| /* |
| * 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: semantics. |
| * |
| * 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/uaccess.h> |
| #include <linux/bitops.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/jiffies.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_arp.h> |
| #include <linux/proc_fs.h> |
| #include <linux/skbuff.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/netlink.h> |
| |
| #include <net/arp.h> |
| #include <net/ip.h> |
| #include <net/protocol.h> |
| #include <net/route.h> |
| #include <net/tcp.h> |
| #include <net/sock.h> |
| #include <net/ip_fib.h> |
| #include <net/netlink.h> |
| #include <net/nexthop.h> |
| #include <net/lwtunnel.h> |
| #include <net/fib_notifier.h> |
| |
| #include "fib_lookup.h" |
| |
| static DEFINE_SPINLOCK(fib_info_lock); |
| static struct hlist_head *fib_info_hash; |
| static struct hlist_head *fib_info_laddrhash; |
| static unsigned int fib_info_hash_size; |
| static unsigned int fib_info_cnt; |
| |
| #define DEVINDEX_HASHBITS 8 |
| #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) |
| static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| |
| #define for_nexthops(fi) { \ |
| int nhsel; const struct fib_nh *nh; \ |
| for (nhsel = 0, nh = (fi)->fib_nh; \ |
| nhsel < (fi)->fib_nhs; \ |
| nh++, nhsel++) |
| |
| #define change_nexthops(fi) { \ |
| int nhsel; struct fib_nh *nexthop_nh; \ |
| for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
| nhsel < (fi)->fib_nhs; \ |
| nexthop_nh++, nhsel++) |
| |
| #else /* CONFIG_IP_ROUTE_MULTIPATH */ |
| |
| /* Hope, that gcc will optimize it to get rid of dummy loop */ |
| |
| #define for_nexthops(fi) { \ |
| int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \ |
| for (nhsel = 0; nhsel < 1; nhsel++) |
| |
| #define change_nexthops(fi) { \ |
| int nhsel; \ |
| struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
| for (nhsel = 0; nhsel < 1; nhsel++) |
| |
| #endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
| |
| #define endfor_nexthops(fi) } |
| |
| |
| const struct fib_prop fib_props[RTN_MAX + 1] = { |
| [RTN_UNSPEC] = { |
| .error = 0, |
| .scope = RT_SCOPE_NOWHERE, |
| }, |
| [RTN_UNICAST] = { |
| .error = 0, |
| .scope = RT_SCOPE_UNIVERSE, |
| }, |
| [RTN_LOCAL] = { |
| .error = 0, |
| .scope = RT_SCOPE_HOST, |
| }, |
| [RTN_BROADCAST] = { |
| .error = 0, |
| .scope = RT_SCOPE_LINK, |
| }, |
| [RTN_ANYCAST] = { |
| .error = 0, |
| .scope = RT_SCOPE_LINK, |
| }, |
| [RTN_MULTICAST] = { |
| .error = 0, |
| .scope = RT_SCOPE_UNIVERSE, |
| }, |
| [RTN_BLACKHOLE] = { |
| .error = -EINVAL, |
| .scope = RT_SCOPE_UNIVERSE, |
| }, |
| [RTN_UNREACHABLE] = { |
| .error = -EHOSTUNREACH, |
| .scope = RT_SCOPE_UNIVERSE, |
| }, |
| [RTN_PROHIBIT] = { |
| .error = -EACCES, |
| .scope = RT_SCOPE_UNIVERSE, |
| }, |
| [RTN_THROW] = { |
| .error = -EAGAIN, |
| .scope = RT_SCOPE_UNIVERSE, |
| }, |
| [RTN_NAT] = { |
| .error = -EINVAL, |
| .scope = RT_SCOPE_NOWHERE, |
| }, |
| [RTN_XRESOLVE] = { |
| .error = -EINVAL, |
| .scope = RT_SCOPE_NOWHERE, |
| }, |
| }; |
| |
| static void rt_fibinfo_free(struct rtable __rcu **rtp) |
| { |
| struct rtable *rt = rcu_dereference_protected(*rtp, 1); |
| |
| if (!rt) |
| return; |
| |
| /* Not even needed : RCU_INIT_POINTER(*rtp, NULL); |
| * because we waited an RCU grace period before calling |
| * free_fib_info_rcu() |
| */ |
| |
| dst_dev_put(&rt->dst); |
| dst_release_immediate(&rt->dst); |
| } |
| |
| static void free_nh_exceptions(struct fib_nh *nh) |
| { |
| struct fnhe_hash_bucket *hash; |
| int i; |
| |
| hash = rcu_dereference_protected(nh->nh_exceptions, 1); |
| if (!hash) |
| return; |
| for (i = 0; i < FNHE_HASH_SIZE; i++) { |
| struct fib_nh_exception *fnhe; |
| |
| fnhe = rcu_dereference_protected(hash[i].chain, 1); |
| while (fnhe) { |
| struct fib_nh_exception *next; |
| |
| next = rcu_dereference_protected(fnhe->fnhe_next, 1); |
| |
| rt_fibinfo_free(&fnhe->fnhe_rth_input); |
| rt_fibinfo_free(&fnhe->fnhe_rth_output); |
| |
| kfree(fnhe); |
| |
| fnhe = next; |
| } |
| } |
| kfree(hash); |
| } |
| |
| static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp) |
| { |
| int cpu; |
| |
| if (!rtp) |
| return; |
| |
| for_each_possible_cpu(cpu) { |
| struct rtable *rt; |
| |
| rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1); |
| if (rt) { |
| dst_dev_put(&rt->dst); |
| dst_release_immediate(&rt->dst); |
| } |
| } |
| free_percpu(rtp); |
| } |
| |
| /* Release a nexthop info record */ |
| static void free_fib_info_rcu(struct rcu_head *head) |
| { |
| struct fib_info *fi = container_of(head, struct fib_info, rcu); |
| struct dst_metrics *m; |
| |
| change_nexthops(fi) { |
| if (nexthop_nh->nh_dev) |
| dev_put(nexthop_nh->nh_dev); |
| lwtstate_put(nexthop_nh->nh_lwtstate); |
| free_nh_exceptions(nexthop_nh); |
| rt_fibinfo_free_cpus(nexthop_nh->nh_pcpu_rth_output); |
| rt_fibinfo_free(&nexthop_nh->nh_rth_input); |
| } endfor_nexthops(fi); |
| |
| m = fi->fib_metrics; |
| if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt)) |
| kfree(m); |
| kfree(fi); |
| } |
| |
| void free_fib_info(struct fib_info *fi) |
| { |
| if (fi->fib_dead == 0) { |
| pr_warn("Freeing alive fib_info %p\n", fi); |
| return; |
| } |
| fib_info_cnt--; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| change_nexthops(fi) { |
| if (nexthop_nh->nh_tclassid) |
| fi->fib_net->ipv4.fib_num_tclassid_users--; |
| } endfor_nexthops(fi); |
| #endif |
| call_rcu(&fi->rcu, free_fib_info_rcu); |
| } |
| EXPORT_SYMBOL_GPL(free_fib_info); |
| |
| void fib_release_info(struct fib_info *fi) |
| { |
| spin_lock_bh(&fib_info_lock); |
| if (fi && --fi->fib_treeref == 0) { |
| hlist_del(&fi->fib_hash); |
| if (fi->fib_prefsrc) |
| hlist_del(&fi->fib_lhash); |
| change_nexthops(fi) { |
| if (!nexthop_nh->nh_dev) |
| continue; |
| hlist_del(&nexthop_nh->nh_hash); |
| } endfor_nexthops(fi) |
