diff options
author | Julian Anastasov <ja@ssi.bg> | 2019-05-05 15:14:40 +0300 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-05-31 17:48:16 +0200 |
commit | 508f744c0de38f517a94cc2d0bf8e118271b9645 (patch) | |
tree | 1ccd8e5f5c74ae679335bdcd9627fc6dc929da9a | |
parent | 2aa3c9f48bc28ca0effd9877e010ad54c8a630e5 (diff) |
ipvs: strip udp tunnel headers from icmp errors
Recognize UDP tunnels in received ICMP errors and
properly strip the tunnel headers. GUE is what we
have for now.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r-- | net/netfilter/ipvs/ip_vs_core.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 4447ee512b88..d1d7b2483fd7 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -39,6 +39,7 @@ #include <net/tcp.h> #include <net/udp.h> #include <net/icmp.h> /* for icmp_send */ +#include <net/gue.h> #include <net/route.h> #include <net/ip6_checksum.h> #include <net/netns/generic.h> /* net_generic() */ @@ -1579,6 +1580,41 @@ ip_vs_try_to_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, return 1; } +/* Check the UDP tunnel and return its header length */ +static int ipvs_udp_decap(struct netns_ipvs *ipvs, struct sk_buff *skb, + unsigned int offset, __u16 af, + const union nf_inet_addr *daddr, __u8 *proto) +{ + struct udphdr _udph, *udph; + struct ip_vs_dest *dest; + + udph = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (!udph) + goto unk; + offset += sizeof(struct udphdr); + dest = ip_vs_find_tunnel(ipvs, af, daddr, udph->dest); + if (!dest) + goto unk; + if (dest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GUE) { + struct guehdr _gueh, *gueh; + + gueh = skb_header_pointer(skb, offset, sizeof(_gueh), &_gueh); + if (!gueh) + goto unk; + if (gueh->control != 0 || gueh->version != 0) + goto unk; + /* Later we can support also IPPROTO_IPV6 */ + if (gueh->proto_ctype != IPPROTO_IPIP) + goto unk; + *proto = gueh->proto_ctype; + return sizeof(struct udphdr) + sizeof(struct guehdr) + + (gueh->hlen << 2); + } + +unk: + return 0; +} + /* * Handle ICMP messages in the outside-to-inside direction (incoming). * Find any that might be relevant, check against existing connections, @@ -1658,6 +1694,30 @@ ip_vs_in_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb, int *related, if (cih == NULL) return NF_ACCEPT; /* The packet looks wrong, ignore */ ipip = true; + } else if (cih->protocol == IPPROTO_UDP && /* Can be UDP encap */ + /* Error for our tunnel must arrive at LOCAL_IN */ + (skb_rtable(skb)->rt_flags & RTCF_LOCAL)) { + __u8 iproto; + int ulen; + + /* Non-first fragment has no UDP header */ + if (unlikely(cih->frag_off & htons(IP_OFFSET))) + return NF_ACCEPT; + offset2 = offset + cih->ihl * 4; + ulen = ipvs_udp_decap(ipvs, skb, offset2, AF_INET, raddr, + &iproto); + if (ulen > 0) { + /* Skip IP and UDP tunnel headers */ + offset = offset2 + ulen; + /* Now we should be at the original IP header */ + cih = skb_header_pointer(skb, offset, sizeof(_ciph), + &_ciph); + if (cih && cih->version == 4 && cih->ihl >= 5 && + iproto == IPPROTO_IPIP) + ipip = true; + else + return NF_ACCEPT; + } } pd = ip_vs_proto_data_get(ipvs, cih->protocol); |