3 * Hashtables keyed by network addresses
5 * (c) 2007 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Trivial IP Encryption (TrIPE).
12 * TrIPE is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * TrIPE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 /*----- Header files ------------------------------------------------------*/
31 #define AM_LOAD(n) (((n) * 3)/2)
33 /*----- Main code ---------------------------------------------------------*/
35 /* --- @am_create@ --- *
37 * Arguments: @addrmap *m@ = pointer to map
41 * Use: Create an address map, properly set up.
44 void am_create(addrmap *m)
46 hash_create(&m->t, 16);
47 m->load = AM_LOAD(m->t.mask + 1);
50 /* --- @am_destroy@ --- *
52 * Arguments: @addrmap *m@ = pointer to map
56 * Use: Destroy an address map, throwing away all the entries.
59 void am_destroy(addrmap *m)
64 for (hash_mkiter(&i, &m->t); (p = hash_next(&i)) != 0; )
71 * Arguments: @const addr *a@ = pointer to address
73 * Returns: The hash of the address.
76 uint32 hash(const addr *a)
78 switch (a->sa.sa_family) {
80 return (U32((AF_INET * 0x4eaac1b7ul) +
81 (a->sin.sin_addr.s_addr * 0xa5dbc837) +
82 (a->sin.sin_port * 0x3b049e83)));
90 * Arguments: @const addr *a, *b@ = pointer to addresses
92 * Returns: Nonzero if the addresses are equal.
95 int addreq(const addr *a, const addr *b)
97 if (a->sa.sa_family != b->sa.sa_family)
99 switch (a->sa.sa_family) {
101 return (a->sin.sin_addr.s_addr == b->sin.sin_addr.s_addr &&
102 a->sin.sin_port == b->sin.sin_port);
108 /* --- @am_find@ --- *
110 * Arguments: @addrmap *m@ = pointer to map
111 * @const addr *a@ = address to look up
112 * @size_t sz@ = size of block to allocate
113 * @unsigned *f@ = where to store flags
115 * Returns: Pointer to found item, or null.
117 * Use: Finds a record with the given IP address, set @*f@ nonzero
118 * and returns it. If @sz@ is zero, and no match was found,
119 * return null; otherwise allocate a new block of @sz@ bytes,
120 * clear @*f@ to zero and return the block pointer.
123 void *am_find(addrmap *m, const addr *a, size_t sz, unsigned *f)
129 bb = HASH_BIN(&m->t, h);
130 for (b = bb; *b; b = &(*b)->next) {
131 i = (addrmap_base *)*b;
132 if (i->b.hash == h && addreq(a, &i->a)) {
143 i = x_alloc(m->t.a, sz);
151 if (!m->load && hash_extend(&m->t))
152 m->load = AM_LOAD(m->t.mask + 1);
156 /* --- @am_remove@ --- *
158 * Arguments: @addrmap *m@ = pointer to map
159 * @void *i@ = pointer to the item
163 * Use: Removes an item from the map.
166 void am_remove(addrmap *m, void *i)
168 hash_remove(&m->t, i);
172 /*----- That's all, folks -------------------------------------------------*/