]> git.ipfire.org Git - thirdparty/cups.git/blame - scheduler/process.c
Import CUPS 1.4svn-r7226.
[thirdparty/cups.git] / scheduler / process.c
CommitLineData
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 *
a4924f6c
MS
17 * cupsdCreateProfile() - Create an execution profile for a subprocess.
18 * cupsdDestroyProfile() - Delete an execution profile.
19 * cupsdEndProcess() - End a process.
20 * cupsdFinishProcess() - Finish a process and get its name.
21 * cupsdStartProcess() - Start a process.
22 * compare_procs() - Compare two processes.
23 * cupsd_requote() - Make a regular-expression version of a string.
ef416fc2 24 */
25
26/*
27 * Include necessary headers...
28 */
29
30#include "cupsd.h"
31#include <grp.h>
a4924f6c 32#ifdef __APPLE__
4400e98d 33# include <libgen.h>
e53920b9 34#endif /* __APPLE__ */
a4924f6c
MS
35#ifdef HAVE_SANDBOX_H
36# define __APPLE_API_PRIVATE
37# include <sandbox.h>
38#endif /* HAVE_SANDBOX_H */
ef416fc2 39
40
e00b005a 41/*
42 * Process structure...
43 */
44
45typedef struct
46{
47 int pid; /* Process ID */
48 char name[1]; /* Name of process */
49} cupsd_proc_t;
50
51
52/*
53 * Local globals...
54 */
55
56static cups_array_t *process_array = NULL;
57
58
59/*
60 * Local functions...
61 */
62
63static int compare_procs(cupsd_proc_t *a, cupsd_proc_t *b);
a4924f6c
MS
64#ifdef HAVE_SANDBOX_H
65static char *cupsd_requote(char *dst, const char *src, size_t dstsize);
66#endif /* HAVE_SANDBOX_H */
67
68
69/*
70 * 'cupsdCreateProfile()' - Create an execution profile for a subprocess.
71 */
72
73void * /* O - Profile or NULL on error */
74cupsdCreateProfile(int job_id) /* I - Job ID or 0 for none */
75{
76#ifdef HAVE_SANDBOX_H
77 cups_file_t *fp; /* File pointer */
78 char profile[1024], /* File containing the profile */
79 cache[1024], /* Quoted CacheDir */
80 request[1024], /* Quoted RequestRoot */
81 root[1024], /* Quoted ServerRoot */
82 temp[1024]; /* Quoted TempDir */
83
84
85 if ((fp = cupsTempFile2(profile, sizeof(profile))) == NULL)
86 {
87 cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to create security profile: %s",
88 strerror(errno));
89 return (NULL);
90 }
91
92 cupsd_requote(cache, CacheDir, sizeof(cache));
93 cupsd_requote(request, RequestRoot, sizeof(request));
94 cupsd_requote(root, ServerRoot, sizeof(root));
95 cupsd_requote(temp, TempDir, sizeof(temp));
96
97 cupsFilePuts(fp, "(version 1)\n");
98 cupsFilePuts(fp, "(debug deny)\n");
99 cupsFilePuts(fp, "(allow default)\n");
100 cupsFilePrintf(fp,
101 "(deny file-write* file-read-data file-read-metadata\n"
102 " (regex #\"^%s\"))\n", request);
103 cupsFilePrintf(fp,
104 "(deny file-write*\n"
105 " (regex #\"^%s\" #\"^/private/etc\" #\"^/usr/local/etc\" "
106 "#\"^/Library\" #\"^/System\"))\n", root);
107 cupsFilePrintf(fp,
108 "(allow file-write* file-read-data file-read-metadata\n"
109 " (regex #\"^%s$\" #\"^%s/\" #\"^%s$\" #\"^%s/\"))\n",
110 temp, temp, cache, cache);
111 if (job_id)
112 cupsFilePrintf(fp,
113 "(allow file-read-data file-read-metadata\n"
114 " (regex #\"^%s/([ac]%05d|d%05d-[0-9][0-9][0-9])$\"))\n",
115 request);
116
117 cupsFileClose(fp);
118
119 return ((void *)strdup(profile));
120#else
121
122 return (NULL);
123#endif /* HAVE_SANDBOX_H */
124}
125
126
127/*
128 * 'cupsdDestroyProfile()' - Delete an execution profile.
129 */
130
131void
132cupsdDestroyProfile(void *profile) /* I - Profile */
133{
134#ifdef HAVE_SANDBOX_H
135 if (profile)
136 {
137 unlink((char *)profile);
138 free(profile);
139 }
140#endif /* HAVE_SANDBOX_H */
141}
e00b005a 142
143
ef416fc2 144/*
145 * 'cupsdEndProcess()' - End a process.
146 */
147
148int /* O - 0 on success, -1 on failure */
149cupsdEndProcess(int pid, /* I - Process ID */
150 int force) /* I - Force child to die */
151{
152 if (force)
153 return (kill(pid, SIGKILL));
154 else
155 return (kill(pid, SIGTERM));
156}
157
158
e00b005a 159/*
160 * 'cupsdFinishProcess()' - Finish a process and get its name.
