Convert process-wrapper to C++.

No functional changes.

Change-Id: Ia87c19b70dd1ff8fa7465ad90c499cf351b9687b
PiperOrigin-RevId: 156188343

src/main/tools/BUILD

@@ -1,20 +1,28 @@
 package(default_visibility = ["//src:__subpackages__"])
 
+cc_library(
+    name = "process-tools",
+    srcs = [
+        "process-tools.cc",
+        "process-tools.h",
+    ],
+)
+
 cc_binary(
     name = "process-wrapper",
     srcs = select({
         "//src:windows_msvc": ["process-wrapper-windows.cc"],
         "//conditions:default": [
-            "process-tools.c",
-            "process-tools.h",
-            "process-wrapper.c",
+            "process-wrapper.cc",
         ],
     }),
-    copts = select({
+    linkopts = ["-lm"],
+    deps = select({
         "//src:windows_msvc": [],
-        "//conditions:default": ["-std=c99"],
+        "//conditions:default": [
+            ":process-tools",
+        ],
     }),
-    linkopts = ["-lm"],
 )
 
 cc_binary(

src/main/tools/build-runfiles.cc

@@ -241,7 +241,7 @@ class RunfilesCreator {
 
     errno = 0;
     const std::string prefix = (path == "." ? "" : path + "/");
-    while ((entry = readdir(dh)) != NULL) {
+    while ((entry = readdir(dh)) != nullptr) {
       if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, "..")) continue;
 
       std::string entry_path = prefix + entry->d_name;
@@ -383,7 +383,7 @@ class RunfilesCreator {
       PDIE("opendir '%s'", path.c_str());
     }
     errno = 0;
-    while ((entry = readdir(dh)) != NULL) {
+    while ((entry = readdir(dh)) != nullptr) {
       if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, "..")) continue;
       const std::string entry_path = path + '/' + entry->d_name;
       FileType entry_file_type = DentryToFileType(entry_path, entry->d_type);
@@ -441,7 +441,7 @@ int main(int argc, char **argv) {
   std::string manifest_file = input_filename;
   if (input_filename[0] != '/') {
     char cwd_buf[PATH_MAX];
-    if (getcwd(cwd_buf, sizeof(cwd_buf)) == NULL) {
+    if (getcwd(cwd_buf, sizeof(cwd_buf)) == nullptr) {
       PDIE("getcwd failed");
     }
     manifest_file = std::string(cwd_buf) + '/' + manifest_file;

src/main/tools/linux-sandbox-options.cc

@@ -12,17 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "linux-sandbox-options.h"
-#include "linux-sandbox-utils.h"
-
 #define DIE(args...)                                     \
   {                                                      \
     fprintf(stderr, __FILE__ ":" S__LINE__ ": \"" args); \
     fprintf(stderr, "\": ");                             \
-    perror(NULL);                                        \
+    perror(nullptr);                                     \
     exit(EXIT_FAILURE);                                  \
   }
 
+#include "src/main/tools/linux-sandbox-options.h"
+
 #include <errno.h>
 #include <sched.h>
 #include <stdarg.h>
@@ -32,13 +31,14 @@
 #include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
-
 #include <fstream>
 #include <iostream>
 #include <memory>
 #include <string>
 #include <vector>
 
+#include "src/main/tools/linux-sandbox-utils.h"
+
 using std::ifstream;
 using std::unique_ptr;
 using std::vector;
@@ -260,6 +260,6 @@ void ParseOptions(int argc, char *argv[]) {
   }
 
   if (opt.working_dir.empty()) {
-    opt.working_dir = getcwd(NULL, 0);
+    opt.working_dir = getcwd(nullptr, 0);
   }
 }

src/main/tools/linux-sandbox-options.h

@@ -17,7 +17,6 @@
 
 #include <stdbool.h>
 #include <stddef.h>
-
 #include <string>
 #include <vector>
 

src/main/tools/linux-sandbox-pid1.cc

@@ -17,9 +17,9 @@
  * mount, UTS, IPC and PID namespace.
  */
 
-#include "linux-sandbox-options.h"
-#include "linux-sandbox-utils.h"
-#include "linux-sandbox.h"
+#include "src/main/tools/linux-sandbox-options.h"
+#include "src/main/tools/linux-sandbox-utils.h"
+#include "src/main/tools/linux-sandbox.h"
 
 // Note that we define DIE() here and not in a shared header, because we want to
 // use _exit() in the
@@ -28,7 +28,7 @@
   {                                                      \
     fprintf(stderr, __FILE__ ":" S__LINE__ ": \"" args); \
     fprintf(stderr, "\": ");                             \
-    perror(NULL);                                        \
+    perror(nullptr);                                     \
     _exit(EXIT_FAILURE);                                 \
   }
 
