaining = (high - low) + 1;
246 :
247 33 : rand = prandom_u32();
248 33 : first = reciprocal_scale(rand, remaining) + low;
249 : /*
250 : * force rand to be an odd multiple of UDP_HTABLE_SIZE
251 : */
252 33 : rand = (rand | 1) * (udptable->mask + 1);
253 33 : last = first + udptable->mask + 1;
254 33 : do {
255 33 : hslot = udp_hashslot(udptable, net, first);
256 33 : bitmap_zero(bitmap, PORTS_PER_CHAIN);
257 33 : spin_lock_bh(&hslot->lock);
258 33 : udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
259 : udptable->log);
260 :
261 33 : snum = first;
262 : /*
263 : * Iterate on all possible values of snum for this hash.
264 : * Using steps of an odd multiple of UDP_HTABLE_SIZE
265 : * give us randomization and full range coverage.
266 : */
267 33 : do {
268 66 : if (low <= snum && snum <= high &&
269 33 : !test_bit(snum >> udptable->log, bitmap) &&
270 66 : !inet_is_local_reserved_port(net, snum))
271 33 : goto found;
272 0 : snum += rand;
273 0 : } while (snum != first);
274 0 : spin_unlock_bh(&hslot->lock);
275 0 : cond_resched();
276 0 : } while (++first != last);
277 0 : goto fail;
278 : } else {
279 2 : hslot = udp_hashslot(udptable, net, snum);
280 2 : spin_lock_bh(&hslot->lock);
281 2 : if (hslot->count > 10) {
282 0 : int exist;
283 0 : unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
284 :
285 0 : slot2 &= udptable->mask;
286 0 : hash2_nulladdr &= udptable->mask;
287 :
288 0 : hslot2 = udp_hashslot2(udptable, slot2);
289 0 : if (hslot->count < hslot2->count)
290 0 : goto scan_primary_hash;
291 :
292 0 : exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
293 0 : if (!exist && (hash2_nulladdr != slot2)) {
294 0 : hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
295 0 : exist = udp_lib_lport_inuse2(net, snum, hslot2,
296 : sk);
297 : }
298 0 : if (exist)
299 0 : goto fail_unlock;
300 : else
301 0 : goto found;
302 : }
303 2 : scan_primary_hash:
304 2 : if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
305 0 : goto fail_unlock;
306 : }
307 2 : found:
308 35 : inet_sk(sk)->inet_num = snum;
309 35 : udp_sk(sk)->udp_port_hash = snum;
310 35 : udp_sk(sk)->udp_portaddr_hash ^= snum;
311 35 : if (sk_unhashed(sk)) {
312 35 : if (sk->sk_reuseport &&
313 0 : udp_reuseport_add_sock(sk, hslot)) {
314 0 : inet_sk(sk)->inet_num = 0;
315 0 : udp_sk(sk)->udp_port_hash = 0;
316 0 : udp_sk(sk)->udp_portaddr_hash ^= snum;
317 0 : goto fail_unlock;
318 : }
319 :
320 35 : sk_add_node_rcu(sk, &hslot->head);
321 35 : hslot->count++;
322 35 : sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
323 :
324 35 : hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
325 35 : spin_lock(&hslot2->lock);
326 35 : if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
327 : sk->sk_family == AF_INET6)
328 : hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
329 : &hslot2->head);
330 : else
331 35 : hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
332 : &hslot2->head);
333 35 : hslot2->count++;
334 35 : spin_unlock(&hslot2->lock);
335 : }
336 35 : sock_set_flag(sk, SOCK_RCU_FREE);
337 35 : error = 0;
338 35 : fail_unlock:
339 35 : spin_unlock_bh(&hslot->lock);
340 35 : fail:
341 35 : return error;
342 : }
343 : EXPORT_SYMBOL(udp_lib_get_port);
344 :
345 35 : int udp_v4_get_port(struct sock *sk, unsigned short snum)
346 : {
347 35 : unsigned int hash2_nulladdr =
348 35 : ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
349 35 : unsigned int hash2_partial =
350 35 : ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
351 :
352 : /* precompute partial secondary hash */
353 35 : udp_sk(sk)->udp_portaddr_hash = hash2_partial;
354 35 : return udp_lib_get_port(sk, snum, hash2_nulladdr);
355 : }
356 :
357 14 : static int compute_score(struct sock *sk, struct net *net,
358 : __be32 saddr, __be16 sport,
359 : __be32 daddr, unsigned short hnum,
360 : int dif, int sdif)
361 : {
362 14 : int score;
363 14 : struct inet_sock *inet;
364 14 : bool dev_match;
365 :
366 14 : if (!net_eq(sock_net(sk), net) ||
367 14 : udp_sk(sk)->udp_port_hash != hnum ||
368 : ipv6_only_sock(sk))
369 : return -1;
370 :
371 14 : if (sk->sk_rcv_saddr != daddr)
372 : return -1;
373 :
374 14 : score = (sk->sk_family == PF_INET) ? 2 : 1;
375 :
376 14 : inet = inet_sk(sk);
377 14 : if (inet->inet_daddr) {
378 14 : if (inet->inet_daddr != saddr)
379 : return -1;
380 14 : score += 4;
381 : }
382 :
383 14 : if (inet->inet_dport) {
384 14 : if (inet->inet_dport != sport)
385 : return -1;
386 14 : score += 4;
387 : }
388 :
389 14 : dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
390 : dif, sdif);
391 0 : if (!dev_match)
392 : return -1;
393 14 : score += 4;
394 :
395 14 : if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
396 0 : score++;
397 : return score;
398 : }
399 :
400 0 : static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
401 : const __u16 lport, const __be32 faddr,
402 : const __be16 fport)
403 : {
404 0 : static u32 udp_ehash_secret __read_mostly;
405 :
406 0 : net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
407 :
408 0 : return __inet_ehashfn(laddr, lport, faddr, fport,
409 0 : udp_ehash_secret + net_hash_mix(net));
410 : }
411 :
412 14 : static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
413 : struct sk_buff *skb,
414 : __be32 saddr, __be16 sport,
415 : __be32 daddr, unsigned short hnum)
416 : {
417 14 : struct sock *reuse_sk = NULL;
418 14 : u32 hash;
419 :
420 14 : if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
421 0 : hash = udp_ehashfn(net, daddr, hnum, saddr, sport);
422 0 : reuse_sk = reuseport_select_sock(sk, hash, skb,
423 : sizeof(struct udphdr));
424 : }
425 14 : return reuse_sk;
426 : }
427 :
428 : /* called with rcu_read_lock() */
429 14 : static struct sock *udp4_lib_lookup2(struct net *net,
430 : __be32 saddr, __be16 sport,
431 : __be32 daddr, unsigned int hnum,
432 : int dif, int sdif,
433 : struct udp_hslot *hslot2,
434 : struct sk_buff *skb)
435 : {
436 14 : struct sock *sk, *result;
437 14 : int score, badness;
438 :
439 14 : result = NULL;
440 14 : badness = 0;
441 56 : udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
442 14 : score = compute_score(sk, net, saddr, sport,
443 : daddr, hnum, dif, sdif);
444 14 : if (score > badness) {
445 14 : result = lookup_reuseport(net, sk, skb,
446 : saddr, sport, daddr, hnum);
447 : /* Fall back to scoring if group has connections */
448 14 : if (result && !reuseport_has_conns(sk, false))
449 0 : return result;
450 :
451 14 : result = result ? : sk;
452 : badness = score;
453 : }
454 : }
455 : return result;
456 : }
457 :
458 0 : static struct sock *udp4_lookup_run_bpf(struct net *net,
459 : struct udp_table *udptable,
460 : struct sk_buff *skb,
461 : __be32 saddr, __be16 sport,
462 : __be32 daddr, u16 hnum)
463 : {
464 0 : struct sock *sk, *reuse_sk;
465 0 : bool no_reuseport;
466 :
467 0 : if (udptable != &udp_table)
468 : return NULL; /* only UDP is supported */
469 :
470 0 : no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP,
471 : saddr, sport, daddr, hnum, &sk);
472 0 : if (no_reuseport || IS_ERR_OR_NULL(sk))
473 0 : return sk;
474 :
475 0 : reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
476 0 : if (reuse_sk)
477 0 : sk = reuse_sk;
478 0 : return sk;
479 : }
480 :
481 : /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
482 : * harder than this. -DaveM
483 : */
484 14 : struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
485 : __be16 sport, __be32 daddr, __be16 dport, int dif,
486 : int sdif, struct udp_table *udptable, struct sk_buff *skb)
487 : {
488 14 : unsigned short hnum = ntohs(dport);
489 14 : unsigned int hash2, slot2;
490 14 : struct udp_hslot *hslot2;
491 14 : struct sock *result, *sk;
492 :
493 14 : hash2 = ipv4_portaddr_hash(net, daddr, hnum);
494 14 : slot2 = hash2 & udptable->mask;
495 14 : hslot2 = &udptable->hash2[slot2];
496 :
497 : /* Lookup connected or non-wildcard socket */
498 14 : result = udp4_lib_lookup2(net, saddr, sport,
499 : daddr, hnum, dif, sdif,
500 : hslot2, skb);
501 28 : if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
502 14 : goto done;
503 :
504 : /* Lookup redirect from BPF */
505 0 : if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
506 0 : sk = udp4_lookup_run_bpf(net, udptable, skb,
507 : saddr, sport, daddr, hnum);
508 0 : if (sk) {
509 0 : result = sk;
510 0 : goto done;
511 : }
512 : }
513 :
514 : /* Got non-wildcard socket or error on first lookup */
515 0 : if (result)
516 0 : goto done;
517 :
518 : /* Lookup wildcard sockets */
519 0 : hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
520 0 : slot2 = hash2 & udptable->mask;
521 0 : hslot2 = &udptable->hash2[slot2];
522 :
523 0 : result = udp4_lib_lookup2(net, saddr, sport,
524 : htonl(INADDR_ANY), hnum, dif, sdif,
525 : hslot2, skb);
526 14 : done:
527 14 : if (IS_ERR(result))
528 0 : return NULL;
529 : return result;
530 : }
531 : EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
532 :
533 0 : static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
534 : __be16 sport, __be16 dport,
535 : struct udp_table *udptable)
536 : {
537 0 : const struct iphdr *iph = ip_hdr(skb);
538 :
539 0 : return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
540 : iph->daddr, dport, inet_iif(skb),
541 : inet_sdif(skb), udptable, skb);
542 : }
543 :
544 0 : struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
545 : __be16 sport, __be16 dport)
546 : {
547 0 : const struct iphdr *iph = ip_hdr(skb);
548 :
549 0 : return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
550 : iph->daddr, dport, inet_iif(skb),
551 : inet_sdif(skb), &udp_table, NULL);
552 : }
553 :
554 : /* Must be called under rcu_read_lock().
555 : * Does increment socket refcount.
556 : */
557 : #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
558 : struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
559 : __be32 daddr, __be16 dport, int dif)
560 : {
561 : struct sock *sk;
562 :
563 : sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
564 : dif, 0, &udp_table, NULL);
565 : if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
566 : sk = NULL;
567 : return sk;
568 : }
569 : EXPORT_SYMBOL_GPL(udp4_lib_lookup);
570 : #endif
571 :
572 2 : static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
573 : __be16 loc_port, __be32 loc_addr,
574 : __be16 rmt_port, __be32 rmt_addr,
575 : int dif, int sdif, unsigned short hnum)
576 : {
577 2 : struct inet_sock *inet = inet_sk(sk);
578 :
579 2 : if (!net_eq(sock_net(sk), net) ||
580 2 : udp_sk(sk)->udp_port_hash != hnum ||
581 2 : (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
582 2 : (inet->inet_dport != rmt_port && inet->inet_dport) ||
583 2 : (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
584 0 : ipv6_only_sock(sk) ||
585 2 : !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
586 : return false;
587 2 : if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
588 0 : return false;
589 : return true;
590 : }
591 :
592 : DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
593 0 : void udp_encap_enable(void)
594 : {
595 0 : static_branch_inc(&udp_encap_needed_key);
596 0 : }
597 : EXPORT_SYMBOL(udp_encap_enable);
598 :
599 0 : void udp_encap_disable(void)
600 : {
601 0 : static_branch_dec(&udp_encap_needed_key);
602 0 : }
603 : EXPORT_SYMBOL(udp_encap_disable);
604 :
605 : /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
606 : * through error handlers in encapsulations looking for a match.
607 : */
608 0 : static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
609 : {
610 0 : int i;
611 :
612 0 : for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
613 0 : int (*handler)(struct sk_buff *skb, u32 info);
614 0 : const struct ip_tunnel_encap_ops *encap;
615 :
616 0 : encap = rcu_dereference(iptun_encaps[i]);
617 0 : if (!encap)
618 0 : continue;
619 0 : handler = encap->err_handler;
620 0 : if (handler && !handler(skb, info))
621 : return 0;
622 : }
623 :
624 : return -ENOENT;
625 : }
626 :
627 : /* Try to match ICMP errors to UDP tunnels by looking up a socket without
628 : * reversing source and destination port: this will match tunnels that force the
629 : * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
630 : * lwtunnels might actually break this assumption by being configured with
631 : * different destination ports on endpoints, in this case we won't be able to
632 : * trace ICMP messages back to them.
633 : *
634 : * If this doesn't match any socket, probe tunnels with arbitrary destination
635 : * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
636 : * we've sent packets to won't necessarily match the local destination port.
637 : *
638 : * Then ask the tunnel implementation to match the error against a valid
639 : * association.
640 : *
641 : * Return an error if we can't find a match, the socket if we need further
642 : * processing, zero otherwise.
