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import of dnsmasq-2.37.tar.gz

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This commit is contained in:
Simon Kelley
2007-02-05 14:57:57 +00:00
parent 832af0bafb
commit 1b7ecd111d
25 changed files with 2013 additions and 1640 deletions
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50
src/cache.c
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@@ -1,4 +1,4 @@
/* dnsmasq is Copyright (c) 2000-2005 Simon Kelley
/* dnsmasq is Copyright (c) 2000-2007 Simon Kelley
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
@@ -157,9 +157,24 @@ static struct crec **hash_bucket(char *name)
static void cache_hash(struct crec *crecp)
{
struct crec **bucket = hash_bucket(cache_get_name(crecp));
crecp->hash_next = *bucket;
*bucket = crecp;
/* maintain an invariant that all entries with F_REVERSE set
are at the start of the hash-chain and all non-reverse
immortal entries are at the end of the hash-chain.
This allows reverse searches and garbage collection to be optimised */
struct crec **up = hash_bucket(cache_get_name(crecp));
if (!(crecp->flags & F_REVERSE))
{
while (*up && ((*up)->flags & F_REVERSE))
up = &((*up)->hash_next);
if (crecp->flags & F_IMMORTAL)
while (*up && (!(*up)->flags & F_IMMORTAL))
up = &((*up)->hash_next);
}
crecp->hash_next = *up;
*up = crecp;
}
static void cache_free(struct crec *crecp)
@@ -258,13 +273,18 @@ static int cache_scan_free(char *name, struct all_addr *addr, time_t now, unsign
If (flags == 0) remove any expired entries in the whole cache.
In the flags & F_FORWARD case, the return code is valid, and returns zero if the
name exists in the cache as a HOSTS or DHCP entry (these are never deleted) */
struct crec *crecp, **up;
name exists in the cache as a HOSTS or DHCP entry (these are never deleted)
We take advantage of the fact that hash chains have stuff in the order <reverse>,<other>,<immortal>
so that when we hit an entry which isn't reverse and is immortal, we're done. */
struct crec *crecp, **up;
if (flags & F_FORWARD)
{
for (up = hash_bucket(name), crecp = *up; crecp; crecp = crecp->hash_next)
for (up = hash_bucket(name), crecp = *up;
crecp && ((crecp->flags & F_REVERSE) || !(crecp->flags & F_IMMORTAL));
crecp = crecp->hash_next)
if (is_expired(now, crecp) || is_outdated_cname_pointer(crecp))
{
*up = crecp->hash_next;
@@ -296,7 +316,9 @@ static int cache_scan_free(char *name, struct all_addr *addr, time_t now, unsign
int addrlen = INADDRSZ;
#endif
for (i = 0; i < hash_size; i++)
for (crecp = hash_table[i], up = &hash_table[i]; crecp; crecp = crecp->hash_next)
for (crecp = hash_table[i], up = &hash_table[i];
crecp && ((crecp->flags & F_REVERSE) || !(crecp->flags & F_IMMORTAL));
crecp = crecp->hash_next)
if (is_expired(now, crecp))
{
*up = crecp->hash_next;
@@ -567,12 +589,16 @@ struct crec *cache_find_by_addr(struct crec *crecp, struct all_addr *addr,
else
{
/* first search, look for relevant entries and push to top of list
also free anything which has expired */
also free anything which has expired. All the reverse entries are at the
start of the hash chain, so we can give up when we find the first
non-REVERSE one. */
int i;
struct crec **up, **chainp = &ans;
for(i=0; i<hash_size; i++)
for (crecp = hash_table[i], up = &hash_table[i]; crecp; crecp = crecp->hash_next)
for (i=0; i<hash_size; i++)
for (crecp = hash_table[i], up = &hash_table[i];
crecp && (crecp->flags & F_REVERSE);
crecp = crecp->hash_next)
if (!is_expired(now, crecp))
{
if ((crecp->flags & F_REVERSE) &&