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 return reuseport_alloc(sk);
238 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
240 * @sk: socket struct in question
241 * @snum: port number to look up
242 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
245 int udp_lib_get_port(struct sock *sk, unsigned short snum,
246 unsigned int hash2_nulladdr)
248 struct udp_hslot *hslot, *hslot2;
249 struct udp_table *udptable = sk->sk_prot->h.udp_table;
251 struct net *net = sock_net(sk);
254 int low, high, remaining;
256 unsigned short first, last;
257 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
259 inet_get_local_port_range(net, &low, &high);
260 remaining = (high - low) + 1;
262 rand = prandom_u32();
263 first = reciprocal_scale(rand, remaining) + low;
265 * force rand to be an odd multiple of UDP_HTABLE_SIZE
267 rand = (rand | 1) * (udptable->mask + 1);
268 last = first + udptable->mask + 1;
270 hslot = udp_hashslot(udptable, net, first);
271 bitmap_zero(bitmap, PORTS_PER_CHAIN);
272 spin_lock_bh(&hslot->lock);
273 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
278 * Iterate on all possible values of snum for this hash.
279 * Using steps of an odd multiple of UDP_HTABLE_SIZE
280 * give us randomization and full range coverage.
283 if (low <= snum && snum <= high &&
284 !test_bit(snum >> udptable->log, bitmap) &&
285 !inet_is_local_reserved_port(net, snum))
288 } while (snum != first);
289 spin_unlock_bh(&hslot->lock);
291 } while (++first != last);
294 hslot = udp_hashslot(udptable, net, snum);
295 spin_lock_bh(&hslot->lock);
296 if (hslot->count > 10) {
298 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
300 slot2 &= udptable->mask;
301 hash2_nulladdr &= udptable->mask;
303 hslot2 = udp_hashslot2(udptable, slot2);
304 if (hslot->count < hslot2->count)
305 goto scan_primary_hash;
307 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
308 if (!exist && (hash2_nulladdr != slot2)) {
309 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
310 exist = udp_lib_lport_inuse2(net, snum, hslot2,
319 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
323 inet_sk(sk)->inet_num = snum;
324 udp_sk(sk)->udp_port_hash = snum;
325 udp_sk(sk)->udp_portaddr_hash ^= snum;
326 if (sk_unhashed(sk)) {
327 if (sk->sk_reuseport &&
328 udp_reuseport_add_sock(sk, hslot)) {
329 inet_sk(sk)->inet_num = 0;
330 udp_sk(sk)->udp_port_hash = 0;
331 udp_sk(sk)->udp_portaddr_hash ^= snum;
335 sk_add_node_rcu(sk, &hslot->head);
337 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
339 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
340 spin_lock(&hslot2->lock);
341 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
342 sk->sk_family == AF_INET6)
343 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
346 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
349 spin_unlock(&hslot2->lock);
351 sock_set_flag(sk, SOCK_RCU_FREE);
354 spin_unlock_bh(&hslot->lock);
358 EXPORT_SYMBOL(udp_lib_get_port);
360 static u32 udp4_portaddr_hash(const struct net *net, __be32 saddr,
363 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
366 int udp_v4_get_port(struct sock *sk, unsigned short snum)
368 unsigned int hash2_nulladdr =
369 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
370 unsigned int hash2_partial =
371 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
373 /* precompute partial secondary hash */
374 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
375 return udp_lib_get_port(sk, snum, hash2_nulladdr);
378 static int compute_score(struct sock *sk, struct net *net,
379 __be32 saddr, __be16 sport,
380 __be32 daddr, unsigned short hnum,
381 int dif, int sdif, bool exact_dif)
384 struct inet_sock *inet;
386 if (!net_eq(sock_net(sk), net) ||
387 udp_sk(sk)->udp_port_hash != hnum ||
391 score = (sk->sk_family == PF_INET) ? 2 : 1;
394 if (inet->inet_rcv_saddr) {
395 if (inet->inet_rcv_saddr != daddr)
400 if (inet->inet_daddr) {
401 if (inet->inet_daddr != saddr)
406 if (inet->inet_dport) {
407 if (inet->inet_dport != sport)
412 if (sk->sk_bound_dev_if || exact_dif) {
413 bool dev_match = (sk->sk_bound_dev_if == dif ||
414 sk->sk_bound_dev_if == sdif);
418 if (sk->sk_bound_dev_if)
422 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
427 static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
428 const __u16 lport, const __be32 faddr,
431 static u32 udp_ehash_secret __read_mostly;
433 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
435 return __inet_ehashfn(laddr, lport, faddr, fport,
436 udp_ehash_secret + net_hash_mix(net));
439 /* called with rcu_read_lock() */
440 static struct sock *udp4_lib_lookup2(struct net *net,
441 __be32 saddr, __be16 sport,
442 __be32 daddr, unsigned int hnum,
443 int dif, int sdif, bool exact_dif,
444 struct udp_hslot *hslot2,
447 struct sock *sk, *result;
448 int score, badness, matches = 0, reuseport = 0;
453 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
454 score = compute_score(sk, net, saddr, sport,
455 daddr, hnum, dif, sdif, exact_dif);
456 if (score > badness) {
457 reuseport = sk->sk_reuseport;
459 hash = udp_ehashfn(net, daddr, hnum,
461 result = reuseport_select_sock(sk, hash, skb,
462 sizeof(struct udphdr));
469 } else if (score == badness && reuseport) {
471 if (reciprocal_scale(hash, matches) == 0)
473 hash = next_pseudo_random32(hash);
479 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
480 * harder than this. -DaveM
482 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
483 __be16 sport, __be32 daddr, __be16 dport, int dif,
484 int sdif, struct udp_table *udptable, struct sk_buff *skb)
486 struct sock *sk, *result;
487 unsigned short hnum = ntohs(dport);
488 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
489 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
490 bool exact_dif = udp_lib_exact_dif_match(net, skb);
491 int score, badness, matches = 0, reuseport = 0;
494 if (hslot->count > 10) {
495 hash2 = udp4_portaddr_hash(net, daddr, hnum);
496 slot2 = hash2 & udptable->mask;
497 hslot2 = &udptable->hash2[slot2];
498 if (hslot->count < hslot2->count)
501 result = udp4_lib_lookup2(net, saddr, sport,
502 daddr, hnum, dif, sdif,
503 exact_dif, hslot2, skb);
505 unsigned int old_slot2 = slot2;
506 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
507 slot2 = hash2 & udptable->mask;
508 /* avoid searching the same slot again. */
509 if (unlikely(slot2 == old_slot2))
512 hslot2 = &udptable->hash2[slot2];
513 if (hslot->count < hslot2->count)
516 result = udp4_lib_lookup2(net, saddr, sport,
517 daddr, hnum, dif, sdif,
518 exact_dif, hslot2, skb);
525 sk_for_each_rcu(sk, &hslot->head) {
526 score = compute_score(sk, net, saddr, sport,
527 daddr, hnum, dif, sdif, exact_dif);
528 if (score > badness) {
529 reuseport = sk->sk_reuseport;
531 hash = udp_ehashfn(net, daddr, hnum,
533 result = reuseport_select_sock(sk, hash, skb,
534 sizeof(struct udphdr));
541 } else if (score == badness && reuseport) {
543 if (reciprocal_scale(hash, matches) == 0)
545 hash = next_pseudo_random32(hash);
550 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
552 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
553 __be16 sport, __be16 dport,
554 struct udp_table *udptable)
556 const struct iphdr *iph = ip_hdr(skb);
558 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
559 iph->daddr, dport, inet_iif(skb),
560 inet_sdif(skb), udptable, skb);
563 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
564 __be16 sport, __be16 dport)
566 const struct iphdr *iph = ip_hdr(skb);
568 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
569 iph->daddr, dport, inet_iif(skb),
570 inet_sdif(skb), &udp_table, NULL);
572 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb);
574 /* Must be called under rcu_read_lock().
