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authorChristoph Hellwig <hch@lst.de>2020-05-28 08:12:16 +0300
committerDavid S. Miller <davem@davemloft.net>2020-05-28 21:11:44 +0300
commit26cfabf9cdd273650126d84a48a7f8dedbcded48 (patch)
treec4db68de1b6ef5052a693c5180446e6de357516f /net/core
parentce3d9544cecacd40389c399d2b7ca31acc533b70 (diff)
downloadlinux-26cfabf9cdd273650126d84a48a7f8dedbcded48.tar.xz
net: add sock_set_rcvbuf
Add a helper to directly set the SO_RCVBUFFORCE sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/sock.c59
1 files changed, 32 insertions, 27 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index 728f5fb156a0..3c6ebf952e9a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -789,6 +789,35 @@ void sock_set_keepalive(struct sock *sk)
}
EXPORT_SYMBOL(sock_set_keepalive);
+static void __sock_set_rcvbuf(struct sock *sk, int val)
+{
+ /* Ensure val * 2 fits into an int, to prevent max_t() from treating it
+ * as a negative value.
+ */
+ val = min_t(int, val, INT_MAX / 2);
+ sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
+
+ /* We double it on the way in to account for "struct sk_buff" etc.
+ * overhead. Applications assume that the SO_RCVBUF setting they make
+ * will allow that much actual data to be received on that socket.
+ *
+ * Applications are unaware that "struct sk_buff" and other overheads
+ * allocate from the receive buffer during socket buffer allocation.
+ *
+ * And after considering the possible alternatives, returning the value
+ * we actually used in getsockopt is the most desirable behavior.
+ */
+ WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
+}
+
+void sock_set_rcvbuf(struct sock *sk, int val)
+{
+ lock_sock(sk);
+ __sock_set_rcvbuf(sk, val);
+ release_sock(sk);
+}
+EXPORT_SYMBOL(sock_set_rcvbuf);
+
/*
* This is meant for all protocols to use and covers goings on
* at the socket level. Everything here is generic.
@@ -885,30 +914,7 @@ set_sndbuf:
* play 'guess the biggest size' games. RCVBUF/SNDBUF
* are treated in BSD as hints
*/
- val = min_t(u32, val, sysctl_rmem_max);
-set_rcvbuf:
- /* Ensure val * 2 fits into an int, to prevent max_t()
- * from treating it as a negative value.
- */
- val = min_t(int, val, INT_MAX / 2);
- sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
- /*
- * We double it on the way in to account for
- * "struct sk_buff" etc. overhead. Applications
- * assume that the SO_RCVBUF setting they make will
- * allow that much actual data to be received on that
- * socket.
- *
- * Applications are unaware that "struct sk_buff" and
- * other overheads allocate from the receive buffer
- * during socket buffer allocation.
- *
- * And after considering the possible alternatives,
- * returning the value we actually used in getsockopt
- * is the most desirable behavior.
- */
- WRITE_ONCE(sk->sk_rcvbuf,
- max_t(int, val * 2, SOCK_MIN_RCVBUF));
+ __sock_set_rcvbuf(sk, min_t(u32, val, sysctl_rmem_max));
break;
case SO_RCVBUFFORCE:
@@ -920,9 +926,8 @@ set_rcvbuf:
/* No negative values (to prevent underflow, as val will be
* multiplied by 2).
*/
- if (val < 0)
- val = 0;
- goto set_rcvbuf;
+ __sock_set_rcvbuf(sk, max(val, 0));
+ break;
case SO_KEEPALIVE:
if (sk->sk_prot->keepalive)