diff options
| -rw-r--r-- | net/packet/af_packet.c | 71 |
1 files changed, 31 insertions, 40 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 020562164b56..e0516a22be2e 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -415,7 +415,7 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, { struct sock *sk = sock->sk; struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; - struct sk_buff *skb; + struct sk_buff *skb = NULL; struct net_device *dev; __be16 proto = 0; int err; @@ -437,6 +437,7 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, */ saddr->spkt_device[13] = 0; +retry: rcu_read_lock(); dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); err = -ENODEV; @@ -456,58 +457,48 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, if (len > dev->mtu + dev->hard_header_len) goto out_unlock; - err = -ENOBUFS; - skb = sock_wmalloc(sk, len + LL_RESERVED_SPACE(dev), 0, GFP_KERNEL); - - /* - * If the write buffer is full, then tough. At this level the user - * gets to deal with the problem - do your own algorithmic backoffs. - * That's far more flexible. - */ - - if (skb == NULL) - goto out_unlock; - - /* - * Fill it in - */ - - /* FIXME: Save some space for broken drivers that write a - * hard header at transmission time by themselves. PPP is the - * notable one here. This should really be fixed at the driver level. - */ - skb_reserve(skb, LL_RESERVED_SPACE(dev)); - skb_reset_network_header(skb); - - /* Try to align data part correctly */ - if (dev->header_ops) { - skb->data -= dev->hard_header_len; - skb->tail -= dev->hard_header_len; - if (len < dev->hard_header_len) - skb_reset_network_header(skb); + if (!skb) { + size_t reserved = LL_RESERVED_SPACE(dev); + unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; + + rcu_read_unlock(); + skb = sock_wmalloc(sk, len + reserved, 0, GFP_KERNEL); + if (skb == NULL) + return -ENOBUFS; + /* FIXME: Save some space for broken drivers that write a hard + * header at transmission time by themselves. PPP is the notable + * one here. This should really be fixed at the driver level. + */ + skb_reserve(skb, reserved); + skb_reset_network_header(skb); + + /* Try to align data part correctly */ + if (hhlen) { + skb->data -= hhlen; + skb->tail -= hhlen; + if (len < hhlen) + skb_reset_network_header(skb); + } + err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); + if (err) + goto out_free; + goto retry; } - /* Returns -EFAULT on error */ - err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); + skb->protocol = proto; skb->dev = dev; skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; - if (err) - goto out_free; - - /* - * Now send it - */ dev_queue_xmit(skb); rcu_read_unlock(); return len; -out_free: - kfree_skb(skb); out_unlock: rcu_read_unlock(); +out_free: + kfree_skb(skb); return err; } |