| /* |
| * Linux INET6 implementation |
| * Forwarding Information Database |
| * |
| * Authors: |
| * Pedro Roque <roque@di.fc.ul.pt> |
| * |
| * $Id: ip6_fib.c,v 1.25 2001/10/31 21:55:55 davem Exp $ |
| * |
| * 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. |
| */ |
| |
| /* |
| * Changes: |
| * Yuji SEKIYA @USAGI: Support default route on router node; |
| * remove ip6_null_entry from the top of |
| * routing table. |
| */ |
| #include <linux/errno.h> |
| #include <linux/types.h> |
| #include <linux/net.h> |
| #include <linux/route.h> |
| #include <linux/netdevice.h> |
| #include <linux/in6.h> |
| #include <linux/init.h> |
| #include <linux/list.h> |
| |
| #ifdef CONFIG_PROC_FS |
| #include <linux/proc_fs.h> |
| #endif |
| |
| #include <net/ipv6.h> |
| #include <net/ndisc.h> |
| #include <net/addrconf.h> |
| |
| #include <net/ip6_fib.h> |
| #include <net/ip6_route.h> |
| |
| #define RT6_DEBUG 2 |
| |
| #if RT6_DEBUG >= 3 |
| #define RT6_TRACE(x...) printk(KERN_DEBUG x) |
| #else |
| #define RT6_TRACE(x...) do { ; } while (0) |
| #endif |
| |
| struct rt6_statistics rt6_stats; |
| |
| static kmem_cache_t * fib6_node_kmem __read_mostly; |
| |
| enum fib_walk_state_t |
| { |
| #ifdef CONFIG_IPV6_SUBTREES |
| FWS_S, |
| #endif |
| FWS_L, |
| FWS_R, |
| FWS_C, |
| FWS_U |
| }; |
| |
| struct fib6_cleaner_t |
| { |
| struct fib6_walker_t w; |
| int (*func)(struct rt6_info *, void *arg); |
| void *arg; |
| }; |
| |
| DEFINE_RWLOCK(fib6_walker_lock); |
| |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| #define FWS_INIT FWS_S |
| #define SUBTREE(fn) ((fn)->subtree) |
| #else |
| #define FWS_INIT FWS_L |
| #define SUBTREE(fn) NULL |
| #endif |
| |
| static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt); |
| static struct fib6_node * fib6_repair_tree(struct fib6_node *fn); |
| |
| /* |
| * A routing update causes an increase of the serial number on the |
| * affected subtree. This allows for cached routes to be asynchronously |
| * tested when modifications are made to the destination cache as a |
| * result of redirects, path MTU changes, etc. |
| */ |
| |
| static __u32 rt_sernum; |
| |
| static DEFINE_TIMER(ip6_fib_timer, fib6_run_gc, 0, 0); |
| |
| struct fib6_walker_t fib6_walker_list = { |
| .prev = &fib6_walker_list, |
| .next = &fib6_walker_list, |
| }; |
| |
| #define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next) |
| |
| static __inline__ u32 fib6_new_sernum(void) |
| { |
| u32 n = ++rt_sernum; |
| if ((__s32)n <= 0) |
| rt_sernum = n = 1; |
| return n; |
| } |
| |
| /* |
| * Auxiliary address test functions for the radix tree. |
| * |
| * These assume a 32bit processor (although it will work on |
| * 64bit processors) |
| */ |
| |
| /* |
| * test bit |
| */ |
| |
| static __inline__ int addr_bit_set(void *token, int fn_bit) |
| { |
| __u32 *addr = token; |
| |
| return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5]; |
| } |
| |
| static __inline__ struct fib6_node * node_alloc(void) |
| { |
| struct fib6_node *fn; |
| |
| if ((fn = kmem_cache_alloc(fib6_node_kmem, SLAB_ATOMIC)) != NULL) |
| memset(fn, 0, sizeof(struct fib6_node)); |
| |
| return fn; |
| } |
| |
| static __inline__ void node_free(struct fib6_node * fn) |
| { |
| kmem_cache_free(fib6_node_kmem, fn); |
| } |
| |
| static __inline__ void rt6_release(struct rt6_info *rt) |
| { |
| if (atomic_dec_and_test(&rt->rt6i_ref)) |
| dst_free(&rt->u.dst); |
| } |
| |
| static struct fib6_table fib6_main_tbl = { |
| .tb6_id = RT6_TABLE_MAIN, |
| .tb6_lock = RW_LOCK_UNLOCKED, |
| .tb6_root = { |
| .leaf = &ip6_null_entry, |
| .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO, |
