2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * The User Datagram Protocol (UDP).
8 * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
13 * Alan Cox, <Alan.Cox@linux.org>
14 * Hirokazu Takahashi, <taka@valinux.co.jp>
17 * Alan Cox : verify_area() calls
18 * Alan Cox : stopped close while in use off icmp
19 * messages. Not a fix but a botch that
20 * for udp at least is 'valid'.
21 * Alan Cox : Fixed icmp handling properly
22 * Alan Cox : Correct error for oversized datagrams
23 * Alan Cox : Tidied select() semantics.
24 * Alan Cox : udp_err() fixed properly, also now
25 * select and read wake correctly on errors
26 * Alan Cox : udp_send verify_area moved to avoid mem leak
27 * Alan Cox : UDP can count its memory
28 * Alan Cox : send to an unknown connection causes
29 * an ECONNREFUSED off the icmp, but
31 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
32 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
33 * bug no longer crashes it.
34 * Fred Van Kempen : Net2e support for sk->broadcast.
35 * Alan Cox : Uses skb_free_datagram
36 * Alan Cox : Added get/set sockopt support.
37 * Alan Cox : Broadcasting without option set returns EACCES.
38 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
39 * Alan Cox : Use ip_tos and ip_ttl
40 * Alan Cox : SNMP Mibs
41 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
42 * Matt Dillon : UDP length checks.
43 * Alan Cox : Smarter af_inet used properly.
44 * Alan Cox : Use new kernel side addressing.
45 * Alan Cox : Incorrect return on truncated datagram receive.
46 * Arnt Gulbrandsen : New udp_send and stuff
47 * Alan Cox : Cache last socket
48 * Alan Cox : Route cache
49 * Jon Peatfield : Minor efficiency fix to sendto().
50 * Mike Shaver : RFC1122 checks.
51 * Alan Cox : Nonblocking error fix.
52 * Willy Konynenberg : Transparent proxying support.
53 * Mike McLagan : Routing by source
54 * David S. Miller : New socket lookup architecture.
55 * Last socket cache retained as it
56 * does have a high hit rate.
57 * Olaf Kirch : Don't linearise iovec on sendmsg.
58 * Andi Kleen : Some cleanups, cache destination entry
60 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
61 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
62 * return ENOTCONN for unconnected sockets (POSIX)
63 * Janos Farkas : don't deliver multi/broadcasts to a different
64 * bound-to-device socket
65 * Hirokazu Takahashi : HW checksumming for outgoing UDP
67 * Hirokazu Takahashi : sendfile() on UDP works now.
68 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
69 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
70 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
71 * a single port at the same time.
72 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
73 * James Chapman : Add L2TP encapsulation type.
76 * This program is free software; you can redistribute it and/or
77 * modify it under the terms of the GNU General Public License
78 * as published by the Free Software Foundation; either version
79 * 2 of the License, or (at your option) any later version.
82 #include <asm/system.h>
83 #include <asm/uaccess.h>
84 #include <asm/ioctls.h>
85 #include <linux/types.h>
86 #include <linux/fcntl.h>
87 #include <linux/module.h>
88 #include <linux/socket.h>
89 #include <linux/sockios.h>
90 #include <linux/igmp.h>
92 #include <linux/errno.h>
93 #include <linux/timer.h>
95 #include <linux/inet.h>
96 #include <linux/netdevice.h>
97 #include <net/tcp_states.h>
98 #include <linux/skbuff.h>
99 #include <linux/proc_fs.h>
100 #include <linux/seq_file.h>
101 #include <net/net_namespace.h>
102 #include <net/icmp.h>
103 #include <net/route.h>
104 #include <net/checksum.h>
105 #include <net/xfrm.h>
106 #include "udp_impl.h"
109 * Snmp MIB for the UDP layer
112 DEFINE_SNMP_STAT(struct udp_mib
, udp_statistics
) __read_mostly
;
113 EXPORT_SYMBOL(udp_statistics
);
115 DEFINE_SNMP_STAT(struct udp_mib
, udp_stats_in6
) __read_mostly
;
116 EXPORT_SYMBOL(udp_stats_in6
);
118 struct hlist_head udp_hash
[UDP_HTABLE_SIZE
];
119 DEFINE_RWLOCK(udp_hash_lock
);
121 static inline int __udp_lib_lport_inuse(__u16 num
,
122 const struct hlist_head udptable
[])
125 struct hlist_node
*node
;
127 sk_for_each(sk
, node
, &udptable
[num
& (UDP_HTABLE_SIZE
- 1)])
128 if (sk
->sk_hash
== num
)
134 * __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
136 * @sk: socket struct in question
137 * @snum: port number to look up
