1 /* Guts of POSIX spawn interface. Generic POSIX.1 version.
2 Copyright (C) 2000-2005, 2006 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library 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 GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
27 #include "spawn_int.h"
28 #include <not-cancel.h>
31 /* The Unix standard contains a long explanation of the way to signal
32 an error after the fork() was successful. Since no new wait status
33 was wanted there is no way to signal an error using one of the
34 available methods. The committee chose to signal an error by a
35 normal program exit with the exit code 127. */
36 #define SPAWN_ERROR 127
39 /* The file is accessible but it is not an executable file. Invoke
40 the shell to interpret it as a script. */
43 script_execute (const char *file
, char *const argv
[], char *const envp
[])
45 /* Count the arguments. */
50 /* Construct an argument list for the shell. */
52 char *new_argv
[argc
+ 1];
53 new_argv
[0] = (char *) _PATH_BSHELL
;
54 new_argv
[1] = (char *) file
;
57 new_argv
[argc
] = argv
[argc
- 1];
61 /* Execute the shell. */
62 __execve (new_argv
[0], new_argv
, envp
);
67 /* Spawn a new process executing PATH with the attributes describes in *ATTRP.
68 Before running the process perform the actions described in FILE-ACTIONS. */
70 __spawni (pid_t
*pid
, const char *file
,
71 const posix_spawn_file_actions_t
*file_actions
,
72 const posix_spawnattr_t
*attrp
, char *const argv
[],
73 char *const envp
[], int use_path
)
76 char *path
, *p
, *name
;
81 short int flags
= attrp
== NULL
? 0 : attrp
->__flags
;
83 /* Generate the new process. */
84 if ((flags
& POSIX_SPAWN_USEVFORK
) != 0
85 /* If no major work is done, allow using vfork. Note that we
86 might perform the path searching. But this would be done by
87 a call to execvp(), too, and such a call must be OK according
89 || ((flags
& (POSIX_SPAWN_SETSIGMASK
| POSIX_SPAWN_SETSIGDEF
90 | POSIX_SPAWN_SETSCHEDPARAM
| POSIX_SPAWN_SETSCHEDULER
91 | POSIX_SPAWN_SETPGROUP
| POSIX_SPAWN_RESETIDS
)) == 0
92 && file_actions
== NULL
))
102 /* The call was successful. Store the PID if necessary. */
109 /* Set signal mask. */
110 if ((flags
& POSIX_SPAWN_SETSIGMASK
) != 0
111 && __sigprocmask (SIG_SETMASK
, &attrp
->__ss
, NULL
) != 0)
114 /* Set signal default action. */
115 if ((flags
& POSIX_SPAWN_SETSIGDEF
) != 0)
117 /* We have to iterate over all signals. This could possibly be
118 done better but it requires system specific solutions since
119 the sigset_t data type can be very different on different
124 memset (&sa
, '\0', sizeof (sa
));
125 sa
.sa_handler
= SIG_DFL
;
127 for (sig
= 1; sig
<= _NSIG
; ++sig
)
128 if (__sigismember (&attrp
->__sd
, sig
) != 0
129 && __sigaction (sig
, &sa
, NULL
) != 0)
134 #ifdef _POSIX_PRIORITY_SCHEDULING
135 /* Set the scheduling algorithm and parameters. */
136 if ((flags
& (POSIX_SPAWN_SETSCHEDPARAM
| POSIX_SPAWN_SETSCHEDULER
))
137 == POSIX_SPAWN_SETSCHEDPARAM
)
139 if (__sched_setparam (0, &attrp
->__sp
) == -1)
142 else if ((flags
& POSIX_SPAWN_SETSCHEDULER
) != 0)
144 if (__sched_setscheduler (0, attrp
->__policy
,
145 (flags
& POSIX_SPAWN_SETSCHEDPARAM
) != 0
146 ? &attrp
->__sp
: NULL
) == -1)
151 /* Set the process group ID. */
152 if ((flags
& POSIX_SPAWN_SETPGROUP
) != 0
153 && __setpgid (0, attrp
->__pgrp
) != 0)
156 /* Set the effective user and group IDs. */
157 if ((flags
& POSIX_SPAWN_RESETIDS
) != 0
158 && (seteuid (__getuid ()) != 0 || setegid (__getgid ()) != 0))
161 /* Execute the file actions. */
162 if (file_actions
!= NULL
)
166 for (cnt
= 0; cnt
< file_actions
->__used
; ++cnt
)
168 struct __spawn_action
*action
= &file_actions
->__actions
[cnt
];
173 if (close_not_cancel (action
->action
.close_action
.fd
) != 0)
174 /* Signal the error. */
180 int new_fd
= open_not_cancel (action
->action
.open_action
.path
,
181 action
->action
.open_action
.oflag
183 action
->action
.open_action
.mode
);
186 /* The `open' call failed. */
189 /* Make sure the desired file descriptor is used. */
190 if (new_fd
!= action
->action
.open_action
.fd
)
192 if (__dup2 (new_fd
, action
->action
.open_action
.fd
)
193 != action
->action
.open_action
.fd
)
194 /* The `dup2' call failed. */
197 if (close_not_cancel (new_fd
) != 0)
198 /* The `close' call failed. */
205 if (__dup2 (action
->action
.dup2_action
.fd
,
206 action
->action
.dup2_action
.newfd
)
207 != action
->action
.dup2_action
.newfd
)
208 /* The `dup2' call failed. */
215 if (! use_path
|| strchr (file
, '/') != NULL
)
217 /* The FILE parameter is actually a path. */
218 __execve (file
, argv
, envp
);
220 if (errno
== ENOEXEC
)
221 script_execute (file
, argv
, envp
);
223 /* Oh, oh. `execve' returns. This is bad. */
227 /* We have to search for FILE on the path. */
228 path
= getenv ("PATH");
231 /* There is no `PATH' in the environment.
232 The default search path is the current directory
233 followed by the path `confstr' returns for `_CS_PATH'. */
234 len
= confstr (_CS_PATH
, (char *) NULL
, 0);
235 path
= (char *) __alloca (1 + len
);
237 (void) confstr (_CS_PATH
, path
+ 1, len
);
240 len
= strlen (file
) + 1;
241 pathlen
= strlen (path
);
242 name
= __alloca (pathlen
+ len
+ 1);
243 /* Copy the file name at the top. */
244 name
= (char *) memcpy (name
+ pathlen
+ 1, file
, len
);
245 /* And add the slash. */
254 p
= __strchrnul (path
, ':');
257 /* Two adjacent colons, or a colon at the beginning or the end
258 of `PATH' means to search the current directory. */
261 startp
= (char *) memcpy (name
- (p
- path
), path
, p
- path
);
263 /* Try to execute this name. If it works, execv will not return. */
264 __execve (startp
, argv
, envp
);
266 if (errno
== ENOEXEC
)
267 script_execute (startp
, argv
, envp
);
275 /* Those errors indicate the file is missing or not executable
276 by us, in which case we want to just try the next path
281 /* Some other error means we found an executable file, but
282 something went wrong executing it; return the error to our
287 while (*p
++ != '\0');
289 /* Return with an error. */