v4.19.13 snapshot.
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
new file mode 100644
index 0000000..5bc0c89
--- /dev/null
+++ b/net/ipv4/fib_trie.c
@@ -0,0 +1,2739 @@
+/*
+ * 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.
+ *
+ * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
+ * & Swedish University of Agricultural Sciences.
+ *
+ * Jens Laas <jens.laas@data.slu.se> Swedish University of
+ * Agricultural Sciences.
+ *
+ * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet
+ *
+ * This work is based on the LPC-trie which is originally described in:
+ *
+ * An experimental study of compression methods for dynamic tries
+ * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
+ * http://www.csc.kth.se/~snilsson/software/dyntrie2/
+ *
+ *
+ * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+ *
+ *
+ * Code from fib_hash has been reused which includes the following header:
+ *
+ *
+ * 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 FIB: lookup engine and maintenance routines.
+ *
+ *
+ * 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.
+ *
+ * Substantial contributions to this work comes from:
+ *
+ * David S. Miller, <davem@davemloft.net>
+ * Stephen Hemminger <shemminger@osdl.org>
+ * Paul E. McKenney <paulmck@us.ibm.com>
+ * Patrick McHardy <kaber@trash.net>
+ */
+
+#define VERSION "0.409"
+
+#include <linux/cache.h>
+#include <linux/uaccess.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/rcupdate.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/vmalloc.h>
+#include <linux/notifier.h>
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+#include <net/fib_notifier.h>
+#include <trace/events/fib.h>
+#include "fib_lookup.h"
+
+static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net,
+ enum fib_event_type event_type, u32 dst,
+ int dst_len, struct fib_alias *fa)
+{
+ struct fib_entry_notifier_info info = {
+ .dst = dst,
+ .dst_len = dst_len,
+ .fi = fa->fa_info,
+ .tos = fa->fa_tos,
+ .type = fa->fa_type,
+ .tb_id = fa->tb_id,
+ };
+ return call_fib4_notifier(nb, net, event_type, &info.info);
+}
+
+static int call_fib_entry_notifiers(struct net *net,
+ enum fib_event_type event_type, u32 dst,
+ int dst_len, struct fib_alias *fa,
+ struct netlink_ext_ack *extack)
+{
+ struct fib_entry_notifier_info info = {
+ .info.extack = extack,
+ .dst = dst,
+ .dst_len = dst_len,
+ .fi = fa->fa_info,
+ .tos = fa->fa_tos,
+ .type = fa->fa_type,
+ .tb_id = fa->tb_id,
+ };
+ return call_fib4_notifiers(net, event_type, &info.info);
+}
+
+#define MAX_STAT_DEPTH 32
+
+#define KEYLENGTH (8*sizeof(t_key))
+#define KEY_MAX ((t_key)~0)
+
+typedef unsigned int t_key;
+
+#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
+#define IS_TNODE(n) ((n)->bits)
+#define IS_LEAF(n) (!(n)->bits)
+
+struct key_vector {
+ t_key key;
+ unsigned char pos; /* 2log(KEYLENGTH) bits needed */
+ unsigned char bits; /* 2log(KEYLENGTH) bits needed */
+ unsigned char slen;
+ union {
+ /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
+ struct hlist_head leaf;
+ /* This array is valid if (pos | bits) > 0 (TNODE) */
+ struct key_vector __rcu *tnode[0];
+ };
+};
+
+struct tnode {
+ struct rcu_head rcu;
+ t_key empty_children; /* KEYLENGTH bits needed */
+ t_key full_children; /* KEYLENGTH bits needed */
+ struct key_vector __rcu *parent;
+ struct key_vector kv[1];
+#define tn_bits kv[0].bits
+};
+
+#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
+#define LEAF_SIZE TNODE_SIZE(1)
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+struct trie_use_stats {
+ unsigned int gets;
+ unsigned int backtrack;
+ unsigned int semantic_match_passed;
+ unsigned int semantic_match_miss;
+ unsigned int null_node_hit;
+ unsigned int resize_node_skipped;
+};
+#endif
+
+struct trie_stat {
+ unsigned int totdepth;
+ unsigned int maxdepth;
+ unsigned int tnodes;
+ unsigned int leaves;
+ unsigned int nullpointers;
+ unsigned int prefixes;
+ unsigned int nodesizes[MAX_STAT_DEPTH];
+};
+
+struct trie {
+ struct key_vector kv[1];
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie_use_stats __percpu *stats;
+#endif
+};
+
+static struct key_vector *resize(struct trie *t, struct key_vector *tn);
+static size_t tnode_free_size;
+
+/*
+ * synchronize_rcu after call_rcu for that many pages; it should be especially
+ * useful before resizing the root node with PREEMPT_NONE configs; the value was
+ * obtained experimentally, aiming to avoid visible slowdown.
+ */
+static const int sync_pages = 128;
+
+static struct kmem_cache *fn_alias_kmem __ro_after_init;
+static struct kmem_cache *trie_leaf_kmem __ro_after_init;
+
+static inline struct tnode *tn_info(struct key_vector *kv)
+{
+ return container_of(kv, struct tnode, kv[0]);
+}
+
+/* caller must hold RTNL */
+#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
+#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
+
+/* caller must hold RCU read lock or RTNL */
+#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
+#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
+
+/* wrapper for rcu_assign_pointer */
+static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
+{
+ if (n)
+ rcu_assign_pointer(tn_info(n)->parent, tp);
+}
+
+#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
+
+/* This provides us with the number of children in this node, in the case of a
+ * leaf this will return 0 meaning none of the children are accessible.
+ */
+static inline unsigned long child_length(const struct key_vector *tn)
+{
+ return (1ul << tn->bits) & ~(1ul);
+}
+
+#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
+
+static inline unsigned long get_index(t_key key, struct key_vector *kv)
+{
+ unsigned long index = key ^ kv->key;
+
+ if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
+ return 0;
+
+ return index >> kv->pos;
+}
+
+/* To understand this stuff, an understanding of keys and all their bits is
+ * necessary. Every node in the trie has a key associated with it, but not
+ * all of the bits in that key are significant.
+ *
+ * Consider a node 'n' and its parent 'tp'.
+ *
+ * If n is a leaf, every bit in its key is significant. Its presence is
+ * necessitated by path compression, since during a tree traversal (when
+ * searching for a leaf - unless we are doing an insertion) we will completely
+ * ignore all skipped bits we encounter. Thus we need to verify, at the end of
+ * a potentially successful search, that we have indeed been walking the
+ * correct key path.
+ *
+ * Note that we can never "miss" the correct key in the tree if present by
+ * following the wrong path. Path compression ensures that segments of the key
+ * that are the same for all keys with a given prefix are skipped, but the
+ * skipped part *is* identical for each node in the subtrie below the skipped
+ * bit! trie_insert() in this implementation takes care of that.
+ *
+ * if n is an internal node - a 'tnode' here, the various parts of its key
+ * have many different meanings.
+ *
+ * Example:
+ * _________________________________________________________________
+ * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
+ * -----------------------------------------------------------------
+ * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
+ *
+ * _________________________________________________________________
+ * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
+ * -----------------------------------------------------------------
+ * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+ *
+ * tp->pos = 22
+ * tp->bits = 3
+ * n->pos = 13
+ * n->bits = 4
+ *
+ * First, let's just ignore the bits that come before the parent tp, that is
+ * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
+ * point we do not use them for anything.
+ *
+ * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
+ * index into the parent's child array. That is, they will be used to find
+ * 'n' among tp's children.
+ *
+ * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
+ * for the node n.
+ *
+ * All the bits we have seen so far are significant to the node n. The rest
+ * of the bits are really not needed or indeed known in n->key.
+ *
+ * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
+ * n's child array, and will of course be different for each child.
+ *
+ * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
+ * at this point.
+ */
+
+static const int halve_threshold = 25;
+static const int inflate_threshold = 50;
+static const int halve_threshold_root = 15;
+static const int inflate_threshold_root = 30;
+
+static void __alias_free_mem(struct rcu_head *head)
+{
+ struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
+ kmem_cache_free(fn_alias_kmem, fa);
+}
+
+static inline void alias_free_mem_rcu(struct fib_alias *fa)
+{
+ call_rcu(&fa->rcu, __alias_free_mem);
+}
+
+#define TNODE_KMALLOC_MAX \
+ ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
+#define TNODE_VMALLOC_MAX \
+ ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
+
+static void __node_free_rcu(struct rcu_head *head)
+{
+ struct tnode *n = container_of(head, struct tnode, rcu);
+
+ if (!n->tn_bits)
+ kmem_cache_free(trie_leaf_kmem, n);
+ else
+ kvfree(n);
+}
+
+#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
+
+static struct tnode *tnode_alloc(int bits)
+{
+ size_t size;
+
+ /* verify bits is within bounds */
+ if (bits > TNODE_VMALLOC_MAX)
+ return NULL;
+
+ /* determine size and verify it is non-zero and didn't overflow */
+ size = TNODE_SIZE(1ul << bits);
+
+ if (size <= PAGE_SIZE)
+ return kzalloc(size, GFP_KERNEL);
+ else
+ return vzalloc(size);
+}
+
+static inline void empty_child_inc(struct key_vector *n)
+{
+ ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children;
+}
+
+static inline void empty_child_dec(struct key_vector *n)
+{
+ tn_info(n)->empty_children-- ? : tn_info(n)->full_children--;
+}
+
+static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
+{
+ struct key_vector *l;
+ struct tnode *kv;
+
+ kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
+ if (!kv)
+ return NULL;
+
+ /* initialize key vector */
+ l = kv->kv;
+ l->key = key;
+ l->pos = 0;
+ l->bits = 0;
+ l->slen = fa->fa_slen;
+
+ /* link leaf to fib alias */
+ INIT_HLIST_HEAD(&l->leaf);
+ hlist_add_head(&fa->fa_list, &l->leaf);
+
+ return l;
+}
+
+static struct key_vector *tnode_new(t_key key, int pos, int bits)
+{
+ unsigned int shift = pos + bits;
+ struct key_vector *tn;
+ struct tnode *tnode;
+
+ /* verify bits and pos their msb bits clear and values are valid */
+ BUG_ON(!bits || (shift > KEYLENGTH));
+
+ tnode = tnode_alloc(bits);
+ if (!tnode)
+ return NULL;
+
+ pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
+ sizeof(struct key_vector *) << bits);
+
+ if (bits == KEYLENGTH)
+ tnode->full_children = 1;
+ else
+ tnode->empty_children = 1ul << bits;
+
+ tn = tnode->kv;
+ tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
+ tn->pos = pos;
+ tn->bits = bits;
+ tn->slen = pos;
+
+ return tn;
+}
+
+/* Check whether a tnode 'n' is "full", i.e. it is an internal node
+ * and no bits are skipped. See discussion in dyntree paper p. 6
+ */
+static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
+{
+ return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
+}
+
+/* Add a child at position i overwriting the old value.
