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/swap.h>
82 #include <linux/types.h>
83 #include <linux/fcntl.h>
84 #include <linux/module.h>
85 #include <linux/socket.h>
86 #include <linux/sockios.h>
87 #include <linux/igmp.h>
88 #include <linux/inetdevice.h>
90 #include <linux/errno.h>
91 #include <linux/timer.h>
93 #include <linux/inet.h>
94 #include <linux/netdevice.h>
95 #include <linux/slab.h>
96 #include <net/tcp_states.h>
97 #include <linux/skbuff.h>
98 #include <linux/proc_fs.h>
99 #include <linux/seq_file.h>
100 #include <net/net_namespace.h>
101 #include <net/icmp.h>
102 #include <net/inet_hashtables.h>
103 #include <net/ip_tunnels.h>
104 #include <net/route.h>
105 #include <net/checksum.h>
106 #include <net/xfrm.h>
107 #include <trace/events/udp.h>
108 #include <linux/static_key.h>
109 #include <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>
116 struct udp_table udp_table __read_mostly
;
117 EXPORT_SYMBOL(udp_table
);
119 long sysctl_udp_mem
[3] __read_mostly
;
120 EXPORT_SYMBOL(sysctl_udp_mem
);
122 atomic_long_t udp_memory_allocated
;
123 EXPORT_SYMBOL(udp_memory_allocated
);
125 #define MAX_UDP_PORTS 65536
126 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
128 /* IPCB reference means this can not be used from early demux */
129 static bool udp_lib_exact_dif_match(struct net
*net
, struct sk_buff
*skb
)
131 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
132 if (!net
->ipv4
.sysctl_udp_l3mdev_accept
&&
133 skb
&& ipv4_l3mdev_skb(IPCB(skb
)->flags
))
139 static int udp_lib_lport_inuse(struct net
*net
, __u16 num
,
140 const struct udp_hslot
*hslot
,
141 unsigned long *bitmap
,
142 struct sock
*sk
, unsigned int log
)
145 kuid_t uid
= sock_i_uid(sk
);
147 sk_for_each(sk2
, &hslot
->head
) {
148 if (net_eq(sock_net(sk2
), net
) &&
150 (bitmap
|| udp_sk(sk2
)->udp_port_hash
== num
) &&
151 (!sk2
->sk_reuse
|| !sk
->sk_reuse
) &&
152 (!sk2
->sk_bound_dev_if
|| !sk
->sk_bound_dev_if
||
153 sk2
->sk_bound_dev_if
== sk
->sk_bound_dev_if
) &&
154 inet_rcv_saddr_equal(sk
, sk2
, true)) {
155 if (sk2
->sk_reuseport
&& sk
->sk_reuseport
&&
156 !rcu_access_pointer(sk
->sk_reuseport_cb
) &&
157 uid_eq(uid
, sock_i_uid(sk2
))) {
163 __set_bit(udp_sk(sk2
)->udp_port_hash
>> log
,
172 * Note: we still hold spinlock of primary hash chain, so no other writer
173 * can insert/delete a socket with local_port == num
175 static int udp_lib_lport_inuse2(struct net
*net
, __u16 num
,
176 struct udp_hslot
*hslot2
,
180 kuid_t uid
= sock_i_uid(sk
);
183 spin_lock(&hslot2
->lock
);
184 udp_portaddr_for_each_entry(sk2
, &hslot2
->head
) {
185 if (net_eq(sock_net(sk2
), net
) &&
187 (udp_sk(sk2
)->udp_port_hash
== num
) &&
188 (!sk2
->sk_reuse
|| !sk
->sk_reuse
) &&
189 (!sk2
->sk_bound_dev_if
|| !sk
->sk_bound_dev_if
||
190 sk2
->sk_bound_dev_if
== sk
->sk_bound_dev_if
) &&
191 inet_rcv_saddr_equal(sk
, sk2
, true)) {
192 if (sk2
->sk_reuseport
&& sk
->sk_reuseport
&&
193 !rcu_access_pointer(sk
->sk_reuseport_cb
) &&
194 uid_eq(uid
, sock_i_uid(sk2
))) {
202 spin_unlock(&hslot2
->lock
);
206 static int udp_reuseport_add_sock(struct sock
*sk
, struct udp_hslot
*hslot
)
208 struct net
*net
= sock_net(sk
);
209 kuid_t uid
= sock_i_uid(sk
);
212 sk_for_each(sk2
, &hslot
->head
) {
213 if (net_eq(sock_net(sk2
), net
) &&
215 sk2
->sk_family
== sk
->sk_family
&&
216 ipv6_only_sock(sk2
) == ipv6_only_sock(sk
) &&
217 (udp_sk(sk2
)->udp_port_hash
== udp_sk(sk
)->udp_port_hash
) &&
218 (sk2
->sk_bound_dev_if
== sk
->sk_bound_dev_if
) &&
219 sk2
->sk_reuseport
&& uid_eq(uid
, sock_i_uid(sk2
)) &&
220 inet_rcv_saddr_equal(sk
, sk2
, false)) {
221 return reuseport_add_sock(sk
, sk2
,
222 inet_rcv_saddr_any(sk
));
226 return reuseport_alloc(sk
, inet_rcv_saddr_any(sk
));
230 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
232 * @sk: socket struct in question
233 * @snum: port number to look up
234 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
237 int udp_lib_get_port(struct sock
*sk
, unsigned short snum
,
238 unsigned int hash2_nulladdr
)
240 struct udp_hslot
*hslot
, *hslot2
;
241 struct udp_table
*udptable
= sk
->sk_prot
->h
.udp_table
;
243 struct net
*net
= sock_net(sk
);
246 int low
, high
, remaining
;
248 unsigned short first
, last
;
249 DECLARE_BITMAP(bitmap
, PORTS_PER_CHAIN
);
251 inet_get_local_port_range(net
, &low
, &high
);
252 remaining
= (high
- low
) + 1;
254 rand
= prandom_u32();
255 first
= reciprocal_scale(rand
, remaining
) + low
;
257 * force rand to be an odd multiple of UDP_HTABLE_SIZE
259 rand
= (rand
| 1) * (udptable
->mask
+ 1);
260 last
= first
+ udptable
->mask
+ 1;
262 hslot
= udp_hashslot(udptable
, net
, first
);
263 bitmap_zero(bitmap
, PORTS_PER_CHAIN
);
264 spin_lock_bh(&hslot
->lock
);
265 udp_lib_lport_inuse(net
, snum
, hslot
, bitmap
, sk
,
270 * Iterate on all possible values of snum for this hash.
271 * Using steps of an odd multiple of UDP_HTABLE_SIZE
272 * give us randomization and full range coverage.
275 if (low
<= snum
&& snum
<= high
&&
276 !test_bit(snum
>> udptable
->log
, bitmap
) &&
277 !inet_is_local_reserved_port(net
, snum
))
280 } while (snum
!= first
);
281 spin_unlock_bh(&hslot
->lock
);
283 } while (++first
!= last
);
286 hslot
= udp_hashslot(udptable
, net
, snum
);
287 spin_lock_bh(&hslot
->lock
);
288 if (hslot
->count
> 10) {
290 unsigned int slot2
= udp_sk(sk
)->udp_portaddr_hash
^ snum
;
292 slot2
&= udptable
->mask
;
293 hash2_nulladdr
&= udptable
->mask
;
295 hslot2
= udp_hashslot2(udptable
, slot2
);
296 if (hslot
->count
< hslot2
->count
)
297 goto scan_primary_hash
;
299 exist
= udp_lib_lport_inuse2(net
, snum
, hslot2
, sk
);
300 if (!exist
&& (hash2_nulladdr
!= slot2
)) {
301 hslot2
= udp_hashslot2(udptable
, hash2_nulladdr
);
302 exist
= udp_lib_lport_inuse2(net
, snum
, hslot2
,
311 if (udp_lib_lport_inuse(net
, snum
, hslot
, NULL
, sk
, 0))
315 inet_sk(sk
)->inet_num
= snum
;
316 udp_sk(sk
)->udp_port_hash
= snum
;
317 udp_sk(sk
)->udp_portaddr_hash
^= snum
;
318 if (sk_unhashed(sk
)) {
319 if (sk
->sk_reuseport
&&
320 udp_reuseport_add_sock(sk
, hslot
)) {
321 inet_sk(sk
)->inet_num
= 0;
322 udp_sk(sk
)->udp_port_hash
= 0;
323 udp_sk(sk
)->udp_portaddr_hash
^= snum
;
327 sk_add_node_rcu(sk
, &hslot
->head
);
329 sock_prot_inuse_add(sock_net(sk
), sk
->sk_prot
, 1);
331 hslot2
= udp_hashslot2(udptable
, udp_sk(sk
)->udp_portaddr_hash
);
332 spin_lock(&hslot2
->lock
);
333 if (IS_ENABLED(CONFIG_IPV6
) && sk
->sk_reuseport
&&
334 sk
->sk_family
== AF_INET6
)
335 hlist_add_tail_rcu(&udp_sk(sk
)->udp_portaddr_node
,
338 hlist_add_head_rcu(&udp_sk(sk
)->udp_portaddr_node
,
341 spin_unlock(&hslot2
->lock
);
343 sock_set_flag(sk
, SOCK_RCU_FREE
);
346 spin_unlock_bh(&hslot
->lock
);
350 EXPORT_SYMBOL(udp_lib_get_port
);
352 int udp_v4_get_port(struct sock
*sk
, unsigned short snum
)
354 unsigned int hash2_nulladdr
=
355 ipv4_portaddr_hash(sock_net(sk
), htonl(INADDR_ANY
), snum
);
356 unsigned int hash2_partial
=
357 ipv4_portaddr_hash(sock_net(sk
), inet_sk(sk
)->inet_rcv_saddr
, 0);
359 /* precompute partial secondary hash */
360 udp_sk(sk
)->udp_portaddr_hash
= hash2_partial
;
361 return udp_lib_get_port(sk
, snum
, hash2_nulladdr
);
364 static int compute_score(struct sock
*sk
, struct net
*net
,
365 __be32 saddr
, __be16 sport
,
366 __be32 daddr
, unsigned short hnum
,
367 int dif
, int sdif
, bool exact_dif
)
370 struct inet_sock
*inet
;
373 if (!net_eq(sock_net(sk
), net
) ||
374 udp_sk(sk
)->udp_port_hash
!= hnum
||
378 if (sk
->sk_rcv_saddr
!= daddr
)
381 score
= (sk
->sk_family
== PF_INET
) ? 2 : 1;
384 if (inet
->inet_daddr
) {
385 if (inet
->inet_daddr
!= saddr
)
390 if (inet
->inet_dport
) {
391 if (inet
->inet_dport
!= sport
)
396 dev_match
= udp_sk_bound_dev_eq(net
, sk
->sk_bound_dev_if
,
402 if (sk
->sk_incoming_cpu
== raw_smp_processor_id())
407 static u32
udp_ehashfn(const struct net
*net
, const __be32 laddr
,
408 const __u16 lport
, const __be32 faddr
,
411 static u32 udp_ehash_secret __read_mostly
;
413 net_get_random_once(&udp_ehash_secret
, sizeof(udp_ehash_secret
));
415 return __inet_ehashfn(laddr
, lport
, faddr
, fport
,
416 udp_ehash_secret
+ net_hash_mix(net
));
419 /* called with rcu_read_lock() */
420 static struct sock
*udp4_lib_lookup2(struct net
*net
,
421 __be32 saddr
, __be16 sport
,
422 __be32 daddr
, unsigned int hnum
,
423 int dif
, int sdif
, bool exact_dif
,
424 struct udp_hslot
*hslot2
,
427 struct sock
*sk
, *result
;
433 udp_portaddr_for_each_entry_rcu(sk
, &hslot2
->head
) {
434 score
= compute_score(sk
, net
, saddr
, sport
,
435 daddr
, hnum
, dif
, sdif
, exact_dif
);
436 if (score
> badness
) {
437 if (sk
->sk_reuseport
) {
438 hash
= udp_ehashfn(net
, daddr
, hnum
,
440 result
= reuseport_select_sock(sk
, hash
, skb
,
441 sizeof(struct udphdr
));
452 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
453 * harder than this. -DaveM
455 struct sock
*__udp4_lib_lookup(struct net
*net
, __be32 saddr
,
456 __be16 sport
, __be32 daddr
, __be16 dport
, int dif
,
457 int sdif
, struct udp_table
*udptable
, struct sk_buff
*skb
)
460 unsigned short hnum
= ntohs(dport
);
461 unsigned int hash2
, slot2
;
462 struct udp_hslot
*hslot2
;
463 bool exact_dif
= udp_lib_exact_dif_match(net
, skb
);
465 hash2
= ipv4_portaddr_hash(net
, daddr
, hnum
);
466 slot2
= hash2
& udptable
->mask
;
467 hslot2
= &udptable
->hash2
[slot2
];
469 result
= udp4_lib_lookup2(net
, saddr
, sport
,
470 daddr
, hnum
, dif
, sdif
,
471 exact_dif
, hslot2
, skb
);
473 hash2
= ipv4_portaddr_hash(net
, htonl(INADDR_ANY
), hnum
);
474 slot2
= hash2
& udptable
->mask
;
475 hslot2
= &udptable
->hash2
[slot2
];
477 result
= udp4_lib_lookup2(net
, saddr
, sport
,
478 htonl(INADDR_ANY
), hnum
, dif
, sdif
,
479 exact_dif
, hslot2
, skb
);
481 if (unlikely(IS_ERR(result
)))
485 EXPORT_SYMBOL_GPL(__udp4_lib_lookup
);
487 static inline struct sock
*__udp4_lib_lookup_skb(struct sk_buff
*skb
,
488 __be16 sport
, __be16 dport
,
489 struct udp_table
*udptable
)
491 const struct iphdr
*iph
= ip_hdr(skb
);
493 return __udp4_lib_lookup(dev_net(skb
->dev
), iph
->saddr
, sport
,
494 iph
->daddr
, dport
, inet_iif(skb
),
495 inet_sdif(skb
), udptable
, skb
);
498 struct sock
*udp4_lib_lookup_skb(struct sk_buff
*skb
,
499 __be16 sport
, __be16 dport
)
501 return __udp4_lib_lookup_skb(skb
, sport
, dport
, &udp_table
);
503 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb
);
505 /* Must be called under rcu_read_lock().
