Commit 2a3b791e authored by Julius Volz's avatar Julius Volz Committed by Simon Horman

IPVS: Add/adjust Netfilter hook functions and helpers for v6

Add Netfilter hook functions or modify existing ones, if possible, to
process IPv6 packets. Some support functions are also added/modified for
this. ip_vs_nat_icmp_v6() was already added in the patch that added the v6
xmit functions, as it is called from one of them.
Signed-off-by: default avatarJulius Volz <juliusv@google.com>
Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
parent cd17f9ed
......@@ -39,6 +39,11 @@
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#ifdef CONFIG_IP_VS_IPV6
#include <net/ipv6.h>
#include <linux/netfilter_ipv6.h>
#endif
#include <net/ip_vs.h>
......@@ -60,6 +65,7 @@ EXPORT_SYMBOL(ip_vs_get_debug_level);
/* ID used in ICMP lookups */
#define icmp_id(icmph) (((icmph)->un).echo.id)
#define icmpv6_id(icmph) (icmph->icmp6_dataun.u_echo.identifier)
const char *ip_vs_proto_name(unsigned proto)
{
......@@ -74,6 +80,10 @@ const char *ip_vs_proto_name(unsigned proto)
return "TCP";
case IPPROTO_ICMP:
return "ICMP";
#ifdef CONFIG_IP_VS_IPV6
case IPPROTO_ICMPV6:
return "ICMPv6";
#endif
default:
sprintf(buf, "IP_%d", proto);
return buf;
......@@ -425,7 +435,8 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
{
__be16 _ports[2], *pptr;
struct ip_vs_iphdr iph;
ip_vs_fill_iphdr(AF_INET, skb_network_header(skb), &iph);
int unicast;
ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
if (pptr == NULL) {
......@@ -433,11 +444,17 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
return NF_DROP;
}
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
else
#endif
unicast = (inet_addr_type(&init_net, iph.daddr.ip) == RTN_UNICAST);
/* if it is fwmark-based service, the cache_bypass sysctl is up
and the destination is RTN_UNICAST (and not local), then create
and the destination is a non-local unicast, then create
a cache_bypass connection entry */
if (sysctl_ip_vs_cache_bypass && svc->fwmark
&& (inet_addr_type(&init_net, iph.daddr.ip) == RTN_UNICAST)) {
if (sysctl_ip_vs_cache_bypass && svc->fwmark && unicast) {
int ret, cs;
struct ip_vs_conn *cp;
......@@ -445,7 +462,7 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
/* create a new connection entry */
IP_VS_DBG(6, "ip_vs_leave: create a cache_bypass entry\n");
cp = ip_vs_conn_new(AF_INET, iph.protocol,
cp = ip_vs_conn_new(svc->af, iph.protocol,
&iph.saddr, pptr[0],
&iph.daddr, pptr[1],
0, 0,
......@@ -489,7 +506,14 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
* created, the TCP RST packet cannot be sent, instead that
* ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
*/
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0,
skb->dev);
else
#endif
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
return NF_DROP;
}
......@@ -528,6 +552,14 @@ static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user)
return err;
}
#ifdef CONFIG_IP_VS_IPV6
static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user)
{
/* TODO IPv6: Find out what to do here for IPv6 */
return 0;
}
#endif
/*
* Packet has been made sufficiently writable in caller
* - inout: 1=in->out, 0=out->in
......@@ -727,11 +759,117 @@ static int ip_vs_out_icmp(struct sk_buff *skb, int *related)
return verdict;
}
static inline int is_tcp_reset(const struct sk_buff *skb)
#ifdef CONFIG_IP_VS_IPV6
static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related)
{
struct ipv6hdr *iph;
struct icmp6hdr _icmph, *ic;
struct ipv6hdr _ciph, *cih; /* The ip header contained
within the ICMP */
struct ip_vs_iphdr ciph;
struct ip_vs_conn *cp;
struct ip_vs_protocol *pp;
unsigned int offset, verdict;
*related = 1;
/* reassemble IP fragments */
if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
if (ip_vs_gather_frags_v6(skb, IP_DEFRAG_VS_OUT))
return NF_STOLEN;
}
iph = ipv6_hdr(skb);
offset = sizeof(struct ipv6hdr);
ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
if (ic == NULL)
return NF_DROP;
IP_VS_DBG(12, "Outgoing ICMPv6 (%d,%d) " NIP6_FMT "->" NIP6_FMT "\n",
ic->icmp6_type, ntohs(icmpv6_id(ic)),
NIP6(iph->saddr), NIP6(iph->daddr));
/*
* Work through seeing if this is for us.
* These checks are supposed to be in an order that means easy
* things are checked first to speed up processing.... however
* this means that some packets will manage to get a long way
* down this stack and then be rejected, but that's life.