+ * Update the value of full_children and empty_children.
+ */
+static void put_child(struct key_vector *tn, unsigned long i,
+ struct key_vector *n)
+{
+ struct key_vector *chi = get_child(tn, i);
+ int isfull, wasfull;
+
+ BUG_ON(i >= child_length(tn));
+
+ /* update emptyChildren, overflow into fullChildren */
+ if (!n && chi)
+ empty_child_inc(tn);
+ if (n && !chi)
+ empty_child_dec(tn);
+
+ /* update fullChildren */
+ wasfull = tnode_full(tn, chi);
+ isfull = tnode_full(tn, n);
+
+ if (wasfull && !isfull)
+ tn_info(tn)->full_children--;
+ else if (!wasfull && isfull)
+ tn_info(tn)->full_children++;
+
+ if (n && (tn->slen < n->slen))
+ tn->slen = n->slen;
+
+ rcu_assign_pointer(tn->tnode[i], n);
+}
+
+static void update_children(struct key_vector *tn)
+{
+ unsigned long i;
+
+ /* update all of the child parent pointers */
+ for (i = child_length(tn); i;) {
+ struct key_vector *inode = get_child(tn, --i);
+
+ if (!inode)
+ continue;
+
+ /* Either update the children of a tnode that
+ * already belongs to us or update the child
+ * to point to ourselves.
+ */
+ if (node_parent(inode) == tn)
+ update_children(inode);
+ else
+ node_set_parent(inode, tn);
+ }
+}
+
+static inline void put_child_root(struct key_vector *tp, t_key key,
+ struct key_vector *n)
+{
+ if (IS_TRIE(tp))
+ rcu_assign_pointer(tp->tnode[0], n);
+ else
+ put_child(tp, get_index(key, tp), n);
+}
+
+static inline void tnode_free_init(struct key_vector *tn)
+{
+ tn_info(tn)->rcu.next = NULL;
+}
+
+static inline void tnode_free_append(struct key_vector *tn,
+ struct key_vector *n)
+{
+ tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
+ tn_info(tn)->rcu.next = &tn_info(n)->rcu;
+}
+
+static void tnode_free(struct key_vector *tn)
+{
+ struct callback_head *head = &tn_info(tn)->rcu;
+
+ while (head) {
+ head = head->next;
+ tnode_free_size += TNODE_SIZE(1ul << tn->bits);
+ node_free(tn);
+
+ tn = container_of(head, struct tnode, rcu)->kv;
+ }
+
+ if (tnode_free_size >= PAGE_SIZE * sync_pages) {
+ tnode_free_size = 0;
+ synchronize_rcu();
+ }
+}
+
+static struct key_vector *replace(struct trie *t,
+ struct key_vector *oldtnode,
+ struct key_vector *tn)
+{
+ struct key_vector *tp = node_parent(oldtnode);
+ unsigned long i;
+
+ /* setup the parent pointer out of and back into this node */
+ NODE_INIT_PARENT(tn, tp);
+ put_child_root(tp, tn->key, tn);
+
+ /* update all of the child parent pointers */
+ update_children(tn);
+
+ /* all pointers should be clean so we are done */
+ tnode_free(oldtnode);
+
+ /* resize children now that oldtnode is freed */
+ for (i = child_length(tn); i;) {
+ struct key_vector *inode = get_child(tn, --i);
+
+ /* resize child node */
+ if (tnode_full(tn, inode))
+ tn = resize(t, inode);
+ }
+
+ return tp;
+}
+
+static struct key_vector *inflate(struct trie *t,
+ struct key_vector *oldtnode)
+{
+ struct key_vector *tn;
+ unsigned long i;
+ t_key m;
+
+ pr_debug("In inflate\n");
+
+ tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
+ if (!tn)
+ goto notnode;
+
+ /* prepare oldtnode to be freed */
+ tnode_free_init(oldtnode);
+
+ /* Assemble all of the pointers in our cluster, in this case that
+ * represents all of the pointers out of our allocated nodes that
+ * point to existing tnodes and the links between our allocated
+ * nodes.
+ */
+ for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
+ struct key_vector *inode = get_child(oldtnode, --i);
+ struct key_vector *node0, *node1;
+ unsigned long j, k;
+
+ /* An empty child */
+ if (!inode)
+ continue;
+
+ /* A leaf or an internal node with skipped bits */
+ if (!tnode_full(oldtnode, inode)) {
+ put_child(tn, get_index(inode->key, tn), inode);
+ continue;
+ }
+
+ /* drop the node in the old tnode free list */
+ tnode_free_append(oldtnode, inode);
+
+ /* An internal node with two children */
+ if (inode->bits == 1) {
+ put_child(tn, 2 * i + 1, get_child(inode, 1));
+ put_child(tn, 2 * i, get_child(inode, 0));
+ continue;
+ }
+
+ /* We will replace this node 'inode' with two new
+ * ones, 'node0' and 'node1', each with half of the
+ * original children. The two new nodes will have
+ * a position one bit further down the key and this
+ * means that the "significant" part of their keys
+ * (see the discussion near the top of this file)
+ * will differ by one bit, which will be "0" in
+ * node0's key and "1" in node1's key. Since we are
+ * moving the key position by one step, the bit that
+ * we are moving away from - the bit at position
+ * (tn->pos) - is the one that will differ between
+ * node0 and node1. So... we synthesize that bit in the
+ * two new keys.
+ */
+ node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
+ if (!node1)
+ goto nomem;
+ node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
+
+ tnode_free_append(tn, node1);
+ if (!node0)
+ goto nomem;
+ tnode_free_append(tn, node0);
+
+ /* populate child pointers in new nodes */
+ for (k = child_length(inode), j = k / 2; j;) {
+ put_child(node1, --j, get_child(inode, --k));
+ put_child(node0, j, get_child(inode, j));
+ put_child(node1, --j, get_child(inode, --k));
+ put_child(node0, j, get_child(inode, j));
+ }
+
+ /* link new nodes to parent */
+ NODE_INIT_PARENT(node1, tn);
+ NODE_INIT_PARENT(node0, tn);
+
+ /* link parent to nodes */
+ put_child(tn, 2 * i + 1, node1);
+ put_child(tn, 2 * i, node0);
+ }
+
+ /* setup the parent pointers into and out of this node */
+ return replace(t, oldtnode, tn);
+nomem:
+ /* all pointers should be clean so we are done */
+ tnode_free(tn);
+notnode:
+ return NULL;
+}
+
+static struct key_vector *halve(struct trie *t,
+ struct key_vector *oldtnode)
+{
+ struct key_vector *tn;
+ unsigned long i;
+
+ pr_debug("In halve\n");
+
+ tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
+ if (!tn)
+ goto notnode;
+
+ /* prepare oldtnode to be freed */
+ tnode_free_init(oldtnode);
+
+ /* Assemble all of the pointers in our cluster, in this case that
+ * represents all of the pointers out of our allocated nodes that
+ * point to existing tnodes and the links between our allocated
+ * nodes.
