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 it under
13 * the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 3 of the License, or (at your
15 * option) any later version.
17 * TrIPE is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE. If not, see <https://www.gnu.org/licenses/>.
26 /*----- Header files ------------------------------------------------------*/
30 #define AM_LOAD(n) (((n) * 3)/2)
32 /*----- Main code ---------------------------------------------------------*/
34 /* --- @am_create@ --- *
36 * Arguments: @addrmap *m@ = pointer to map
40 * Use: Create an address map, properly set up.
43 void am_create(addrmap *m)
45 hash_create(&m->t, 16);
46 m->load = AM_LOAD(m->t.mask + 1);
49 /* --- @am_destroy@ --- *
51 * Arguments: @addrmap *m@ = pointer to map
55 * Use: Destroy an address map, throwing away all the entries.
58 void am_destroy(addrmap *m)
63 for (hash_mkiter(&i, &m->t); (p = hash_next(&i)) != 0; )
70 * Arguments: @const addr *a@ = pointer to address
72 * Returns: The hash of the address.
75 static uint32 hash(const addr *a)
80 switch (a->sa.sa_family) {
82 return (U32(0x4eaac1b7ul*AF_INET +
83 0xa5dbc837ul*a->sin.sin_addr.s_addr +
84 0x3b049e83ul*a->sin.sin_port));
86 for (i = 0, h = 0; i < 16; i++)
87 h = 0x6bd26a67ul*h + a->sin6.sin6_addr.s6_addr[i];
88 return (U32(0x4eaac1b7ul*AF_INET6 +
90 0x1d94eab4ul*a->sin6.sin6_scope_id +
91 0x3b049e83ul*a->sin6.sin6_port));
99 * Arguments: @const addr *a, *b@ = pointer to addresses
101 * Returns: Nonzero if the addresses are equal.
104 static int addreq(const addr *a, const addr *b)
106 if (a->sa.sa_family != b->sa.sa_family)
108 switch (a->sa.sa_family) {
110 return (a->sin.sin_addr.s_addr == b->sin.sin_addr.s_addr &&
111 a->sin.sin_port == b->sin.sin_port);
113 return (!memcmp(a->sin6.sin6_addr.s6_addr,
114 b->sin6.sin6_addr.s6_addr, 16) &&
115 a->sin6.sin6_port == b->sin6.sin6_port);
121 /* --- @am_find@ --- *
123 * Arguments: @addrmap *m@ = pointer to map
124 * @const addr *a@ = address to look up
125 * @size_t sz@ = size of block to allocate
126 * @unsigned *f@ = where to store flags
128 * Returns: Pointer to found item, or null.
130 * Use: Finds a record with the given IP address, set @*f@ nonzero
131 * and returns it. If @sz@ is zero, and no match was found,
132 * return null; otherwise allocate a new block of @sz@ bytes,
133 * clear @*f@ to zero and return the block pointer.
136 void *am_find(addrmap *m, const addr *a, size_t sz, unsigned *f)
142 bb = HASH_BIN(&m->t, h);
143 for (b = bb; *b; b = &(*b)->next) {
144 i = (addrmap_base *)*b;
145 if (i->b.hash == h && addreq(a, &i->a)) {
156 i = x_alloc(m->t.a, sz);
164 if (!m->load && hash_extend(&m->t))
165 m->load = AM_LOAD(m->t.mask + 1);
169 /* --- @am_remove@ --- *
171 * Arguments: @addrmap *m@ = pointer to map
172 * @void *i@ = pointer to the item
176 * Use: Removes an item from the map.
179 void am_remove(addrmap *m, void *i)
181 hash_remove(&m->t, i);
185 /*----- That's all, folks -------------------------------------------------*/