| fi->fib_dead = 1; |
| fib_info_put(fi); |
| } |
| spin_unlock_bh(&fib_info_lock); |
| } |
| |
| static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) |
| { |
| const struct fib_nh *onh = ofi->fib_nh; |
| |
| for_nexthops(fi) { |
| if (nh->nh_oif != onh->nh_oif || |
| nh->nh_gw != onh->nh_gw || |
| nh->nh_scope != onh->nh_scope || |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| nh->nh_weight != onh->nh_weight || |
| #endif |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| nh->nh_tclassid != onh->nh_tclassid || |
| #endif |
| lwtunnel_cmp_encap(nh->nh_lwtstate, onh->nh_lwtstate) || |
| ((nh->nh_flags ^ onh->nh_flags) & ~RTNH_COMPARE_MASK)) |
| return -1; |
| onh++; |
| } endfor_nexthops(fi); |
| return 0; |
| } |
| |
| static inline unsigned int fib_devindex_hashfn(unsigned int val) |
| { |
| unsigned int mask = DEVINDEX_HASHSIZE - 1; |
| |
| return (val ^ |
| (val >> DEVINDEX_HASHBITS) ^ |
| (val >> (DEVINDEX_HASHBITS * 2))) & mask; |
| } |
| |
| static inline unsigned int fib_info_hashfn(const struct fib_info *fi) |
| { |
| unsigned int mask = (fib_info_hash_size - 1); |
| unsigned int val = fi->fib_nhs; |
| |
| val ^= (fi->fib_protocol << 8) | fi->fib_scope; |
| val ^= (__force u32)fi->fib_prefsrc; |
| val ^= fi->fib_priority; |
| for_nexthops(fi) { |
| val ^= fib_devindex_hashfn(nh->nh_oif); |
| } endfor_nexthops(fi) |
| |
| return (val ^ (val >> 7) ^ (val >> 12)) & mask; |
| } |
| |
| static struct fib_info *fib_find_info(const struct fib_info *nfi) |
| { |
| struct hlist_head *head; |
| struct fib_info *fi; |
| unsigned int hash; |
| |
| hash = fib_info_hashfn(nfi); |
| head = &fib_info_hash[hash]; |
| |
| hlist_for_each_entry(fi, head, fib_hash) { |
| if (!net_eq(fi->fib_net, nfi->fib_net)) |
| continue; |
| if (fi->fib_nhs != nfi->fib_nhs) |
| continue; |
| if (nfi->fib_protocol == fi->fib_protocol && |
| nfi->fib_scope == fi->fib_scope && |
| nfi->fib_prefsrc == fi->fib_prefsrc && |
| nfi->fib_priority == fi->fib_priority && |
| nfi->fib_type == fi->fib_type && |
| memcmp(nfi->fib_metrics, fi->fib_metrics, |
| sizeof(u32) * RTAX_MAX) == 0 && |
| !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) && |
| (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) |
| return fi; |
| } |
| |
| return NULL; |
| } |
| |
| /* Check, that the gateway is already configured. |
| * Used only by redirect accept routine. |
| */ |
| int ip_fib_check_default(__be32 gw, struct net_device *dev) |
| { |
| struct hlist_head *head; |
| struct fib_nh *nh; |
| unsigned int hash; |
| |
| spin_lock(&fib_info_lock); |
| |
| hash = fib_devindex_hashfn(dev->ifindex); |
| head = &fib_info_devhash[hash]; |
| hlist_for_each_entry(nh, head, nh_hash) { |
| if (nh->nh_dev == dev && |
| nh->nh_gw == gw && |
| !(nh->nh_flags & RTNH_F_DEAD)) { |
| spin_unlock(&fib_info_lock); |
| return 0; |
| } |
| } |
| |
| spin_unlock(&fib_info_lock); |
| |
| return -1; |
| } |
| |
| static inline size_t fib_nlmsg_size(struct fib_info *fi) |
| { |
| size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) |
| + nla_total_size(4) /* RTA_TABLE */ |
| + nla_total_size(4) /* RTA_DST */ |
| + nla_total_size(4) /* RTA_PRIORITY */ |
| + nla_total_size(4) /* RTA_PREFSRC */ |
| + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */ |
| |
| /* space for nested metrics */ |
| payload += nla_total_size((RTAX_MAX * nla_total_size(4))); |
| |
| if (fi->fib_nhs) { |
| size_t nh_encapsize = 0; |
| /* Also handles the special case fib_nhs == 1 */ |
| |
| /* each nexthop is packed in an attribute */ |
| size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); |
| |
| /* may contain flow and gateway attribute */ |
| nhsize += 2 * nla_total_size(4); |
| |
| /* grab encap info */ |
| for_nexthops(fi) { |
| if (nh->nh_lwtstate) { |
| /* RTA_ENCAP_TYPE */ |
| nh_encapsize += lwtunnel_get_encap_size( |
| nh->nh_lwtstate); |
| /* RTA_ENCAP */ |
| nh_encapsize += nla_total_size(2); |
| } |
| } endfor_nexthops(fi); |
| |
| /* all nexthops are packed in a nested attribute */ |
| payload += nla_total_size((fi->fib_nhs * nhsize) + |
| nh_encapsize); |
| |
| } |
| |
| return payload; |
| } |
| |
| void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
| int dst_len, u32 tb_id, const struct nl_info *info, |
| unsigned int nlm_flags) |
| { |
| struct sk_buff *skb; |
| u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
| int err = -ENOBUFS; |
| |
| skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
| if (!skb) |
| goto errout; |
| |
| err = fib_dump_info(skb, info->portid, seq, event, tb_id, |
| fa->fa_type, key, dst_len, |
| fa->fa_tos, fa->fa_info, nlm_flags); |
| if (err < 0) { |
| /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ |
| WARN_ON(err == -EMSGSIZE); |
| kfree_skb(skb); |
| goto errout; |
| } |
| rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE, |
| info->nlh, GFP_KERNEL); |
| return; |
| errout: |
| if (err < 0) |
| rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); |
| } |
| |
| static int fib_detect_death(struct fib_info *fi, int order, |
| struct fib_info **last_resort, int *last_idx, |
| int dflt) |
| { |
| struct neighbour *n; |
| int state = NUD_NONE; |
| |
| n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev); |
| if (n) { |
| state = n->nud_state; |
| neigh_release(n); |
| } else { |
| return 0; |
| } |
| if (state == NUD_REACHABLE) |
| return 0; |
| if ((state & NUD_VALID) && order != dflt) |
| return 0; |
| if ((state & NUD_VALID) || |
| (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) { |
| *last_resort = fi; |
| *last_idx = order; |
| } |
| return 1; |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| |
| static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining, |
| struct netlink_ext_ack *extack) |
| { |
| int nhs = 0; |
| |
| while (rtnh_ok(rtnh, remaining)) { |
| nhs++; |
