IPVS: Add and bind IPv6 xmit functions

Add xmit functions for IPv6. Also add the already needed __ip_vs_get_out_rt_v6()
to ip_vs_core.c. Bind the new xmit functions to v6 connections.

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

3 files changed, 453 insertions, 1 deletions

diff --git a/net/ipv4/ipvs/ip_vs_conn.c b/net/ipv4/ipvs/ip_vs_conn.c
index 15eec282b17c..f5dddad6d5e4 100644
--- a/net/ipv4/ipvs/ip_vs_conn.c
+++ b/net/ipv4/ipvs/ip_vs_conn.c
@@ -389,6 +389,33 @@ static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
         }
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
+{
+        switch (IP_VS_FWD_METHOD(cp)) {
+        case IP_VS_CONN_F_MASQ:
+                cp->packet_xmit = ip_vs_nat_xmit_v6;
+                break;
+
+        case IP_VS_CONN_F_TUNNEL:
+                cp->packet_xmit = ip_vs_tunnel_xmit_v6;
+                break;
+
+        case IP_VS_CONN_F_DROUTE:
+                cp->packet_xmit = ip_vs_dr_xmit_v6;
+                break;
+
+        case IP_VS_CONN_F_LOCALNODE:
+                cp->packet_xmit = ip_vs_null_xmit;
+                break;
+
+        case IP_VS_CONN_F_BYPASS:
+                cp->packet_xmit = ip_vs_bypass_xmit_v6;
+                break;
+        }
+}
+#endif
+
 
 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 {
@@ -694,7 +721,12 @@ ip_vs_conn_new(int af, int proto, const union nf_inet_addr *caddr, __be16 cport,
         cp->timeout = 3*HZ;
 
         /* Bind its packet transmitter */
-        ip_vs_bind_xmit(cp);
+#ifdef CONFIG_IP_VS_IPV6
+        if (af == AF_INET6)
+                ip_vs_bind_xmit_v6(cp);
+        else
+#endif
+                ip_vs_bind_xmit(cp);
 