161 */
162
163const char * /* O - Process name */
164cupsdFinishProcess(int pid, /* I - Process ID */
165 char *name, /* I - Name buffer */
166 int namelen) /* I - Size of name buffer */
167{
168 cupsd_proc_t key, /* Search key */
169 *proc; /* Matching process */
170
171
172 key.pid = pid;
173
174 if ((proc = (cupsd_proc_t *)cupsArrayFind(process_array, &key)) != NULL)
175 {
176 strlcpy(name, proc->name, namelen);
177 cupsArrayRemove(process_array, proc);
178 free(proc);
179
180 return (name);
181 }
182 else
183 return ("unknown");
184}
185
186
ef416fc2 187/*
188 * 'cupsdStartProcess()' - Start a process.
189 */
190
191int /* O - Process ID or 0 */
192cupsdStartProcess(
193 const char *command, /* I - Full path to command */
194 char *argv[], /* I - Command-line arguments */
195 char *envp[], /* I - Environment */
196 int infd, /* I - Standard input file descriptor */
197 int outfd, /* I - Standard output file descriptor */
198 int errfd, /* I - Standard error file descriptor */
199 int backfd, /* I - Backchannel file descriptor */
f7deaa1a 200 int sidefd, /* I - Sidechannel file descriptor */
ef416fc2 201 int root, /* I - Run as root? */
a4924f6c 202 void *profile, /* I - Security profile to use */
ef416fc2 203 int *pid) /* O - Process ID */
204{
e00b005a 205 cupsd_proc_t *proc; /* New process record */
ef416fc2 206#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
e00b005a 207 struct sigaction action; /* POSIX signal handler */
ef416fc2 208#endif /* HAVE_SIGACTION && !HAVE_SIGSET */
e53920b9 209#if defined(__APPLE__)
e00b005a 210 char processPath[1024], /* CFProcessPath environment variable */
211 linkpath[1024]; /* Link path for symlinks... */
212 int linkbytes; /* Bytes for link path */
e53920b9 213#endif /* __APPLE__ */
ef416fc2 214
215
216 cupsdLogMessage(CUPSD_LOG_DEBUG2,
217 "cupsdStartProcess(\"%s\", %p, %p, %d, %d, %d)",
218 command, argv, envp, infd, outfd, errfd);
219
76cd9e37
MS
220 if (access(command, X_OK))
221 {
222 cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to execute %s: %s", command,
223 strerror(errno));
7dfedb92 224 *pid = 0;
76cd9e37
MS
225 return (0);
226 }
227
e53920b9 228#if defined(__APPLE__)
229 if (envp)
e00b005a 230 {
231 /*
e53920b9 232 * Add special voodoo magic for MacOS X - this allows MacOS X
233 * programs to access their bundle resources properly...
e00b005a 234 */
235
e53920b9 236 if ((linkbytes = readlink(command, linkpath, sizeof(linkpath) - 1)) > 0)
237 {
238 /*
239 * Yes, this is a symlink to the actual program, nul-terminate and
240 * use it...
241 */
242
243 linkpath[linkbytes] = '\0';
e00b005a 244
e53920b9 245 if (linkpath[0] == '/')
246 snprintf(processPath, sizeof(processPath), "CFProcessPath=%s",
247 linkpath);
248 else
249 snprintf(processPath, sizeof(processPath), "CFProcessPath=%s/%s",
f7deaa1a 250 dirname((char *)command), linkpath);
e53920b9 251 }
e00b005a 252 else
e53920b9 253 snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", command);
bd7854cb 254
e53920b9 255 envp[0] = processPath; /* Replace <CFProcessPath> string */
256 }
257#endif /* __APPLE__ */
e00b005a 258
ef416fc2 259 /*
260 * Block signals before forking...
261 */
262
263 cupsdHoldSignals();
264
265 if ((*pid = fork()) == 0)
266 {
267 /*
268 * Child process goes here...
269 *
270 * Update stdin/stdout/stderr as needed...
271 */
272
273 if (infd != 0)
274 {
275 close(0);
276 if (infd > 0)
277 dup(infd);
278 else
279 open("/dev/null", O_RDONLY);
280 }
281 if (outfd != 1)
282 {
283 close(1);
284 if (outfd > 0)
285 dup(outfd);
286 else
287 open("/dev/null", O_WRONLY);
288 }
289 if (errfd != 2)
290 {
291 close(2);
292 if (errfd > 0)
293 dup(errfd);
294 else
295 open("/dev/null", O_WRONLY);
296 }
297 if (backfd != 3)
298 {
299 close(3);
300 if (backfd > 0)
301 dup(backfd);
302 else
303 open("/dev/null", O_RDWR);
304 fcntl(3, F_SETFL, O_NDELAY);
305 }
f7deaa1a 306 if (sidefd != 4 && sidefd > 0)
307 {
308 close(4);
309 dup(sidefd);
310 fcntl(4, F_SETFL, O_NDELAY);
311 }
ef416fc2 312
313 /*
314 * Change the priority of the process based on the FilterNice setting.
