Allow overlap in resolv uid => DNS iface mapping

When multiple rules exist covering a given uid the one added most
recently will be used.

This allows us to handle the simultaneous tuns case where a new tun is
coming online for an already running VPN.

_resolv_clear_iface_for_uid_range now also takes the iface and removes
only that matching (iface, uid range) entry.

Bug: 12134439
Change-Id: I9b9cfcfae2f38c409022a8c76ccadad7e2babd78

libc/arch-arm/cortex-a15/bionic/memcpy_base.S

@@ -74,8 +74,10 @@ ENTRY(MEMCPY_BASE)
         cmp     r2, #16
         blo     .L_copy_less_than_16_unknown_align
 
-        cmp     r2, #832
-        bge     .L_check_alignment
+        // TODO: The aligned copy code is extremely slow copying some large
+        //       buffers so always go through the unaligned path for now.
+        //cmp     r2, #832
+        //bge     .L_check_alignment
 
 .L_copy_unknown_alignment:
         // Unknown alignment of src and dst.

libc/arch-arm/krait/bionic/memcpy_base.S

@@ -79,7 +79,7 @@ ENTRY(MEMCPY_BASE)
 1:      /* The main loop copies 64 bytes at a time */
         vld1.8      {d0  - d3},   [r1]!
         vld1.8      {d4  - d7},   [r1]!
-        pld         [r1, #(32*2)]
+        pld         [r1, #(32*8)]
         subs        r2, r2, #64
         vst1.8      {d0  - d3},   [r0, :128]!
         vst1.8      {d4  - d7},   [r0, :128]!

libc/netbsd/resolv/res_cache.c

@@ -1852,9 +1852,7 @@ static void _remove_pidiface_info_locked(int pid);
 static struct resolv_pidiface_info* _get_pid_iface_info_locked(int pid);
 
 /* remove a resolv_pidiface_info structure from _res_uidiface_list */
-static int _remove_uidiface_info_locked(int uid_start, int uid_end);
-/* check if a range [low,high] overlaps with any already existing ranges in the uid=>iface map*/
-static int  _resolv_check_uid_range_overlap_locked(int uid_start, int uid_end);
+static int _remove_uidiface_info_locked(const char* iface, int uid_start, int uid_end);
 /* get a resolv_uidiface_info structure from _res_uidiface_list with a certain uid */
 static struct resolv_uidiface_info* _get_uid_iface_info_locked(int uid);
 
@@ -2433,11 +2431,11 @@ _resolv_get_pids_associated_interface(int pid, char* buff, int buffLen)
 }
 
 static int
-_remove_uidiface_info_locked(int uid_start, int uid_end) {
+_remove_uidiface_info_locked(const char* ifname, int uid_start, int uid_end) {
     struct resolv_uidiface_info* result = _res_uidiface_list.next;
     struct resolv_uidiface_info* prev = &_res_uidiface_list;
-
-    while (result != NULL && result->uid_start != uid_start && result->uid_end != uid_end) {
+    while (result != NULL && !(result->uid_start == uid_start && result->uid_end == uid_end &&
+            !strcmp(result->ifname, ifname))) {
         prev = result;
         result = result->next;
     }
@@ -2461,19 +2459,6 @@ _get_uid_iface_info_locked(int uid)
     return result;
 }
 
-static int
-_resolv_check_uid_range_overlap_locked(int uid_start, int uid_end)
-{
-    struct resolv_uidiface_info* cur = _res_uidiface_list.next;
-    while (cur != NULL) {
-        if (cur->uid_start <= uid_end && cur->uid_end >= uid_start) {
-            return -1;
-        }
-        cur = cur->next;
-    }
-    return 0;
-}
-
 void
 _resolv_clear_iface_uid_range_mapping()
 {
@@ -2518,8 +2503,6 @@ _resolv_set_iface_for_uid_range(const char* ifname, int uid_start, int uid_end)
         return -1;
     }
     pthread_mutex_lock(&_res_uidiface_list_lock);
-    //check that we aren't adding an overlapping range
-    if (!_resolv_check_uid_range_overlap_locked(uid_start, uid_end)) {
     uidiface_info = calloc(sizeof(*uidiface_info), 1);
     if (uidiface_info) {
         uidiface_info->uid_start = uid_start;
@@ -2538,25 +2521,20 @@ _resolv_set_iface_for_uid_range(const char* ifname, int uid_start, int uid_end)
         rv = -1;
         errno = EINVAL;
     }
-    } else {
-        XLOG("_resolv_set_iface_for_uid_range range [%d,%d] overlaps\n", uid_start, uid_end);
-        rv = -1;
-        errno = EINVAL;
-    }
 
     pthread_mutex_unlock(&_res_uidiface_list_lock);
     return rv;
 }
 
 int
-_resolv_clear_iface_for_uid_range(int uid_start, int uid_end)
+_resolv_clear_iface_for_uid_range(const char* ifname, int uid_start, int uid_end)
 {
     pthread_once(&_res_cache_once, _res_cache_init);
     pthread_mutex_lock(&_res_uidiface_list_lock);
 
-    int rv = _remove_uidiface_info_locked(uid_start, uid_end);
+    int rv = _remove_uidiface_info_locked(ifname, uid_start, uid_end);
 
-    XLOG("_resolv_clear_iface_for_uid_range: [%d,%d]\n", uid_start, uid_end);
+    XLOG("_resolv_clear_iface_for_uid_range: [%d,%d] iface %s\n", uid_start, uid_end, ifname);
 
     pthread_mutex_unlock(&_res_uidiface_list_lock);
 

libc/netbsd/resolv/res_query.c

@@ -272,6 +272,15 @@ res_nsearch(res_state statp,
 	    (dots && !trailing_dot && (statp->options & RES_DNSRCH) != 0U)) {
 		int done = 0;
 
