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1 | /* | |
2 | * Side-channel API code for CUPS. | |
3 | * | |
4 | * Copyright 2007-2014 by Apple Inc. | |
5 | * Copyright 2006 by Easy Software Products. | |
6 | * | |
7 | * Licensed under Apache License v2.0. See the file "LICENSE" for more information. | |
8 | */ | |
9 | ||
10 | /* | |
11 | * Include necessary headers... | |
12 | */ | |
13 | ||
14 | #include "sidechannel.h" | |
15 | #include "cups-private.h" | |
16 | #include "debug-internal.h" | |
17 | #ifdef _WIN32 | |
18 | # include <io.h> | |
19 | #else | |
20 | # include <unistd.h> | |
21 | # include <sys/select.h> | |
22 | # include <sys/time.h> | |
23 | #endif /* _WIN32 */ | |
24 | #ifdef HAVE_POLL | |
25 | # include <poll.h> | |
26 | #endif /* HAVE_POLL */ | |
27 | ||
28 | ||
29 | /* | |
30 | * Buffer size for side-channel requests... | |
31 | */ | |
32 | ||
33 | #define _CUPS_SC_MAX_DATA 65535 | |
34 | #define _CUPS_SC_MAX_BUFFER 65540 | |
35 | ||
36 | ||
37 | /* | |
38 | * 'cupsSideChannelDoRequest()' - Send a side-channel command to a backend and wait for a response. | |
39 | * | |
40 | * This function is normally only called by filters, drivers, or port | |
41 | * monitors in order to communicate with the backend used by the current | |
42 | * printer. Programs must be prepared to handle timeout or "not | |
43 | * implemented" status codes, which indicate that the backend or device | |
44 | * do not support the specified side-channel command. | |
45 | * | |
46 | * The "datalen" parameter must be initialized to the size of the buffer | |
47 | * pointed to by the "data" parameter. cupsSideChannelDoRequest() will | |
48 | * update the value to contain the number of data bytes in the buffer. | |
49 | * | |
50 | * @since CUPS 1.3/macOS 10.5@ | |
51 | */ | |
52 | ||
53 | cups_sc_status_t /* O - Status of command */ | |
54 | cupsSideChannelDoRequest( | |
55 | cups_sc_command_t command, /* I - Command to send */ | |
56 | char *data, /* O - Response data buffer pointer */ | |
57 | int *datalen, /* IO - Size of data buffer on entry, number of bytes in buffer on return */ | |
58 | double timeout) /* I - Timeout in seconds */ | |
59 | { | |
60 | cups_sc_status_t status; /* Status of command */ | |
61 | cups_sc_command_t rcommand; /* Response command */ | |
62 | ||
63 | ||
64 | if (cupsSideChannelWrite(command, CUPS_SC_STATUS_NONE, NULL, 0, timeout)) | |
65 | return (CUPS_SC_STATUS_TIMEOUT); | |
66 | ||
67 | if (cupsSideChannelRead(&rcommand, &status, data, datalen, timeout)) | |
68 | return (CUPS_SC_STATUS_TIMEOUT); | |
69 | ||
70 | if (rcommand != command) | |
71 | return (CUPS_SC_STATUS_BAD_MESSAGE); | |
72 | ||
73 | return (status); | |
74 | } | |
75 | ||
76 | ||
77 | /* | |
78 | * 'cupsSideChannelRead()' - Read a side-channel message. | |
79 | * | |
80 | * This function is normally only called by backend programs to read | |
81 | * commands from a filter, driver, or port monitor program. The | |
82 | * caller must be prepared to handle incomplete or invalid messages | |
83 | * and return the corresponding status codes. | |
84 | * | |
85 | * The "datalen" parameter must be initialized to the size of the buffer | |
86 | * pointed to by the "data" parameter. cupsSideChannelDoRequest() will | |
87 | * update the value to contain the number of data bytes in the buffer. | |
88 | * | |
89 | * @since CUPS 1.3/macOS 10.5@ | |
90 | */ | |
91 | ||
92 | int /* O - 0 on success, -1 on error */ | |
93 | cupsSideChannelRead( | |
