diff options
| -rw-r--r-- | net/packet/af_packet.c | 60 |
1 files changed, 37 insertions, 23 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index b7d6d7ff8cbe..853811a5b030 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -294,6 +294,7 @@ struct packet_sock { unsigned int tp_reserve; unsigned int tp_loss:1; unsigned int tp_tstamp; + struct net_device __rcu *cached_dev; struct packet_type prot_hook ____cacheline_aligned_in_smp; }; @@ -349,11 +350,15 @@ static void __fanout_link(struct sock *sk, struct packet_sock *po); static void register_prot_hook(struct sock *sk) { struct packet_sock *po = pkt_sk(sk); + if (!po->running) { - if (po->fanout) + if (po->fanout) { __fanout_link(sk, po); - else + } else { dev_add_pack(&po->prot_hook); + rcu_assign_pointer(po->cached_dev, po->prot_hook.dev); + } + sock_hold(sk); po->running = 1; } @@ -371,10 +376,13 @@ static void __unregister_prot_hook(struct sock *sk, bool sync) struct packet_sock *po = pkt_sk(sk); po->running = 0; - if (po->fanout) + if (po->fanout) { __fanout_unlink(sk, po); - else + } else { __dev_remove_pack(&po->prot_hook); + RCU_INIT_POINTER(po->cached_dev, NULL); + } + __sock_put(sk); if (sync) { @@ -2044,12 +2052,24 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, return tp_len; } +static struct net_device *packet_cached_dev_get(struct packet_sock *po) +{ + struct net_device *dev; + + rcu_read_lock(); + dev = rcu_dereference(po->cached_dev); + if (dev) + dev_hold(dev); + rcu_read_unlock(); + + return dev; +} + static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) { struct sk_buff *skb; struct net_device *dev; __be16 proto; - bool need_rls_dev = false; int err, reserve = 0; void *ph; struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; @@ -2063,7 +2083,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) err = -EBUSY; if (saddr == NULL) { - dev = po->prot_hook.dev; + dev = packet_cached_dev_get(po); proto = po->num; addr = NULL; } else { @@ -2077,19 +2097,17 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) proto = saddr->sll_protocol; addr = saddr->sll_addr; dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); - need_rls_dev = true; } err = -ENXIO; if (unlikely(dev == NULL)) goto out; - - reserve = dev->hard_header_len; - err = -ENETDOWN; if (unlikely(!(dev->flags & IFF_UP))) goto out_put; + reserve = dev->hard_header_len; + size_max = po->tx_ring.frame_size - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); @@ -2166,8 +2184,7 @@ out_status: __packet_set_status(po, ph, status); kfree_skb(skb); out_put: - if (need_rls_dev) - dev_put(dev); + dev_put(dev); out: mutex_unlock(&po->pg_vec_lock); return err; @@ -2205,7 +2222,6 @@ static int packet_snd(struct socket *sock, struct sk_buff *skb; struct net_device *dev; __be16 proto; - bool need_rls_dev = false; unsigned char *addr; int err, reserve = 0; struct virtio_net_hdr vnet_hdr = { 0 }; @@ -2221,7 +2237,7 @@ static int packet_snd(struct socket *sock, */ if (saddr == NULL) { - dev = po->prot_hook.dev; + dev = packet_cached_dev_get(po); proto = po->num; addr = NULL; } else { @@ -2233,19 +2249,17 @@ static int packet_snd(struct socket *sock, proto = saddr->sll_protocol; addr = saddr->sll_addr; dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); - need_rls_dev = true; } err = -ENXIO; - if (dev == NULL) + if (unlikely(dev == NULL)) goto out_unlock; - if (sock->type == SOCK_RAW) - reserve = dev->hard_header_len; - err = -ENETDOWN; - if (!(dev->flags & IFF_UP)) + if (unlikely(!(dev->flags & IFF_UP))) goto out_unlock; + if (sock->type == SOCK_RAW) + reserve = dev->hard_header_len; if (po->has_vnet_hdr) { vnet_hdr_len = sizeof(vnet_hdr); @@ -2378,15 +2392,14 @@ static int packet_snd(struct socket *sock, if (err > 0 && (err = net_xmit_errno(err)) != 0) goto out_unlock; - if (need_rls_dev) - dev_put(dev); + dev_put(dev); return len; out_free: kfree_skb(skb); out_unlock: - if (dev && need_rls_dev) + if (dev) dev_put(dev); out: return err; @@ -2603,6 +2616,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol, po = pkt_sk(sk); sk->sk_family = PF_PACKET; po->num = proto; + RCU_INIT_POINTER(po->cached_dev, NULL); sk->sk_destruct = packet_sock_destruct; sk_refcnt_debug_inc(sk); |