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 /* fully reclaim rmem/fwd memory allocated for skb */
1167 static void udp_rmem_release(struct sock *sk, int size, int partial,
1168 bool rx_queue_lock_held)
1170 struct udp_sock *up = udp_sk(sk);
1171 struct sk_buff_head *sk_queue;
1174 if (likely(partial)) {
1175 up->forward_deficit += size;
1176 size = up->forward_deficit;
1177 if (size < (sk->sk_rcvbuf >> 2) &&
1178 !skb_queue_empty(&up->reader_queue))
1181 size += up->forward_deficit;
1183 up->forward_deficit = 0;
1185 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1186 * if the called don't held it already
1188 sk_queue = &sk->sk_receive_queue;
1189 if (!rx_queue_lock_held)
1190 spin_lock(&sk_queue->lock);
1193 sk->sk_forward_alloc += size;
1194 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1195 sk->sk_forward_alloc -= amt;
1198 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1200 atomic_sub(size, &sk->sk_rmem_alloc);
1202 /* this can save us from acquiring the rx queue lock on next receive */
1203 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1205 if (!rx_queue_lock_held)
1206 spin_unlock(&sk_queue->lock);
1209 /* Note: called with reader_queue.lock held.
1210 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1211 * This avoids a cache line miss while receive_queue lock is held.
1212 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1214 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1216 udp_rmem_release(sk, skb->dev_scratch, 1, false);
1218 EXPORT_SYMBOL(udp_skb_destructor);
1220 /* as above, but the caller held the rx queue lock, too */
1221 void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1223 udp_rmem_release(sk, skb->dev_scratch, 1, true);
1226 /* Idea of busylocks is to let producers grab an extra spinlock
1227 * to relieve pressure on the receive_queue spinlock shared by consumer.
1228 * Under flood, this means that only one producer can be in line
1229 * trying to acquire the receive_queue spinlock.
1230 * These busylock can be allocated on a per cpu manner, instead of a
1231 * per socket one (that would consume a cache line per socket)
1233 static int udp_busylocks_log __read_mostly;
1234 static spinlock_t *udp_busylocks __read_mostly;
1236 static spinlock_t *busylock_acquire(void *ptr)
1240 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1245 static void busylock_release(spinlock_t *busy)
1251 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1253 struct sk_buff_head *list = &sk->sk_receive_queue;
1254 int rmem, delta, amt, err = -ENOMEM;
1255 spinlock_t *busy = NULL;
1258 /* try to avoid the costly atomic add/sub pair when the receive
1259 * queue is full; always allow at least a packet
1261 rmem = atomic_read(&sk->sk_rmem_alloc);
1262 if (rmem > sk->sk_rcvbuf)
1265 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1266 * having linear skbs :
1267 * - Reduce memory overhead and thus increase receive queue capacity
1268 * - Less cache line misses at copyout() time
1269 * - Less work at consume_skb() (less alien page frag freeing)
1271 if (rmem > (sk->sk_rcvbuf >> 1)) {
1274 busy = busylock_acquire(sk);
1276 size = skb->truesize;
1277 /* Copy skb->truesize into skb->dev_scratch to avoid a cache line miss
1278 * in udp_skb_destructor()
1280 skb->dev_scratch = size;
1282 /* we drop only if the receive buf is full and the receive
1283 * queue contains some other skb
1285 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1286 if (rmem > (size + sk->sk_rcvbuf))
1289 spin_lock(&list->lock);
1290 if (size >= sk->sk_forward_alloc) {
1291 amt = sk_mem_pages(size);
1292 delta = amt << SK_MEM_QUANTUM_SHIFT;
1293 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1295 spin_unlock(&list->lock);
1299 sk->sk_forward_alloc += delta;
1302 sk->sk_forward_alloc -= size;
1304 /* no need to setup a destructor, we will explicitly release the
1305 * forward allocated memory on dequeue
1307 sock_skb_set_dropcount(sk, skb);
1309 __skb_queue_tail(list, skb);
1310 spin_unlock(&list->lock);
1312 if (!sock_flag(sk, SOCK_DEAD))
1313 sk->sk_data_ready(sk);
1315 busylock_release(busy);
1319 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1322 atomic_inc(&sk->sk_drops);
1323 busylock_release(busy);
1326 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1328 void udp_destruct_sock(struct sock *sk)
1330 /* reclaim completely the forward allocated memory */
1331 struct udp_sock *up = udp_sk(sk);
1332 unsigned int total = 0;
1333 struct sk_buff *skb;
1335 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1336 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1337 total += skb->truesize;
1340 udp_rmem_release(sk, total, 0, true);
1342 inet_sock_destruct(sk);
1344 EXPORT_SYMBOL_GPL(udp_destruct_sock);
1346 int udp_init_sock(struct sock *sk)
1348 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1349 sk->sk_destruct = udp_destruct_sock;
1352 EXPORT_SYMBOL_GPL(udp_init_sock);
1354 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1356 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1357 bool slow = lock_sock_fast(sk);
1359 sk_peek_offset_bwd(sk, len);
1360 unlock_sock_fast(sk, slow);
1364 EXPORT_SYMBOL_GPL(skb_consume_udp);
1366 static struct sk_buff *__first_packet_length(struct sock *sk,
1367 struct sk_buff_head *rcvq,
1370 struct sk_buff *skb;
1372 while ((skb = skb_peek(rcvq)) != NULL &&
1373 udp_lib_checksum_complete(skb)) {
1374 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1376 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1378 atomic_inc(&sk->sk_drops);
1379 __skb_unlink(skb, rcvq);
1380 *total += skb->truesize;
1387 * first_packet_length - return length of first packet in receive queue
1390 * Drops all bad checksum frames, until a valid one is found.
