summaryrefslogtreecommitdiff
path: root/src/openvpn/list.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/openvpn/list.c')
-rw-r--r--src/openvpn/list.c649
1 files changed, 649 insertions, 0 deletions
diff --git a/src/openvpn/list.c b/src/openvpn/list.c
new file mode 100644
index 0000000..ea6bd74
--- /dev/null
+++ b/src/openvpn/list.c
@@ -0,0 +1,649 @@
+/*
+ * OpenVPN -- An application to securely tunnel IP networks
+ * over a single TCP/UDP port, with support for SSL/TLS-based
+ * session authentication and key exchange,
+ * packet encryption, packet authentication, and
+ * packet compression.
+ *
+ * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * 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 (see the file COPYING included with this
+ * distribution); if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if P2MP_SERVER
+
+#include "list.h"
+#include "misc.h"
+
+#include "memdbg.h"
+
+struct hash *
+hash_init (const int n_buckets,
+ const uint32_t iv,
+ uint32_t (*hash_function)(const void *key, uint32_t iv),
+ bool (*compare_function)(const void *key1, const void *key2))
+{
+ struct hash *h;
+ int i;
+
+ ASSERT (n_buckets > 0);
+ ALLOC_OBJ_CLEAR (h, struct hash);
+ h->n_buckets = (int) adjust_power_of_2 (n_buckets);
+ h->mask = h->n_buckets - 1;
+ h->hash_function = hash_function;
+ h->compare_function = compare_function;
+ h->iv = iv;
+ ALLOC_ARRAY (h->buckets, struct hash_bucket, h->n_buckets);
+ for (i = 0; i < h->n_buckets; ++i)
+ {
+ struct hash_bucket *b = &h->buckets[i];
+ b->list = NULL;
+ }
+ return h;
+}
+
+void
+hash_free (struct hash *hash)
+{
+ int i;
+ for (i = 0; i < hash->n_buckets; ++i)
+ {
+ struct hash_bucket *b = &hash->buckets[i];
+ struct hash_element *he = b->list;
+
+ while (he)
+ {
+ struct hash_element *next = he->next;
+ free (he);
+ he = next;
+ }
+ }
+ free (hash->buckets);
+ free (hash);
+}
+
+struct hash_element *
+hash_lookup_fast (struct hash *hash,
+ struct hash_bucket *bucket,
+ const void *key,
+ uint32_t hv)
+{
+ struct hash_element *he;
+ struct hash_element *prev = NULL;
+
+ he = bucket->list;
+
+ while (he)
+ {
+ if (hv == he->hash_value && (*hash->compare_function)(key, he->key))
+ {
+ /* move to head of list */
+ if (prev)
+ {
+ prev->next = he->next;
+ he->next = bucket->list;
+ bucket->list = he;
+ }
+ return he;
+ }
+ prev = he;
+ he = he->next;
+ }
+
+ return NULL;
+}
+
+bool
+hash_remove_fast (struct hash *hash,
+ struct hash_bucket *bucket,
+ const void *key,
+ uint32_t hv)
+{
+ struct hash_element *he;
+ struct hash_element *prev = NULL;
+
+ he = bucket->list;
+
+ while (he)
+ {
+ if (hv == he->hash_value && (*hash->compare_function)(key, he->key))
+ {
+ if (prev)
+ prev->next = he->next;
+ else
+ bucket->list = he->next;
+ free (he);
+ --hash->n_elements;
+ return true;
+ }
+ prev = he;
+ he = he->next;
+ }
+ return false;
+}
+
+bool
+hash_add (struct hash *hash, const void *key, void *value, bool replace)
+{
+ uint32_t hv;
+ struct hash_bucket *bucket;
+ struct hash_element *he;
+ bool ret = false;
+
+ hv = hash_value (hash, key);
+ bucket = &hash->buckets[hv & hash->mask];
+
+ if ((he = hash_lookup_fast (hash, bucket, key, hv))) /* already exists? */
