2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * The User Datagram Protocol (UDP).
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
12 * Hirokazu Takahashi, <taka@valinux.co.jp>
15 * Alan Cox : verify_area() calls
16 * Alan Cox : stopped close while in use off icmp
17 * messages. Not a fix but a botch that
18 * for udp at least is 'valid'.
19 * Alan Cox : Fixed icmp handling properly
20 * Alan Cox : Correct error for oversized datagrams
21 * Alan Cox : Tidied select() semantics.
22 * Alan Cox : udp_err() fixed properly, also now
23 * select and read wake correctly on errors
24 * Alan Cox : udp_send verify_area moved to avoid mem leak
25 * Alan Cox : UDP can count its memory
26 * Alan Cox : send to an unknown connection causes
27 * an ECONNREFUSED off the icmp, but
29 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
31 * bug no longer crashes it.
32 * Fred Van Kempen : Net2e support for sk->broadcast.
33 * Alan Cox : Uses skb_free_datagram
34 * Alan Cox : Added get/set sockopt support.
35 * Alan Cox : Broadcasting without option set returns EACCES.
36 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
37 * Alan Cox : Use ip_tos and ip_ttl
38 * Alan Cox : SNMP Mibs
39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
40 * Matt Dillon : UDP length checks.
41 * Alan Cox : Smarter af_inet used properly.
42 * Alan Cox : Use new kernel side addressing.
43 * Alan Cox : Incorrect return on truncated datagram receive.
44 * Arnt Gulbrandsen : New udp_send and stuff
45 * Alan Cox : Cache last socket
46 * Alan Cox : Route cache
47 * Jon Peatfield : Minor efficiency fix to sendto().
48 * Mike Shaver : RFC1122 checks.
49 * Alan Cox : Nonblocking error fix.
50 * Willy Konynenberg : Transparent proxying support.
51 * Mike McLagan : Routing by source
52 * David S. Miller : New socket lookup architecture.
53 * Last socket cache retained as it
54 * does have a high hit rate.
55 * Olaf Kirch : Don't linearise iovec on sendmsg.
56 * Andi Kleen : Some cleanups, cache destination entry
58 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
59 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
60 * return ENOTCONN for unconnected sockets (POSIX)
61 * Janos Farkas : don't deliver multi/broadcasts to a different
62 * bound-to-device socket
63 * Hirokazu Takahashi : HW checksumming for outgoing UDP
65 * Hirokazu Takahashi : sendfile() on UDP works now.
66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
69 * a single port at the same time.
70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71 * James Chapman : Add L2TP encapsulation type.
74 * This program is free software; you can redistribute it and/or
75 * modify it under the terms of the GNU General Public License
76 * as published by the Free Software Foundation; either version
77 * 2 of the License, or (at your option) any later version.
80 #define pr_fmt(fmt) "UDP: " fmt
82 #include <linux/uaccess.h>
83 #include <asm/ioctls.h>
84 #include <linux/bootmem.h>
85 #include <linux/highmem.h>
86 #include <linux/swap.h>
87 #include <linux/types.h>
88 #include <linux/fcntl.h>
89 #include <linux/module.h>
90 #include <linux/socket.h>
91 #include <linux/sockios.h>
92 #include <linux/igmp.h>
93 #include <linux/inetdevice.h>
95 #include <linux/errno.h>
96 #include <linux/timer.h>
98 #include <linux/inet.h>
99 #include <linux/netdevice.h>
100 #include <linux/slab.h>
101 #include <net/tcp_states.h>
102 #include <linux/skbuff.h>
103 #include <linux/proc_fs.h>
104 #include <linux/seq_file.h>
105 #include <net/net_namespace.h>
106 #include <net/icmp.h>
107 #include <net/inet_hashtables.h>
108 #include <net/route.h>
109 #include <net/checksum.h>
110 #include <net/xfrm.h>
111 #include <trace/events/udp.h>
112 #include <linux/static_key.h>
113 #include <trace/events/skb.h>
114 #include <net/busy_poll.h>
115 #include "udp_impl.h"
116 #include <net/sock_reuseport.h>
117 #include <net/addrconf.h>
119 struct udp_table udp_table __read_mostly;
120 EXPORT_SYMBOL(udp_table);
122 long sysctl_udp_mem[3] __read_mostly;
123 EXPORT_SYMBOL(sysctl_udp_mem);
125 int sysctl_udp_rmem_min __read_mostly;
126 EXPORT_SYMBOL(sysctl_udp_rmem_min);
128 int sysctl_udp_wmem_min __read_mostly;
129 EXPORT_SYMBOL(sysctl_udp_wmem_min);
131 atomic_long_t udp_memory_allocated;
132 EXPORT_SYMBOL(udp_memory_allocated);
134 #define MAX_UDP_PORTS 65536
135 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
137 /* IPCB reference means this can not be used from early demux */
138 static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
140 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
141 if (!net->ipv4.sysctl_udp_l3mdev_accept &&
142 skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
148 static int udp_lib_lport_inuse(struct net *net, __u16 num,
149 const struct udp_hslot *hslot,
150 unsigned long *bitmap,
151 struct sock *sk, unsigned int log)
154 kuid_t uid = sock_i_uid(sk);
156 sk_for_each(sk2, &hslot->head) {
157 if (net_eq(sock_net(sk2), net) &&
159 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
160 (!sk2->sk_reuse || !sk->sk_reuse) &&
161 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
162 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
163 inet_rcv_saddr_equal(sk, sk2, true)) {
164 if (sk2->sk_reuseport && sk->sk_reuseport &&
165 !rcu_access_pointer(sk->sk_reuseport_cb) &&
166 uid_eq(uid, sock_i_uid(sk2))) {
172 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
181 * Note: we still hold spinlock of primary hash chain, so no other writer
182 * can insert/delete a socket with local_port == num
184 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
185 struct udp_hslot *hslot2,
189 kuid_t uid = sock_i_uid(sk);
192 spin_lock(&hslot2->lock);
193 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
194 if (net_eq(sock_net(sk2), net) &&
196 (udp_sk(sk2)->udp_port_hash == num) &&
197 (!sk2->sk_reuse || !sk->sk_reuse) &&
198 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
199 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
200 inet_rcv_saddr_equal(sk, sk2, true)) {
201 if (sk2->sk_reuseport && sk->sk_reuseport &&
202 !rcu_access_pointer(sk->sk_reuseport_cb) &&
203 uid_eq(uid, sock_i_uid(sk2))) {
211 spin_unlock(&hslot2->lock);
215 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
217 struct net *net = sock_net(sk);
218 kuid_t uid = sock_i_uid(sk);
221 sk_for_each(sk2, &hslot->head) {
222 if (net_eq(sock_net(sk2), net) &&
224 sk2->sk_family == sk->sk_family &&
225 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
226 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
227 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
228 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
229 inet_rcv_saddr_equal(sk, sk2, false)) {
230 return reuseport_add_sock(sk, sk2);
234 /* Initial allocation may have already happened via setsockopt */
235 if (!rcu_access_pointer(sk->sk_reuseport_cb))
236 return reuseport_alloc(sk);
241 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
243 * @sk: socket struct in question
244 * @snum: port number to look up
245 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
248 int udp_lib_get_port(struct sock *sk, unsigned short snum,
249 unsigned int hash2_nulladdr)
251 struct udp_hslot *hslot, *hslot2;
252 struct udp_table *udptable = sk->sk_prot->h.udp_table;
254 struct net *net = sock_net(sk);
257 int low, high, remaining;
259 unsigned short first, last;
260 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
262 inet_get_local_port_range(net, &low, &high);
263 remaining = (high - low) + 1;
265 rand = prandom_u32();
266 first = reciprocal_scale(rand, remaining) + low;
268 * force rand to be an odd multiple of UDP_HTABLE_SIZE
270 rand = (rand | 1) * (udptable->mask + 1);
271 last = first + udptable->mask + 1;
273 hslot = udp_hashslot(udptable, net, first);
274 bitmap_zero(bitmap, PORTS_PER_CHAIN);
275 spin_lock_bh(&hslot->lock);
276 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
281 * Iterate on all possible values of snum for this hash.
