[IPV6] MROUTE: Support PIM-SM (SSM).

Based on ancient patch by Mickael Hoerdt
<hoerdt@clarinet.u-strasbg.fr>, which is available at
<http://www-r2.u-strasbg.fr/~hoerdt/dev/linux_ipv6_mforwarding/patch-linux-ipv6-mforwarding-0.1a>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

diff --git a/include/linux/mroute6.h b/include/linux/mroute6.h
index b92190304e0b24e76663e98a89478da484dba26c..f6469fb90840c98c530989cf6af527cae3616ede 100644 (file)
--- a/include/linux/mroute6.h
+++ b/include/linux/mroute6.h
@@ -23,6 +23,8 @@
 #define MRT6_ADD_MFC   (MRT6_BASE+4)   /* Add a multicast forwarding entry     */
 #define MRT6_DEL_MFC   (MRT6_BASE+5)   /* Delete a multicast forwarding entry  */
 #define MRT6_VERSION   (MRT6_BASE+6)   /* Get the kernel multicast version     */
+#define MRT6_ASSERT    (MRT6_BASE+7)   /* Activate PIM assert mode             */
+#define MRT6_PIM       (MRT6_BASE+8)   /* enable PIM code      */
 
 #define SIOCGETMIFCNT_IN6      SIOCPROTOPRIVATE        /* IP protocol privates */
 #define SIOCGETSGCNT_IN6       (SIOCPROTOPRIVATE+1)
@@ -217,6 +219,8 @@ static inline int ip6mr_sk_done(struct sock *sk) { return 0; }
 
 struct mrt6msg {
 #define MRT6MSG_NOCACHE                1
+#define MRT6MSG_WRONGMIF       2
+#define MRT6MSG_WHOLEPKT       3               /* used for use level encap */
        __u8            im6_mbz;                /* must be zero            */
        __u8            im6_msgtype;            /* what type of message    */
        __u16           im6_mif;                /* mif rec'd on            */

diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 9a2ea81e499ffd731d6584d94aefe49b4e570790..82f987b4ef8478dc98cd324dbd420de3ab4d29a0 100644 (file)
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -216,3 +216,10 @@ config IPV6_MROUTE
          Experimental support for IPv6 multicast forwarding.
          If unsure, say N.
 
+config IPV6_PIMSM_V2
+       bool "IPv6: PIM-SM version 2 support (EXPERIMENTAL)"
+       depends on IPV6_MROUTE
+       ---help---
+         Support for IPv6 PIM multicast routing protocol PIM-SMv2.
+         If unsure, say N.
+

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 1bdf3c177d58a43ede30f4ca1e6d5416413170e1..2b70774be61fb5b6afe5ce1191086e80dcea2a85 100644 (file)
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -54,6 +54,7 @@
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
 #include <linux/mroute6.h>
+#include <linux/pim.h>
 #include <net/addrconf.h>
 #include <linux/netfilter_ipv6.h>
 
@@ -75,6 +76,13 @@ static int maxvif;
 
 #define MIF_EXISTS(idx) (vif6_table[idx].dev != NULL)
 
+static int mroute_do_assert;                           /* Set in PIM assert    */
+#ifdef CONFIG_IPV6_PIMSM_V2
+static int mroute_do_pim;
+#else
+#define mroute_do_pim 0
+#endif
+
 static struct mfc6_cache *mfc6_cache_array[MFC_LINES]; /* Forwarding cache     */
 
 static struct mfc6_cache *mfc_unres_queue;             /* Queue of unresolved entries */
@@ -97,6 +105,10 @@ static int ip6_mr_forward(struct sk_buff *skb, struct mfc6_cache *cache);
 static int ip6mr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert);
 static int ip6mr_fill_mroute(struct sk_buff *skb, struct mfc6_cache *c, struct rtmsg *rtm);
 
+#ifdef CONFIG_IPV6_PIMSM_V2
+static struct inet6_protocol pim6_protocol;
+#endif
+
 static struct timer_list ipmr_expire_timer;
 
 
@@ -339,6 +351,132 @@ static struct file_operations ip6mr_mfc_fops = {
 };
 #endif
 