575 * Does increment socket refcount.
577 #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
578 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
579 IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
580 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
581 __be32 daddr, __be16 dport, int dif)
585 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
586 dif, 0, &udp_table, NULL);
587 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
591 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
594 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
595 __be16 loc_port, __be32 loc_addr,
596 __be16 rmt_port, __be32 rmt_addr,
597 int dif, int sdif, unsigned short hnum)
599 struct inet_sock *inet = inet_sk(sk);
601 if (!net_eq(sock_net(sk), net) ||
602 udp_sk(sk)->udp_port_hash != hnum ||
603 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
604 (inet->inet_dport != rmt_port && inet->inet_dport) ||
605 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
606 ipv6_only_sock(sk) ||
607 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
608 sk->sk_bound_dev_if != sdif))
610 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
616 * This routine is called by the ICMP module when it gets some
617 * sort of error condition. If err < 0 then the socket should
618 * be closed and the error returned to the user. If err > 0
619 * it's just the icmp type << 8 | icmp code.
620 * Header points to the ip header of the error packet. We move
621 * on past this. Then (as it used to claim before adjustment)
622 * header points to the first 8 bytes of the udp header. We need
623 * to find the appropriate port.
626 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
628 struct inet_sock *inet;
629 const struct iphdr *iph = (const struct iphdr *)skb->data;
630 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
631 const int type = icmp_hdr(skb)->type;
632 const int code = icmp_hdr(skb)->code;
636 struct net *net = dev_net(skb->dev);
638 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
639 iph->saddr, uh->source, skb->dev->ifindex, 0,
642 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
643 return; /* No socket for error */
652 case ICMP_TIME_EXCEEDED:
655 case ICMP_SOURCE_QUENCH:
657 case ICMP_PARAMETERPROB:
661 case ICMP_DEST_UNREACH:
662 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
663 ipv4_sk_update_pmtu(skb, sk, info);
664 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
672 if (code <= NR_ICMP_UNREACH) {
673 harderr = icmp_err_convert[code].fatal;
674 err = icmp_err_convert[code].errno;
678 ipv4_sk_redirect(skb, sk);
683 * RFC1122: OK. Passes ICMP errors back to application, as per
686 if (!inet->recverr) {
687 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
690 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
693 sk->sk_error_report(sk);
698 void udp_err(struct sk_buff *skb, u32 info)
700 __udp4_lib_err(skb, info, &udp_table);
704 * Throw away all pending data and cancel the corking. Socket is locked.
706 void udp_flush_pending_frames(struct sock *sk)
708 struct udp_sock *up = udp_sk(sk);
713 ip_flush_pending_frames(sk);
716 EXPORT_SYMBOL(udp_flush_pending_frames);
719 * udp4_hwcsum - handle outgoing HW checksumming
720 * @skb: sk_buff containing the filled-in UDP header
721 * (checksum field must be zeroed out)
722 * @src: source IP address
723 * @dst: destination IP address
725 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
727 struct udphdr *uh = udp_hdr(skb);
728 int offset = skb_transport_offset(skb);
729 int len = skb->len - offset;
733 if (!skb_has_frag_list(skb)) {
735 * Only one fragment on the socket.
737 skb->csum_start = skb_transport_header(skb) - skb->head;
738 skb->csum_offset = offsetof(struct udphdr, check);
739 uh->check = ~csum_tcpudp_magic(src, dst, len,
742 struct sk_buff *frags;
745 * HW-checksum won't work as there are two or more
746 * fragments on the socket so that all csums of sk_buffs
749 skb_walk_frags(skb, frags) {
750 csum = csum_add(csum, frags->csum);
754 csum = skb_checksum(skb, offset, hlen, csum);
755 skb->ip_summed = CHECKSUM_NONE;
757 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
759 uh->check = CSUM_MANGLED_0;
762 EXPORT_SYMBOL_GPL(udp4_hwcsum);
764 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
765 * for the simple case like when setting the checksum for a UDP tunnel.
767 void udp_set_csum(bool nocheck, struct sk_buff *skb,
768 __be32 saddr, __be32 daddr, int len)
770 struct udphdr *uh = udp_hdr(skb);
774 } else if (skb_is_gso(skb)) {
775 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
776 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
778 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
780 uh->check = CSUM_MANGLED_0;
782 skb->ip_summed = CHECKSUM_PARTIAL;
783 skb->csum_start = skb_transport_header(skb) - skb->head;
784 skb->csum_offset = offsetof(struct udphdr, check);
785 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
788 EXPORT_SYMBOL(udp_set_csum);
790 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
792 struct sock *sk = skb->sk;
793 struct inet_sock *inet = inet_sk(sk);
796 int is_udplite = IS_UDPLITE(sk);
797 int offset = skb_transport_offset(skb);
798 int len = skb->len - offset;
802 * Create a UDP header
805 uh->source = inet->inet_sport;
806 uh->dest = fl4->fl4_dport;
807 uh->len = htons(len);
810 if (is_udplite) /* UDP-Lite */
811 csum = udplite_csum(skb);
813 else if (sk->sk_no_check_tx) { /* UDP csum off */
815 skb->ip_summed = CHECKSUM_NONE;
818 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
820 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
824 csum = udp_csum(skb);
826 /* add protocol-dependent pseudo-header */
827 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
828 sk->sk_protocol, csum);
830 uh->check = CSUM_MANGLED_0;
833 err = ip_send_skb(sock_net(sk), skb);
835 if (err == -ENOBUFS && !inet->recverr) {
836 UDP_INC_STATS(sock_net(sk),
837 UDP_MIB_SNDBUFERRORS, is_udplite);
841 UDP_INC_STATS(sock_net(sk),
842 UDP_MIB_OUTDATAGRAMS, is_udplite);
847 * Push out all pending data as one UDP datagram. Socket is locked.
849 int udp_push_pending_frames(struct sock *sk)
851 struct udp_sock *up = udp_sk(sk);
852 struct inet_sock *inet = inet_sk(sk);
853 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
857 skb = ip_finish_skb(sk, fl4);
861 err = udp_send_skb(skb, fl4);
868 EXPORT_SYMBOL(udp_push_pending_frames);
870 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
872 struct inet_sock *inet = inet_sk(sk);
873 struct udp_sock *up = udp_sk(sk);
874 struct flowi4 fl4_stack;
877 struct ipcm_cookie ipc;
878 struct rtable *rt = NULL;
881 __be32 daddr, faddr, saddr;
884 int err, is_udplite = IS_UDPLITE(sk);
885 int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
886 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
888 struct ip_options_data opt_copy;
897 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
905 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
907 fl4 = &inet->cork.fl.u.ip4;
910 * There are pending frames.
911 * The socket lock must be held while it's corked.
914 if (likely(up->pending)) {
915 if (unlikely(up->pending != AF_INET)) {
923 ulen += sizeof(struct udphdr);
926 * Get and verify the address.
