1 /* $NetBSD: simple_exec.c,v 1.1.1.1 2011/04/13 18:15:43 elric Exp $ */
2
3 /*
4 * Copyright (c) 1998 - 2001, 2004 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37
38 #include <stdarg.h>
39 #include <stdlib.h>
40 #ifdef HAVE_SYS_TYPES_H
41 #include <sys/types.h>
42 #endif
43 #ifdef HAVE_SYS_WAIT_H
44 #include <sys/wait.h>
45 #endif
46 #ifdef HAVE_UNISTD_H
47 #include <unistd.h>
48 #endif
49 #include <errno.h>
50
51 #include <krb5/roken.h>
52
53 #define EX_NOEXEC 126
54 #define EX_NOTFOUND 127
55
56 /* return values:
57 SE_E_UNSPECIFIED on `unspecified' system errors
58 SE_E_FORKFAILED on fork failures
59 SE_E_WAITPIDFAILED on waitpid errors
60 SE_E_EXECTIMEOUT exec timeout
61 0- is return value from subprocess
62 SE_E_NOEXEC if the program couldn't be executed
63 SE_E_NOTFOUND if the program couldn't be found
64 128- is 128 + signal that killed subprocess
65
66 possible values `func' can return:
67 ((time_t)-2) exit loop w/o killing child and return
68 `exec timeout'/-4 from simple_exec
69 ((time_t)-1) kill child with SIGTERM and wait for child to exit
70 0 don't timeout again
71 n seconds to next timeout
72 */
73
74 static int sig_alarm;
75
76 static RETSIGTYPE
sigtimeout(int sig)77 sigtimeout(int sig)
78 {
79 sig_alarm = 1;
80 SIGRETURN(0);
81 }
82
83 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
wait_for_process_timed(pid_t pid,time_t (* func)(void *),void * ptr,time_t timeout)84 wait_for_process_timed(pid_t pid, time_t (*func)(void *),
85 void *ptr, time_t timeout)
86 {
87 RETSIGTYPE (*old_func)(int sig) = NULL;
88 unsigned int oldtime = 0;
89 int ret;
90
91 sig_alarm = 0;
92
93 if (func) {
94 old_func = signal(SIGALRM, sigtimeout);
95 oldtime = alarm(timeout);
96 }
97
98 while(1) {
99 int status;
100
101 while(waitpid(pid, &status, 0) < 0) {
102 if (errno != EINTR) {
103 ret = SE_E_WAITPIDFAILED;
104 goto out;
105 }
106 if (func == NULL)
107 continue;
108 if (sig_alarm == 0)
109 continue;
110 timeout = (*func)(ptr);
111 if (timeout == (time_t)-1) {
112 kill(pid, SIGTERM);
113 continue;
114 } else if (timeout == (time_t)-2) {
115 ret = SE_E_EXECTIMEOUT;
116 goto out;
117 }
118 alarm(timeout);
119 }
120 if(WIFSTOPPED(status))
121 continue;
122 if(WIFEXITED(status)) {
123 ret = WEXITSTATUS(status);
124 break;
125 }
126 if(WIFSIGNALED(status)) {
127 ret = WTERMSIG(status) + 128;
128 break;
129 }
130 }
131 out:
132 if (func) {
133 signal(SIGALRM, old_func);
134 alarm(oldtime);
135 }
136 return ret;
137 }
138
139 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
wait_for_process(pid_t pid)140 wait_for_process(pid_t pid)
141 {
142 return wait_for_process_timed(pid, NULL, NULL, 0);
143 }
144
145 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
pipe_execv(FILE ** stdin_fd,FILE ** stdout_fd,FILE ** stderr_fd,const char * file,...)146 pipe_execv(FILE **stdin_fd, FILE **stdout_fd, FILE **stderr_fd,
147 const char *file, ...)
