From cc7747d2de2d28c520e53f135c1f8236d051709e Mon Sep 17 00:00:00 2001
From: Chenbo Feng <fengc@google.com>
Date: Tue, 24 Jul 2018 12:36:37 -0700
Subject: [PATCH] Skip the test if cannot open ctrl file

The shell access to the proc/xt_qtaguid/ctrl file is blocked in next
android release since no apps or users should directly read/write to
those proc files anymore. This CTS test is checking some critical kernel
behavior to make sure the xt_qtaguid module have specific kernel fixes.
So if the ctrl file is not accessible, there is no way to verify those
critical fixes, we can only skipped the test. These testcases are also
added in VTS qtaguid test so we can still check the devices have those
kernel fixes.

Bug: 110906349
Test: atest CtsNativeNetTestCases
Change-Id: Iae0512bb37f8b93577a134f15affb4f2a448be18
---
 .../native/qtaguid/src/NativeQtaguidTest.cpp  | 61 +++++++------------
 1 file changed, 21 insertions(+), 40 deletions(-)

diff --git a/tests/cts/net/native/qtaguid/src/NativeQtaguidTest.cpp b/tests/cts/net/native/qtaguid/src/NativeQtaguidTest.cpp
index 1892a44ebd..7dc6240667 100644
--- a/tests/cts/net/native/qtaguid/src/NativeQtaguidTest.cpp
+++ b/tests/cts/net/native/qtaguid/src/NativeQtaguidTest.cpp
@@ -18,36 +18,29 @@
 #include <error.h>
 #include <errno.h>
 #include <inttypes.h>
+#include <fcntl.h>
 #include <string.h>
 #include <sys/socket.h>
-#include <sys/utsname.h>
 
 #include <gtest/gtest.h>
 #include <qtaguid/qtaguid.h>
 
-int hasQtaguidKernelSupport() {
-    struct utsname buf;
-    int kernel_version_major;
-    int kernel_version_minor;
-
-    int ret = uname(&buf);
-    if (ret) {
-        ret = -errno;
-        return ret;
-    }
-    char dummy;
-    ret = sscanf(buf.release, "%d.%d%c", &kernel_version_major, &kernel_version_minor, &dummy);
-    if (ret < 3)
-        return -EINVAL;
-
-    if ((kernel_version_major == 4 && kernel_version_minor < 9) ||
-        (kernel_version_major < 4)) {
-        return 1;
-    } else {
-        return access("/proc/net/xt_qtaguid/ctrl", F_OK) != -1;
-    }
+int canAccessQtaguidFile() {
+    int fd = open("/proc/net/xt_qtaguid/ctrl", O_RDONLY | O_CLOEXEC);
+    close(fd);
+    return fd != -1;
 }
 
+#define SKIP_IF_QTAGUID_NOT_SUPPORTED()                                                       \
+  do {                                                                                        \
+    int res = canAccessQtaguidFile();                                                      \
+    ASSERT_LE(0, res);                                                                        \
+    if (!res) {                                                                               \
+          GTEST_LOG_(INFO) << "This test is skipped since kernel may not have the module\n";  \
+          return;                                                                             \
+    }                                                                                         \
+  } while (0)
+
 int getCtrlSkInfo(int tag, uid_t uid, uint64_t* sk_addr, int* ref_cnt) {
     FILE *fp;
     fp = fopen("/proc/net/xt_qtaguid/ctrl", "r");
@@ -95,12 +88,8 @@ void checkNoSocketPointerLeaks(int family) {
 }
 
 TEST (NativeQtaguidTest, close_socket_without_untag) {
-    int res = hasQtaguidKernelSupport();
-    ASSERT_LE(0, res);
-    if (!res) {
-          GTEST_LOG_(INFO) << "This test is skipped since kernel may not have the module\n";
-          return;
-    }
+    SKIP_IF_QTAGUID_NOT_SUPPORTED();
+
     int sockfd = socket(AF_INET, SOCK_STREAM, 0);
     uid_t uid = getuid();
     int tag = arc4random();
@@ -114,12 +103,8 @@ TEST (NativeQtaguidTest, close_socket_without_untag) {
 }
 
 TEST (NativeQtaguidTest, close_socket_without_untag_ipv6) {
-    int res = hasQtaguidKernelSupport();
-    ASSERT_LE(0, res);
-    if (!res) {
-          GTEST_LOG_(INFO) << "This test is skipped since kernel may not have the module\n";
-          return;
-    }
+    SKIP_IF_QTAGUID_NOT_SUPPORTED();
+
     int sockfd = socket(AF_INET6, SOCK_STREAM, 0);
     uid_t uid = getuid();
     int tag = arc4random();
@@ -133,12 +118,8 @@ TEST (NativeQtaguidTest, close_socket_without_untag_ipv6) {
 }
 
 TEST (NativeQtaguidTest, no_socket_addr_leak) {
-    int res = hasQtaguidKernelSupport();
-    ASSERT_LE(0, res);
-    if (!res) {
-          GTEST_LOG_(INFO) << "This test is skipped since kernel may not have the module\n";
-          return;
-    }
+  SKIP_IF_QTAGUID_NOT_SUPPORTED();
+
   checkNoSocketPointerLeaks(AF_INET);
   checkNoSocketPointerLeaks(AF_INET6);
 }