@@ -84,14 +84,14 @@ static void SetupSelfDestruction(int *sync_pipe) {
 static void SetupMountNamespace() {
   // Fully isolate our mount namespace private from outside events, so that
   // mounts in the outside environment do not affect our sandbox.
-  if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL) < 0) {
+  if (mount(nullptr, "/", nullptr, MS_REC | MS_PRIVATE, nullptr) < 0) {
     DIE("mount");
   }
 }
 
 static void WriteFile(const std::string &filename, const char *fmt, ...) {
   FILE *stream = fopen(filename.c_str(), "w");
-  if (stream == NULL) {
+  if (stream == nullptr) {
     DIE("fopen(%s)", filename.c_str());
   }
 
@@ -130,7 +130,7 @@ static void SetupUserNamespace() {
   } else if (opt.fake_username) {
     // Change our username to 'nobody'.
     struct passwd *pwd = getpwnam("nobody");
-    if (pwd == NULL) {
+    if (pwd == nullptr) {
       DIE("unable to find passwd entry for user nobody")
     }
 
@@ -160,8 +160,8 @@ static void MountFilesystems() {
   for (const std::string &tmpfs_dir : opt.tmpfs_dirs) {
     PRINT_DEBUG("tmpfs: %s", tmpfs_dir.c_str());
     if (mount("tmpfs", tmpfs_dir.c_str(), "tmpfs",
-              MS_NOSUID | MS_NODEV | MS_NOATIME, NULL) < 0) {
-      DIE("mount(tmpfs, %s, tmpfs, MS_NOSUID | MS_NODEV | MS_NOATIME, NULL)",
+              MS_NOSUID | MS_NODEV | MS_NOATIME, nullptr) < 0) {
+      DIE("mount(tmpfs, %s, tmpfs, MS_NOSUID | MS_NODEV | MS_NOATIME, nullptr)",
           tmpfs_dir.c_str());
     }
   }
@@ -170,26 +170,27 @@ static void MountFilesystems() {
   // do this is by bind-mounting it upon itself.
   PRINT_DEBUG("working dir: %s", opt.working_dir.c_str());
 
-  if (mount(opt.working_dir.c_str(), opt.working_dir.c_str(), NULL, MS_BIND,
-            NULL) < 0) {
-    DIE("mount(%s, %s, NULL, MS_BIND, NULL)", opt.working_dir.c_str(),
+  if (mount(opt.working_dir.c_str(), opt.working_dir.c_str(), nullptr, MS_BIND,
+            nullptr) < 0) {
+    DIE("mount(%s, %s, nullptr, MS_BIND, nullptr)", opt.working_dir.c_str(),
         opt.working_dir.c_str());
   }
 
   for (size_t i = 0; i < opt.bind_mount_sources.size(); i++) {
     std::string source = opt.bind_mount_sources.at(i);
     std::string target = opt.bind_mount_targets.at(i);
     PRINT_DEBUG("bind mount: %s -> %s", source.c_str(), target.c_str());
-    if (mount(source.c_str(), target.c_str(), NULL, MS_BIND, NULL) < 0) {
-      DIE("mount(%s, %s, NULL, MS_BIND, NULL)", source.c_str(), target.c_str());
+    if (mount(source.c_str(), target.c_str(), nullptr, MS_BIND, nullptr) < 0) {
+      DIE("mount(%s, %s, nullptr, MS_BIND, nullptr)", source.c_str(),
+          target.c_str());
     }
   }
 
   for (const std::string &writable_file : opt.writable_files) {
     PRINT_DEBUG("writable: %s", writable_file.c_str());
-    if (mount(writable_file.c_str(), writable_file.c_str(), NULL, MS_BIND,
-              NULL) < 0) {
-      DIE("mount(%s, %s, NULL, MS_BIND, NULL)", writable_file.c_str(),
+    if (mount(writable_file.c_str(), writable_file.c_str(), nullptr, MS_BIND,
+              nullptr) < 0) {
+      DIE("mount(%s, %s, nullptr, MS_BIND, nullptr)", writable_file.c_str(),
           writable_file.c_str());
     }
   }
@@ -221,34 +222,34 @@ static bool ShouldBeWritable(const std::string &mnt_dir) {
 // ShouldBeWritable returns true.
 static void MakeFilesystemMostlyReadOnly() {
   FILE *mounts = setmntent("/proc/self/mounts", "r");
-  if (mounts == NULL) {
+  if (mounts == nullptr) {
     DIE("setmntent");
   }
 
   struct mntent *ent;
-  while ((ent = getmntent(mounts)) != NULL) {
+  while ((ent = getmntent(mounts)) != nullptr) {
     int mountFlags = MS_BIND | MS_REMOUNT;
 