+ */
+ for (i = child_length(oldtnode); i;) {
+ struct key_vector *node1 = get_child(oldtnode, --i);
+ struct key_vector *node0 = get_child(oldtnode, --i);
+ struct key_vector *inode;
+
+ /* At least one of the children is empty */
+ if (!node1 || !node0) {
+ put_child(tn, i / 2, node1 ? : node0);
+ continue;
+ }
+
+ /* Two nonempty children */
+ inode = tnode_new(node0->key, oldtnode->pos, 1);
+ if (!inode)
+ goto nomem;
+ tnode_free_append(tn, inode);
+
+ /* initialize pointers out of node */
+ put_child(inode, 1, node1);
+ put_child(inode, 0, node0);
+ NODE_INIT_PARENT(inode, tn);
+
+ /* link parent to node */
+ put_child(tn, i / 2, inode);
+ }
+
+ /* setup the parent pointers into and out of this node */
+ return replace(t, oldtnode, tn);
+nomem:
+ /* all pointers should be clean so we are done */
+ tnode_free(tn);
+notnode:
+ return NULL;
+}
+
+static struct key_vector *collapse(struct trie *t,
+ struct key_vector *oldtnode)
+{
+ struct key_vector *n, *tp;
+ unsigned long i;
+
+ /* scan the tnode looking for that one child that might still exist */
+ for (n = NULL, i = child_length(oldtnode); !n && i;)
+ n = get_child(oldtnode, --i);
+
+ /* compress one level */
+ tp = node_parent(oldtnode);
+ put_child_root(tp, oldtnode->key, n);
+ node_set_parent(n, tp);
+
+ /* drop dead node */
+ node_free(oldtnode);
+
+ return tp;
+}
+
+static unsigned char update_suffix(struct key_vector *tn)
+{
+ unsigned char slen = tn->pos;
+ unsigned long stride, i;
+ unsigned char slen_max;
+
+ /* only vector 0 can have a suffix length greater than or equal to
+ * tn->pos + tn->bits, the second highest node will have a suffix
+ * length at most of tn->pos + tn->bits - 1
+ */
+ slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
+
+ /* search though the list of children looking for nodes that might
+ * have a suffix greater than the one we currently have. This is
+ * why we start with a stride of 2 since a stride of 1 would
+ * represent the nodes with suffix length equal to tn->pos
+ */
+ for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
+ struct key_vector *n = get_child(tn, i);
+
+ if (!n || (n->slen <= slen))
+ continue;
+
+ /* update stride and slen based on new value */
+ stride <<= (n->slen - slen);
+ slen = n->slen;
+ i &= ~(stride - 1);
+
+ /* stop searching if we have hit the maximum possible value */
+ if (slen >= slen_max)
+ break;
+ }
+
+ tn->slen = slen;
+
+ return slen;
+}
+
+/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
+ * the Helsinki University of Technology and Matti Tikkanen of Nokia
+ * Telecommunications, page 6:
+ * "A node is doubled if the ratio of non-empty children to all
+ * children in the *doubled* node is at least 'high'."
+ *
+ * 'high' in this instance is the variable 'inflate_threshold'. It
+ * is expressed as a percentage, so we multiply it with
+ * child_length() and instead of multiplying by 2 (since the
+ * child array will be doubled by inflate()) and multiplying
+ * the left-hand side by 100 (to handle the percentage thing) we
+ * multiply the left-hand side by 50.
+ *
+ * The left-hand side may look a bit weird: child_length(tn)
+ * - tn->empty_children is of course the number of non-null children
+ * in the current node. tn->full_children is the number of "full"
+ * children, that is non-null tnodes with a skip value of 0.
+ * All of those will be doubled in the resulting inflated tnode, so
+ * we just count them one extra time here.
+ *
+ * A clearer way to write this would be:
+ *
+ * to_be_doubled = tn->full_children;
+ * not_to_be_doubled = child_length(tn) - tn->empty_children -
+ * tn->full_children;
+ *
+ * new_child_length = child_length(tn) * 2;
+ *
+ * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
+ * new_child_length;
+ * if (new_fill_factor >= inflate_threshold)
+ *
+ * ...and so on, tho it would mess up the while () loop.
+ *
+ * anyway,
+ * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
+ * inflate_threshold
+ *
+ * avoid a division:
+ * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
+ * inflate_threshold * new_child_length
+ *
+ * expand not_to_be_doubled and to_be_doubled, and shorten:
+ * 100 * (child_length(tn) - tn->empty_children +
+ * tn->full_children) >= inflate_threshold * new_child_length
+ *
+ * expand new_child_length:
+ * 100 * (child_length(tn) - tn->empty_children +
+ * tn->full_children) >=
+ * inflate_threshold * child_length(tn) * 2
+ *
+ * shorten again:
+ * 50 * (tn->full_children + child_length(tn) -
+ * tn->empty_children) >= inflate_threshold *
+ * child_length(tn)
+ *
+ */
+static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
+{
+ unsigned long used = child_length(tn);
+ unsigned long threshold = used;
+
+ /* Keep root node larger */
+ threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
+ used -= tn_info(tn)->empty_children;
+ used += tn_info(tn)->full_children;
+
+ /* if bits == KEYLENGTH then pos = 0, and will fail below */
+
+ return (used > 1) && tn->pos && ((50 * used) >= threshold);
+}
+
+static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
+{
+ unsigned long used = child_length(tn);
+ unsigned long threshold = used;
+
+ /* Keep root node larger */
+ threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
+ used -= tn_info(tn)->empty_children;
+
+ /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
+
+ return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
+}
+
+static inline bool should_collapse(struct key_vector *tn)
+{
+ unsigned long used = child_length(tn);
+
+ used -= tn_info(tn)->empty_children;
+
+ /* account for bits == KEYLENGTH case */
+ if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
+ used -= KEY_MAX;
+
+ /* One child or none, time to drop us from the trie */
+ return used < 2;
+}
+
+#define MAX_WORK 10
+static struct key_vector *resize(struct trie *t, struct key_vector *tn)
+{
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie_use_stats __percpu *stats = t->stats;
+#endif
+ struct key_vector *tp = node_parent(tn);
+ unsigned long cindex = get_index(tn->key, tp);
+ int max_work = MAX_WORK;
+
+ pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+ tn, inflate_threshold, halve_threshold);
+
+ /* track the tnode via the pointer from the parent instead of
+ * doing it ourselves. This way we can let RCU fully do its
+ * thing without us interfering
+ */
+ BUG_ON(tn != get_child(tp, cindex));
+
+ /* Double as long as the resulting node has a number of
+ * nonempty nodes that are above the threshold.
+ */
+ while (should_inflate(tp, tn) && max_work) {
+ tp = inflate(t, tn);
+ if (!tp) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->resize_node_skipped);
+#endif
+ break;
+ }
+
+ max_work--;
+ tn = get_child(tp, cindex);
+ }
+
+ /* update parent in case inflate failed */
+ tp = node_parent(tn);
+
+ /* Return if at least one inflate is run */
+ if (max_work != MAX_WORK)
+ return tp;
+
+ /* Halve as long as the number of empty children in this
+ * node is above threshold.
+ */
+ while (should_halve(tp, tn) && max_work) {
+ tp = halve(t, tn);
+ if (!tp) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->resize_node_skipped);
+#endif
+ break;
+ }
+
+ max_work--;
+ tn = get_child(tp, cindex);
+ }
+
+ /* Only one child remains */
+ if (should_collapse(tn))
+ return collapse(t, tn);
+
+ /* update parent in case halve failed */
+ return node_parent(tn);
+}
+
+static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
+{
+ unsigned char node_slen = tn->slen;
+
+ while ((node_slen > tn->pos) && (node_slen > slen)) {
+ slen = update_suffix(tn);
+ if (node_slen == slen)
+ break;
+
+ tn = node_parent(tn);
+ node_slen = tn->slen;
+ }
+}
+
+static void node_push_suffix(struct key_vector *tn, unsigned char slen)
+{
+ while (tn->slen < slen) {
+ tn->slen = slen;
+ tn = node_parent(tn);
+ }
+}
+
+/* rcu_read_lock needs to be hold by caller from readside */
+static struct key_vector *fib_find_node(struct trie *t,
+ struct key_vector **tp, u32 key)
+{
+ struct key_vector *pn, *n = t->kv;
+ unsigned long index = 0;
+
+ do {
+ pn = n;
+ n = get_child_rcu(n, index);
+
+ if (!n)
+ break;
+
+ index = get_cindex(key, n);
+
+ /* This bit of code is a bit tricky but it combines multiple
+ * checks into a single check. The prefix consists of the
+ * prefix plus zeros for the bits in the cindex. The index
+ * is the difference between the key and this value. From
+ * this we can actually derive several pieces of data.
+ * if (index >= (1ul << bits))
+ * we have a mismatch in skip bits and failed
+ * else
+ * we know the value is cindex
+ *
+ * This check is safe even if bits == KEYLENGTH due to the
+ * fact that we can only allocate a node with 32 bits if a
+ * long is greater than 32 bits.
+ */
+ if (index >= (1ul << n->bits)) {
+ n = NULL;
+ break;
+ }
+
+ /* keep searching until we find a perfect match leaf or NULL */
+ } while (IS_TNODE(n));
+
+ *tp = pn;
+
+ return n;
+}
+
+/* Return the first fib alias matching TOS with
+ * priority less than or equal to PRIO.
