commit b066fccc5c977f3e464676d58a7fa550d368f426
author Mark Salyzyn <salyzyn@google.com> Fri May 05 14:44:35 2017 -0700
committer Mark Salyzyn <salyzyn@google.com> Mon May 08 14:04:13 2017 -0700
tree 5371a7e99c4ab965fcdc7c77342631c184083285
parent 823816ee9f3ee7519a282d3a089d23f0e96018ef

init: add "+passcred" for socket to set SO_PASSCRED

In the init scripts for socket, the type can have a suffix of
"+passcred" to request that the socket be bound to report SO_PASSCRED
credentials as part of socket transactions.

Test: gTest logd-unit-tests --gtest_filter=logd.statistics right after boot
      (fails without logd.rc change)
Bug: 37985222
Change-Id: Ie5b50e99fb92fa9bec9a32463a0e6df26a968bfd

init/descriptors.cpp

diff --git a/init/descriptors.cpp b/init/descriptors.cpp
index b2142ca..6f729a3 100644
--- a/init/descriptors.cpp
+++ b/init/descriptors.cpp
@@ -23,6 +23,7 @@
 
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 #include <cutils/android_get_control_file.h>
 #include <cutils/sockets.h>
@@ -77,10 +78,12 @@
 }
 
 int SocketInfo::Create(const std::string& context) const {
-  int flags = ((type() == "stream" ? SOCK_STREAM :
-                (type() == "dgram" ? SOCK_DGRAM :
-                 SOCK_SEQPACKET)));
-  return create_socket(name().c_str(), flags, perm(), uid(), gid(), context.c_str(), sehandle);
+    auto types = android::base::Split(type(), "+");
+    int flags =
+        ((types[0] == "stream" ? SOCK_STREAM : (types[0] == "dgram" ? SOCK_DGRAM : SOCK_SEQPACKET)));
+    bool passcred = types.size() > 1 && types[1] == "passcred";
+    return CreateSocket(name().c_str(), flags, passcred, perm(), uid(), gid(), context.c_str(),
+                        sehandle);
 }
 
 const std::string SocketInfo::key() const {

init/property_service.cpp

diff --git a/init/property_service.cpp b/init/property_service.cpp
index e01cd0b..7722750 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -659,8 +659,8 @@
 void start_property_service() {
     property_set("ro.property_service.version", "2");
 
-    property_set_fd = create_socket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
-                                    0666, 0, 0, nullptr, sehandle);
+    property_set_fd = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
+                                   false, 0666, 0, 0, nullptr, sehandle);
     if (property_set_fd == -1) {
         PLOG(ERROR) << "start_property_service socket creation failed";
         exit(1);

init/service.cpp

diff --git a/init/service.cpp b/init/service.cpp
index 4d9edc4..296c04c 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -525,7 +525,9 @@
 
 // name type perm [ uid gid context ]
 bool Service::ParseSocket(const std::vector<std::string>& args, std::string* err) {
-    if (args[2] != "dgram" && args[2] != "stream" && args[2] != "seqpacket") {
+    if (!android::base::StartsWith(args[2], "dgram") &&
+        !android::base::StartsWith(args[2], "stream") &&
+        !android::base::StartsWith(args[2], "seqpacket")) {
         *err = "socket type must be 'dgram', 'stream' or 'seqpacket'";
         return false;
     }

init/util.cpp

diff --git a/init/util.cpp b/init/util.cpp
index e7f724b..5afe285 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -78,13 +78,13 @@
 }
 
 /*
- * create_socket - creates a Unix domain socket in ANDROID_SOCKET_DIR
+ * CreateSocket - creates a Unix domain socket in ANDROID_SOCKET_DIR
  * ("/dev/socket") as dictated in init.rc. This socket is inherited by the
  * daemon. We communicate the file descriptor's value via the environment
  * variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo").
  */
-int create_socket(const char* name, int type, mode_t perm, uid_t uid, gid_t gid,
-                  const char* socketcon, selabel_handle* sehandle) {
+int CreateSocket(const char* name, int type, bool passcred, mode_t perm, uid_t uid, gid_t gid,
+                 const char* socketcon, selabel_handle* sehandle) {
     if (socketcon) {
         if (setsockcreatecon(socketcon) == -1) {
             PLOG(ERROR) << "setsockcreatecon(\"" << socketcon << "\") failed";
@@ -118,6 +118,14 @@
         }
     }
 
+    if (passcred) {
+        int on = 1;
+        if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on))) {
+            PLOG(ERROR) << "Failed to set SO_PASSCRED '" << name << "'";
+            return -1;
+        }
+    }
+
     int ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr));
     int savederrno = errno;
 

init/util.h

diff --git a/init/util.h b/init/util.h
index 4c33909..f3252c2 100644
--- a/init/util.h
+++ b/init/util.h
@@ -35,8 +35,8 @@
 using android::base::boot_clock;
 using namespace std::chrono_literals;
 
-int create_socket(const char* name, int type, mode_t perm, uid_t uid, gid_t gid,
-                  const char* socketcon, selabel_handle* sehandle);
+int CreateSocket(const char* name, int type, bool passcred, mode_t perm, uid_t uid, gid_t gid,
+                 const char* socketcon, selabel_handle* sehandle);
 
 bool ReadFile(const std::string& path, std::string* content, std::string* err);
 bool WriteFile(const std::string& path, const std::string& content, std::string* err);