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authorVolker Lendecke <vl@samba.org>2009-12-22 13:53:13 +0100
committerVolker Lendecke <vl@samba.org>2009-12-22 13:54:43 +0100
commitb6f446ca35810f13208ab82ec9720271fb64af44 (patch)
treecc4235ebca83e10537e9df0b63da5f620d63d639 /source3/smbd
parent585900deb58944f35bdf03c0b8cba3509d5b0076 (diff)
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s3: Move smb_splice_chain to smbd/process.c, its only user
Diffstat (limited to 'source3/smbd')
-rw-r--r--source3/smbd/process.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/source3/smbd/process.c b/source3/smbd/process.c
index cc2e290227..572f37dbbe 100644
--- a/source3/smbd/process.c
+++ b/source3/smbd/process.c
@@ -1608,6 +1608,180 @@ static void fixup_chain_error_packet(struct smb_request *req)
SCVAL(req->outbuf, smb_vwv0, 0xff);
}
+/**
+ * @brief Find the smb_cmd offset of the last command pushed
+ * @param[in] buf The buffer we're building up
+ * @retval Where can we put our next andx cmd?
+ *
+ * While chaining requests, the "next" request we're looking at needs to put
+ * its SMB_Command before the data the previous request already built up added
+ * to the chain. Find the offset to the place where we have to put our cmd.
+ */
+
+static bool find_andx_cmd_ofs(uint8_t *buf, size_t *pofs)
+{
+ uint8_t cmd;
+ size_t ofs;
+
+ cmd = CVAL(buf, smb_com);
+
+ SMB_ASSERT(is_andx_req(cmd));
+
+ ofs = smb_vwv0;
+
+ while (CVAL(buf, ofs) != 0xff) {
+
+ if (!is_andx_req(CVAL(buf, ofs))) {
+ return false;
+ }
+
+ /*
+ * ofs is from start of smb header, so add the 4 length
+ * bytes. The next cmd is right after the wct field.
+ */
+ ofs = SVAL(buf, ofs+2) + 4 + 1;
+
+ SMB_ASSERT(ofs+4 < talloc_get_size(buf));
+ }
+
+ *pofs = ofs;
+ return true;
+}
+
+/**
+ * @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] bytes_alignment How shall we align "bytes"?
+ * @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.
+ */
+
+static bool smb_splice_chain(uint8_t **poutbuf, uint8_t smb_command,
+ uint8_t wct, const uint16_t *vwv,
+ size_t bytes_alignment,
+ uint32_t num_bytes, const uint8_t *bytes)
+{
+ uint8_t *outbuf;
+ size_t old_size, new_size;
+ size_t ofs;
+ size_t chain_padding = 0;
+ size_t bytes_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 the wct field of subsequent requests to a 4-byte
+ * boundary
+ */
+ chain_padding = 4 - (old_size % 4);
+ }
+
+ /*
+ * After the old request comes the new wct field (1 byte), the vwv's
+ * and the num_bytes field. After at we might need to align the bytes
+ * given to us to "bytes_alignment", increasing the num_bytes value.
+ */
+
+ new_size = old_size + chain_padding + 1 + wct * sizeof(uint16_t) + 2;
+
+ if ((bytes_alignment != 0) && ((new_size % bytes_alignment) != 0)) {
+ bytes_padding = bytes_alignment - (new_size % bytes_alignment);
+ }
+
+ new_size += bytes_padding + num_bytes;
+
+ if ((smb_command != SMBwriteX) && (new_size > 0xffff)) {
+ DEBUG(1, ("splice_chain: %u bytes won't fit\n",
+ (unsigned)new_size));
+ return false;
+ }
+
+ outbuf = TALLOC_REALLOC_ARRAY(NULL, *poutbuf, uint8_t, 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, uint8_t, old_size);
+ return false;
+ }
+
+ if (chain_padding != 0) {
+ memset(outbuf + old_size, 0, chain_padding);
+ old_size += chain_padding;
+ }
+
+ SCVAL(outbuf, andx_cmd_ofs, smb_command);
+ SSVAL(outbuf, andx_cmd_ofs + 2, old_size - 4);
+ }
+
+ ofs = old_size;
+
+ /*
+ * Push the chained request:
+ *
+ * wct field
+ */
+
+ SCVAL(outbuf, ofs, wct);
+ ofs += 1;
+
+ /*
+ * vwv array
+ */
+
+ memcpy(outbuf + ofs, vwv, sizeof(uint16_t) * wct);
+ ofs += sizeof(uint16_t) * wct;
+
+ /*
+ * bcc (byte count)
+ */
+
+ SSVAL(outbuf, ofs, num_bytes + bytes_padding);
+ ofs += sizeof(uint16_t);
+
+ /*
+ * padding
+ */
+
+ if (bytes_padding != 0) {
+ memset(outbuf + ofs, 0, bytes_padding);
+ ofs += bytes_padding;
+ }
+
+ /*
+ * The bytes field
+ */
+
+ memcpy(outbuf + ofs, bytes, num_bytes);
+
+ return true;
+}
+
/****************************************************************************
Construct a chained reply and add it to the already made reply
****************************************************************************/