2 Unix SMB/CIFS mplementation.
4 helper layer for breaking up streams into discrete requests
6 Copyright (C) Andrew Tridgell 2005
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include "dlinklist.h"
26 #include "lib/events/events.h"
27 #include "lib/socket/socket.h"
28 #include "lib/tls/tls.h"
29 #include "lib/stream/packet.h"
32 struct packet_context {
33 packet_callback_fn_t callback;
34 packet_full_request_fn_t full_request;
35 packet_error_handler_fn_t error_handler;
38 uint32_t initial_read;
39 struct tls_context *tls;
40 struct socket_context *sock;
41 struct event_context *ev;
51 BOOL destructor_called;
54 struct send_element *next, *prev;
61 a destructor used when we are processing packets to prevent freeing of this
62 context while it is being used
64 static int packet_destructor(void *p)
66 struct packet_context *pc = talloc_get_type(p, struct packet_context);
69 pc->destructor_called = True;
70 /* now we refuse the talloc_free() request. The free will
71 happen again in the packet_recv() code */
80 initialise a packet receiver
82 struct packet_context *packet_init(TALLOC_CTX *mem_ctx)
84 struct packet_context *pc = talloc_zero(mem_ctx, struct packet_context);
86 talloc_set_destructor(pc, packet_destructor);
93 set the request callback, called when a full request is ready
95 void packet_set_callback(struct packet_context *pc, packet_callback_fn_t callback)
97 pc->callback = callback;
101 set the error handler
103 void packet_set_error_handler(struct packet_context *pc, packet_error_handler_fn_t handler)
105 pc->error_handler = handler;
109 set the private pointer passed to the callback functions
111 void packet_set_private(struct packet_context *pc, void *private)
113 pc->private = private;
117 set the full request callback. Should return as follows:
118 NT_STATUS_OK == blob is a full request.
119 STATUS_MORE_ENTRIES == blob is not complete yet
120 any error == blob is not a valid
122 void packet_set_full_request(struct packet_context *pc, packet_full_request_fn_t callback)
124 pc->full_request = callback;
128 set a tls context to use. You must either set a tls_context or a socket_context
130 void packet_set_tls(struct packet_context *pc, struct tls_context *tls)
136 set a socket context to use. You must either set a tls_context or a socket_context
138 void packet_set_socket(struct packet_context *pc, struct socket_context *sock)
144 set an event context. If this is set then the code will ensure that
145 packets arrive with separate events, by creating a immediate event
146 for any secondary packets when more than one packet is read at one
147 time on a socket. This can matter for code that relies on not
148 getting more than one packet per event
150 void packet_set_event_context(struct packet_context *pc, struct event_context *ev)
156 tell the packet layer the fde for the socket
158 void packet_set_fde(struct packet_context *pc, struct fd_event *fde)
164 tell the packet layer to serialise requests, so we don't process two
165 requests at once on one connection. You must have set the
166 event_context and fde
168 void packet_set_serialise(struct packet_context *pc)
170 pc->serialise = True;
174 tell the packet layer how much to read when starting a new packet
175 this ensures it doesn't overread
177 void packet_set_initial_read(struct packet_context *pc, uint32_t initial_read)
179 pc->initial_read = initial_read;
183 tell the packet system not to steal/free blobs given to packet_send()
185 void packet_set_nofree(struct packet_context *pc)
192 tell the caller we have an error
194 static void packet_error(struct packet_context *pc, NTSTATUS status)
198 if (pc->error_handler) {
199 pc->error_handler(pc->private, status);
202 /* default error handler is to free the callers private pointer */
203 if (!NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)) {
204 DEBUG(0,("packet_error on %s - %s\n",
205 talloc_get_name(pc->private), nt_errstr(status)));
207 talloc_free(pc->private);
213 tell the caller we have EOF
215 static void packet_eof(struct packet_context *pc)
217 packet_error(pc, NT_STATUS_END_OF_FILE);
222 used to put packets on event boundaries
224 static void packet_next_event(struct event_context *ev, struct timed_event *te,
225 struct timeval t, void *private)
227 struct packet_context *pc = talloc_get_type(private, struct packet_context);
228 if (pc->num_read != 0 && pc->packet_size != 0 &&
229 pc->packet_size <= pc->num_read) {
236 call this when the socket becomes readable to kick off the whole
237 stream parsing process
239 void packet_recv(struct packet_context *pc)
246 if (pc->processing) {
247 EVENT_FD_NOT_READABLE(pc->fde);
252 if (pc->recv_disable) {
253 EVENT_FD_NOT_READABLE(pc->fde);
257 if (pc->packet_size != 0 && pc->num_read >= pc->packet_size) {
261 if (pc->packet_size != 0) {
262 /* we've already worked out how long this next packet is, so skip the
263 socket_pending() call */
264 npending = pc->packet_size - pc->num_read;