282 * Using steps of an odd multiple of UDP_HTABLE_SIZE
283 * give us randomization and full range coverage.
286 if (low <= snum && snum <= high &&
287 !test_bit(snum >> udptable->log, bitmap) &&
288 !inet_is_local_reserved_port(net, snum))
291 } while (snum != first);
292 spin_unlock_bh(&hslot->lock);
294 } while (++first != last);
297 hslot = udp_hashslot(udptable, net, snum);
298 spin_lock_bh(&hslot->lock);
299 if (hslot->count > 10) {
301 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
303 slot2 &= udptable->mask;
304 hash2_nulladdr &= udptable->mask;
306 hslot2 = udp_hashslot2(udptable, slot2);
307 if (hslot->count < hslot2->count)
308 goto scan_primary_hash;
310 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
311 if (!exist && (hash2_nulladdr != slot2)) {
312 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
313 exist = udp_lib_lport_inuse2(net, snum, hslot2,
322 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
326 inet_sk(sk)->inet_num = snum;
327 udp_sk(sk)->udp_port_hash = snum;
328 udp_sk(sk)->udp_portaddr_hash ^= snum;
329 if (sk_unhashed(sk)) {
330 if (sk->sk_reuseport &&
331 udp_reuseport_add_sock(sk, hslot)) {
332 inet_sk(sk)->inet_num = 0;
333 udp_sk(sk)->udp_port_hash = 0;
334 udp_sk(sk)->udp_portaddr_hash ^= snum;
338 sk_add_node_rcu(sk, &hslot->head);
340 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
342 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
343 spin_lock(&hslot2->lock);
344 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
345 sk->sk_family == AF_INET6)
346 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
349 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
352 spin_unlock(&hslot2->lock);
354 sock_set_flag(sk, SOCK_RCU_FREE);
357 spin_unlock_bh(&hslot->lock);
361 EXPORT_SYMBOL(udp_lib_get_port);
363 static u32 udp4_portaddr_hash(const struct net *net, __be32 saddr,
366 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
369 int udp_v4_get_port(struct sock *sk, unsigned short snum)
371 unsigned int hash2_nulladdr =
372 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
373 unsigned int hash2_partial =
374 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
376 /* precompute partial secondary hash */
377 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
378 return udp_lib_get_port(sk, snum, hash2_nulladdr);
381 static int compute_score(struct sock *sk, struct net *net,
382 __be32 saddr, __be16 sport,
383 __be32 daddr, unsigned short hnum, int dif,
387 struct inet_sock *inet;
389 if (!net_eq(sock_net(sk), net) ||
390 udp_sk(sk)->udp_port_hash != hnum ||
394 score = (sk->sk_family == PF_INET) ? 2 : 1;
397 if (inet->inet_rcv_saddr) {
398 if (inet->inet_rcv_saddr != daddr)
403 if (inet->inet_daddr) {
404 if (inet->inet_daddr != saddr)
409 if (inet->inet_dport) {
410 if (inet->inet_dport != sport)
415 if (sk->sk_bound_dev_if || exact_dif) {
416 if (sk->sk_bound_dev_if != dif)
420 if (sk->sk_incoming_cpu == raw_smp_processor_id())
425 static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
426 const __u16 lport, const __be32 faddr,
429 static u32 udp_ehash_secret __read_mostly;
431 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
433 return __inet_ehashfn(laddr, lport, faddr, fport,
434 udp_ehash_secret + net_hash_mix(net));
437 /* called with rcu_read_lock() */
438 static struct sock *udp4_lib_lookup2(struct net *net,
439 __be32 saddr, __be16 sport,
440 __be32 daddr, unsigned int hnum, int dif, bool exact_dif,
441 struct udp_hslot *hslot2,
444 struct sock *sk, *result;
445 int score, badness, matches = 0, reuseport = 0;
450 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
451 score = compute_score(sk, net, saddr, sport,
452 daddr, hnum, dif, exact_dif);
453 if (score > badness) {
454 reuseport = sk->sk_reuseport;
456 hash = udp_ehashfn(net, daddr, hnum,
458 result = reuseport_select_sock(sk, hash, skb,
459 sizeof(struct udphdr));
466 } else if (score == badness && reuseport) {
468 if (reciprocal_scale(hash, matches) == 0)
470 hash = next_pseudo_random32(hash);
476 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
477 * harder than this. -DaveM
479 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
480 __be16 sport, __be32 daddr, __be16 dport,
481 int dif, struct udp_table *udptable, struct sk_buff *skb)
483 struct sock *sk, *result;
484 unsigned short hnum = ntohs(dport);
485 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
486 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
487 bool exact_dif = udp_lib_exact_dif_match(net, skb);
488 int score, badness, matches = 0, reuseport = 0;
491 if (hslot->count > 10) {
492 hash2 = udp4_portaddr_hash(net, daddr, hnum);
493 slot2 = hash2 & udptable->mask;
494 hslot2 = &udptable->hash2[slot2];
495 if (hslot->count < hslot2->count)
498 result = udp4_lib_lookup2(net, saddr, sport,
500 exact_dif, hslot2, skb);
502 unsigned int old_slot2 = slot2;
503 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
504 slot2 = hash2 & udptable->mask;
505 /* avoid searching the same slot again. */
506 if (unlikely(slot2 == old_slot2))
509 hslot2 = &udptable->hash2[slot2];
510 if (hslot->count < hslot2->count)
513 result = udp4_lib_lookup2(net, saddr, sport,
515 exact_dif, hslot2, skb);
522 sk_for_each_rcu(sk, &hslot->head) {
523 score = compute_score(sk, net, saddr, sport,
524 daddr, hnum, dif, exact_dif);
525 if (score > badness) {
526 reuseport = sk->sk_reuseport;
528 hash = udp_ehashfn(net, daddr, hnum,
530 result = reuseport_select_sock(sk, hash, skb,
531 sizeof(struct udphdr));
538 } else if (score == badness && reuseport) {
540 if (reciprocal_scale(hash, matches) == 0)
542 hash = next_pseudo_random32(hash);
547 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
549 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
550 __be16 sport, __be16 dport,
551 struct udp_table *udptable)
553 const struct iphdr *iph = ip_hdr(skb);
555 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
556 iph->daddr, dport, inet_iif(skb),
560 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
561 __be16 sport, __be16 dport)
563 return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table);
565 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb);
567 /* Must be called under rcu_read_lock().
568 * Does increment socket refcount.
570 #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
571 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
572 IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
573 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
574 __be32 daddr, __be16 dport, int dif)
578 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
579 dif, &udp_table, NULL);
580 if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
584 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
587 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
588 __be16 loc_port, __be32 loc_addr,
589 __be16 rmt_port, __be32 rmt_addr,
590 int dif, unsigned short hnum)
592 struct inet_sock *inet = inet_sk(sk);
594 if (!net_eq(sock_net(sk), net) ||
595 udp_sk(sk)->udp_port_hash != hnum ||
596 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
597 (inet->inet_dport != rmt_port && inet->inet_dport) ||
598 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
599 ipv6_only_sock(sk) ||
600 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
602 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif))
608 * This routine is called by the ICMP module when it gets some
609 * sort of error condition. If err < 0 then the socket should
610 * be closed and the error returned to the user. If err > 0
611 * it's just the icmp type << 8 | icmp code.
612 * Header points to the ip header of the error packet. We move
613 * on past this. Then (as it used to claim before adjustment)
614 * header points to the first 8 bytes of the udp header. We need
615 * to find the appropriate port.
618 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
620 struct inet_sock *inet;
621 const struct iphdr *iph = (const struct iphdr *)skb->data;
622 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
623 const int type = icmp_hdr(skb)->type;
624 const int code = icmp_hdr(skb)->code;
628 struct net *net = dev_net(skb->dev);
630 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
631 iph->saddr, uh->source, skb->dev->ifindex, udptable,
634 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
635 return; /* No socket for error */
644 case ICMP_TIME_EXCEEDED:
647 case ICMP_SOURCE_QUENCH:
649 case ICMP_PARAMETERPROB:
653 case ICMP_DEST_UNREACH:
654 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
655 ipv4_sk_update_pmtu(skb, sk, info);
656 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
664 if (code <= NR_ICMP_UNREACH) {
665 harderr = icmp_err_convert[code].fatal;
666 err = icmp_err_convert[code].errno;
670 ipv4_sk_redirect(skb, sk);
675 * RFC1122: OK. Passes ICMP errors back to application, as per
678 if (!inet->recverr) {
679 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
682 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
685 sk->sk_error_report(sk);
690 void udp_err(struct sk_buff *skb, u32 info)
692 __udp4_lib_err(skb, info, &udp_table);
696 * Throw away all pending data and cancel the corking. Socket is locked.
