fchown DNS lookup sockets to AID_DNS.
Currently DNS lookups are all sent as UID 0. In N we added an
AID_DNS user, but we never used it. A separate UID allows us to
account for and route DNS traffic differently from other UID 0
traffic such as kernel-originated traffic.
Bug: 70673901
Test: DNS lookups continue to work
Test: netd_{unit,integration}_test pass
Change-Id: Ife3ca7df45de51b92437d2cfe627fb4703b672fb
diff --git a/libc/dns/resolv/res_send.c b/libc/dns/resolv/res_send.c
index 3b94fcf..18bb752 100644
--- a/libc/dns/resolv/res_send.c
+++ b/libc/dns/resolv/res_send.c
@@ -100,6 +100,7 @@
#ifdef ANDROID_CHANGES
#include "resolv_netid.h"
#include "resolv_private.h"
+#include "private/android_filesystem_config.h"
#else
#include <resolv.h>
#endif
@@ -820,6 +821,7 @@
return (-1);
}
}
+ fchown(statp->_vcsock, AID_DNS, -1);
if (statp->_mark != MARK_UNSET) {
if (setsockopt(statp->_vcsock, SOL_SOCKET,
SO_MARK, &statp->_mark, sizeof(statp->_mark)) < 0) {
@@ -1122,6 +1124,7 @@
}
}
+ fchown(EXT(statp).nssocks[ns], AID_DNS, -1);
if (statp->_mark != MARK_UNSET) {
if (setsockopt(EXT(statp).nssocks[ns], SOL_SOCKET,
SO_MARK, &(statp->_mark), sizeof(statp->_mark)) < 0) {