trie.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2011 Daniel Borkmann.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #include <stdint.h>
   8 #include <string.h>
   9 #include <netinet/in.h>
  10
  11 #include "patricia.h"
  12 #include "locking.h"
  13 #include "trie.h"
  14 #include "ipv4.h"
  15 #include "ipv6.h"
  16
  17 static struct patricia_node *tree = NULL;
  18
  19 static struct rwlock tree_lock;
  20
  21 void trie_addr_lookup(char *buff, size_t len, int ipv4, int *fd,
  22                       struct sockaddr_storage *addr, size_t *alen)
  23 {
  24         void *data;
  25         size_t dlen;
  26         struct ipv4hdr *hdr4 = (void *) buff;
  27         struct ipv6hdr *hdr6 = (void *) buff;
  28
  29         data = ipv4 ? (void *) &hdr4->h_daddr : (void *) &hdr6->daddr;
  30         dlen = ipv4 ? sizeof(hdr4->h_daddr) : sizeof(hdr6->daddr);
  31
  32         if (unlikely((ipv4 && ((struct ipv4hdr *) buff)->h_version != 4) ||
  33                      (!ipv4 && ((struct ipv6hdr *) buff)->version  != 6))) {
  34                 memset(addr, 0, sizeof(*addr));
  35                 (*alen) = 0;
  36                 (*fd) = -1;
  37                 return;
  38         }
  39
  40         rwlock_rd_lock(&tree_lock);
  41         (*fd) = ptree_search_data_exact(data, dlen, addr, alen, tree);
  42         rwlock_unlock(&tree_lock);
  43 }
  44
  45 int trie_addr_maybe_update(char *buff, size_t len, int ipv4, int fd,
  46                            struct sockaddr_storage *addr, size_t alen)
  47 {
  48         int ret;
  49         void *data;
  50         size_t dlen;
  51         struct ipv4hdr *hdr4 = (void *) buff;
  52         struct ipv6hdr *hdr6 = (void *) buff;
  53
  54         data = ipv4 ? (void *) &hdr4->h_saddr : (void *) &hdr6->saddr;
  55         dlen = ipv4 ? sizeof(hdr4->h_saddr) : sizeof(hdr6->saddr);
  56
  57         if (unlikely((ipv4 && ((struct ipv4hdr *) buff)->h_version != 4) ||
  58                      (!ipv4 && ((struct ipv6hdr *) buff)->version  != 6)))
  59                 return -1;
  60
  61         rwlock_wr_lock(&tree_lock);
  62         ret = ptree_add_entry(data, dlen, fd, addr, alen, &tree);
  63         rwlock_unlock(&tree_lock);
  64
  65         return ret;
  66 }
  67
  68 void trie_addr_remove(int fd)
  69 {
  70         int found = 1;
  71         struct patricia_node *n = NULL;
  72
  73         rwlock_wr_lock(&tree_lock);
  74
  75         while (found) {
  76                 ptree_get_key(fd, tree, &n);
  77                 if (n) {
  78                         ptree_del_entry(n->key, n->klen, &tree);
  79                         n = NULL;
  80                 } else
  81                         found = 0;
  82         }
  83
  84         rwlock_unlock(&tree_lock);
  85 }
  86
  87 void trie_addr_remove_addr(struct sockaddr_storage *addr, size_t alen)
  88 {
  89         int found = 1;
  90         struct patricia_node *n = NULL;
  91
  92         rwlock_wr_lock(&tree_lock);
  93
  94         while (found) {
  95                 ptree_get_key_addr(addr, alen, tree, &n);
  96                 if (n) {
  97                         ptree_del_entry(n->key, n->klen, &tree);
  98                         n = NULL;
  99                 } else
 100                         found = 0;
 101         }
 102
 103         rwlock_unlock(&tree_lock);
 104 }
 105
 106 void trie_init(void)
 107 {
 108         rwlock_init(&tree_lock);
 109 }
 110
 111 void trie_cleanup(void)
 112 {
 113         rwlock_wr_lock(&tree_lock);
 114         ptree_free(tree);
 115         rwlock_unlock(&tree_lock);
 116         rwlock_destroy(&tree_lock);
 117 }