138 * @udptable: hash list table, must be of UDP_HTABLE_SIZE
139 * @saddr_comp: AF-dependent comparison of bound local IP addresses
141 int __udp_lib_get_port(struct sock
*sk
, unsigned short snum
,
142 struct hlist_head udptable
[],
143 int (*saddr_comp
)(const struct sock
*sk1
,
144 const struct sock
*sk2
) )
146 struct hlist_node
*node
;
147 struct hlist_head
*head
;
151 write_lock_bh(&udp_hash_lock
);
154 int i
, low
, high
, remaining
;
155 unsigned rover
, best
, best_size_so_far
;
157 inet_get_local_port_range(&low
, &high
);
158 remaining
= (high
- low
) + 1;
160 best_size_so_far
= UINT_MAX
;
161 best
= rover
= net_random() % remaining
+ low
;
163 /* 1st pass: look for empty (or shortest) hash chain */
164 for (i
= 0; i
< UDP_HTABLE_SIZE
; i
++) {
167 head
= &udptable
[rover
& (UDP_HTABLE_SIZE
- 1)];
168 if (hlist_empty(head
))
171 sk_for_each(sk2
, node
, head
) {
172 if (++size
>= best_size_so_far
)
175 best_size_so_far
= size
;
178 /* fold back if end of range */
180 rover
= low
+ ((rover
- low
)
181 & (UDP_HTABLE_SIZE
- 1));
186 /* 2nd pass: find hole in shortest hash chain */
188 for (i
= 0; i
< (1 << 16) / UDP_HTABLE_SIZE
; i
++) {
189 if (! __udp_lib_lport_inuse(rover
, udptable
))
191 rover
+= UDP_HTABLE_SIZE
;
193 rover
= low
+ ((rover
- low
)
194 & (UDP_HTABLE_SIZE
- 1));
198 /* All ports in use! */
204 head
= &udptable
[snum
& (UDP_HTABLE_SIZE
- 1)];
206 sk_for_each(sk2
, node
, head
)
207 if (sk2
->sk_hash
== snum
&&
209 (!sk2
->sk_reuse
|| !sk
->sk_reuse
) &&
210 (!sk2
->sk_bound_dev_if
|| !sk
->sk_bound_dev_if
211 || sk2
->sk_bound_dev_if
== sk
->sk_bound_dev_if
) &&
212 (*saddr_comp
)(sk
, sk2
) )
216 inet_sk(sk
)->num
= snum
;
218 if (sk_unhashed(sk
)) {
219 head
= &udptable
[snum
& (UDP_HTABLE_SIZE
- 1)];
220 sk_add_node(sk
, head
);
221 sock_prot_inc_use(sk
->sk_prot
);
225 write_unlock_bh(&udp_hash_lock
);
229 int udp_get_port(struct sock
*sk
, unsigned short snum
,
230 int (*scmp
)(const struct sock
*, const struct sock
*))
232 return __udp_lib_get_port(sk
, snum
, udp_hash
, scmp
);
235 int ipv4_rcv_saddr_equal(const struct sock
*sk1
, const struct sock
*sk2
)
237 struct inet_sock
*inet1
= inet_sk(sk1
), *inet2
= inet_sk(sk2
);
239 return ( !ipv6_only_sock(sk2
) &&
240 (!inet1
->rcv_saddr
|| !inet2
->rcv_saddr
||
241 inet1
->rcv_saddr
== inet2
->rcv_saddr
));
244 static inline int udp_v4_get_port(struct sock
*sk
, unsigned short snum
)
246 return udp_get_port(sk
, snum
, ipv4_rcv_saddr_equal
);
249 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
250 * harder than this. -DaveM
252 static struct sock
*__udp4_lib_lookup(__be32 saddr
, __be16 sport
,
253 __be32 daddr
, __be16 dport
,
254 int dif
, struct hlist_head udptable
[])
256 struct sock
*sk
, *result
= NULL
;
257 struct hlist_node
*node
;
258 unsigned short hnum
= ntohs(dport
);
261 read_lock(&udp_hash_lock
);
262 sk_for_each(sk
, node
, &udptable
[hnum
& (UDP_HTABLE_SIZE
- 1)]) {
263 struct inet_sock
*inet
= inet_sk(sk
);
265 if (sk
->sk_hash
== hnum
&& !ipv6_only_sock(sk
)) {
266 int score
= (sk
->sk_family
== PF_INET
? 1 : 0);
267 if (inet
->rcv_saddr
) {
268 if (inet
->rcv_saddr
!= daddr
)
273 if (inet
->daddr
!= saddr
)
278 if (inet
->dport
!= sport
)
282 if (sk
->sk_bound_dev_if
) {
283 if (sk
->sk_bound_dev_if
!= dif
)
290 } else if (score
> badness
) {
298 read_unlock(&udp_hash_lock
);
302 static inline struct sock
*udp_v4_mcast_next(struct sock
*sk
,
303 __be16 loc_port
, __be32 loc_addr
,
304 __be16 rmt_port
, __be32 rmt_addr
,
307 struct hlist_node
*node
;
309 unsigned short hnum
= ntohs(loc_port
);
311 sk_for_each_from(s
, node
) {
312 struct inet_sock
*inet
= inet_sk(s
);
314 if (s
->sk_hash
!= hnum
||
315 (inet
->daddr
&& inet
->daddr
!= rmt_addr
) ||
316 (inet
->dport
!= rmt_port
&& inet
->dport
) ||
317 (inet
->rcv_saddr
&& inet
->rcv_saddr
!= loc_addr
) ||
319 (s
->sk_bound_dev_if
&& s
->sk_bound_dev_if
!= dif
))
321 if (!ip_mc_sf_allow(s
, loc_addr
, rmt_addr
, dif
))
331 * This routine is called by the ICMP module when it gets some
332 * sort of error condition. If err < 0 then the socket should
333 * be closed and the error returned to the user. If err > 0
334 * it's just the icmp type << 8 | icmp code.
335 * Header points to the ip header of the error packet. We move
336 * on past this. Then (as it used to claim before adjustment)
337 * header points to the first 8 bytes of the udp header. We need
338 * to find the appropriate port.