94 | cups_sc_command_t *command, /* O - Command code */ | |
95 | cups_sc_status_t *status, /* O - Status code */ | |
96 | char *data, /* O - Data buffer pointer */ | |
97 | int *datalen, /* IO - Size of data buffer on entry, number of bytes in buffer on return */ | |
98 | double timeout) /* I - Timeout in seconds */ | |
99 | { | |
100 | char *buffer; /* Message buffer */ | |
101 | ssize_t bytes; /* Bytes read */ | |
102 | int templen; /* Data length from message */ | |
103 | int nfds; /* Number of file descriptors */ | |
104 | #ifdef HAVE_POLL | |
105 | struct pollfd pfd; /* Poll structure for poll() */ | |
106 | #else /* select() */ | |
107 | fd_set input_set; /* Input set for select() */ | |
108 | struct timeval stimeout; /* Timeout value for select() */ | |
109 | #endif /* HAVE_POLL */ | |
110 | ||
111 | ||
112 | DEBUG_printf(("cupsSideChannelRead(command=%p, status=%p, data=%p, " | |
113 | "datalen=%p(%d), timeout=%.3f)", command, status, data, | |
114 | datalen, datalen ? *datalen : -1, timeout)); | |
115 | ||
116 | /* | |
117 | * Range check input... | |
118 | */ | |
119 | ||
120 | if (!command || !status) | |
121 | return (-1); | |
122 | ||
123 | /* | |
124 | * See if we have pending data on the side-channel socket... | |
125 | */ | |
126 | ||
127 | #ifdef HAVE_POLL | |
128 | pfd.fd = CUPS_SC_FD; | |
129 | pfd.events = POLLIN; | |
130 | ||
131 | while ((nfds = poll(&pfd, 1, | |
132 | timeout < 0.0 ? -1 : (int)(timeout * 1000))) < 0 && | |
133 | (errno == EINTR || errno == EAGAIN)) | |
134 | ; | |
135 | ||
136 | #else /* select() */ | |
137 | FD_ZERO(&input_set); | |
138 | FD_SET(CUPS_SC_FD, &input_set); | |
139 | ||
140 | stimeout.tv_sec = (int)timeout; | |
141 | stimeout.tv_usec = (int)(timeout * 1000000) % 1000000; | |
142 | ||
143 | while ((nfds = select(CUPS_SC_FD + 1, &input_set, NULL, NULL, | |
144 | timeout < 0.0 ? NULL : &stimeout)) < 0 && | |
145 | (errno == EINTR || errno == EAGAIN)) | |
146 | ; | |
147 | ||
148 | #endif /* HAVE_POLL */ | |
149 | ||
150 | if (nfds < 1) | |
151 | { | |
152 | *command = CUPS_SC_CMD_NONE; | |
153 | *status = nfds==0 ? CUPS_SC_STATUS_TIMEOUT : CUPS_SC_STATUS_IO_ERROR; | |
154 | return (-1); | |
155 | } | |
156 | ||
157 | /* | |
158 | * Read a side-channel message for the format: | |
159 | * | |
160 | * Byte(s) Description | |
161 | * ------- ------------------------------------------- | |
162 | * 0 Command code | |
163 | * 1 Status code | |
164 | * 2-3 Data length (network byte order) | |
165 | * 4-N Data | |
166 | */ | |
167 | ||
168 | if ((buffer = _cupsBufferGet(_CUPS_SC_MAX_BUFFER)) == NULL) | |
169 | { | |
170 | *command = CUPS_SC_CMD_NONE; | |
171 | *status = CUPS_SC_STATUS_TOO_BIG; | |
172 | ||
173 | return (-1); | |
174 | } | |
175 | ||
176 | while ((bytes = read(CUPS_SC_FD, buffer, _CUPS_SC_MAX_BUFFER)) < 0) | |
177 | if (errno != EINTR && errno != EAGAIN) | |
178 | { | |
179 | DEBUG_printf(("1cupsSideChannelRead: Read error: %s", strerror(errno))); | |
180 | ||
181 | _cupsBufferRelease(buffer); | |
182 | ||
183 | *command = CUPS_SC_CMD_NONE; | |
184 | *status = CUPS_SC_STATUS_IO_ERROR; | |
185 | ||
186 | return (-1); | |
187 | } | |
188 | ||
189 | /* | |
190 | * Watch for EOF or too few bytes... | |
191 | */ | |
192 | ||
193 | if (bytes < 4) | |
194 | { | |
195 | DEBUG_printf(("1cupsSideChannelRead: Short read of " CUPS_LLFMT " bytes", CUPS_LLCAST bytes)); | |
196 | ||
197 | _cupsBufferRelease(buffer); | |
198 | ||
199 | *command = CUPS_SC_CMD_NONE; | |
200 | *status = CUPS_SC_STATUS_BAD_MESSAGE; | |
201 | ||
202 | return (-1); | |
