net: ipv6: send pkttoobig immediately if orig frag size > mtu

[firefly-linux-kernel-4.4.55.git] / net / ipv6 / udp_offload.c

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 3bb3a891a42416b23ddb278d3fd7c051d25cfcf7..2f65b022627b90481a7738b16c82bf770ed300c8 100644 (file)
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -46,11 +46,12 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
        unsigned int mss;
        unsigned int unfrag_ip6hlen, unfrag_len;
        struct frag_hdr *fptr;
-       u8 *mac_start, *prevhdr;
+       u8 *packet_start, *prevhdr;
        u8 nexthdr;
        u8 frag_hdr_sz = sizeof(struct frag_hdr);
        int offset;
        __wsum csum;
+       int tnl_hlen;
 
        mss = skb_shinfo(skb)->gso_size;
        if (unlikely(skb->len <= mss))
@@ -83,9 +84,11 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
        skb->ip_summed = CHECKSUM_NONE;
 
        /* Check if there is enough headroom to insert fragment header. */
-       if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) &&
-           pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
-               goto out;
+       tnl_hlen = skb_tnl_header_len(skb);
+       if (skb_mac_header(skb) < skb->head + tnl_hlen + frag_hdr_sz) {
+               if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
+                       goto out;
+       }
 
        /* Find the unfragmentable header and shift it left by frag_hdr_sz
         * bytes to insert fragment header.
@@ -93,18 +96,19 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
        unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
        nexthdr = *prevhdr;
        *prevhdr = NEXTHDR_FRAGMENT;
-       unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +
-                    unfrag_ip6hlen;
-       mac_start = skb_mac_header(skb);
-       memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len);
+       unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
+                    unfrag_ip6hlen + tnl_hlen;
+       packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
+       memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
 
+       SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
        skb->mac_header -= frag_hdr_sz;
        skb->network_header -= frag_hdr_sz;
 
        fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
        fptr->nexthdr = nexthdr;
        fptr->reserved = 0;
-       ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(skb));
+       fptr->identification = skb_shinfo(skb)->ip6_frag_id;
 
        /* Fragment the skb. ipv6 header and the remaining fields of the
         * fragment header are updated in ipv6_gso_segment()