1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * Definitions for the UDP-Lite (RFC 3828 3 * Definitions for the UDP-Lite (RFC 3828) code.
4 */ 4 */
5 #ifndef _UDPLITE_H 5 #ifndef _UDPLITE_H
6 #define _UDPLITE_H 6 #define _UDPLITE_H
7 7
8 #include <net/ip6_checksum.h> 8 #include <net/ip6_checksum.h>
9 #include <net/udp.h> <<
10 9
11 /* UDP-Lite socket options */ 10 /* UDP-Lite socket options */
12 #define UDPLITE_SEND_CSCOV 10 /* sender part 11 #define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */
13 #define UDPLITE_RECV_CSCOV 11 /* receiver pa 12 #define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */
14 13
15 extern struct proto udplite_prot; 14 extern struct proto udplite_prot;
16 extern struct udp_table udplite_table; 15 extern struct udp_table udplite_table;
17 16
18 /* 17 /*
19 * Checksum computation is all in softwar 18 * Checksum computation is all in software, hence simpler getfrag.
20 */ 19 */
21 static __inline__ int udplite_getfrag(void *fr 20 static __inline__ int udplite_getfrag(void *from, char *to, int offset,
22 int len, 21 int len, int odd, struct sk_buff *skb)
23 { 22 {
24 struct msghdr *msg = from; 23 struct msghdr *msg = from;
25 return copy_from_iter_full(to, len, &m 24 return copy_from_iter_full(to, len, &msg->msg_iter) ? 0 : -EFAULT;
26 } 25 }
27 26
28 /* 27 /*
29 * Checksumming routines 28 * Checksumming routines
30 */ 29 */
31 static inline int udplite_checksum_init(struct 30 static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
32 { 31 {
33 u16 cscov; 32 u16 cscov;
34 33
35 /* In UDPv4 a zero checksum means that 34 /* In UDPv4 a zero checksum means that the transmitter generated no
36 * checksum. UDP-Lite (like IPv6) mand 35 * checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
37 * with a zero checksum field are ille 36 * with a zero checksum field are illegal. */
38 if (uh->check == 0) { 37 if (uh->check == 0) {
39 net_dbg_ratelimited("UDPLite: 38 net_dbg_ratelimited("UDPLite: zeroed checksum field\n");
40 return 1; 39 return 1;
41 } 40 }
42 41
43 cscov = ntohs(uh->len); 42 cscov = ntohs(uh->len);
44 43
45 if (cscov == 0) /* Indicates 44 if (cscov == 0) /* Indicates that full coverage is required. */
46 ; 45 ;
47 else if (cscov < 8 || cscov > skb->le 46 else if (cscov < 8 || cscov > skb->len) {
48 /* 47 /*
49 * Coverage length violates RF 48 * Coverage length violates RFC 3828: log and discard silently.
50 */ 49 */
51 net_dbg_ratelimited("UDPLite: 50 net_dbg_ratelimited("UDPLite: bad csum coverage %d/%d\n",
52 cscov, skb 51 cscov, skb->len);
53 return 1; 52 return 1;
54 53
55 } else if (cscov < skb->len) { 54 } else if (cscov < skb->len) {
56 UDP_SKB_CB(skb)->partial_cov = 55 UDP_SKB_CB(skb)->partial_cov = 1;
57 UDP_SKB_CB(skb)->cscov = cscov 56 UDP_SKB_CB(skb)->cscov = cscov;
58 if (skb->ip_summed == CHECKSUM 57 if (skb->ip_summed == CHECKSUM_COMPLETE)
59 skb->ip_summed = CHECK 58 skb->ip_summed = CHECKSUM_NONE;
60 skb->csum_valid = 0; 59 skb->csum_valid = 0;
61 } 60 }
62 61
63 return 0; 62 return 0;
64 } 63 }
65 64
>> 65 /* Slow-path computation of checksum. Socket is locked. */
>> 66 static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
>> 67 {
>> 68 const struct udp_sock *up = udp_sk(skb->sk);
>> 69 int cscov = up->len;
>> 70 __wsum csum = 0;
>> 71
>> 72 if (up->pcflag & UDPLITE_SEND_CC) {
>> 73 /*
>> 74 * Sender has set `partial coverage' option on UDP-Lite socket.
>> 75 * The special case "up->pcslen == 0" signifies full coverage.
>> 76 */
>> 77 if (up->pcslen < up->len) {
>> 78 if (0 < up->pcslen)
>> 79 cscov = up->pcslen;
>> 80 udp_hdr(skb)->len = htons(up->pcslen);
>> 81 }
>> 82 /*
>> 83 * NOTE: Causes for the error case `up->pcslen > up->len':
>> 84 * (i) Application error (will not be penalized).
>> 85 * (ii) Payload too big for send buffer: data is split
>> 86 * into several packets, each with its own header.
>> 87 * In this case (e.g. last segment), coverage may
>> 88 * exceed packet length.
>> 89 * Since packets with coverage length > packet length are
>> 90 * illegal, we fall back to the defaults here.
>> 91 */
>> 92 }
>> 93
>> 94 skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
>> 95
>> 96 skb_queue_walk(&sk->sk_write_queue, skb) {
>> 97 const int off = skb_transport_offset(skb);
>> 98 const int len = skb->len - off;
>> 99
>> 100 csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
>> 101
>> 102 if ((cscov -= len) <= 0)
>> 103 break;
>> 104 }
>> 105 return csum;
>> 106 }
>> 107
66 /* Fast-path computation of checksum. Socket m 108 /* Fast-path computation of checksum. Socket may not be locked. */
67 static inline __wsum udplite_csum(struct sk_bu 109 static inline __wsum udplite_csum(struct sk_buff *skb)
68 { 110 {
>> 111 const struct udp_sock *up = udp_sk(skb->sk);
69 const int off = skb_transport_offset(s 112 const int off = skb_transport_offset(skb);
70 const struct sock *sk = skb->sk; <<
71 int len = skb->len - off; 113 int len = skb->len - off;
72 114
73 if (udp_test_bit(UDPLITE_SEND_CC, sk)) !! 115 if ((up->pcflag & UDPLITE_SEND_CC) && up->pcslen < len) {
74 u16 pcslen = READ_ONCE(udp_sk( !! 116 if (0 < up->pcslen)
75 !! 117 len = up->pcslen;
76 if (pcslen < len) { !! 118 udp_hdr(skb)->len = htons(up->pcslen);
77 if (pcslen > 0) <<
78 len = pcslen; <<
79 udp_hdr(skb)->len = ht <<
80 } <<
81 } 119 }
82 skb->ip_summed = CHECKSUM_NONE; /* 120 skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
83 121
84 return skb_checksum(skb, off, len, 0); 122 return skb_checksum(skb, off, len, 0);
85 } 123 }
86 124
87 void udplite4_register(void); 125 void udplite4_register(void);
>> 126 int udplite_get_port(struct sock *sk, unsigned short snum,
>> 127 int (*scmp)(const struct sock *, const struct sock *));
88 #endif /* _UDPLITE_H */ 128 #endif /* _UDPLITE_H */
89 129
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