341 void __udp4_lib_err(struct sk_buff
*skb
, u32 info
, struct hlist_head udptable
[])
343 struct inet_sock
*inet
;
344 struct iphdr
*iph
= (struct iphdr
*)skb
->data
;
345 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+(iph
->ihl
<<2));
346 const int type
= icmp_hdr(skb
)->type
;
347 const int code
= icmp_hdr(skb
)->code
;
352 sk
= __udp4_lib_lookup(iph
->daddr
, uh
->dest
, iph
->saddr
, uh
->source
,
353 skb
->dev
->ifindex
, udptable
);
355 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS
);
356 return; /* No socket for error */
365 case ICMP_TIME_EXCEEDED
:
368 case ICMP_SOURCE_QUENCH
:
370 case ICMP_PARAMETERPROB
:
374 case ICMP_DEST_UNREACH
:
375 if (code
== ICMP_FRAG_NEEDED
) { /* Path MTU discovery */
376 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
) {
384 if (code
<= NR_ICMP_UNREACH
) {
385 harderr
= icmp_err_convert
[code
].fatal
;
386 err
= icmp_err_convert
[code
].errno
;
392 * RFC1122: OK. Passes ICMP errors back to application, as per
395 if (!inet
->recverr
) {
396 if (!harderr
|| sk
->sk_state
!= TCP_ESTABLISHED
)
399 ip_icmp_error(sk
, skb
, err
, uh
->dest
, info
, (u8
*)(uh
+1));
402 sk
->sk_error_report(sk
);
407 void udp_err(struct sk_buff
*skb
, u32 info
)
409 return __udp4_lib_err(skb
, info
, udp_hash
);
413 * Throw away all pending data and cancel the corking. Socket is locked.
415 static void udp_flush_pending_frames(struct sock
*sk
)
417 struct udp_sock
*up
= udp_sk(sk
);
422 ip_flush_pending_frames(sk
);
427 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
428 * @sk: socket we are sending on
429 * @skb: sk_buff containing the filled-in UDP header
430 * (checksum field must be zeroed out)
432 static void udp4_hwcsum_outgoing(struct sock
*sk
, struct sk_buff
*skb
,
433 __be32 src
, __be32 dst
, int len
)
436 struct udphdr
*uh
= udp_hdr(skb
);
439 if (skb_queue_len(&sk
->sk_write_queue
) == 1) {
441 * Only one fragment on the socket.
443 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
444 skb
->csum_offset
= offsetof(struct udphdr
, check
);
445 uh
->check
= ~csum_tcpudp_magic(src
, dst
, len
, IPPROTO_UDP
, 0);
448 * HW-checksum won't work as there are two or more
449 * fragments on the socket so that all csums of sk_buffs
452 offset
= skb_transport_offset(skb
);
453 skb
->csum
= skb_checksum(skb
, offset
, skb
->len
- offset
, 0);
455 skb
->ip_summed
= CHECKSUM_NONE
;
457 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
458 csum
= csum_add(csum
, skb
->csum
);
461 uh
->check
= csum_tcpudp_magic(src
, dst
, len
, IPPROTO_UDP
, csum
);
463 uh
->check
= CSUM_MANGLED_0
;
468 * Push out all pending data as one UDP datagram. Socket is locked.
470 static int udp_push_pending_frames(struct sock
*sk
)
472 struct udp_sock
*up
= udp_sk(sk
);
473 struct inet_sock
*inet
= inet_sk(sk
);
474 struct flowi
*fl
= &inet
->cork
.fl
;
478 int is_udplite
= IS_UDPLITE(sk
);
481 /* Grab the skbuff where UDP header space exists. */
482 if ((skb
= skb_peek(&sk
->sk_write_queue
)) == NULL
)
486 * Create a UDP header
489 uh
->source
= fl
->fl_ip_sport
;
490 uh
->dest
= fl
->fl_ip_dport
;
491 uh
->len
= htons(up
->len
);
494 if (is_udplite
) /* UDP-Lite */
495 csum
= udplite_csum_outgoing(sk
, skb
);
497 else if (sk
->sk_no_check
== UDP_CSUM_NOXMIT
) { /* UDP csum disabled */
499 skb
->ip_summed
= CHECKSUM_NONE
;
502 } else if (skb
->ip_summed
== CHECKSUM_PARTIAL
) { /* UDP hardware csum */
504 udp4_hwcsum_outgoing(sk
, skb
, fl
->fl4_src
,fl
->fl4_dst
, up
->len
);
507 } else /* `normal' UDP */
508 csum
= udp_csum_outgoing(sk
, skb
);
510 /* add protocol-dependent pseudo-header */
511 uh
->check
= csum_tcpudp_magic(fl
->fl4_src
, fl
->fl4_dst
, up
->len
,
512 sk
->sk_protocol
, csum
);
514 uh
->check
= CSUM_MANGLED_0
;
517 err
= ip_push_pending_frames(sk
);
522 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS
, is_udplite
);
526 int udp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
529 struct inet_sock
*inet
= inet_sk(sk
);
530 struct udp_sock
*up
= udp_sk(sk
);
532 struct ipcm_cookie ipc
;
533 struct rtable
*rt
= NULL
;
536 __be32 daddr
, faddr
, saddr
;
539 int err
, is_udplite
= IS_UDPLITE(sk
);
540 int corkreq
= up
->corkflag
|| msg
->msg_flags
&MSG_MORE
;
541 int (*getfrag
)(void *, char *, int, int, int, struct sk_buff
*);
550 if (msg
->msg_flags
&MSG_OOB
) /* Mirror BSD error message compatibility */
557 * There are pending frames.
558 * The socket lock must be held while it's corked.
561 if (likely(up
->pending
)) {
562 if (unlikely(up
->pending
!= AF_INET
)) {
570 ulen
+= sizeof(struct udphdr
);
573 * Get and verify the address.
576 struct sockaddr_in
* usin
= (struct sockaddr_in
*)msg
->msg_name
;
577 if (msg
->msg_namelen
< sizeof(*usin
))
579 if (usin
->sin_family
!= AF_INET
) {
580 if (usin
->sin_family
!= AF_UNSPEC
)
581 return -EAFNOSUPPORT
;
584 daddr
= usin
->sin_addr
.s_addr
;
585 dport
= usin
->sin_port
;
589 if (sk
->sk_state
!= TCP_ESTABLISHED
)
590 return -EDESTADDRREQ
;
593 /* Open fast path for connected socket.
