From 5d424d5a674f782d0659a3b66d951f412901faee Mon Sep 17 00:00:00 2001 From: John Heffner Date: Mon, 20 Mar 2006 17:53:41 -0800 Subject: [TCP]: MTU probing Implementation of packetization layer path mtu discovery for TCP, based on the internet-draft currently found at . Signed-off-by: John Heffner Signed-off-by: David S. Miller --- include/net/tcp.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/net/tcp.h') diff --git a/include/net/tcp.h b/include/net/tcp.h index 77f21c65bbca..16879fa560de 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -60,6 +60,9 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); /* Minimal RCV_MSS. */ #define TCP_MIN_RCVMSS 536U +/* The least MTU to use for probing */ +#define TCP_BASE_MSS 512 + /* After receiving this amount of duplicate ACKs fast retransmit starts. */ #define TCP_FASTRETRANS_THRESH 3 @@ -219,6 +222,8 @@ extern int sysctl_tcp_nometrics_save; extern int sysctl_tcp_moderate_rcvbuf; extern int sysctl_tcp_tso_win_divisor; extern int sysctl_tcp_abc; +extern int sysctl_tcp_mtu_probing; +extern int sysctl_tcp_base_mss; extern atomic_t tcp_memory_allocated; extern atomic_t tcp_sockets_allocated; @@ -447,6 +452,10 @@ extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, extern void tcp_initialize_rcv_mss(struct sock *sk); +extern int tcp_mtu_to_mss(struct sock *sk, int pmtu); +extern int tcp_mss_to_mtu(struct sock *sk, int mss); +extern void tcp_mtup_init(struct sock *sk); + static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) { tp->pred_flags = htonl((tp->tcp_header_len << 26) | -- cgit v1.2.3-59-g8ed1b