+ */
+static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
+ u8 tos, u32 prio, u32 tb_id)
+{
+ struct fib_alias *fa;
+
+ if (!fah)
+ return NULL;
+
+ hlist_for_each_entry(fa, fah, fa_list) {
+ if (fa->fa_slen < slen)
+ continue;
+ if (fa->fa_slen != slen)
+ break;
+ if (fa->tb_id > tb_id)
+ continue;
+ if (fa->tb_id != tb_id)
+ break;
+ if (fa->fa_tos > tos)
+ continue;
+ if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
+ return fa;
+ }
+
+ return NULL;
+}
+
+static void trie_rebalance(struct trie *t, struct key_vector *tn)
+{
+ while (!IS_TRIE(tn))
+ tn = resize(t, tn);
+}
+
+static int fib_insert_node(struct trie *t, struct key_vector *tp,
+ struct fib_alias *new, t_key key)
+{
+ struct key_vector *n, *l;
+
+ l = leaf_new(key, new);
+ if (!l)
+ goto noleaf;
+
+ /* retrieve child from parent node */
+ n = get_child(tp, get_index(key, tp));
+
+ /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
+ *
+ * Add a new tnode here
+ * first tnode need some special handling
+ * leaves us in position for handling as case 3
+ */
+ if (n) {
+ struct key_vector *tn;
+
+ tn = tnode_new(key, __fls(key ^ n->key), 1);
+ if (!tn)
+ goto notnode;
+
+ /* initialize routes out of node */
+ NODE_INIT_PARENT(tn, tp);
+ put_child(tn, get_index(key, tn) ^ 1, n);
+
+ /* start adding routes into the node */
+ put_child_root(tp, key, tn);
+ node_set_parent(n, tn);
+
+ /* parent now has a NULL spot where the leaf can go */
+ tp = tn;
+ }
+
+ /* Case 3: n is NULL, and will just insert a new leaf */
+ node_push_suffix(tp, new->fa_slen);
+ NODE_INIT_PARENT(l, tp);
+ put_child_root(tp, key, l);
+ trie_rebalance(t, tp);
+
+ return 0;
+notnode:
+ node_free(l);
+noleaf:
+ return -ENOMEM;
+}
+
+/* fib notifier for ADD is sent before calling fib_insert_alias with
+ * the expectation that the only possible failure ENOMEM
+ */
+static int fib_insert_alias(struct trie *t, struct key_vector *tp,
+ struct key_vector *l, struct fib_alias *new,
+ struct fib_alias *fa, t_key key)
+{
+ if (!l)
+ return fib_insert_node(t, tp, new, key);
+
+ if (fa) {
+ hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
+ } else {
+ struct fib_alias *last;
+
+ hlist_for_each_entry(last, &l->leaf, fa_list) {
+ if (new->fa_slen < last->fa_slen)
+ break;
+ if ((new->fa_slen == last->fa_slen) &&
+ (new->tb_id > last->tb_id))
+ break;
+ fa = last;
+ }
+
+ if (fa)
+ hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
+ else
+ hlist_add_head_rcu(&new->fa_list, &l->leaf);
+ }
+
+ /* if we added to the tail node then we need to update slen */
+ if (l->slen < new->fa_slen) {
+ l->slen = new->fa_slen;
+ node_push_suffix(tp, new->fa_slen);
+ }
+
+ return 0;
+}
+
+static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
+{
+ if (plen > KEYLENGTH) {
+ NL_SET_ERR_MSG(extack, "Invalid prefix length");
+ return false;
+ }
+
+ if ((plen < KEYLENGTH) && (key << plen)) {
+ NL_SET_ERR_MSG(extack,
+ "Invalid prefix for given prefix length");
+ return false;
+ }
+
+ return true;
+}
+
+/* Caller must hold RTNL. */
+int fib_table_insert(struct net *net, struct fib_table *tb,
+ struct fib_config *cfg, struct netlink_ext_ack *extack)
+{
+ enum fib_event_type event = FIB_EVENT_ENTRY_ADD;
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct fib_alias *fa, *new_fa;
+ struct key_vector *l, *tp;
+ u16 nlflags = NLM_F_EXCL;
+ struct fib_info *fi;
+ u8 plen = cfg->fc_dst_len;
+ u8 slen = KEYLENGTH - plen;
+ u8 tos = cfg->fc_tos;
+ u32 key;
+ int err;
+
+ key = ntohl(cfg->fc_dst);
+
+ if (!fib_valid_key_len(key, plen, extack))
+ return -EINVAL;
+
+ pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
+
+ fi = fib_create_info(cfg, extack);
+ if (IS_ERR(fi)) {
+ err = PTR_ERR(fi);
+ goto err;
+ }
+
+ l = fib_find_node(t, &tp, key);
+ fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
+ tb->tb_id) : NULL;
+
+ /* Now fa, if non-NULL, points to the first fib alias
+ * with the same keys [prefix,tos,priority], if such key already
+ * exists or to the node before which we will insert new one.
+ *
+ * If fa is NULL, we will need to allocate a new one and
+ * insert to the tail of the section matching the suffix length
+ * of the new alias.
+ */
+
+ if (fa && fa->fa_tos == tos &&
+ fa->fa_info->fib_priority == fi->fib_priority) {
+ struct fib_alias *fa_first, *fa_match;
+
+ err = -EEXIST;
+ if (cfg->fc_nlflags & NLM_F_EXCL)
+ goto out;
+
+ nlflags &= ~NLM_F_EXCL;
+
+ /* We have 2 goals:
+ * 1. Find exact match for type, scope, fib_info to avoid
+ * duplicate routes
+ * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
+ */
+ fa_match = NULL;
+ fa_first = fa;
+ hlist_for_each_entry_from(fa, fa_list) {
+ if ((fa->fa_slen != slen) ||
+ (fa->tb_id != tb->tb_id) ||
+ (fa->fa_tos != tos))
+ break;
+ if (fa->fa_info->fib_priority != fi->fib_priority)
+ break;
+ if (fa->fa_type == cfg->fc_type &&
+ fa->fa_info == fi) {
+ fa_match = fa;
+ break;
+ }
+ }
+
+ if (cfg->fc_nlflags & NLM_F_REPLACE) {
+ struct fib_info *fi_drop;
+ u8 state;
+
+ nlflags |= NLM_F_REPLACE;
+ fa = fa_first;
+ if (fa_match) {
+ if (fa == fa_match)
+ err = 0;
+ goto out;
+ }
+ err = -ENOBUFS;
+ new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+ if (!new_fa)
+ goto out;
+
+ fi_drop = fa->fa_info;
+ new_fa->fa_tos = fa->fa_tos;
+ new_fa->fa_info = fi;
+ new_fa->fa_type = cfg->fc_type;
+ state = fa->fa_state;
+ new_fa->fa_state = state & ~FA_S_ACCESSED;
+ new_fa->fa_slen = fa->fa_slen;
+ new_fa->tb_id = tb->tb_id;
+ new_fa->fa_default = -1;
+
+ err = call_fib_entry_notifiers(net,
+ FIB_EVENT_ENTRY_REPLACE,
+ key, plen, new_fa,
+ extack);
+ if (err)
+ goto out_free_new_fa;
+
+ rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
+ tb->tb_id, &cfg->fc_nlinfo, nlflags);
+
+ hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
+
+ alias_free_mem_rcu(fa);
+
+ fib_release_info(fi_drop);
+ if (state & FA_S_ACCESSED)
+ rt_cache_flush(cfg->fc_nlinfo.nl_net);
+
+ goto succeeded;
+ }
+ /* Error if we find a perfect match which
+ * uses the same scope, type, and nexthop
+ * information.
+ */
+ if (fa_match)
+ goto out;
+
+ if (cfg->fc_nlflags & NLM_F_APPEND) {
+ event = FIB_EVENT_ENTRY_APPEND;
+ nlflags |= NLM_F_APPEND;
+ } else {
+ fa = fa_first;
+ }
+ }
+ err = -ENOENT;
+ if (!(cfg->fc_nlflags & NLM_F_CREATE))
+ goto out;
+
+ nlflags |= NLM_F_CREATE;
+ err = -ENOBUFS;
+ new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+ if (!new_fa)
+ goto out;
+
+ new_fa->fa_info = fi;
+ new_fa->fa_tos = tos;
+ new_fa->fa_type = cfg->fc_type;
+ new_fa->fa_state = 0;
+ new_fa->fa_slen = slen;
+ new_fa->tb_id = tb->tb_id;
+ new_fa->fa_default = -1;
+
+ err = call_fib_entry_notifiers(net, event, key, plen, new_fa, extack);
+ if (err)
+ goto out_free_new_fa;
+
+ /* Insert new entry to the list. */
+ err = fib_insert_alias(t, tp, l, new_fa, fa, key);
+ if (err)
+ goto out_fib_notif;
+
+ if (!plen)
+ tb->tb_num_default++;
+
+ rt_cache_flush(cfg->fc_nlinfo.nl_net);
+ rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
+ &cfg->fc_nlinfo, nlflags);
+succeeded:
+ return 0;
+
+out_fib_notif:
+ /* notifier was sent that entry would be added to trie, but
+ * the add failed and need to recover. Only failure for
+ * fib_insert_alias is ENOMEM.
+ */
+ NL_SET_ERR_MSG(extack, "Failed to insert route into trie");
+ call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key,
+ plen, new_fa, NULL);
+out_free_new_fa:
+ kmem_cache_free(fn_alias_kmem, new_fa);
+out:
+ fib_release_info(fi);
+err:
+ return err;
+}
+
+static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
+{
+ t_key prefix = n->key;
+
+ return (key ^ prefix) & (prefix | -prefix);
+}
+
+/* should be called with rcu_read_lock */
+int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
+ struct fib_result *res, int fib_flags)
+{
+ struct trie *t = (struct trie *) tb->tb_data;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie_use_stats __percpu *stats = t->stats;
+#endif
+ const t_key key = ntohl(flp->daddr);
+ struct key_vector *n, *pn;
+ struct fib_alias *fa;
+ unsigned long index;
+ t_key cindex;
+
+ pn = t->kv;
+ cindex = 0;
+
+ n = get_child_rcu(pn, cindex);
+ if (!n) {
+ trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
+ return -EAGAIN;
+ }
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->gets);
+#endif
+
+ /* Step 1: Travel to the longest prefix match in the trie */
+ for (;;) {
+ index = get_cindex(key, n);
+
+ /* This bit of code is a bit tricky but it combines multiple
+ * checks into a single check. The prefix consists of the
+ * prefix plus zeros for the "bits" in the prefix. The index
+ * is the difference between the key and this value. From
+ * this we can actually derive several pieces of data.
