1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
7 * The User Datagram Protocol (UDP).
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
12 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
13 * Hirokazu Takahashi, <taka@valinux.co.jp>
16 * Alan Cox : verify_area() calls
17 * Alan Cox : stopped close while in use off icmp
18 * messages. Not a fix but a botch that
19 * for udp at least is 'valid'.
20 * Alan Cox : Fixed icmp handling properly
21 * Alan Cox : Correct error for oversized datagrams
22 * Alan Cox : Tidied select() semantics.
23 * Alan Cox : udp_err() fixed properly, also now
24 * select and read wake correctly on errors
25 * Alan Cox : udp_send verify_area moved to avoid mem leak
26 * Alan Cox : UDP can count its memory
27 * Alan Cox : send to an unknown connection causes
28 * an ECONNREFUSED off the icmp, but
30 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
31 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
32 * bug no longer crashes it.
33 * Fred Van Kempen : Net2e support for sk->broadcast.
34 * Alan Cox : Uses skb_free_datagram
35 * Alan Cox : Added get/set sockopt support.
36 * Alan Cox : Broadcasting without option set returns EACCES.
37 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
38 * Alan Cox : Use ip_tos and ip_ttl
39 * Alan Cox : SNMP Mibs
40 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
41 * Matt Dillon : UDP length checks.
42 * Alan Cox : Smarter af_inet used properly.
43 * Alan Cox : Use new kernel side addressing.
44 * Alan Cox : Incorrect return on truncated datagram receive.
45 * Arnt Gulbrandsen : New udp_send and stuff
46 * Alan Cox : Cache last socket
47 * Alan Cox : Route cache
48 * Jon Peatfield : Minor efficiency fix to sendto().
49 * Mike Shaver : RFC1122 checks.
50 * Alan Cox : Nonblocking error fix.
51 * Willy Konynenberg : Transparent proxying support.
52 * Mike McLagan : Routing by source
53 * David S. Miller : New socket lookup architecture.
54 * Last socket cache retained as it
55 * does have a high hit rate.
56 * Olaf Kirch : Don't linearise iovec on sendmsg.
57 * Andi Kleen : Some cleanups, cache destination entry
59 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
60 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
61 * return ENOTCONN for unconnected sockets (POSIX)
62 * Janos Farkas : don't deliver multi/broadcasts to a different
63 * bound-to-device socket
64 * Hirokazu Takahashi : HW checksumming for outgoing UDP
66 * Hirokazu Takahashi : sendfile() on UDP works now.
67 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
68 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
69 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
70 * a single port at the same time.
71 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
72 * James Chapman : Add L2TP encapsulation type.
75 #define pr_fmt(fmt) "UDP: " fmt
77 #include <linux/uaccess.h>
78 #include <asm/ioctls.h>
79 #include <linux/memblock.h>
80 #include <linux/highmem.h>
81 #include <linux/types.h>
82 #include <linux/fcntl.h>
83 #include <linux/module.h>
84 #include <linux/socket.h>
85 #include <linux/sockios.h>
86 #include <linux/igmp.h>
87 #include <linux/inetdevice.h>
89 #include <linux/errno.h>
90 #include <linux/timer.h>
92 #include <linux/inet.h>
93 #include <linux/netdevice.h>
94 #include <linux/slab.h>
95 #include <net/tcp_states.h>
96 #include <linux/skbuff.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <net/net_namespace.h>
100 #include <net/icmp.h>
101 #include <net/inet_hashtables.h>
102 #include <net/ip_tunnels.h>
103 #include <net/route.h>
104 #include <net/checksum.h>
105 #include <net/xfrm.h>
106 #include <trace/events/udp.h>
107 #include <linux/static_key.h>
108 #include <linux/btf_ids.h>
109 #include <trace/events/skb.h>
110 #include <net/busy_poll.h>
111 #include "udp_impl.h"
112 #include <net/sock_reuseport.h>
113 #include <net/addrconf.h>
114 #include <net/udp_tunnel.h>
115 #if IS_ENABLED(CONFIG_IPV6)
116 #include <net/ipv6_stubs.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 atomic_long_t udp_memory_allocated;
126 EXPORT_SYMBOL(udp_memory_allocated);
128 #define MAX_UDP_PORTS 65536
129 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
131 static int udp_lib_lport_inuse(struct net *net, __u16 num,
132 const struct udp_hslot *hslot,
133 unsigned long *bitmap,
134 struct sock *sk, unsigned int log)
137 kuid_t uid = sock_i_uid(sk);
139 sk_for_each(sk2, &hslot->head) {
140 if (net_eq(sock_net(sk2), net) &&
142 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
143 (!sk2->sk_reuse || !sk->sk_reuse) &&
144 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
145 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
146 inet_rcv_saddr_equal(sk, sk2, true)) {
147 if (sk2->sk_reuseport && sk->sk_reuseport &&
148 !rcu_access_pointer(sk->sk_reuseport_cb) &&
149 uid_eq(uid, sock_i_uid(sk2))) {
155 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
164 * Note: we still hold spinlock of primary hash chain, so no other writer
165 * can insert/delete a socket with local_port == num
167 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
168 struct udp_hslot *hslot2,
172 kuid_t uid = sock_i_uid(sk);
175 spin_lock(&hslot2->lock);
176 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
177 if (net_eq(sock_net(sk2), net) &&
179 (udp_sk(sk2)->udp_port_hash == num) &&
180 (!sk2->sk_reuse || !sk->sk_reuse) &&
181 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
182 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
183 inet_rcv_saddr_equal(sk, sk2, true)) {
184 if (sk2->sk_reuseport && sk->sk_reuseport &&
185 !rcu_access_pointer(sk->sk_reuseport_cb) &&
186 uid_eq(uid, sock_i_uid(sk2))) {
194 spin_unlock(&hslot2->lock);
198 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
200 struct net *net = sock_net(sk);
201 kuid_t uid = sock_i_uid(sk);
204 sk_for_each(sk2, &hslot->head) {
205 if (net_eq(sock_net(sk2), net) &&
207 sk2->sk_family == sk->sk_family &&
208 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
209 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
210 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
211 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
212 inet_rcv_saddr_equal(sk, sk2, false)) {
213 return reuseport_add_sock(sk, sk2,
214 inet_rcv_saddr_any(sk));
218 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
222 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
224 * @sk: socket struct in question
225 * @snum: port number to look up
226 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
229 int udp_lib_get_port(struct sock *sk, unsigned short snum,
230 unsigned int hash2_nulladdr)
232 struct udp_hslot *hslot, *hslot2;
233 struct udp_table *udptable = sk->sk_prot->h.udp_table;
235 struct net *net = sock_net(sk);
238 int low, high, remaining;
240 unsigned short first, last;
241 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
243 inet_get_local_port_range(net, &low, &high);
244 remaining = (high - low) + 1;
246 rand = prandom_u32();
247 first = reciprocal_scale(rand, remaining) + low;
249 * force rand to be an odd multiple of UDP_HTABLE_SIZE
251 rand = (rand | 1) * (udptable->mask + 1);
252 last = first + udptable->mask + 1;
254 hslot = udp_hashslot(udptable, net, first);
255 bitmap_zero(bitmap, PORTS_PER_CHAIN);
256 spin_lock_bh(&hslot->lock);
257 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
262 * Iterate on all possible values of snum for this hash.
263 * Using steps of an odd multiple of UDP_HTABLE_SIZE
264 * give us randomization and full range coverage.
