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net/ipv4/fib_semantics.c
30.3 KB
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/* * 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. * |
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* 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. */ |
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#include <asm/uaccess.h> |
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#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> |
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#include <linux/inetdevice.h> |
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#include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/proc_fs.h> #include <linux/skbuff.h> |
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#include <linux/init.h> |
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#include <linux/slab.h> |
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#include <net/arp.h> |
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#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> |
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#include <net/netlink.h> |
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#include <net/nexthop.h> |
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#include "fib_lookup.h" |
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static DEFINE_SPINLOCK(fib_info_lock); |
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static struct hlist_head *fib_info_hash; static struct hlist_head *fib_info_laddrhash; |
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static unsigned int fib_info_hash_size; |
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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 static DEFINE_SPINLOCK(fib_multipath_lock); |
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#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++) |
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#else /* CONFIG_IP_ROUTE_MULTIPATH */ /* Hope, that gcc will optimize it to get rid of dummy loop */ |
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#define for_nexthops(fi) { \ int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \ for (nhsel = 0; nhsel < 1; nhsel++) |
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#define change_nexthops(fi) { \ int nhsel; \ struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ for (nhsel = 0; nhsel < 1; nhsel++) |
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#endif /* CONFIG_IP_ROUTE_MULTIPATH */ #define endfor_nexthops(fi) } |
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const struct fib_prop fib_props[RTN_MAX + 1] = { |
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[RTN_UNSPEC] = { |
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.error = 0, .scope = RT_SCOPE_NOWHERE, |
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}, [RTN_UNICAST] = { |
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.error = 0, .scope = RT_SCOPE_UNIVERSE, |
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}, [RTN_LOCAL] = { |
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.error = 0, .scope = RT_SCOPE_HOST, |
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}, [RTN_BROADCAST] = { |
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.error = 0, .scope = RT_SCOPE_LINK, |
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}, [RTN_ANYCAST] = { |
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.error = 0, .scope = RT_SCOPE_LINK, |
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}, [RTN_MULTICAST] = { |
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.error = 0, .scope = RT_SCOPE_UNIVERSE, |
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}, [RTN_BLACKHOLE] = { |
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.error = -EINVAL, .scope = RT_SCOPE_UNIVERSE, |
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}, [RTN_UNREACHABLE] = { |
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.error = -EHOSTUNREACH, .scope = RT_SCOPE_UNIVERSE, |
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}, [RTN_PROHIBIT] = { |
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.error = -EACCES, .scope = RT_SCOPE_UNIVERSE, |
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}, [RTN_THROW] = { |
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.error = -EAGAIN, .scope = RT_SCOPE_UNIVERSE, |
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}, [RTN_NAT] = { |
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.error = -EINVAL, .scope = RT_SCOPE_NOWHERE, |
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}, [RTN_XRESOLVE] = { |
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.error = -EINVAL, .scope = RT_SCOPE_NOWHERE, |
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}, |
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}; |
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static void free_nh_exceptions(struct fib_nh *nh) { struct fnhe_hash_bucket *hash = nh->nh_exceptions; int i; for (i = 0; i < FNHE_HASH_SIZE; i++) { struct fib_nh_exception *fnhe; |
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fnhe = rcu_dereference_protected(hash[i].chain, 1); |
