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ef416fc2 | 1 | /* |
f7deaa1a | 2 | * "$Id: process.c 6326 2007-03-11 17:50:18Z mike $" |
ef416fc2 | 3 | * |
4 | * Process management routines for the Common UNIX Printing System (CUPS). | |
5 | * | |
f7deaa1a | 6 | * Copyright 1997-2007 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> | |
e53920b9 | 38 | #if defined(__APPLE__) |
4400e98d | 39 | # include <libgen.h> |
e53920b9 | 40 | #endif /* __APPLE__ */ |
ef416fc2 | 41 | |
42 | ||
e00b005a | 43 | /* |
44 | * Process structure... | |
45 | */ | |
46 | ||
47 | typedef struct | |
48 | { | |
49 | int pid; /* Process ID */ | |
50 | char name[1]; /* Name of process */ | |
51 | } cupsd_proc_t; | |
52 | ||
53 | ||
54 | /* | |
55 | * Local globals... | |
56 | */ | |
57 | ||
58 | static cups_array_t *process_array = NULL; | |
59 | ||
60 | ||
61 | /* | |
62 | * Local functions... | |
63 | */ | |
64 | ||
65 | static int compare_procs(cupsd_proc_t *a, cupsd_proc_t *b); | |
66 | ||
67 | ||
ef416fc2 | 68 | /* |
69 | * 'cupsdEndProcess()' - End a process. | |
70 | */ | |
71 | ||
72 | int /* O - 0 on success, -1 on failure */ | |
73 | cupsdEndProcess(int pid, /* I - Process ID */ | |
74 | int force) /* I - Force child to die */ | |
75 | { | |
76 | if (force) | |
77 | return (kill(pid, SIGKILL)); | |
78 | else | |
79 | return (kill(pid, SIGTERM)); | |
80 | } | |
81 | ||
82 | ||
e00b005a | 83 | /* |
84 | * 'cupsdFinishProcess()' - Finish a process and get its name. | |
85 | */ | |
86 | ||
87 | const char * /* O - Process name */ | |
88 | cupsdFinishProcess(int pid, /* I - Process ID */ | |
89 | char *name, /* I - Name buffer */ | |
90 | int namelen) /* I - Size of name buffer */ | |
91 | { | |
92 | cupsd_proc_t key, /* Search key */ | |
93 | *proc; /* Matching process */ | |
94 | ||
95 | ||
96 | key.pid = pid; | |
97 | ||
98 | if ((proc = (cupsd_proc_t *)cupsArrayFind(process_array, &key)) != NULL) | |
99 | { | |
100 | strlcpy(name, proc->name, namelen); | |
101 | cupsArrayRemove(process_array, proc); | |
102 | free(proc); | |
103 | ||
104 | return (name); | |
105 | } | |
106 | else | |
107 | return ("unknown"); | |
108 | } | |
109 | ||
110 | ||
ef416fc2 | 111 | /* |
112 | * 'cupsdStartProcess()' - Start a process. | |
113 | */ | |
114 | ||
115 | int /* O - Process ID or 0 */ | |
116 | cupsdStartProcess( | |
117 | const char *command, /* I - Full path to command */ | |
118 | char *argv[], /* I - Command-line arguments */ | |
119 | char *envp[], /* I - Environment */ | |
120 | int infd, /* I - Standard input file descriptor */ | |
121 | int outfd, /* I - Standard output file descriptor */ | |
122 | int errfd, /* I - Standard error file descriptor */ | |
123 | int backfd, /* I - Backchannel file descriptor */ | |
f7deaa1a | 124 | int sidefd, /* I - Sidechannel file descriptor */ |
ef416fc2 | 125 | int root, /* I - Run as root? */ |
126 | int *pid) /* O - Process ID */ | |
127 | { | |
e00b005a | 128 | cupsd_proc_t *proc; /* New process record */ |
ef416fc2 | 129 | #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET) |
e00b005a | 130 | struct sigaction action; /* POSIX signal handler */ |