929 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
930 if (msg->msg_namelen < sizeof(*usin))
932 if (usin->sin_family != AF_INET) {
933 if (usin->sin_family != AF_UNSPEC)
934 return -EAFNOSUPPORT;
937 daddr = usin->sin_addr.s_addr;
938 dport = usin->sin_port;
942 if (sk->sk_state != TCP_ESTABLISHED)
943 return -EDESTADDRREQ;
944 daddr = inet->inet_daddr;
945 dport = inet->inet_dport;
946 /* Open fast path for connected socket.
947 Route will not be used, if at least one option is set.
952 ipc.sockc.tsflags = sk->sk_tsflags;
953 ipc.addr = inet->inet_saddr;
954 ipc.oif = sk->sk_bound_dev_if;
956 if (msg->msg_controllen) {
957 err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6);
967 struct ip_options_rcu *inet_opt;
970 inet_opt = rcu_dereference(inet->inet_opt);
972 memcpy(&opt_copy, inet_opt,
973 sizeof(*inet_opt) + inet_opt->opt.optlen);
974 ipc.opt = &opt_copy.opt;
980 ipc.addr = faddr = daddr;
982 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
984 if (ipc.opt && ipc.opt->opt.srr) {
989 faddr = ipc.opt->opt.faddr;
992 tos = get_rttos(&ipc, inet);
993 if (sock_flag(sk, SOCK_LOCALROUTE) ||
994 (msg->msg_flags & MSG_DONTROUTE) ||
995 (ipc.opt && ipc.opt->opt.is_strictroute)) {
1000 if (ipv4_is_multicast(daddr)) {
1002 ipc.oif = inet->mc_index;
1004 saddr = inet->mc_addr;
1006 } else if (!ipc.oif)
1007 ipc.oif = inet->uc_index;
1010 rt = (struct rtable *)sk_dst_check(sk, 0);
1013 struct net *net = sock_net(sk);
1014 __u8 flow_flags = inet_sk_flowi_flags(sk);
1018 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1019 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1021 faddr, saddr, dport, inet->inet_sport,
1024 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
1025 rt = ip_route_output_flow(net, fl4, sk);
1029 if (err == -ENETUNREACH)
1030 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1035 if ((rt->rt_flags & RTCF_BROADCAST) &&
1036 !sock_flag(sk, SOCK_BROADCAST))
1039 sk_dst_set(sk, dst_clone(&rt->dst));
1042 if (msg->msg_flags&MSG_CONFIRM)
1048 daddr = ipc.addr = fl4->daddr;
1050 /* Lockless fast path for the non-corking case. */
1052 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1053 sizeof(struct udphdr), &ipc, &rt,
1056 if (!IS_ERR_OR_NULL(skb))
1057 err = udp_send_skb(skb, fl4);
1062 if (unlikely(up->pending)) {
1063 /* The socket is already corked while preparing it. */
1064 /* ... which is an evident application bug. --ANK */
1067 net_dbg_ratelimited("socket already corked\n");
1072 * Now cork the socket to pend data.
1074 fl4 = &inet->cork.fl.u.ip4;
1077 fl4->fl4_dport = dport;
1078 fl4->fl4_sport = inet->inet_sport;
1079 up->pending = AF_INET;
1083 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1084 sizeof(struct udphdr), &ipc, &rt,
1085 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1087 udp_flush_pending_frames(sk);
1089 err = udp_push_pending_frames(sk);
1090 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1102 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1103 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1104 * we don't have a good statistic (IpOutDiscards but it can be too many
1105 * things). We could add another new stat but at least for now that
1106 * seems like overkill.
1108 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1109 UDP_INC_STATS(sock_net(sk),
1110 UDP_MIB_SNDBUFERRORS, is_udplite);
1115 if (msg->msg_flags & MSG_PROBE)
1116 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1117 if (!(msg->msg_flags&MSG_PROBE) || len)
1118 goto back_from_confirm;
1122 EXPORT_SYMBOL(udp_sendmsg);
1124 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1125 size_t size, int flags)
1127 struct inet_sock *inet = inet_sk(sk);
1128 struct udp_sock *up = udp_sk(sk);
1131 if (flags & MSG_SENDPAGE_NOTLAST)
1135 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1137 /* Call udp_sendmsg to specify destination address which
1138 * sendpage interface can't pass.
1139 * This will succeed only when the socket is connected.
1141 ret = udp_sendmsg(sk, &msg, 0);
1148 if (unlikely(!up->pending)) {
1151 net_dbg_ratelimited("cork failed\n");
1155 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1156 page, offset, size, flags);
1157 if (ret == -EOPNOTSUPP) {
1159 return sock_no_sendpage(sk->sk_socket, page, offset,
1163 udp_flush_pending_frames(sk);
1168 if (!(READ_ONCE(up->corkflag) || (flags&MSG_MORE)))
1169 ret = udp_push_pending_frames(sk);
1177 #define UDP_SKB_IS_STATELESS 0x80000000
1179 static void udp_set_dev_scratch(struct sk_buff *skb)
1181 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1183 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1184 scratch->_tsize_state = skb->truesize;
1185 #if BITS_PER_LONG == 64
1186 scratch->len = skb->len;
1187 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1188 scratch->is_linear = !skb_is_nonlinear(skb);
1190 /* all head states execept sp (dst, sk, nf) are always cleared by
1191 * udp_rcv() and we need to preserve secpath, if present, to eventually
1192 * process IP_CMSG_PASSSEC at recvmsg() time
1194 if (likely(!skb_sec_path(skb)))
1195 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1198 static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1200 /* We come here after udp_lib_checksum_complete() returned 0.
1201 * This means that __skb_checksum_complete() might have
1202 * set skb->csum_valid to 1.
1203 * On 64bit platforms, we can set csum_unnecessary
1204 * to true, but only if the skb is not shared.
1206 #if BITS_PER_LONG == 64
1207 if (!skb_shared(skb))
1208 udp_skb_scratch(skb)->csum_unnecessary = true;
1212 static int udp_skb_truesize(struct sk_buff *skb)
1214 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1217 static bool udp_skb_has_head_state(struct sk_buff *skb)
1219 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1222 /* fully reclaim rmem/fwd memory allocated for skb */
1223 static void udp_rmem_release(struct sock *sk, int size, int partial,
1224 bool rx_queue_lock_held)
1226 struct udp_sock *up = udp_sk(sk);
1227 struct sk_buff_head *sk_queue;
1230 if (likely(partial)) {
1231 up->forward_deficit += size;
1232 size = up->forward_deficit;
1233 if (size < (sk->sk_rcvbuf >> 2) &&
1234 !skb_queue_empty(&up->reader_queue))
1237 size += up->forward_deficit;
1239 up->forward_deficit = 0;
1241 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1242 * if the called don't held it already
1244 sk_queue = &sk->sk_receive_queue;
1245 if (!rx_queue_lock_held)
1246 spin_lock(&sk_queue->lock);
1249 sk->sk_forward_alloc += size;
1250 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1251 sk->sk_forward_alloc -= amt;
1254 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1256 atomic_sub(size, &sk->sk_rmem_alloc);
1258 /* this can save us from acquiring the rx queue lock on next receive */
1259 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1261 if (!rx_queue_lock_held)
1262 spin_unlock(&sk_queue->lock);
1265 /* Note: called with reader_queue.lock held.
1266 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1267 * This avoids a cache line miss while receive_queue lock is held.
1268 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1270 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1272 prefetch(&skb->data);
1273 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1275 EXPORT_SYMBOL(udp_skb_destructor);
1277 /* as above, but the caller held the rx queue lock, too */
1278 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1280 prefetch(&skb->data);
1281 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1284 /* Idea of busylocks is to let producers grab an extra spinlock
1285 * to relieve pressure on the receive_queue spinlock shared by consumer.