506 * Does increment socket refcount.
508 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
509 struct sock
*udp4_lib_lookup(struct net
*net
, __be32 saddr
, __be16 sport
,
510 __be32 daddr
, __be16 dport
, int dif
)
514 sk
= __udp4_lib_lookup(net
, saddr
, sport
, daddr
, dport
,
515 dif
, 0, &udp_table
, NULL
);
516 if (sk
&& !refcount_inc_not_zero(&sk
->sk_refcnt
))
520 EXPORT_SYMBOL_GPL(udp4_lib_lookup
);
523 static inline bool __udp_is_mcast_sock(struct net
*net
, struct sock
*sk
,
524 __be16 loc_port
, __be32 loc_addr
,
525 __be16 rmt_port
, __be32 rmt_addr
,
526 int dif
, int sdif
, unsigned short hnum
)
528 struct inet_sock
*inet
= inet_sk(sk
);
530 if (!net_eq(sock_net(sk
), net
) ||
531 udp_sk(sk
)->udp_port_hash
!= hnum
||
532 (inet
->inet_daddr
&& inet
->inet_daddr
!= rmt_addr
) ||
533 (inet
->inet_dport
!= rmt_port
&& inet
->inet_dport
) ||
534 (inet
->inet_rcv_saddr
&& inet
->inet_rcv_saddr
!= loc_addr
) ||
535 ipv6_only_sock(sk
) ||
536 (sk
->sk_bound_dev_if
&& sk
->sk_bound_dev_if
!= dif
&&
537 sk
->sk_bound_dev_if
!= sdif
))
539 if (!ip_mc_sf_allow(sk
, loc_addr
, rmt_addr
, dif
, sdif
))
544 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key
);
545 void udp_encap_enable(void)
547 static_branch_inc(&udp_encap_needed_key
);
549 EXPORT_SYMBOL(udp_encap_enable
);
551 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
552 * through error handlers in encapsulations looking for a match.
554 static int __udp4_lib_err_encap_no_sk(struct sk_buff
*skb
, u32 info
)
558 for (i
= 0; i
< MAX_IPTUN_ENCAP_OPS
; i
++) {
559 int (*handler
)(struct sk_buff
*skb
, u32 info
);
560 const struct ip_tunnel_encap_ops
*encap
;
562 encap
= rcu_dereference(iptun_encaps
[i
]);
565 handler
= encap
->err_handler
;
566 if (handler
&& !handler(skb
, info
))
573 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
574 * reversing source and destination port: this will match tunnels that force the
575 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
576 * lwtunnels might actually break this assumption by being configured with
577 * different destination ports on endpoints, in this case we won't be able to
578 * trace ICMP messages back to them.
580 * If this doesn't match any socket, probe tunnels with arbitrary destination
581 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
582 * we've sent packets to won't necessarily match the local destination port.
584 * Then ask the tunnel implementation to match the error against a valid
587 * Return an error if we can't find a match, the socket if we need further
588 * processing, zero otherwise.
590 static struct sock
*__udp4_lib_err_encap(struct net
*net
,
591 const struct iphdr
*iph
,
593 struct udp_table
*udptable
,
594 struct sk_buff
*skb
, u32 info
)
596 int network_offset
, transport_offset
;
599 network_offset
= skb_network_offset(skb
);
600 transport_offset
= skb_transport_offset(skb
);
602 /* Network header needs to point to the outer IPv4 header inside ICMP */
603 skb_reset_network_header(skb
);
605 /* Transport header needs to point to the UDP header */
606 skb_set_transport_header(skb
, iph
->ihl
<< 2);
608 sk
= __udp4_lib_lookup(net
, iph
->daddr
, uh
->source
,
609 iph
->saddr
, uh
->dest
, skb
->dev
->ifindex
, 0,
612 int (*lookup
)(struct sock
*sk
, struct sk_buff
*skb
);
613 struct udp_sock
*up
= udp_sk(sk
);
615 lookup
= READ_ONCE(up
->encap_err_lookup
);
616 if (!lookup
|| lookup(sk
, skb
))
621 sk
= ERR_PTR(__udp4_lib_err_encap_no_sk(skb
, info
));
623 skb_set_transport_header(skb
, transport_offset
);
624 skb_set_network_header(skb
, network_offset
);
630 * This routine is called by the ICMP module when it gets some
631 * sort of error condition. If err < 0 then the socket should
632 * be closed and the error returned to the user. If err > 0
633 * it's just the icmp type << 8 | icmp code.
634 * Header points to the ip header of the error packet. We move
635 * on past this. Then (as it used to claim before adjustment)
636 * header points to the first 8 bytes of the udp header. We need
637 * to find the appropriate port.
640 int __udp4_lib_err(struct sk_buff
*skb
, u32 info
, struct udp_table
*udptable
)
642 struct inet_sock
*inet
;
643 const struct iphdr
*iph
= (const struct iphdr
*)skb
->data
;
644 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+(iph
->ihl
<<2));
645 const int type
= icmp_hdr(skb
)->type
;
646 const int code
= icmp_hdr(skb
)->code
;
651 struct net
*net
= dev_net(skb
->dev
);
653 sk
= __udp4_lib_lookup(net
, iph
->daddr
, uh
->dest
,
654 iph
->saddr
, uh
->source
, skb
->dev
->ifindex
,
655 inet_sdif(skb
), udptable
, NULL
);
657 /* No socket for error: try tunnels before discarding */
658 sk
= ERR_PTR(-ENOENT
);
659 if (static_branch_unlikely(&udp_encap_needed_key
)) {
660 sk
= __udp4_lib_err_encap(net
, iph
, uh
, udptable
, skb
,
667 __ICMP_INC_STATS(net
, ICMP_MIB_INERRORS
);
680 case ICMP_TIME_EXCEEDED
:
683 case ICMP_SOURCE_QUENCH
:
685 case ICMP_PARAMETERPROB
:
689 case ICMP_DEST_UNREACH
:
690 if (code
== ICMP_FRAG_NEEDED
) { /* Path MTU discovery */
691 ipv4_sk_update_pmtu(skb
, sk
, info
);
692 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
) {
700 if (code
<= NR_ICMP_UNREACH
) {
701 harderr
= icmp_err_convert
[code
].fatal
;
702 err
= icmp_err_convert
[code
].errno
;
706 ipv4_sk_redirect(skb
, sk
);
711 * RFC1122: OK. Passes ICMP errors back to application, as per
715 /* ...not for tunnels though: we don't have a sending socket */
718 if (!inet
->recverr
) {
719 if (!harderr
|| sk
->sk_state
!= TCP_ESTABLISHED
)
722 ip_icmp_error(sk
, skb
, err
, uh
->dest
, info
, (u8
*)(uh
+1));
725 sk
->sk_error_report(sk
);
730 int udp_err(struct sk_buff
*skb
, u32 info
)
732 return __udp4_lib_err(skb
, info
, &udp_table
);
736 * Throw away all pending data and cancel the corking. Socket is locked.
738 void udp_flush_pending_frames(struct sock
*sk
)
740 struct udp_sock
*up
= udp_sk(sk
);
745 ip_flush_pending_frames(sk
);
748 EXPORT_SYMBOL(udp_flush_pending_frames
);
751 * udp4_hwcsum - handle outgoing HW checksumming
752 * @skb: sk_buff containing the filled-in UDP header
753 * (checksum field must be zeroed out)
754 * @src: source IP address
755 * @dst: destination IP address
757 void udp4_hwcsum(struct sk_buff
*skb
, __be32 src
, __be32 dst
)
759 struct udphdr
*uh
= udp_hdr(skb
);
760 int offset
= skb_transport_offset(skb
);
761 int len
= skb
->len
- offset
;
765 if (!skb_has_frag_list(skb
)) {
767 * Only one fragment on the socket.
769 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
770 skb
->csum_offset
= offsetof(struct udphdr
, check
);
771 uh
->check
= ~csum_tcpudp_magic(src
, dst
, len
,
774 struct sk_buff
*frags
;
777 * HW-checksum won't work as there are two or more
778 * fragments on the socket so that all csums of sk_buffs
781 skb_walk_frags(skb
, frags
) {
782 csum
= csum_add(csum
, frags
->csum
);
786 csum
= skb_checksum(skb
, offset
, hlen
, csum
);
787 skb
->ip_summed
= CHECKSUM_NONE
;
789 uh
->check
= csum_tcpudp_magic(src
, dst
, len
, IPPROTO_UDP
, csum
);
791 uh
->check
= CSUM_MANGLED_0
;
794 EXPORT_SYMBOL_GPL(udp4_hwcsum
);
796 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
797 * for the simple case like when setting the checksum for a UDP tunnel.