ef416fc2 | 131 | #endif /* HAVE_SIGACTION && !HAVE_SIGSET */ |
e53920b9 | 132 | #if defined(__APPLE__) |
e00b005a | 133 | char processPath[1024], /* CFProcessPath environment variable */ |
134 | linkpath[1024]; /* Link path for symlinks... */ | |
135 | int linkbytes; /* Bytes for link path */ | |
e53920b9 | 136 | #endif /* __APPLE__ */ |
ef416fc2 | 137 | |
138 | ||
139 | cupsdLogMessage(CUPSD_LOG_DEBUG2, | |
140 | "cupsdStartProcess(\"%s\", %p, %p, %d, %d, %d)", | |
141 | command, argv, envp, infd, outfd, errfd); | |
142 | ||
e53920b9 | 143 | #if defined(__APPLE__) |
144 | if (envp) | |
e00b005a | 145 | { |
146 | /* | |
e53920b9 | 147 | * Add special voodoo magic for MacOS X - this allows MacOS X |
148 | * programs to access their bundle resources properly... | |
e00b005a | 149 | */ |
150 | ||
e53920b9 | 151 | if ((linkbytes = readlink(command, linkpath, sizeof(linkpath) - 1)) > 0) |
152 | { | |
153 | /* | |
154 | * Yes, this is a symlink to the actual program, nul-terminate and | |
155 | * use it... | |
156 | */ | |
157 | ||
158 | linkpath[linkbytes] = '\0'; | |
e00b005a | 159 | |
e53920b9 | 160 | if (linkpath[0] == '/') |
161 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", | |
162 | linkpath); | |
163 | else | |
164 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s/%s", | |
f7deaa1a | 165 | dirname((char *)command), linkpath); |
e53920b9 | 166 | } |
e00b005a | 167 | else |
e53920b9 | 168 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", command); |
bd7854cb | 169 | |
e53920b9 | 170 | envp[0] = processPath; /* Replace <CFProcessPath> string */ |
171 | } | |
172 | #endif /* __APPLE__ */ | |
e00b005a | 173 | |
ef416fc2 | 174 | /* |
175 | * Block signals before forking... | |
176 | */ | |
177 | ||
178 | cupsdHoldSignals(); | |
179 | ||
180 | if ((*pid = fork()) == 0) | |
181 | { | |
182 | /* | |
183 | * Child process goes here... | |
184 | * | |
185 | * Update stdin/stdout/stderr as needed... | |
186 | */ | |
187 | ||
188 | if (infd != 0) | |
189 | { | |
190 | close(0); | |
191 | if (infd > 0) | |
192 | dup(infd); | |
193 | else | |
194 | open("/dev/null", O_RDONLY); | |
195 | } | |
196 | if (outfd != 1) | |
197 | { | |
198 | close(1); | |
199 | if (outfd > 0) | |
200 | dup(outfd); | |
201 | else | |
202 | open("/dev/null", O_WRONLY); | |
203 | } | |
204 | if (errfd != 2) | |
205 | { | |
206 | close(2); | |
207 | if (errfd > 0) | |
208 | dup(errfd); | |
209 | else | |
210 | open("/dev/null", O_WRONLY); | |
211 | } | |
212 | if (backfd != 3) | |
213 | { | |
214 | close(3); | |
215 | if (backfd > 0) | |
216 | dup(backfd); | |
217 | else | |
218 | open("/dev/null", O_RDWR); | |
219 | fcntl(3, F_SETFL, O_NDELAY); | |
220 | } | |
f7deaa1a | 221 | if (sidefd != 4 && sidefd > 0) |
222 | { | |
223 | close(4); | |
224 | dup(sidefd); | |
225 | fcntl(4, F_SETFL, O_NDELAY); | |
226 | } | |
ef416fc2 | 227 | |
228 | /* | |
229 | * Change the priority of the process based on the FilterNice setting. | |
230 | * (this is not done for backends...) | |
231 | */ | |
232 | ||
233 | if (!root) | |
234 | nice(FilterNice); | |