+ {
+ if (replace)
+ {
+ he->value = value;
+ ret = true;
+ }
+ }
+ else
+ {
+ hash_add_fast (hash, bucket, key, hv, value);
+ ret = true;
+ }
+
+ return ret;
+}
+
+void
+hash_remove_by_value (struct hash *hash, void *value)
+{
+ struct hash_iterator hi;
+ struct hash_element *he;
+
+ hash_iterator_init (hash, &hi);
+ while ((he = hash_iterator_next (&hi)))
+ {
+ if (he->value == value)
+ hash_iterator_delete_element (&hi);
+ }
+ hash_iterator_free (&hi);
+}
+
+static void
+hash_remove_marked (struct hash *hash, struct hash_bucket *bucket)
+{
+ struct hash_element *prev = NULL;
+ struct hash_element *he = bucket->list;
+
+ while (he)
+ {
+ if (!he->key) /* marked? */
+ {
+ struct hash_element *newhe;
+ if (prev)
+ newhe = prev->next = he->next;
+ else
+ newhe = bucket->list = he->next;
+ free (he);
+ --hash->n_elements;
+ he = newhe;
+ }
+ else
+ {
+ prev = he;
+ he = he->next;
+ }
+ }
+}
+
+uint32_t
+void_ptr_hash_function (const void *key, uint32_t iv)
+{
+ return hash_func ((const void *)&key, sizeof (key), iv);
+}
+
+bool
+void_ptr_compare_function (const void *key1, const void *key2)
+{
+ return key1 == key2;
+}
+
+void
+hash_iterator_init_range (struct hash *hash,
+ struct hash_iterator *hi,
+ int start_bucket,
+ int end_bucket)
+{
+ if (end_bucket > hash->n_buckets)
+ end_bucket = hash->n_buckets;
+
+ ASSERT (start_bucket >= 0 && start_bucket <= end_bucket);
+
+ hi->hash = hash;
+ hi->elem = NULL;
+ hi->bucket = NULL;
+ hi->last = NULL;
+ hi->bucket_marked = false;
+ hi->bucket_index_start = start_bucket;
+ hi->bucket_index_end = end_bucket;
+ hi->bucket_index = hi->bucket_index_start - 1;
+}
+
+void
+hash_iterator_init (struct hash *hash,
+ struct hash_iterator *hi)
+{
+ hash_iterator_init_range (hash, hi, 0, hash->n_buckets);
+}
+
+static inline void
+hash_iterator_lock (struct hash_iterator *hi, struct hash_bucket *b)
+{
+ hi->bucket = b;
+ hi->last = NULL;
+ hi->bucket_marked = false;
+}
+
+static inline void
+hash_iterator_unlock (struct hash_iterator *hi)
+{
+ if (hi->bucket)
+ {
+ if (hi->bucket_marked)
+ {
+ hash_remove_marked (hi->hash, hi->bucket);
+ hi->bucket_marked = false;
+ }
+ hi->bucket = NULL;
+ hi->last = NULL;
+ }
+}
+
+static inline void
+hash_iterator_advance (struct hash_iterator *hi)
+{
+ hi->last = hi->elem;
+ hi->elem = hi->elem->next;
+}
+
+void
+hash_iterator_free (struct hash_iterator *hi)
+{
+ hash_iterator_unlock (hi);
+}
+
+struct hash_element *
+hash_iterator_next (struct hash_iterator *hi)
+{
+ struct hash_element *ret = NULL;
+ if (hi->elem)
+ {
+ ret = hi->elem;
+ hash_iterator_advance (hi);
+ }
+ else
+ {
+ while (++hi->bucket_index < hi->bucket_index_end)
+ {
+ struct hash_bucket *b;
+ hash_iterator_unlock (hi);
+ b = &hi->hash->buckets[hi->bucket_index];
+ if (b->list)
+ {
+ hash_iterator_lock (hi, b);
+ hi->elem = b->list;
+ if (hi->elem)
+ {
+ ret = hi->elem;
+ hash_iterator_advance (hi);
+ break;
+ }
+ }
+ }
+ }
+ return ret;
+}
+
+void
+hash_iterator_delete_element (struct hash_iterator *hi)
+{
+ ASSERT (hi->last);
+ hi->last->key = NULL;
+ hi->bucket_marked = true;
+}
+
+
+#ifdef LIST_TEST
+
+/*
+ * Test the hash code by implementing a simple
+ * word frequency algorithm.
