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 <herbert@gondor.apana.org.au>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/udp.h b/include/net/udp.h
index e82f3a8..67ea6fc 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -144,6 +144,17 @@
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 afdffe6..673a024 100644
--- a/include/net/udplite.h
+++ b/include/net/udplite.h
@@ -115,6 +115,18 @@
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 d37baaa..61c22ee 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -663,46 +663,106 @@
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 @@
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;