799 void udp_set_csum(bool nocheck
, struct sk_buff
*skb
,
800 __be32 saddr
, __be32 daddr
, int len
)
802 struct udphdr
*uh
= udp_hdr(skb
);
806 } else if (skb_is_gso(skb
)) {
807 uh
->check
= ~udp_v4_check(len
, saddr
, daddr
, 0);
808 } else if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
810 uh
->check
= udp_v4_check(len
, saddr
, daddr
, lco_csum(skb
));
812 uh
->check
= CSUM_MANGLED_0
;
814 skb
->ip_summed
= CHECKSUM_PARTIAL
;
815 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
816 skb
->csum_offset
= offsetof(struct udphdr
, check
);
817 uh
->check
= ~udp_v4_check(len
, saddr
, daddr
, 0);
820 EXPORT_SYMBOL(udp_set_csum
);
822 static int udp_send_skb(struct sk_buff
*skb
, struct flowi4
*fl4
,
823 struct inet_cork
*cork
)
825 struct sock
*sk
= skb
->sk
;
826 struct inet_sock
*inet
= inet_sk(sk
);
829 int is_udplite
= IS_UDPLITE(sk
);
830 int offset
= skb_transport_offset(skb
);
831 int len
= skb
->len
- offset
;
835 * Create a UDP header
838 uh
->source
= inet
->inet_sport
;
839 uh
->dest
= fl4
->fl4_dport
;
840 uh
->len
= htons(len
);
843 if (cork
->gso_size
) {
844 const int hlen
= skb_network_header_len(skb
) +
845 sizeof(struct udphdr
);
847 if (hlen
+ cork
->gso_size
> cork
->fragsize
) {
851 if (skb
->len
> cork
->gso_size
* UDP_MAX_SEGMENTS
) {
855 if (sk
->sk_no_check_tx
) {
859 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
|| is_udplite
||
860 dst_xfrm(skb_dst(skb
))) {
865 skb_shinfo(skb
)->gso_size
= cork
->gso_size
;
866 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP_L4
;
867 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(len
- sizeof(uh
),
872 if (is_udplite
) /* UDP-Lite */
873 csum
= udplite_csum(skb
);
875 else if (sk
->sk_no_check_tx
) { /* UDP csum off */
877 skb
->ip_summed
= CHECKSUM_NONE
;
880 } else if (skb
->ip_summed
== CHECKSUM_PARTIAL
) { /* UDP hardware csum */
883 udp4_hwcsum(skb
, fl4
->saddr
, fl4
->daddr
);
887 csum
= udp_csum(skb
);
889 /* add protocol-dependent pseudo-header */
890 uh
->check
= csum_tcpudp_magic(fl4
->saddr
, fl4
->daddr
, len
,
891 sk
->sk_protocol
, csum
);
893 uh
->check
= CSUM_MANGLED_0
;
896 err
= ip_send_skb(sock_net(sk
), skb
);
898 if (err
== -ENOBUFS
&& !inet
->recverr
) {
899 UDP_INC_STATS(sock_net(sk
),
900 UDP_MIB_SNDBUFERRORS
, is_udplite
);
904 UDP_INC_STATS(sock_net(sk
),
905 UDP_MIB_OUTDATAGRAMS
, is_udplite
);
910 * Push out all pending data as one UDP datagram. Socket is locked.
912 int udp_push_pending_frames(struct sock
*sk
)
914 struct udp_sock
*up
= udp_sk(sk
);
915 struct inet_sock
*inet
= inet_sk(sk
);
916 struct flowi4
*fl4
= &inet
->cork
.fl
.u
.ip4
;
920 skb
= ip_finish_skb(sk
, fl4
);
924 err
= udp_send_skb(skb
, fl4
, &inet
->cork
.base
);
931 EXPORT_SYMBOL(udp_push_pending_frames
);
933 static int __udp_cmsg_send(struct cmsghdr
*cmsg
, u16
*gso_size
)
935 switch (cmsg
->cmsg_type
) {
937 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof(__u16
)))
939 *gso_size
= *(__u16
*)CMSG_DATA(cmsg
);
946 int udp_cmsg_send(struct sock
*sk
, struct msghdr
*msg
, u16
*gso_size
)
948 struct cmsghdr
*cmsg
;
949 bool need_ip
= false;
952 for_each_cmsghdr(cmsg
, msg
) {
953 if (!CMSG_OK(msg
, cmsg
))
956 if (cmsg
->cmsg_level
!= SOL_UDP
) {
961 err
= __udp_cmsg_send(cmsg
, gso_size
);
968 EXPORT_SYMBOL_GPL(udp_cmsg_send
);
970 int udp_sendmsg(struct sock
*sk
, struct msghdr
*msg
, size_t len
)
972 struct inet_sock
*inet
= inet_sk(sk
);
973 struct udp_sock
*up
= udp_sk(sk
);
974 DECLARE_SOCKADDR(struct sockaddr_in
*, usin
, msg
->msg_name
);
975 struct flowi4 fl4_stack
;
978 struct ipcm_cookie ipc
;
979 struct rtable
*rt
= NULL
;
982 __be32 daddr
, faddr
, saddr
;
985 int err
, is_udplite
= IS_UDPLITE(sk
);
986 int corkreq
= up
->corkflag
|| msg
->msg_flags
&MSG_MORE
;
987 int (*getfrag
)(void *, char *, int, int, int, struct sk_buff
*);
989 struct ip_options_data opt_copy
;
998 if (msg
->msg_flags
& MSG_OOB
) /* Mirror BSD error message compatibility */
1001 getfrag
= is_udplite
? udplite_getfrag
: ip_generic_getfrag
;
1003 fl4
= &inet
->cork
.fl
.u
.ip4
;
1006 * There are pending frames.
1007 * The socket lock must be held while it's corked.
1010 if (likely(up
->pending
)) {
1011 if (unlikely(up
->pending
!= AF_INET
)) {
1015 goto do_append_data
;
1019 ulen
+= sizeof(struct udphdr
);
1022 * Get and verify the address.
1025 if (msg
->msg_namelen
< sizeof(*usin
))
1027 if (usin
->sin_family
!= AF_INET
) {
1028 if (usin
->sin_family
!= AF_UNSPEC
)
1029 return -EAFNOSUPPORT
;
1032 daddr
= usin
->sin_addr
.s_addr
;
1033 dport
= usin
->sin_port
;
1037 if (sk
->sk_state
!= TCP_ESTABLISHED
)
1038 return -EDESTADDRREQ
;
1039 daddr
= inet
->inet_daddr
;
1040 dport
= inet
->inet_dport
;
1041 /* Open fast path for connected socket.
1042 Route will not be used, if at least one option is set.
1047 ipcm_init_sk(&ipc
, inet
);
1048 ipc
.gso_size
= up
->gso_size
;
1050 if (msg
->msg_controllen
) {
1051 err
= udp_cmsg_send(sk
, msg
, &ipc
.gso_size
);
1053 err
= ip_cmsg_send(sk
, msg
, &ipc
,
1054 sk
->sk_family
== AF_INET6
);
1055 if (unlikely(err
< 0)) {
1064 struct ip_options_rcu
*inet_opt
;
1067 inet_opt
= rcu_dereference(inet
->inet_opt
);
1069 memcpy(&opt_copy
, inet_opt
,
1070 sizeof(*inet_opt
) + inet_opt
->opt
.optlen
);
1071 ipc
.opt
= &opt_copy
.opt
;
1076 if (cgroup_bpf_enabled
&& !connected
) {
1077 err
= BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk
,
1078 (struct sockaddr
*)usin
, &ipc
.addr
);
1082 if (usin
->sin_port
== 0) {
1083 /* BPF program set invalid port. Reject it. */
1087 daddr
= usin
->sin_addr
.s_addr
;
1088 dport
= usin
->sin_port
;
1093 ipc
.addr
= faddr
= daddr
;
1095 if (ipc
.opt
&& ipc
.opt
->opt
.srr
) {
1100 faddr
= ipc
.opt
->opt
.faddr
;
1103 tos
= get_rttos(&ipc
, inet
);
1104 if (sock_flag(sk
, SOCK_LOCALROUTE
) ||
1105 (msg
->msg_flags
& MSG_DONTROUTE
) ||
1106 (ipc
.opt
&& ipc
.opt
->opt
.is_strictroute
)) {
1111 if (ipv4_is_multicast(daddr
)) {
1112 if (!ipc
.oif
|| netif_index_is_l3_master(sock_net(sk
), ipc
.oif
))
1113 ipc
.oif
= inet
->mc_index
;
1115 saddr
= inet
->mc_addr
;
1117 } else if (!ipc
.oif
) {
1118 ipc
.oif
= inet
->uc_index
;
1119 } else if (ipv4_is_lbcast(daddr
) && inet
->uc_index
) {
1120 /* oif is set, packet is to local broadcast and
1121 * and uc_index is set. oif is most likely set
1122 * by sk_bound_dev_if. If uc_index != oif check if the
1123 * oif is an L3 master and uc_index is an L3 slave.
1124 * If so, we want to allow the send using the uc_index.
1126 if (ipc
.oif
!= inet
->uc_index
&&
1127 ipc
.oif
== l3mdev_master_ifindex_by_index(sock_net(sk
),
1129 ipc
.oif
= inet
->uc_index
;
1134 rt
= (struct rtable
*)sk_dst_check(sk
, 0);
1137 struct net
*net
= sock_net(sk
);
1138 __u8 flow_flags
= inet_sk_flowi_flags(sk
);
1142 flowi4_init_output(fl4
, ipc
.oif
, sk
->sk_mark
, tos
,
1143 RT_SCOPE_UNIVERSE
, sk
->sk_protocol
,
1145 faddr
, saddr
, dport
, inet
->inet_sport
,
1148 security_sk_classify_flow(sk
, flowi4_to_flowi(fl4
));
1149 rt
= ip_route_output_flow(net
, fl4
, sk
);
1153 if (err
== -ENETUNREACH
)
1154 IP_INC_STATS(net
, IPSTATS_MIB_OUTNOROUTES
);
1159 if ((rt
->rt_flags
& RTCF_BROADCAST
) &&
1160 !sock_flag(sk
, SOCK_BROADCAST
))
1163 sk_dst_set(sk
, dst_clone(&rt
->dst
));
1166 if (msg
->msg_flags
&MSG_CONFIRM
)
1172 daddr
= ipc
.addr
= fl4
->daddr
;
1174 /* Lockless fast path for the non-corking case. */
1176 struct inet_cork cork
;
1178 skb
= ip_make_skb(sk
, fl4
, getfrag
, msg
, ulen
,
1179 sizeof(struct udphdr
), &ipc
, &rt
,
1180 &cork
, msg
->msg_flags
);
1182 if (!IS_ERR_OR_NULL(skb
))
1183 err
= udp_send_skb(skb
, fl4
, &cork
);
1188 if (unlikely(up
->pending
)) {
1189 /* The socket is already corked while preparing it. */
1190 /* ... which is an evident application bug. --ANK */
1193 net_dbg_ratelimited("socket already corked\n");
1198 * Now cork the socket to pend data.
1200 fl4
= &inet
->cork
.fl
.u
.ip4
;
1203 fl4
->fl4_dport
= dport
;
1204 fl4
->fl4_sport
= inet
->inet_sport
;
1205 up
->pending
= AF_INET
;
1209 err
= ip_append_data(sk
, fl4
, getfrag
, msg
, ulen
,
1210 sizeof(struct udphdr
), &ipc
, &rt
,
1211 corkreq
? msg
->msg_flags
|MSG_MORE
: msg
->msg_flags
);
1213 udp_flush_pending_frames(sk
);
1215 err
= udp_push_pending_frames(sk
);
1216 else if (unlikely(skb_queue_empty(&sk
->sk_write_queue
)))
1228 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1229 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1230 * we don't have a good statistic (IpOutDiscards but it can be too many
1231 * things). We could add another new stat but at least for now that
1232 * seems like overkill.
