1 /* exechelp.h - Definitions for the fork and exec helpers
2 * Copyright (C) 2004, 2009, 2010 Free Software Foundation, Inc.
4 * This file is part of GnuPG.
6 * This file is free software; you can redistribute it and/or modify
7 * it under the terms of either
9 * - the GNU Lesser General Public License as published by the Free
10 * Software Foundation; either version 3 of the License, or (at
11 * your option) any later version.
15 * - the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
19 * or both in parallel, as here.
21 * This file is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, see <https://www.gnu.org/licenses/>.
30 #ifndef GNUPG_COMMON_EXECHELP_H
31 #define GNUPG_COMMON_EXECHELP_H
34 /* Return the maximum number of currently allowed file descriptors.
35 Only useful on POSIX systems. */
36 int get_max_fds (void);
39 /* Close all file descriptors starting with descriptor FIRST. If
40 EXCEPT is not NULL, it is expected to be a list of file descriptors
41 which are not to close. This list shall be sorted in ascending
42 order with its end marked by -1. */
43 void close_all_fds (int first, int *except);
46 /* Returns an array with all currently open file descriptors. The end
47 of the array is marked by -1. The caller needs to release this
48 array using the *standard free* and not with xfree. This allow the
49 use of this function right at startup even before libgcrypt has
50 been initialized. Returns NULL on error and sets ERRNO accordingly. */
51 int *get_all_open_fds (void);
54 /* Portable function to create a pipe. Under Windows the write end is
55 inheritable. If R_FP is not NULL, an estream is created for the
56 write end and stored at R_FP. */
57 gpg_error_t gnupg_create_inbound_pipe (int filedes[2],
58 estream_t *r_fp, int nonblock);
60 /* Portable function to create a pipe. Under Windows the read end is
61 inheritable. If R_FP is not NULL, an estream is created for the
62 write end and stored at R_FP. */
63 gpg_error_t gnupg_create_outbound_pipe (int filedes[2],
64 estream_t *r_fp, int nonblock);
66 /* Portable function to create a pipe. Under Windows both ends are
68 gpg_error_t gnupg_create_pipe (int filedes[2]);
71 #define GNUPG_SPAWN_NONBLOCK 16
72 #define GNUPG_SPAWN_RUN_ASFW 64
73 #define GNUPG_SPAWN_DETACHED 128
76 /* Fork and exec the program PGMNAME.
78 If R_INFP is NULL connect stdin of the new process to /dev/null; if
79 it is not NULL store the address of a pointer to a new estream
80 there. If R_OUTFP is NULL connect stdout of the new process to
81 /dev/null; if it is not NULL store the address of a pointer to a
82 new estream there. If R_ERRFP is NULL connect stderr of the new
83 process to /dev/null; if it is not NULL store the address of a
84 pointer to a new estream there. On success the pid of the new
85 process is stored at PID. On error -1 is stored at PID and if
86 R_OUTFP or R_ERRFP are not NULL, NULL is stored there.
88 The arguments for the process are expected in the NULL terminated
89 array ARGV. The program name itself should not be included there.
90 If PREEXEC is not NULL, the given function will be called right
93 IF EXCEPT is not NULL, it is expected to be an ordered list of file
94 descriptors, terminated by an entry with the value (-1). These
95 file descriptors won't be closed before spawning a new program.
97 Returns 0 on success or an error code. Calling gnupg_wait_process
98 and gnupg_release_process is required if the function succeeded.
100 FLAGS is a bit vector:
103 If set the two output streams are created in non-blocking
104 mode and the input stream is switched to non-blocking mode.
105 This is merely a convenience feature because the caller
106 could do the same with gpgrt_set_nonblock. Does not yet
110 If set the process will be started as a background process.
111 This flag is only useful under W32 (but not W32CE) systems,
112 so that no new console is created and pops up a console
113 window when starting the server. Does not work on W32CE.
116 On W32 (but not on W32CE) run AllowSetForegroundWindow for
117 the child. Note that due to unknown problems this actually
118 allows SetForegroundWindow for all childs of this process.
122 gnupg_spawn_process (const char *pgmname, const char *argv[],
123 int *execpt, void (*preexec)(void), unsigned int flags,
130 /* Simplified version of gnupg_spawn_process. This function forks and
131 then execs PGMNAME, while connecting INFD to stdin, OUTFD to stdout
132 and ERRFD to stderr (any of them may be -1 to connect them to
133 /dev/null). The arguments for the process are expected in the NULL
134 terminated array ARGV. The program name itself should not be
135 included there. Calling gnupg_wait_process and
136 gnupg_release_process is required. Returns 0 on success or an
138 gpg_error_t gnupg_spawn_process_fd (const char *pgmname,
140 int infd, int outfd, int errfd,
144 /* If HANG is true, waits for the process identified by PID to exit;
145 if HANG is false, checks whether the process has terminated.
146 PGMNAME should be the same as supplied to the spawn function and is
147 only used for diagnostics. Return values:
150 The process exited successful. 0 is stored at R_EXITCODE.
153 The process exited without success. The exit code of process
154 is then stored at R_EXITCODE. An exit code of -1 indicates
155 that the process terminated abnormally (e.g. due to a signal).
158 The process is still running (returned only if HANG is false).
161 An invalid PID has been specified.
163 Other error codes may be returned as well. Unless otherwise noted,
164 -1 will be stored at R_EXITCODE. R_EXITCODE may be passed as NULL
165 if the exit code is not required (in that case an error messge will
166 be printed). Note that under Windows PID is not the process id but
167 the handle of the process. */
168 gpg_error_t gnupg_wait_process (const char *pgmname, pid_t pid, int hang,
171 /* Like gnupg_wait_process, but for COUNT processes. */
172 gpg_error_t gnupg_wait_processes (const char **pgmnames, pid_t *pids,
173 size_t count, int hang, int *r_exitcodes);
176 /* Kill a process; that is send an appropriate signal to the process.
177 gnupg_wait_process must be called to actually remove the process
178 from the system. An invalid PID is ignored. */
179 void gnupg_kill_process (pid_t pid);
181 /* Release the process identified by PID. This function is actually
182 only required for Windows but it does not harm to always call it.
183 It is a nop if PID is invalid. */
184 void gnupg_release_process (pid_t pid);
187 /* Spawn a new process and immediately detach from it. The name of
188 the program to exec is PGMNAME and its arguments are in ARGV (the
189 programname is automatically passed as first argument).
190 Environment strings in ENVP are set. An error is returned if
191 pgmname is not executable; to make this work it is necessary to
192 provide an absolute file name. */
193 gpg_error_t gnupg_spawn_process_detached (const char *pgmname,
195 const char *envp[] );
199 #endif /*GNUPG_COMMON_EXECHELP_H*/