summaryrefslogtreecommitdiffstats
path: root/lib/spawni.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:06:57 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:06:57 +0000
commita3eed2c248067f0319cb72bcc8b5e2c7054ea6dc (patch)
treefd79d650c7ffee81608955be5f4fd8edd791834e /lib/spawni.c
parentInitial commit. (diff)
downloadwget-a3eed2c248067f0319cb72bcc8b5e2c7054ea6dc.tar.xz
wget-a3eed2c248067f0319cb72bcc8b5e2c7054ea6dc.zip
Adding upstream version 1.20.1.upstream/1.20.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/spawni.c')
-rw-r--r--lib/spawni.c380
1 files changed, 380 insertions, 0 deletions
diff --git a/lib/spawni.c b/lib/spawni.c
new file mode 100644
index 0000000..05dc8b4
--- /dev/null
+++ b/lib/spawni.c
@@ -0,0 +1,380 @@
+/* Guts of POSIX spawn interface. Generic POSIX.1 version.
+ Copyright (C) 2000-2006, 2008-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <spawn.h>
+#include "spawn_int.h"
+
+#include <alloca.h>
+#include <errno.h>
+
+#include <fcntl.h>
+#ifndef O_LARGEFILE
+# define O_LARGEFILE 0
+#endif
+
+#if _LIBC || HAVE_PATHS_H
+# include <paths.h>
+#else
+# define _PATH_BSHELL BOURNE_SHELL
+#endif
+
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#if _LIBC
+# include <not-cancel.h>
+#else
+# define close_not_cancel close
+# define open_not_cancel open
+#endif
+
+#if _LIBC
+# include <local-setxid.h>
+#else
+# if !HAVE_SETEUID
+# define seteuid(id) setresuid (-1, id, -1)
+# endif
+# if !HAVE_SETEGID
+# define setegid(id) setresgid (-1, id, -1)
+# endif
+# define local_seteuid(id) seteuid (id)
+# define local_setegid(id) setegid (id)
+#endif
+
+#if _LIBC
+# define alloca __alloca
+# define execve __execve
+# define dup2 __dup2
+# define fork __fork
+# define getgid __getgid
+# define getuid __getuid
+# define sched_setparam __sched_setparam
+# define sched_setscheduler __sched_setscheduler
+# define setpgid __setpgid
+# define sigaction __sigaction
+# define sigismember __sigismember
+# define sigprocmask __sigprocmask
+# define strchrnul __strchrnul
+# define vfork __vfork
+#else
+# undef internal_function
+# define internal_function /* empty */
+#endif
+
+
+/* The Unix standard contains a long explanation of the way to signal
+ an error after the fork() was successful. Since no new wait status
+ was wanted there is no way to signal an error using one of the
+ available methods. The committee chose to signal an error by a
+ normal program exit with the exit code 127. */
+#define SPAWN_ERROR 127
+
+
+#if defined _WIN32 && ! defined __CYGWIN__
+
+/* Native Windows API. */
+int
+__spawni (pid_t *pid, const char *file,
+ const posix_spawn_file_actions_t *file_actions,
+ const posix_spawnattr_t *attrp, char *const argv[],
+ char *const envp[], int use_path)
+{
+ /* Not yet implemented. */
+ return ENOSYS;
+}
+
+#else
+
+
+/* The file is accessible but it is not an executable file. Invoke
+ the shell to interpret it as a script. */
+static void
+internal_function
+script_execute (const char *file, char *const argv[], char *const envp[])
+{
+ /* Count the arguments. */
+ int argc = 0;
+ while (argv[argc++])
+ ;
+
+ /* Construct an argument list for the shell. */
+ {
+ char **new_argv = (char **) alloca ((argc + 1) * sizeof (char *));