267 if (low <= snum && snum <= high &&
268 !test_bit(snum >> udptable->log, bitmap) &&
269 !inet_is_local_reserved_port(net, snum))
272 } while (snum != first);
273 spin_unlock_bh(&hslot->lock);
275 } while (++first != last);
278 hslot = udp_hashslot(udptable, net, snum);
279 spin_lock_bh(&hslot->lock);
280 if (hslot->count > 10) {
282 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
284 slot2 &= udptable->mask;
285 hash2_nulladdr &= udptable->mask;
287 hslot2 = udp_hashslot2(udptable, slot2);
288 if (hslot->count < hslot2->count)
289 goto scan_primary_hash;
291 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
292 if (!exist && (hash2_nulladdr != slot2)) {
293 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
294 exist = udp_lib_lport_inuse2(net, snum, hslot2,
303 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
307 inet_sk(sk)->inet_num = snum;
308 udp_sk(sk)->udp_port_hash = snum;
309 udp_sk(sk)->udp_portaddr_hash ^= snum;
310 if (sk_unhashed(sk)) {
311 if (sk->sk_reuseport &&
312 udp_reuseport_add_sock(sk, hslot)) {
313 inet_sk(sk)->inet_num = 0;
314 udp_sk(sk)->udp_port_hash = 0;
315 udp_sk(sk)->udp_portaddr_hash ^= snum;
319 sk_add_node_rcu(sk, &hslot->head);
321 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
323 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
324 spin_lock(&hslot2->lock);
325 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
326 sk->sk_family == AF_INET6)
327 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
330 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
333 spin_unlock(&hslot2->lock);
335 sock_set_flag(sk, SOCK_RCU_FREE);
338 spin_unlock_bh(&hslot->lock);
342 EXPORT_SYMBOL(udp_lib_get_port);
344 int udp_v4_get_port(struct sock *sk, unsigned short snum)
346 unsigned int hash2_nulladdr =
347 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
348 unsigned int hash2_partial =
349 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
351 /* precompute partial secondary hash */
352 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
353 return udp_lib_get_port(sk, snum, hash2_nulladdr);
356 static int compute_score(struct sock *sk, struct net *net,
357 __be32 saddr, __be16 sport,
358 __be32 daddr, unsigned short hnum,
362 struct inet_sock *inet;
365 if (!net_eq(sock_net(sk), net) ||
366 udp_sk(sk)->udp_port_hash != hnum ||
370 if (sk->sk_rcv_saddr != daddr)
373 score = (sk->sk_family == PF_INET) ? 2 : 1;
376 if (inet->inet_daddr) {
377 if (inet->inet_daddr != saddr)
382 if (inet->inet_dport) {
383 if (inet->inet_dport != sport)
388 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
392 if (sk->sk_bound_dev_if)
395 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
400 static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
401 const __u16 lport, const __be32 faddr,
404 static u32 udp_ehash_secret __read_mostly;
406 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
408 return __inet_ehashfn(laddr, lport, faddr, fport,
409 udp_ehash_secret + net_hash_mix(net));
412 static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
414 __be32 saddr, __be16 sport,
415 __be32 daddr, unsigned short hnum)
417 struct sock *reuse_sk = NULL;
420 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
421 hash = udp_ehashfn(net, daddr, hnum, saddr, sport);
422 reuse_sk = reuseport_select_sock(sk, hash, skb,
423 sizeof(struct udphdr));
428 /* called with rcu_read_lock() */
429 static struct sock *udp4_lib_lookup2(struct net *net,
430 __be32 saddr, __be16 sport,
431 __be32 daddr, unsigned int hnum,
433 struct udp_hslot *hslot2,
436 struct sock *sk, *result;
441 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
442 score = compute_score(sk, net, saddr, sport,
443 daddr, hnum, dif, sdif);
444 if (score > badness) {
445 result = lookup_reuseport(net, sk, skb,
446 saddr, sport, daddr, hnum);
447 /* Fall back to scoring if group has connections */
448 if (result && !reuseport_has_conns(sk, false))
451 result = result ? : sk;
458 static struct sock *udp4_lookup_run_bpf(struct net *net,
459 struct udp_table *udptable,
461 __be32 saddr, __be16 sport,
462 __be32 daddr, u16 hnum)
464 struct sock *sk, *reuse_sk;
467 if (udptable != &udp_table)
468 return NULL; /* only UDP is supported */
470 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP,
471 saddr, sport, daddr, hnum, &sk);
472 if (no_reuseport || IS_ERR_OR_NULL(sk))
475 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
481 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
482 * harder than this. -DaveM
484 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
485 __be16 sport, __be32 daddr, __be16 dport, int dif,
486 int sdif, struct udp_table *udptable, struct sk_buff *skb)
488 unsigned short hnum = ntohs(dport);
489 unsigned int hash2, slot2;
490 struct udp_hslot *hslot2;
491 struct sock *result, *sk;
493 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
494 slot2 = hash2 & udptable->mask;
495 hslot2 = &udptable->hash2[slot2];
497 /* Lookup connected or non-wildcard socket */
498 result = udp4_lib_lookup2(net, saddr, sport,
499 daddr, hnum, dif, sdif,
501 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
504 /* Lookup redirect from BPF */
505 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
506 sk = udp4_lookup_run_bpf(net, udptable, skb,
507 saddr, sport, daddr, hnum);
514 /* Got non-wildcard socket or error on first lookup */
518 /* Lookup wildcard sockets */
519 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
520 slot2 = hash2 & udptable->mask;
521 hslot2 = &udptable->hash2[slot2];
523 result = udp4_lib_lookup2(net, saddr, sport,
524 htonl(INADDR_ANY), hnum, dif, sdif,
531 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
533 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
534 __be16 sport, __be16 dport,
535 struct udp_table *udptable)
537 const struct iphdr *iph = ip_hdr(skb);
539 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
540 iph->daddr, dport, inet_iif(skb),
541 inet_sdif(skb), udptable, skb);
544 struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
545 __be16 sport, __be16 dport)
547 const struct iphdr *iph = ip_hdr(skb);
549 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
550 iph->daddr, dport, inet_iif(skb),
551 inet_sdif(skb), &udp_table, NULL);
554 /* Must be called under rcu_read_lock().
555 * Does increment socket refcount.
557 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
558 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
559 __be32 daddr, __be16 dport, int dif)
563 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
564 dif, 0, &udp_table, NULL);
565 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
569 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
572 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
573 __be16 loc_port, __be32 loc_addr,
574 __be16 rmt_port, __be32 rmt_addr,
575 int dif, int sdif, unsigned short hnum)
577 struct inet_sock *inet = inet_sk(sk);
579 if (!net_eq(sock_net(sk), net) ||
580 udp_sk(sk)->udp_port_hash != hnum ||
581 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
582 (inet->inet_dport != rmt_port && inet->inet_dport) ||
583 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
584 ipv6_only_sock(sk) ||
585 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
587 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
592 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
593 void udp_encap_enable(void)
595 static_branch_inc(&udp_encap_needed_key);
597 EXPORT_SYMBOL(udp_encap_enable);
599 void udp_encap_disable(void)
601 static_branch_dec(&udp_encap_needed_key);
603 EXPORT_SYMBOL(udp_encap_disable);
605 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
606 * through error handlers in encapsulations looking for a match.
608 static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
612 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
613 int (*handler)(struct sk_buff *skb, u32 info);
614 const struct ip_tunnel_encap_ops *encap;
616 encap = rcu_dereference(iptun_encaps[i]);
619 handler = encap->err_handler;
620 if (handler && !handler(skb, info))
627 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
628 * reversing source and destination port: this will match tunnels that force the
629 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
630 * lwtunnels might actually break this assumption by being configured with
631 * different destination ports on endpoints, in this case we won't be able to
632 * trace ICMP messages back to them.
634 * If this doesn't match any socket, probe tunnels with arbitrary destination
635 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
636 * we've sent packets to won't necessarily match the local destination port.
638 * Then ask the tunnel implementation to match the error against a valid
641 * Return an error if we can't find a match, the socket if we need further
642 * processing, zero otherwise.
644 static struct sock *__udp4_lib_err_encap(struct net *net,
645 const struct iphdr *iph,
647 struct udp_table *udptable,
649 struct sk_buff *skb, u32 info)
651 int (*lookup)(struct sock *sk, struct sk_buff *skb);
652 int network_offset, transport_offset;
655 network_offset = skb_network_offset(skb);
656 transport_offset = skb_transport_offset(skb);
658 /* Network header needs to point to the outer IPv4 header inside ICMP */
659 skb_reset_network_header(skb);
661 /* Transport header needs to point to the UDP header */
662 skb_set_transport_header(skb, iph->ihl << 2);
667 lookup = READ_ONCE(up->encap_err_lookup);
668 if (lookup && lookup(sk, skb))
674 sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
675 iph->saddr, uh->dest, skb->dev->ifindex, 0,
680 lookup = READ_ONCE(up->encap_err_lookup);
681 if (!lookup || lookup(sk, skb))
687 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info));
689 skb_set_transport_header(skb, transport_offset);
690 skb_set_network_header(skb, network_offset);
696 * This routine is called by the ICMP module when it gets some
697 * sort of error condition. If err < 0 then the socket should
698 * be closed and the error returned to the user. If err > 0
699 * it's just the icmp type << 8 | icmp code.
700 * Header points to the ip header of the error packet. We move
701 * on past this. Then (as it used to claim before adjustment)
702 * header points to the first 8 bytes of the udp header. We need
703 * to find the appropriate port.
706 int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
708 struct inet_sock *inet;
709 const struct iphdr *iph = (const struct iphdr *)skb->data;
710 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
711 const int type = icmp_hdr(skb)->type;
712 const int code = icmp_hdr(skb)->code;
717 struct net *net = dev_net(skb->dev);
719 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
720 iph->saddr, uh->source, skb->dev->ifindex,
721 inet_sdif(skb), udptable, NULL);
723 if (!sk || udp_sk(sk)->encap_type) {
724 /* No socket for error: try tunnels before discarding */
725 if (static_branch_unlikely(&udp_encap_needed_key)) {
726 sk = __udp4_lib_err_encap(net, iph, uh, udptable, sk, skb,
731 sk = ERR_PTR(-ENOENT);
734 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
747 case ICMP_TIME_EXCEEDED:
750 case ICMP_SOURCE_QUENCH:
752 case ICMP_PARAMETERPROB:
756 case ICMP_DEST_UNREACH:
757 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
758 ipv4_sk_update_pmtu(skb, sk, info);
759 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
767 if (code <= NR_ICMP_UNREACH) {
768 harderr = icmp_err_convert[code].fatal;
769 err = icmp_err_convert[code].errno;
773 ipv4_sk_redirect(skb, sk);
778 * RFC1122: OK. Passes ICMP errors back to application, as per
782 /* ...not for tunnels though: we don't have a sending socket */
785 if (!inet->recverr) {
786 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
789 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
797 int udp_err(struct sk_buff *skb, u32 info)
799 return __udp4_lib_err(skb, info, &udp_table);
803 * Throw away all pending data and cancel the corking. Socket is locked.
805 void udp_flush_pending_frames(struct sock *sk)
807 struct udp_sock *up = udp_sk(sk);
812 ip_flush_pending_frames(sk);
815 EXPORT_SYMBOL(udp_flush_pending_frames);
818 * udp4_hwcsum - handle outgoing HW checksumming
819 * @skb: sk_buff containing the filled-in UDP header
820 * (checksum field must be zeroed out)
821 * @src: source IP address
822 * @dst: destination IP address
824 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
826 struct udphdr *uh = udp_hdr(skb);
827 int offset = skb_transport_offset(skb);
828 int len = skb->len - offset;
832 if (!skb_has_frag_list(skb)) {
834 * Only one fragment on the socket.
