[PATCH RFC v3 81/90] net: use net_may() for privileged socket options

[Josef Bacik <josef@toxicpanda.com>]

Some socket options affect how the network namespace treats packets, not
just the socket, and require a capability. Convert their checks.

These accept CAP_NET_ADMIN or CAP_NET_RAW today, and now accept
NET_RIGHT_SOCKOPT or NET_RIGHT_RAW: SO_MARK, both as an option and as a
control message, SO_PRIORITY outside of the unprivileged range,
IP_TRANSPARENT and IPV6_TRANSPARENT.

This one requires CAP_NET_ADMIN, and now NET_RIGHT_SOCKOPT: SO_TXTIME with
a clock other than CLOCK_MONOTONIC.

These require CAP_NET_RAW, and now NET_RIGHT_RAW: SO_BINDTODEVICE on a
socket that is already bound to a device, and the IPv6 hop-by-hop and
destination options.

Not converted: IP_IPSEC_POLICY, IP_XFRM_POLICY and their IPv6
counterparts, and SO_ATTACH_FILTER on a TCP socket.

No functional change.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 net/core/sock.c          | 16 ++++++++--------
 net/ipv4/ip_sockglue.c   |  4 ++--
 net/ipv6/ipv6_sockglue.c |  7 +++----
 3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 352310066e35..ba870aa6b967 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -462,8 +462,8 @@ static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
 static bool sk_set_prio_allowed(const struct sock *sk, int val)
 {
 	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
-		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
-		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
+		sockopt_net_may(sk, NET_RIGHT_RAW) ||
+		sockopt_net_may(sk, NET_RIGHT_SOCKOPT));
 }
 
 static bool sock_needs_netstamp(const struct sock *sk)
@@ -642,7 +642,7 @@ static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
 
 	/* Sorry... */
 	ret = -EPERM;
-	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
+	if (sk->sk_bound_dev_if && !net_may(net, NET_RIGHT_RAW))
 		goto out;
 
 	ret = -EINVAL;
@@ -1540,8 +1540,8 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
 		break;
 
 	case SO_MARK:
-		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
-		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+		if (!sockopt_net_may(sk, NET_RIGHT_RAW) &&
+		    !sockopt_net_may(sk, NET_RIGHT_SOCKOPT)) {
 			ret = -EPERM;
 			break;
 		}
@@ -1649,7 +1649,7 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
 		 * scheduler has enough safe guards.
 		 */
 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
-		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+		    !sockopt_net_may(sk, NET_RIGHT_SOCKOPT)) {
 			ret = -EPERM;
 			break;
 		}
@@ -3172,8 +3172,8 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
 
 	switch (cmsg->cmsg_type) {
 	case SO_MARK:
-		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
-		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+		if (!net_may(sock_net(sk), NET_RIGHT_RAW) &&
+		    !net_may(sock_net(sk), NET_RIGHT_SOCKOPT))
 			return -EPERM;
 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
 			return -EINVAL;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index e06c1f48ecad..cc9e0bc952f2 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1008,8 +1008,8 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 		inet_assign_bit(MC_ALL, sk, val);
 		return 0;
 	case IP_TRANSPARENT:
-		if (!!val && !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
-		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+		if (!!val && !sockopt_net_may(sk, NET_RIGHT_RAW) &&
+		    !sockopt_net_may(sk, NET_RIGHT_SOCKOPT))
 			return -EPERM;
 		if (optlen < 1)
 			return -EINVAL;
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 4b3536571c98..d2880493d33b 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -304,12 +304,11 @@ static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct ipv6_opt_hdr *new = NULL;
-	struct net *net = sock_net(sk);
 	struct ipv6_txoptions *opt;
 	int err;
 
 	/* hop-by-hop / destination options are privileged option */
-	if (optname != IPV6_RTHDR && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW))
+	if (optname != IPV6_RTHDR && !sockopt_net_may(sk, NET_RIGHT_RAW))
 		return -EPERM;
 
 	/* remove any sticky options header with a zero option
@@ -405,8 +404,8 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		inet_assign_bit(FREEBIND, sk, valbool);
 		return 0;
 	case IPV6_TRANSPARENT:
-		if (valbool && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW) &&
-		    !sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN))
+		if (valbool && !sockopt_net_may(sk, NET_RIGHT_RAW) &&
+		    !sockopt_net_may(sk, NET_RIGHT_SOCKOPT))
 			return -EPERM;
 		if (optlen < sizeof(int))
 			return -EINVAL;

-- 
2.55.0