- read /system/etc/resolv.conf instead of /etc/resolv.conf
- - get the list of servers and the search domains for this process's
- current interface from the dns cache. This information is sent
- from the framework via cache functions.
+ - read the list of servers from system properties. the code looks for
+ 'net.dns1', 'net.dns2', etc.. Each property should contain the IP
+ address of a DNS server.
+
+ these properties are set/modified by other parts of the Android system
+ (e.g. the dhcpd daemon).
+
+ the implementation also supports per-process DNS server list, using the
+ properties 'net.dns1.<pid>', 'net.dns2.<pid>', etc... Where <pid> stands
+ for the numerical ID of the current process.
- when performing a query, use a properly randomized Query ID (instead of
a incremented one), for increased security.
void endservent(void);
void freehostent(struct hostent *);
struct hostent *gethostbyaddr(const void *, socklen_t, int);
-struct hostent *android_gethostbyaddrforiface(const void *, socklen_t, int, const char*);
int gethostbyaddr_r(const void *, int, int, struct hostent *, char *, size_t, struct hostent **, int *);
struct hostent *gethostbyname(const char *);
int gethostbyname_r(const char *, struct hostent *, char *, size_t, struct hostent **, int *);
struct hostent *gethostbyname2(const char *, int);
int gethostbyname2_r(const char *, int, struct hostent *, char *, size_t, struct hostent **, int *);
-struct hostent *android_gethostbynameforiface(const char *, int, const char *);
struct hostent *gethostent(void);
int gethostent_r(struct hostent *, char *, size_t, struct hostent **, int *);
struct hostent *getipnodebyaddr(const void *, size_t, int, int *);
void setnetent(int);
void setprotoent(int);
int getaddrinfo(const char *, const char *, const struct addrinfo *, struct addrinfo **);
-int android_getaddrinfoforiface(const char *, const char *, const struct addrinfo *, const char *, struct addrinfo **);
int getnameinfo(const struct sockaddr *, socklen_t, char *, size_t, char *, size_t, int);
-int android_getnameinfoforiface(const struct sockaddr *, socklen_t, char *, size_t, char *, size_t, int, const char *);
void freeaddrinfo(struct addrinfo *);
const char *gai_strerror(int);
void setnetgrent(const char *);
#include <sys/param.h>
#include <sys/socket.h>
-#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "arpa_nameser.h"
#include <stdio.h>
#include <strings.h>
#include <syslog.h>
-#include <unistd.h>
#ifndef LOG_AUTH
# define LOG_AUTH 0
#include <stdlib.h>
#include <string.h>
-// This should be synchronized to ResponseCode.h
-static const int DnsProxyQueryResult = 222;
-
static const char const AskedForGot[] =
"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
static int _dns_gethtbyaddr(void *, void *, va_list);
static int _dns_gethtbyname(void *, void *, va_list);
-static struct hostent *gethostbyname_internal(const char *, int, res_state, const char *);
+static struct hostent *gethostbyname_internal(const char *, int, res_state);
static const ns_src default_dns_files[] = {
{ NSSRC_FILES, NS_SUCCESS },
assert(name != NULL);
- /* try IPv6 first - if that fails do IPv4 */
if (res->options & RES_USE_INET6) {
- hp = gethostbyname_internal(name, AF_INET6, res, NULL);
+ hp = gethostbyname_internal(name, AF_INET6, res);
if (hp) {
__res_put_state(res);
return hp;
}
}
- hp = gethostbyname_internal(name, AF_INET, res, NULL);
+ hp = gethostbyname_internal(name, AF_INET, res);
__res_put_state(res);
return hp;
}
struct hostent *
gethostbyname2(const char *name, int af)
{
- return android_gethostbynameforiface(name, af, NULL);
-}
-
-struct hostent *
-android_gethostbynameforiface(const char *name, int af, const char *iface)
-{
struct hostent *hp;
res_state res = __res_get_state();
if (res == NULL)
return NULL;
- hp = gethostbyname_internal(name, af, res, iface);
+ hp = gethostbyname_internal(name, af, res);
__res_put_state(res);
return hp;
}
-static struct hostent *gethostbyname_internal_real(const char *name, int af, res_state res);
-
-// very similar in proxy-ness to android_getaddrinfo_proxy
static struct hostent *
-gethostbyname_internal(const char *name, int af, res_state res, const char *iface)
-{
- int sock;
- const int one = 1;
- struct sockaddr_un proxy_addr;
- const char *cache_mode = getenv("ANDROID_DNS_MODE");
- FILE* proxy = NULL;
-
- if (cache_mode != NULL && strcmp(cache_mode, "local") == 0) {