698 void udp_flush_pending_frames(struct sock *sk)
700 struct udp_sock *up = udp_sk(sk);
705 ip_flush_pending_frames(sk);
708 EXPORT_SYMBOL(udp_flush_pending_frames);
711 * udp4_hwcsum - handle outgoing HW checksumming
712 * @skb: sk_buff containing the filled-in UDP header
713 * (checksum field must be zeroed out)
714 * @src: source IP address
715 * @dst: destination IP address
717 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
719 struct udphdr *uh = udp_hdr(skb);
720 int offset = skb_transport_offset(skb);
721 int len = skb->len - offset;
725 if (!skb_has_frag_list(skb)) {
727 * Only one fragment on the socket.
729 skb->csum_start = skb_transport_header(skb) - skb->head;
730 skb->csum_offset = offsetof(struct udphdr, check);
731 uh->check = ~csum_tcpudp_magic(src, dst, len,
734 struct sk_buff *frags;
737 * HW-checksum won't work as there are two or more
738 * fragments on the socket so that all csums of sk_buffs
741 skb_walk_frags(skb, frags) {
742 csum = csum_add(csum, frags->csum);
746 csum = skb_checksum(skb, offset, hlen, csum);
747 skb->ip_summed = CHECKSUM_NONE;
749 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
751 uh->check = CSUM_MANGLED_0;
754 EXPORT_SYMBOL_GPL(udp4_hwcsum);
756 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
757 * for the simple case like when setting the checksum for a UDP tunnel.
759 void udp_set_csum(bool nocheck, struct sk_buff *skb,
760 __be32 saddr, __be32 daddr, int len)
762 struct udphdr *uh = udp_hdr(skb);
766 } else if (skb_is_gso(skb)) {
767 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
768 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
770 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
772 uh->check = CSUM_MANGLED_0;
774 skb->ip_summed = CHECKSUM_PARTIAL;
775 skb->csum_start = skb_transport_header(skb) - skb->head;
776 skb->csum_offset = offsetof(struct udphdr, check);
777 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
780 EXPORT_SYMBOL(udp_set_csum);
782 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
784 struct sock *sk = skb->sk;
785 struct inet_sock *inet = inet_sk(sk);
788 int is_udplite = IS_UDPLITE(sk);
789 int offset = skb_transport_offset(skb);
790 int len = skb->len - offset;
794 * Create a UDP header
797 uh->source = inet->inet_sport;
798 uh->dest = fl4->fl4_dport;
799 uh->len = htons(len);
802 if (is_udplite) /* UDP-Lite */
803 csum = udplite_csum(skb);
805 else if (sk->sk_no_check_tx) { /* UDP csum disabled */
807 skb->ip_summed = CHECKSUM_NONE;
810 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
812 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
816 csum = udp_csum(skb);
818 /* add protocol-dependent pseudo-header */
819 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
820 sk->sk_protocol, csum);
822 uh->check = CSUM_MANGLED_0;
825 err = ip_send_skb(sock_net(sk), skb);
827 if (err == -ENOBUFS && !inet->recverr) {
828 UDP_INC_STATS(sock_net(sk),
829 UDP_MIB_SNDBUFERRORS, is_udplite);
833 UDP_INC_STATS(sock_net(sk),
834 UDP_MIB_OUTDATAGRAMS, is_udplite);
839 * Push out all pending data as one UDP datagram. Socket is locked.
841 int udp_push_pending_frames(struct sock *sk)
843 struct udp_sock *up = udp_sk(sk);
844 struct inet_sock *inet = inet_sk(sk);
845 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
849 skb = ip_finish_skb(sk, fl4);
853 err = udp_send_skb(skb, fl4);
860 EXPORT_SYMBOL(udp_push_pending_frames);
862 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
864 struct inet_sock *inet = inet_sk(sk);
865 struct udp_sock *up = udp_sk(sk);
866 struct flowi4 fl4_stack;
869 struct ipcm_cookie ipc;
870 struct rtable *rt = NULL;
873 __be32 daddr, faddr, saddr;
876 int err, is_udplite = IS_UDPLITE(sk);
877 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
878 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
880 struct ip_options_data opt_copy;
889 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
897 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
899 fl4 = &inet->cork.fl.u.ip4;
902 * There are pending frames.
903 * The socket lock must be held while it's corked.
906 if (likely(up->pending)) {
907 if (unlikely(up->pending != AF_INET)) {
915 ulen += sizeof(struct udphdr);
918 * Get and verify the address.
921 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
922 if (msg->msg_namelen < sizeof(*usin))
924 if (usin->sin_family != AF_INET) {
925 if (usin->sin_family != AF_UNSPEC)
926 return -EAFNOSUPPORT;
929 daddr = usin->sin_addr.s_addr;
930 dport = usin->sin_port;
934 if (sk->sk_state != TCP_ESTABLISHED)
935 return -EDESTADDRREQ;
936 daddr = inet->inet_daddr;
937 dport = inet->inet_dport;
938 /* Open fast path for connected socket.
939 Route will not be used, if at least one option is set.
944 ipc.sockc.tsflags = sk->sk_tsflags;
945 ipc.addr = inet->inet_saddr;
946 ipc.oif = sk->sk_bound_dev_if;
948 if (msg->msg_controllen) {
949 err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6);
959 struct ip_options_rcu *inet_opt;
962 inet_opt = rcu_dereference(inet->inet_opt);
964 memcpy(&opt_copy, inet_opt,
965 sizeof(*inet_opt) + inet_opt->opt.optlen);
966 ipc.opt = &opt_copy.opt;
972 ipc.addr = faddr = daddr;
974 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
976 if (ipc.opt && ipc.opt->opt.srr) {
979 faddr = ipc.opt->opt.faddr;
982 tos = get_rttos(&ipc, inet);
983 if (sock_flag(sk, SOCK_LOCALROUTE) ||
984 (msg->msg_flags & MSG_DONTROUTE) ||
985 (ipc.opt && ipc.opt->opt.is_strictroute)) {
990 if (ipv4_is_multicast(daddr)) {
992 ipc.oif = inet->mc_index;
994 saddr = inet->mc_addr;
997 ipc.oif = inet->uc_index;
1000 rt = (struct rtable *)sk_dst_check(sk, 0);
1003 struct net *net = sock_net(sk);
1004 __u8 flow_flags = inet_sk_flowi_flags(sk);
1008 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1009 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1011 faddr, saddr, dport, inet->inet_sport,
1014 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
1015 rt = ip_route_output_flow(net, fl4, sk);
1019 if (err == -ENETUNREACH)
1020 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1025 if ((rt->rt_flags & RTCF_BROADCAST) &&
1026 !sock_flag(sk, SOCK_BROADCAST))
1029 sk_dst_set(sk, dst_clone(&rt->dst));
1032 if (msg->msg_flags&MSG_CONFIRM)
1038 daddr = ipc.addr = fl4->daddr;
1040 /* Lockless fast path for the non-corking case. */
1042 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1043 sizeof(struct udphdr), &ipc, &rt,
1046 if (!IS_ERR_OR_NULL(skb))
1047 err = udp_send_skb(skb, fl4);
1052 if (unlikely(up->pending)) {
1053 /* The socket is already corked while preparing it. */
1054 /* ... which is an evident application bug. --ANK */
1057 net_dbg_ratelimited("cork app bug 2\n");
1062 * Now cork the socket to pend data.
1064 fl4 = &inet->cork.fl.u.ip4;
1067 fl4->fl4_dport = dport;
1068 fl4->fl4_sport = inet->inet_sport;
1069 up->pending = AF_INET;
1073 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1074 sizeof(struct udphdr), &ipc, &rt,
1075 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1077 udp_flush_pending_frames(sk);
1079 err = udp_push_pending_frames(sk);
1080 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1091 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1092 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1093 * we don't have a good statistic (IpOutDiscards but it can be too many
1094 * things). We could add another new stat but at least for now that
1095 * seems like overkill.