1391 * Returns the length of found skb, or -1 if none is found.
1393 static int first_packet_length(struct sock *sk)
1395 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1396 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1397 struct sk_buff *skb;
1401 spin_lock_bh(&rcvq->lock);
1402 skb = __first_packet_length(sk, rcvq, &total);
1403 if (!skb && !skb_queue_empty(sk_queue)) {
1404 spin_lock(&sk_queue->lock);
1405 skb_queue_splice_tail_init(sk_queue, rcvq);
1406 spin_unlock(&sk_queue->lock);
1408 skb = __first_packet_length(sk, rcvq, &total);
1410 res = skb ? skb->len : -1;
1412 udp_rmem_release(sk, total, 1, false);
1413 spin_unlock_bh(&rcvq->lock);
1418 * IOCTL requests applicable to the UDP protocol
1421 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1426 int amount = sk_wmem_alloc_get(sk);
1428 return put_user(amount, (int __user *)arg);
1433 int amount = max_t(int, 0, first_packet_length(sk));
1435 return put_user(amount, (int __user *)arg);
1439 return -ENOIOCTLCMD;
1444 EXPORT_SYMBOL(udp_ioctl);
1446 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1447 int noblock, int *peeked, int *off, int *err)
1449 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1450 struct sk_buff_head *queue;
1451 struct sk_buff *last;
1455 queue = &udp_sk(sk)->reader_queue;
1456 flags |= noblock ? MSG_DONTWAIT : 0;
1457 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1459 struct sk_buff *skb;
1461 error = sock_error(sk);
1470 spin_lock_bh(&queue->lock);
1471 skb = __skb_try_recv_from_queue(sk, queue, flags,
1476 spin_unlock_bh(&queue->lock);
1481 if (skb_queue_empty(sk_queue)) {
1482 spin_unlock_bh(&queue->lock);
1486 /* refill the reader queue and walk it again
1487 * keep both queues locked to avoid re-acquiring
1488 * the sk_receive_queue lock if fwd memory scheduling
1492 spin_lock(&sk_queue->lock);
1493 skb_queue_splice_tail_init(sk_queue, queue);
1495 skb = __skb_try_recv_from_queue(sk, queue, flags,
1496 udp_skb_dtor_locked,
1499 spin_unlock(&sk_queue->lock);
1500 spin_unlock_bh(&queue->lock);
1507 if (!sk_can_busy_loop(sk))
1510 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1511 } while (!skb_queue_empty(sk_queue));
1513 /* sk_queue is empty, reader_queue may contain peeked packets */
1515 !__skb_wait_for_more_packets(sk, &error, &timeo,
1516 (struct sk_buff *)sk_queue));
1521 EXPORT_SYMBOL_GPL(__skb_recv_udp);
1524 * This should be easy, if there is something there we
1525 * return it, otherwise we block.
1528 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1529 int flags, int *addr_len)
1531 struct inet_sock *inet = inet_sk(sk);
1532 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1533 struct sk_buff *skb;
1534 unsigned int ulen, copied;
1535 int peeked, peeking, off;
1537 int is_udplite = IS_UDPLITE(sk);
1538 bool checksum_valid = false;
1540 if (flags & MSG_ERRQUEUE)
1541 return ip_recv_error(sk, msg, len, addr_len);
1544 peeking = off = sk_peek_offset(sk, flags);
1545 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
1551 if (copied > ulen - off)
1552 copied = ulen - off;
1553 else if (copied < ulen)
1554 msg->msg_flags |= MSG_TRUNC;
1557 * If checksum is needed at all, try to do it while copying the
1558 * data. If the data is truncated, or if we only want a partial
1559 * coverage checksum (UDP-Lite), do it before the copy.
