2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2003
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 this file implements functions for manipulating the 'struct request_context' structure in smbd
27 /* we over allocate the data buffer to prevent too many realloc calls */
28 #define REQ_OVER_ALLOCATION 256
30 /* destroy a request structure */
31 void req_destroy(struct request_context *req)
33 /* the request might be marked protected. This is done by the
34 * SMBecho code for example */
35 if (req->control_flags & REQ_CONTROL_PROTECTED) {
39 /* ahh, its so nice to destroy a complex structure in such a
41 talloc_destroy(req->mem_ctx);
44 /****************************************************************************
45 construct a basic request packet, mostly used to construct async packets
46 such as change notify and oplock break requests
47 ****************************************************************************/
48 struct request_context *init_smb_request(struct server_context *smb)
50 struct request_context *req;
53 /* each request gets its own talloc context. The request
54 structure itself is also allocated inside this context, so
55 we need to allocate it before we construct the request
57 mem_ctx = talloc_init("request_context[%d]", smb->socket.pkt_count);
62 smb->socket.pkt_count++;
64 req = talloc(mem_ctx, sizeof(*req));
71 /* setup the request context */
73 req->mem_ctx = mem_ctx;
80 setup a chained reply in req->out with the given word count and initial data buffer size.
82 static void req_setup_chain_reply(struct request_context *req, unsigned wct, unsigned buflen)
84 uint32_t chain_base_size = req->out.size;
86 /* we need room for the wct value, the words, the buffer length and the buffer */
87 req->out.size += 1 + VWV(wct) + 2 + buflen;
89 /* over allocate by a small amount */
90 req->out.allocated = req->out.size + REQ_OVER_ALLOCATION;
92 req->out.buffer = talloc_realloc(req->mem_ctx, req->out.buffer, req->out.allocated);
93 if (!req->out.buffer) {
94 exit_server(req->smb, "allocation failed");
97 req->out.hdr = req->out.buffer + NBT_HDR_SIZE;
98 req->out.vwv = req->out.buffer + chain_base_size + 1;
100 req->out.data = req->out.vwv + VWV(wct) + 2;
101 req->out.data_size = buflen;
102 req->out.ptr = req->out.data;
104 SCVAL(req->out.buffer, chain_base_size, wct);
105 SSVAL(req->out.vwv, VWV(wct), buflen);
110 setup a reply in req->out with the given word count and initial data buffer size.
111 the caller will then fill in the command words and data before calling req_send_reply() to
112 send the reply on its way
114 void req_setup_reply(struct request_context *req, unsigned wct, unsigned buflen)
116 if (req->chain_count != 0) {
117 req_setup_chain_reply(req, wct, buflen);
121 req->out.size = NBT_HDR_SIZE + MIN_SMB_SIZE + wct*2 + buflen;
123 /* over allocate by a small amount */
124 req->out.allocated = req->out.size + REQ_OVER_ALLOCATION;
126 req->out.buffer = talloc(req->mem_ctx, req->out.allocated);
127 if (!req->out.buffer) {
128 exit_server(req->smb, "allocation failed");
131 req->out.hdr = req->out.buffer + NBT_HDR_SIZE;
132 req->out.vwv = req->out.hdr + HDR_VWV;
134 req->out.data = req->out.vwv + VWV(wct) + 2;
135 req->out.data_size = buflen;
136 req->out.ptr = req->out.data;
138 SIVAL(req->out.hdr, HDR_RCLS, 0);
140 SCVAL(req->out.hdr, HDR_WCT, wct);
141 SSVAL(req->out.vwv, VWV(wct), buflen);
144 memcpy(req->out.hdr, "\377SMB", 4);
145 SCVAL(req->out.hdr,HDR_FLG, FLAG_REPLY | FLAG_CASELESS_PATHNAMES);
146 SSVAL(req->out.hdr,HDR_FLG2,
147 (req->flags2 & FLAGS2_UNICODE_STRINGS) |
148 FLAGS2_LONG_PATH_COMPONENTS | FLAGS2_32_BIT_ERROR_CODES | FLAGS2_EXTENDED_SECURITY);
150 SSVAL(req->out.hdr,HDR_PIDHIGH,0);
151 memset(req->out.hdr + HDR_SS_FIELD, 0, 10);
154 /* copy the cmd, tid, pid, uid and mid from the request */
155 SCVAL(req->out.hdr,HDR_COM,CVAL(req->in.hdr,HDR_COM));
156 SSVAL(req->out.hdr,HDR_TID,SVAL(req->in.hdr,HDR_TID));
157 SSVAL(req->out.hdr,HDR_PID,SVAL(req->in.hdr,HDR_PID));
158 SSVAL(req->out.hdr,HDR_UID,SVAL(req->in.hdr,HDR_UID));
159 SSVAL(req->out.hdr,HDR_MID,SVAL(req->in.hdr,HDR_MID));
161 SSVAL(req->out.hdr,HDR_TID,0);
162 SSVAL(req->out.hdr,HDR_PID,0);
163 SSVAL(req->out.hdr,HDR_UID,0);
164 SSVAL(req->out.hdr,HDR_MID,0);
169 work out the maximum data size we will allow for this reply, given
170 the negotiated max_xmit. The basic reply packet must be setup before
173 note that this is deliberately a signed integer reply
175 int req_max_data(struct request_context *req)
178 ret = req->smb->negotiate.max_send;
179 ret -= PTR_DIFF(req->out.data, req->out.hdr);
180 if (ret < 0) ret = 0;
186 grow the allocation of the data buffer portion of a reply
187 packet. Note that as this can reallocate the packet buffer this
188 invalidates any local pointers into the packet.