1097 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1098 UDP_INC_STATS(sock_net(sk),
1099 UDP_MIB_SNDBUFERRORS, is_udplite);
1104 if (msg->msg_flags & MSG_PROBE)
1105 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1106 if (!(msg->msg_flags&MSG_PROBE) || len)
1107 goto back_from_confirm;
1111 EXPORT_SYMBOL(udp_sendmsg);
1113 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1114 size_t size, int flags)
1116 struct inet_sock *inet = inet_sk(sk);
1117 struct udp_sock *up = udp_sk(sk);
1120 if (flags & MSG_SENDPAGE_NOTLAST)
1124 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1126 /* Call udp_sendmsg to specify destination address which
1127 * sendpage interface can't pass.
1128 * This will succeed only when the socket is connected.
1130 ret = udp_sendmsg(sk, &msg, 0);
1137 if (unlikely(!up->pending)) {
1140 net_dbg_ratelimited("udp cork app bug 3\n");
1144 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1145 page, offset, size, flags);
1146 if (ret == -EOPNOTSUPP) {
1148 return sock_no_sendpage(sk->sk_socket, page, offset,
1152 udp_flush_pending_frames(sk);
1157 if (!(up->corkflag || (flags&MSG_MORE)))
1158 ret = udp_push_pending_frames(sk);
1166 /* Copy as much information as possible into skb->dev_scratch to avoid
1167 * possibly multiple cache miss on dequeue();
1169 #if BITS_PER_LONG == 64
1171 /* we can store multiple info here: truesize, len and the bit needed to
1172 * compute skb_csum_unnecessary will be on cold cache lines at recvmsg
1174 * skb->len can be stored on 16 bits since the udp header has been already
1175 * validated and pulled.
1177 struct udp_dev_scratch {
1181 bool csum_unnecessary;
1184 static void udp_set_dev_scratch(struct sk_buff *skb)
1186 struct udp_dev_scratch *scratch;
1188 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1189 scratch = (struct udp_dev_scratch *)&skb->dev_scratch;
1190 scratch->truesize = skb->truesize;
1191 scratch->len = skb->len;
1192 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1193 scratch->is_linear = !skb_is_nonlinear(skb);
1196 static int udp_skb_truesize(struct sk_buff *skb)
1198 return ((struct udp_dev_scratch *)&skb->dev_scratch)->truesize;
1201 static unsigned int udp_skb_len(struct sk_buff *skb)
1203 return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;
1206 static bool udp_skb_csum_unnecessary(struct sk_buff *skb)
1208 return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;
1211 static bool udp_skb_is_linear(struct sk_buff *skb)
1213 return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;
1217 static void udp_set_dev_scratch(struct sk_buff *skb)
1219 skb->dev_scratch = skb->truesize;
1222 static int udp_skb_truesize(struct sk_buff *skb)
1224 return skb->dev_scratch;
1227 static unsigned int udp_skb_len(struct sk_buff *skb)
1232 static bool udp_skb_csum_unnecessary(struct sk_buff *skb)
1234 return skb_csum_unnecessary(skb);
1237 static bool udp_skb_is_linear(struct sk_buff *skb)
1239 return !skb_is_nonlinear(skb);
1243 /* fully reclaim rmem/fwd memory allocated for skb */
1244 static void udp_rmem_release(struct sock *sk, int size, int partial,
1245 bool rx_queue_lock_held)
1247 struct udp_sock *up = udp_sk(sk);
1248 struct sk_buff_head *sk_queue;
1251 if (likely(partial)) {
1252 up->forward_deficit += size;
1253 size = up->forward_deficit;
1254 if (size < (sk->sk_rcvbuf >> 2) &&
1255 !skb_queue_empty(&up->reader_queue))
1258 size += up->forward_deficit;
1260 up->forward_deficit = 0;
1262 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1263 * if the called don't held it already
1265 sk_queue = &sk->sk_receive_queue;
1266 if (!rx_queue_lock_held)
1267 spin_lock(&sk_queue->lock);
1270 sk->sk_forward_alloc += size;
1271 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1272 sk->sk_forward_alloc -= amt;
1275 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1277 atomic_sub(size, &sk->sk_rmem_alloc);
1279 /* this can save us from acquiring the rx queue lock on next receive */
1280 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1282 if (!rx_queue_lock_held)
1283 spin_unlock(&sk_queue->lock);
1286 /* Note: called with reader_queue.lock held.
1287 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1288 * This avoids a cache line miss while receive_queue lock is held.
1289 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1291 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1293 prefetch(&skb->data);
1294 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1296 EXPORT_SYMBOL(udp_skb_destructor);
1298 /* as above, but the caller held the rx queue lock, too */
1299 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1301 prefetch(&skb->data);
1302 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1305 /* Idea of busylocks is to let producers grab an extra spinlock
1306 * to relieve pressure on the receive_queue spinlock shared by consumer.
1307 * Under flood, this means that only one producer can be in line
1308 * trying to acquire the receive_queue spinlock.
1309 * These busylock can be allocated on a per cpu manner, instead of a
1310 * per socket one (that would consume a cache line per socket)
1312 static int udp_busylocks_log __read_mostly;
1313 static spinlock_t *udp_busylocks __read_mostly;
1315 static spinlock_t *busylock_acquire(void *ptr)
1319 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1324 static void busylock_release(spinlock_t *busy)
1330 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1332 struct sk_buff_head *list = &sk->sk_receive_queue;
1333 int rmem, delta, amt, err = -ENOMEM;
1334 spinlock_t *busy = NULL;
1337 /* try to avoid the costly atomic add/sub pair when the receive
1338 * queue is full; always allow at least a packet
1340 rmem = atomic_read(&sk->sk_rmem_alloc);
1341 if (rmem > sk->sk_rcvbuf)
1344 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1345 * having linear skbs :
1346 * - Reduce memory overhead and thus increase receive queue capacity
1347 * - Less cache line misses at copyout() time
1348 * - Less work at consume_skb() (less alien page frag freeing)
1350 if (rmem > (sk->sk_rcvbuf >> 1)) {
1353 busy = busylock_acquire(sk);
1355 size = skb->truesize;
1356 udp_set_dev_scratch(skb);
1358 /* we drop only if the receive buf is full and the receive
1359 * queue contains some other skb
1361 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1362 if (rmem > (size + sk->sk_rcvbuf))
1365 spin_lock(&list->lock);
1366 if (size >= sk->sk_forward_alloc) {
1367 amt = sk_mem_pages(size);
1368 delta = amt << SK_MEM_QUANTUM_SHIFT;
1369 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1371 spin_unlock(&list->lock);
1375 sk->sk_forward_alloc += delta;
1378 sk->sk_forward_alloc -= size;
1380 /* no need to setup a destructor, we will explicitly release the
1381 * forward allocated memory on dequeue
1383 sock_skb_set_dropcount(sk, skb);
1385 __skb_queue_tail(list, skb);
1386 spin_unlock(&list->lock);
1388 if (!sock_flag(sk, SOCK_DEAD))
1389 sk->sk_data_ready(sk);
1391 busylock_release(busy);
1395 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1398 atomic_inc(&sk->sk_drops);
1399 busylock_release(busy);
1402 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1404 void udp_destruct_sock(struct sock *sk)
1406 /* reclaim completely the forward allocated memory */
1407 struct udp_sock *up = udp_sk(sk);
1408 unsigned int total = 0;
1409 struct sk_buff *skb;
1411 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1412 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1413 total += skb->truesize;
1416 udp_rmem_release(sk, total, 0, true);
1418 inet_sock_destruct(sk);
1420 EXPORT_SYMBOL_GPL(udp_destruct_sock);
1422 int udp_init_sock(struct sock *sk)
1424 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1425 sk->sk_destruct = udp_destruct_sock;
1428 EXPORT_SYMBOL_GPL(udp_init_sock);
1430 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1432 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1433 bool slow = lock_sock_fast(sk);
1435 sk_peek_offset_bwd(sk, len);
1436 unlock_sock_fast(sk, slow);
1439 consume_stateless_skb(skb);
1441 EXPORT_SYMBOL_GPL(skb_consume_udp);
1443 static struct sk_buff *__first_packet_length(struct sock *sk,
1444 struct sk_buff_head *rcvq,
1447 struct sk_buff *skb;
1449 while ((skb = skb_peek(rcvq)) != NULL &&
1450 udp_lib_checksum_complete(skb)) {
1451 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1453 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1455 atomic_inc(&sk->sk_drops);
1456 __skb_unlink(skb, rcvq);
1457 *total += skb->truesize;
1464 * first_packet_length - return length of first packet in receive queue
1467 * Drops all bad checksum frames, until a valid one is found.