1562 if (copied < ulen || peeking ||
1563 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1564 checksum_valid = !udp_lib_checksum_complete(skb);
1565 if (!checksum_valid)
1569 if (checksum_valid || skb_csum_unnecessary(skb))
1570 err = skb_copy_datagram_msg(skb, off, msg, copied);
1572 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1578 if (unlikely(err)) {
1580 atomic_inc(&sk->sk_drops);
1581 UDP_INC_STATS(sock_net(sk),
1582 UDP_MIB_INERRORS, is_udplite);
1589 UDP_INC_STATS(sock_net(sk),
1590 UDP_MIB_INDATAGRAMS, is_udplite);
1592 sock_recv_ts_and_drops(msg, sk, skb);
1594 /* Copy the address. */
1596 sin->sin_family = AF_INET;
1597 sin->sin_port = udp_hdr(skb)->source;
1598 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1599 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1600 *addr_len = sizeof(*sin);
1602 if (inet->cmsg_flags)
1603 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1606 if (flags & MSG_TRUNC)
1609 skb_consume_udp(sk, skb, peeking ? -err : err);
1613 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1614 udp_skb_destructor)) {
1615 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1616 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1620 /* starting over for a new packet, but check if we need to yield */
1622 msg->msg_flags &= ~MSG_TRUNC;
1626 int __udp_disconnect(struct sock *sk, int flags)
1628 struct inet_sock *inet = inet_sk(sk);
1630 * 1003.1g - break association.
1633 sk->sk_state = TCP_CLOSE;
1634 inet->inet_daddr = 0;
1635 inet->inet_dport = 0;
1636 sock_rps_reset_rxhash(sk);
1637 sk->sk_bound_dev_if = 0;
1638 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1639 inet_reset_saddr(sk);
1641 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1642 sk->sk_prot->unhash(sk);
1643 inet->inet_sport = 0;
1648 EXPORT_SYMBOL(__udp_disconnect);
1650 int udp_disconnect(struct sock *sk, int flags)
1653 __udp_disconnect(sk, flags);
1657 EXPORT_SYMBOL(udp_disconnect);
1659 void udp_lib_unhash(struct sock *sk)
1661 if (sk_hashed(sk)) {
1662 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1663 struct udp_hslot *hslot, *hslot2;
1665 hslot = udp_hashslot(udptable, sock_net(sk),
1666 udp_sk(sk)->udp_port_hash);
1667 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1669 spin_lock_bh(&hslot->lock);
1670 if (rcu_access_pointer(sk->sk_reuseport_cb))
1671 reuseport_detach_sock(sk);
1672 if (sk_del_node_init_rcu(sk)) {
1674 inet_sk(sk)->inet_num = 0;
1675 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1677 spin_lock(&hslot2->lock);
1678 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1680 spin_unlock(&hslot2->lock);
1682 spin_unlock_bh(&hslot->lock);
1685 EXPORT_SYMBOL(udp_lib_unhash);
1688 * inet_rcv_saddr was changed, we must rehash secondary hash
1690 void udp_lib_rehash(struct sock *sk, u16 newhash)
1692 if (sk_hashed(sk)) {
1693 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1694 struct udp_hslot *hslot, *hslot2, *nhslot2;
1696 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1697 nhslot2 = udp_hashslot2(udptable, newhash);
1698 udp_sk(sk)->udp_portaddr_hash = newhash;
1700 if (hslot2 != nhslot2 ||
1701 rcu_access_pointer(sk->sk_reuseport_cb)) {
1702 hslot = udp_hashslot(udptable, sock_net(sk),
1703 udp_sk(sk)->udp_port_hash);
1704 /* we must lock primary chain too */
1705 spin_lock_bh(&hslot->lock);
1706 if (rcu_access_pointer(sk->sk_reuseport_cb))
1707 reuseport_detach_sock(sk);
1709 if (hslot2 != nhslot2) {
1710 spin_lock(&hslot2->lock);
1711 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1713 spin_unlock(&hslot2->lock);
1715 spin_lock(&nhslot2->lock);
1716 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1719 spin_unlock(&nhslot2->lock);
1722 spin_unlock_bh(&hslot->lock);
1726 EXPORT_SYMBOL(udp_lib_rehash);
1728 static void udp_v4_rehash(struct sock *sk)
1730 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1731 inet_sk(sk)->inet_rcv_saddr,
1732 inet_sk(sk)->inet_num);
1733 udp_lib_rehash(sk, new_hash);
1736 int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1740 if (inet_sk(sk)->inet_daddr) {
1741 sock_rps_save_rxhash(sk, skb);
1742 sk_mark_napi_id(sk, skb);
1743 sk_incoming_cpu_update(sk);
1745 sk_mark_napi_id_once(sk, skb);
1748 rc = __udp_enqueue_schedule_skb(sk, skb);
1750 int is_udplite = IS_UDPLITE(sk);
1752 /* Note that an ENOMEM error is charged twice */
1754 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1756 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1758 trace_udp_fail_queue_rcv_skb(rc, sk);
1765 static struct static_key udp_encap_needed __read_mostly;
1766 void udp_encap_enable(void)
1768 if (!static_key_enabled(&udp_encap_needed))
1769 static_key_slow_inc(&udp_encap_needed);
1771 EXPORT_SYMBOL(udp_encap_enable);
1776 * >0: "udp encap" protocol resubmission
1778 * Note that in the success and error cases, the skb is assumed to
1779 * have either been requeued or freed.