190 To cope with this req->out.ptr is supplied. This will be updated to
191 point at the same offset into the packet as before this call
193 static void req_grow_allocation(struct request_context *req, unsigned new_size)
198 delta = new_size - req->out.data_size;
199 if (delta + req->out.size <= req->out.allocated) {
200 /* it fits in the preallocation */
204 /* we need to realloc */
205 req->out.allocated = req->out.size + delta + REQ_OVER_ALLOCATION;
206 buf2 = talloc_realloc(req->mem_ctx, req->out.buffer, req->out.allocated);
208 smb_panic("out of memory in req_grow_allocation");
211 if (buf2 == req->out.buffer) {
212 /* the malloc library gave us the same pointer */
216 /* update the pointers into the packet */
217 req->out.data = buf2 + PTR_DIFF(req->out.data, req->out.buffer);
218 req->out.ptr = buf2 + PTR_DIFF(req->out.ptr, req->out.buffer);
219 req->out.vwv = buf2 + PTR_DIFF(req->out.vwv, req->out.buffer);
220 req->out.hdr = buf2 + PTR_DIFF(req->out.hdr, req->out.buffer);
222 req->out.buffer = buf2;
227 grow the data buffer portion of a reply packet. Note that as this
228 can reallocate the packet buffer this invalidates any local pointers
231 To cope with this req->out.ptr is supplied. This will be updated to
232 point at the same offset into the packet as before this call
234 void req_grow_data(struct request_context *req, unsigned new_size)
238 if (!(req->control_flags & REQ_CONTROL_LARGE) && new_size > req_max_data(req)) {
239 smb_panic("reply buffer too large!");
242 req_grow_allocation(req, new_size);
244 delta = new_size - req->out.data_size;
246 req->out.size += delta;
247 req->out.data_size += delta;
249 /* set the BCC to the new data size */
250 SSVAL(req->out.vwv, VWV(req->out.wct), new_size);
254 send a reply and destroy the request buffer
256 note that this only looks at req->out.buffer and req->out.size, allowing manually
257 constructed packets to be sent
259 void req_send_reply_nosign(struct request_context *req)
261 if (req->out.size > NBT_HDR_SIZE) {
262 _smb_setlen(req->out.buffer, req->out.size - NBT_HDR_SIZE);
265 if (write_data(req->smb->socket.fd, req->out.buffer, req->out.size) != req->out.size) {
266 smb_panic("failed to send reply\n");
273 possibly sign a message then send a reply and destroy the request buffer
275 note that this only looks at req->out.buffer and req->out.size, allowing manually
276 constructed packets to be sent
278 void req_send_reply(struct request_context *req)
280 if (req->out.size > NBT_HDR_SIZE) {
281 _smb_setlen(req->out.buffer, req->out.size - NBT_HDR_SIZE);
284 req_sign_packet(req);
286 req_send_reply_nosign(req);
292 construct and send an error packet with a forced DOS error code
293 this is needed to match win2000 behaviour for some parts of the protocol
295 void req_reply_dos_error(struct request_context *req, uint8 eclass, uint16 ecode)
297 /* if the basic packet hasn't been setup yet then do it now */
298 if (req->out.buffer == NULL) {
299 req_setup_reply(req, 0, 0);
302 SCVAL(req->out.hdr, HDR_RCLS, eclass);
303 SSVAL(req->out.hdr, HDR_ERR, ecode);
305 SSVAL(req->out.hdr, HDR_FLG2, SVAL(req->out.hdr, HDR_FLG2) & ~FLAGS2_32_BIT_ERROR_CODES);
311 construct and send an error packet, then destroy the request
312 auto-converts to DOS error format when appropriate
314 void req_reply_error(struct request_context *req, NTSTATUS status)
316 req_setup_reply(req, 0, 0);
318 /* error returns never have any data */
319 req_grow_data(req, 0);
321 if (!lp_nt_status_support() || !(req->smb->negotiate.client_caps & CAP_STATUS32)) {
322 /* convert to DOS error codes */
325 ntstatus_to_dos(status, &eclass, &ecode);
