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Revert "dns cache per interface iteration 2"

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This reverts commit f1464ff956

Change-Id: I3496b9a8cb54614fe3eea016d1391c8a89f3db38
This commit is contained in:
Robert Greenwalt
2013-01-19 00:40:24 +00:00
committed by Android (Google) Code Review
parent f1464ff956
commit b002a2ff77
13 changed files with 258 additions and 574 deletions
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342
libc/netbsd/resolv/res_cache.c
View File

@@ -43,7 +43,6 @@
#include <arpa/inet.h>
#include "resolv_private.h"
#include "resolv_iface.h"
#include "res_private.h"
/* This code implements a small and *simple* DNS resolver cache.
*
@@ -1250,16 +1249,9 @@ typedef struct resolv_cache_info {
struct resolv_cache_info* next;
char* nameservers[MAXNS +1];
struct addrinfo* nsaddrinfo[MAXNS + 1];
char defdname[256];
int dnsrch_offset[MAXDNSRCH+1]; // offsets into defdname
char* domains;
} CacheInfo;
typedef struct resolv_pidiface_info {
int pid;
char ifname[IF_NAMESIZE + 1];
struct resolv_pidiface_info* next;
} PidIfaceInfo;
#define HTABLE_VALID(x) ((x) != NULL && (x) != HTABLE_DELETED)
static void
@@ -1312,7 +1304,6 @@ _cache_check_pending_request_locked( struct resolv_cache* cache, Entry* key )
}
} else {
struct timespec ts = {0,0};
XLOG("Waiting for previous request");
ts.tv_sec = _time_now() + PENDING_REQUEST_TIMEOUT;
pthread_cond_timedwait(&ri->cond, &cache->lock, &ts);
}
@@ -1408,8 +1399,9 @@ _res_cache_get_max_entries( void )
if (cache_mode == NULL || strcmp(cache_mode, "local") != 0) {
// Don't use the cache in local mode. This is used by the
// proxy itself.
XLOG("setup cache for non-cache process. size=0, %s", cache_mode);
return 0;
// TODO - change this to 0 when all dns stuff uses proxy (5918973)
XLOG("setup cache for non-cache process. size=1");
return 1;
}
if (__system_property_get(DNS_CACHE_SIZE_PROP_NAME, cache_size) > 0) {
@@ -1548,7 +1540,7 @@ _cache_lookup_p( Cache* cache,
pnode = &node->hlink;
}
return pnode;
return pnode;
}
/* Add a new entry to the hash table. 'lookup' must be the
@@ -1789,28 +1781,20 @@ Exit:
/****************************************************************************/
/****************************************************************************/
static pthread_once_t _res_cache_once = PTHREAD_ONCE_INIT;
static pthread_once_t _res_cache_once;
// Head of the list of caches. Protected by _res_cache_list_lock.
static struct resolv_cache_info _res_cache_list;
// List of pid iface pairs
static struct resolv_pidiface_info _res_pidiface_list;
// name of the current default inteface
static char _res_default_ifname[IF_NAMESIZE + 1];
// lock protecting everything in the _resolve_cache_info structs (next ptr, etc)
static pthread_mutex_t _res_cache_list_lock;
// lock protecting the _res_pid_iface_list
static pthread_mutex_t _res_pidiface_list_lock;
/* lookup the default interface name */
static char *_get_default_iface_locked();
/* find the first cache that has an associated interface and return the name of the interface */
static char* _find_any_iface_name_locked( void );
/* insert resolv_cache_info into the list of resolv_cache_infos */
static void _insert_cache_info_locked(struct resolv_cache_info* cache_info);
/* creates a resolv_cache_info */
@@ -1831,14 +1815,8 @@ static int _get_nameserver_locked(const char* ifname, int n, char* addr, int add
static struct addrinfo* _get_nameserver_addr_locked(const char* ifname, int n);
/* lookup the inteface's address */
static struct in_addr* _get_addr_locked(const char * ifname);
/* return 1 if the provided list of name servers differs from the list of name servers
* currently attached to the provided cache_info */
static int _resolv_is_nameservers_equal_locked(struct resolv_cache_info* cache_info,
char** servers, int numservers);
/* remove a resolv_pidiface_info structure from _res_pidiface_list */
static void _remove_pidiface_info_locked(int pid);
/* get a resolv_pidiface_info structure from _res_pidiface_list with a certain pid */
static struct resolv_pidiface_info* _get_pid_iface_info_locked(int pid);
static void
_res_cache_init(void)
@@ -1852,36 +1830,37 @@ _res_cache_init(void)