594 Route will not be used, if at least one option is set.
598 ipc
.addr
= inet
->saddr
;
600 ipc
.oif
= sk
->sk_bound_dev_if
;
601 if (msg
->msg_controllen
) {
602 err
= ip_cmsg_send(msg
, &ipc
);
613 ipc
.addr
= faddr
= daddr
;
615 if (ipc
.opt
&& ipc
.opt
->srr
) {
618 faddr
= ipc
.opt
->faddr
;
621 tos
= RT_TOS(inet
->tos
);
622 if (sock_flag(sk
, SOCK_LOCALROUTE
) ||
623 (msg
->msg_flags
& MSG_DONTROUTE
) ||
624 (ipc
.opt
&& ipc
.opt
->is_strictroute
)) {
629 if (MULTICAST(daddr
)) {
631 ipc
.oif
= inet
->mc_index
;
633 saddr
= inet
->mc_addr
;
638 rt
= (struct rtable
*)sk_dst_check(sk
, 0);
641 struct flowi fl
= { .oif
= ipc
.oif
,
646 .proto
= sk
->sk_protocol
,
648 { .sport
= inet
->sport
,
649 .dport
= dport
} } };
650 security_sk_classify_flow(sk
, &fl
);
651 err
= ip_route_output_flow(&rt
, &fl
, sk
, 1);
653 if (err
== -ENETUNREACH
)
654 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES
);
659 if ((rt
->rt_flags
& RTCF_BROADCAST
) &&
660 !sock_flag(sk
, SOCK_BROADCAST
))
663 sk_dst_set(sk
, dst_clone(&rt
->u
.dst
));
666 if (msg
->msg_flags
&MSG_CONFIRM
)
672 daddr
= ipc
.addr
= rt
->rt_dst
;
675 if (unlikely(up
->pending
)) {
676 /* The socket is already corked while preparing it. */
677 /* ... which is an evident application bug. --ANK */
680 LIMIT_NETDEBUG(KERN_DEBUG
"udp cork app bug 2\n");
685 * Now cork the socket to pend data.
687 inet
->cork
.fl
.fl4_dst
= daddr
;
688 inet
->cork
.fl
.fl_ip_dport
= dport
;
689 inet
->cork
.fl
.fl4_src
= saddr
;
690 inet
->cork
.fl
.fl_ip_sport
= inet
->sport
;
691 up
->pending
= AF_INET
;
695 getfrag
= is_udplite
? udplite_getfrag
: ip_generic_getfrag
;
696 err
= ip_append_data(sk
, getfrag
, msg
->msg_iov
, ulen
,
697 sizeof(struct udphdr
), &ipc
, rt
,
698 corkreq
? msg
->msg_flags
|MSG_MORE
: msg
->msg_flags
);
700 udp_flush_pending_frames(sk
);
702 err
= udp_push_pending_frames(sk
);
703 else if (unlikely(skb_queue_empty(&sk
->sk_write_queue
)))
714 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
715 * ENOBUFS might not be good (it's not tunable per se), but otherwise
716 * we don't have a good statistic (IpOutDiscards but it can be too many
717 * things). We could add another new stat but at least for now that
718 * seems like overkill.
720 if (err
== -ENOBUFS
|| test_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
)) {
721 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS
, is_udplite
);
726 dst_confirm(&rt
->u
.dst
);
727 if (!(msg
->msg_flags
&MSG_PROBE
) || len
)
728 goto back_from_confirm
;
733 int udp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
734 size_t size
, int flags
)
736 struct udp_sock
*up
= udp_sk(sk
);
740 struct msghdr msg
= { .msg_flags
= flags
|MSG_MORE
};
742 /* Call udp_sendmsg to specify destination address which
743 * sendpage interface can't pass.
744 * This will succeed only when the socket is connected.
746 ret
= udp_sendmsg(NULL
, sk
, &msg
, 0);
753 if (unlikely(!up
->pending
)) {
756 LIMIT_NETDEBUG(KERN_DEBUG
"udp cork app bug 3\n");
760 ret
= ip_append_page(sk
, page
, offset
, size
, flags
);
761 if (ret
== -EOPNOTSUPP
) {
763 return sock_no_sendpage(sk
->sk_socket
, page
, offset
,
767 udp_flush_pending_frames(sk
);
772 if (!(up
->corkflag
|| (flags
&MSG_MORE
)))
773 ret
= udp_push_pending_frames(sk
);
782 * IOCTL requests applicable to the UDP protocol
785 int udp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
790 int amount
= atomic_read(&sk
->sk_wmem_alloc
);
791 return put_user(amount
, (int __user
*)arg
);
797 unsigned long amount
;
800 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
801 skb
= skb_peek(&sk
->sk_receive_queue
);
804 * We will only return the amount
805 * of this packet since that is all
808 amount
= skb
->len
- sizeof(struct udphdr
);
810 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
811 return put_user(amount
, (int __user
*)arg
);
822 * This should be easy, if there is something there we
823 * return it, otherwise we block.
826 int udp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
827 size_t len
, int noblock
, int flags
, int *addr_len
)
829 struct inet_sock
*inet
= inet_sk(sk
);
830 struct sockaddr_in
*sin
= (struct sockaddr_in
*)msg
->msg_name
;
832 unsigned int ulen
, copied
;
835 int is_udplite
= IS_UDPLITE(sk
);
838 * Check any passed addresses
841 *addr_len
=sizeof(*sin
);
843 if (flags
& MSG_ERRQUEUE
)
844 return ip_recv_error(sk
, msg
, len
);
847 skb
= __skb_recv_datagram(sk
, flags
| (noblock
? MSG_DONTWAIT
: 0),
852 ulen
= skb
->len
- sizeof(struct udphdr
);
856 else if (copied
< ulen
)
857 msg
->msg_flags
|= MSG_TRUNC
;
860 * If checksum is needed at all, try to do it while copying the
861 * data. If the data is truncated, or if we only want a partial
862 * coverage checksum (UDP-Lite), do it before the copy.
