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ef416fc2 | 1 | /* |
2e4ff8af | 2 | * "$Id: process.c 6987 2007-09-25 15:43:44Z 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 | ||
76cd9e37 MS |
134 | if (access(command, X_OK)) |
135 | { | |
136 | cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to execute %s: %s", command, | |
137 | strerror(errno)); | |
7dfedb92 | 138 | *pid = 0; |
76cd9e37 MS |
139 | return (0); |
140 | } | |
141 | ||
e53920b9 | 142 | #if defined(__APPLE__) |
143 | if (envp) | |
e00b005a | 144 | { |
145 | /* | |
e53920b9 | 146 | * Add special voodoo magic for MacOS X - this allows MacOS X |
147 | * programs to access their bundle resources properly... | |
e00b005a | 148 | */ |
149 | ||
e53920b9 | 150 | if ((linkbytes = readlink(command, linkpath, sizeof(linkpath) - 1)) > 0) |
151 | { | |
152 | /* | |
153 | * Yes, this is a symlink to the actual program, nul-terminate and | |
154 | * use it... | |
155 | */ | |
156 | ||
157 | linkpath[linkbytes] = '\0'; | |
e00b005a | 158 | |
e53920b9 | 159 | if (linkpath[0] == '/') |
160 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", | |
161 | linkpath); | |
162 | else | |
163 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s/%s", | |
f7deaa1a | 164 | dirname((char *)command), linkpath); |
e53920b9 | 165 | } |
e00b005a | 166 | else |
e53920b9 | 167 | snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", command); |
bd7854cb | 168 | |
e53920b9 | 169 | envp[0] = processPath; /* Replace <CFProcessPath> string */ |
170 | } | |
171 | #endif /* __APPLE__ */ | |
e00b005a | 172 | |
ef416fc2 | 173 | /* |
174 | * Block signals before forking... | |
175 | */ | |
176 | ||
177 | cupsdHoldSignals(); | |
178 | ||
179 | if ((*pid = fork()) == 0) | |
180 | { | |
181 | /* | |
182 | * Child process goes here... | |
183 | * | |
184 | * Update stdin/stdout/stderr as needed... | |
185 | */ | |
186 | ||
187 | if (infd != 0) | |
188 | { | |
189 | close(0); | |
190 | if (infd > 0) | |
191 | dup(infd); | |
192 | else | |
193 | open("/dev/null", O_RDONLY); | |
194 | } | |
195 | if (outfd != 1) | |
196 | { | |
197 | close(1); | |
198 | if (outfd > 0) | |
199 | dup(outfd); | |
200 | else | |
201 | open("/dev/null", O_WRONLY); | |
202 | } | |
203 | if (errfd != 2) | |
204 | { | |
205 | close(2); | |
206 | if (errfd > 0) | |
207 | dup(errfd); | |
208 | else | |
209 | open("/dev/null", O_WRONLY); | |
210 | } | |
211 | if (backfd != 3) | |
212 | { | |
213 | close(3); | |
214 | if (backfd > 0) | |
215 | dup(backfd); | |
216 | else | |
217 | open("/dev/null", O_RDWR); | |
218 | fcntl(3, F_SETFL, O_NDELAY); | |
219 | } | |
f7deaa1a | 220 | if (sidefd != 4 && sidefd > 0) |
221 | { | |
222 | close(4); | |
223 | dup(sidefd); | |
224 | fcntl(4, F_SETFL, O_NDELAY); | |
225 | } | |
ef416fc2 | 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 | /* | |
2e4ff8af | 353 | * End of "$Id: process.c 6987 2007-09-25 15:43:44Z mike $". |
ef416fc2 | 354 | */ |