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sctp: fix the issue that flags are ignored when using kernel_connect

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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 <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2018-05-20 16:39:10 +08:00 committed by David S. Miller
parent 6741c4bb38
commit 644fbdeacf
4 changed files with 39 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/net/sctp/sctp.h
View File

@ -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);

2
net/sctp/ipv6.c
View File

@ -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,

2
net/sctp/protocol.c
View File

@ -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. */

51
net/sctp/socket.c
View File

@ -1086,7 +1086,7 @@ out:
*/
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 @@ out_nounlock:
* 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,