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while (fnhe) { struct fib_nh_exception *next; |
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next = rcu_dereference_protected(fnhe->fnhe_next, 1); |
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kfree(fnhe); fnhe = next; } } kfree(hash); } |
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/* Release a nexthop info record */ |
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static void free_fib_info_rcu(struct rcu_head *head) { struct fib_info *fi = container_of(head, struct fib_info, rcu); |
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change_nexthops(fi) { if (nexthop_nh->nh_dev) dev_put(nexthop_nh->nh_dev); |
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if (nexthop_nh->nh_exceptions) free_nh_exceptions(nexthop_nh); |
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if (nexthop_nh->nh_rth_output) dst_release(&nexthop_nh->nh_rth_output->dst); |
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if (nexthop_nh->nh_rth_input) dst_release(&nexthop_nh->nh_rth_input->dst); |
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} endfor_nexthops(fi); release_net(fi->fib_net); |
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if (fi->fib_metrics != (u32 *) dst_default_metrics) kfree(fi->fib_metrics); kfree(fi); } |
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void free_fib_info(struct fib_info *fi) { if (fi->fib_dead == 0) { |
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pr_warn("Freeing alive fib_info %p ", fi); |
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return; } |
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fib_info_cnt--; |
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#ifdef CONFIG_IP_ROUTE_CLASSID change_nexthops(fi) { if (nexthop_nh->nh_tclassid) |
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fi->fib_net->ipv4.fib_num_tclassid_users--; |
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} endfor_nexthops(fi); #endif |
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call_rcu(&fi->rcu, free_fib_info_rcu); |
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} void fib_release_info(struct fib_info *fi) { |
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spin_lock_bh(&fib_info_lock); |
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if (fi && --fi->fib_treeref == 0) { hlist_del(&fi->fib_hash); if (fi->fib_prefsrc) hlist_del(&fi->fib_lhash); change_nexthops(fi) { |
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if (!nexthop_nh->nh_dev) |
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continue; |
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hlist_del(&nexthop_nh->nh_hash); |
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} endfor_nexthops(fi) fi->fib_dead = 1; fib_info_put(fi); } |
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spin_unlock_bh(&fib_info_lock); |
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} |
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static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) |
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{ 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 |
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#ifdef CONFIG_IP_ROUTE_CLASSID |
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nh->nh_tclassid != onh->nh_tclassid || #endif |
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((nh->nh_flags ^ onh->nh_flags) & ~RTNH_F_DEAD)) |
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return -1; onh++; } endfor_nexthops(fi); return 0; } |
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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; } |
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static inline unsigned int fib_info_hashfn(const struct fib_info *fi) { |
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unsigned int mask = (fib_info_hash_size - 1); |
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unsigned int val = fi->fib_nhs; |
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val ^= (fi->fib_protocol << 8) | fi->fib_scope; |
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val ^= (__force u32)fi->fib_prefsrc; |
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val ^= fi->fib_priority; |
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for_nexthops(fi) { val ^= fib_devindex_hashfn(nh->nh_oif); } endfor_nexthops(fi) |
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return (val ^ (val >> 7) ^ (val >> 12)) & mask; } static struct fib_info *fib_find_info(const struct fib_info *nfi) { struct hlist_head *head; struct hlist_node *node; struct fib_info *fi; unsigned int hash; hash = fib_info_hashfn(nfi); head = &fib_info_hash[hash]; hlist_for_each_entry(fi, node, head, fib_hash) { |
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if (!net_eq(fi->fib_net, nfi->fib_net)) |
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continue; |
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if (fi->fib_nhs != nfi->fib_nhs) continue; if (nfi->fib_protocol == fi->fib_protocol && |
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nfi->fib_scope == fi->fib_scope && |
