diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index e1e021594cff..03964e088180 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -468,6 +468,17 @@ tcp_syncookies - BOOLEAN SYN flood warnings in logs not being really flooded, your server is seriously misconfigured. +tcp_fastopen - INTEGER + Enable TCP Fast Open feature (draft-ietf-tcpm-fastopen) to send data + in the opening SYN packet. To use this feature, the client application + must not use connect(). Instead, it should use sendmsg() or sendto() + with MSG_FASTOPEN flag which performs a TCP handshake automatically. + + The values (bitmap) are: + 1: Enables sending data in the opening SYN on the client + + Default: 0 + tcp_syn_retries - INTEGER Number of times initial SYNs for an active TCP connection attempt will be retransmitted. Should not be higher than 255. Default value diff --git a/include/linux/socket.h b/include/linux/socket.h index 25d6322fb635..ba7b2e817cfa 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -268,6 +268,7 @@ struct ucred { #define MSG_SENDPAGE_NOTLAST 0x20000 /* sendpage() internal : not the last page */ #define MSG_EOF MSG_FIN +#define MSG_FASTOPEN 0x20000000 /* Send data in TCP SYN */ #define MSG_CMSG_CLOEXEC 0x40000000 /* Set close_on_exit for file descriptor received through SCM_RIGHTS */ diff --git a/include/net/inet_common.h b/include/net/inet_common.h index 22fac9892b16..234008782c8c 100644 --- a/include/net/inet_common.h +++ b/include/net/inet_common.h @@ -14,9 +14,11 @@ struct sockaddr; struct socket; extern int inet_release(struct socket *sock); -extern int inet_stream_connect(struct socket *sock, struct sockaddr * uaddr, +extern int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags); -extern int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr, +extern int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags); +extern int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags); extern int inet_accept(struct socket *sock, struct socket *newsock, int flags); extern int inet_sendmsg(struct kiocb *iocb, struct socket *sock, diff --git a/include/net/tcp.h b/include/net/tcp.h index 867557b4244a..c0258100d70c 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -212,6 +212,9 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); /* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */ #define TCP_INIT_CWND 10 +/* Bit Flags for sysctl_tcp_fastopen */ +#define TFO_CLIENT_ENABLE 1 + extern struct inet_timewait_death_row tcp_death_row; /* sysctl variables for tcp */ diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index edc414625be2..fe4582ca969a 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -585,8 +585,8 @@ static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias) * Connect to a remote host. There is regrettably still a little * TCP 'magic' in here. */ -int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, - int addr_len, int flags) +int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags) { struct sock *sk = sock->sk; int err; @@ -595,8 +595,6 @@ int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, if (addr_len < sizeof(uaddr->sa_family)) return -EINVAL; - lock_sock(sk); - if (uaddr->sa_family == AF_UNSPEC) { err = sk->sk_prot->disconnect(sk, flags); sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; @@ -663,7 +661,6 @@ int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, sock->state = SS_CONNECTED; err = 0; out: - release_sock(sk); return err; sock_error: @@ -673,6 +670,18 @@ int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, sock->state = SS_DISCONNECTING; goto out; } +EXPORT_SYMBOL(__inet_stream_connect); + +int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags) +{ + int err; + + lock_sock(sock->sk); + err = __inet_stream_connect(sock, uaddr, addr_len, flags); + release_sock(sock->sk); + return err; +} EXPORT_SYMBOL(inet_stream_connect); /* diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4252cd8f39fd..581ecf02c6b5 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -270,6 +270,7 @@ #include #include +#include #include #include #include @@ -982,26 +983,67 @@ static inline int select_size(const struct sock *sk, bool sg) return tmp; } +void tcp_free_fastopen_req(struct tcp_sock *tp) +{ + if (tp->fastopen_req != NULL) { + kfree(tp->fastopen_req); + tp->fastopen_req = NULL; + } +} + +static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *size) +{ + struct tcp_sock *tp = tcp_sk(sk); + int err, flags; + + if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE)) + return -EOPNOTSUPP; + if (tp->fastopen_req != NULL) + return -EALREADY; /* Another Fast Open is in progress */ + + tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), + sk->sk_allocation); + if (unlikely(tp->fastopen_req == NULL)) + return -ENOBUFS; + tp->fastopen_req->data = msg; + + flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; + err = __inet_stream_connect(sk->sk_socket, msg->msg_name, + msg->msg_namelen, flags); + *size = tp->fastopen_req->copied; + tcp_free_fastopen_req(tp); + return err; +} + int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t size) { struct iovec *iov; struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; - int iovlen, flags, err, copied; - int mss_now = 0, size_goal; + int iovlen, flags, err, copied = 0; + int mss_now = 0, size_goal, copied_syn = 0, offset = 0; bool sg; long timeo; lock_sock(sk); flags = msg->msg_flags; + if (flags & MSG_FASTOPEN) { + err = tcp_sendmsg_fastopen(sk, msg, &copied_syn); + if (err == -EINPROGRESS && copied_syn > 0) + goto out; + else if (err) + goto out_err; + offset = copied_syn; + } + timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); /* Wait for a connection to finish. */ if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) - goto out_err; + goto do_error; if (unlikely(tp->repair)) { if (tp->repair_queue == TCP_RECV_QUEUE) { @@ -1037,6 +1079,15 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, unsigned char __user *from = iov->iov_base; iov++; + if (unlikely(offset > 0)) { /* Skip bytes copied in SYN */ + if (offset >= seglen) { + offset -= seglen; + continue; + } + seglen -= offset; + from += offset; + offset = 0; + } while (seglen > 0) { int copy = 0; @@ -1199,7 +1250,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (copied && likely(!tp->repair)) tcp_push(sk, flags, mss_now, tp->nonagle); release_sock(sk); - return copied; + return copied + copied_syn; do_fault: if (!skb->len) { @@ -1212,7 +1263,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, } do_error: - if (copied) + if (copied + copied_syn) goto out; out_err: err = sk_stream_error(sk, flags, err); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 01aa77a97020..1d8b75a58981 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1952,6 +1952,9 @@ void tcp_v4_destroy_sock(struct sock *sk) tp->cookie_values = NULL; } + /* If socket is aborted during connect operation */ + tcp_free_fastopen_req(tp); + sk_sockets_allocated_dec(sk); sock_release_memcg(sk); }