203 | } | |
204 | ||
205 | /* | |
206 | * Validate the command code in the message... | |
207 | */ | |
208 | ||
209 | if (buffer[0] < CUPS_SC_CMD_SOFT_RESET || | |
210 | buffer[0] >= CUPS_SC_CMD_MAX) | |
211 | { | |
212 | DEBUG_printf(("1cupsSideChannelRead: Bad command %d!", buffer[0])); | |
213 | ||
214 | _cupsBufferRelease(buffer); | |
215 | ||
216 | *command = CUPS_SC_CMD_NONE; | |
217 | *status = CUPS_SC_STATUS_BAD_MESSAGE; | |
218 | ||
219 | return (-1); | |
220 | } | |
221 | ||
222 | *command = (cups_sc_command_t)buffer[0]; | |
223 | ||
224 | /* | |
225 | * Validate the data length in the message... | |
226 | */ | |
227 | ||
228 | templen = ((buffer[2] & 255) << 8) | (buffer[3] & 255); | |
229 | ||
230 | if (templen > 0 && (!data || !datalen)) | |
231 | { | |
232 | /* | |
233 | * Either the response is bigger than the provided buffer or the | |
234 | * response is bigger than we've read... | |
235 | */ | |
236 | ||
237 | *status = CUPS_SC_STATUS_TOO_BIG; | |
238 | } | |
239 | else if (!datalen || templen > *datalen || templen > (bytes - 4)) | |
240 | { | |
241 | /* | |
242 | * Either the response is bigger than the provided buffer or the | |
243 | * response is bigger than we've read... | |
244 | */ | |
245 | ||
246 | *status = CUPS_SC_STATUS_TOO_BIG; | |
247 | } | |
248 | else | |
249 | { | |
250 | /* | |
251 | * The response data will fit, copy it over and provide the actual | |
252 | * length... | |
253 | */ | |
254 | ||
255 | *status = (cups_sc_status_t)buffer[1]; | |
256 | *datalen = templen; | |
257 | ||
258 | memcpy(data, buffer + 4, (size_t)templen); | |
259 | } | |
260 | ||
261 | _cupsBufferRelease(buffer); | |
262 | ||
263 | DEBUG_printf(("1cupsSideChannelRead: Returning status=%d", *status)); | |
264 | ||
265 | return (0); | |
266 | } | |
267 | ||
268 | ||
269 | /* | |
270 | * 'cupsSideChannelSNMPGet()' - Query a SNMP OID's value. | |
271 | * | |
272 | * This function asks the backend to do a SNMP OID query on behalf of the | |
273 | * filter, port monitor, or backend using the default community name. | |
274 | * | |
275 | * "oid" contains a numeric OID consisting of integers separated by periods, | |
276 | * for example ".1.3.6.1.2.1.43". Symbolic names from SNMP MIBs are not | |
277 | * supported and must be converted to their numeric forms. | |
278 | * | |
279 | * On input, "data" and "datalen" provide the location and size of the | |
280 | * buffer to hold the OID value as a string. HEX-String (binary) values are | |
281 | * converted to hexadecimal strings representing the binary data, while | |
282 | * NULL-Value and unknown OID types are returned as the empty string. | |
283 | * The returned "datalen" does not include the trailing nul. | |
284 | * | |
285 | * @code CUPS_SC_STATUS_NOT_IMPLEMENTED@ is returned by backends that do not | |
286 | * support SNMP queries. @code CUPS_SC_STATUS_NO_RESPONSE@ is returned when | |
287 | * the printer does not respond to the SNMP query. | |
288 | * | |
289 | * @since CUPS 1.4/macOS 10.6@ | |
290 | */ | |
291 | ||
292 | cups_sc_status_t /* O - Query status */ | |
293 | cupsSideChannelSNMPGet( | |
294 | const char *oid, /* I - OID to query */ | |
295 | char *data, /* I - Buffer for OID value */ | |
296 | int *datalen, /* IO - Size of OID buffer on entry, size of value on return */ | |
297 | double timeout) /* I - Timeout in seconds */ | |
298 | { | |
299 | cups_sc_status_t status; /* Status of command */ | |
300 | cups_sc_command_t rcommand; /* Response command */ | |