643 : */
644 0 : static struct sock *__udp4_lib_err_encap(struct net *net,
645 : const struct iphdr *iph,
646 : struct udphdr *uh,
647 : struct udp_table *udptable,
648 : struct sk_buff *skb, u32 info)
649 : {
650 0 : int network_offset, transport_offset;
651 0 : struct sock *sk;
652 :
653 0 : network_offset = skb_network_offset(skb);
654 0 : transport_offset = skb_transport_offset(skb);
655 :
656 : /* Network header needs to point to the outer IPv4 header inside ICMP */
657 0 : skb_reset_network_header(skb);
658 :
659 : /* Transport header needs to point to the UDP header */
660 0 : skb_set_transport_header(skb, iph->ihl << 2);
661 :
662 0 : sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
663 0 : iph->saddr, uh->dest, skb->dev->ifindex, 0,
664 : udptable, NULL);
665 0 : if (sk) {
666 0 : int (*lookup)(struct sock *sk, struct sk_buff *skb);
667 0 : struct udp_sock *up = udp_sk(sk);
668 :
669 0 : lookup = READ_ONCE(up->encap_err_lookup);
670 0 : if (!lookup || lookup(sk, skb))
671 : sk = NULL;
672 : }
673 :
674 0 : if (!sk)
675 0 : sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info));
676 :
677 0 : skb_set_transport_header(skb, transport_offset);
678 0 : skb_set_network_header(skb, network_offset);
679 :
680 0 : return sk;
681 : }
682 :
683 : /*
684 : * This routine is called by the ICMP module when it gets some
685 : * sort of error condition. If err < 0 then the socket should
686 : * be closed and the error returned to the user. If err > 0
687 : * it's just the icmp type << 8 | icmp code.
688 : * Header points to the ip header of the error packet. We move
689 : * on past this. Then (as it used to claim before adjustment)
690 : * header points to the first 8 bytes of the udp header. We need
691 : * to find the appropriate port.
692 : */
693 :
694 14 : int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
695 : {
696 14 : struct inet_sock *inet;
697 14 : const struct iphdr *iph = (const struct iphdr *)skb->data;
698 14 : struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
699 14 : const int type = icmp_hdr(skb)->type;
700 14 : const int code = icmp_hdr(skb)->code;
701 14 : bool tunnel = false;
702 14 : struct sock *sk;
703 14 : int harderr;
704 14 : int err;
705 14 : struct net *net = dev_net(skb->dev);
706 :
707 14 : sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
708 14 : iph->saddr, uh->source, skb->dev->ifindex,
709 : inet_sdif(skb), udptable, NULL);
710 14 : if (!sk || udp_sk(sk)->encap_type) {
711 : /* No socket for error: try tunnels before discarding */
712 0 : sk = ERR_PTR(-ENOENT);
713 0 : if (static_branch_unlikely(&udp_encap_needed_key)) {
714 0 : sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb,
715 : info);
716 0 : if (!sk)
717 : return 0;
718 : }
719 :
720 0 : if (IS_ERR(sk)) {
721 0 : __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
722 0 : return PTR_ERR(sk);
723 : }
724 :
725 : tunnel = true;
726 : }
727 :
728 14 : err = 0;
729 14 : harderr = 0;
730 14 : inet = inet_sk(sk);
731 :
732 14 : switch (type) {
733 : default:
734 : case ICMP_TIME_EXCEEDED:
735 : err = EHOSTUNREACH;
736 : break;
737 0 : case ICMP_SOURCE_QUENCH:
738 0 : goto out;
739 0 : case ICMP_PARAMETERPROB:
740 0 : err = EPROTO;
741 0 : harderr = 1;
742 0 : break;
743 14 : case ICMP_DEST_UNREACH:
744 14 : if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
745 0 : ipv4_sk_update_pmtu(skb, sk, info);
746 0 : if (inet->pmtudisc != IP_PMTUDISC_DONT) {
747 : err = EMSGSIZE;
748 : harderr = 1;
749 : break;
750 : }
751 0 : goto out;
752 : }
753 14 : err = EHOSTUNREACH;
754 14 : if (code <= NR_ICMP_UNREACH) {
755 14 : harderr = icmp_err_convert[code].fatal;
756 14 : err = icmp_err_convert[code].errno;
757 : }
758 : break;
759 0 : case ICMP_REDIRECT:
760 0 : ipv4_sk_redirect(skb, sk);
761 0 : goto out;
762 : }
763 :
764 : /*
765 : * RFC1122: OK. Passes ICMP errors back to application, as per
766 : * 4.1.3.3.
767 : */
768 14 : if (tunnel) {
769 : /* ...not for tunnels though: we don't have a sending socket */
770 0 : goto out;
771 : }
772 14 : if (!inet->recverr) {
773 14 : if (!harderr || sk->sk_state != TCP_ESTABLISHED)
774 14 : goto out;
775 : } else
776 0 : ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
777 :
778 0 : sk->sk_err = err;
779 0 : sk->sk_error_report(sk);
780 : out:
781 : return 0;
782 : }
783 :
784 14 : int udp_err(struct sk_buff *skb, u32 info)
785 : {
786 14 : return __udp4_lib_err(skb, info, &udp_table);
787 : }
788 :
789 : /*
790 : * Throw away all pending data and cancel the corking. Socket is locked.
791 : */
792 39 : void udp_flush_pending_frames(struct sock *sk)
793 : {
794 39 : struct udp_sock *up = udp_sk(sk);
795 :
796 39 : if (up->pending) {
797 0 : up->len = 0;
798 0 : up->pending = 0;
799 0 : ip_flush_pending_frames(sk);
800 : }
801 39 : }
802 : EXPORT_SYMBOL(udp_flush_pending_frames);
803 :
804 : /**
805 : * udp4_hwcsum - handle outgoing HW checksumming
806 : * @skb: sk_buff containing the filled-in UDP header
807 : * (checksum field must be zeroed out)
808 : * @src: source IP address
809 : * @dst: destination IP address
810 : */
811 0 : void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
812 : {
813 0 : struct udphdr *uh = udp_hdr(skb);
814 0 : int offset = skb_transport_offset(skb);
815 0 : int len = skb->len - offset;
816 0 : int hlen = len;
817 0 : __wsum csum = 0;
818 :
819 0 : if (!skb_has_frag_list(skb)) {
820 : /*
821 : * Only one fragment on the socket.
822 : */
823 0 : skb->csum_start = skb_transport_header(skb) - skb->head;
824 0 : skb->csum_offset = offsetof(struct udphdr, check);
825 0 : uh->check = ~csum_tcpudp_magic(src, dst, len,
826 : IPPROTO_UDP, 0);
827 : } else {
828 : struct sk_buff *frags;
829 :
830 : /*
831 : * HW-checksum won't work as there are two or more
832 : * fragments on the socket so that all csums of sk_buffs
833 : * should be together
834 : */
835 0 : skb_walk_frags(skb, frags) {
836 0 : csum = csum_add(csum, frags->csum);
837 0 : hlen -= frags->len;
838 : }
839 :
840 0 : csum = skb_checksum(skb, offset, hlen, csum);
841 0 : skb->ip_summed = CHECKSUM_NONE;
842 :
843 0 : uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
844 0 : if (uh->check == 0)
845 0 : uh->check = CSUM_MANGLED_0;
846 : }
847 0 : }
848 : EXPORT_SYMBOL_GPL(udp4_hwcsum);
849 :
850 : /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
851 : * for the simple case like when setting the checksum for a UDP tunnel.
852 : */
853 0 : void udp_set_csum(bool nocheck, struct sk_buff *skb,
854 : __be32 saddr, __be32 daddr, int len)
855 : {
856 0 : struct udphdr *uh = udp_hdr(skb);
857 :
858 0 : if (nocheck) {
859 0 : uh->check = 0;
860 0 : } else if (skb_is_gso(skb)) {
861 0 : uh->check = ~udp_v4_check(len, saddr, daddr, 0);
862 0 : } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
863 0 : uh->check = 0;
864 0 : uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
865 0 : if (uh->check == 0)
866 0 : uh->check = CSUM_MANGLED_0;
867 : } else {
868 0 : skb->ip_summed = CHECKSUM_PARTIAL;
869 0 : skb->csum_start = skb_transport_header(skb) - skb->head;
870 0 : skb->csum_offset = offsetof(struct udphdr, check);
871 0 : uh->check = ~udp_v4_check(len, saddr, daddr, 0);
872 : }
873 0 : }
874 : EXPORT_SYMBOL(udp_set_csum);
875 :
876 14 : static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
877 : struct inet_cork *cork)
878 : {
879 14 : struct sock *sk = skb->sk;
880 14 : struct inet_sock *inet = inet_sk(sk);
881 14 : struct udphdr *uh;
882 14 : int err;
883 14 : int is_udplite = IS_UDPLITE(sk);
884 14 : int offset = skb_transport_offset(skb);
885 14 : int len = skb->len - offset;
886 14 : int datalen = len - sizeof(*uh);
887 14 : __wsum csum = 0;
888 :
889 : /*
890 : * Create a UDP header
891 : */
892 14 : uh = udp_hdr(skb);
893 14 : uh->source = inet->inet_sport;
894 14 : uh->dest = fl4->fl4_dport;
895 14 : uh->len = htons(len);
896 14 : uh->check = 0;
897 :
898 14 : if (cork->gso_size) {
899 0 : const int hlen = skb_network_header_len(skb) +
900 : sizeof(struct udphdr);
901 :
902 0 : if (hlen + cork->gso_size > cork->fragsize) {
903 0 : kfree_skb(skb);
904 0 : return -EINVAL;
905 : }
906 0 : if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
907 0 : kfree_skb(skb);
908 0 : return -EINVAL;
909 : }
910 0 : if (sk->sk_no_check_tx) {
911 0 : kfree_skb(skb);
912 0 : return -EINVAL;
913 : }
914 0 : if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
915 0 : dst_xfrm(skb_dst(skb))) {
916 0 : kfree_skb(skb);
917 0 : return -EIO;
918 : }
919 :
920 0 : if (datalen > cork->gso_size) {
921 0 : skb_shinfo(skb)->gso_size = cork->gso_size;
922 0 : skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
923 0 : skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
924 : cork->gso_size);
925 : }
926 0 : goto csum_partial;
927 : }
928 :
929 14 : if (is_udplite) /* UDP-Lite */
930 0 : csum = udplite_csum(skb);
931 :
932 14 : else if (sk->sk_no_check_tx) { /* UDP csum off */
933 :
934 0 : skb->ip_summed = CHECKSUM_NONE;
935 0 : goto send;
936 :
937 14 : } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
938 0 : csum_partial:
939 :
940 0 : udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
941 0 : goto send;
942 :
943 : } else
944 14 : csum = udp_csum(skb);
945 :
946 : /* add protocol-dependent pseudo-header */
947 14 : uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
948 14 : sk->sk_protocol, csum);
949 14 : if (uh->check == 0)
950 0 : uh->check = CSUM_MANGLED_0;
951 :
952 14 : send:
953 14 : err = ip_send_skb(sock_net(sk), skb);
954 14 : if (err) {
955 0 : if (err == -ENOBUFS && !inet->recverr) {
956 0 : UDP_INC_STATS(sock_net(sk),
957 : UDP_MIB_SNDBUFERRORS, is_udplite);
958 : err = 0;
959 : }
960 : } else
961 14 : UDP_INC_STATS(sock_net(sk),
962 : UDP_MIB_OUTDATAGRAMS, is_udplite);
963 : return err;
964 : }
965 :
966 : /*
967 : * Push out all pending data as one UDP datagram. Socket is locked.
968 : */
969 0 : int udp_push_pending_frames(struct sock *sk)
970 : {
971 0 : struct udp_sock *up = udp_sk(sk);
972 0 : struct inet_sock *inet = inet_sk(sk);
973 0 : struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
974 0 : struct sk_buff *skb;
975 0 : int err = 0;
976 :
977 0 : skb = ip_finish_skb(sk, fl4);
978 0 : if (!skb)
979 0 : goto out;
980 :
981 0 : err = udp_send_skb(skb, fl4, &inet->cork.base);
982 :
983 0 : out:
984 0 : up->len = 0;
985 0 : up->pending = 0;
986 0 : return err;
987 : }
988 : EXPORT_SYMBOL(udp_push_pending_frames);
989 :
990 0 : static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
991 : {
992 0 : switch (cmsg->cmsg_type) {
993 0 : case UDP_SEGMENT:
994 0 : if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
995 : return -EINVAL;
996 0 : *gso_size = *(__u16 *)CMSG_DATA(cmsg);
997 0 : return 0;
998 : default:
999 : return -EINVAL;
1000 : }
1001 : }
1002 :
1003 0 : int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
1004 : {
1005 0 : struct cmsghdr *cmsg;
1006 0 : bool need_ip = false;
1007 0 : int err;
1008 :
1009 0 : for_each_cmsghdr(cmsg, msg) {
1010 0 : if (!CMSG_OK(msg, cmsg))
1011 : return -EINVAL;
1012 :
1013 0 : if (cmsg->cmsg_level != SOL_UDP) {
1014 0 : need_ip = true;
1015 0 : continue;
1016 : }
1017 :
1018 0 : err = __udp_cmsg_send(cmsg, gso_size);
1019 0 : if (err)
1020 : return err;
1021 : }
1022 :
1023 0 : return need_ip;
1024 : }
1025 : EXPORT_SYMBOL_GPL(udp_cmsg_send);
1026 :
1027 14 : int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1028 : {
1029 14 : struct inet_sock *inet = inet_sk(sk);
1030 14 : struct udp_sock *up = udp_sk(sk);
1031 14 : DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1032 14 : struct flowi4 fl4_stack;
1033 14 : struct flowi4 *fl4;
1034 14 : int ulen = len;
1035 14 : struct ipcm_cookie ipc;
1036 14 : struct rtable *rt = NULL;
1037 14 : int free = 0;
1038 14 : int connected = 0;
1039 14 : __be32 daddr, faddr, saddr;
1040 14 : __be16 dport;
1041 14 : u8 tos;
1042 14 : int err, is_udplite = IS_UDPLITE(sk);
1043 14 : int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1044 14 : int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1045 14 : struct sk_buff *skb;
1046 14 : struct ip_options_data opt_copy;
1047 :
1048 14 : if (len > 0xFFFF)
1049 : return -EMSGSIZE;
1050 :
1051 : /*
1052 : * Check the flags.
