Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 2 | /* |
| 3 | * Definitions for the UDP-Lite (RFC 3828) code. |
| 4 | */ |
| 5 | #ifndef _UDPLITE_H |
| 6 | #define _UDPLITE_H |
| 7 | |
David S. Miller | 6bb100b | 2006-11-15 01:09:32 -0800 | [diff] [blame] | 8 | #include <net/ip6_checksum.h> |
Jakub Kicinski | 949d6b4 | 2022-07-20 16:57:58 -0700 | [diff] [blame] | 9 | #include <net/udp.h> |
David S. Miller | 6bb100b | 2006-11-15 01:09:32 -0800 | [diff] [blame] | 10 | |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 11 | /* 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 | |
| 15 | extern struct proto udplite_prot; |
Eric Dumazet | 645ca70 | 2008-10-29 01:41:45 -0700 | [diff] [blame] | 16 | extern struct udp_table udplite_table; |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 17 | |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 18 | /* |
| 19 | * Checksum computation is all in software, hence simpler getfrag. |
| 20 | */ |
| 21 | static __inline__ int udplite_getfrag(void *from, char *to, int offset, |
| 22 | int len, int odd, struct sk_buff *skb) |
| 23 | { |
Al Viro | f69e6d1 | 2014-11-24 13:23:40 -0500 | [diff] [blame] | 24 | struct msghdr *msg = from; |
Al Viro | 0b62fca | 2016-11-03 18:17:31 -0400 | [diff] [blame] | 25 | return copy_from_iter_full(to, len, &msg->msg_iter) ? 0 : -EFAULT; |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 26 | } |
| 27 | |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 28 | /* |
| 29 | * Checksumming routines |
| 30 | */ |
| 31 | static 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 Perches | ba7a46f | 2014-11-11 10:59:17 -0800 | [diff] [blame] | 39 | net_dbg_ratelimited("UDPLite: zeroed checksum field\n"); |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 40 | return 1; |
| 41 | } |
| 42 | |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 43 | cscov = ntohs(uh->len); |
| 44 | |
| 45 | if (cscov == 0) /* Indicates that full coverage is required. */ |
Herbert Xu | 759e5d0 | 2007-03-25 20:10:56 -0700 | [diff] [blame] | 46 | ; |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 47 | else if (cscov < 8 || cscov > skb->len) { |
| 48 | /* |
| 49 | * Coverage length violates RFC 3828: log and discard silently. |
| 50 | */ |
Joe Perches | ba7a46f | 2014-11-11 10:59:17 -0800 | [diff] [blame] | 51 | net_dbg_ratelimited("UDPLite: bad csum coverage %d/%d\n", |
| 52 | cscov, skb->len); |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 53 | return 1; |
| 54 | |
Herbert Xu | 759e5d0 | 2007-03-25 20:10:56 -0700 | [diff] [blame] | 55 | } else if (cscov < skb->len) { |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 56 | UDP_SKB_CB(skb)->partial_cov = 1; |
Herbert Xu | 759e5d0 | 2007-03-25 20:10:56 -0700 | [diff] [blame] | 57 | UDP_SKB_CB(skb)->cscov = cscov; |
| 58 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
| 59 | skb->ip_summed = CHECKSUM_NONE; |
Alexey Kodanev | 15f35d4 | 2018-02-15 20:18:43 +0300 | [diff] [blame] | 60 | skb->csum_valid = 0; |
Herbert Xu | 759e5d0 | 2007-03-25 20:10:56 -0700 | [diff] [blame] | 61 | } |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 62 | |
| 63 | return 0; |
| 64 | } |
| 65 | |
Gerrit Renker | f36c23b | 2011-10-17 19:07:30 -0400 | [diff] [blame] | 66 | /* Fast-path computation of checksum. Socket may not be locked. */ |
Herbert Xu | f6b9664f | 2011-03-01 02:36:48 +0000 | [diff] [blame] | 67 | static inline __wsum udplite_csum(struct sk_buff *skb) |
| 68 | { |
Gerrit Renker | f36c23b | 2011-10-17 19:07:30 -0400 | [diff] [blame] | 69 | const struct udp_sock *up = udp_sk(skb->sk); |
Herbert Xu | f6b9664f | 2011-03-01 02:36:48 +0000 | [diff] [blame] | 70 | const int off = skb_transport_offset(skb); |
Gerrit Renker | f36c23b | 2011-10-17 19:07:30 -0400 | [diff] [blame] | 71 | int len = skb->len - off; |
Herbert Xu | f6b9664f | 2011-03-01 02:36:48 +0000 | [diff] [blame] | 72 | |
Gerrit Renker | f36c23b | 2011-10-17 19:07:30 -0400 | [diff] [blame] | 73 | 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 Xu | f6b9664f | 2011-03-01 02:36:48 +0000 | [diff] [blame] | 78 | skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */ |
| 79 | |
Gerrit Renker | f36c23b | 2011-10-17 19:07:30 -0400 | [diff] [blame] | 80 | return skb_checksum(skb, off, len, 0); |
Herbert Xu | f6b9664f | 2011-03-01 02:36:48 +0000 | [diff] [blame] | 81 | } |
| 82 | |
Joe Perches | 1607343 | 2013-09-23 11:33:39 -0700 | [diff] [blame] | 83 | void udplite4_register(void); |
| 84 | int udplite_get_port(struct sock *sk, unsigned short snum, |
| 85 | int (*scmp)(const struct sock *, const struct sock *)); |
Gerrit Renker | ba4e58e | 2006-11-27 11:10:57 -0800 | [diff] [blame] | 86 | #endif /* _UDPLITE_H */ |