Linker namespace configuration for the Resolv APEX.

Support netd to load resolv Apex.
Switch namespaces when switching library paths between
/system and the APEX, so that internal library dependencies in both
locations are loaded from their own directory.

Bug: 119527674
Test: make; flash; lsof -p $(pidof netd)
Test: 1. manual test datacall/wifi work
      2. manual test tethering work
      3. system/netd/tests/runtests.sh
Change-Id: I3f69e85f2f529636f0ef29a2d9d71ad582c46dfb
diff --git a/rootdir/etc/ld.config.legacy.txt b/rootdir/etc/ld.config.legacy.txt
index 83eb3b6..1321c24 100644
--- a/rootdir/etc/ld.config.legacy.txt
+++ b/rootdir/etc/ld.config.legacy.txt
@@ -35,11 +35,11 @@
 # APEX related namespaces.
 ###############################################################################
 
-additional.namespaces = runtime,conscrypt,media
+additional.namespaces = runtime,conscrypt,media,resolv
 
 # Keep in sync with ld.config.txt in the com.android.runtime APEX.
-namespace.default.links = runtime
-namespace.default.asan.links = runtime
+namespace.default.links = runtime,resolv
+namespace.default.asan.links = runtime,resolv
 # Visible because some libraries are dlopen'ed, e.g. libopenjdk is dlopen'ed by
 # libart.
 namespace.default.visible = true
@@ -49,6 +49,8 @@
 namespace.default.link.runtime.shared_libs += libnativehelper.so
 namespace.default.link.runtime.shared_libs += libnativeloader.so
 
+namespace.default.link.resolv.shared_libs = libnetd_resolv.so
+
 ###############################################################################
 # "runtime" APEX namespace
 #
@@ -99,6 +101,22 @@
 namespace.conscrypt.link.default.shared_libs += libdl.so
 
 ###############################################################################
+# "resolv" APEX namespace
+#
+# This namespace is for libraries within the resolv APEX.
+###############################################################################
+namespace.resolv.isolated = true
+namespace.resolv.visible = true
+
+namespace.resolv.search.paths = /apex/com.android.resolv/${LIB}
+namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
+namespace.resolv.links = default
+namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libm.so
+namespace.resolv.link.default.shared_libs += libdl.so
+namespace.resolv.link.default.shared_libs += libbinder_ndk.so
+
+###############################################################################
 # Namespace config for binaries under /postinstall.
 # Only one default namespace is defined and it has no directories other than
 # /system/lib and /product/lib in the search paths. This is because linker
diff --git a/rootdir/etc/ld.config.txt b/rootdir/etc/ld.config.txt
index 05f75bf..f37f922 100644
--- a/rootdir/etc/ld.config.txt
+++ b/rootdir/etc/ld.config.txt
@@ -28,7 +28,7 @@
 dir.postinstall = /postinstall
 
 [system]
-additional.namespaces = runtime,conscrypt,media,sphal,vndk,rs
+additional.namespaces = runtime,conscrypt,media,resolv,sphal,vndk,rs
 
 ###############################################################################
 # "default" namespace
@@ -73,7 +73,6 @@
 namespace.default.permitted.paths += /%PRODUCT_SERVICES%/priv-app
 namespace.default.permitted.paths += /data
 namespace.default.permitted.paths += /mnt/expand
-namespace.default.permitted.paths += /apex/com.android.resolv/${LIB}
 
 namespace.default.asan.search.paths  = /data/asan/system/${LIB}
 namespace.default.asan.search.paths +=           /system/${LIB}
@@ -105,10 +104,9 @@
 namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/app
 namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/priv-app
 namespace.default.asan.permitted.paths += /mnt/expand
-namespace.default.asan.permitted.paths += /apex/com.android.resolv/${LIB}
 
 # Keep in sync with ld.config.txt in the com.android.runtime APEX.
-namespace.default.links = runtime
+namespace.default.links = runtime,resolv
 # Visible because some libraries are dlopen'ed, e.g. libopenjdk is dlopen'ed by
 # libart.
 namespace.default.visible = true
@@ -118,6 +116,8 @@
 namespace.default.link.runtime.shared_libs += libnativehelper.so
 namespace.default.link.runtime.shared_libs += libnativeloader.so
 
+namespace.default.link.resolv.shared_libs = libnetd_resolv.so
+
 ###############################################################################
 # "runtime" APEX namespace
 #
@@ -168,6 +168,22 @@
 namespace.conscrypt.link.default.shared_libs += libdl.so
 
 ###############################################################################
+# "resolv" APEX namespace
+#
+# This namespace is for libraries within the resolv APEX.
+###############################################################################
+namespace.resolv.isolated = true
+namespace.resolv.visible = true
+
+namespace.resolv.search.paths = /apex/com.android.resolv/${LIB}
+namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
+namespace.resolv.links = default
+namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libm.so
+namespace.resolv.link.default.shared_libs += libdl.so
+namespace.resolv.link.default.shared_libs += libbinder_ndk.so
+
+###############################################################################
 # "sphal" namespace
 #
 # SP-HAL(Sameprocess-HAL)s are the only vendor libraries that are allowed to be
diff --git a/rootdir/etc/ld.config.vndk_lite.txt b/rootdir/etc/ld.config.vndk_lite.txt
index 335369e..a8ed04f 100644
--- a/rootdir/etc/ld.config.vndk_lite.txt
+++ b/rootdir/etc/ld.config.vndk_lite.txt
@@ -28,7 +28,7 @@
 dir.postinstall = /postinstall
 
 [system]
-additional.namespaces = runtime,conscrypt,media,sphal,vndk,rs
+additional.namespaces = runtime,conscrypt,media,resolv,sphal,vndk,rs
 
 ###############################################################################
 # "default" namespace
@@ -57,7 +57,7 @@
 
 # Keep in sync with the platform namespace in the com.android.runtime APEX
 # ld.config.txt.
-namespace.default.links = runtime
+namespace.default.links = runtime,resolv
 # Visible because some libraries are dlopen'ed, e.g. libopenjdk is dlopen'ed by
 # libart.
 namespace.default.visible = true
@@ -66,6 +66,8 @@
 namespace.default.link.runtime.shared_libs += libnativehelper.so
 namespace.default.link.runtime.shared_libs += libnativeloader.so
 
+namespace.default.link.resolv.shared_libs = libnetd_resolv.so
+
 ###############################################################################
 # "runtime" APEX namespace
 #
@@ -117,6 +119,22 @@
 namespace.conscrypt.link.default.shared_libs += libdl.so
 
 ###############################################################################
+# "resolv" APEX namespace
+#
+# This namespace is for libraries within the resolv APEX.
+###############################################################################
+namespace.resolv.isolated = true
+namespace.resolv.visible = true
+
+namespace.resolv.search.paths = /apex/com.android.resolv/${LIB}
+namespace.resolv.asan.search.paths = /apex/com.android.resolv/${LIB}
+namespace.resolv.links = default
+namespace.resolv.link.default.shared_libs  = libc.so
+namespace.resolv.link.default.shared_libs += libm.so
+namespace.resolv.link.default.shared_libs += libdl.so
+namespace.resolv.link.default.shared_libs += libbinder_ndk.so
+
+###############################################################################
 # "sphal" namespace
 #
 # SP-HAL(Sameprocess-HAL)s are the only vendor libraries that are allowed to be