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ef416fc2 | 1 | /* |
e00b005a | 2 | * "$Id: process.c 5046 2006-02-01 22:11:58Z mike $" |
ef416fc2 | 3 | * |
4 | * Process management routines for the Common UNIX Printing System (CUPS). | |
5 | * | |
e00b005a | 6 | * Copyright 1997-2006 by Easy Software Products, all rights reserved. |
ef416fc2 | 7 | * |
8 | * These coded instructions, statements, and computer programs are the | |
9 | * property of Easy Software Products and are protected by Federal | |
10 | * copyright law. Distribution and use rights are outlined in the file | |
11 | * "LICENSE.txt" which should have been included with this file. If this | |
12 | * file is missing or damaged please contact Easy Software Products | |
13 | * at: | |
14 | * | |
15 | * Attn: CUPS Licensing Information | |
16 | * Easy Software Products | |
17 | * 44141 Airport View Drive, Suite 204 | |
18 | * Hollywood, Maryland 20636 USA | |
19 | * | |
20 | * Voice: (301) 373-9600 | |
21 | * EMail: cups-info@cups.org | |
22 | * WWW: http://www.cups.org | |
23 | * | |
24 | * Contents: | |
25 | * | |
e00b005a | 26 | * cupsdEndProcess() - End a process. |
27 | * cupsdFinishProcess() - Finish a process and get its name. | |
28 | * cupsdStartProcess() - Start a process. | |
29 | * compare_procs() - Compare two processes. | |
ef416fc2 | 30 | */ |
31 | ||
32 | /* | |
33 | * Include necessary headers... | |
34 | */ | |
35 | ||
36 | #include "cupsd.h" | |
37 | #include <grp.h> | |
38 | ||
39 | ||
e00b005a | 40 | /* |
41 | * Process structure... | |
42 | */ | |
43 | ||
44 | typedef struct | |
45 | { | |
46 | int pid; /* Process ID */ | |
47 | char name[1]; /* Name of process */ | |
48 | } cupsd_proc_t; | |
49 | ||
50 | ||
51 | /* | |
52 | * Local globals... | |
53 | */ | |
54 | ||
55 | static cups_array_t *process_array = NULL; | |
56 | ||
57 | ||
58 | /* | |
59 | * Local functions... | |
60 | */ | |
61 | ||
62 | static int compare_procs(cupsd_proc_t *a, cupsd_proc_t *b); | |
63 | ||
64 | ||
ef416fc2 | 65 | /* |
66 | * 'cupsdEndProcess()' - End a process. | |
67 | */ | |
68 | ||
69 | int /* O - 0 on success, -1 on failure */ | |
70 | cupsdEndProcess(int pid, /* I - Process ID */ | |
71 | int force) /* I - Force child to die */ | |
72 | { | |
73 | if (force) | |
74 | return (kill(pid, SIGKILL)); | |
75 | else | |
76 | return (kill(pid, SIGTERM)); | |
77 | } | |
78 | ||
79 | ||
e00b005a | 80 | /* |
81 | * 'cupsdFinishProcess()' - Finish a process and get its name. | |
82 | */ | |
83 | ||
84 | const char * /* O - Process name */ | |
85 | cupsdFinishProcess(int pid, /* I - Process ID */ | |
86 | char *name, /* I - Name buffer */ | |
87 | int namelen) /* I - Size of name buffer */ | |
88 | { | |
89 | cupsd_proc_t key, /* Search key */ | |
90 | *proc; /* Matching process */ | |
91 | ||
92 | ||
93 | key.pid = pid; | |
94 | ||
95 | if ((proc = (cupsd_proc_t *)cupsArrayFind(process_array, &key)) != NULL) | |
96 | { | |
97 | strlcpy(name, proc->name, namelen); | |
98 | cupsArrayRemove(process_array, proc); | |
99 | free(proc); | |
100 | ||
101 | return (name); | |
102 | } | |
103 | else | |
104 | return ("unknown"); | |
105 | } | |
106 | ||
107 | ||
ef416fc2 | 108 | /* |
109 | * 'cupsdStartProcess()' - Start a process. | |
110 | */ | |
111 | ||
112 | int /* O - Process ID or 0 */ | |
113 | cupsdStartProcess( | |
114 | const char *command, /* I - Full path to command */ | |
115 | char *argv[], /* I - Command-line arguments */ | |