+ * if (index >= (1ul << bits))
+ * we have a mismatch in skip bits and failed
+ * else
+ * we know the value is cindex
+ *
+ * This check is safe even if bits == KEYLENGTH due to the
+ * fact that we can only allocate a node with 32 bits if a
+ * long is greater than 32 bits.
+ */
+ if (index >= (1ul << n->bits))
+ break;
+
+ /* we have found a leaf. Prefixes have already been compared */
+ if (IS_LEAF(n))
+ goto found;
+
+ /* only record pn and cindex if we are going to be chopping
+ * bits later. Otherwise we are just wasting cycles.
+ */
+ if (n->slen > n->pos) {
+ pn = n;
+ cindex = index;
+ }
+
+ n = get_child_rcu(n, index);
+ if (unlikely(!n))
+ goto backtrace;
+ }
+
+ /* Step 2: Sort out leaves and begin backtracing for longest prefix */
+ for (;;) {
+ /* record the pointer where our next node pointer is stored */
+ struct key_vector __rcu **cptr = n->tnode;
+
+ /* This test verifies that none of the bits that differ
+ * between the key and the prefix exist in the region of
+ * the lsb and higher in the prefix.
+ */
+ if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
+ goto backtrace;
+
+ /* exit out and process leaf */
+ if (unlikely(IS_LEAF(n)))
+ break;
+
+ /* Don't bother recording parent info. Since we are in
+ * prefix match mode we will have to come back to wherever
+ * we started this traversal anyway
+ */
+
+ while ((n = rcu_dereference(*cptr)) == NULL) {
+backtrace:
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ if (!n)
+ this_cpu_inc(stats->null_node_hit);
+#endif
+ /* If we are at cindex 0 there are no more bits for
+ * us to strip at this level so we must ascend back
+ * up one level to see if there are any more bits to
+ * be stripped there.
+ */
+ while (!cindex) {
+ t_key pkey = pn->key;
+
+ /* If we don't have a parent then there is
+ * nothing for us to do as we do not have any
+ * further nodes to parse.
+ */
+ if (IS_TRIE(pn)) {
+ trace_fib_table_lookup(tb->tb_id, flp,
+ NULL, -EAGAIN);
+ return -EAGAIN;
+ }
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->backtrack);
+#endif
+ /* Get Child's index */
+ pn = node_parent_rcu(pn);
+ cindex = get_index(pkey, pn);
+ }
+
+ /* strip the least significant bit from the cindex */
+ cindex &= cindex - 1;
+
+ /* grab pointer for next child node */
+ cptr = &pn->tnode[cindex];
+ }
+ }
+
+found:
+ /* this line carries forward the xor from earlier in the function */
+ index = key ^ n->key;
+
+ /* Step 3: Process the leaf, if that fails fall back to backtracing */
+ hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
+ struct fib_info *fi = fa->fa_info;
+ int nhsel, err;
+
+ if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
+ if (index >= (1ul << fa->fa_slen))
+ continue;
+ }
+ if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
+ continue;
+ if (fi->fib_dead)
+ continue;
+ if (fa->fa_info->fib_scope < flp->flowi4_scope)
+ continue;
+ fib_alias_accessed(fa);
+ err = fib_props[fa->fa_type].error;
+ if (unlikely(err < 0)) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->semantic_match_passed);
+#endif
+ trace_fib_table_lookup(tb->tb_id, flp, NULL, err);
+ return err;
+ }
+ if (fi->fib_flags & RTNH_F_DEAD)
+ continue;
+ for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
+ const struct fib_nh *nh = &fi->fib_nh[nhsel];
+ struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev);
+
+ if (nh->nh_flags & RTNH_F_DEAD)
+ continue;
+ if (in_dev &&
+ IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
+ nh->nh_flags & RTNH_F_LINKDOWN &&
+ !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
+ continue;
+ if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
+ if (flp->flowi4_oif &&
+ flp->flowi4_oif != nh->nh_oif)
+ continue;
+ }
+
+ if (!(fib_flags & FIB_LOOKUP_NOREF))
+ refcount_inc(&fi->fib_clntref);
+
+ res->prefix = htonl(n->key);
+ res->prefixlen = KEYLENGTH - fa->fa_slen;
+ res->nh_sel = nhsel;
+ res->type = fa->fa_type;
+ res->scope = fi->fib_scope;
+ res->fi = fi;
+ res->table = tb;
+ res->fa_head = &n->leaf;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->semantic_match_passed);
+#endif
+ trace_fib_table_lookup(tb->tb_id, flp, nh, err);
+
+ return err;
+ }
+ }
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->semantic_match_miss);
+#endif
+ goto backtrace;
+}
+EXPORT_SYMBOL_GPL(fib_table_lookup);
+
+static void fib_remove_alias(struct trie *t, struct key_vector *tp,
+ struct key_vector *l, struct fib_alias *old)
+{
+ /* record the location of the previous list_info entry */
+ struct hlist_node **pprev = old->fa_list.pprev;
+ struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
+
+ /* remove the fib_alias from the list */
+ hlist_del_rcu(&old->fa_list);
+
+ /* if we emptied the list this leaf will be freed and we can sort
+ * out parent suffix lengths as a part of trie_rebalance
+ */
+ if (hlist_empty(&l->leaf)) {
+ if (tp->slen == l->slen)
+ node_pull_suffix(tp, tp->pos);
+ put_child_root(tp, l->key, NULL);
+ node_free(l);
+ trie_rebalance(t, tp);
+ return;
+ }
+
+ /* only access fa if it is pointing at the last valid hlist_node */
+ if (*pprev)
+ return;
+
+ /* update the trie with the latest suffix length */
+ l->slen = fa->fa_slen;
+ node_pull_suffix(tp, fa->fa_slen);
+}
+
+/* Caller must hold RTNL. */
+int fib_table_delete(struct net *net, struct fib_table *tb,
+ struct fib_config *cfg, struct netlink_ext_ack *extack)
+{
+ struct trie *t = (struct trie *) tb->tb_data;
+ struct fib_alias *fa, *fa_to_delete;
+ struct key_vector *l, *tp;
+ u8 plen = cfg->fc_dst_len;
+ u8 slen = KEYLENGTH - plen;
+ u8 tos = cfg->fc_tos;
+ u32 key;
+
+ key = ntohl(cfg->fc_dst);
+
+ if (!fib_valid_key_len(key, plen, extack))
+ return -EINVAL;
+
+ l = fib_find_node(t, &tp, key);
+ if (!l)
+ return -ESRCH;
+
+ fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
+ if (!fa)
+ return -ESRCH;
+
+ pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
+
+ fa_to_delete = NULL;
+ hlist_for_each_entry_from(fa, fa_list) {
+ struct fib_info *fi = fa->fa_info;
+
+ if ((fa->fa_slen != slen) ||
+ (fa->tb_id != tb->tb_id) ||
+ (fa->fa_tos != tos))
+ break;
+
+ if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
+ (cfg->fc_scope == RT_SCOPE_NOWHERE ||
+ fa->fa_info->fib_scope == cfg->fc_scope) &&
+ (!cfg->fc_prefsrc ||
+ fi->fib_prefsrc == cfg->fc_prefsrc) &&
+ (!cfg->fc_protocol ||
+ fi->fib_protocol == cfg->fc_protocol) &&
+ fib_nh_match(cfg, fi, extack) == 0 &&
+ fib_metrics_match(cfg, fi)) {
+ fa_to_delete = fa;
+ break;
+ }
+ }
+
+ if (!fa_to_delete)
+ return -ESRCH;
+
+ call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen,
+ fa_to_delete, extack);
+ rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
+ &cfg->fc_nlinfo, 0);
+
+ if (!plen)
+ tb->tb_num_default--;
+
+ fib_remove_alias(t, tp, l, fa_to_delete);
+
+ if (fa_to_delete->fa_state & FA_S_ACCESSED)
+ rt_cache_flush(cfg->fc_nlinfo.nl_net);
+
+ fib_release_info(fa_to_delete->fa_info);
+ alias_free_mem_rcu(fa_to_delete);
+ return 0;
+}
+
+/* Scan for the next leaf starting at the provided key value */
+static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
+{
+ struct key_vector *pn, *n = *tn;
+ unsigned long cindex;
+
+ /* this loop is meant to try and find the key in the trie */
+ do {
+ /* record parent and next child index */
+ pn = n;
+ cindex = (key > pn->key) ? get_index(key, pn) : 0;
+
+ if (cindex >> pn->bits)
+ break;
+
+ /* descend into the next child */
+ n = get_child_rcu(pn, cindex++);
+ if (!n)
+ break;
+
+ /* guarantee forward progress on the keys */
+ if (IS_LEAF(n) && (n->key >= key))
+ goto found;
+ } while (IS_TNODE(n));
+
+ /* this loop will search for the next leaf with a greater key */
+ while (!IS_TRIE(pn)) {
+ /* if we exhausted the parent node we will need to climb */
+ if (cindex >= (1ul << pn->bits)) {
+ t_key pkey = pn->key;
+
+ pn = node_parent_rcu(pn);
+ cindex = get_index(pkey, pn) + 1;
+ continue;
+ }
+
+ /* grab the next available node */
+ n = get_child_rcu(pn, cindex++);
+ if (!n)
+ continue;
+
