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ef416fc2 | 1 | /* |
bc44d920 | 2 | * "$Id: process.c 6649 2007-07-11 21:46:42Z mike $" |
ef416fc2 | 3 | * |
4 | * Process management routines for the Common UNIX Printing System (CUPS). | |
5 | * | |
bc44d920 | 6 | * Copyright 2007 by Apple Inc. |
f7deaa1a | 7 | * Copyright 1997-2007 by Easy Software Products, all rights reserved. |
ef416fc2 | 8 | * |
9 | * These coded instructions, statements, and computer programs are the | |
bc44d920 | 10 | * property of Apple Inc. and are protected by Federal copyright |
11 | * law. Distribution and use rights are outlined in the file "LICENSE.txt" | |
12 | * which should have been included with this file. If this file is | |
13 | * file is missing or damaged, see the license at "http://www.cups.org/". | |
ef416fc2 | 14 | * |
15 | * Contents: | |
16 | * | |
e00b005a | 17 | * cupsdEndProcess() - End a process. |
18 | * cupsdFinishProcess() - Finish a process and get its name. | |
19 | * cupsdStartProcess() - Start a process. | |
20 | * compare_procs() - Compare two processes. | |
ef416fc2 | 21 | */ |
22 | ||
23 | /* | |
24 | * Include necessary headers... | |
25 | */ | |
26 | ||
27 | #include "cupsd.h" | |
28 | #include <grp.h> | |
e53920b9 | 29 | #if defined(__APPLE__) |
4400e98d | 30 | # include <libgen.h> |
e53920b9 | 31 | #endif /* __APPLE__ */ |
ef416fc2 | 32 | |
33 | ||
e00b005a | 34 | /* |
35 | * Process structure... | |
36 | */ | |
37 | ||
38 | typedef struct | |
39 | { | |
40 | int pid; /* Process ID */ | |
41 | char name[1]; /* Name of process */ | |
42 | } cupsd_proc_t; | |
43 | ||
44 | ||
45 | /* | |
46 | * Local globals... | |
47 | */ | |
48 | ||
49 | static cups_array_t *process_array = NULL; | |
50 | ||
51 | ||
52 | /* | |
53 | * Local functions... | |
54 | */ | |
55 | ||
56 | static int compare_procs(cupsd_proc_t *a, cupsd_proc_t *b); | |
57 | ||
58 | ||
ef416fc2 | 59 | /* |
60 | * 'cupsdEndProcess()' - End a process. | |
61 | */ | |
62 | ||
63 | int /* O - 0 on success, -1 on failure */ | |
64 | cupsdEndProcess(int pid, /* I - Process ID */ | |
65 | int force) /* I - Force child to die */ | |
66 | { | |
67 | if (force) | |
68 | return (kill(pid, SIGKILL)); | |
69 | else | |
70 | return (kill(pid, SIGTERM)); | |
71 | } | |
72 | ||
73 | ||
e00b005a | 74 | /* |
75 | * 'cupsdFinishProcess()' - Finish a process and get its name. | |
76 | */ | |
77 | ||
78 | const char * /* O - Process name */ | |
79 | cupsdFinishProcess(int pid, /* I - Process ID */ | |
80 | char *name, /* I - Name buffer */ | |
81 | int namelen) /* I - Size of name buffer */ | |
82 | { | |
83 | cupsd_proc_t key, /* Search key */ | |
84 | *proc; /* Matching process */ | |
85 | ||
86 | ||
87 | key.pid = pid; | |
88 | ||
89 | if ((proc = (cupsd_proc_t *)cupsArrayFind(process_array, &key)) != NULL) | |
90 | { | |
91 | strlcpy(name, proc->name, namelen); | |
92 | cupsArrayRemove(process_array, proc); | |
93 | free(proc); | |
94 | ||
95 | return (name); | |
96 | } | |
97 | else | |
98 | return ("unknown"); | |
99 | } | |
100 | ||
101 | ||
ef416fc2 | 102 | /* |
103 | * 'cupsdStartProcess()' - Start a process. | |
104 | */ | |
105 | ||
106 | int /* O - Process ID or 0 */ | |
107 | cupsdStartProcess( | |
108 | const char *command, /* I - Full path to command */ | |
109 | char *argv[], /* I - Command-line arguments */ | |
110 | char *envp[], /* I - Environment */ | |
