From f6b9664f8b711cf4fd53e70aa0d21f72d5bf806c Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 1 Mar 2011 02:36:48 +0000 Subject: [PATCH] udp: Switch to ip_finish_skb This patch converts UDP to use the new ip_finish_skb API. This would then allows us to more easily use ip_make_skb which allows UDP to run without a socket lock. Signed-off-by: Herbert Xu Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/udp.h | 11 ++++ include/net/udplite.h | 12 ++++ net/ipv4/udp.c | 135 ++++++++++++++++++++++++------------------ 3 files changed, 99 insertions(+), 59 deletions(-) diff --git a/include/net/udp.h b/include/net/udp.h index e82f3a8c0f8f..67ea6fcb3ec0 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -144,6 +144,17 @@ static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb) return csum; } +static inline __wsum udp_csum(struct sk_buff *skb) +{ + __wsum csum = csum_partial(skb_transport_header(skb), + sizeof(struct udphdr), skb->csum); + + for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) { + csum = csum_add(csum, skb->csum); + } + return csum; +} + /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ static inline void udp_lib_hash(struct sock *sk) { diff --git a/include/net/udplite.h b/include/net/udplite.h index afdffe607b24..673a024c6b2a 100644 --- a/include/net/udplite.h +++ b/include/net/udplite.h @@ -115,6 +115,18 @@ static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb) return csum; } +static inline __wsum udplite_csum(struct sk_buff *skb) +{ + struct sock *sk = skb->sk; + int cscov = udplite_sender_cscov(udp_sk(sk), udp_hdr(skb)); + const int off = skb_transport_offset(skb); + const int len = skb->len - off; + + skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */ + + return skb_checksum(skb, off, min(cscov, len), 0); +} + extern void udplite4_register(void); extern int udplite_get_port(struct sock *sk, unsigned short snum, int (*scmp)(const struct sock *, const struct sock *)); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index d37baaa1dbe3..61c22ee7d4ba 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -663,46 +663,106 @@ void udp_flush_pending_frames(struct sock *sk) EXPORT_SYMBOL(udp_flush_pending_frames); /** - * udp4_hwcsum_outgoing - handle outgoing HW checksumming - * @sk: socket we are sending on + * udp4_hwcsum - handle outgoing HW checksumming * @skb: sk_buff containing the filled-in UDP header * (checksum field must be zeroed out) + * @src: source IP address + * @dst: destination IP address */ -static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, - __be32 src, __be32 dst, int len) +static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) { - unsigned int offset; struct udphdr *uh = udp_hdr(skb); + struct sk_buff *frags = skb_shinfo(skb)->frag_list; + int offset = skb_transport_offset(skb); + int len = skb->len - offset; + int hlen = len; __wsum csum = 0; - if (skb_queue_len(&sk->sk_write_queue) == 1) { + if (!frags) { /* * Only one fragment on the socket. */ skb->csum_start = skb_transport_header(skb) - skb->head; skb->csum_offset = offsetof(struct udphdr, check); - uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0); + uh->check = ~csum_tcpudp_magic(src, dst, len, + IPPROTO_UDP, 0); } else { /* * HW-checksum won't work as there are two or more * fragments on the socket so that all csums of sk_buffs * should be together */ - offset = skb_transport_offset(skb); - skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); + do { + csum = csum_add(csum, frags->csum); + hlen -= frags->len; + } while ((frags = frags->next)); + csum = skb_checksum(skb, offset, hlen, csum); skb->ip_summed = CHECKSUM_NONE; - skb_queue_walk(&sk->sk_write_queue, skb) { - csum = csum_add(csum, skb->csum); - } - uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); if (uh->check == 0) uh->check = CSUM_MANGLED_0; } } +static int udp_send_skb(struct sk_buff *skb, __be32 daddr, __be32 dport) +{ + struct sock *sk = skb->sk; + struct inet_sock *inet = inet_sk(sk); + struct udphdr *uh; + struct rtable *rt = (struct rtable *)skb_dst(skb); + int err = 0; + int is_udplite = IS_UDPLITE(sk); + int offset = skb_transport_offset(skb); + int len = skb->len - offset; + __wsum csum = 0; + + /* + * Create a UDP header + */ + uh = udp_hdr(skb); + uh->source = inet->inet_sport; + uh->dest = dport; + uh->len = htons(len); + uh->check = 0; + + if (is_udplite) /* UDP-Lite */ + csum = udplite_csum(skb); + + else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ + + skb->ip_summed = CHECKSUM_NONE; + goto send; + + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ + + udp4_hwcsum(skb, rt->rt_src, daddr); + goto send; + + } else + csum = udp_csum(skb); + + /* add protocol-dependent pseudo-header */ + uh->check = csum_tcpudp_magic(rt->rt_src, daddr, len, + sk->sk_protocol, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + +send: + err = ip_send_skb(skb); + if (err) { + if (err == -ENOBUFS && !inet->recverr) { + UDP_INC_STATS_USER(sock_net(sk), + UDP_MIB_SNDBUFERRORS, is_udplite); + err = 0; + } + } else + UDP_INC_STATS_USER(sock_net(sk), + UDP_MIB_OUTDATAGRAMS, is_udplite); + return err; +} + /* * Push out all pending data as one UDP datagram. Socket is locked. */ @@ -712,57 +772,14 @@ static int udp_push_pending_frames(struct sock *sk) struct inet_sock *inet = inet_sk(sk); struct flowi *fl = &inet->cork.fl; struct sk_buff *skb; - struct udphdr *uh; int err = 0; - int is_udplite = IS_UDPLITE(sk); - __wsum csum = 0; - /* Grab the skbuff where UDP header space exists. */ - if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) + skb = ip_finish_skb(sk); + if (!skb) goto out; - /* - * Create a UDP header - */ - uh = udp_hdr(skb); - uh->source = fl->fl_ip_sport; - uh->dest = fl->fl_ip_dport; - uh->len = htons(up->len); - uh->check = 0; + err = udp_send_skb(skb, fl->fl4_dst, fl->fl_ip_dport); - if (is_udplite) /* UDP-Lite */ - csum = udplite_csum_outgoing(sk, skb); - - else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ - - skb->ip_summed = CHECKSUM_NONE; - goto send; - - } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ - - udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len); - goto send; - - } else /* `normal' UDP */ - csum = udp_csum_outgoing(sk, skb); - - /* add protocol-dependent pseudo-header */ - uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, - sk->sk_protocol, csum); - if (uh->check == 0) - uh->check = CSUM_MANGLED_0; - -send: - err = ip_push_pending_frames(sk); - if (err) { - if (err == -ENOBUFS && !inet->recverr) { - UDP_INC_STATS_USER(sock_net(sk), - UDP_MIB_SNDBUFERRORS, is_udplite); - err = 0; - } - } else - UDP_INC_STATS_USER(sock_net(sk), - UDP_MIB_OUTDATAGRAMS, is_udplite); out: up->len = 0; up->pending = 0;