+ /* no need to compare keys since we bumped the index */
+ if (IS_LEAF(n))
+ goto found;
+
+ /* Rescan start scanning in new node */
+ pn = n;
+ cindex = 0;
+ }
+
+ *tn = pn;
+ return NULL; /* Root of trie */
+found:
+ /* if we are at the limit for keys just return NULL for the tnode */
+ *tn = pn;
+ return n;
+}
+
+static void fib_trie_free(struct fib_table *tb)
+{
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct key_vector *pn = t->kv;
+ unsigned long cindex = 1;
+ struct hlist_node *tmp;
+ struct fib_alias *fa;
+
+ /* walk trie in reverse order and free everything */
+ for (;;) {
+ struct key_vector *n;
+
+ if (!(cindex--)) {
+ t_key pkey = pn->key;
+
+ if (IS_TRIE(pn))
+ break;
+
+ n = pn;
+ pn = node_parent(pn);
+
+ /* drop emptied tnode */
+ put_child_root(pn, n->key, NULL);
+ node_free(n);
+
+ cindex = get_index(pkey, pn);
+
+ continue;
+ }
+
+ /* grab the next available node */
+ n = get_child(pn, cindex);
+ if (!n)
+ continue;
+
+ if (IS_TNODE(n)) {
+ /* record pn and cindex for leaf walking */
+ pn = n;
+ cindex = 1ul << n->bits;
+
+ continue;
+ }
+
+ hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
+ hlist_del_rcu(&fa->fa_list);
+ alias_free_mem_rcu(fa);
+ }
+
+ put_child_root(pn, n->key, NULL);
+ node_free(n);
+ }
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ free_percpu(t->stats);
+#endif
+ kfree(tb);
+}
+
+struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
+{
+ struct trie *ot = (struct trie *)oldtb->tb_data;
+ struct key_vector *l, *tp = ot->kv;
+ struct fib_table *local_tb;
+ struct fib_alias *fa;
+ struct trie *lt;
+ t_key key = 0;
+
+ if (oldtb->tb_data == oldtb->__data)
+ return oldtb;
+
+ local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
+ if (!local_tb)
+ return NULL;
+
+ lt = (struct trie *)local_tb->tb_data;
+
+ while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
+ struct key_vector *local_l = NULL, *local_tp;
+
+ hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
+ struct fib_alias *new_fa;
+
+ if (local_tb->tb_id != fa->tb_id)
+ continue;
+
+ /* clone fa for new local table */
+ new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+ if (!new_fa)
+ goto out;
+
+ memcpy(new_fa, fa, sizeof(*fa));
+
+ /* insert clone into table */
+ if (!local_l)
+ local_l = fib_find_node(lt, &local_tp, l->key);
+
+ if (fib_insert_alias(lt, local_tp, local_l, new_fa,
+ NULL, l->key)) {
+ kmem_cache_free(fn_alias_kmem, new_fa);
+ goto out;
+ }
+ }
+
+ /* stop loop if key wrapped back to 0 */
+ key = l->key + 1;
+ if (key < l->key)
+ break;
+ }
+
+ return local_tb;
+out:
+ fib_trie_free(local_tb);
+
+ return NULL;
+}
+
+/* Caller must hold RTNL */
+void fib_table_flush_external(struct fib_table *tb)
+{
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct key_vector *pn = t->kv;
+ unsigned long cindex = 1;
+ struct hlist_node *tmp;
+ struct fib_alias *fa;
+
+ /* walk trie in reverse order */
+ for (;;) {
+ unsigned char slen = 0;
+ struct key_vector *n;
+
+ if (!(cindex--)) {
+ t_key pkey = pn->key;
+
+ /* cannot resize the trie vector */
+ if (IS_TRIE(pn))
+ break;
+
+ /* update the suffix to address pulled leaves */
+ if (pn->slen > pn->pos)
+ update_suffix(pn);
+
+ /* resize completed node */
+ pn = resize(t, pn);
+ cindex = get_index(pkey, pn);
+
+ continue;
+ }
+
+ /* grab the next available node */
+ n = get_child(pn, cindex);
+ if (!n)
+ continue;
+
+ if (IS_TNODE(n)) {
+ /* record pn and cindex for leaf walking */
+ pn = n;
+ cindex = 1ul << n->bits;
+
+ continue;
+ }
+
+ hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
+ /* if alias was cloned to local then we just
+ * need to remove the local copy from main
+ */
+ if (tb->tb_id != fa->tb_id) {
+ hlist_del_rcu(&fa->fa_list);
+ alias_free_mem_rcu(fa);
+ continue;
+ }
+
+ /* record local slen */
+ slen = fa->fa_slen;
+ }
+
+ /* update leaf slen */
+ n->slen = slen;
+
+ if (hlist_empty(&n->leaf)) {
+ put_child_root(pn, n->key, NULL);
+ node_free(n);
+ }
+ }
+}
+
+/* Caller must hold RTNL. */
+int fib_table_flush(struct net *net, struct fib_table *tb)
+{
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct key_vector *pn = t->kv;
+ unsigned long cindex = 1;
+ struct hlist_node *tmp;
+ struct fib_alias *fa;
+ int found = 0;
+
+ /* walk trie in reverse order */
+ for (;;) {
+ unsigned char slen = 0;
+ struct key_vector *n;
+
+ if (!(cindex--)) {
+ t_key pkey = pn->key;
+
+ /* cannot resize the trie vector */
+ if (IS_TRIE(pn))
+ break;
+
+ /* update the suffix to address pulled leaves */
+ if (pn->slen > pn->pos)
+ update_suffix(pn);
+
+ /* resize completed node */
+ pn = resize(t, pn);
+ cindex = get_index(pkey, pn);
+
+ continue;
+ }
+
+ /* grab the next available node */
+ n = get_child(pn, cindex);
+ if (!n)
+ continue;
+
+ if (IS_TNODE(n)) {
+ /* record pn and cindex for leaf walking */
+ pn = n;
+ cindex = 1ul << n->bits;
+
+ continue;
+ }
+
+ hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
+ struct fib_info *fi = fa->fa_info;
+
+ if (!fi || !(fi->fib_flags & RTNH_F_DEAD) ||
+ tb->tb_id != fa->tb_id) {
+ slen = fa->fa_slen;
+ continue;
+ }
+
+ call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
+ n->key,
+ KEYLENGTH - fa->fa_slen, fa,
+ NULL);
+ hlist_del_rcu(&fa->fa_list);
+ fib_release_info(fa->fa_info);
+ alias_free_mem_rcu(fa);
+ found++;
+ }
+
+ /* update leaf slen */
+ n->slen = slen;
+
+ if (hlist_empty(&n->leaf)) {
+ put_child_root(pn, n->key, NULL);
+ node_free(n);
+ }
+ }
+
+ pr_debug("trie_flush found=%d\n", found);
+ return found;
+}
+
+static void fib_leaf_notify(struct net *net, struct key_vector *l,
+ struct fib_table *tb, struct notifier_block *nb)
+{
+ struct fib_alias *fa;
+
+ hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
+ struct fib_info *fi = fa->fa_info;
+
+ if (!fi)
+ continue;
+
+ /* local and main table can share the same trie,
+ * so don't notify twice for the same entry.
+ */
+ if (tb->tb_id != fa->tb_id)
+ continue;
+
+ call_fib_entry_notifier(nb, net, FIB_EVENT_ENTRY_ADD, l->key,
+ KEYLENGTH - fa->fa_slen, fa);
+ }
+}
+
+static void fib_table_notify(struct net *net, struct fib_table *tb,
+ struct notifier_block *nb)
+{
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct key_vector *l, *tp = t->kv;
+ t_key key = 0;
+
+ while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
+ fib_leaf_notify(net, l, tb, nb);
+
+ key = l->key + 1;
+ /* stop in case of wrap around */
+ if (key < l->key)
+ break;
+ }
+}
+
+void fib_notify(struct net *net, struct notifier_block *nb)
+{
+ unsigned int h;
+
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ struct fib_table *tb;
+
+ hlist_for_each_entry_rcu(tb, head, tb_hlist)
+ fib_table_notify(net, tb, nb);
+ }
+}
+
+static void __trie_free_rcu(struct rcu_head *head)
+{
+ struct fib_table *tb = container_of(head, struct fib_table, rcu);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie *t = (struct trie *)tb->tb_data;
+
+ if (tb->tb_data == tb->__data)
+ free_percpu(t->stats);
+#endif /* CONFIG_IP_FIB_TRIE_STATS */
+ kfree(tb);
+}
+
+void fib_free_table(struct fib_table *tb)
+{
+ call_rcu(&tb->rcu, __trie_free_rcu);
+}
+
+static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
+ struct sk_buff *skb, struct netlink_callback *cb)
+{
+ __be32 xkey = htonl(l->key);
+ struct fib_alias *fa;
+ int i, s_i;
+
+ s_i = cb->args[4];
+ i = 0;
+
+ /* rcu_read_lock is hold by caller */
+ hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
+ int err;
+
+ if (i < s_i) {
+ i++;
+ continue;
+ }
+
+ if (tb->tb_id != fa->tb_id) {
+ i++;
+ continue;
+ }
+
+ err = fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, RTM_NEWROUTE,
+ tb->tb_id, fa->fa_type,
+ xkey, KEYLENGTH - fa->fa_slen,
+ fa->fa_tos, fa->fa_info, NLM_F_MULTI);
+ if (err < 0) {
+ cb->args[4] = i;
+ return err;
+ }
+ i++;
+ }
+
+ cb->args[4] = i;
+ return skb->len;
+}
+
+/* rcu_read_lock needs to be hold by caller from readside */
+int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct key_vector *l, *tp = t->kv;
+ /* Dump starting at last key.
