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-rw-r--r--net/ipv6/tcp_ipv6.c139
1 files changed, 40 insertions, 99 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1941c5c888d3..13c65144a00a 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -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) |
@@ -1036,7 +1023,8 @@ 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;
}
}
@@ -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)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 00:59:58 +0000