315 * (this is not done for backends...)
316 */
317
318 if (!root)
319 nice(FilterNice);
320
321 /*
322 * Change user to something "safe"...
323 */
324
325 if (!root && !RunUser)
326 {
327 /*
328 * Running as root, so change to non-priviledged user...
329 */
330
331 if (setgid(Group))
e00b005a 332 exit(errno);
ef416fc2 333
334 if (setgroups(1, &Group))
e00b005a 335 exit(errno);
ef416fc2 336
337 if (setuid(User))
338 exit(errno);
339 }
340 else
341 {
342 /*
343 * Reset group membership to just the main one we belong to.
344 */
345
e00b005a 346 setgid(Group);
ef416fc2 347 setgroups(1, &Group);
348 }
349
350 /*
351 * Change umask to restrict permissions on created files...
352 */
353
354 umask(077);
355
356 /*
357 * Unblock signals before doing the exec...
358 */
359
360#ifdef HAVE_SIGSET
361 sigset(SIGTERM, SIG_DFL);
362 sigset(SIGCHLD, SIG_DFL);
363#elif defined(HAVE_SIGACTION)
364 memset(&action, 0, sizeof(action));
365
366 sigemptyset(&action.sa_mask);
367 action.sa_handler = SIG_DFL;
368
369 sigaction(SIGTERM, &action, NULL);
370 sigaction(SIGCHLD, &action, NULL);
371#else
372 signal(SIGTERM, SIG_DFL);
373 signal(SIGCHLD, SIG_DFL);
374#endif /* HAVE_SIGSET */
375
376 cupsdReleaseSignals();
377
a4924f6c
MS
378#ifdef HAVE_SANDBOX_H
379 /*
380 * Run in a separate security profile...
381 */
382
383 if (profile)
384 {
385 char *error; /* Sandbox error, if any */
386
387 if (sandbox_init((char *)profile, SANDBOX_NAMED_EXTERNAL, &error))
388 {
389 fprintf(stderr, "ERROR: sandbox_init failed: %s (%s)\n", error,
390 strerror(errno));
391 sandbox_free_error(error);
392 }
393 }
394#endif /* HAVE_SANDBOX_H */
395
ef416fc2 396 /*
397 * Execute the command; if for some reason this doesn't work,
398 * return the error code...
399 */
400
401 if (envp)
402 execve(command, argv, envp);
403 else
404 execv(command, argv);
405
406 perror(command);
407
408 exit(errno);
409 }
410 else if (*pid < 0)
411 {
412 /*
413 * Error - couldn't fork a new process!
414 */
415
416 cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to fork %s - %s.", command,
417 strerror(errno));
418
419 *pid = 0;
420 }
e00b005a 421 else
422 {
423 if (!process_array)
424 process_array = cupsArrayNew((cups_array_func_t)compare_procs, NULL);
425
426 if (process_array)
427 {
428 if ((proc = calloc(1, sizeof(cupsd_proc_t) + strlen(command))) != NULL)
429 {
430 proc->pid = *pid;
431 strcpy(proc->name, command);
432
433 cupsArrayAdd(process_array, proc);
434 }
435 }
436 }
ef416fc2 437
438 cupsdReleaseSignals();
439
440 return (*pid);
441}
442
443
444/*
e00b005a 445 * 'compare_procs()' - Compare two processes.
446 */
447
448static int /* O - Result of comparison */
449compare_procs(cupsd_proc_t *a, /* I - First process */
450 cupsd_proc_t *b) /* I - Second process */
451{
452 return (a->pid - b->pid);
453}
454
455
a4924f6c
MS
456#ifdef HAVE_SANDBOX_H
457/*
458 * 'cupsd_requote()' - Make a regular-expression version of a string.
459 */
460
461static char * /* O - Quoted string */
462cupsd_requote(char *dst, /* I - Destination buffer */
463 const char *src, /* I - Source string */
464 size_t dstsize) /* I - Size of destination buffer */
465{
466 int ch; /* Current character */
467 char *dstptr, /* Current position in buffer */
468 *dstend; /* End of destination buffer */
469
470
471 dstptr = dst;
472 dstend = dst + dstsize - 2;
473
474 while (*src && dstptr < dstend)
475 {
476 ch = *src++;
477
478 if (strchr(".?*()[]^$\\", ch))
479 *dstptr++ = '\\';
480
481 *dstptr++ = ch;
482 }
483
484 *dstptr = '\0';
485
486 return (dst);
487}
488#endif /* HAVE_SANDBOX_H */
489
490
e00b005a 491/*
2e4ff8af 492 * End of "$Id: process.c 6987 2007-09-25 15:43:44Z mike $".
ef416fc2 493 */