+#ifdef CONFIG_IPV6_PIMSM_V2
+static int reg_vif_num = -1;
+
+static int pim6_rcv(struct sk_buff *skb)
+{
+       struct pimreghdr *pim;
+       struct ipv6hdr   *encap;
+       struct net_device  *reg_dev = NULL;
+
+       if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
+               goto drop;
+
+       pim = (struct pimreghdr *)skb_transport_header(skb);
+       if (pim->type != ((PIM_VERSION << 4) | PIM_REGISTER) ||
+           (pim->flags & PIM_NULL_REGISTER) ||
+           (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
+            (u16)csum_fold(skb_checksum(skb, 0, skb->len, 0))))
+               goto drop;
+
+       /* check if the inner packet is destined to mcast group */
+       encap = (struct ipv6hdr *)(skb_transport_header(skb) +
+                                  sizeof(*pim));
+
+       if (!ipv6_addr_is_multicast(&encap->daddr) ||
+           encap->payload_len == 0 ||
+           ntohs(encap->payload_len) + sizeof(*pim) > skb->len)
+               goto drop;
+
+       read_lock(&mrt_lock);
+       if (reg_vif_num >= 0)
+               reg_dev = vif6_table[reg_vif_num].dev;
+       if (reg_dev)
+               dev_hold(reg_dev);
+       read_unlock(&mrt_lock);
+
+       if (reg_dev == NULL)
+               goto drop;
+
+       skb->mac_header = skb->network_header;
+       skb_pull(skb, (u8 *)encap - skb->data);
+       skb_reset_network_header(skb);
+       skb->dev = reg_dev;
+       skb->protocol = htons(ETH_P_IP);
+       skb->ip_summed = 0;
+       skb->pkt_type = PACKET_HOST;
+       dst_release(skb->dst);
+       ((struct net_device_stats *)netdev_priv(reg_dev))->rx_bytes += skb->len;
+       ((struct net_device_stats *)netdev_priv(reg_dev))->rx_packets++;
+       skb->dst = NULL;
+       nf_reset(skb);
+       netif_rx(skb);
+       dev_put(reg_dev);
+       return 0;
+ drop:
+       kfree_skb(skb);
+       return 0;
+}
+
+static struct inet6_protocol pim6_protocol = {
+       .handler        =       pim6_rcv,
+};
+
+/* Service routines creating virtual interfaces: PIMREG */
+
+static int reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       read_lock(&mrt_lock);
+       ((struct net_device_stats *)netdev_priv(dev))->tx_bytes += skb->len;
+       ((struct net_device_stats *)netdev_priv(dev))->tx_packets++;
+       ip6mr_cache_report(skb, reg_vif_num, MRT6MSG_WHOLEPKT);
+       read_unlock(&mrt_lock);
+       kfree_skb(skb);
+       return 0;
+}
+
+static struct net_device_stats *reg_vif_get_stats(struct net_device *dev)
+{
+       return (struct net_device_stats *)netdev_priv(dev);
+}
+
+static void reg_vif_setup(struct net_device *dev)
+{
+       dev->type               = ARPHRD_PIMREG;
+       dev->mtu                = 1500 - sizeof(struct ipv6hdr) - 8;
+       dev->flags              = IFF_NOARP;
+       dev->hard_start_xmit    = reg_vif_xmit;
+       dev->get_stats          = reg_vif_get_stats;
+       dev->destructor         = free_netdev;
+}
+
+static struct net_device *ip6mr_reg_vif(void)
+{
+       struct net_device *dev;
+       struct inet6_dev *in_dev;
+
+       dev = alloc_netdev(sizeof(struct net_device_stats), "pim6reg",
+                          reg_vif_setup);
+
+       if (dev == NULL)
+               return NULL;
+
+       if (register_netdevice(dev)) {
+               free_netdev(dev);
+               return NULL;
+       }
+       dev->iflink = 0;
+
+       in_dev = ipv6_find_idev(dev);
+       if (!in_dev)
+               goto failure;
+
+       if (dev_open(dev))
+               goto failure;
+
+       return dev;
+
+failure:
+       /* allow the register to be completed before unregistering. */
+       rtnl_unlock();
+       rtnl_lock();
+
+       unregister_netdevice(dev);
+       return NULL;
+}
+#endif
+
 /*
  *     Delete a VIF entry
  */
@@ -361,6 +499,11 @@ static int mif6_delete(int vifi)
                return -EADDRNOTAVAIL;
        }
 
+#ifdef CONFIG_IPV6_PIMSM_V2
+       if (vifi == reg_vif_num)
+               reg_vif_num = -1;
+#endif
+
        if (vifi + 1 == maxvif) {
                int tmp;
                for (tmp = vifi - 1; tmp >= 0; tmp--) {
@@ -480,6 +623,19 @@ static int mif6_add(struct mif6ctl *vifc, int mrtsock)
                return -EADDRINUSE;
 
        switch (vifc->mif6c_flags) {
+#ifdef CONFIG_IPV6_PIMSM_V2
+       case MIFF_REGISTER:
+               /*
+                * Special Purpose VIF in PIM
+                * All the packets will be sent to the daemon
+                */
+               if (reg_vif_num >= 0)
+                       return -EADDRINUSE;
+               dev = ip6mr_reg_vif();
+               if (!dev)
+                       return -ENOBUFS;
+               break;
+#endif
        case 0:
                dev = dev_get_by_index(&init_net, vifc->mif6c_pifi);
                if (!dev)
@@ -512,6 +668,10 @@ static int mif6_add(struct mif6ctl *vifc, int mrtsock)
        write_lock_bh(&mrt_lock);
        dev_hold(dev);
        v->dev = dev;
+#ifdef CONFIG_IPV6_PIMSM_V2
+       if (v->flags & MIFF_REGISTER)
+               reg_vif_num = vifi;
+#endif
        if (vifi + 1 > maxvif)
                maxvif = vifi + 1;
        write_unlock_bh(&mrt_lock);
@@ -599,7 +759,13 @@ static int ip6mr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
        struct mrt6msg *msg;
        int ret;
 
-       skb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(*msg), GFP_ATOMIC);
+#ifdef CONFIG_IPV6_PIMSM_V2
+       if (assert == MRT6MSG_WHOLEPKT)
+               skb = skb_realloc_headroom(pkt, -skb_network_offset(pkt)
+                                               +sizeof(*msg));
+       else
+#endif
+               skb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(*msg), GFP_ATOMIC);
 
        if (!skb)
                return -ENOBUFS;
@@ -609,6 +775,29 @@ static int ip6mr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
 
        skb->ip_summed = CHECKSUM_UNNECESSARY;
 
+#ifdef CONFIG_IPV6_PIMSM_V2
+       if (assert == MRT6MSG_WHOLEPKT) {
+               /* Ugly, but we have no choice with this interface.
+                  Duplicate old header, fix length etc.
+                  And all this only to mangle msg->im6_msgtype and
+                  to set msg->im6_mbz to "mbz" :-)
+                */
+               skb_push(skb, -skb_network_offset(pkt));
+
+               skb_push(skb, sizeof(*msg));
+               skb_reset_transport_header(skb);
+               msg = (struct mrt6msg *)skb_transport_header(skb);
+               msg->im6_mbz = 0;
+               msg->im6_msgtype = MRT6MSG_WHOLEPKT;
+               msg->im6_mif = reg_vif_num;
+               msg->im6_pad = 0;
+               ipv6_addr_copy(&msg->im6_src, &ipv6_hdr(pkt)->saddr);
+               ipv6_addr_copy(&msg->im6_dst, &ipv6_hdr(pkt)->daddr);
+
+               skb->ip_summed = CHECKSUM_UNNECESSARY;
+       } else
+#endif
+       {
        /*
         *      Copy the IP header
         */
@@ -635,6 +824,7 @@ static int ip6mr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
        skb->ip_summed = CHECKSUM_UNNECESSARY;
 
        skb_pull(skb, sizeof(struct ipv6hdr));
+       }
 
        if (mroute6_socket == NULL) {
                kfree_skb(skb);
@@ -1033,6 +1223,44 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, int
                rtnl_unlock();
                return ret;
 
+       /*
+        *      Control PIM assert (to activate pim will activate assert)
+        */
+       case MRT6_ASSERT:
+       {
+               int v;
+               if (get_user(v, (int __user *)optval))
+                       return -EFAULT;
+               mroute_do_assert = !!v;
+               return 0;
+       }
+
+#ifdef CONFIG_IPV6_PIMSM_V2
+       case MRT6_PIM:
+       {
+               int v, ret;
+               if (get_user(v, (int __user *)optval))
+                       return -EFAULT;
+               v = !!v;
+               rtnl_lock();
+               ret = 0;
+               if (v != mroute_do_pim) {
+                       mroute_do_pim = v;
+                       mroute_do_assert = v;
+                       if (mroute_do_pim)
+                               ret = inet6_add_protocol(&pim6_protocol,
+                                                        IPPROTO_PIM);
+                       else
+                               ret = inet6_del_protocol(&pim6_protocol,
+                                                        IPPROTO_PIM);
+                       if (ret < 0)
+                               ret = -EAGAIN;
+               }
+               rtnl_unlock();
+               return ret;
+       }
+
+#endif
        /*
         *      Spurious command, or MRT_VERSION which you cannot
         *      set.
@@ -1056,6 +1284,14 @@ int ip6_mroute_getsockopt(struct sock *sk, int optname, char __user *optval,
        case MRT6_VERSION:
                val = 0x0305;
                break;
+#ifdef CONFIG_IPV6_PIMSM_V2
+       case MRT6_PIM:
+               val = mroute_do_pim;
+               break;
+#endif
+       case MRT6_ASSERT:
+               val = mroute_do_assert;
+               break;
        default:
                return -ENOPROTOOPT;
        }
@@ -1151,6 +1387,18 @@ static int ip6mr_forward2(struct sk_buff *skb, struct mfc6_cache *c, int vifi)
        if (vif->dev == NULL)
                goto out_free;
 
+#ifdef CONFIG_IPV6_PIMSM_V2
+       if (vif->flags & MIFF_REGISTER) {
+               vif->pkt_out++;
+               vif->bytes_out += skb->len;
+               ((struct net_device_stats *)netdev_priv(vif->dev))->tx_bytes += skb->len;
+               ((struct net_device_stats *)netdev_priv(vif->dev))->tx_packets++;
+               ip6mr_cache_report(skb, vifi, MRT6MSG_WHOLEPKT);
+               kfree_skb(skb);
+               return 0;
+       }
+#endif
+
        ipv6h = ipv6_hdr(skb);
 
        fl = (struct flowi) {
@@ -1220,6 +1468,30 @@ static int ip6_mr_forward(struct sk_buff *skb, struct mfc6_cache *cache)
        cache->mfc_un.res.pkt++;
        cache->mfc_un.res.bytes += skb->len;
 
+       /*
+        * Wrong interface: drop packet and (maybe) send PIM assert.
+        */
+       if (vif6_table[vif].dev != skb->dev) {
+               int true_vifi;
+
+               cache->mfc_un.res.wrong_if++;
+               true_vifi = ip6mr_find_vif(skb->dev);
+
+               if (true_vifi >= 0 && mroute_do_assert &&
+                   /* pimsm uses asserts, when switching from RPT to SPT,
+                      so that we cannot check that packet arrived on an oif.
+                      It is bad, but otherwise we would need to move pretty
+                      large chunk of pimd to kernel. Ough... --ANK
+                    */
+                   (mroute_do_pim || cache->mfc_un.res.ttls[true_vifi] < 255) &&
+                   time_after(jiffies,
+                              cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
+                       cache->mfc_un.res.last_assert = jiffies;
+                       ip6mr_cache_report(skb, true_vifi, MRT6MSG_WRONGMIF);
+               }
+               goto dont_forward;
+       }
+
        vif6_table[vif].pkt_in++;
        vif6_table[vif].bytes_in += skb->len;
 
@@ -1241,6 +1513,7 @@ static int ip6_mr_forward(struct sk_buff *skb, struct mfc6_cache *cache)
                return 0;
        }
 
+dont_forward:
        kfree_skb(skb);
        return 0;
 }