836 skb->csum_start = skb_transport_header(skb) - skb->head;
837 skb->csum_offset = offsetof(struct udphdr, check);
838 uh->check = ~csum_tcpudp_magic(src, dst, len,
841 struct sk_buff *frags;
844 * HW-checksum won't work as there are two or more
845 * fragments on the socket so that all csums of sk_buffs
848 skb_walk_frags(skb, frags) {
849 csum = csum_add(csum, frags->csum);
853 csum = skb_checksum(skb, offset, hlen, csum);
854 skb->ip_summed = CHECKSUM_NONE;
856 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
858 uh->check = CSUM_MANGLED_0;
861 EXPORT_SYMBOL_GPL(udp4_hwcsum);
863 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
864 * for the simple case like when setting the checksum for a UDP tunnel.
866 void udp_set_csum(bool nocheck, struct sk_buff *skb,
867 __be32 saddr, __be32 daddr, int len)
869 struct udphdr *uh = udp_hdr(skb);
873 } else if (skb_is_gso(skb)) {
874 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
875 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
877 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
879 uh->check = CSUM_MANGLED_0;
881 skb->ip_summed = CHECKSUM_PARTIAL;
882 skb->csum_start = skb_transport_header(skb) - skb->head;
883 skb->csum_offset = offsetof(struct udphdr, check);
884 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
887 EXPORT_SYMBOL(udp_set_csum);
889 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
890 struct inet_cork *cork)
892 struct sock *sk = skb->sk;
893 struct inet_sock *inet = inet_sk(sk);
896 int is_udplite = IS_UDPLITE(sk);
897 int offset = skb_transport_offset(skb);
898 int len = skb->len - offset;
899 int datalen = len - sizeof(*uh);
903 * Create a UDP header
906 uh->source = inet->inet_sport;
907 uh->dest = fl4->fl4_dport;
908 uh->len = htons(len);
911 if (cork->gso_size) {
912 const int hlen = skb_network_header_len(skb) +
913 sizeof(struct udphdr);
915 if (hlen + cork->gso_size > cork->fragsize) {
919 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
923 if (sk->sk_no_check_tx) {
927 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
928 dst_xfrm(skb_dst(skb))) {
933 if (datalen > cork->gso_size) {
934 skb_shinfo(skb)->gso_size = cork->gso_size;
935 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
936 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
942 if (is_udplite) /* UDP-Lite */
943 csum = udplite_csum(skb);
945 else if (sk->sk_no_check_tx) { /* UDP csum off */
947 skb->ip_summed = CHECKSUM_NONE;
950 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
953 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
957 csum = udp_csum(skb);
959 /* add protocol-dependent pseudo-header */
960 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
961 sk->sk_protocol, csum);
963 uh->check = CSUM_MANGLED_0;
966 err = ip_send_skb(sock_net(sk), skb);
968 if (err == -ENOBUFS && !inet->recverr) {
969 UDP_INC_STATS(sock_net(sk),
970 UDP_MIB_SNDBUFERRORS, is_udplite);
974 UDP_INC_STATS(sock_net(sk),
975 UDP_MIB_OUTDATAGRAMS, is_udplite);
980 * Push out all pending data as one UDP datagram. Socket is locked.
982 int udp_push_pending_frames(struct sock *sk)
984 struct udp_sock *up = udp_sk(sk);
985 struct inet_sock *inet = inet_sk(sk);
986 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
990 skb = ip_finish_skb(sk, fl4);
994 err = udp_send_skb(skb, fl4, &inet->cork.base);
1001 EXPORT_SYMBOL(udp_push_pending_frames);
1003 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
1005 switch (cmsg->cmsg_type) {
1007 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
1009 *gso_size = *(__u16 *)CMSG_DATA(cmsg);
1016 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
1018 struct cmsghdr *cmsg;
1019 bool need_ip = false;
1022 for_each_cmsghdr(cmsg, msg) {
1023 if (!CMSG_OK(msg, cmsg))
1026 if (cmsg->cmsg_level != SOL_UDP) {
1031 err = __udp_cmsg_send(cmsg, gso_size);
1038 EXPORT_SYMBOL_GPL(udp_cmsg_send);
1040 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1042 struct inet_sock *inet = inet_sk(sk);
1043 struct udp_sock *up = udp_sk(sk);
1044 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1045 struct flowi4 fl4_stack;
1048 struct ipcm_cookie ipc;
1049 struct rtable *rt = NULL;
1052 __be32 daddr, faddr, saddr;
1055 int err, is_udplite = IS_UDPLITE(sk);
1056 int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
1057 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1058 struct sk_buff *skb;
1059 struct ip_options_data opt_copy;
1068 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
1071 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1073 fl4 = &inet->cork.fl.u.ip4;
1076 * There are pending frames.
1077 * The socket lock must be held while it's corked.
1080 if (likely(up->pending)) {
1081 if (unlikely(up->pending != AF_INET)) {
1085 goto do_append_data;
1089 ulen += sizeof(struct udphdr);
1092 * Get and verify the address.
1095 if (msg->msg_namelen < sizeof(*usin))
1097 if (usin->sin_family != AF_INET) {
1098 if (usin->sin_family != AF_UNSPEC)
1099 return -EAFNOSUPPORT;
1102 daddr = usin->sin_addr.s_addr;
1103 dport = usin->sin_port;
1107 if (sk->sk_state != TCP_ESTABLISHED)
1108 return -EDESTADDRREQ;
1109 daddr = inet->inet_daddr;
1110 dport = inet->inet_dport;
1111 /* Open fast path for connected socket.
1112 Route will not be used, if at least one option is set.
1117 ipcm_init_sk(&ipc, inet);
1118 ipc.gso_size = READ_ONCE(up->gso_size);
1120 if (msg->msg_controllen) {
1121 err = udp_cmsg_send(sk, msg, &ipc.gso_size);
1123 err = ip_cmsg_send(sk, msg, &ipc,
1124 sk->sk_family == AF_INET6);
1125 if (unlikely(err < 0)) {
1134 struct ip_options_rcu *inet_opt;
1137 inet_opt = rcu_dereference(inet->inet_opt);
1139 memcpy(&opt_copy, inet_opt,
1140 sizeof(*inet_opt) + inet_opt->opt.optlen);
1141 ipc.opt = &opt_copy.opt;
1146 if (cgroup_bpf_enabled(CGROUP_UDP4_SENDMSG) && !connected) {
1147 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1148 (struct sockaddr *)usin, &ipc.addr);
1152 if (usin->sin_port == 0) {
1153 /* BPF program set invalid port. Reject it. */
1157 daddr = usin->sin_addr.s_addr;
1158 dport = usin->sin_port;
1163 ipc.addr = faddr = daddr;
1165 if (ipc.opt && ipc.opt->opt.srr) {
1170 faddr = ipc.opt->opt.faddr;
1173 tos = get_rttos(&ipc, inet);
1174 if (sock_flag(sk, SOCK_LOCALROUTE) ||
1175 (msg->msg_flags & MSG_DONTROUTE) ||
1176 (ipc.opt && ipc.opt->opt.is_strictroute)) {
1181 if (ipv4_is_multicast(daddr)) {
1182 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
1183 ipc.oif = inet->mc_index;
1185 saddr = inet->mc_addr;
1187 } else if (!ipc.oif) {
1188 ipc.oif = inet->uc_index;
1189 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
1190 /* oif is set, packet is to local broadcast and
1191 * uc_index is set. oif is most likely set
1192 * by sk_bound_dev_if. If uc_index != oif check if the
1193 * oif is an L3 master and uc_index is an L3 slave.
1194 * If so, we want to allow the send using the uc_index.
1196 if (ipc.oif != inet->uc_index &&
1197 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
1199 ipc.oif = inet->uc_index;
1204 rt = (struct rtable *)sk_dst_check(sk, 0);
1207 struct net *net = sock_net(sk);
1208 __u8 flow_flags = inet_sk_flowi_flags(sk);
1212 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos,
1213 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1215 faddr, saddr, dport, inet->inet_sport,
1218 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
1219 rt = ip_route_output_flow(net, fl4, sk);
1223 if (err == -ENETUNREACH)
1224 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1229 if ((rt->rt_flags & RTCF_BROADCAST) &&
1230 !sock_flag(sk, SOCK_BROADCAST))
1233 sk_dst_set(sk, dst_clone(&rt->dst));
1236 if (msg->msg_flags&MSG_CONFIRM)
1242 daddr = ipc.addr = fl4->daddr;
1244 /* Lockless fast path for the non-corking case. */
1246 struct inet_cork cork;
1248 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1249 sizeof(struct udphdr), &ipc, &rt,
1250 &cork, msg->msg_flags);
1252 if (!IS_ERR_OR_NULL(skb))
1253 err = udp_send_skb(skb, fl4, &cork);
1258 if (unlikely(up->pending)) {
1259 /* The socket is already corked while preparing it. */
1260 /* ... which is an evident application bug. --ANK */
1263 net_dbg_ratelimited("socket already corked\n");
1268 * Now cork the socket to pend data.
1270 fl4 = &inet->cork.fl.u.ip4;
1273 fl4->fl4_dport = dport;
1274 fl4->fl4_sport = inet->inet_sport;
1275 up->pending = AF_INET;
1279 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1280 sizeof(struct udphdr), &ipc, &rt,
1281 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1283 udp_flush_pending_frames(sk);
1285 err = udp_push_pending_frames(sk);
1286 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1298 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1299 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1300 * we don't have a good statistic (IpOutDiscards but it can be too many
1301 * things). We could add another new stat but at least for now that
1302 * seems like overkill.
