diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_output.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 7b7cf3811348..834e89fc541b 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1150,7 +1150,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len) } /* Calculate MSS. Not accounting for SACKs here. */ -int tcp_mtu_to_mss(const struct sock *sk, int pmtu) +int tcp_mtu_to_mss(struct sock *sk, int pmtu) { const struct tcp_sock *tp = tcp_sk(sk); const struct inet_connection_sock *icsk = inet_csk(sk); @@ -1161,6 +1161,14 @@ int tcp_mtu_to_mss(const struct sock *sk, int pmtu) */ mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr); + /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */ + if (icsk->icsk_af_ops->net_frag_header_len) { + const struct dst_entry *dst = __sk_dst_get(sk); + + if (dst && dst_allfrag(dst)) + mss_now -= icsk->icsk_af_ops->net_frag_header_len; + } + /* Clamp it (mss_clamp does not include tcp options) */ if (mss_now > tp->rx_opt.mss_clamp) mss_now = tp->rx_opt.mss_clamp; @@ -1179,7 +1187,7 @@ int tcp_mtu_to_mss(const struct sock *sk, int pmtu) } /* Inverse of above */ -int tcp_mss_to_mtu(const struct sock *sk, int mss) +int tcp_mss_to_mtu(struct sock *sk, int mss) { const struct tcp_sock *tp = tcp_sk(sk); const struct inet_connection_sock *icsk = inet_csk(sk); @@ -1190,6 +1198,13 @@ int tcp_mss_to_mtu(const struct sock *sk, int mss) icsk->icsk_ext_hdr_len + icsk->icsk_af_ops->net_header_len; + /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */ + if (icsk->icsk_af_ops->net_frag_header_len) { + const struct dst_entry *dst = __sk_dst_get(sk); + + if (dst && dst_allfrag(dst)) + mtu += icsk->icsk_af_ops->net_frag_header_len; + } return mtu; } |