xref: /freebsd/crypto/heimdal/lib/roken/simple_exec.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (c) 1998 - 2001, 2004 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <config.h>
35 
36 #include <stdarg.h>
37 #include <stdlib.h>
38 #ifdef HAVE_SYS_TYPES_H
39 #include <sys/types.h>
40 #endif
41 #ifdef HAVE_SYS_WAIT_H
42 #include <sys/wait.h>
43 #endif
44 #ifdef HAVE_UNISTD_H
45 #include <unistd.h>
46 #endif
47 #include <errno.h>
48 
49 #include "roken.h"
50 
51 #define EX_NOEXEC	126
52 #define EX_NOTFOUND	127
53 
54 /* return values:
55    SE_E_UNSPECIFIED   on `unspecified' system errors
56    SE_E_FORKFAILED    on fork failures
57    SE_E_WAITPIDFAILED on waitpid errors
58    SE_E_EXECTIMEOUT   exec timeout
59    0-   is return value from subprocess
60    SE_E_NOEXEC        if the program couldn't be executed
61    SE_E_NOTFOUND      if the program couldn't be found
62    128- is 128 + signal that killed subprocess
63 
64    possible values `func' can return:
65    ((time_t)-2)		exit loop w/o killing child and return
66    			`exec timeout'/-4 from simple_exec
67    ((time_t)-1)		kill child with SIGTERM and wait for child to exit
68    0			don't timeout again
69    n			seconds to next timeout
70    */
71 
72 static int sig_alarm;
73 
74 static RETSIGTYPE
75 sigtimeout(int sig)
76 {
77     sig_alarm = 1;
78     SIGRETURN(0);
79 }
80 
81 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
82 wait_for_process_timed(pid_t pid, time_t (*func)(void *),
83 		       void *ptr, time_t timeout)
84 {
85     RETSIGTYPE (*old_func)(int sig) = NULL;
86     unsigned int oldtime = 0;
87     int ret;
88 
89     sig_alarm = 0;
90 
91     if (func) {
92 	old_func = signal(SIGALRM, sigtimeout);
93 	oldtime = alarm(timeout);
94     }
95 
96     while(1) {
97 	int status;
98 
99 	while(waitpid(pid, &status, 0) < 0) {
100 	    if (errno != EINTR) {
101 		ret = SE_E_WAITPIDFAILED;
102 		goto out;
103 	    }
104 	    if (func == NULL)
105 		continue;
106 	    if (sig_alarm == 0)
107 		continue;
108 	    timeout = (*func)(ptr);
109 	    if (timeout == (time_t)-1) {
110 		kill(pid, SIGTERM);
111 		continue;
112 	    } else if (timeout == (time_t)-2) {
113 		ret = SE_E_EXECTIMEOUT;
114 		goto out;
115 	    }
116 	    alarm(timeout);
117 	}
118 	if(WIFSTOPPED(status))
119 	    continue;
120 	if(WIFEXITED(status)) {
121 	    ret = WEXITSTATUS(status);
122 	    break;
123 	}
124 	if(WIFSIGNALED(status)) {
125 	    ret = WTERMSIG(status) + 128;
126 	    break;
127 	}
128     }
129  out:
130     if (func) {
131 	signal(SIGALRM, old_func);
132 	alarm(oldtime);
133     }
134     return ret;
135 }
136 
137 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
138 wait_for_process(pid_t pid)
139 {
140     return wait_for_process_timed(pid, NULL, NULL, 0);
141 }
142 
143 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
144 pipe_execv(FILE **stdin_fd, FILE **stdout_fd, FILE **stderr_fd,
145 	   const char *file, ...)
