net: Correct comparisons and calculations using skb->tail and skb-transport_header

This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h
index aab73757bc4da4c4b5fce8390ec1234a86ea55c0..3bd22795c3e259e1f1f55176c808c6fdcc994600 100644 (file)
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -134,12 +134,14 @@ static inline int INET_ECN_set_ce(struct sk_buff *skb)
 {
        switch (skb->protocol) {
        case cpu_to_be16(ETH_P_IP):
-               if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
+               if (skb_network_header(skb) + sizeof(struct iphdr) <=
+                   skb_tail_pointer(skb))
                        return IP_ECN_set_ce(ip_hdr(skb));
                break;
 
        case cpu_to_be16(ETH_P_IPV6):
-               if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
+               if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
+                   skb_tail_pointer(skb))
                        return IP6_ECN_set_ce(ipv6_hdr(skb));
                break;
        }

diff --git a/net/core/dev.c b/net/core/dev.c
index b2e9057be3bfe5615770ec605c0e20b51558065d..d4d874a25e45c1342aca9ceae8517f12b1297339 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1724,7 +1724,7 @@ static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
                        skb_reset_mac_header(skb2);
 
                        if (skb_network_header(skb2) < skb2->data ||
-                           skb2->network_header > skb2->tail) {
+                           skb_network_header(skb2) > skb_tail_pointer(skb2)) {
                                net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
                                                     ntohs(skb2->protocol),
                                                     dev->name);
@@ -3892,7 +3892,7 @@ static void skb_gro_reset_offset(struct sk_buff *skb)
        NAPI_GRO_CB(skb)->frag0 = NULL;
        NAPI_GRO_CB(skb)->frag0_len = 0;
 
-       if (skb->mac_header == skb->tail &&
+       if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
            pinfo->nr_frags &&
            !PageHighMem(skb_frag_page(frag0))) {
                NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);