dns cache per interface iteration 2
name server addresses are read from the dns
cache associated wih the interface on which
the request shall be done.
processes which has requested to issue dns request
using specific interface are now proxied to netd.
added methods to attach/detach a process to a specific
dns cache/interface.
added getaddrinfoforinface method which takes an
interface as an argument.
bug:4815099
bug:5465296
Change-Id: I7a8fe1980cdf99d4d296ddc5c6411f0c72162263
diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c
index 326b09c..aed6b94 100644
--- a/libc/netbsd/net/getaddrinfo.c
+++ b/libc/netbsd/net/getaddrinfo.c
@@ -214,7 +214,7 @@
static int str2number(const char *);
static int explore_fqdn(const struct addrinfo *, const char *,
- const char *, struct addrinfo **);
+ const char *, struct addrinfo **, const char *iface);
static int explore_null(const struct addrinfo *,
const char *, struct addrinfo **);
static int explore_numeric(const struct addrinfo *, const char *,
@@ -402,17 +402,15 @@
return _test_connect(PF_INET, &addr.generic, sizeof(addr.in));
}
-// Returns 0 on success, else returns non-zero on error (in which case
-// getaddrinfo should continue as normal)
+// Returns 0 on success, else returns on error.
static int
android_getaddrinfo_proxy(
const char *hostname, const char *servname,
- const struct addrinfo *hints, struct addrinfo **res)
+ const struct addrinfo *hints, struct addrinfo **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;
int success = 0;
@@ -421,33 +419,17 @@
// allocated in the process (before failing).
*res = NULL;
- 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.
+ // Bogus things we can't serialize. Don't use the proxy. These will fail - let them.
if ((hostname != NULL &&
strcspn(hostname, " \n\r\t^'\"") != strlen(hostname)) ||
(servname != NULL &&
strcspn(servname, " \n\r\t^'\"") != strlen(servname))) {
- return -1;
+ return EAI_NODATA;
}
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
- return -1;
+ return EAI_NODATA;
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
@@ -459,18 +441,20 @@
(const struct sockaddr*) &proxy_addr,
sizeof(proxy_addr))) != 0) {
close(sock);
- return -1;
+ return EAI_NODATA;
}
// Send the request.
proxy = fdopen(sock, "r+");
- if (fprintf(proxy, "getaddrinfo %s %s %d %d %d %d",
+ if (fprintf(proxy, "getaddrinfo %s %s %d %d %d %d %s %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) < 0) {
+ hints == NULL ? -1 : hints->ai_protocol,
+ iface == NULL ? "^" : iface,
+ getpid()) < 0) {
goto exit;
}
// literal NULL byte at end, required by FrameworkListener
@@ -488,6 +472,7 @@
int result_code = (int)strtol(buf, NULL, 10);
// verify the code itself
if (result_code != DnsProxyQueryResult ) {
+ fread(buf, 1, sizeof(buf), proxy);
goto exit;
}
@@ -580,20 +565,26 @@
return 0;
}
- // Proxy failed; fall through to local
- // resolver case. But first clean up any
- // memory we might've allocated.
+ // Proxy failed;
+ // clean up memory we might've allocated.
if (*res) {
freeaddrinfo(*res);
*res = NULL;
}
- return -1;
+ return EAI_NODATA;
}
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;
@@ -601,12 +592,12 @@
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;
@@ -739,9 +730,10 @@
/*
* BEGIN ANDROID CHANGES; proxying to the cache
*/
- if (android_getaddrinfo_proxy(hostname, servname, hints, res) == 0) {
- return 0;
- }
+ 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);
+ }
/*
* hostname as alphabetical name.
@@ -770,7 +762,7 @@
pai->ai_protocol = ex->e_protocol;
error = explore_fqdn(pai, hostname, servname,
- &cur->ai_next);
+ &cur->ai_next, iface);
while (cur && cur->ai_next)
cur = cur->ai_next;
@@ -803,7 +795,7 @@
*/
static int
explore_fqdn(const struct addrinfo *pai, const char *hostname,
- const char *servname, struct addrinfo **res)
+ const char *servname, struct addrinfo **res, const char *iface)
{
struct addrinfo *result;
struct addrinfo *cur;
@@ -829,7 +821,7 @@
return 0;
switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
- default_dns_files, hostname, pai)) {
+ default_dns_files, hostname, pai, iface)) {
case NS_TRYAGAIN:
error = EAI_AGAIN;
goto free;
@@ -1897,9 +1889,11 @@
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));
@@ -1981,6 +1975,12 @@
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);