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-rw-r--r--lib/spawn-pipe.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/lib/spawn-pipe.c b/lib/spawn-pipe.c
new file mode 100644
index 0000000..ec9bd9d
--- /dev/null
+++ b/lib/spawn-pipe.c
@@ -0,0 +1,453 @@
+/* Creation of subprocesses, communicating via pipes.
+ Copyright (C) 2001-2004, 2006-2018 Free Software Foundation, Inc.
+ Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+
+/* Tell clang not to warn about the 'child' variable, below. */
+#if defined __clang__
+# pragma clang diagnostic ignored "-Wconditional-uninitialized"
+#endif
+
+#include <config.h>
+
+/* Specification. */
+#include "spawn-pipe.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include "error.h"
+#include "fatal-signal.h"
+#include "unistd-safer.h"
+#include "wait-process.h"
+#include "gettext.h"
+
+#define _(str) gettext (str)
+
+#if (defined _WIN32 && ! defined __CYGWIN__) || defined __KLIBC__
+
+/* Native Windows API. */
+# include <process.h>
+# include "w32spawn.h"
+
+#else
+
+/* Unix API. */
+# include <spawn.h>
+
+#endif
+
+
+#ifdef EINTR
+
+/* EINTR handling for close().
+ These functions can return -1/EINTR even though we don't have any
+ signal handlers set up, namely when we get interrupted via SIGSTOP. */
+
+static int
+nonintr_close (int fd)
+{
+ int retval;
+
+ do
+ retval = close (fd);
+ while (retval < 0 && errno == EINTR);
+
+ return retval;
+}
+#undef close /* avoid warning related to gnulib module unistd */
+#define close nonintr_close
+
+#if defined _WIN32 && ! defined __CYGWIN__
+static int
+nonintr_open (const char *pathname, int oflag, mode_t mode)
+{
+ int retval;
+
+ do
+ retval = open (pathname, oflag, mode);
+ while (retval < 0 && errno == EINTR);
+
+ return retval;
+}
+# undef open /* avoid warning on VMS */
+# define open nonintr_open
+#endif
+
+#endif
+
+
+/* Open a pipe connected to a child process.
+ *
+ * write system read
+ * parent -> fd[1] -> STDIN_FILENO -> child if pipe_stdin
+ * parent <- fd[0] <- STDOUT_FILENO <- child if pipe_stdout
+ * read system write
+ *
+ * At least one of pipe_stdin, pipe_stdout must be true.
+ * pipe_stdin and prog_stdin together determine the child's standard input.
+ * pipe_stdout and prog_stdout together determine the child's standard output.
+ * If pipe_stdin is true, prog_stdin is ignored.
+ * If pipe_stdout is true, prog_stdout is ignored.
+ */
+static pid_t
+create_pipe (const char *progname,
+ const char *prog_path, char **prog_argv,
+ bool pipe_stdin, bool pipe_stdout,
+ const char *prog_stdin, const char *prog_stdout,
+ bool null_stderr,
+ bool slave_process, bool exit_on_error,
+ int fd[2])
+{
+#if (defined _WIN32 && ! defined __CYGWIN__) || defined __KLIBC__
+
+ /* Native Windows API.
+ This uses _pipe(), dup2(), and spawnv(). It could also be implemented
+ using the low-level functions CreatePipe(), DuplicateHandle(),
+ CreateProcess() and _open_osfhandle(); see the GNU make and GNU clisp
+ and cvs source code. */
+ int ifd[2];
+ int ofd[2];
+ int orig_stdin;
+ int orig_stdout;
+ int orig_stderr;
+ int child;
+ int nulloutfd;
+ int stdinfd;
+ int stdoutfd;
+ int saved_errno;
+
+ /* FIXME: Need to free memory allocated by prepare_spawn. */
+ prog_argv = prepare_spawn (prog_argv);
+
+ if (pipe_stdout)
+ if (pipe2_safer (ifd, O_BINARY | O_CLOEXEC) < 0)
+ error (EXIT_FAILURE, errno, _("cannot create pipe"));
+ if (pipe_stdin)
+ if (pipe2_safer (ofd, O_BINARY | O_CLOEXEC) < 0)
+ error (EXIT_FAILURE, errno, _("cannot create pipe"));
+/* Data flow diagram:
+ *
+ * write system read
+ * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
+ * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
+ * read system write
+ *
+ */
+
+ /* Save standard file handles of parent process. */
+ if (pipe_stdin || prog_stdin != NULL)
+ orig_stdin = dup_safer_noinherit (STDIN_FILENO);
+ if (pipe_stdout || prog_stdout != NULL)
+ orig_stdout = dup_safer_noinherit (STDOUT_FILENO);
+ if (null_stderr)
+ orig_stderr = dup_safer_noinherit (STDERR_FILENO);
+ child = -1;
+
+ /* Create standard file handles of child process. */
+ nulloutfd = -1;
+ stdinfd = -1;
+ stdoutfd = -1;
+ if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
+ && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
+ && (!null_stderr
+ || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
+ && (nulloutfd == STDERR_FILENO
+ || (dup2 (nulloutfd, STDERR_FILENO) >= 0
+ && close (nulloutfd) >= 0))))
+ && (pipe_stdin
+ || prog_stdin == NULL
+ || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
+ && (stdinfd == STDIN_FILENO
+ || (dup2 (stdinfd, STDIN_FILENO) >= 0
+ && close (stdinfd) >= 0))))
+ && (pipe_stdout
+ || prog_stdout == NULL
+ || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
+ && (stdoutfd == STDOUT_FILENO
+ || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
+ && close (stdoutfd) >= 0)))))
+ /* The child process doesn't inherit ifd[0], ifd[1], ofd[0], ofd[1],
+ but it inherits all open()ed or dup2()ed file handles (which is what
+ we want in the case of STD*_FILENO). */
+ /* Use spawnvpe and pass the environment explicitly. This is needed if
+ the program has modified the environment using putenv() or [un]setenv().