1781 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1783 struct udp_sock *up = udp_sk(sk);
1784 int is_udplite = IS_UDPLITE(sk);
1787 * Charge it to the socket, dropping if the queue is full.
1789 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1793 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1794 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1797 * This is an encapsulation socket so pass the skb to
1798 * the socket's udp_encap_rcv() hook. Otherwise, just
1799 * fall through and pass this up the UDP socket.
1800 * up->encap_rcv() returns the following value:
1801 * =0 if skb was successfully passed to the encap
1802 * handler or was discarded by it.
1803 * >0 if skb should be passed on to UDP.
1804 * <0 if skb should be resubmitted as proto -N
1807 /* if we're overly short, let UDP handle it */
1808 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1812 /* Verify checksum before giving to encap */
1813 if (udp_lib_checksum_complete(skb))
1816 ret = encap_rcv(sk, skb);
1818 __UDP_INC_STATS(sock_net(sk),
1819 UDP_MIB_INDATAGRAMS,
1825 /* FALLTHROUGH -- it's a UDP Packet */
1829 * UDP-Lite specific tests, ignored on UDP sockets
1831 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1834 * MIB statistics other than incrementing the error count are
1835 * disabled for the following two types of errors: these depend
1836 * on the application settings, not on the functioning of the
1837 * protocol stack as such.
1839 * RFC 3828 here recommends (sec 3.3): "There should also be a
1840 * way ... to ... at least let the receiving application block
1841 * delivery of packets with coverage values less than a value
1842 * provided by the application."
1844 if (up->pcrlen == 0) { /* full coverage was set */
1845 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
1846 UDP_SKB_CB(skb)->cscov, skb->len);
1849 /* The next case involves violating the min. coverage requested
1850 * by the receiver. This is subtle: if receiver wants x and x is
1851 * greater than the buffersize/MTU then receiver will complain
1852 * that it wants x while sender emits packets of smaller size y.
1853 * Therefore the above ...()->partial_cov statement is essential.
1855 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1856 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
1857 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1862 if (rcu_access_pointer(sk->sk_filter) &&
1863 udp_lib_checksum_complete(skb))
1866 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
1869 udp_csum_pull_header(skb);
1871 ipv4_pktinfo_prepare(sk, skb);
1872 return __udp_queue_rcv_skb(sk, skb);
1875 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1877 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1878 atomic_inc(&sk->sk_drops);
1883 /* For TCP sockets, sk_rx_dst is protected by socket lock
1884 * For UDP, we use xchg() to guard against concurrent changes.
1886 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1888 struct dst_entry *old;
1891 old = xchg(&sk->sk_rx_dst, dst);
1896 * Multicasts and broadcasts go to each listener.
1898 * Note: called only from the BH handler context.
1900 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1902 __be32 saddr, __be32 daddr,
1903 struct udp_table *udptable,
1906 struct sock *sk, *first = NULL;
1907 unsigned short hnum = ntohs(uh->dest);
1908 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
1909 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
1910 unsigned int offset = offsetof(typeof(*sk), sk_node);
1911 int dif = skb->dev->ifindex;
1912 struct hlist_node *node;
1913 struct sk_buff *nskb;
1916 hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
1918 hash2 = udp4_portaddr_hash(net, daddr, hnum) & udptable->mask;
1920 hslot = &udptable->hash2[hash2];
1921 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
1924 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
1925 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
1926 uh->source, saddr, dif, hnum))
1933 nskb = skb_clone(skb, GFP_ATOMIC);
1935 if (unlikely(!nskb)) {
1936 atomic_inc(&sk->sk_drops);
1937 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
1939 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
1943 if (udp_queue_rcv_skb(sk, nskb) > 0)
1947 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
1948 if (use_hash2 && hash2 != hash2_any) {
1954 if (udp_queue_rcv_skb(first, skb) > 0)
1958 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
1959 proto == IPPROTO_UDPLITE);
1964 /* Initialize UDP checksum. If exited with zero value (success),
1965 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1966 * Otherwise, csum completion requires chacksumming packet body,
1967 * including udp header and folding it to skb->csum.