148 {
149 int in_fd[2], out_fd[2], err_fd[2];
150 pid_t pid;
151 va_list ap;
152 char **argv;
153
154 if(stdin_fd != NULL)
155 pipe(in_fd);
156 if(stdout_fd != NULL)
157 pipe(out_fd);
158 if(stderr_fd != NULL)
159 pipe(err_fd);
160 pid = fork();
161 switch(pid) {
162 case 0:
163 va_start(ap, file);
164 argv = vstrcollect(&ap);
165 va_end(ap);
166 if(argv == NULL)
167 exit(-1);
168
169 /* close pipes we're not interested in */
170 if(stdin_fd != NULL)
171 close(in_fd[1]);
172 if(stdout_fd != NULL)
173 close(out_fd[0]);
174 if(stderr_fd != NULL)
175 close(err_fd[0]);
176
177 /* pipe everything caller doesn't care about to /dev/null */
178 if(stdin_fd == NULL)
179 in_fd[0] = open(_PATH_DEVNULL, O_RDONLY);
180 if(stdout_fd == NULL)
181 out_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
182 if(stderr_fd == NULL)
183 err_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
184
185 /* move to proper descriptors */
186 if(in_fd[0] != STDIN_FILENO) {
187 dup2(in_fd[0], STDIN_FILENO);
188 close(in_fd[0]);
189 }
190 if(out_fd[1] != STDOUT_FILENO) {
191 dup2(out_fd[1], STDOUT_FILENO);
192 close(out_fd[1]);
193 }
194 if(err_fd[1] != STDERR_FILENO) {
195 dup2(err_fd[1], STDERR_FILENO);
196 close(err_fd[1]);
197 }
198
199 closefrom(3);
200
201 execv(file, argv);
202 exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
203 case -1:
204 if(stdin_fd != NULL) {
205 close(in_fd[0]);
206 close(in_fd[1]);
207 }
208 if(stdout_fd != NULL) {
209 close(out_fd[0]);
210 close(out_fd[1]);
211 }
212 if(stderr_fd != NULL) {
213 close(err_fd[0]);
214 close(err_fd[1]);
215 }
216 return SE_E_FORKFAILED;
217 default:
218 if(stdin_fd != NULL) {
219 close(in_fd[0]);
220 *stdin_fd = fdopen(in_fd[1], "w");
221 }
222 if(stdout_fd != NULL) {
223 close(out_fd[1]);
224 *stdout_fd = fdopen(out_fd[0], "r");
225 }
226 if(stderr_fd != NULL) {
227 close(err_fd[1]);
228 *stderr_fd = fdopen(err_fd[0], "r");
229 }
230 }
231 return pid;
232 }
233
234 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
simple_execvp_timed(const char * file,char * const args[],time_t (* func)(void *),void * ptr,time_t timeout)235 simple_execvp_timed(const char *file, char *const args[],
236 time_t (*func)(void *), void *ptr, time_t timeout)
237 {
238 pid_t pid = fork();
239 switch(pid){
240 case -1:
241 return SE_E_FORKFAILED;
242 case 0:
243 execvp(file, args);
244 exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
245 default:
246 return wait_for_process_timed(pid, func, ptr, timeout);
247 }
248 }
249
250 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
simple_execvp(const char * file,char * const args[])251 simple_execvp(const char *file, char *const args[])
252 {
253 return simple_execvp_timed(file, args, NULL, NULL, 0);
254 }
255
256 /* gee, I'd like a execvpe */
257 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
simple_execve_timed(const char * file,char * const args[],char * const envp[],time_t (* func)(void *),void * ptr,time_t timeout)258 simple_execve_timed(const char *file, char *const args[], char *const envp[],
259 time_t (*func)(void *), void *ptr, time_t timeout)
260 {
261 pid_t pid = fork();
262 switch(pid){
263 case -1:
264 return SE_E_FORKFAILED;
265 case 0:
266 execve(file, args, envp);
267 exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
268 default:
269 return wait_for_process_timed(pid, func, ptr, timeout);
270 }
271 }
272
273 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
simple_execve(const char * file,char * const args[],char * const envp[])274 simple_execve(const char *file, char *const args[], char *const envp[])
275 {
276 return simple_execve_timed(file, args, envp, NULL, NULL, 0);
277 }
278
279 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
simple_execlp(const char * file,...)280 simple_execlp(const char *file, ...)
281 {
282 va_list ap;
283 char **argv;
284 int ret;
285
286 va_start(ap, file);
287 argv = vstrcollect(&ap);
288 va_end(ap);
289 if(argv == NULL)
290 return SE_E_UNSPECIFIED;
291 ret = simple_execvp(file, argv);
292 free(argv);
293 return ret;
294 }
295
296 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
simple_execle(const char * file,...)297 simple_execle(const char *file, ... /* ,char *const envp[] */)
298 {
299 va_list ap;
300 char **argv;
301 char *const* envp;
302 int ret;
303
304 va_start(ap, file);
305 argv = vstrcollect(&ap);
306 envp = va_arg(ap, char **);
307 va_end(ap);
308 if(argv == NULL)
309 return SE_E_UNSPECIFIED;
310 ret = simple_execve(file, argv, envp);
311 free(argv);
312 return ret;
313 }
314