326 req_reply_dos_error(req, eclass, ecode);
330 if (NT_STATUS_IS_DOS(status)) {
331 /* its a encoded DOS error, using the reserved range */
332 SSVAL(req->out.hdr, HDR_RCLS, NT_STATUS_DOS_CLASS(status));
333 SSVAL(req->out.hdr, HDR_ERR, NT_STATUS_DOS_CODE(status));
334 SSVAL(req->out.hdr, HDR_FLG2, SVAL(req->out.hdr, HDR_FLG2) & ~FLAGS2_32_BIT_ERROR_CODES);
336 SIVAL(req->out.hdr, HDR_RCLS, NT_STATUS_V(status));
337 SSVAL(req->out.hdr, HDR_FLG2, SVAL(req->out.hdr, HDR_FLG2) | FLAGS2_32_BIT_ERROR_CODES);
345 push a string into the data portion of the request packet, growing it if necessary
346 this gets quite tricky - please be very careful to cover all cases when modifying this
348 if dest is NULL, then put the string at the end of the data portion of the packet
350 if dest_len is -1 then no limit applies
352 size_t req_push_str(struct request_context *req, char *dest, const char *str, int dest_len, unsigned flags)
357 const int max_bytes_per_char = 3;
359 if (!(flags & (STR_ASCII|STR_UNICODE))) {
360 flags |= (req->flags2 & FLAGS2_UNICODE_STRINGS) ? STR_UNICODE : STR_ASCII;
364 dest = req->out.data + req->out.data_size;
367 if (dest_len != -1) {
370 len = (strlen(str)+2) * max_bytes_per_char;
373 grow_size = len + PTR_DIFF(dest, req->out.data);
374 buf0 = req->out.buffer;
376 req_grow_allocation(req, grow_size);
378 if (buf0 != req->out.buffer) {
379 dest = req->out.buffer + PTR_DIFF(dest, buf0);
382 len = push_string(req->out.hdr, dest, str, len, flags);
384 grow_size = len + PTR_DIFF(dest, req->out.data);
386 if (grow_size > req->out.data_size) {
387 req_grow_data(req, grow_size);
394 append raw bytes into the data portion of the request packet
395 return the number of bytes added
397 size_t req_append_bytes(struct request_context *req,
398 const uint8 *bytes, size_t byte_len)
400 req_grow_allocation(req, byte_len + req->out.data_size);
401 memcpy(req->out.data + req->out.data_size, bytes, byte_len);
402 req_grow_data(req, byte_len + req->out.data_size);
406 append variable block (type 5 buffer) into the data portion of the request packet
407 return the number of bytes added
409 size_t req_append_var_block(struct request_context *req,
410 const uint8 *bytes, uint16 byte_len)
412 req_grow_allocation(req, byte_len + 3 + req->out.data_size);
413 SCVAL(req->out.data + req->out.data_size, 0, 5);
414 SSVAL(req->out.data + req->out.data_size, 1, byte_len); /* add field length */
416 memcpy(req->out.data + req->out.data_size + 3, bytes, byte_len);
418 req_grow_data(req, byte_len + 3 + req->out.data_size);
422 pull a UCS2 string from a request packet, returning a talloced unix string
424 the string length is limited by the 3 things:
425 - the data size in the request (end of packet)
426 - the passed 'byte_len' if it is not -1
427 - the end of string (null termination)
429 Note that 'byte_len' is the number of bytes in the packet
431 on failure zero is returned and *dest is set to NULL, otherwise the number
432 of bytes consumed in the packet is returned
434 static size_t req_pull_ucs2(struct request_context *req, const char **dest, const char *src, int byte_len, unsigned flags)
436 int src_len, src_len2, alignment=0;
439 if (!(flags & STR_NOALIGN) && ucs2_align(req->in.buffer, src, flags)) {
442 if (byte_len != -1) {
447 if (flags & STR_NO_RANGE_CHECK) {
450 src_len = req->in.data_size - PTR_DIFF(src, req->in.data);
456 if (byte_len != -1 && src_len > byte_len) {
461 src_len2 = strnlen_w((const smb_ucs2_t *)src, src_len/2) * 2;
463 if (src_len2 <= src_len - 2) {
464 /* include the termination if we didn't reach the end of the packet */
468 ret = convert_string_talloc(req->mem_ctx, CH_UCS2, CH_UNIX, src, src_len2, (const void **)dest);