| rtnh = rtnh_next(rtnh, &remaining); |
| } |
| |
| /* leftover implies invalid nexthop configuration, discard it */ |
| if (remaining > 0) { |
| NL_SET_ERR_MSG(extack, |
| "Invalid nexthop configuration - extra data after nexthops"); |
| nhs = 0; |
| } |
| |
| return nhs; |
| } |
| |
| static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
| int remaining, struct fib_config *cfg, |
| struct netlink_ext_ack *extack) |
| { |
| int ret; |
| |
| change_nexthops(fi) { |
| int attrlen; |
| |
| if (!rtnh_ok(rtnh, remaining)) { |
| NL_SET_ERR_MSG(extack, |
| "Invalid nexthop configuration - extra data after nexthop"); |
| return -EINVAL; |
| } |
| |
| if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { |
| NL_SET_ERR_MSG(extack, |
| "Invalid flags for nexthop - can not contain DEAD or LINKDOWN"); |
| return -EINVAL; |
| } |
| |
| nexthop_nh->nh_flags = |
| (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; |
| nexthop_nh->nh_oif = rtnh->rtnh_ifindex; |
| nexthop_nh->nh_weight = rtnh->rtnh_hops + 1; |
| |
| attrlen = rtnh_attrlen(rtnh); |
| if (attrlen > 0) { |
| struct nlattr *nla, *attrs = rtnh_attrs(rtnh); |
| |
| nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
| nexthop_nh->nh_gw = nla ? nla_get_in_addr(nla) : 0; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| nla = nla_find(attrs, attrlen, RTA_FLOW); |
| nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; |
| if (nexthop_nh->nh_tclassid) |
| fi->fib_net->ipv4.fib_num_tclassid_users++; |
| #endif |
| nla = nla_find(attrs, attrlen, RTA_ENCAP); |
| if (nla) { |
| struct lwtunnel_state *lwtstate; |
| struct nlattr *nla_entype; |
| |
| nla_entype = nla_find(attrs, attrlen, |
| RTA_ENCAP_TYPE); |
| if (!nla_entype) { |
| NL_SET_BAD_ATTR(extack, nla); |
| NL_SET_ERR_MSG(extack, |
| "Encap type is missing"); |
| goto err_inval; |
| } |
| |
| ret = lwtunnel_build_state(nla_get_u16( |
| nla_entype), |
| nla, AF_INET, cfg, |
| &lwtstate, extack); |
| if (ret) |
| goto errout; |
| nexthop_nh->nh_lwtstate = |
| lwtstate_get(lwtstate); |
| } |
| } |
| |
| rtnh = rtnh_next(rtnh, &remaining); |
| } endfor_nexthops(fi); |
| |
| return 0; |
| |
| err_inval: |
| ret = -EINVAL; |
| |
| errout: |
| return ret; |
| } |
| |
| static void fib_rebalance(struct fib_info *fi) |
| { |
| int total; |
| int w; |
| struct in_device *in_dev; |
| |
| if (fi->fib_nhs < 2) |
| return; |
| |
| total = 0; |
| for_nexthops(fi) { |
| if (nh->nh_flags & RTNH_F_DEAD) |
| continue; |
| |
| in_dev = __in_dev_get_rtnl(nh->nh_dev); |
| |
| if (in_dev && |
| IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && |
| nh->nh_flags & RTNH_F_LINKDOWN) |
| continue; |
| |
| total += nh->nh_weight; |
| } endfor_nexthops(fi); |
| |
| w = 0; |
| change_nexthops(fi) { |
| int upper_bound; |
| |
| in_dev = __in_dev_get_rtnl(nexthop_nh->nh_dev); |
| |
| if (nexthop_nh->nh_flags & RTNH_F_DEAD) { |
| upper_bound = -1; |
| } else if (in_dev && |
| IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && |
| nexthop_nh->nh_flags & RTNH_F_LINKDOWN) { |
| upper_bound = -1; |
| } else { |
| w += nexthop_nh->nh_weight; |
| upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, |
| total) - 1; |
| } |
| |
| atomic_set(&nexthop_nh->nh_upper_bound, upper_bound); |
| } endfor_nexthops(fi); |
| } |
| #else /* CONFIG_IP_ROUTE_MULTIPATH */ |
| |
| #define fib_rebalance(fi) do { } while (0) |
| |
| #endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
| |
| static int fib_encap_match(u16 encap_type, |
| struct nlattr *encap, |
| const struct fib_nh *nh, |
| const struct fib_config *cfg, |
| struct netlink_ext_ack *extack) |
| { |
| struct lwtunnel_state *lwtstate; |
| int ret, result = 0; |
| |
| if (encap_type == LWTUNNEL_ENCAP_NONE) |
| return 0; |
| |
| ret = lwtunnel_build_state(encap_type, encap, AF_INET, |
| cfg, &lwtstate, extack); |
| if (!ret) { |
| result = lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate); |
| lwtstate_free(lwtstate); |
| } |
| |
| return result; |
| } |
| |
| int fib_nh_match(struct fib_config *cfg, struct fib_info *fi, |
| struct netlink_ext_ack *extack) |
| { |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| struct rtnexthop *rtnh; |
| int remaining; |
| #endif |
| |
| if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
| return 1; |
| |
| if (cfg->fc_oif || cfg->fc_gw) { |
| if (cfg->fc_encap) { |
| if (fib_encap_match(cfg->fc_encap_type, cfg->fc_encap, |
| fi->fib_nh, cfg, extack)) |
| return 1; |
| } |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| if (cfg->fc_flow && |
| cfg->fc_flow != fi->fib_nh->nh_tclassid) |
| return 1; |
| #endif |
| if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && |
| (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) |
| return 0; |
| return 1; |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (!cfg->fc_mp) |
| return 0; |
| |
| rtnh = cfg->fc_mp; |
| remaining = cfg->fc_mp_len; |
| |
| for_nexthops(fi) { |
| int attrlen; |
| |
| if (!rtnh_ok(rtnh, remaining)) |
| return -EINVAL; |
| |
| if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) |
| return 1; |
| |
| attrlen = rtnh_attrlen(rtnh); |
| if (attrlen > 0) { |
| struct nlattr *nla, *attrs = rtnh_attrs(rtnh); |
| |
| nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
| if (nla && nla_get_in_addr(nla) != nh->nh_gw) |
| return 1; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| nla = nla_find(attrs, attrlen, RTA_FLOW); |
| if (nla && nla_get_u32(nla) != nh->nh_tclassid) |
| return 1; |
| #endif |
| } |
| |
| rtnh = rtnh_next(rtnh, &remaining); |
| } endfor_nexthops(fi); |
| #endif |
| return 0; |
| } |
| |
| bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) |
| { |
| struct nlattr *nla; |
| int remaining; |
| |
| if (!cfg->fc_mx) |
| return true; |
| |
| nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { |
| int type = nla_type(nla); |
| u32 fi_val, val; |
| |
