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-rw-r--r--pfinet/linux-src/net/ipv6/ip6_fib.c1205
1 files changed, 1205 insertions, 0 deletions
diff --git a/pfinet/linux-src/net/ipv6/ip6_fib.c b/pfinet/linux-src/net/ipv6/ip6_fib.c
new file mode 100644
index 00000000..69735248
--- /dev/null
+++ b/pfinet/linux-src/net/ipv6/ip6_fib.c
@@ -0,0 +1,1205 @@
+/*
+ * Linux INET6 implementation
+ * Forwarding Information Database
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ *
+ * $Id: ip6_fib.c,v 1.1 2007/10/08 21:12:30 stesie 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.
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/net.h>
+#include <linux/route.h>
+#include <linux/netdevice.h>
+#include <linux/in6.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
+#undef CONFIG_IPV6_SUBTREES
+
+#if RT6_DEBUG >= 1
+#define BUG_TRAP(x) ({ if (!(x)) { printk("Assertion (" #x ") failed at " __FILE__ "(%d):" __FUNCTION__ "\n", __LINE__); } })
+#else
+#define BUG_TRAP(x) do { ; } while (0)
+#endif
+
+#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;
+
+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;
+};
+
+#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 void fib6_repair_tree(struct fib6_node *fn);
+
+/*
+ * A routing update causes an increase of the serial number on the
+ * afected 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 = 0;
+
+static struct timer_list ip6_fib_timer = {
+ NULL, NULL,
+ 0,
+ ~0UL,
+ fib6_run_gc
+};
+
+static struct fib6_walker_t fib6_walker_list = {
+ &fib6_walker_list, &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)
+ */
+
+/*
+ * compare "prefix length" bits of an address
+ */
+
+static __inline__ int addr_match(void *token1, void *token2, int prefixlen)
+{
+ __u32 *a1 = token1;
+ __u32 *a2 = token2;
+ int pdw;
+ int pbi;
+
+ pdw = prefixlen >> 5; /* num of whole __u32 in prefix */
+ pbi = prefixlen & 0x1f; /* num of bits in incomplete u32 in prefix */
+
+ if (pdw)
+ if (memcmp(a1, a2, pdw << 2))
+ return 0;
+
+ if (pbi) {
+ __u32 mask;
+
+ mask = htonl((0xffffffff) << (32 - pbi));
+
+ if ((a1[pdw] ^ a2[pdw]) & mask)
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * 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];
+}
+
+/*
+ * find the first different bit between two addresses
+ * length of address must be a multiple of 32bits
+ */
+
+static __inline__ int addr_diff(void *token1, void *token2, int addrlen)
+{
+ __u32 *a1 = token1;
+ __u32 *a2 = token2;
+ int i;
+
+ addrlen >>= 2;
+
+ for (i = 0; i < addrlen; i++) {
+ __u32 xb;
+
+ xb = a1[i] ^ a2[i];
+
+ if (xb) {
+ int j = 31;
+
+ xb = ntohl(xb);
+
+ while (test_bit(j, &xb) == 0)
+ j--;
+
+ return (i * 32 + 31 - j);
+ }
+ }
+
+ /*
+ * we should *never* get to this point since that
+ * would mean the addrs are equal
+ *
+ * However, we do get to it 8) And exacly, when
+ * addresses are equal 8)
+ *
+ * ip route add 1111::/128 via ...
+ * ip route add 1111::/64 via ...
+ * and we are here.
+ *
+ * Ideally, this function should stop comparison
+ * at prefix length. It does not, but it is still OK,
+ * if returned value is greater than prefix length.
+ * --ANK (980803)
+ */
+
+ return addrlen<<5;
+}
+
+static __inline__ struct fib6_node * node_alloc(void)
+{
+ struct fib6_node *fn;
+
+ if ((fn = kmalloc(sizeof(struct fib6_node), GFP_ATOMIC)) != NULL) {
+ memset(fn, 0, sizeof(struct fib6_node));
+ rt6_stats.fib_nodes++;
+ }
+
+ return fn;
+}
+
+static __inline__ void node_free(struct fib6_node * fn)
+{
+ rt6_stats.fib_nodes--;
+ kfree(fn);
+}
+
+static __inline__ void rt6_release(struct rt6_info *rt)
+{
+ if (atomic_dec_and_test(&rt->rt6i_ref))
+ dst_free(&rt->u.dst);
+}
+
+
+/*
+ * Routing Table
+ *
+ * return the apropriate 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;
+
+ if (plen == 0)
+ return fn;
+
+ do {
+ key = (struct rt6key *)((u8 *)fn->leaf + offset);
+
+ /*
+ * Prefix match
+ */
+ if (plen < fn->fn_bit ||
+ !addr_match(&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 wlaked 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 addr_diff: bit may be an invalid value,
+ but if it is >= plen, the value is ignored in any case.