865 if (copied
< ulen
|| UDP_SKB_CB(skb
)->partial_cov
) {
866 if (udp_lib_checksum_complete(skb
))
870 if (skb_csum_unnecessary(skb
))
871 err
= skb_copy_datagram_iovec(skb
, sizeof(struct udphdr
),
872 msg
->msg_iov
, copied
);
874 err
= skb_copy_and_csum_datagram_iovec(skb
, sizeof(struct udphdr
), msg
->msg_iov
);
884 UDP_INC_STATS_USER(UDP_MIB_INDATAGRAMS
, is_udplite
);
886 sock_recv_timestamp(msg
, sk
, skb
);
888 /* Copy the address. */
891 sin
->sin_family
= AF_INET
;
892 sin
->sin_port
= udp_hdr(skb
)->source
;
893 sin
->sin_addr
.s_addr
= ip_hdr(skb
)->saddr
;
894 memset(sin
->sin_zero
, 0, sizeof(sin
->sin_zero
));
896 if (inet
->cmsg_flags
)
897 ip_cmsg_recv(msg
, skb
);
900 if (flags
& MSG_TRUNC
)
904 skb_free_datagram(sk
, skb
);
909 if (!skb_kill_datagram(sk
, skb
, flags
))
910 UDP_INC_STATS_USER(UDP_MIB_INERRORS
, is_udplite
);
918 int udp_disconnect(struct sock
*sk
, int flags
)
920 struct inet_sock
*inet
= inet_sk(sk
);
922 * 1003.1g - break association.
925 sk
->sk_state
= TCP_CLOSE
;
928 sk
->sk_bound_dev_if
= 0;
929 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
930 inet_reset_saddr(sk
);
932 if (!(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
)) {
933 sk
->sk_prot
->unhash(sk
);
943 * >0: "udp encap" protocol resubmission
945 * Note that in the success and error cases, the skb is assumed to
946 * have either been requeued or freed.
948 int udp_queue_rcv_skb(struct sock
* sk
, struct sk_buff
*skb
)
950 struct udp_sock
*up
= udp_sk(sk
);
952 int is_udplite
= IS_UDPLITE(sk
);
955 * Charge it to the socket, dropping if the queue is full.
957 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
961 if (up
->encap_type
) {
963 * This is an encapsulation socket so pass the skb to
964 * the socket's udp_encap_rcv() hook. Otherwise, just
965 * fall through and pass this up the UDP socket.
966 * up->encap_rcv() returns the following value:
967 * =0 if skb was successfully passed to the encap
968 * handler or was discarded by it.
969 * >0 if skb should be passed on to UDP.
970 * <0 if skb should be resubmitted as proto -N
973 /* if we're overly short, let UDP handle it */
974 if (skb
->len
> sizeof(struct udphdr
) &&
975 up
->encap_rcv
!= NULL
) {
978 ret
= (*up
->encap_rcv
)(sk
, skb
);
980 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS
,
986 /* FALLTHROUGH -- it's a UDP Packet */
990 * UDP-Lite specific tests, ignored on UDP sockets
992 if ((is_udplite
& UDPLITE_RECV_CC
) && UDP_SKB_CB(skb
)->partial_cov
) {
995 * MIB statistics other than incrementing the error count are
996 * disabled for the following two types of errors: these depend
997 * on the application settings, not on the functioning of the
998 * protocol stack as such.
1000 * RFC 3828 here recommends (sec 3.3): "There should also be a
1001 * way ... to ... at least let the receiving application block
1002 * delivery of packets with coverage values less than a value
1003 * provided by the application."
1005 if (up
->pcrlen
== 0) { /* full coverage was set */
1006 LIMIT_NETDEBUG(KERN_WARNING
"UDPLITE: partial coverage "
1007 "%d while full coverage %d requested\n",
1008 UDP_SKB_CB(skb
)->cscov
, skb
->len
);
1011 /* The next case involves violating the min. coverage requested
1012 * by the receiver. This is subtle: if receiver wants x and x is
1013 * greater than the buffersize/MTU then receiver will complain
1014 * that it wants x while sender emits packets of smaller size y.
1015 * Therefore the above ...()->partial_cov statement is essential.
1017 if (UDP_SKB_CB(skb
)->cscov
< up
->pcrlen
) {
1018 LIMIT_NETDEBUG(KERN_WARNING
1019 "UDPLITE: coverage %d too small, need min %d\n",
1020 UDP_SKB_CB(skb
)->cscov
, up
->pcrlen
);
1025 if (sk
->sk_filter
) {
1026 if (udp_lib_checksum_complete(skb
))
1030 if ((rc
= sock_queue_rcv_skb(sk
,skb
)) < 0) {
1031 /* Note that an ENOMEM error is charged twice */
1033 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS
, is_udplite
);
1040 UDP_INC_STATS_BH(UDP_MIB_INERRORS
, is_udplite
);
1046 * Multicasts and broadcasts go to each listener.
1048 * Note: called only from the BH handler context,
1049 * so we don't need to lock the hashes.
1051 static int __udp4_lib_mcast_deliver(struct sk_buff
*skb
,
1053 __be32 saddr
, __be32 daddr
,
1054 struct hlist_head udptable
[])
1059 read_lock(&udp_hash_lock
);
1060 sk
= sk_head(&udptable
[ntohs(uh
->dest
) & (UDP_HTABLE_SIZE
- 1)]);
1061 dif
= skb
->dev
->ifindex
;
1062 sk
= udp_v4_mcast_next(sk
, uh
->dest
, daddr
, uh
->source
, saddr
, dif
);
1064 struct sock
*sknext
= NULL
;
1067 struct sk_buff
*skb1
= skb
;
1069 sknext
= udp_v4_mcast_next(sk_next(sk
), uh
->dest
, daddr
,
1070 uh
->source
, saddr
, dif
);
1072 skb1
= skb_clone(skb
, GFP_ATOMIC
);
1075 int ret
= udp_queue_rcv_skb(sk
, skb1
);
1077 /* we should probably re-process instead
1078 * of dropping packets here. */
1085 read_unlock(&udp_hash_lock
);
1089 /* Initialize UDP checksum. If exited with zero value (success),
1090 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1091 * Otherwise, csum completion requires chacksumming packet body,
1092 * including udp header and folding it to skb->csum.