1234 if (err
== -ENOBUFS
|| test_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
)) {
1235 UDP_INC_STATS(sock_net(sk
),
1236 UDP_MIB_SNDBUFERRORS
, is_udplite
);
1241 if (msg
->msg_flags
& MSG_PROBE
)
1242 dst_confirm_neigh(&rt
->dst
, &fl4
->daddr
);
1243 if (!(msg
->msg_flags
&MSG_PROBE
) || len
)
1244 goto back_from_confirm
;
1248 EXPORT_SYMBOL(udp_sendmsg
);
1250 int udp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
1251 size_t size
, int flags
)
1253 struct inet_sock
*inet
= inet_sk(sk
);
1254 struct udp_sock
*up
= udp_sk(sk
);
1257 if (flags
& MSG_SENDPAGE_NOTLAST
)
1261 struct msghdr msg
= { .msg_flags
= flags
|MSG_MORE
};
1263 /* Call udp_sendmsg to specify destination address which
1264 * sendpage interface can't pass.
1265 * This will succeed only when the socket is connected.
1267 ret
= udp_sendmsg(sk
, &msg
, 0);
1274 if (unlikely(!up
->pending
)) {
1277 net_dbg_ratelimited("cork failed\n");
1281 ret
= ip_append_page(sk
, &inet
->cork
.fl
.u
.ip4
,
1282 page
, offset
, size
, flags
);
1283 if (ret
== -EOPNOTSUPP
) {
1285 return sock_no_sendpage(sk
->sk_socket
, page
, offset
,
1289 udp_flush_pending_frames(sk
);
1294 if (!(up
->corkflag
|| (flags
&MSG_MORE
)))
1295 ret
= udp_push_pending_frames(sk
);
1303 #define UDP_SKB_IS_STATELESS 0x80000000
1305 static void udp_set_dev_scratch(struct sk_buff
*skb
)
1307 struct udp_dev_scratch
*scratch
= udp_skb_scratch(skb
);
1309 BUILD_BUG_ON(sizeof(struct udp_dev_scratch
) > sizeof(long));
1310 scratch
->_tsize_state
= skb
->truesize
;
1311 #if BITS_PER_LONG == 64
1312 scratch
->len
= skb
->len
;
1313 scratch
->csum_unnecessary
= !!skb_csum_unnecessary(skb
);
1314 scratch
->is_linear
= !skb_is_nonlinear(skb
);
1316 /* all head states execept sp (dst, sk, nf) are always cleared by
1317 * udp_rcv() and we need to preserve secpath, if present, to eventually
1318 * process IP_CMSG_PASSSEC at recvmsg() time
1320 if (likely(!skb_sec_path(skb
)))
1321 scratch
->_tsize_state
|= UDP_SKB_IS_STATELESS
;
1324 static int udp_skb_truesize(struct sk_buff
*skb
)
1326 return udp_skb_scratch(skb
)->_tsize_state
& ~UDP_SKB_IS_STATELESS
;
1329 static bool udp_skb_has_head_state(struct sk_buff
*skb
)
1331 return !(udp_skb_scratch(skb
)->_tsize_state
& UDP_SKB_IS_STATELESS
);
1334 /* fully reclaim rmem/fwd memory allocated for skb */
1335 static void udp_rmem_release(struct sock
*sk
, int size
, int partial
,
1336 bool rx_queue_lock_held
)
1338 struct udp_sock
*up
= udp_sk(sk
);
1339 struct sk_buff_head
*sk_queue
;
1342 if (likely(partial
)) {
1343 up
->forward_deficit
+= size
;
1344 size
= up
->forward_deficit
;
1345 if (size
< (sk
->sk_rcvbuf
>> 2))
1348 size
+= up
->forward_deficit
;
1350 up
->forward_deficit
= 0;
1352 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1353 * if the called don't held it already
1355 sk_queue
= &sk
->sk_receive_queue
;
1356 if (!rx_queue_lock_held
)
1357 spin_lock(&sk_queue
->lock
);
1360 sk
->sk_forward_alloc
+= size
;
1361 amt
= (sk
->sk_forward_alloc
- partial
) & ~(SK_MEM_QUANTUM
- 1);
1362 sk
->sk_forward_alloc
-= amt
;
1365 __sk_mem_reduce_allocated(sk
, amt
>> SK_MEM_QUANTUM_SHIFT
);
1367 atomic_sub(size
, &sk
->sk_rmem_alloc
);
1369 /* this can save us from acquiring the rx queue lock on next receive */
1370 skb_queue_splice_tail_init(sk_queue
, &up
->reader_queue
);
1372 if (!rx_queue_lock_held
)
1373 spin_unlock(&sk_queue
->lock
);
1376 /* Note: called with reader_queue.lock held.
1377 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1378 * This avoids a cache line miss while receive_queue lock is held.
1379 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1381 void udp_skb_destructor(struct sock
*sk
, struct sk_buff
*skb
)
1383 prefetch(&skb
->data
);
1384 udp_rmem_release(sk
, udp_skb_truesize(skb
), 1, false);
1386 EXPORT_SYMBOL(udp_skb_destructor
);
1388 /* as above, but the caller held the rx queue lock, too */
1389 static void udp_skb_dtor_locked(struct sock
*sk
, struct sk_buff
*skb
)
1391 prefetch(&skb
->data
);
1392 udp_rmem_release(sk
, udp_skb_truesize(skb
), 1, true);
1395 /* Idea of busylocks is to let producers grab an extra spinlock
1396 * to relieve pressure on the receive_queue spinlock shared by consumer.
1397 * Under flood, this means that only one producer can be in line
1398 * trying to acquire the receive_queue spinlock.
1399 * These busylock can be allocated on a per cpu manner, instead of a
1400 * per socket one (that would consume a cache line per socket)
1402 static int udp_busylocks_log __read_mostly
;
1403 static spinlock_t
*udp_busylocks __read_mostly
;
1405 static spinlock_t
*busylock_acquire(void *ptr
)
1409 busy
= udp_busylocks
+ hash_ptr(ptr
, udp_busylocks_log
);
1414 static void busylock_release(spinlock_t
*busy
)
1420 int __udp_enqueue_schedule_skb(struct sock
*sk
, struct sk_buff
*skb
)
1422 struct sk_buff_head
*list
= &sk
->sk_receive_queue
;
1423 int rmem
, delta
, amt
, err
= -ENOMEM
;
1424 spinlock_t
*busy
= NULL
;
1427 /* try to avoid the costly atomic add/sub pair when the receive
1428 * queue is full; always allow at least a packet
1430 rmem
= atomic_read(&sk
->sk_rmem_alloc
);
1431 if (rmem
> sk
->sk_rcvbuf
)
1434 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1435 * having linear skbs :
1436 * - Reduce memory overhead and thus increase receive queue capacity
1437 * - Less cache line misses at copyout() time
1438 * - Less work at consume_skb() (less alien page frag freeing)
1440 if (rmem
> (sk
->sk_rcvbuf
>> 1)) {
1443 busy
= busylock_acquire(sk
);
1445 size
= skb
->truesize
;
1446 udp_set_dev_scratch(skb
);
1448 /* we drop only if the receive buf is full and the receive
1449 * queue contains some other skb
1451 rmem
= atomic_add_return(size
, &sk
->sk_rmem_alloc
);
1452 if (rmem
> (size
+ sk
->sk_rcvbuf
))
1455 spin_lock(&list
->lock
);
1456 if (size
>= sk
->sk_forward_alloc
) {
1457 amt
= sk_mem_pages(size
);
1458 delta
= amt
<< SK_MEM_QUANTUM_SHIFT
;
1459 if (!__sk_mem_raise_allocated(sk
, delta
, amt
, SK_MEM_RECV
)) {
1461 spin_unlock(&list
->lock
);
1465 sk
->sk_forward_alloc
+= delta
;
1468 sk
->sk_forward_alloc
-= size
;
1470 /* no need to setup a destructor, we will explicitly release the
1471 * forward allocated memory on dequeue
1473 sock_skb_set_dropcount(sk
, skb
);
1475 __skb_queue_tail(list
, skb
);
1476 spin_unlock(&list
->lock
);
1478 if (!sock_flag(sk
, SOCK_DEAD
))
1479 sk
->sk_data_ready(sk
);
1481 busylock_release(busy
);
1485 atomic_sub(skb
->truesize
, &sk
->sk_rmem_alloc
);
1488 atomic_inc(&sk
->sk_drops
);
1489 busylock_release(busy
);
1492 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb
);
1494 void udp_destruct_sock(struct sock
*sk
)
1496 /* reclaim completely the forward allocated memory */
1497 struct udp_sock
*up
= udp_sk(sk
);
1498 unsigned int total
= 0;
1499 struct sk_buff
*skb
;
1501 skb_queue_splice_tail_init(&sk
->sk_receive_queue
, &up
->reader_queue
);
1502 while ((skb
= __skb_dequeue(&up
->reader_queue
)) != NULL
) {
1503 total
+= skb
->truesize
;
1506 udp_rmem_release(sk
, total
, 0, true);
1508 inet_sock_destruct(sk
);
1510 EXPORT_SYMBOL_GPL(udp_destruct_sock
);
1512 int udp_init_sock(struct sock
*sk
)
1514 skb_queue_head_init(&udp_sk(sk
)->reader_queue
);
1515 sk
->sk_destruct
= udp_destruct_sock
;
1518 EXPORT_SYMBOL_GPL(udp_init_sock
);
1520 void skb_consume_udp(struct sock
*sk
, struct sk_buff
*skb
, int len
)
1522 if (unlikely(READ_ONCE(sk
->sk_peek_off
) >= 0)) {
1523 bool slow
= lock_sock_fast(sk
);
1525 sk_peek_offset_bwd(sk
, len
);
1526 unlock_sock_fast(sk
, slow
);
1529 if (!skb_unref(skb
))
1532 /* In the more common cases we cleared the head states previously,
1533 * see __udp_queue_rcv_skb().
1535 if (unlikely(udp_skb_has_head_state(skb
)))
1536 skb_release_head_state(skb
);
1537 __consume_stateless_skb(skb
);
1539 EXPORT_SYMBOL_GPL(skb_consume_udp
);
1541 static struct sk_buff
*__first_packet_length(struct sock
*sk
,
1542 struct sk_buff_head
*rcvq
,
1545 struct sk_buff
*skb
;
1547 while ((skb
= skb_peek(rcvq
)) != NULL
) {
1548 if (udp_lib_checksum_complete(skb
)) {
1549 __UDP_INC_STATS(sock_net(sk
), UDP_MIB_CSUMERRORS
,
1551 __UDP_INC_STATS(sock_net(sk
), UDP_MIB_INERRORS
,
1553 atomic_inc(&sk
->sk_drops
);
1554 __skb_unlink(skb
, rcvq
);
1555 *total
+= skb
->truesize
;
1558 /* the csum related bits could be changed, refresh
1561 udp_set_dev_scratch(skb
);
1569 * first_packet_length - return length of first packet in receive queue
1572 * Drops all bad checksum frames, until a valid one is found.
1573 * Returns the length of found skb, or -1 if none is found.