111 | int infd, /* I - Standard input file descriptor */ | |
112 | int outfd, /* I - Standard output file descriptor */ | |
113 | int errfd, /* I - Standard error file descriptor */ | |
114 | int backfd, /* I - Backchannel file descriptor */ | |
f7deaa1a | 115 | int sidefd, /* I - Sidechannel file descriptor */ |
ef416fc2 | 116 | int root, /* I - Run as root? */ |
117 | int *pid) /* O - Process ID */ | |
118 | { | |
e00b005a | 119 | cupsd_proc_t *proc; /* New process record */ |
ef416fc2 | 120 | #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET) |
e00b005a | 121 | struct sigaction action; /* POSIX signal handler */ |
ef416fc2 | 122 | #endif /* HAVE_SIGACTION && !HAVE_SIGSET */ |
e53920b9 | 123 | #if defined(__APPLE__) |
e00b005a | 124 | char processPath[1024], /* CFProcessPath environment variable */ |
125 | linkpath[1024]; /* Link path for symlinks... */ | |
126 | int linkbytes; /* Bytes for link path */ | |
e53920b9 | 127 | #endif /* __APPLE__ */ |
ef416fc2 | 128 | |
129 | ||
130 | cupsdLogMessage(CUPSD_LOG_DEBUG2, | |
131 | "cupsdStartProcess(\"%s\", %p, %p, %d, %d, %d)", | |
132 | command, argv, envp, infd, outfd, errfd); | |
133 | ||
e53920b9 | 134 | #if defined(__APPLE__) |
135 | if (envp) | |
e00b005a | 136 | { |
137 | /* | |
e53920b9 | 138 | * Add special voodoo magic for MacOS X - this allows MacOS X |
139 | * programs to access their bundle resources properly... | |
e00b005a | 140 | */ |
141 | ||
e53920b9 | 142 | if ((linkbytes = readlink(command, linkpath, sizeof(linkpath) - 1)) > 0) |
143 | { | |
144 | /* | |
145 | * Yes, this is a symlink to the actual program, nul-terminate and | |
146 | * use it... | |
147 | */ | |
148 | ||
149 | linkpath[linkbytes] = '\0'; | |
e00b005a | 150 | |
e53920b9 | 151 | if (linkpath[0] == '/') |
152 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", | |
153 | linkpath); | |
154 | else | |
155 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s/%s", | |
f7deaa1a | 156 | dirname((char *)command), linkpath); |
e53920b9 | 157 | } |
e00b005a | 158 | else |
e53920b9 | 159 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", command); |
bd7854cb | 160 | |
e53920b9 | 161 | envp[0] = processPath; /* Replace <CFProcessPath> string */ |
162 | } | |
163 | #endif /* __APPLE__ */ | |
e00b005a | 164 | |
ef416fc2 | 165 | /* |
166 | * Block signals before forking... | |
167 | */ | |
168 | ||
169 | cupsdHoldSignals(); | |
170 | ||
171 | if ((*pid = fork()) == 0) | |
172 | { | |
173 | /* | |
174 | * Child process goes here... | |
175 | * | |
176 | * Update stdin/stdout/stderr as needed... | |
177 | */ | |
178 | ||
179 | if (infd != 0) | |
180 | { | |
181 | close(0); | |
182 | if (infd > 0) | |
183 | dup(infd); | |
184 | else | |
185 | open("/dev/null", O_RDONLY); | |
186 | } | |
187 | if (outfd != 1) | |
188 | { | |
189 | close(1); | |
190 | if (outfd > 0) | |
191 | dup(outfd); | |
192 | else | |
193 | open("/dev/null", O_WRONLY); | |
194 | } | |
195 | if (errfd != 2) | |
196 | { | |
197 | close(2); | |
198 | if (errfd > 0) | |
199 | dup(errfd); | |
200 | else | |
201 | open("/dev/null", O_WRONLY); | |
202 | } | |
203 | if (backfd != 3) | |
204 | { | |
205 | close(3); | |
206 | if (backfd > 0) | |
207 | dup(backfd); | |
208 | else | |
209 | open("/dev/null", O_RDWR); | |
210 | fcntl(3, F_SETFL, O_NDELAY); | |
211 | } | |
f7deaa1a | 212 | if (sidefd != 4 && sidefd > 0) |
213 | { | |
214 | close(4); | |