memset(&_res_default_ifname, 0, sizeof(_res_default_ifname));
memset(&_res_cache_list, 0, sizeof(_res_cache_list));
memset(&_res_pidiface_list, 0, sizeof(_res_pidiface_list));
pthread_mutex_init(&_res_cache_list_lock, NULL);
pthread_mutex_init(&_res_pidiface_list_lock, NULL);
}
struct resolv_cache*
__get_res_cache(const char* ifname)
__get_res_cache(void)
{
struct resolv_cache *cache;
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_cache_list_lock);
char* iface;
if (ifname == NULL || ifname[0] == '\0') {
iface = _get_default_iface_locked();
if (iface[0] == '\0') {
char* tmp = _find_any_iface_name_locked();
if (tmp) {
iface = tmp;
}
}
} else {
iface = (char *) ifname;
}
char* ifname = _get_default_iface_locked();
cache = _get_res_cache_for_iface_locked(iface);
// if default interface not set then use the first cache
// associated with an interface as the default one.
if (ifname[0] == '\0') {
struct resolv_cache_info* cache_info = _res_cache_list.next;
while (cache_info) {
if (cache_info->ifname[0] != '\0') {
ifname = cache_info->ifname;
break;
}
cache_info = cache_info->next;
}
}
cache = _get_res_cache_for_iface_locked(ifname);
pthread_mutex_unlock(&_res_cache_list_lock);
XLOG("_get_res_cache: iface = %s, cache=%p\n", iface, cache);
XLOG("_get_res_cache. default_ifname = %s\n", ifname);
return cache;
}
@@ -2037,29 +2016,11 @@ _find_cache_info_locked(const char* ifname)
static char*
_get_default_iface_locked(void)
{
char* iface = _res_default_ifname;
return iface;
}
static char*
_find_any_iface_name_locked( void ) {
char* ifname = NULL;
struct resolv_cache_info* cache_info = _res_cache_list.next;
while (cache_info) {
if (cache_info->ifname[0] != '\0') {
ifname = cache_info->ifname;
break;
}
cache_info = cache_info->next;
}
return ifname;
}
void
_resolv_set_default_iface(const char* ifname)
{
@@ -2083,19 +2044,16 @@ _resolv_set_nameservers_for_iface(const char* ifname, char** servers, int numser
int i, rt, index;
struct addrinfo hints;
char sbuf[NI_MAXSERV];
register char *cp;
int *offset;
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_cache_list_lock);
pthread_mutex_lock(&_res_cache_list_lock);
// creates the cache if not created
_get_res_cache_for_iface_locked(ifname);
struct resolv_cache_info* cache_info = _find_cache_info_locked(ifname);
if (cache_info != NULL &&
!_resolv_is_nameservers_equal_locked(cache_info, servers, numservers)) {
if (cache_info != NULL) {
// free current before adding new
_free_nameservers_locked(cache_info);
@@ -2111,68 +2069,15 @@ _resolv_set_nameservers_for_iface(const char* ifname, char** servers, int numser
if (rt == 0) {
cache_info->nameservers[index] = strdup(servers[i]);
index++;
XLOG("_resolv_set_nameservers_for_iface: iface = %s, addr = %s\n",
ifname, servers[i]);
} else {
cache_info->nsaddrinfo[index] = NULL;
}
}
// code moved from res_init.c, load_domain_search_list
strlcpy(cache_info->defdname, domains, sizeof(cache_info->defdname));
if ((cp = strchr(cache_info->defdname, '\n')) != NULL)
*cp = '\0';
cp = cache_info->defdname;
offset = cache_info->dnsrch_offset;
while (offset < cache_info->dnsrch_offset + MAXDNSRCH) {
while (*cp == ' ' || *cp == '\t') /* skip leading white space */
cp++;
if (*cp == '\0') /* stop if nothing more to do */
break;
*offset++ = cp - cache_info->defdname; /* record this search domain */
while (*cp) { /* zero-terminate it */
if (*cp == ' '|| *cp == '\t') {
*cp++ = '\0';
break;
}
cp++;
}
}
*offset = -1; /* cache_info->dnsrch_offset has MAXDNSRCH+1 items */
// flush cache since new settings
_flush_cache_for_iface_locked(ifname);
cache_info->domains = strdup(domains);
}
pthread_mutex_unlock(&_res_cache_list_lock);
}
static int
_resolv_is_nameservers_equal_locked(struct resolv_cache_info* cache_info,
char** servers, int numservers)
{
int i;
char** ns;
int equal = 1;
// compare each name server against current name servers
if (numservers > MAXNS) numservers = MAXNS;
for (i = 0; i < numservers && equal; i++) {
ns = cache_info->nameservers;
equal = 0;
while(*ns) {
if (strcmp(*ns, servers[i]) == 0) {
equal = 1;
break;
}
ns++;
}
}
return equal;
}
static void
_free_nameservers_locked(struct resolv_cache_info* cache_info)
{
@@ -2315,192 +2220,3 @@ _get_addr_locked(const char * ifname)
}
return NULL;
}
static void