+ On Windows, programs have two environments, one in the "environment
+ block" of the process and managed through SetEnvironmentVariable(), and
+ one inside the process, in the location retrieved by the 'environ'
+ macro. When using spawnvp() without 'e', the child process inherits a
+ copy of the environment block - ignoring the effects of putenv() and
+ [un]setenv(). */
+ {
+ child = spawnvpe (P_NOWAIT, prog_path, (const char **) prog_argv,
+ (const char **) environ);
+ if (child < 0 && errno == ENOEXEC)
+ {
+ /* prog is not a native executable. Try to execute it as a
+ shell script. Note that prepare_spawn() has already prepended
+ a hidden element "sh.exe" to prog_argv. */
+ --prog_argv;
+ child = spawnvpe (P_NOWAIT, prog_argv[0], (const char **) prog_argv,
+ (const char **) environ);
+ }
+ }
+ if (child == -1)
+ saved_errno = errno;
+ if (stdinfd >= 0)
+ close (stdinfd);
+ if (stdoutfd >= 0)
+ close (stdoutfd);
+ if (nulloutfd >= 0)
+ close (nulloutfd);
+
+ /* Restore standard file handles of parent process. */
+ if (null_stderr)
+ undup_safer_noinherit (orig_stderr, STDERR_FILENO);
+ if (pipe_stdout || prog_stdout != NULL)
+ undup_safer_noinherit (orig_stdout, STDOUT_FILENO);
+ if (pipe_stdin || prog_stdin != NULL)
+ undup_safer_noinherit (orig_stdin, STDIN_FILENO);
+
+ if (pipe_stdin)
+ close (ofd[0]);
+ if (pipe_stdout)
+ close (ifd[1]);
+ if (child == -1)
+ {
+ if (exit_on_error || !null_stderr)
+ error (exit_on_error ? EXIT_FAILURE : 0, saved_errno,
+ _("%s subprocess failed"), progname);
+ if (pipe_stdout)
+ close (ifd[0]);
+ if (pipe_stdin)
+ close (ofd[1]);
+ errno = saved_errno;
+ return -1;
+ }
+
+ if (pipe_stdout)
+ fd[0] = ifd[0];
+ if (pipe_stdin)
+ fd[1] = ofd[1];
+ return child;
+
+#else
+
+ /* Unix API. */
+ int ifd[2];
+ int ofd[2];
+ sigset_t blocked_signals;
+ posix_spawn_file_actions_t actions;
+ bool actions_allocated;
+ posix_spawnattr_t attrs;
+ bool attrs_allocated;
+ int err;
+ pid_t child;
+
+ if (pipe_stdout)
+ if (pipe_safer (ifd) < 0)
+ error (EXIT_FAILURE, errno, _("cannot create pipe"));
+ if (pipe_stdin)
+ if (pipe_safer (ofd) < 0)
+ error (EXIT_FAILURE, errno, _("cannot create pipe"));
+/* Data flow diagram:
+ *
+ * write system read
+ * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
+ * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
+ * read system write
+ *
+ */
+
+ if (slave_process)
+ {
+ sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
+ block_fatal_signals ();
+ }
+ actions_allocated = false;
+ attrs_allocated = false;
+ if ((err = posix_spawn_file_actions_init (&actions)) != 0
+ || (actions_allocated = true,
+ (pipe_stdin
+ && (err = posix_spawn_file_actions_adddup2 (&actions,
+ ofd[0], STDIN_FILENO))
+ != 0)
+ || (pipe_stdout
+ && (err = posix_spawn_file_actions_adddup2 (&actions,
+ ifd[1], STDOUT_FILENO))
+ != 0)
+ || (pipe_stdin
+ && (err = posix_spawn_file_actions_addclose (&actions, ofd[0]))
+ != 0)
+ || (pipe_stdout
+ && (err = posix_spawn_file_actions_addclose (&actions, ifd[1]))
+ != 0)
+ || (pipe_stdin
+ && (err = posix_spawn_file_actions_addclose (&actions, ofd[1]))
+ != 0)
+ || (pipe_stdout
+ && (err = posix_spawn_file_actions_addclose (&actions, ifd[0]))
+ != 0)
+ || (null_stderr
+ && (err = posix_spawn_file_actions_addopen (&actions,
+ STDERR_FILENO,