1468 * Returns the length of found skb, or -1 if none is found.
1470 static int first_packet_length(struct sock *sk)
1472 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1473 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1474 struct sk_buff *skb;
1478 spin_lock_bh(&rcvq->lock);
1479 skb = __first_packet_length(sk, rcvq, &total);
1480 if (!skb && !skb_queue_empty(sk_queue)) {
1481 spin_lock(&sk_queue->lock);
1482 skb_queue_splice_tail_init(sk_queue, rcvq);
1483 spin_unlock(&sk_queue->lock);
1485 skb = __first_packet_length(sk, rcvq, &total);
1487 res = skb ? skb->len : -1;
1489 udp_rmem_release(sk, total, 1, false);
1490 spin_unlock_bh(&rcvq->lock);
1495 * IOCTL requests applicable to the UDP protocol
1498 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1503 int amount = sk_wmem_alloc_get(sk);
1505 return put_user(amount, (int __user *)arg);
1510 int amount = max_t(int, 0, first_packet_length(sk));
1512 return put_user(amount, (int __user *)arg);
1516 return -ENOIOCTLCMD;
1521 EXPORT_SYMBOL(udp_ioctl);
1523 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1524 int noblock, int *peeked, int *off, int *err)
1526 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1527 struct sk_buff_head *queue;
1528 struct sk_buff *last;
1532 queue = &udp_sk(sk)->reader_queue;
1533 flags |= noblock ? MSG_DONTWAIT : 0;
1534 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1536 struct sk_buff *skb;
1538 error = sock_error(sk);
1545 spin_lock_bh(&queue->lock);
1546 skb = __skb_try_recv_from_queue(sk, queue, flags,
1551 spin_unlock_bh(&queue->lock);
1555 if (skb_queue_empty(sk_queue)) {
1556 spin_unlock_bh(&queue->lock);
1560 /* refill the reader queue and walk it again
1561 * keep both queues locked to avoid re-acquiring
1562 * the sk_receive_queue lock if fwd memory scheduling
1565 spin_lock(&sk_queue->lock);
1566 skb_queue_splice_tail_init(sk_queue, queue);
1568 skb = __skb_try_recv_from_queue(sk, queue, flags,
1569 udp_skb_dtor_locked,
1572 spin_unlock(&sk_queue->lock);
1573 spin_unlock_bh(&queue->lock);
1578 if (!sk_can_busy_loop(sk))
1581 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1582 } while (!skb_queue_empty(sk_queue));
1584 /* sk_queue is empty, reader_queue may contain peeked packets */
1586 !__skb_wait_for_more_packets(sk, &error, &timeo,
1587 (struct sk_buff *)sk_queue));
1592 EXPORT_SYMBOL_GPL(__skb_recv_udp);
1594 static int copy_linear_skb(struct sk_buff *skb, int len, int off,
1595 struct iov_iter *to)
1597 int n, copy = len - off;
1599 n = copy_to_iter(skb->data + off, copy, to);
1607 * This should be easy, if there is something there we
1608 * return it, otherwise we block.
1611 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1612 int flags, int *addr_len)
1614 struct inet_sock *inet = inet_sk(sk);
1615 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1616 struct sk_buff *skb;
1617 unsigned int ulen, copied;
1618 int peeked, peeking, off;
1620 int is_udplite = IS_UDPLITE(sk);
1621 bool checksum_valid = false;
1623 if (flags & MSG_ERRQUEUE)
1624 return ip_recv_error(sk, msg, len, addr_len);
1627 peeking = off = sk_peek_offset(sk, flags);
1628 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
1632 ulen = udp_skb_len(skb);
1634 if (copied > ulen - off)
1635 copied = ulen - off;
1636 else if (copied < ulen)
1637 msg->msg_flags |= MSG_TRUNC;
1640 * If checksum is needed at all, try to do it while copying the
1641 * data. If the data is truncated, or if we only want a partial
1642 * coverage checksum (UDP-Lite), do it before the copy.
1645 if (copied < ulen || peeking ||
1646 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1647 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1648 !__udp_lib_checksum_complete(skb);
1649 if (!checksum_valid)
1653 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1654 if (udp_skb_is_linear(skb))
1655 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1657 err = skb_copy_datagram_msg(skb, off, msg, copied);
1659 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1665 if (unlikely(err)) {
1667 atomic_inc(&sk->sk_drops);
1668 UDP_INC_STATS(sock_net(sk),
1669 UDP_MIB_INERRORS, is_udplite);
1676 UDP_INC_STATS(sock_net(sk),
1677 UDP_MIB_INDATAGRAMS, is_udplite);
1679 sock_recv_ts_and_drops(msg, sk, skb);
1681 /* Copy the address. */
1683 sin->sin_family = AF_INET;
1684 sin->sin_port = udp_hdr(skb)->source;
1685 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1686 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1687 *addr_len = sizeof(*sin);
1689 if (inet->cmsg_flags)
1690 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1693 if (flags & MSG_TRUNC)
1696 skb_consume_udp(sk, skb, peeking ? -err : err);
1700 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1701 udp_skb_destructor)) {
1702 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1703 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1707 /* starting over for a new packet, but check if we need to yield */
1709 msg->msg_flags &= ~MSG_TRUNC;
1713 int __udp_disconnect(struct sock *sk, int flags)
1715 struct inet_sock *inet = inet_sk(sk);
1717 * 1003.1g - break association.
1720 sk->sk_state = TCP_CLOSE;
1721 inet->inet_daddr = 0;
1722 inet->inet_dport = 0;
1723 sock_rps_reset_rxhash(sk);
1724 sk->sk_bound_dev_if = 0;
1725 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1726 inet_reset_saddr(sk);
1728 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1729 sk->sk_prot->unhash(sk);
1730 inet->inet_sport = 0;
1735 EXPORT_SYMBOL(__udp_disconnect);
1737 int udp_disconnect(struct sock *sk, int flags)
1740 __udp_disconnect(sk, flags);
1744 EXPORT_SYMBOL(udp_disconnect);
1746 void udp_lib_unhash(struct sock *sk)
1748 if (sk_hashed(sk)) {
1749 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1750 struct udp_hslot *hslot, *hslot2;
1752 hslot = udp_hashslot(udptable, sock_net(sk),
1753 udp_sk(sk)->udp_port_hash);
1754 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1756 spin_lock_bh(&hslot->lock);
1757 if (rcu_access_pointer(sk->sk_reuseport_cb))
1758 reuseport_detach_sock(sk);
1759 if (sk_del_node_init_rcu(sk)) {
1761 inet_sk(sk)->inet_num = 0;
1762 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1764 spin_lock(&hslot2->lock);
1765 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1767 spin_unlock(&hslot2->lock);
1769 spin_unlock_bh(&hslot->lock);
1772 EXPORT_SYMBOL(udp_lib_unhash);
1775 * inet_rcv_saddr was changed, we must rehash secondary hash
1777 void udp_lib_rehash(struct sock *sk, u16 newhash)
1779 if (sk_hashed(sk)) {
1780 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1781 struct udp_hslot *hslot, *hslot2, *nhslot2;
1783 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1784 nhslot2 = udp_hashslot2(udptable, newhash);
1785 udp_sk(sk)->udp_portaddr_hash = newhash;
1787 if (hslot2 != nhslot2 ||
1788 rcu_access_pointer(sk->sk_reuseport_cb)) {
1789 hslot = udp_hashslot(udptable, sock_net(sk),
1790 udp_sk(sk)->udp_port_hash);
1791 /* we must lock primary chain too */
1792 spin_lock_bh(&hslot->lock);
1793 if (rcu_access_pointer(sk->sk_reuseport_cb))
1794 reuseport_detach_sock(sk);
1796 if (hslot2 != nhslot2) {
1797 spin_lock(&hslot2->lock);
1798 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1800 spin_unlock(&hslot2->lock);
1802 spin_lock(&nhslot2->lock);
1803 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1806 spin_unlock(&nhslot2->lock);
1809 spin_unlock_bh(&hslot->lock);
1813 EXPORT_SYMBOL(udp_lib_rehash);
1815 static void udp_v4_rehash(struct sock *sk)
1817 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1818 inet_sk(sk)->inet_rcv_saddr,
1819 inet_sk(sk)->inet_num);
1820 udp_lib_rehash(sk, new_hash);
1823 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1827 if (inet_sk(sk)->inet_daddr) {
1828 sock_rps_save_rxhash(sk, skb);
1829 sk_mark_napi_id(sk, skb);
1830 sk_incoming_cpu_update(sk);
1832 sk_mark_napi_id_once(sk, skb);
1835 /* clear all pending head states while they are hot in the cache */
1836 skb_release_head_state(skb);
1838 rc = __udp_enqueue_schedule_skb(sk, skb);
1840 int is_udplite = IS_UDPLITE(sk);
1842 /* Note that an ENOMEM error is charged twice */
1844 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1846 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1848 trace_udp_fail_queue_rcv_skb(rc, sk);
1855 static struct static_key udp_encap_needed __read_mostly;
1856 void udp_encap_enable(void)
1858 if (!static_key_enabled(&udp_encap_needed))
1859 static_key_slow_inc(&udp_encap_needed);
1861 EXPORT_SYMBOL(udp_encap_enable);
1866 * >0: "udp encap" protocol resubmission
1868 * Note that in the success and error cases, the skb is assumed to
1869 * have either been requeued or freed.
