blob: 299c14ce2bb949029624710798810919cccb7934 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Gerrit Renkerba4e58e2006-11-27 11:10:57 -08002/*
3 * Definitions for the UDP-Lite (RFC 3828) code.
4 */
5#ifndef _UDPLITE_H
6#define _UDPLITE_H
7
David S. Miller6bb100b2006-11-15 01:09:32 -08008#include <net/ip6_checksum.h>
Jakub Kicinski949d6b42022-07-20 16:57:58 -07009#include <net/udp.h>
David S. Miller6bb100b2006-11-15 01:09:32 -080010
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080011/* UDP-Lite socket options */
12#define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */
13#define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */
14
15extern struct proto udplite_prot;
Eric Dumazet645ca702008-10-29 01:41:45 -070016extern struct udp_table udplite_table;
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080017
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080018/*
19 * Checksum computation is all in software, hence simpler getfrag.
20 */
21static __inline__ int udplite_getfrag(void *from, char *to, int offset,
22 int len, int odd, struct sk_buff *skb)
23{
Al Virof69e6d12014-11-24 13:23:40 -050024 struct msghdr *msg = from;
Al Viro0b62fca2016-11-03 18:17:31 -040025 return copy_from_iter_full(to, len, &msg->msg_iter) ? 0 : -EFAULT;
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080026}
27
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080028/*
29 * Checksumming routines
30 */
31static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
32{
33 u16 cscov;
34
35 /* In UDPv4 a zero checksum means that the transmitter generated no
36 * checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
37 * with a zero checksum field are illegal. */
38 if (uh->check == 0) {
Joe Perchesba7a46f2014-11-11 10:59:17 -080039 net_dbg_ratelimited("UDPLite: zeroed checksum field\n");
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080040 return 1;
41 }
42
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080043 cscov = ntohs(uh->len);
44
45 if (cscov == 0) /* Indicates that full coverage is required. */
Herbert Xu759e5d02007-03-25 20:10:56 -070046 ;
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080047 else if (cscov < 8 || cscov > skb->len) {
48 /*
49 * Coverage length violates RFC 3828: log and discard silently.
50 */
Joe Perchesba7a46f2014-11-11 10:59:17 -080051 net_dbg_ratelimited("UDPLite: bad csum coverage %d/%d\n",
52 cscov, skb->len);
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080053 return 1;
54
Herbert Xu759e5d02007-03-25 20:10:56 -070055 } else if (cscov < skb->len) {
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080056 UDP_SKB_CB(skb)->partial_cov = 1;
Herbert Xu759e5d02007-03-25 20:10:56 -070057 UDP_SKB_CB(skb)->cscov = cscov;
58 if (skb->ip_summed == CHECKSUM_COMPLETE)
59 skb->ip_summed = CHECKSUM_NONE;
Alexey Kodanev15f35d42018-02-15 20:18:43 +030060 skb->csum_valid = 0;
Herbert Xu759e5d02007-03-25 20:10:56 -070061 }
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080062
63 return 0;
64}
65
Gerrit Renkerf36c23b2011-10-17 19:07:30 -040066/* Fast-path computation of checksum. Socket may not be locked. */
Herbert Xuf6b9664f2011-03-01 02:36:48 +000067static inline __wsum udplite_csum(struct sk_buff *skb)
68{
Gerrit Renkerf36c23b2011-10-17 19:07:30 -040069 const struct udp_sock *up = udp_sk(skb->sk);
Herbert Xuf6b9664f2011-03-01 02:36:48 +000070 const int off = skb_transport_offset(skb);
Gerrit Renkerf36c23b2011-10-17 19:07:30 -040071 int len = skb->len - off;
Herbert Xuf6b9664f2011-03-01 02:36:48 +000072
Gerrit Renkerf36c23b2011-10-17 19:07:30 -040073 if ((up->pcflag & UDPLITE_SEND_CC) && up->pcslen < len) {
74 if (0 < up->pcslen)
75 len = up->pcslen;
76 udp_hdr(skb)->len = htons(up->pcslen);
77 }
Herbert Xuf6b9664f2011-03-01 02:36:48 +000078 skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
79
Gerrit Renkerf36c23b2011-10-17 19:07:30 -040080 return skb_checksum(skb, off, len, 0);
Herbert Xuf6b9664f2011-03-01 02:36:48 +000081}
82
Joe Perches16073432013-09-23 11:33:39 -070083void udplite4_register(void);
84int udplite_get_port(struct sock *sk, unsigned short snum,
85 int (*scmp)(const struct sock *, const struct sock *));
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080086#endif /* _UDPLITE_H */