1304 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1305 UDP_INC_STATS(sock_net(sk),
1306 UDP_MIB_SNDBUFERRORS, is_udplite);
1311 if (msg->msg_flags & MSG_PROBE)
1312 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1313 if (!(msg->msg_flags&MSG_PROBE) || len)
1314 goto back_from_confirm;
1318 EXPORT_SYMBOL(udp_sendmsg);
1320 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1321 size_t size, int flags)
1323 struct inet_sock *inet = inet_sk(sk);
1324 struct udp_sock *up = udp_sk(sk);
1327 if (flags & MSG_SENDPAGE_NOTLAST)
1331 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1333 /* Call udp_sendmsg to specify destination address which
1334 * sendpage interface can't pass.
1335 * This will succeed only when the socket is connected.
1337 ret = udp_sendmsg(sk, &msg, 0);
1344 if (unlikely(!up->pending)) {
1347 net_dbg_ratelimited("cork failed\n");
1351 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1352 page, offset, size, flags);
1353 if (ret == -EOPNOTSUPP) {
1355 return sock_no_sendpage(sk->sk_socket, page, offset,
1359 udp_flush_pending_frames(sk);
1364 if (!(READ_ONCE(up->corkflag) || (flags&MSG_MORE)))
1365 ret = udp_push_pending_frames(sk);
1373 #define UDP_SKB_IS_STATELESS 0x80000000
1375 /* all head states (dst, sk, nf conntrack) except skb extensions are
1376 * cleared by udp_rcv().
1378 * We need to preserve secpath, if present, to eventually process
1379 * IP_CMSG_PASSSEC at recvmsg() time.
1381 * Other extensions can be cleared.
1383 static bool udp_try_make_stateless(struct sk_buff *skb)
1385 if (!skb_has_extensions(skb))
1388 if (!secpath_exists(skb)) {
1396 static void udp_set_dev_scratch(struct sk_buff *skb)
1398 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1400 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1401 scratch->_tsize_state = skb->truesize;
1402 #if BITS_PER_LONG == 64
1403 scratch->len = skb->len;
1404 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1405 scratch->is_linear = !skb_is_nonlinear(skb);
1407 if (udp_try_make_stateless(skb))
1408 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1411 static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1413 /* We come here after udp_lib_checksum_complete() returned 0.
1414 * This means that __skb_checksum_complete() might have
1415 * set skb->csum_valid to 1.
1416 * On 64bit platforms, we can set csum_unnecessary
1417 * to true, but only if the skb is not shared.
1419 #if BITS_PER_LONG == 64
1420 if (!skb_shared(skb))
1421 udp_skb_scratch(skb)->csum_unnecessary = true;
1425 static int udp_skb_truesize(struct sk_buff *skb)
1427 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1430 static bool udp_skb_has_head_state(struct sk_buff *skb)
1432 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1435 /* fully reclaim rmem/fwd memory allocated for skb */
1436 static void udp_rmem_release(struct sock *sk, int size, int partial,
1437 bool rx_queue_lock_held)
1439 struct udp_sock *up = udp_sk(sk);
1440 struct sk_buff_head *sk_queue;
1443 if (likely(partial)) {
1444 up->forward_deficit += size;
1445 size = up->forward_deficit;
1446 if (size < (sk->sk_rcvbuf >> 2) &&
1447 !skb_queue_empty(&up->reader_queue))
1450 size += up->forward_deficit;
1452 up->forward_deficit = 0;
1454 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1455 * if the called don't held it already
1457 sk_queue = &sk->sk_receive_queue;
1458 if (!rx_queue_lock_held)
1459 spin_lock(&sk_queue->lock);
1462 sk->sk_forward_alloc += size;
1463 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1464 sk->sk_forward_alloc -= amt;
1467 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1469 atomic_sub(size, &sk->sk_rmem_alloc);
1471 /* this can save us from acquiring the rx queue lock on next receive */
1472 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1474 if (!rx_queue_lock_held)
1475 spin_unlock(&sk_queue->lock);
1478 /* Note: called with reader_queue.lock held.
1479 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1480 * This avoids a cache line miss while receive_queue lock is held.
1481 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1483 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1485 prefetch(&skb->data);
1486 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1488 EXPORT_SYMBOL(udp_skb_destructor);
1490 /* as above, but the caller held the rx queue lock, too */
1491 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1493 prefetch(&skb->data);
1494 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1497 /* Idea of busylocks is to let producers grab an extra spinlock
1498 * to relieve pressure on the receive_queue spinlock shared by consumer.
1499 * Under flood, this means that only one producer can be in line
1500 * trying to acquire the receive_queue spinlock.
1501 * These busylock can be allocated on a per cpu manner, instead of a
1502 * per socket one (that would consume a cache line per socket)
1504 static int udp_busylocks_log __read_mostly;
1505 static spinlock_t *udp_busylocks __read_mostly;
1507 static spinlock_t *busylock_acquire(void *ptr)
1511 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1516 static void busylock_release(spinlock_t *busy)
1522 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1524 struct sk_buff_head *list = &sk->sk_receive_queue;
1525 int rmem, delta, amt, err = -ENOMEM;
1526 spinlock_t *busy = NULL;
1529 /* try to avoid the costly atomic add/sub pair when the receive
1530 * queue is full; always allow at least a packet
1532 rmem = atomic_read(&sk->sk_rmem_alloc);
1533 if (rmem > sk->sk_rcvbuf)
1536 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1537 * having linear skbs :
1538 * - Reduce memory overhead and thus increase receive queue capacity
1539 * - Less cache line misses at copyout() time
1540 * - Less work at consume_skb() (less alien page frag freeing)
1542 if (rmem > (sk->sk_rcvbuf >> 1)) {
1545 busy = busylock_acquire(sk);
1547 size = skb->truesize;
1548 udp_set_dev_scratch(skb);
1550 /* we drop only if the receive buf is full and the receive
1551 * queue contains some other skb
1553 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1554 if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
1557 spin_lock(&list->lock);
1558 if (size >= sk->sk_forward_alloc) {
1559 amt = sk_mem_pages(size);
1560 delta = amt << SK_MEM_QUANTUM_SHIFT;
1561 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1563 spin_unlock(&list->lock);
1567 sk->sk_forward_alloc += delta;
1570 sk->sk_forward_alloc -= size;
1572 /* no need to setup a destructor, we will explicitly release the
1573 * forward allocated memory on dequeue
1575 sock_skb_set_dropcount(sk, skb);
1577 __skb_queue_tail(list, skb);
1578 spin_unlock(&list->lock);
1580 if (!sock_flag(sk, SOCK_DEAD))
1581 sk->sk_data_ready(sk);
1583 busylock_release(busy);
1587 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1590 atomic_inc(&sk->sk_drops);
1591 busylock_release(busy);
1594 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1596 void udp_destruct_sock(struct sock *sk)
1598 /* reclaim completely the forward allocated memory */
1599 struct udp_sock *up = udp_sk(sk);
1600 unsigned int total = 0;
1601 struct sk_buff *skb;
1603 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1604 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1605 total += skb->truesize;
1608 udp_rmem_release(sk, total, 0, true);
1610 inet_sock_destruct(sk);
1612 EXPORT_SYMBOL_GPL(udp_destruct_sock);
1614 int udp_init_sock(struct sock *sk)
1616 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1617 sk->sk_destruct = udp_destruct_sock;
1620 EXPORT_SYMBOL_GPL(udp_init_sock);
1622 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1624 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1625 bool slow = lock_sock_fast(sk);
1627 sk_peek_offset_bwd(sk, len);
1628 unlock_sock_fast(sk, slow);
1631 if (!skb_unref(skb))
1634 /* In the more common cases we cleared the head states previously,
1635 * see __udp_queue_rcv_skb().
1637 if (unlikely(udp_skb_has_head_state(skb)))
1638 skb_release_head_state(skb);
1639 __consume_stateless_skb(skb);
1641 EXPORT_SYMBOL_GPL(skb_consume_udp);
1643 static struct sk_buff *__first_packet_length(struct sock *sk,
1644 struct sk_buff_head *rcvq,
1647 struct sk_buff *skb;
1649 while ((skb = skb_peek(rcvq)) != NULL) {
1650 if (udp_lib_checksum_complete(skb)) {
1651 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1653 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1655 atomic_inc(&sk->sk_drops);
1656 __skb_unlink(skb, rcvq);
1657 *total += skb->truesize;
1660 udp_skb_csum_unnecessary_set(skb);
1668 * first_packet_length - return length of first packet in receive queue
1671 * Drops all bad checksum frames, until a valid one is found.
1672 * Returns the length of found skb, or -1 if none is found.