235 | ||
236 | /* | |
237 | * Change user to something "safe"... | |
238 | */ | |
239 | ||
240 | if (!root && !RunUser) | |
241 | { | |
242 | /* | |
243 | * Running as root, so change to non-priviledged user... | |
244 | */ | |
245 | ||
246 | if (setgid(Group)) | |
e00b005a | 247 | exit(errno); |
ef416fc2 | 248 | |
249 | if (setgroups(1, &Group)) | |
e00b005a | 250 | exit(errno); |
ef416fc2 | 251 | |
252 | if (setuid(User)) | |
253 | exit(errno); | |
254 | } | |
255 | else | |
256 | { | |
257 | /* | |
258 | * Reset group membership to just the main one we belong to. | |
259 | */ | |
260 | ||
e00b005a | 261 | setgid(Group); |
ef416fc2 | 262 | setgroups(1, &Group); |
263 | } | |
264 | ||
265 | /* | |
266 | * Change umask to restrict permissions on created files... | |
267 | */ | |
268 | ||
269 | umask(077); | |
270 | ||
271 | /* | |
272 | * Unblock signals before doing the exec... | |
273 | */ | |
274 | ||
275 | #ifdef HAVE_SIGSET | |
276 | sigset(SIGTERM, SIG_DFL); | |
277 | sigset(SIGCHLD, SIG_DFL); | |
278 | #elif defined(HAVE_SIGACTION) | |
279 | memset(&action, 0, sizeof(action)); | |
280 | ||
281 | sigemptyset(&action.sa_mask); | |
282 | action.sa_handler = SIG_DFL; | |
283 | ||
284 | sigaction(SIGTERM, &action, NULL); | |
285 | sigaction(SIGCHLD, &action, NULL); | |
286 | #else | |
287 | signal(SIGTERM, SIG_DFL); | |
288 | signal(SIGCHLD, SIG_DFL); | |
289 | #endif /* HAVE_SIGSET */ | |
290 | ||
291 | cupsdReleaseSignals(); | |
292 | ||
293 | /* | |
294 | * Execute the command; if for some reason this doesn't work, | |
295 | * return the error code... | |
296 | */ | |
297 | ||
298 | if (envp) | |
299 | execve(command, argv, envp); | |
300 | else | |
301 | execv(command, argv); | |
302 | ||
303 | perror(command); | |
304 | ||
305 | exit(errno); | |
306 | } | |
307 | else if (*pid < 0) | |
308 | { | |
309 | /* | |
310 | * Error - couldn't fork a new process! | |
311 | */ | |
312 | ||
313 | cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to fork %s - %s.", command, | |
314 | strerror(errno)); | |
315 | ||
316 | *pid = 0; | |
317 | } | |
e00b005a | 318 | else |
319 | { | |
320 | if (!process_array) | |
321 | process_array = cupsArrayNew((cups_array_func_t)compare_procs, NULL); | |
322 | ||
323 | if (process_array) | |
324 | { | |
325 | if ((proc = calloc(1, sizeof(cupsd_proc_t) + strlen(command))) != NULL) | |
326 | { | |
327 | proc->pid = *pid; | |
328 | strcpy(proc->name, command); | |
329 | ||
330 | cupsArrayAdd(process_array, proc); | |
331 | } | |
332 | } | |
333 | } | |
ef416fc2 | 334 | |
335 | cupsdReleaseSignals(); | |
336 | ||
337 | return (*pid); | |
338 | } | |
339 | ||
340 | ||
341 | /* | |
e00b005a | 342 | * 'compare_procs()' - Compare two processes. |
343 | */ | |
344 | ||
345 | static int /* O - Result of comparison */ | |
346 | compare_procs(cupsd_proc_t *a, /* I - First process */ | |
347 | cupsd_proc_t *b) /* I - Second process */ | |
348 | { | |
349 | return (a->pid - b->pid); | |
350 | } | |
351 | ||
352 | ||
353 | /* | |
f7deaa1a | 354 | * End of "$Id: process.c 6326 2007-03-11 17:50:18Z mike $". |
ef416fc2 | 355 | */ |