tcpv6: combine tcp_v6_send_(reset|ack)
$ codiff tcp_ipv6.o.old tcp_ipv6.o.new
net/ipv6/tcp_ipv6.c:
tcp_v6_md5_hash_hdr | -144
tcp_v6_send_ack | -585
tcp_v6_send_reset | -540
3 functions changed, 1269 bytes removed, diff: -1269
net/ipv6/tcp_ipv6.c:
tcp_v6_send_response | +791
1 function changed, 791 bytes added, diff: +791
tcp_ipv6.o.new:
4 functions changed, 791 bytes added, 1269 bytes removed, diff: -478
I choose to leave the reset related netns comment in place (not
the one that is killed) as I cannot understand its English so
it's a bit hard for me to evaluate its usefulness :-).
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1941c5c..13c6514 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -942,110 +942,8 @@
return 0;
}
-static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
-{
- struct tcphdr *th = tcp_hdr(skb), *t1;
- struct sk_buff *buff;
- struct flowi fl;
- struct net *net = dev_net(skb->dst->dev);
- struct sock *ctl_sk = net->ipv6.tcp_sk;
- unsigned int tot_len = sizeof(struct tcphdr);
- __be32 *topt;
-#ifdef CONFIG_TCP_MD5SIG
- struct tcp_md5sig_key *key;
-#endif
-
- if (th->rst)
- return;
-
- if (!ipv6_unicast_destination(skb))
- return;
-
-#ifdef CONFIG_TCP_MD5SIG
- if (sk)
- key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
- else
- key = NULL;
-
- if (key)
- tot_len += TCPOLEN_MD5SIG_ALIGNED;
-#endif
-
- /*
- * We need to grab some memory, and put together an RST,
- * and then put it into the queue to be sent.
- */
-
- buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
- GFP_ATOMIC);
- if (buff == NULL)
- return;
-
- skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
-
- t1 = (struct tcphdr *) skb_push(buff, tot_len);
-
- /* Swap the send and the receive. */
- memset(t1, 0, sizeof(*t1));
- t1->dest = th->source;
- t1->source = th->dest;
- t1->doff = tot_len / 4;
- t1->rst = 1;
-
- if(th->ack) {
- t1->seq = th->ack_seq;
- } else {
- t1->ack = 1;
- t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
- + skb->len - (th->doff<<2));
- }
-
- topt = (__be32 *)(t1 + 1);
-
-#ifdef CONFIG_TCP_MD5SIG
- if (key) {
- *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
- (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
- tcp_v6_md5_hash_hdr((__u8 *)topt, key,
- &ipv6_hdr(skb)->saddr,
- &ipv6_hdr(skb)->daddr, t1);
- }
-#endif
-
- buff->csum = csum_partial((char *)t1, tot_len, 0);
-
- memset(&fl, 0, sizeof(fl));
- ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
- ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
-
- t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
- tot_len, IPPROTO_TCP,
- buff->csum);
-
- fl.proto = IPPROTO_TCP;
- fl.oif = inet6_iif(skb);
- fl.fl_ip_dport = t1->dest;
- fl.fl_ip_sport = t1->source;
- security_skb_classify_flow(skb, &fl);
-
- /* Pass a socket to ip6_dst_lookup either it is for RST
- * Underlying function will use this to retrieve the network
- * namespace
- */
- if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
- if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
- ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
- TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
- TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
- return;
- }
- }
-
- kfree_skb(buff);
-}
-
-static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
- struct tcp_md5sig_key *key)
+static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
+ u32 ts, struct tcp_md5sig_key *key, int rst)
{
struct tcphdr *th = tcp_hdr(skb), *t1;
struct sk_buff *buff;
@@ -1078,7 +976,8 @@
t1->doff = tot_len / 4;
t1->seq = htonl(seq);
t1->ack_seq = htonl(ack);
- t1->ack = 1;
+ t1->ack = !rst || !th->ack;
+ t1->rst = rst;
t1->window = htons(win);
topt = (__be32 *)(t1 + 1);
@@ -1116,10 +1015,16 @@
fl.fl_ip_sport = t1->source;
security_skb_classify_flow(skb, &fl);
+ /* Pass a socket to ip6_dst_lookup either it is for RST
+ * Underlying function will use this to retrieve the network
+ * namespace
+ */
if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
+ if (rst)
+ TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
return;
}
}
@@ -1127,6 +1032,42 @@
kfree_skb(buff);
}
+static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
+{
+ struct tcphdr *th = tcp_hdr(skb);
+ u32 seq = 0, ack_seq = 0;
+#ifdef CONFIG_TCP_MD5SIG
+ struct tcp_md5sig_key *key;
+#endif
+
+ if (th->rst)
+ return;
+
+ if (!ipv6_unicast_destination(skb))
+ return;
+
+#ifdef CONFIG_TCP_MD5SIG
+ if (sk)
+ key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
+ else
+ key = NULL;
+#endif
+
+ if (th->ack)
+ seq = ntohl(th->ack_seq);
+ else
+ ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
+ (th->doff << 2);
+
+ tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
+}
+
+static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
+ struct tcp_md5sig_key *key)
+{
+ tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
+}
+
static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
struct inet_timewait_sock *tw = inet_twsk(sk);