265 } else if (pc->initial_read != 0) {
266 npending = pc->initial_read - pc->num_read;
269 status = tls_socket_pending(pc->tls, &npending);
270 } else if (pc->sock) {
271 status = socket_pending(pc->sock, &npending);
273 status = NT_STATUS_CONNECTION_DISCONNECTED;
275 if (!NT_STATUS_IS_OK(status)) {
276 packet_error(pc, status);
286 /* possibly expand the partial packet buffer */
287 if (npending + pc->num_read > pc->partial.length) {
288 status = data_blob_realloc(pc, &pc->partial, npending+pc->num_read);
289 if (!NT_STATUS_IS_OK(status)) {
290 packet_error(pc, status);
296 status = tls_socket_recv(pc->tls, pc->partial.data + pc->num_read,
299 status = socket_recv(pc->sock, pc->partial.data + pc->num_read,
300 npending, &nread, 0);
302 if (NT_STATUS_IS_ERR(status)) {
303 packet_error(pc, status);
306 if (!NT_STATUS_IS_OK(status)) {
315 pc->num_read += nread;
318 if (pc->partial.length != pc->num_read) {
319 status = data_blob_realloc(pc, &pc->partial, pc->num_read);
320 if (!NT_STATUS_IS_OK(status)) {
321 packet_error(pc, status);
326 /* see if its a full request */
328 blob.length = pc->num_read;
329 status = pc->full_request(pc->private, blob, &pc->packet_size);
330 if (NT_STATUS_IS_ERR(status)) {
331 packet_error(pc, status);
334 if (!NT_STATUS_IS_OK(status)) {
338 if (pc->packet_size > pc->num_read) {
339 /* the caller made an error */
340 DEBUG(0,("Invalid packet_size %lu greater than num_read %lu\n",
341 (long)pc->packet_size, (long)pc->num_read));
342 packet_error(pc, NT_STATUS_INVALID_PARAMETER);
346 /* it is a full request - give it to the caller */
348 blob.length = pc->num_read;
350 if (pc->packet_size < pc->num_read) {
351 pc->partial = data_blob_talloc(pc, blob.data + pc->packet_size,
352 pc->num_read - pc->packet_size);
353 if (pc->partial.data == NULL) {
354 packet_error(pc, NT_STATUS_NO_MEMORY);
357 status = data_blob_realloc(pc, &blob, pc->packet_size);
358 if (!NT_STATUS_IS_OK(status)) {
359 packet_error(pc, status);
363 pc->partial = data_blob(NULL, 0);
365 pc->num_read -= pc->packet_size;
374 status = pc->callback(pc->private, blob);
378 if (pc->destructor_called) {
383 if (pc->processing) {
384 if (pc->processing > 1) {
385 EVENT_FD_READABLE(pc->fde);
390 if (!NT_STATUS_IS_OK(status)) {
391 packet_error(pc, status);
395 if (pc->partial.length == 0) {
399 /* we got multiple packets in one tcp read */
400 if (pc->ev == NULL) {
405 blob.length = pc->num_read;
407 status = pc->full_request(pc->private, blob, &pc->packet_size);
408 if (NT_STATUS_IS_ERR(status)) {
409 packet_error(pc, status);
413 if (!NT_STATUS_IS_OK(status)) {
417 event_add_timed(pc->ev, pc, timeval_zero(), packet_next_event, pc);
422 temporarily disable receiving
424 void packet_recv_disable(struct packet_context *pc)
426 EVENT_FD_NOT_READABLE(pc->fde);
427 pc->recv_disable = True;
433 void packet_recv_enable(struct packet_context *pc)
435 EVENT_FD_READABLE(pc->fde);
436 pc->recv_disable = False;
437 if (pc->num_read != 0 && pc->packet_size >= pc->num_read) {
438 event_add_timed(pc->ev, pc, timeval_zero(), packet_next_event, pc);
443 trigger a run of the send queue
445 void packet_queue_run(struct packet_context *pc)
447 while (pc->send_queue) {
448 struct send_element *el = pc->send_queue;
451 DATA_BLOB blob = data_blob_const(el->blob.data + el->nsent,
452 el->blob.length - el->nsent);
455 status = tls_socket_send(pc->tls, &blob, &nwritten);
457 status = socket_send(pc->sock, &blob, &nwritten, 0);
459 if (NT_STATUS_IS_ERR(status)) {
460 packet_error(pc, NT_STATUS_NET_WRITE_FAULT);
463 if (!NT_STATUS_IS_OK(status)) {
466 el->nsent += nwritten;
467 if (el->nsent == el->blob.length) {
468 DLIST_REMOVE(pc->send_queue, el);
473 /* we're out of requests to send, so don't wait for write
475 EVENT_FD_NOT_WRITEABLE(pc->fde);
479 put a packet in the send queue
481 NTSTATUS packet_send(struct packet_context *pc, DATA_BLOB blob)
483 struct send_element *el;
484 el = talloc(pc, struct send_element);
485 NT_STATUS_HAVE_NO_MEMORY(el);
487 DLIST_ADD_END(pc->send_queue, el, struct send_element *);
491 /* if we aren't going to free the packet then we must reference it
492 to ensure it doesn't disappear before going out */
494 if (!talloc_reference(el, blob.data)) {
495 return NT_STATUS_NO_MEMORY;
498 talloc_steal(el, blob.data);
501 EVENT_FD_WRITEABLE(pc->fde);
508 a full request checker for NBT formatted packets (first 3 bytes are length)
510 NTSTATUS packet_full_request_nbt(void *private, DATA_BLOB blob, size_t *size)
512 if (blob.length < 4) {
513 return STATUS_MORE_ENTRIES;
515 *size = 4 + smb_len(blob.data);
516 if (*size > blob.length) {
517 return STATUS_MORE_ENTRIES;
524 work out if a packet is complete for protocols that use a 32 bit network byte
527 NTSTATUS packet_full_request_u32(void *private, DATA_BLOB blob, size_t *size)
529 if (blob.length < 4) {
530 return STATUS_MORE_ENTRIES;
532 *size = 4 + RIVAL(blob.data, 0);
533 if (*size > blob.length) {
534 return STATUS_MORE_ENTRIES;