EXTRA_DIST = linux bsd solaris cygwin mingw openssl gcrypt
tincd_SOURCES = \
- utils.c getopt.c getopt1.c list.c splay_tree.c dropin.c fake-getaddrinfo.c fake-getnameinfo.c \
+ utils.c getopt.c getopt1.c list.c splay_tree.c dropin.c fake-getaddrinfo.c fake-getnameinfo.c hash.c \
buffer.c conf.c connection.c control.c edge.c graph.c logger.c meta.c net.c net_packet.c net_setup.c \
net_socket.c netutl.c node.c process.c protocol.c protocol_auth.c protocol_edge.c protocol_misc.c \
protocol_key.c protocol_subnet.c route.c sptps.c subnet.c subnet_parse.c tincd.c \
noinst_HEADERS = \
xalloc.h utils.h getopt.h list.h splay_tree.h dropin.h fake-getaddrinfo.h fake-getnameinfo.h fake-gai-errnos.h ipv6.h ipv4.h ethernet.h \
buffer.h conf.h connection.h control.h control_common.h device.h edge.h graph.h info.h logger.h meta.h net.h netutl.h node.h process.h \
- protocol.h route.h subnet.h sptps.h tincctl.h top.h bsd/tunemu.h
+ protocol.h route.h subnet.h sptps.h tincctl.h top.h bsd/tunemu.h hash.h
nodist_noinst_HEADERS = \
cipher.h crypto.h ecdh.h ecdsa.h digest.h prf.h rsa.h ecdsagen.h rsagen.h
--- /dev/null
+/*
+ hash.c -- hash table management
+ Copyright (C) 2012 Guus Sliepen <guus@tinc-vpn.org>
+
+ 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.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "system.h"
+
+#include "hash.h"
+#include "xalloc.h"
+
+/* Generic hash function */
+
+static uint32_t hash_function(const void *p, size_t len) {
+ const uint8_t *q = p;
+ uint32_t hash = 0;
+ while(len > 0) {
+ for(int i = len > 4 ? 4 : len; --i;)
+ hash += q[i] << (8 * i);
+ hash *= 0x9e370001UL; // Golden ratio prime.
+ len -= 4;
+ }
+ return hash;
+}
+
+/* Map 32 bits int onto 0..n-1, without throwing away too many bits if n is 2^8 or 2^16 */
+
+static uint32_t modulo(uint32_t hash, size_t n) {
+ if(n == 0x100)
+ return (hash >> 24) ^ ((hash >> 16) & 0xff) ^ ((hash >> 8) & 0xff) ^ (hash & 0xff);
+ else if(n == 0x10000)
+ return (hash >> 16) ^ (hash & 0xffff);
+ else
+ return hash % n;
+}
+
+/* (De)allocation */
+
+hash_t *hash_alloc(size_t n, size_t size) {
+ hash_t *hash = xmalloc_and_zero(sizeof *hash);
+ hash->n = n;
+ hash->size = size;
+ hash->keys = xmalloc(hash->n * hash->size);
+ hash->values = xmalloc_and_zero(hash->n * sizeof *hash->values);
+ return hash;
+}
+
+void hash_free(hash_t *hash) {
+ free(hash->keys);
+ free(hash->values);
+ free(hash);
+}
+
+/* Searching and inserting */
+
+void hash_insert(hash_t *hash, const void *key, const void *value) {
+ uint32_t i = modulo(hash_function(key, hash->size), hash->n);
+ memcpy(hash->keys + i * hash->size, key, hash->size);
+ hash->values[i] = value;
+}
+
+void *hash_search(const hash_t *hash, const void *key) {
+ uint32_t i = modulo(hash_function(key, hash->size), hash->n);
+ if(hash->values[i] && !memcmp(key, hash->keys + i * hash->size, hash->size)) {
+ return (void *)hash->values[i];
+ }
+ return NULL;
+}
+
+void *hash_search_or_insert(hash_t *hash, const void *key, const void *value) {
+ uint32_t i = modulo(hash_function(key, hash->size), hash->n);
+ if(hash->values[i] && !memcmp(key, hash->keys + i * hash->size, hash->size))
+ return (void *)hash->values[i];
+ memcpy(hash->keys + i * hash->size, key, hash->size);
+ hash->values[i] = value;
+ return NULL;
+}
+
+/* Utility functions */
+
+void hash_clear(hash_t *hash) {
+ memset(hash->values, 0, hash->n * sizeof *hash->values);
+}
+
+void hash_resize(hash_t *hash, size_t n) {
+ hash->keys = xrealloc(hash->keys, n * hash->size);
+ hash->values = xrealloc(hash->values, n * sizeof *hash->values);
+ if(n > hash->n)
+ memset(hash->values + hash->n, 0, (n - hash->n) * sizeof *hash->values);
+}
--- /dev/null
+/*
+ hash.h -- header file for hash.c
+ Copyright (C) 2012 Guus Sliepen <guus@tinc-vpn.org>
+
+ 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.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifndef __TINC_HASH_H__
+#define __TINC_HASH_H__
+
+typedef struct hash_t {
+ size_t n;
+ size_t size;
+ char *keys;
+ const void **values;
+} hash_t;
+
+extern hash_t *hash_alloc(size_t n, size_t size) __attribute__ ((__malloc__));
+extern void hash_free(hash_t *);
+
+extern void hash_insert(hash_t *, const void *key, const void *value);
+
+extern void *hash_search(const hash_t *, const void *key);
+extern void *hash_search_or_insert(hash_t *, const void *key, const void *value);
+
+extern void hash_clear(hash_t *);
+extern void hash_resize(hash_t *, size_t n);
+
+#endif /* __TINC_HASH_H__ */
projects / meshlink / commitdiff