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Merge "Revert "dns cache per interface iteration 2""

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This commit is contained in:
Robert Greenwalt 2013-01-19 00:40:38 +00:00 committed by Android (Google) Code Review
commit 1136b7d821
13 changed files with 258 additions and 574 deletions
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13
libc/docs/OVERVIEW.TXT
View file

@ -282,9 +282,16 @@ DNS resolver:
- 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.

4
libc/include/netdb.h
View file

@ -207,13 +207,11 @@ void endprotoent(void);
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 *);
@ -241,9 +239,7 @@ void sethostent(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 *);

151
libc/netbsd/gethnamaddr.c
View file

@ -56,7 +56,6 @@
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "arpa_nameser.h"
@ -70,7 +69,6 @@
#include <stdio.h>
#include <strings.h>
#include <syslog.h>
#include <unistd.h>
#ifndef LOG_AUTH
# define LOG_AUTH 0
@ -82,9 +80,6 @@
#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\"";
@ -126,7 +121,7 @@ static struct hostent *_gethtbyname2(const char *, int);
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 },
@ -495,160 +490,39 @@ gethostbyname(const char *name)
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;
struct resolv_cache* cache;
res_static rs = __res_get_static();
static const ns_dtab dtab[] = {
@ -766,13 +640,6 @@ gethostbyname_internal_real(const char *name, int af, res_state res)
struct hostent *
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;
@ -820,7 +687,7 @@ android_gethostbyaddrforiface(const void *addr,
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;
@ -1257,7 +1124,6 @@ _dns_gethtbyaddr(void *rv, void *cb_data, va_list ap)
const unsigned char *uaddr;
int len, af, advance;
res_state res;
const char* iface;
res_static rs = __res_get_static();
assert(rv != NULL);
@ -1265,7 +1131,6 @@ _dns_gethtbyaddr(void *rv, void *cb_data, va_list ap)
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:
@ -1307,8 +1172,6 @@ _dns_gethtbyaddr(void *rv, void *cb_data, va_list ap)
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);

73
libc/netbsd/net/getaddrinfo.c
View file

@ -214,7 +214,7 @@ struct res_target {
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 *,
@ -402,15 +402,17 @@ _have_ipv4() {
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;
@ -419,17 +421,33 @@ android_getaddrinfo_proxy(
// 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));
@ -441,20 +459,18 @@ android_getaddrinfo_proxy(
(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
@ -564,25 +580,19 @@ exit:
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;
@ -591,12 +601,12 @@ android_getaddrinfoforiface(const char *hostname, const char *servname,
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;
@ -729,9 +739,8 @@ android_getaddrinfoforiface(const char *hostname, const char *servname,
/*
* 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;
}
/*
@ -761,7 +770,7 @@ android_getaddrinfoforiface(const char *hostname, const char *servname,
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;
@ -794,7 +803,7 @@ android_getaddrinfoforiface(const char *hostname, const char *servname,
*/
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;
@ -820,7 +829,7 @@ explore_fqdn(const struct addrinfo *pai, const char *hostname,
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;
@ -1888,11 +1897,9 @@ _dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
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));
@ -1974,12 +1981,6 @@ _dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
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);

32
libc/netbsd/net/getnameinfo.c
View file

@ -99,7 +99,7 @@ struct sockinet {
};
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));
@ -121,17 +121,12 @@ static const int DnsProxyQueryResult = 222;
* appropriate function to call.
*/
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,
@ -141,14 +136,14 @@ int android_getnameinfoforiface(const struct sockaddr* sa, socklen_t salen, char
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;
@ -163,6 +158,15 @@ android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr,
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) {
@ -191,8 +195,7 @@ android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr,
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;
}
@ -243,7 +246,7 @@ android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr,
* 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;
@ -251,7 +254,6 @@ getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags, iface)
char *serv;
socklen_t servlen;
int flags;
const char* iface;
{
const struct afd *afd;
struct servent *sp;
@ -396,14 +398,14 @@ getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags, iface)
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);

338
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) {
@ -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();
// 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 = _get_res_cache_for_iface_locked(iface);
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;
cache_info->domains = strdup(domains);
}
cp++;
}
}
*offset = -1; /* cache_info->dnsrch_offset has MAXDNSRCH+1 items */
// flush cache since new settings
_flush_cache_for_iface_locked(ifname);
}
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;

20
libc/private/resolv_cache.h
View file

@ -28,13 +28,13 @@
#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 */
@ -67,14 +67,8 @@ extern struct in_addr* _resolv_get_addr_of_default_iface();
/* 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 */

15
libc/private/resolv_iface.h
View file

@ -60,21 +60,6 @@ extern void _resolv_flush_cache_for_default_iface();
/* 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

4
libc/private/resolv_private.h
View file

@ -56,7 +56,6 @@
#include <resolv.h>
#include "resolv_static.h"
#include <net/if.h>
/*
* Revision information. This is the release date in YYYYMMDD format.
@ -140,7 +139,6 @@ struct res_sym {
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
@ -493,7 +491,7 @@ void res_setservers(res_state,
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