diff options
Diffstat (limited to 'net/ipv6/icmp.c')
| -rw-r--r-- | net/ipv6/icmp.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 867aebc34248..fd11f5856ce8 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -564,16 +564,22 @@ void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) * Either an IPv4 header for SIT encap * an IPv4 header + GRE header for GRE encap */ -int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type) +int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type, + unsigned int data_len) { struct in6_addr temp_saddr; struct rt6_info *rt; struct sk_buff *skb2; + u32 info = 0; if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8)) return 1; - skb2 = skb_clone(skb, GFP_ATOMIC); + /* RFC 4884 (partial) support for ICMP extensions */ + if (data_len < 128 || (data_len & 7) || skb->len < data_len) + data_len = 0; + + skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC); if (!skb2) return 1; @@ -588,12 +594,26 @@ int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type) skb2->dev = rt->dst.dev; ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr); + + if (data_len) { + /* RFC 4884 (partial) support : + * insert 0 padding at the end, before the extensions + */ + __skb_push(skb2, nhs); + skb_reset_network_header(skb2); + memmove(skb2->data, skb2->data + nhs, data_len - nhs); + memset(skb2->data + data_len - nhs, 0, nhs); + /* RFC 4884 4.5 : Length is measured in 64-bit words, + * and stored in reserved[0] + */ + info = (data_len/8) << 24; + } if (type == ICMP_TIME_EXCEEDED) icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, - 0, &temp_saddr); + info, &temp_saddr); else icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, - 0, &temp_saddr); + info, &temp_saddr); if (rt) ip6_rt_put(rt); |