1286 * Under flood, this means that only one producer can be in line
1287 * trying to acquire the receive_queue spinlock.
1288 * These busylock can be allocated on a per cpu manner, instead of a
1289 * per socket one (that would consume a cache line per socket)
1291 static int udp_busylocks_log __read_mostly;
1292 static spinlock_t *udp_busylocks __read_mostly;
1294 static spinlock_t *busylock_acquire(void *ptr)
1298 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1303 static void busylock_release(spinlock_t *busy)
1309 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1311 struct sk_buff_head *list = &sk->sk_receive_queue;
1312 int rmem, delta, amt, err = -ENOMEM;
1313 spinlock_t *busy = NULL;
1316 /* try to avoid the costly atomic add/sub pair when the receive
1317 * queue is full; always allow at least a packet
1319 rmem = atomic_read(&sk->sk_rmem_alloc);
1320 if (rmem > sk->sk_rcvbuf)
1323 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1324 * having linear skbs :
1325 * - Reduce memory overhead and thus increase receive queue capacity
1326 * - Less cache line misses at copyout() time
1327 * - Less work at consume_skb() (less alien page frag freeing)
1329 if (rmem > (sk->sk_rcvbuf >> 1)) {
1332 busy = busylock_acquire(sk);
1334 size = skb->truesize;
1335 udp_set_dev_scratch(skb);
1337 /* we drop only if the receive buf is full and the receive
1338 * queue contains some other skb
1340 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1341 if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
1344 spin_lock(&list->lock);
1345 if (size >= sk->sk_forward_alloc) {
1346 amt = sk_mem_pages(size);
1347 delta = amt << SK_MEM_QUANTUM_SHIFT;
1348 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1350 spin_unlock(&list->lock);
1354 sk->sk_forward_alloc += delta;
1357 sk->sk_forward_alloc -= size;
1359 /* no need to setup a destructor, we will explicitly release the
1360 * forward allocated memory on dequeue
1362 sock_skb_set_dropcount(sk, skb);
1364 __skb_queue_tail(list, skb);
1365 spin_unlock(&list->lock);
1367 if (!sock_flag(sk, SOCK_DEAD))
1368 sk->sk_data_ready(sk);
1370 busylock_release(busy);
1374 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1377 atomic_inc(&sk->sk_drops);
1378 busylock_release(busy);
1381 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1383 void udp_destruct_sock(struct sock *sk)
1385 /* reclaim completely the forward allocated memory */
1386 struct udp_sock *up = udp_sk(sk);
1387 unsigned int total = 0;
1388 struct sk_buff *skb;
1390 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1391 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1392 total += skb->truesize;
1395 udp_rmem_release(sk, total, 0, true);
1397 inet_sock_destruct(sk);
1399 EXPORT_SYMBOL_GPL(udp_destruct_sock);
1401 int udp_init_sock(struct sock *sk)
1403 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1404 sk->sk_destruct = udp_destruct_sock;
1407 EXPORT_SYMBOL_GPL(udp_init_sock);
1409 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1411 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1412 bool slow = lock_sock_fast(sk);
1414 sk_peek_offset_bwd(sk, len);
1415 unlock_sock_fast(sk, slow);
1418 if (!skb_unref(skb))
1421 /* In the more common cases we cleared the head states previously,
1422 * see __udp_queue_rcv_skb().
1424 if (unlikely(udp_skb_has_head_state(skb)))
1425 skb_release_head_state(skb);
1426 __consume_stateless_skb(skb);
1428 EXPORT_SYMBOL_GPL(skb_consume_udp);
1430 static struct sk_buff *__first_packet_length(struct sock *sk,
1431 struct sk_buff_head *rcvq,
1434 struct sk_buff *skb;
1436 while ((skb = skb_peek(rcvq)) != NULL) {
1437 if (udp_lib_checksum_complete(skb)) {
1438 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1440 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1442 atomic_inc(&sk->sk_drops);
1443 __skb_unlink(skb, rcvq);
1444 *total += skb->truesize;
1447 udp_skb_csum_unnecessary_set(skb);
1455 * first_packet_length - return length of first packet in receive queue
1458 * Drops all bad checksum frames, until a valid one is found.
1459 * Returns the length of found skb, or -1 if none is found.
1461 static int first_packet_length(struct sock *sk)
1463 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1464 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1465 struct sk_buff *skb;
1469 spin_lock_bh(&rcvq->lock);
1470 skb = __first_packet_length(sk, rcvq, &total);
1471 if (!skb && !skb_queue_empty_lockless(sk_queue)) {
1472 spin_lock(&sk_queue->lock);
1473 skb_queue_splice_tail_init(sk_queue, rcvq);
1474 spin_unlock(&sk_queue->lock);
1476 skb = __first_packet_length(sk, rcvq, &total);
1478 res = skb ? skb->len : -1;
1480 udp_rmem_release(sk, total, 1, false);
1481 spin_unlock_bh(&rcvq->lock);
1486 * IOCTL requests applicable to the UDP protocol
1489 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1494 int amount = sk_wmem_alloc_get(sk);
1496 return put_user(amount, (int __user *)arg);
1501 int amount = max_t(int, 0, first_packet_length(sk));
1503 return put_user(amount, (int __user *)arg);
1507 return -ENOIOCTLCMD;
1512 EXPORT_SYMBOL(udp_ioctl);
1514 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1515 int noblock, int *peeked, int *off, int *err)
1517 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1518 struct sk_buff_head *queue;
1519 struct sk_buff *last;
1523 queue = &udp_sk(sk)->reader_queue;
1524 flags |= noblock ? MSG_DONTWAIT : 0;
1525 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1527 struct sk_buff *skb;
1529 error = sock_error(sk);
1536 spin_lock_bh(&queue->lock);
1537 skb = __skb_try_recv_from_queue(sk, queue, flags,
1542 spin_unlock_bh(&queue->lock);
1546 if (skb_queue_empty_lockless(sk_queue)) {
1547 spin_unlock_bh(&queue->lock);
1551 /* refill the reader queue and walk it again
1552 * keep both queues locked to avoid re-acquiring
1553 * the sk_receive_queue lock if fwd memory scheduling
1556 spin_lock(&sk_queue->lock);
1557 skb_queue_splice_tail_init(sk_queue, queue);
1559 skb = __skb_try_recv_from_queue(sk, queue, flags,
1560 udp_skb_dtor_locked,
1563 spin_unlock(&sk_queue->lock);
1564 spin_unlock_bh(&queue->lock);
1569 if (!sk_can_busy_loop(sk))
1572 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1573 } while (!skb_queue_empty_lockless(sk_queue));
1575 /* sk_queue is empty, reader_queue may contain peeked packets */
1577 !__skb_wait_for_more_packets(sk, &error, &timeo,
1578 (struct sk_buff *)sk_queue));
1583 EXPORT_SYMBOL(__skb_recv_udp);
1586 * This should be easy, if there is something there we
1587 * return it, otherwise we block.