_remove_pidiface_info_locked(int pid) {
struct resolv_pidiface_info* result = &_res_pidiface_list;
struct resolv_pidiface_info* prev = NULL;
while (result != NULL && result->pid != pid) {
prev = result;
result = result->next;
}
if (prev != NULL && result != NULL) {
prev->next = result->next;
free(result);
}
}
static struct resolv_pidiface_info*
_get_pid_iface_info_locked(int pid)
{
struct resolv_pidiface_info* result = &_res_pidiface_list;
while (result != NULL && result->pid != pid) {
result = result->next;
}
return result;
}
void
_resolv_set_iface_for_pid(const char* ifname, int pid)
{
// make sure the pid iface list is created
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_pidiface_list_lock);
struct resolv_pidiface_info* pidiface_info = _get_pid_iface_info_locked(pid);
if (!pidiface_info) {
pidiface_info = calloc(sizeof(*pidiface_info), 1);
if (pidiface_info) {
pidiface_info->pid = pid;
int len = sizeof(pidiface_info->ifname);
strncpy(pidiface_info->ifname, ifname, len - 1);
pidiface_info->ifname[len - 1] = '\0';
pidiface_info->next = _res_pidiface_list.next;
_res_pidiface_list.next = pidiface_info;
XLOG("_resolv_set_iface_for_pid: pid %d , iface %s\n", pid, ifname);
} else {
XLOG("_resolv_set_iface_for_pid failing calloc");
}
}
pthread_mutex_unlock(&_res_pidiface_list_lock);
}
void
_resolv_clear_iface_for_pid(int pid)
{
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_pidiface_list_lock);
_remove_pidiface_info_locked(pid);
XLOG("_resolv_clear_iface_for_pid: pid %d\n", pid);
pthread_mutex_unlock(&_res_pidiface_list_lock);
}
int
_resolv_get_pids_associated_interface(int pid, char* buff, int buffLen)
{
int len = 0;
if (!buff) {
return -1;
}
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_pidiface_list_lock);
struct resolv_pidiface_info* pidiface_info = _get_pid_iface_info_locked(pid);
buff[0] = '\0';
if (pidiface_info) {
len = strlen(pidiface_info->ifname);
if (len < buffLen) {
strncpy(buff, pidiface_info->ifname, len);
buff[len] = '\0';
}
}
XLOG("_resolv_get_pids_associated_interface buff: %s\n", buff);
pthread_mutex_unlock(&_res_pidiface_list_lock);
return len;
}
int
_resolv_get_default_iface(char* buff, int buffLen)
{
char* ifname;
int len = 0;
if (!buff || buffLen == 0) {
return -1;
}
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_cache_list_lock);
ifname = _get_default_iface_locked();
// if default interface not set. Get first cache with an interface
if (ifname[0] == '\0') {
ifname = _find_any_iface_name_locked();
}
if (ifname) {
len = strlen(ifname);
if (len < buffLen) {
strncpy(buff, ifname, len);
buff[len] = '\0';
}
} else {
buff[0] = '\0';
}
pthread_mutex_unlock(&_res_cache_list_lock);
return len;
}
int
_resolv_populate_res_for_iface(res_state statp)
{
int nserv;
struct resolv_cache_info* info = NULL;
if (statp) {
struct addrinfo* ai;
if (statp->iface[0] == '\0') { // no interface set assign default
_resolv_get_default_iface(statp->iface, sizeof(statp->iface));
}
pthread_once(&_res_cache_once, _res_cache_init);
pthread_mutex_lock(&_res_cache_list_lock);
info = _find_cache_info_locked(statp->iface);
if (info == NULL) return 0;
XLOG("_resolv_populate_res_for_iface: %s\n", statp->iface);
for (nserv = 0; nserv < MAXNS; nserv++) {
ai = info->nsaddrinfo[nserv];
if (ai == NULL) {
break;
}
if ((size_t) ai->ai_addrlen <= sizeof(statp->_u._ext.ext->nsaddrs[0])) {
if (statp->_u._ext.ext != NULL) {
memcpy(&statp->_u._ext.ext->nsaddrs[nserv], ai->ai_addr, ai->ai_addrlen);
statp->nsaddr_list[nserv].sin_family = AF_UNSPEC;
} else {
if ((size_t) ai->ai_addrlen
<= sizeof(statp->nsaddr_list[0])) {
memcpy(&statp->nsaddr_list[nserv], ai->ai_addr,
ai->ai_addrlen);
} else {
statp->nsaddr_list[nserv].sin_family = AF_UNSPEC;
}
}
} else {
XLOG("_resolv_populate_res_for_iface found too long addrlen");
}
}
statp->nscount = nserv;
// now do search domains. Note that we cache the offsets as this code runs alot
// but the setting/offset-computer only runs when set/changed
strlcpy(statp->defdname, info->defdname, sizeof(statp->defdname));
register char **pp = statp->dnsrch;
register int *p = info->dnsrch_offset;
while (pp < statp->dnsrch + MAXDNSRCH && *p != -1) {
*pp++ = &statp->defdname + *p++;
}
pthread_mutex_unlock(&_res_cache_list_lock);
}
return nserv;
}

6
libc/netbsd/resolv/res_data.c
View File

@@ -82,7 +82,13 @@ extern struct __res_state _nres;
int res_ourserver_p(const res_state, const struct sockaddr *);
#ifdef ANDROID_CHANGES
static int res_need_init() {
return ((_nres.options & RES_INIT) == 0U) || res_get_dns_changed();
}
#else
#define res_need_init() ((_nres.options & RES_INIT) == 0U)
#endif
int
res_init(void) {

149
libc/netbsd/resolv/res_init.c
View File

@@ -111,6 +111,13 @@ __RCSID("$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $");
/* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
#ifdef ANDROID_CHANGES
#include "resolv_private.h"
#define MAX_DNS_PROPERTIES 8
#define DNS_PROP_NAME_PREFIX "net.dns"
#define DNS_CHANGE_PROP_NAME "net.dnschange"
#define DNS_SEARCH_PROP_NAME "net.dns.search"
static const prop_info *dns_change_prop;
static int dns_last_change_counter;
static int _get_dns_change_count();
#else
#include <resolv.h>
#endif
@@ -164,6 +171,41 @@ res_ninit(res_state statp) {
return (__res_vinit(statp, 0));
}
#ifdef ANDROID_CHANGES
static int load_domain_search_list(res_state statp) {
char propvalue[PROP_VALUE_MAX];
register char *cp, **pp;
if(__system_property_get(DNS_SEARCH_PROP_NAME, propvalue) >= 1) {
strlcpy(statp->defdname, propvalue, sizeof(statp->defdname));
if ((cp = strchr(statp->defdname, '\n')) != NULL)
*cp = '\0';
cp = statp->defdname;
pp = statp->dnsrch;
while ( pp < statp->dnsrch + MAXDNSRCH ) {
while (*cp == ' ' || *cp == '\t') /* skip leading white space */
cp++;
if (*cp == '\0') /* stop if nothing more */
break;
*pp++ = cp; /* record this search domain */
while (*cp) { /* zero-terminate it */
if (*cp == ' ' || *cp == '\t') {
*cp++ = '\0';
break;
}
cp++;
}
}
*pp = NULL; /* statp->dnsrch has MAXDNSRCH+1 items */
if (pp > statp->dnsrch)
return 1;
}
statp->defdname[0] = '\0'; /* no default domain name on Android */
statp->dnsrch[0] = NULL;
return 0;
}
#endif
/* This function has to be reachable by res_data.c but not publicly. */
int
__res_vinit(res_state statp, int preinit) {
@@ -178,6 +220,12 @@ __res_vinit(res_state statp, int preinit) {
char *net;
int dots;
union res_sockaddr_union u[2];
#ifdef ANDROID_CHANGES
pid_t mypid = getpid();
int use_proc_props = 0;
int found_prop;
char dnsProperty[PROP_VALUE_MAX];
#endif
if ((statp->options & RES_INIT) != 0U)
res_ndestroy(statp);
@@ -270,8 +318,74 @@ __res_vinit(res_state statp, int preinit) {
if (nserv > 0)
statp->nscount = nserv;
#endif
#ifdef ANDROID_CHANGES /* READ FROM SYSTEM PROPERTIES */
dns_last_change_counter = _get_dns_change_count();
#ifndef ANDROID_CHANGES /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
nserv = 0;
for(n = 1; n <= MAX_DNS_PROPERTIES && nserv < MAXNS; n++) {
char propname[PROP_NAME_MAX];
char propvalue[PROP_VALUE_MAX];
struct addrinfo hints, *ai;
char sbuf[NI_MAXSERV];
const size_t minsiz = sizeof(statp->_u._ext.ext->nsaddrs[0]);
/*
* Check first for process-specific properties, and if those don't
* exist, try the generic properties.
*/
found_prop = 0;
if (n == 1 || use_proc_props) {
snprintf(propname, sizeof(propname), "%s%d.%d", DNS_PROP_NAME_PREFIX, n, mypid);
if(__system_property_get(propname, propvalue) < 1) {
if (use_proc_props) {
break;
}
} else {
found_prop = 1;
