diff options
Diffstat (limited to 'net/ipv4/fib_frontend.c')
| -rw-r--r-- | net/ipv4/fib_frontend.c | 1251 |
1 files changed, 1251 insertions, 0 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c new file mode 100644 index 000000000..872494e6e --- /dev/null +++ b/net/ipv4/fib_frontend.c @@ -0,0 +1,1251 @@ +/* + * 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(); +} |