1590 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1591 int flags, int *addr_len)
1593 struct inet_sock *inet = inet_sk(sk);
1594 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1595 struct sk_buff *skb;
1596 unsigned int ulen, copied;
1597 int peeked, peeking, off;
1599 int is_udplite = IS_UDPLITE(sk);
1600 bool checksum_valid = false;
1602 if (flags & MSG_ERRQUEUE)
1603 return ip_recv_error(sk, msg, len, addr_len);
1606 peeking = flags & MSG_PEEK;
1607 off = sk_peek_offset(sk, flags);
1608 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
1612 ulen = udp_skb_len(skb);
1614 if (copied > ulen - off)
1615 copied = ulen - off;
1616 else if (copied < ulen)
1617 msg->msg_flags |= MSG_TRUNC;
1620 * If checksum is needed at all, try to do it while copying the
1621 * data. If the data is truncated, or if we only want a partial
1622 * coverage checksum (UDP-Lite), do it before the copy.
1625 if (copied < ulen || peeking ||
1626 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1627 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1628 !__udp_lib_checksum_complete(skb);
1629 if (!checksum_valid)
1633 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1634 if (udp_skb_is_linear(skb))
1635 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1637 err = skb_copy_datagram_msg(skb, off, msg, copied);
1639 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1645 if (unlikely(err)) {
1647 atomic_inc(&sk->sk_drops);
1648 UDP_INC_STATS(sock_net(sk),
1649 UDP_MIB_INERRORS, is_udplite);
1656 UDP_INC_STATS(sock_net(sk),
1657 UDP_MIB_INDATAGRAMS, is_udplite);
1659 sock_recv_ts_and_drops(msg, sk, skb);
1661 /* Copy the address. */
1663 sin->sin_family = AF_INET;
1664 sin->sin_port = udp_hdr(skb)->source;
1665 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1666 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1667 *addr_len = sizeof(*sin);
1669 if (inet->cmsg_flags)
1670 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1673 if (flags & MSG_TRUNC)
1676 skb_consume_udp(sk, skb, peeking ? -err : err);
1680 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1681 udp_skb_destructor)) {
1682 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1683 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1687 /* starting over for a new packet, but check if we need to yield */
1689 msg->msg_flags &= ~MSG_TRUNC;
1693 int __udp_disconnect(struct sock *sk, int flags)
1695 struct inet_sock *inet = inet_sk(sk);
1697 * 1003.1g - break association.
1700 sk->sk_state = TCP_CLOSE;
1701 inet->inet_daddr = 0;
1702 inet->inet_dport = 0;
1703 sock_rps_reset_rxhash(sk);
1704 sk->sk_bound_dev_if = 0;
1705 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1706 inet_reset_saddr(sk);
1708 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1709 sk->sk_prot->unhash(sk);
1710 inet->inet_sport = 0;
1715 EXPORT_SYMBOL(__udp_disconnect);
1717 int udp_disconnect(struct sock *sk, int flags)
1720 __udp_disconnect(sk, flags);
1724 EXPORT_SYMBOL(udp_disconnect);
1726 void udp_lib_unhash(struct sock *sk)
1728 if (sk_hashed(sk)) {
1729 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1730 struct udp_hslot *hslot, *hslot2;
1732 hslot = udp_hashslot(udptable, sock_net(sk),
1733 udp_sk(sk)->udp_port_hash);
1734 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1736 spin_lock_bh(&hslot->lock);
1737 if (rcu_access_pointer(sk->sk_reuseport_cb))
1738 reuseport_detach_sock(sk);
1739 if (sk_del_node_init_rcu(sk)) {
1741 inet_sk(sk)->inet_num = 0;
1742 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1744 spin_lock(&hslot2->lock);
1745 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1747 spin_unlock(&hslot2->lock);
1749 spin_unlock_bh(&hslot->lock);
1752 EXPORT_SYMBOL(udp_lib_unhash);
1755 * inet_rcv_saddr was changed, we must rehash secondary hash
1757 void udp_lib_rehash(struct sock *sk, u16 newhash)
1759 if (sk_hashed(sk)) {
1760 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1761 struct udp_hslot *hslot, *hslot2, *nhslot2;
1763 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1764 nhslot2 = udp_hashslot2(udptable, newhash);
1765 udp_sk(sk)->udp_portaddr_hash = newhash;
1767 if (hslot2 != nhslot2 ||
1768 rcu_access_pointer(sk->sk_reuseport_cb)) {
1769 hslot = udp_hashslot(udptable, sock_net(sk),
1770 udp_sk(sk)->udp_port_hash);
1771 /* we must lock primary chain too */
1772 spin_lock_bh(&hslot->lock);
1773 if (rcu_access_pointer(sk->sk_reuseport_cb))
1774 reuseport_detach_sock(sk);
1776 if (hslot2 != nhslot2) {
1777 spin_lock(&hslot2->lock);
1778 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1780 spin_unlock(&hslot2->lock);
1782 spin_lock(&nhslot2->lock);
1783 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1786 spin_unlock(&nhslot2->lock);
1789 spin_unlock_bh(&hslot->lock);
1793 EXPORT_SYMBOL(udp_lib_rehash);
1795 static void udp_v4_rehash(struct sock *sk)
1797 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1798 inet_sk(sk)->inet_rcv_saddr,
1799 inet_sk(sk)->inet_num);
1800 udp_lib_rehash(sk, new_hash);
1803 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1807 if (inet_sk(sk)->inet_daddr) {
1808 sock_rps_save_rxhash(sk, skb);
1809 sk_mark_napi_id(sk, skb);
1810 sk_incoming_cpu_update(sk);
1812 sk_mark_napi_id_once(sk, skb);
1815 rc = __udp_enqueue_schedule_skb(sk, skb);
1817 int is_udplite = IS_UDPLITE(sk);
1819 /* Note that an ENOMEM error is charged twice */
1821 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1823 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1825 trace_udp_fail_queue_rcv_skb(rc, sk);
1832 static struct static_key udp_encap_needed __read_mostly;
1833 void udp_encap_enable(void)
1835 static_key_enable(&udp_encap_needed);
1837 EXPORT_SYMBOL(udp_encap_enable);
1842 * >0: "udp encap" protocol resubmission
1844 * Note that in the success and error cases, the skb is assumed to
1845 * have either been requeued or freed.
1847 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1849 struct udp_sock *up = udp_sk(sk);
1850 int is_udplite = IS_UDPLITE(sk);
1853 * Charge it to the socket, dropping if the queue is full.
1855 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1859 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1860 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1863 * This is an encapsulation socket so pass the skb to
1864 * the socket's udp_encap_rcv() hook. Otherwise, just
1865 * fall through and pass this up the UDP socket.
1866 * up->encap_rcv() returns the following value:
1867 * =0 if skb was successfully passed to the encap
1868 * handler or was discarded by it.
1869 * >0 if skb should be passed on to UDP.
1870 * <0 if skb should be resubmitted as proto -N
1873 /* if we're overly short, let UDP handle it */
1874 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1878 /* Verify checksum before giving to encap */
1879 if (udp_lib_checksum_complete(skb))
1882 ret = encap_rcv(sk, skb);
1884 __UDP_INC_STATS(sock_net(sk),
1885 UDP_MIB_INDATAGRAMS,
1891 /* FALLTHROUGH -- it's a UDP Packet */
1895 * UDP-Lite specific tests, ignored on UDP sockets
1897 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1900 * MIB statistics other than incrementing the error count are
1901 * disabled for the following two types of errors: these depend
1902 * on the application settings, not on the functioning of the
1903 * protocol stack as such.
1905 * RFC 3828 here recommends (sec 3.3): "There should also be a
1906 * way ... to ... at least let the receiving application block
1907 * delivery of packets with coverage values less than a value
1908 * provided by the application."
