/* * IP multicast routing support for mrouted 3.6/3.8 * * (c) 1995 Alan Cox, * Linux Consultancy and Custom Driver Development * * 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. * * Fixes: * Michael Chastain : Incorrect size of copying. * Alan Cox : Added the cache manager code * Alan Cox : Fixed the clone/copy bug and device race. * Mike McLagan : Routing by source * Malcolm Beattie : Buffer handling fixes. * Alexey Kuznetsov : Double buffer free and other fixes. * SVR Anand : Fixed several multicast bugs and problems. * Alexey Kuznetsov : Status, optimisations and more. * Brad Parker : Better behaviour on mrouted upcall * overflow. * Carlos Picoto : PIMv1 Support * Pavlin Ivanov Radoslavov: PIMv2 Registers must checksum only PIM header * Relax this requirement to work with older peers. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2) #define CONFIG_IP_PIMSM 1 #endif struct mr_table { struct list_head list; #ifdef CONFIG_NET_NS struct net *net; #endif u32 id; struct sock __rcu *mroute_sk; struct timer_list ipmr_expire_timer; struct list_head mfc_unres_queue; struct list_head mfc_cache_array[MFC_LINES]; struct vif_device vif_table[MAXVIFS]; int maxvif; atomic_t cache_resolve_queue_len; int mroute_do_assert; int mroute_do_pim; #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2) int mroute_reg_vif_num; #endif }; struct ipmr_rule { struct fib_rule common; }; struct ipmr_result { struct mr_table *mrt; }; /* 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 */ #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL) /* 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 struct mr_table *ipmr_new_table(struct net *net, u32 id); static int ip_mr_forward(struct net *net, struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *cache, int local); static int ipmr_cache_report(struct mr_table *mrt, struct sk_buff *pkt, vifi_t vifi, int assert); static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm); static void ipmr_expire_process(unsigned long arg); #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES #define ipmr_for_each_table(mrt, net) \ list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list) static struct mr_table *ipmr_get_table(struct net *net, u32 id) { struct mr_table *mrt; ipmr_for_each_table(mrt, net) { if (mrt->id == id) return mrt; } return NULL; } static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, struct mr_table **mrt) { struct ipmr_result res; struct fib_lookup_arg arg = { .result = &res, }; int err; err = fib_rules_lookup(net->ipv4.mr_rules_ops, flowi4_to_flowi(flp4), 0, &arg); if (err < 0) return err; *mrt = res.mrt; return 0; } static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp, int flags, struct fib_lookup_arg *arg) { struct ipmr_result *res = arg->result; struct mr_table *mrt; switch (rule->action) { case FR_ACT_TO_TBL: break; case FR_ACT_UNREACHABLE: return -ENETUNREACH; case FR_ACT_PROHIBIT: return -EACCES; case FR_ACT_BLACKHOLE: default: return -EINVAL; } mrt = ipmr_get_table(rule->fr_net, rule->table); if (mrt == NULL) return -EAGAIN; res->mrt = mrt; return 0; } static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) { return 1; } static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = { FRA_GENERIC_POLICY, }; static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb, struct fib_rule_hdr *frh, struct nlattr **tb) { return 0; } static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, struct nlattr **tb) { return 1; } static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb, struct fib_rule_hdr *frh) { frh->dst_len = 0; frh->src_len = 0; frh->tos = 0; return 0; } static const struct fib_rules_ops __net_initdata ipmr_rules_ops_template = { .family = RTNL_FAMILY_IPMR, .rule_size = sizeof(struct ipmr_rule), .addr_size = sizeof(u32), .action = ipmr_rule_action, .match = ipmr_rule_match, .configure = ipmr_rule_configure, .compare = ipmr_rule_compare, .default_pref = fib_default_rule_pref, .fill = ipmr_rule_fill, .nlgroup = RTNLGRP_IPV4_RULE, .policy = ipmr_rule_policy, .owner = THIS_MODULE, }; static int __net_init ipmr_rules_init(struct net *net) { struct fib_rules_ops *ops; struct mr_table *mrt; int err; ops = fib_rules_register(&ipmr_rules_ops_template, net); if (IS_ERR(ops)) return PTR_ERR(ops); INIT_LIST_HEAD(&net->ipv4.mr_tables); mrt = ipmr_new_table(net, RT_TABLE_DEFAULT); if (mrt == NULL) { err = -ENOMEM; goto err1; } err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0); if (err < 0) goto err2; net->ipv4.mr_rules_ops = ops; return 0; err2: kfree(mrt); err1: fib_rules_unregister(ops); return err; } static void __net_exit ipmr_rules_exit(struct net *net) { struct mr_table *mrt, *next; list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) { list_del(&mrt->list); kfree(mrt); } fib_rules_unregister(net->ipv4.mr_rules_ops); } #else #define ipmr_for_each_table(mrt, net) \ for (mrt = net->ipv4.mrt; mrt; mrt = NULL) static struct mr_table *ipmr_get_table(struct net *net, u32 id) { return net->ipv4.mrt; } static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, struct mr_table **mrt) { *mrt = net->ipv4.mrt; return 0; } static int __net_init ipmr_rules_init(struct net *net) { net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT); return net->ipv4.mrt ? 0 : -ENOMEM; } static void __net_exit ipmr_rules_exit(struct net *net) { kfree(net->ipv4.mrt); } #endif static struct mr_table *ipmr_new_table(struct net *net, u32 id) { struct mr_table *mrt; unsigned int i; mrt = ipmr_get_table(net, id); if (mrt != NULL) return mrt; mrt = kzalloc(sizeof(*mrt), GFP_KERNEL); if (mrt == NULL) return NULL; write_pnet(&mrt->net, net); mrt->id = id; /* Forwarding cache */ for (i = 0; i < MFC_LINES; i++) INIT_LIST_HEAD(&mrt->mfc_cache_array[i]); INIT_LIST_HEAD(&mrt->mfc_unres_queue); setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process, (unsigned long)mrt); #ifdef CONFIG_IP_PIMSM mrt->mroute_reg_vif_num = -1; #endif #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables); #endif return mrt; } /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */ static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v) { struct net *net = dev_net(dev); dev_close(dev); dev = __dev_get_by_name(net, "tunl0"); if (dev) { const struct net_device_ops *ops = dev->netdev_ops; struct ifreq ifr; struct ip_tunnel_parm p; memset(&p, 0, sizeof(p)); p.iph.daddr = v->vifc_rmt_addr.s_addr; p.iph.saddr = v->vifc_lcl_addr.s_addr; p.iph.version = 4; p.iph.ihl = 5; p.iph.protocol = IPPROTO_IPIP; sprintf(p.name, "dvmrp%d", v->vifc_vifi); ifr.ifr_ifru.ifru_data = (__force void __user *)&p; if (ops->ndo_do_ioctl) { mm_segment_t oldfs = get_fs(); set_fs(KERNEL_DS); ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL); set_fs(oldfs); } } } static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v) { struct net_device *dev; dev = __dev_get_by_name(net, "tunl0"); if (dev) { const struct net_device_ops *ops = dev->netdev_ops; int err; struct ifreq ifr; struct ip_tunnel_parm p; struct in_device *in_dev; memset(&p, 0, sizeof(p)); p.iph.daddr = v->vifc_rmt_addr.s_addr; p.iph.saddr = v->vifc_lcl_addr.s_addr; p.iph.version = 4; p.iph.ihl = 5; p.iph.protocol = IPPROTO_IPIP; sprintf(p.name, "dvmrp%d", v->vifc_vifi); ifr.ifr_ifru.ifru_data = (__force void __user *)&p; if (ops->ndo_do_ioctl) { mm_segment_t oldfs = get_fs(); set_fs(KERNEL_DS); err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL); set_fs(oldfs); } else { err = -EOPNOTSUPP; } dev = NULL; if (err == 0 && (dev = __dev_get_by_name(net, p.name)) != NULL) { dev->flags |= IFF_MULTICAST; in_dev = __in_dev_get_rtnl(dev); if (in_dev == NULL) goto failure; ipv4_devconf_setall(in_dev); IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0; if (dev_open(dev)) goto failure; dev_hold(dev); } } return dev; failure: /* allow the register to be completed before unregistering. */ rtnl_unlock(); rtnl_lock(); unregister_netdevice(dev); return NULL; } #ifdef CONFIG_IP_PIMSM static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev) { struct net *net = dev_net(dev); struct mr_table *mrt; struct flowi4 fl4 = { .flowi4_oif = dev->ifindex, .flowi4_iif = skb->skb_iif, .flowi4_mark = skb->mark, }; int err; err = ipmr_fib_lookup(net, &fl4, &mrt); if (err < 0) { kfree_skb(skb); return err; } read_lock(&mrt_lock); dev->stats.tx_bytes += skb->len; dev->stats.tx_packets++; ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT); read_unlock(&mrt_lock); kfree_skb(skb); return NETDEV_TX_OK; } static const struct net_device_ops reg_vif_netdev_ops = { .ndo_start_xmit = reg_vif_xmit, }; static void reg_vif_setup(struct net_device *dev) { dev->type = ARPHRD_PIMREG; dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 8; dev->flags = IFF_NOARP; dev->netdev_ops = ®_vif_netdev_ops, dev->destructor = free_netdev; dev->features |= NETIF_F_NETNS_LOCAL; } static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt) { struct net_device *dev; struct in_device *in_dev; char name[IFNAMSIZ]; if (mrt->id == RT_TABLE_DEFAULT) sprintf(name, "pimreg"); else sprintf(name, "pimreg%u", mrt->id); dev = alloc_netdev(0, name, reg_vif_setup); if (dev == NULL) return NULL; dev_net_set(dev, net); if (register_netdevice(dev)) { free_netdev(dev); return NULL; } dev->iflink = 0; rcu_read_lock(); in_dev = __in_dev_get_rcu(dev); if (!in_dev) { rcu_read_unlock(); goto failure; } ipv4_devconf_setall(in_dev); IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0; rcu_read_unlock(); if (dev_open(dev)) goto failure; dev_hold(dev); 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 * @notify: Set to 1, if the caller is a notifier_call */ static int vif_delete(struct mr_table *mrt, int vifi, int notify, struct list_head *head) { struct vif_device *v; struct net_device *dev; struct in_device *in_dev; if (vifi < 0 || vifi >= mrt->maxvif) return -EADDRNOTAVAIL; v = &mrt->vif_table[vifi]; write_lock_bh(&mrt_lock); dev = v->dev; v->dev = NULL; if (!dev) { write_unlock_bh(&mrt_lock); return -EADDRNOTAVAIL; } #ifdef CONFIG_IP_PIMSM if (vifi == mrt->mroute_reg_vif_num) mrt->mroute_reg_vif_num = -1; #endif if (vifi + 1 == mrt->maxvif) { int tmp; for (tmp = vifi - 1; tmp >= 0; tmp--) { if (VIF_EXISTS(mrt, tmp)) break; } mrt->maxvif = tmp+1; } write_unlock_bh(&mrt_lock); dev_set_allmulti(dev, -1); in_dev = __in_dev_get_rtnl(dev); if (in_dev) { IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--; ip_rt_multicast_event(in_dev); } if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify) unregister_netdevice_queue(dev, head); dev_put(dev); return 0; } static void ipmr_cache_free_rcu(struct rcu_head *head) { struct mfc_cache *c = container_of(head, struct mfc_cache, rcu); kmem_cache_free(mrt_cachep, c); } static inline void ipmr_cache_free(struct mfc_cache *c) { call_rcu(&c->rcu, ipmr_cache_free_rcu); } /* Destroy an unresolved cache entry, killing queued skbs * and reporting error to netlink readers. */ static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c) { struct net *net = read_pnet(&mrt->net); struct sk_buff *skb; struct nlmsgerr *e; atomic_dec(&mrt->cache_resolve_queue_len); while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) { if (ip_hdr(skb)->version == 0) { struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr)); nlh->nlmsg_type = NLMSG_ERROR; nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr)); skb_trim(skb, nlh->nlmsg_len); e = NLMSG_DATA(nlh); e->error = -ETIMEDOUT; memset(&e->msg, 0, sizeof(e->msg)); rtnl_unicast(skb, net, NETLINK_CB(skb).pid); } else { kfree_skb(skb); } } ipmr_cache_free(c); } /* Timer process for the unresolved queue. */ static void ipmr_expire_process(unsigned long arg) { struct mr_table *mrt = (struct mr_table *)arg; unsigned long now; unsigned long expires; struct mfc_cache *c, *next; if (!spin_trylock(&mfc_unres_lock)) { mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10); return; } if (list_empty(&mrt->mfc_unres_queue)) goto out; now = jiffies; expires = 10*HZ; list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) { if (time_after(c->mfc_un.unres.expires, now)) { unsigned long interval = c->mfc_un.unres.expires - now; if (interval < expires) expires = interval; continue; } list_del(&c->list); ipmr_destroy_unres(mrt, c); } if (!list_empty(&mrt->mfc_unres_queue)) mod_timer(&mrt->ipmr_expire_timer, jiffies + expires); out: spin_unlock(&mfc_unres_lock); } /* Fill oifs list. It is called under write locked mrt_lock. */ static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_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 < mrt->maxvif; vifi++) { if (VIF_EXISTS(mrt, 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 vif_add(struct net *net, struct mr_table *mrt, struct vifctl *vifc, int mrtsock) { int vifi = vifc->vifc_vifi; struct vif_device *v = &mrt->vif_table[vifi]; struct net_device *dev; struct in_device *in_dev; int err; /* Is vif busy ? */ if (VIF_EXISTS(mrt, vifi)) return -EADDRINUSE; switch (vifc->vifc_flags) { #ifdef CONFIG_IP_PIMSM case VIFF_REGISTER: /* * Special Purpose VIF in PIM * All the packets will be sent to the daemon */ if (mrt->mroute_reg_vif_num >= 0) return -EADDRINUSE; dev = ipmr_reg_vif(net, mrt); if (!dev) return -ENOBUFS; err = dev_set_allmulti(dev, 1); if (err) { unregister_netdevice(dev); dev_put(dev); return err; } break; #endif case VIFF_TUNNEL: dev = ipmr_new_tunnel(net, vifc); if (!dev) return -ENOBUFS; err = dev_set_allmulti(dev, 1); if (err) { ipmr_del_tunnel(dev, vifc); dev_put(dev); return err; } break; case VIFF_USE_IFINDEX: case 0: if (vifc->vifc_flags == VIFF_USE_IFINDEX) { dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex); if (dev && __in_dev_get_rtnl(dev) == NULL) { dev_put(dev); return -EADDRNOTAVAIL; } } else { dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr); } if (!dev) return -EADDRNOTAVAIL; err = dev_set_allmulti(dev, 1); if (err) { dev_put(dev); return err; } break; default: return -EINVAL; } in_dev = __in_dev_get_rtnl(dev); if (!in_dev) { dev_put(dev); return -EADDRNOTAVAIL; } IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++; ip_rt_multicast_event(in_dev); /* Fill in the VIF structures */ v->rate_limit = vifc->vifc_rate_limit; v->local = vifc->vifc_lcl_addr.s_addr; v->remote = vifc->vifc_rmt_addr.s_addr; v->flags = vifc->vifc_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 & (VIFF_TUNNEL | VIFF_REGISTER)) v->link = dev->iflink; /* And finish update writing critical data */ write_lock_bh(&mrt_lock); v->dev = dev; #ifdef CONFIG_IP_PIMSM if (v->flags & VIFF_REGISTER) mrt->mroute_reg_vif_num = vifi; #endif if (vifi+1 > mrt->maxvif) mrt->maxvif = vifi+1; write_unlock_bh(&mrt_lock); return 0; } /* called with rcu_read_lock() */ static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt, __be32 origin, __be32 mcastgrp) { int line = MFC_HASH(mcastgrp, origin); struct mfc_cache *c; list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) { if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp) return c; } return NULL; } /* * Allocate a multicast cache entry */ static struct mfc_cache *ipmr_cache_alloc(void) { struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL); if (c) c->mfc_un.res.minvif = MAXVIFS; return c; } static struct mfc_cache *ipmr_cache_alloc_unres(void) { struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC); if (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 ipmr_cache_resolve(struct net *net, struct mr_table *mrt, struct mfc_cache *uc, struct mfc_cache *c) { struct sk_buff *skb; struct nlmsgerr *e; /* Play the pending entries through our router */ while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) { if (ip_hdr(skb)->version == 0) { struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr)); if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) { nlh->nlmsg_len = skb_tail_pointer(skb) - (u8 *)nlh; } else { nlh->nlmsg_type = NLMSG_ERROR; nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr)); skb_trim(skb, nlh->nlmsg_len); e = NLMSG_DATA(nlh); e->error = -EMSGSIZE; memset(&e->msg, 0, sizeof(e->msg)); } rtnl_unicast(skb, net, NETLINK_CB(skb).pid); } else { ip_mr_forward(net, mrt, skb, c, 0); } } } /* * Bounce a cache query up to mrouted. We could use netlink for this but mrouted * expects the following bizarre scheme. * * Called under mrt_lock. */ static int ipmr_cache_report(struct mr_table *mrt, struct sk_buff *pkt, vifi_t vifi, int assert) { struct sk_buff *skb; const int ihl = ip_hdrlen(pkt); struct igmphdr *igmp; struct igmpmsg *msg; struct sock *mroute_sk; int ret; #ifdef CONFIG_IP_PIMSM if (assert == IGMPMSG_WHOLEPKT) skb = skb_realloc_headroom(pkt, sizeof(struct iphdr)); else #endif skb = alloc_skb(128, GFP_ATOMIC); if (!skb) return -ENOBUFS; #ifdef CONFIG_IP_PIMSM if (assert == IGMPMSG_WHOLEPKT) { /* Ugly, but we have no choice with this interface. * Duplicate old header, fix ihl, length etc. * And all this only to mangle msg->im_msgtype and * to set msg->im_mbz to "mbz" :-) */ skb_push(skb, sizeof(struct iphdr)); skb_reset_network_header(skb); skb_reset_transport_header(skb); msg = (struct igmpmsg *)skb_network_header(skb); memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr)); msg->im_msgtype = IGMPMSG_WHOLEPKT; msg->im_mbz = 0; msg->im_vif = mrt->mroute_reg_vif_num; ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2; ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) + sizeof(struct iphdr)); } else #endif { /* Copy the IP header */ skb->network_header = skb->tail; skb_put(skb, ihl); skb_copy_to_linear_data(skb, pkt->data, ihl); ip_hdr(skb)->protocol = 0; /* Flag to the kernel this is a route add */ msg = (struct igmpmsg *)skb_network_header(skb); msg->im_vif = vifi; skb_dst_set(skb, dst_clone(skb_dst(pkt))); /* Add our header */ igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr)); igmp->type = msg->im_msgtype = assert; igmp->code = 0; ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */ skb->transport_header = skb->network_header; } rcu_read_lock(); mroute_sk = rcu_dereference(mrt->mroute_sk); if (mroute_sk == NULL) { rcu_read_unlock(); kfree_skb(skb); return -EINVAL; } /* Deliver to mrouted */ ret = sock_queue_rcv_skb(mroute_sk, skb); rcu_read_unlock(); if (ret < 0) { if (net_ratelimit()) printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n"); kfree_skb(skb); } return ret; } /* * Queue a packet for resolution. It gets locked cache entry! */ static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb) { bool found = false; int err; struct mfc_cache *c; const struct iphdr *iph = ip_hdr(skb); spin_lock_bh(&mfc_unres_lock); list_for_each_entry(c, &mrt->mfc_unres_queue, list) { if (c->mfc_mcastgrp == iph->daddr && c->mfc_origin == iph->saddr) { found = true; break; } } if (!found) { /* Create a new entry if allowable */ if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 || (c = ipmr_cache_alloc_unres()) == NULL) { spin_unlock_bh(&mfc_unres_lock); kfree_skb(skb); return -ENOBUFS; } /* Fill in the new cache entry */ c->mfc_parent = -1; c->mfc_origin = iph->saddr; c->mfc_mcastgrp = iph->daddr; /* Reflect first query at mrouted. */ err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE); if (err < 0) { /* If the report failed throw the cache entry out - Brad Parker */ spin_unlock_bh(&mfc_unres_lock); ipmr_cache_free(c); kfree_skb(skb); return err; } atomic_inc(&mrt->cache_resolve_queue_len); list_add(&c->list, &mrt->mfc_unres_queue); if (atomic_read(&mrt->cache_resolve_queue_len) == 1) mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires); } /* 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; } /* * MFC cache manipulation by user space mroute daemon */ static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc) { int line; struct mfc_cache *c, *next; line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr); list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) { if (c->mfc_origin == mfc->mfcc_origin.s_addr && c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) { list_del_rcu(&c->list); ipmr_cache_free(c); return 0; } } return -ENOENT; } static int ipmr_mfc_add(struct net *net, struct mr_table *mrt, struct mfcctl *mfc, int mrtsock) { bool found = false; int line; struct mfc_cache *uc, *c; if (mfc->mfcc_parent >= MAXVIFS) return -ENFILE; line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr); list_for_each_entry(c, &mrt->mfc_cache_array[line], list) { if (c->mfc_origin == mfc->mfcc_origin.s_addr && c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) { found = true; break; } } if (found) { write_lock_bh(&mrt_lock); c->mfc_parent = mfc->mfcc_parent; ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls); if (!mrtsock) c->mfc_flags |= MFC_STATIC; write_unlock_bh(&mrt_lock); return 0; } if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr)) return -EINVAL; c = ipmr_cache_alloc(); if (c == NULL) return -ENOMEM; c->mfc_origin = mfc->mfcc_origin.s_addr; c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr; c->mfc_parent = mfc->mfcc_parent; ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls); if (!mrtsock) c->mfc_flags |= MFC_STATIC; list_add_rcu(&c->list, &mrt->mfc_cache_array[line]); /* * Check to see if we resolved a queued list. If so we * need to send on the frames and tidy up. */ found = false; spin_lock_bh(&mfc_unres_lock); list_for_each_entry(uc, &mrt->mfc_unres_queue, list) { if (uc->mfc_origin == c->mfc_origin && uc->mfc_mcastgrp == c->mfc_mcastgrp) { list_del(&uc->list); atomic_dec(&mrt->cache_resolve_queue_len); found = true; break; } } if (list_empty(&mrt->mfc_unres_queue)) del_timer(&mrt->ipmr_expire_timer); spin_unlock_bh(&mfc_unres_lock); if (found) { ipmr_cache_resolve(net, mrt, uc, c); ipmr_cache_free(uc); } return 0; } /* * Close the multicast socket, and clear the vif tables etc */ static void mroute_clean_tables(struct mr_table *mrt) { int i; LIST_HEAD(list); struct mfc_cache *c, *next; /* Shut down all active vif entries */ for (i = 0; i < mrt->maxvif; i++) { if (!(mrt->vif_table[i].flags & VIFF_STATIC)) vif_delete(mrt, i, 0, &list); } unregister_netdevice_many(&list); /* Wipe the cache */ for (i = 0; i < MFC_LINES; i++) { list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) { if (c->mfc_flags & MFC_STATIC) continue; list_del_rcu(&c->list); ipmr_cache_free(c); } } if (atomic_read(&mrt->cache_resolve_queue_len) != 0) { spin_lock_bh(&mfc_unres_lock); list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) { list_del(&c->list); ipmr_destroy_unres(mrt, c); } spin_unlock_bh(&mfc_unres_lock); } } /* called from ip_ra_control(), before an RCU grace period, * we dont need to call synchronize_rcu() here */ static void mrtsock_destruct(struct sock *sk) { struct net *net = sock_net(sk); struct mr_table *mrt; rtnl_lock(); ipmr_for_each_table(mrt, net) { if (sk == rtnl_dereference(mrt->mroute_sk)) { IPV4_DEVCONF_ALL(net, MC_FORWARDING)--; RCU_INIT_POINTER(mrt->mroute_sk, NULL); mroute_clean_tables(mrt); } } rtnl_unlock(); } /* * 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 ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen) { int ret; struct vifctl vif; struct mfcctl mfc; struct net *net = sock_net(sk); struct mr_table *mrt; mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); if (mrt == NULL) return -ENOENT; if (optname != MRT_INIT) { if (sk != rcu_access_pointer(mrt->mroute_sk) && !capable(CAP_NET_ADMIN)) return -EACCES; } switch (optname) { case MRT_INIT: if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num != IPPROTO_IGMP) return -EOPNOTSUPP; if (optlen != sizeof(int)) return -ENOPROTOOPT; rtnl_lock(); if (rtnl_dereference(mrt->mroute_sk)) { rtnl_unlock(); return -EADDRINUSE; } ret = ip_ra_control(sk, 1, mrtsock_destruct); if (ret == 0) { rcu_assign_pointer(mrt->mroute_sk, sk); IPV4_DEVCONF_ALL(net, MC_FORWARDING)++; } rtnl_unlock(); return ret; case MRT_DONE: if (sk != rcu_access_pointer(mrt->mroute_sk)) return -EACCES; return ip_ra_control(sk, 0, NULL); case MRT_ADD_VIF: case MRT_DEL_VIF: if (optlen != sizeof(vif)) return -EINVAL; if (copy_from_user(&vif, optval, sizeof(vif))) return -EFAULT; if (vif.vifc_vifi >= MAXVIFS) return -ENFILE; rtnl_lock(); if (optname == MRT_ADD_VIF) { ret = vif_add(net, mrt, &vif, sk == rtnl_dereference(mrt->mroute_sk)); } else { ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL); } rtnl_unlock(); return ret; /* * Manipulate the forwarding caches. These live * in a sort of kernel/user symbiosis. */ case MRT_ADD_MFC: case MRT_DEL_MFC: if (optlen != sizeof(mfc)) return -EINVAL; if (copy_from_user(&mfc, optval, sizeof(mfc))) return -EFAULT; rtnl_lock(); if (optname == MRT_DEL_MFC) ret = ipmr_mfc_delete(mrt, &mfc); else ret = ipmr_mfc_add(net, mrt, &mfc, sk == rtnl_dereference(mrt->mroute_sk)); rtnl_unlock(); return ret; /* * Control PIM assert. */ case MRT_ASSERT: { int v; if (get_user(v, (int __user *)optval)) return -EFAULT; mrt->mroute_do_assert = (v) ? 1 : 0; return 0; } #ifdef CONFIG_IP_PIMSM case MRT_PIM: { int v; if (get_user(v, (int __user *)optval)) return -EFAULT; v = (v) ? 1 : 0; rtnl_lock(); ret = 0; if (v != mrt->mroute_do_pim) { mrt->mroute_do_pim = v; mrt->mroute_do_assert = v; } rtnl_unlock(); return ret; } #endif #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES case MRT_TABLE: { u32 v; if (optlen != sizeof(u32)) return -EINVAL; if (get_user(v, (u32 __user *)optval)) return -EFAULT; rtnl_lock(); ret = 0; if (sk == rtnl_dereference(mrt->mroute_sk)) { ret = -EBUSY; } else { if (!ipmr_new_table(net, v)) ret = -ENOMEM; raw_sk(sk)->ipmr_table = v; } rtnl_unlock(); return ret; } #endif /* * Spurious command, or MRT_VERSION which you cannot * set. */ default: return -ENOPROTOOPT; } } /* * Getsock opt support for the multicast routing system. */ int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen) { int olr; int val; struct net *net = sock_net(sk); struct mr_table *mrt; mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); if (mrt == NULL) return -ENOENT; if (optname != MRT_VERSION && #ifdef CONFIG_IP_PIMSM optname != MRT_PIM && #endif optname != MRT_ASSERT) return -ENOPROTOOPT; if (get_user(olr, optlen)) return -EFAULT; olr = min_t(unsigned int, olr, sizeof(int)); if (olr < 0) return -EINVAL; if (put_user(olr, optlen)) return -EFAULT; if (optname == MRT_VERSION) val = 0x0305; #ifdef CONFIG_IP_PIMSM else if (optname == MRT_PIM) val = mrt->mroute_do_pim; #endif else val = mrt->mroute_do_assert; if (copy_to_user(optval, &val, olr)) return -EFAULT; return 0; } /* * The IP multicast ioctl support routines. */ int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg) { struct sioc_sg_req sr; struct sioc_vif_req vr; struct vif_device *vif; struct mfc_cache *c; struct net *net = sock_net(sk); struct mr_table *mrt; mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); if (mrt == NULL) return -ENOENT; switch (cmd) { case SIOCGETVIFCNT: if (copy_from_user(&vr, arg, sizeof(vr))) return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { 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: if (copy_from_user(&sr, arg, sizeof(sr))) return -EFAULT; rcu_read_lock(); c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_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; rcu_read_unlock(); if (copy_to_user(arg, &sr, sizeof(sr))) return -EFAULT; return 0; } rcu_read_unlock(); return -EADDRNOTAVAIL; default: return -ENOIOCTLCMD; } } #ifdef CONFIG_COMPAT struct compat_sioc_sg_req { struct in_addr src; struct in_addr grp; compat_ulong_t pktcnt; compat_ulong_t bytecnt; compat_ulong_t wrong_if; }; struct compat_sioc_vif_req { vifi_t vifi; /* Which iface */ compat_ulong_t icount; compat_ulong_t ocount; compat_ulong_t ibytes; compat_ulong_t obytes; }; int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) { struct compat_sioc_sg_req sr; struct compat_sioc_vif_req vr; struct vif_device *vif; struct mfc_cache *c; struct net *net = sock_net(sk); struct mr_table *mrt; mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); if (mrt == NULL) return -ENOENT; switch (cmd) { case SIOCGETVIFCNT: if (copy_from_user(&vr, arg, sizeof(vr))) return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { 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: if (copy_from_user(&sr, arg, sizeof(sr))) return -EFAULT; rcu_read_lock(); c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_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; rcu_read_unlock(); if (copy_to_user(arg, &sr, sizeof(sr))) return -EFAULT; return 0; } rcu_read_unlock(); return -EADDRNOTAVAIL; default: return -ENOIOCTLCMD; } } #endif static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = ptr; struct net *net = dev_net(dev); struct mr_table *mrt; struct vif_device *v; int ct; LIST_HEAD(list); if (event != NETDEV_UNREGISTER) return NOTIFY_DONE; ipmr_for_each_table(mrt, net) { v = &mrt->vif_table[0]; for (ct = 0; ct < mrt->maxvif; ct++, v++) { if (v->dev == dev) vif_delete(mrt, ct, 1, &list); } } unregister_netdevice_many(&list); return NOTIFY_DONE; } static struct notifier_block ip_mr_notifier = { .notifier_call = ipmr_device_event, }; /* * Encapsulate a packet by attaching a valid IPIP header to it. * This avoids tunnel drivers and other mess and gives us the speed so * important for multicast video. */ static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr) { struct iphdr *iph; const struct iphdr *old_iph = ip_hdr(skb); skb_push(skb, sizeof(struct iphdr)); skb->transport_header = skb->network_header; skb_reset_network_header(skb); iph = ip_hdr(skb); iph->version = 4; iph->tos = old_iph->tos; iph->ttl = old_iph->ttl; iph->frag_off = 0; iph->daddr = daddr; iph->saddr = saddr; iph->protocol = IPPROTO_IPIP; iph->ihl = 5; iph->tot_len = htons(skb->len); ip_select_ident(iph, skb_dst(skb), NULL); ip_send_check(iph); memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); nf_reset(skb); } static inline int ipmr_forward_finish(struct sk_buff *skb) { struct ip_options *opt = &(IPCB(skb)->opt); IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS); if (unlikely(opt->optlen)) ip_forward_options(skb); return dst_output(skb); } /* * Processing handlers for ipmr_forward */ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *c, int vifi) { const struct iphdr *iph = ip_hdr(skb); struct vif_device *vif = &mrt->vif_table[vifi]; struct net_device *dev; struct rtable *rt; struct flowi4 fl4; int encap = 0; if (vif->dev == NULL) goto out_free; #ifdef CONFIG_IP_PIMSM if (vif->flags & VIFF_REGISTER) { vif->pkt_out++; vif->bytes_out += skb->len; vif->dev->stats.tx_bytes += skb->len; vif->dev->stats.tx_packets++; ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT); goto out_free; } #endif if (vif->flags & VIFF_TUNNEL) { rt = ip_route_output_ports(net, &fl4, NULL, vif->remote, vif->local, 0, 0, IPPROTO_IPIP, RT_TOS(iph->tos), vif->link); if (IS_ERR(rt)) goto out_free; encap = sizeof(struct iphdr); } else { rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0, 0, 0, IPPROTO_IPIP, RT_TOS(iph->tos), vif->link); if (IS_ERR(rt)) goto out_free; } dev = rt->dst.dev; if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) { /* Do not fragment multicasts. Alas, IPv4 does not * allow to send ICMP, so that packets will disappear * to blackhole. */ IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS); ip_rt_put(rt); goto out_free; } encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len; if (skb_cow(skb, encap)) { ip_rt_put(rt); goto out_free; } vif->pkt_out++; vif->bytes_out += skb->len; skb_dst_drop(skb); skb_dst_set(skb, &rt->dst); ip_decrease_ttl(ip_hdr(skb)); /* FIXME: forward and output firewalls used to be called here. * What do we do with netfilter? -- RR */ if (vif->flags & VIFF_TUNNEL) { ip_encap(skb, vif->local, vif->remote); /* FIXME: extra output firewall step used to be here. --RR */ vif->dev->stats.tx_packets++; vif->dev->stats.tx_bytes += skb->len; } IPCB(skb)->flags |= IPSKB_FORWARDED; /* * 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. */ NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev, ipmr_forward_finish); return; out_free: kfree_skb(skb); } static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev) { int ct; for (ct = mrt->maxvif-1; ct >= 0; ct--) { if (mrt->vif_table[ct].dev == dev) break; } return ct; } /* "local" means that we should preserve one skb (for local delivery) */ static int ip_mr_forward(struct net *net, struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *cache, int local) { int psend = -1; int vif, ct; vif = cache->mfc_parent; cache->mfc_un.res.pkt++; cache->mfc_un.res.bytes += skb->len; /* * Wrong interface: drop packet and (maybe) send PIM assert. */ if (mrt->vif_table[vif].dev != skb->dev) { int true_vifi; if (rt_is_output_route(skb_rtable(skb))) { /* It is our own packet, looped back. * Very complicated situation... * * The best workaround until routing daemons will be * fixed is not to redistribute packet, if it was * send through wrong interface. It means, that * multicast applications WILL NOT work for * (S,G), which have default multicast route pointing * to wrong oif. In any case, it is not a good * idea to use multicasting applications on router. */ goto dont_forward; } cache->mfc_un.res.wrong_if++; true_vifi = ipmr_find_vif(mrt, skb->dev); if (true_vifi >= 0 && mrt->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 */ (mrt->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; ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF); } goto dont_forward; } mrt->vif_table[vif].pkt_in++; mrt->vif_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 (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) { if (psend != -1) { struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); if (skb2) ipmr_queue_xmit(net, mrt, skb2, cache, psend); } psend = ct; } } if (psend != -1) { if (local) { struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); if (skb2) ipmr_queue_xmit(net, mrt, skb2, cache, psend); } else { ipmr_queue_xmit(net, mrt, skb, cache, psend); return 0; } } dont_forward: if (!local) kfree_skb(skb); return 0; } static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb) { struct rtable *rt = skb_rtable(skb); struct iphdr *iph = ip_hdr(skb); struct flowi4 fl4 = { .daddr = iph->daddr, .saddr = iph->saddr, .flowi4_tos = RT_TOS(iph->tos), .flowi4_oif = rt->rt_oif, .flowi4_iif = rt->rt_iif, .flowi4_mark = rt->rt_mark, }; struct mr_table *mrt; int err; err = ipmr_fib_lookup(net, &fl4, &mrt); if (err) return ERR_PTR(err); return mrt; } /* * Multicast packets for forwarding arrive here * Called with rcu_read_lock(); */ int ip_mr_input(struct sk_buff *skb) { struct mfc_cache *cache; struct net *net = dev_net(skb->dev); int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL; struct mr_table *mrt; /* Packet is looped back after forward, it should not be * forwarded second time, but still can be delivered locally. */ if (IPCB(skb)->flags & IPSKB_FORWARDED) goto dont_forward; mrt = ipmr_rt_fib_lookup(net, skb); if (IS_ERR(mrt)) { kfree_skb(skb); return PTR_ERR(mrt); } if (!local) { if (IPCB(skb)->opt.router_alert) { if (ip_call_ra_chain(skb)) return 0; } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) { /* IGMPv1 (and broken IGMPv2 implementations sort of * Cisco IOS <= 11.2(8)) do not put router alert * option to IGMP packets destined to routable * groups. It is very bad, because it means * that we can forward NO IGMP messages. */ struct sock *mroute_sk; mroute_sk = rcu_dereference(mrt->mroute_sk); if (mroute_sk) { nf_reset(skb); raw_rcv(mroute_sk, skb); return 0; } } } /* already under rcu_read_lock() */ cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); /* * No usable cache entry */ if (cache == NULL) { int vif; if (local) { struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); ip_local_deliver(skb); if (skb2 == NULL) return -ENOBUFS; skb = skb2; } read_lock(&mrt_lock); vif = ipmr_find_vif(mrt, skb->dev); if (vif >= 0) { int err2 = ipmr_cache_unresolved(mrt, vif, skb); read_unlock(&mrt_lock); return err2; } read_unlock(&mrt_lock); kfree_skb(skb); return -ENODEV; } read_lock(&mrt_lock); ip_mr_forward(net, mrt, skb, cache, local); read_unlock(&mrt_lock); if (local) return ip_local_deliver(skb); return 0; dont_forward: if (local) return ip_local_deliver(skb); kfree_skb(skb); return 0; } #ifdef CONFIG_IP_PIMSM /* called with rcu_read_lock() */ static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb, unsigned int pimlen) { struct net_device *reg_dev = NULL; struct iphdr *encap; encap = (struct iphdr *)(skb_transport_header(skb) + pimlen); /* * Check that: * a. packet is really sent to a multicast group * b. packet is not a NULL-REGISTER * c. packet is not truncated */ if (!ipv4_is_multicast(encap->daddr) || encap->tot_len == 0 || ntohs(encap->tot_len) + pimlen > skb->len) return 1; read_lock(&mrt_lock); if (mrt->mroute_reg_vif_num >= 0) reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev; read_unlock(&mrt_lock); if (reg_dev == NULL) return 1; skb->mac_header = skb->network_header; skb_pull(skb, (u8 *)encap - skb->data); skb_reset_network_header(skb); skb->protocol = htons(ETH_P_IP); skb->ip_summed = CHECKSUM_NONE; skb->pkt_type = PACKET_HOST; skb_tunnel_rx(skb, reg_dev); netif_rx(skb); return NET_RX_SUCCESS; } #endif #ifdef CONFIG_IP_PIMSM_V1 /* * Handle IGMP messages of PIMv1 */ int pim_rcv_v1(struct sk_buff *skb) { struct igmphdr *pim; struct net *net = dev_net(skb->dev); struct mr_table *mrt; if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr))) goto drop; pim = igmp_hdr(skb); mrt = ipmr_rt_fib_lookup(net, skb); if (IS_ERR(mrt)) goto drop; if (!mrt->mroute_do_pim || pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) goto drop; if (__pim_rcv(mrt, skb, sizeof(*pim))) { drop: kfree_skb(skb); } return 0; } #endif #ifdef CONFIG_IP_PIMSM_V2 static int pim_rcv(struct sk_buff *skb) { struct pimreghdr *pim; struct net *net = dev_net(skb->dev); struct mr_table *mrt; if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr))) 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 && csum_fold(skb_checksum(skb, 0, skb->len, 0)))) goto drop; mrt = ipmr_rt_fib_lookup(net, skb); if (IS_ERR(mrt)) goto drop; if (__pim_rcv(mrt, skb, sizeof(*pim))) { drop: kfree_skb(skb); } return 0; } #endif static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm) { int ct; struct rtnexthop *nhp; u8 *b = skb_tail_pointer(skb); struct rtattr *mp_head; /* If cache is unresolved, don't try to parse IIF and OIF */ if (c->mfc_parent >= MAXVIFS) return -ENOENT; if (VIF_EXISTS(mrt, c->mfc_parent)) RTA_PUT(skb, RTA_IIF, 4, &mrt->vif_table[c->mfc_parent].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 (VIF_EXISTS(mrt, ct) && 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 = mrt->vif_table[ct].dev->ifindex; nhp->rtnh_len = sizeof(*nhp); } } mp_head->rta_type = RTA_MULTIPATH; mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head; rtm->rtm_type = RTN_MULTICAST; return 1; rtattr_failure: nlmsg_trim(skb, b); return -EMSGSIZE; } int ipmr_get_route(struct net *net, struct sk_buff *skb, __be32 saddr, __be32 daddr, struct rtmsg *rtm, int nowait) { struct mfc_cache *cache; struct mr_table *mrt; int err; mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); if (mrt == NULL) return -ENOENT; rcu_read_lock(); cache = ipmr_cache_find(mrt, saddr, daddr); if (cache == NULL) { struct sk_buff *skb2; struct iphdr *iph; struct net_device *dev; int vif = -1; if (nowait) { rcu_read_unlock(); return -EAGAIN; } dev = skb->dev; read_lock(&mrt_lock); if (dev) vif = ipmr_find_vif(mrt, dev); if (vif < 0) { read_unlock(&mrt_lock); rcu_read_unlock(); return -ENODEV; } skb2 = skb_clone(skb, GFP_ATOMIC); if (!skb2) { read_unlock(&mrt_lock); rcu_read_unlock(); return -ENOMEM; } skb_push(skb2, sizeof(struct iphdr)); skb_reset_network_header(skb2); iph = ip_hdr(skb2); iph->ihl = sizeof(struct iphdr) >> 2; iph->saddr = saddr; iph->daddr = daddr; iph->version = 0; err = ipmr_cache_unresolved(mrt, vif, skb2); read_unlock(&mrt_lock); rcu_read_unlock(); return err; } read_lock(&mrt_lock); if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY)) cache->mfc_flags |= MFC_NOTIFY; err = __ipmr_fill_mroute(mrt, skb, cache, rtm); read_unlock(&mrt_lock); rcu_read_unlock(); return err; } static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, u32 pid, u32 seq, struct mfc_cache *c) { struct nlmsghdr *nlh; struct rtmsg *rtm; nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI); if (nlh == NULL) return -EMSGSIZE; rtm = nlmsg_data(nlh); rtm->rtm_family = RTNL_FAMILY_IPMR; rtm->rtm_dst_len = 32; rtm->rtm_src_len = 32; rtm->rtm_tos = 0; rtm->rtm_table = mrt->id; NLA_PUT_U32(skb, RTA_TABLE, mrt->id); rtm->rtm_type = RTN_MULTICAST; rtm->rtm_scope = RT_SCOPE_UNIVERSE; rtm->rtm_protocol = RTPROT_UNSPEC; rtm->rtm_flags = 0; NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin); NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp); if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0) goto nla_put_failure; return nlmsg_end(skb, nlh); nla_put_failure: nlmsg_cancel(skb, nlh); return -EMSGSIZE; } static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); struct mr_table *mrt; struct mfc_cache *mfc; unsigned int t = 0, s_t; unsigned int h = 0, s_h; unsigned int e = 0, s_e; s_t = cb->args[0]; s_h = cb->args[1]; s_e = cb->args[2]; rcu_read_lock(); ipmr_for_each_table(mrt, net) { if (t < s_t) goto next_table; if (t > s_t) s_h = 0; for (h = s_h; h < MFC_LINES; h++) { list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) { if (e < s_e) goto next_entry; if (ipmr_fill_mroute(mrt, skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, mfc) < 0) goto done; next_entry: e++; } e = s_e = 0; } s_h = 0; next_table: t++; } done: rcu_read_unlock(); cb->args[2] = e; cb->args[1] = h; cb->args[0] = t; return skb->len; } #ifdef CONFIG_PROC_FS /* * The /proc interfaces to multicast routing : * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif */ struct ipmr_vif_iter { struct seq_net_private p; struct mr_table *mrt; int ct; }; static struct vif_device *ipmr_vif_seq_idx(struct net *net, struct ipmr_vif_iter *iter, loff_t pos) { struct mr_table *mrt = iter->mrt; for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) { if (!VIF_EXISTS(mrt, iter->ct)) continue; if (pos-- == 0) return &mrt->vif_table[iter->ct]; } return NULL; } static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos) __acquires(mrt_lock) { struct ipmr_vif_iter *iter = seq->private; struct net *net = seq_file_net(seq); struct mr_table *mrt; mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); if (mrt == NULL) return ERR_PTR(-ENOENT); iter->mrt = mrt; read_lock(&mrt_lock); return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1) : SEQ_START_TOKEN; } static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct ipmr_vif_iter *iter = seq->private; struct net *net = seq_file_net(seq); struct mr_table *mrt = iter->mrt; ++*pos; if (v == SEQ_START_TOKEN) return ipmr_vif_seq_idx(net, iter, 0); while (++iter->ct < mrt->maxvif) { if (!VIF_EXISTS(mrt, iter->ct)) continue; return &mrt->vif_table[iter->ct]; } return NULL; } static void ipmr_vif_seq_stop(struct