use_proc_props = 1;
}
}
if (!found_prop) {
snprintf(propname, sizeof(propname), "%s%d", DNS_PROP_NAME_PREFIX, n);
if(__system_property_get(propname, propvalue) < 1) {
break;
}
}
cp = propvalue;
while (*cp == ' ' || *cp == '\t')
cp++;
cp[strcspn(cp, ";# \t\n")] = '\0';
if ((*cp != '\0') && (*cp != '\n')) {
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM; /*dummy*/
hints.ai_flags = AI_NUMERICHOST;
sprintf(sbuf, "%u", NAMESERVER_PORT);
if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
(size_t)ai->ai_addrlen <= minsiz) {
if (statp->_u._ext.ext != NULL) {
memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
ai->ai_addr, ai->ai_addrlen);
}
if ((size_t)ai->ai_addrlen <=
sizeof(statp->nsaddr_list[nserv])) {
memcpy(&statp->nsaddr_list[nserv],
ai->ai_addr, ai->ai_addrlen);
} else {
statp->nsaddr_list[nserv].sin_family = 0;
}
freeaddrinfo(ai);
nserv++;
}
}
}
/* Add the domain search list */
havesearch = load_domain_search_list(statp);
#else /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
#define MATCH(line, name) \
(!strncmp(line, name, sizeof(name) - 1) && \
(line[sizeof(name) - 1] == ' ' || \
@@ -793,17 +907,32 @@ res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
}
#ifdef ANDROID_CHANGES
void res_setiface(res_state statp, const char* iface)
static int _get_dns_change_count()
{
if (statp != NULL) {
// set interface
if (iface && iface[0] != '\0') {
int len = sizeof(statp->iface);
strncpy(statp->iface, iface, len - 1);
statp->iface[len - 1] = '\0';
} else {
statp->iface[0] = '\0';
if (dns_change_prop == NULL) {
dns_change_prop = __system_property_find(DNS_CHANGE_PROP_NAME);
}
if (dns_change_prop != NULL) {
char propvalue[PROP_VALUE_MAX];
if (__system_property_read(dns_change_prop, NULL, propvalue) >= 1) {
return atoi(propvalue);
}
}
return -1;
}
int res_get_dns_changed()
{
int change_count;
change_count = _get_dns_change_count();
if (change_count != dns_last_change_counter) {
if (change_count != -1) {
dns_last_change_counter = change_count;
}
return 1;
} else {
return 0;
}
}
#endif /* ANDROID_CHANGES */

15
libc/netbsd/resolv/res_send.c
View File

@@ -370,13 +370,10 @@ res_nsend(res_state statp,
ResolvCacheStatus cache_status = RESOLV_CACHE_UNSUPPORTED;
#endif
#if !USE_RESOLV_CACHE
if (statp->nscount == 0) {
errno = ESRCH;
return (-1);
}
#endif
if (anssiz < HFIXEDSZ) {
errno = EINVAL;
return (-1);
@@ -388,8 +385,7 @@ res_nsend(res_state statp,
terrno = ETIMEDOUT;
#if USE_RESOLV_CACHE
// get the cache associated with the interface
cache = __get_res_cache(statp->iface);
cache = __get_res_cache();
if (cache != NULL) {
int anslen = 0;
cache_status = _resolv_cache_lookup(
@@ -398,17 +394,8 @@ res_nsend(res_state statp,
if (cache_status == RESOLV_CACHE_FOUND) {
return anslen;
} else {
// had a cache miss for a known interface, so populate the thread private
// data so the normal resolve path can do its thing
_resolv_populate_res_for_iface(statp);
}
}
if (statp->nscount == 0) {
errno = ESRCH;
return (-1);
}
#endif
/*

2
libc/netbsd/resolv/res_state.c
View File

@@ -50,7 +50,7 @@
#endif
static pthread_key_t _res_key;
static pthread_once_t _res_once = PTHREAD_ONCE_INIT;
static pthread_once_t _res_once;
typedef struct {
int _h_errno;