301 | char *real_data; /* Real data buffer for response */ | |
302 | int real_datalen, /* Real length of data buffer */ | |
303 | real_oidlen; /* Length of returned OID string */ | |
304 | ||
305 | ||
306 | DEBUG_printf(("cupsSideChannelSNMPGet(oid=\"%s\", data=%p, datalen=%p(%d), " | |
307 | "timeout=%.3f)", oid, data, datalen, datalen ? *datalen : -1, | |
308 | timeout)); | |
309 | ||
310 | /* | |
311 | * Range check input... | |
312 | */ | |
313 | ||
314 | if (!oid || !*oid || !data || !datalen || *datalen < 2) | |
315 | return (CUPS_SC_STATUS_BAD_MESSAGE); | |
316 | ||
317 | *data = '\0'; | |
318 | ||
319 | /* | |
320 | * Send the request to the backend and wait for a response... | |
321 | */ | |
322 | ||
323 | if (cupsSideChannelWrite(CUPS_SC_CMD_SNMP_GET, CUPS_SC_STATUS_NONE, oid, | |
324 | (int)strlen(oid) + 1, timeout)) | |
325 | return (CUPS_SC_STATUS_TIMEOUT); | |
326 | ||
327 | if ((real_data = _cupsBufferGet(_CUPS_SC_MAX_BUFFER)) == NULL) | |
328 | return (CUPS_SC_STATUS_TOO_BIG); | |
329 | ||
330 | real_datalen = _CUPS_SC_MAX_BUFFER; | |
331 | if (cupsSideChannelRead(&rcommand, &status, real_data, &real_datalen, timeout)) | |
332 | { | |
333 | _cupsBufferRelease(real_data); | |
334 | return (CUPS_SC_STATUS_TIMEOUT); | |
335 | } | |
336 | ||
337 | if (rcommand != CUPS_SC_CMD_SNMP_GET) | |
338 | { | |
339 | _cupsBufferRelease(real_data); | |
340 | return (CUPS_SC_STATUS_BAD_MESSAGE); | |
341 | } | |
342 | ||
343 | if (status == CUPS_SC_STATUS_OK) | |
344 | { | |
345 | /* | |
346 | * Parse the response of the form "oid\0value"... | |
347 | */ | |
348 | ||
349 | real_oidlen = (int)strlen(real_data) + 1; | |
350 | real_datalen -= real_oidlen; | |
351 | ||
352 | if ((real_datalen + 1) > *datalen) | |
353 | { | |
354 | _cupsBufferRelease(real_data); | |
355 | return (CUPS_SC_STATUS_TOO_BIG); | |
356 | } | |
357 | ||
358 | memcpy(data, real_data + real_oidlen, (size_t)real_datalen); | |
359 | data[real_datalen] = '\0'; | |
360 | ||
361 | *datalen = real_datalen; | |
362 | } | |
363 | ||
364 | _cupsBufferRelease(real_data); | |
365 | ||
366 | return (status); | |
367 | } | |
368 | ||
369 | ||
370 | /* | |
371 | * 'cupsSideChannelSNMPWalk()' - Query multiple SNMP OID values. | |
372 | * | |
373 | * This function asks the backend to do multiple SNMP OID queries on behalf | |
374 | * of the filter, port monitor, or backend using the default community name. | |
375 | * All OIDs under the "parent" OID are queried and the results are sent to | |
376 | * the callback function you provide. | |
377 | * | |
378 | * "oid" contains a numeric OID consisting of integers separated by periods, | |
379 | * for example ".1.3.6.1.2.1.43". Symbolic names from SNMP MIBs are not | |
380 | * supported and must be converted to their numeric forms. | |
381 | * | |
382 | * "timeout" specifies the timeout for each OID query. The total amount of | |
383 | * time will depend on the number of OID values found and the time required | |
384 | * for each query. | |
385 | * | |
386 | * "cb" provides a function to call for every value that is found. "context" | |
387 | * is an application-defined pointer that is sent to the callback function | |
388 | * along with the OID and current data. The data passed to the callback is the | |
389 | * same as returned by @link cupsSideChannelSNMPGet@. | |
390 | * | |
391 | * @code CUPS_SC_STATUS_NOT_IMPLEMENTED@ is returned by backends that do not | |
392 | * support SNMP queries. @code CUPS_SC_STATUS_NO_RESPONSE@ is returned when | |