1575 static int first_packet_length(struct sock
*sk
)
1577 struct sk_buff_head
*rcvq
= &udp_sk(sk
)->reader_queue
;
1578 struct sk_buff_head
*sk_queue
= &sk
->sk_receive_queue
;
1579 struct sk_buff
*skb
;
1583 spin_lock_bh(&rcvq
->lock
);
1584 skb
= __first_packet_length(sk
, rcvq
, &total
);
1585 if (!skb
&& !skb_queue_empty(sk_queue
)) {
1586 spin_lock(&sk_queue
->lock
);
1587 skb_queue_splice_tail_init(sk_queue
, rcvq
);
1588 spin_unlock(&sk_queue
->lock
);
1590 skb
= __first_packet_length(sk
, rcvq
, &total
);
1592 res
= skb
? skb
->len
: -1;
1594 udp_rmem_release(sk
, total
, 1, false);
1595 spin_unlock_bh(&rcvq
->lock
);
1600 * IOCTL requests applicable to the UDP protocol
1603 int udp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
1608 int amount
= sk_wmem_alloc_get(sk
);
1610 return put_user(amount
, (int __user
*)arg
);
1615 int amount
= max_t(int, 0, first_packet_length(sk
));
1617 return put_user(amount
, (int __user
*)arg
);
1621 return -ENOIOCTLCMD
;
1626 EXPORT_SYMBOL(udp_ioctl
);
1628 struct sk_buff
*__skb_recv_udp(struct sock
*sk
, unsigned int flags
,
1629 int noblock
, int *off
, int *err
)
1631 struct sk_buff_head
*sk_queue
= &sk
->sk_receive_queue
;
1632 struct sk_buff_head
*queue
;
1633 struct sk_buff
*last
;
1637 queue
= &udp_sk(sk
)->reader_queue
;
1638 flags
|= noblock
? MSG_DONTWAIT
: 0;
1639 timeo
= sock_rcvtimeo(sk
, flags
& MSG_DONTWAIT
);
1641 struct sk_buff
*skb
;
1643 error
= sock_error(sk
);
1649 spin_lock_bh(&queue
->lock
);
1650 skb
= __skb_try_recv_from_queue(sk
, queue
, flags
,
1654 spin_unlock_bh(&queue
->lock
);
1658 if (skb_queue_empty(sk_queue
)) {
1659 spin_unlock_bh(&queue
->lock
);
1663 /* refill the reader queue and walk it again
1664 * keep both queues locked to avoid re-acquiring
1665 * the sk_receive_queue lock if fwd memory scheduling
1668 spin_lock(&sk_queue
->lock
);
1669 skb_queue_splice_tail_init(sk_queue
, queue
);
1671 skb
= __skb_try_recv_from_queue(sk
, queue
, flags
,
1672 udp_skb_dtor_locked
,
1674 spin_unlock(&sk_queue
->lock
);
1675 spin_unlock_bh(&queue
->lock
);
1680 if (!sk_can_busy_loop(sk
))
1683 sk_busy_loop(sk
, flags
& MSG_DONTWAIT
);
1684 } while (!skb_queue_empty(sk_queue
));
1686 /* sk_queue is empty, reader_queue may contain peeked packets */
1688 !__skb_wait_for_more_packets(sk
, &error
, &timeo
,
1689 (struct sk_buff
*)sk_queue
));
1694 EXPORT_SYMBOL(__skb_recv_udp
);
1697 * This should be easy, if there is something there we
1698 * return it, otherwise we block.
1701 int udp_recvmsg(struct sock
*sk
, struct msghdr
*msg
, size_t len
, int noblock
,
1702 int flags
, int *addr_len
)
1704 struct inet_sock
*inet
= inet_sk(sk
);
1705 DECLARE_SOCKADDR(struct sockaddr_in
*, sin
, msg
->msg_name
);
1706 struct sk_buff
*skb
;
1707 unsigned int ulen
, copied
;
1708 int off
, err
, peeking
= flags
& MSG_PEEK
;
1709 int is_udplite
= IS_UDPLITE(sk
);
1710 bool checksum_valid
= false;
1712 if (flags
& MSG_ERRQUEUE
)
1713 return ip_recv_error(sk
, msg
, len
, addr_len
);
1716 off
= sk_peek_offset(sk
, flags
);
1717 skb
= __skb_recv_udp(sk
, flags
, noblock
, &off
, &err
);
1721 ulen
= udp_skb_len(skb
);
1723 if (copied
> ulen
- off
)
1724 copied
= ulen
- off
;
1725 else if (copied
< ulen
)
1726 msg
->msg_flags
|= MSG_TRUNC
;
1729 * If checksum is needed at all, try to do it while copying the
1730 * data. If the data is truncated, or if we only want a partial
1731 * coverage checksum (UDP-Lite), do it before the copy.
1734 if (copied
< ulen
|| peeking
||
1735 (is_udplite
&& UDP_SKB_CB(skb
)->partial_cov
)) {
1736 checksum_valid
= udp_skb_csum_unnecessary(skb
) ||
1737 !__udp_lib_checksum_complete(skb
);
1738 if (!checksum_valid
)
1742 if (checksum_valid
|| udp_skb_csum_unnecessary(skb
)) {
1743 if (udp_skb_is_linear(skb
))
1744 err
= copy_linear_skb(skb
, copied
, off
, &msg
->msg_iter
);
1746 err
= skb_copy_datagram_msg(skb
, off
, msg
, copied
);
1748 err
= skb_copy_and_csum_datagram_msg(skb
, off
, msg
);
1754 if (unlikely(err
)) {
1756 atomic_inc(&sk
->sk_drops
);
1757 UDP_INC_STATS(sock_net(sk
),
1758 UDP_MIB_INERRORS
, is_udplite
);
1765 UDP_INC_STATS(sock_net(sk
),
1766 UDP_MIB_INDATAGRAMS
, is_udplite
);
1768 sock_recv_ts_and_drops(msg
, sk
, skb
);
1770 /* Copy the address. */
1772 sin
->sin_family
= AF_INET
;
1773 sin
->sin_port
= udp_hdr(skb
)->source
;
1774 sin
->sin_addr
.s_addr
= ip_hdr(skb
)->saddr
;
1775 memset(sin
->sin_zero
, 0, sizeof(sin
->sin_zero
));
1776 *addr_len
= sizeof(*sin
);
1779 if (udp_sk(sk
)->gro_enabled
)
1780 udp_cmsg_recv(msg
, sk
, skb
);
1782 if (inet
->cmsg_flags
)
1783 ip_cmsg_recv_offset(msg
, sk
, skb
, sizeof(struct udphdr
), off
);
1786 if (flags
& MSG_TRUNC
)
1789 skb_consume_udp(sk
, skb
, peeking
? -err
: err
);
1793 if (!__sk_queue_drop_skb(sk
, &udp_sk(sk
)->reader_queue
, skb
, flags
,
1794 udp_skb_destructor
)) {
1795 UDP_INC_STATS(sock_net(sk
), UDP_MIB_CSUMERRORS
, is_udplite
);
1796 UDP_INC_STATS(sock_net(sk
), UDP_MIB_INERRORS
, is_udplite
);
1800 /* starting over for a new packet, but check if we need to yield */
1802 msg
->msg_flags
&= ~MSG_TRUNC
;
1806 int udp_pre_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
)
1808 /* This check is replicated from __ip4_datagram_connect() and
1809 * intended to prevent BPF program called below from accessing bytes
1810 * that are out of the bound specified by user in addr_len.
1812 if (addr_len
< sizeof(struct sockaddr_in
))
1815 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk
, uaddr
);
1817 EXPORT_SYMBOL(udp_pre_connect
);
1819 int __udp_disconnect(struct sock
*sk
, int flags
)
1821 struct inet_sock
*inet
= inet_sk(sk
);
1823 * 1003.1g - break association.
1826 sk
->sk_state
= TCP_CLOSE
;
1827 inet
->inet_daddr
= 0;
1828 inet
->inet_dport
= 0;
1829 sock_rps_reset_rxhash(sk
);
1830 sk
->sk_bound_dev_if
= 0;
1831 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
1832 inet_reset_saddr(sk
);
1834 if (!(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
)) {
1835 sk
->sk_prot
->unhash(sk
);
1836 inet
->inet_sport
= 0;
1841 EXPORT_SYMBOL(__udp_disconnect
);
1843 int udp_disconnect(struct sock
*sk
, int flags
)
1846 __udp_disconnect(sk
, flags
);
1850 EXPORT_SYMBOL(udp_disconnect
);
1852 void udp_lib_unhash(struct sock
*sk
)
1854 if (sk_hashed(sk
)) {
1855 struct udp_table
*udptable
= sk
->sk_prot
->h
.udp_table
;
1856 struct udp_hslot
*hslot
, *hslot2
;
1858 hslot
= udp_hashslot(udptable
, sock_net(sk
),
1859 udp_sk(sk
)->udp_port_hash
);
1860 hslot2
= udp_hashslot2(udptable
, udp_sk(sk
)->udp_portaddr_hash
);
1862 spin_lock_bh(&hslot
->lock
);
1863 if (rcu_access_pointer(sk
->sk_reuseport_cb
))
1864 reuseport_detach_sock(sk
);
1865 if (sk_del_node_init_rcu(sk
)) {
1867 inet_sk(sk
)->inet_num
= 0;
1868 sock_prot_inuse_add(sock_net(sk
), sk
->sk_prot
, -1);
1870 spin_lock(&hslot2
->lock
);
1871 hlist_del_init_rcu(&udp_sk(sk
)->udp_portaddr_node
);
1873 spin_unlock(&hslot2
->lock
);
1875 spin_unlock_bh(&hslot
->lock
);
1878 EXPORT_SYMBOL(udp_lib_unhash
);
1881 * inet_rcv_saddr was changed, we must rehash secondary hash
1883 void udp_lib_rehash(struct sock
*sk
, u16 newhash
)
1885 if (sk_hashed(sk
)) {
1886 struct udp_table
*udptable
= sk
->sk_prot
->h
.udp_table
;
1887 struct udp_hslot
*hslot
, *hslot2
, *nhslot2
;
1889 hslot2
= udp_hashslot2(udptable
, udp_sk(sk
)->udp_portaddr_hash
);
1890 nhslot2
= udp_hashslot2(udptable
, newhash
);
1891 udp_sk(sk
)->udp_portaddr_hash
= newhash
;
1893 if (hslot2
!= nhslot2
||
1894 rcu_access_pointer(sk
->sk_reuseport_cb
)) {
1895 hslot
= udp_hashslot(udptable
, sock_net(sk
),
1896 udp_sk(sk
)->udp_port_hash
);
1897 /* we must lock primary chain too */
1898 spin_lock_bh(&hslot
->lock
);
1899 if (rcu_access_pointer(sk
->sk_reuseport_cb
))
1900 reuseport_detach_sock(sk
);
1902 if (hslot2
!= nhslot2
) {
1903 spin_lock(&hslot2
->lock
);
1904 hlist_del_init_rcu(&udp_sk(sk
)->udp_portaddr_node
);
1906 spin_unlock(&hslot2
->lock
);
1908 spin_lock(&nhslot2
->lock
);
1909 hlist_add_head_rcu(&udp_sk(sk
)->udp_portaddr_node
,
1912 spin_unlock(&nhslot2
->lock
);
1915 spin_unlock_bh(&hslot
->lock
);
1919 EXPORT_SYMBOL(udp_lib_rehash
);
1921 void udp_v4_rehash(struct sock
*sk
)
1923 u16 new_hash
= ipv4_portaddr_hash(sock_net(sk
),
1924 inet_sk(sk
)->inet_rcv_saddr
,
1925 inet_sk(sk
)->inet_num
);
1926 udp_lib_rehash(sk
, new_hash
);
1929 static int __udp_queue_rcv_skb(struct sock
*sk
, struct sk_buff
*skb
)
1933 if (inet_sk(sk
)->inet_daddr
) {
1934 sock_rps_save_rxhash(sk
, skb
);
1935 sk_mark_napi_id(sk
, skb
);
1936 sk_incoming_cpu_update(sk
);
1938 sk_mark_napi_id_once(sk
, skb
);
1941 rc
= __udp_enqueue_schedule_skb(sk
, skb
);
1943 int is_udplite
= IS_UDPLITE(sk
);
1945 /* Note that an ENOMEM error is charged twice */
1947 UDP_INC_STATS(sock_net(sk
), UDP_MIB_RCVBUFERRORS
,
1949 UDP_INC_STATS(sock_net(sk
), UDP_MIB_INERRORS
, is_udplite
);
1951 trace_udp_fail_queue_rcv_skb(rc
, sk
);
1961 * >0: "udp encap" protocol resubmission
1963 * Note that in the success and error cases, the skb is assumed to
1964 * have either been requeued or freed.
