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Commit 626e264d authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
Browse files

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: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 81ada62d

net/ipv6/tcp_ipv6.c

+40 −99
Original line number Diff line number Diff line
@@ -942,7 +942,8 @@ static int tcp_v6_gso_send_check(struct sk_buff *skb) 
	return 0;

}



static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)

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;
@@ -951,31 +952,14 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) 
	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;



	if (ts)

		tot_len += TCPOLEN_TSTAMP_ALIGNED;

#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)
@@ -990,18 +974,21 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) 
	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));

	}

	t1->seq = htonl(seq);

	t1->ack_seq = htonl(ack);

	t1->ack = !rst || !th->ack;

	t1->rst = rst;

	t1->window = htons(win);



	topt = (__be32 *)(t1 + 1);



	if (ts) {

		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |

				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);

		*topt++ = htonl(tcp_time_stamp);

		*topt++ = htonl(ts);

	}



#ifdef CONFIG_TCP_MD5SIG

	if (key) {

		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
@@ -1036,6 +1023,7 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) 
		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;

		}
@@ -1044,87 +1032,40 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) 
	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_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;



	if (ts)

		tot_len += TCPOLEN_TSTAMP_ALIGNED;

	struct tcphdr *th = tcp_hdr(skb);

	u32 seq = 0, ack_seq = 0;

#ifdef CONFIG_TCP_MD5SIG

	if (key)

		tot_len += TCPOLEN_MD5SIG_ALIGNED;

	struct tcp_md5sig_key *key;

#endif



	buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,

			 GFP_ATOMIC);

	if (buff == NULL)

	if (th->rst)

		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->seq = htonl(seq);

	t1->ack_seq = htonl(ack);

	t1->ack = 1;

	t1->window = htons(win);



	topt = (__be32 *)(t1 + 1);



	if (ts) {

		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |

				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);

		*topt++ = htonl(tcp_time_stamp);

		*topt++ = htonl(ts);

	}

	if (!ipv6_unicast_destination(skb))

		return;



#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);

	}

	if (sk)

		key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);

	else

		key = NULL;

#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);

	if (th->ack)

		seq = ntohl(th->ack_seq);

	else

		ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -

			  (th->doff << 2);



	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);

			return;

		}

	tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);

}



	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)

{

	tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);

}



static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)