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Diffstat (limited to 'net/ipv4/fib_trie.c')
| -rw-r--r-- | net/ipv4/fib_trie.c | 2751 |
1 files changed, 2751 insertions, 0 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c new file mode 100644 index 000000000..48d712550 --- /dev/null +++ b/net/ipv4/fib_trie.c @@ -0,0 +1,2751 @@ +/* + * 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(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, bool flush_all) +{ + 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 || tb->tb_id != fa->tb_id || + (!(fi->fib_flags & RTNH_F_DEAD) && + !fib_props[fa->fa_type].error)) { + slen = fa->fa_slen; + continue; + } + + /* Do not flush error routes if network namespace is + * not being dismantled + */ + if (!flush_all && fib_props[fa->fa_type].error) { + 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)); + + rcu_read_lock(); + 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 + } + cond_resched_rcu(); + } + rcu_read_unlock(); + + 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 */ |