Add tmp file to ramdom_fd for parcel fuzzing

This happens on host under ashmem_create_region, but not on device. Add
it as an explicit option to get more coverage on device.

Test: binder_parcel_fuzzer
Bug: 294593418
Change-Id: Icfb7c91543540d2b16df791b659fef414c8ec563

1 files changed, 59 insertions, 34 deletions

diff --git a/libs/binder/tests/parcel_fuzzer/random_fd.cpp b/libs/binder/tests/parcel_fuzzer/random_fd.cpp
index e4dbb2d955..7390d497c4 100644
--- a/libs/binder/tests/parcel_fuzzer/random_fd.cpp
+++ b/libs/binder/tests/parcel_fuzzer/random_fd.cpp
@@ -29,40 +29,65 @@ std::vector<unique_fd> getRandomFds(FuzzedDataProvider* provider) {
     const char* fdType;
 
     std::vector<unique_fd> fds = provider->PickValueInArray<
-            std::function<std::vector<unique_fd>()>>({
-            [&]() {
-                fdType = "ashmem";
-                std::vector<unique_fd> ret;
-                ret.push_back(unique_fd(
-                        ashmem_create_region("binder test region",
-                                             provider->ConsumeIntegralInRange<size_t>(0, 4096))));
-                return ret;
-            },
-            [&]() {
-                fdType = "/dev/null";
-                std::vector<unique_fd> ret;
-                ret.push_back(unique_fd(open("/dev/null", O_RDWR)));
-                return ret;
-            },
-            [&]() {
-                fdType = "pipefd";
-
-                int pipefds[2];
-
-                int flags = O_CLOEXEC;
-                if (provider->ConsumeBool()) flags |= O_DIRECT;
-                if (provider->ConsumeBool()) flags |= O_NONBLOCK;
-
-                CHECK_EQ(0, pipe2(pipefds, flags)) << flags;
-
-                if (provider->ConsumeBool()) std::swap(pipefds[0], pipefds[1]);
-
-                std::vector<unique_fd> ret;
-                ret.push_back(unique_fd(pipefds[0]));
-                ret.push_back(unique_fd(pipefds[1]));
-                return ret;
-            },
-    })();
+            std::function<std::vector<unique_fd>()>>(
+            {[&]() {
+                 fdType = "ashmem";
+                 std::vector<unique_fd> ret;
+                 ret.push_back(unique_fd(
+                         ashmem_create_region("binder test region",
+                                              provider->ConsumeIntegralInRange<size_t>(0, 4096))));
+                 return ret;
+             },
+             [&]() {
+                 fdType = "/dev/null";
+                 std::vector<unique_fd> ret;
+                 ret.push_back(unique_fd(open("/dev/null", O_RDWR)));
+                 return ret;
+             },
+             [&]() {
+                 fdType = "pipefd";
+
+                 int pipefds[2];
+
+                 int flags = O_CLOEXEC;
+                 if (provider->ConsumeBool()) flags |= O_DIRECT;
+                 if (provider->ConsumeBool()) flags |= O_NONBLOCK;
+
+                 CHECK_EQ(0, pipe2(pipefds, flags)) << flags;
+
+                 if (provider->ConsumeBool()) std::swap(pipefds[0], pipefds[1]);
+
+                 std::vector<unique_fd> ret;
+                 ret.push_back(unique_fd(pipefds[0]));
+                 ret.push_back(unique_fd(pipefds[1]));
+                 return ret;
+             },
+             [&]() {
+                 fdType = "tempfd";
+                 char name[PATH_MAX];
+#if defined(__ANDROID__)
+                 snprintf(name, sizeof(name), "/data/local/tmp/android-tempfd-test-%d-XXXXXX",
+                          getpid());
+#else
+                 snprintf(name, sizeof(name), "/tmp/android-tempfd-test-%d-XXXXXX", getpid());
+#endif
+                 int fd = mkstemp(name);
+                 CHECK_NE(fd, -1) << "Failed to create file " << name << ", errno: " << errno;
+                 unlink(name);
+                 if (provider->ConsumeBool()) {
+                     CHECK_NE(TEMP_FAILURE_RETRY(
+                                      ftruncate(fd,
+                                                provider->ConsumeIntegralInRange<size_t>(0, 4096))),
+                              -1)
+                             << "Failed to truncate file, errno: " << errno;
+                 }
+
+                 std::vector<unique_fd> ret;
+                 ret.push_back(unique_fd(fd));
+                 return ret;
+             }
+
+            })();
 
     for (const auto& fd : fds) CHECK(fd.ok()) << fd.get() << " " << fdType;