1053 : */
1054 :
1055 14 : if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
1056 : return -EOPNOTSUPP;
1057 :
1058 14 : getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1059 :
1060 14 : fl4 = &inet->cork.fl.u.ip4;
1061 14 : if (up->pending) {
1062 : /*
1063 : * There are pending frames.
1064 : * The socket lock must be held while it's corked.
1065 : */
1066 0 : lock_sock(sk);
1067 0 : if (likely(up->pending)) {
1068 0 : if (unlikely(up->pending != AF_INET)) {
1069 0 : release_sock(sk);
1070 0 : return -EINVAL;
1071 : }
1072 0 : goto do_append_data;
1073 : }
1074 0 : release_sock(sk);
1075 : }
1076 14 : ulen += sizeof(struct udphdr);
1077 :
1078 : /*
1079 : * Get and verify the address.
1080 : */
1081 14 : if (usin) {
1082 0 : if (msg->msg_namelen < sizeof(*usin))
1083 : return -EINVAL;
1084 0 : if (usin->sin_family != AF_INET) {
1085 0 : if (usin->sin_family != AF_UNSPEC)
1086 : return -EAFNOSUPPORT;
1087 : }
1088 :
1089 0 : daddr = usin->sin_addr.s_addr;
1090 0 : dport = usin->sin_port;
1091 0 : if (dport == 0)
1092 : return -EINVAL;
1093 : } else {
1094 14 : if (sk->sk_state != TCP_ESTABLISHED)
1095 : return -EDESTADDRREQ;
1096 14 : daddr = inet->inet_daddr;
1097 14 : dport = inet->inet_dport;
1098 : /* Open fast path for connected socket.
1099 : Route will not be used, if at least one option is set.
1100 : */
1101 14 : connected = 1;
1102 : }
1103 :
1104 14 : ipcm_init_sk(&ipc, inet);
1105 14 : ipc.gso_size = up->gso_size;
1106 :
1107 14 : if (msg->msg_controllen) {
1108 0 : err = udp_cmsg_send(sk, msg, &ipc.gso_size);
1109 0 : if (err > 0)
1110 0 : err = ip_cmsg_send(sk, msg, &ipc,
1111 0 : sk->sk_family == AF_INET6);
1112 0 : if (unlikely(err < 0)) {
1113 0 : kfree(ipc.opt);
1114 0 : return err;
1115 : }
1116 0 : if (ipc.opt)
1117 0 : free = 1;
1118 : connected = 0;
1119 : }
1120 14 : if (!ipc.opt) {
1121 14 : struct ip_options_rcu *inet_opt;
1122 :
1123 14 : rcu_read_lock();
1124 14 : inet_opt = rcu_dereference(inet->inet_opt);
1125 14 : if (inet_opt) {
1126 0 : memcpy(&opt_copy, inet_opt,
1127 0 : sizeof(*inet_opt) + inet_opt->opt.optlen);
1128 0 : ipc.opt = &opt_copy.opt;
1129 : }
1130 14 : rcu_read_unlock();
1131 : }
1132 :
1133 14 : if (cgroup_bpf_enabled(BPF_CGROUP_UDP4_SENDMSG) && !connected) {
1134 : err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1135 : (struct sockaddr *)usin, &ipc.addr);
1136 : if (err)
1137 : goto out_free;
1138 : if (usin) {
1139 : if (usin->sin_port == 0) {
1140 : /* BPF program set invalid port. Reject it. */
1141 : err = -EINVAL;
1142 : goto out_free;
1143 : }
1144 : daddr = usin->sin_addr.s_addr;
1145 : dport = usin->sin_port;
1146 : }
1147 : }
1148 :
1149 14 : saddr = ipc.addr;
1150 14 : ipc.addr = faddr = daddr;
1151 :
1152 14 : if (ipc.opt && ipc.opt->opt.srr) {
1153 0 : if (!daddr) {
1154 0 : err = -EINVAL;
1155 0 : goto out_free;
1156 : }
1157 0 : faddr = ipc.opt->opt.faddr;
1158 0 : connected = 0;
1159 : }
1160 14 : tos = get_rttos(&ipc, inet);
1161 14 : if (sock_flag(sk, SOCK_LOCALROUTE) ||
1162 14 : (msg->msg_flags & MSG_DONTROUTE) ||
1163 14 : (ipc.opt && ipc.opt->opt.is_strictroute)) {
1164 0 : tos |= RTO_ONLINK;
1165 0 : connected = 0;
1166 : }
1167 :
1168 14 : if (ipv4_is_multicast(daddr)) {
1169 0 : if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
1170 0 : ipc.oif = inet->mc_index;
1171 0 : if (!saddr)
1172 0 : saddr = inet->mc_addr;
1173 : connected = 0;
1174 14 : } else if (!ipc.oif) {
1175 14 : ipc.oif = inet->uc_index;
1176 14 : } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
1177 : /* oif is set, packet is to local broadcast and
1178 : * uc_index is set. oif is most likely set
1179 : * by sk_bound_dev_if. If uc_index != oif check if the
1180 : * oif is an L3 master and uc_index is an L3 slave.
1181 : * If so, we want to allow the send using the uc_index.
1182 : */
1183 : if (ipc.oif != inet->uc_index &&
1184 14 : ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
1185 : inet->uc_index)) {
1186 : ipc.oif = inet->uc_index;
1187 : }
1188 : }
1189 :
1190 14 : if (connected)
1191 14 : rt = (struct rtable *)sk_dst_check(sk, 0);
1192 :
1193 14 : if (!rt) {
1194 0 : struct net *net = sock_net(sk);
1195 0 : __u8 flow_flags = inet_sk_flowi_flags(sk);
1196 :
1197 0 : fl4 = &fl4_stack;
1198 :
1199 0 : flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos,
1200 0 : RT_SCOPE_UNIVERSE, sk->sk_protocol,
1201 : flow_flags,
1202 0 : faddr, saddr, dport, inet->inet_sport,
1203 : sk->sk_uid);
1204 :
1205 0 : security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
1206 0 : rt = ip_route_output_flow(net, fl4, sk);
1207 0 : if (IS_ERR(rt)) {
1208 0 : err = PTR_ERR(rt);
1209 0 : rt = NULL;
1210 0 : if (err == -ENETUNREACH)
1211 0 : IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1212 0 : goto out;
1213 : }
1214 :
1215 0 : err = -EACCES;
1216 0 : if ((rt->rt_flags & RTCF_BROADCAST) &&
1217 0 : !sock_flag(sk, SOCK_BROADCAST))
1218 0 : goto out;
1219 0 : if (connected)
1220 0 : sk_dst_set(sk, dst_clone(&rt->dst));
1221 : }
1222 :
1223 14 : if (msg->msg_flags&MSG_CONFIRM)
1224 0 : goto do_confirm;
1225 14 : back_from_confirm:
1226 :
1227 14 : saddr = fl4->saddr;
1228 14 : if (!ipc.addr)
1229 0 : daddr = ipc.addr = fl4->daddr;
1230 :
1231 : /* Lockless fast path for the non-corking case. */
1232 14 : if (!corkreq) {
1233 14 : struct inet_cork cork;
1234 :
1235 14 : skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1236 : sizeof(struct udphdr), &ipc, &rt,
1237 : &cork, msg->msg_flags);
1238 14 : err = PTR_ERR(skb);
1239 28 : if (!IS_ERR_OR_NULL(skb))
1240 14 : err = udp_send_skb(skb, fl4, &cork);
1241 14 : goto out;
1242 : }
1243 :
1244 0 : lock_sock(sk);
1245 0 : if (unlikely(up->pending)) {
1246 : /* The socket is already corked while preparing it. */
1247 : /* ... which is an evident application bug. --ANK */
1248 0 : release_sock(sk);
1249 :
1250 0 : net_dbg_ratelimited("socket already corked\n");
1251 0 : err = -EINVAL;
1252 0 : goto out;
1253 : }
1254 : /*
1255 : * Now cork the socket to pend data.
1256 : */
1257 0 : fl4 = &inet->cork.fl.u.ip4;
1258 0 : fl4->daddr = daddr;
1259 0 : fl4->saddr = saddr;
1260 0 : fl4->fl4_dport = dport;
1261 0 : fl4->fl4_sport = inet->inet_sport;
1262 0 : up->pending = AF_INET;
1263 :
1264 0 : do_append_data:
1265 0 : up->len += ulen;
1266 0 : err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1267 : sizeof(struct udphdr), &ipc, &rt,
1268 0 : corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1269 0 : if (err)
1270 0 : udp_flush_pending_frames(sk);
1271 0 : else if (!corkreq)
1272 0 : err = udp_push_pending_frames(sk);
1273 0 : else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1274 0 : up->pending = 0;
1275 0 : release_sock(sk);
1276 :
1277 14 : out:
1278 14 : ip_rt_put(rt);
1279 14 : out_free:
1280 14 : if (free)
1281 0 : kfree(ipc.opt);
1282 14 : if (!err)
1283 : return len;
1284 : /*
1285 : * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1286 : * ENOBUFS might not be good (it's not tunable per se), but otherwise
1287 : * we don't have a good statistic (IpOutDiscards but it can be too many
1288 : * things). We could add another new stat but at least for now that
1289 : * seems like overkill.
1290 : */
1291 0 : if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1292 0 : UDP_INC_STATS(sock_net(sk),
1293 : UDP_MIB_SNDBUFERRORS, is_udplite);
1294 : }
1295 : return err;
1296 :
1297 0 : do_confirm:
1298 0 : if (msg->msg_flags & MSG_PROBE)
1299 0 : dst_confirm_neigh(&rt->dst, &fl4->daddr);
1300 0 : if (!(msg->msg_flags&MSG_PROBE) || len)
1301 0 : goto back_from_confirm;
1302 0 : err = 0;
1303 0 : goto out;
1304 : }
1305 : EXPORT_SYMBOL(udp_sendmsg);
1306 :
1307 0 : int udp_sendpage(struct sock *sk, struct page *page, int offset,
1308 : size_t size, int flags)
1309 : {
1310 0 : struct inet_sock *inet = inet_sk(sk);
1311 0 : struct udp_sock *up = udp_sk(sk);
1312 0 : int ret;
1313 :
1314 0 : if (flags & MSG_SENDPAGE_NOTLAST)
1315 0 : flags |= MSG_MORE;
1316 :
1317 0 : if (!up->pending) {
1318 0 : struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1319 :
1320 : /* Call udp_sendmsg to specify destination address which
1321 : * sendpage interface can't pass.
1322 : * This will succeed only when the socket is connected.
1323 : */
1324 0 : ret = udp_sendmsg(sk, &msg, 0);
1325 0 : if (ret < 0)
1326 0 : return ret;
1327 : }
1328 :
1329 0 : lock_sock(sk);
1330 :
1331 0 : if (unlikely(!up->pending)) {
1332 0 : release_sock(sk);
1333 :
1334 0 : net_dbg_ratelimited("cork failed\n");
1335 0 : return -EINVAL;
1336 : }
1337 :
1338 0 : ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1339 : page, offset, size, flags);
1340 0 : if (ret == -EOPNOTSUPP) {
1341 0 : release_sock(sk);
1342 0 : return sock_no_sendpage(sk->sk_socket, page, offset,
1343 : size, flags);
1344 : }
1345 0 : if (ret < 0) {
1346 0 : udp_flush_pending_frames(sk);
1347 0 : goto out;
1348 : }
1349 :
1350 0 : up->len += size;
1351 0 : if (!(up->corkflag || (flags&MSG_MORE)))
1352 0 : ret = udp_push_pending_frames(sk);
1353 0 : if (!ret)
1354 0 : ret = size;
1355 0 : out:
1356 0 : release_sock(sk);
1357 0 : return ret;
1358 : }
1359 :
1360 : #define UDP_SKB_IS_STATELESS 0x80000000
1361 :
1362 : /* all head states (dst, sk, nf conntrack) except skb extensions are
1363 : * cleared by udp_rcv().
1364 : *
1365 : * We need to preserve secpath, if present, to eventually process
1366 : * IP_CMSG_PASSSEC at recvmsg() time.
1367 : *
1368 : * Other extensions can be cleared.
1369 : */
1370 2 : static bool udp_try_make_stateless(struct sk_buff *skb)
1371 : {
1372 2 : if (!skb_has_extensions(skb))
1373 2 : return true;
1374 :
1375 : if (!secpath_exists(skb)) {
1376 : skb_ext_reset(skb);
1377 : return true;
1378 : }
1379 :
1380 : return false;
1381 : }
1382 :
1383 2 : static void udp_set_dev_scratch(struct sk_buff *skb)
1384 : {
1385 2 : struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1386 :
1387 2 : BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1388 2 : scratch->_tsize_state = skb->truesize;
1389 : #if BITS_PER_LONG == 64
1390 2 : scratch->len = skb->len;
1391 2 : scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1392 2 : scratch->is_linear = !skb_is_nonlinear(skb);
1393 : #endif
1394 2 : if (udp_try_make_stateless(skb))
1395 2 : scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1396 2 : }
1397 :
1398 2 : static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1399 : {
1400 : /* We come here after udp_lib_checksum_complete() returned 0.