1910 if (up->pcrlen == 0) { /* full coverage was set */
1911 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
1912 UDP_SKB_CB(skb)->cscov, skb->len);
1915 /* The next case involves violating the min. coverage requested
1916 * by the receiver. This is subtle: if receiver wants x and x is
1917 * greater than the buffersize/MTU then receiver will complain
1918 * that it wants x while sender emits packets of smaller size y.
1919 * Therefore the above ...()->partial_cov statement is essential.
1921 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1922 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
1923 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1928 prefetch(&sk->sk_rmem_alloc);
1929 if (rcu_access_pointer(sk->sk_filter) &&
1930 udp_lib_checksum_complete(skb))
1933 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
1936 udp_csum_pull_header(skb);
1938 ipv4_pktinfo_prepare(sk, skb);
1939 return __udp_queue_rcv_skb(sk, skb);
1942 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1944 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1945 atomic_inc(&sk->sk_drops);
1950 /* For TCP sockets, sk_rx_dst is protected by socket lock
1951 * For UDP, we use xchg() to guard against concurrent changes.
1953 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1955 struct dst_entry *old;
1957 if (dst_hold_safe(dst)) {
1958 old = xchg((__force struct dst_entry **)&sk->sk_rx_dst, dst);
1964 EXPORT_SYMBOL(udp_sk_rx_dst_set);
1967 * Multicasts and broadcasts go to each listener.
1969 * Note: called only from the BH handler context.
1971 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1973 __be32 saddr, __be32 daddr,
1974 struct udp_table *udptable,
1977 struct sock *sk, *first = NULL;
1978 unsigned short hnum = ntohs(uh->dest);
1979 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
1980 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
1981 unsigned int offset = offsetof(typeof(*sk), sk_node);
1982 int dif = skb->dev->ifindex;
1983 int sdif = inet_sdif(skb);
1984 struct hlist_node *node;
1985 struct sk_buff *nskb;
1988 hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
1990 hash2 = udp4_portaddr_hash(net, daddr, hnum) & udptable->mask;
1992 hslot = &udptable->hash2[hash2];
1993 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
1996 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
1997 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
1998 uh->source, saddr, dif, sdif, hnum))
2005 nskb = skb_clone(skb, GFP_ATOMIC);
2007 if (unlikely(!nskb)) {
2008 atomic_inc(&sk->sk_drops);
2009 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2011 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2015 if (udp_queue_rcv_skb(sk, nskb) > 0)
2019 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2020 if (use_hash2 && hash2 != hash2_any) {
2026 if (udp_queue_rcv_skb(first, skb) > 0)
2030 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2031 proto == IPPROTO_UDPLITE);
2036 /* Initialize UDP checksum. If exited with zero value (success),
2037 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2038 * Otherwise, csum completion requires chacksumming packet body,
2039 * including udp header and folding it to skb->csum.
2041 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2046 UDP_SKB_CB(skb)->partial_cov = 0;
2047 UDP_SKB_CB(skb)->cscov = skb->len;
2049 if (proto == IPPROTO_UDPLITE) {
2050 err = udplite_checksum_init(skb, uh);
2054 if (UDP_SKB_CB(skb)->partial_cov) {
2055 skb->csum = inet_compute_pseudo(skb, proto);
2060 /* Note, we are only interested in != 0 or == 0, thus the
2063 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2064 inet_compute_pseudo);
2068 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2069 /* If SW calculated the value, we know it's bad */
2070 if (skb->csum_complete_sw)
2073 /* HW says the value is bad. Let's validate that.
2074 * skb->csum is no longer the full packet checksum,
2075 * so don't treat it as such.
2077 skb_checksum_complete_unset(skb);
2083 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2084 * return code conversion for ip layer consumption
2086 static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2091 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2092 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
2093 inet_compute_pseudo);
2095 ret = udp_queue_rcv_skb(sk, skb);
2097 /* a return value > 0 means to resubmit the input, but
2098 * it wants the return to be -protocol, or 0
2106 * All we need to do is get the socket, and then do a checksum.
2109 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2114 unsigned short ulen;
2115 struct rtable *rt = skb_rtable(skb);
2116 __be32 saddr, daddr;
2117 struct net *net = dev_net(skb->dev);
2120 * Validate the packet.
2122 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2123 goto drop; /* No space for header. */
2126 ulen = ntohs(uh->len);
2127 saddr = ip_hdr(skb)->saddr;
2128 daddr = ip_hdr(skb)->daddr;
2130 if (ulen > skb->len)
2133 if (proto == IPPROTO_UDP) {
2134 /* UDP validates ulen. */
2135 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2140 if (udp4_csum_init(skb, uh, proto))
2143 sk = skb_steal_sock(skb);
2145 struct dst_entry *dst = skb_dst(skb);
2148 if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
2149 udp_sk_rx_dst_set(sk, dst);
2151 ret = udp_unicast_rcv_skb(sk, skb, uh);
2156 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2157 return __udp4_lib_mcast_deliver(net, skb, uh,
2158 saddr, daddr, udptable, proto);
2160 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2162 return udp_unicast_rcv_skb(sk, skb, uh);
2164 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2168 /* No socket. Drop packet silently, if checksum is wrong */
2169 if (udp_lib_checksum_complete(skb))
2172 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2173 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2176 * Hmm. We got an UDP packet to a port to which we
2177 * don't wanna listen. Ignore it.
2183 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2184 proto == IPPROTO_UDPLITE ? "Lite" : "",
2185 &saddr, ntohs(uh->source),
2187 &daddr, ntohs(uh->dest));
2192 * RFC1122: OK. Discards the bad packet silently (as far as
2193 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2195 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2196 proto == IPPROTO_UDPLITE ? "Lite" : "",
2197 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2199 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2201 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2206 /* We can only early demux multicast if there is a single matching socket.
2207 * If more than one socket found returns NULL
2209 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2210 __be16 loc_port, __be32 loc_addr,
2211 __be16 rmt_port, __be32 rmt_addr,
2214 struct sock *sk, *result;
2215 unsigned short hnum = ntohs(loc_port);
2216 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2217 struct udp_hslot *hslot = &udp_table.hash[slot];
2219 /* Do not bother scanning a too big list */
2220 if (hslot->count > 10)
2224 sk_for_each_rcu(sk, &hslot->head) {
2225 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2226 rmt_port, rmt_addr, dif, sdif, hnum)) {
2236 /* For unicast we should only early demux connected sockets or we can
2237 * break forwarding setups. The chains here can be long so only check
2238 * if the first socket is an exact match and if not move on.
2240 static struct sock *__udp4_lib_demux_lookup(struct net *net,
2241 __be16 loc_port, __be32 loc_addr,
2242 __be16 rmt_port, __be32 rmt_addr,
2245 unsigned short hnum = ntohs(loc_port);
2246 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
2247 unsigned int slot2 = hash2 & udp_table.mask;
2248 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2249 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2250 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2253 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2254 if (INET_MATCH(sk, net, acookie, rmt_addr,
2255 loc_addr, ports, dif, sdif))
2257 /* Only check first socket in chain */
2263 int udp_v4_early_demux(struct sk_buff *skb)
2265 struct net *net = dev_net(skb->dev);
2266 struct in_device *in_dev = NULL;
2267 const struct iphdr *iph;
2268 const struct udphdr *uh;
2269 struct sock *sk = NULL;
2270 struct dst_entry *dst;
2271 int dif = skb->dev->ifindex;
2272 int sdif = inet_sdif(skb);
2275 /* validate the packet */
2276 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2282 if (skb->pkt_type == PACKET_MULTICAST) {
2283 in_dev = __in_dev_get_rcu(skb->dev);
2288 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2293 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2294 uh->source, iph->saddr,
2296 } else if (skb->pkt_type == PACKET_HOST) {
2297 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2298 uh->source, iph->saddr, dif, sdif);
2301 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2305 skb->destructor = sock_efree;
2306 dst = rcu_dereference(sk->sk_rx_dst);
2309 dst = dst_check(dst, 0);
2313 /* set noref for now.