- res_setiface(res, iface);
- return gethostbyname_internal_real(name, af, res);
- }
-
- sock = socket(AF_UNIX, SOCK_STREAM, 0);
- if (sock < 0) {
- return NULL;
- }
-
- setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
- memset(&proxy_addr, 0, sizeof(proxy_addr));
- proxy_addr.sun_family = AF_UNIX;
- strlcpy(proxy_addr.sun_path, "/dev/socket/dnsproxyd", sizeof(proxy_addr.sun_path));
- if (TEMP_FAILURE_RETRY(connect(sock,
- (const struct sockaddr*) &proxy_addr,
- sizeof(proxy_addr))) != 0) {
- close(sock);
- return NULL;
- }
-
- proxy = fdopen(sock, "r+");
- /* This is writing to system/netd/DnsProxyListener.cpp and changes
- * here need to be matched there */
- if (fprintf(proxy, "gethostbyname %d %s %d",
- getpid(),
- iface == NULL ? "^" : iface,
- name == NULL ? "^" : name,
- af) < 0) {
- goto exit;
- }
-
- if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
- goto exit;
- }
-
- uint32_t size;
- char *buf = (char *)&size;
- if (fread(buf, 1, sizeof(size), proxy) != 1) {
- goto exit;
- }
-
- /* This is reading serialized data from system/netd/DnsProxyListener.cpp
- * and changes here need to be matched there */
- int result_code = (int)strtol(buf, NULL, 10);
- if (result_code != DnsProxyQueryResult) goto exit;
-
- if (fread(buf, 1, sizeof(size), proxy) != 1) goto exit;
- size = ntohl(size);
-
- res_static rs = __res_get_static();
- memset(&rs->host, 0, sizeof(rs->host));
- char *ptr = rs->hostbuf;
-
- if (fread(ptr, 1, size, proxy) != 1) goto exit;
- ptr += size;
- rs->host.h_name = rs->hostbuf;
-
- char **aliases = rs->host_aliases;
- rs->host.h_aliases = rs->host_aliases;
- while (1) {
- if (fread(buf, 1, sizeof(size), proxy) != 1) goto exit;
- size = ntohl(size);
- if (fread(ptr, 1, size, proxy) != 1) goto exit;
- if (size == 1) {
- *aliases = NULL;
- break;
- }
- *aliases++ = ptr;
- ptr += size;
- }
-
- if (fread(buf, 1, sizeof(size), proxy) != 1) goto exit;
- rs->host.h_addrtype = ntohl(size);
-
- if (fread(buf, 1, sizeof(size), proxy) != 1) goto exit;
- rs->host.h_length = ntohl(size);
-
- char **addrs = rs->h_addr_ptrs;
- rs->host.h_addr_list = rs->h_addr_ptrs;
- while (1) {
- if (fread(buf, 1, sizeof(size), proxy) != 1) goto exit;
- size = ntohl(size);
- if (fread(ptr, 1, size, proxy) != 1) goto exit;
- if (size == 1) {
- *addrs = NULL;
- break;
- }
- *addrs++ = ptr;
- ptr += size;
- }
-
- fclose(proxy);
- return &rs->host;
-
-exit:
- if (proxy != NULL) {
- fclose(proxy);
- }
- return NULL;
-}
-
-
-static struct hostent *
-gethostbyname_internal_real(const char *name, int af, res_state res)
+gethostbyname_internal(const char *name, int af, res_state res)
{
const char *cp;
char *bp, *ep;
int size;
struct hostent *hp;
- res_static rs = __res_get_static();
+ struct resolv_cache* cache;
+ res_static rs = __res_get_static();
static const ns_dtab dtab[] = {
NS_FILES_CB(_gethtbyname, NULL)
gethostbyaddr(const void *addr,
socklen_t len, int af)
{
- return android_gethostbyaddrforiface(addr, len, af, NULL);
-}
-
-struct hostent *
-android_gethostbyaddrforiface(const void *addr,
- socklen_t len, int af, const char* iface)
-{
const u_char *uaddr = (const u_char *)addr;
socklen_t size;
struct hostent *hp;
hp = NULL;
h_errno = NETDB_INTERNAL;
if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyaddr",
- default_dns_files, uaddr, len, af, iface) != NS_SUCCESS)
+ default_dns_files, uaddr, len, af) != NS_SUCCESS)
return NULL;
h_errno = NETDB_SUCCESS;
return hp;
const unsigned char *uaddr;
int len, af, advance;
res_state res;
- const char* iface;
res_static rs = __res_get_static();
assert(rv != NULL);
uaddr = va_arg(ap, unsigned char *);
len = va_arg(ap, int);
af = va_arg(ap, int);
- iface = va_arg(ap, char *);
switch (af) {
case AF_INET:
free(buf);
return NS_NOTFOUND;
}
- res_setiface(res, iface);
- _resolv_populate_res_for_iface(res);
n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf));
if (n < 0) {
free(buf);
static int str2number(const char *);
static int explore_fqdn(const struct addrinfo *, const char *,
- const char *, struct addrinfo **, const char *iface);
+ const char *, struct addrinfo **);
static int explore_null(const struct addrinfo *,
const char *, struct addrinfo **);
static int explore_numeric(const struct addrinfo *, const char *,
return _test_connect(PF_INET, &addr.generic, sizeof(addr.in));
}
-// Returns 0 on success, else returns on error.
