/* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * IPv4 Forwarding Information Base: FIB frontend. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> * * 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 <linux/module.h> #include <asm/uaccess.h> #include <asm/system.h> #include <linux/bitops.h> #include <linux/capability.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/socket.h> #include <linux/sockios.h> #include <linux/errno.h> #include <linux/in.h> #include <linux/inet.h> #include <linux/inetdevice.h> #include <linux/netdevice.h> #include <linux/if_addr.h> #include <linux/if_arp.h> #include <linux/skbuff.h> #include <linux/init.h> #include <linux/list.h> #include <net/ip.h> #include <net/protocol.h> #include <net/route.h> #include <net/tcp.h> #include <net/sock.h> #include <net/arp.h> #include <net/ip_fib.h> #include <net/rtnetlink.h> #ifndef CONFIG_IP_MULTIPLE_TABLES static int __net_init fib4_rules_init(struct net *net) { struct fib_table *local_table, *main_table; local_table = fib_hash_table(RT_TABLE_LOCAL); if (local_table == NULL) return -ENOMEM; main_table = fib_hash_table(RT_TABLE_MAIN); if (main_table == NULL) goto fail; hlist_add_head_rcu(&local_table->tb_hlist, &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); hlist_add_head_rcu(&main_table->tb_hlist, &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); return 0; fail: kfree(local_table); return -ENOMEM; } #else struct fib_table *fib_new_table(struct net *net, u32 id) { struct fib_table *tb; unsigned int h; if (id == 0) id = RT_TABLE_MAIN; tb = fib_get_table(net, id); if (tb) return tb; tb = fib_hash_table(id); if (!tb) return NULL; h = id & (FIB_TABLE_HASHSZ - 1); hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); return tb; } struct fib_table *fib_get_table(struct net *net, u32 id) { struct fib_table *tb; struct hlist_node *node; struct hlist_head *head; unsigned int h; if (id == 0) id = RT_TABLE_MAIN; h = id & (FIB_TABLE_HASHSZ - 1); rcu_read_lock(); head = &net->ipv4.fib_table_hash[h]; hlist_for_each_entry_rcu(tb, node, head, tb_hlist) { if (tb->tb_id == id) { rcu_read_unlock(); return tb; } } rcu_read_unlock(); return NULL; } #endif /* CONFIG_IP_MULTIPLE_TABLES */ void fib_select_default(struct net *net, const struct flowi *flp, struct fib_result *res) { struct fib_table *tb; int table = RT_TABLE_MAIN; #ifdef CONFIG_IP_MULTIPLE_TABLES if (res->r == NULL || res->r->action != FR_ACT_TO_TBL) return; table = res->r->table; #endif tb = fib_get_table(net, table); if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) tb->tb_select_default(tb, flp, res); } static void fib_flush(struct net *net) { int flushed = 0; struct fib_table *tb; struct hlist_node *node; struct hlist_head *head; unsigned int h; for (h = 0; h < FIB_TABLE_HASHSZ; h++) { head = &net->ipv4.fib_table_hash[h]; hlist_for_each_entry(tb, node, head, tb_hlist) flushed += tb->tb_flush(tb); } if (flushed) rt_cache_flush(net, -1); } /* * Find the first device with a given source address. */ struct net_device * ip_dev_find(struct net *net, __be32 addr) { struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } }; struct fib_result res; struct net_device *dev = NULL; struct fib_table *local_table; #ifdef CONFIG_IP_MULTIPLE_TABLES res.r = NULL; #endif local_table = fib_get_table(net, RT_TABLE_LOCAL); if (!local_table || local_table->tb_lookup(local_table, &fl, &res)) return NULL; if (res.type != RTN_LOCAL) goto out; dev = FIB_RES_DEV(res); if (dev) dev_hold(dev); out: fib_res_put(&res); return dev; } /* * Find address type as if only "dev" was present in the system. If * on_dev is NULL then all interfaces are taken into consideration. */ static inline unsigned __inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr) { struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } }; struct fib_result res; unsigned ret = RTN_BROADCAST; struct fib_table *local_table; if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) return RTN_BROADCAST; if (ipv4_is_multicast(addr)) return RTN_MULTICAST; #ifdef CONFIG_IP_MULTIPLE_TABLES res.r = NULL; #endif local_table = fib_get_table(net, RT_TABLE_LOCAL); if (local_table) { ret = RTN_UNICAST; if (!local_table->tb_lookup(local_table, &fl, &res)) { if (!dev || dev == res.fi->fib_dev) ret = res.type; fib_res_put(&res); } } return ret; } unsigned int inet_addr_type(struct net *net, __be32 addr) { return __inet_dev_addr_type(net, NULL, addr); } unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr) { return __inet_dev_addr_type(net, dev, addr); } /* Given (packet source, input interface) and optional (dst, oif, tos): - (main) check, that source is valid i.e. not broadcast or our local address. - figure out what "logical" interface this packet arrived and calculate "specific destination" address. - check, that packet arrived from expected physical interface. */ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif, struct net_device *dev, __be32 *spec_dst, u32 *itag) { struct in_device *in_dev; struct flowi fl = { .nl_u = { .ip4_u = { .daddr = src, .saddr = dst, .tos = tos } }, .iif = oif }; struct fib_result res; int no_addr, rpf; int ret; struct net *net; no_addr = rpf = 0; rcu_read_lock(); in_dev = __in_dev_get_rcu(dev); if (in_dev) { no_addr = in_dev->ifa_list == NULL; rpf = IN_DEV_RPFILTER(in_dev); } rcu_read_unlock(); if (in_dev == NULL) goto e_inval; net = dev_net(dev); if (fib_lookup(net, &fl, &res)) goto last_resort; if (res.type != RTN_UNICAST) goto e_inval_res; *spec_dst = FIB_RES_PREFSRC(res); fib_combine_itag(itag, &res); #ifdef CONFIG_IP_ROUTE_MULTIPATH if (FIB_RES_DEV(res) == dev || res.fi->fib_nhs > 1) #else if (FIB_RES_DEV(res) == dev) #endif { ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; fib_res_put(&res); return ret; } fib_res_put(&res); if (no_addr) goto last_resort; if (rpf == 1) goto e_inval; fl.oif = dev->ifindex; ret = 0; if (fib_lookup(net, &fl, &res) == 0) { if (res.type == RTN_UNICAST) { *spec_dst = FIB_RES_PREFSRC(res); ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; } fib_res_put(&res); } return ret; last_resort: if (rpf) goto e_inval; *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); *itag = 0; return 0; e_inval_res: fib_res_put(&res); e_inval: return -EINVAL; } static inline __be32 sk_extract_addr(struct sockaddr *addr) { return ((struct sockaddr_in *) addr)->sin_addr.s_addr; } static int put_rtax(struct nlattr *mx, int len, int type, u32 value) { struct nlattr *nla; nla = (struct nlattr *) ((char *) mx + len); nla->nla_type = type; nla->nla_len = nla_attr_size(4); *(u32 *) nla_data(nla) = value; return len + nla_total_size(4); } static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, struct fib_config *cfg) { __be32 addr; int plen; memset(cfg, 0, sizeof(*cfg)); cfg->fc_nlinfo.nl_net = net; if (rt->rt_dst.sa_family != AF_INET) return -EAFNOSUPPORT; /* * Check mask for validity: * a) it must be contiguous. * b) destination must have all host bits clear. * c) if application forgot to set correct family (AF_INET), * reject request unless it is absolutely clear i.e. * both family and mask are zero. */ plen = 32; addr = sk_extract_addr(&rt->rt_dst); if (!(rt->rt_flags & RTF_HOST)) { __be32 mask = sk_extract_addr(&rt->rt_genmask); if (rt->rt_genmask.sa_family != AF_INET) { if (mask || rt->rt_genmask.sa_family) return -EAFNOSUPPORT; } if (bad_mask(mask, addr)) return -EINVAL; plen = inet_mask_len(mask); } cfg->fc_dst_len = plen; cfg->fc_dst = addr; if (cmd != SIOCDELRT) { cfg->fc_nlflags = NLM_F_CREATE; cfg->fc_protocol = RTPROT_BOOT; } if (rt->rt_metric) cfg->fc_priority = rt->rt_metric - 1; if (rt->rt_flags & RTF_REJECT) { cfg->fc_scope = RT_SCOPE_HOST; cfg->fc_type = RTN_UNREACHABLE; return 0; } cfg->fc_scope = RT_SCOPE_NOWHERE; cfg->fc_type = RTN_UNICAST; if (rt->rt_dev) { char *colon; struct net_device *dev; char devname[IFNAMSIZ]; if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) return -EFAULT; devname[IFNAMSIZ-1] = 0; colon = strchr(devname, ':'); if (colon) *colon = 0; dev = __dev_get_by_name(net, devname); if (!dev) return -ENODEV; cfg->fc_oif = dev->ifindex; if (colon) { struct in_ifaddr *ifa; struct in_device *in_dev = __in_dev_get_rtnl(dev); if (!in_dev) return -ENODEV; *colon = ':'; for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) if (strcmp(ifa->ifa_label, devname) == 0) break; if (ifa == NULL) return -ENODEV; cfg->fc_prefsrc = ifa->ifa_local; } } addr = sk_extract_addr(&rt->rt_gateway); if (rt->rt_gateway.sa_family == AF_INET && addr) { cfg->fc_gw = addr; if (rt->rt_flags & RTF_GATEWAY && inet_addr_type(net, addr) == RTN_UNICAST) cfg->fc_scope = RT_SCOPE_UNIVERSE; } if (cmd == SIOCDELRT) return 0; if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) return -EINVAL; if (cfg->fc_scope == RT_SCOPE_NOWHERE) cfg->fc_scope = RT_SCOPE_LINK; if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { struct nlattr *mx; int len = 0; mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); if (mx == NULL) return -ENOMEM; if (rt->rt_flags & RTF_MTU) len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); if (rt->rt_flags & RTF_WINDOW) len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); if (rt->rt_flags & RTF_IRTT) len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); cfg->fc_mx = mx; cfg->fc_mx_len = len; } return 0; } /* * Handle IP routing ioctl calls. These are used to manipulate the routing tables */ int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) { struct fib_config cfg; struct rtentry rt; int err; switch (cmd) { case SIOCADDRT: /* Add a route */ case SIOCDELRT: /* Delete a route */ if (!capable(CAP_NET_ADMIN)) return -EPERM; if (copy_from_user(&rt, arg, sizeof(rt))) return -EFAULT; rtnl_lock(); err = rtentry_to_fib_config(net, cmd, &rt, &cfg); if (err == 0) { struct fib_table *tb; if (cmd == SIOCDELRT) { tb = fib_get_table(net, cfg.fc_table); if (tb) err = tb->tb_delete(tb, &cfg); else err = -ESRCH; } else { tb = fib_new_table(net, cfg.fc_table); if (tb) err = tb->tb_insert(tb, &cfg); else err = -ENOBUFS; } /* allocated by rtentry_to_fib_config() */ kfree(cfg.fc_mx); } rtnl_unlock(); return err; } return -EINVAL; } const struct nla_policy rtm_ipv4_policy[RTA_MAX+1] = { [RTA_DST] = { .type = NLA_U32 }, [RTA_SRC] = { .type = NLA_U32 }, [RTA_IIF] = { .type = NLA_U32 }, [RTA_OIF] = { .type = NLA_U32 }, [RTA_GATEWAY] = { .type = NLA_U32 }, [RTA_PRIORITY] = { .type = NLA_U32 }, [RTA_PREFSRC] = { .type = NLA_U32 }, [RTA_METRICS] = { .type = NLA_NESTED }, [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, [RTA_FLOW] = { .type = NLA_U32 }, }; static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh, struct fib_config *cfg) { struct nlattr *attr; int err, remaining; struct rtmsg *rtm; err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); if (err < 0) goto errout; memset(cfg, 0, sizeof(*cfg)); rtm = nlmsg_data(nlh); cfg->fc_dst_len = rtm->rtm_dst_len; cfg->fc_tos = rtm->rtm_tos; cfg->fc_table = rtm->rtm_table; cfg->fc_protocol = rtm->rtm_protocol; cfg->fc_scope = rtm->rtm_scope; cfg->fc_type = rtm->rtm_type; cfg->fc_flags = rtm->rtm_flags; cfg->fc_nlflags = nlh->nlmsg_flags; cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; cfg->fc_nlinfo.nlh = nlh; cfg->fc_nlinfo.nl_net = net; if (cfg->fc_type > RTN_MAX) { err = -EINVAL; goto errout; } nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { switch (nla_type(attr)) { case RTA_DST: cfg->fc_dst = nla_get_be32(attr); break; case RTA_OIF: cfg->fc_oif = nla_get_u32(attr); break; case RTA_GATEWAY: cfg->fc_gw = nla_get_be32(attr); break; case RTA_PRIORITY: cfg->fc_priority = nla_get_u32(attr); break; case RTA_PREFSRC: cfg->fc_prefsrc = nla_get_be32(attr); break; case RTA_METRICS: cfg->fc_mx = nla_data(attr); cfg->fc_mx_len = nla_len(attr); break; case RTA_MULTIPATH: cfg->fc_mp = nla_data(attr); cfg->fc_mp_len = nla_len(attr); break; case RTA_FLOW: cfg->fc_flow = nla_get_u32(attr); break; case RTA_TABLE: cfg->fc_table = nla_get_u32(attr); break; } } return 0; errout: return err; } static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) { struct net *net = sock_net(skb->sk); struct fib_config cfg; struct fib_table *tb; int err; err = rtm_to_fib_config(net, skb, nlh, &cfg); if (err < 0) goto errout; tb = fib_get_table(net, cfg.fc_table); if (tb == NULL) { err = -ESRCH; goto errout; } err = tb->tb_delete(tb, &cfg); errout: return err; } static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) { struct net *net = sock_net(skb->sk); struct fib_config cfg; struct fib_table *tb; int err; err = rtm_to_fib_config(net, skb, nlh, &cfg); if (err < 0) goto errout; tb = fib_new_table(net, cfg.fc_table); if (tb == NULL) { err = -ENOBUFS; goto errout; } err = tb->tb_insert(tb, &cfg); errout: return err; } static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); unsigned int h, s_h; unsigned int e = 0, s_e; struct fib_table *tb; struct hlist_node *node; struct hlist_head *head; int dumped = 0; if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) return ip_rt_dump(skb, cb); s_h = cb->args[0]; s_e = cb->args[1]; for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { e = 0; head = &net->ipv4.fib_table_hash[h]; hlist_for_each_entry(tb, node, head, tb_hlist) { if (e < s_e) goto next; if (dumped) memset(&cb->args[2], 0, sizeof(cb->args) - 2 * sizeof(cb->args[0])); if (tb->tb_dump(tb, skb, cb) < 0) goto out; dumped = 1; next: e++; } } out: cb->args[1] = e; cb->args[0] = h; return skb->len; } /* Prepare and feed intra-kernel routing request. Really, it should be netlink message, but :-( netlink can be not configured, so that we feed it directly to fib engine. It is legal, because all events occur only when netlink is already locked. */ static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) { struct net *net = dev_net(ifa->ifa_dev->dev); struct fib_table *tb; struct fib_config cfg = { .fc_protocol = RTPROT_KERNEL, .fc_type = type, .fc_dst = dst, .fc_dst_len = dst_len, .fc_prefsrc = ifa->ifa_local, .fc_oif = ifa->ifa_dev->dev->ifindex, .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, .fc_nlinfo = { .nl_net = net, }, }; if (type == RTN_UNICAST) tb = fib_new_table(net, RT_TABLE_MAIN); else tb = fib_new_table(net, RT_TABLE_LOCAL); if (tb == NULL) return; cfg.fc_table = tb->tb_id; if (type != RTN_LOCAL) cfg.fc_scope = RT_SCOPE_LINK; else cfg.fc_scope = RT_SCOPE_HOST; if (cmd == RTM_NEWROUTE) tb->tb_insert(tb, &cfg); else tb->tb_delete(tb, &cfg); } void fib_add_ifaddr(struct in_ifaddr *ifa) { struct in_device *in_dev = ifa->ifa_dev; struct net_device *dev = in_dev->dev; struct in_ifaddr *prim = ifa; __be32 mask = ifa->ifa_mask; __be32 addr = ifa->ifa_local; __be32 prefix = ifa->ifa_address&mask; if (ifa->ifa_flags&IFA_F_SECONDARY) { prim = inet_ifa_byprefix(in_dev, prefix, mask); if (prim == NULL) { printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n"); return; } } fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); if (!(dev->flags&IFF_UP)) return; /* Add broadcast address, if it is explicitly assigned. */ if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) && (prefix != addr || ifa->ifa_prefixlen < 32)) { fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim); /* Add network specific broadcasts, when it takes a sense */ if (ifa->ifa_prefixlen < 31) { fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim); } } } static void fib_del_ifaddr(struct in_ifaddr *ifa) { struct in_device *in_dev = ifa->ifa_dev; struct net_device *dev = in_dev->dev; struct in_ifaddr *ifa1; struct in_ifaddr *prim = ifa; __be32 brd = ifa->ifa_address|~ifa->ifa_mask; __be32 any = ifa->ifa_address&ifa->ifa_mask; #define LOCAL_OK 1 #define BRD_OK 2 #define BRD0_OK 4 #define BRD1_OK 8 unsigned ok = 0; if (!(ifa->ifa_flags&IFA_F_SECONDARY)) fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, any, ifa->ifa_prefixlen, prim); else { prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); if (prim == NULL) { printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n"); return; } } /* Deletion is more complicated than add. We should take care of not to delete too much :-) Scan address list to be sure that addresses are really gone. */ for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { if (ifa->ifa_local == ifa1->ifa_local) ok |= LOCAL_OK; if (ifa->ifa_broadcast == ifa1->ifa_broadcast) ok |= BRD_OK; if (brd == ifa1->ifa_broadcast) ok |= BRD1_OK; if (any == ifa1->ifa_broadcast) ok |= BRD0_OK; } if (!(ok&BRD_OK)) fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); if (!(ok&BRD1_OK)) fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); if (!(ok&BRD0_OK)) fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); if (!(ok&LOCAL_OK)) { fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); /* Check, that this local address finally disappeared. */ if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { /* And the last, but not the least thing. We must flush stray FIB entries. First of all, we scan fib_info list searching for stray nexthop entries, then ignite fib_flush. */ if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) fib_flush(dev_net(dev)); } } #undef LOCAL_OK #undef BRD_OK #undef BRD0_OK #undef BRD1_OK } static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb ) { struct fib_result res; struct flowi fl = { .mark = frn->fl_mark, .nl_u = { .ip4_u = { .daddr = frn->fl_addr, .tos = frn->fl_tos, .scope = frn->fl_scope } } }; #ifdef CONFIG_IP_MULTIPLE_TABLES res.r = NULL; #endif frn->err = -ENOENT; if (tb) { local_bh_disable(); frn->tb_id = tb->tb_id; frn->err = tb->tb_lookup(tb, &fl, &res); if (!frn->err) { frn->prefixlen = res.prefixlen; frn->nh_sel = res.nh_sel; frn->type = res.type; frn->scope = res.scope; fib_res_put(&res); } local_bh_enable(); } } static void nl_fib_input(struct sk_buff *skb) { struct net *net; struct fib_result_nl *frn; struct nlmsghdr *nlh; struct fib_table *tb; u32 pid; net = sock_net(skb->sk); nlh = nlmsg_hdr(skb); if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) return; skb = skb_clone(skb, GFP_KERNEL); if (skb == NULL) return; nlh = nlmsg_hdr(skb); frn = (struct fib_result_nl *) NLMSG_DATA(nlh); tb = fib_get_table(net, frn->tb_id_in); nl_fib_lookup(frn, tb); pid = NETLINK_CB(skb).pid; /* pid of sending process */ NETLINK_CB(skb).pid = 0; /* from kernel */ NETLINK_CB(skb).dst_group = 0; /* unicast */ netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); } static int nl_fib_lookup_init(struct net *net) { struct sock *sk; sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, nl_fib_input, NULL, THIS_MODULE); if (sk == NULL) return -EAFNOSUPPORT; net->ipv4.fibnl = sk; return 0; } static void nl_fib_lookup_exit(struct net *net) { netlink_kernel_release(net->ipv4.fibnl); net->ipv4.fibnl = NULL; } static void fib_disable_ip(struct net_device *dev, int force) { if (fib_sync_down_dev(dev, force)) fib_flush(dev_net(dev)); rt_cache_flush(dev_net(dev), 0); arp_ifdown(dev); } static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) { struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; struct net_device *dev = ifa->ifa_dev->dev; switch (event) { case NETDEV_UP: fib_add_ifaddr(ifa); #ifdef CONFIG_IP_ROUTE_MULTIPATH fib_sync_up(dev); #endif rt_cache_flush(dev_net(dev), -1); break; case NETDEV_DOWN: fib_del_ifaddr(ifa); if (ifa->ifa_dev->ifa_list == NULL) { /* Last address was deleted from this interface. Disable IP. */ fib_disable_ip(dev, 1); } else { rt_cache_flush(dev_net(dev), -1); } break; } return NOTIFY_DONE; } static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = ptr; struct in_device *in_dev = __in_dev_get_rtnl(dev); if (event == NETDEV_UNREGISTER) { fib_disable_ip(dev, 2); return NOTIFY_DONE; } if (!in_dev) return NOTIFY_DONE; switch (event) { case NETDEV_UP: for_ifa(in_dev) { fib_add_ifaddr(ifa); } endfor_ifa(in_dev); #ifdef CONFIG_IP_ROUTE_MULTIPATH fib_sync_up(dev); #endif rt_cache_flush(dev_net(dev), -1); break; case NETDEV_DOWN: fib_disable_ip(dev, 0); break; case NETDEV_CHANGEMTU: case NETDEV_CHANGE: rt_cache_flush(dev_net(dev), 0); break; } return NOTIFY_DONE; } static struct notifier_block fib_inetaddr_notifier = { .notifier_call = fib_inetaddr_event, }; static struct notifier_block fib_netdev_notifier = { .notifier_call = fib_netdev_event, }; static int __net_init ip_fib_net_init(struct net *net) { int err; unsigned int i; net->ipv4.fib_table_hash = kzalloc( sizeof(struct hlist_head)*FIB_TABLE_HASHSZ, GFP_KERNEL); if (net->ipv4.fib_table_hash == NULL) return -ENOMEM; for (i = 0; i < FIB_TABLE_HASHSZ; i++) INIT_HLIST_HEAD(&net->ipv4.fib_table_hash[i]); err = fib4_rules_init(net); if (err < 0) goto fail; return 0; fail: kfree(net->ipv4.fib_table_hash); return err; } static void __net_exit ip_fib_net_exit(struct net *net) { unsigned int i; #ifdef CONFIG_IP_MULTIPLE_TABLES fib4_rules_exit(net); #endif for (i = 0; i < FIB_TABLE_HASHSZ; i++) { struct fib_table *tb; struct hlist_head *head; struct hlist_node *node, *tmp; head = &net->ipv4.fib_table_hash[i]; hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { hlist_del(node); tb->tb_flush(tb); kfree(tb); } } kfree(net->ipv4.fib_table_hash); } static int __net_init fib_net_init(struct net *net) { int error; error = ip_fib_net_init(net); if (error < 0) goto out; error = nl_fib_lookup_init(net); if (error < 0) goto out_nlfl; error = fib_proc_init(net); if (error < 0) goto out_proc; out: return error; out_proc: nl_fib_lookup_exit(net); out_nlfl: ip_fib_net_exit(net); goto out; } static void __net_exit fib_net_exit(struct net *net) { fib_proc_exit(net); nl_fib_lookup_exit(net); ip_fib_net_exit(net); } static struct pernet_operations fib_net_ops = { .init = fib_net_init, .exit = fib_net_exit, }; void __init ip_fib_init(void) { rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); register_pernet_subsys(&fib_net_ops); register_netdevice_notifier(&fib_netdev_notifier); register_inetaddr_notifier(&fib_inetaddr_notifier); fib_hash_init(); } EXPORT_SYMBOL(inet_addr_type); EXPORT_SYMBOL(inet_dev_addr_type); EXPORT_SYMBOL(ip_dev_find);