1 /* Guts of POSIX spawn interface. Generic POSIX.1 version.
2 Copyright (C) 2000-2006, 2008-2019 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
22 #include "spawn_int.h"
29 # define O_LARGEFILE 0
32 #if _LIBC || HAVE_PATHS_H
35 # define _PATH_BSHELL BOURNE_SHELL
44 # include <not-cancel.h>
46 # define close_not_cancel close
47 # define open_not_cancel open
51 # include <local-setxid.h>
54 # define seteuid(id) setresuid (-1, id, -1)
57 # define setegid(id) setresgid (-1, id, -1)
59 # define local_seteuid(id) seteuid (id)
60 # define local_setegid(id) setegid (id)
64 # define alloca __alloca
65 # define execve __execve
68 # define getgid __getgid
69 # define getuid __getuid
70 # define sched_setparam __sched_setparam
71 # define sched_setscheduler __sched_setscheduler
72 # define setpgid __setpgid
73 # define sigaction __sigaction
74 # define sigismember __sigismember
75 # define sigprocmask __sigprocmask
76 # define strchrnul __strchrnul
77 # define vfork __vfork
79 # undef internal_function
80 # define internal_function /* empty */
84 /* The Unix standard contains a long explanation of the way to signal
85 an error after the fork() was successful. Since no new wait status
86 was wanted there is no way to signal an error using one of the
87 available methods. The committee chose to signal an error by a
88 normal program exit with the exit code 127. */
89 #define SPAWN_ERROR 127
92 #if defined _WIN32 && ! defined __CYGWIN__
94 /* Native Windows API. */
96 __spawni (pid_t
*pid
, const char *file
,
97 const posix_spawn_file_actions_t
*file_actions
,
98 const posix_spawnattr_t
*attrp
, char *const argv
[],
99 char *const envp
[], int use_path
)
101 /* Not yet implemented. */
108 /* The file is accessible but it is not an executable file. Invoke
109 the shell to interpret it as a script. */
112 script_execute (const char *file
, char *const argv
[], char *const envp
[])
114 /* Count the arguments. */
119 /* Construct an argument list for the shell. */
121 char **new_argv
= (char **) alloca ((argc
+ 1) * sizeof (char *));
122 new_argv
[0] = (char *) _PATH_BSHELL
;
123 new_argv
[1] = (char *) file
;
126 new_argv
[argc
] = argv
[argc
- 1];
130 /* Execute the shell. */
131 execve (new_argv
[0], new_argv
, envp
);
136 /* Spawn a new process executing PATH with the attributes describes in *ATTRP.
137 Before running the process perform the actions described in FILE-ACTIONS. */
139 __spawni (pid_t
*pid
, const char *file
,
140 const posix_spawn_file_actions_t
*file_actions
,
141 const posix_spawnattr_t
*attrp
, char *const argv
[],
142 char *const envp
[], int use_path
)
145 char *path
, *p
, *name
;
150 short int flags
= attrp
== NULL
? 0 : attrp
->_flags
;
153 "variable 'flags' might be clobbered by 'longjmp' or 'vfork'" */
156 /* Generate the new process. */
158 if ((flags
& POSIX_SPAWN_USEVFORK
) != 0
159 /* If no major work is done, allow using vfork. Note that we
160 might perform the path searching. But this would be done by
161 a call to execvp(), too, and such a call must be OK according
163 || ((flags
& (POSIX_SPAWN_SETSIGMASK
| POSIX_SPAWN_SETSIGDEF
164 | POSIX_SPAWN_SETSCHEDPARAM
| POSIX_SPAWN_SETSCHEDULER
165 | POSIX_SPAWN_SETPGROUP
| POSIX_SPAWN_RESETIDS
)) == 0
166 && file_actions
== NULL
))
177 /* The call was successful. Store the PID if necessary. */
184 /* Set signal mask. */
185 if ((flags
& POSIX_SPAWN_SETSIGMASK
) != 0
186 && sigprocmask (SIG_SETMASK
, &attrp
->_ss
, NULL
) != 0)
189 /* Set signal default action. */
190 if ((flags
& POSIX_SPAWN_SETSIGDEF
) != 0)
192 /* We have to iterate over all signals. This could possibly be
193 done better but it requires system specific solutions since
194 the sigset_t data type can be very different on different
199 memset (&sa
, '\0', sizeof (sa
));