+// Returns 0 on success, else returns non-zero on error (in which case
+// getaddrinfo should continue as normal)
static int
android_getaddrinfo_proxy(
const char *hostname, const char *servname,
- const struct addrinfo *hints, struct addrinfo **res, const char *iface)
+ const struct addrinfo *hints, struct addrinfo **res)
{
int sock;
const int one = 1;
struct sockaddr_un proxy_addr;
+ const char* cache_mode = getenv("ANDROID_DNS_MODE");
FILE* proxy = NULL;
int success = 0;
// allocated in the process (before failing).
*res = NULL;
- // Bogus things we can't serialize. Don't use the proxy. These will fail - let them.
+ if (cache_mode != NULL && strcmp(cache_mode, "local") == 0) {
+ // Don't use the proxy in local mode. This is used by the
+ // proxy itself.
+ return -1;
+ }
+
+ // Temporary cautious hack to disable the DNS proxy for processes
+ // requesting special treatment. Ideally the DNS proxy should
+ // accomodate these apps, though.
+ char propname[PROP_NAME_MAX];
+ char propvalue[PROP_VALUE_MAX];
+ snprintf(propname, sizeof(propname), "net.dns1.%d", getpid());
+ if (__system_property_get(propname, propvalue) > 0) {
+ return -1;
+ }
+
+ // Bogus things we can't serialize. Don't use the proxy.
if ((hostname != NULL &&
strcspn(hostname, " \n\r\t^'\"") != strlen(hostname)) ||
(servname != NULL &&
strcspn(servname, " \n\r\t^'\"") != strlen(servname))) {
- return EAI_NODATA;
+ return -1;
}
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
- return EAI_NODATA;
+ return -1;
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
(const struct sockaddr*) &proxy_addr,
sizeof(proxy_addr))) != 0) {
close(sock);
- return EAI_NODATA;
+ return -1;
}
// Send the request.
proxy = fdopen(sock, "r+");
- if (fprintf(proxy, "getaddrinfo %s %s %d %d %d %d %s %d",
+ if (fprintf(proxy, "getaddrinfo %s %s %d %d %d %d",
hostname == NULL ? "^" : hostname,
servname == NULL ? "^" : servname,
hints == NULL ? -1 : hints->ai_flags,
hints == NULL ? -1 : hints->ai_family,
hints == NULL ? -1 : hints->ai_socktype,
- hints == NULL ? -1 : hints->ai_protocol,
- iface == NULL ? "^" : iface,
- getpid()) < 0) {
+ hints == NULL ? -1 : hints->ai_protocol) < 0) {
goto exit;
}
// literal NULL byte at end, required by FrameworkListener
return 0;
}
- // Proxy failed;
- // clean up memory we might've allocated.
+ // Proxy failed; fall through to local
+ // resolver case. But first clean up any
+ // memory we might've allocated.