         if (unlikely(pp && atomic_read(&pp->appcnt)))
                 ip_vs_bind_app(cp, pp);
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index 2d5a4331709b..d6f5bf9049ad 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -570,6 +570,49 @@ void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
                         "Forwarding altered incoming ICMP");
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
+                    struct ip_vs_conn *cp, int inout)
+{
+        struct ipv6hdr *iph      = ipv6_hdr(skb);
+        unsigned int icmp_offset = sizeof(struct ipv6hdr);
+        struct icmp6hdr *icmph   = (struct icmp6hdr *)(skb_network_header(skb) +
+                                                      icmp_offset);
+        struct ipv6hdr *ciph     = (struct ipv6hdr *)(icmph + 1);
+
+        if (inout) {
+                iph->saddr = cp->vaddr.in6;
+                ciph->daddr = cp->vaddr.in6;
+        } else {
+                iph->daddr = cp->daddr.in6;
+                ciph->saddr = cp->daddr.in6;
+        }
+
+        /* the TCP/UDP port */
+        if (IPPROTO_TCP == ciph->nexthdr || IPPROTO_UDP == ciph->nexthdr) {
+                __be16 *ports = (void *)ciph + sizeof(struct ipv6hdr);
+
+                if (inout)
+                        ports[1] = cp->vport;
+                else
+                        ports[0] = cp->dport;
+        }
+
+        /* And finally the ICMP checksum */
+        icmph->icmp6_cksum = 0;
+        /* TODO IPv6: is this correct for ICMPv6? */
+        ip_vs_checksum_complete(skb, icmp_offset);
+        skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+        if (inout)
+                IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
+                        "Forwarding altered outgoing ICMPv6");
+        else
+                IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
+                        "Forwarding altered incoming ICMPv6");
+}
+#endif
+
 /*
  *      Handle ICMP messages in the inside-to-outside direction (outgoing).
  *      Find any that might be relevant, check against existing connections,
diff --git a/net/ipv4/ipvs/ip_vs_xmit.c b/net/ipv4/ipvs/ip_vs_xmit.c
index fd8342ec7e15..02ddc2b3ce2e 100644
--- a/net/ipv4/ipvs/ip_vs_xmit.c
+++ b/net/ipv4/ipvs/ip_vs_xmit.c
@@ -281,6 +281,70 @@ ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         return NF_STOLEN;
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+                     struct ip_vs_protocol *pp)
+{
+        struct rt6_info *rt;                    /* Route to the other host */
+        struct ipv6hdr  *iph = ipv6_hdr(skb);
+        int    mtu;
+        struct flowi fl = {
+                .oif = 0,
+                .nl_u = {
+                        .ip6_u = {
+                                .daddr = iph->daddr,
+                                .saddr = { .s6_addr32 = {0, 0, 0, 0} }, } },
+        };
+
+        EnterFunction(10);
+
+        rt = (struct rt6_info *)ip6_route_output(&init_net, NULL, &fl);
+        if (!rt) {
+                IP_VS_DBG_RL("ip_vs_bypass_xmit_v6(): ip6_route_output error, "
+                             "dest: " NIP6_FMT "\n", NIP6(iph->daddr));
+                goto tx_error_icmp;
+        }
+
+        /* MTU checking */
+        mtu = dst_mtu(&rt->u.dst);
+        if (skb->len > mtu) {
+                dst_release(&rt->u.dst);
+                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+                IP_VS_DBG_RL("ip_vs_bypass_xmit_v6(): frag needed\n");
+                goto tx_error;
+        }
+
+        /*
+         * Call ip_send_check because we are not sure it is called
+         * after ip_defrag. Is copy-on-write needed?
+         */
+        skb = skb_share_check(skb, GFP_ATOMIC);
+        if (unlikely(skb == NULL)) {
+                dst_release(&rt->u.dst);
+                return NF_STOLEN;
+        }
+
+        /* drop old route */
+        dst_release(skb->dst);
+        skb->dst = &rt->u.dst;
+
+        /* Another hack: avoid icmp_send in ip_fragment */
+        skb->local_df = 1;
+
+        IP_VS_XMIT(PF_INET6, skb, rt);
+
+        LeaveFunction(10);
+        return NF_STOLEN;
+
+ tx_error_icmp:
+        dst_link_failure(skb);
+ tx_error:
+        kfree_skb(skb);
+        LeaveFunction(10);
+        return NF_STOLEN;
+}
+#endif
 
 /*
  *      NAT transmitter (only for outside-to-inside nat forwarding)
@@ -360,6 +424,83 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         goto tx_error;
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+                  struct ip_vs_protocol *pp)
+{
+        struct rt6_info *rt;            /* Route to the other host */
+        int mtu;
+
+        EnterFunction(10);
+
+        /* check if it is a connection of no-client-port */
+        if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) {
+                __be16 _pt, *p;
+                p = skb_header_pointer(skb, sizeof(struct ipv6hdr),
+                                       sizeof(_pt), &_pt);
+                if (p == NULL)
+                        goto tx_error;
+                ip_vs_conn_fill_cport(cp, *p);
+                IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p));
+        }
+
+        rt = __ip_vs_get_out_rt_v6(cp);
+        if (!rt)
+                goto tx_error_icmp;
+
+        /* MTU checking */
+        mtu = dst_mtu(&rt->u.dst);
+        if (skb->len > mtu) {
+                dst_release(&rt->u.dst);
+                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+                IP_VS_DBG_RL_PKT(0, pp, skb, 0,
+                                 "ip_vs_nat_xmit_v6(): frag needed for");
+                goto tx_error;
+        }
+
+        /* copy-on-write the packet before mangling it */
+        if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
+                goto tx_error_put;
+
+        if (skb_cow(skb, rt->u.dst.dev->hard_header_len))
+                goto tx_error_put;
+
+        /* drop old route */
+        dst_release(skb->dst);
+        skb->dst = &rt->u.dst;
+
+        /* mangle the packet */
+        if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp))
+                goto tx_error;
+        ipv6_hdr(skb)->daddr = cp->daddr.in6;
+
+        IP_VS_DBG_PKT(10, pp, skb, 0, "After DNAT");
+
+        /* FIXME: when application helper enlarges the packet and the length
+           is larger than the MTU of outgoing device, there will be still
+           MTU problem. */
+
+        /* Another hack: avoid icmp_send in ip_fragment */
+        skb->local_df = 1;
+
+        IP_VS_XMIT(PF_INET6, skb, rt);
+
+        LeaveFunction(10);
+        return NF_STOLEN;
+
+tx_error_icmp:
+        dst_link_failure(skb);
+tx_error:
+        LeaveFunction(10);
+        kfree_skb(skb);
+        return NF_STOLEN;
+tx_error_put:
+        dst_release(&rt->u.dst);
+        goto tx_error;
+}
+#endif
+
 
