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authorNeil Horman <nhorman@tuxdriver.com>2017-06-30 13:32:57 -0400
committerDavid S. Miller <davem@davemloft.net>2017-07-01 15:26:11 -0700
commit2cb5c8e378d10a57aa1c9eaee36bea46c27dd2b9 (patch)
treecc8f2f7500a0b48952c742c169fe858e536a9eba /net
parent15324b25d5792b92c44714e20694a2df3a3a7b8f (diff)
downloadlinux-2cb5c8e378d10a57aa1c9eaee36bea46c27dd2b9.tar.bz2
sctp: Add peeloff-flags socket option
Based on a request raised on the sctp devel list, there is a need to augment the sctp_peeloff operation while specifying the O_CLOEXEC and O_NONBLOCK flags (simmilar to the socket syscall). Since modifying the SCTP_SOCKOPT_PEELOFF socket option would break user space ABI for existing programs, this patch creates a new socket option SCTP_SOCKOPT_PEELOFF_FLAGS, which accepts a third flags parameter to allow atomic assignment of the socket descriptor flags. Tested successfully by myself and the requestor Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Vlad Yasevich <vyasevich@gmail.com> CC: "David S. Miller" <davem@davemloft.net> CC: Andreas Steinmetz <ast@domdv.de> CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/sctp/socket.c87
1 files changed, 72 insertions, 15 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 0af103f85c79..1db478e34520 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4933,11 +4933,47 @@ int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp)
}
EXPORT_SYMBOL(sctp_do_peeloff);
+static int sctp_getsockopt_peeloff_common(struct sock *sk, sctp_peeloff_arg_t *peeloff,
+ struct file **newfile, unsigned flags)
+{
+ struct socket *newsock;
+ int retval;
+
+ retval = sctp_do_peeloff(sk, peeloff->associd, &newsock);
+ if (retval < 0)
+ goto out;
+
+ /* Map the socket to an unused fd that can be returned to the user. */
+ retval = get_unused_fd_flags(flags & SOCK_CLOEXEC);
+ if (retval < 0) {
+ sock_release(newsock);
+ goto out;
+ }
+
+ *newfile = sock_alloc_file(newsock, 0, NULL);
+ if (IS_ERR(*newfile)) {
+ put_unused_fd(retval);
+ sock_release(newsock);
+ retval = PTR_ERR(*newfile);
+ *newfile = NULL;
+ return retval;
+ }
+
+ pr_debug("%s: sk:%p, newsk:%p, sd:%d\n", __func__, sk, newsock->sk,
+ retval);
+
+ peeloff->sd = retval;
+
+ if (flags & SOCK_NONBLOCK)
+ (*newfile)->f_flags |= O_NONBLOCK;
+out:
+ return retval;
+}
+
static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval, int __user *optlen)
{
sctp_peeloff_arg_t peeloff;
- struct socket *newsock;
- struct file *newfile;
+ struct file *newfile = NULL;
int retval = 0;
if (len < sizeof(sctp_peeloff_arg_t))
@@ -4946,26 +4982,44 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval
if (copy_from_user(&peeloff, optval, len))
return -EFAULT;
- retval = sctp_do_peeloff(sk, peeloff.associd, &newsock);
+ retval = sctp_getsockopt_peeloff_common(sk, &peeloff, &newfile, 0);
if (retval < 0)
goto out;
- /* Map the socket to an unused fd that can be returned to the user. */
- retval = get_unused_fd_flags(0);
- if (retval < 0) {
- sock_release(newsock);
- goto out;
+ /* Return the fd mapped to the new socket. */
+ if (put_user(len, optlen)) {
+ fput(newfile);
+ put_unused_fd(retval);
+ return -EFAULT;
}
- newfile = sock_alloc_file(newsock, 0, NULL);
- if (IS_ERR(newfile)) {
+ if (copy_to_user(optval, &peeloff, len)) {
+ fput(newfile);
put_unused_fd(retval);
- sock_release(newsock);
- return PTR_ERR(newfile);
+ return -EFAULT;
}
+ fd_install(retval, newfile);
+out:
+ return retval;
+}
- pr_debug("%s: sk:%p, newsk:%p, sd:%d\n", __func__, sk, newsock->sk,
- retval);
+static int sctp_getsockopt_peeloff_flags(struct sock *sk, int len,
+ char __user *optval, int __user *optlen)
+{
+ sctp_peeloff_flags_arg_t peeloff;
+ struct file *newfile = NULL;
+ int retval = 0;
+
+ if (len < sizeof(sctp_peeloff_flags_arg_t))
+ return -EINVAL;
+ len = sizeof(sctp_peeloff_flags_arg_t);
+ if (copy_from_user(&peeloff, optval, len))
+ return -EFAULT;
+
+ retval = sctp_getsockopt_peeloff_common(sk, &peeloff.p_arg,
+ &newfile, peeloff.flags);
+ if (retval < 0)
+ goto out;
/* Return the fd mapped to the new socket. */
if (put_user(len, optlen)) {
@@ -4973,7 +5027,7 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval
put_unused_fd(retval);
return -EFAULT;
}
- peeloff.sd = retval;
+
if (copy_to_user(optval, &peeloff, len)) {
fput(newfile);
put_unused_fd(retval);
@@ -6759,6 +6813,9 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname,
case SCTP_SOCKOPT_PEELOFF:
retval = sctp_getsockopt_peeloff(sk, len, optval, optlen);
break;
+ case SCTP_SOCKOPT_PEELOFF_FLAGS:
+ retval = sctp_getsockopt_peeloff_flags(sk, len, optval, optlen);
+ break;
case SCTP_PEER_ADDR_PARAMS:
retval = sctp_getsockopt_peer_addr_params(sk, len, optval,
optlen);