udp: remove headers from UDP packets before queueing

Remove UDP transport headers before queueing packets for reception.
This change simplifies a follow-up patch to add MSG_PEEK support.

Signed-off-by: Sam Kumar <samanthakumar@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sock.h b/include/net/sock.h
index 09aec75eb1844587e77b045b013e88da1a6d78e5..b75998952482c581e7b980c9d742c8be63a95497 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1864,6 +1864,7 @@ void sk_reset_timer(struct sock *sk, struct timer_list *timer,
 
 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
 
+int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 
 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);

diff --git a/include/net/udp.h b/include/net/udp.h
index d870ec1611c4e011256d6b301c8c6655f719e5cf..a0b0da97164c03a9ad6c796247181e242254a682 100644 (file)
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -158,6 +158,15 @@ static inline __sum16 udp_v4_check(int len, __be32 saddr,
 void udp_set_csum(bool nocheck, struct sk_buff *skb,
                  __be32 saddr, __be32 daddr, int len);
 
+static inline void udp_csum_pull_header(struct sk_buff *skb)
+{
+       if (skb->ip_summed == CHECKSUM_NONE)
+               skb->csum = csum_partial(udp_hdr(skb), sizeof(struct udphdr),
+                                        skb->csum);
+       skb_pull_rcsum(skb, sizeof(struct udphdr));
+       UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr);
+}
+
 struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
                                 struct udphdr *uh);
 int udp_gro_complete(struct sk_buff *skb, int nhoff);

diff --git a/net/core/sock.c b/net/core/sock.c
index 2f517ea56786127ce2e5c12684a35d9833f68d9b..e12197b359fdb016ffff853c55e7b999cb9d21b2 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -402,9 +402,8 @@ static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
 }
 
 
-int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
-       int err;
        unsigned long flags;
        struct sk_buff_head *list = &sk->sk_receive_queue;
 
@@ -414,10 +413,6 @@ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
                return -ENOMEM;
        }
 
-       err = sk_filter(sk, skb);
-       if (err)
-               return err;
-
        if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
                atomic_inc(&sk->sk_drops);
                return -ENOBUFS;
@@ -440,6 +435,18 @@ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
                sk->sk_data_ready(sk);
        return 0;
 }
+EXPORT_SYMBOL(__sock_queue_rcv_skb);
+
+int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+       int err;
+
+       err = sk_filter(sk, skb);
+       if (err)
+               return err;
+
+       return __sock_queue_rcv_skb(sk, skb);
+}
 EXPORT_SYMBOL(sock_queue_rcv_skb);
 
 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 355bdb221057c75b9a6fda1a490f0885401505f9..cf747e86ce526846b9aa1132f93a699576c883af 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1309,7 +1309,7 @@ try_again:
        if (!skb)
                goto out;
 
-       ulen = skb->len - sizeof(struct udphdr);
+       ulen = skb->len;
        copied = len;
        if (copied > ulen)
                copied = ulen;
@@ -1329,11 +1329,9 @@ try_again:
        }
 
        if (checksum_valid || skb_csum_unnecessary(skb))
-               err = skb_copy_datagram_msg(skb, sizeof(struct udphdr),
-                                           msg, copied);
+               err = skb_copy_datagram_msg(skb, 0, msg, copied);
        else {
-               err = skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr),
-                                                    msg);
+               err = skb_copy_and_csum_datagram_msg(skb, 0, msg);
 
                if (err == -EINVAL)
                        goto csum_copy_err;
@@ -1500,7 +1498,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
                sk_incoming_cpu_update(sk);
        }
 
-       rc = sock_queue_rcv_skb(sk, skb);
+       rc = __sock_queue_rcv_skb(sk, skb);
        if (rc < 0) {
                int is_udplite = IS_UDPLITE(sk);
 
@@ -1616,10 +1614,14 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
                }
        }
 
-       if (rcu_access_pointer(sk->sk_filter) &&
-           udp_lib_checksum_complete(skb))
-               goto csum_error;
+       if (rcu_access_pointer(sk->sk_filter)) {
+               if (udp_lib_checksum_complete(skb))
+                       goto csum_error;
+               if (sk_filter(sk, skb))
+                       goto drop;
+       }
 
+       udp_csum_pull_header(skb);
        if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
                UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
                                 is_udplite);

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 78a7dfd127072e9205f8cc65fda51ea982b920a1..84c8d7b668203298b96d28b16307c23d501ae547 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -376,7 +376,7 @@ try_again:
        if (!skb)
                goto out;
 
-       ulen = skb->len - sizeof(struct udphdr);
+       ulen = skb->len;
        copied = len;
        if (copied > ulen)
                copied = ulen;
@@ -398,10 +398,9 @@ try_again:
        }
 
        if (checksum_valid || skb_csum_unnecessary(skb))
-               err = skb_copy_datagram_msg(skb, sizeof(struct udphdr),
-                                           msg, copied);
+               err = skb_copy_datagram_msg(skb, 0, msg, copied);
        else {
-               err = skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg);
+               err = skb_copy_and_csum_datagram_msg(skb, 0, msg);
                if (err == -EINVAL)
                        goto csum_copy_err;
        }
@@ -554,7 +553,7 @@ static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
                sk_incoming_cpu_update(sk);
        }
 
-       rc = sock_queue_rcv_skb(sk, skb);
+       rc = __sock_queue_rcv_skb(sk, skb);
        if (rc < 0) {
                int is_udplite = IS_UDPLITE(sk);
 
@@ -648,8 +647,11 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
        if (rcu_access_pointer(sk->sk_filter)) {
                if (udp_lib_checksum_complete(skb))
                        goto csum_error;
+               if (sk_filter(sk, skb))
+                       goto drop;
        }
 
+       udp_csum_pull_header(skb);
        if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
                UDP6_INC_STATS_BH(sock_net(sk),
                                  UDP_MIB_RCVBUFERRORS, is_udplite);