2314 * any place which wants to hold dst has to call
2317 skb_dst_set_noref(skb, dst);
2319 /* for unconnected multicast sockets we need to validate
2320 * the source on each packet
2322 if (!inet_sk(sk)->inet_daddr && in_dev)
2323 return ip_mc_validate_source(skb, iph->daddr,
2325 iph->tos & IPTOS_RT_MASK,
2326 skb->dev, in_dev, &itag);
2331 int udp_rcv(struct sk_buff *skb)
2333 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2336 void udp_destroy_sock(struct sock *sk)
2338 struct udp_sock *up = udp_sk(sk);
2339 bool slow = lock_sock_fast(sk);
2341 /* protects from races with udp_abort() */
2342 sock_set_flag(sk, SOCK_DEAD);
2343 udp_flush_pending_frames(sk);
2344 unlock_sock_fast(sk, slow);
2345 if (static_key_false(&udp_encap_needed) && up->encap_type) {
2346 void (*encap_destroy)(struct sock *sk);
2347 encap_destroy = ACCESS_ONCE(up->encap_destroy);
2354 * Socket option code for UDP
2356 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2357 char __user *optval, unsigned int optlen,
2358 int (*push_pending_frames)(struct sock *))
2360 struct udp_sock *up = udp_sk(sk);
2363 int is_udplite = IS_UDPLITE(sk);
2365 if (optlen < sizeof(int))
2368 if (get_user(val, (int __user *)optval))
2371 valbool = val ? 1 : 0;
2376 WRITE_ONCE(up->corkflag, 1);
2378 WRITE_ONCE(up->corkflag, 0);
2380 push_pending_frames(sk);
2388 case UDP_ENCAP_ESPINUDP:
2389 case UDP_ENCAP_ESPINUDP_NON_IKE:
2390 up->encap_rcv = xfrm4_udp_encap_rcv;
2392 case UDP_ENCAP_L2TPINUDP:
2393 up->encap_type = val;
2402 case UDP_NO_CHECK6_TX:
2403 up->no_check6_tx = valbool;
2406 case UDP_NO_CHECK6_RX:
2407 up->no_check6_rx = valbool;
2411 * UDP-Lite's partial checksum coverage (RFC 3828).
2413 /* The sender sets actual checksum coverage length via this option.
2414 * The case coverage > packet length is handled by send module. */
2415 case UDPLITE_SEND_CSCOV:
2416 if (!is_udplite) /* Disable the option on UDP sockets */
2417 return -ENOPROTOOPT;
2418 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2420 else if (val > USHRT_MAX)
2423 up->pcflag |= UDPLITE_SEND_CC;
2426 /* The receiver specifies a minimum checksum coverage value. To make
2427 * sense, this should be set to at least 8 (as done below). If zero is
2428 * used, this again means full checksum coverage. */
2429 case UDPLITE_RECV_CSCOV:
2430 if (!is_udplite) /* Disable the option on UDP sockets */
2431 return -ENOPROTOOPT;
2432 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2434 else if (val > USHRT_MAX)
2437 up->pcflag |= UDPLITE_RECV_CC;
2447 EXPORT_SYMBOL(udp_lib_setsockopt);
2449 int udp_setsockopt(struct sock *sk, int level, int optname,
2450 char __user *optval, unsigned int optlen)
2452 if (level == SOL_UDP || level == SOL_UDPLITE)
2453 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2454 udp_push_pending_frames);
2455 return ip_setsockopt(sk, level, optname, optval, optlen);
2458 #ifdef CONFIG_COMPAT
2459 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2460 char __user *optval, unsigned int optlen)
2462 if (level == SOL_UDP || level == SOL_UDPLITE)
2463 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2464 udp_push_pending_frames);
2465 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2469 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2470 char __user *optval, int __user *optlen)
2472 struct udp_sock *up = udp_sk(sk);
2475 if (get_user(len, optlen))
2478 len = min_t(unsigned int, len, sizeof(int));
2485 val = READ_ONCE(up->corkflag);
2489 val = up->encap_type;
2492 case UDP_NO_CHECK6_TX:
2493 val = up->no_check6_tx;
2496 case UDP_NO_CHECK6_RX:
2497 val = up->no_check6_rx;
2500 /* The following two cannot be changed on UDP sockets, the return is
2501 * always 0 (which corresponds to the full checksum coverage of UDP). */
2502 case UDPLITE_SEND_CSCOV:
2506 case UDPLITE_RECV_CSCOV:
2511 return -ENOPROTOOPT;
2514 if (put_user(len, optlen))
2516 if (copy_to_user(optval, &val, len))
2520 EXPORT_SYMBOL(udp_lib_getsockopt);
2522 int udp_getsockopt(struct sock *sk, int level, int optname,
2523 char __user *optval, int __user *optlen)
2525 if (level == SOL_UDP || level == SOL_UDPLITE)
2526 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2527 return ip_getsockopt(sk, level, optname, optval, optlen);
2530 #ifdef CONFIG_COMPAT
2531 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2532 char __user *optval, int __user *optlen)
2534 if (level == SOL_UDP || level == SOL_UDPLITE)
2535 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2536 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2540 * udp_poll - wait for a UDP event.
2541 * @file - file struct
2543 * @wait - poll table
2545 * This is same as datagram poll, except for the special case of
2546 * blocking sockets. If application is using a blocking fd
2547 * and a packet with checksum error is in the queue;
2548 * then it could get return from select indicating data available
2549 * but then block when reading it. Add special case code
2550 * to work around these arguably broken applications.