*/
if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
(ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
(ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
*related = 0;
return NF_ACCEPT;
}
/* Now find the contained IP header */
offset += sizeof(_icmph);
cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
if (cih == NULL)
return NF_ACCEPT; /* The packet looks wrong, ignore */
pp = ip_vs_proto_get(cih->nexthdr);
if (!pp)
return NF_ACCEPT;
/* Is the embedded protocol header present? */
/* TODO: we don't support fragmentation at the moment anyways */
if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
return NF_ACCEPT;
IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMPv6 for");
offset += sizeof(struct ipv6hdr);
ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
/* The embedded headers contain source and dest in reverse order */
cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1);
if (!cp)
return NF_ACCEPT;
verdict = NF_DROP;
if (IP_VS_FWD_METHOD(cp) != 0) {
IP_VS_ERR("shouldn't reach here, because the box is on the "
"half connection in the tun/dr module.\n");
}
/* Ensure the checksum is correct */
if (!skb_csum_unnecessary(skb)
&& ip_vs_checksum_complete(skb, sizeof(struct ipv6hdr))) {
/* Failed checksum! */
IP_VS_DBG(1, "Forward ICMPv6: failed checksum from "
NIP6_FMT "!\n",
NIP6(iph->saddr));
goto out;
}
if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr)
offset += 2 * sizeof(__u16);
if (!skb_make_writable(skb, offset))
goto out;
ip_vs_nat_icmp_v6(skb, pp, cp, 1);
/* do the statistics and put it back */
ip_vs_out_stats(cp, skb);
skb->ipvs_property = 1;
verdict = NF_ACCEPT;
out:
__ip_vs_conn_put(cp);
return verdict;
}
#endif
static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
{
struct tcphdr _tcph, *th;
th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
if (th == NULL)
return 0;
return th->rst;
......@@ -750,38 +888,64 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb,
struct ip_vs_iphdr iph;
struct ip_vs_protocol *pp;
struct ip_vs_conn *cp;
int af;
EnterFunction(11);
af = (skb->protocol == __constant_htons(ETH_P_IP)) ? AF_INET : AF_INET6;
if (skb->ipvs_property)
return NF_ACCEPT;
ip_vs_fill_iphdr(AF_INET, skb_network_header(skb), &iph);
if (unlikely(iph.protocol == IPPROTO_ICMP)) {
int related, verdict = ip_vs_out_icmp(skb, &related);
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) {
if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
int related, verdict = ip_vs_out_icmp_v6(skb, &related);
if (related)
return verdict;
ip_vs_fill_iphdr(AF_INET, skb_network_header(skb), &iph);
}
if (related)
return verdict;
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
}
} else
#endif
if (unlikely(iph.protocol == IPPROTO_ICMP)) {
int related, verdict = ip_vs_out_icmp(skb, &related);
if (related)
return verdict;
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
}
pp = ip_vs_proto_get(iph.protocol);
if (unlikely(!pp))
return NF_ACCEPT;
/* reassemble IP fragments */
if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) &&
!pp->dont_defrag)) {
if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT))
return NF_STOLEN;
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) {
if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
int related, verdict = ip_vs_out_icmp_v6(skb, &related);
ip_vs_fill_iphdr(AF_INET, skb_network_header(skb), &iph);
}
if (related)
return verdict;
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
}
} else
#endif
if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) &&
!pp->dont_defrag)) {
if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT))
return NF_STOLEN;
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
}
/*
* Check if the packet belongs to an existing entry
*/
cp = pp->conn_out_get(AF_INET, skb, pp, &iph, iph.len, 0);
cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0);
if (unlikely(!cp)) {
if (sysctl_ip_vs_nat_icmp_send &&
......@@ -794,16 +958,26 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb,
if (pptr == NULL)
return NF_ACCEPT; /* Not for me */
if (ip_vs_lookup_real_service(iph.protocol,
iph.saddr.ip, pptr[0])) {
iph.saddr.ip,
pptr[0])) {
/*
* Notify the real server: there is no
* existing entry if it is not RST
* packet or not TCP packet.
*/
if (iph.protocol != IPPROTO_TCP
|| !is_tcp_reset(skb)) {
icmp_send(skb,ICMP_DEST_UNREACH,
ICMP_PORT_UNREACH, 0);
|| !is_tcp_reset(skb, iph.len)) {
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6)
icmpv6_send(skb,
ICMPV6_DEST_UNREACH,
ICMPV6_PORT_UNREACH,
0, skb->dev);
else
#endif
icmp_send(skb,
ICMP_DEST_UNREACH,
ICMP_PORT_UNREACH, 0);
return NF_DROP;
}
}
......@@ -821,8 +995,16 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb,
/* mangle the packet */
if (pp->snat_handler && !pp->snat_handler(skb, pp, cp))
goto drop;
ip_hdr(skb)->saddr = cp->vaddr.ip;
ip_send_check(ip_hdr(skb));
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6)
ipv6_hdr(skb)->saddr = cp->vaddr.in6;
else
#endif
{
ip_hdr(skb)->saddr = cp->vaddr.ip;
ip_send_check(ip_hdr(skb));
}
/* For policy routing, packets originating from this
* machine itself may be routed differently to packets
......@@ -830,8 +1012,14 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb,
* if it came from this machine itself. So re-compute
* the routing information.