| if (!type) |
| continue; |
| if (type > RTAX_MAX) |
| return false; |
| |
| if (type == RTAX_CC_ALGO) { |
| char tmp[TCP_CA_NAME_MAX]; |
| bool ecn_ca = false; |
| |
| nla_strlcpy(tmp, nla, sizeof(tmp)); |
| val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca); |
| } else { |
| if (nla_len(nla) != sizeof(u32)) |
| return false; |
| val = nla_get_u32(nla); |
| } |
| |
| fi_val = fi->fib_metrics->metrics[type - 1]; |
| if (type == RTAX_FEATURES) |
| fi_val &= ~DST_FEATURE_ECN_CA; |
| |
| if (fi_val != val) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| |
| /* |
| * Picture |
| * ------- |
| * |
| * Semantics of nexthop is very messy by historical reasons. |
| * We have to take into account, that: |
| * a) gateway can be actually local interface address, |
| * so that gatewayed route is direct. |
| * b) gateway must be on-link address, possibly |
| * described not by an ifaddr, but also by a direct route. |
| * c) If both gateway and interface are specified, they should not |
| * contradict. |
| * d) If we use tunnel routes, gateway could be not on-link. |
| * |
| * Attempt to reconcile all of these (alas, self-contradictory) conditions |
| * results in pretty ugly and hairy code with obscure logic. |
| * |
| * I chose to generalized it instead, so that the size |
| * of code does not increase practically, but it becomes |
| * much more general. |
| * Every prefix is assigned a "scope" value: "host" is local address, |
| * "link" is direct route, |
| * [ ... "site" ... "interior" ... ] |
| * and "universe" is true gateway route with global meaning. |
| * |
| * Every prefix refers to a set of "nexthop"s (gw, oif), |
| * where gw must have narrower scope. This recursion stops |
| * when gw has LOCAL scope or if "nexthop" is declared ONLINK, |
| * which means that gw is forced to be on link. |
| * |
| * Code is still hairy, but now it is apparently logically |
| * consistent and very flexible. F.e. as by-product it allows |
| * to co-exists in peace independent exterior and interior |
| * routing processes. |
| * |
| * Normally it looks as following. |
| * |
| * {universe prefix} -> (gw, oif) [scope link] |
| * | |
| * |-> {link prefix} -> (gw, oif) [scope local] |
| * | |
| * |-> {local prefix} (terminal node) |
| */ |
| static int fib_check_nh(struct fib_config *cfg, struct fib_nh *nh, |
| struct netlink_ext_ack *extack) |
| { |
| int err = 0; |
| struct net *net; |
| struct net_device *dev; |
| |
| net = cfg->fc_nlinfo.nl_net; |
| if (nh->nh_gw) { |
| struct fib_result res; |
| |
| if (nh->nh_flags & RTNH_F_ONLINK) { |
| unsigned int addr_type; |
| |
| if (cfg->fc_scope >= RT_SCOPE_LINK) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop has invalid scope"); |
| return -EINVAL; |
| } |
| dev = __dev_get_by_index(net, nh->nh_oif); |
| if (!dev) |
| return -ENODEV; |
| if (!(dev->flags & IFF_UP)) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop device is not up"); |
| return -ENETDOWN; |
| } |
| addr_type = inet_addr_type_dev_table(net, dev, nh->nh_gw); |
| if (addr_type != RTN_UNICAST) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop has invalid gateway"); |
| return -EINVAL; |
| } |
| if (!netif_carrier_ok(dev)) |
| nh->nh_flags |= RTNH_F_LINKDOWN; |
| nh->nh_dev = dev; |
| dev_hold(dev); |
| nh->nh_scope = RT_SCOPE_LINK; |
| return 0; |
| } |
| rcu_read_lock(); |
| { |
| struct fib_table *tbl = NULL; |
| struct flowi4 fl4 = { |
| .daddr = nh->nh_gw, |
| .flowi4_scope = cfg->fc_scope + 1, |
| .flowi4_oif = nh->nh_oif, |
| .flowi4_iif = LOOPBACK_IFINDEX, |
| }; |
| |
| /* It is not necessary, but requires a bit of thinking */ |
| if (fl4.flowi4_scope < RT_SCOPE_LINK) |
| fl4.flowi4_scope = RT_SCOPE_LINK; |
| |
| if (cfg->fc_table && cfg->fc_table != RT_TABLE_MAIN) |
| tbl = fib_get_table(net, cfg->fc_table); |
| |
| if (tbl) |
| err = fib_table_lookup(tbl, &fl4, &res, |
| FIB_LOOKUP_IGNORE_LINKSTATE | |
| FIB_LOOKUP_NOREF); |
| |
| /* on error or if no table given do full lookup. This |
| * is needed for example when nexthops are in the local |
| * table rather than the given table |
| */ |
| if (!tbl || err) { |
| err = fib_lookup(net, &fl4, &res, |
| FIB_LOOKUP_IGNORE_LINKSTATE); |
| } |
| |
| if (err) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop has invalid gateway"); |
| rcu_read_unlock(); |
| return err; |
| } |
| } |
| err = -EINVAL; |
| if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) { |
| NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); |
| goto out; |
| } |
| nh->nh_scope = res.scope; |
| nh->nh_oif = FIB_RES_OIF(res); |
| nh->nh_dev = dev = FIB_RES_DEV(res); |
| if (!dev) { |
| NL_SET_ERR_MSG(extack, |
| "No egress device for nexthop gateway"); |
| goto out; |
| } |
| dev_hold(dev); |
| if (!netif_carrier_ok(dev)) |
| nh->nh_flags |= RTNH_F_LINKDOWN; |
| err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN; |
| } else { |
| struct in_device *in_dev; |
| |
| if (nh->nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) { |
| NL_SET_ERR_MSG(extack, |
| "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set"); |
| return -EINVAL; |
| } |
| rcu_read_lock(); |
| err = -ENODEV; |
| in_dev = inetdev_by_index(net, nh->nh_oif); |
| if (!in_dev) |
| goto out; |
| err = -ENETDOWN; |
| if (!(in_dev->dev->flags & IFF_UP)) { |
| NL_SET_ERR_MSG(extack, "Device for nexthop is not up"); |
| goto out; |
| } |
| nh->nh_dev = in_dev->dev; |
| dev_hold(nh->nh_dev); |
| nh->nh_scope = RT_SCOPE_HOST; |
| if (!netif_carrier_ok(nh->nh_dev)) |
| nh->nh_flags |= RTNH_F_LINKDOWN; |
| err = 0; |
| } |
| out: |
| rcu_read_unlock(); |
| return err; |
| } |
| |
| static inline unsigned int fib_laddr_hashfn(__be32 val) |
| { |
| unsigned int mask = (fib_info_hash_size - 1); |
| |
| return ((__force u32)val ^ |
| ((__force u32)val >> 7) ^ |
| ((__force u32)val >> 14)) & mask; |
| } |
| |
