diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 691660b9b7ef..af399cac5205 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2911,22 +2911,40 @@ static int packet_release(struct socket *sock) * Attach a packet hook. */ -static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto) +static int packet_do_bind(struct sock *sk, const char *name, int ifindex, + __be16 proto) { struct packet_sock *po = pkt_sk(sk); struct net_device *dev_curr; __be16 proto_curr; bool need_rehook; + struct net_device *dev = NULL; + int ret = 0; + bool unlisted = false; - if (po->fanout) { - if (dev) - dev_put(dev); - + if (po->fanout) return -EINVAL; - } lock_sock(sk); spin_lock(&po->bind_lock); + rcu_read_lock(); + + if (name) { + dev = dev_get_by_name_rcu(sock_net(sk), name); + if (!dev) { + ret = -ENODEV; + goto out_unlock; + } + } else if (ifindex) { + dev = dev_get_by_index_rcu(sock_net(sk), ifindex); + if (!dev) { + ret = -ENODEV; + goto out_unlock; + } + } + + if (dev) + dev_hold(dev); proto_curr = po->prot_hook.type; dev_curr = po->prot_hook.dev; @@ -2934,14 +2952,29 @@ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto) need_rehook = proto_curr != proto || dev_curr != dev; if (need_rehook) { - unregister_prot_hook(sk, true); + if (po->running) { + rcu_read_unlock(); + __unregister_prot_hook(sk, true); + rcu_read_lock(); + dev_curr = po->prot_hook.dev; + if (dev) + unlisted = !dev_get_by_index_rcu(sock_net(sk), + dev->ifindex); + } po->num = proto; po->prot_hook.type = proto; - po->prot_hook.dev = dev; - po->ifindex = dev ? dev->ifindex : 0; - packet_cached_dev_assign(po, dev); + if (unlikely(unlisted)) { + dev_put(dev); + po->prot_hook.dev = NULL; + po->ifindex = -1; + packet_cached_dev_reset(po); + } else { + po->prot_hook.dev = dev; + po->ifindex = dev ? dev->ifindex : 0; + packet_cached_dev_assign(po, dev); + } } if (dev_curr) dev_put(dev_curr); @@ -2949,7 +2982,7 @@ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto) if (proto == 0 || !need_rehook) goto out_unlock; - if (!dev || (dev->flags & IFF_UP)) { + if (!unlisted && (!dev || (dev->flags & IFF_UP))) { register_prot_hook(sk); } else { sk->sk_err = ENETDOWN; @@ -2958,9 +2991,10 @@ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto) } out_unlock: + rcu_read_unlock(); spin_unlock(&po->bind_lock); release_sock(sk); - return 0; + return ret; } /* @@ -2972,8 +3006,6 @@ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, { struct sock *sk = sock->sk; char name[15]; - struct net_device *dev; - int err = -ENODEV; /* * Check legality @@ -2983,19 +3015,13 @@ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, return -EINVAL; strlcpy(name, uaddr->sa_data, sizeof(name)); - dev = dev_get_by_name(sock_net(sk), name); - if (dev) - err = packet_do_bind(sk, dev, pkt_sk(sk)->num); - return err; + return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); } static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; struct sock *sk = sock->sk; - struct net_device *dev = NULL; - int err; - /* * Check legality @@ -3006,16 +3032,8 @@ static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len if (sll->sll_family != AF_PACKET) return -EINVAL; - if (sll->sll_ifindex) { - err = -ENODEV; - dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); - if (dev == NULL) - goto out; - } - err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); - -out: - return err; + return packet_do_bind(sk, NULL, sll->sll_ifindex, + sll->sll_protocol ? : pkt_sk(sk)->num); } static struct proto packet_proto = {