*/
if (ip_route_me_harder(skb, RTN_LOCAL) != 0)
goto drop;
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) {
if (ip6_route_me_harder(skb) != 0)
goto drop;
} else
#endif
if (ip_route_me_harder(skb, RTN_LOCAL) != 0)
goto drop;
IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT");
......@@ -949,6 +1137,94 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
return verdict;
}
#ifdef CONFIG_IP_VS_IPV6
static int
ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
{
struct ipv6hdr *iph;
struct icmp6hdr _icmph, *ic;
struct ipv6hdr _ciph, *cih; /* The ip header contained
within the ICMP */
struct ip_vs_iphdr ciph;
struct ip_vs_conn *cp;
struct ip_vs_protocol *pp;
unsigned int offset, verdict;
*related = 1;
/* reassemble IP fragments */
if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
if (ip_vs_gather_frags_v6(skb, hooknum == NF_INET_LOCAL_IN ?
IP_DEFRAG_VS_IN :
IP_DEFRAG_VS_FWD))
return NF_STOLEN;
}
iph = ipv6_hdr(skb);
offset = sizeof(struct ipv6hdr);
ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
if (ic == NULL)
return NF_DROP;
IP_VS_DBG(12, "Incoming ICMPv6 (%d,%d) " NIP6_FMT "->" NIP6_FMT "\n",
ic->icmp6_type, ntohs(icmpv6_id(ic)),
NIP6(iph->saddr), NIP6(iph->daddr));
/*
* Work through seeing if this is for us.
* These checks are supposed to be in an order that means easy
* things are checked first to speed up processing.... however
* this means that some packets will manage to get a long way
* down this stack and then be rejected, but that's life.
*/
if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
(ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
(ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
*related = 0;
return NF_ACCEPT;
}
/* Now find the contained IP header */
offset += sizeof(_icmph);
cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
if (cih == NULL)
return NF_ACCEPT; /* The packet looks wrong, ignore */
pp = ip_vs_proto_get(cih->nexthdr);
if (!pp)
return NF_ACCEPT;
/* Is the embedded protocol header present? */
/* TODO: we don't support fragmentation at the moment anyways */
if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
return NF_ACCEPT;
IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMPv6 for");
offset += sizeof(struct ipv6hdr);
ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
/* The embedded headers contain source and dest in reverse order */
cp = pp->conn_in_get(AF_INET6, skb, pp, &ciph, offset, 1);
if (!cp)
return NF_ACCEPT;
verdict = NF_DROP;
/* do the statistics and put it back */
ip_vs_in_stats(cp, skb);
if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr)
offset += 2 * sizeof(__u16);
verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset);
/* do not touch skb anymore */
__ip_vs_conn_put(cp);
return verdict;
}
#endif
/*
* Check if it's for virtual services, look it up,
* and send it on its way...
......@@ -961,9 +1237,11 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb,
struct ip_vs_iphdr iph;
struct ip_vs_protocol *pp;
struct ip_vs_conn *cp;
int ret, restart;
int ret, restart, af;
af = (skb->protocol == __constant_htons(ETH_P_IP)) ? AF_INET : AF_INET6;
ip_vs_fill_iphdr(AF_INET, skb_network_header(skb), &iph);
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
/*
* Big tappo: only PACKET_HOST (neither loopback nor mcasts)
......@@ -974,7 +1252,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb,
IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s ignored\n",
skb->pkt_type,
iph.protocol,
IP_VS_DBG_ADDR(AF_INET, &iph.daddr));
IP_VS_DBG_ADDR(af, &iph.daddr));
return NF_ACCEPT;
}
......@@ -983,7 +1261,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb,
if (related)
return verdict;
ip_vs_fill_iphdr(AF_INET, skb_network_header(skb), &iph);
ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
}
/* Protocol supported? */
......@@ -994,12 +1272,12 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb,
/*
* Check if the packet belongs to an existing connection entry
*/
cp = pp->conn_in_get(AF_INET, skb, pp, &iph, iph.len, 0);
cp = pp->conn_in_get(af, skb, pp, &iph, iph.len, 0);
if (unlikely(!cp)) {
int v;
if (!pp->conn_schedule(AF_INET, skb, pp, &v, &cp))
if (!pp->conn_schedule(af, skb, pp, &v, &cp))
return v;
}
......@@ -1082,6 +1360,21 @@ ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb,
return ip_vs_in_icmp(skb, &r, hooknum);
}
#ifdef CONFIG_IP_VS_IPV6
static unsigned int
ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
int r;
if (ipv6_hdr(skb)->nexthdr != IPPROTO_ICMPV6)
return NF_ACCEPT;
return ip_vs_in_icmp_v6(skb, &r, hooknum);
}
#endif
static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
/* After packet filtering, forward packet through VS/DR, VS/TUN,
......
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