1674 static int first_packet_length(struct sock *sk)
1676 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1677 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1678 struct sk_buff *skb;
1682 spin_lock_bh(&rcvq->lock);
1683 skb = __first_packet_length(sk, rcvq, &total);
1684 if (!skb && !skb_queue_empty_lockless(sk_queue)) {
1685 spin_lock(&sk_queue->lock);
1686 skb_queue_splice_tail_init(sk_queue, rcvq);
1687 spin_unlock(&sk_queue->lock);
1689 skb = __first_packet_length(sk, rcvq, &total);
1691 res = skb ? skb->len : -1;
1693 udp_rmem_release(sk, total, 1, false);
1694 spin_unlock_bh(&rcvq->lock);
1699 * IOCTL requests applicable to the UDP protocol
1702 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1707 int amount = sk_wmem_alloc_get(sk);
1709 return put_user(amount, (int __user *)arg);
1714 int amount = max_t(int, 0, first_packet_length(sk));
1716 return put_user(amount, (int __user *)arg);
1720 return -ENOIOCTLCMD;
1725 EXPORT_SYMBOL(udp_ioctl);
1727 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1728 int noblock, int *off, int *err)
1730 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1731 struct sk_buff_head *queue;
1732 struct sk_buff *last;
1736 queue = &udp_sk(sk)->reader_queue;
1737 flags |= noblock ? MSG_DONTWAIT : 0;
1738 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1740 struct sk_buff *skb;
1742 error = sock_error(sk);
1748 spin_lock_bh(&queue->lock);
1749 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1752 if (!(flags & MSG_PEEK))
1753 udp_skb_destructor(sk, skb);
1754 spin_unlock_bh(&queue->lock);
1758 if (skb_queue_empty_lockless(sk_queue)) {
1759 spin_unlock_bh(&queue->lock);
1763 /* refill the reader queue and walk it again
1764 * keep both queues locked to avoid re-acquiring
1765 * the sk_receive_queue lock if fwd memory scheduling
1768 spin_lock(&sk_queue->lock);
1769 skb_queue_splice_tail_init(sk_queue, queue);
1771 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1773 if (skb && !(flags & MSG_PEEK))
1774 udp_skb_dtor_locked(sk, skb);
1775 spin_unlock(&sk_queue->lock);
1776 spin_unlock_bh(&queue->lock);
1781 if (!sk_can_busy_loop(sk))
1784 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1785 } while (!skb_queue_empty_lockless(sk_queue));
1787 /* sk_queue is empty, reader_queue may contain peeked packets */
1789 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
1791 (struct sk_buff *)sk_queue));
1796 EXPORT_SYMBOL(__skb_recv_udp);
1798 int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
1799 sk_read_actor_t recv_actor)
1804 struct sk_buff *skb;
1807 skb = skb_recv_udp(sk, 0, 1, &err);
1811 if (udp_lib_checksum_complete(skb)) {
1812 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1814 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1816 atomic_inc(&sk->sk_drops);
1821 used = recv_actor(desc, skb, 0, skb->len);
1827 } else if (used <= skb->len) {
1838 EXPORT_SYMBOL(udp_read_sock);
1841 * This should be easy, if there is something there we
1842 * return it, otherwise we block.
1845 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1846 int flags, int *addr_len)
1848 struct inet_sock *inet = inet_sk(sk);
1849 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1850 struct sk_buff *skb;
1851 unsigned int ulen, copied;
1852 int off, err, peeking = flags & MSG_PEEK;
1853 int is_udplite = IS_UDPLITE(sk);
1854 bool checksum_valid = false;
1856 if (flags & MSG_ERRQUEUE)
1857 return ip_recv_error(sk, msg, len, addr_len);
1860 off = sk_peek_offset(sk, flags);
1861 skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
1865 ulen = udp_skb_len(skb);
1867 if (copied > ulen - off)
1868 copied = ulen - off;
1869 else if (copied < ulen)
1870 msg->msg_flags |= MSG_TRUNC;
1873 * If checksum is needed at all, try to do it while copying the
1874 * data. If the data is truncated, or if we only want a partial
1875 * coverage checksum (UDP-Lite), do it before the copy.
1878 if (copied < ulen || peeking ||
1879 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1880 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1881 !__udp_lib_checksum_complete(skb);
1882 if (!checksum_valid)
1886 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1887 if (udp_skb_is_linear(skb))
1888 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1890 err = skb_copy_datagram_msg(skb, off, msg, copied);
1892 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1898 if (unlikely(err)) {
1900 atomic_inc(&sk->sk_drops);
1901 UDP_INC_STATS(sock_net(sk),
1902 UDP_MIB_INERRORS, is_udplite);
1909 UDP_INC_STATS(sock_net(sk),
1910 UDP_MIB_INDATAGRAMS, is_udplite);
1912 sock_recv_ts_and_drops(msg, sk, skb);
1914 /* Copy the address. */
1916 sin->sin_family = AF_INET;
1917 sin->sin_port = udp_hdr(skb)->source;
1918 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1919 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1920 *addr_len = sizeof(*sin);
1922 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk,
1923 (struct sockaddr *)sin);
1926 if (udp_sk(sk)->gro_enabled)
1927 udp_cmsg_recv(msg, sk, skb);
1929 if (inet->cmsg_flags)
1930 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1933 if (flags & MSG_TRUNC)
1936 skb_consume_udp(sk, skb, peeking ? -err : err);
1940 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1941 udp_skb_destructor)) {
1942 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1943 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1947 /* starting over for a new packet, but check if we need to yield */
1949 msg->msg_flags &= ~MSG_TRUNC;
1953 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1955 /* This check is replicated from __ip4_datagram_connect() and
1956 * intended to prevent BPF program called below from accessing bytes
1957 * that are out of the bound specified by user in addr_len.
1959 if (addr_len < sizeof(struct sockaddr_in))
1962 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
1964 EXPORT_SYMBOL(udp_pre_connect);
1966 int __udp_disconnect(struct sock *sk, int flags)
1968 struct inet_sock *inet = inet_sk(sk);
1970 * 1003.1g - break association.
1973 sk->sk_state = TCP_CLOSE;
1974 inet->inet_daddr = 0;
1975 inet->inet_dport = 0;
1976 sock_rps_reset_rxhash(sk);
1977 sk->sk_bound_dev_if = 0;
1978 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
1979 inet_reset_saddr(sk);
1980 if (sk->sk_prot->rehash &&
1981 (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1982 sk->sk_prot->rehash(sk);
1985 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1986 sk->sk_prot->unhash(sk);
1987 inet->inet_sport = 0;
1992 EXPORT_SYMBOL(__udp_disconnect);
1994 int udp_disconnect(struct sock *sk, int flags)
1997 __udp_disconnect(sk, flags);
2001 EXPORT_SYMBOL(udp_disconnect);
2003 void udp_lib_unhash(struct sock *sk)
2005 if (sk_hashed(sk)) {
2006 struct udp_table *udptable = sk->sk_prot->h.udp_table;
2007 struct udp_hslot *hslot, *hslot2;
2009 hslot = udp_hashslot(udptable, sock_net(sk),
2010 udp_sk(sk)->udp_port_hash);
2011 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
2013 spin_lock_bh(&hslot->lock);
2014 if (rcu_access_pointer(sk->sk_reuseport_cb))
2015 reuseport_detach_sock(sk);
2016 if (sk_del_node_init_rcu(sk)) {
2018 inet_sk(sk)->inet_num = 0;
2019 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
2021 spin_lock(&hslot2->lock);
2022 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2024 spin_unlock(&hslot2->lock);
2026 spin_unlock_bh(&hslot->lock);
2029 EXPORT_SYMBOL(udp_lib_unhash);
2032 * inet_rcv_saddr was changed, we must rehash secondary hash
2034 void udp_lib_rehash(struct sock *sk, u16 newhash)
2036 if (sk_hashed(sk)) {
2037 struct udp_table *udptable = sk->sk_prot->h.udp_table;
2038 struct udp_hslot *hslot, *hslot2, *nhslot2;
2040 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
2041 nhslot2 = udp_hashslot2(udptable, newhash);
2042 udp_sk(sk)->udp_portaddr_hash = newhash;
2044 if (hslot2 != nhslot2 ||
2045 rcu_access_pointer(sk->sk_reuseport_cb)) {
2046 hslot = udp_hashslot(udptable, sock_net(sk),
2047 udp_sk(sk)->udp_port_hash);
2048 /* we must lock primary chain too */
2049 spin_lock_bh(&hslot->lock);
2050 if (rcu_access_pointer(sk->sk_reuseport_cb))
2051 reuseport_detach_sock(sk);
2053 if (hslot2 != nhslot2) {
2054 spin_lock(&hslot2->lock);
2055 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2057 spin_unlock(&hslot2->lock);
2059 spin_lock(&nhslot2->lock);
2060 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
2063 spin_unlock(&nhslot2->lock);
2066 spin_unlock_bh(&hslot->lock);
2070 EXPORT_SYMBOL(udp_lib_rehash);
2072 void udp_v4_rehash(struct sock *sk)
2074 u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
2075 inet_sk(sk)->inet_rcv_saddr,
2076 inet_sk(sk)->inet_num);
2077 udp_lib_rehash(sk, new_hash);
2080 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2084 if (inet_sk(sk)->inet_daddr) {
2085 sock_rps_save_rxhash(sk, skb);
2086 sk_mark_napi_id(sk, skb);
2087 sk_incoming_cpu_update(sk);
2089 sk_mark_napi_id_once(sk, skb);
2092 rc = __udp_enqueue_schedule_skb(sk, skb);
2094 int is_udplite = IS_UDPLITE(sk);
2096 /* Note that an ENOMEM error is charged twice */
2098 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
2101 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
2103 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2105 trace_udp_fail_queue_rcv_skb(rc, sk);
2115 * >0: "udp encap" protocol resubmission
2117 * Note that in the success and error cases, the skb is assumed to
2118 * have either been requeued or freed.
2120 static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
2122 struct udp_sock *up = udp_sk(sk);
2123 int is_udplite = IS_UDPLITE(sk);
2126 * Charge it to the socket, dropping if the queue is full.
