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Diffstat (limited to 'net/packet/af_packet.c')
-rw-r--r--net/packet/af_packet.c91
1 files changed, 51 insertions, 40 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2e8286b47c2..ac27c86ef6d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -244,11 +244,15 @@ 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;
}
@@ -266,10 +270,13 @@ 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) {
@@ -2052,12 +2059,24 @@ 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;
@@ -2070,7 +2089,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
mutex_lock(&po->pg_vec_lock);
if (saddr == NULL) {
- dev = po->prot_hook.dev;
+ dev = packet_cached_dev_get(po);
proto = po->num;
addr = NULL;
} else {
@@ -2084,19 +2103,17 @@ 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));
@@ -2173,8 +2190,7 @@ 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;
@@ -2212,7 +2228,6 @@ 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 };
@@ -2228,7 +2243,7 @@ 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 {
@@ -2240,19 +2255,17 @@ 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);
@@ -2386,15 +2399,14 @@ 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;
@@ -2614,6 +2626,7 @@ 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);
@@ -2660,7 +2673,6 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
struct sock *sk = sock->sk;
struct sk_buff *skb;
int copied, err;
- struct sockaddr_ll *sll;
int vnet_hdr_len = 0;
err = -EINVAL;
@@ -2744,22 +2756,10 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
goto out_free;
}
- /*
- * If the address length field is there to be filled in, we fill
- * it in now.
+ /* You lose any data beyond the buffer you gave. If it worries
+ * a user program they can ask the device for its MTU
+ * anyway.
*/
-
- sll = &PACKET_SKB_CB(skb)->sa.ll;
- if (sock->type == SOCK_PACKET)
- msg->msg_namelen = sizeof(struct sockaddr_pkt);
- else
- msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
-
- /*
- * You lose any data beyond the buffer you gave. If it worries a
- * user program they can ask the device for its MTU anyway.
- */
-
copied = skb->len;
if (copied > len) {
copied = len;
@@ -2772,9 +2772,20 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
sock_recv_ts_and_drops(msg, sk, skb);
- if (msg->msg_name)
+ if (msg->msg_name) {
+ /* If the address length field is there to be filled
+ * in, we fill it in now.
+ */
+ if (sock->type == SOCK_PACKET) {
+ msg->msg_namelen = sizeof(struct sockaddr_pkt);
+ } else {
+ struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
+ msg->msg_namelen = sll->sll_halen +
+ offsetof(struct sockaddr_ll, sll_addr);
+ }
memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
msg->msg_namelen);
+ }
if (pkt_sk(sk)->auxdata) {
struct tpacket_auxdata aux;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-18 18:04:20 +0000