+ */
+
+struct word
+{
+ const char *word;
+ int n;
+};
+
+static uint32_t
+word_hash_function (const void *key, uint32_t iv)
+{
+ const char *str = (const char *) key;
+ const int len = strlen (str);
+ return hash_func ((const uint8_t *)str, len, iv);
+}
+
+static bool
+word_compare_function (const void *key1, const void *key2)
+{
+ return strcmp ((const char *)key1, (const char *)key2) == 0;
+}
+
+static void
+print_nhash (struct hash *hash)
+{
+ struct hash_iterator hi;
+ struct hash_element *he;
+ int count = 0;
+
+ hash_iterator_init (hash, &hi, true);
+
+ while ((he = hash_iterator_next (&hi)))
+ {
+ printf ("%d ", (int) he->value);
+ ++count;
+ }
+ printf ("\n");
+
+ hash_iterator_free (&hi);
+ ASSERT (count == hash_n_elements (hash));
+}
+
+static void
+rmhash (struct hash *hash, const char *word)
+{
+ hash_remove (hash, word);
+}
+
+void
+list_test (void)
+{
+ openvpn_thread_init ();
+
+ {
+ struct gc_arena gc = gc_new ();
+ struct hash *hash = hash_init (10000, get_random (), word_hash_function, word_compare_function);
+ struct hash *nhash = hash_init (256, get_random (), word_hash_function, word_compare_function);
+
+ printf ("hash_init n_buckets=%d mask=0x%08x\n", hash->n_buckets, hash->mask);
+
+ /* parse words from stdin */
+ while (true)
+ {
+ char buf[256];
+ char wordbuf[256];
+ int wbi;
+ int bi;
+ char c;
+
+ if (!fgets(buf, sizeof(buf), stdin))
+ break;
+
+ bi = wbi = 0;
+ do
+ {
+ c = buf[bi++];
+ if (isalnum (c) || c == '_')
+ {
+ ASSERT (wbi < (int) sizeof (wordbuf));
+ wordbuf[wbi++] = c;
+ }
+ else
+ {
+ if (wbi)
+ {
+ struct word *w;
+ ASSERT (wbi < (int) sizeof (wordbuf));
+ wordbuf[wbi++] = '\0';
+
+ /* word is parsed from stdin */
+
+ /* does it already exist in table? */
+ w = (struct word *) hash_lookup (hash, wordbuf);
+
+ if (w)
+ {
+ /* yes, increment count */
+ ++w->n;
+ }
+ else
+ {
+ /* no, make a new object */
+ ALLOC_OBJ_GC (w, struct word, &gc);
+ w->word = string_alloc (wordbuf, &gc);
+ w->n = 1;
+ ASSERT (hash_add (hash, w->word, w, false));
+ ASSERT (hash_add (nhash, w->word, (void*) ((random() & 0x0F) + 1), false));
+ }
+ }
+ wbi = 0;
+ }
+ } while (c);
+ }
+
+#if 1
+ /* remove some words from the table */
+ {
+ rmhash (hash, "true");
+ rmhash (hash, "false");
+ }
+#endif
+
+ /* output contents of hash table */
+ {
+ int base;
+ int inc = 0;
+ int count = 0;
+
+ for (base = 0; base < hash_n_buckets (hash); base += inc) {
+ struct hash_iterator hi;
+ struct hash_element *he;
+ inc = (get_random () % 3) + 1;
+ hash_iterator_init_range (hash, &hi, true, base, base + inc);
+
+ while ((he = hash_iterator_next (&hi)))
+ {
+ struct word *w = (struct word *) he->value;
+ printf ("%6d '%s'\n", w->n, w->word);
+ ++count;
+ }
+
+ hash_iterator_free (&hi);
+ }
+ ASSERT (count == hash_n_elements (hash));
+ }
+
+#if 1
+ /* test hash_remove_by_value function */
+ {
+ int i;
+ for (i = 1; i <= 16; ++i)
+ {
+ printf ("[%d] ***********************************\n", i);
+ print_nhash (nhash);
+ hash_remove_by_value (nhash, (void *) i, true);
+ }
+ printf ("FINAL **************************\n");
+ print_nhash (nhash);
+ }
+#endif
+
+ hash_free (hash);
+ hash_free (nhash);
+ gc_free (&gc);
+ }
+
+ openvpn_thread_cleanup ();
+}
+
+#endif
+
+/*
+--------------------------------------------------------------------
+hash() -- hash a variable-length key into a 32-bit value
+ k : the key (the unaligned variable-length array of bytes)
+ len : the length of the key, counting by bytes
+ level : can be any 4-byte value
+Returns a 32-bit value. Every bit of the key affects every bit of
+the return value. Every 1-bit and 2-bit delta achieves avalanche.
+About 36+6len instructions.
+
+The best hash table sizes are powers of 2. There is no need to do
+mod a prime (mod is sooo slow!). If you need less than 32 bits,
+use a bitmask. For example, if you need only 10 bits, do
+ h = (h & hashmask(10));
+In which case, the hash table should have hashsize(10) elements.
+
+If you are hashing n strings (uint8_t **)k, do it like this:
+ for (i=0, h=0; i<n; ++i) h = hash( k[i], len[i], h);
+
+By Bob Jenkins, 1996. bob_jenkins@burtleburtle.net. You may use this
+code any way you wish, private, educational, or commercial. It's free.
+
+See http://burlteburtle.net/bob/hash/evahash.html
+Use for hash table lookup, or anything where one collision in 2^32 is
+acceptable. Do NOT use for cryptographic purposes.