+ new_argv[0] = (char *) _PATH_BSHELL;
+ new_argv[1] = (char *) file;
+ while (argc > 1)
+ {
+ new_argv[argc] = argv[argc - 1];
+ --argc;
+ }
+
+ /* Execute the shell. */
+ execve (new_argv[0], new_argv, envp);
+ }
+}
+
+
+/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
+ Before running the process perform the actions described in FILE-ACTIONS. */
+int
+__spawni (pid_t *pid, const char *file,
+ const posix_spawn_file_actions_t *file_actions,
+ const posix_spawnattr_t *attrp, char *const argv[],
+ char *const envp[], int use_path)
+{
+ pid_t new_pid;
+ char *path, *p, *name;
+ size_t len;
+ size_t pathlen;
+
+ /* Do this once. */
+ short int flags = attrp == NULL ? 0 : attrp->_flags;
+
+ /* Avoid gcc warning
+ "variable 'flags' might be clobbered by 'longjmp' or 'vfork'" */
+ (void) &flags;
+
+ /* Generate the new process. */
+#if HAVE_VFORK
+ if ((flags & POSIX_SPAWN_USEVFORK) != 0
+ /* If no major work is done, allow using vfork. Note that we
+ might perform the path searching. But this would be done by
+ a call to execvp(), too, and such a call must be OK according
+ to POSIX. */
+ || ((flags & (POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF
+ | POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER
+ | POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_RESETIDS)) == 0
+ && file_actions == NULL))
+ new_pid = vfork ();
+ else
+#endif
+ new_pid = fork ();
+
+ if (new_pid != 0)
+ {
+ if (new_pid < 0)
+ return errno;
+
+ /* The call was successful. Store the PID if necessary. */
+ if (pid != NULL)
+ *pid = new_pid;
+
+ return 0;
+ }
+
+ /* Set signal mask. */
+ if ((flags & POSIX_SPAWN_SETSIGMASK) != 0
+ && sigprocmask (SIG_SETMASK, &attrp->_ss, NULL) != 0)
+ _exit (SPAWN_ERROR);
+
+ /* Set signal default action. */
+ if ((flags & POSIX_SPAWN_SETSIGDEF) != 0)
+ {
+ /* We have to iterate over all signals. This could possibly be
+ done better but it requires system specific solutions since
+ the sigset_t data type can be very different on different
+ architectures. */
+ int sig;
+ struct sigaction sa;
+
+ memset (&sa, '\0', sizeof (sa));
+ sa.sa_handler = SIG_DFL;
+
+ for (sig = 1; sig <= NSIG; ++sig)
+ if (sigismember (&attrp->_sd, sig) != 0
+ && sigaction (sig, &sa, NULL) != 0)
+ _exit (SPAWN_ERROR);
+
+ }
+
+#if (_LIBC ? defined _POSIX_PRIORITY_SCHEDULING : HAVE_SCHED_SETPARAM && HAVE_SCHED_SETSCHEDULER)
+ /* Set the scheduling algorithm and parameters. */
+ if ((flags & (POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER))
+ == POSIX_SPAWN_SETSCHEDPARAM)
+ {
+ if (sched_setparam (0, &attrp->_sp) == -1)
+ _exit (SPAWN_ERROR);
+ }
+ else if ((flags & POSIX_SPAWN_SETSCHEDULER) != 0)
+ {
+ if (sched_setscheduler (0, attrp->_policy,
+ (flags & POSIX_SPAWN_SETSCHEDPARAM) != 0
+ ? &attrp->_sp : NULL) == -1)
+ _exit (SPAWN_ERROR);
+ }
+#endif
+
+ /* Set the process group ID. */
+ if ((flags & POSIX_SPAWN_SETPGROUP) != 0
+ && setpgid (0, attrp->_pgrp) != 0)
+ _exit (SPAWN_ERROR);
+
+ /* Set the effective user and group IDs. */
+ if ((flags & POSIX_SPAWN_RESETIDS) != 0
+ && (local_seteuid (getuid ()) != 0
+ || local_setegid (getgid ()) != 0))
+ _exit (SPAWN_ERROR);
+
+ /* Execute the file actions. */
+ if (file_actions != NULL)
+ {
+ int cnt;
+
+ for (cnt = 0; cnt < file_actions->_used; ++cnt)