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nfi->fib_prefsrc == fi->fib_prefsrc && nfi->fib_priority == fi->fib_priority && memcmp(nfi->fib_metrics, fi->fib_metrics, |
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sizeof(u32) * RTAX_MAX) == 0 && |
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((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_F_DEAD) == 0 && |
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(nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) return fi; } return NULL; } |
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/* Check, that the gateway is already configured. |
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* Used only by redirect accept routine. |
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*/ |
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int ip_fib_check_default(__be32 gw, struct net_device *dev) |
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{ struct hlist_head *head; struct hlist_node *node; struct fib_nh *nh; unsigned int hash; |
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spin_lock(&fib_info_lock); |
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hash = fib_devindex_hashfn(dev->ifindex); head = &fib_info_devhash[hash]; hlist_for_each_entry(nh, node, head, nh_hash) { if (nh->nh_dev == dev && nh->nh_gw == gw && |
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!(nh->nh_flags & RTNH_F_DEAD)) { |
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spin_unlock(&fib_info_lock); |
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return 0; } } |
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spin_unlock(&fib_info_lock); |
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return -1; } |
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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 */ /* space for nested metrics */ payload += nla_total_size((RTAX_MAX * nla_total_size(4))); if (fi->fib_nhs) { /* 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); /* all nexthops are packed in a nested attribute */ payload += nla_total_size(fi->fib_nhs * nhsize); } return payload; } |
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void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
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int dst_len, u32 tb_id, struct nl_info *info, unsigned int nlm_flags) |
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{ struct sk_buff *skb; |
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u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
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int err = -ENOBUFS; |
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|
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skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
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if (skb == NULL) goto errout; |
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|
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err = fib_dump_info(skb, info->pid, seq, event, tb_id, |
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fa->fa_type, key, dst_len, |
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fa->fa_tos, fa->fa_info, nlm_flags); |
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if (err < 0) { /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ WARN_ON(err == -EMSGSIZE); kfree_skb(skb); goto errout; } |
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rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE, info->nlh, GFP_KERNEL); return; |
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errout: if (err < 0) |
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rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); |
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} /* Return the first fib alias matching TOS with * priority less than or equal to PRIO. */ struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio) { if (fah) { struct fib_alias *fa; list_for_each_entry(fa, fah, fa_list) { if (fa->fa_tos > tos) continue; if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos) return fa; } } return NULL; } int fib_detect_death(struct fib_info *fi, int order, |
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struct fib_info **last_resort, int *last_idx, int dflt) |
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{ 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); } |
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if (state == NUD_REACHABLE) |
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return 0; |
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if ((state & NUD_VALID) && order != dflt) |
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return 0; |
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if ((state & NUD_VALID) || (*last_idx < 0 && order > dflt)) { |
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*last_resort = fi; *last_idx = order; } return 1; } #ifdef CONFIG_IP_ROUTE_MULTIPATH |
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static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining) |
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{ int nhs = 0; |
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while (rtnh_ok(rtnh, remaining)) { |
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nhs++; |