200 sa
.sa_handler
= SIG_DFL
;
202 for (sig
= 1; sig
<= NSIG
; ++sig
)
203 if (sigismember (&attrp
->_sd
, sig
) != 0
204 && sigaction (sig
, &sa
, NULL
) != 0)
209 #if (_LIBC ? defined _POSIX_PRIORITY_SCHEDULING : HAVE_SCHED_SETPARAM && HAVE_SCHED_SETSCHEDULER)
210 /* Set the scheduling algorithm and parameters. */
211 if ((flags
& (POSIX_SPAWN_SETSCHEDPARAM
| POSIX_SPAWN_SETSCHEDULER
))
212 == POSIX_SPAWN_SETSCHEDPARAM
)
214 if (sched_setparam (0, &attrp
->_sp
) == -1)
217 else if ((flags
& POSIX_SPAWN_SETSCHEDULER
) != 0)
219 if (sched_setscheduler (0, attrp
->_policy
,
220 (flags
& POSIX_SPAWN_SETSCHEDPARAM
) != 0
221 ? &attrp
->_sp
: NULL
) == -1)
226 /* Set the process group ID. */
227 if ((flags
& POSIX_SPAWN_SETPGROUP
) != 0
228 && setpgid (0, attrp
->_pgrp
) != 0)
231 /* Set the effective user and group IDs. */
232 if ((flags
& POSIX_SPAWN_RESETIDS
) != 0
233 && (local_seteuid (getuid ()) != 0
234 || local_setegid (getgid ()) != 0))
237 /* Execute the file actions. */
238 if (file_actions
!= NULL
)
242 for (cnt
= 0; cnt
< file_actions
->_used
; ++cnt
)
244 struct __spawn_action
*action
= &file_actions
->_actions
[cnt
];
249 if (close_not_cancel (action
->action
.close_action
.fd
) != 0)
250 /* Signal the error. */
256 int new_fd
= open_not_cancel (action
->action
.open_action
.path
,
257 action
->action
.open_action
.oflag
259 action
->action
.open_action
.mode
);
262 /* The 'open' call failed. */
265 /* Make sure the desired file descriptor is used. */
266 if (new_fd
!= action
->action
.open_action
.fd
)
268 if (dup2 (new_fd
, action
->action
.open_action
.fd
)
269 != action
->action
.open_action
.fd
)
270 /* The 'dup2' call failed. */
273 if (close_not_cancel (new_fd
) != 0)
274 /* The 'close' call failed. */
281 if (dup2 (action
->action
.dup2_action
.fd
,
282 action
->action
.dup2_action
.newfd
)
283 != action
->action
.dup2_action
.newfd
)
284 /* The 'dup2' call failed. */
289 if (chdir (action
->action
.chdir_action
.path
) < 0)
290 /* The 'chdir' call failed. */
294 case spawn_do_fchdir
:
295 if (fchdir (action
->action
.fchdir_action
.fd
) < 0)
296 /* The 'fchdir' call failed. */
303 if (! use_path
|| strchr (file
, '/') != NULL
)
305 /* The FILE parameter is actually a path. */
306 execve (file
, argv
, envp
);
308 if (errno
== ENOEXEC
)
309 script_execute (file
, argv
, envp
);
311 /* Oh, oh. 'execve' returns. This is bad. */
315 /* We have to search for FILE on the path. */
316 path
= getenv ("PATH");
320 /* There is no 'PATH' in the environment.
321 The default search path is the current directory
322 followed by the path 'confstr' returns for '_CS_PATH'. */
323 len
= confstr (_CS_PATH
, (char *) NULL
, 0);
324 path
= (char *) alloca (1 + len
);
326 (void) confstr (_CS_PATH
, path
+ 1, len
);
328 /* Pretend that the PATH contains only the current directory. */
333 len
= strlen (file
) + 1;
334 pathlen
= strlen (path
);
335 name
= alloca (pathlen
+ len
+ 1);
336 /* Copy the file name at the top. */
337 name
= (char *) memcpy (name
+ pathlen
+ 1, file
, len
);
338 /* And add the slash. */
347 p
= strchrnul (path
, ':');
350 /* Two adjacent colons, or a colon at the beginning or the end
351 of 'PATH' means to search the current directory. */
354 startp
= (char *) memcpy (name
- (p
- path
), path
, p
- path
);
356 /* Try to execute this name. If it works, execv will not return. */
357 execve (startp
, argv
, envp
);
359 if (errno
== ENOEXEC
)
360 script_execute (startp
, argv
, envp
);
368 /* Those errors indicate the file is missing or not executable
369 by us, in which case we want to just try the next path
374 /* Some other error means we found an executable file, but
375 something went wrong executing it; return the error to our
380 while (*p
++ != '\0');
382 /* Return with an error. */