if (*res) {
freeaddrinfo(*res);
*res = NULL;
}
- return EAI_NODATA;
+ return -1;
}
int
getaddrinfo(const char *hostname, const char *servname,
const struct addrinfo *hints, struct addrinfo **res)
{
- return android_getaddrinfoforiface(hostname, servname, hints, NULL, res);
-}
-
-int
-android_getaddrinfoforiface(const char *hostname, const char *servname,
- const struct addrinfo *hints, const char *iface, struct addrinfo **res)
-{
struct addrinfo sentinel;
struct addrinfo *cur;
int error = 0;
struct addrinfo ai0;
struct addrinfo *pai;
const struct explore *ex;
- const char* cache_mode = getenv("ANDROID_DNS_MODE");
/* hostname is allowed to be NULL */
/* servname is allowed to be NULL */
/* hints is allowed to be NULL */
assert(res != NULL);
+
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
pai = &ai;
/*
* BEGIN ANDROID CHANGES; proxying to the cache
*/
- if (cache_mode == NULL || strcmp(cache_mode, "local") != 0) {
- // we're not the proxy - pass the request to them
- return android_getaddrinfo_proxy(hostname, servname, hints, res, iface);
- }
+ if (android_getaddrinfo_proxy(hostname, servname, hints, res) == 0) {
+ return 0;
+ }
/*
* hostname as alphabetical name.
pai->ai_protocol = ex->e_protocol;
error = explore_fqdn(pai, hostname, servname,
- &cur->ai_next, iface);
+ &cur->ai_next);
while (cur && cur->ai_next)
cur = cur->ai_next;
*/
static int
explore_fqdn(const struct addrinfo *pai, const char *hostname,
- const char *servname, struct addrinfo **res, const char *iface)
+ const char *servname, struct addrinfo **res)
{
struct addrinfo *result;
struct addrinfo *cur;
return 0;
switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
- default_dns_files, hostname, pai, iface)) {
+ default_dns_files, hostname, pai)) {
case NS_TRYAGAIN:
error = EAI_AGAIN;
goto free;
struct addrinfo sentinel, *cur;
struct res_target q, q2;
res_state res;
- const char* iface;
name = va_arg(ap, char *);
pai = va_arg(ap, const struct addrinfo *);
- iface = va_arg(ap, char *);
//fprintf(stderr, "_dns_getaddrinfo() name = '%s'\n", name);
memset(&q, 0, sizeof(q));
return NS_NOTFOUND;
}
- /* this just sets our iface val in the thread private data so we don't have to
- * modify the api's all the way down to res_send.c's res_nsend. We could
- * fully populate the thread private data here, but if we get down there
- * and have a cache hit that would be wasted, so we do the rest there on miss
- */
- res_setiface(res, iface);
if (res_searchN(name, &q, res) < 0) {
__res_put_state(res);
free(buf);
};
static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *,
- socklen_t, char *, socklen_t, int, const char*));
+ socklen_t, char *, socklen_t, int));
#ifdef INET6
static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
socklen_t, int));
*/
int getnameinfo(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags)
{
- return android_getnameinfoforiface(sa, salen, host, hostlen, serv, servlen, flags, NULL);
-}
-
-int android_getnameinfoforiface(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags, const char* iface)
-{
switch (sa->sa_family) {
case AF_INET:
case AF_INET6:
return getnameinfo_inet(sa, salen, host, hostlen,
- serv, servlen, flags, iface);
+ serv, servlen, flags);
#if defined(ANDROID_CHANGES) && defined(AF_LINK)
case AF_LINK:
return getnameinfo_link(sa, salen, host, hostlen,
- serv, servlen, flags);
+ serv, servlen, flags);
#endif
default:
return EAI_FAMILY;
}
}
+
#ifdef ANDROID_CHANGES
/* On success length of the host name is returned. A return
* value of 0 means there's no host name associated with
* the address. On failure -1 is returned in which case
* normal execution flow shall continue. */
static int
-android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr, socklen_t addrLen, int addrFamily, const char* iface)
-{
+android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr, socklen_t addrLen, int addrFamily) {
int sock;
const int one = 1;
return -1;
}
+ // Temporary cautious hack to disable the DNS proxy for processes
+ // requesting special treatment. Ideally the DNS proxy should
+ // accomodate these apps, though.
+ char propname[PROP_NAME_MAX];
+ char propvalue[PROP_VALUE_MAX];
+ snprintf(propname, sizeof(propname), "net.dns1.%d", getpid());
+ if (__system_property_get(propname, propvalue) > 0) {
+ return -1;
+ }
// create socket
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
if (addrStr == NULL) {
goto exit;
}
- if (fprintf(proxy, "gethostbyaddr %s %d %d %d %s",
- addrStr, addrLen, addrFamily, getpid(), iface == NULL ? "^" : iface) < 0) {
+ if (fprintf(proxy, "gethostbyaddr %s %d %d", addrStr, addrLen, addrFamily) < 0) {
goto exit;
}
* Format an IPv4 or IPv6 sockaddr into a printable string.