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rtnh = rtnh_next(rtnh, &remaining); } /* leftover implies invalid nexthop configuration, discard it */ return remaining > 0 ? 0 : nhs; |
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} |
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static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, int remaining, struct fib_config *cfg) |
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{ |
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change_nexthops(fi) { |
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int attrlen; if (!rtnh_ok(rtnh, remaining)) |
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return -EINVAL; |
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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; |
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attrlen = rtnh_attrlen(rtnh); if (attrlen > 0) { struct nlattr *nla, *attrs = rtnh_attrs(rtnh); nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
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nexthop_nh->nh_gw = nla ? nla_get_be32(nla) : 0; |
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#ifdef CONFIG_IP_ROUTE_CLASSID |
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nla = nla_find(attrs, attrlen, RTA_FLOW); |
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nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; |
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if (nexthop_nh->nh_tclassid) |
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fi->fib_net->ipv4.fib_num_tclassid_users++; |
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#endif } |
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rtnh = rtnh_next(rtnh, &remaining); |
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} endfor_nexthops(fi); |
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return 0; } #endif |
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int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) |
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{ #ifdef CONFIG_IP_ROUTE_MULTIPATH |
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struct rtnexthop *rtnh; int remaining; |
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#endif |
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if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
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return 1; |
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if (cfg->fc_oif || cfg->fc_gw) { if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) |
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return 0; return 1; } #ifdef CONFIG_IP_ROUTE_MULTIPATH |
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if (cfg->fc_mp == NULL) |
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return 0; |
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rtnh = cfg->fc_mp; remaining = cfg->fc_mp_len; |
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|
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for_nexthops(fi) { |
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int attrlen; |
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if (!rtnh_ok(rtnh, remaining)) |
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return -EINVAL; |
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if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) |
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return 1; |
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attrlen = rtnh_attrlen(rtnh); if (attrlen < 0) { struct nlattr *nla, *attrs = rtnh_attrs(rtnh); nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
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if (nla && nla_get_be32(nla) != nh->nh_gw) |
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return 1; |
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#ifdef CONFIG_IP_ROUTE_CLASSID |
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|
488 489 |
nla = nla_find(attrs, attrlen, RTA_FLOW); if (nla && nla_get_u32(nla) != nh->nh_tclassid) |
1da177e4c
|
490 491 492 |
return 1; #endif } |
4e902c574
|
493 494 |
rtnh = rtnh_next(rtnh, &remaining); |
1da177e4c
|
495 496 497 498 499 500 501 |
} endfor_nexthops(fi); #endif return 0; } /* |
6a31d2a97
|
502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 |
* 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) |
1da177e4c
|
543 |
*/ |
4e902c574
|
544 545 |
static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, struct fib_nh *nh) |
1da177e4c
|
546 547 |
{ int err; |
86167a377
|
548 |
struct net *net; |
6a31d2a97
|
549 |
struct net_device *dev; |
1da177e4c
|
550 |
|
86167a377
|
551 |
net = cfg->fc_nlinfo.nl_net; |
1da177e4c
|
552 553 |
if (nh->nh_gw) { struct fib_result res; |
6a31d2a97
|
554 |
if (nh->nh_flags & RTNH_F_ONLINK) { |
1da177e4c
|
555 |
|
4e902c574
|
556 |
if (cfg->fc_scope >= RT_SCOPE_LINK) |
1da177e4c
|
557 |
return -EINVAL; |
86167a377
|
558 |
if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST) |
1da177e4c
|
559 |
return -EINVAL; |
6a31d2a97
|
560 561 |
dev = __dev_get_by_index(net, nh->nh_oif); if (!dev) |
1da177e4c
|
562 |
return -ENODEV; |
6a31d2a97
|
563 |
if (!(dev->flags & IFF_UP)) |
1da177e4c
|