| }, |
| }; |
| |
| #ifdef CONFIG_IPV6_MULTIPLE_TABLES |
| |
| static struct fib6_table fib6_local_tbl = { |
| .tb6_id = RT6_TABLE_LOCAL, |
| .tb6_lock = RW_LOCK_UNLOCKED, |
| .tb6_root = { |
| .leaf = &ip6_null_entry, |
| .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO, |
| }, |
| }; |
| |
| #define FIB_TABLE_HASHSZ 256 |
| static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ]; |
| |
| static struct fib6_table *fib6_alloc_table(u32 id) |
| { |
| struct fib6_table *table; |
| |
| table = kzalloc(sizeof(*table), GFP_ATOMIC); |
| if (table != NULL) { |
| table->tb6_id = id; |
| table->tb6_lock = RW_LOCK_UNLOCKED; |
| table->tb6_root.leaf = &ip6_null_entry; |
| table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; |
| } |
| |
| return table; |
| } |
| |
| static void fib6_link_table(struct fib6_table *tb) |
| { |
| unsigned int h; |
| |
| h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1); |
| |
| /* |
| * No protection necessary, this is the only list mutatation |
| * operation, tables never disappear once they exist. |
| */ |
| hlist_add_head_rcu(&tb->tb6_hlist, &fib_table_hash[h]); |
| } |
| |
| struct fib6_table *fib6_new_table(u32 id) |
| { |
| struct fib6_table *tb; |
| |
| if (id == 0) |
| id = RT6_TABLE_MAIN; |
| tb = fib6_get_table(id); |
| if (tb) |
| return tb; |
| |
| tb = fib6_alloc_table(id); |
| if (tb != NULL) |
| fib6_link_table(tb); |
| |
| return tb; |
| } |
| |
| struct fib6_table *fib6_get_table(u32 id) |
| { |
| struct fib6_table *tb; |
| struct hlist_node *node; |
| unsigned int h; |
| |
| if (id == 0) |
| id = RT6_TABLE_MAIN; |
| h = id & (FIB_TABLE_HASHSZ - 1); |
| rcu_read_lock(); |
| hlist_for_each_entry_rcu(tb, node, &fib_table_hash[h], tb6_hlist) { |
| if (tb->tb6_id == id) { |
| rcu_read_unlock(); |
| return tb; |
| } |
| } |
| rcu_read_unlock(); |
| |
| return NULL; |
| } |
| |
| static void __init fib6_tables_init(void) |
| { |
| fib6_link_table(&fib6_main_tbl); |
| fib6_link_table(&fib6_local_tbl); |
| } |
| |
| #else |
| |
| struct fib6_table *fib6_new_table(u32 id) |
| { |
| return fib6_get_table(id); |
| } |
| |
| struct fib6_table *fib6_get_table(u32 id) |
| { |
| return &fib6_main_tbl; |
| } |
| |
| struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags, |
| pol_lookup_t lookup) |
| { |
| return (struct dst_entry *) lookup(&fib6_main_tbl, fl, flags); |
| } |
| |
| static void __init fib6_tables_init(void) |
| { |
| } |
| |
| #endif |
| |
| |
| /* |
| * Routing Table |
| * |
| * return the appropriate node for a routing tree "add" operation |
| * by either creating and inserting or by returning an existing |
| * node. |
| */ |
| |
| static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr, |
| int addrlen, int plen, |
| int offset) |
| { |
| struct fib6_node *fn, *in, *ln; |
| struct fib6_node *pn = NULL; |
| struct rt6key *key; |
| int bit; |
| int dir = 0; |
| __u32 sernum = fib6_new_sernum(); |
| |
| RT6_TRACE("fib6_add_1\n"); |
| |
| /* insert node in tree */ |
| |
| fn = root; |
| |
| do { |
| key = (struct rt6key *)((u8 *)fn->leaf + offset); |
| |
| /* |
| * Prefix match |
| */ |
| if (plen < fn->fn_bit || |
| !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) |
| goto insert_above; |
| |
| /* |
| * Exact match ? |
| */ |
| |
| if (plen == fn->fn_bit) { |
| /* clean up an intermediate node */ |
| if ((fn->fn_flags & RTN_RTINFO) == 0) { |
| rt6_release(fn->leaf); |
| fn->leaf = NULL; |
| } |
| |
| fn->fn_sernum = sernum; |
| |
| return fn; |
| } |
| |
| /* |
| * We have more bits to go |
| */ |
| |
| /* Try to walk down on tree. */ |
| fn->fn_sernum = sernum; |
| dir = addr_bit_set(addr, fn->fn_bit); |