+ "/dev/null", O_RDWR,
+ 0))
+ != 0)
+ || (!pipe_stdin
+ && prog_stdin != NULL
+ && (err = posix_spawn_file_actions_addopen (&actions,
+ STDIN_FILENO,
+ prog_stdin, O_RDONLY,
+ 0))
+ != 0)
+ || (!pipe_stdout
+ && prog_stdout != NULL
+ && (err = posix_spawn_file_actions_addopen (&actions,
+ STDOUT_FILENO,
+ prog_stdout, O_WRONLY,
+ 0))
+ != 0)
+ || (slave_process
+ && ((err = posix_spawnattr_init (&attrs)) != 0
+ || (attrs_allocated = true,
+ (err = posix_spawnattr_setsigmask (&attrs,
+ &blocked_signals))
+ != 0
+ || (err = posix_spawnattr_setflags (&attrs,
+ POSIX_SPAWN_SETSIGMASK))
+ != 0)))
+ || (err = posix_spawnp (&child, prog_path, &actions,
+ attrs_allocated ? &attrs : NULL, prog_argv,
+ environ))
+ != 0))
+ {
+ if (actions_allocated)
+ posix_spawn_file_actions_destroy (&actions);
+ if (attrs_allocated)
+ posix_spawnattr_destroy (&attrs);
+ if (slave_process)
+ unblock_fatal_signals ();
+ if (exit_on_error || !null_stderr)
+ error (exit_on_error ? EXIT_FAILURE : 0, err,
+ _("%s subprocess failed"), progname);
+ if (pipe_stdout)
+ {
+ close (ifd[0]);
+ close (ifd[1]);
+ }
+ if (pipe_stdin)
+ {
+ close (ofd[0]);
+ close (ofd[1]);
+ }
+ errno = err;
+ return -1;
+ }
+ posix_spawn_file_actions_destroy (&actions);
+ if (attrs_allocated)
+ posix_spawnattr_destroy (&attrs);
+ if (slave_process)
+ {
+ register_slave_subprocess (child);
+ unblock_fatal_signals ();
+ }
+ if (pipe_stdin)
+ close (ofd[0]);
+ if (pipe_stdout)
+ close (ifd[1]);
+
+ if (pipe_stdout)
+ fd[0] = ifd[0];
+ if (pipe_stdin)
+ fd[1] = ofd[1];
+ return child;
+
+#endif
+}
+
+/* Open a bidirectional pipe.
+ *
+ * write system read
+ * parent -> fd[1] -> STDIN_FILENO -> child
+ * parent <- fd[0] <- STDOUT_FILENO <- child
+ * read system write
+ *
+ */
+pid_t
+create_pipe_bidi (const char *progname,
+ const char *prog_path, char **prog_argv,
+ bool null_stderr,
+ bool slave_process, bool exit_on_error,
+ int fd[2])
+{
+ pid_t result = create_pipe (progname, prog_path, prog_argv,
+ true, true, NULL, NULL,
+ null_stderr, slave_process, exit_on_error,
+ fd);
+ return result;
+}
+
+/* Open a pipe for input from a child process.
+ * The child's stdin comes from a file.
+ *
+ * read system write
+ * parent <- fd[0] <- STDOUT_FILENO <- child
+ *
+ */
+pid_t
+create_pipe_in (const char *progname,
+ const char *prog_path, char **prog_argv,
+ const char *prog_stdin, bool null_stderr,
+ bool slave_process, bool exit_on_error,
+ int fd[1])
+{
+ int iofd[2];
+ pid_t result = create_pipe (progname, prog_path, prog_argv,
+ false, true, prog_stdin, NULL,
+ null_stderr, slave_process, exit_on_error,
+ iofd);
+ if (result != -1)
+ fd[0] = iofd[0];
+ return result;
+}
+
+/* Open a pipe for output to a child process.
+ * The child's stdout goes to a file.
+ *
+ * write system read
+ * parent -> fd[0] -> STDIN_FILENO -> child
+ *
+ */
+pid_t
+create_pipe_out (const char *progname,
+ const char *prog_path, char **prog_argv,
+ const char *prog_stdout, bool null_stderr,
+ bool slave_process, bool exit_on_error,
+ int fd[1])
+{
+ int iofd[2];
+ pid_t result = create_pipe (progname, prog_path, prog_argv,
+ true, false, NULL, prog_stdout,
+ null_stderr, slave_process, exit_on_error,
+ iofd);
+ if (result != -1)
+ fd[0] = iofd[1];
+ return result;
+}
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