1 files changed, 89 insertions, 0 deletions
diff --git a/libexec_spawn.c b/libexec_spawn.c
new file mode 100644
index 0000000..f0b46e6
--- /dev/null
+++ b/libexec_spawn.c
@@ -0,0 +1,89 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+int
+libexec_spawn(pid_t *out, struct libexec_command *cmd,
+              int (*after_fork)(struct libexec_command *cmd, int new_fd, void *user),
+              void *user, struct libexec_document **docsp, size_t *ndocsp, int doc_fd_flags)
+{
+	int fds[2], error, new_fd;
+	size_t i;
+	ssize_t r;
+
+	if (!docsp || !ndocsp || !out || !cmd) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	*out = -1;
+
+	if (pipe2(fds, O_CLOEXEC))
+		return -1;
+
+	new_fd = fds[1];
+	for (i = 0; i < cmd->nplumings; i++)
+		if (cmd->plumings[i].fd >= new_fd)
+			new_fd = cmd->plumings[i].fd + 1;
+
+	if (new_fd != fds[1]) {
+		new_fd = fcntl(fds[1], F_DUPFD_CLOEXEC, new_fd);
+		if (new_fd == -1)
+			goto fail;
+		fds[1] = new_fd;
+	}
+
+	if (libexec_get_documents(cmd, docsp, ndocsp, doc_fd_flags))
+		goto fail;
+
+	*out = fork();
+	switch (*out) {
+	case -1:
+		goto fail;
+
+	case 0:
+		close(fds[0]);
+		if (after_fork)
+			if ((*after_fork)(cmd, fds[1], user))
+				goto child_fail;
+		libexec_exec(cmd);
+	child_fail:
+		error = errno;
+	write_again:
+		r = write(fds[1], &error, sizeof(error));
+		if (r <= 0) {
+			if (errno == EINTR)
+				goto write_again;
+			abort();
+		}
+		_exit(1);
+
+	default:
+		close(fds[1]);
+	read_again:
+		r = read(fds[0], &error, sizeof(error));
+		if (r < 0) {
+			if (errno == EINTR)
+				goto read_again;
+		} else if (r == 0) {
+			return 0;
+		} else if ((size_t)r >= sizeof(error)) {
+			errno = error;
+		}
+
+		return -1;
+	}
+
+fail:
+	error = errno;
+	close(fds[0]);
+	close(fds[1]);
+	errno = error;
+	return -1;
+}
+
+
+#else
+LIBEXEC_CONST__ int main(void) {return 0;} /* TODO test */
+#endif