| static struct hlist_head *fib_info_hash_alloc(int bytes) |
| { |
| if (bytes <= PAGE_SIZE) |
| return kzalloc(bytes, GFP_KERNEL); |
| else |
| return (struct hlist_head *) |
| __get_free_pages(GFP_KERNEL | __GFP_ZERO, |
| get_order(bytes)); |
| } |
| |
| static void fib_info_hash_free(struct hlist_head *hash, int bytes) |
| { |
| if (!hash) |
| return; |
| |
| if (bytes <= PAGE_SIZE) |
| kfree(hash); |
| else |
| free_pages((unsigned long) hash, get_order(bytes)); |
| } |
| |
| static void fib_info_hash_move(struct hlist_head *new_info_hash, |
| struct hlist_head *new_laddrhash, |
| unsigned int new_size) |
| { |
| struct hlist_head *old_info_hash, *old_laddrhash; |
| unsigned int old_size = fib_info_hash_size; |
| unsigned int i, bytes; |
| |
| spin_lock_bh(&fib_info_lock); |
| old_info_hash = fib_info_hash; |
| old_laddrhash = fib_info_laddrhash; |
| fib_info_hash_size = new_size; |
| |
| for (i = 0; i < old_size; i++) { |
| struct hlist_head *head = &fib_info_hash[i]; |
| struct hlist_node *n; |
| struct fib_info *fi; |
| |
| hlist_for_each_entry_safe(fi, n, head, fib_hash) { |
| struct hlist_head *dest; |
| unsigned int new_hash; |
| |
| new_hash = fib_info_hashfn(fi); |
| dest = &new_info_hash[new_hash]; |
| hlist_add_head(&fi->fib_hash, dest); |
| } |
| } |
| fib_info_hash = new_info_hash; |
| |
| for (i = 0; i < old_size; i++) { |
| struct hlist_head *lhead = &fib_info_laddrhash[i]; |
| struct hlist_node *n; |
| struct fib_info *fi; |
| |
| hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) { |
| struct hlist_head *ldest; |
| unsigned int new_hash; |
| |
| new_hash = fib_laddr_hashfn(fi->fib_prefsrc); |
| ldest = &new_laddrhash[new_hash]; |
| hlist_add_head(&fi->fib_lhash, ldest); |
| } |
| } |
| fib_info_laddrhash = new_laddrhash; |
| |
| spin_unlock_bh(&fib_info_lock); |
| |
| bytes = old_size * sizeof(struct hlist_head *); |
| fib_info_hash_free(old_info_hash, bytes); |
| fib_info_hash_free(old_laddrhash, bytes); |
| } |
| |
| __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh) |
| { |
| nh->nh_saddr = inet_select_addr(nh->nh_dev, |
| nh->nh_gw, |
| nh->nh_parent->fib_scope); |
| nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid); |
| |
| return nh->nh_saddr; |
| } |
| |
| static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc) |
| { |
| if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
| fib_prefsrc != cfg->fc_dst) { |
| u32 tb_id = cfg->fc_table; |
| int rc; |
| |
| if (tb_id == RT_TABLE_MAIN) |
| tb_id = RT_TABLE_LOCAL; |
| |
| rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net, |
| fib_prefsrc, tb_id); |
| |
| if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) { |
| rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net, |
| fib_prefsrc, RT_TABLE_LOCAL); |
| } |
| |
| if (rc != RTN_LOCAL) |
| return false; |
| } |
| return true; |
| } |
| |
| static int |
| fib_convert_metrics(struct fib_info *fi, const struct fib_config *cfg) |
| { |
| return ip_metrics_convert(fi->fib_net, cfg->fc_mx, cfg->fc_mx_len, |
| fi->fib_metrics->metrics); |
| } |
| |
| struct fib_info *fib_create_info(struct fib_config *cfg, |
| struct netlink_ext_ack *extack) |
| { |
| int err; |
| struct fib_info *fi = NULL; |
| struct fib_info *ofi; |
| int nhs = 1; |
| struct net *net = cfg->fc_nlinfo.nl_net; |
| |
| if (cfg->fc_type > RTN_MAX) |
| goto err_inval; |
| |
| /* Fast check to catch the most weird cases */ |
| if (fib_props[cfg->fc_type].scope > cfg->fc_scope) { |
| NL_SET_ERR_MSG(extack, "Invalid scope"); |
| goto err_inval; |
| } |
| |
| if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { |
| NL_SET_ERR_MSG(extack, |
| "Invalid rtm_flags - can not contain DEAD or LINKDOWN"); |
| goto err_inval; |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (cfg->fc_mp) { |
| nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack); |
| if (nhs == 0) |
| goto err_inval; |
| } |
| #endif |
| |
| err = -ENOBUFS; |
| if (fib_info_cnt >= fib_info_hash_size) { |
| unsigned int new_size = fib_info_hash_size << 1; |
| struct hlist_head *new_info_hash; |
| struct hlist_head *new_laddrhash; |
| unsigned int bytes; |
| |
| if (!new_size) |
| new_size = 16; |
| bytes = new_size * sizeof(struct hlist_head *); |
| new_info_hash = fib_info_hash_alloc(bytes); |
| new_laddrhash = fib_info_hash_alloc(bytes); |
| if (!new_info_hash || !new_laddrhash) { |
| fib_info_hash_free(new_info_hash, bytes); |
| fib_info_hash_free(new_laddrhash, bytes); |
| } else |
| fib_info_hash_move(new_info_hash, new_laddrhash, new_size); |
| |
| if (!fib_info_hash_size) |
| goto failure; |
| } |
| |
| fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); |
| if (!fi) |
| goto failure; |
| if (cfg->fc_mx) { |
| fi->fib_metrics = kzalloc(sizeof(*fi->fib_metrics), GFP_KERNEL); |
| if (unlikely(!fi->fib_metrics)) { |
| kfree(fi); |
| return ERR_PTR(err); |
| } |
| refcount_set(&fi->fib_metrics->refcnt, 1); |
| } else { |
| fi->fib_metrics = (struct dst_metrics *)&dst_default_metrics; |
| } |
| fib_info_cnt++; |
| fi->fib_net = net; |
| fi->fib_protocol = cfg->fc_protocol; |
| fi->fib_scope = cfg->fc_scope; |
| fi->fib_flags = cfg->fc_flags; |
| fi->fib_priority = cfg->fc_priority; |
| fi->fib_prefsrc = cfg->fc_prefsrc; |
| fi->fib_type = cfg->fc_type; |
| fi->fib_tb_id = cfg->fc_table; |
| |
| fi->fib_nhs = nhs; |
| change_nexthops(fi) { |
| nexthop_nh->nh_parent = fi; |
| nexthop_nh->nh_pcpu_rth_output = alloc_percpu(struct rtable __rcu *); |
| if (!nexthop_nh->nh_pcpu_rth_output) |
| goto failure; |
| } endfor_nexthops(fi) |
| |
| err = fib_convert_metrics(fi, cfg); |
| if (err) |
| goto failure; |
| |
| if (cfg->fc_mp) { |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, extack); |
| if (err != 0) |
| goto failure; |
| if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop device index does not match RTA_OIF"); |
| goto err_inval; |
| } |
