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| author | Eric Dumazet <edumazet@google.com> | 2016-06-19 07:52:06 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-06-19 08:11:39 +0300 |
| commit | 20e1954fe238dbe5f8d3a979e593fe352bd703cf (patch) | |
| tree | 22aced0e24480c8f2c62b89934868e64bbc70baa /net/ipv4 | |
| parent | 9b8c6d7bf2e08a7d3eb6660a2bfaf29b8b49c329 (diff) | |
| download | linux-20e1954fe238dbe5f8d3a979e593fe352bd703cf.tar.xz | |
ipv6: RFC 4884 partial support for SIT/GRE tunnels
When receiving an ICMPv4 message containing extensions as
defined in RFC 4884, and translating it to ICMPv6 at SIT
or GRE tunnel, we need some extra manipulation in order
to properly forward the extensions.
This patch only takes care of Time Exceeded messages as they
are the ones that typically carry information from various
routers in a fabric during a traceroute session.
It also avoids complex skb logic if the data_len is not
a multiple of 8.
RFC states :
The "original datagram" field MUST contain at least 128 octets.
If the original datagram did not contain 128 octets, the
"original datagram" field MUST be zero padded to 128 octets.
In practice routers use 128 bytes of original datagram, not more.
Initial translation was added in commit ca15a078bd90
("sit: generate icmpv6 error when receiving icmpv4 error")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Oussama Ghorbel <ghorbel@pivasoftware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_gre.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index ab4cff8e563d..8eec78f53f9e 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -144,6 +144,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info, const struct iphdr *iph; const int type = icmp_hdr(skb)->type; const int code = icmp_hdr(skb)->code; + unsigned int data_len = 0; struct ip_tunnel *t; switch (type) { @@ -169,6 +170,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info, case ICMP_TIME_EXCEEDED: if (code != ICMP_EXC_TTL) return; + data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ break; case ICMP_REDIRECT: @@ -189,7 +191,8 @@ static void ipgre_err(struct sk_buff *skb, u32 info, #if IS_ENABLED(CONFIG_IPV6) if (tpi->proto == htons(ETH_P_IPV6) && - !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, type)) + !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, + type, data_len)) return; #endif |