| pn = fn; |
| fn = dir ? fn->right: fn->left; |
| } while (fn); |
| |
| /* |
| * We walked to the bottom of tree. |
| * Create new leaf node without children. |
| */ |
| |
| ln = node_alloc(); |
| |
| if (ln == NULL) |
| return NULL; |
| ln->fn_bit = plen; |
| |
| ln->parent = pn; |
| ln->fn_sernum = sernum; |
| |
| if (dir) |
| pn->right = ln; |
| else |
| pn->left = ln; |
| |
| return ln; |
| |
| |
| insert_above: |
| /* |
| * split since we don't have a common prefix anymore or |
| * we have a less significant route. |
| * we've to insert an intermediate node on the list |
| * this new node will point to the one we need to create |
| * and the current |
| */ |
| |
| pn = fn->parent; |
| |
| /* find 1st bit in difference between the 2 addrs. |
| |
| See comment in __ipv6_addr_diff: bit may be an invalid value, |
| but if it is >= plen, the value is ignored in any case. |
| */ |
| |
| bit = __ipv6_addr_diff(addr, &key->addr, addrlen); |
| |
| /* |
| * (intermediate)[in] |
| * / \ |
| * (new leaf node)[ln] (old node)[fn] |
| */ |
| if (plen > bit) { |
| in = node_alloc(); |
| ln = node_alloc(); |
| |
| if (in == NULL || ln == NULL) { |
| if (in) |
| node_free(in); |
| if (ln) |
| node_free(ln); |
| return NULL; |
| } |
| |
| /* |
| * new intermediate node. |
| * RTN_RTINFO will |
| * be off since that an address that chooses one of |
| * the branches would not match less specific routes |
| * in the other branch |
| */ |
| |
| in->fn_bit = bit; |
| |
| in->parent = pn; |
| in->leaf = fn->leaf; |
| atomic_inc(&in->leaf->rt6i_ref); |
| |
| in->fn_sernum = sernum; |
| |
| /* update parent pointer */ |
| if (dir) |
| pn->right = in; |
| else |
| pn->left = in; |
| |
| ln->fn_bit = plen; |
| |
| ln->parent = in; |
| fn->parent = in; |
| |
| ln->fn_sernum = sernum; |
| |
| if (addr_bit_set(addr, bit)) { |
| in->right = ln; |
| in->left = fn; |
| } else { |
| in->left = ln; |
| in->right = fn; |
| } |
| } else { /* plen <= bit */ |
| |
| /* |
| * (new leaf node)[ln] |
| * / \ |
| * (old node)[fn] NULL |
| */ |
| |
| ln = node_alloc(); |
| |
| if (ln == NULL) |
| return NULL; |
| |
| ln->fn_bit = plen; |
| |
| ln->parent = pn; |
| |
| ln->fn_sernum = sernum; |
| |
| if (dir) |
| pn->right = ln; |
| else |
| pn->left = ln; |
| |
| if (addr_bit_set(&key->addr, plen)) |
| ln->right = fn; |
| else |
| ln->left = fn; |
| |
| fn->parent = ln; |
| } |
| return ln; |
| } |
| |
| /* |
| * Insert routing information in a node. |
| */ |
| |
| static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, |
| struct nlmsghdr *nlh, struct netlink_skb_parms *req) |
| { |
| struct rt6_info *iter = NULL; |
| struct rt6_info **ins; |
| |
| ins = &fn->leaf; |
| |
| if (fn->fn_flags&RTN_TL_ROOT && |
| fn->leaf == &ip6_null_entry && |
| !(rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ){ |
| fn->leaf = rt; |
| rt->u.next = NULL; |
| goto out; |
| } |
| |
| for (iter = fn->leaf; iter; iter=iter->u.next) { |
| /* |
| * Search for duplicates |
| */ |
| |
| if (iter->rt6i_metric == rt->rt6i_metric) { |
| /* |
| * Same priority level |
| */ |
| |
| if (iter->rt6i_dev == rt->rt6i_dev && |
| iter->rt6i_idev == rt->rt6i_idev && |
| ipv6_addr_equal(&iter->rt6i_gateway, |
| &rt->rt6i_gateway)) { |
| if (!(iter->rt6i_flags&RTF_EXPIRES)) |
| return -EEXIST; |
| iter->rt6i_expires = rt->rt6i_expires; |
| if (!(rt->rt6i_flags&RTF_EXPIRES)) { |
| iter->rt6i_flags &= ~RTF_EXPIRES; |
| iter->rt6i_expires = 0; |
| } |
| return -EEXIST; |
| } |
| } |
| |
| if (iter->rt6i_metric > rt->rt6i_metric) |
| break; |
| |
| ins = &iter->u.next; |
| } |
| |
| /* |
| * insert node |
| */ |
| |
| out: |