146 {
147     int in_fd[2], out_fd[2], err_fd[2];
148     pid_t pid;
149     va_list ap;
150     char **argv;
151 
152     if(stdin_fd != NULL)
153 	pipe(in_fd);
154     if(stdout_fd != NULL)
155 	pipe(out_fd);
156     if(stderr_fd != NULL)
157 	pipe(err_fd);
158     pid = fork();
159     switch(pid) {
160     case 0:
161 	va_start(ap, file);
162 	argv = vstrcollect(&ap);
163 	va_end(ap);
164 	if(argv == NULL)
165 	    exit(-1);
166 
167 	/* close pipes we're not interested in */
168 	if(stdin_fd != NULL)
169 	    close(in_fd[1]);
170 	if(stdout_fd != NULL)
171 	    close(out_fd[0]);
172 	if(stderr_fd != NULL)
173 	    close(err_fd[0]);
174 
175 	/* pipe everything caller doesn't care about to /dev/null */
176 	if(stdin_fd == NULL)
177 	    in_fd[0] = open(_PATH_DEVNULL, O_RDONLY);
178 	if(stdout_fd == NULL)
179 	    out_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
180 	if(stderr_fd == NULL)
181 	    err_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
182 
183 	/* move to proper descriptors */
184 	if(in_fd[0] != STDIN_FILENO) {
185 	    dup2(in_fd[0], STDIN_FILENO);
186 	    close(in_fd[0]);
187 	}
188 	if(out_fd[1] != STDOUT_FILENO) {
189 	    dup2(out_fd[1], STDOUT_FILENO);
190 	    close(out_fd[1]);
191 	}
192 	if(err_fd[1] != STDERR_FILENO) {
193 	    dup2(err_fd[1], STDERR_FILENO);
194 	    close(err_fd[1]);
195 	}
196 
197 	closefrom(3);
198 
199 	execv(file, argv);
200 	exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
201     case -1:
202 	if(stdin_fd != NULL) {
203 	    close(in_fd[0]);
204 	    close(in_fd[1]);
205 	}
206 	if(stdout_fd != NULL) {
207 	    close(out_fd[0]);
208 	    close(out_fd[1]);
209 	}
210 	if(stderr_fd != NULL) {
211 	    close(err_fd[0]);
212 	    close(err_fd[1]);
213 	}
214 	return SE_E_FORKFAILED;
215     default:
216 	if(stdin_fd != NULL) {
217 	    close(in_fd[0]);
218 	    *stdin_fd = fdopen(in_fd[1], "w");
219 	}
220 	if(stdout_fd != NULL) {
221 	    close(out_fd[1]);
222 	    *stdout_fd = fdopen(out_fd[0], "r");
223 	}
224 	if(stderr_fd != NULL) {
225 	    close(err_fd[1]);
226 	    *stderr_fd = fdopen(err_fd[0], "r");
227 	}
228     }
229     return pid;
230 }
231 
232 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
233 simple_execvp_timed(const char *file, char *const args[],
234 		    time_t (*func)(void *), void *ptr, time_t timeout)
235 {
236     pid_t pid = fork();
237     switch(pid){
238     case -1:
239 	return SE_E_FORKFAILED;
240     case 0:
241 	execvp(file, args);
242 	exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
243     default:
244 	return wait_for_process_timed(pid, func, ptr, timeout);
245     }
246 }
247 
248 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
249 simple_execvp(const char *file, char *const args[])
250 {
251     return simple_execvp_timed(file, args, NULL, NULL, 0);
252 }
253 
254 /* gee, I'd like a execvpe */
255 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
256 simple_execve_timed(const char *file, char *const args[], char *const envp[],
257 		    time_t (*func)(void *), void *ptr, time_t timeout)
258 {
259     pid_t pid = fork();
260     switch(pid){
261     case -1:
262 	return SE_E_FORKFAILED;
263     case 0:
264 	execve(file, args, envp);
265 	exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
266     default:
267 	return wait_for_process_timed(pid, func, ptr, timeout);
268     }
269 }
270 
271 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
272 simple_execve(const char *file, char *const args[], char *const envp[])
273 {
274     return simple_execve_timed(file, args, envp, NULL, NULL, 0);
275 }
276 
277 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
278 simple_execlp(const char *file, ...)
279 {
280     va_list ap;
281     char **argv;
282     int ret;
283 
284     va_start(ap, file);
285     argv = vstrcollect(&ap);
286     va_end(ap);
287     if(argv == NULL)
288 	return SE_E_UNSPECIFIED;
289     ret = simple_execvp(file, argv);
290     free(argv);
291     return ret;
292 }
293 
294 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
295 simple_execle(const char *file, ... /* ,char *const envp[] */)
296 {
297     va_list ap;
298     char **argv;
299     char *const* envp;
300     int ret;
301 
302     va_start(ap, file);
303     argv = vstrcollect(&ap);
304     envp = va_arg(ap, char **);
305     va_end(ap);
306     if(argv == NULL)
307 	return SE_E_UNSPECIFIED;
308     ret = simple_execve(file, argv, envp);
309     free(argv);
310     return ret;
311 }
312