475 return src_len2 + alignment;
479 pull a ascii string from a request packet, returning a talloced string
481 the string length is limited by the 3 things:
482 - the data size in the request (end of packet)
483 - the passed 'byte_len' if it is not -1
484 - the end of string (null termination)
486 Note that 'byte_len' is the number of bytes in the packet
488 on failure zero is returned and *dest is set to NULL, otherwise the number
489 of bytes consumed in the packet is returned
491 static size_t req_pull_ascii(struct request_context *req, const char **dest, const char *src, int byte_len, unsigned flags)
493 int src_len, src_len2;
496 if (flags & STR_NO_RANGE_CHECK) {
499 src_len = req->in.data_size - PTR_DIFF(src, req->in.data);
504 if (byte_len != -1 && src_len > byte_len) {
509 src_len2 = strnlen(src, src_len);
510 if (src_len2 <= src_len - 1) {
511 /* include the termination if we didn't reach the end of the packet */
515 ret = convert_string_talloc(req->mem_ctx, CH_DOS, CH_UNIX, src, src_len2, (const void **)dest);
526 pull a string from a request packet, returning a talloced string
528 the string length is limited by the 3 things:
529 - the data size in the request (end of packet)
530 - the passed 'byte_len' if it is not -1
531 - the end of string (null termination)
533 Note that 'byte_len' is the number of bytes in the packet
535 on failure zero is returned and *dest is set to NULL, otherwise the number
536 of bytes consumed in the packet is returned
538 size_t req_pull_string(struct request_context *req, const char **dest, const char *src, int byte_len, unsigned flags)
540 if (!(flags & STR_ASCII) &&
541 (((flags & STR_UNICODE) || (req->flags2 & FLAGS2_UNICODE_STRINGS)))) {
542 return req_pull_ucs2(req, dest, src, byte_len, flags);
545 return req_pull_ascii(req, dest, src, byte_len, flags);
550 pull a ASCII4 string buffer from a request packet, returning a talloced string
552 an ASCII4 buffer is a null terminated string that has a prefix
553 of the character 0x4. It tends to be used in older parts of the protocol.
555 on failure *dest is set to the zero length string. This seems to
556 match win2000 behaviour
558 size_t req_pull_ascii4(struct request_context *req, const char **dest, const char *src, unsigned flags)
562 if (PTR_DIFF(src, req->in.data) + 1 > req->in.data_size) {
563 /* win2000 treats this as the NULL string! */
564 (*dest) = talloc_strdup(req->mem_ctx, "");
568 /* this consumes the 0x4 byte. We don't check whether the byte
569 is actually 0x4 or not. This matches win2000 server
573 ret = req_pull_string(req, dest, src, -1, flags);
575 (*dest) = talloc_strdup(req->mem_ctx, "");
583 pull a DATA_BLOB from a request packet, returning a talloced blob
585 return False if any part is outside the data portion of the packet
587 BOOL req_pull_blob(struct request_context *req, const char *src, int len, DATA_BLOB *blob)
589 if (len != 0 && req_data_oob(req, src, len)) {
593 (*blob) = data_blob_talloc(req->mem_ctx, src, len);
598 /* check that a lump of data in a request is within the bounds of the data section of
600 BOOL req_data_oob(struct request_context *req, const char *ptr, uint32_t count)
606 /* be careful with wraparound! */
607 if (ptr < req->in.data ||
608 ptr >= req->in.data + req->in.data_size ||
609 count > req->in.data_size ||
610 ptr + count > req->in.data + req->in.data_size) {
618 pull an open file handle from a packet, taking account of the chained_fnum
620 uint16 req_fnum(struct request_context *req, const char *base, unsigned offset)
622 if (req->chained_fnum != -1) {
623 return req->chained_fnum;
625 return SVAL(base, offset);