+
+--------------------------------------------------------------------
+
+mix -- mix 3 32-bit values reversibly.
+For every delta with one or two bit set, and the deltas of all three
+ high bits or all three low bits, whether the original value of a,b,c
+ is almost all zero or is uniformly distributed,
+* If mix() is run forward or backward, at least 32 bits in a,b,c
+ have at least 1/4 probability of changing.
+* If mix() is run forward, every bit of c will change between 1/3 and
+ 2/3 of the time. (Well, 22/100 and 78/100 for some 2-bit deltas.)
+mix() was built out of 36 single-cycle latency instructions in a
+ structure that could supported 2x parallelism, like so:
+ a -= b;
+ a -= c; x = (c>>13);
+ b -= c; a ^= x;
+ b -= a; x = (a<<8);
+ c -= a; b ^= x;
+ c -= b; x = (b>>13);
+ ...
+ Unfortunately, superscalar Pentiums and Sparcs can't take advantage
+ of that parallelism. They've also turned some of those single-cycle
+ latency instructions into multi-cycle latency instructions. Still,
+ this is the fastest good hash I could find. There were about 2^^68
+ to choose from. I only looked at a billion or so.
+
+James Yonan Notes:
+
+* This function is faster than it looks, and appears to be
+ appropriate for our usage in OpenVPN which is primarily
+ for hash-table based address lookup (IPv4, IPv6, and Ethernet MAC).
+ NOTE: This function is never used for cryptographic purposes, only
+ to produce evenly-distributed indexes into hash tables.
+
+* Benchmark results: 11.39 machine cycles per byte on a P2 266Mhz,
+ and 12.1 machine cycles per byte on a
+ 2.2 Ghz P4 when hashing a 6 byte string.
+--------------------------------------------------------------------
+*/
+
+#define mix(a,b,c) \
+{ \
+ a -= b; a -= c; a ^= (c>>13); \
+ b -= c; b -= a; b ^= (a<<8); \
+ c -= a; c -= b; c ^= (b>>13); \
+ a -= b; a -= c; a ^= (c>>12); \
+ b -= c; b -= a; b ^= (a<<16); \
+ c -= a; c -= b; c ^= (b>>5); \
+ a -= b; a -= c; a ^= (c>>3); \
+ b -= c; b -= a; b ^= (a<<10); \
+ c -= a; c -= b; c ^= (b>>15); \
+}
+
+uint32_t
+hash_func (const uint8_t *k, uint32_t length, uint32_t initval)
+{
+ uint32_t a, b, c, len;
+
+ /* Set up the internal state */
+ len = length;
+ a = b = 0x9e3779b9; /* the golden ratio; an arbitrary value */
+ c = initval; /* the previous hash value */
+
+ /*---------------------------------------- handle most of the key */
+ while (len >= 12)
+ {
+ a += (k[0] + ((uint32_t) k[1] << 8)
+ + ((uint32_t) k[2] << 16)
+ + ((uint32_t) k[3] << 24));
+ b += (k[4] + ((uint32_t) k[5] << 8)
+ + ((uint32_t) k[6] << 16)
+ + ((uint32_t) k[7] << 24));
+ c += (k[8] + ((uint32_t) k[9] << 8)
+ + ((uint32_t) k[10] << 16)
+ + ((uint32_t) k[11] << 24));
+ mix (a, b, c);
+ k += 12;
+ len -= 12;
+ }
+
+ /*------------------------------------- handle the last 11 bytes */
+ c += length;
+ switch (len) /* all the case statements fall through */
+ {
+ case 11:
+ c += ((uint32_t) k[10] << 24);
+ case 10:
+ c += ((uint32_t) k[9] << 16);
+ case 9:
+ c += ((uint32_t) k[8] << 8);
+ /* the first byte of c is reserved for the length */
+ case 8:
+ b += ((uint32_t) k[7] << 24);
+ case 7:
+ b += ((uint32_t) k[6] << 16);
+ case 6:
+ b += ((uint32_t) k[5] << 8);
+ case 5:
+ b += k[4];
+ case 4:
+ a += ((uint32_t) k[3] << 24);
+ case 3:
+ a += ((uint32_t) k[2] << 16);
+ case 2:
+ a += ((uint32_t) k[1] << 8);
+ case 1:
+ a += k[0];
+ /* case 0: nothing left to add */
+ }
+ mix (a, b, c);
+ /*-------------------------------------- report the result */
+ return c;
+}
+
+#else
+static void dummy(void) {}
+#endif /* P2MP_SERVER */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 17:43:51 +0000