IPVS: Extend protocol DNAT/SNAT and state handlers
Julius Volz [Tue, 2 Sep 2008 13:55:42 +0000 (15:55 +0200)]
Extend protocol DNAT/SNAT and state handlers to work with IPv6. Also
change/introduce new checksumming helper functions for this.

Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

include/net/ip_vs.h
net/ipv4/ipvs/ip_vs_proto_tcp.c
net/ipv4/ipvs/ip_vs_proto_udp.c

index 68f004f..c173f1a 100644 (file)
@@ -904,6 +904,17 @@ static inline __wsum ip_vs_check_diff4(__be32 old, __be32 new, __wsum oldsum)
        return csum_partial((char *) diff, sizeof(diff), oldsum);
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+static inline __wsum ip_vs_check_diff16(const __be32 *old, const __be32 *new,
+                                       __wsum oldsum)
+{
+       __be32 diff[8] = { ~old[3], ~old[2], ~old[1], ~old[0],
+                           new[3],  new[2],  new[1],  new[0] };
+
+       return csum_partial((char *) diff, sizeof(diff), oldsum);
+}
+#endif
+
 static inline __wsum ip_vs_check_diff2(__be16 old, __be16 new, __wsum oldsum)
 {
        __be16 diff[2] = { ~old, new };
index 9211afa..3daae43 100644 (file)
@@ -114,11 +114,21 @@ tcp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
 
 
 static inline void
-tcp_fast_csum_update(struct tcphdr *tcph, __be32 oldip, __be32 newip,
+tcp_fast_csum_update(int af, struct tcphdr *tcph,
+                    const union nf_inet_addr *oldip,
+                    const union nf_inet_addr *newip,
                     __be16 oldport, __be16 newport)
 {
+#ifdef CONFIG_IP_VS_IPV6
+       if (af == AF_INET6)
+               tcph->check =
+                       csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
+                                        ip_vs_check_diff2(oldport, newport,
+                                               ~csum_unfold(tcph->check))));
+       else
+#endif
        tcph->check =
-               csum_fold(ip_vs_check_diff4(oldip, newip,
+               csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
                                 ip_vs_check_diff2(oldport, newport,
                                                ~csum_unfold(tcph->check))));
 }
@@ -129,7 +139,14 @@ tcp_snat_handler(struct sk_buff *skb,
                 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
        struct tcphdr *tcph;
-       const unsigned int tcphoff = ip_hdrlen(skb);
+       unsigned int tcphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+       if (cp->af == AF_INET6)
+               tcphoff = sizeof(struct ipv6hdr);
+       else
+#endif
+               tcphoff = ip_hdrlen(skb);
 
        /* csum_check requires unshared skb */
        if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
@@ -137,7 +154,7 @@ tcp_snat_handler(struct sk_buff *skb,
 
        if (unlikely(cp->app != NULL)) {
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
+               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
                        return 0;
 
                /* Call application helper if needed */
@@ -145,13 +162,13 @@ tcp_snat_handler(struct sk_buff *skb,
                        return 0;
        }
 
-       tcph = (void *)ip_hdr(skb) + tcphoff;
+       tcph = (void *)skb_network_header(skb) + tcphoff;
        tcph->source = cp->vport;
 
        /* Adjust TCP checksums */
        if (!cp->app) {
                /* Only port and addr are changed, do fast csum update */
-               tcp_fast_csum_update(tcph, cp->daddr.ip, cp->vaddr.ip,
+               tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
                                     cp->dport, cp->vport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
                        skb->ip_summed = CHECKSUM_NONE;
@@ -159,9 +176,20 @@ tcp_snat_handler(struct sk_buff *skb,
                /* full checksum calculation */
                tcph->check = 0;
                skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
-               tcph->check = csum_tcpudp_magic(cp->vaddr.ip, cp->caddr.ip,
-                                               skb->len - tcphoff,
-                                               cp->protocol, skb->csum);
+#ifdef CONFIG_IP_VS_IPV6
+               if (cp->af == AF_INET6)
+                       tcph->check = csum_ipv6_magic(&cp->vaddr.in6,
+                                                     &cp->caddr.in6,
+                                                     skb->len - tcphoff,
+                                                     cp->protocol, skb->csum);
+               else
+#endif
+                       tcph->check = csum_tcpudp_magic(cp->vaddr.ip,
+                                                       cp->caddr.ip,
+                                                       skb->len - tcphoff,
+                                                       cp->protocol,
+                                                       skb->csum);
+
                IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
                          pp->name, tcph->check,
                          (char*)&(tcph->check) - (char*)tcph);
@@ -175,7 +203,14 @@ tcp_dnat_handler(struct sk_buff *skb,
                 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
        struct tcphdr *tcph;
-       const unsigned int tcphoff = ip_hdrlen(skb);
+       unsigned int tcphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+       if (cp->af == AF_INET6)
+               tcphoff = sizeof(struct ipv6hdr);
+       else
+#endif
+               tcphoff = ip_hdrlen(skb);
 
