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authorFlorian Westphal <fw@strlen.de>2021-04-01 16:19:44 -0700
committerDavid S. Miller <davem@davemloft.net>2021-04-02 14:21:50 -0700
commitdc87efdb1a5cd46134a9d490480160e303bc6eef (patch)
tree57040990350f1bf27ddecf5f015c445fcf4b888f /net/ipv6/tcp_ipv6.c
parent781bf13d4f3b033002f7f6728ac0b0d1ebe8f176 (diff)
downloadlinux-dc87efdb1a5cd46134a9d490480160e303bc6eef.tar.gz
mptcp: add mptcp reset option support
The MPTCP reset option allows to carry a mptcp-specific error code that provides more information on the nature of a connection reset. Reset option data received gets stored in the subflow context so it can be sent to userspace via the 'subflow closed' netlink event. When a subflow is closed, the desired error code that should be sent to the peer is also placed in the subflow context structure. If a reset is sent before subflow establishment could complete, e.g. on HMAC failure during an MP_JOIN operation, the mptcp skb extension is used to store the reset information. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
-rw-r--r--net/ipv6/tcp_ipv6.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index bff22d6ef516a..5f47c0b6e3de8 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -879,8 +879,8 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
struct sock *ctl_sk = net->ipv6.tcp_sk;
unsigned int tot_len = sizeof(struct tcphdr);
+ __be32 mrst = 0, *topt;
struct dst_entry *dst;
- __be32 *topt;
__u32 mark = 0;
if (tsecr)
@@ -890,6 +890,15 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
tot_len += TCPOLEN_MD5SIG_ALIGNED;
#endif
+#ifdef CONFIG_MPTCP
+ if (rst && !key) {
+ mrst = mptcp_reset_option(skb);
+
+ if (mrst)
+ tot_len += sizeof(__be32);
+ }
+#endif
+
buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
GFP_ATOMIC);
if (!buff)
@@ -920,6 +929,9 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
*topt++ = htonl(tsecr);
}
+ if (mrst)
+ *topt++ = mrst;
+
#ifdef CONFIG_TCP_MD5SIG
if (key) {
*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |