--- /dev/null
+/*
+ * 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 <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/cache.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.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>
+#include <net/xfrm.h>
+
+#ifndef CONFIG_IP_MULTIPLE_TABLES
+
+static int __net_init fib4_rules_init(struct net *net)
+{
+ struct fib_table *local_table, *main_table;
+
+ main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
+ if (!main_table)
+ return -ENOMEM;
+
+ local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
+ if (!local_table)
+ 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:
+ fib_free_table(main_table);
+ return -ENOMEM;
+}
+#else
+
+struct fib_table *fib_new_table(struct net *net, u32 id)
+{
+ struct fib_table *tb, *alias = NULL;
+ unsigned int h;
+
+ if (id == 0)
+ id = RT_TABLE_MAIN;
+ tb = fib_get_table(net, id);
+ if (tb)
+ return tb;
+
+ if (id == RT_TABLE_LOCAL)
+ alias = fib_new_table(net, RT_TABLE_MAIN);
+
+ tb = fib_trie_table(id, alias);
+ if (!tb)
+ return NULL;
+
+ switch (id) {
+ case RT_TABLE_LOCAL:
+ rcu_assign_pointer(net->ipv4.fib_local, tb);
+ break;
+ case RT_TABLE_MAIN:
+ rcu_assign_pointer(net->ipv4.fib_main, tb);
+ break;
+ case RT_TABLE_DEFAULT:
+ rcu_assign_pointer(net->ipv4.fib_default, tb);
+ break;
+ default:
+ break;
+ }
+
+ h = id & (FIB_TABLE_HASHSZ - 1);
+ hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
+ return tb;
+}
+
+/* caller must hold either rtnl or rcu read lock */
+struct fib_table *fib_get_table(struct net *net, u32 id)
+{
+ struct fib_table *tb;
+ struct hlist_head *head;
+ unsigned int h;
+
+ if (id == 0)
+ id = RT_TABLE_MAIN;
+ h = id & (FIB_TABLE_HASHSZ - 1);
+
+ head = &net->ipv4.fib_table_hash[h];
+ hlist_for_each_entry_rcu(tb, head, tb_hlist) {
+ if (tb->tb_id == id)
+ return tb;
+ }
+ return NULL;
+}
+#endif /* CONFIG_IP_MULTIPLE_TABLES */
+
+static void fib_replace_table(struct net *net, struct fib_table *old,
+ struct fib_table *new)
+{
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+ switch (new->tb_id) {
+ case RT_TABLE_LOCAL:
+ rcu_assign_pointer(net->ipv4.fib_local, new);
+ break;
+ case RT_TABLE_MAIN:
+ rcu_assign_pointer(net->ipv4.fib_main, new);
+ break;
+ case RT_TABLE_DEFAULT:
+ rcu_assign_pointer(net->ipv4.fib_default, new);
+ break;
+ default:
+ break;
+ }
+
+#endif
+ /* replace the old table in the hlist */
+ hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
+}
+
+int fib_unmerge(struct net *net)
+{
+ struct fib_table *old, *new;
+
+ /* attempt to fetch local table if it has been allocated */
+ old = fib_get_table(net, RT_TABLE_LOCAL);
+ if (!old)
+ return 0;
+
+ new = fib_trie_unmerge(old);
+ if (!new)
+ return -ENOMEM;
+
+ /* replace merged table with clean table */
+ if (new != old) {
+ fib_replace_table(net, old, new);
+ fib_free_table(old);
+ }
+
+ return 0;
+}
+
+static void fib_flush(struct net *net)
+{
+ int flushed = 0;
+ unsigned int h;
+
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ struct hlist_node *tmp;
+ struct fib_table *tb;
+
+ hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
+ flushed += fib_table_flush(tb);
+ }
+
+ if (flushed)
+ rt_cache_flush(net);
+}
+
+void fib_flush_external(struct net *net)
+{
+ struct fib_table *tb;
+ 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, head, tb_hlist)
+ fib_table_flush_external(tb);
+ }
+}
+
+/*
+ * 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 int __inet_dev_addr_type(struct net *net,
+ const struct net_device *dev,
+ __be32 addr)
+{
+ struct flowi4 fl4 = { .daddr = addr };
+ struct fib_result res;
+ unsigned int 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;
+
+ rcu_read_lock();
+
+ local_table = fib_get_table(net, RT_TABLE_LOCAL);
+ if (local_table) {
+ ret = RTN_UNICAST;
+ if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
+ if (!dev || dev == res.fi->fib_dev)
+ ret = res.type;
+ }
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+
+unsigned int inet_addr_type(struct net *net, __be32 addr)
+{
+ return __inet_dev_addr_type(net, NULL, addr);
+}
+EXPORT_SYMBOL(inet_addr_type);
+
+unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
+ __be32 addr)
+{
+ return __inet_dev_addr_type(net, dev, addr);
+}
+EXPORT_SYMBOL(inet_dev_addr_type);
+
+__be32 fib_compute_spec_dst(struct sk_buff *skb)
+{
+ struct net_device *dev = skb->dev;
+ struct in_device *in_dev;
+ struct fib_result res;
+ struct rtable *rt;
+ struct flowi4 fl4;
+ struct net *net;
+ int scope;
+
+ rt = skb_rtable(skb);
+ if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
+ RTCF_LOCAL)
+ return ip_hdr(skb)->daddr;
+
+ in_dev = __in_dev_get_rcu(dev);
+ BUG_ON(!in_dev);
+
+ net = dev_net(dev);
+
+ scope = RT_SCOPE_UNIVERSE;
+ if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
+ fl4.flowi4_oif = 0;
+ fl4.flowi4_iif = LOOPBACK_IFINDEX;
+ fl4.daddr = ip_hdr(skb)->saddr;
+ fl4.saddr = 0;
+ fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
+ fl4.flowi4_scope = scope;
+ fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
+ if (!fib_lookup(net, &fl4, &res))
+ return FIB_RES_PREFSRC(net, res);
+ } else {
+ scope = RT_SCOPE_LINK;
+ }
+
+ return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
+}
+
+/* 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.
+ * called with rcu_read_lock()
+ */
+static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
+ u8 tos, int oif, struct net_device *dev,
+ int rpf, struct in_device *idev, u32 *itag)
+{
+ int ret, no_addr;
+ struct fib_result res;
+ struct flowi4 fl4;
+ struct net *net;
+ bool dev_match;
+
+ fl4.flowi4_oif = 0;
+ fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
+ fl4.daddr = src;
+ fl4.saddr = dst;
+ fl4.flowi4_tos = tos;
+ fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
+
+ no_addr = idev->ifa_list == NULL;
+
+ fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
+
+ net = dev_net(dev);
+ if (fib_lookup(net, &fl4, &res))
+ goto last_resort;
+ if (res.type != RTN_UNICAST &&
+ (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
+ goto e_inval;
+ if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
+ (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
+ goto last_resort;
+ fib_combine_itag(itag, &res);
+ dev_match = false;
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ for (ret = 0; ret < res.fi->fib_nhs; ret++) {
+ struct fib_nh *nh = &res.fi->fib_nh[ret];
+
+ if (nh->nh_dev == dev) {
+ dev_match = true;
+ break;
+ }
+ }
+#else
+ if (FIB_RES_DEV(res) == dev)
+ dev_match = true;
+#endif
+ if (dev_match) {
+ ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
+ return ret;
+ }
+ if (no_addr)
+ goto last_resort;
+ if (rpf == 1)
+ goto e_rpf;
+ fl4.flowi4_oif = dev->ifindex;
+
+ ret = 0;
+ if (fib_lookup(net, &fl4, &res) == 0) {
+ if (res.type == RTN_UNICAST)
+ ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
+ }
+ return ret;
+
+last_resort:
+ if (rpf)
+ goto e_rpf;
+ *itag = 0;
+ return 0;
+
+e_inval:
+ return -EINVAL;
+e_rpf:
+ return -EXDEV;
+}
+
+/* Ignore rp_filter for packets protected by IPsec. */
+int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
+ u8 tos, int oif, struct net_device *dev,
+ struct in_device *idev, u32 *itag)
+{
+ int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
+
+ if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
+ IN_DEV_ACCEPT_LOCAL(idev) &&
+ (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
+ *itag = 0;
+ return 0;
+ }
+ return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
+}
+
+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)
+ 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)
+ 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 (!ns_capable(net->user_ns, 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 = fib_table_delete(tb, &cfg);
+ else
+ err = -ESRCH;
+ } else {
+ tb = fib_new_table(net, cfg.fc_table);
+ if (tb)
+ err = fib_table_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.portid = NETLINK_CB(skb).portid;
+ 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)
+{
+ 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) {
+ err = -ESRCH;
+ goto errout;
+ }
+
+ err = fib_table_delete(tb, &cfg);
+errout:
+ return err;
+}
+
+static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ 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) {
+ err = -ENOBUFS;
+ goto errout;
+ }
+
+ err = fib_table_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_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 skb->len;
+
+ s_h = cb->args[0];
+ s_e = cb->args[1];
+
+ rcu_read_lock();
+
+ 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_rcu(tb, 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 (fib_table_dump(tb, skb, cb) < 0)
+ goto out;
+ dumped = 1;
+next:
+ e++;
+ }
+ }
+out:
+ rcu_read_unlock();
+
+ 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)
+ 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)
+ fib_table_insert(tb, &cfg);
+ else
+ fib_table_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) {
+ pr_warn("%s: bug: prim == NULL\n", __func__);
+ 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);
+ }
+ }
+}
+
+/* Delete primary or secondary address.
+ * Optionally, on secondary address promotion consider the addresses
+ * from subnet iprim as deleted, even if they are in device list.
+ * In this case the secondary ifa can be in device list.
+ */
+void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
+{
+ struct in_device *in_dev = ifa->ifa_dev;
+ struct net_device *dev = in_dev->dev;
+ struct in_ifaddr *ifa1;
+ struct in_ifaddr *prim = ifa, *prim1 = NULL;
+ __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 int ok = 0;
+ int subnet = 0; /* Primary network */
+ int gone = 1; /* Address is missing */
+ int same_prefsrc = 0; /* Another primary with same IP */
+
+ if (ifa->ifa_flags & IFA_F_SECONDARY) {
+ prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
+ if (!prim) {
+ pr_warn("%s: bug: prim == NULL\n", __func__);
+ return;
+ }
+ if (iprim && iprim != prim) {
+ pr_warn("%s: bug: iprim != prim\n", __func__);
+ return;
+ }
+ } else if (!ipv4_is_zeronet(any) &&
+ (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
+ fib_magic(RTM_DELROUTE,
+ dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
+ any, ifa->ifa_prefixlen, prim);
+ subnet = 1;
+ }
+
+ /* 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 (ifa1 == ifa) {
+ /* promotion, keep the IP */
+ gone = 0;
+ continue;
+ }
+ /* Ignore IFAs from our subnet */
+ if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
+ inet_ifa_match(ifa1->ifa_address, iprim))
+ continue;
+
+ /* Ignore ifa1 if it uses different primary IP (prefsrc) */
+ if (ifa1->ifa_flags & IFA_F_SECONDARY) {
+ /* Another address from our subnet? */
+ if (ifa1->ifa_mask == prim->ifa_mask &&
+ inet_ifa_match(ifa1->ifa_address, prim))
+ prim1 = prim;
+ else {
+ /* We reached the secondaries, so
+ * same_prefsrc should be determined.
+ */
+ if (!same_prefsrc)
+ continue;
+ /* Search new prim1 if ifa1 is not
+ * using the current prim1
+ */
+ if (!prim1 ||
+ ifa1->ifa_mask != prim1->ifa_mask ||
+ !inet_ifa_match(ifa1->ifa_address, prim1))
+ prim1 = inet_ifa_byprefix(in_dev,
+ ifa1->ifa_address,
+ ifa1->ifa_mask);
+ if (!prim1)
+ continue;
+ if (prim1->ifa_local != prim->ifa_local)
+ continue;
+ }
+ } else {
+ if (prim->ifa_local != ifa1->ifa_local)
+ continue;
+ prim1 = ifa1;
+ if (prim != prim1)
+ same_prefsrc = 1;
+ }
+ 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;
+ /* primary has network specific broadcasts */
+ if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
+ __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
+ __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
+
+ if (!ipv4_is_zeronet(any1)) {
+ if (ifa->ifa_broadcast == brd1 ||
+ ifa->ifa_broadcast == any1)
+ ok |= BRD_OK;
+ if (brd == brd1 || brd == any1)
+ ok |= BRD1_OK;
+ if (any == brd1 || any == any1)
+ ok |= BRD0_OK;
+ }
+ }
+ }
+
+ if (!(ok & BRD_OK))
+ fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
+ if (subnet && ifa->ifa_prefixlen < 31) {
+ 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 (gone &&
+ 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 net *net, struct fib_result_nl *frn)
+{
+
+ struct fib_result res;
+ struct flowi4 fl4 = {
+ .flowi4_mark = frn->fl_mark,
+ .daddr = frn->fl_addr,
+ .flowi4_tos = frn->fl_tos,
+ .flowi4_scope = frn->fl_scope,
+ };
+ struct fib_table *tb;
+
+ rcu_read_lock();
+
+ tb = fib_get_table(net, frn->tb_id_in);
+
+ frn->err = -ENOENT;
+ if (tb) {
+ local_bh_disable();
+
+ frn->tb_id = tb->tb_id;
+ frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
+
+ if (!frn->err) {
+ frn->prefixlen = res.prefixlen;
+ frn->nh_sel = res.nh_sel;
+ frn->type = res.type;
+ frn->scope = res.scope;
+ }
+ local_bh_enable();
+ }
+
+ rcu_read_unlock();
+}
+
+static void nl_fib_input(struct sk_buff *skb)
+{
+ struct net *net;
+ struct fib_result_nl *frn;
+ struct nlmsghdr *nlh;
+ u32 portid;
+
+ net = sock_net(skb->sk);
+ nlh = nlmsg_hdr(skb);
+ if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
+ nlmsg_len(nlh) < sizeof(*frn))
+ return;
+
+ skb = netlink_skb_clone(skb, GFP_KERNEL);
+ if (!skb)
+ return;
+ nlh = nlmsg_hdr(skb);
+
+ frn = (struct fib_result_nl *) nlmsg_data(nlh);
+ nl_fib_lookup(net, frn);
+
+ portid = NETLINK_CB(skb).portid; /* netlink portid */
+ NETLINK_CB(skb).portid = 0; /* from kernel */
+ NETLINK_CB(skb).dst_group = 0; /* unicast */
+ netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
+}
+
+static int __net_init nl_fib_lookup_init(struct net *net)
+{
+ struct sock *sk;
+ struct netlink_kernel_cfg cfg = {
+ .input = nl_fib_input,
+ };
+
+ sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
+ if (!sk)
+ 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));
+ 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;
+ struct net *net = dev_net(dev);
+
+ switch (event) {
+ case NETDEV_UP:
+ fib_add_ifaddr(ifa);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ fib_sync_up(dev);
+#endif
+ atomic_inc(&net->ipv4.dev_addr_genid);
+ rt_cache_flush(dev_net(dev));
+ break;
+ case NETDEV_DOWN:
+ fib_del_ifaddr(ifa, NULL);
+ atomic_inc(&net->ipv4.dev_addr_genid);
+ if (!ifa->ifa_dev->ifa_list) {
+ /* Last address was deleted from this interface.
+ * Disable IP.
+ */
+ fib_disable_ip(dev, 1);
+ } else {
+ rt_cache_flush(dev_net(dev));
+ }
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct in_device *in_dev;
+ struct net *net = dev_net(dev);
+
+ if (event == NETDEV_UNREGISTER) {
+ fib_disable_ip(dev, 2);
+ rt_flush_dev(dev);
+ return NOTIFY_DONE;
+ }
+
+ in_dev = __in_dev_get_rtnl(dev);
+ 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
+ atomic_inc(&net->ipv4.dev_addr_genid);
+ rt_cache_flush(net);
+ break;
+ case NETDEV_DOWN:
+ fib_disable_ip(dev, 0);
+ break;
+ case NETDEV_CHANGEMTU:
+ case NETDEV_CHANGE:
+ rt_cache_flush(net);
+ 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;
+ size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
+
+ /* Avoid false sharing : Use at least a full cache line */
+ size = max_t(size_t, size, L1_CACHE_BYTES);
+
+ net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
+ if (!net->ipv4.fib_table_hash)
+ return -ENOMEM;
+
+ err = fib4_rules_init(net);
+ if (err < 0)
+ goto fail;
+ return 0;
+
+fail:
+ kfree(net->ipv4.fib_table_hash);
+ return err;
+}
+
+static void ip_fib_net_exit(struct net *net)
+{
+ unsigned int i;
+
+ rtnl_lock();
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+ RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
+ RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
+ RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
+#endif
+ for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[i];
+ struct hlist_node *tmp;
+ struct fib_table *tb;
+
+ hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
+ hlist_del(&tb->tb_hlist);
+ fib_table_flush(tb);
+ fib_free_table(tb);
+ }
+ }
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+ fib4_rules_exit(net);
+#endif
+ rtnl_unlock();
+ kfree(net->ipv4.fib_table_hash);
+}
+
+static int __net_init fib_net_init(struct net *net)
+{
+ int error;
+
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ net->ipv4.fib_num_tclassid_users = 0;
+#endif
+ 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, NULL);
+ rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
+ rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
+
+ register_pernet_subsys(&fib_net_ops);
+ register_netdevice_notifier(&fib_netdev_notifier);
+ register_inetaddr_notifier(&fib_inetaddr_notifier);
+
+ fib_trie_init();
+}
Code Review / kvmfornfv.git / blobdiff