        /* csum_check requires unshared skb */
        if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
@@ -183,7 +218,7 @@ tcp_dnat_handler(struct sk_buff *skb,
 
        if (unlikely(cp->app != NULL)) {
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
+               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
                        return 0;
 
                /*
@@ -194,7 +229,7 @@ tcp_dnat_handler(struct sk_buff *skb,
                        return 0;
        }
 
-       tcph = (void *)ip_hdr(skb) + tcphoff;
+       tcph = (void *)skb_network_header(skb) + tcphoff;
        tcph->dest = cp->dport;
 
        /*
@@ -202,7 +237,7 @@ tcp_dnat_handler(struct sk_buff *skb,
         */
        if (!cp->app) {
                /* Only port and addr are changed, do fast csum update */
-               tcp_fast_csum_update(tcph, cp->vaddr.ip, cp->daddr.ip,
+               tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr,
                                     cp->vport, cp->dport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
                        skb->ip_summed = CHECKSUM_NONE;
@@ -210,9 +245,19 @@ tcp_dnat_handler(struct sk_buff *skb,
                /* full checksum calculation */
                tcph->check = 0;
                skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
-               tcph->check = csum_tcpudp_magic(cp->caddr.ip, cp->daddr.ip,
-                                               skb->len - tcphoff,
-                                               cp->protocol, skb->csum);
+#ifdef CONFIG_IP_VS_IPV6
+               if (cp->af == AF_INET6)
+                       tcph->check = csum_ipv6_magic(&cp->caddr.in6,
+                                                     &cp->daddr.in6,
+                                                     skb->len - tcphoff,
+                                                     cp->protocol, skb->csum);
+               else
+#endif
+                       tcph->check = csum_tcpudp_magic(cp->caddr.ip,
+                                                       cp->daddr.ip,
+                                                       skb->len - tcphoff,
+                                                       cp->protocol,
+                                                       skb->csum);
                skb->ip_summed = CHECKSUM_UNNECESSARY;
        }
        return 1;
@@ -487,7 +532,13 @@ tcp_state_transition(struct ip_vs_conn *cp, int direction,
 {
        struct tcphdr _tcph, *th;
 
-       th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
+#ifdef CONFIG_IP_VS_IPV6
+       int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
+#else
+       int ihl = ip_hdrlen(skb);
+#endif
+
+       th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph);
        if (th == NULL)
                return 0;
 
index d3a1b1f..6cca0ad 100644 (file)
@@ -120,13 +120,23 @@ udp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
 
 
 static inline void
-udp_fast_csum_update(struct udphdr *uhdr, __be32 oldip, __be32 newip,
+udp_fast_csum_update(int af, struct udphdr *uhdr,
+                    const union nf_inet_addr *oldip,
+                    const union nf_inet_addr *newip,
                     __be16 oldport, __be16 newport)
 {
-       uhdr->check =
-               csum_fold(ip_vs_check_diff4(oldip, newip,
-                                ip_vs_check_diff2(oldport, newport,
-                                       ~csum_unfold(uhdr->check))));
+#ifdef CONFIG_IP_VS_IPV6
+       if (af == AF_INET6)
+               uhdr->check =
+                       csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
+                                        ip_vs_check_diff2(oldport, newport,
+                                               ~csum_unfold(uhdr->check))));
+       else
+#endif
+               uhdr->check =
+                       csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
+                                        ip_vs_check_diff2(oldport, newport,
+                                               ~csum_unfold(uhdr->check))));
        if (!uhdr->check)
                uhdr->check = CSUM_MANGLED_0;
 }
@@ -136,7 +146,14 @@ udp_snat_handler(struct sk_buff *skb,
                 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
        struct udphdr *udph;
-       const unsigned int udphoff = ip_hdrlen(skb);
+       unsigned int udphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+       if (cp->af == AF_INET6)
+               udphoff = sizeof(struct ipv6hdr);
+       else
+#endif
+               udphoff = ip_hdrlen(skb);
 