| rt->u.next = iter; |
| *ins = rt; |
| rt->rt6i_node = fn; |
| atomic_inc(&rt->rt6i_ref); |
| inet6_rt_notify(RTM_NEWROUTE, rt, nlh, req); |
| rt6_stats.fib_rt_entries++; |
| |
| if ((fn->fn_flags & RTN_RTINFO) == 0) { |
| rt6_stats.fib_route_nodes++; |
| fn->fn_flags |= RTN_RTINFO; |
| } |
| |
| return 0; |
| } |
| |
| static __inline__ void fib6_start_gc(struct rt6_info *rt) |
| { |
| if (ip6_fib_timer.expires == 0 && |
| (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE))) |
| mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); |
| } |
| |
| void fib6_force_start_gc(void) |
| { |
| if (ip6_fib_timer.expires == 0) |
| mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); |
| } |
| |
| /* |
| * Add routing information to the routing tree. |
| * <destination addr>/<source addr> |
| * with source addr info in sub-trees |
| */ |
| |
| int fib6_add(struct fib6_node *root, struct rt6_info *rt, |
| struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) |
| { |
| struct fib6_node *fn; |
| int err = -ENOMEM; |
| |
| fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr), |
| rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst)); |
| |
| if (fn == NULL) |
| goto out; |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (rt->rt6i_src.plen) { |
| struct fib6_node *sn; |
| |
| if (fn->subtree == NULL) { |
| struct fib6_node *sfn; |
| |
| /* |
| * Create subtree. |
| * |
| * fn[main tree] |
| * | |
| * sfn[subtree root] |
| * \ |
| * sn[new leaf node] |
| */ |
| |
| /* Create subtree root node */ |
| sfn = node_alloc(); |
| if (sfn == NULL) |
| goto st_failure; |
| |
| sfn->leaf = &ip6_null_entry; |
| atomic_inc(&ip6_null_entry.rt6i_ref); |
| sfn->fn_flags = RTN_ROOT; |
| sfn->fn_sernum = fib6_new_sernum(); |
| |
| /* Now add the first leaf node to new subtree */ |
| |
| sn = fib6_add_1(sfn, &rt->rt6i_src.addr, |
| sizeof(struct in6_addr), rt->rt6i_src.plen, |
| offsetof(struct rt6_info, rt6i_src)); |
| |
| if (sn == NULL) { |
| /* If it is failed, discard just allocated |
| root, and then (in st_failure) stale node |
| in main tree. |
| */ |
| node_free(sfn); |
| goto st_failure; |
| } |
| |
| /* Now link new subtree to main tree */ |
| sfn->parent = fn; |
| fn->subtree = sfn; |
| if (fn->leaf == NULL) { |
| fn->leaf = rt; |
| atomic_inc(&rt->rt6i_ref); |
| } |
| } else { |
| sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, |
| sizeof(struct in6_addr), rt->rt6i_src.plen, |
| offsetof(struct rt6_info, rt6i_src)); |
| |
| if (sn == NULL) |
| goto st_failure; |
| } |
| |
| fn = sn; |
| } |
| #endif |
| |
| err = fib6_add_rt2node(fn, rt, nlh, req); |
| |
| if (err == 0) { |
| fib6_start_gc(rt); |
| if (!(rt->rt6i_flags&RTF_CACHE)) |
| fib6_prune_clones(fn, rt); |
| } |
| |
| out: |
| if (err) |
| dst_free(&rt->u.dst); |
| return err; |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* Subtree creation failed, probably main tree node |
| is orphan. If it is, shoot it. |
| */ |
| st_failure: |
| if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) |
| fib6_repair_tree(fn); |
| dst_free(&rt->u.dst); |
| return err; |
| #endif |
| } |
| |
| /* |
| * Routing tree lookup |
| * |
| */ |
| |
| struct lookup_args { |
| int offset; /* key offset on rt6_info */ |
| struct in6_addr *addr; /* search key */ |
| }; |
| |
| static struct fib6_node * fib6_lookup_1(struct fib6_node *root, |
| struct lookup_args *args) |
| { |
| struct fib6_node *fn; |
| int dir; |
| |
| /* |
| * Descend on a tree |
| */ |
| |
| fn = root; |
| |
| for (;;) { |
| struct fib6_node *next; |
| |
| dir = addr_bit_set(args->addr, fn->fn_bit); |
| |
| next = dir ? fn->right : fn->left; |
| |
