forked from Minki/linux
db8dac20d5
This reverts commitdb1ed684f6("[IPV6] UDP: Rename IPv6 UDP files."), commit8be8af8fa4("[IPV4] UDP: Move IPv4-specific bits to other file.") and commite898d4db27("[UDP]: Allow users to configure UDP-Lite."). First, udplite is of such small cost, and it is a core protocol just like TCP and normal UDP are. We spent enormous amounts of effort to make udplite share as much code with core UDP as possible. All of that work is less valuable if we're just going to slap a config option on udplite support. It is also causing build failures, as reported on linux-next, showing that the changeset was not tested very well. In fact, this is the second build failure resulting from the udplite change. Finally, the config options provided was a bool, instead of a modular option. Meaning the udplite code does not even get build tested by allmodconfig builds, and furthermore the user is not presented with a reasonable modular build option which is particularly needed by distribution vendors. Signed-off-by: David S. Miller <davem@davemloft.net>
122 lines
3.4 KiB
C
122 lines
3.4 KiB
C
/*
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* Definitions for the UDP-Lite (RFC 3828) code.
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*/
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#ifndef _UDPLITE_H
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#define _UDPLITE_H
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#include <net/ip6_checksum.h>
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/* UDP-Lite socket options */
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#define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */
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#define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */
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extern struct proto udplite_prot;
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extern struct hlist_head udplite_hash[UDP_HTABLE_SIZE];
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/*
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* Checksum computation is all in software, hence simpler getfrag.
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*/
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static __inline__ int udplite_getfrag(void *from, char *to, int offset,
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int len, int odd, struct sk_buff *skb)
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{
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return memcpy_fromiovecend(to, (struct iovec *) from, offset, len);
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}
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/* Designate sk as UDP-Lite socket */
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static inline int udplite_sk_init(struct sock *sk)
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{
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udp_sk(sk)->pcflag = UDPLITE_BIT;
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return 0;
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}
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/*
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* Checksumming routines
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*/
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static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
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{
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u16 cscov;
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/* In UDPv4 a zero checksum means that the transmitter generated no
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* checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
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* with a zero checksum field are illegal. */
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if (uh->check == 0) {
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LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: zeroed checksum field\n");
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return 1;
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}
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cscov = ntohs(uh->len);
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if (cscov == 0) /* Indicates that full coverage is required. */
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;
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else if (cscov < 8 || cscov > skb->len) {
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/*
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* Coverage length violates RFC 3828: log and discard silently.
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*/
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LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d\n",
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cscov, skb->len);
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return 1;
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} else if (cscov < skb->len) {
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UDP_SKB_CB(skb)->partial_cov = 1;
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UDP_SKB_CB(skb)->cscov = cscov;
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->ip_summed = CHECKSUM_NONE;
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}
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return 0;
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}
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static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh)
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{
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int cscov = up->len;
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/*
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* Sender has set `partial coverage' option on UDP-Lite socket
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*/
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if (up->pcflag & UDPLITE_SEND_CC) {
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if (up->pcslen < up->len) {
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/* up->pcslen == 0 means that full coverage is required,
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* partial coverage only if 0 < up->pcslen < up->len */
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if (0 < up->pcslen) {
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cscov = up->pcslen;
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}
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uh->len = htons(up->pcslen);
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}
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/*
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* NOTE: Causes for the error case `up->pcslen > up->len':
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* (i) Application error (will not be penalized).
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* (ii) Payload too big for send buffer: data is split
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* into several packets, each with its own header.
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* In this case (e.g. last segment), coverage may
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* exceed packet length.
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* Since packets with coverage length > packet length are
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* illegal, we fall back to the defaults here.
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*/
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}
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return cscov;
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}
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static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
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{
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int cscov = udplite_sender_cscov(udp_sk(sk), udp_hdr(skb));
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__wsum csum = 0;
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skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
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skb_queue_walk(&sk->sk_write_queue, skb) {
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const int off = skb_transport_offset(skb);
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const int len = skb->len - off;
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csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
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if ((cscov -= len) <= 0)
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break;
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}
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return csum;
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}
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extern void udplite4_register(void);
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extern int udplite_get_port(struct sock *sk, unsigned short snum,
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int (*scmp)(const struct sock *, const struct sock *));
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#endif /* _UDPLITE_H */
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