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-rw-r--r--source3/libsmb/async_smb.c144
1 files changed, 98 insertions, 46 deletions
diff --git a/source3/libsmb/async_smb.c b/source3/libsmb/async_smb.c
index d371e057e3..cf6886ff19 100644
--- a/source3/libsmb/async_smb.c
+++ b/source3/libsmb/async_smb.c
@@ -218,6 +218,102 @@ static bool find_andx_cmd_ofs(char *buf, size_t *pofs)
}
/**
+ * @brief Do the smb chaining at a buffer level
+ * @param[in] poutbuf Pointer to the talloc'ed buffer to be modified
+ * @param[in] smb_command The command that we want to issue
+ * @param[in] wct How many words?
+ * @param[in] vwv The words, already in network order
+ * @param[in] num_bytes How many bytes?
+ * @param[in] bytes The data the request ships
+ *
+ * smb_splice_chain() adds the vwv and bytes to the request already present in
+ * *poutbuf.
+ */
+
+bool smb_splice_chain(char **poutbuf, uint8_t smb_command,
+ uint8_t wct, const uint16_t *vwv,
+ uint16_t num_bytes, const uint8_t *bytes)
+{
+ char *outbuf;
+ size_t old_size, new_size;
+ size_t ofs;
+ size_t padding = 0;
+ bool first_request;
+
+ old_size = talloc_get_size(*poutbuf);
+
+ /*
+ * old_size == smb_wct means we're pushing the first request in for
+ * libsmb/
+ */
+
+ first_request = (old_size == smb_wct);
+
+ if (!first_request && ((old_size % 4) != 0)) {
+ /*
+ * Align subsequent requests to a 4-byte boundary
+ */
+ padding = 4 - (old_size % 4);
+ }
+
+ /*
+ * We need space for the wct field, the words, the byte count field
+ * and the bytes themselves.
+ */
+ new_size = old_size + padding
+ + 1 + wct * sizeof(uint16_t) + 2 + num_bytes;
+
+ if (new_size > 0xffff) {
+ DEBUG(1, ("splice_chain: %u bytes won't fit\n",
+ (unsigned)new_size));
+ return false;
+ }
+
+ outbuf = TALLOC_REALLOC_ARRAY(NULL, *poutbuf, char, new_size);
+ if (outbuf == NULL) {
+ DEBUG(0, ("talloc failed\n"));
+ return false;
+ }
+ *poutbuf = outbuf;
+
+ if (first_request) {
+ SCVAL(outbuf, smb_com, smb_command);
+ } else {
+ size_t andx_cmd_ofs;
+
+ if (!find_andx_cmd_ofs(outbuf, &andx_cmd_ofs)) {
+ DEBUG(1, ("invalid command chain\n"));
+ *poutbuf = TALLOC_REALLOC_ARRAY(
+ NULL, *poutbuf, char, old_size);
+ return false;
+ }
+
+ if (padding != 0) {
+ memset(outbuf + old_size, 0, padding);
+ old_size += padding;
+ }
+
+ SCVAL(outbuf, andx_cmd_ofs, smb_command);
+ SSVAL(outbuf, andx_cmd_ofs + 2, old_size - 4);
+ }
+
+ ofs = old_size;
+
+ SCVAL(outbuf, ofs, wct);
+ ofs += 1;
+
+ memcpy(outbuf + ofs, vwv, sizeof(uint16_t) * wct);
+ ofs += sizeof(uint16_t) * wct;
+
+ SSVAL(outbuf, ofs, num_bytes);
+ ofs += sizeof(uint16_t);
+
+ memcpy(outbuf + ofs, bytes, num_bytes);
+
+ return true;
+}
+
+/**
* @brief Destroy an async_req that is the visible part of a cli_request
* @param[in] req The request to kill
* @retval Return 0 to make talloc happy
@@ -286,10 +382,7 @@ static struct async_req *cli_request_chain(TALLOC_CTX *mem_ctx,
const uint8_t *bytes)
{
struct async_req **tmp_reqs;
- char *tmp_buf;
struct cli_request *req;
- size_t old_size, new_size;
- size_t ofs;
req = cli->chain_accumulator;
@@ -313,52 +406,11 @@ static struct async_req *cli_request_chain(TALLOC_CTX *mem_ctx,
talloc_set_destructor(req->async[req->num_async-1],
cli_async_req_destructor);
- old_size = talloc_get_size(req->outbuf);
-
- /*
- * We need space for the wct field, the words, the byte count field
- * and the bytes themselves.
- */
- new_size = old_size + 1 + wct * sizeof(uint16_t) + 2 + num_bytes;
-
- if (new_size > 0xffff) {
- DEBUG(1, ("cli_request_chain: %u bytes won't fit\n",
- (unsigned)new_size));
+ if (!smb_splice_chain(&req->outbuf, smb_command, wct, vwv,
+ num_bytes, bytes)) {
goto fail;
}
- tmp_buf = TALLOC_REALLOC_ARRAY(NULL, req->outbuf, char, new_size);
- if (tmp_buf == NULL) {
- DEBUG(0, ("talloc failed\n"));
- goto fail;
- }
- req->outbuf = tmp_buf;
-
- if (old_size == smb_wct) {
- SCVAL(req->outbuf, smb_com, smb_command);
- } else {
- size_t andx_cmd_ofs;
- if (!find_andx_cmd_ofs(req->outbuf, &andx_cmd_ofs)) {
- DEBUG(1, ("invalid command chain\n"));
- goto fail;
- }
- SCVAL(req->outbuf, andx_cmd_ofs, smb_command);
- SSVAL(req->outbuf, andx_cmd_ofs + 2, old_size - 4);
- }
-
- ofs = old_size;
-
- SCVAL(req->outbuf, ofs, wct);
- ofs += 1;
-
- memcpy(req->outbuf + ofs, vwv, sizeof(uint16_t) * wct);
- ofs += sizeof(uint16_t) * wct;
-
- SSVAL(req->outbuf, ofs, num_bytes);
- ofs += sizeof(uint16_t);
-
- memcpy(req->outbuf + ofs, bytes, num_bytes);
-
return req->async[req->num_async-1];
fail: