[IPV6] MROUTE: Support multicast forwarding.
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/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
new file mode 100644
index 0000000..1bdf3c1
--- /dev/null
+++ b/net/ipv6/ip6mr.c
@@ -0,0 +1,1384 @@
+/*
+ * Linux IPv6 multicast routing support for BSD pim6sd
+ * Based on net/ipv4/ipmr.c.
+ *
+ * (c) 2004 Mickael Hoerdt, <hoerdt@clarinet.u-strasbg.fr>
+ * LSIIT Laboratory, Strasbourg, France
+ * (c) 2004 Jean-Philippe Andriot, <jean-philippe.andriot@6WIND.com>
+ * 6WIND, Paris, France
+ * Copyright (C)2007,2008 USAGI/WIDE Project
+ * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/raw.h>
+#include <net/route.h>
+#include <linux/notifier.h>
+#include <linux/if_arp.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/ipip.h>
+#include <net/checksum.h>
+#include <net/netlink.h>
+
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <linux/mroute6.h>
+#include <net/addrconf.h>
+#include <linux/netfilter_ipv6.h>
+
+struct sock *mroute6_socket;
+
+
+/* Big lock, protecting vif table, mrt cache and mroute socket state.
+ Note that the changes are semaphored via rtnl_lock.
+ */
+
+static DEFINE_RWLOCK(mrt_lock);
+
+/*
+ * Multicast router control variables
+ */
+
+static struct mif_device vif6_table[MAXMIFS]; /* Devices */
+static int maxvif;
+
+#define MIF_EXISTS(idx) (vif6_table[idx].dev != NULL)
+
+static struct mfc6_cache *mfc6_cache_array[MFC_LINES]; /* Forwarding cache */
+
+static struct mfc6_cache *mfc_unres_queue; /* Queue of unresolved entries */
+static atomic_t cache_resolve_queue_len; /* Size of unresolved */
+
+/* Special spinlock for queue of unresolved entries */
+static DEFINE_SPINLOCK(mfc_unres_lock);
+
+/* We return to original Alan's scheme. Hash table of resolved
+ entries is changed only in process context and protected
+ with weak lock mrt_lock. Queue of unresolved entries is protected
+ with strong spinlock mfc_unres_lock.
+
+ In this case data path is free of exclusive locks at all.
+ */
+
+static struct kmem_cache *mrt_cachep __read_mostly;
+
+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);
+
+static struct timer_list ipmr_expire_timer;
+
+
+#ifdef CONFIG_PROC_FS
+
+struct ipmr_mfc_iter {
+ struct mfc6_cache **cache;
+ int ct;
+};
+
+
+static struct mfc6_cache *ipmr_mfc_seq_idx(struct ipmr_mfc_iter *it, loff_t pos)
+{
+ struct mfc6_cache *mfc;
+
+ it->cache = mfc6_cache_array;
+ read_lock(&mrt_lock);
+ for (it->ct = 0; it->ct < ARRAY_SIZE(mfc6_cache_array); it->ct++)
+ for (mfc = mfc6_cache_array[it->ct]; mfc; mfc = mfc->next)
+ if (pos-- == 0)
+ return mfc;
+ read_unlock(&mrt_lock);
+
+ it->cache = &mfc_unres_queue;
+ spin_lock_bh(&mfc_unres_lock);
+ for (mfc = mfc_unres_queue; mfc; mfc = mfc->next)
+ if (pos-- == 0)
+ return mfc;
+ spin_unlock_bh(&mfc_unres_lock);
+
+ it->cache = NULL;
+ return NULL;
+}
+
+
+
+
+/*
+ * The /proc interfaces to multicast routing /proc/ip6_mr_cache /proc/ip6_mr_vif
+ */
+
+struct ipmr_vif_iter {
+ int ct;
+};
+
+static struct mif_device *ip6mr_vif_seq_idx(struct ipmr_vif_iter *iter,
+ loff_t pos)
+{
+ for (iter->ct = 0; iter->ct < maxvif; ++iter->ct) {
+ if (!MIF_EXISTS(iter->ct))
+ continue;
+ if (pos-- == 0)
+ return &vif6_table[iter->ct];
+ }
+ return NULL;
+}
+
+static void *ip6mr_vif_seq_start(struct seq_file *seq, loff_t *pos)
+ __acquires(mrt_lock)
+{
+ read_lock(&mrt_lock);
+ return (*pos ? ip6mr_vif_seq_idx(seq->private, *pos - 1)
+ : SEQ_START_TOKEN);
+}
+
+static void *ip6mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct ipmr_vif_iter *iter = seq->private;
+
+ ++*pos;
+ if (v == SEQ_START_TOKEN)
+ return ip6mr_vif_seq_idx(iter, 0);
+
+ while (++iter->ct < maxvif) {
+ if (!MIF_EXISTS(iter->ct))
+ continue;
+ return &vif6_table[iter->ct];
+ }
+ return NULL;
+}
+
+static void ip6mr_vif_seq_stop(struct seq_file *seq, void *v)
+ __releases(mrt_lock)
+{
+ read_unlock(&mrt_lock);
+}
+
+static int ip6mr_vif_seq_show(struct seq_file *seq, void *v)
+{
+ if (v == SEQ_START_TOKEN) {
+ seq_puts(seq,
+ "Interface BytesIn PktsIn BytesOut PktsOut Flags\n");
+ } else {
+ const struct mif_device *vif = v;
+ const char *name = vif->dev ? vif->dev->name : "none";
+
+ seq_printf(seq,
+ "%2Zd %-10s %8ld %7ld %8ld %7ld %05X\n",
+ vif - vif6_table,
+ name, vif->bytes_in, vif->pkt_in,
+ vif->bytes_out, vif->pkt_out,
+ vif->flags);
+ }
+ return 0;
+}
+
+static struct seq_operations ip6mr_vif_seq_ops = {
+ .start = ip6mr_vif_seq_start,
+ .next = ip6mr_vif_seq_next,
+ .stop = ip6mr_vif_seq_stop,
+ .show = ip6mr_vif_seq_show,
+};
+
+static int ip6mr_vif_open(struct inode *inode, struct file *file)
+{
+ return seq_open_private(file, &ip6mr_vif_seq_ops,
+ sizeof(struct ipmr_vif_iter));
+}
+
+static struct file_operations ip6mr_vif_fops = {
+ .owner = THIS_MODULE,
+ .open = ip6mr_vif_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ return (*pos ? ipmr_mfc_seq_idx(seq->private, *pos - 1)
+ : SEQ_START_TOKEN);
+}
+
+static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct mfc6_cache *mfc = v;
+ struct ipmr_mfc_iter *it = seq->private;
+
+ ++*pos;
+
+ if (v == SEQ_START_TOKEN)
+ return ipmr_mfc_seq_idx(seq->private, 0);
+
+ if (mfc->next)
+ return mfc->next;
+
+ if (it->cache == &mfc_unres_queue)
+ goto end_of_list;
+
+ BUG_ON(it->cache != mfc6_cache_array);
+
+ while (++it->ct < ARRAY_SIZE(mfc6_cache_array)) {
+ mfc = mfc6_cache_array[it->ct];
+ if (mfc)
+ return mfc;
+ }
+
+ /* exhausted cache_array, show unresolved */
+ read_unlock(&mrt_lock);
+ it->cache = &mfc_unres_queue;
+ it->ct = 0;
+
+ spin_lock_bh(&mfc_unres_lock);
+ mfc = mfc_unres_queue;
+ if (mfc)
+ return mfc;
+
+ end_of_list:
+ spin_unlock_bh(&mfc_unres_lock);
+ it->cache = NULL;
+
+ return NULL;
+}
+
+static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
+{
+ struct ipmr_mfc_iter *it = seq->private;
+
+ if (it->cache == &mfc_unres_queue)
+ spin_unlock_bh(&mfc_unres_lock);
+ else if (it->cache == mfc6_cache_array)
+ read_unlock(&mrt_lock);
+}
+
+static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
+{
+ int n;
+
+ if (v == SEQ_START_TOKEN) {
+ seq_puts(seq,
+ "Group "
+ "Origin "
+ "Iif Pkts Bytes Wrong Oifs\n");
+ } else {
+ const struct mfc6_cache *mfc = v;
+ const struct ipmr_mfc_iter *it = seq->private;
+
+ seq_printf(seq,
+ NIP6_FMT " " NIP6_FMT " %-3d %8ld %8ld %8ld",
+ NIP6(mfc->mf6c_mcastgrp), NIP6(mfc->mf6c_origin),
+ mfc->mf6c_parent,
+ mfc->mfc_un.res.pkt,
+ mfc->mfc_un.res.bytes,
+ mfc->mfc_un.res.wrong_if);
+
+ if (it->cache != &mfc_unres_queue) {
+ for (n = mfc->mfc_un.res.minvif;
+ n < mfc->mfc_un.res.maxvif; n++) {
+ if (MIF_EXISTS(n) &&
+ mfc->mfc_un.res.ttls[n] < 255)
+ seq_printf(seq,
+ " %2d:%-3d",
+ n, mfc->mfc_un.res.ttls[n]);
+ }
+ }
+ seq_putc(seq, '\n');
+ }
+ return 0;
+}
+
+static struct seq_operations ipmr_mfc_seq_ops = {
+ .start = ipmr_mfc_seq_start,
+ .next = ipmr_mfc_seq_next,
+ .stop = ipmr_mfc_seq_stop,
+ .show = ipmr_mfc_seq_show,
+};
+
+static int ipmr_mfc_open(struct inode *inode, struct file *file)
+{
+ return seq_open_private(file, &ipmr_mfc_seq_ops,
+ sizeof(struct ipmr_mfc_iter));
+}
+
+static struct file_operations ip6mr_mfc_fops = {
+ .owner = THIS_MODULE,
+ .open = ipmr_mfc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif
+
+/*
+ * Delete a VIF entry
+ */
+
+static int mif6_delete(int vifi)
+{
+ struct mif_device *v;
+ struct net_device *dev;
+ if (vifi < 0 || vifi >= maxvif)
+ return -EADDRNOTAVAIL;
+
+ v = &vif6_table[vifi];
+
+ write_lock_bh(&mrt_lock);
+ dev = v->dev;
+ v->dev = NULL;
+
+ if (!dev) {
+ write_unlock_bh(&mrt_lock);
+ return -EADDRNOTAVAIL;
+ }
+
+ if (vifi + 1 == maxvif) {
+ int tmp;
+ for (tmp = vifi - 1; tmp >= 0; tmp--) {
+ if (MIF_EXISTS(tmp))
+ break;
+ }
+ maxvif = tmp + 1;
+ }
+
+ write_unlock_bh(&mrt_lock);
+
+ dev_set_allmulti(dev, -1);
+
+ if (v->flags & MIFF_REGISTER)
+ unregister_netdevice(dev);
+
+ dev_put(dev);
+ return 0;
+}
+
+/* Destroy an unresolved cache entry, killing queued skbs
+ and reporting error to netlink readers.
+ */
+
+static void ip6mr_destroy_unres(struct mfc6_cache *c)
+{
+ struct sk_buff *skb;
+
+ atomic_dec(&cache_resolve_queue_len);
+
+ while((skb = skb_dequeue(&c->mfc_un.unres.unresolved)) != NULL) {
+ if (ipv6_hdr(skb)->version == 0) {
+ struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct ipv6hdr));
+ nlh->nlmsg_type = NLMSG_ERROR;
+ nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
+ skb_trim(skb, nlh->nlmsg_len);
+ ((struct nlmsgerr *)NLMSG_DATA(nlh))->error = -ETIMEDOUT;
+ rtnl_unicast(skb, &init_net, NETLINK_CB(skb).pid);
+ } else
+ kfree_skb(skb);
+ }
+
+ kmem_cache_free(mrt_cachep, c);
+}
+
+
+/* Single timer process for all the unresolved queue. */
+
+static void ipmr_do_expire_process(unsigned long dummy)
+{
+ unsigned long now = jiffies;
+ unsigned long expires = 10 * HZ;
+ struct mfc6_cache *c, **cp;
+
+ cp = &mfc_unres_queue;
+
+ while ((c = *cp) != NULL) {
+ if (time_after(c->mfc_un.unres.expires, now)) {
+ /* not yet... */
+ unsigned long interval = c->mfc_un.unres.expires - now;
+ if (interval < expires)
+ expires = interval;
+ cp = &c->next;
+ continue;
+ }
+
+ *cp = c->next;
+ ip6mr_destroy_unres(c);
+ }
+
+ if (atomic_read(&cache_resolve_queue_len))
+ mod_timer(&ipmr_expire_timer, jiffies + expires);
+}
+
+static void ipmr_expire_process(unsigned long dummy)
+{
+ if (!spin_trylock(&mfc_unres_lock)) {
+ mod_timer(&ipmr_expire_timer, jiffies + 1);
+ return;
+ }
+
+ if (atomic_read(&cache_resolve_queue_len))
+ ipmr_do_expire_process(dummy);
+
+ spin_unlock(&mfc_unres_lock);
+}
+
+/* Fill oifs list. It is called under write locked mrt_lock. */
+
+static void ip6mr_update_thresholds(struct mfc6_cache *cache, unsigned char *ttls)
+{
+ int vifi;
+
+ cache->mfc_un.res.minvif = MAXVIFS;
+ cache->mfc_un.res.maxvif = 0;
+ memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
+
+ for (vifi = 0; vifi < maxvif; vifi++) {
+ if (MIF_EXISTS(vifi) && ttls[vifi] && ttls[vifi] < 255) {
+ cache->mfc_un.res.ttls[vifi] = ttls[vifi];
+ if (cache->mfc_un.res.minvif > vifi)
+ cache->mfc_un.res.minvif = vifi;
+ if (cache->mfc_un.res.maxvif <= vifi)
+ cache->mfc_un.res.maxvif = vifi + 1;
+ }
+ }
+}
+
+static int mif6_add(struct mif6ctl *vifc, int mrtsock)
+{
+ int vifi = vifc->mif6c_mifi;
+ struct mif_device *v = &vif6_table[vifi];
+ struct net_device *dev;
+
+ /* Is vif busy ? */
+ if (MIF_EXISTS(vifi))
+ return -EADDRINUSE;
+
+ switch (vifc->mif6c_flags) {
+ case 0:
+ dev = dev_get_by_index(&init_net, vifc->mif6c_pifi);
+ if (!dev)
+ return -EADDRNOTAVAIL;
+ dev_put(dev);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ dev_set_allmulti(dev, 1);
+
+ /*
+ * Fill in the VIF structures
+ */
+ v->rate_limit = vifc->vifc_rate_limit;
+ v->flags = vifc->mif6c_flags;
+ if (!mrtsock)
+ v->flags |= VIFF_STATIC;
+ v->threshold = vifc->vifc_threshold;
+ v->bytes_in = 0;
+ v->bytes_out = 0;
+ v->pkt_in = 0;
+ v->pkt_out = 0;
+ v->link = dev->ifindex;
+ if (v->flags & MIFF_REGISTER)
+ v->link = dev->iflink;
+
+ /* And finish update writing critical data */
+ write_lock_bh(&mrt_lock);
+ dev_hold(dev);
+ v->dev = dev;
+ if (vifi + 1 > maxvif)
+ maxvif = vifi + 1;
+ write_unlock_bh(&mrt_lock);
+ return 0;
+}
+
+static struct mfc6_cache *ip6mr_cache_find(struct in6_addr *origin, struct in6_addr *mcastgrp)
+{
+ int line = MFC6_HASH(mcastgrp, origin);
+ struct mfc6_cache *c;
+
+ for (c = mfc6_cache_array[line]; c; c = c->next) {
+ if (ipv6_addr_equal(&c->mf6c_origin, origin) &&
+ ipv6_addr_equal(&c->mf6c_mcastgrp, mcastgrp))
+ break;
+ }
+ return c;
+}
+
+/*
+ * Allocate a multicast cache entry
+ */
+static struct mfc6_cache *ip6mr_cache_alloc(void)
+{
+ struct mfc6_cache *c = kmem_cache_alloc(mrt_cachep, GFP_KERNEL);
+ if (c == NULL)
+ return NULL;
+ memset(c, 0, sizeof(*c));
+ c->mfc_un.res.minvif = MAXVIFS;
+ return c;
+}
+
+static struct mfc6_cache *ip6mr_cache_alloc_unres(void)
+{
+ struct mfc6_cache *c = kmem_cache_alloc(mrt_cachep, GFP_ATOMIC);
+ if (c == NULL)
+ return NULL;
+ memset(c, 0, sizeof(*c));
+ skb_queue_head_init(&c->mfc_un.unres.unresolved);
+ c->mfc_un.unres.expires = jiffies + 10 * HZ;
+ return c;
+}
+
+/*
+ * A cache entry has gone into a resolved state from queued
+ */
+
+static void ip6mr_cache_resolve(struct mfc6_cache *uc, struct mfc6_cache *c)
+{
+ struct sk_buff *skb;
+
+ /*
+ * Play the pending entries through our router
+ */
+
+ while((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
+ if (ipv6_hdr(skb)->version == 0) {
+ int err;
+ struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct ipv6hdr));
+
+ if (ip6mr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) {
+ nlh->nlmsg_len = skb->tail - (u8 *)nlh;
+ } else {
+ nlh->nlmsg_type = NLMSG_ERROR;
+ nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
+ skb_trim(skb, nlh->nlmsg_len);
+ ((struct nlmsgerr *)NLMSG_DATA(nlh))->error = -EMSGSIZE;
+ }
+ err = rtnl_unicast(skb, &init_net, NETLINK_CB(skb).pid);
+ } else
+ ip6_mr_forward(skb, c);
+ }
+}
+
+/*
+ * Bounce a cache query up to pim6sd. We could use netlink for this but pim6sd
+ * expects the following bizarre scheme.
+ *
+ * Called under mrt_lock.
+ */
+
+static int ip6mr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
+{
+ struct sk_buff *skb;
+ struct mrt6msg *msg;
+ int ret;
+
+ skb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(*msg), GFP_ATOMIC);
+
+ if (!skb)
+ return -ENOBUFS;
+
+ /* I suppose that internal messages
+ * do not require checksums */
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ /*
+ * Copy the IP header
+ */
+
+ skb_put(skb, sizeof(struct ipv6hdr));
+ skb_reset_network_header(skb);
+ skb_copy_to_linear_data(skb, ipv6_hdr(pkt), sizeof(struct ipv6hdr));
+
+ /*
+ * Add our header
+ */
+ skb_put(skb, sizeof(*msg));
+ skb_reset_transport_header(skb);
+ msg = (struct mrt6msg *)skb_transport_header(skb);
+
+ msg->im6_mbz = 0;
+ msg->im6_msgtype = assert;
+ msg->im6_mif = vifi;
+ 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->dst = dst_clone(pkt->dst);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ skb_pull(skb, sizeof(struct ipv6hdr));
+
+ if (mroute6_socket == NULL) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ /*
+ * Deliver to user space multicast routing algorithms
+ */
+ if ((ret = sock_queue_rcv_skb(mroute6_socket, skb)) < 0) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "mroute6: pending queue full, dropping entries.\n");
+ kfree_skb(skb);
+ }
+
+ return ret;
+}
+
+/*
+ * Queue a packet for resolution. It gets locked cache entry!
+ */
+
+static int
+ip6mr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
+{
+ int err;
+ struct mfc6_cache *c;
+
+ spin_lock_bh(&mfc_unres_lock);
+ for (c = mfc_unres_queue; c; c = c->next) {
+ if (ipv6_addr_equal(&c->mf6c_mcastgrp, &ipv6_hdr(skb)->daddr) &&
+ ipv6_addr_equal(&c->mf6c_origin, &ipv6_hdr(skb)->saddr))
+ break;
+ }
+
+ if (c == NULL) {
+ /*
+ * Create a new entry if allowable
+ */
+
+ if (atomic_read(&cache_resolve_queue_len) >= 10 ||
+ (c = ip6mr_cache_alloc_unres()) == NULL) {
+ spin_unlock_bh(&mfc_unres_lock);
+
+ kfree_skb(skb);
+ return -ENOBUFS;
+ }
+
+ /*
+ * Fill in the new cache entry
+ */
+ c->mf6c_parent = -1;
+ c->mf6c_origin = ipv6_hdr(skb)->saddr;
+ c->mf6c_mcastgrp = ipv6_hdr(skb)->daddr;
+
+ /*
+ * Reflect first query at pim6sd
+ */
+ if ((err = ip6mr_cache_report(skb, vifi, MRT6MSG_NOCACHE)) < 0) {
+ /* If the report failed throw the cache entry
+ out - Brad Parker
+ */
+ spin_unlock_bh(&mfc_unres_lock);
+
+ kmem_cache_free(mrt_cachep, c);
+ kfree_skb(skb);
+ return err;
+ }
+
+ atomic_inc(&cache_resolve_queue_len);
+ c->next = mfc_unres_queue;
+ mfc_unres_queue = c;
+
+ ipmr_do_expire_process(1);
+ }
+
+ /*
+ * See if we can append the packet
+ */
+ if (c->mfc_un.unres.unresolved.qlen > 3) {
+ kfree_skb(skb);
+ err = -ENOBUFS;
+ } else {
+ skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
+ err = 0;
+ }
+
+ spin_unlock_bh(&mfc_unres_lock);
+ return err;
+}
+
+/*
+ * MFC6 cache manipulation by user space
+ */
+
+static int ip6mr_mfc_delete(struct mf6cctl *mfc)
+{
+ int line;
+ struct mfc6_cache *c, **cp;
+
+ line = MFC6_HASH(&mfc->mf6cc_mcastgrp.sin6_addr, &mfc->mf6cc_origin.sin6_addr);
+
+ for (cp = &mfc6_cache_array[line]; (c = *cp) != NULL; cp = &c->next) {
+ if (ipv6_addr_equal(&c->mf6c_origin, &mfc->mf6cc_origin.sin6_addr) &&
+ ipv6_addr_equal(&c->mf6c_mcastgrp, &mfc->mf6cc_mcastgrp.sin6_addr)) {
+ write_lock_bh(&mrt_lock);
+ *cp = c->next;
+ write_unlock_bh(&mrt_lock);
+
+ kmem_cache_free(mrt_cachep, c);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+static int ip6mr_device_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct mif_device *v;
+ int ct;
+
+ if (dev_net(dev) != &init_net)
+ return NOTIFY_DONE;
+
+ if (event != NETDEV_UNREGISTER)
+ return NOTIFY_DONE;
+
+ v = &vif6_table[0];
+ for (ct = 0; ct < maxvif; ct++, v++) {
+ if (v->dev == dev)
+ mif6_delete(ct);
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block ip6_mr_notifier = {
+ .notifier_call = ip6mr_device_event
+};
+
+/*
+ * Setup for IP multicast routing
+ */
+
+void __init ip6_mr_init(void)
+{
+ mrt_cachep = kmem_cache_create("ip6_mrt_cache",
+ sizeof(struct mfc6_cache),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL);
+ if (!mrt_cachep)
+ panic("cannot allocate ip6_mrt_cache");
+
+ setup_timer(&ipmr_expire_timer, ipmr_expire_process, 0);
+ register_netdevice_notifier(&ip6_mr_notifier);
+#ifdef CONFIG_PROC_FS
+ proc_net_fops_create(&init_net, "ip6_mr_vif", 0, &ip6mr_vif_fops);
+ proc_net_fops_create(&init_net, "ip6_mr_cache", 0, &ip6mr_mfc_fops);
+#endif
+}
+
+
+static int ip6mr_mfc_add(struct mf6cctl *mfc, int mrtsock)
+{
+ int line;
+ struct mfc6_cache *uc, *c, **cp;
+ unsigned char ttls[MAXVIFS];
+ int i;
+
+ memset(ttls, 255, MAXVIFS);
+ for (i = 0; i < MAXVIFS; i++) {
+ if (IF_ISSET(i, &mfc->mf6cc_ifset))
+ ttls[i] = 1;
+
+ }
+
+ line = MFC6_HASH(&mfc->mf6cc_mcastgrp.sin6_addr, &mfc->mf6cc_origin.sin6_addr);
+
+ for (cp = &mfc6_cache_array[line]; (c = *cp) != NULL; cp = &c->next) {
+ if (ipv6_addr_equal(&c->mf6c_origin, &mfc->mf6cc_origin.sin6_addr) &&
+ ipv6_addr_equal(&c->mf6c_mcastgrp, &mfc->mf6cc_mcastgrp.sin6_addr))
+ break;
+ }
+
+ if (c != NULL) {
+ write_lock_bh(&mrt_lock);
+ c->mf6c_parent = mfc->mf6cc_parent;
+ ip6mr_update_thresholds(c, ttls);
+ if (!mrtsock)
+ c->mfc_flags |= MFC_STATIC;
+ write_unlock_bh(&mrt_lock);
+ return 0;
+ }
+
+ if (!ipv6_addr_is_multicast(&mfc->mf6cc_mcastgrp.sin6_addr))
+ return -EINVAL;
+
+ c = ip6mr_cache_alloc();
+ if (c == NULL)
+ return -ENOMEM;
+
+ c->mf6c_origin = mfc->mf6cc_origin.sin6_addr;
+ c->mf6c_mcastgrp = mfc->mf6cc_mcastgrp.sin6_addr;
+ c->mf6c_parent = mfc->mf6cc_parent;
+ ip6mr_update_thresholds(c, ttls);
+ if (!mrtsock)
+ c->mfc_flags |= MFC_STATIC;
+
+ write_lock_bh(&mrt_lock);
+ c->next = mfc6_cache_array[line];
+ mfc6_cache_array[line] = c;
+ write_unlock_bh(&mrt_lock);
+
+ /*
+ * Check to see if we resolved a queued list. If so we
+ * need to send on the frames and tidy up.