2128 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
2132 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
2133 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
2136 * This is an encapsulation socket so pass the skb to
2137 * the socket's udp_encap_rcv() hook. Otherwise, just
2138 * fall through and pass this up the UDP socket.
2139 * up->encap_rcv() returns the following value:
2140 * =0 if skb was successfully passed to the encap
2141 * handler or was discarded by it.
2142 * >0 if skb should be passed on to UDP.
2143 * <0 if skb should be resubmitted as proto -N
2146 /* if we're overly short, let UDP handle it */
2147 encap_rcv = READ_ONCE(up->encap_rcv);
2151 /* Verify checksum before giving to encap */
2152 if (udp_lib_checksum_complete(skb))
2155 ret = encap_rcv(sk, skb);
2157 __UDP_INC_STATS(sock_net(sk),
2158 UDP_MIB_INDATAGRAMS,
2164 /* FALLTHROUGH -- it's a UDP Packet */
2168 * UDP-Lite specific tests, ignored on UDP sockets
2170 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
2173 * MIB statistics other than incrementing the error count are
2174 * disabled for the following two types of errors: these depend
2175 * on the application settings, not on the functioning of the
2176 * protocol stack as such.
2178 * RFC 3828 here recommends (sec 3.3): "There should also be a
2179 * way ... to ... at least let the receiving application block
2180 * delivery of packets with coverage values less than a value
2181 * provided by the application."
2183 if (up->pcrlen == 0) { /* full coverage was set */
2184 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2185 UDP_SKB_CB(skb)->cscov, skb->len);
2188 /* The next case involves violating the min. coverage requested
2189 * by the receiver. This is subtle: if receiver wants x and x is
2190 * greater than the buffersize/MTU then receiver will complain
2191 * that it wants x while sender emits packets of smaller size y.
2192 * Therefore the above ...()->partial_cov statement is essential.
2194 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
2195 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2196 UDP_SKB_CB(skb)->cscov, up->pcrlen);
2201 prefetch(&sk->sk_rmem_alloc);
2202 if (rcu_access_pointer(sk->sk_filter) &&
2203 udp_lib_checksum_complete(skb))
2206 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
2209 udp_csum_pull_header(skb);
2211 ipv4_pktinfo_prepare(sk, skb);
2212 return __udp_queue_rcv_skb(sk, skb);
2215 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2217 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2218 atomic_inc(&sk->sk_drops);
2223 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2225 struct sk_buff *next, *segs;
2228 if (likely(!udp_unexpected_gso(sk, skb)))
2229 return udp_queue_rcv_one_skb(sk, skb);
2231 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET);
2232 __skb_push(skb, -skb_mac_offset(skb));
2233 segs = udp_rcv_segment(sk, skb, true);
2234 skb_list_walk_safe(segs, skb, next) {
2235 __skb_pull(skb, skb_transport_offset(skb));
2237 udp_post_segment_fix_csum(skb);
2238 ret = udp_queue_rcv_one_skb(sk, skb);
2240 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret);
2245 /* For TCP sockets, sk_rx_dst is protected by socket lock
2246 * For UDP, we use xchg() to guard against concurrent changes.
2248 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2250 struct dst_entry *old;
2252 if (dst_hold_safe(dst)) {
2253 old = xchg(&sk->sk_rx_dst, dst);
2259 EXPORT_SYMBOL(udp_sk_rx_dst_set);
2262 * Multicasts and broadcasts go to each listener.
2264 * Note: called only from the BH handler context.
2266 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2268 __be32 saddr, __be32 daddr,
2269 struct udp_table *udptable,
2272 struct sock *sk, *first = NULL;
2273 unsigned short hnum = ntohs(uh->dest);
2274 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2275 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2276 unsigned int offset = offsetof(typeof(*sk), sk_node);
2277 int dif = skb->dev->ifindex;
2278 int sdif = inet_sdif(skb);
2279 struct hlist_node *node;
2280 struct sk_buff *nskb;
2283 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2285 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2287 hslot = &udptable->hash2[hash2];
2288 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2291 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2292 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2293 uh->source, saddr, dif, sdif, hnum))
2300 nskb = skb_clone(skb, GFP_ATOMIC);
2302 if (unlikely(!nskb)) {
2303 atomic_inc(&sk->sk_drops);
2304 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2306 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2310 if (udp_queue_rcv_skb(sk, nskb) > 0)
2314 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2315 if (use_hash2 && hash2 != hash2_any) {
2321 if (udp_queue_rcv_skb(first, skb) > 0)
2325 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2326 proto == IPPROTO_UDPLITE);
2331 /* Initialize UDP checksum. If exited with zero value (success),
2332 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2333 * Otherwise, csum completion requires checksumming packet body,
2334 * including udp header and folding it to skb->csum.
2336 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2341 UDP_SKB_CB(skb)->partial_cov = 0;
2342 UDP_SKB_CB(skb)->cscov = skb->len;
2344 if (proto == IPPROTO_UDPLITE) {
2345 err = udplite_checksum_init(skb, uh);
2349 if (UDP_SKB_CB(skb)->partial_cov) {
2350 skb->csum = inet_compute_pseudo(skb, proto);
2355 /* Note, we are only interested in != 0 or == 0, thus the
2358 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2359 inet_compute_pseudo);
2363 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2364 /* If SW calculated the value, we know it's bad */
2365 if (skb->csum_complete_sw)
2368 /* HW says the value is bad. Let's validate that.
2369 * skb->csum is no longer the full packet checksum,
2370 * so don't treat it as such.
2372 skb_checksum_complete_unset(skb);
2378 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2379 * return code conversion for ip layer consumption
2381 static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2386 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2387 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo);
2389 ret = udp_queue_rcv_skb(sk, skb);
2391 /* a return value > 0 means to resubmit the input, but
2392 * it wants the return to be -protocol, or 0
2400 * All we need to do is get the socket, and then do a checksum.
2403 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2408 unsigned short ulen;
2409 struct rtable *rt = skb_rtable(skb);
2410 __be32 saddr, daddr;
2411 struct net *net = dev_net(skb->dev);
2415 * Validate the packet.
2417 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2418 goto drop; /* No space for header. */
2421 ulen = ntohs(uh->len);
2422 saddr = ip_hdr(skb)->saddr;
2423 daddr = ip_hdr(skb)->daddr;
2425 if (ulen > skb->len)
2428 if (proto == IPPROTO_UDP) {
2429 /* UDP validates ulen. */
2430 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2435 if (udp4_csum_init(skb, uh, proto))
2438 sk = skb_steal_sock(skb, &refcounted);
2440 struct dst_entry *dst = skb_dst(skb);
2443 if (unlikely(sk->sk_rx_dst != dst))
2444 udp_sk_rx_dst_set(sk, dst);
2446 ret = udp_unicast_rcv_skb(sk, skb, uh);
2452 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2453 return __udp4_lib_mcast_deliver(net, skb, uh,
2454 saddr, daddr, udptable, proto);
2456 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2458 return udp_unicast_rcv_skb(sk, skb, uh);
2460 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2464 /* No socket. Drop packet silently, if checksum is wrong */
2465 if (udp_lib_checksum_complete(skb))
2468 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2469 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2472 * Hmm. We got an UDP packet to a port to which we
2473 * don't wanna listen. Ignore it.
2479 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2480 proto == IPPROTO_UDPLITE ? "Lite" : "",
2481 &saddr, ntohs(uh->source),
2483 &daddr, ntohs(uh->dest));
2488 * RFC1122: OK. Discards the bad packet silently (as far as
2489 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2491 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2492 proto == IPPROTO_UDPLITE ? "Lite" : "",
2493 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2495 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2497 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2502 /* We can only early demux multicast if there is a single matching socket.
2503 * If more than one socket found returns NULL
2505 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2506 __be16 loc_port, __be32 loc_addr,
2507 __be16 rmt_port, __be32 rmt_addr,
2510 struct sock *sk, *result;
2511 unsigned short hnum = ntohs(loc_port);
2512 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2513 struct udp_hslot *hslot = &udp_table.hash[slot];
2515 /* Do not bother scanning a too big list */
2516 if (hslot->count > 10)
2520 sk_for_each_rcu(sk, &hslot->head) {
2521 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2522 rmt_port, rmt_addr, dif, sdif, hnum)) {
2532 /* For unicast we should only early demux connected sockets or we can
2533 * break forwarding setups. The chains here can be long so only check
2534 * if the first socket is an exact match and if not move on.
2536 static struct sock *__udp4_lib_demux_lookup(struct net *net,
2537 __be16 loc_port, __be32 loc_addr,
2538 __be16 rmt_port, __be32 rmt_addr,
2541 unsigned short hnum = ntohs(loc_port);
2542 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2543 unsigned int slot2 = hash2 & udp_table.mask;
2544 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2545 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2546 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2549 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2550 if (INET_MATCH(sk, net, acookie, rmt_addr,
2551 loc_addr, ports, dif, sdif))
2553 /* Only check first socket in chain */
2559 int udp_v4_early_demux(struct sk_buff *skb)
2561 struct net *net = dev_net(skb->dev);
2562 struct in_device *in_dev = NULL;
2563 const struct iphdr *iph;
2564 const struct udphdr *uh;
2565 struct sock *sk = NULL;
2566 struct dst_entry *dst;
2567 int dif = skb->dev->ifindex;
2568 int sdif = inet_sdif(skb);
2571 /* validate the packet */
2572 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2578 if (skb->pkt_type == PACKET_MULTICAST) {
2579 in_dev = __in_dev_get_rcu(skb->dev);
2584 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2589 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2590 uh->source, iph->saddr,
2592 } else if (skb->pkt_type == PACKET_HOST) {
2593 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2594 uh->source, iph->saddr, dif, sdif);
2597 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2601 skb->destructor = sock_efree;
2602 dst = READ_ONCE(sk->sk_rx_dst);
2605 dst = dst_check(dst, 0);
2609 /* set noref for now.