| if (next) { |
| fn = next; |
| continue; |
| } |
| |
| break; |
| } |
| |
| while ((fn->fn_flags & RTN_ROOT) == 0) { |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (fn->subtree) { |
| struct fib6_node *st; |
| struct lookup_args *narg; |
| |
| narg = args + 1; |
| |
| if (narg->addr) { |
| st = fib6_lookup_1(fn->subtree, narg); |
| |
| if (st && !(st->fn_flags & RTN_ROOT)) |
| return st; |
| } |
| } |
| #endif |
| |
| if (fn->fn_flags & RTN_RTINFO) { |
| struct rt6key *key; |
| |
| key = (struct rt6key *) ((u8 *) fn->leaf + |
| args->offset); |
| |
| if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) |
| return fn; |
| } |
| |
| fn = fn->parent; |
| } |
| |
| return NULL; |
| } |
| |
| struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr, |
| struct in6_addr *saddr) |
| { |
| struct lookup_args args[2]; |
| struct fib6_node *fn; |
| |
| args[0].offset = offsetof(struct rt6_info, rt6i_dst); |
| args[0].addr = daddr; |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| args[1].offset = offsetof(struct rt6_info, rt6i_src); |
| args[1].addr = saddr; |
| #endif |
| |
| fn = fib6_lookup_1(root, args); |
| |
| if (fn == NULL || fn->fn_flags & RTN_TL_ROOT) |
| fn = root; |
| |
| return fn; |
| } |
| |
| /* |
| * Get node with specified destination prefix (and source prefix, |
| * if subtrees are used) |
| */ |
| |
| |
| static struct fib6_node * fib6_locate_1(struct fib6_node *root, |
| struct in6_addr *addr, |
| int plen, int offset) |
| { |
| struct fib6_node *fn; |
| |
| for (fn = root; fn ; ) { |
| struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); |
| |
| /* |
| * Prefix match |
| */ |
| if (plen < fn->fn_bit || |
| !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) |
| return NULL; |
| |
| if (plen == fn->fn_bit) |
| return fn; |
| |
| /* |
| * We have more bits to go |
| */ |
| if (addr_bit_set(addr, fn->fn_bit)) |
| fn = fn->right; |
| else |
| fn = fn->left; |
| } |
| return NULL; |
| } |
| |
| struct fib6_node * fib6_locate(struct fib6_node *root, |
| struct in6_addr *daddr, int dst_len, |
| struct in6_addr *saddr, int src_len) |
| { |
| struct fib6_node *fn; |
| |
| fn = fib6_locate_1(root, daddr, dst_len, |
| offsetof(struct rt6_info, rt6i_dst)); |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (src_len) { |
| BUG_TRAP(saddr!=NULL); |
| if (fn == NULL) |
| fn = fn->subtree; |
| if (fn) |
| fn = fib6_locate_1(fn, saddr, src_len, |
| offsetof(struct rt6_info, rt6i_src)); |
| } |
| #endif |
| |
| if (fn && fn->fn_flags&RTN_RTINFO) |
| return fn; |
| |
| return NULL; |
| } |
| |
| |
| /* |
| * Deletion |
| * |
| */ |
| |
| static struct rt6_info * fib6_find_prefix(struct fib6_node *fn) |
| { |
| if (fn->fn_flags&RTN_ROOT) |
| return &ip6_null_entry; |
| |
| while(fn) { |
| if(fn->left) |
| return fn->left->leaf; |
| |
| if(fn->right) |
| return fn->right->leaf; |
| |
| fn = SUBTREE(fn); |
| } |
| return NULL; |
| } |
| |
| /* |
| * Called to trim the tree of intermediate nodes when possible. "fn" |
| * is the node we want to try and remove. |
| */ |
| |
| static struct fib6_node * fib6_repair_tree(struct fib6_node *fn) |
| { |
| int children; |
| int nstate; |
| struct fib6_node *child, *pn; |
| struct fib6_walker_t *w; |
| int iter = 0; |
| |
| for (;;) { |
| RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); |
| iter++; |
| |
| BUG_TRAP(!(fn->fn_flags&RTN_RTINFO)); |
| BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT)); |
| BUG_TRAP(fn->leaf==NULL); |
| |
| children = 0; |
| child = NULL; |
| if (fn->right) child = fn->right, children |= 1; |
| if (fn->left) child = fn->left, children |= 2; |
| |