393 | * the printer does not respond to the first SNMP query. | |
394 | * | |
395 | * @since CUPS 1.4/macOS 10.6@ | |
396 | */ | |
397 | ||
398 | cups_sc_status_t /* O - Status of first query of @code CUPS_SC_STATUS_OK@ on success */ | |
399 | cupsSideChannelSNMPWalk( | |
400 | const char *oid, /* I - First numeric OID to query */ | |
401 | double timeout, /* I - Timeout for each query in seconds */ | |
402 | cups_sc_walk_func_t cb, /* I - Function to call with each value */ | |
403 | void *context) /* I - Application-defined pointer to send to callback */ | |
404 | { | |
405 | cups_sc_status_t status; /* Status of command */ | |
406 | cups_sc_command_t rcommand; /* Response command */ | |
407 | char *real_data; /* Real data buffer for response */ | |
408 | int real_datalen; /* Real length of data buffer */ | |
409 | size_t real_oidlen, /* Length of returned OID string */ | |
410 | oidlen; /* Length of first OID */ | |
411 | const char *current_oid; /* Current OID */ | |
412 | char last_oid[2048]; /* Last OID */ | |
413 | ||
414 | ||
415 | DEBUG_printf(("cupsSideChannelSNMPWalk(oid=\"%s\", timeout=%.3f, cb=%p, " | |
416 | "context=%p)", oid, timeout, cb, context)); | |
417 | ||
418 | /* | |
419 | * Range check input... | |
420 | */ | |
421 | ||
422 | if (!oid || !*oid || !cb) | |
423 | return (CUPS_SC_STATUS_BAD_MESSAGE); | |
424 | ||
425 | if ((real_data = _cupsBufferGet(_CUPS_SC_MAX_BUFFER)) == NULL) | |
426 | return (CUPS_SC_STATUS_TOO_BIG); | |
427 | ||
428 | /* | |
429 | * Loop until the OIDs don't match... | |
430 | */ | |
431 | ||
432 | current_oid = oid; | |
433 | oidlen = strlen(oid); | |
434 | last_oid[0] = '\0'; | |
435 | ||
436 | do | |
437 | { | |
438 | /* | |
439 | * Send the request to the backend and wait for a response... | |
440 | */ | |
441 | ||
442 | if (cupsSideChannelWrite(CUPS_SC_CMD_SNMP_GET_NEXT, CUPS_SC_STATUS_NONE, | |
443 | current_oid, (int)strlen(current_oid) + 1, timeout)) | |
444 | { | |
445 | _cupsBufferRelease(real_data); | |
446 | return (CUPS_SC_STATUS_TIMEOUT); | |
447 | } | |
448 | ||
449 | real_datalen = _CUPS_SC_MAX_BUFFER; | |
450 | if (cupsSideChannelRead(&rcommand, &status, real_data, &real_datalen, | |
451 | timeout)) | |
452 | { | |
453 | _cupsBufferRelease(real_data); | |
454 | return (CUPS_SC_STATUS_TIMEOUT); | |
455 | } | |
456 | ||
457 | if (rcommand != CUPS_SC_CMD_SNMP_GET_NEXT) | |
458 | { | |
459 | _cupsBufferRelease(real_data); | |
460 | return (CUPS_SC_STATUS_BAD_MESSAGE); | |
461 | } | |
462 | ||
463 | if (status == CUPS_SC_STATUS_OK) | |
464 | { | |
465 | /* | |
466 | * Parse the response of the form "oid\0value"... | |
467 | */ | |
468 | ||
469 | if (strncmp(real_data, oid, oidlen) || real_data[oidlen] != '.' || | |
470 | !strcmp(real_data, last_oid)) | |
471 | { | |
472 | /* | |
473 | * Done with this set of OIDs... | |
474 | */ | |
475 | ||
476 | _cupsBufferRelease(real_data); | |
477 | return (CUPS_SC_STATUS_OK); | |
478 | } | |
479 | ||
480 | if ((size_t)real_datalen < sizeof(real_data)) | |
481 | real_data[real_datalen] = '\0'; | |
482 | ||
483 | real_oidlen = strlen(real_data) + 1; | |
484 | real_datalen -= (int)real_oidlen; | |
485 | ||
486 | /* | |
487 | * Call the callback with the OID and data... | |
488 | */ | |
489 | ||
490 | (*cb)(real_data, real_data + real_oidlen, real_datalen, context); | |
491 | ||
492 | /* | |
493 | * Update the current OID... | |
494 | */ | |
495 | ||
496 | current_oid = real_data; | |
497 | strlcpy(last_oid, current_oid, sizeof(last_oid)); | |
498 | } | |
499 | } | |