2610 * any place which wants to hold dst has to call
2613 skb_dst_set_noref(skb, dst);
2615 /* for unconnected multicast sockets we need to validate
2616 * the source on each packet
2618 if (!inet_sk(sk)->inet_daddr && in_dev)
2619 return ip_mc_validate_source(skb, iph->daddr,
2621 iph->tos & IPTOS_RT_MASK,
2622 skb->dev, in_dev, &itag);
2627 int udp_rcv(struct sk_buff *skb)
2629 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2632 void udp_destroy_sock(struct sock *sk)
2634 struct udp_sock *up = udp_sk(sk);
2635 bool slow = lock_sock_fast(sk);
2637 /* protects from races with udp_abort() */
2638 sock_set_flag(sk, SOCK_DEAD);
2639 udp_flush_pending_frames(sk);
2640 unlock_sock_fast(sk, slow);
2641 if (static_branch_unlikely(&udp_encap_needed_key)) {
2642 if (up->encap_type) {
2643 void (*encap_destroy)(struct sock *sk);
2644 encap_destroy = READ_ONCE(up->encap_destroy);
2648 if (up->encap_enabled)
2649 static_branch_dec(&udp_encap_needed_key);
2654 * Socket option code for UDP
2656 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2657 sockptr_t optval, unsigned int optlen,
2658 int (*push_pending_frames)(struct sock *))
2660 struct udp_sock *up = udp_sk(sk);
2663 int is_udplite = IS_UDPLITE(sk);
2665 if (optlen < sizeof(int))
2668 if (copy_from_sockptr(&val, optval, sizeof(val)))
2671 valbool = val ? 1 : 0;
2676 WRITE_ONCE(up->corkflag, 1);
2678 WRITE_ONCE(up->corkflag, 0);
2680 push_pending_frames(sk);
2689 case UDP_ENCAP_ESPINUDP:
2690 case UDP_ENCAP_ESPINUDP_NON_IKE:
2691 #if IS_ENABLED(CONFIG_IPV6)
2692 if (sk->sk_family == AF_INET6)
2693 up->encap_rcv = ipv6_stub->xfrm6_udp_encap_rcv;
2696 up->encap_rcv = xfrm4_udp_encap_rcv;
2699 case UDP_ENCAP_L2TPINUDP:
2700 up->encap_type = val;
2702 udp_tunnel_encap_enable(sk->sk_socket);
2711 case UDP_NO_CHECK6_TX:
2712 up->no_check6_tx = valbool;
2715 case UDP_NO_CHECK6_RX:
2716 up->no_check6_rx = valbool;
2720 if (val < 0 || val > USHRT_MAX)
2722 WRITE_ONCE(up->gso_size, val);
2728 /* when enabling GRO, accept the related GSO packet type */
2730 udp_tunnel_encap_enable(sk->sk_socket);
2731 up->gro_enabled = valbool;
2732 up->accept_udp_l4 = valbool;
2737 * UDP-Lite's partial checksum coverage (RFC 3828).
2739 /* The sender sets actual checksum coverage length via this option.
2740 * The case coverage > packet length is handled by send module. */
2741 case UDPLITE_SEND_CSCOV:
2742 if (!is_udplite) /* Disable the option on UDP sockets */
2743 return -ENOPROTOOPT;
2744 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2746 else if (val > USHRT_MAX)
2749 up->pcflag |= UDPLITE_SEND_CC;
2752 /* The receiver specifies a minimum checksum coverage value. To make
2753 * sense, this should be set to at least 8 (as done below). If zero is
2754 * used, this again means full checksum coverage. */
2755 case UDPLITE_RECV_CSCOV:
2756 if (!is_udplite) /* Disable the option on UDP sockets */
2757 return -ENOPROTOOPT;
2758 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2760 else if (val > USHRT_MAX)
2763 up->pcflag |= UDPLITE_RECV_CC;
2773 EXPORT_SYMBOL(udp_lib_setsockopt);
2775 int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
2776 unsigned int optlen)
2778 if (level == SOL_UDP || level == SOL_UDPLITE)
2779 return udp_lib_setsockopt(sk, level, optname,
2781 udp_push_pending_frames);
2782 return ip_setsockopt(sk, level, optname, optval, optlen);
2785 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2786 char __user *optval, int __user *optlen)
2788 struct udp_sock *up = udp_sk(sk);
2791 if (get_user(len, optlen))
2794 len = min_t(unsigned int, len, sizeof(int));
2801 val = READ_ONCE(up->corkflag);
2805 val = up->encap_type;
2808 case UDP_NO_CHECK6_TX:
2809 val = up->no_check6_tx;
2812 case UDP_NO_CHECK6_RX:
2813 val = up->no_check6_rx;
2817 val = READ_ONCE(up->gso_size);
2821 val = up->gro_enabled;
2824 /* The following two cannot be changed on UDP sockets, the return is
2825 * always 0 (which corresponds to the full checksum coverage of UDP). */
2826 case UDPLITE_SEND_CSCOV:
2830 case UDPLITE_RECV_CSCOV:
2835 return -ENOPROTOOPT;
2838 if (put_user(len, optlen))
2840 if (copy_to_user(optval, &val, len))
2844 EXPORT_SYMBOL(udp_lib_getsockopt);
2846 int udp_getsockopt(struct sock *sk, int level, int optname,
2847 char __user *optval, int __user *optlen)
2849 if (level == SOL_UDP || level == SOL_UDPLITE)
2850 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2851 return ip_getsockopt(sk, level, optname, optval, optlen);
2855 * udp_poll - wait for a UDP event.
2856 * @file: - file struct
2858 * @wait: - poll table
2860 * This is same as datagram poll, except for the special case of
2861 * blocking sockets. If application is using a blocking fd
2862 * and a packet with checksum error is in the queue;
2863 * then it could get return from select indicating data available
2864 * but then block when reading it. Add special case code
2865 * to work around these arguably broken applications.
2867 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2869 __poll_t mask = datagram_poll(file, sock, wait);
2870 struct sock *sk = sock->sk;
2872 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
2873 mask |= EPOLLIN | EPOLLRDNORM;
2875 /* Check for false positives due to checksum errors */
2876 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2877 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2878 mask &= ~(EPOLLIN | EPOLLRDNORM);
2880 /* psock ingress_msg queue should not contain any bad checksum frames */
2881 if (sk_is_readable(sk))
2882 mask |= EPOLLIN | EPOLLRDNORM;
2886 EXPORT_SYMBOL(udp_poll);
2888 int udp_abort(struct sock *sk, int err)
2892 /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
2895 if (sock_flag(sk, SOCK_DEAD))
2899 sk_error_report(sk);
2900 __udp_disconnect(sk, 0);
2907 EXPORT_SYMBOL_GPL(udp_abort);
2909 struct proto udp_prot = {
2911 .owner = THIS_MODULE,
2912 .close = udp_lib_close,
2913 .pre_connect = udp_pre_connect,
2914 .connect = ip4_datagram_connect,
2915 .disconnect = udp_disconnect,
2917 .init = udp_init_sock,
2918 .destroy = udp_destroy_sock,
2919 .setsockopt = udp_setsockopt,
2920 .getsockopt = udp_getsockopt,
2921 .sendmsg = udp_sendmsg,
2922 .recvmsg = udp_recvmsg,
2923 .sendpage = udp_sendpage,
2924 .release_cb = ip4_datagram_release_cb,
2925 .hash = udp_lib_hash,
2926 .unhash = udp_lib_unhash,
2927 .rehash = udp_v4_rehash,
2928 .get_port = udp_v4_get_port,
2929 #ifdef CONFIG_BPF_SYSCALL
2930 .psock_update_sk_prot = udp_bpf_update_proto,
2932 .memory_allocated = &udp_memory_allocated,
2933 .sysctl_mem = sysctl_udp_mem,
2934 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2935 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2936 .obj_size = sizeof(struct udp_sock),
2937 .h.udp_table = &udp_table,
2938 .diag_destroy = udp_abort,
2940 EXPORT_SYMBOL(udp_prot);
2942 /* ------------------------------------------------------------------------ */
2943 #ifdef CONFIG_PROC_FS
2945 static struct sock *udp_get_first(struct seq_file *seq, int start)
2948 struct udp_seq_afinfo *afinfo;
2949 struct udp_iter_state *state = seq->private;
2950 struct net *net = seq_file_net(seq);
2952 if (state->bpf_seq_afinfo)
2953 afinfo = state->bpf_seq_afinfo;
2955 afinfo = PDE_DATA(file_inode(seq->file));
2957 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask;
2959 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket];
2961 if (hlist_empty(&hslot->head))
2964 spin_lock_bh(&hslot->lock);
2965 sk_for_each(sk, &hslot->head) {
2966 if (!net_eq(sock_net(sk), net))
2968 if (afinfo->family == AF_UNSPEC ||
2969 sk->sk_family == afinfo->family)
2972 spin_unlock_bh(&hslot->lock);
2979 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2981 struct udp_seq_afinfo *afinfo;
2982 struct udp_iter_state *state = seq->private;
2983 struct net *net = seq_file_net(seq);
2985 if (state->bpf_seq_afinfo)
2986 afinfo = state->bpf_seq_afinfo;
2988 afinfo = PDE_DATA(file_inode(seq->file));
2992 } while (sk && (!net_eq(sock_net(sk), net) ||
2993 (afinfo->family != AF_UNSPEC &&
2994 sk->sk_family != afinfo->family)));
2997 if (state->bucket <= afinfo->udp_table->mask)
