From 70c58997c1e864c96dfdf072572047303db8f42a Mon Sep 17 00:00:00 2001 From: Ferenc Fejes Date: Sat, 30 May 2020 23:09:01 +0200 Subject: [PATCH] bpf: Allow SO_BINDTODEVICE opt in bpf_setsockopt Extending the supported sockopts in bpf_setsockopt with SO_BINDTODEVICE. We call sock_bindtoindex with parameter lock_sk = false in this context because we already owning the socket. Signed-off-by: Ferenc Fejes Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/4149e304867b8d5a606a305bc59e29b063e51f49.1590871065.git.fejes@inf.elte.hu --- net/core/filter.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 85ff827aab73..ae82bcb03124 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4248,6 +4248,9 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { static int _bpf_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen, u32 flags) { + char devname[IFNAMSIZ]; + struct net *net; + int ifindex; int ret = 0; int val; @@ -4257,7 +4260,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, sock_owned_by_me(sk); if (level == SOL_SOCKET) { - if (optlen != sizeof(int)) + if (optlen != sizeof(int) && optname != SO_BINDTODEVICE) return -EINVAL; val = *((int *)optval); @@ -4298,6 +4301,29 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, sk_dst_reset(sk); } break; + case SO_BINDTODEVICE: + ret = -ENOPROTOOPT; +#ifdef CONFIG_NETDEVICES + optlen = min_t(long, optlen, IFNAMSIZ - 1); + strncpy(devname, optval, optlen); + devname[optlen] = 0; + + ifindex = 0; + if (devname[0] != '\0') { + struct net_device *dev; + + ret = -ENODEV; + + net = sock_net(sk); + dev = dev_get_by_name(net, devname); + if (!dev) + break; + ifindex = dev->ifindex; + dev_put(dev); + } + ret = sock_bindtoindex(sk, ifindex, false); +#endif + break; default: ret = -EINVAL; }