| if (children == 3 || SUBTREE(fn) |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* Subtree root (i.e. fn) may have one child */ |
| || (children && fn->fn_flags&RTN_ROOT) |
| #endif |
| ) { |
| fn->leaf = fib6_find_prefix(fn); |
| #if RT6_DEBUG >= 2 |
| if (fn->leaf==NULL) { |
| BUG_TRAP(fn->leaf); |
| fn->leaf = &ip6_null_entry; |
| } |
| #endif |
| atomic_inc(&fn->leaf->rt6i_ref); |
| return fn->parent; |
| } |
| |
| pn = fn->parent; |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (SUBTREE(pn) == fn) { |
| BUG_TRAP(fn->fn_flags&RTN_ROOT); |
| SUBTREE(pn) = NULL; |
| nstate = FWS_L; |
| } else { |
| BUG_TRAP(!(fn->fn_flags&RTN_ROOT)); |
| #endif |
| if (pn->right == fn) pn->right = child; |
| else if (pn->left == fn) pn->left = child; |
| #if RT6_DEBUG >= 2 |
| else BUG_TRAP(0); |
| #endif |
| if (child) |
| child->parent = pn; |
| nstate = FWS_R; |
| #ifdef CONFIG_IPV6_SUBTREES |
| } |
| #endif |
| |
| read_lock(&fib6_walker_lock); |
| FOR_WALKERS(w) { |
| if (child == NULL) { |
| if (w->root == fn) { |
| w->root = w->node = NULL; |
| RT6_TRACE("W %p adjusted by delroot 1\n", w); |
| } else if (w->node == fn) { |
| RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); |
| w->node = pn; |
| w->state = nstate; |
| } |
| } else { |
| if (w->root == fn) { |
| w->root = child; |
| RT6_TRACE("W %p adjusted by delroot 2\n", w); |
| } |
| if (w->node == fn) { |
| w->node = child; |
| if (children&2) { |
| RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); |
| w->state = w->state>=FWS_R ? FWS_U : FWS_INIT; |
| } else { |
| RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); |
| w->state = w->state>=FWS_C ? FWS_U : FWS_INIT; |
| } |
| } |
| } |
| } |
| read_unlock(&fib6_walker_lock); |
| |
| node_free(fn); |
| if (pn->fn_flags&RTN_RTINFO || SUBTREE(pn)) |
| return pn; |
| |
| rt6_release(pn->leaf); |
| pn->leaf = NULL; |
| fn = pn; |
| } |
| } |
| |
| static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, |
| struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) |
| { |
| struct fib6_walker_t *w; |
| struct rt6_info *rt = *rtp; |
| |
| RT6_TRACE("fib6_del_route\n"); |
| |
| /* Unlink it */ |
| *rtp = rt->u.next; |
| rt->rt6i_node = NULL; |
| rt6_stats.fib_rt_entries--; |
| rt6_stats.fib_discarded_routes++; |
| |
| /* Adjust walkers */ |
| read_lock(&fib6_walker_lock); |
| FOR_WALKERS(w) { |
| if (w->state == FWS_C && w->leaf == rt) { |
| RT6_TRACE("walker %p adjusted by delroute\n", w); |
| w->leaf = rt->u.next; |
| if (w->leaf == NULL) |
| w->state = FWS_U; |
| } |
| } |
| read_unlock(&fib6_walker_lock); |
| |
| rt->u.next = NULL; |
| |
| if (fn->leaf == NULL && fn->fn_flags&RTN_TL_ROOT) |
| fn->leaf = &ip6_null_entry; |
| |
| /* If it was last route, expunge its radix tree node */ |
| if (fn->leaf == NULL) { |
| fn->fn_flags &= ~RTN_RTINFO; |
| rt6_stats.fib_route_nodes--; |
| fn = fib6_repair_tree(fn); |
| } |
| |
| if (atomic_read(&rt->rt6i_ref) != 1) { |
| /* This route is used as dummy address holder in some split |
| * nodes. It is not leaked, but it still holds other resources, |
| * which must be released in time. So, scan ascendant nodes |
| * and replace dummy references to this route with references |
| * to still alive ones. |
| */ |
| while (fn) { |
| if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) { |
| fn->leaf = fib6_find_prefix(fn); |
| atomic_inc(&fn->leaf->rt6i_ref); |
| rt6_release(rt); |
| } |
| fn = fn->parent; |
| } |
| /* No more references are possible at this point. */ |
| if (atomic_read(&rt->rt6i_ref) != 1) BUG(); |
| } |
| |
| inet6_rt_notify(RTM_DELROUTE, rt, nlh, req); |
| rt6_release(rt); |
| } |
| |