2998 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
2999 return udp_get_first(seq, state->bucket + 1);
3004 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
3006 struct sock *sk = udp_get_first(seq, 0);
3009 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
3011 return pos ? NULL : sk;
3014 void *udp_seq_start(struct seq_file *seq, loff_t *pos)
3016 struct udp_iter_state *state = seq->private;
3017 state->bucket = MAX_UDP_PORTS;
3019 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
3021 EXPORT_SYMBOL(udp_seq_start);
3023 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3027 if (v == SEQ_START_TOKEN)
3028 sk = udp_get_idx(seq, 0);
3030 sk = udp_get_next(seq, v);
3035 EXPORT_SYMBOL(udp_seq_next);
3037 void udp_seq_stop(struct seq_file *seq, void *v)
3039 struct udp_seq_afinfo *afinfo;
3040 struct udp_iter_state *state = seq->private;
3042 if (state->bpf_seq_afinfo)
3043 afinfo = state->bpf_seq_afinfo;
3045 afinfo = PDE_DATA(file_inode(seq->file));
3047 if (state->bucket <= afinfo->udp_table->mask)
3048 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
3050 EXPORT_SYMBOL(udp_seq_stop);
3052 /* ------------------------------------------------------------------------ */
3053 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
3056 struct inet_sock *inet = inet_sk(sp);
3057 __be32 dest = inet->inet_daddr;
3058 __be32 src = inet->inet_rcv_saddr;
3059 __u16 destp = ntohs(inet->inet_dport);
3060 __u16 srcp = ntohs(inet->inet_sport);
3062 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
3063 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
3064 bucket, src, srcp, dest, destp, sp->sk_state,
3065 sk_wmem_alloc_get(sp),
3068 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
3070 refcount_read(&sp->sk_refcnt), sp,
3071 atomic_read(&sp->sk_drops));
3074 int udp4_seq_show(struct seq_file *seq, void *v)
3076 seq_setwidth(seq, 127);
3077 if (v == SEQ_START_TOKEN)
3078 seq_puts(seq, " sl local_address rem_address st tx_queue "
3079 "rx_queue tr tm->when retrnsmt uid timeout "
3080 "inode ref pointer drops");
3082 struct udp_iter_state *state = seq->private;
3084 udp4_format_sock(v, seq, state->bucket);
3090 #ifdef CONFIG_BPF_SYSCALL
3091 struct bpf_iter__udp {
3092 __bpf_md_ptr(struct bpf_iter_meta *, meta);
3093 __bpf_md_ptr(struct udp_sock *, udp_sk);
3094 uid_t uid __aligned(8);
3095 int bucket __aligned(8);
3098 static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
3099 struct udp_sock *udp_sk, uid_t uid, int bucket)
3101 struct bpf_iter__udp ctx;
3103 meta->seq_num--; /* skip SEQ_START_TOKEN */
3105 ctx.udp_sk = udp_sk;
3107 ctx.bucket = bucket;
3108 return bpf_iter_run_prog(prog, &ctx);
3111 static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
3113 struct udp_iter_state *state = seq->private;
3114 struct bpf_iter_meta meta;
3115 struct bpf_prog *prog;
3116 struct sock *sk = v;
3119 if (v == SEQ_START_TOKEN)
3122 uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
3124 prog = bpf_iter_get_info(&meta, false);
3125 return udp_prog_seq_show(prog, &meta, v, uid, state->bucket);
3128 static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
3130 struct bpf_iter_meta meta;
3131 struct bpf_prog *prog;
3135 prog = bpf_iter_get_info(&meta, true);
3137 (void)udp_prog_seq_show(prog, &meta, v, 0, 0);
3140 udp_seq_stop(seq, v);
3143 static const struct seq_operations bpf_iter_udp_seq_ops = {
3144 .start = udp_seq_start,
3145 .next = udp_seq_next,
3146 .stop = bpf_iter_udp_seq_stop,
3147 .show = bpf_iter_udp_seq_show,
3151 const struct seq_operations udp_seq_ops = {
3152 .start = udp_seq_start,
3153 .next = udp_seq_next,
3154 .stop = udp_seq_stop,
3155 .show = udp4_seq_show,
3157 EXPORT_SYMBOL(udp_seq_ops);
3159 static struct udp_seq_afinfo udp4_seq_afinfo = {
3161 .udp_table = &udp_table,
3164 static int __net_init udp4_proc_init_net(struct net *net)
3166 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
3167 sizeof(struct udp_iter_state), &udp4_seq_afinfo))
3172 static void __net_exit udp4_proc_exit_net(struct net *net)
3174 remove_proc_entry("udp", net->proc_net);
3177 static struct pernet_operations udp4_net_ops = {
3178 .init = udp4_proc_init_net,
3179 .exit = udp4_proc_exit_net,
3182 int __init udp4_proc_init(void)
3184 return register_pernet_subsys(&udp4_net_ops);
3187 void udp4_proc_exit(void)
3189 unregister_pernet_subsys(&udp4_net_ops);
3191 #endif /* CONFIG_PROC_FS */
3193 static __initdata unsigned long uhash_entries;
3194 static int __init set_uhash_entries(char *str)
3201 ret = kstrtoul(str, 0, &uhash_entries);
3205 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
3206 uhash_entries = UDP_HTABLE_SIZE_MIN;
3209 __setup("uhash_entries=", set_uhash_entries);
3211 void __init udp_table_init(struct udp_table *table, const char *name)
3215 table->hash = alloc_large_system_hash(name,
3216 2 * sizeof(struct udp_hslot),
3218 21, /* one slot per 2 MB */
3222 UDP_HTABLE_SIZE_MIN,
3225 table->hash2 = table->hash + (table->mask + 1);
3226 for (i = 0; i <= table->mask; i++) {
3227 INIT_HLIST_HEAD(&table->hash[i].head);
3228 table->hash[i].count = 0;
3229 spin_lock_init(&table->hash[i].lock);
3231 for (i = 0; i <= table->mask; i++) {
3232 INIT_HLIST_HEAD(&table->hash2[i].head);
3233 table->hash2[i].count = 0;
3234 spin_lock_init(&table->hash2[i].lock);
3238 u32 udp_flow_hashrnd(void)
3240 static u32 hashrnd __read_mostly;
3242 net_get_random_once(&hashrnd, sizeof(hashrnd));
3246 EXPORT_SYMBOL(udp_flow_hashrnd);
3248 static void __udp_sysctl_init(struct net *net)
3250 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM;
3251 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM;
3253 #ifdef CONFIG_NET_L3_MASTER_DEV
3254 net->ipv4.sysctl_udp_l3mdev_accept = 0;
3258 static int __net_init udp_sysctl_init(struct net *net)
3260 __udp_sysctl_init(net);
3264 static struct pernet_operations __net_initdata udp_sysctl_ops = {
3265 .init = udp_sysctl_init,
3268 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3269 DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
3270 struct udp_sock *udp_sk, uid_t uid, int bucket)
3272 static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
3274 struct udp_iter_state *st = priv_data;
3275 struct udp_seq_afinfo *afinfo;
3278 afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN);
3282 afinfo->family = AF_UNSPEC;
3283 afinfo->udp_table = &udp_table;
3284 st->bpf_seq_afinfo = afinfo;
3285 ret = bpf_iter_init_seq_net(priv_data, aux);
3291 static void bpf_iter_fini_udp(void *priv_data)
3293 struct udp_iter_state *st = priv_data;
3295 kfree(st->bpf_seq_afinfo);
3296 bpf_iter_fini_seq_net(priv_data);
3299 static const struct bpf_iter_seq_info udp_seq_info = {
3300 .seq_ops = &bpf_iter_udp_seq_ops,
3301 .init_seq_private = bpf_iter_init_udp,
3302 .fini_seq_private = bpf_iter_fini_udp,
3303 .seq_priv_size = sizeof(struct udp_iter_state),
3306 static struct bpf_iter_reg udp_reg_info = {
3308 .ctx_arg_info_size = 1,
3310 { offsetof(struct bpf_iter__udp, udp_sk),
3311 PTR_TO_BTF_ID_OR_NULL },
3313 .seq_info = &udp_seq_info,
3316 static void __init bpf_iter_register(void)
3318 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP];
3319 if (bpf_iter_reg_target(&udp_reg_info))
3320 pr_warn("Warning: could not register bpf iterator udp\n");
3324 void __init udp_init(void)
3326 unsigned long limit;
3329 udp_table_init(&udp_table, "UDP");
3330 limit = nr_free_buffer_pages() / 8;
3331 limit = max(limit, 128UL);
3332 sysctl_udp_mem[0] = limit / 4 * 3;
3333 sysctl_udp_mem[1] = limit;
3334 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
3336 __udp_sysctl_init(&init_net);
3338 /* 16 spinlocks per cpu */
3339 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
3340 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
3343 panic("UDP: failed to alloc udp_busylocks\n");
3344 for (i = 0; i < (1U << udp_busylocks_log); i++)
3345 spin_lock_init(udp_busylocks + i);
3347 if (register_pernet_subsys(&udp_sysctl_ops))
3348 panic("UDP: failed to init sysctl parameters.\n");
3350 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3351 bpf_iter_register();