1401 : * This means that __skb_checksum_complete() might have
1402 : * set skb->csum_valid to 1.
1403 : * On 64bit platforms, we can set csum_unnecessary
1404 : * to true, but only if the skb is not shared.
1405 : */
1406 : #if BITS_PER_LONG == 64
1407 2 : if (!skb_shared(skb))
1408 2 : udp_skb_scratch(skb)->csum_unnecessary = true;
1409 : #endif
1410 2 : }
1411 :
1412 2 : static int udp_skb_truesize(struct sk_buff *skb)
1413 : {
1414 2 : return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1415 : }
1416 :
1417 2 : static bool udp_skb_has_head_state(struct sk_buff *skb)
1418 : {
1419 2 : return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1420 : }
1421 :
1422 : /* fully reclaim rmem/fwd memory allocated for skb */
1423 41 : static void udp_rmem_release(struct sock *sk, int size, int partial,
1424 : bool rx_queue_lock_held)
1425 : {
1426 41 : struct udp_sock *up = udp_sk(sk);
1427 41 : struct sk_buff_head *sk_queue;
1428 41 : int amt;
1429 :
1430 41 : if (likely(partial)) {
1431 2 : up->forward_deficit += size;
1432 2 : size = up->forward_deficit;
1433 2 : if (size < (sk->sk_rcvbuf >> 2) &&
1434 2 : !skb_queue_empty(&up->reader_queue))
1435 : return;
1436 : } else {
1437 39 : size += up->forward_deficit;
1438 : }
1439 41 : up->forward_deficit = 0;
1440 :
1441 : /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1442 : * if the called don't held it already
1443 : */
1444 41 : sk_queue = &sk->sk_receive_queue;
1445 41 : if (!rx_queue_lock_held)
1446 2 : spin_lock(&sk_queue->lock);
1447 :
1448 :
1449 41 : sk->sk_forward_alloc += size;
1450 41 : amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1451 41 : sk->sk_forward_alloc -= amt;
1452 :
1453 41 : if (amt)
1454 0 : __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1455 :
1456 41 : atomic_sub(size, &sk->sk_rmem_alloc);
1457 :
1458 : /* this can save us from acquiring the rx queue lock on next receive */
1459 41 : skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1460 :
1461 41 : if (!rx_queue_lock_held)
1462 2 : spin_unlock(&sk_queue->lock);
1463 : }
1464 :
1465 : /* Note: called with reader_queue.lock held.
1466 : * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1467 : * This avoids a cache line miss while receive_queue lock is held.
1468 : * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1469 : */
1470 2 : void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1471 : {
1472 2 : prefetch(&skb->data);
1473 2 : udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1474 2 : }
1475 : EXPORT_SYMBOL(udp_skb_destructor);
1476 :
1477 : /* as above, but the caller held the rx queue lock, too */
1478 0 : static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1479 : {
1480 0 : prefetch(&skb->data);
1481 0 : udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1482 0 : }
1483 :
1484 : /* Idea of busylocks is to let producers grab an extra spinlock
1485 : * to relieve pressure on the receive_queue spinlock shared by consumer.
1486 : * Under flood, this means that only one producer can be in line
1487 : * trying to acquire the receive_queue spinlock.
1488 : * These busylock can be allocated on a per cpu manner, instead of a
1489 : * per socket one (that would consume a cache line per socket)
1490 : */
1491 : static int udp_busylocks_log __read_mostly;
1492 : static spinlock_t *udp_busylocks __read_mostly;
1493 :
1494 0 : static spinlock_t *busylock_acquire(void *ptr)
1495 : {
1496 0 : spinlock_t *busy;
1497 :
1498 0 : busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1499 0 : spin_lock(busy);
1500 0 : return busy;
1501 : }
1502 :
1503 2 : static void busylock_release(spinlock_t *busy)
1504 : {
1505 2 : if (busy)
1506 0 : spin_unlock(busy);
1507 : }
1508 :
1509 2 : int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1510 : {
1511 2 : struct sk_buff_head *list = &sk->sk_receive_queue;
1512 2 : int rmem, delta, amt, err = -ENOMEM;
1513 2 : spinlock_t *busy = NULL;
1514 2 : int size;
1515 :
1516 : /* try to avoid the costly atomic add/sub pair when the receive
1517 : * queue is full; always allow at least a packet
1518 : */
1519 2 : rmem = atomic_read(&sk->sk_rmem_alloc);
1520 2 : if (rmem > sk->sk_rcvbuf)
1521 0 : goto drop;
1522 :
1523 : /* Under mem pressure, it might be helpful to help udp_recvmsg()
1524 : * having linear skbs :
1525 : * - Reduce memory overhead and thus increase receive queue capacity
1526 : * - Less cache line misses at copyout() time
1527 : * - Less work at consume_skb() (less alien page frag freeing)
1528 : */
1529 2 : if (rmem > (sk->sk_rcvbuf >> 1)) {
1530 0 : skb_condense(skb);
1531 :
1532 0 : busy = busylock_acquire(sk);
1533 : }
1534 2 : size = skb->truesize;
1535 2 : udp_set_dev_scratch(skb);
1536 :
1537 : /* we drop only if the receive buf is full and the receive
1538 : * queue contains some other skb
1539 : */
1540 2 : rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1541 2 : if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
1542 0 : goto uncharge_drop;
1543 :
1544 2 : spin_lock(&list->lock);
1545 2 : if (size >= sk->sk_forward_alloc) {
1546 1 : amt = sk_mem_pages(size);
1547 1 : delta = amt << SK_MEM_QUANTUM_SHIFT;
1548 1 : if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1549 0 : err = -ENOBUFS;
1550 0 : spin_unlock(&list->lock);
1551 0 : goto uncharge_drop;
1552 : }
1553 :
1554 1 : sk->sk_forward_alloc += delta;
1555 : }
1556 :
1557 2 : sk->sk_forward_alloc -= size;
1558 :
1559 : /* no need to setup a destructor, we will explicitly release the
1560 : * forward allocated memory on dequeue
1561 : */
1562 2 : sock_skb_set_dropcount(sk, skb);
1563 :
1564 2 : __skb_queue_tail(list, skb);
1565 2 : spin_unlock(&list->lock);
1566 :
1567 2 : if (!sock_flag(sk, SOCK_DEAD))
1568 2 : sk->sk_data_ready(sk);
1569 :
1570 2 : busylock_release(busy);
1571 : return 0;
1572 :
1573 0 : uncharge_drop:
1574 0 : atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1575 :
1576 0 : drop:
1577 0 : atomic_inc(&sk->sk_drops);
1578 0 : busylock_release(busy);
1579 : return err;
1580 : }
1581 : EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1582 :
1583 39 : void udp_destruct_sock(struct sock *sk)
1584 : {
1585 : /* reclaim completely the forward allocated memory */
1586 39 : struct udp_sock *up = udp_sk(sk);
1587 39 : unsigned int total = 0;
1588 39 : struct sk_buff *skb;
1589 :
1590 39 : skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1591 39 : while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1592 0 : total += skb->truesize;
1593 0 : kfree_skb(skb);
1594 : }
1595 39 : udp_rmem_release(sk, total, 0, true);
1596 :
1597 39 : inet_sock_destruct(sk);
1598 39 : }
1599 : EXPORT_SYMBOL_GPL(udp_destruct_sock);
1600 :
1601 42 : int udp_init_sock(struct sock *sk)
1602 : {
1603 42 : skb_queue_head_init(&udp_sk(sk)->reader_queue);
1604 42 : sk->sk_destruct = udp_destruct_sock;
1605 42 : return 0;
1606 : }
1607 : EXPORT_SYMBOL_GPL(udp_init_sock);
1608 :
1609 2 : void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1610 : {
1611 2 : if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1612 0 : bool slow = lock_sock_fast(sk);
1613 :
1614 0 : sk_peek_offset_bwd(sk, len);
1615 0 : unlock_sock_fast(sk, slow);
1616 : }
1617 :
1618 2 : if (!skb_unref(skb))
1619 : return;
1620 :
1621 : /* In the more common cases we cleared the head states previously,
1622 : * see __udp_queue_rcv_skb().
1623 : */
1624 2 : if (unlikely(udp_skb_has_head_state(skb)))
1625 0 : skb_release_head_state(skb);
1626 2 : __consume_stateless_skb(skb);
1627 : }
1628 : EXPORT_SYMBOL_GPL(skb_consume_udp);
1629 :
1630 4 : static struct sk_buff *__first_packet_length(struct sock *sk,
1631 : struct sk_buff_head *rcvq,
1632 : int *total)
1633 : {
1634 4 : struct sk_buff *skb;
1635 :
1636 4 : while ((skb = skb_peek(rcvq)) != NULL) {
1637 2 : if (udp_lib_checksum_complete(skb)) {
1638 0 : __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1639 : IS_UDPLITE(sk));
1640 0 : __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1641 : IS_UDPLITE(sk));
1642 0 : atomic_inc(&sk->sk_drops);
1643 0 : __skb_unlink(skb, rcvq);
1644 0 : *total += skb->truesize;
1645 0 : kfree_skb(skb);
1646 : } else {
1647 2 : udp_skb_csum_unnecessary_set(skb);
1648 2 : break;
1649 : }
1650 : }
1651 4 : return skb;
1652 : }
1653 :
1654 : /**
1655 : * first_packet_length - return length of first packet in receive queue
1656 : * @sk: socket
1657 : *
1658 : * Drops all bad checksum frames, until a valid one is found.
1659 : * Returns the length of found skb, or -1 if none is found.
1660 : */
1661 2 : static int first_packet_length(struct sock *sk)
1662 : {
1663 2 : struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1664 2 : struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1665 2 : struct sk_buff *skb;
1666 2 : int total = 0;
1667 2 : int res;
1668 :
1669 2 : spin_lock_bh(&rcvq->lock);
1670 2 : skb = __first_packet_length(sk, rcvq, &total);
1671 2 : if (!skb && !skb_queue_empty_lockless(sk_queue)) {
1672 2 : spin_lock(&sk_queue->lock);
1673 2 : skb_queue_splice_tail_init(sk_queue, rcvq);
1674 2 : spin_unlock(&sk_queue->lock);
1675 :
1676 2 : skb = __first_packet_length(sk, rcvq, &total);
1677 : }
1678 2 : res = skb ? skb->len : -1;
1679 2 : if (total)
1680 0 : udp_rmem_release(sk, total, 1, false);
1681 2 : spin_unlock_bh(&rcvq->lock);
1682 2 : return res;
1683 : }
1684 :
1685 : /*
1686 : * IOCTL requests applicable to the UDP protocol
1687 : */
1688 :
1689 16 : int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1690 : {
1691 16 : switch (cmd) {
1692 : case SIOCOUTQ:
1693 : {
1694 0 : int amount = sk_wmem_alloc_get(sk);
1695 :
1696 0 : return put_user(amount, (int __user *)arg);
1697 : }
1698 :
1699 0 : case SIOCINQ:
1700 : {
1701 0 : int amount = max_t(int, 0, first_packet_length(sk));
1702 :
1703 0 : return put_user(amount, (int __user *)arg);
1704 : }
1705 :
1706 : default:
1707 : return -ENOIOCTLCMD;
1708 : }
1709 :
1710 : return 0;
1711 : }
1712 : EXPORT_SYMBOL(udp_ioctl);
1713 :
1714 2 : struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1715 : int noblock, int *off, int *err)
1716 : {
1717 2 : struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1718 2 : struct sk_buff_head *queue;
1719 2 : struct sk_buff *last;
1720 2 : long timeo;
1721 2 : int error;
1722 :
1723 2 : queue = &udp_sk(sk)->reader_queue;
1724 2 : flags |= noblock ? MSG_DONTWAIT : 0;
1725 4 : timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1726 2 : do {
1727 2 : struct sk_buff *skb;
1728 :
1729 2 : error = sock_error(sk);
1730 2 : if (error)
1731 : break;
1732 :
1733 2 : error = -EAGAIN;
1734 2 : do {
1735 2 : spin_lock_bh(&queue->lock);
1736 2 : skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1737 : err, &last);
1738 2 : if (skb) {
1739 2 : if (!(flags & MSG_PEEK))
1740 2 : udp_skb_destructor(sk, skb);
1741 2 : spin_unlock_bh(&queue->lock);
1742 2 : return skb;
1743 : }
1744 :
1745 0 : if (skb_queue_empty_lockless(sk_queue)) {
1746 0 : spin_unlock_bh(&queue->lock);
1747 0 : goto busy_check;
1748 : }
1749 :
1750 : /* refill the reader queue and walk it again
1751 : * keep both queues locked to avoid re-acquiring
1752 : * the sk_receive_queue lock if fwd memory scheduling
1753 : * is needed.
1754 : */
1755 0 : spin_lock(&sk_queue->lock);
1756 0 : skb_queue_splice_tail_init(sk_queue, queue);
1757 :
1758 0 : skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1759 : err, &last);
1760 0 : if (skb && !(flags & MSG_PEEK))
1761 0 : udp_skb_dtor_locked(sk, skb);
1762 0 : spin_unlock(&sk_queue->lock);
1763 0 : spin_unlock_bh(&queue->lock);
1764 0 : if (skb)
1765 0 : return skb;
1766 :
1767 0 : busy_check:
1768 0 : if (!sk_can_busy_loop(sk))
1769 : break;
1770 :
1771 0 : sk_busy_loop(sk, flags & MSG_DONTWAIT);
1772 0 : } while (!skb_queue_empty_lockless(sk_queue));
1773 :
1774 : /* sk_queue is empty, reader_queue may contain peeked packets */
1775 0 : } while (timeo &&
1776 0 : !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
1777 : &error, &timeo,
1778 0 : (struct sk_buff *)sk_queue));
1779 :
1780 0 : *err = error;
1781 0 : return NULL;
1782 : }
1783 : EXPORT_SYMBOL(__skb_recv_udp);
1784 :
1785 : /*
1786 : * This should be easy, if there is something there we
1787 : * return it, otherwise we block.