1969 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1974 UDP_SKB_CB(skb)->partial_cov = 0;
1975 UDP_SKB_CB(skb)->cscov = skb->len;
1977 if (proto == IPPROTO_UDPLITE) {
1978 err = udplite_checksum_init(skb, uh);
1983 /* Note, we are only interested in != 0 or == 0, thus the
1986 return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
1987 inet_compute_pseudo);
1991 * All we need to do is get the socket, and then do a checksum.
1994 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1999 unsigned short ulen;
2000 struct rtable *rt = skb_rtable(skb);
2001 __be32 saddr, daddr;
2002 struct net *net = dev_net(skb->dev);
2005 * Validate the packet.
2007 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2008 goto drop; /* No space for header. */
2011 ulen = ntohs(uh->len);
2012 saddr = ip_hdr(skb)->saddr;
2013 daddr = ip_hdr(skb)->daddr;
2015 if (ulen > skb->len)
2018 if (proto == IPPROTO_UDP) {
2019 /* UDP validates ulen. */
2020 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2025 if (udp4_csum_init(skb, uh, proto))
2028 sk = skb_steal_sock(skb);
2030 struct dst_entry *dst = skb_dst(skb);
2033 if (unlikely(sk->sk_rx_dst != dst))
2034 udp_sk_rx_dst_set(sk, dst);
2036 ret = udp_queue_rcv_skb(sk, skb);
2038 /* a return value > 0 means to resubmit the input, but
2039 * it wants the return to be -protocol, or 0
2046 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2047 return __udp4_lib_mcast_deliver(net, skb, uh,
2048 saddr, daddr, udptable, proto);
2050 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2054 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2055 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
2056 inet_compute_pseudo);
2058 ret = udp_queue_rcv_skb(sk, skb);
2060 /* a return value > 0 means to resubmit the input, but
2061 * it wants the return to be -protocol, or 0
2068 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2072 /* No socket. Drop packet silently, if checksum is wrong */
2073 if (udp_lib_checksum_complete(skb))
2076 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2077 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2080 * Hmm. We got an UDP packet to a port to which we
2081 * don't wanna listen. Ignore it.
2087 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2088 proto == IPPROTO_UDPLITE ? "Lite" : "",
2089 &saddr, ntohs(uh->source),
2091 &daddr, ntohs(uh->dest));
2096 * RFC1122: OK. Discards the bad packet silently (as far as
2097 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2099 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2100 proto == IPPROTO_UDPLITE ? "Lite" : "",
2101 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2103 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2105 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2110 /* We can only early demux multicast if there is a single matching socket.
2111 * If more than one socket found returns NULL
2113 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2114 __be16 loc_port, __be32 loc_addr,
2115 __be16 rmt_port, __be32 rmt_addr,
2118 struct sock *sk, *result;
2119 unsigned short hnum = ntohs(loc_port);
2120 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2121 struct udp_hslot *hslot = &udp_table.hash[slot];
2123 /* Do not bother scanning a too big list */
2124 if (hslot->count > 10)
2128 sk_for_each_rcu(sk, &hslot->head) {
2129 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2130 rmt_port, rmt_addr, dif, hnum)) {
2140 /* For unicast we should only early demux connected sockets or we can
2141 * break forwarding setups. The chains here can be long so only check
2142 * if the first socket is an exact match and if not move on.