+ */
+ spin_lock_bh(&mfc_unres_lock);
+ for (cp = &mfc_unres_queue; (uc = *cp) != NULL;
+ cp = &uc->next) {
+ if (ipv6_addr_equal(&uc->mf6c_origin, &c->mf6c_origin) &&
+ ipv6_addr_equal(&uc->mf6c_mcastgrp, &c->mf6c_mcastgrp)) {
+ *cp = uc->next;
+ if (atomic_dec_and_test(&cache_resolve_queue_len))
+ del_timer(&ipmr_expire_timer);
+ break;
+ }
+ }
+ spin_unlock_bh(&mfc_unres_lock);
+
+ if (uc) {
+ ip6mr_cache_resolve(uc, c);
+ kmem_cache_free(mrt_cachep, uc);
+ }
+ return 0;
+}
+
+/*
+ * Close the multicast socket, and clear the vif tables etc
+ */
+
+static void mroute_clean_tables(struct sock *sk)
+{
+ int i;
+
+ /*
+ * Shut down all active vif entries
+ */
+ for (i = 0; i < maxvif; i++) {
+ if (!(vif6_table[i].flags & VIFF_STATIC))
+ mif6_delete(i);
+ }
+
+ /*
+ * Wipe the cache
+ */
+ for (i = 0; i < ARRAY_SIZE(mfc6_cache_array); i++) {
+ struct mfc6_cache *c, **cp;
+
+ cp = &mfc6_cache_array[i];
+ while ((c = *cp) != NULL) {
+ if (c->mfc_flags & MFC_STATIC) {
+ cp = &c->next;
+ continue;
+ }
+ write_lock_bh(&mrt_lock);
+ *cp = c->next;
+ write_unlock_bh(&mrt_lock);
+
+ kmem_cache_free(mrt_cachep, c);
+ }
+ }
+
+ if (atomic_read(&cache_resolve_queue_len) != 0) {
+ struct mfc6_cache *c;
+
+ spin_lock_bh(&mfc_unres_lock);
+ while (mfc_unres_queue != NULL) {
+ c = mfc_unres_queue;
+ mfc_unres_queue = c->next;
+ spin_unlock_bh(&mfc_unres_lock);
+
+ ip6mr_destroy_unres(c);
+
+ spin_lock_bh(&mfc_unres_lock);
+ }
+ spin_unlock_bh(&mfc_unres_lock);
+ }
+}
+
+static int ip6mr_sk_init(struct sock *sk)
+{
+ int err = 0;
+
+ rtnl_lock();
+ write_lock_bh(&mrt_lock);
+ if (likely(mroute6_socket == NULL))
+ mroute6_socket = sk;
+ else
+ err = -EADDRINUSE;
+ write_unlock_bh(&mrt_lock);
+
+ rtnl_unlock();
+
+ return err;
+}
+
+int ip6mr_sk_done(struct sock *sk)
+{
+ int err = 0;
+
+ rtnl_lock();
+ if (sk == mroute6_socket) {
+ write_lock_bh(&mrt_lock);
+ mroute6_socket = NULL;
+ write_unlock_bh(&mrt_lock);
+
+ mroute_clean_tables(sk);
+ } else
+ err = -EACCES;
+ rtnl_unlock();
+
+ return err;
+}
+
+/*
+ * Socket options and virtual interface manipulation. The whole
+ * virtual interface system is a complete heap, but unfortunately
+ * that's how BSD mrouted happens to think. Maybe one day with a proper
+ * MOSPF/PIM router set up we can clean this up.
+ */
+
+int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, int optlen)
+{
+ int ret;
+ struct mif6ctl vif;
+ struct mf6cctl mfc;
+ mifi_t mifi;
+
+ if (optname != MRT6_INIT) {
+ if (sk != mroute6_socket && !capable(CAP_NET_ADMIN))
+ return -EACCES;
+ }
+
+ switch (optname) {
+ case MRT6_INIT:
+ if (sk->sk_type != SOCK_RAW ||
+ inet_sk(sk)->num != IPPROTO_ICMPV6)
+ return -EOPNOTSUPP;
+ if (optlen < sizeof(int))
+ return -EINVAL;
+
+ return ip6mr_sk_init(sk);
+
+ case MRT6_DONE:
+ return ip6mr_sk_done(sk);
+
+ case MRT6_ADD_MIF:
+ if (optlen < sizeof(vif))
+ return -EINVAL;
+ if (copy_from_user(&vif, optval, sizeof(vif)))
+ return -EFAULT;
+ if (vif.mif6c_mifi >= MAXVIFS)
+ return -ENFILE;
+ rtnl_lock();
+ ret = mif6_add(&vif, sk == mroute6_socket);
+ rtnl_unlock();
+ return ret;
+
+ case MRT6_DEL_MIF:
+ if (optlen < sizeof(mifi_t))
+ return -EINVAL;
+ if (copy_from_user(&mifi, optval, sizeof(mifi_t)))
+ return -EFAULT;
+ rtnl_lock();
+ ret = mif6_delete(mifi);
+ rtnl_unlock();
+ return ret;
+
+ /*
+ * Manipulate the forwarding caches. These live
+ * in a sort of kernel/user symbiosis.
+ */
+ case MRT6_ADD_MFC:
+ case MRT6_DEL_MFC:
+ if (optlen < sizeof(mfc))
+ return -EINVAL;
+ if (copy_from_user(&mfc, optval, sizeof(mfc)))
+ return -EFAULT;
+ rtnl_lock();
+ if (optname == MRT6_DEL_MFC)
+ ret = ip6mr_mfc_delete(&mfc);
+ else
+ ret = ip6mr_mfc_add(&mfc, sk == mroute6_socket);
+ rtnl_unlock();
+ return ret;
+
+ /*
+ * Spurious command, or MRT_VERSION which you cannot
+ * set.