1966 static int udp_queue_rcv_one_skb(struct sock
*sk
, struct sk_buff
*skb
)
1968 struct udp_sock
*up
= udp_sk(sk
);
1969 int is_udplite
= IS_UDPLITE(sk
);
1972 * Charge it to the socket, dropping if the queue is full.
1974 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
1978 if (static_branch_unlikely(&udp_encap_needed_key
) && up
->encap_type
) {
1979 int (*encap_rcv
)(struct sock
*sk
, struct sk_buff
*skb
);
1982 * This is an encapsulation socket so pass the skb to
1983 * the socket's udp_encap_rcv() hook. Otherwise, just
1984 * fall through and pass this up the UDP socket.
1985 * up->encap_rcv() returns the following value:
1986 * =0 if skb was successfully passed to the encap
1987 * handler or was discarded by it.
1988 * >0 if skb should be passed on to UDP.
1989 * <0 if skb should be resubmitted as proto -N
1992 /* if we're overly short, let UDP handle it */
1993 encap_rcv
= READ_ONCE(up
->encap_rcv
);
1997 /* Verify checksum before giving to encap */
1998 if (udp_lib_checksum_complete(skb
))
2001 ret
= encap_rcv(sk
, skb
);
2003 __UDP_INC_STATS(sock_net(sk
),
2004 UDP_MIB_INDATAGRAMS
,
2010 /* FALLTHROUGH -- it's a UDP Packet */
2014 * UDP-Lite specific tests, ignored on UDP sockets
2016 if ((is_udplite
& UDPLITE_RECV_CC
) && UDP_SKB_CB(skb
)->partial_cov
) {
2019 * MIB statistics other than incrementing the error count are
2020 * disabled for the following two types of errors: these depend
2021 * on the application settings, not on the functioning of the
2022 * protocol stack as such.
2024 * RFC 3828 here recommends (sec 3.3): "There should also be a
2025 * way ... to ... at least let the receiving application block
2026 * delivery of packets with coverage values less than a value
2027 * provided by the application."
2029 if (up
->pcrlen
== 0) { /* full coverage was set */
2030 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2031 UDP_SKB_CB(skb
)->cscov
, skb
->len
);
2034 /* The next case involves violating the min. coverage requested
2035 * by the receiver. This is subtle: if receiver wants x and x is
2036 * greater than the buffersize/MTU then receiver will complain
2037 * that it wants x while sender emits packets of smaller size y.
2038 * Therefore the above ...()->partial_cov statement is essential.
2040 if (UDP_SKB_CB(skb
)->cscov
< up
->pcrlen
) {
2041 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2042 UDP_SKB_CB(skb
)->cscov
, up
->pcrlen
);
2047 prefetch(&sk
->sk_rmem_alloc
);
2048 if (rcu_access_pointer(sk
->sk_filter
) &&
2049 udp_lib_checksum_complete(skb
))
2052 if (sk_filter_trim_cap(sk
, skb
, sizeof(struct udphdr
)))
2055 udp_csum_pull_header(skb
);
2057 ipv4_pktinfo_prepare(sk
, skb
);
2058 return __udp_queue_rcv_skb(sk
, skb
);
2061 __UDP_INC_STATS(sock_net(sk
), UDP_MIB_CSUMERRORS
, is_udplite
);
2063 __UDP_INC_STATS(sock_net(sk
), UDP_MIB_INERRORS
, is_udplite
);
2064 atomic_inc(&sk
->sk_drops
);
2069 static int udp_queue_rcv_skb(struct sock
*sk
, struct sk_buff
*skb
)
2071 struct sk_buff
*next
, *segs
;
2074 if (likely(!udp_unexpected_gso(sk
, skb
)))
2075 return udp_queue_rcv_one_skb(sk
, skb
);
2077 BUILD_BUG_ON(sizeof(struct udp_skb_cb
) > SKB_SGO_CB_OFFSET
);
2078 __skb_push(skb
, -skb_mac_offset(skb
));
2079 segs
= udp_rcv_segment(sk
, skb
, true);
2080 for (skb
= segs
; skb
; skb
= next
) {
2082 __skb_pull(skb
, skb_transport_offset(skb
));
2083 ret
= udp_queue_rcv_one_skb(sk
, skb
);
2085 ip_protocol_deliver_rcu(dev_net(skb
->dev
), skb
, -ret
);
2090 /* For TCP sockets, sk_rx_dst is protected by socket lock
2091 * For UDP, we use xchg() to guard against concurrent changes.
2093 bool udp_sk_rx_dst_set(struct sock
*sk
, struct dst_entry
*dst
)
2095 struct dst_entry
*old
;
2097 if (dst_hold_safe(dst
)) {
2098 old
= xchg(&sk
->sk_rx_dst
, dst
);
2104 EXPORT_SYMBOL(udp_sk_rx_dst_set
);
2107 * Multicasts and broadcasts go to each listener.
2109 * Note: called only from the BH handler context.
2111 static int __udp4_lib_mcast_deliver(struct net
*net
, struct sk_buff
*skb
,
2113 __be32 saddr
, __be32 daddr
,
2114 struct udp_table
*udptable
,
2117 struct sock
*sk
, *first
= NULL
;
2118 unsigned short hnum
= ntohs(uh
->dest
);
2119 struct udp_hslot
*hslot
= udp_hashslot(udptable
, net
, hnum
);
2120 unsigned int hash2
= 0, hash2_any
= 0, use_hash2
= (hslot
->count
> 10);
2121 unsigned int offset
= offsetof(typeof(*sk
), sk_node
);
2122 int dif
= skb
->dev
->ifindex
;
2123 int sdif
= inet_sdif(skb
);
2124 struct hlist_node
*node
;
2125 struct sk_buff
*nskb
;
2128 hash2_any
= ipv4_portaddr_hash(net
, htonl(INADDR_ANY
), hnum
) &
2130 hash2
= ipv4_portaddr_hash(net
, daddr
, hnum
) & udptable
->mask
;
2132 hslot
= &udptable
->hash2
[hash2
];
2133 offset
= offsetof(typeof(*sk
), __sk_common
.skc_portaddr_node
);
2136 sk_for_each_entry_offset_rcu(sk
, node
, &hslot
->head
, offset
) {
2137 if (!__udp_is_mcast_sock(net
, sk
, uh
->dest
, daddr
,
2138 uh
->source
, saddr
, dif
, sdif
, hnum
))
2145 nskb
= skb_clone(skb
, GFP_ATOMIC
);
2147 if (unlikely(!nskb
)) {
2148 atomic_inc(&sk
->sk_drops
);
2149 __UDP_INC_STATS(net
, UDP_MIB_RCVBUFERRORS
,
2151 __UDP_INC_STATS(net
, UDP_MIB_INERRORS
,
2155 if (udp_queue_rcv_skb(sk
, nskb
) > 0)
2159 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2160 if (use_hash2
&& hash2
!= hash2_any
) {
2166 if (udp_queue_rcv_skb(first
, skb
) > 0)
2170 __UDP_INC_STATS(net
, UDP_MIB_IGNOREDMULTI
,
2171 proto
== IPPROTO_UDPLITE
);
2176 /* Initialize UDP checksum. If exited with zero value (success),
2177 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2178 * Otherwise, csum completion requires chacksumming packet body,
2179 * including udp header and folding it to skb->csum.
2181 static inline int udp4_csum_init(struct sk_buff
*skb
, struct udphdr
*uh
,
2186 UDP_SKB_CB(skb
)->partial_cov
= 0;
2187 UDP_SKB_CB(skb
)->cscov
= skb
->len
;
2189 if (proto
== IPPROTO_UDPLITE
) {
2190 err
= udplite_checksum_init(skb
, uh
);
2194 if (UDP_SKB_CB(skb
)->partial_cov
) {
2195 skb
->csum
= inet_compute_pseudo(skb
, proto
);
2200 /* Note, we are only interested in != 0 or == 0, thus the
2203 err
= (__force
int)skb_checksum_init_zero_check(skb
, proto
, uh
->check
,
2204 inet_compute_pseudo
);
2208 if (skb
->ip_summed
== CHECKSUM_COMPLETE
&& !skb
->csum_valid
) {
2209 /* If SW calculated the value, we know it's bad */
2210 if (skb
->csum_complete_sw
)
2213 /* HW says the value is bad. Let's validate that.
2214 * skb->csum is no longer the full packet checksum,
2215 * so don't treat it as such.
2217 skb_checksum_complete_unset(skb
);
2223 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2224 * return code conversion for ip layer consumption
2226 static int udp_unicast_rcv_skb(struct sock
*sk
, struct sk_buff
*skb
,
2231 if (inet_get_convert_csum(sk
) && uh
->check
&& !IS_UDPLITE(sk
))
2232 skb_checksum_try_convert(skb
, IPPROTO_UDP
, uh
->check
,
2233 inet_compute_pseudo
);
2235 ret
= udp_queue_rcv_skb(sk
, skb
);
2237 /* a return value > 0 means to resubmit the input, but
2238 * it wants the return to be -protocol, or 0
2246 * All we need to do is get the socket, and then do a checksum.
2249 int __udp4_lib_rcv(struct sk_buff
*skb
, struct udp_table
*udptable
,
2254 unsigned short ulen
;
2255 struct rtable
*rt
= skb_rtable(skb
);
2256 __be32 saddr
, daddr
;
2257 struct net
*net
= dev_net(skb
->dev
);
2260 * Validate the packet.
2262 if (!pskb_may_pull(skb
, sizeof(struct udphdr
)))
2263 goto drop
; /* No space for header. */
2266 ulen
= ntohs(uh
->len
);
2267 saddr
= ip_hdr(skb
)->saddr
;
2268 daddr
= ip_hdr(skb
)->daddr
;
2270 if (ulen
> skb
->len
)
2273 if (proto
== IPPROTO_UDP
) {
2274 /* UDP validates ulen. */
2275 if (ulen
< sizeof(*uh
) || pskb_trim_rcsum(skb
, ulen
))
2280 if (udp4_csum_init(skb
, uh
, proto
))
2283 sk
= skb_steal_sock(skb
);
2285 struct dst_entry
*dst
= skb_dst(skb
);
2288 if (unlikely(sk
->sk_rx_dst
!= dst
))
2289 udp_sk_rx_dst_set(sk
, dst
);
2291 ret
= udp_unicast_rcv_skb(sk
, skb
, uh
);
2296 if (rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
))
2297 return __udp4_lib_mcast_deliver(net
, skb
, uh
,
2298 saddr
, daddr
, udptable
, proto
);
2300 sk
= __udp4_lib_lookup_skb(skb
, uh
->source
, uh
->dest
, udptable
);
2302 return udp_unicast_rcv_skb(sk
, skb
, uh
);
2304 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
2308 /* No socket. Drop packet silently, if checksum is wrong */
2309 if (udp_lib_checksum_complete(skb
))
2312 __UDP_INC_STATS(net
, UDP_MIB_NOPORTS
, proto
== IPPROTO_UDPLITE
);
2313 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_PORT_UNREACH
, 0);
2316 * Hmm. We got an UDP packet to a port to which we
2317 * don't wanna listen. Ignore it.