+ * Note: 0.0.0.0/0 (ie default) is first key.
+ */
+ int count = cb->args[2];
+ t_key key = cb->args[3];
+
+ while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
+ int err;
+
+ err = fn_trie_dump_leaf(l, tb, skb, cb);
+ if (err < 0) {
+ cb->args[3] = key;
+ cb->args[2] = count;
+ return err;
+ }
+
+ ++count;
+ key = l->key + 1;
+
+ memset(&cb->args[4], 0,
+ sizeof(cb->args) - 4*sizeof(cb->args[0]));
+
+ /* stop loop if key wrapped back to 0 */
+ if (key < l->key)
+ break;
+ }
+
+ cb->args[3] = key;
+ cb->args[2] = count;
+
+ return skb->len;
+}
+
+void __init fib_trie_init(void)
+{
+ fn_alias_kmem = kmem_cache_create("ip_fib_alias",
+ sizeof(struct fib_alias),
+ 0, SLAB_PANIC, NULL);
+
+ trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
+ LEAF_SIZE,
+ 0, SLAB_PANIC, NULL);
+}
+
+struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
+{
+ struct fib_table *tb;
+ struct trie *t;
+ size_t sz = sizeof(*tb);
+
+ if (!alias)
+ sz += sizeof(struct trie);
+
+ tb = kzalloc(sz, GFP_KERNEL);
+ if (!tb)
+ return NULL;
+
+ tb->tb_id = id;
+ tb->tb_num_default = 0;
+ tb->tb_data = (alias ? alias->__data : tb->__data);
+
+ if (alias)
+ return tb;
+
+ t = (struct trie *) tb->tb_data;
+ t->kv[0].pos = KEYLENGTH;
+ t->kv[0].slen = KEYLENGTH;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ t->stats = alloc_percpu(struct trie_use_stats);
+ if (!t->stats) {
+ kfree(tb);
+ tb = NULL;
+ }
+#endif
+
+ return tb;
+}
+
+#ifdef CONFIG_PROC_FS
+/* Depth first Trie walk iterator */
+struct fib_trie_iter {
+ struct seq_net_private p;
+ struct fib_table *tb;
+ struct key_vector *tnode;
+ unsigned int index;
+ unsigned int depth;
+};
+
+static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
+{
+ unsigned long cindex = iter->index;
+ struct key_vector *pn = iter->tnode;
+ t_key pkey;
+
+ pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
+ iter->tnode, iter->index, iter->depth);
+
+ while (!IS_TRIE(pn)) {
+ while (cindex < child_length(pn)) {
+ struct key_vector *n = get_child_rcu(pn, cindex++);
+
+ if (!n)
+ continue;
+
+ if (IS_LEAF(n)) {
+ iter->tnode = pn;
+ iter->index = cindex;
+ } else {
+ /* push down one level */
+ iter->tnode = n;
+ iter->index = 0;
+ ++iter->depth;
+ }
+
+ return n;
+ }
+
+ /* Current node exhausted, pop back up */
+ pkey = pn->key;
+ pn = node_parent_rcu(pn);
+ cindex = get_index(pkey, pn) + 1;
+ --iter->depth;
+ }
+
+ /* record root node so further searches know we are done */
+ iter->tnode = pn;
+ iter->index = 0;
+
+ return NULL;
+}
+
+static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
+ struct trie *t)
+{
+ struct key_vector *n, *pn;
+
+ if (!t)
+ return NULL;
+
+ pn = t->kv;
+ n = rcu_dereference(pn->tnode[0]);
+ if (!n)
+ return NULL;
+
+ if (IS_TNODE(n)) {
+ iter->tnode = n;
+ iter->index = 0;
+ iter->depth = 1;
+ } else {
+ iter->tnode = pn;
+ iter->index = 0;
+ iter->depth = 0;
+ }
+
+ return n;
+}
+
+static void trie_collect_stats(struct trie *t, struct trie_stat *s)
+{
+ struct key_vector *n;
+ struct fib_trie_iter iter;
+
+ memset(s, 0, sizeof(*s));
+
+ rcu_read_lock();
+ for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
+ if (IS_LEAF(n)) {
+ struct fib_alias *fa;
+
+ s->leaves++;
+ s->totdepth += iter.depth;
+ if (iter.depth > s->maxdepth)
+ s->maxdepth = iter.depth;
+
+ hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
+ ++s->prefixes;
+ } else {
+ s->tnodes++;
+ if (n->bits < MAX_STAT_DEPTH)
+ s->nodesizes[n->bits]++;
+ s->nullpointers += tn_info(n)->empty_children;
+ }
+ }
+ rcu_read_unlock();
+}
+
+/*
+ * This outputs /proc/net/fib_triestats
+ */
+static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
+{
+ unsigned int i, max, pointers, bytes, avdepth;
+
+ if (stat->leaves)
+ avdepth = stat->totdepth*100 / stat->leaves;
+ else
+ avdepth = 0;
+
+ seq_printf(seq, "\tAver depth: %u.%02d\n",
+ avdepth / 100, avdepth % 100);
+ seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
+
+ seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
+ bytes = LEAF_SIZE * stat->leaves;
+
+ seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
+ bytes += sizeof(struct fib_alias) * stat->prefixes;
+
+ seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
+ bytes += TNODE_SIZE(0) * stat->tnodes;
+
+ max = MAX_STAT_DEPTH;
+ while (max > 0 && stat->nodesizes[max-1] == 0)
+ max--;
+
+ pointers = 0;
+ for (i = 1; i < max; i++)
+ if (stat->nodesizes[i] != 0) {
+ seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
+ pointers += (1<<i) * stat->nodesizes[i];
+ }
+ seq_putc(seq, '\n');
+ seq_printf(seq, "\tPointers: %u\n", pointers);
+
+ bytes += sizeof(struct key_vector *) * pointers;
+ seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
+ seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
+}
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+static void trie_show_usage(struct seq_file *seq,
+ const struct trie_use_stats __percpu *stats)
+{
+ struct trie_use_stats s = { 0 };
+ int cpu;
+
+ /* loop through all of the CPUs and gather up the stats */
+ for_each_possible_cpu(cpu) {
+ const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
+
+ s.gets += pcpu->gets;
+ s.backtrack += pcpu->backtrack;
+ s.semantic_match_passed += pcpu->semantic_match_passed;
+ s.semantic_match_miss += pcpu->semantic_match_miss;
+ s.null_node_hit += pcpu->null_node_hit;
+ s.resize_node_skipped += pcpu->resize_node_skipped;
+ }
+
+ seq_printf(seq, "\nCounters:\n---------\n");
+ seq_printf(seq, "gets = %u\n", s.gets);
+ seq_printf(seq, "backtracks = %u\n", s.backtrack);
+ seq_printf(seq, "semantic match passed = %u\n",
+ s.semantic_match_passed);
+ seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
+ seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
+ seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
+}
+#endif /* CONFIG_IP_FIB_TRIE_STATS */
+
+static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
+{
+ if (tb->tb_id == RT_TABLE_LOCAL)
+ seq_puts(seq, "Local:\n");
+ else if (tb->tb_id == RT_TABLE_MAIN)
+ seq_puts(seq, "Main:\n");
+ else
+ seq_printf(seq, "Id %d:\n", tb->tb_id);
+}
+
+
+static int fib_triestat_seq_show(struct seq_file *seq, void *v)
+{
+ struct net *net = (struct net *)seq->private;
+ unsigned int h;
+
+ seq_printf(seq,
+ "Basic info: size of leaf:"
+ " %zd bytes, size of tnode: %zd bytes.\n",
+ LEAF_SIZE, TNODE_SIZE(0));
+
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ struct fib_table *tb;
+
+ hlist_for_each_entry_rcu(tb, head, tb_hlist) {
+ struct trie *t = (struct trie *) tb->tb_data;
+ struct trie_stat stat;
+
+ if (!t)
+ continue;
+
+ fib_table_print(seq, tb);
+
+ trie_collect_stats(t, &stat);
+ trie_show_stats(seq, &stat);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ trie_show_usage(seq, t->stats);
+#endif
+ }
+ }
+
+ return 0;
+}
+
+static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
+{
+ struct fib_trie_iter *iter = seq->private;
+ struct net *net = seq_file_net(seq);
+ loff_t idx = 0;
+ unsigned int h;
+
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ struct fib_table *tb;
+
+ hlist_for_each_entry_rcu(tb, head, tb_hlist) {
+ struct key_vector *n;
+
+ for (n = fib_trie_get_first(iter,
+ (struct trie *) tb->tb_data);
+ n; n = fib_trie_get_next(iter))
+ if (pos == idx++) {
+ iter->tb = tb;
+ return n;
+ }
+ }
+ }
+
+ return NULL;
+}
+
+static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
+ __acquires(RCU)
+{
+ rcu_read_lock();
+ return fib_trie_get_idx(seq, *pos);
+}
+
+static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct fib_trie_iter *iter = seq->private;
+ struct net *net = seq_file_net(seq);
+ struct fib_table *tb = iter->tb;
+ struct hlist_node *tb_node;