+ */
+ default:
+ return -ENOPROTOOPT;
+ }
+}
+
+/*
+ * Getsock opt support for the multicast routing system.
+ */
+
+int ip6_mroute_getsockopt(struct sock *sk, int optname, char __user *optval,
+ int __user *optlen)
+{
+ int olr;
+ int val;
+
+ switch (optname) {
+ case MRT6_VERSION:
+ val = 0x0305;
+ break;
+ default:
+ return -ENOPROTOOPT;
+ }
+
+ if (get_user(olr, optlen))
+ return -EFAULT;
+
+ olr = min_t(int, olr, sizeof(int));
+ if (olr < 0)
+ return -EINVAL;
+
+ if (put_user(olr, optlen))
+ return -EFAULT;
+ if (copy_to_user(optval, &val, olr))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * The IP multicast ioctl support routines.
+ */
+
+int ip6mr_ioctl(struct sock *sk, int cmd, void __user *arg)
+{
+ struct sioc_sg_req6 sr;
+ struct sioc_mif_req6 vr;
+ struct mif_device *vif;
+ struct mfc6_cache *c;
+
+ switch (cmd) {
+ case SIOCGETMIFCNT_IN6:
+ if (copy_from_user(&vr, arg, sizeof(vr)))
+ return -EFAULT;
+ if (vr.mifi >= maxvif)
+ return -EINVAL;
+ read_lock(&mrt_lock);
+ vif = &vif6_table[vr.mifi];
+ if (MIF_EXISTS(vr.mifi)) {
+ vr.icount = vif->pkt_in;
+ vr.ocount = vif->pkt_out;
+ vr.ibytes = vif->bytes_in;
+ vr.obytes = vif->bytes_out;
+ read_unlock(&mrt_lock);
+
+ if (copy_to_user(arg, &vr, sizeof(vr)))
+ return -EFAULT;
+ return 0;
+ }
+ read_unlock(&mrt_lock);
+ return -EADDRNOTAVAIL;
+ case SIOCGETSGCNT_IN6:
+ if (copy_from_user(&sr, arg, sizeof(sr)))
+ return -EFAULT;
+
+ read_lock(&mrt_lock);
+ c = ip6mr_cache_find(&sr.src.sin6_addr, &sr.grp.sin6_addr);
+ if (c) {
+ sr.pktcnt = c->mfc_un.res.pkt;
+ sr.bytecnt = c->mfc_un.res.bytes;
+ sr.wrong_if = c->mfc_un.res.wrong_if;
+ read_unlock(&mrt_lock);
+
+ if (copy_to_user(arg, &sr, sizeof(sr)))
+ return -EFAULT;
+ return 0;
+ }
+ read_unlock(&mrt_lock);
+ return -EADDRNOTAVAIL;
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+
+static inline int ip6mr_forward2_finish(struct sk_buff *skb)
+{
+ /* XXX stats */
+ return dst_output(skb);
+}
+
+/*
+ * Processing handlers for ip6mr_forward
+ */
+
+static int ip6mr_forward2(struct sk_buff *skb, struct mfc6_cache *c, int vifi)
+{
+ struct ipv6hdr *ipv6h;
+ struct mif_device *vif = &vif6_table[vifi];
+ struct net_device *dev;
+ struct dst_entry *dst;
+ struct flowi fl;
+
+ if (vif->dev == NULL)
+ goto out_free;
+
+ ipv6h = ipv6_hdr(skb);
+
+ fl = (struct flowi) {
+ .oif = vif->link,
+ .nl_u = { .ip6_u =
+ { .daddr = ipv6h->daddr, }
+ }
+ };
+
+ dst = ip6_route_output(&init_net, NULL, &fl);
+ if (!dst)
+ goto out_free;
+
+ dst_release(skb->dst);
+ skb->dst = dst;
+
+ /*
+ * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
+ * not only before forwarding, but after forwarding on all output
+ * interfaces. It is clear, if mrouter runs a multicasting
+ * program, it should receive packets not depending to what interface
+ * program is joined.
+ * If we will not make it, the program will have to join on all
+ * interfaces. On the other hand, multihoming host (or router, but
+ * not mrouter) cannot join to more than one interface - it will
+ * result in receiving multiple packets.