1094 static inline int udp4_csum_init(struct sk_buff
*skb
, struct udphdr
*uh
,
1097 const struct iphdr
*iph
;
1100 UDP_SKB_CB(skb
)->partial_cov
= 0;
1101 UDP_SKB_CB(skb
)->cscov
= skb
->len
;
1103 if (proto
== IPPROTO_UDPLITE
) {
1104 err
= udplite_checksum_init(skb
, uh
);
1110 if (uh
->check
== 0) {
1111 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1112 } else if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
1113 if (!csum_tcpudp_magic(iph
->saddr
, iph
->daddr
, skb
->len
,
1115 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1117 if (!skb_csum_unnecessary(skb
))
1118 skb
->csum
= csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
1119 skb
->len
, proto
, 0);
1120 /* Probably, we should checksum udp header (it should be in cache
1121 * in any case) and data in tiny packets (< rx copybreak).
1128 * All we need to do is get the socket, and then do a checksum.
1131 int __udp4_lib_rcv(struct sk_buff
*skb
, struct hlist_head udptable
[],
1135 struct udphdr
*uh
= udp_hdr(skb
);
1136 unsigned short ulen
;
1137 struct rtable
*rt
= (struct rtable
*)skb
->dst
;
1138 __be32 saddr
= ip_hdr(skb
)->saddr
;
1139 __be32 daddr
= ip_hdr(skb
)->daddr
;
1142 * Validate the packet.
1144 if (!pskb_may_pull(skb
, sizeof(struct udphdr
)))
1145 goto drop
; /* No space for header. */
1147 ulen
= ntohs(uh
->len
);
1148 if (ulen
> skb
->len
)
1151 if (proto
== IPPROTO_UDP
) {
1152 /* UDP validates ulen. */
1153 if (ulen
< sizeof(*uh
) || pskb_trim_rcsum(skb
, ulen
))
1158 if (udp4_csum_init(skb
, uh
, proto
))
1161 if (rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
))
1162 return __udp4_lib_mcast_deliver(skb
, uh
, saddr
, daddr
, udptable
);
1164 sk
= __udp4_lib_lookup(saddr
, uh
->source
, daddr
, uh
->dest
,
1165 inet_iif(skb
), udptable
);
1168 int ret
= udp_queue_rcv_skb(sk
, skb
);
1171 /* a return value > 0 means to resubmit the input, but
1172 * it wants the return to be -protocol, or 0
1179 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
1183 /* No socket. Drop packet silently, if checksum is wrong */
1184 if (udp_lib_checksum_complete(skb
))
1187 UDP_INC_STATS_BH(UDP_MIB_NOPORTS
, proto
== IPPROTO_UDPLITE
);
1188 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_PORT_UNREACH
, 0);
1191 * Hmm. We got an UDP packet to a port to which we
1192 * don't wanna listen. Ignore it.
1198 LIMIT_NETDEBUG(KERN_DEBUG
"UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
1199 proto
== IPPROTO_UDPLITE
? "-Lite" : "",
1210 * RFC1122: OK. Discards the bad packet silently (as far as
1211 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1213 LIMIT_NETDEBUG(KERN_DEBUG
"UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
1214 proto
== IPPROTO_UDPLITE
? "-Lite" : "",
1221 UDP_INC_STATS_BH(UDP_MIB_INERRORS
, proto
== IPPROTO_UDPLITE
);
1226 int udp_rcv(struct sk_buff
*skb
)
1228 return __udp4_lib_rcv(skb
, udp_hash
, IPPROTO_UDP
);
1231 int udp_destroy_sock(struct sock
*sk
)
1234 udp_flush_pending_frames(sk
);
1240 * Socket option code for UDP
1242 int udp_lib_setsockopt(struct sock
*sk
, int level
, int optname
,
1243 char __user
*optval
, int optlen
,
1244 int (*push_pending_frames
)(struct sock
*))
1246 struct udp_sock
*up
= udp_sk(sk
);
1249 int is_udplite
= IS_UDPLITE(sk
);
1251 if (optlen
<sizeof(int))
1254 if (get_user(val
, (int __user
*)optval
))
1264 (*push_pending_frames
)(sk
);
1272 case UDP_ENCAP_ESPINUDP
:
1273 case UDP_ENCAP_ESPINUDP_NON_IKE
:
1274 up
->encap_rcv
= xfrm4_udp_encap_rcv
;
1276 case UDP_ENCAP_L2TPINUDP
:
1277 up
->encap_type
= val
;
1286 * UDP-Lite's partial checksum coverage (RFC 3828).
1288 /* The sender sets actual checksum coverage length via this option.
