Add NDK API for getprocdns,setprocdns

The API allows callers to control the default network that is used for
DNS hostname resolution.

Test: atest CtsNetTestCases
      Tests in change I00143cafcd3eb1d71e8d5c7ea9c839a99dc6f4ce
Bug: 171540887
Change-Id: I42f0d9b17b3058f6e10fd2e651278b290f26667f

1 files changed, 32 insertions, 0 deletions

diff --git a/native/android/net.c b/native/android/net.c
index d4b888845b27..e2f36a77b7c6 100644
--- a/native/android/net.c
+++ b/native/android/net.c
@@ -90,6 +90,38 @@ int android_getprocnetwork(net_handle_t *network) {
     return 0;
 }
 
+int android_setprocdns(net_handle_t network) {
+    unsigned netid;
+    if (!getnetidfromhandle(network, &netid)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    int rval = setNetworkForResolv(netid);
+    if (rval < 0) {
+        errno = -rval;
+        rval = -1;
+    }
+    return rval;
+}
+
+int android_getprocdns(net_handle_t *network) {
+    if (network == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    unsigned netid;
+    int rval = getNetworkForDns(&netid);
+    if (rval < 0) {
+        errno = -rval;
+        return -1;
+    }
+
+    *network = gethandlefromnetid(netid);
+    return 0;
+}
+
 int android_getaddrinfofornetwork(net_handle_t network,
         const char *node, const char *service,
         const struct addrinfo *hints, struct addrinfo **res) {