2552 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2554 unsigned int mask = datagram_poll(file, sock, wait);
2555 struct sock *sk = sock->sk;
2557 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
2558 mask |= POLLIN | POLLRDNORM;
2560 sock_rps_record_flow(sk);
2562 /* Check for false positives due to checksum errors */
2563 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2564 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2565 mask &= ~(POLLIN | POLLRDNORM);
2570 EXPORT_SYMBOL(udp_poll);
2572 int udp_abort(struct sock *sk, int err)
2576 /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
2579 if (sock_flag(sk, SOCK_DEAD))
2583 sk->sk_error_report(sk);
2584 __udp_disconnect(sk, 0);
2591 EXPORT_SYMBOL_GPL(udp_abort);
2593 struct proto udp_prot = {
2595 .owner = THIS_MODULE,
2596 .close = udp_lib_close,
2597 .connect = ip4_datagram_connect,
2598 .disconnect = udp_disconnect,
2600 .init = udp_init_sock,
2601 .destroy = udp_destroy_sock,
2602 .setsockopt = udp_setsockopt,
2603 .getsockopt = udp_getsockopt,
2604 .sendmsg = udp_sendmsg,
2605 .recvmsg = udp_recvmsg,
2606 .sendpage = udp_sendpage,
2607 .release_cb = ip4_datagram_release_cb,
2608 .hash = udp_lib_hash,
2609 .unhash = udp_lib_unhash,
2610 .rehash = udp_v4_rehash,
2611 .get_port = udp_v4_get_port,
2612 .memory_allocated = &udp_memory_allocated,
2613 .sysctl_mem = sysctl_udp_mem,
2614 .sysctl_wmem = &sysctl_udp_wmem_min,
2615 .sysctl_rmem = &sysctl_udp_rmem_min,
2616 .obj_size = sizeof(struct udp_sock),
2617 .h.udp_table = &udp_table,
2618 #ifdef CONFIG_COMPAT
2619 .compat_setsockopt = compat_udp_setsockopt,
2620 .compat_getsockopt = compat_udp_getsockopt,
2622 .diag_destroy = udp_abort,
2624 EXPORT_SYMBOL(udp_prot);
2626 /* ------------------------------------------------------------------------ */
2627 #ifdef CONFIG_PROC_FS
2629 static struct sock *udp_get_first(struct seq_file *seq, int start)
2632 struct udp_iter_state *state = seq->private;
2633 struct net *net = seq_file_net(seq);
2635 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2637 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2639 if (hlist_empty(&hslot->head))
2642 spin_lock_bh(&hslot->lock);
2643 sk_for_each(sk, &hslot->head) {
2644 if (!net_eq(sock_net(sk), net))
2646 if (sk->sk_family == state->family)
2649 spin_unlock_bh(&hslot->lock);
2656 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2658 struct udp_iter_state *state = seq->private;
2659 struct net *net = seq_file_net(seq);
2663 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2666 if (state->bucket <= state->udp_table->mask)
2667 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2668 return udp_get_first(seq, state->bucket + 1);
2673 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2675 struct sock *sk = udp_get_first(seq, 0);
2678 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2680 return pos ? NULL : sk;
2683 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2685 struct udp_iter_state *state = seq->private;
2686 state->bucket = MAX_UDP_PORTS;
2688 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2691 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2695 if (v == SEQ_START_TOKEN)
2696 sk = udp_get_idx(seq, 0);
2698 sk = udp_get_next(seq, v);
2704 static void udp_seq_stop(struct seq_file *seq, void *v)
2706 struct udp_iter_state *state = seq->private;
2708 if (state->bucket <= state->udp_table->mask)
2709 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2712 int udp_seq_open(struct inode *inode, struct file *file)
2714 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2715 struct udp_iter_state *s;
2718 err = seq_open_net(inode, file, &afinfo->seq_ops,
2719 sizeof(struct udp_iter_state));
2723 s = ((struct seq_file *)file->private_data)->private;
2724 s->family = afinfo->family;
2725 s->udp_table = afinfo->udp_table;
2728 EXPORT_SYMBOL(udp_seq_open);
2730 /* ------------------------------------------------------------------------ */
2731 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2733 struct proc_dir_entry *p;
2736 afinfo->seq_ops.start = udp_seq_start;
2737 afinfo->seq_ops.next = udp_seq_next;
2738 afinfo->seq_ops.stop = udp_seq_stop;
2740 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2741 afinfo->seq_fops, afinfo);
2746 EXPORT_SYMBOL(udp_proc_register);
2748 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2750 remove_proc_entry(afinfo->name, net->proc_net);
2752 EXPORT_SYMBOL(udp_proc_unregister);
2754 /* ------------------------------------------------------------------------ */
2755 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2758 struct inet_sock *inet = inet_sk(sp);
2759 __be32 dest = inet->inet_daddr;
2760 __be32 src = inet->inet_rcv_saddr;
2761 __u16 destp = ntohs(inet->inet_dport);
2762 __u16 srcp = ntohs(inet->inet_sport);
2764 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2765 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2766 bucket, src, srcp, dest, destp, sp->sk_state,
2767 sk_wmem_alloc_get(sp),
2770 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2772 refcount_read(&sp->sk_refcnt), sp,
2773 atomic_read(&sp->sk_drops));
2776 int udp4_seq_show(struct seq_file *seq, void *v)
2778 seq_setwidth(seq, 127);
2779 if (v == SEQ_START_TOKEN)
2780 seq_puts(seq, " sl local_address rem_address st tx_queue "
2781 "rx_queue tr tm->when retrnsmt uid timeout "
2782 "inode ref pointer drops");
2784 struct udp_iter_state *state = seq->private;
2786 udp4_format_sock(v, seq, state->bucket);
2792 static const struct file_operations udp_afinfo_seq_fops = {
2793 .owner = THIS_MODULE,
2794 .open = udp_seq_open,
2796 .llseek = seq_lseek,
2797 .release = seq_release_net
2800 /* ------------------------------------------------------------------------ */
2801 static struct udp_seq_afinfo udp4_seq_afinfo = {
2804 .udp_table = &udp_table,
2805 .seq_fops = &udp_afinfo_seq_fops,
2807 .show = udp4_seq_show,
2811 static int __net_init udp4_proc_init_net(struct net *net)
2813 return udp_proc_register(net, &udp4_seq_afinfo);
2816 static void __net_exit udp4_proc_exit_net(struct net *net)
2818 udp_proc_unregister(net, &udp4_seq_afinfo);
2821 static struct pernet_operations udp4_net_ops = {
2822 .init = udp4_proc_init_net,
2823 .exit = udp4_proc_exit_net,
2826 int __init udp4_proc_init(void)
2828 return register_pernet_subsys(&udp4_net_ops);
2831 void udp4_proc_exit(void)
2833 unregister_pernet_subsys(&udp4_net_ops);
2835 #endif /* CONFIG_PROC_FS */
2837 static __initdata unsigned long uhash_entries;
2838 static int __init set_uhash_entries(char *str)
2845 ret = kstrtoul(str, 0, &uhash_entries);
2849 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2850 uhash_entries = UDP_HTABLE_SIZE_MIN;
2853 __setup("uhash_entries=", set_uhash_entries);
2855 void __init udp_table_init(struct udp_table *table, const char *name)
2859 table->hash = alloc_large_system_hash(name,
2860 2 * sizeof(struct udp_hslot),
2862 21, /* one slot per 2 MB */
2866 UDP_HTABLE_SIZE_MIN,
2869 table->hash2 = table->hash + (table->mask + 1);
2870 for (i = 0; i <= table->mask; i++) {
2871 INIT_HLIST_HEAD(&table->hash[i].head);
2872 table->hash[i].count = 0;
2873 spin_lock_init(&table->hash[i].lock);
2875 for (i = 0; i <= table->mask; i++) {
2876 INIT_HLIST_HEAD(&table->hash2[i].head);
2877 table->hash2[i].count = 0;
2878 spin_lock_init(&table->hash2[i].lock);
2882 u32 udp_flow_hashrnd(void)
2884 static u32 hashrnd __read_mostly;
2886 net_get_random_once(&hashrnd, sizeof(hashrnd));
2890 EXPORT_SYMBOL(udp_flow_hashrnd);
2892 void __init udp_init(void)
2894 unsigned long limit;
2897 udp_table_init(&udp_table, "UDP");
2898 limit = nr_free_buffer_pages() / 8;
2899 limit = max(limit, 128UL);
2900 sysctl_udp_mem[0] = limit / 4 * 3;
2901 sysctl_udp_mem[1] = limit;
2902 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2904 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2905 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2907 /* 16 spinlocks per cpu */
2908 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
2909 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
2912 panic("UDP: failed to alloc udp_busylocks\n");
2913 for (i = 0; i < (1U << udp_busylocks_log); i++)
2914 spin_lock_init(udp_busylocks + i);