[Devel] [PATCH vz9 22/27] ve/net/core: allow to call setsockopt(SO_SNDBUFFORCE) from Containers

[Nikita Yushchenko]

From: Konstantin Khorenko <khorenko at virtuozzo.com>

"nft" util (in CentOS 8 environment) does use setsockopt(SO_SNDBUFFORCE)
unconditionally, so we have to allow it from inside a Container.

At the same time we don't want to allow a Container to set too much
memory for a socket, so just threat SO_SNDBUFFORCE like SO_SNDBUF if
called inside a Container.

Simple rule to test:
 # nft add rule filter INPUT ct state related,established accept

https://jira.sw.ru/browse/PSBM-98794

Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
Acked-by: Andrey Ryabinin <aryabinin at virtuozzo.com>

(cherry picked from vz7 commit 8f3567b1f4af7d33c15856ae402ef2025909fd14)
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>

(cherry-picked from vz8 commit cb15883dde11 ("ve/net/core: allow to call
setsockopt(SO_SNDBUFFORCE) from Containers"))

Signed-off-by: Nikita Yushchenko <nikita.yushchenko at virtuozzo.com>
---
 net/core/sock.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 35db91ba6ff8..8ad8f92ba7d8 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1006,6 +1006,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
 		break;
 	case SO_SNDBUF:
+unpriv_sndbuf:
 		/* Don't error on this BSD doesn't and if you think
 		 * about it this is right. Otherwise apps have to
 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
@@ -1025,11 +1026,15 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case SO_SNDBUFFORCE:
-		if (!capable(CAP_NET_ADMIN)) {
+		if (!ve_capable(CAP_NET_ADMIN)) {
 			ret = -EPERM;
 			break;
 		}
 
+		/* nft utility uses this sockopt in CentOS 8 env */
+		if (!ve_is_super(get_exec_env()))
+			goto unpriv_sndbuf;
+
 		/* No negative values (to prevent underflow, as val will be
 		 * multiplied by 2).
 		 */
-- 
2.30.2