projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| ba4e58ec GR |
1 | /* |
| 2 | * Definitions for the UDP-Lite (RFC 3828) code. | |
| 3 | */ | |
| 4 | #ifndef _UDPLITE_H | |
| 5 | #define _UDPLITE_H | |
| 6 | ||
| 7 | /* UDP-Lite socket options */ | |
| 8 | #define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */ | |
| 9 | #define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */ | |
| 10 | ||
| 11 | extern struct proto udplite_prot; | |
| 12 | extern struct hlist_head udplite_hash[UDP_HTABLE_SIZE]; | |
| 13 | ||
| 14 | /* UDP-Lite does not have a standardized MIB yet, so we inherit from UDP */ | |
| 15 | DECLARE_SNMP_STAT(struct udp_mib, udplite_statistics); | |
| 16 | ||
| 17 | /* | |
| 18 | * Checksum computation is all in software, hence simpler getfrag. | |
| 19 | */ | |
| 20 | static __inline__ int udplite_getfrag(void *from, char *to, int offset, | |
| 21 | int len, int odd, struct sk_buff *skb) | |
| 22 | { | |
| 23 | return memcpy_fromiovecend(to, (struct iovec *) from, offset, len); | |
| 24 | } | |
| 25 | ||
| 26 | /* Designate sk as UDP-Lite socket */ | |
| 27 | static inline int udplite_sk_init(struct sock *sk) | |
| 28 | { | |
| 29 | udp_sk(sk)->pcflag = UDPLITE_BIT; | |
| 30 | return 0; | |
| 31 | } | |
| 32 | ||
| 33 | /* | |
| 34 | * Checksumming routines | |
| 35 | */ | |
| 36 | static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh) | |
| 37 | { | |
| 38 | u16 cscov; | |
| 39 | ||
| 40 | /* In UDPv4 a zero checksum means that the transmitter generated no | |
| 41 | * checksum. UDP-Lite (like IPv6) mandates checksums, hence packets | |
| 42 | * with a zero checksum field are illegal. */ | |
| 43 | if (uh->check == 0) { | |
| 44 | LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: zeroed checksum field\n"); | |
| 45 | return 1; | |
| 46 | } | |
| 47 | ||
| 48 | UDP_SKB_CB(skb)->partial_cov = 0; | |
| 49 | cscov = ntohs(uh->len); | |
| 50 | ||
| 51 | if (cscov == 0) /* Indicates that full coverage is required. */ | |
| 52 | cscov = skb->len; | |
| 53 | else if (cscov < 8 || cscov > skb->len) { | |
| 54 | /* | |
| 55 | * Coverage length violates RFC 3828: log and discard silently. | |
| 56 | */ | |
| 57 | LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d\n", | |
| 58 | cscov, skb->len); | |
| 59 | return 1; | |
| 60 | ||
| 61 | } else if (cscov < skb->len) | |
| 62 | UDP_SKB_CB(skb)->partial_cov = 1; | |
| 63 | ||
| 64 | UDP_SKB_CB(skb)->cscov = cscov; | |
| 65 | ||
| 66 | /* | |
| 67 | * There is no known NIC manufacturer supporting UDP-Lite yet, | |
| 68 | * hence ip_summed is always (re-)set to CHECKSUM_NONE. | |
| 69 | */ | |
| 70 | skb->ip_summed = CHECKSUM_NONE; | |
| 71 | ||
| 72 | return 0; | |
| 73 | } | |
| 74 | ||
| 75 | static __inline__ int udplite4_csum_init(struct sk_buff *skb, struct udphdr *uh) | |
| 76 | { | |
| 77 | int rc = udplite_checksum_init(skb, uh); | |
| 78 | ||
| 79 | if (!rc) | |
| 80 | skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr, | |
| 81 | skb->nh.iph->daddr, | |
| 82 | skb->len, IPPROTO_UDPLITE, 0); | |
| 83 | return rc; | |
| 84 | } | |
| 85 | ||
| 86 | static __inline__ int udplite6_csum_init(struct sk_buff *skb, struct udphdr *uh) | |
| 87 | { | |
| 88 | int rc = udplite_checksum_init(skb, uh); | |
| 89 | ||
| 90 | if (!rc) | |
| 91 | skb->csum = ~csum_ipv6_magic(&skb->nh.ipv6h->saddr, | |
| 92 | &skb->nh.ipv6h->daddr, | |
| 93 | skb->len, IPPROTO_UDPLITE, 0); | |
| 94 | return rc; | |
| 95 | } | |
| 96 | ||
| 97 | static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh) | |
| 98 | { | |
| 99 | int cscov = up->len; | |
| 100 | ||
| 101 | /* | |
| 102 | * Sender has set `partial coverage' option on UDP-Lite socket | |
| 103 | */ | |
| 104 | if (up->pcflag & UDPLITE_SEND_CC) { | |
| 105 | if (up->pcslen < up->len) { | |
| 106 | /* up->pcslen == 0 means that full coverage is required, | |
| 107 | * partial coverage only if 0 < up->pcslen < up->len */ | |
| 108 | if (0 < up->pcslen) { | |
| 109 | cscov = up->pcslen; | |
| 110 | } | |
| 111 | uh->len = htons(up->pcslen); | |
| 112 | } | |
| 113 | /* | |
| 114 | * NOTE: Causes for the error case `up->pcslen > up->len': | |
| 115 | * (i) Application error (will not be penalized). | |
| 116 | * (ii) Payload too big for send buffer: data is split | |
| 117 | * into several packets, each with its own header. | |
| 118 | * In this case (e.g. last segment), coverage may | |
| 119 | * exceed packet length. | |
| 120 | * Since packets with coverage length > packet length are | |
| 121 | * illegal, we fall back to the defaults here. | |
| 122 | */ | |
| 123 | } | |
| 124 | return cscov; | |
| 125 | } | |
| 126 | ||
| 868c86bc | 127 | static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb) |
| ba4e58ec | 128 | { |
| ba4e58ec | 129 | int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh); |
| 868c86bc | 130 | __wsum csum = 0; |
| ba4e58ec GR |
131 | |
| 132 | skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */ | |
| 133 | ||
| 134 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
| 135 | off = skb->h.raw - skb->data; | |
| 136 | len = skb->len - off; | |
| 137 | ||
| 138 | csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum); | |
| 139 | ||
| 140 | if ((cscov -= len) <= 0) | |
| 141 | break; | |
| 142 | } | |
| 143 | return csum; | |
| 144 | } | |
| 145 | ||
| 146 | extern void udplite4_register(void); | |
| 147 | extern int udplite_get_port(struct sock *sk, unsigned short snum, | |
| 148 | int (*scmp)(const struct sock *, const struct sock *)); | |
| 149 | #endif /* _UDPLITE_H */ |