        /* csum_check requires unshared skb */
        if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
@@ -144,7 +161,7 @@ udp_snat_handler(struct sk_buff *skb,
 
        if (unlikely(cp->app != NULL)) {
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
+               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
                        return 0;
 
                /*
@@ -154,7 +171,7 @@ udp_snat_handler(struct sk_buff *skb,
                        return 0;
        }
 
-       udph = (void *)ip_hdr(skb) + udphoff;
+       udph = (void *)skb_network_header(skb) + udphoff;
        udph->source = cp->vport;
 
        /*
@@ -162,7 +179,7 @@ udp_snat_handler(struct sk_buff *skb,
         */
        if (!cp->app && (udph->check != 0)) {
                /* Only port and addr are changed, do fast csum update */
-               udp_fast_csum_update(udph, cp->daddr.ip, cp->vaddr.ip,
+               udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
                                     cp->dport, cp->vport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
                        skb->ip_summed = CHECKSUM_NONE;
@@ -170,9 +187,19 @@ udp_snat_handler(struct sk_buff *skb,
                /* full checksum calculation */
                udph->check = 0;
                skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
-               udph->check = csum_tcpudp_magic(cp->vaddr.ip, cp->caddr.ip,
-                                               skb->len - udphoff,
-                                               cp->protocol, skb->csum);
+#ifdef CONFIG_IP_VS_IPV6
+               if (cp->af == AF_INET6)
+                       udph->check = csum_ipv6_magic(&cp->vaddr.in6,
+                                                     &cp->caddr.in6,
+                                                     skb->len - udphoff,
+                                                     cp->protocol, skb->csum);
+               else
+#endif
+                       udph->check = csum_tcpudp_magic(cp->vaddr.ip,
+                                                       cp->caddr.ip,
+                                                       skb->len - udphoff,
+                                                       cp->protocol,
+                                                       skb->csum);
                if (udph->check == 0)
                        udph->check = CSUM_MANGLED_0;
                IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
@@ -188,7 +215,14 @@ udp_dnat_handler(struct sk_buff *skb,
                 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
        struct udphdr *udph;
-       unsigned int udphoff = ip_hdrlen(skb);
+       unsigned int udphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+       if (cp->af == AF_INET6)
+               udphoff = sizeof(struct ipv6hdr);
+       else
+#endif
+               udphoff = ip_hdrlen(skb);
 
        /* csum_check requires unshared skb */
        if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
@@ -196,7 +230,7 @@ udp_dnat_handler(struct sk_buff *skb,
 
        if (unlikely(cp->app != NULL)) {
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
+               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
                        return 0;
 
                /*
@@ -207,7 +241,7 @@ udp_dnat_handler(struct sk_buff *skb,
                        return 0;
        }
 
-       udph = (void *)ip_hdr(skb) + udphoff;
+       udph = (void *)skb_network_header(skb) + udphoff;
        udph->dest = cp->dport;
 
        /*
@@ -215,7 +249,7 @@ udp_dnat_handler(struct sk_buff *skb,
         */
        if (!cp->app && (udph->check != 0)) {
                /* Only port and addr are changed, do fast csum update */
-               udp_fast_csum_update(udph, cp->vaddr.ip, cp->daddr.ip,
+               udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
                                     cp->vport, cp->dport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
                        skb->ip_summed = CHECKSUM_NONE;
@@ -223,9 +257,19 @@ udp_dnat_handler(struct sk_buff *skb,
                /* full checksum calculation */
                udph->check = 0;
                skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
-               udph->check = csum_tcpudp_magic(cp->caddr.ip, cp->daddr.ip,
-                                               skb->len - udphoff,
-                                               cp->protocol, skb->csum);
+#ifdef CONFIG_IP_VS_IPV6
+               if (cp->af == AF_INET6)
+                       udph->check = csum_ipv6_magic(&cp->caddr.in6,
+                                                     &cp->daddr.in6,
+                                                     skb->len - udphoff,
+                                                     cp->protocol, skb->csum);
+               else
+#endif
+                       udph->check = csum_tcpudp_magic(cp->caddr.ip,
+                                                       cp->daddr.ip,
+                                                       skb->len - udphoff,
+                                                       cp->protocol,
+                                                       skb->csum);
                if (udph->check == 0)
                        udph->check = CSUM_MANGLED_0;
                skb->ip_summed = CHECKSUM_UNNECESSARY;