1289 * The case coverage > packet length is handled by send module. */
1290 case UDPLITE_SEND_CSCOV
:
1291 if (!is_udplite
) /* Disable the option on UDP sockets */
1292 return -ENOPROTOOPT
;
1293 if (val
!= 0 && val
< 8) /* Illegal coverage: use default (8) */
1296 up
->pcflag
|= UDPLITE_SEND_CC
;
1299 /* The receiver specifies a minimum checksum coverage value. To make
1300 * sense, this should be set to at least 8 (as done below). If zero is
1301 * used, this again means full checksum coverage. */
1302 case UDPLITE_RECV_CSCOV
:
1303 if (!is_udplite
) /* Disable the option on UDP sockets */
1304 return -ENOPROTOOPT
;
1305 if (val
!= 0 && val
< 8) /* Avoid silly minimal values. */
1308 up
->pcflag
|= UDPLITE_RECV_CC
;
1319 int udp_setsockopt(struct sock
*sk
, int level
, int optname
,
1320 char __user
*optval
, int optlen
)
1322 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
1323 return udp_lib_setsockopt(sk
, level
, optname
, optval
, optlen
,
1324 udp_push_pending_frames
);
1325 return ip_setsockopt(sk
, level
, optname
, optval
, optlen
);
1328 #ifdef CONFIG_COMPAT
1329 int compat_udp_setsockopt(struct sock
*sk
, int level
, int optname
,
1330 char __user
*optval
, int optlen
)
1332 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
1333 return udp_lib_setsockopt(sk
, level
, optname
, optval
, optlen
,
1334 udp_push_pending_frames
);
1335 return compat_ip_setsockopt(sk
, level
, optname
, optval
, optlen
);
1339 int udp_lib_getsockopt(struct sock
*sk
, int level
, int optname
,
1340 char __user
*optval
, int __user
*optlen
)
1342 struct udp_sock
*up
= udp_sk(sk
);
1345 if (get_user(len
,optlen
))
1348 len
= min_t(unsigned int, len
, sizeof(int));
1359 val
= up
->encap_type
;
1362 /* The following two cannot be changed on UDP sockets, the return is
1363 * always 0 (which corresponds to the full checksum coverage of UDP). */
1364 case UDPLITE_SEND_CSCOV
:
1368 case UDPLITE_RECV_CSCOV
:
1373 return -ENOPROTOOPT
;
1376 if (put_user(len
, optlen
))
1378 if (copy_to_user(optval
, &val
,len
))
1383 int udp_getsockopt(struct sock
*sk
, int level
, int optname
,
1384 char __user
*optval
, int __user
*optlen
)
1386 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
1387 return udp_lib_getsockopt(sk
, level
, optname
, optval
, optlen
);
1388 return ip_getsockopt(sk
, level
, optname
, optval
, optlen
);
1391 #ifdef CONFIG_COMPAT
1392 int compat_udp_getsockopt(struct sock
*sk
, int level
, int optname
,
1393 char __user
*optval
, int __user
*optlen
)
1395 if (level
== SOL_UDP
|| level
== SOL_UDPLITE
)
1396 return udp_lib_getsockopt(sk
, level
, optname
, optval
, optlen
);
1397 return compat_ip_getsockopt(sk
, level
, optname
, optval
, optlen
);
1401 * udp_poll - wait for a UDP event.
1402 * @file - file struct
1404 * @wait - poll table
1406 * This is same as datagram poll, except for the special case of
1407 * blocking sockets. If application is using a blocking fd
1408 * and a packet with checksum error is in the queue;
1409 * then it could get return from select indicating data available
1410 * but then block when reading it. Add special case code
1411 * to work around these arguably broken applications.
1413 unsigned int udp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
1415 unsigned int mask
= datagram_poll(file
, sock
, wait
);
1416 struct sock
*sk
= sock
->sk
;
1417 int is_lite
= IS_UDPLITE(sk
);
1419 /* Check for false positives due to checksum errors */
1420 if ( (mask
& POLLRDNORM
) &&
1421 !(file
->f_flags
& O_NONBLOCK
) &&
1422 !(sk
->sk_shutdown
& RCV_SHUTDOWN
)){
1423 struct sk_buff_head
*rcvq
= &sk
->sk_receive_queue
;
1424 struct sk_buff
*skb
;
1426 spin_lock_bh(&rcvq
->lock
);
1427 while ((skb
= skb_peek(rcvq
)) != NULL
&&
1428 udp_lib_checksum_complete(skb
)) {
1429 UDP_INC_STATS_BH(UDP_MIB_INERRORS
, is_lite
);
1430 __skb_unlink(skb
, rcvq
);
1433 spin_unlock_bh(&rcvq
->lock
);
1435 /* nothing to see, move along */
1437 mask
&= ~(POLLIN
| POLLRDNORM
);
1444 DEFINE_PROTO_INUSE(udp
)
1446 struct proto udp_prot
= {
1448 .owner
= THIS_MODULE
,
1449 .close
= udp_lib_close
,
1450 .connect
= ip4_datagram_connect
,
1451 .disconnect
= udp_disconnect
,
1453 .destroy
= udp_destroy_sock
,
1454 .setsockopt
= udp_setsockopt
,
1455 .getsockopt
= udp_getsockopt
,
1456 .sendmsg
= udp_sendmsg
,
1457 .recvmsg
= udp_recvmsg
,
1458 .sendpage
= udp_sendpage
,
1459 .backlog_rcv
= udp_queue_rcv_skb
,
1460 .hash
= udp_lib_hash
,
1461 .unhash
= udp_lib_unhash
,
1462 .get_port
= udp_v4_get_port
,
1463 .obj_size
= sizeof(struct udp_sock
),
1464 #ifdef CONFIG_COMPAT
1465 .compat_setsockopt
= compat_udp_setsockopt
,
1466 .compat_getsockopt
= compat_udp_getsockopt