+ unsigned int h;
+ struct key_vector *n;
+
+ ++*pos;
+ /* next node in same table */
+ n = fib_trie_get_next(iter);
+ if (n)
+ return n;
+
+ /* walk rest of this hash chain */
+ h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
+ while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
+ tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
+ n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
+ if (n)
+ goto found;
+ }
+
+ /* new hash chain */
+ while (++h < FIB_TABLE_HASHSZ) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ hlist_for_each_entry_rcu(tb, head, tb_hlist) {
+ n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
+ if (n)
+ goto found;
+ }
+ }
+ return NULL;
+
+found:
+ iter->tb = tb;
+ return n;
+}
+
+static void fib_trie_seq_stop(struct seq_file *seq, void *v)
+ __releases(RCU)
+{
+ rcu_read_unlock();
+}
+
+static void seq_indent(struct seq_file *seq, int n)
+{
+ while (n-- > 0)
+ seq_puts(seq, " ");
+}
+
+static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
+{
+ switch (s) {
+ case RT_SCOPE_UNIVERSE: return "universe";
+ case RT_SCOPE_SITE: return "site";
+ case RT_SCOPE_LINK: return "link";
+ case RT_SCOPE_HOST: return "host";
+ case RT_SCOPE_NOWHERE: return "nowhere";
+ default:
+ snprintf(buf, len, "scope=%d", s);
+ return buf;
+ }
+}
+
+static const char *const rtn_type_names[__RTN_MAX] = {
+ [RTN_UNSPEC] = "UNSPEC",
+ [RTN_UNICAST] = "UNICAST",
+ [RTN_LOCAL] = "LOCAL",
+ [RTN_BROADCAST] = "BROADCAST",
+ [RTN_ANYCAST] = "ANYCAST",
+ [RTN_MULTICAST] = "MULTICAST",
+ [RTN_BLACKHOLE] = "BLACKHOLE",
+ [RTN_UNREACHABLE] = "UNREACHABLE",
+ [RTN_PROHIBIT] = "PROHIBIT",
+ [RTN_THROW] = "THROW",
+ [RTN_NAT] = "NAT",
+ [RTN_XRESOLVE] = "XRESOLVE",
+};
+
+static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
+{
+ if (t < __RTN_MAX && rtn_type_names[t])
+ return rtn_type_names[t];
+ snprintf(buf, len, "type %u", t);
+ return buf;
+}
+
+/* Pretty print the trie */
+static int fib_trie_seq_show(struct seq_file *seq, void *v)
+{
+ const struct fib_trie_iter *iter = seq->private;
+ struct key_vector *n = v;
+
+ if (IS_TRIE(node_parent_rcu(n)))
+ fib_table_print(seq, iter->tb);
+
+ if (IS_TNODE(n)) {
+ __be32 prf = htonl(n->key);
+
+ seq_indent(seq, iter->depth-1);
+ seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
+ &prf, KEYLENGTH - n->pos - n->bits, n->bits,
+ tn_info(n)->full_children,
+ tn_info(n)->empty_children);
+ } else {
+ __be32 val = htonl(n->key);
+ struct fib_alias *fa;
+
+ seq_indent(seq, iter->depth);
+ seq_printf(seq, " |-- %pI4\n", &val);
+
+ hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
+ char buf1[32], buf2[32];
+
+ seq_indent(seq, iter->depth + 1);
+ seq_printf(seq, " /%zu %s %s",
+ KEYLENGTH - fa->fa_slen,
+ rtn_scope(buf1, sizeof(buf1),
+ fa->fa_info->fib_scope),
+ rtn_type(buf2, sizeof(buf2),
+ fa->fa_type));
+ if (fa->fa_tos)
+ seq_printf(seq, " tos=%d", fa->fa_tos);
+ seq_putc(seq, '\n');
+ }
+ }
+
+ return 0;
+}
+
+static const struct seq_operations fib_trie_seq_ops = {
+ .start = fib_trie_seq_start,
+ .next = fib_trie_seq_next,
+ .stop = fib_trie_seq_stop,
+ .show = fib_trie_seq_show,
+};
+
+struct fib_route_iter {
+ struct seq_net_private p;
+ struct fib_table *main_tb;
+ struct key_vector *tnode;
+ loff_t pos;
+ t_key key;
+};
+
+static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
+ loff_t pos)
+{
+ struct key_vector *l, **tp = &iter->tnode;
+ t_key key;
+
+ /* use cached location of previously found key */
+ if (iter->pos > 0 && pos >= iter->pos) {
+ key = iter->key;
+ } else {
+ iter->pos = 1;
+ key = 0;
+ }
+
+ pos -= iter->pos;
+
+ while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
+ key = l->key + 1;
+ iter->pos++;
+ l = NULL;
+
+ /* handle unlikely case of a key wrap */
+ if (!key)
+ break;
+ }
+
+ if (l)
+ iter->key = l->key; /* remember it */
+ else
+ iter->pos = 0; /* forget it */
+
+ return l;
+}
+
+static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
+ __acquires(RCU)
+{
+ struct fib_route_iter *iter = seq->private;
+ struct fib_table *tb;
+ struct trie *t;
+
+ rcu_read_lock();
+
+ tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
+ if (!tb)
+ return NULL;
+
+ iter->main_tb = tb;
+ t = (struct trie *)tb->tb_data;
+ iter->tnode = t->kv;
+
+ if (*pos != 0)
+ return fib_route_get_idx(iter, *pos);
+
+ iter->pos = 0;
+ iter->key = KEY_MAX;
+
+ return SEQ_START_TOKEN;
+}
+
+static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct fib_route_iter *iter = seq->private;
+ struct key_vector *l = NULL;
+ t_key key = iter->key + 1;
+
+ ++*pos;
+
+ /* only allow key of 0 for start of sequence */
+ if ((v == SEQ_START_TOKEN) || key)
+ l = leaf_walk_rcu(&iter->tnode, key);
+
+ if (l) {
+ iter->key = l->key;
+ iter->pos++;
+ } else {
+ iter->pos = 0;
+ }
+
+ return l;
+}
+
+static void fib_route_seq_stop(struct seq_file *seq, void *v)
+ __releases(RCU)
+{
+ rcu_read_unlock();
+}
+
+static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
+{
+ unsigned int flags = 0;
+
+ if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
+ flags = RTF_REJECT;
+ if (fi && fi->fib_nh->nh_gw)
+ flags |= RTF_GATEWAY;
+ if (mask == htonl(0xFFFFFFFF))
+ flags |= RTF_HOST;
+ flags |= RTF_UP;
+ return flags;
+}
+
+/*
+ * This outputs /proc/net/route.
+ * The format of the file is not supposed to be changed
+ * and needs to be same as fib_hash output to avoid breaking
+ * legacy utilities
+ */
+static int fib_route_seq_show(struct seq_file *seq, void *v)
+{
+ struct fib_route_iter *iter = seq->private;
+ struct fib_table *tb = iter->main_tb;
+ struct fib_alias *fa;
+ struct key_vector *l = v;
+ __be32 prefix;
+
+ if (v == SEQ_START_TOKEN) {
+ seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
+ "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
+ "\tWindow\tIRTT");
+ return 0;
+ }
+
+ prefix = htonl(l->key);
+
+ hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
+ const struct fib_info *fi = fa->fa_info;
+ __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
+ unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
+
+ if ((fa->fa_type == RTN_BROADCAST) ||
+ (fa->fa_type == RTN_MULTICAST))
+ continue;
+
+ if (fa->tb_id != tb->tb_id)
+ continue;
+
+ seq_setwidth(seq, 127);
+
+ if (fi)
+ seq_printf(seq,
+ "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
+ "%d\t%08X\t%d\t%u\t%u",
+ fi->fib_dev ? fi->fib_dev->name : "*",
+ prefix,
+ fi->fib_nh->nh_gw, flags, 0, 0,
+ fi->fib_priority,
+ mask,
+ (fi->fib_advmss ?
+ fi->fib_advmss + 40 : 0),
+ fi->fib_window,
+ fi->fib_rtt >> 3);
+ else
+ seq_printf(seq,
+ "*\t%08X\t%08X\t%04X\t%d\t%u\t"
+ "%d\t%08X\t%d\t%u\t%u",
+ prefix, 0, flags, 0, 0, 0,
+ mask, 0, 0, 0);
+
+ seq_pad(seq, '\n');
+ }
+
+ return 0;
+}
+
+static const struct seq_operations fib_route_seq_ops = {
+ .start = fib_route_seq_start,
+ .next = fib_route_seq_next,
+ .stop = fib_route_seq_stop,
+ .show = fib_route_seq_show,
+};
+
+int __net_init fib_proc_init(struct net *net)
+{
+ if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops,
+ sizeof(struct fib_trie_iter)))
+ goto out1;
+
+ if (!proc_create_net_single("fib_triestat", 0444, net->proc_net,
+ fib_triestat_seq_show, NULL))
+ goto out2;
+
+ if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops,
+ sizeof(struct fib_route_iter)))
+ goto out3;
+
+ return 0;
+
+out3:
+ remove_proc_entry("fib_triestat", net->proc_net);
+out2:
+ remove_proc_entry("fib_trie", net->proc_net);
+out1:
+ return -ENOMEM;
+}
+
+void __net_exit fib_proc_exit(struct net *net)
+{
+ remove_proc_entry("fib_trie", net->proc_net);
+ remove_proc_entry("fib_triestat", net->proc_net);
+ remove_proc_entry("route", net->proc_net);
+}
+
+#endif /* CONFIG_PROC_FS */