 /*
  *   IP Tunneling transmitter
@@ -491,6 +632,112 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         return NF_STOLEN;
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+                     struct ip_vs_protocol *pp)
+{
+        struct rt6_info *rt;            /* Route to the other host */
+        struct net_device *tdev;        /* Device to other host */
+        struct ipv6hdr  *old_iph = ipv6_hdr(skb);
+        sk_buff_data_t old_transport_header = skb->transport_header;
+        struct ipv6hdr  *iph;           /* Our new IP header */
+        unsigned int max_headroom;      /* The extra header space needed */
+        int    mtu;
+
+        EnterFunction(10);
+
+        if (skb->protocol != htons(ETH_P_IPV6)) {
+                IP_VS_DBG_RL("ip_vs_tunnel_xmit_v6(): protocol error, "
+                             "ETH_P_IPV6: %d, skb protocol: %d\n",
+                             htons(ETH_P_IPV6), skb->protocol);
+                goto tx_error;
+        }
+
+        rt = __ip_vs_get_out_rt_v6(cp);
+        if (!rt)
+                goto tx_error_icmp;
+
+        tdev = rt->u.dst.dev;
+
+        mtu = dst_mtu(&rt->u.dst) - sizeof(struct ipv6hdr);
+        /* TODO IPv6: do we need this check in IPv6? */
+        if (mtu < 1280) {
+                dst_release(&rt->u.dst);
+                IP_VS_DBG_RL("ip_vs_tunnel_xmit_v6(): mtu less than 1280\n");
+                goto tx_error;
+        }
+        if (skb->dst)
+                skb->dst->ops->update_pmtu(skb->dst, mtu);
+
+        if (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr)) {
+                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+                dst_release(&rt->u.dst);
+                IP_VS_DBG_RL("ip_vs_tunnel_xmit_v6(): frag needed\n");
+                goto tx_error;
+        }
+
+        /*
+         * Okay, now see if we can stuff it in the buffer as-is.
+         */
+        max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr);
+
+        if (skb_headroom(skb) < max_headroom
+            || skb_cloned(skb) || skb_shared(skb)) {
+                struct sk_buff *new_skb =
+                        skb_realloc_headroom(skb, max_headroom);
+                if (!new_skb) {
+                        dst_release(&rt->u.dst);
+                        kfree_skb(skb);
+                        IP_VS_ERR_RL("ip_vs_tunnel_xmit_v6(): no memory\n");
+                        return NF_STOLEN;
+                }
+                kfree_skb(skb);
+                skb = new_skb;
+                old_iph = ipv6_hdr(skb);
+        }
+
+        skb->transport_header = old_transport_header;
+
+        skb_push(skb, sizeof(struct ipv6hdr));
+        skb_reset_network_header(skb);
+        memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+
+        /* drop old route */
+        dst_release(skb->dst);
+        skb->dst = &rt->u.dst;
+
+        /*
+         *      Push down and install the IPIP header.
+         */
+        iph                     =       ipv6_hdr(skb);
+        iph->version            =       6;
+        iph->nexthdr            =       IPPROTO_IPV6;
+        iph->payload_len        =       old_iph->payload_len + sizeof(old_iph);
+        iph->priority           =       old_iph->priority;
+        memset(&iph->flow_lbl, 0, sizeof(iph->flow_lbl));
+        iph->daddr              =       rt->rt6i_dst.addr;
+        iph->saddr              =       cp->vaddr.in6; /* rt->rt6i_src.addr; */
+        iph->hop_limit          =       old_iph->hop_limit;
+
+        /* Another hack: avoid icmp_send in ip_fragment */
+        skb->local_df = 1;
+
+        ip6_local_out(skb);
+
+        LeaveFunction(10);
+
+        return NF_STOLEN;
+
+tx_error_icmp:
+        dst_link_failure(skb);
+tx_error:
+        kfree_skb(skb);
+        LeaveFunction(10);
+        return NF_STOLEN;
+}
+#endif
+
 