2144 static struct sock *__udp4_lib_demux_lookup(struct net *net,
2145 __be16 loc_port, __be32 loc_addr,
2146 __be16 rmt_port, __be32 rmt_addr,
2149 unsigned short hnum = ntohs(loc_port);
2150 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
2151 unsigned int slot2 = hash2 & udp_table.mask;
2152 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2153 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2154 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2157 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2158 if (INET_MATCH(sk, net, acookie, rmt_addr,
2159 loc_addr, ports, dif))
2161 /* Only check first socket in chain */
2167 void udp_v4_early_demux(struct sk_buff *skb)
2169 struct net *net = dev_net(skb->dev);
2170 const struct iphdr *iph;
2171 const struct udphdr *uh;
2172 struct sock *sk = NULL;
2173 struct dst_entry *dst;
2174 int dif = skb->dev->ifindex;
2177 /* validate the packet */
2178 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2184 if (skb->pkt_type == PACKET_BROADCAST ||
2185 skb->pkt_type == PACKET_MULTICAST) {
2186 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
2191 /* we are supposed to accept bcast packets */
2192 if (skb->pkt_type == PACKET_MULTICAST) {
2193 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2199 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2200 uh->source, iph->saddr, dif);
2201 } else if (skb->pkt_type == PACKET_HOST) {
2202 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2203 uh->source, iph->saddr, dif);
2206 if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
2210 skb->destructor = sock_efree;
2211 dst = READ_ONCE(sk->sk_rx_dst);
2214 dst = dst_check(dst, 0);
2216 /* DST_NOCACHE can not be used without taking a reference */
2217 if (dst->flags & DST_NOCACHE) {
2218 if (likely(atomic_inc_not_zero(&dst->__refcnt)))
2219 skb_dst_set(skb, dst);
2221 skb_dst_set_noref(skb, dst);
2226 int udp_rcv(struct sk_buff *skb)
2228 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2231 void udp_destroy_sock(struct sock *sk)
2233 struct udp_sock *up = udp_sk(sk);
2234 bool slow = lock_sock_fast(sk);
2235 udp_flush_pending_frames(sk);
2236 unlock_sock_fast(sk, slow);
2237 if (static_key_false(&udp_encap_needed) && up->encap_type) {
2238 void (*encap_destroy)(struct sock *sk);
2239 encap_destroy = ACCESS_ONCE(up->encap_destroy);
2246 * Socket option code for UDP
2248 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2249 char __user *optval, unsigned int optlen,
2250 int (*push_pending_frames)(struct sock *))
2252 struct udp_sock *up = udp_sk(sk);
2255 int is_udplite = IS_UDPLITE(sk);
2257 if (optlen < sizeof(int))
2260 if (get_user(val, (int __user *)optval))
2263 valbool = val ? 1 : 0;
2272 push_pending_frames(sk);
2280 case UDP_ENCAP_ESPINUDP:
2281 case UDP_ENCAP_ESPINUDP_NON_IKE:
2282 up->encap_rcv = xfrm4_udp_encap_rcv;
2284 case UDP_ENCAP_L2TPINUDP:
2285 up->encap_type = val;
2294 case UDP_NO_CHECK6_TX:
2295 up->no_check6_tx = valbool;
2298 case UDP_NO_CHECK6_RX:
2299 up->no_check6_rx = valbool;
2303 * UDP-Lite's partial checksum coverage (RFC 3828).
2305 /* The sender sets actual checksum coverage length via this option.
2306 * The case coverage > packet length is handled by send module. */
2307 case UDPLITE_SEND_CSCOV:
2308 if (!is_udplite) /* Disable the option on UDP sockets */
2309 return -ENOPROTOOPT;
2310 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2312 else if (val > USHRT_MAX)
2315 up->pcflag |= UDPLITE_SEND_CC;
2318 /* The receiver specifies a minimum checksum coverage value. To make
2319 * sense, this should be set to at least 8 (as done below). If zero is
2320 * used, this again means full checksum coverage. */
2321 case UDPLITE_RECV_CSCOV:
2322 if (!is_udplite) /* Disable the option on UDP sockets */
2323 return -ENOPROTOOPT;
2324 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2326 else if (val > USHRT_MAX)
2329 up->pcflag |= UDPLITE_RECV_CC;
2339 EXPORT_SYMBOL(udp_lib_setsockopt);
2341 int udp_setsockopt(struct sock *sk, int level, int optname,
2342 char __user *optval, unsigned int optlen)
2344 if (level == SOL_UDP || level == SOL_UDPLITE)
2345 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2346 udp_push_pending_frames);
2347 return ip_setsockopt(sk, level, optname, optval, optlen);
2350 #ifdef CONFIG_COMPAT
2351 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2352 char __user *optval, unsigned int optlen)
2354 if (level == SOL_UDP || level == SOL_UDPLITE)
2355 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2356 udp_push_pending_frames);
2357 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2361 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2362 char __user *optval, int __user *optlen)
2364 struct udp_sock *up = udp_sk(sk);
2367 if (get_user(len, optlen))
2370 len = min_t(unsigned int, len, sizeof(int));
2381 val = up->encap_type;
2384 case UDP_NO_CHECK6_TX:
2385 val = up->no_check6_tx;
2388 case UDP_NO_CHECK6_RX:
2389 val = up->no_check6_rx;
2392 /* The following two cannot be changed on UDP sockets, the return is
2393 * always 0 (which corresponds to the full checksum coverage of UDP). */
2394 case UDPLITE_SEND_CSCOV:
2398 case UDPLITE_RECV_CSCOV:
2403 return -ENOPROTOOPT;
2406 if (put_user(len, optlen))
2408 if (copy_to_user(optval, &val, len))
2412 EXPORT_SYMBOL(udp_lib_getsockopt);
2414 int udp_getsockopt(struct sock *sk, int level, int optname,
2415 char __user *optval, int __user *optlen)
2417 if (level == SOL_UDP || level == SOL_UDPLITE)
2418 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2419 return ip_getsockopt(sk, level, optname, optval, optlen);
2422 #ifdef CONFIG_COMPAT
2423 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2424 char __user *optval, int __user *optlen)
2426 if (level == SOL_UDP || level == SOL_UDPLITE)
2427 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2428 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2432 * udp_poll - wait for a UDP event.