1788 : */
1789 :
1790 2 : int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1791 : int flags, int *addr_len)
1792 : {
1793 2 : struct inet_sock *inet = inet_sk(sk);
1794 2 : DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1795 2 : struct sk_buff *skb;
1796 2 : unsigned int ulen, copied;
1797 2 : int off, err, peeking = flags & MSG_PEEK;
1798 2 : int is_udplite = IS_UDPLITE(sk);
1799 2 : bool checksum_valid = false;
1800 :
1801 2 : if (flags & MSG_ERRQUEUE)
1802 0 : return ip_recv_error(sk, msg, len, addr_len);
1803 :
1804 2 : try_again:
1805 2 : off = sk_peek_offset(sk, flags);
1806 2 : skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
1807 2 : if (!skb)
1808 0 : return err;
1809 :
1810 2 : ulen = udp_skb_len(skb);
1811 2 : copied = len;
1812 2 : if (copied > ulen - off)
1813 : copied = ulen - off;
1814 0 : else if (copied < ulen)
1815 0 : msg->msg_flags |= MSG_TRUNC;
1816 :
1817 : /*
1818 : * If checksum is needed at all, try to do it while copying the
1819 : * data. If the data is truncated, or if we only want a partial
1820 : * coverage checksum (UDP-Lite), do it before the copy.
1821 : */
1822 :
1823 2 : if (copied < ulen || peeking ||
1824 0 : (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1825 0 : checksum_valid = udp_skb_csum_unnecessary(skb) ||
1826 0 : !__udp_lib_checksum_complete(skb);
1827 0 : if (!checksum_valid)
1828 0 : goto csum_copy_err;
1829 : }
1830 :
1831 2 : if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1832 2 : if (udp_skb_is_linear(skb))
1833 0 : err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1834 : else
1835 2 : err = skb_copy_datagram_msg(skb, off, msg, copied);
1836 : } else {
1837 0 : err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1838 :
1839 0 : if (err == -EINVAL)
1840 0 : goto csum_copy_err;
1841 : }
1842 :
1843 2 : if (unlikely(err)) {
1844 0 : if (!peeking) {
1845 0 : atomic_inc(&sk->sk_drops);
1846 0 : UDP_INC_STATS(sock_net(sk),
1847 : UDP_MIB_INERRORS, is_udplite);
1848 : }
1849 0 : kfree_skb(skb);
1850 0 : return err;
1851 : }
1852 :
1853 2 : if (!peeking)
1854 2 : UDP_INC_STATS(sock_net(sk),
1855 : UDP_MIB_INDATAGRAMS, is_udplite);
1856 :
1857 2 : sock_recv_ts_and_drops(msg, sk, skb);
1858 :
1859 : /* Copy the address. */
1860 2 : if (sin) {
1861 2 : sin->sin_family = AF_INET;
1862 2 : sin->sin_port = udp_hdr(skb)->source;
1863 2 : sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1864 2 : memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1865 2 : *addr_len = sizeof(*sin);
1866 :
1867 2 : BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk,
1868 : (struct sockaddr *)sin);
1869 : }
1870 :
1871 2 : if (udp_sk(sk)->gro_enabled)
1872 0 : udp_cmsg_recv(msg, sk, skb);
1873 :
1874 2 : if (inet->cmsg_flags)
1875 0 : ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1876 :
1877 2 : err = copied;
1878 2 : if (flags & MSG_TRUNC)
1879 0 : err = ulen;
1880 :
1881 2 : skb_consume_udp(sk, skb, peeking ? -err : err);
1882 2 : return err;
1883 :
1884 0 : csum_copy_err:
1885 0 : if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1886 : udp_skb_destructor)) {
1887 0 : UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1888 0 : UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1889 : }
1890 0 : kfree_skb(skb);
1891 :
1892 : /* starting over for a new packet, but check if we need to yield */
1893 0 : cond_resched();
1894 0 : msg->msg_flags &= ~MSG_TRUNC;
1895 0 : goto try_again;
1896 : }
1897 :
1898 0 : int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1899 : {
1900 : /* This check is replicated from __ip4_datagram_connect() and
1901 : * intended to prevent BPF program called below from accessing bytes
1902 : * that are out of the bound specified by user in addr_len.
1903 : */
1904 0 : if (addr_len < sizeof(struct sockaddr_in))
1905 0 : return -EINVAL;
1906 :
1907 : return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
1908 : }
1909 : EXPORT_SYMBOL(udp_pre_connect);
1910 :
1911 0 : int __udp_disconnect(struct sock *sk, int flags)
1912 : {
1913 0 : struct inet_sock *inet = inet_sk(sk);
1914 : /*
1915 : * 1003.1g - break association.
1916 : */
1917 :
1918 0 : sk->sk_state = TCP_CLOSE;
1919 0 : inet->inet_daddr = 0;
1920 0 : inet->inet_dport = 0;
1921 0 : sock_rps_reset_rxhash(sk);
1922 0 : sk->sk_bound_dev_if = 0;
1923 0 : if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
1924 0 : inet_reset_saddr(sk);
1925 0 : if (sk->sk_prot->rehash &&
1926 : (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1927 0 : sk->sk_prot->rehash(sk);
1928 : }
1929 :
1930 0 : if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1931 0 : sk->sk_prot->unhash(sk);
1932 0 : inet->inet_sport = 0;
1933 : }
1934 0 : sk_dst_reset(sk);
1935 0 : return 0;
1936 : }
1937 : EXPORT_SYMBOL(__udp_disconnect);
1938 :
1939 0 : int udp_disconnect(struct sock *sk, int flags)
1940 : {
1941 0 : lock_sock(sk);
1942 0 : __udp_disconnect(sk, flags);
1943 0 : release_sock(sk);
1944 0 : return 0;
1945 : }
1946 : EXPORT_SYMBOL(udp_disconnect);
1947 :
1948 39 : void udp_lib_unhash(struct sock *sk)
1949 : {
1950 39 : if (sk_hashed(sk)) {
1951 32 : struct udp_table *udptable = sk->sk_prot->h.udp_table;
1952 32 : struct udp_hslot *hslot, *hslot2;
1953 :
1954 32 : hslot = udp_hashslot(udptable, sock_net(sk),
1955 32 : udp_sk(sk)->udp_port_hash);
1956 32 : hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1957 :
1958 32 : spin_lock_bh(&hslot->lock);
1959 32 : if (rcu_access_pointer(sk->sk_reuseport_cb))
1960 0 : reuseport_detach_sock(sk);
1961 32 : if (sk_del_node_init_rcu(sk)) {
1962 32 : hslot->count--;
1963 32 : inet_sk(sk)->inet_num = 0;
1964 32 : sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1965 :
1966 32 : spin_lock(&hslot2->lock);
1967 32 : hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1968 32 : hslot2->count--;
1969 32 : spin_unlock(&hslot2->lock);
1970 : }
1971 32 : spin_unlock_bh(&hslot->lock);
1972 : }
1973 39 : }
1974 : EXPORT_SYMBOL(udp_lib_unhash);
1975 :
1976 : /*
1977 : * inet_rcv_saddr was changed, we must rehash secondary hash
1978 : */
1979 13 : void udp_lib_rehash(struct sock *sk, u16 newhash)
1980 : {
1981 13 : if (sk_hashed(sk)) {
1982 13 : struct udp_table *udptable = sk->sk_prot->h.udp_table;
1983 13 : struct udp_hslot *hslot, *hslot2, *nhslot2;
1984 :
1985 13 : hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1986 13 : nhslot2 = udp_hashslot2(udptable, newhash);
1987 13 : udp_sk(sk)->udp_portaddr_hash = newhash;
1988 :
1989 13 : if (hslot2 != nhslot2 ||
1990 0 : rcu_access_pointer(sk->sk_reuseport_cb)) {
1991 13 : hslot = udp_hashslot(udptable, sock_net(sk),
1992 13 : udp_sk(sk)->udp_port_hash);
1993 : /* we must lock primary chain too */
1994 13 : spin_lock_bh(&hslot->lock);
1995 13 : if (rcu_access_pointer(sk->sk_reuseport_cb))
1996 0 : reuseport_detach_sock(sk);
1997 :
1998 13 : if (hslot2 != nhslot2) {
1999 13 : spin_lock(&hslot2->lock);
2000 13 : hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2001 13 : hslot2->count--;
2002 13 : spin_unlock(&hslot2->lock);
2003 :
2004 13 : spin_lock(&nhslot2->lock);
2005 13 : hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
2006 : &nhslot2->head);
2007 13 : nhslot2->count++;
2008 13 : spin_unlock(&nhslot2->lock);
2009 : }
2010 :
2011 13 : spin_unlock_bh(&hslot->lock);
2012 : }
2013 : }
2014 13 : }
2015 : EXPORT_SYMBOL(udp_lib_rehash);
2016 :
2017 13 : void udp_v4_rehash(struct sock *sk)
2018 : {
2019 13 : u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
2020 13 : inet_sk(sk)->inet_rcv_saddr,
2021 13 : inet_sk(sk)->inet_num);
2022 13 : udp_lib_rehash(sk, new_hash);
2023 13 : }
2024 :
2025 2 : static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2026 : {
2027 2 : int rc;
2028 :
2029 2 : if (inet_sk(sk)->inet_daddr) {
2030 0 : sock_rps_save_rxhash(sk, skb);
2031 0 : sk_mark_napi_id(sk, skb);
2032 0 : sk_incoming_cpu_update(sk);
2033 : } else {
2034 2 : sk_mark_napi_id_once(sk, skb);
2035 : }
2036 :
2037 2 : rc = __udp_enqueue_schedule_skb(sk, skb);
2038 2 : if (rc < 0) {
2039 0 : int is_udplite = IS_UDPLITE(sk);
2040 :
2041 : /* Note that an ENOMEM error is charged twice */
2042 0 : if (rc == -ENOMEM)
2043 0 : UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
2044 : is_udplite);
2045 : else
2046 0 : UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
2047 : is_udplite);
2048 0 : UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2049 0 : kfree_skb(skb);
2050 0 : trace_udp_fail_queue_rcv_skb(rc, sk);
2051 0 : return -1;
2052 : }
2053 :
2054 : return 0;
2055 : }
2056 :
2057 : /* returns:
2058 : * -1: error
2059 : * 0: success
2060 : * >0: "udp encap" protocol resubmission
2061 : *
2062 : * Note that in the success and error cases, the skb is assumed to
2063 : * have either been requeued or freed.
2064 : */
2065 2 : static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
2066 : {
2067 2 : struct udp_sock *up = udp_sk(sk);
2068 2 : int is_udplite = IS_UDPLITE(sk);
2069 :
2070 : /*
2071 : * Charge it to the socket, dropping if the queue is full.
2072 : */
2073 2 : if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
2074 : goto drop;
2075 2 : nf_reset_ct(skb);
2076 :
2077 2 : if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
2078 0 : int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
2079 :
2080 : /*
2081 : * This is an encapsulation socket so pass the skb to
2082 : * the socket's udp_encap_rcv() hook. Otherwise, just
2083 : * fall through and pass this up the UDP socket.
2084 : * up->encap_rcv() returns the following value:
2085 : * =0 if skb was successfully passed to the encap
2086 : * handler or was discarded by it.
2087 : * >0 if skb should be passed on to UDP.
2088 : * <0 if skb should be resubmitted as proto -N
2089 : */
2090 :
2091 : /* if we're overly short, let UDP handle it */
2092 0 : encap_rcv = READ_ONCE(up->encap_rcv);
2093 0 : if (encap_rcv) {
2094 0 : int ret;
2095 :
2096 : /* Verify checksum before giving to encap */
2097 0 : if (udp_lib_checksum_complete(skb))
2098 0 : goto csum_error;
2099 :
2100 0 : ret = encap_rcv(sk, skb);
2101 0 : if (ret <= 0) {
2102 0 : __UDP_INC_STATS(sock_net(sk),
2103 : UDP_MIB_INDATAGRAMS,
2104 : is_udplite);
2105 0 : return -ret;
2106 : }
2107 : }
2108 :
2109 : /* FALLTHROUGH -- it's a UDP Packet */
2110 : }
2111 :
2112 : /*
2113 : * UDP-Lite specific tests, ignored on UDP sockets
2114 : */
2115 2 : if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
2116 :
2117 : /*
2118 : * MIB statistics other than incrementing the error count are
2119 : * disabled for the following two types of errors: these depend
2120 : * on the application settings, not on the functioning of the
2121 : * protocol stack as such.
2122 : *
2123 : * RFC 3828 here recommends (sec 3.3): "There should also be a
2124 : * way ... to ... at least let the receiving application block
2125 : * delivery of packets with coverage values less than a value
2126 : * provided by the application."
2127 : */
2128 0 : if (up->pcrlen == 0) { /* full coverage was set */
2129 0 : net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2130 : UDP_SKB_CB(skb)->cscov, skb->len);
2131 0 : goto drop;
2132 : }
2133 : /* The next case involves violating the min. coverage requested
2134 : * by the receiver. This is subtle: if receiver wants x and x is
2135 : * greater than the buffersize/MTU then receiver will complain
2136 : * that it wants x while sender emits packets of smaller size y.
2137 : * Therefore the above ...()->partial_cov statement is essential.