1871 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1873 struct udp_sock *up = udp_sk(sk);
1874 int is_udplite = IS_UDPLITE(sk);
1877 * Charge it to the socket, dropping if the queue is full.
1879 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1883 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1884 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1887 * This is an encapsulation socket so pass the skb to
1888 * the socket's udp_encap_rcv() hook. Otherwise, just
1889 * fall through and pass this up the UDP socket.
1890 * up->encap_rcv() returns the following value:
1891 * =0 if skb was successfully passed to the encap
1892 * handler or was discarded by it.
1893 * >0 if skb should be passed on to UDP.
1894 * <0 if skb should be resubmitted as proto -N
1897 /* if we're overly short, let UDP handle it */
1898 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1902 /* Verify checksum before giving to encap */
1903 if (udp_lib_checksum_complete(skb))
1906 ret = encap_rcv(sk, skb);
1908 __UDP_INC_STATS(sock_net(sk),
1909 UDP_MIB_INDATAGRAMS,
1915 /* FALLTHROUGH -- it's a UDP Packet */
1919 * UDP-Lite specific tests, ignored on UDP sockets
1921 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1924 * MIB statistics other than incrementing the error count are
1925 * disabled for the following two types of errors: these depend
1926 * on the application settings, not on the functioning of the
1927 * protocol stack as such.
1929 * RFC 3828 here recommends (sec 3.3): "There should also be a
1930 * way ... to ... at least let the receiving application block
1931 * delivery of packets with coverage values less than a value
1932 * provided by the application."
1934 if (up->pcrlen == 0) { /* full coverage was set */
1935 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
1936 UDP_SKB_CB(skb)->cscov, skb->len);
1939 /* The next case involves violating the min. coverage requested
1940 * by the receiver. This is subtle: if receiver wants x and x is
1941 * greater than the buffersize/MTU then receiver will complain
1942 * that it wants x while sender emits packets of smaller size y.
1943 * Therefore the above ...()->partial_cov statement is essential.
1945 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1946 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
1947 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1952 if (rcu_access_pointer(sk->sk_filter) &&
1953 udp_lib_checksum_complete(skb))
1956 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
1959 udp_csum_pull_header(skb);
1961 ipv4_pktinfo_prepare(sk, skb);
1962 return __udp_queue_rcv_skb(sk, skb);
1965 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1967 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1968 atomic_inc(&sk->sk_drops);
1973 /* For TCP sockets, sk_rx_dst is protected by socket lock
1974 * For UDP, we use xchg() to guard against concurrent changes.
1976 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1978 struct dst_entry *old;
1980 if (dst_hold_safe(dst)) {
1981 old = xchg(&sk->sk_rx_dst, dst);
1987 * Multicasts and broadcasts go to each listener.
1989 * Note: called only from the BH handler context.
1991 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1993 __be32 saddr, __be32 daddr,
1994 struct udp_table *udptable,
1997 struct sock *sk, *first = NULL;
1998 unsigned short hnum = ntohs(uh->dest);
1999 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2000 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2001 unsigned int offset = offsetof(typeof(*sk), sk_node);
2002 int dif = skb->dev->ifindex;
2003 struct hlist_node *node;
2004 struct sk_buff *nskb;
2007 hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2009 hash2 = udp4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2011 hslot = &udptable->hash2[hash2];
2012 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2015 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2016 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2017 uh->source, saddr, dif, hnum))
2024 nskb = skb_clone(skb, GFP_ATOMIC);
2026 if (unlikely(!nskb)) {
2027 atomic_inc(&sk->sk_drops);
2028 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2030 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2034 if (udp_queue_rcv_skb(sk, nskb) > 0)
2038 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2039 if (use_hash2 && hash2 != hash2_any) {
2045 if (udp_queue_rcv_skb(first, skb) > 0)
2049 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2050 proto == IPPROTO_UDPLITE);
2055 /* Initialize UDP checksum. If exited with zero value (success),
2056 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2057 * Otherwise, csum completion requires chacksumming packet body,
2058 * including udp header and folding it to skb->csum.
2060 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2065 UDP_SKB_CB(skb)->partial_cov = 0;
2066 UDP_SKB_CB(skb)->cscov = skb->len;
2068 if (proto == IPPROTO_UDPLITE) {
2069 err = udplite_checksum_init(skb, uh);
2074 /* Note, we are only interested in != 0 or == 0, thus the
2077 return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2078 inet_compute_pseudo);
2082 * All we need to do is get the socket, and then do a checksum.
2085 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2090 unsigned short ulen;
2091 struct rtable *rt = skb_rtable(skb);
2092 __be32 saddr, daddr;
2093 struct net *net = dev_net(skb->dev);
2096 * Validate the packet.
2098 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2099 goto drop; /* No space for header. */
2102 ulen = ntohs(uh->len);
2103 saddr = ip_hdr(skb)->saddr;
2104 daddr = ip_hdr(skb)->daddr;
2106 if (ulen > skb->len)
2109 if (proto == IPPROTO_UDP) {
2110 /* UDP validates ulen. */
2111 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2116 if (udp4_csum_init(skb, uh, proto))
2119 sk = skb_steal_sock(skb);
2121 struct dst_entry *dst = skb_dst(skb);
2124 if (unlikely(sk->sk_rx_dst != dst))
2125 udp_sk_rx_dst_set(sk, dst);
2127 ret = udp_queue_rcv_skb(sk, skb);
2129 /* a return value > 0 means to resubmit the input, but
2130 * it wants the return to be -protocol, or 0
2137 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2138 return __udp4_lib_mcast_deliver(net, skb, uh,
2139 saddr, daddr, udptable, proto);
2141 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2145 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2146 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
2147 inet_compute_pseudo);
2149 ret = udp_queue_rcv_skb(sk, skb);
2151 /* a return value > 0 means to resubmit the input, but
2152 * it wants the return to be -protocol, or 0
2159 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2163 /* No socket. Drop packet silently, if checksum is wrong */
2164 if (udp_lib_checksum_complete(skb))
2167 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2168 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2171 * Hmm. We got an UDP packet to a port to which we
2172 * don't wanna listen. Ignore it.