2433 * @file - file struct
2435 * @wait - poll table
2437 * This is same as datagram poll, except for the special case of
2438 * blocking sockets. If application is using a blocking fd
2439 * and a packet with checksum error is in the queue;
2440 * then it could get return from select indicating data available
2441 * but then block when reading it. Add special case code
2442 * to work around these arguably broken applications.
2444 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2446 unsigned int mask = datagram_poll(file, sock, wait);
2447 struct sock *sk = sock->sk;
2449 if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
2450 mask |= POLLIN | POLLRDNORM;
2452 sock_rps_record_flow(sk);
2454 /* Check for false positives due to checksum errors */
2455 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2456 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2457 mask &= ~(POLLIN | POLLRDNORM);
2462 EXPORT_SYMBOL(udp_poll);
2464 int udp_abort(struct sock *sk, int err)
2469 sk->sk_error_report(sk);
2470 __udp_disconnect(sk, 0);
2476 EXPORT_SYMBOL_GPL(udp_abort);
2478 struct proto udp_prot = {
2480 .owner = THIS_MODULE,
2481 .close = udp_lib_close,
2482 .connect = ip4_datagram_connect,
2483 .disconnect = udp_disconnect,
2485 .init = udp_init_sock,
2486 .destroy = udp_destroy_sock,
2487 .setsockopt = udp_setsockopt,
2488 .getsockopt = udp_getsockopt,
2489 .sendmsg = udp_sendmsg,
2490 .recvmsg = udp_recvmsg,
2491 .sendpage = udp_sendpage,
2492 .release_cb = ip4_datagram_release_cb,
2493 .hash = udp_lib_hash,
2494 .unhash = udp_lib_unhash,
2495 .rehash = udp_v4_rehash,
2496 .get_port = udp_v4_get_port,
2497 .memory_allocated = &udp_memory_allocated,
2498 .sysctl_mem = sysctl_udp_mem,
2499 .sysctl_wmem = &sysctl_udp_wmem_min,
2500 .sysctl_rmem = &sysctl_udp_rmem_min,
2501 .obj_size = sizeof(struct udp_sock),
2502 .h.udp_table = &udp_table,
2503 #ifdef CONFIG_COMPAT
2504 .compat_setsockopt = compat_udp_setsockopt,
2505 .compat_getsockopt = compat_udp_getsockopt,
2507 .diag_destroy = udp_abort,
2509 EXPORT_SYMBOL(udp_prot);
2511 /* ------------------------------------------------------------------------ */
2512 #ifdef CONFIG_PROC_FS
2514 static struct sock *udp_get_first(struct seq_file *seq, int start)
2517 struct udp_iter_state *state = seq->private;
2518 struct net *net = seq_file_net(seq);
2520 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2522 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2524 if (hlist_empty(&hslot->head))
2527 spin_lock_bh(&hslot->lock);
2528 sk_for_each(sk, &hslot->head) {
2529 if (!net_eq(sock_net(sk), net))
2531 if (sk->sk_family == state->family)
2534 spin_unlock_bh(&hslot->lock);
2541 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2543 struct udp_iter_state *state = seq->private;
2544 struct net *net = seq_file_net(seq);
2548 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2551 if (state->bucket <= state->udp_table->mask)
2552 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2553 return udp_get_first(seq, state->bucket + 1);
2558 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2560 struct sock *sk = udp_get_first(seq, 0);
2563 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2565 return pos ? NULL : sk;
2568 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2570 struct udp_iter_state *state = seq->private;
2571 state->bucket = MAX_UDP_PORTS;
2573 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2576 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2580 if (v == SEQ_START_TOKEN)
2581 sk = udp_get_idx(seq, 0);
2583 sk = udp_get_next(seq, v);
2589 static void udp_seq_stop(struct seq_file *seq, void *v)
2591 struct udp_iter_state *state = seq->private;
2593 if (state->bucket <= state->udp_table->mask)
2594 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2597 int udp_seq_open(struct inode *inode, struct file *file)
2599 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2600 struct udp_iter_state *s;
2603 err = seq_open_net(inode, file, &afinfo->seq_ops,
2604 sizeof(struct udp_iter_state));
2608 s = ((struct seq_file *)file->private_data)->private;
2609 s->family = afinfo->family;
2610 s->udp_table = afinfo->udp_table;
2613 EXPORT_SYMBOL(udp_seq_open);
2615 /* ------------------------------------------------------------------------ */
