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authorVolker Lendecke <vl@samba.org>2008-08-25 15:56:26 +0200
committerVolker Lendecke <vl@samba.org>2008-08-28 18:15:58 +0200
commit65dcdf9c32e8ac43344b23db528206c02fcb967c (patch)
treebba77729bd0177f54a66c42ecbd67b033abe031f
parent77d1b29e25512982a1f912adac46bb954ee3d19f (diff)
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This adds the code to allow chained requests in libsmb/
This is not compiled yet, but it makes the patches much easier to read if it is add in bulk. (This used to be commit b4c539ba041bab8856c83816f08a35b5f5b21740)
-rw-r--r--source3/libsmb/async_smb.c534
1 files changed, 534 insertions, 0 deletions
diff --git a/source3/libsmb/async_smb.c b/source3/libsmb/async_smb.c
index e36e514a16..e764147432 100644
--- a/source3/libsmb/async_smb.c
+++ b/source3/libsmb/async_smb.c
@@ -135,6 +135,540 @@ static int cli_request_destructor(struct cli_request *req)
return 0;
}
+#if 0
+
+/**
+ * Is the SMB command able to hold an AND_X successor
+ * @param[in] cmd The SMB command in question
+ * @retval Can we add a chained request after "cmd"?
+ */
+
+static bool is_andx_req(uint8_t cmd)
+{
+ switch (cmd) {
+ case SMBtconX:
+ case SMBlockingX:
+ case SMBopenX:
+ case SMBreadX:
+ case SMBwriteX:
+ case SMBsesssetupX:
+ case SMBulogoffX:
+ case SMBntcreateX:
+ return true;
+ break;
+ default:
+ break;
+ }
+
+ return false;
+}
+
+/**
+ * @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(char *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 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
+ *
+ * This destructor is a bit tricky: Because a cli_request can host more than
+ * one async_req for chained requests, we need to make sure that the
+ * "cli_request" that we were part of is correctly destroyed at the right
+ * time. This is done by NULLing out ourself from the "async" member of our
+ * "cli_request". If there is none left, then also TALLOC_FREE() the
+ * cli_request, which was a talloc child of the client connection cli_state.
+ */
+
+static int cli_async_req_destructor(struct async_req *req)
+{
+ struct cli_request *cli_req = cli_request_get(req);
+ int i, pending;
+ bool found = false;
+
+ pending = 0;
+
+ for (i=0; i<cli_req->num_async; i++) {
+ if (cli_req->async[i] == req) {
+ cli_req->async[i] = NULL;
+ found = true;
+ }
+ if (cli_req->async[i] != NULL) {
+ pending += 1;
+ }
+ }
+
+ SMB_ASSERT(found);
+
+ if (pending == 0) {
+ TALLOC_FREE(cli_req);
+ }
+
+ return 0;
+}
+
+/**
+ * @brief Chain up a request
+ * @param[in] mem_ctx The TALLOC_CTX for the result
+ * @param[in] ev The event context that will call us back
+ * @param[in] cli The cli_state we queue the request up for
+ * @param[in] smb_command The command that we want to issue
+ * @param[in] additional_flags open_and_x wants to add oplock header flags
+ * @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
+ *
+ * cli_request_chain() is the core of the SMB request marshalling routine. It
+ * will create a new async_req structure in the cli->chain_accumulator->async
+ * array and marshall the smb_cmd, the vwv array and the bytes into
+ * cli->chain_accumulator->outbuf.
+ */
+
+static struct async_req *cli_request_chain(TALLOC_CTX *mem_ctx,
+ struct event_context *ev,
+ struct cli_state *cli,
+ uint8_t smb_command,
+ uint8_t additional_flags,
+ uint8_t wct, const uint16_t *vwv,
+ uint16_t num_bytes,
+ 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;
+
+ tmp_reqs = TALLOC_REALLOC_ARRAY(req, req->async, struct async_req *,
+ req->num_async + 1);
+ if (tmp_reqs == NULL) {
+ DEBUG(0, ("talloc failed\n"));
+ return NULL;
+ }
+ req->async = tmp_reqs;
+ req->num_async += 1;
+
+ req->async[req->num_async-1] = async_req_new(mem_ctx, ev);
+ if (req->async[req->num_async-1] == NULL) {
+ DEBUG(0, ("async_req_new failed\n"));
+ req->num_async -= 1;
+ return NULL;
+ }
+ req->async[req->num_async-1]->private_data = req;
+ req->async[req->num_async-1]->print = cli_request_print;
+ 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));
+ 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:
+ TALLOC_FREE(req->async[req->num_async-1]);
+ req->num_async -= 1;
+ return NULL;
+}
+
+/**
+ * @brief prepare a cli_state to accept a chain of requests
+ * @param[in] cli The cli_state we want to queue up in
+ * @param[in] ev The event_context that will call us back for the socket
+ * @param[in] size_hint How many bytes are expected, just an optimization
+ * @retval Did we have enough memory?
