From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xin Long Subject: [PATCH net] sctp: fix the issue that flags are ignored when using kernel_connect Date: Sun, 20 May 2018 16:39:10 +0800 Message-ID: <4863916c3e574b0d860725466d7d4a2f445fbe5b.1526805550.git.lucien.xin@gmail.com> Cc: davem@davemloft.net, Marcelo Ricardo Leitner , Neil Horman , mkubecek@suse.cz To: network dev , linux-sctp@vger.kernel.org Return-path: Received: from mail-pl0-f66.google.com ([209.85.160.66]:45056 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925AbeETIjS (ORCPT ); Sun, 20 May 2018 04:39:18 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags param can't be passed into its proto .connect where this flags is really needed. sctp works around it by getting flags from socket file in __sctp_connect. It works for connecting from userspace, as inherently the user sock has socket file and it passes f_flags as the flags param into the proto_ops .connect. However, the sock created by sock_create_kern doesn't have a socket file, and it passes the flags (like O_NONBLOCK) by using the flags param in kernel_connect, which calls proto_ops .connect later. So to fix it, this patch defines a new proto_ops .connect for sctp, sctp_inet_connect, which calls __sctp_connect() directly with this flags param. After this, the sctp's proto .connect can be removed. Note that sctp_inet_connect doesn't need to do some checks that are not needed for sctp, which makes thing better than with inet_dgram_connect. Suggested-by: Marcelo Ricardo Leitner Signed-off-by: Xin Long --- include/net/sctp/sctp.h | 2 ++ net/sctp/ipv6.c | 2 +- net/sctp/protocol.c | 2 +- net/sctp/socket.c | 51 +++++++++++++++++++++++++++++++++---------------- 4 files changed, 39 insertions(+), 18 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 28b996d..35498e6 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -103,6 +103,8 @@ void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); /* * sctp/socket.c */ +int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags); int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); int sctp_inet_listen(struct socket *sock, int backlog); void sctp_write_space(struct sock *sk); diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index 4224711..0cd2e76 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -1006,7 +1006,7 @@ static const struct proto_ops inet6_seqpacket_ops = { .owner = THIS_MODULE, .release = inet6_release, .bind = inet6_bind, - .connect = inet_dgram_connect, + .connect = sctp_inet_connect, .socketpair = sock_no_socketpair, .accept = inet_accept, .getname = sctp_getname, diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index d685f84..6bf0a99 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -1012,7 +1012,7 @@ static const struct proto_ops inet_seqpacket_ops = { .owner = THIS_MODULE, .release = inet_release, /* Needs to be wrapped... */ .bind = inet_bind, - .connect = inet_dgram_connect, + .connect = sctp_inet_connect, .socketpair = sock_no_socketpair, .accept = inet_accept, .getname = inet_getname, /* Semantics are different. */ diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 80835ac..ae7e7c6 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1086,7 +1086,7 @@ static int sctp_setsockopt_bindx(struct sock *sk, */ static int __sctp_connect(struct sock *sk, struct sockaddr *kaddrs, - int addrs_size, + int addrs_size, int flags, sctp_assoc_t *assoc_id) { struct net *net = sock_net(sk); @@ -1104,7 +1104,6 @@ static int __sctp_connect(struct sock *sk, union sctp_addr *sa_addr = NULL; void *addr_buf; unsigned short port; - unsigned int f_flags = 0; sp = sctp_sk(sk); ep = sp->ep; @@ -1254,13 +1253,7 @@ static int __sctp_connect(struct sock *sk, sp->pf->to_sk_daddr(sa_addr, sk); sk->sk_err = 0; - /* in-kernel sockets don't generally have a file allocated to them - * if all they do is call sock_create_kern(). - */ - if (sk->sk_socket->file) - f_flags = sk->sk_socket->file->f_flags; - - timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK); + timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); if (assoc_id) *assoc_id = asoc->assoc_id; @@ -1348,7 +1341,7 @@ static int __sctp_setsockopt_connectx(struct sock *sk, sctp_assoc_t *assoc_id) { struct sockaddr *kaddrs; - int err = 0; + int err = 0, flags = 0; pr_debug("%s: sk:%p addrs:%p addrs_size:%d\n", __func__, sk, addrs, addrs_size); @@ -1367,7 +1360,13 @@ static int __sctp_setsockopt_connectx(struct sock *sk, if (err) goto out_free; - err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id); + /* in-kernel sockets don't generally have a file allocated to them + * if all they do is call sock_create_kern(). + */ + if (sk->sk_socket->file) + flags = sk->sk_socket->file->f_flags; + + err = __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id); out_free: kvfree(kaddrs); @@ -4397,16 +4396,26 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, * len: the size of the address. */ static int sctp_connect(struct sock *sk, struct sockaddr *addr, - int addr_len) + int addr_len, int flags) { - int err = 0; + struct inet_sock *inet = inet_sk(sk); struct sctp_af *af; + int err = 0; lock_sock(sk); pr_debug("%s: sk:%p, sockaddr:%p, addr_len:%d\n", __func__, sk, addr, addr_len); + /* We may need to bind the socket. */ + if (!inet->inet_num) { + if (sk->sk_prot->get_port(sk, 0)) { + release_sock(sk); + return -EAGAIN; + } + inet->inet_sport = htons(inet->inet_num); + } + /* Validate addr_len before calling common connect/connectx routine. */ af = sctp_get_af_specific(addr->sa_family); if (!af || addr_len < af->sockaddr_len) { @@ -4415,13 +4424,25 @@ static int sctp_connect(struct sock *sk, struct sockaddr *addr, /* Pass correct addr len to common routine (so it knows there * is only one address being passed. */ - err = __sctp_connect(sk, addr, af->sockaddr_len, NULL); + err = __sctp_connect(sk, addr, af->sockaddr_len, flags, NULL); } release_sock(sk); return err; } +int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags) +{ + if (addr_len < sizeof(uaddr->sa_family)) + return -EINVAL; + + if (uaddr->sa_family == AF_UNSPEC) + return -EOPNOTSUPP; + + return sctp_connect(sock->sk, uaddr, addr_len, flags); +} + /* FIXME: Write comments. */ static int sctp_disconnect(struct sock *sk, int flags) { @@ -8724,7 +8745,6 @@ struct proto sctp_prot = { .name = "SCTP", .owner = THIS_MODULE, .close = sctp_close, - .connect = sctp_connect, .disconnect = sctp_disconnect, .accept = sctp_accept, .ioctl = sctp_ioctl, @@ -8767,7 +8787,6 @@ struct proto sctpv6_prot = { .name = "SCTPv6", .owner = THIS_MODULE, .close = sctp_close, - .connect = sctp_connect, .disconnect = sctp_disconnect, .accept = sctp_accept, .ioctl = sctp_ioctl, -- 2.1.0