116 | char *envp[], /* I - Environment */ | |
117 | int infd, /* I - Standard input file descriptor */ | |
118 | int outfd, /* I - Standard output file descriptor */ | |
119 | int errfd, /* I - Standard error file descriptor */ | |
120 | int backfd, /* I - Backchannel file descriptor */ | |
121 | int root, /* I - Run as root? */ | |
122 | int *pid) /* O - Process ID */ | |
123 | { | |
e00b005a | 124 | cupsd_proc_t *proc; /* New process record */ |
ef416fc2 | 125 | #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET) |
e00b005a | 126 | struct sigaction action; /* POSIX signal handler */ |
ef416fc2 | 127 | #endif /* HAVE_SIGACTION && !HAVE_SIGSET */ |
e00b005a | 128 | #if defined(__APPLE__) && __GNUC__ < 4 |
129 | int envc; /* Number of environment variables */ | |
130 | char processPath[1024], /* CFProcessPath environment variable */ | |
131 | linkpath[1024]; /* Link path for symlinks... */ | |
132 | int linkbytes; /* Bytes for link path */ | |
133 | #endif /* __APPLE__ && __GNUC__ < 4 */ | |
ef416fc2 | 134 | |
135 | ||
136 | cupsdLogMessage(CUPSD_LOG_DEBUG2, | |
137 | "cupsdStartProcess(\"%s\", %p, %p, %d, %d, %d)", | |
138 | command, argv, envp, infd, outfd, errfd); | |
139 | ||
e00b005a | 140 | #if defined(__APPLE__) && __GNUC__ < 4 |
141 | /* | |
142 | * Add special voodoo magic for MacOS X 10.3 and earlier - this allows | |
143 | * MacOS X programs to access their bundle resources properly... | |
144 | */ | |
145 | ||
146 | for (envc = 0; envc < MAX_ENV && envp[envc]; envc ++); | |
147 | /* All callers pass in a MAX_ENV element array of environment strings */ | |
148 | ||
149 | if (envc < (MAX_ENV - 1)) | |
150 | { | |
151 | /* | |
152 | * We have room, try to read the symlink path for this command... | |
153 | */ | |
154 | ||
155 | if ((linkbytes = readlink(linkpath, sizeof(linkpath) - 1)) > 0) | |
156 | { | |
157 | /* | |
158 | * Yes, this is a symlink to the actual program, nul-terminate and | |
159 | * use it... | |
160 | */ | |
161 | ||
162 | linkpath[linkbytes] = '\0'; | |
163 | ||
164 | if (linkpath[0] == '/') | |
165 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", | |
166 | linkpath); | |
167 | else | |
168 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s/%s", | |
169 | dirname(command), linkpath); | |
170 | } | |
171 | else | |
172 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", command); | |
173 | ||
174 | envp[envc++] = processPath; | |
175 | envp[envc] = NULL; | |
176 | } | |
177 | #endif /* __APPLE__ && __GNUC__ > 3 */ | |
178 | ||
ef416fc2 | 179 | /* |
180 | * Block signals before forking... | |
181 | */ | |
182 | ||
183 | cupsdHoldSignals(); | |
184 | ||
185 | if ((*pid = fork()) == 0) | |
186 | { | |
187 | /* | |
188 | * Child process goes here... | |
189 | * | |
190 | * Update stdin/stdout/stderr as needed... | |
191 | */ | |
192 | ||
193 | if (infd != 0) | |
194 | { | |
195 | close(0); | |
196 | if (infd > 0) | |
197 | dup(infd); | |
198 | else | |
199 | open("/dev/null", O_RDONLY); | |
200 | } | |
201 | if (outfd != 1) | |
202 | { | |
203 | close(1); | |
204 | if (outfd > 0) | |
205 | dup(outfd); | |
206 | else | |
207 | open("/dev/null", O_WRONLY); | |
208 | } | |
209 | if (errfd != 2) | |
210 | { | |
211 | close(2); | |
212 | if (errfd > 0) | |
213 | dup(errfd); | |
214 | else | |
215 | open("/dev/null", O_WRONLY); | |
216 | } | |
217 | if (backfd != 3) | |
218 | { | |
219 | close(3); | |
220 | if (backfd > 0) | |