564 565 566 567 568 569 |
return -ENETDOWN; nh->nh_dev = dev; dev_hold(dev); nh->nh_scope = RT_SCOPE_LINK; return 0; } |
ebc0ffae5
|
570 |
rcu_read_lock(); |
1da177e4c
|
571 |
{ |
9ade22861
|
572 573 574 575 |
struct flowi4 fl4 = { .daddr = nh->nh_gw, .flowi4_scope = cfg->fc_scope + 1, .flowi4_oif = nh->nh_oif, |
4e902c574
|
576 |
}; |
1da177e4c
|
577 578 |
/* It is not necessary, but requires a bit of thinking */ |
9ade22861
|
579 580 581 |
if (fl4.flowi4_scope < RT_SCOPE_LINK) fl4.flowi4_scope = RT_SCOPE_LINK; err = fib_lookup(net, &fl4, &res); |
ebc0ffae5
|
582 583 |
if (err) { rcu_read_unlock(); |
1da177e4c
|
584 |
return err; |
ebc0ffae5
|
585 |
} |
1da177e4c
|
586 587 588 589 590 591 |
} err = -EINVAL; if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) goto out; nh->nh_scope = res.scope; nh->nh_oif = FIB_RES_OIF(res); |
6a31d2a97
|
592 593 |
nh->nh_dev = dev = FIB_RES_DEV(res); if (!dev) |
1da177e4c
|
594 |
goto out; |
6a31d2a97
|
595 |
dev_hold(dev); |
8723e1b4a
|
596 |
err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN; |
1da177e4c
|
597 598 |
} else { struct in_device *in_dev; |
6a31d2a97
|
599 |
if (nh->nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) |
1da177e4c
|
600 |
return -EINVAL; |
8723e1b4a
|
601 602 |
rcu_read_lock(); err = -ENODEV; |
86167a377
|
603 |
in_dev = inetdev_by_index(net, nh->nh_oif); |
1da177e4c
|
604 |
if (in_dev == NULL) |
8723e1b4a
|
605 606 607 608 |
goto out; err = -ENETDOWN; if (!(in_dev->dev->flags & IFF_UP)) goto out; |
1da177e4c
|
609 610 611 |
nh->nh_dev = in_dev->dev; dev_hold(nh->nh_dev); nh->nh_scope = RT_SCOPE_HOST; |
8723e1b4a
|
612 |
err = 0; |
1da177e4c
|
613 |
} |
8723e1b4a
|
614 615 616 |
out: rcu_read_unlock(); return err; |
1da177e4c
|
617 |
} |
81f7bf6cb
|
618 |
static inline unsigned int fib_laddr_hashfn(__be32 val) |
1da177e4c
|
619 |
{ |
123b9731b
|
620 |
unsigned int mask = (fib_info_hash_size - 1); |
1da177e4c
|
621 |
|
6a31d2a97
|
622 623 624 |
return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask; |
1da177e4c
|
625 |
} |
123b9731b
|
626 |
static struct hlist_head *fib_info_hash_alloc(int bytes) |
1da177e4c
|
627 628 |
{ if (bytes <= PAGE_SIZE) |
88f834916
|
629 |
return kzalloc(bytes, GFP_KERNEL); |
1da177e4c
|
630 631 |
else return (struct hlist_head *) |
6a31d2a97
|
632 633 |
__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(bytes)); |
1da177e4c
|
634 |
} |
123b9731b
|
635 |
static void fib_info_hash_free(struct hlist_head *hash, int bytes) |
1da177e4c
|
636 637 638 639 640 641 642 643 644 |
{ if (!hash) return; if (bytes <= PAGE_SIZE) kfree(hash); else free_pages((unsigned long) hash, get_order(bytes)); } |
123b9731b
|
645 646 647 |
static void fib_info_hash_move(struct hlist_head *new_info_hash, struct hlist_head *new_laddrhash, unsigned int new_size) |
1da177e4c
|
648 |
{ |
b7656e7f2
|
649 |
struct hlist_head *old_info_hash, *old_laddrhash; |
123b9731b
|
650 |
unsigned int old_size = fib_info_hash_size; |
b7656e7f2
|
651 |
unsigned int i, bytes; |
1da177e4c
|
652 |
|
832b4c5e1
|
653 |
spin_lock_bh(&fib_info_lock); |
b7656e7f2
|
654 655 |
old_info_hash = fib_info_hash; old_laddrhash = fib_info_laddrhash; |
123b9731b
|
656 |
fib_info_hash_size = new_size; |
1da177e4c
|
657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 |
for (i = 0; i < old_size; i++) { struct hlist_head *head = &fib_info_hash[i]; struct hlist_node *node, *n; struct fib_info *fi; hlist_for_each_entry_safe(fi, node, n, head, fib_hash) { struct hlist_head *dest; unsigned int new_hash; hlist_del(&fi->fib_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 *node, *n; struct fib_info *fi; hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) { struct hlist_head *ldest; unsigned int new_hash; hlist_del(&fi->fib_lhash); 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; |
832b4c5e1
|
693 |
spin_unlock_bh(&fib_info_lock); |
b7656e7f2
|
694 695 |
bytes = old_size * sizeof(struct hlist_head *); |
123b9731b
|
696 697 |
fib_info_hash_free(old_info_hash, bytes); fib_info_hash_free(old_laddrhash, bytes); |
1da177e4c
|
698 |
} |
436c3b66e
|
699 700 701 702 |
__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, |
37e826c51
|
703 |
nh->nh_parent->fib_scope); |
436c3b66e
|
704 705 706 707 |
nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid); return nh->nh_saddr; } |
4e902c574
|
708 |
struct fib_info *fib_create_info(struct fib_config *cfg) |
1da177e4c
|
709 710 711 712 |
{ int err; struct fib_info *fi = NULL; struct fib_info *ofi; |
1da177e4c
|
713 |
int nhs = 1; |
7462bd744
|
714 |
struct net *net = cfg->fc_nlinfo.nl_net; |
1da177e4c
|
715 |
|
4c8237cd7
|
716 717 |
if (cfg->fc_type > RTN_MAX) goto err_inval; |
1da177e4c
|
718 |
/* Fast check to catch the most weird cases */ |
4e902c574
|
719 |
if (fib_props[cfg->fc_type].scope > cfg->fc_scope) |
1da177e4c
|
720 721 722 |
goto err_inval; #ifdef CONFIG_IP_ROUTE_MULTIPATH |
4e902c574
|
723 724 |
if (cfg->fc_mp) { nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); |
1da177e4c
|
725 726 727 728 |
if (nhs == 0) goto err_inval; } #endif |
1da177e4c
|
729 730 |
err = -ENOBUFS; |
123b9731b
|
731 732 |
if (fib_info_cnt >= fib_info_hash_size) { unsigned int new_size = fib_info_hash_size << 1; |
1da177e4c
|
733 734 735 736 737 738 739 |