2323 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2324 proto
== IPPROTO_UDPLITE
? "Lite" : "",
2325 &saddr
, ntohs(uh
->source
),
2327 &daddr
, ntohs(uh
->dest
));
2332 * RFC1122: OK. Discards the bad packet silently (as far as
2333 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2335 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2336 proto
== IPPROTO_UDPLITE
? "Lite" : "",
2337 &saddr
, ntohs(uh
->source
), &daddr
, ntohs(uh
->dest
),
2339 __UDP_INC_STATS(net
, UDP_MIB_CSUMERRORS
, proto
== IPPROTO_UDPLITE
);
2341 __UDP_INC_STATS(net
, UDP_MIB_INERRORS
, proto
== IPPROTO_UDPLITE
);
2346 /* We can only early demux multicast if there is a single matching socket.
2347 * If more than one socket found returns NULL
2349 static struct sock
*__udp4_lib_mcast_demux_lookup(struct net
*net
,
2350 __be16 loc_port
, __be32 loc_addr
,
2351 __be16 rmt_port
, __be32 rmt_addr
,
2354 struct sock
*sk
, *result
;
2355 unsigned short hnum
= ntohs(loc_port
);
2356 unsigned int slot
= udp_hashfn(net
, hnum
, udp_table
.mask
);
2357 struct udp_hslot
*hslot
= &udp_table
.hash
[slot
];
2359 /* Do not bother scanning a too big list */
2360 if (hslot
->count
> 10)
2364 sk_for_each_rcu(sk
, &hslot
->head
) {
2365 if (__udp_is_mcast_sock(net
, sk
, loc_port
, loc_addr
,
2366 rmt_port
, rmt_addr
, dif
, sdif
, hnum
)) {
2376 /* For unicast we should only early demux connected sockets or we can
2377 * break forwarding setups. The chains here can be long so only check
2378 * if the first socket is an exact match and if not move on.
2380 static struct sock
*__udp4_lib_demux_lookup(struct net
*net
,
2381 __be16 loc_port
, __be32 loc_addr
,
2382 __be16 rmt_port
, __be32 rmt_addr
,
2385 unsigned short hnum
= ntohs(loc_port
);
2386 unsigned int hash2
= ipv4_portaddr_hash(net
, loc_addr
, hnum
);
2387 unsigned int slot2
= hash2
& udp_table
.mask
;
2388 struct udp_hslot
*hslot2
= &udp_table
.hash2
[slot2
];
2389 INET_ADDR_COOKIE(acookie
, rmt_addr
, loc_addr
);
2390 const __portpair ports
= INET_COMBINED_PORTS(rmt_port
, hnum
);
2393 udp_portaddr_for_each_entry_rcu(sk
, &hslot2
->head
) {
2394 if (INET_MATCH(sk
, net
, acookie
, rmt_addr
,
2395 loc_addr
, ports
, dif
, sdif
))
2397 /* Only check first socket in chain */
2403 int udp_v4_early_demux(struct sk_buff
*skb
)
2405 struct net
*net
= dev_net(skb
->dev
);
2406 struct in_device
*in_dev
= NULL
;
2407 const struct iphdr
*iph
;
2408 const struct udphdr
*uh
;
2409 struct sock
*sk
= NULL
;
2410 struct dst_entry
*dst
;
2411 int dif
= skb
->dev
->ifindex
;
2412 int sdif
= inet_sdif(skb
);
2415 /* validate the packet */
2416 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + sizeof(struct udphdr
)))
2422 if (skb
->pkt_type
== PACKET_MULTICAST
) {
2423 in_dev
= __in_dev_get_rcu(skb
->dev
);
2428 ours
= ip_check_mc_rcu(in_dev
, iph
->daddr
, iph
->saddr
,
2433 sk
= __udp4_lib_mcast_demux_lookup(net
, uh
->dest
, iph
->daddr
,
2434 uh
->source
, iph
->saddr
,
2436 } else if (skb
->pkt_type
== PACKET_HOST
) {
2437 sk
= __udp4_lib_demux_lookup(net
, uh
->dest
, iph
->daddr
,
2438 uh
->source
, iph
->saddr
, dif
, sdif
);
2441 if (!sk
|| !refcount_inc_not_zero(&sk
->sk_refcnt
))
2445 skb
->destructor
= sock_efree
;
2446 dst
= READ_ONCE(sk
->sk_rx_dst
);
2449 dst
= dst_check(dst
, 0);
2453 /* set noref for now.
2454 * any place which wants to hold dst has to call
2457 skb_dst_set_noref(skb
, dst
);
2459 /* for unconnected multicast sockets we need to validate
2460 * the source on each packet
2462 if (!inet_sk(sk
)->inet_daddr
&& in_dev
)
2463 return ip_mc_validate_source(skb
, iph
->daddr
,
2464 iph
->saddr
, iph
->tos
,
2465 skb
->dev
, in_dev
, &itag
);
2470 int udp_rcv(struct sk_buff
*skb
)
2472 return __udp4_lib_rcv(skb
, &udp_table
, IPPROTO_UDP
);
2475 void udp_destroy_sock(struct sock
*sk
)
2477 struct udp_sock
*up
= udp_sk(sk
);
2478 bool slow
= lock_sock_fast(sk
);
2479 udp_flush_pending_frames(sk
);
2480 unlock_sock_fast(sk
, slow
);
2481 if (static_branch_unlikely(&udp_encap_needed_key
)) {
2482 if (up
->encap_type
) {
2483 void (*encap_destroy
)(struct sock
*sk
);
2484 encap_destroy
= READ_ONCE(up
->encap_destroy
);
2488 if (up
->encap_enabled
)
2489 static_branch_dec(&udp_encap_needed_key
);
2494 * Socket option code for UDP
2496 int udp_lib_setsockopt(struct sock
*sk
, int level
, int optname
,
2497 char __user
*optval
, unsigned int optlen
,
2498 int (*push_pending_frames
)(struct sock
*))
2500 struct udp_sock
*up
= udp_sk(sk
);
2503 int is_udplite
= IS_UDPLITE(sk
);
2505 if (optlen
< sizeof(int))
2508 if (get_user(val
, (int __user
*)optval
))
2511 valbool
= val
? 1 : 0;
2520 push_pending_frames(sk
);
2528 case UDP_ENCAP_ESPINUDP
:
2529 case UDP_ENCAP_ESPINUDP_NON_IKE
:
2530 up
->encap_rcv
= xfrm4_udp_encap_rcv
;
2532 case UDP_ENCAP_L2TPINUDP
:
2533 up
->encap_type
= val
;
2535 udp_tunnel_encap_enable(sk
->sk_socket
);
2544 case UDP_NO_CHECK6_TX
:
2545 up
->no_check6_tx
= valbool
;
2548 case UDP_NO_CHECK6_RX
:
2549 up
->no_check6_rx
= valbool
;
2553 if (val
< 0 || val
> USHRT_MAX
)
2561 udp_tunnel_encap_enable(sk
->sk_socket
);
2562 up
->gro_enabled
= valbool
;
2567 * UDP-Lite's partial checksum coverage (RFC 3828).
2569 /* The sender sets actual checksum coverage length via this option.
2570 * The case coverage > packet length is handled by send module. */
2571 case UDPLITE_SEND_CSCOV
:
2572 if (!is_udplite
) /* Disable the option on UDP sockets */
2573 return -ENOPROTOOPT
;
2574 if (val
!= 0 && val
< 8) /* Illegal coverage: use default (8) */
2576 else if (val
> USHRT_MAX
)
2579 up
->pcflag
|= UDPLITE_SEND_CC
;
2582 /* The receiver specifies a minimum checksum coverage value. To make
2583 * sense, this should be set to at least 8 (as done below). If zero is
2584 * used, this again means full checksum coverage. */
2585 case UDPLITE_RECV_CSCOV
:
2586 if (!is_udplite
) /* Disable the option on UDP sockets */
2587 return -ENOPROTOOPT
;
2588 if (val
!= 0 && val
< 8) /* Avoid silly minimal values. */
2590 else if (val
> USHRT_MAX
)
2593 up
->pcflag
|= UDPLITE_RECV_CC
;
2603 EXPORT_SYMBOL(udp_lib_setsockopt
);
2605 int udp_setsockopt(struct sock
*sk
, int level
, int optname
,
2606 char __user
*optval
, unsigned int optlen
)
2608 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
2609 return udp_lib_setsockopt(sk
, level
, optname
, optval
, optlen
,
2610 udp_push_pending_frames
);
2611 return ip_setsockopt(sk
, level
, optname
, optval
, optlen
);
2614 #ifdef CONFIG_COMPAT
2615 int compat_udp_setsockopt(struct sock
*sk
, int level
, int optname
,
2616 char __user
*optval
, unsigned int optlen
)
2618 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
2619 return udp_lib_setsockopt(sk
, level
, optname
, optval
, optlen
,
2620 udp_push_pending_frames
);
2621 return compat_ip_setsockopt(sk
, level
, optname
, optval
, optlen
);
2625 int udp_lib_getsockopt(struct sock
*sk
, int level
, int optname
,
2626 char __user
*optval
, int __user
*optlen
)
2628 struct udp_sock
*up
= udp_sk(sk
);
2631 if (get_user(len
, optlen
))
2634 len
= min_t(unsigned int, len
, sizeof(int));
2645 val
= up
->encap_type
;
2648 case UDP_NO_CHECK6_TX
:
2649 val
= up
->no_check6_tx
;
2652 case UDP_NO_CHECK6_RX
:
2653 val
= up
->no_check6_rx
;
2660 /* The following two cannot be changed on UDP sockets, the return is
2661 * always 0 (which corresponds to the full checksum coverage of UDP). */
2662 case UDPLITE_SEND_CSCOV
:
2666 case UDPLITE_RECV_CSCOV
:
2671 return -ENOPROTOOPT
;
2674 if (put_user(len
, optlen
))
2676 if (copy_to_user(optval
, &val
, len
))
2680 EXPORT_SYMBOL(udp_lib_getsockopt
);
2682 int udp_getsockopt(struct sock
*sk
, int level
, int optname
,
2683 char __user
*optval
, int __user
*optlen
)
2685 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
2686 return udp_lib_getsockopt(sk
, level
, optname
, optval
, optlen
);
2687 return ip_getsockopt(sk
, level
, optname
, optval
, optlen
);
2690 #ifdef CONFIG_COMPAT
2691 int compat_udp_getsockopt(struct sock
*sk
, int level
, int optname
,
2692 char __user
*optval
, int __user
*optlen
)
2694 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
2695 return udp_lib_getsockopt(sk
, level
, optname
, optval
, optlen
);
2696 return compat_ip_getsockopt(sk
, level
, optname
, optval
, optlen
);
2700 * udp_poll - wait for a UDP event.
2701 * @file - file struct
2703 * @wait - poll table
2705 * This is same as datagram poll, except for the special case of
2706 * blocking sockets. If application is using a blocking fd
2707 * and a packet with checksum error is in the queue;
2708 * then it could get return from select indicating data available
2709 * but then block when reading it. Add special case code
2710 * to work around these arguably broken applications.