221 | dup(backfd); | |
222 | else | |
223 | open("/dev/null", O_RDWR); | |
224 | fcntl(3, F_SETFL, O_NDELAY); | |
225 | } | |
226 | ||
227 | /* | |
228 | * Change the priority of the process based on the FilterNice setting. | |
229 | * (this is not done for backends...) | |
230 | */ | |
231 | ||
232 | if (!root) | |
233 | nice(FilterNice); | |
234 | ||
235 | /* | |
236 | * Change user to something "safe"... | |
237 | */ | |
238 | ||
239 | if (!root && !RunUser) | |
240 | { | |
241 | /* | |
242 | * Running as root, so change to non-priviledged user... | |
243 | */ | |
244 | ||
245 | if (setgid(Group)) | |
e00b005a | 246 | exit(errno); |
ef416fc2 | 247 | |
248 | if (setgroups(1, &Group)) | |
e00b005a | 249 | exit(errno); |
ef416fc2 | 250 | |
251 | if (setuid(User)) | |
252 | exit(errno); | |
253 | } | |
254 | else | |
255 | { | |
256 | /* | |
257 | * Reset group membership to just the main one we belong to. | |
258 | */ | |
259 | ||
e00b005a | 260 | setgid(Group); |
ef416fc2 | 261 | setgroups(1, &Group); |
262 | } | |
263 | ||
264 | /* | |
265 | * Change umask to restrict permissions on created files... | |
266 | */ | |
267 | ||
268 | umask(077); | |
269 | ||
270 | /* | |
271 | * Unblock signals before doing the exec... | |
272 | */ | |
273 | ||
274 | #ifdef HAVE_SIGSET | |
275 | sigset(SIGTERM, SIG_DFL); | |
276 | sigset(SIGCHLD, SIG_DFL); | |
277 | #elif defined(HAVE_SIGACTION) | |
278 | memset(&action, 0, sizeof(action)); | |
279 | ||
280 | sigemptyset(&action.sa_mask); | |
281 | action.sa_handler = SIG_DFL; | |
282 | ||
283 | sigaction(SIGTERM, &action, NULL); | |
284 | sigaction(SIGCHLD, &action, NULL); | |
285 | #else | |
286 | signal(SIGTERM, SIG_DFL); | |
287 | signal(SIGCHLD, SIG_DFL); | |
288 | #endif /* HAVE_SIGSET */ | |
289 | ||
290 | cupsdReleaseSignals(); | |
291 | ||
292 | /* | |
293 | * Execute the command; if for some reason this doesn't work, | |
294 | * return the error code... | |
295 | */ | |
296 | ||
297 | if (envp) | |
298 | execve(command, argv, envp); | |
299 | else | |
300 | execv(command, argv); | |
301 | ||
302 | perror(command); | |
303 | ||
304 | exit(errno); | |
305 | } | |
306 | else if (*pid < 0) | |
307 | { | |
308 | /* | |
309 | * Error - couldn't fork a new process! | |
310 | */ | |
311 | ||
312 | cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to fork %s - %s.", command, | |
313 | strerror(errno)); | |
314 | ||
315 | *pid = 0; | |
316 | } | |
e00b005a | 317 | else |
318 | { | |
319 | if (!process_array) | |
320 | process_array = cupsArrayNew((cups_array_func_t)compare_procs, NULL); | |
321 | ||
322 | if (process_array) | |
323 | { | |
324 | if ((proc = calloc(1, sizeof(cupsd_proc_t) + strlen(command))) != NULL) | |
325 | { | |
326 | proc->pid = *pid; | |
327 | strcpy(proc->name, command); | |
328 | ||
329 | cupsArrayAdd(process_array, proc); | |
330 | } | |
331 | } | |
332 | } | |
ef416fc2 | 333 | |
334 | cupsdReleaseSignals(); | |
335 | ||
336 | return (*pid); | |
337 | } | |
338 | ||
339 | ||
340 | /* | |
e00b005a | 341 | * 'compare_procs()' - Compare two processes. |
342 | */ | |
343 | ||
344 | static int /* O - Result of comparison */ | |
345 | compare_procs(cupsd_proc_t *a, /* I - First process */ | |
346 | cupsd_proc_t *b) /* I - Second process */ | |
347 | { | |
348 | return (a->pid - b->pid); | |
349 | } | |
350 | ||
351 | ||
352 | /* | |
353 | * End of "$Id: process.c 5046 2006-02-01 22:11:58Z mike $". | |
ef416fc2 | 354 | */ |