struct hlist_head *new_info_hash; struct hlist_head *new_laddrhash; unsigned int bytes; if (!new_size) new_size = 1; bytes = new_size * sizeof(struct hlist_head *); |
123b9731b
|
740 741 |
new_info_hash = fib_info_hash_alloc(bytes); new_laddrhash = fib_info_hash_alloc(bytes); |
1da177e4c
|
742 |
if (!new_info_hash || !new_laddrhash) { |
123b9731b
|
743 744 |
fib_info_hash_free(new_info_hash, bytes); fib_info_hash_free(new_laddrhash, bytes); |
88f834916
|
745 |
} else |
123b9731b
|
746 |
fib_info_hash_move(new_info_hash, new_laddrhash, new_size); |
1da177e4c
|
747 |
|
123b9731b
|
748 |
if (!fib_info_hash_size) |
1da177e4c
|
749 750 |
goto failure; } |
0da974f4f
|
751 |
fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); |
1da177e4c
|
752 753 |
if (fi == NULL) goto failure; |
725d1e1b4
|
754 755 756 757 758 759 |
if (cfg->fc_mx) { fi->fib_metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL); if (!fi->fib_metrics) goto failure; } else fi->fib_metrics = (u32 *) dst_default_metrics; |
1da177e4c
|
760 |
fib_info_cnt++; |
1da177e4c
|
761 |
|
57d7a6009
|
762 |
fi->fib_net = hold_net(net); |
4e902c574
|
763 |
fi->fib_protocol = cfg->fc_protocol; |
37e826c51
|
764 |
fi->fib_scope = cfg->fc_scope; |
4e902c574
|
765 766 767 |
fi->fib_flags = cfg->fc_flags; fi->fib_priority = cfg->fc_priority; fi->fib_prefsrc = cfg->fc_prefsrc; |
1da177e4c
|
768 769 770 |
fi->fib_nhs = nhs; change_nexthops(fi) { |
71fceff0e
|
771 |
nexthop_nh->nh_parent = fi; |
1da177e4c
|
772 |
} endfor_nexthops(fi) |
4e902c574
|
773 774 775 776 777 |
if (cfg->fc_mx) { struct nlattr *nla; int remaining; nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { |
8f4c1f9b0
|
778 |
int type = nla_type(nla); |
4e902c574
|
779 780 |
if (type) { |
6fac26252
|
781 |
u32 val; |
4e902c574
|
782 |
if (type > RTAX_MAX) |
1da177e4c
|
783 |
goto err_inval; |
6fac26252
|
784 785 786 |
val = nla_get_u32(nla); if (type == RTAX_ADVMSS && val > 65535 - 40) val = 65535 - 40; |
710ab6c03
|
787 788 |
if (type == RTAX_MTU && val > 65535 - 15) val = 65535 - 15; |
6fac26252
|
789 |
fi->fib_metrics[type - 1] = val; |
1da177e4c
|
790 |
} |
1da177e4c
|
791 792 |
} } |
1da177e4c
|
793 |
|
4e902c574
|
794 |
if (cfg->fc_mp) { |
1da177e4c
|
795 |
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
4e902c574
|
796 797 |
err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); if (err != 0) |
1da177e4c
|
798 |
goto failure; |
4e902c574
|
799 |
if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) |
1da177e4c
|
800 |
goto err_inval; |
4e902c574
|
801 |
if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) |
1da177e4c
|
802 |
goto err_inval; |
c7066f70d
|
803 |
#ifdef CONFIG_IP_ROUTE_CLASSID |
4e902c574
|
804 |
if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) |
1da177e4c
|
805 806 807 808 809 810 811 |
goto err_inval; #endif #else goto err_inval; #endif } else { struct fib_nh *nh = fi->fib_nh; |
4e902c574
|
812 813 814 815 |
nh->nh_oif = cfg->fc_oif; nh->nh_gw = cfg->fc_gw; nh->nh_flags = cfg->fc_flags; |
c7066f70d
|
816 |
#ifdef CONFIG_IP_ROUTE_CLASSID |
4e902c574
|
817 |
nh->nh_tclassid = cfg->fc_flow; |
7a9bc9b81
|
818 |
if (nh->nh_tclassid) |
f4530fa57
|
819 |
fi->fib_net->ipv4.fib_num_tclassid_users++; |
1da177e4c
|
820 |
#endif |
1da177e4c
|
821 822 823 824 |
#ifdef CONFIG_IP_ROUTE_MULTIPATH nh->nh_weight = 1; #endif } |
4e902c574
|
825 826 |
if (fib_props[cfg->fc_type].error) { if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) |
1da177e4c
|
827 828 |
goto err_inval; goto link_it; |
4c8237cd7
|
829 830 831 832 833 834 835 836 837 838 839 |
} else { switch (cfg->fc_type) { case RTN_UNICAST: case RTN_LOCAL: case RTN_BROADCAST: case RTN_ANYCAST: case RTN_MULTICAST: break; default: goto err_inval; } |
1da177e4c
|
840 |
} |
4e902c574
|
841 |
if (cfg->fc_scope > RT_SCOPE_HOST) |
1da177e4c
|
842 |
goto err_inval; |
4e902c574
|
843 |
if (cfg->fc_scope == RT_SCOPE_HOST) { |
1da177e4c
|
844 845 846 847 848 849 |
struct fib_nh *nh = fi->fib_nh; /* Local address is added. */ if (nhs != 1 || nh->nh_gw) goto err_inval; nh->nh_scope = RT_SCOPE_NOWHERE; |
7462bd744
|
850 |
nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif); |
1da177e4c
|
851 852 853 854 855 |
err = -ENODEV; if (nh->nh_dev == NULL) goto failure; } else { change_nexthops(fi) { |
6a31d2a97
|
856 857 |
err = fib_check_nh(cfg, fi, nexthop_nh); if (err != 0) |
1da177e4c
|
858 859 860 861 862 |
goto failure; } endfor_nexthops(fi) } if (fi->fib_prefsrc) { |
4e902c574
|
863 864 |
if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || fi->fib_prefsrc != cfg->fc_dst) |
7462bd744
|
865 |
if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL) |
1da177e4c
|
866 867 |
goto err_inval; } |
1fc050a13
|
868 |
change_nexthops(fi) { |
436c3b66e
|
869 |
fib_info_update_nh_saddr(net, nexthop_nh); |
1fc050a13
|
870 |
} endfor_nexthops(fi) |
1da177e4c
|
871 |
link_it: |
6a31d2a97
|
872 873 |
ofi = fib_find_info(fi); if (ofi) { |
1da177e4c
|
874 875 876 877 878 879 880 881 |
fi->fib_dead = 1; free_fib_info(fi); ofi->fib_treeref++; return ofi; } fi->fib_treeref++; atomic_inc(&fi->fib_clntref); |
832b4c5e1
|
882 |
spin_lock_bh(&fib_info_lock); |
1da177e4c
|
883 884 885 886 887 888 889 890 891 892 893 |
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; |