215 | dup(sidefd); | |
216 | fcntl(4, F_SETFL, O_NDELAY); | |
217 | } | |
ef416fc2 | 218 | |
219 | /* | |
220 | * Change the priority of the process based on the FilterNice setting. | |
221 | * (this is not done for backends...) | |
222 | */ | |
223 | ||
224 | if (!root) | |
225 | nice(FilterNice); | |
226 | ||
227 | /* | |
228 | * Change user to something "safe"... | |
229 | */ | |
230 | ||
231 | if (!root && !RunUser) | |
232 | { | |
233 | /* | |
234 | * Running as root, so change to non-priviledged user... | |
235 | */ | |
236 | ||
237 | if (setgid(Group)) | |
e00b005a | 238 | exit(errno); |
ef416fc2 | 239 | |
240 | if (setgroups(1, &Group)) | |
e00b005a | 241 | exit(errno); |
ef416fc2 | 242 | |
243 | if (setuid(User)) | |
244 | exit(errno); | |
245 | } | |
246 | else | |
247 | { | |
248 | /* | |
249 | * Reset group membership to just the main one we belong to. | |
250 | */ | |
251 | ||
e00b005a | 252 | setgid(Group); |
ef416fc2 | 253 | setgroups(1, &Group); |
254 | } | |
255 | ||
256 | /* | |
257 | * Change umask to restrict permissions on created files... | |
258 | */ | |
259 | ||
260 | umask(077); | |
261 | ||
262 | /* | |
263 | * Unblock signals before doing the exec... | |
264 | */ | |
265 | ||
266 | #ifdef HAVE_SIGSET | |
267 | sigset(SIGTERM, SIG_DFL); | |
268 | sigset(SIGCHLD, SIG_DFL); | |
269 | #elif defined(HAVE_SIGACTION) | |
270 | memset(&action, 0, sizeof(action)); | |
271 | ||
272 | sigemptyset(&action.sa_mask); | |
273 | action.sa_handler = SIG_DFL; | |
274 | ||
275 | sigaction(SIGTERM, &action, NULL); | |
276 | sigaction(SIGCHLD, &action, NULL); | |
277 | #else | |
278 | signal(SIGTERM, SIG_DFL); | |
279 | signal(SIGCHLD, SIG_DFL); | |
280 | #endif /* HAVE_SIGSET */ | |
281 | ||
282 | cupsdReleaseSignals(); | |
283 | ||
284 | /* | |
285 | * Execute the command; if for some reason this doesn't work, | |
286 | * return the error code... | |
287 | */ | |
288 | ||
289 | if (envp) | |
290 | execve(command, argv, envp); | |
291 | else | |
292 | execv(command, argv); | |
293 | ||
294 | perror(command); | |
295 | ||
296 | exit(errno); | |
297 | } | |
298 | else if (*pid < 0) | |
299 | { | |
300 | /* | |
301 | * Error - couldn't fork a new process! | |
302 | */ | |
303 | ||
304 | cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to fork %s - %s.", command, | |
305 | strerror(errno)); | |
306 | ||
307 | *pid = 0; | |
308 | } | |
e00b005a | 309 | else |
310 | { | |
311 | if (!process_array) | |
312 | process_array = cupsArrayNew((cups_array_func_t)compare_procs, NULL); | |
313 | ||
314 | if (process_array) | |
315 | { | |
316 | if ((proc = calloc(1, sizeof(cupsd_proc_t) + strlen(command))) != NULL) | |
317 | { | |
318 | proc->pid = *pid; | |
319 | strcpy(proc->name, command); | |
320 | ||
321 | cupsArrayAdd(process_array, proc); | |
322 | } | |
323 | } | |
324 | } | |
ef416fc2 | 325 | |
326 | cupsdReleaseSignals(); | |
327 | ||
328 | return (*pid); | |
329 | } | |
330 | ||
331 | ||
332 | /* | |
e00b005a | 333 | * 'compare_procs()' - Compare two processes. |
334 | */ | |
335 | ||
336 | static int /* O - Result of comparison */ | |
337 | compare_procs(cupsd_proc_t *a, /* I - First process */ | |
338 | cupsd_proc_t *b) /* I - Second process */ | |
339 | { | |
340 | return (a->pid - b->pid); | |
341 | } | |
342 | ||
343 | ||
344 | /* | |
bc44d920 | 345 | * End of "$Id: process.c 6649 2007-07-11 21:46:42Z mike $". |
ef416fc2 | 346 | */ |