500 | while (status == CUPS_SC_STATUS_OK); | |
501 | ||
502 | _cupsBufferRelease(real_data); | |
503 | ||
504 | return (status); | |
505 | } | |
506 | ||
507 | ||
508 | /* | |
509 | * 'cupsSideChannelWrite()' - Write a side-channel message. | |
510 | * | |
511 | * This function is normally only called by backend programs to send | |
512 | * responses to a filter, driver, or port monitor program. | |
513 | * | |
514 | * @since CUPS 1.3/macOS 10.5@ | |
515 | */ | |
516 | ||
517 | int /* O - 0 on success, -1 on error */ | |
518 | cupsSideChannelWrite( | |
519 | cups_sc_command_t command, /* I - Command code */ | |
520 | cups_sc_status_t status, /* I - Status code */ | |
521 | const char *data, /* I - Data buffer pointer */ | |
522 | int datalen, /* I - Number of bytes of data */ | |
523 | double timeout) /* I - Timeout in seconds */ | |
524 | { | |
525 | char *buffer; /* Message buffer */ | |
526 | ssize_t bytes; /* Bytes written */ | |
527 | #ifdef HAVE_POLL | |
528 | struct pollfd pfd; /* Poll structure for poll() */ | |
529 | #else /* select() */ | |
530 | fd_set output_set; /* Output set for select() */ | |
531 | struct timeval stimeout; /* Timeout value for select() */ | |
532 | #endif /* HAVE_POLL */ | |
533 | ||
534 | ||
535 | /* | |
536 | * Range check input... | |
537 | */ | |
538 | ||
539 | if (command < CUPS_SC_CMD_SOFT_RESET || command >= CUPS_SC_CMD_MAX || | |
540 | datalen < 0 || datalen > _CUPS_SC_MAX_DATA || (datalen > 0 && !data)) | |
541 | return (-1); | |
542 | ||
543 | /* | |
544 | * See if we can safely write to the side-channel socket... | |
545 | */ | |
546 | ||
547 | #ifdef HAVE_POLL | |
548 | pfd.fd = CUPS_SC_FD; | |
549 | pfd.events = POLLOUT; | |
550 | ||
551 | if (timeout < 0.0) | |
552 | { | |
553 | if (poll(&pfd, 1, -1) < 1) | |
554 | return (-1); | |
555 | } | |
556 | else if (poll(&pfd, 1, (int)(timeout * 1000)) < 1) | |
557 | return (-1); | |
558 | ||
559 | #else /* select() */ | |
560 | FD_ZERO(&output_set); | |
561 | FD_SET(CUPS_SC_FD, &output_set); | |
562 | ||
563 | if (timeout < 0.0) | |
564 | { | |
565 | if (select(CUPS_SC_FD + 1, NULL, &output_set, NULL, NULL) < 1) | |
566 | return (-1); | |
567 | } | |
568 | else | |
569 | { | |
570 | stimeout.tv_sec = (int)timeout; | |
571 | stimeout.tv_usec = (int)(timeout * 1000000) % 1000000; | |
572 | ||
573 | if (select(CUPS_SC_FD + 1, NULL, &output_set, NULL, &stimeout) < 1) | |
574 | return (-1); | |
575 | } | |
576 | #endif /* HAVE_POLL */ | |
577 | ||
578 | /* | |
579 | * Write a side-channel message in the format: | |
580 | * | |
581 | * Byte(s) Description | |
582 | * ------- ------------------------------------------- | |
583 | * 0 Command code | |
584 | * 1 Status code | |
585 | * 2-3 Data length (network byte order) <= 16384 | |
586 | * 4-N Data | |
587 | */ | |
588 | ||
589 | if ((buffer = _cupsBufferGet((size_t)datalen + 4)) == NULL) | |
590 | return (-1); | |
591 | ||
592 | buffer[0] = command; | |
593 | buffer[1] = status; | |
594 | buffer[2] = (char)(datalen >> 8); | |
595 | buffer[3] = (char)(datalen & 255); | |
596 | ||
597 | bytes = 4; | |
598 | ||
599 | if (datalen > 0) | |
600 | { | |
601 | memcpy(buffer + 4, data, (size_t)datalen); | |
602 | bytes += datalen; | |
603 | } | |
604 | ||
605 | while (write(CUPS_SC_FD, buffer, (size_t)bytes) < 0) | |
606 | if (errno != EINTR && errno != EAGAIN) | |
607 | { | |
608 | _cupsBufferRelease(buffer); | |
609 | return (-1); | |
610 | } | |
611 | ||
612 | _cupsBufferRelease(buffer); | |
613 | ||
614 | return (0); | |
615 | } |