+		/* Unfortunately we need to load interface info
+		 * (dns servers, search domains) before
+		 * the domain stuff is tried.  Will have a better
+		 * fix after thread pools are used as this will
+		 * be loaded once for the thread instead of each
+		 * time a query is tried.
+		 */
+		_resolv_populate_res_for_iface(statp);
+
 		for (domain = (const char * const *)statp->dnsrch;
 		     *domain && !done;
 		     domain++) {

libc/private/resolv_iface.h

@@ -79,13 +79,12 @@ extern void _resolv_clear_iface_pid_mapping();
 extern int _resolv_get_pids_associated_interface(int pid, char* buff, int buffLen);
 
 
-/** set a uid range to use the name servers of the specified interface
- *  If [low,high] overlaps with an already existing rule -1 is returned */
+/** set a uid range to use the name servers of the specified interface */
 extern int _resolv_set_iface_for_uid_range(const char* ifname, int uid_start, int uid_end);
 
-/* clear a uid range from being associated with an interface
- * If the range given is not mapped -1 is returned. */
-extern int _resolv_clear_iface_for_uid_range(int uid_start, int uid_end);
+/** Remove a mapping added by _resolv_set_iface_for_uid_range.
+ *  If no such rule exists -1 is returned. */
+extern int _resolv_clear_iface_for_uid_range(const char* ifname, int uid_start, int uid_end);
 
 /* clear the entire mapping of uid ranges to interfaces. */
 extern void _resolv_clear_iface_uid_range_mapping();
@@ -94,6 +93,7 @@ extern void _resolv_clear_iface_uid_range_mapping();
  *  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.
+ *  If there are multiple rules covering uid the most recently added rule will be returned.
  *  Arguments:   uid The uid 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 */

tests/Android.mk

@@ -122,13 +122,36 @@ include $(BUILD_NATIVE_TEST)
 include $(CLEAR_VARS)
 LOCAL_MODULE := bionic-unit-tests-static
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
-LOCAL_CFLAGS += $(test_c_flags)
 LOCAL_FORCE_STATIC_EXECUTABLE := true
-LOCAL_SRC_FILES := $(test_src_files)
-LOCAL_STATIC_LIBRARIES += libstlport_static libstdc++ libm libc bionic-unit-tests-unwind-test-impl
-LOCAL_WHOLE_STATIC_LIBRARIES := $(test_fortify_static_libraries)
+LOCAL_WHOLE_STATIC_LIBRARIES += libBionicTests
+LOCAL_STATIC_LIBRARIES += libstlport_static libstdc++ libm libc
 include $(BUILD_NATIVE_TEST)
 
+# -----------------------------------------------------------------------------
+# We build the static unit tests as a library so they can be used both for
+# bionic-unit-tests-static and also as part of CTS.
+# -----------------------------------------------------------------------------
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libBionicTests
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
+LOCAL_CFLAGS += $(test_c_flags)
+LOCAL_SRC_FILES := $(test_src_files)
+LOCAL_CFLAGS += \
+    -DGTEST_OS_LINUX_ANDROID \
+    -DGTEST_HAS_STD_STRING \
+
+LOCAL_C_INCLUDES += \
+    bionic bionic/libstdc++/include \
+    external/gtest/include \
+    external/stlport/stlport \
+
+LOCAL_WHOLE_STATIC_LIBRARIES := \
+    $(test_fortify_static_libraries) \
+    bionic-unit-tests-unwind-test-impl \
+
+include $(BUILD_STATIC_LIBRARY)
+
 # -----------------------------------------------------------------------------
 # Test library for the unit tests.
 # -----------------------------------------------------------------------------

tests/property_benchmark.cpp

@@ -32,10 +32,10 @@ struct LocalPropertyTestState {
     LocalPropertyTestState(int nprops) : nprops(nprops), valid(false) {
         static const char prop_name_chars[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_";
 
-        char dir_template[] = "/data/nativetest/prop-XXXXXX";
+        char dir_template[] = "/data/local/tmp/prop-XXXXXX";
         char *dirname = mkdtemp(dir_template);
         if (!dirname) {
-            perror("making temp file for test state failed (is /data/nativetest writable?)");
+            perror("making temp file for test state failed (is /data/local/tmp writable?)");
             return;
         }
 

tests/statvfs_test.cpp

@@ -35,7 +35,7 @@ TEST(statvfs, statvfs) {
 #endif
 
 #if __BIONIC__
-  ASSERT_EQ(0, statvfs("/data/data", &sb));
+  ASSERT_EQ(0, statvfs("/data/local/tmp", &sb));
   ASSERT_NE(0U, sb.f_bfree);
   ASSERT_NE(0U, sb.f_ffree);
   ASSERT_NE(0U, sb.f_fsid);
@@ -59,7 +59,7 @@ TEST(statvfs, fstatvfs) {
 #endif
 
 #if __BIONIC__
-  fd = open("/data/data", O_RDONLY);
+  fd = open("/data/local/tmp", O_RDONLY);
   ASSERT_EQ(0, fstatvfs(fd, &sb));
   close(fd);
   ASSERT_NE(0U, sb.f_bfree);

tests/system_properties_test.cpp

@@ -28,10 +28,10 @@ extern void *__system_property_area__;
 
 struct LocalPropertyTestState {
     LocalPropertyTestState() : valid(false) {
-        char dir_template[] = "/data/nativetest/prop-XXXXXX";
+        char dir_template[] = "/data/local/tmp/prop-XXXXXX";
         char *dirname = mkdtemp(dir_template);
         if (!dirname) {
-            perror("making temp file for test state failed (is /data/nativetest writable?)");
+            perror("making temp file for test state failed (is /data/local/tmp writable?)");
             return;
         }