2616 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2618 struct proc_dir_entry *p;
2621 afinfo->seq_ops.start = udp_seq_start;
2622 afinfo->seq_ops.next = udp_seq_next;
2623 afinfo->seq_ops.stop = udp_seq_stop;
2625 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2626 afinfo->seq_fops, afinfo);
2631 EXPORT_SYMBOL(udp_proc_register);
2633 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2635 remove_proc_entry(afinfo->name, net->proc_net);
2637 EXPORT_SYMBOL(udp_proc_unregister);
2639 /* ------------------------------------------------------------------------ */
2640 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2643 struct inet_sock *inet = inet_sk(sp);
2644 __be32 dest = inet->inet_daddr;
2645 __be32 src = inet->inet_rcv_saddr;
2646 __u16 destp = ntohs(inet->inet_dport);
2647 __u16 srcp = ntohs(inet->inet_sport);
2649 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2650 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2651 bucket, src, srcp, dest, destp, sp->sk_state,
2652 sk_wmem_alloc_get(sp),
2653 sk_rmem_alloc_get(sp),
2655 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2657 atomic_read(&sp->sk_refcnt), sp,
2658 atomic_read(&sp->sk_drops));
2661 int udp4_seq_show(struct seq_file *seq, void *v)
2663 seq_setwidth(seq, 127);
2664 if (v == SEQ_START_TOKEN)
2665 seq_puts(seq, " sl local_address rem_address st tx_queue "
2666 "rx_queue tr tm->when retrnsmt uid timeout "
2667 "inode ref pointer drops");
2669 struct udp_iter_state *state = seq->private;
2671 udp4_format_sock(v, seq, state->bucket);
2677 static const struct file_operations udp_afinfo_seq_fops = {
2678 .owner = THIS_MODULE,
2679 .open = udp_seq_open,
2681 .llseek = seq_lseek,
2682 .release = seq_release_net
2685 /* ------------------------------------------------------------------------ */
2686 static struct udp_seq_afinfo udp4_seq_afinfo = {
2689 .udp_table = &udp_table,
2690 .seq_fops = &udp_afinfo_seq_fops,
2692 .show = udp4_seq_show,
2696 static int __net_init udp4_proc_init_net(struct net *net)
2698 return udp_proc_register(net, &udp4_seq_afinfo);
2701 static void __net_exit udp4_proc_exit_net(struct net *net)
2703 udp_proc_unregister(net, &udp4_seq_afinfo);
2706 static struct pernet_operations udp4_net_ops = {
2707 .init = udp4_proc_init_net,
2708 .exit = udp4_proc_exit_net,
2711 int __init udp4_proc_init(void)
2713 return register_pernet_subsys(&udp4_net_ops);
2716 void udp4_proc_exit(void)
2718 unregister_pernet_subsys(&udp4_net_ops);
2720 #endif /* CONFIG_PROC_FS */
2722 static __initdata unsigned long uhash_entries;
2723 static int __init set_uhash_entries(char *str)
2730 ret = kstrtoul(str, 0, &uhash_entries);
2734 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2735 uhash_entries = UDP_HTABLE_SIZE_MIN;
2738 __setup("uhash_entries=", set_uhash_entries);
2740 void __init udp_table_init(struct udp_table *table, const char *name)
2744 table->hash = alloc_large_system_hash(name,
2745 2 * sizeof(struct udp_hslot),
2747 21, /* one slot per 2 MB */
2751 UDP_HTABLE_SIZE_MIN,
2754 table->hash2 = table->hash + (table->mask + 1);
2755 for (i = 0; i <= table->mask; i++) {
2756 INIT_HLIST_HEAD(&table->hash[i].head);
2757 table->hash[i].count = 0;
2758 spin_lock_init(&table->hash[i].lock);
2760 for (i = 0; i <= table->mask; i++) {
2761 INIT_HLIST_HEAD(&table->hash2[i].head);
2762 table->hash2[i].count = 0;
2763 spin_lock_init(&table->hash2[i].lock);
2767 u32 udp_flow_hashrnd(void)
2769 static u32 hashrnd __read_mostly;
2771 net_get_random_once(&hashrnd, sizeof(hashrnd));
2775 EXPORT_SYMBOL(udp_flow_hashrnd);
2777 void __init udp_init(void)
2779 unsigned long limit;
2782 udp_table_init(&udp_table, "UDP");
2783 limit = nr_free_buffer_pages() / 8;
2784 limit = max(limit, 128UL);
2785 sysctl_udp_mem[0] = limit / 4 * 3;
2786 sysctl_udp_mem[1] = limit;
2787 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2789 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2790 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2792 /* 16 spinlocks per cpu */
2793 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
2794 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
2797 panic("UDP: failed to alloc udp_busylocks\n");
2798 for (i = 0; i < (1U << udp_busylocks_log); i++)
2799 spin_lock_init(udp_busylocks + i);