seq_file *seq, void *v) __releases(mrt_lock) { read_unlock(&mrt_lock); } static int ipmr_vif_seq_show(struct seq_file *seq, void *v) { struct ipmr_vif_iter *iter = seq->private; struct mr_table *mrt = iter->mrt; if (v == SEQ_START_TOKEN) { seq_puts(seq, "Interface BytesIn PktsIn BytesOut PktsOut Flags Local Remote\n"); } else { const struct vif_device *vif = v; const char *name = vif->dev ? vif->dev->name : "none"; seq_printf(seq, "%2Zd %-10s %8ld %7ld %8ld %7ld %05X %08X %08X\n", vif - mrt->vif_table, name, vif->bytes_in, vif->pkt_in, vif->bytes_out, vif->pkt_out, vif->flags, vif->local, vif->remote); } return 0; } static const struct seq_operations ipmr_vif_seq_ops = { .start = ipmr_vif_seq_start, .next = ipmr_vif_seq_next, .stop = ipmr_vif_seq_stop, .show = ipmr_vif_seq_show, }; static int ipmr_vif_open(struct inode *inode, struct file *file) { return seq_open_net(inode, file, &ipmr_vif_seq_ops, sizeof(struct ipmr_vif_iter)); } static const struct file_operations ipmr_vif_fops = { .owner = THIS_MODULE, .open = ipmr_vif_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_net, }; struct ipmr_mfc_iter { struct seq_net_private p; struct mr_table *mrt; struct list_head *cache; int ct; }; static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net, struct ipmr_mfc_iter *it, loff_t pos) { struct mr_table *mrt = it->mrt; struct mfc_cache *mfc; rcu_read_lock(); for (it->ct = 0; it->ct < MFC_LINES; it->ct++) { it->cache = &mrt->mfc_cache_array[it->ct]; list_for_each_entry_rcu(mfc, it->cache, list) if (pos-- == 0) return mfc; } rcu_read_unlock(); spin_lock_bh(&mfc_unres_lock); it->cache = &mrt->mfc_unres_queue; list_for_each_entry(mfc, it->cache, list) if (pos-- == 0) return mfc; spin_unlock_bh(&mfc_unres_lock); it->cache = NULL; return NULL; } static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos) { struct ipmr_mfc_iter *it = seq->private; struct net *net = seq_file_net(seq); struct mr_table *mrt; mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); if (mrt == NULL) return ERR_PTR(-ENOENT); it->mrt = mrt; it->cache = NULL; it->ct = 0; return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1) : SEQ_START_TOKEN; } static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct mfc_cache *mfc = v; struct ipmr_mfc_iter *it = seq->private; struct net *net = seq_file_net(seq); struct mr_table *mrt = it->mrt; ++*pos; if (v == SEQ_START_TOKEN) return ipmr_mfc_seq_idx(net, seq->private, 0); if (mfc->list.next != it->cache) return list_entry(mfc->list.next, struct mfc_cache, list); if (it->cache == &mrt->mfc_unres_queue) goto end_of_list; BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]); while (++it->ct < MFC_LINES) { it->cache = &mrt->mfc_cache_array[it->ct]; if (list_empty(it->cache)) continue; return list_first_entry(it->cache, struct mfc_cache, list); } /* exhausted cache_array, show unresolved */ rcu_read_unlock(); it->cache = &mrt->mfc_unres_queue; it->ct = 0; spin_lock_bh(&mfc_unres_lock); if (!list_empty(it->cache)) return list_first_entry(it->cache, struct mfc_cache, list); 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; struct mr_table *mrt = it->mrt; if (it->cache == &mrt->mfc_unres_queue) spin_unlock_bh(&mfc_unres_lock); else if (it->cache == &mrt->mfc_cache_array[it->ct]) rcu_read_unlock(); } 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 mfc_cache *mfc = v; const struct ipmr_mfc_iter *it = seq->private; const struct mr_table *mrt = it->mrt; seq_printf(seq, "%08X %08X %-3hd", (__force u32) mfc->mfc_mcastgrp, (__force u32) mfc->mfc_origin, mfc->mfc_parent); if (it->cache != &mrt->mfc_unres_queue) { seq_printf(seq, " %8lu %8lu %8lu", mfc->mfc_un.res.pkt, mfc->mfc_un.res.bytes, mfc->mfc_un.res.wrong_if); for (n = mfc->mfc_un.res.minvif; n < mfc->mfc_un.res.maxvif; n++) { if (VIF_EXISTS(mrt, n) && mfc->mfc_un.res.ttls[n] < 255) seq_printf(seq, " %2d:%-3d", n, mfc->mfc_un.res.ttls[n]); } } else { /* unresolved mfc_caches don't contain * pkt, bytes and wrong_if values */ seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul); } seq_putc(seq, '\n'); } return 0; } static const 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_net(inode, file, &ipmr_mfc_seq_ops, sizeof(struct ipmr_mfc_iter)); } static const struct file_operations ipmr_mfc_fops = { .owner = THIS_MODULE, .open = ipmr_mfc_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_net, }; #endif #ifdef CONFIG_IP_PIMSM_V2 static const struct net_protocol pim_protocol = { .handler = pim_rcv, .netns_ok = 1, }; #endif /* * Setup for IP multicast routing */ static int __net_init ipmr_net_init(struct net *net) { int err; err = ipmr_rules_init(net); if (err < 0) goto fail; #ifdef CONFIG_PROC_FS err = -ENOMEM; if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops)) goto proc_vif_fail; if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops)) goto proc_cache_fail; #endif return 0; #ifdef CONFIG_PROC_FS proc_cache_fail: proc_net_remove(net, "ip_mr_vif"); proc_vif_fail: ipmr_rules_exit(net); #endif fail: return err; } static void __net_exit ipmr_net_exit(struct net *net) { #ifdef CONFIG_PROC_FS proc_net_remove(net, "ip_mr_cache"); proc_net_remove(net, "ip_mr_vif"); #endif ipmr_rules_exit(net); } static struct pernet_operations ipmr_net_ops = { .init = ipmr_net_init, .exit = ipmr_net_exit, }; int __init ip_mr_init(void) { int err; mrt_cachep = kmem_cache_create("ip_mrt_cache", sizeof(struct mfc_cache), 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); if (!mrt_cachep) return -ENOMEM; err = register_pernet_subsys(&ipmr_net_ops); if (err) goto reg_pernet_fail; err = register_netdevice_notifier(&ip_mr_notifier); if (err) goto reg_notif_fail; #ifdef CONFIG_IP_PIMSM_V2 if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) { printk(KERN_ERR "ip_mr_init: can't add PIM protocol\n"); err = -EAGAIN; goto add_proto_fail; } #endif rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute, NULL); return 0; #ifdef CONFIG_IP_PIMSM_V2 add_proto_fail: unregister_netdevice_notifier(&ip_mr_notifier); #endif reg_notif_fail: unregister_pernet_subsys(&ipmr_net_ops); reg_pernet_fail: kmem_cache_destroy(mrt_cachep); return err; }