 /*
  *      Direct Routing transmitter
@@ -548,6 +795,60 @@ ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         return NF_STOLEN;
 }
 
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+                 struct ip_vs_protocol *pp)
+{
+        struct rt6_info *rt;                    /* Route to the other host */
+        int    mtu;
+
+        EnterFunction(10);
+
+        rt = __ip_vs_get_out_rt_v6(cp);
+        if (!rt)
+                goto tx_error_icmp;
+
+        /* MTU checking */
+        mtu = dst_mtu(&rt->u.dst);
+        if (skb->len > mtu) {
+                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+                dst_release(&rt->u.dst);
+                IP_VS_DBG_RL("ip_vs_dr_xmit_v6(): frag needed\n");
+                goto tx_error;
+        }
+
+        /*
+         * Call ip_send_check because we are not sure it is called
+         * after ip_defrag. Is copy-on-write needed?
+         */
+        skb = skb_share_check(skb, GFP_ATOMIC);
+        if (unlikely(skb == NULL)) {
+                dst_release(&rt->u.dst);
+                return NF_STOLEN;
+        }
+
+        /* drop old route */
+        dst_release(skb->dst);
+        skb->dst = &rt->u.dst;
+
+        /* Another hack: avoid icmp_send in ip_fragment */
+        skb->local_df = 1;
+
+        IP_VS_XMIT(PF_INET6, skb, rt);
+
+        LeaveFunction(10);
+        return NF_STOLEN;
+
+tx_error_icmp:
+        dst_link_failure(skb);
+tx_error:
+        kfree_skb(skb);
+        LeaveFunction(10);
+        return NF_STOLEN;
+}
+#endif
+
 
 /*
  *      ICMP packet transmitter
@@ -625,3 +926,79 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         ip_rt_put(rt);
         goto tx_error;
 }
+
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+                struct ip_vs_protocol *pp, int offset)
+{
+        struct rt6_info *rt;    /* Route to the other host */
+        int mtu;
+        int rc;
+
+        EnterFunction(10);
+
+        /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
+           forwarded directly here, because there is no need to
+           translate address/port back */
+        if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
+                if (cp->packet_xmit)
+                        rc = cp->packet_xmit(skb, cp, pp);
+                else
+                        rc = NF_ACCEPT;
+                /* do not touch skb anymore */
+                atomic_inc(&cp->in_pkts);
+                goto out;
+        }
+
+        /*
+         * mangle and send the packet here (only for VS/NAT)
+         */
+
+        rt = __ip_vs_get_out_rt_v6(cp);
+        if (!rt)
+                goto tx_error_icmp;
+
+        /* MTU checking */
+        mtu = dst_mtu(&rt->u.dst);
+        if (skb->len > mtu) {
+                dst_release(&rt->u.dst);
+                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+                IP_VS_DBG_RL("ip_vs_in_icmp(): frag needed\n");
+                goto tx_error;
+        }
+
+        /* copy-on-write the packet before mangling it */
+        if (!skb_make_writable(skb, offset))
+                goto tx_error_put;
+
+        if (skb_cow(skb, rt->u.dst.dev->hard_header_len))
+                goto tx_error_put;
+
+        /* drop the old route when skb is not shared */
+        dst_release(skb->dst);
+        skb->dst = &rt->u.dst;
+
+        ip_vs_nat_icmp_v6(skb, pp, cp, 0);
+
+        /* Another hack: avoid icmp_send in ip_fragment */
+        skb->local_df = 1;
+
+        IP_VS_XMIT(PF_INET6, skb, rt);
+
+        rc = NF_STOLEN;
+        goto out;
+
+tx_error_icmp:
+        dst_link_failure(skb);
+tx_error:
+        dev_kfree_skb(skb);
+        rc = NF_STOLEN;
+out:
+        LeaveFunction(10);
+        return rc;
+tx_error_put:
+        dst_release(&rt->u.dst);
+        goto tx_error;
+}
+#endif