diff options
Diffstat (limited to 'net/ipv4/ip_fragment.c')
| -rw-r--r-- | net/ipv4/ip_fragment.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 0e0ab98abc6..763589ad673 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -682,6 +682,42 @@ int ip_defrag(struct sk_buff *skb, u32 user) } EXPORT_SYMBOL(ip_defrag); +struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) +{ + const struct iphdr *iph; + u32 len; + + if (skb->protocol != htons(ETH_P_IP)) + return skb; + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + return skb; + + iph = ip_hdr(skb); + if (iph->ihl < 5 || iph->version != 4) + return skb; + if (!pskb_may_pull(skb, iph->ihl*4)) + return skb; + iph = ip_hdr(skb); + len = ntohs(iph->tot_len); + if (skb->len < len || len < (iph->ihl * 4)) + return skb; + + if (ip_is_fragment(ip_hdr(skb))) { + skb = skb_share_check(skb, GFP_ATOMIC); + if (skb) { + if (pskb_trim_rcsum(skb, len)) + return skb; + memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); + if (ip_defrag(skb, user)) + return NULL; + skb->rxhash = 0; + } + } + return skb; +} +EXPORT_SYMBOL(ip_check_defrag); + #ifdef CONFIG_SYSCTL static int zero; |