2138 : */
2139 0 : if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
2140 0 : net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2141 : UDP_SKB_CB(skb)->cscov, up->pcrlen);
2142 0 : goto drop;
2143 : }
2144 : }
2145 :
2146 2 : prefetch(&sk->sk_rmem_alloc);
2147 2 : if (rcu_access_pointer(sk->sk_filter) &&
2148 0 : udp_lib_checksum_complete(skb))
2149 0 : goto csum_error;
2150 :
2151 2 : if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
2152 0 : goto drop;
2153 :
2154 2 : udp_csum_pull_header(skb);
2155 :
2156 2 : ipv4_pktinfo_prepare(sk, skb);
2157 2 : return __udp_queue_rcv_skb(sk, skb);
2158 :
2159 0 : csum_error:
2160 0 : __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2161 0 : drop:
2162 0 : __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2163 0 : atomic_inc(&sk->sk_drops);
2164 0 : kfree_skb(skb);
2165 0 : return -1;
2166 : }
2167 :
2168 2 : static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2169 : {
2170 2 : struct sk_buff *next, *segs;
2171 2 : int ret;
2172 :
2173 2 : if (likely(!udp_unexpected_gso(sk, skb)))
2174 2 : return udp_queue_rcv_one_skb(sk, skb);
2175 :
2176 0 : BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET);
2177 0 : __skb_push(skb, -skb_mac_offset(skb));
2178 0 : segs = udp_rcv_segment(sk, skb, true);
2179 0 : skb_list_walk_safe(segs, skb, next) {
2180 0 : __skb_pull(skb, skb_transport_offset(skb));
2181 0 : ret = udp_queue_rcv_one_skb(sk, skb);
2182 0 : if (ret > 0)
2183 0 : ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret);
2184 : }
2185 : return 0;
2186 : }
2187 :
2188 : /* For TCP sockets, sk_rx_dst is protected by socket lock
2189 : * For UDP, we use xchg() to guard against concurrent changes.
2190 : */
2191 0 : bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2192 : {
2193 0 : struct dst_entry *old;
2194 :
2195 0 : if (dst_hold_safe(dst)) {
2196 0 : old = xchg(&sk->sk_rx_dst, dst);
2197 0 : dst_release(old);
2198 0 : return old != dst;
2199 : }
2200 : return false;
2201 : }
2202 : EXPORT_SYMBOL(udp_sk_rx_dst_set);
2203 :
2204 : /*
2205 : * Multicasts and broadcasts go to each listener.
2206 : *
2207 : * Note: called only from the BH handler context.
2208 : */
2209 2 : static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2210 : struct udphdr *uh,
2211 : __be32 saddr, __be32 daddr,
2212 : struct udp_table *udptable,
2213 : int proto)
2214 : {
2215 2 : struct sock *sk, *first = NULL;
2216 2 : unsigned short hnum = ntohs(uh->dest);
2217 2 : struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2218 2 : unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2219 2 : unsigned int offset = offsetof(typeof(*sk), sk_node);
2220 2 : int dif = skb->dev->ifindex;
2221 2 : int sdif = inet_sdif(skb);
2222 2 : struct hlist_node *node;
2223 2 : struct sk_buff *nskb;
2224 :
2225 2 : if (use_hash2) {
2226 0 : hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2227 : udptable->mask;
2228 0 : hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2229 0 : start_lookup:
2230 0 : hslot = &udptable->hash2[hash2];
2231 0 : offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2232 : }
2233 :
2234 8 : sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2235 2 : if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2236 2 : uh->source, saddr, dif, sdif, hnum))
2237 0 : continue;
2238 :
2239 2 : if (!first) {
2240 2 : first = sk;
2241 2 : continue;
2242 : }
2243 0 : nskb = skb_clone(skb, GFP_ATOMIC);
2244 :
2245 0 : if (unlikely(!nskb)) {
2246 0 : atomic_inc(&sk->sk_drops);
2247 0 : __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2248 : IS_UDPLITE(sk));
2249 0 : __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2250 : IS_UDPLITE(sk));
2251 0 : continue;
2252 : }
2253 0 : if (udp_queue_rcv_skb(sk, nskb) > 0)
2254 0 : consume_skb(nskb);
2255 : }
2256 :
2257 : /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2258 2 : if (use_hash2 && hash2 != hash2_any) {
2259 0 : hash2 = hash2_any;
2260 0 : goto start_lookup;
2261 : }
2262 :
2263 2 : if (first) {
2264 2 : if (udp_queue_rcv_skb(first, skb) > 0)
2265 0 : consume_skb(skb);
2266 : } else {
2267 0 : kfree_skb(skb);
2268 0 : __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2269 : proto == IPPROTO_UDPLITE);
2270 : }
2271 2 : return 0;
2272 : }
2273 :
2274 : /* Initialize UDP checksum. If exited with zero value (success),
2275 : * CHECKSUM_UNNECESSARY means, that no more checks are required.
2276 : * Otherwise, csum completion requires checksumming packet body,
2277 : * including udp header and folding it to skb->csum.
2278 : */
2279 2 : static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2280 : int proto)
2281 : {
2282 2 : int err;
2283 :
2284 2 : UDP_SKB_CB(skb)->partial_cov = 0;
2285 2 : UDP_SKB_CB(skb)->cscov = skb->len;
2286 :
2287 2 : if (proto == IPPROTO_UDPLITE) {
2288 0 : err = udplite_checksum_init(skb, uh);
2289 0 : if (err)
2290 : return err;
2291 :
2292 0 : if (UDP_SKB_CB(skb)->partial_cov) {
2293 0 : skb->csum = inet_compute_pseudo(skb, proto);
2294 0 : return 0;
2295 : }
2296 : }
2297 :
2298 : /* Note, we are only interested in != 0 or == 0, thus the
2299 : * force to int.
2300 : */
2301 2 : err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2302 : inet_compute_pseudo);
2303 2 : if (err)
2304 : return err;
2305 :
2306 2 : if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2307 : /* If SW calculated the value, we know it's bad */
2308 0 : if (skb->csum_complete_sw)
2309 : return 1;
2310 :
2311 : /* HW says the value is bad. Let's validate that.
2312 : * skb->csum is no longer the full packet checksum,
2313 : * so don't treat it as such.
2314 : */
2315 0 : skb_checksum_complete_unset(skb);
2316 : }
2317 :
2318 : return 0;
2319 : }
2320 :
2321 : /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2322 : * return code conversion for ip layer consumption
2323 : */
2324 0 : static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2325 : struct udphdr *uh)
2326 : {
2327 0 : int ret;
2328 :
2329 0 : if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2330 0 : skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo);
2331 :
2332 0 : ret = udp_queue_rcv_skb(sk, skb);
2333 :
2334 : /* a return value > 0 means to resubmit the input, but
2335 : * it wants the return to be -protocol, or 0
2336 : */
2337 0 : if (ret > 0)
2338 0 : return -ret;
2339 : return 0;
2340 : }
2341 :
2342 : /*
2343 : * All we need to do is get the socket, and then do a checksum.
2344 : */
2345 :
2346 2 : int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2347 : int proto)
2348 : {
2349 2 : struct sock *sk;
2350 2 : struct udphdr *uh;
2351 2 : unsigned short ulen;
2352 2 : struct rtable *rt = skb_rtable(skb);
2353 2 : __be32 saddr, daddr;
2354 2 : struct net *net = dev_net(skb->dev);
2355 2 : bool refcounted;
2356 :
2357 : /*
2358 : * Validate the packet.
2359 : */
2360 2 : if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2361 0 : goto drop; /* No space for header. */
2362 :
2363 2 : uh = udp_hdr(skb);
2364 2 : ulen = ntohs(uh->len);
2365 2 : saddr = ip_hdr(skb)->saddr;
2366 2 : daddr = ip_hdr(skb)->daddr;
2367 :
2368 2 : if (ulen > skb->len)
2369 0 : goto short_packet;
2370 :
2371 2 : if (proto == IPPROTO_UDP) {
2372 : /* UDP validates ulen. */
2373 2 : if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2374 0 : goto short_packet;
2375 2 : uh = udp_hdr(skb);
2376 : }
2377 :
2378 2 : if (udp4_csum_init(skb, uh, proto))
2379 0 : goto csum_error;
2380 :
2381 2 : sk = skb_steal_sock(skb, &refcounted);
2382 2 : if (sk) {
2383 0 : struct dst_entry *dst = skb_dst(skb);
2384 0 : int ret;
2385 :
2386 0 : if (unlikely(sk->sk_rx_dst != dst))
2387 0 : udp_sk_rx_dst_set(sk, dst);
2388 :
2389 0 : ret = udp_unicast_rcv_skb(sk, skb, uh);
2390 0 : if (refcounted)
2391 0 : sock_put(sk);
2392 0 : return ret;
2393 : }
2394 :
2395 2 : if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2396 2 : return __udp4_lib_mcast_deliver(net, skb, uh,
2397 : saddr, daddr, udptable, proto);
2398 :
2399 0 : sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2400 0 : if (sk)
2401 0 : return udp_unicast_rcv_skb(sk, skb, uh);
2402 :
2403 0 : if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2404 : goto drop;
2405 0 : nf_reset_ct(skb);
2406 :
2407 : /* No socket. Drop packet silently, if checksum is wrong */
2408 0 : if (udp_lib_checksum_complete(skb))
2409 0 : goto csum_error;
2410 :
2411 0 : __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2412 0 : icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2413 :
2414 : /*
2415 : * Hmm. We got an UDP packet to a port to which we
2416 : * don't wanna listen. Ignore it.
2417 : */
2418 0 : kfree_skb(skb);
2419 0 : return 0;
2420 :
2421 0 : short_packet:
2422 0 : net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2423 : proto == IPPROTO_UDPLITE ? "Lite" : "",
2424 : &saddr, ntohs(uh->source),
2425 : ulen, skb->len,
2426 : &daddr, ntohs(uh->dest));
2427 0 : goto drop;
2428 :
2429 0 : csum_error:
2430 : /*
2431 : * RFC1122: OK. Discards the bad packet silently (as far as
2432 : * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2433 : */
2434 0 : net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2435 : proto == IPPROTO_UDPLITE ? "Lite" : "",
2436 : &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2437 : ulen);
2438 0 : __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2439 0 : drop:
2440 0 : __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2441 0 : kfree_skb(skb);
2442 0 : return 0;
2443 : }
2444 :
2445 : /* We can only early demux multicast if there is a single matching socket.
2446 : * If more than one socket found returns NULL
2447 : */
2448 0 : static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2449 : __be16 loc_port, __be32 loc_addr,
2450 : __be16 rmt_port, __be32 rmt_addr,
2451 : int dif, int sdif)
2452 : {
2453 0 : struct sock *sk, *result;
2454 0 : unsigned short hnum = ntohs(loc_port);
2455 0 : unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2456 0 : struct udp_hslot *hslot = &udp_table.hash[slot];
2457 :
2458 : /* Do not bother scanning a too big list */
2459 0 : if (hslot->count > 10)
2460 : return NULL;
2461 :
2462 0 : result = NULL;
2463 0 : sk_for_each_rcu(sk, &hslot->head) {
2464 0 : if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2465 : rmt_port, rmt_addr, dif, sdif, hnum)) {
2466 0 : if (result)
2467 : return NULL;
2468 : result = sk;
2469 : }
2470 : }
2471 :
2472 : return result;
2473 : }
2474 :
2475 : /* For unicast we should only early demux connected sockets or we can
2476 : * break forwarding setups. The chains here can be long so only check
2477 : * if the first socket is an exact match and if not move on.
2478 : */
2479 0 : static struct sock *__udp4_lib_demux_lookup(struct net *net,
2480 : __be16 loc_port, __be32 loc_addr,
2481 : __be16 rmt_port, __be32 rmt_addr,
2482 : int dif, int sdif)
2483 : {
2484 0 : unsigned short hnum = ntohs(loc_port);
2485 0 : unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2486 0 : unsigned int slot2 = hash2 & udp_table.mask;
2487 0 : struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2488 0 : INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2489 0 : const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2490 0 : struct sock *sk;
2491 :
2492 0 : udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2493 0 : if (INET_MATCH(sk, net, acookie, rmt_addr,
2494 : loc_addr, ports, dif, sdif))
2495 0 : return sk;
2496 : /* Only check first socket in chain */
2497 : break;
2498 : }
2499 : return NULL;
2500 : }
2501 :
2502 2 : int udp_v4_early_demux(struct sk_buff *skb)
2503 : {
2504 2 : struct net *net = dev_net(skb->dev);
2505 2 : struct in_device *in_dev = NULL;
2506 2 : const struct iphdr *iph;
2507 2 : const struct udphdr *uh;
2508 2 : struct sock *sk = NULL;
2509 2 : struct dst_entry *dst;
2510 2 : int dif = skb->dev->ifindex;
2511 2 : int sdif = inet_sdif(skb);
2512 2 : int ours;
2513 :
2514 : /* validate the packet */
2515 2 : if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2516 : return 0;
2517 :
2518 2 : iph = ip_hdr(skb);
2519 2 : uh = udp_hdr(skb);
2520 :
2521 2 : if (skb->pkt_type == PACKET_MULTICAST) {
2522 0 : in_dev = __in_dev_get_rcu(skb->dev);
2523 :
2524 0 : if (!in_dev)
2525 : return 0;
2526 :
2527 0 : ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2528 0 : iph->protocol);
2529 0 : if (!ours)
2530 : return 0;
2531 :
2532 0 : sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2533 0 : uh->source, iph->saddr,
2534 : dif, sdif);
2535 2 : } else if (skb->pkt_type == PACKET_HOST) {
2536 0 : sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2537 0 : uh->source, iph->saddr, dif, sdif);
2538 : }
2539 :
2540 0 : if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2541 2 : return 0;
2542 :
2543 0 : skb->sk = sk;
2544 0 : skb->destructor = sock_efree;
2545 0 : dst = READ_ONCE(sk->sk_rx_dst);
2546 :
2547 0 : if (dst)
2548 0 : dst = dst_check(dst, 0);
2549 0 : if (dst) {
2550 0 : u32 itag = 0;
2551 :
2552 : /* set noref for now.