| if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop gateway does not match RTA_GATEWAY"); |
| goto err_inval; |
| } |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) { |
| NL_SET_ERR_MSG(extack, |
| "Nexthop class id does not match RTA_FLOW"); |
| goto err_inval; |
| } |
| #endif |
| #else |
| NL_SET_ERR_MSG(extack, |
| "Multipath support not enabled in kernel"); |
| goto err_inval; |
| #endif |
| } else { |
| struct fib_nh *nh = fi->fib_nh; |
| |
| if (cfg->fc_encap) { |
| struct lwtunnel_state *lwtstate; |
| |
| if (cfg->fc_encap_type == LWTUNNEL_ENCAP_NONE) { |
| NL_SET_ERR_MSG(extack, |
| "LWT encap type not specified"); |
| goto err_inval; |
| } |
| err = lwtunnel_build_state(cfg->fc_encap_type, |
| cfg->fc_encap, AF_INET, cfg, |
| &lwtstate, extack); |
| if (err) |
| goto failure; |
| |
| nh->nh_lwtstate = lwtstate_get(lwtstate); |
| } |
| nh->nh_oif = cfg->fc_oif; |
| nh->nh_gw = cfg->fc_gw; |
| nh->nh_flags = cfg->fc_flags; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| nh->nh_tclassid = cfg->fc_flow; |
| if (nh->nh_tclassid) |
| fi->fib_net->ipv4.fib_num_tclassid_users++; |
| #endif |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| nh->nh_weight = 1; |
| #endif |
| } |
| |
| if (fib_props[cfg->fc_type].error) { |
| if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) { |
| NL_SET_ERR_MSG(extack, |
| "Gateway, device and multipath can not be specified for this route type"); |
| goto err_inval; |
| } |
| goto link_it; |
| } else { |
| switch (cfg->fc_type) { |
| case RTN_UNICAST: |
| case RTN_LOCAL: |
| case RTN_BROADCAST: |
| case RTN_ANYCAST: |
| case RTN_MULTICAST: |
| break; |
| default: |
| NL_SET_ERR_MSG(extack, "Invalid route type"); |
| goto err_inval; |
| } |
| } |
| |
| if (cfg->fc_scope > RT_SCOPE_HOST) { |
| NL_SET_ERR_MSG(extack, "Invalid scope"); |
| goto err_inval; |
| } |
| |
| if (cfg->fc_scope == RT_SCOPE_HOST) { |
| struct fib_nh *nh = fi->fib_nh; |
| |
| /* Local address is added. */ |
| if (nhs != 1) { |
| NL_SET_ERR_MSG(extack, |
| "Route with host scope can not have multiple nexthops"); |
| goto err_inval; |
| } |
| if (nh->nh_gw) { |
| NL_SET_ERR_MSG(extack, |
| "Route with host scope can not have a gateway"); |
| goto err_inval; |
| } |
| nh->nh_scope = RT_SCOPE_NOWHERE; |
| nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif); |
| err = -ENODEV; |
| if (!nh->nh_dev) |
| goto failure; |
| } else { |
| int linkdown = 0; |
| |
| change_nexthops(fi) { |
| err = fib_check_nh(cfg, nexthop_nh, extack); |
| if (err != 0) |
| goto failure; |
| if (nexthop_nh->nh_flags & RTNH_F_LINKDOWN) |
| linkdown++; |
| } endfor_nexthops(fi) |
| if (linkdown == fi->fib_nhs) |
| fi->fib_flags |= RTNH_F_LINKDOWN; |
| } |
| |
| if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) { |
| NL_SET_ERR_MSG(extack, "Invalid prefsrc address"); |
| goto err_inval; |
| } |
| |
| change_nexthops(fi) { |
| fib_info_update_nh_saddr(net, nexthop_nh); |
| } endfor_nexthops(fi) |
| |
| fib_rebalance(fi); |
| |
| link_it: |
| ofi = fib_find_info(fi); |
| if (ofi) { |
| fi->fib_dead = 1; |
| free_fib_info(fi); |
| ofi->fib_treeref++; |
| return ofi; |
| } |
| |
| fi->fib_treeref++; |
| refcount_set(&fi->fib_clntref, 1); |
| spin_lock_bh(&fib_info_lock); |
| hlist_add_head(&fi->fib_hash, |
| &fib_info_hash[fib_info_hashfn(fi)]); |
| if (fi->fib_prefsrc) { |
| struct hlist_head *head; |
| |
| head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; |
| hlist_add_head(&fi->fib_lhash, head); |
| } |
| change_nexthops(fi) { |
| struct hlist_head *head; |
| unsigned int hash; |
| |
| if (!nexthop_nh->nh_dev) |
| continue; |
| hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex); |
| head = &fib_info_devhash[hash]; |
| hlist_add_head(&nexthop_nh->nh_hash, head); |
| } endfor_nexthops(fi) |
| spin_unlock_bh(&fib_info_lock); |
| return fi; |
| |
| err_inval: |
| err = -EINVAL; |
| |
| failure: |
| if (fi) { |
| fi->fib_dead = 1; |
| free_fib_info(fi); |
| } |
| |
| return ERR_PTR(err); |
| } |
| |
| int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, |
| u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos, |
| struct fib_info *fi, unsigned int flags) |
| { |
| struct nlmsghdr *nlh; |
| struct rtmsg *rtm; |
| |
| nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); |
| if (!nlh) |
| return -EMSGSIZE; |
| |
| rtm = nlmsg_data(nlh); |
| rtm->rtm_family = AF_INET; |
| rtm->rtm_dst_len = dst_len; |
| rtm->rtm_src_len = 0; |
| rtm->rtm_tos = tos; |
| if (tb_id < 256) |
| rtm->rtm_table = tb_id; |
| else |
| rtm->rtm_table = RT_TABLE_COMPAT; |
| if (nla_put_u32(skb, RTA_TABLE, tb_id)) |
| goto nla_put_failure; |
| rtm->rtm_type = type; |
| rtm->rtm_flags = fi->fib_flags; |
| rtm->rtm_scope = fi->fib_scope; |
| rtm->rtm_protocol = fi->fib_protocol; |
| |
| if (rtm->rtm_dst_len && |
| nla_put_in_addr(skb, RTA_DST, dst)) |
| goto nla_put_failure; |
| if (fi->fib_priority && |
| nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority)) |
| goto nla_put_failure; |
| if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0) |
| goto nla_put_failure; |
| |
| if (fi->fib_prefsrc && |
| nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc)) |
| goto nla_put_failure; |
| if (fi->fib_nhs == 1) { |
| if (fi->fib_nh->nh_gw && |
| nla_put_in_addr(skb, RTA_GATEWAY, fi->fib_nh->nh_gw)) |
| goto nla_put_failure; |
| if (fi->fib_nh->nh_oif && |
| nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif)) |
| goto nla_put_failure; |
| if (fi->fib_nh->nh_flags & RTNH_F_LINKDOWN) { |
| struct in_device *in_dev; |
| |
| rcu_read_lock(); |
| in_dev = __in_dev_get_rcu(fi->fib_nh->nh_dev); |
| if (in_dev && |
| IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) |
| rtm->rtm_flags |= RTNH_F_DEAD; |
| rcu_read_unlock(); |
| } |
| if (fi->fib_nh->nh_flags & RTNH_F_OFFLOAD) |
