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tcpv6: combine tcp_v6_send_(reset|ack)
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$ 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>
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Ilpo Järvinen authored and David S. Miller committed Oct 9, 2008
1 parent 81ada62 commit 626e264
Showing 1 changed file with 40 additions and 99 deletions.
139 changes: 40 additions & 99 deletions net/ipv6/tcp_ipv6.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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)
Expand All @@ -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) |
Expand Down Expand Up @@ -1036,95 +1023,49 @@ 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);
TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
if (rst)
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_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)
Expand Down

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