,
1468 REF_PROTO_INUSE(udp
)
1471 /* ------------------------------------------------------------------------ */
1472 #ifdef CONFIG_PROC_FS
1474 static struct sock
*udp_get_first(struct seq_file
*seq
)
1477 struct udp_iter_state
*state
= seq
->private;
1479 for (state
->bucket
= 0; state
->bucket
< UDP_HTABLE_SIZE
; ++state
->bucket
) {
1480 struct hlist_node
*node
;
1481 sk_for_each(sk
, node
, state
->hashtable
+ state
->bucket
) {
1482 if (sk
->sk_family
== state
->family
)
1491 static struct sock
*udp_get_next(struct seq_file
*seq
, struct sock
*sk
)
1493 struct udp_iter_state
*state
= seq
->private;
1499 } while (sk
&& sk
->sk_family
!= state
->family
);
1501 if (!sk
&& ++state
->bucket
< UDP_HTABLE_SIZE
) {
1502 sk
= sk_head(state
->hashtable
+ state
->bucket
);
1508 static struct sock
*udp_get_idx(struct seq_file
*seq
, loff_t pos
)
1510 struct sock
*sk
= udp_get_first(seq
);
1513 while (pos
&& (sk
= udp_get_next(seq
, sk
)) != NULL
)
1515 return pos
? NULL
: sk
;
1518 static void *udp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
1520 read_lock(&udp_hash_lock
);
1521 return *pos
? udp_get_idx(seq
, *pos
-1) : (void *)1;
1524 static void *udp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
1529 sk
= udp_get_idx(seq
, 0);
1531 sk
= udp_get_next(seq
, v
);
1537 static void udp_seq_stop(struct seq_file
*seq
, void *v
)
1539 read_unlock(&udp_hash_lock
);
1542 static int udp_seq_open(struct inode
*inode
, struct file
*file
)
1544 struct udp_seq_afinfo
*afinfo
= PDE(inode
)->data
;
1545 struct seq_file
*seq
;
1547 struct udp_iter_state
*s
= kzalloc(sizeof(*s
), GFP_KERNEL
);
1551 s
->family
= afinfo
->family
;
1552 s
->hashtable
= afinfo
->hashtable
;
1553 s
->seq_ops
.start
= udp_seq_start
;
1554 s
->seq_ops
.next
= udp_seq_next
;
1555 s
->seq_ops
.show
= afinfo
->seq_show
;
1556 s
->seq_ops
.stop
= udp_seq_stop
;
1558 rc
= seq_open(file
, &s
->seq_ops
);
1562 seq
= file
->private_data
;
1571 /* ------------------------------------------------------------------------ */
1572 int udp_proc_register(struct udp_seq_afinfo
*afinfo
)
1574 struct proc_dir_entry
*p
;
1579 afinfo
->seq_fops
->owner
= afinfo
->owner
;
1580 afinfo
->seq_fops
->open
= udp_seq_open
;
1581 afinfo
->seq_fops
->read
= seq_read
;
1582 afinfo
->seq_fops
->llseek
= seq_lseek
;
1583 afinfo
->seq_fops
->release
= seq_release_private
;
1585 p
= proc_net_fops_create(&init_net
, afinfo
->name
, S_IRUGO
, afinfo
->seq_fops
);
1593 void udp_proc_unregister(struct udp_seq_afinfo
*afinfo
)
1597 proc_net_remove(&init_net
, afinfo
->name
);
1598 memset(afinfo
->seq_fops
, 0, sizeof(*afinfo
->seq_fops
));
1601 /* ------------------------------------------------------------------------ */
1602 static void udp4_format_sock(struct sock
*sp
, char *tmpbuf
, int bucket
)
1604 struct inet_sock
*inet
= inet_sk(sp
);
1605 __be32 dest
= inet
->daddr
;
1606 __be32 src
= inet
->rcv_saddr
;
1607 __u16 destp
= ntohs(inet
->dport
);
1608 __u16 srcp
= ntohs(inet
->sport
);
1610 sprintf(tmpbuf
, "%4d: %08X:%04X %08X:%04X"
1611 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
1612 bucket
, src
, srcp
, dest
, destp
, sp
->sk_state
,
1613 atomic_read(&sp
->sk_wmem_alloc
),
1614 atomic_read(&sp
->sk_rmem_alloc
),
1615 0, 0L, 0, sock_i_uid(sp
), 0, sock_i_ino(sp
),
1616 atomic_read(&sp
->sk_refcnt
), sp
);
1619 int udp4_seq_show(struct seq_file
*seq
, void *v
)
1621 if (v
== SEQ_START_TOKEN
)
1622 seq_printf(seq
, "%-127s\n",
1623 " sl local_address rem_address st tx_queue "
1624 "rx_queue tr tm->when retrnsmt uid timeout "
1628 struct udp_iter_state
*state
= seq
->private;
1630 udp4_format_sock(v
, tmpbuf
, state
->bucket
);
1631 seq_printf(seq
, "%-127s\n", tmpbuf
);
1636 /* ------------------------------------------------------------------------ */
1637 static struct file_operations udp4_seq_fops
;
1638 static struct udp_seq_afinfo udp4_seq_afinfo
= {
1639 .owner
= THIS_MODULE
,
1642 .hashtable
= udp_hash
,
1643 .seq_show
= udp4_seq_show
,
1644 .seq_fops
= &udp4_seq_fops
,
1647 int __init
udp4_proc_init(void)
1649 return udp_proc_register(&udp4_seq_afinfo
);
1652 void udp4_proc_exit(void)
1654 udp_proc_unregister(&udp4_seq_afinfo
);
1656 #endif /* CONFIG_PROC_FS */
1658 EXPORT_SYMBOL(udp_disconnect
);
1659 EXPORT_SYMBOL(udp_hash
);
1660 EXPORT_SYMBOL(udp_hash_lock
);
1661 EXPORT_SYMBOL(udp_ioctl
);
1662 EXPORT_SYMBOL(udp_get_port
);
1663 EXPORT_SYMBOL(udp_prot
);
1664 EXPORT_SYMBOL(udp_sendmsg
);
1665 EXPORT_SYMBOL(udp_lib_getsockopt
);
1666 EXPORT_SYMBOL(udp_lib_setsockopt
);
1667 EXPORT_SYMBOL(udp_poll
);
1669 #ifdef CONFIG_PROC_FS
1670 EXPORT_SYMBOL(udp_proc_register
);
1671 EXPORT_SYMBOL(udp_proc_unregister
);