| rtm->rtm_flags |= RTNH_F_OFFLOAD; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| if (fi->fib_nh[0].nh_tclassid && |
| nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid)) |
| goto nla_put_failure; |
| #endif |
| if (fi->fib_nh->nh_lwtstate && |
| lwtunnel_fill_encap(skb, fi->fib_nh->nh_lwtstate) < 0) |
| goto nla_put_failure; |
| } |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (fi->fib_nhs > 1) { |
| struct rtnexthop *rtnh; |
| struct nlattr *mp; |
| |
| mp = nla_nest_start(skb, RTA_MULTIPATH); |
| if (!mp) |
| goto nla_put_failure; |
| |
| for_nexthops(fi) { |
| rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
| if (!rtnh) |
| goto nla_put_failure; |
| |
| rtnh->rtnh_flags = nh->nh_flags & 0xFF; |
| if (nh->nh_flags & RTNH_F_LINKDOWN) { |
| struct in_device *in_dev; |
| |
| rcu_read_lock(); |
| in_dev = __in_dev_get_rcu(nh->nh_dev); |
| if (in_dev && |
| IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) |
| rtnh->rtnh_flags |= RTNH_F_DEAD; |
| rcu_read_unlock(); |
| } |
| rtnh->rtnh_hops = nh->nh_weight - 1; |
| rtnh->rtnh_ifindex = nh->nh_oif; |
| |
| if (nh->nh_gw && |
| nla_put_in_addr(skb, RTA_GATEWAY, nh->nh_gw)) |
| goto nla_put_failure; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| if (nh->nh_tclassid && |
| nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) |
| goto nla_put_failure; |
| #endif |
| if (nh->nh_lwtstate && |
| lwtunnel_fill_encap(skb, nh->nh_lwtstate) < 0) |
| goto nla_put_failure; |
| |
| /* length of rtnetlink header + attributes */ |
| rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; |
| } endfor_nexthops(fi); |
| |
| nla_nest_end(skb, mp); |
| } |
| #endif |
| nlmsg_end(skb, nlh); |
| return 0; |
| |
| nla_put_failure: |
| nlmsg_cancel(skb, nlh); |
| return -EMSGSIZE; |
| } |
| |
| /* |
| * Update FIB if: |
| * - local address disappeared -> we must delete all the entries |
| * referring to it. |
| * - device went down -> we must shutdown all nexthops going via it. |
| */ |
| int fib_sync_down_addr(struct net_device *dev, __be32 local) |
| { |
| int ret = 0; |
| unsigned int hash = fib_laddr_hashfn(local); |
| struct hlist_head *head = &fib_info_laddrhash[hash]; |
| int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN; |
| struct net *net = dev_net(dev); |
| struct fib_info *fi; |
| |
| if (!fib_info_laddrhash || local == 0) |
| return 0; |
| |
| hlist_for_each_entry(fi, head, fib_lhash) { |
| if (!net_eq(fi->fib_net, net) || |
| fi->fib_tb_id != tb_id) |
| continue; |
| if (fi->fib_prefsrc == local) { |
| fi->fib_flags |= RTNH_F_DEAD; |
| ret++; |
| } |
| } |
| return ret; |
| } |
| |
| static int call_fib_nh_notifiers(struct fib_nh *fib_nh, |
| enum fib_event_type event_type) |
| { |
| struct in_device *in_dev = __in_dev_get_rtnl(fib_nh->nh_dev); |
| struct fib_nh_notifier_info info = { |
| .fib_nh = fib_nh, |
| }; |
| |
| switch (event_type) { |
| case FIB_EVENT_NH_ADD: |
| if (fib_nh->nh_flags & RTNH_F_DEAD) |
| break; |
| if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && |
| fib_nh->nh_flags & RTNH_F_LINKDOWN) |
| break; |
| return call_fib4_notifiers(dev_net(fib_nh->nh_dev), event_type, |
| &info.info); |
| case FIB_EVENT_NH_DEL: |
| if ((in_dev && IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && |
| fib_nh->nh_flags & RTNH_F_LINKDOWN) || |
| (fib_nh->nh_flags & RTNH_F_DEAD)) |
| return call_fib4_notifiers(dev_net(fib_nh->nh_dev), |
| event_type, &info.info); |
| default: |
| break; |
| } |
| |
| return NOTIFY_DONE; |
| } |
| |
| /* Update the PMTU of exceptions when: |
| * - the new MTU of the first hop becomes smaller than the PMTU |
| * - the old MTU was the same as the PMTU, and it limited discovery of |
| * larger MTUs on the path. With that limit raised, we can now |
| * discover larger MTUs |
| * A special case is locked exceptions, for which the PMTU is smaller |
| * than the minimal accepted PMTU: |
| * - if the new MTU is greater than the PMTU, don't make any change |
| * - otherwise, unlock and set PMTU |
| */ |
| static void nh_update_mtu(struct fib_nh *nh, u32 new, u32 orig) |
| { |
| struct fnhe_hash_bucket *bucket; |
| int i; |
| |
| bucket = rcu_dereference_protected(nh->nh_exceptions, 1); |
| if (!bucket) |
| return; |
| |
| for (i = 0; i < FNHE_HASH_SIZE; i++) { |
| struct fib_nh_exception *fnhe; |
| |
| for (fnhe = rcu_dereference_protected(bucket[i].chain, 1); |
| fnhe; |
| fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) { |
| if (fnhe->fnhe_mtu_locked) { |
| if (new <= fnhe->fnhe_pmtu) { |
| fnhe->fnhe_pmtu = new; |
| fnhe->fnhe_mtu_locked = false; |
| } |
| } else if (new < fnhe->fnhe_pmtu || |
| orig == fnhe->fnhe_pmtu) { |
| fnhe->fnhe_pmtu = new; |
| } |
| } |
| } |
| } |
| |
| void fib_sync_mtu(struct net_device *dev, u32 orig_mtu) |
| { |
| unsigned int hash = fib_devindex_hashfn(dev->ifindex); |
| struct hlist_head *head = &fib_info_devhash[hash]; |
| struct fib_nh *nh; |
| |
| hlist_for_each_entry(nh, head, nh_hash) { |
| if (nh->nh_dev == dev) |
| nh_update_mtu(nh, dev->mtu, orig_mtu); |
| } |
| } |
| |
| /* Event force Flags Description |
| * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host |
| * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host |
| * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed |
| * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed |
| */ |
| int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force) |
| { |
| int ret = 0; |
| int scope = RT_SCOPE_NOWHERE; |
| struct fib_info *prev_fi = NULL; |
| unsigned int hash = fib_devindex_hashfn(dev->ifindex); |
| struct hlist_head *head = &fib_info_devhash[hash]; |
| struct fib_nh *nh; |
| |
| if (force) |
| scope = -1; |
| |
| hlist_for_each_entry(nh, head, nh_hash) { |
| struct fib_info *fi = nh->nh_parent; |
| int dead; |
| |
| BUG_ON(!fi->fib_nhs); |
| if (nh->nh_dev != dev || fi == prev_fi) |
| continue; |
| prev_fi = fi; |
| dead = 0; |