| int fib6_del(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) |
| { |
| struct fib6_node *fn = rt->rt6i_node; |
| struct rt6_info **rtp; |
| |
| #if RT6_DEBUG >= 2 |
| if (rt->u.dst.obsolete>0) { |
| BUG_TRAP(fn==NULL); |
| return -ENOENT; |
| } |
| #endif |
| if (fn == NULL || rt == &ip6_null_entry) |
| return -ENOENT; |
| |
| BUG_TRAP(fn->fn_flags&RTN_RTINFO); |
| |
| if (!(rt->rt6i_flags&RTF_CACHE)) |
| fib6_prune_clones(fn, rt); |
| |
| /* |
| * Walk the leaf entries looking for ourself |
| */ |
| |
| for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.next) { |
| if (*rtp == rt) { |
| fib6_del_route(fn, rtp, nlh, _rtattr, req); |
| return 0; |
| } |
| } |
| return -ENOENT; |
| } |
| |
| /* |
| * Tree traversal function. |
| * |
| * Certainly, it is not interrupt safe. |
| * However, it is internally reenterable wrt itself and fib6_add/fib6_del. |
| * It means, that we can modify tree during walking |
| * and use this function for garbage collection, clone pruning, |
| * cleaning tree when a device goes down etc. etc. |
| * |
| * It guarantees that every node will be traversed, |
| * and that it will be traversed only once. |
| * |
| * Callback function w->func may return: |
| * 0 -> continue walking. |
| * positive value -> walking is suspended (used by tree dumps, |
| * and probably by gc, if it will be split to several slices) |
| * negative value -> terminate walking. |
| * |
| * The function itself returns: |
| * 0 -> walk is complete. |
| * >0 -> walk is incomplete (i.e. suspended) |
| * <0 -> walk is terminated by an error. |
| */ |
| |
| int fib6_walk_continue(struct fib6_walker_t *w) |
| { |
| struct fib6_node *fn, *pn; |
| |
| for (;;) { |
| fn = w->node; |
| if (fn == NULL) |
| return 0; |
| |
| if (w->prune && fn != w->root && |
| fn->fn_flags&RTN_RTINFO && w->state < FWS_C) { |
| w->state = FWS_C; |
| w->leaf = fn->leaf; |
| } |
| switch (w->state) { |
| #ifdef CONFIG_IPV6_SUBTREES |
| case FWS_S: |
| if (SUBTREE(fn)) { |
| w->node = SUBTREE(fn); |
| continue; |
| } |
| w->state = FWS_L; |
| #endif |
| case FWS_L: |
| if (fn->left) { |
| w->node = fn->left; |
| w->state = FWS_INIT; |
| continue; |
| } |
| w->state = FWS_R; |
| case FWS_R: |
| if (fn->right) { |
| w->node = fn->right; |
| w->state = FWS_INIT; |
| continue; |
| } |
| w->state = FWS_C; |
| w->leaf = fn->leaf; |
| case FWS_C: |
| if (w->leaf && fn->fn_flags&RTN_RTINFO) { |
| int err = w->func(w); |
| if (err) |
| return err; |
| continue; |
| } |
| w->state = FWS_U; |
| case FWS_U: |
| if (fn == w->root) |
| return 0; |
| pn = fn->parent; |
| w->node = pn; |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (SUBTREE(pn) == fn) { |
| BUG_TRAP(fn->fn_flags&RTN_ROOT); |
| w->state = FWS_L; |
| continue; |
| } |
| #endif |
| if (pn->left == fn) { |
| w->state = FWS_R; |
| continue; |
| } |
| if (pn->right == fn) { |
| w->state = FWS_C; |
| w->leaf = w->node->leaf; |
| continue; |
| } |
| #if RT6_DEBUG >= 2 |
| BUG_TRAP(0); |
| #endif |
| } |
| } |
| } |
| |
| int fib6_walk(struct fib6_walker_t *w) |
| { |
| int res; |
| |
| w->state = FWS_INIT; |
| w->node = w->root; |
| |
| fib6_walker_link(w); |
| res = fib6_walk_continue(w); |
| if (res <= 0) |
| fib6_walker_unlink(w); |
| return res; |
| } |
| |
| static int fib6_clean_node(struct fib6_walker_t *w) |
| { |
| int res; |
| struct rt6_info *rt; |
| struct fib6_cleaner_t *c = (struct fib6_cleaner_t*)w; |
| |
| for (rt = w->leaf; rt; rt = rt->u.next) { |
| res = c->func(rt, c->arg); |
| if (res < 0) { |
| w->leaf = rt; |
| res = fib6_del(rt, NULL, NULL, NULL); |
| if (res) { |
| #if RT6_DEBUG >= 2 |
| printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res); |