2712 __poll_t
udp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
2714 __poll_t mask
= datagram_poll(file
, sock
, wait
);
2715 struct sock
*sk
= sock
->sk
;
2717 if (!skb_queue_empty(&udp_sk(sk
)->reader_queue
))
2718 mask
|= EPOLLIN
| EPOLLRDNORM
;
2720 /* Check for false positives due to checksum errors */
2721 if ((mask
& EPOLLRDNORM
) && !(file
->f_flags
& O_NONBLOCK
) &&
2722 !(sk
->sk_shutdown
& RCV_SHUTDOWN
) && first_packet_length(sk
) == -1)
2723 mask
&= ~(EPOLLIN
| EPOLLRDNORM
);
2728 EXPORT_SYMBOL(udp_poll
);
2730 int udp_abort(struct sock
*sk
, int err
)
2735 sk
->sk_error_report(sk
);
2736 __udp_disconnect(sk
, 0);
2742 EXPORT_SYMBOL_GPL(udp_abort
);
2744 struct proto udp_prot
= {
2746 .owner
= THIS_MODULE
,
2747 .close
= udp_lib_close
,
2748 .pre_connect
= udp_pre_connect
,
2749 .connect
= ip4_datagram_connect
,
2750 .disconnect
= udp_disconnect
,
2752 .init
= udp_init_sock
,
2753 .destroy
= udp_destroy_sock
,
2754 .setsockopt
= udp_setsockopt
,
2755 .getsockopt
= udp_getsockopt
,
2756 .sendmsg
= udp_sendmsg
,
2757 .recvmsg
= udp_recvmsg
,
2758 .sendpage
= udp_sendpage
,
2759 .release_cb
= ip4_datagram_release_cb
,
2760 .hash
= udp_lib_hash
,
2761 .unhash
= udp_lib_unhash
,
2762 .rehash
= udp_v4_rehash
,
2763 .get_port
= udp_v4_get_port
,
2764 .memory_allocated
= &udp_memory_allocated
,
2765 .sysctl_mem
= sysctl_udp_mem
,
2766 .sysctl_wmem_offset
= offsetof(struct net
, ipv4
.sysctl_udp_wmem_min
),
2767 .sysctl_rmem_offset
= offsetof(struct net
, ipv4
.sysctl_udp_rmem_min
),
2768 .obj_size
= sizeof(struct udp_sock
),
2769 .h
.udp_table
= &udp_table
,
2770 #ifdef CONFIG_COMPAT
2771 .compat_setsockopt
= compat_udp_setsockopt
,
2772 .compat_getsockopt
= compat_udp_getsockopt
,
2774 .diag_destroy
= udp_abort
,
2776 EXPORT_SYMBOL(udp_prot
);
2778 /* ------------------------------------------------------------------------ */
2779 #ifdef CONFIG_PROC_FS
2781 static struct sock
*udp_get_first(struct seq_file
*seq
, int start
)
2784 struct udp_seq_afinfo
*afinfo
= PDE_DATA(file_inode(seq
->file
));
2785 struct udp_iter_state
*state
= seq
->private;
2786 struct net
*net
= seq_file_net(seq
);
2788 for (state
->bucket
= start
; state
->bucket
<= afinfo
->udp_table
->mask
;
2790 struct udp_hslot
*hslot
= &afinfo
->udp_table
->hash
[state
->bucket
];
2792 if (hlist_empty(&hslot
->head
))
2795 spin_lock_bh(&hslot
->lock
);
2796 sk_for_each(sk
, &hslot
->head
) {
2797 if (!net_eq(sock_net(sk
), net
))
2799 if (sk
->sk_family
== afinfo
->family
)
2802 spin_unlock_bh(&hslot
->lock
);
2809 static struct sock
*udp_get_next(struct seq_file
*seq
, struct sock
*sk
)
2811 struct udp_seq_afinfo
*afinfo
= PDE_DATA(file_inode(seq
->file
));
2812 struct udp_iter_state
*state
= seq
->private;
2813 struct net
*net
= seq_file_net(seq
);
2817 } while (sk
&& (!net_eq(sock_net(sk
), net
) || sk
->sk_family
!= afinfo
->family
));
2820 if (state
->bucket
<= afinfo
->udp_table
->mask
)
2821 spin_unlock_bh(&afinfo
->udp_table
->hash
[state
->bucket
].lock
);
2822 return udp_get_first(seq
, state
->bucket
+ 1);
2827 static struct sock
*udp_get_idx(struct seq_file
*seq
, loff_t pos
)
2829 struct sock
*sk
= udp_get_first(seq
, 0);
2832 while (pos
&& (sk
= udp_get_next(seq
, sk
)) != NULL
)
2834 return pos
? NULL
: sk
;
2837 void *udp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2839 struct udp_iter_state
*state
= seq
->private;
2840 state
->bucket
= MAX_UDP_PORTS
;
2842 return *pos
? udp_get_idx(seq
, *pos
-1) : SEQ_START_TOKEN
;
2844 EXPORT_SYMBOL(udp_seq_start
);
2846 void *udp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2850 if (v
== SEQ_START_TOKEN
)
2851 sk
= udp_get_idx(seq
, 0);
2853 sk
= udp_get_next(seq
, v
);
2858 EXPORT_SYMBOL(udp_seq_next
);
2860 void udp_seq_stop(struct seq_file
*seq
, void *v
)
2862 struct udp_seq_afinfo
*afinfo
= PDE_DATA(file_inode(seq
->file
));
2863 struct udp_iter_state
*state
= seq
->private;
2865 if (state
->bucket
<= afinfo
->udp_table
->mask
)
2866 spin_unlock_bh(&afinfo
->udp_table
->hash
[state
->bucket
].lock
);
2868 EXPORT_SYMBOL(udp_seq_stop
);
2870 /* ------------------------------------------------------------------------ */
2871 static void udp4_format_sock(struct sock
*sp
, struct seq_file
*f
,
2874 struct inet_sock
*inet
= inet_sk(sp
);
2875 __be32 dest
= inet
->inet_daddr
;
2876 __be32 src
= inet
->inet_rcv_saddr
;
2877 __u16 destp
= ntohs(inet
->inet_dport
);
2878 __u16 srcp
= ntohs(inet
->inet_sport
);
2880 seq_printf(f
, "%5d: %08X:%04X %08X:%04X"
2881 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
2882 bucket
, src
, srcp
, dest
, destp
, sp
->sk_state
,
2883 sk_wmem_alloc_get(sp
),
2886 from_kuid_munged(seq_user_ns(f
), sock_i_uid(sp
)),
2888 refcount_read(&sp
->sk_refcnt
), sp
,
2889 atomic_read(&sp
->sk_drops
));
2892 int udp4_seq_show(struct seq_file
*seq
, void *v
)
2894 seq_setwidth(seq
, 127);
2895 if (v
== SEQ_START_TOKEN
)
2896 seq_puts(seq
, " sl local_address rem_address st tx_queue "
2897 "rx_queue tr tm->when retrnsmt uid timeout "
2898 "inode ref pointer drops");
2900 struct udp_iter_state
*state
= seq
->private;
2902 udp4_format_sock(v
, seq
, state
->bucket
);
2908 const struct seq_operations udp_seq_ops
= {
2909 .start
= udp_seq_start
,
2910 .next
= udp_seq_next
,
2911 .stop
= udp_seq_stop
,
2912 .show
= udp4_seq_show
,
2914 EXPORT_SYMBOL(udp_seq_ops
);
2916 static struct udp_seq_afinfo udp4_seq_afinfo
= {
2918 .udp_table
= &udp_table
,
2921 static int __net_init
udp4_proc_init_net(struct net
*net
)
2923 if (!proc_create_net_data("udp", 0444, net
->proc_net
, &udp_seq_ops
,
2924 sizeof(struct udp_iter_state
), &udp4_seq_afinfo
))
2929 static void __net_exit
udp4_proc_exit_net(struct net
*net
)
2931 remove_proc_entry("udp", net
->proc_net
);
2934 static struct pernet_operations udp4_net_ops
= {
2935 .init
= udp4_proc_init_net
,
2936 .exit
= udp4_proc_exit_net
,
2939 int __init
udp4_proc_init(void)
2941 return register_pernet_subsys(&udp4_net_ops
);
2944 void udp4_proc_exit(void)
2946 unregister_pernet_subsys(&udp4_net_ops
);
2948 #endif /* CONFIG_PROC_FS */
2950 static __initdata
unsigned long uhash_entries
;
2951 static int __init
set_uhash_entries(char *str
)
2958 ret
= kstrtoul(str
, 0, &uhash_entries
);
2962 if (uhash_entries
&& uhash_entries
< UDP_HTABLE_SIZE_MIN
)
2963 uhash_entries
= UDP_HTABLE_SIZE_MIN
;
2966 __setup("uhash_entries=", set_uhash_entries
);
2968 void __init
udp_table_init(struct udp_table
*table
, const char *name
)
2972 table
->hash
= alloc_large_system_hash(name
,
2973 2 * sizeof(struct udp_hslot
),
2975 21, /* one slot per 2 MB */
2979 UDP_HTABLE_SIZE_MIN
,
2982 table
->hash2
= table
->hash
+ (table
->mask
+ 1);
2983 for (i
= 0; i
<= table
->mask
; i
++) {
2984 INIT_HLIST_HEAD(&table
->hash
[i
].head
);
2985 table
->hash
[i
].count
= 0;
2986 spin_lock_init(&table
->hash
[i
].lock
);
2988 for (i
= 0; i
<= table
->mask
; i
++) {
2989 INIT_HLIST_HEAD(&table
->hash2
[i
].head
);
2990 table
->hash2
[i
].count
= 0;
2991 spin_lock_init(&table
->hash2
[i
].lock
);
2995 u32
udp_flow_hashrnd(void)
2997 static u32 hashrnd __read_mostly
;
2999 net_get_random_once(&hashrnd
, sizeof(hashrnd
));
3003 EXPORT_SYMBOL(udp_flow_hashrnd
);
3005 static void __udp_sysctl_init(struct net
*net
)
3007 net
->ipv4
.sysctl_udp_rmem_min
= SK_MEM_QUANTUM
;
3008 net
->ipv4
.sysctl_udp_wmem_min
= SK_MEM_QUANTUM
;
3010 #ifdef CONFIG_NET_L3_MASTER_DEV
3011 net
->ipv4
.sysctl_udp_l3mdev_accept
= 0;
3015 static int __net_init
udp_sysctl_init(struct net
*net
)
3017 __udp_sysctl_init(net
);
3021 static struct pernet_operations __net_initdata udp_sysctl_ops
= {
3022 .init
= udp_sysctl_init
,
3025 void __init
udp_init(void)
3027 unsigned long limit
;
3030 udp_table_init(&udp_table
, "UDP");
3031 limit
= nr_free_buffer_pages() / 8;
3032 limit
= max(limit
, 128UL);
3033 sysctl_udp_mem
[0] = limit
/ 4 * 3;
3034 sysctl_udp_mem
[1] = limit
;
3035 sysctl_udp_mem
[2] = sysctl_udp_mem
[0] * 2;
3037 __udp_sysctl_init(&init_net
);
3039 /* 16 spinlocks per cpu */
3040 udp_busylocks_log
= ilog2(nr_cpu_ids
) + 4;
3041 udp_busylocks
= kmalloc(sizeof(spinlock_t
) << udp_busylocks_log
,
3044 panic("UDP: failed to alloc udp_busylocks\n");
3045 for (i
= 0; i
< (1U << udp_busylocks_log
); i
++)
3046 spin_lock_init(udp_busylocks
+ i
);
3048 if (register_pernet_subsys(&udp_sysctl_ops
))
3049 panic("UDP: failed to init sysctl parameters.\n");