+ {
+ struct __spawn_action *action = &file_actions->_actions[cnt];
+
+ switch (action->tag)
+ {
+ case spawn_do_close:
+ if (close_not_cancel (action->action.close_action.fd) != 0)
+ /* Signal the error. */
+ _exit (SPAWN_ERROR);
+ break;
+
+ case spawn_do_open:
+ {
+ int new_fd = open_not_cancel (action->action.open_action.path,
+ action->action.open_action.oflag
+ | O_LARGEFILE,
+ action->action.open_action.mode);
+
+ if (new_fd == -1)
+ /* The 'open' call failed. */
+ _exit (SPAWN_ERROR);
+
+ /* Make sure the desired file descriptor is used. */
+ if (new_fd != action->action.open_action.fd)
+ {
+ if (dup2 (new_fd, action->action.open_action.fd)
+ != action->action.open_action.fd)
+ /* The 'dup2' call failed. */
+ _exit (SPAWN_ERROR);
+
+ if (close_not_cancel (new_fd) != 0)
+ /* The 'close' call failed. */
+ _exit (SPAWN_ERROR);
+ }
+ }
+ break;
+
+ case spawn_do_dup2:
+ if (dup2 (action->action.dup2_action.fd,
+ action->action.dup2_action.newfd)
+ != action->action.dup2_action.newfd)
+ /* The 'dup2' call failed. */
+ _exit (SPAWN_ERROR);
+ break;
+
+ case spawn_do_chdir:
+ if (chdir (action->action.chdir_action.path) < 0)
+ /* The 'chdir' call failed. */
+ _exit (SPAWN_ERROR);
+ break;
+ }
+ }
+ }
+
+ if (! use_path || strchr (file, '/') != NULL)
+ {
+ /* The FILE parameter is actually a path. */
+ execve (file, argv, envp);
+
+ if (errno == ENOEXEC)
+ script_execute (file, argv, envp);
+
+ /* Oh, oh. 'execve' returns. This is bad. */
+ _exit (SPAWN_ERROR);
+ }
+
+ /* We have to search for FILE on the path. */
+ path = getenv ("PATH");
+ if (path == NULL)
+ {
+#if HAVE_CONFSTR
+ /* There is no 'PATH' in the environment.
+ The default search path is the current directory
+ followed by the path 'confstr' returns for '_CS_PATH'. */
+ len = confstr (_CS_PATH, (char *) NULL, 0);
+ path = (char *) alloca (1 + len);
+ path[0] = ':';
+ (void) confstr (_CS_PATH, path + 1, len);
+#else
+ /* Pretend that the PATH contains only the current directory. */
+ path = "";
+#endif
+ }
+
+ len = strlen (file) + 1;
+ pathlen = strlen (path);
+ name = alloca (pathlen + len + 1);
+ /* Copy the file name at the top. */
+ name = (char *) memcpy (name + pathlen + 1, file, len);
+ /* And add the slash. */
+ *--name = '/';
+
+ p = path;
+ do
+ {
+ char *startp;
+
+ path = p;
+ p = strchrnul (path, ':');
+
+ if (p == path)
+ /* Two adjacent colons, or a colon at the beginning or the end
+ of 'PATH' means to search the current directory. */
+ startp = name + 1;
+ else
+ startp = (char *) memcpy (name - (p - path), path, p - path);
+
+ /* Try to execute this name. If it works, execv will not return. */
+ execve (startp, argv, envp);
+
+ if (errno == ENOEXEC)
+ script_execute (startp, argv, envp);
+
+ switch (errno)
+ {
+ case EACCES:
+ case ENOENT:
+ case ESTALE:
+ case ENOTDIR:
+ /* Those errors indicate the file is missing or not executable
+ by us, in which case we want to just try the next path
+ directory. */
+ break;
+
+ default:
+ /* Some other error means we found an executable file, but
+ something went wrong executing it; return the error to our
+ caller. */
+ _exit (SPAWN_ERROR);
+ }
+ }
+ while (*p++ != '\0');
+
+ /* Return with an error. */
+ _exit (SPAWN_ERROR);
+}
+
+#endif