2553 : * any place which wants to hold dst has to call
2554 : * dst_hold_safe()
2555 : */
2556 0 : skb_dst_set_noref(skb, dst);
2557 :
2558 : /* for unconnected multicast sockets we need to validate
2559 : * the source on each packet
2560 : */
2561 0 : if (!inet_sk(sk)->inet_daddr && in_dev)
2562 0 : return ip_mc_validate_source(skb, iph->daddr,
2563 : iph->saddr,
2564 0 : iph->tos & IPTOS_RT_MASK,
2565 : skb->dev, in_dev, &itag);
2566 : }
2567 : return 0;
2568 : }
2569 :
2570 2 : int udp_rcv(struct sk_buff *skb)
2571 : {
2572 2 : return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2573 : }
2574 :
2575 39 : void udp_destroy_sock(struct sock *sk)
2576 : {
2577 39 : struct udp_sock *up = udp_sk(sk);
2578 39 : bool slow = lock_sock_fast(sk);
2579 39 : udp_flush_pending_frames(sk);
2580 39 : unlock_sock_fast(sk, slow);
2581 39 : if (static_branch_unlikely(&udp_encap_needed_key)) {
2582 0 : if (up->encap_type) {
2583 0 : void (*encap_destroy)(struct sock *sk);
2584 0 : encap_destroy = READ_ONCE(up->encap_destroy);
2585 0 : if (encap_destroy)
2586 0 : encap_destroy(sk);
2587 : }
2588 0 : if (up->encap_enabled)
2589 0 : static_branch_dec(&udp_encap_needed_key);
2590 : }
2591 39 : }
2592 :
2593 : /*
2594 : * Socket option code for UDP
2595 : */
2596 0 : int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2597 : sockptr_t optval, unsigned int optlen,
2598 : int (*push_pending_frames)(struct sock *))
2599 : {
2600 0 : struct udp_sock *up = udp_sk(sk);
2601 0 : int val, valbool;
2602 0 : int err = 0;
2603 0 : int is_udplite = IS_UDPLITE(sk);
2604 :
2605 0 : if (optlen < sizeof(int))
2606 : return -EINVAL;
2607 :
2608 0 : if (copy_from_sockptr(&val, optval, sizeof(val)))
2609 : return -EFAULT;
2610 :
2611 0 : valbool = val ? 1 : 0;
2612 :
2613 0 : switch (optname) {
2614 0 : case UDP_CORK:
2615 0 : if (val != 0) {
2616 0 : up->corkflag = 1;
2617 : } else {
2618 0 : up->corkflag = 0;
2619 0 : lock_sock(sk);
2620 0 : push_pending_frames(sk);
2621 0 : release_sock(sk);
2622 : }
2623 : break;
2624 :
2625 0 : case UDP_ENCAP:
2626 0 : switch (val) {
2627 0 : case 0:
2628 : #ifdef CONFIG_XFRM
2629 : case UDP_ENCAP_ESPINUDP:
2630 : case UDP_ENCAP_ESPINUDP_NON_IKE:
2631 : #if IS_ENABLED(CONFIG_IPV6)
2632 : if (sk->sk_family == AF_INET6)
2633 : up->encap_rcv = ipv6_stub->xfrm6_udp_encap_rcv;
2634 : else
2635 : #endif
2636 : up->encap_rcv = xfrm4_udp_encap_rcv;
2637 : #endif
2638 0 : fallthrough;
2639 : case UDP_ENCAP_L2TPINUDP:
2640 0 : up->encap_type = val;
2641 0 : lock_sock(sk);
2642 0 : udp_tunnel_encap_enable(sk->sk_socket);
2643 0 : release_sock(sk);
2644 0 : break;
2645 : default:
2646 : err = -ENOPROTOOPT;
2647 : break;
2648 : }
2649 : break;
2650 :
2651 0 : case UDP_NO_CHECK6_TX:
2652 0 : up->no_check6_tx = valbool;
2653 0 : break;
2654 :
2655 0 : case UDP_NO_CHECK6_RX:
2656 0 : up->no_check6_rx = valbool;
2657 0 : break;
2658 :
2659 0 : case UDP_SEGMENT:
2660 0 : if (val < 0 || val > USHRT_MAX)
2661 : return -EINVAL;
2662 0 : up->gso_size = val;
2663 0 : break;
2664 :
2665 : case UDP_GRO:
2666 0 : lock_sock(sk);
2667 0 : if (valbool)
2668 0 : udp_tunnel_encap_enable(sk->sk_socket);
2669 0 : up->gro_enabled = valbool;
2670 0 : release_sock(sk);
2671 0 : break;
2672 :
2673 : /*
2674 : * UDP-Lite's partial checksum coverage (RFC 3828).
2675 : */
2676 : /* The sender sets actual checksum coverage length via this option.
2677 : * The case coverage > packet length is handled by send module. */
2678 0 : case UDPLITE_SEND_CSCOV:
2679 0 : if (!is_udplite) /* Disable the option on UDP sockets */
2680 : return -ENOPROTOOPT;
2681 0 : if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2682 0 : val = 8;
2683 0 : else if (val > USHRT_MAX)
2684 0 : val = USHRT_MAX;
2685 0 : up->pcslen = val;
2686 0 : up->pcflag |= UDPLITE_SEND_CC;
2687 0 : break;
2688 :
2689 : /* The receiver specifies a minimum checksum coverage value. To make
2690 : * sense, this should be set to at least 8 (as done below). If zero is
2691 : * used, this again means full checksum coverage. */
2692 0 : case UDPLITE_RECV_CSCOV:
2693 0 : if (!is_udplite) /* Disable the option on UDP sockets */
2694 : return -ENOPROTOOPT;
2695 0 : if (val != 0 && val < 8) /* Avoid silly minimal values. */
2696 0 : val = 8;
2697 0 : else if (val > USHRT_MAX)
2698 0 : val = USHRT_MAX;
2699 0 : up->pcrlen = val;
2700 0 : up->pcflag |= UDPLITE_RECV_CC;
2701 0 : break;
2702 :
2703 : default:
2704 : err = -ENOPROTOOPT;
2705 : break;
2706 : }
2707 :
2708 : return err;
2709 : }
2710 : EXPORT_SYMBOL(udp_lib_setsockopt);
2711 :
2712 1 : int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
2713 : unsigned int optlen)
2714 : {
2715 1 : if (level == SOL_UDP || level == SOL_UDPLITE)
2716 0 : return udp_lib_setsockopt(sk, level, optname,
2717 : optval, optlen,
2718 : udp_push_pending_frames);
2719 1 : return ip_setsockopt(sk, level, optname, optval, optlen);
2720 : }
2721 :
2722 0 : int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2723 : char __user *optval, int __user *optlen)
2724 : {
2725 0 : struct udp_sock *up = udp_sk(sk);
2726 0 : int val, len;
2727 :
2728 0 : if (get_user(len, optlen))
2729 : return -EFAULT;
2730 :
2731 0 : len = min_t(unsigned int, len, sizeof(int));
2732 :
2733 0 : if (len < 0)
2734 : return -EINVAL;
2735 :
2736 0 : switch (optname) {
2737 0 : case UDP_CORK:
2738 0 : val = up->corkflag;
2739 0 : break;
2740 :
2741 0 : case UDP_ENCAP:
2742 0 : val = up->encap_type;
2743 0 : break;
2744 :
2745 0 : case UDP_NO_CHECK6_TX:
2746 0 : val = up->no_check6_tx;
2747 0 : break;
2748 :
2749 0 : case UDP_NO_CHECK6_RX:
2750 0 : val = up->no_check6_rx;
2751 0 : break;
2752 :
2753 0 : case UDP_SEGMENT:
2754 0 : val = up->gso_size;
2755 0 : break;
2756 :
2757 : /* The following two cannot be changed on UDP sockets, the return is
2758 : * always 0 (which corresponds to the full checksum coverage of UDP). */
2759 0 : case UDPLITE_SEND_CSCOV:
2760 0 : val = up->pcslen;
2761 0 : break;
2762 :
2763 0 : case UDPLITE_RECV_CSCOV:
2764 0 : val = up->pcrlen;
2765 0 : break;
2766 :
2767 : default:
2768 : return -ENOPROTOOPT;
2769 : }
2770 :
2771 0 : if (put_user(len, optlen))
2772 : return -EFAULT;
2773 0 : if (copy_to_user(optval, &val, len))
2774 0 : return -EFAULT;
2775 : return 0;
2776 : }
2777 : EXPORT_SYMBOL(udp_lib_getsockopt);
2778 :
2779 0 : int udp_getsockopt(struct sock *sk, int level, int optname,
2780 : char __user *optval, int __user *optlen)
2781 : {
2782 0 : if (level == SOL_UDP || level == SOL_UDPLITE)
2783 0 : return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2784 0 : return ip_getsockopt(sk, level, optname, optval, optlen);
2785 : }
2786 :
2787 : /**
2788 : * udp_poll - wait for a UDP event.
2789 : * @file: - file struct
2790 : * @sock: - socket
2791 : * @wait: - poll table
2792 : *
2793 : * This is same as datagram poll, except for the special case of
2794 : * blocking sockets. If application is using a blocking fd
2795 : * and a packet with checksum error is in the queue;
2796 : * then it could get return from select indicating data available
2797 : * but then block when reading it. Add special case code
2798 : * to work around these arguably broken applications.
2799 : */
2800 55 : __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2801 : {
2802 55 : __poll_t mask = datagram_poll(file, sock, wait);
2803 55 : struct sock *sk = sock->sk;
2804 :
2805 55 : if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
2806 0 : mask |= EPOLLIN | EPOLLRDNORM;
2807 :
2808 : /* Check for false positives due to checksum errors */
2809 55 : if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2810 2 : !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2811 0 : mask &= ~(EPOLLIN | EPOLLRDNORM);
2812 :
2813 55 : return mask;
2814 :
2815 : }
2816 : EXPORT_SYMBOL(udp_poll);
2817 :
2818 0 : int udp_abort(struct sock *sk, int err)
2819 : {
2820 0 : lock_sock(sk);
2821 :
2822 0 : sk->sk_err = err;
2823 0 : sk->sk_error_report(sk);
2824 0 : __udp_disconnect(sk, 0);
2825 :
2826 0 : release_sock(sk);
2827 :
2828 0 : return 0;
2829 : }
2830 : EXPORT_SYMBOL_GPL(udp_abort);
2831 :
2832 : struct proto udp_prot = {
2833 : .name = "UDP",
2834 : .owner = THIS_MODULE,
2835 : .close = udp_lib_close,
2836 : .pre_connect = udp_pre_connect,
2837 : .connect = ip4_datagram_connect,
2838 : .disconnect = udp_disconnect,
2839 : .ioctl = udp_ioctl,
2840 : .init = udp_init_sock,
2841 : .destroy = udp_destroy_sock,
2842 : .setsockopt = udp_setsockopt,
2843 : .getsockopt = udp_getsockopt,
2844 : .sendmsg = udp_sendmsg,
2845 : .recvmsg = udp_recvmsg,
2846 : .sendpage = udp_sendpage,
2847 : .release_cb = ip4_datagram_release_cb,
2848 : .hash = udp_lib_hash,
2849 : .unhash = udp_lib_unhash,
2850 : .rehash = udp_v4_rehash,
2851 : .get_port = udp_v4_get_port,
2852 : .memory_allocated = &udp_memory_allocated,
2853 : .sysctl_mem = sysctl_udp_mem,
2854 : .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2855 : .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2856 : .obj_size = sizeof(struct udp_sock),
2857 : .h.udp_table = &udp_table,
2858 : .diag_destroy = udp_abort,
2859 : };
2860 : EXPORT_SYMBOL(udp_prot);
2861 :
2862 : /* ------------------------------------------------------------------------ */
2863 : #ifdef CONFIG_PROC_FS
2864 :
2865 0 : static struct sock *udp_get_first(struct seq_file *seq, int start)
2866 : {
2867 0 : struct sock *sk;
2868 0 : struct udp_seq_afinfo *afinfo;
2869 0 : struct udp_iter_state *state = seq->private;
2870 0 : struct net *net = seq_file_net(seq);
2871 :
2872 0 : if (state->bpf_seq_afinfo)
2873 : afinfo = state->bpf_seq_afinfo;
2874 : else
2875 0 : afinfo = PDE_DATA(file_inode(seq->file));
2876 :
2877 0 : for (state->bucket = start; state->bucket <= afinfo->udp_table->mask;
2878 0 : ++state->bucket) {
2879 0 : struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket];
2880 :
2881 0 : if (hlist_empty(&hslot->head))
2882 0 : continue;
2883 :
2884 0 : spin_lock_bh(&hslot->lock);
2885 0 : sk_for_each(sk, &hslot->head) {
2886 0 : if (!net_eq(sock_net(sk), net))
2887 : continue;
2888 0 : if (afinfo->family == AF_UNSPEC ||
2889 0 : sk->sk_family == afinfo->family)
2890 0 : goto found;
2891 : }
2892 0 : spin_unlock_bh(&hslot->lock);
2893 : }
2894 : sk = NULL;
2895 0 : found:
2896 0 : return sk;
2897 : }
2898 :
2899 0 : static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2900 : {
2901 0 : struct udp_seq_afinfo *afinfo;
2902 0 : struct udp_iter_state *state = seq->private;
2903 0 : struct net *net = seq_file_net(seq);
2904 :
2905 0 : if (state->bpf_seq_afinfo)
2906 0 : afinfo = state->bpf_seq_afinfo;
2907 : else
2908 0 : afinfo = PDE_DATA(file_inode(seq->file));
2909 :
2910 0 : do {
2911 0 : sk = sk_next(sk);
2912 0 : } while (sk && (!net_eq(sock_net(sk), net) ||
2913 0 : (afinfo->family != AF_UNSPEC &&
2914 0 : sk->sk_family != afinfo->family)));
2915 :
2916 0 : if (!sk) {