2178 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2179 proto == IPPROTO_UDPLITE ? "Lite" : "",
2180 &saddr, ntohs(uh->source),
2182 &daddr, ntohs(uh->dest));
2187 * RFC1122: OK. Discards the bad packet silently (as far as
2188 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2190 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2191 proto == IPPROTO_UDPLITE ? "Lite" : "",
2192 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2194 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2196 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2201 /* We can only early demux multicast if there is a single matching socket.
2202 * If more than one socket found returns NULL
2204 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2205 __be16 loc_port, __be32 loc_addr,
2206 __be16 rmt_port, __be32 rmt_addr,
2209 struct sock *sk, *result;
2210 unsigned short hnum = ntohs(loc_port);
2211 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2212 struct udp_hslot *hslot = &udp_table.hash[slot];
2214 /* Do not bother scanning a too big list */
2215 if (hslot->count > 10)
2219 sk_for_each_rcu(sk, &hslot->head) {
2220 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2221 rmt_port, rmt_addr, dif, hnum)) {
2231 /* For unicast we should only early demux connected sockets or we can
2232 * break forwarding setups. The chains here can be long so only check
2233 * if the first socket is an exact match and if not move on.
2235 static struct sock *__udp4_lib_demux_lookup(struct net *net,
2236 __be16 loc_port, __be32 loc_addr,
2237 __be16 rmt_port, __be32 rmt_addr,
2240 unsigned short hnum = ntohs(loc_port);
2241 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
2242 unsigned int slot2 = hash2 & udp_table.mask;
2243 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2244 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2245 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2248 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2249 if (INET_MATCH(sk, net, acookie, rmt_addr,
2250 loc_addr, ports, dif))
2252 /* Only check first socket in chain */
2258 void udp_v4_early_demux(struct sk_buff *skb)
2260 struct net *net = dev_net(skb->dev);
2261 const struct iphdr *iph;
2262 const struct udphdr *uh;
2263 struct sock *sk = NULL;
2264 struct dst_entry *dst;
2265 int dif = skb->dev->ifindex;
2268 /* validate the packet */
2269 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2275 if (skb->pkt_type == PACKET_BROADCAST ||
2276 skb->pkt_type == PACKET_MULTICAST) {
2277 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
2282 /* we are supposed to accept bcast packets */
2283 if (skb->pkt_type == PACKET_MULTICAST) {
2284 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2290 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2291 uh->source, iph->saddr, dif);
2292 } else if (skb->pkt_type == PACKET_HOST) {
2293 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2294 uh->source, iph->saddr, dif);
2297 if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
2301 skb->destructor = sock_efree;
2302 dst = READ_ONCE(sk->sk_rx_dst);
2305 dst = dst_check(dst, 0);
2307 /* set noref for now.
2308 * any place which wants to hold dst has to call
2311 skb_dst_set_noref(skb, dst);
2315 int udp_rcv(struct sk_buff *skb)
2317 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2320 void udp_destroy_sock(struct sock *sk)
2322 struct udp_sock *up = udp_sk(sk);
2323 bool slow = lock_sock_fast(sk);
2324 udp_flush_pending_frames(sk);
2325 unlock_sock_fast(sk, slow);
2326 if (static_key_false(&udp_encap_needed) && up->encap_type) {
2327 void (*encap_destroy)(struct sock *sk);
2328 encap_destroy = ACCESS_ONCE(up->encap_destroy);
2335 * Socket option code for UDP
2337 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2338 char __user *optval, unsigned int optlen,
2339 int (*push_pending_frames)(struct sock *))
2341 struct udp_sock *up = udp_sk(sk);
2344 int is_udplite = IS_UDPLITE(sk);
2346 if (optlen < sizeof(int))
2349 if (get_user(val, (int __user *)optval))
2352 valbool = val ? 1 : 0;
2361 push_pending_frames(sk);
2369 case UDP_ENCAP_ESPINUDP:
2370 case UDP_ENCAP_ESPINUDP_NON_IKE:
2371 up->encap_rcv = xfrm4_udp_encap_rcv;
2373 case UDP_ENCAP_L2TPINUDP:
2374 up->encap_type = val;
2383 case UDP_NO_CHECK6_TX:
2384 up->no_check6_tx = valbool;
2387 case UDP_NO_CHECK6_RX:
2388 up->no_check6_rx = valbool;
2392 * UDP-Lite's partial checksum coverage (RFC 3828).
2394 /* The sender sets actual checksum coverage length via this option.
2395 * The case coverage > packet length is handled by send module. */
2396 case UDPLITE_SEND_CSCOV:
2397 if (!is_udplite) /* Disable the option on UDP sockets */
2398 return -ENOPROTOOPT;
2399 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2401 else if (val > USHRT_MAX)
2404 up->pcflag |= UDPLITE_SEND_CC;
2407 /* The receiver specifies a minimum checksum coverage value. To make
2408 * sense, this should be set to at least 8 (as done below). If zero is
2409 * used, this again means full checksum coverage. */
2410 case UDPLITE_RECV_CSCOV:
2411 if (!is_udplite) /* Disable the option on UDP sockets */
2412 return -ENOPROTOOPT;
2413 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2415 else if (val > USHRT_MAX)
2418 up->pcflag |= UDPLITE_RECV_CC;
2428 EXPORT_SYMBOL(udp_lib_setsockopt);
2430 int udp_setsockopt(struct sock *sk, int level, int optname,
2431 char __user *optval, unsigned int optlen)
2433 if (level == SOL_UDP || level == SOL_UDPLITE)
2434 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2435 udp_push_pending_frames);
2436 return ip_setsockopt(sk, level, optname, optval, optlen);
2439 #ifdef CONFIG_COMPAT
2440 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2441 char __user *optval, unsigned int optlen)
2443 if (level == SOL_UDP || level == SOL_UDPLITE)
2444 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2445 udp_push_pending_frames);
2446 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2450 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2451 char __user *optval, int __user *optlen)
2453 struct udp_sock *up = udp_sk(sk);
2456 if (get_user(len, optlen))
2459 len = min_t(unsigned int, len, sizeof(int));
2470 val = up->encap_type;
2473 case UDP_NO_CHECK6_TX:
2474 val = up->no_check6_tx;
2477 case UDP_NO_CHECK6_RX:
2478 val = up->no_check6_rx;
2481 /* The following two cannot be changed on UDP sockets, the return is
2482 * always 0 (which corresponds to the full checksum coverage of UDP). */
2483 case UDPLITE_SEND_CSCOV:
2487 case UDPLITE_RECV_CSCOV:
2492 return -ENOPROTOOPT;
2495 if (put_user(len, optlen))
2497 if (copy_to_user(optval, &val, len))
2501 EXPORT_SYMBOL(udp_lib_getsockopt);
2503 int udp_getsockopt(struct sock *sk, int level, int optname,
2504 char __user *optval, int __user *optlen)
2506 if (level == SOL_UDP || level == SOL_UDPLITE)
2507 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2508 return ip_getsockopt(sk, level, optname, optval, optlen);
2511 #ifdef CONFIG_COMPAT
2512 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2513 char __user *optval, int __user *optlen)
2515 if (level == SOL_UDP || level == SOL_UDPLITE)
2516 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2517 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2521 * udp_poll - wait for a UDP event.
2522 * @file - file struct
2524 * @wait - poll table
2526 * This is same as datagram poll, except for the special case of
2527 * blocking sockets. If application is using a blocking fd
2528 * and a packet with checksum error is in the queue;
2529 * then it could get return from select indicating data available
2530 * but then block when reading it. Add special case code
2531 * to work around these arguably broken applications.