+ */
+ dev = vif->dev;
+ skb->dev = dev;
+ vif->pkt_out++;
+ vif->bytes_out += skb->len;
+
+ /* We are about to write */
+ /* XXX: extension headers? */
+ if (skb_cow(skb, sizeof(*ipv6h) + LL_RESERVED_SPACE(dev)))
+ goto out_free;
+
+ ipv6h = ipv6_hdr(skb);
+ ipv6h->hop_limit--;
+
+ IP6CB(skb)->flags |= IP6SKB_FORWARDED;
+
+ return NF_HOOK(PF_INET6, NF_INET_FORWARD, skb, skb->dev, dev,
+ ip6mr_forward2_finish);
+
+out_free:
+ kfree_skb(skb);
+ return 0;
+}
+
+static int ip6mr_find_vif(struct net_device *dev)
+{
+ int ct;
+ for (ct = maxvif - 1; ct >= 0; ct--) {
+ if (vif6_table[ct].dev == dev)
+ break;
+ }
+ return ct;
+}
+
+static int ip6_mr_forward(struct sk_buff *skb, struct mfc6_cache *cache)
+{
+ int psend = -1;
+ int vif, ct;
+
+ vif = cache->mf6c_parent;
+ cache->mfc_un.res.pkt++;
+ cache->mfc_un.res.bytes += skb->len;
+
+ vif6_table[vif].pkt_in++;
+ vif6_table[vif].bytes_in += skb->len;
+
+ /*
+ * Forward the frame
+ */
+ for (ct = cache->mfc_un.res.maxvif - 1; ct >= cache->mfc_un.res.minvif; ct--) {
+ if (ipv6_hdr(skb)->hop_limit > cache->mfc_un.res.ttls[ct]) {
+ if (psend != -1) {
+ struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+ if (skb2)
+ ip6mr_forward2(skb2, cache, psend);
+ }
+ psend = ct;
+ }
+ }
+ if (psend != -1) {
+ ip6mr_forward2(skb, cache, psend);
+ return 0;
+ }
+
+ kfree_skb(skb);
+ return 0;
+}
+
+
+/*
+ * Multicast packets for forwarding arrive here
+ */
+
+int ip6_mr_input(struct sk_buff *skb)
+{
+ struct mfc6_cache *cache;
+
+ read_lock(&mrt_lock);
+ cache = ip6mr_cache_find(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr);
+
+ /*
+ * No usable cache entry
+ */
+ if (cache == NULL) {
+ int vif;
+
+ vif = ip6mr_find_vif(skb->dev);
+ if (vif >= 0) {
+ int err = ip6mr_cache_unresolved(vif, skb);
+ read_unlock(&mrt_lock);
+
+ return err;
+ }
+ read_unlock(&mrt_lock);
+ kfree_skb(skb);
+ return -ENODEV;
+ }
+
+ ip6_mr_forward(skb, cache);
+
+ read_unlock(&mrt_lock);
+
+ return 0;
+}
+
+
+static int
+ip6mr_fill_mroute(struct sk_buff *skb, struct mfc6_cache *c, struct rtmsg *rtm)
+{
+ int ct;
+ struct rtnexthop *nhp;
+ struct net_device *dev = vif6_table[c->mf6c_parent].dev;
+ u8 *b = skb->tail;
+ struct rtattr *mp_head;
+
+ if (dev)
+ RTA_PUT(skb, RTA_IIF, 4, &dev->ifindex);
+
+ mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
+
+ for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
+ if (c->mfc_un.res.ttls[ct] < 255) {
+ if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
+ goto rtattr_failure;
+ nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
+ nhp->rtnh_flags = 0;
+ nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
+ nhp->rtnh_ifindex = vif6_table[ct].dev->ifindex;
+ nhp->rtnh_len = sizeof(*nhp);
+ }
+ }
+ mp_head->rta_type = RTA_MULTIPATH;
+ mp_head->rta_len = skb->tail - (u8 *)mp_head;
+ rtm->rtm_type = RTN_MULTICAST;
+ return 1;
+
+rtattr_failure:
+ nlmsg_trim(skb, b);
+ return -EMSGSIZE;
+}
+
+int ip6mr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait)
+{
+ int err;
+ struct mfc6_cache *cache;
+ struct rt6_info *rt = (struct rt6_info *)skb->dst;
+
+ read_lock(&mrt_lock);
+ cache = ip6mr_cache_find(&rt->rt6i_src.addr, &rt->rt6i_dst.addr);
+
+ if (!cache) {
+ struct sk_buff *skb2;
+ struct ipv6hdr *iph;
+ struct net_device *dev;
+ int vif;
+
+ if (nowait) {
+ read_unlock(&mrt_lock);
+ return -EAGAIN;
+ }
+
+ dev = skb->dev;
+ if (dev == NULL || (vif = ip6mr_find_vif(dev)) < 0) {
+ read_unlock(&mrt_lock);
+ return -ENODEV;
+ }
+
+ /* really correct? */
+ skb2 = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
+ if (!skb2) {
+ read_unlock(&mrt_lock);
+ return -ENOMEM;
+ }
+
+ skb_reset_transport_header(skb2);
+
+ skb_put(skb2, sizeof(struct ipv6hdr));
+ skb_reset_network_header(skb2);
+
+ iph = ipv6_hdr(skb2);
+ iph->version = 0;
+ iph->priority = 0;
+ iph->flow_lbl[0] = 0;
+ iph->flow_lbl[1] = 0;
+ iph->flow_lbl[2] = 0;
+ iph->payload_len = 0;
+ iph->nexthdr = IPPROTO_NONE;
+ iph->hop_limit = 0;
+ ipv6_addr_copy(&iph->saddr, &rt->rt6i_src.addr);
+ ipv6_addr_copy(&iph->daddr, &rt->rt6i_dst.addr);
+
+ err = ip6mr_cache_unresolved(vif, skb2);
+ read_unlock(&mrt_lock);
+
+ return err;
+ }
+
+ if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))
+ cache->mfc_flags |= MFC_NOTIFY;
+
+ err = ip6mr_fill_mroute(skb, cache, rtm);
+ read_unlock(&mrt_lock);
+ return err;
+}
+