     // MS_REMOUNT does not allow us to change certain flags. This means, we have
     // to first read them out and then pass them in back again. There seems to
     // be no better way than this (an API for just getting the mount flags of a
     // mount entry as a bitmask would be great).
-    if (hasmntopt(ent, "nodev") != NULL) {
+    if (hasmntopt(ent, "nodev") != nullptr) {
       mountFlags |= MS_NODEV;
     }
-    if (hasmntopt(ent, "noexec") != NULL) {
+    if (hasmntopt(ent, "noexec") != nullptr) {
       mountFlags |= MS_NOEXEC;
     }
-    if (hasmntopt(ent, "nosuid") != NULL) {
+    if (hasmntopt(ent, "nosuid") != nullptr) {
       mountFlags |= MS_NOSUID;
     }
-    if (hasmntopt(ent, "noatime") != NULL) {
+    if (hasmntopt(ent, "noatime") != nullptr) {
       mountFlags |= MS_NOATIME;
     }
-    if (hasmntopt(ent, "nodiratime") != NULL) {
+    if (hasmntopt(ent, "nodiratime") != nullptr) {
       mountFlags |= MS_NODIRATIME;
     }
-    if (hasmntopt(ent, "relatime") != NULL) {
+    if (hasmntopt(ent, "relatime") != nullptr) {
       mountFlags |= MS_RELATIME;
     }
 
@@ -258,7 +259,7 @@ static void MakeFilesystemMostlyReadOnly() {
 
     PRINT_DEBUG("remount %s: %s", (mountFlags & MS_RDONLY) ? "ro" : "rw",
                 ent->mnt_dir);
-    if (mount(NULL, ent->mnt_dir, NULL, mountFlags, NULL) < 0) {
+    if (mount(nullptr, ent->mnt_dir, nullptr, mountFlags, nullptr) < 0) {
       // If we get EACCES or EPERM, this might be a mount-point for which we
       // don't have read access. Not much we can do about this, but it also
       // won't do any harm, so let's go on. The same goes for EINVAL or ENOENT,
@@ -272,7 +273,8 @@ static void MakeFilesystemMostlyReadOnly() {
       // should just ignore it.
       if (errno != EACCES && errno != EPERM && errno != EINVAL &&
           errno != ENOENT && errno != ESTALE) {
-        DIE("remount(NULL, %s, NULL, %d, NULL)", ent->mnt_dir, mountFlags);
+        DIE("remount(nullptr, %s, nullptr, %d, nullptr)", ent->mnt_dir,
+            mountFlags);
       }
     }
   }
@@ -283,8 +285,8 @@ static void MakeFilesystemMostlyReadOnly() {
 static void MountProc() {
   // Mount a new proc on top of the old one, because the old one still refers to
   // our parent PID namespace.
-  if (mount("/proc", "/proc", "proc", MS_NODEV | MS_NOEXEC | MS_NOSUID, NULL) <
-      0) {
+  if (mount("/proc", "/proc", "proc", MS_NODEV | MS_NOEXEC | MS_NOSUID,
+            nullptr) < 0) {
     DIE("mount");
   }
 }
@@ -345,8 +347,8 @@ static void InstallSignalHandler(int signum, void (*handler)(int)) {
   }
   // sigaction may fail for certain reserved signals. Ignore failure in this
   // case, but report it in debug mode, just in case.
-  if (sigaction(signum, &sa, NULL) < 0) {
-    PRINT_DEBUG("sigaction(%d, &sa, NULL) failed", signum);
+  if (sigaction(signum, &sa, nullptr) < 0) {
+    PRINT_DEBUG("sigaction(%d, &sa, nullptr) failed", signum);
   }
 }
 

src/main/tools/linux-sandbox.cc

@@ -37,15 +37,11 @@
  *    system are invisible.
  */
 
-#include "linux-sandbox-options.h"
-#include "linux-sandbox-pid1.h"
-#include "linux-sandbox-utils.h"
-
 #define DIE(args...)                                     \
   {                                                      \
     fprintf(stderr, __FILE__ ":" S__LINE__ ": \"" args); \
     fprintf(stderr, "\": ");                             \
-    perror(NULL);                                        \
+    perror(nullptr);                                     \
     exit(EXIT_FAILURE);                                  \
   }
 
@@ -66,10 +62,13 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
-
 #include <string>
 #include <vector>
 
+#include "src/main/tools/linux-sandbox-options.h"
+#include "src/main/tools/linux-sandbox-pid1.h"
+#include "src/main/tools/linux-sandbox-utils.h"
+
 int global_outer_uid;
 int global_outer_gid;
 
@@ -83,15 +82,15 @@ static volatile sig_atomic_t global_signal;
 
 static void CloseFds() {
   DIR *fds = opendir("/proc/self/fd");
-  if (fds == NULL) {
+  if (fds == nullptr) {
     DIE("opendir");
   }
 
   while (1) {
     errno = 0;
     struct dirent *dent = readdir(fds);
 
-    if (dent == NULL) {
+    if (dent == nullptr) {
       if (errno != 0) {
         DIE("readdir");
       }
@@ -125,7 +124,7 @@ static void HandleSignal(int signum, void (*handler)(int)) {
   if (sigemptyset(&sa.sa_mask) < 0) {
     DIE("sigemptyset");
   }
-  if (sigaction(signum, &sa, NULL) < 0) {
+  if (sigaction(signum, &sa, nullptr) < 0) {
     DIE("sigaction");
   }
 }