1 files changed, 138 insertions, 0 deletions
diff --git a/src/shrpx_exec.cc b/src/shrpx_exec.cc
new file mode 100644
index 0000000..d5cd091
--- /dev/null
+++ b/src/shrpx_exec.cc
@@ -0,0 +1,138 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2016 Tatsuhiro Tsujikawa
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "shrpx_exec.h"
+
+#include <cerrno>
+
+#include "shrpx_signal.h"
+#include "shrpx_log.h"
+#include "util.h"
+#include "template.h"
+
+using namespace nghttp2;
+
+namespace shrpx {
+
+// inspired by h2o_read_command function from h2o project:
+// https://github.com/h2o/h2o
+int exec_read_command(Process &proc, char *const argv[]) {
+  int rv;
+  int pfd[2];
+
+#ifdef O_CLOEXEC
+  if (pipe2(pfd, O_CLOEXEC) == -1) {
+    return -1;
+  }
+#else  // !O_CLOEXEC
+  if (pipe(pfd) == -1) {
+    return -1;
+  }
+  util::make_socket_closeonexec(pfd[0]);
+  util::make_socket_closeonexec(pfd[1]);
+#endif // !O_CLOEXEC
+
+  auto closer = defer([&pfd]() {
+    if (pfd[0] != -1) {
+      close(pfd[0]);
+    }
+
+    if (pfd[1] != -1) {
+      close(pfd[1]);
+    }
+  });
+
+  sigset_t oldset;
+
+  rv = shrpx_signal_block_all(&oldset);
+  if (rv != 0) {
+    auto error = errno;
+    LOG(ERROR) << "Blocking all signals failed: errno=" << error;
+
+    return -1;
+  }
+
+  auto pid = fork();
+
+  if (pid == 0) {
+    // This is multithreaded program, and we are allowed to use only
+    // async-signal-safe functions here.
+
+    // child process
+    shrpx_signal_unset_worker_proc_ign_handler();
+
+    rv = shrpx_signal_unblock_all();
+    if (rv != 0) {
+      static constexpr char msg[] = "Unblocking all signals failed\n";
+      while (write(STDERR_FILENO, msg, str_size(msg)) == -1 && errno == EINTR)
+        ;
+      nghttp2_Exit(EXIT_FAILURE);
+    }
+
+    dup2(pfd[1], 1);
+    close(pfd[0]);
+
+    rv = execv(argv[0], argv);
+    if (rv == -1) {
+      static constexpr char msg[] = "Could not execute command\n";
+      while (write(STDERR_FILENO, msg, str_size(msg)) == -1 && errno == EINTR)
+        ;
+      nghttp2_Exit(EXIT_FAILURE);
+    }
+    // unreachable
+  }
+
+  // parent process
+  if (pid == -1) {
+    auto error = errno;
+    LOG(ERROR) << "Could not execute command: " << argv[0]
+               << ", fork() failed, errno=" << error;
+  }
+
+  rv = shrpx_signal_set(&oldset);
+  if (rv != 0) {
+    auto error = errno;
+    LOG(FATAL) << "Restoring all signals failed: errno=" << error;
+
+    nghttp2_Exit(EXIT_FAILURE);
+  }
+
+  if (pid == -1) {
+    return -1;
+  }
+
+  close(pfd[1]);
+  pfd[1] = -1;
+
+  util::make_socket_nonblocking(pfd[0]);
+
+  proc.pid = pid;
+  proc.rfd = pfd[0];
+
+  pfd[0] = -1;
+
+  return 0;
+}
+
+} // namespace shrpx