| change_nexthops(fi) { |
| if (nexthop_nh->nh_flags & RTNH_F_DEAD) |
| dead++; |
| else if (nexthop_nh->nh_dev == dev && |
| nexthop_nh->nh_scope != scope) { |
| switch (event) { |
| case NETDEV_DOWN: |
| case NETDEV_UNREGISTER: |
| nexthop_nh->nh_flags |= RTNH_F_DEAD; |
| /* fall through */ |
| case NETDEV_CHANGE: |
| nexthop_nh->nh_flags |= RTNH_F_LINKDOWN; |
| break; |
| } |
| call_fib_nh_notifiers(nexthop_nh, |
| FIB_EVENT_NH_DEL); |
| dead++; |
| } |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (event == NETDEV_UNREGISTER && |
| nexthop_nh->nh_dev == dev) { |
| dead = fi->fib_nhs; |
| break; |
| } |
| #endif |
| } endfor_nexthops(fi) |
| if (dead == fi->fib_nhs) { |
| switch (event) { |
| case NETDEV_DOWN: |
| case NETDEV_UNREGISTER: |
| fi->fib_flags |= RTNH_F_DEAD; |
| /* fall through */ |
| case NETDEV_CHANGE: |
| fi->fib_flags |= RTNH_F_LINKDOWN; |
| break; |
| } |
| ret++; |
| } |
| |
| fib_rebalance(fi); |
| } |
| |
| return ret; |
| } |
| |
| /* Must be invoked inside of an RCU protected region. */ |
| static void fib_select_default(const struct flowi4 *flp, struct fib_result *res) |
| { |
| struct fib_info *fi = NULL, *last_resort = NULL; |
| struct hlist_head *fa_head = res->fa_head; |
| struct fib_table *tb = res->table; |
| u8 slen = 32 - res->prefixlen; |
| int order = -1, last_idx = -1; |
| struct fib_alias *fa, *fa1 = NULL; |
| u32 last_prio = res->fi->fib_priority; |
| u8 last_tos = 0; |
| |
| hlist_for_each_entry_rcu(fa, fa_head, fa_list) { |
| struct fib_info *next_fi = fa->fa_info; |
| |
| if (fa->fa_slen != slen) |
| continue; |
| if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) |
| continue; |
| if (fa->tb_id != tb->tb_id) |
| continue; |
| if (next_fi->fib_priority > last_prio && |
| fa->fa_tos == last_tos) { |
| if (last_tos) |
| continue; |
| break; |
| } |
| if (next_fi->fib_flags & RTNH_F_DEAD) |
| continue; |
| last_tos = fa->fa_tos; |
| last_prio = next_fi->fib_priority; |
| |
| if (next_fi->fib_scope != res->scope || |
| fa->fa_type != RTN_UNICAST) |
| continue; |
| if (!next_fi->fib_nh[0].nh_gw || |
| next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK) |
| continue; |
| |
| fib_alias_accessed(fa); |
| |
| if (!fi) { |
| if (next_fi != res->fi) |
| break; |
| fa1 = fa; |
| } else if (!fib_detect_death(fi, order, &last_resort, |
| &last_idx, fa1->fa_default)) { |
| fib_result_assign(res, fi); |
| fa1->fa_default = order; |
| goto out; |
| } |
| fi = next_fi; |
| order++; |
| } |
| |
| if (order <= 0 || !fi) { |
| if (fa1) |
| fa1->fa_default = -1; |
| goto out; |
| } |
| |
| if (!fib_detect_death(fi, order, &last_resort, &last_idx, |
| fa1->fa_default)) { |
| fib_result_assign(res, fi); |
| fa1->fa_default = order; |
| goto out; |
| } |
| |
| if (last_idx >= 0) |
| fib_result_assign(res, last_resort); |
| fa1->fa_default = last_idx; |
| out: |
| return; |
| } |
| |
| /* |
| * Dead device goes up. We wake up dead nexthops. |
| * It takes sense only on multipath routes. |
| */ |
| int fib_sync_up(struct net_device *dev, unsigned int nh_flags) |
| { |
| struct fib_info *prev_fi; |
| unsigned int hash; |
| struct hlist_head *head; |
| struct fib_nh *nh; |
| int ret; |
| |
| if (!(dev->flags & IFF_UP)) |
| return 0; |
| |
| if (nh_flags & RTNH_F_DEAD) { |
| unsigned int flags = dev_get_flags(dev); |
| |
| if (flags & (IFF_RUNNING | IFF_LOWER_UP)) |
| nh_flags |= RTNH_F_LINKDOWN; |
| } |
| |
| prev_fi = NULL; |
| hash = fib_devindex_hashfn(dev->ifindex); |
| head = &fib_info_devhash[hash]; |
| ret = 0; |
| |
| hlist_for_each_entry(nh, head, nh_hash) { |
| struct fib_info *fi = nh->nh_parent; |
| int alive; |
| |
| BUG_ON(!fi->fib_nhs); |
| if (nh->nh_dev != dev || fi == prev_fi) |
| continue; |
| |
| prev_fi = fi; |
| alive = 0; |
| change_nexthops(fi) { |
| if (!(nexthop_nh->nh_flags & nh_flags)) { |
| alive++; |
| continue; |
| } |
| if (!nexthop_nh->nh_dev || |
| !(nexthop_nh->nh_dev->flags & IFF_UP)) |
| continue; |
| if (nexthop_nh->nh_dev != dev || |
| !__in_dev_get_rtnl(dev)) |
| continue; |
| alive++; |
| nexthop_nh->nh_flags &= ~nh_flags; |
| call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD); |
| } endfor_nexthops(fi) |
| |
| if (alive > 0) { |
| fi->fib_flags &= ~nh_flags; |
| ret++; |
| } |
| |
| fib_rebalance(fi); |
| } |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| static bool fib_good_nh(const struct fib_nh *nh) |
| { |
| int state = NUD_REACHABLE; |
| |
| if (nh->nh_scope == RT_SCOPE_LINK) { |
| struct neighbour *n; |
| |
| rcu_read_lock_bh(); |
| |
| n = __ipv4_neigh_lookup_noref(nh->nh_dev, |
| (__force u32)nh->nh_gw); |
| if (n) |
| state = n->nud_state; |
| |
| rcu_read_unlock_bh(); |
| } |
| |
| return !!(state & NUD_VALID); |
| } |
| |
| void fib_select_multipath(struct fib_result *res, int hash) |
| { |
| struct fib_info *fi = res->fi; |
| struct net *net = fi->fib_net; |
| bool first = false; |
| |
| for_nexthops(fi) { |
| if (net->ipv4.sysctl_fib_multipath_use_neigh) { |
| if (!fib_good_nh(nh)) |
| continue; |
| if (!first) { |
| res->nh_sel = nhsel; |
| first = true; |
| } |
| } |
| |
| if (hash > atomic_read(&nh->nh_upper_bound)) |
| continue; |
| |
| res->nh_sel = nhsel; |
| return; |
| } endfor_nexthops(fi); |
| } |
| #endif |
| |
| void fib_select_path(struct net *net, struct fib_result *res, |
| struct flowi4 *fl4, const struct sk_buff *skb) |
| { |
| if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) |
| goto check_saddr; |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (res->fi->fib_nhs > 1) { |
| int h = fib_multipath_hash(net, fl4, skb, NULL); |
| |
| fib_select_multipath(res, h); |
| } |
| else |
| #endif |
| if (!res->prefixlen && |
| res->table->tb_num_default > 1 && |
| res->type == RTN_UNICAST) |
| fib_select_default(fl4, res); |
| |
| check_saddr: |
| if (!fl4->saddr) |
| fl4->saddr = FIB_RES_PREFSRC(net, *res); |
| } |