*/
static int
-getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags, iface)
+getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags)
const struct sockaddr *sa;
socklen_t salen;
char *host;
char *serv;
socklen_t servlen;
int flags;
- const char* iface;
{
const struct afd *afd;
struct servent *sp;
char android_proxy_buf[MAXDNAME];
int hostnamelen = android_gethostbyaddr_proxy(android_proxy_buf,
- MAXDNAME, addr, afd->a_addrlen, afd->a_af, iface);
+ MAXDNAME, addr, afd->a_addrlen, afd->a_af);
if (hostnamelen > 0) {
hp = &android_proxy_hostent;
hp->h_name = android_proxy_buf;
} else if (!hostnamelen) {
hp = NULL;
} else {
- hp = android_gethostbyaddrforiface(addr, afd->a_addrlen, afd->a_af, iface);
+ hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
}
#else
hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
#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.
*
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
}
} 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);
}
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) {
pnode = &node->hlink;
}
- return pnode;
+ return pnode;
}
/* Add a new entry to the hash table. 'lookup' must be the
/****************************************************************************/
/****************************************************************************/
-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 */
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)
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;
+ char* ifname = _get_default_iface_locked();
+
+ // 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;
}
- } else {
- iface = (char *) ifname;
}
-
- cache = _get_res_cache_for_iface_locked(iface);
+ 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;
}
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)
{
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);
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)
{
}
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;
-}
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) {
/* 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
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) {
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);
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] == ' ' || \
}
#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 */
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);
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(
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
/*
#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;
#ifndef _RESOLV_CACHE_H_
#define _RESOLV_CACHE_H_
-struct __res_state;
struct resolv_cache; /* forward */
-/* gets the cache for an interface. Set ifname argument to NULL or
- * empty buffer ('\0') to get cache for default interface.
- * returned cache might be NULL*/
-extern struct resolv_cache* __get_res_cache(const char* ifname);
+/* gets the cache for the default interface. Might be NULL*/
+extern struct resolv_cache* __get_res_cache(void);
+
+/* get the cache for a specified interface. Can be NULL*/
+extern struct resolv_cache* __get_res_cache_for_iface(const char* ifname);
/* this gets called everytime we detect some changes in the DNS configuration
* and will flush the cache */
/* gets the address associated with the specified interface */
extern struct in_addr* _resolv_get_addr_of_iface(const char* ifname);
-/* Copy the name of the default interface to provided buffer.
- * Return length of buffer on success on failure -1 is returned */
-extern int _resolv_get_default_iface(char* buff, int buffLen);
-
-/* sets the name server addresses to the provided res_state structure. The
- * name servers are retrieved from the cache which is associated
- * with the interface to which the res_state structure is associated */
-extern int _resolv_populate_res_for_iface(struct __res_state* statp);
+/* Get name of default interface */
+extern char* _resolv_get_default_iface();
typedef enum {
RESOLV_CACHE_UNSUPPORTED, /* the cache can't handle that kind of queries */
/* flush the cache associated with a certain interface */
extern void _resolv_flush_cache_for_iface(const char* ifname);
-/* set a pid to use the name servers of the specified interface */
-extern void _resolv_set_iface_for_pid(const char* ifname, int pid);
-
-/* clear pid from being associated with an interface */
-extern void _resolv_clear_iface_for_pid(int pid);
-
-/** Gets the name of the interface to which the pid is attached.
- * On error, -1 is returned.
- * If no interface is found, 0 is returned and buff is set to empty ('\0').
- * If an interface is found, the name is copied to buff and the length of the name is returned.
- * Arguments: pid The pid to find an interface for
- * buff A buffer to copy the result to
- * buffLen Length of buff. An interface is at most IF_NAMESIZE in length */
-extern int _resolv_get_pids_associated_interface(int pid, char* buff, int buffLen);
-
#endif /* _BIONIC_RESOLV_IFACE_FUNCTIONS_DECLARED */
__END_DECLS
#include <resolv.h>
#include "resolv_static.h"
-#include <net/if.h>
/*
* Revision information. This is the release date in YYYYMMDD format.
struct __res_state_ext;
struct __res_state {
- char iface[IF_NAMESIZE+1];
int retrans; /* retransmission time interval */
int retry; /* number of times to retransmit */
#ifdef sun
int res_getservers(res_state,
union res_sockaddr_union *, int);
-void res_setiface();
+int res_get_dns_changed();
u_int res_randomid(void);
__END_DECLS
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