From 2a3b791e6e1169f374224d164738e9f7be703d77 Mon Sep 17 00:00:00 2001 From: Julius Volz Date: Tue, 2 Sep 2008 15:55:47 +0200 Subject: [PATCH] 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: Julius Volz Signed-off-by: Simon Horman --- net/ipv4/ipvs/ip_vs_core.c | 365 +++++++++++++++++++++++++++++++++---- 1 file changed, 329 insertions(+), 36 deletions(-) diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c index 8bfd7c2f0ebe..035a511e12f7 100644 --- a/net/ipv4/ipvs/ip_vs_core.c +++ b/net/ipv4/ipvs/ip_vs_core.c @@ -39,6 +39,11 @@ #include #include +#ifdef CONFIG_IP_VS_IPV6 +#include +#include +#endif + #include @@ -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, -- 2.30.2