71fceff0e
|
894 |
if (!nexthop_nh->nh_dev) |
1da177e4c
|
895 |
continue; |
71fceff0e
|
896 |
hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex); |
1da177e4c
|
897 |
head = &fib_info_devhash[hash]; |
71fceff0e
|
898 |
hlist_add_head(&nexthop_nh->nh_hash, head); |
1da177e4c
|
899 |
} endfor_nexthops(fi) |
832b4c5e1
|
900 |
spin_unlock_bh(&fib_info_lock); |
1da177e4c
|
901 902 903 904 905 906 |
return fi; err_inval: err = -EINVAL; failure: |
e905a9eda
|
907 |
if (fi) { |
1da177e4c
|
908 909 910 |
fi->fib_dead = 1; free_fib_info(fi); } |
4e902c574
|
911 912 |
return ERR_PTR(err); |
1da177e4c
|
913 |
} |
be403ea18
|
914 |
int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
37e826c51
|
915 |
u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos, |
be403ea18
|
916 |
struct fib_info *fi, unsigned int flags) |
1da177e4c
|
917 |
{ |
be403ea18
|
918 |
struct nlmsghdr *nlh; |
1da177e4c
|
919 |
struct rtmsg *rtm; |
1da177e4c
|
920 |
|
be403ea18
|
921 922 |
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags); if (nlh == NULL) |
26932566a
|
923 |
return -EMSGSIZE; |
be403ea18
|
924 925 |
rtm = nlmsg_data(nlh); |
1da177e4c
|
926 927 928 929 |
rtm->rtm_family = AF_INET; rtm->rtm_dst_len = dst_len; rtm->rtm_src_len = 0; rtm->rtm_tos = tos; |
709772e6e
|
930 931 932 933 |
if (tb_id < 256) rtm->rtm_table = tb_id; else rtm->rtm_table = RT_TABLE_COMPAT; |
f3756b79e
|
934 935 |
if (nla_put_u32(skb, RTA_TABLE, tb_id)) goto nla_put_failure; |
1da177e4c
|
936 937 |
rtm->rtm_type = type; rtm->rtm_flags = fi->fib_flags; |
37e826c51
|
938 |
rtm->rtm_scope = fi->fib_scope; |
1da177e4c
|
939 |
rtm->rtm_protocol = fi->fib_protocol; |
be403ea18
|
940 |
|
f3756b79e
|
941 942 943 944 945 946 |
if (rtm->rtm_dst_len && nla_put_be32(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; |
1da177e4c
|
947 |
if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) |
be403ea18
|
948 |
goto nla_put_failure; |
f3756b79e
|
949 950 951 |
if (fi->fib_prefsrc && nla_put_be32(skb, RTA_PREFSRC, fi->fib_prefsrc)) goto nla_put_failure; |
1da177e4c
|
952 |
if (fi->fib_nhs == 1) { |
f3756b79e
|
953 954 955 956 957 958 |
if (fi->fib_nh->nh_gw && nla_put_be32(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; |
c7066f70d
|
959 |
#ifdef CONFIG_IP_ROUTE_CLASSID |
f3756b79e
|
960 961 962 |
if (fi->fib_nh[0].nh_tclassid && nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid)) goto nla_put_failure; |
8265abc08
|
963 |
#endif |
1da177e4c
|
964 965 966 |
} #ifdef CONFIG_IP_ROUTE_MULTIPATH if (fi->fib_nhs > 1) { |
be403ea18
|
967 968 969 970 971 972 |
struct rtnexthop *rtnh; struct nlattr *mp; mp = nla_nest_start(skb, RTA_MULTIPATH); if (mp == NULL) goto nla_put_failure; |
1da177e4c
|
973 974 |
for_nexthops(fi) { |
be403ea18
|
975 976 977 978 979 980 981 |
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); if (rtnh == NULL) goto nla_put_failure; rtnh->rtnh_flags = nh->nh_flags & 0xFF; rtnh->rtnh_hops = nh->nh_weight - 1; rtnh->rtnh_ifindex = nh->nh_oif; |
f3756b79e
|
982 983 984 |
if (nh->nh_gw && nla_put_be32(skb, RTA_GATEWAY, nh->nh_gw)) goto nla_put_failure; |
c7066f70d
|
985 |
#ifdef CONFIG_IP_ROUTE_CLASSID |
f3756b79e
|
986 987 988 |
if (nh->nh_tclassid && nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) goto nla_put_failure; |
8265abc08
|
989 |
#endif |
be403ea18
|
990 991 |
/* length of rtnetlink header + attributes */ rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; |
1da177e4c
|
992 |
} endfor_nexthops(fi); |
be403ea18
|
993 994 |
nla_nest_end(skb, mp); |
1da177e4c
|
995 996 |
} #endif |
be403ea18
|
997 |
return nlmsg_end(skb, nlh); |
1da177e4c
|
998 |
|
be403ea18
|
999 |
nla_put_failure: |
26932566a
|
1000 1001 |
nlmsg_cancel(skb, nlh); return -EMSGSIZE; |
1da177e4c
|
1002 |
} |
1da177e4c
|
1003 |
/* |
6a31d2a97
|
1004 1005 1006 1007 |
* 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. |
1da177e4c
|
1008 |
*/ |
4814bdbd5
|
1009 |
int fib_sync_down_addr(struct net *net, __be32 local) |
1da177e4c
|
1010 1011 |
{ int ret = 0; |
85326fa54
|
1012 1013 1014 1015 |
unsigned int hash = fib_laddr_hashfn(local); struct hlist_head *head = &fib_info_laddrhash[hash]; struct hlist_node *node; struct fib_info *fi; |
1da177e4c
|
1016 |
|
85326fa54
|
1017 1018 |
if (fib_info_laddrhash == NULL || local == 0) return 0; |
1da177e4c
|
1019 |
|
85326fa54
|
1020 |
hlist_for_each_entry(fi, node, head, fib_lhash) { |
09ad9bc75
|
1021 |
if (!net_eq(fi->fib_net, net)) |
4814bdbd5
|
1022 |
continue; |
85326fa54
|
1023 1024 1025 |
if (fi->fib_prefsrc == local) { fi->fib_flags |= RTNH_F_DEAD; ret++; |
1da177e4c
|
1026 1027 |
} } |
85326fa54
|
1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 |
return ret; } int fib_sync_down_dev(struct net_device *dev, int 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 hlist_node *node; struct fib_nh *nh; |
1da177e4c
|
1040 |
|
85326fa54
|
1041 1042 |
if (force) scope = -1; |
1da177e4c
|
1043 |
|
85326fa54
|
1044 1045 1046 |
hlist_for_each_entry(nh, node, head, nh_hash) { struct fib_info *fi = nh->nh_parent; int dead; |
1da177e4c
|
1047 |
|
85326fa54
|
1048 1049 1050 1051 1052 1053 |
BUG_ON(!fi->fib_nhs); if (nh->nh_dev != dev || fi == prev_fi) continue; prev_fi = fi; dead = 0; change_nexthops(fi) { |
6a31d2a97
|
1054 |