+ */
+
+ bit = 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 rt6_info *iter = NULL;
+ struct rt6_info **ins;
+
+ ins = &fn->leaf;
+
+ 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_flowr == rt->rt6i_flowr) &&
+ (ipv6_addr_cmp(&iter->rt6i_gateway,
+ &rt->rt6i_gateway) == 0)) {
+ 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
+ */
+
+ rt->u.next = iter;
+ *ins = rt;
+ rt->rt6i_node = fn;
+ atomic_inc(&rt->rt6i_ref);
+#ifdef CONFIG_RTNETLINK
+ inet6_rt_notify(RTM_NEWROUTE, rt);
+#endif
+ 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))) {
+ del_timer(&ip6_fib_timer);
+ ip6_fib_timer.expires = jiffies + ip6_rt_gc_interval;
+ add_timer(&ip6_fib_timer);
+ }
+}
+
+/*
+ * 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 fib6_node *fn;
+ int err = -ENOMEM;
+
+ fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
+ rt->rt6i_dst.plen, (u8*) &rt->rt6i_dst - (u8*) rt);
+
+ if (fn == NULL)
+ return -ENOMEM;
+
+#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,
+ (u8*) &rt->rt6i_src - (u8*) rt);
+
+ 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,
+ (u8*) &rt->rt6i_src - (u8*) rt);
+
+ if (sn == NULL)
+ goto st_failure;
+ }
+
+ fn = sn;
+ }
+#endif
+
+ err = fib6_add_rt2node(fn, rt);
+
+ if (err == 0) {
+ fib6_start_gc(rt);
+ if (!(rt->rt6i_flags&RTF_CACHE))
+ fib6_prune_clones(fn, rt);
+ }
+
+ 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, shot it.
+ */
+st_failure:
+ if (fn && !(fn->fn_flags&RTN_RTINFO|RTN_ROOT))
+ fib_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->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 (addr_match(&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 rt6_info *rt = NULL;
+ struct fib6_node *fn;
+
+ args[0].offset = (u8*) &rt->rt6i_dst - (u8*) rt;
+ args[0].addr = daddr;
+
+#ifdef CONFIG_IPV6_SUBTREES
+ args[1].offset = (u8*) &rt->rt6i_src - (u8*) rt;
+ args[1].addr = saddr;
+#endif
+
+ fn = fib6_lookup_1(root, args);
+
+ if (fn == NULL)
+ fn = root;
+
+ return fn;
+}
+
+/*
+ * Get node with sepciafied 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 ||
+ !addr_match(&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 rt6_info *rt = NULL;
+ struct fib6_node *fn;
+
+ fn = fib6_locate_1(root, daddr, dst_len,
+ (u8*) &rt->rt6i_dst - (u8*) rt);
+
+#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,
+ (u8*) &rt->rt6i_src - (u8*) rt);
+ }
+#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 void 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;
+ }
+
+ 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
+
+ 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;
+ }
+ }
+ }
+ }
+
+ node_free(fn);
+ if (pn->fn_flags&RTN_RTINFO || SUBTREE(pn))
+ return;
+
+ rt6_release(pn->leaf);
+ pn->leaf = NULL;
+ fn = pn;
+ }
+}
+
+static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp)
+{
+ 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--;
+
+ /* Adjust walkers */
+ 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;
+ }
+ }
+
+ rt->u.next = NULL;
+
+ /* If it was last route, expunge its radix tree node */
+ if (fn->leaf == NULL) {
+ fn->fn_flags &= ~RTN_RTINFO;
+ rt6_stats.fib_route_nodes--;
+ fib6_repair_tree(fn);
+ }
+
+#ifdef CONFIG_RTNETLINK
+ inet6_rt_notify(RTM_DELROUTE, rt);
+#endif
+ rt6_release(rt);
+}
+
+int fib6_del(struct rt6_info *rt)
+{
+ struct fib6_node *fn = rt->rt6i_node;
+ struct rt6_info **rtp;
+
+#if RT6_DEBUG >= 2
+ if (rt->u.dst.obsolete>0) {
+ BUG_TRAP(rt->u.dst.obsolete>0);
+ return -EFAULT;
+ }
+#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);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+/*
+ * Tree transversal 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);
+ 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.
+ */
+
+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;
+
+ start_bh_atomic();
+ fib6_walk(&c.w);
+ end_bh_atomic();
+}
+
+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;
+
+ /* Age clones. Note, that clones are aged out
+ only if they are not in use now.
+ */
+
+ if (rt->rt6i_flags & RTF_CACHE) {
+ if (atomic_read(&rt->u.dst.use) == 0 &&
+ (long)(now - rt->u.dst.lastuse) >= gc_args.timeout) {
+ RT6_TRACE("aging clone %p\n", rt);
+ return -1;
+ }
+ gc_args.more++;
+ }
+
+ /*
+ * check addrconf expiration here.
+ * They are expired even if they are in use.
+ */
+
+ if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
+ if ((long)(now - rt->rt6i_expires) > 0) {
+ RT6_TRACE("expiring %p\n", rt);
+ return -1;
+ }
+ gc_args.more++;
+ }
+
+ return 0;
+}
+
+void fib6_run_gc(unsigned long dummy)
+{
+ if (dummy != ~0UL)
+ gc_args.timeout = (int)dummy;
+ else
+ gc_args.timeout = ip6_rt_gc_interval;
+
+ gc_args.more = 0;
+
+ fib6_clean_tree(&ip6_routing_table, fib6_age, 0, NULL);
+
+ del_timer(&ip6_fib_timer);
+
+ ip6_fib_timer.expires = 0;
+ if (gc_args.more) {
+ ip6_fib_timer.expires = jiffies + ip6_rt_gc_interval;
+ add_timer(&ip6_fib_timer);
+ }
+}
+
+#ifdef MODULE
+void fib6_gc_cleanup(void)
+{
+ del_timer(&ip6_fib_timer);
+}
+#endif
+
+
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-05 13:22:45 +0000