| #endif |
| continue; |
| } |
| return 0; |
| } |
| BUG_TRAP(res==0); |
| } |
| w->leaf = rt; |
| return 0; |
| } |
| |
| /* |
| * Convenient frontend to tree walker. |
| * |
| * func is called on each route. |
| * It may return -1 -> delete this route. |
| * 0 -> continue walking |
| * |
| * prune==1 -> only immediate children of node (certainly, |
| * ignoring pure split nodes) will be scanned. |
| */ |
| |
| static void fib6_clean_tree(struct fib6_node *root, |
| int (*func)(struct rt6_info *, void *arg), |
| int prune, void *arg) |
| { |
| struct fib6_cleaner_t c; |
| |
| c.w.root = root; |
| c.w.func = fib6_clean_node; |
| c.w.prune = prune; |
| c.func = func; |
| c.arg = arg; |
| |
| fib6_walk(&c.w); |
| } |
| |
| void fib6_clean_all(int (*func)(struct rt6_info *, void *arg), |
| int prune, void *arg) |
| { |
| int i; |
| struct fib6_table *table; |
| |
| for (i = FIB6_TABLE_MIN; i <= FIB6_TABLE_MAX; i++) { |
| table = fib6_get_table(i); |
| if (table != NULL) { |
| write_lock_bh(&table->tb6_lock); |
| fib6_clean_tree(&table->tb6_root, func, prune, arg); |
| write_unlock_bh(&table->tb6_lock); |
| } |
| } |
| } |
| |
| static int fib6_prune_clone(struct rt6_info *rt, void *arg) |
| { |
| if (rt->rt6i_flags & RTF_CACHE) { |
| RT6_TRACE("pruning clone %p\n", rt); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt) |
| { |
| fib6_clean_tree(fn, fib6_prune_clone, 1, rt); |
| } |
| |
| /* |
| * Garbage collection |
| */ |
| |
| static struct fib6_gc_args |
| { |
| int timeout; |
| int more; |
| } gc_args; |
| |
| static int fib6_age(struct rt6_info *rt, void *arg) |
| { |
| unsigned long now = jiffies; |
| |
| /* |
| * check addrconf expiration here. |
| * Routes are expired even if they are in use. |
| * |
| * Also age clones. Note, that clones are aged out |
| * only if they are not in use now. |
| */ |
| |
| if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) { |
| if (time_after(now, rt->rt6i_expires)) { |
| RT6_TRACE("expiring %p\n", rt); |
| return -1; |
| } |
| gc_args.more++; |
| } else if (rt->rt6i_flags & RTF_CACHE) { |
| if (atomic_read(&rt->u.dst.__refcnt) == 0 && |
| time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) { |
| RT6_TRACE("aging clone %p\n", rt); |
| return -1; |
| } else if ((rt->rt6i_flags & RTF_GATEWAY) && |
| (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) { |
| RT6_TRACE("purging route %p via non-router but gateway\n", |
| rt); |
| return -1; |
| } |
| gc_args.more++; |
| } |
| |
| return 0; |
| } |
| |
| static DEFINE_SPINLOCK(fib6_gc_lock); |
| |
| void fib6_run_gc(unsigned long dummy) |
| { |
| if (dummy != ~0UL) { |
| spin_lock_bh(&fib6_gc_lock); |
| gc_args.timeout = dummy ? (int)dummy : ip6_rt_gc_interval; |
| } else { |
| local_bh_disable(); |
| if (!spin_trylock(&fib6_gc_lock)) { |
| mod_timer(&ip6_fib_timer, jiffies + HZ); |
| local_bh_enable(); |
| return; |
| } |
| gc_args.timeout = ip6_rt_gc_interval; |
| } |
| gc_args.more = 0; |
| |
| ndisc_dst_gc(&gc_args.more); |
| fib6_clean_all(fib6_age, 0, NULL); |
| |
| if (gc_args.more) |
| mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); |
| else { |
| del_timer(&ip6_fib_timer); |
| ip6_fib_timer.expires = 0; |
| } |
| spin_unlock_bh(&fib6_gc_lock); |
| } |
| |
| void __init fib6_init(void) |
| { |
| fib6_node_kmem = kmem_cache_create("fib6_nodes", |
| sizeof(struct fib6_node), |
| 0, SLAB_HWCACHE_ALIGN, |
| NULL, NULL); |
| if (!fib6_node_kmem) |
| panic("cannot create fib6_nodes cache"); |
| |
| fib6_tables_init(); |
| } |
| |
| void fib6_gc_cleanup(void) |
| { |
| del_timer(&ip6_fib_timer); |
| kmem_cache_destroy(fib6_node_kmem); |
| } |