2917 0 : if (state->bucket <= afinfo->udp_table->mask)
2918 0 : spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
2919 0 : return udp_get_first(seq, state->bucket + 1);
2920 : }
2921 : return sk;
2922 : }
2923 :
2924 0 : static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2925 : {
2926 0 : struct sock *sk = udp_get_first(seq, 0);
2927 :
2928 0 : if (sk)
2929 0 : while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2930 0 : --pos;
2931 0 : return pos ? NULL : sk;
2932 : }
2933 :
2934 0 : void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2935 : {
2936 0 : struct udp_iter_state *state = seq->private;
2937 0 : state->bucket = MAX_UDP_PORTS;
2938 :
2939 0 : return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2940 : }
2941 : EXPORT_SYMBOL(udp_seq_start);
2942 :
2943 0 : void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2944 : {
2945 0 : struct sock *sk;
2946 :
2947 0 : if (v == SEQ_START_TOKEN)
2948 0 : sk = udp_get_idx(seq, 0);
2949 : else
2950 0 : sk = udp_get_next(seq, v);
2951 :
2952 0 : ++*pos;
2953 0 : return sk;
2954 : }
2955 : EXPORT_SYMBOL(udp_seq_next);
2956 :
2957 0 : void udp_seq_stop(struct seq_file *seq, void *v)
2958 : {
2959 0 : struct udp_seq_afinfo *afinfo;
2960 0 : struct udp_iter_state *state = seq->private;
2961 :
2962 0 : if (state->bpf_seq_afinfo)
2963 : afinfo = state->bpf_seq_afinfo;
2964 : else
2965 0 : afinfo = PDE_DATA(file_inode(seq->file));
2966 :
2967 0 : if (state->bucket <= afinfo->udp_table->mask)
2968 0 : spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
2969 0 : }
2970 : EXPORT_SYMBOL(udp_seq_stop);
2971 :
2972 : /* ------------------------------------------------------------------------ */
2973 0 : static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2974 : int bucket)
2975 : {
2976 0 : struct inet_sock *inet = inet_sk(sp);
2977 0 : __be32 dest = inet->inet_daddr;
2978 0 : __be32 src = inet->inet_rcv_saddr;
2979 0 : __u16 destp = ntohs(inet->inet_dport);
2980 0 : __u16 srcp = ntohs(inet->inet_sport);
2981 :
2982 0 : seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2983 : " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
2984 0 : bucket, src, srcp, dest, destp, sp->sk_state,
2985 : sk_wmem_alloc_get(sp),
2986 : udp_rqueue_get(sp),
2987 : 0, 0L, 0,
2988 : from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2989 : 0, sock_i_ino(sp),
2990 0 : refcount_read(&sp->sk_refcnt), sp,
2991 0 : atomic_read(&sp->sk_drops));
2992 0 : }
2993 :
2994 0 : int udp4_seq_show(struct seq_file *seq, void *v)
2995 : {
2996 0 : seq_setwidth(seq, 127);
2997 0 : if (v == SEQ_START_TOKEN)
2998 0 : seq_puts(seq, " sl local_address rem_address st tx_queue "
2999 : "rx_queue tr tm->when retrnsmt uid timeout "
3000 : "inode ref pointer drops");
3001 : else {
3002 0 : struct udp_iter_state *state = seq->private;
3003 :
3004 0 : udp4_format_sock(v, seq, state->bucket);
3005 : }
3006 0 : seq_pad(seq, '\n');
3007 0 : return 0;
3008 : }
3009 :
3010 : #ifdef CONFIG_BPF_SYSCALL
3011 : struct bpf_iter__udp {
3012 : __bpf_md_ptr(struct bpf_iter_meta *, meta);
3013 : __bpf_md_ptr(struct udp_sock *, udp_sk);
3014 : uid_t uid __aligned(8);
3015 : int bucket __aligned(8);
3016 : };
3017 :
3018 : static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
3019 : struct udp_sock *udp_sk, uid_t uid, int bucket)
3020 : {
3021 : struct bpf_iter__udp ctx;
3022 :
3023 : meta->seq_num--; /* skip SEQ_START_TOKEN */
3024 : ctx.meta = meta;
3025 : ctx.udp_sk = udp_sk;
3026 : ctx.uid = uid;
3027 : ctx.bucket = bucket;
3028 : return bpf_iter_run_prog(prog, &ctx);
3029 : }
3030 :
3031 : static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
3032 : {
3033 : struct udp_iter_state *state = seq->private;
3034 : struct bpf_iter_meta meta;
3035 : struct bpf_prog *prog;
3036 : struct sock *sk = v;
3037 : uid_t uid;
3038 :
3039 : if (v == SEQ_START_TOKEN)
3040 : return 0;
3041 :
3042 : uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
3043 : meta.seq = seq;
3044 : prog = bpf_iter_get_info(&meta, false);
3045 : return udp_prog_seq_show(prog, &meta, v, uid, state->bucket);
3046 : }
3047 :
3048 : static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
3049 : {
3050 : struct bpf_iter_meta meta;
3051 : struct bpf_prog *prog;
3052 :
3053 : if (!v) {
3054 : meta.seq = seq;
3055 : prog = bpf_iter_get_info(&meta, true);
3056 : if (prog)
3057 : (void)udp_prog_seq_show(prog, &meta, v, 0, 0);
3058 : }
3059 :
3060 : udp_seq_stop(seq, v);
3061 : }
3062 :
3063 : static const struct seq_operations bpf_iter_udp_seq_ops = {
3064 : .start = udp_seq_start,
3065 : .next = udp_seq_next,
3066 : .stop = bpf_iter_udp_seq_stop,
3067 : .show = bpf_iter_udp_seq_show,
3068 : };
3069 : #endif
3070 :
3071 : const struct seq_operations udp_seq_ops = {
3072 : .start = udp_seq_start,
3073 : .next = udp_seq_next,
3074 : .stop = udp_seq_stop,
3075 : .show = udp4_seq_show,
3076 : };
3077 : EXPORT_SYMBOL(udp_seq_ops);
3078 :
3079 : static struct udp_seq_afinfo udp4_seq_afinfo = {
3080 : .family = AF_INET,
3081 : .udp_table = &udp_table,
3082 : };
3083 :
3084 1 : static int __net_init udp4_proc_init_net(struct net *net)
3085 : {
3086 1 : if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
3087 : sizeof(struct udp_iter_state), &udp4_seq_afinfo))
3088 0 : return -ENOMEM;
3089 : return 0;
3090 : }
3091 :
3092 0 : static void __net_exit udp4_proc_exit_net(struct net *net)
3093 : {
3094 0 : remove_proc_entry("udp", net->proc_net);
3095 0 : }
3096 :
3097 : static struct pernet_operations udp4_net_ops = {
3098 : .init = udp4_proc_init_net,
3099 : .exit = udp4_proc_exit_net,
3100 : };
3101 :
3102 1 : int __init udp4_proc_init(void)
3103 : {
3104 1 : return register_pernet_subsys(&udp4_net_ops);
3105 : }
3106 :
3107 0 : void udp4_proc_exit(void)
3108 : {
3109 0 : unregister_pernet_subsys(&udp4_net_ops);
3110 0 : }
3111 : #endif /* CONFIG_PROC_FS */
3112 :
3113 : static __initdata unsigned long uhash_entries;
3114 0 : static int __init set_uhash_entries(char *str)
3115 : {
3116 0 : ssize_t ret;
3117 :
3118 0 : if (!str)
3119 : return 0;
3120 :
3121 0 : ret = kstrtoul(str, 0, &uhash_entries);
3122 0 : if (ret)
3123 : return 0;
3124 :
3125 0 : if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
3126 0 : uhash_entries = UDP_HTABLE_SIZE_MIN;
3127 : return 1;
3128 : }
3129 : __setup("uhash_entries=", set_uhash_entries);
3130 :
3131 2 : void __init udp_table_init(struct udp_table *table, const char *name)
3132 : {
3133 2 : unsigned int i;
3134 :
3135 2 : table->hash = alloc_large_system_hash(name,
3136 : 2 * sizeof(struct udp_hslot),
3137 : uhash_entries,
3138 : 21, /* one slot per 2 MB */
3139 : 0,
3140 : &table->log,
3141 : &table->mask,
3142 : UDP_HTABLE_SIZE_MIN,
3143 : 64 * 1024);
3144 :
3145 2 : table->hash2 = table->hash + (table->mask + 1);
3146 1026 : for (i = 0; i <= table->mask; i++) {
3147 1024 : INIT_HLIST_HEAD(&table->hash[i].head);
3148 1024 : table->hash[i].count = 0;
3149 1024 : spin_lock_init(&table->hash[i].lock);
3150 : }
3151 1026 : for (i = 0; i <= table->mask; i++) {
3152 1024 : INIT_HLIST_HEAD(&table->hash2[i].head);
3153 1024 : table->hash2[i].count = 0;
3154 1024 : spin_lock_init(&table->hash2[i].lock);
3155 : }
3156 2 : }
3157 :
3158 0 : u32 udp_flow_hashrnd(void)
3159 : {
3160 0 : static u32 hashrnd __read_mostly;
3161 :
3162 0 : net_get_random_once(&hashrnd, sizeof(hashrnd));
3163 :
3164 0 : return hashrnd;
3165 : }
3166 : EXPORT_SYMBOL(udp_flow_hashrnd);
3167 :
3168 2 : static void __udp_sysctl_init(struct net *net)
3169 : {
3170 2 : net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM;
3171 2 : net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM;
3172 :
3173 : #ifdef CONFIG_NET_L3_MASTER_DEV
3174 : net->ipv4.sysctl_udp_l3mdev_accept = 0;
3175 : #endif
3176 : }
3177 :
3178 1 : static int __net_init udp_sysctl_init(struct net *net)
3179 : {
3180 1 : __udp_sysctl_init(net);
3181 1 : return 0;
3182 : }
3183 :
3184 : static struct pernet_operations __net_initdata udp_sysctl_ops = {
3185 : .init = udp_sysctl_init,
3186 : };
3187 :
3188 : #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3189 : DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
3190 : struct udp_sock *udp_sk, uid_t uid, int bucket)
3191 :
3192 : static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
3193 : {
3194 : struct udp_iter_state *st = priv_data;
3195 : struct udp_seq_afinfo *afinfo;
3196 : int ret;
3197 :
3198 : afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN);
3199 : if (!afinfo)
3200 : return -ENOMEM;
3201 :
3202 : afinfo->family = AF_UNSPEC;
3203 : afinfo->udp_table = &udp_table;
3204 : st->bpf_seq_afinfo = afinfo;
3205 : ret = bpf_iter_init_seq_net(priv_data, aux);
3206 : if (ret)
3207 : kfree(afinfo);
3208 : return ret;
3209 : }
3210 :
3211 : static void bpf_iter_fini_udp(void *priv_data)
3212 : {
3213 : struct udp_iter_state *st = priv_data;
3214 :
3215 : kfree(st->bpf_seq_afinfo);
3216 : bpf_iter_fini_seq_net(priv_data);
3217 : }
3218 :
3219 : static const struct bpf_iter_seq_info udp_seq_info = {
3220 : .seq_ops = &bpf_iter_udp_seq_ops,
3221 : .init_seq_private = bpf_iter_init_udp,
3222 : .fini_seq_private = bpf_iter_fini_udp,
3223 : .seq_priv_size = sizeof(struct udp_iter_state),
3224 : };
3225 :
3226 : static struct bpf_iter_reg udp_reg_info = {
3227 : .target = "udp",
3228 : .ctx_arg_info_size = 1,
3229 : .ctx_arg_info = {
3230 : { offsetof(struct bpf_iter__udp, udp_sk),
3231 : PTR_TO_BTF_ID_OR_NULL },
3232 : },
3233 : .seq_info = &udp_seq_info,
3234 : };
3235 :
3236 : static void __init bpf_iter_register(void)
3237 : {
3238 : udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP];
3239 : if (bpf_iter_reg_target(&udp_reg_info))
3240 : pr_warn("Warning: could not register bpf iterator udp\n");
3241 : }
3242 : #endif
3243 :
3244 1 : void __init udp_init(void)
3245 : {
3246 1 : unsigned long limit;
3247 1 : unsigned int i;
3248 :
3249 1 : udp_table_init(&udp_table, "UDP");
3250 1 : limit = nr_free_buffer_pages() / 8;
3251 1 : limit = max(limit, 128UL);
3252 1 : sysctl_udp_mem[0] = limit / 4 * 3;
3253 1 : sysctl_udp_mem[1] = limit;
3254 1 : sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
3255 :
3256 1 : __udp_sysctl_init(&init_net);
3257 :
3258 : /* 16 spinlocks per cpu */
3259 1 : udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
3260 1 : udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
3261 : GFP_KERNEL);
3262 1 : if (!udp_busylocks)
3263 0 : panic("UDP: failed to alloc udp_busylocks\n");
3264 65 : for (i = 0; i < (1U << udp_busylocks_log); i++)
3265 64 : spin_lock_init(udp_busylocks + i);
3266 :
3267 1 : if (register_pernet_subsys(&udp_sysctl_ops))
3268 0 : panic("UDP: failed to init sysctl parameters.\n");
3269 :
3270 : #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3271 : bpf_iter_register();
3272 : #endif
3273 1 : }
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