if (nexthop_nh->nh_flags & RTNH_F_DEAD) |
85326fa54
|
1055 |
dead++; |
71fceff0e
|
1056 1057 1058 |
else if (nexthop_nh->nh_dev == dev && nexthop_nh->nh_scope != scope) { nexthop_nh->nh_flags |= RTNH_F_DEAD; |
1da177e4c
|
1059 |
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
85326fa54
|
1060 |
spin_lock_bh(&fib_multipath_lock); |
71fceff0e
|
1061 1062 |
fi->fib_power -= nexthop_nh->nh_power; nexthop_nh->nh_power = 0; |
85326fa54
|
1063 |
spin_unlock_bh(&fib_multipath_lock); |
1da177e4c
|
1064 |
#endif |
85326fa54
|
1065 1066 |
dead++; } |
1da177e4c
|
1067 |
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
71fceff0e
|
1068 |
if (force > 1 && nexthop_nh->nh_dev == dev) { |
85326fa54
|
1069 1070 |
dead = fi->fib_nhs; break; |
1da177e4c
|
1071 |
} |
85326fa54
|
1072 1073 1074 1075 1076 |
#endif } endfor_nexthops(fi) if (dead == fi->fib_nhs) { fi->fib_flags |= RTNH_F_DEAD; ret++; |
1da177e4c
|
1077 1078 1079 1080 1081 |
} } return ret; } |
0c838ff1a
|
1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 |
/* Must be invoked inside of an RCU protected region. */ void fib_select_default(struct fib_result *res) { struct fib_info *fi = NULL, *last_resort = NULL; struct list_head *fa_head = res->fa_head; struct fib_table *tb = res->table; int order = -1, last_idx = -1; struct fib_alias *fa; list_for_each_entry_rcu(fa, fa_head, fa_list) { struct fib_info *next_fi = fa->fa_info; |
37e826c51
|
1093 |
if (next_fi->fib_scope != res->scope || |
0c838ff1a
|
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 |
fa->fa_type != RTN_UNICAST) continue; if (next_fi->fib_priority > res->fi->fib_priority) break; 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 == NULL) { if (next_fi != res->fi) break; } else if (!fib_detect_death(fi, order, &last_resort, &last_idx, tb->tb_default)) { fib_result_assign(res, fi); tb->tb_default = order; goto out; } fi = next_fi; order++; } if (order <= 0 || fi == NULL) { tb->tb_default = -1; goto out; } if (!fib_detect_death(fi, order, &last_resort, &last_idx, tb->tb_default)) { fib_result_assign(res, fi); tb->tb_default = order; goto out; } if (last_idx >= 0) fib_result_assign(res, last_resort); tb->tb_default = last_idx; out: |
31d409373
|
1134 |
return; |
0c838ff1a
|
1135 |
} |
1da177e4c
|
1136 1137 1138 |
#ifdef CONFIG_IP_ROUTE_MULTIPATH /* |
6a31d2a97
|
1139 1140 |
* Dead device goes up. We wake up dead nexthops. * It takes sense only on multipath routes. |
1da177e4c
|
1141 |
*/ |
1da177e4c
|
1142 1143 1144 1145 1146 1147 1148 1149 |
int fib_sync_up(struct net_device *dev) { struct fib_info *prev_fi; unsigned int hash; struct hlist_head *head; struct hlist_node *node; struct fib_nh *nh; int ret; |
6a31d2a97
|
1150 |
if (!(dev->flags & IFF_UP)) |
1da177e4c
|
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 |
return 0; prev_fi = NULL; hash = fib_devindex_hashfn(dev->ifindex); head = &fib_info_devhash[hash]; ret = 0; hlist_for_each_entry(nh, node, 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) { |
6a31d2a97
|
1169 |
if (!(nexthop_nh->nh_flags & RTNH_F_DEAD)) { |
1da177e4c
|
1170 1171 1172 |
alive++; continue; } |
71fceff0e
|
1173 |
if (nexthop_nh->nh_dev == NULL || |
6a31d2a97
|
1174 |
!(nexthop_nh->nh_dev->flags & IFF_UP)) |
1da177e4c
|
1175 |
continue; |
71fceff0e
|
1176 1177 |
if (nexthop_nh->nh_dev != dev || !__in_dev_get_rtnl(dev)) |
1da177e4c
|
1178 1179 1180 |
continue; alive++; spin_lock_bh(&fib_multipath_lock); |
71fceff0e
|
1181 1182 |
nexthop_nh->nh_power = 0; nexthop_nh->nh_flags &= ~RTNH_F_DEAD; |
1da177e4c
|
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 |
spin_unlock_bh(&fib_multipath_lock); } endfor_nexthops(fi) if (alive > 0) { fi->fib_flags &= ~RTNH_F_DEAD; ret++; } } return ret; } /* |
6a31d2a97
|
1196 1197 |
* The algorithm is suboptimal, but it provides really * fair weighted route distribution. |
1da177e4c
|
1198 |
*/ |
1b7fe5932
|
1199 |
void fib_select_multipath(struct fib_result *res) |
1da177e4c
|
1200 1201 1202 1203 1204 1205 1206 1207 |
{ struct fib_info *fi = res->fi; int w; spin_lock_bh(&fib_multipath_lock); if (fi->fib_power <= 0) { int power = 0; change_nexthops(fi) { |
6a31d2a97
|
1208 |
if (!(nexthop_nh->nh_flags & RTNH_F_DEAD)) { |
71fceff0e
|
1209 1210 |
power += nexthop_nh->nh_weight; nexthop_nh->nh_power = nexthop_nh->nh_weight; |
1da177e4c
|
1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 |
} } endfor_nexthops(fi); fi->fib_power = power; if (power <= 0) { spin_unlock_bh(&fib_multipath_lock); /* Race condition: route has just become dead. */ res->nh_sel = 0; return; } } /* w should be random number [0..fi->fib_power-1], |
6a31d2a97
|
1224 |
* it is pretty bad approximation. |
1da177e4c
|
1225 1226 1227 1228 1229 |
*/ w = jiffies % fi->fib_power; change_nexthops(fi) { |
6a31d2a97
|
1230 |
if (!(nexthop_nh->nh_flags & RTNH_F_DEAD) && |
71fceff0e
|
1231 |
nexthop_nh->nh_power) { |
6a31d2a97
|
1232 1233 |
w -= nexthop_nh->nh_power; if (w <= 0) { |
71fceff0e
|
1234 |
nexthop_nh->nh_power--; |
1da177e4c
|
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 |
fi->fib_power--; res->nh_sel = nhsel; spin_unlock_bh(&fib_multipath_lock); return; } } } endfor_nexthops(fi); /* Race condition: route has just become dead. */ res->nh_sel = 0; spin_unlock_bh(&fib_multipath_lock); } #endif |