2533 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2535 unsigned int mask = datagram_poll(file, sock, wait);
2536 struct sock *sk = sock->sk;
2538 if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
2539 mask |= POLLIN | POLLRDNORM;
2541 sock_rps_record_flow(sk);
2543 /* Check for false positives due to checksum errors */
2544 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2545 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2546 mask &= ~(POLLIN | POLLRDNORM);
2551 EXPORT_SYMBOL(udp_poll);
2553 int udp_abort(struct sock *sk, int err)
2558 sk->sk_error_report(sk);
2559 __udp_disconnect(sk, 0);
2565 EXPORT_SYMBOL_GPL(udp_abort);
2567 struct proto udp_prot = {
2569 .owner = THIS_MODULE,
2570 .close = udp_lib_close,
2571 .connect = ip4_datagram_connect,
2572 .disconnect = udp_disconnect,
2574 .init = udp_init_sock,
2575 .destroy = udp_destroy_sock,
2576 .setsockopt = udp_setsockopt,
2577 .getsockopt = udp_getsockopt,
2578 .sendmsg = udp_sendmsg,
2579 .recvmsg = udp_recvmsg,
2580 .sendpage = udp_sendpage,
2581 .release_cb = ip4_datagram_release_cb,
2582 .hash = udp_lib_hash,
2583 .unhash = udp_lib_unhash,
2584 .rehash = udp_v4_rehash,
2585 .get_port = udp_v4_get_port,
2586 .memory_allocated = &udp_memory_allocated,
2587 .sysctl_mem = sysctl_udp_mem,
2588 .sysctl_wmem = &sysctl_udp_wmem_min,
2589 .sysctl_rmem = &sysctl_udp_rmem_min,
2590 .obj_size = sizeof(struct udp_sock),
2591 .h.udp_table = &udp_table,
2592 #ifdef CONFIG_COMPAT
2593 .compat_setsockopt = compat_udp_setsockopt,
2594 .compat_getsockopt = compat_udp_getsockopt,
2596 .diag_destroy = udp_abort,
2598 EXPORT_SYMBOL(udp_prot);
2600 /* ------------------------------------------------------------------------ */
2601 #ifdef CONFIG_PROC_FS
2603 static struct sock *udp_get_first(struct seq_file *seq, int start)
2606 struct udp_iter_state *state = seq->private;
2607 struct net *net = seq_file_net(seq);
2609 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2611 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2613 if (hlist_empty(&hslot->head))
2616 spin_lock_bh(&hslot->lock);
2617 sk_for_each(sk, &hslot->head) {
2618 if (!net_eq(sock_net(sk), net))
2620 if (sk->sk_family == state->family)
2623 spin_unlock_bh(&hslot->lock);
2630 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2632 struct udp_iter_state *state = seq->private;
2633 struct net *net = seq_file_net(seq);
2637 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2640 if (state->bucket <= state->udp_table->mask)
2641 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2642 return udp_get_first(seq, state->bucket + 1);
2647 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2649 struct sock *sk = udp_get_first(seq, 0);
2652 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2654 return pos ? NULL : sk;
2657 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2659 struct udp_iter_state *state = seq->private;
2660 state->bucket = MAX_UDP_PORTS;
2662 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2665 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2669 if (v == SEQ_START_TOKEN)
2670 sk = udp_get_idx(seq, 0);
2672 sk = udp_get_next(seq, v);
2678 static void udp_seq_stop(struct seq_file *seq, void *v)
2680 struct udp_iter_state *state = seq->private;
2682 if (state->bucket <= state->udp_table->mask)
2683 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2686 int udp_seq_open(struct inode *inode, struct file *file)
2688 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2689 struct udp_iter_state *s;
2692 err = seq_open_net(inode, file, &afinfo->seq_ops,
2693 sizeof(struct udp_iter_state));
2697 s = ((struct seq_file *)file->private_data)->private;
2698 s->family = afinfo->family;
2699 s->udp_table = afinfo->udp_table;
2702 EXPORT_SYMBOL(udp_seq_open);
2704 /* ------------------------------------------------------------------------ */
2705 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2707 struct proc_dir_entry *p;
2710 afinfo->seq_ops.start = udp_seq_start;
2711 afinfo->seq_ops.next = udp_seq_next;
2712 afinfo->seq_ops.stop = udp_seq_stop;
2714 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2715 afinfo->seq_fops, afinfo);
2720 EXPORT_SYMBOL(udp_proc_register);
2722 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2724 remove_proc_entry(afinfo->name, net->proc_net);
2726 EXPORT_SYMBOL(udp_proc_unregister);
2728 /* ------------------------------------------------------------------------ */
2729 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2732 struct inet_sock *inet = inet_sk(sp);
2733 __be32 dest = inet->inet_daddr;
2734 __be32 src = inet->inet_rcv_saddr;
2735 __u16 destp = ntohs(inet->inet_dport);
2736 __u16 srcp = ntohs(inet->inet_sport);
2738 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2739 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2740 bucket, src, srcp, dest, destp, sp->sk_state,
2741 sk_wmem_alloc_get(sp),
2742 sk_rmem_alloc_get(sp),
2744 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2746 atomic_read(&sp->sk_refcnt), sp,
2747 atomic_read(&sp->sk_drops));
2750 int udp4_seq_show(struct seq_file *seq, void *v)
2752 seq_setwidth(seq, 127);
2753 if (v == SEQ_START_TOKEN)
2754 seq_puts(seq, " sl local_address rem_address st tx_queue "
2755 "rx_queue tr tm->when retrnsmt uid timeout "
2756 "inode ref pointer drops");
2758 struct udp_iter_state *state = seq->private;
2760 udp4_format_sock(v, seq, state->bucket);
2766 static const struct file_operations udp_afinfo_seq_fops = {
2767 .owner = THIS_MODULE,
2768 .open = udp_seq_open,
2770 .llseek = seq_lseek,
2771 .release = seq_release_net
2774 /* ------------------------------------------------------------------------ */
2775 static struct udp_seq_afinfo udp4_seq_afinfo = {
2778 .udp_table = &udp_table,
2779 .seq_fops = &udp_afinfo_seq_fops,
2781 .show = udp4_seq_show,
2785 static int __net_init udp4_proc_init_net(struct net *net)
2787 return udp_proc_register(net, &udp4_seq_afinfo);
2790 static void __net_exit udp4_proc_exit_net(struct net *net)
2792 udp_proc_unregister(net, &udp4_seq_afinfo);
2795 static struct pernet_operations udp4_net_ops = {
2796 .init = udp4_proc_init_net,
2797 .exit = udp4_proc_exit_net,
2800 int __init udp4_proc_init(void)
2802 return register_pernet_subsys(&udp4_net_ops);
2805 void udp4_proc_exit(void)
2807 unregister_pernet_subsys(&udp4_net_ops);
2809 #endif /* CONFIG_PROC_FS */
2811 static __initdata unsigned long uhash_entries;
2812 static int __init set_uhash_entries(char *str)
2819 ret = kstrtoul(str, 0, &uhash_entries);
2823 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2824 uhash_entries = UDP_HTABLE_SIZE_MIN;
2827 __setup("uhash_entries=", set_uhash_entries);
2829 void __init udp_table_init(struct udp_table *table, const char *name)
2833 table->hash = alloc_large_system_hash(name,
2834 2 * sizeof(struct udp_hslot),
2836 21, /* one slot per 2 MB */
2840 UDP_HTABLE_SIZE_MIN,
2843 table->hash2 = table->hash + (table->mask + 1);
2844 for (i = 0; i <= table->mask; i++) {
2845 INIT_HLIST_HEAD(&table->hash[i].head);
2846 table->hash[i].count = 0;
2847 spin_lock_init(&table->hash[i].lock);
2849 for (i = 0; i <= table->mask; i++) {
2850 INIT_HLIST_HEAD(&table->hash2[i].head);
2851 table->hash2[i].count = 0;
2852 spin_lock_init(&table->hash2[i].lock);
2856 u32 udp_flow_hashrnd(void)
2858 static u32 hashrnd __read_mostly;
2860 net_get_random_once(&hashrnd, sizeof(hashrnd));
2864 EXPORT_SYMBOL(udp_flow_hashrnd);
2866 void __init udp_init(void)
2868 unsigned long limit;
2871 udp_table_init(&udp_table, "UDP");
2872 limit = nr_free_buffer_pages() / 8;
2873 limit = max(limit, 128UL);
2874 sysctl_udp_mem[0] = limit / 4 * 3;
2875 sysctl_udp_mem[1] = limit;
2876 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2878 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2879 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2881 /* 16 spinlocks per cpu */
2882 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
2883 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
2886 panic("UDP: failed to alloc udp_busylocks\n");
2887 for (i = 0; i < (1U << udp_busylocks_log); i++)
2888 spin_lock_init(udp_busylocks + i);