+ *
+ * cli_chain_cork() sets up a new cli_request in cli->chain_accumulator. If
+ * cli is used in an async fashion, i.e. if we have outstanding requests, then
+ * we do not have to create a fd event. If cli is used only with the sync
+ * helpers, we need to create the fd_event here.
+ *
+ * If you want to issue a chained request to the server, do a
+ * cli_chain_cork(), then do you cli_open_send(), cli_read_and_x_send(),
+ * cli_close_send() and so on. The async requests that come out of
+ * cli_xxx_send() are normal async requests with the difference that they
+ * won't be shipped individually. But the event_context will still trigger the
+ * req->async.fn to be called on every single request.
+ *
+ * You have to take care yourself that you only issue chainable requests in
+ * the middle of the chain.
+ */
+
+bool cli_chain_cork(struct cli_state *cli, struct event_context *ev,
+ size_t size_hint)
+{
+ struct cli_request *req = NULL;
+
+ SMB_ASSERT(cli->chain_accumulator == NULL);
+
+ if (cli->fd_event == NULL) {
+ SMB_ASSERT(cli->outstanding_requests == NULL);
+ cli->fd_event = event_add_fd(ev, cli, cli->fd,
+ EVENT_FD_READ,
+ cli_state_handler, cli);
+ if (cli->fd_event == NULL) {
+ return false;
+ }
+ }
+
+ req = talloc(cli, struct cli_request);
+ if (req == NULL) {
+ goto fail;
+ }
+ req->cli = cli;
+
+ if (size_hint == 0) {
+ size_hint = 100;
+ }
+ req->outbuf = talloc_array(req, char, smb_wct + size_hint);
+ if (req->outbuf == NULL) {
+ goto fail;
+ }
+ req->outbuf = TALLOC_REALLOC_ARRAY(NULL, req->outbuf, char, smb_wct);
+
+ req->num_async = 0;
+ req->async = NULL;
+
+ req->enc_state = NULL;
+
+ SSVAL(req->outbuf, smb_tid, cli->cnum);
+ cli_setup_packet_buf(cli, req->outbuf);
+
+ req->mid = cli_new_mid(cli);
+ SSVAL(req->outbuf, smb_mid, req->mid);
+
+ cli->chain_accumulator = req;
+
+ DEBUG(10, ("cli_chain_cork: mid=%d\n", req->mid));
+
+ return true;
+ fail:
+ TALLOC_FREE(req);
+ if (cli->outstanding_requests == NULL) {
+ TALLOC_FREE(cli->fd_event);
+ }
+ return false;
+}
+
+/**
+ * Ship a request queued up via cli_request_chain()
+ * @param[in] cl The connection
+ */
+
+void cli_chain_uncork(struct cli_state *cli)
+{
+ struct cli_request *req = cli->chain_accumulator;
+
+ SMB_ASSERT(req != NULL);
+
+ DLIST_ADD_END(cli->outstanding_requests, req, struct cli_request *);
+ talloc_set_destructor(req, cli_request_destructor);
+
+ cli->chain_accumulator = NULL;
+
+ smb_setlen(req->outbuf, talloc_get_size(req->outbuf) - 4);
+
+ cli_calculate_sign_mac(cli, req->outbuf);
+
+ if (cli_encryption_on(cli)) {
+ NTSTATUS status;
+ char *enc_buf;
+
+ status = cli_encrypt_message(cli, req->outbuf, &enc_buf);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0, ("Error in encrypting client message. "
+ "Error %s\n", nt_errstr(status)));
+ TALLOC_FREE(req);
+ return;
+ }
+ req->outbuf = enc_buf;
+ req->enc_state = cli->trans_enc_state;
+ }
+
+ req->sent = 0;
+
+ event_fd_set_writeable(cli->fd_event);
+}
+
+/**
+ * @brief Send a request to the server
+ * @param[in] mem_ctx The TALLOC_CTX for the result
+ * @param[in] ev The event context that will call us back
+ * @param[in] cli The cli_state we queue the request up for
+ * @param[in] smb_command The command that we want to issue
+ * @param[in] additional_flags open_and_x wants to add oplock header flags
+ * @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
+ *
+ * This is the generic routine to be used by the cli_xxx_send routines.
+ */
+
+struct async_req *cli_request_send(TALLOC_CTX *mem_ctx,
+ struct event_context *ev,
+ struct cli_state *cli,
+ uint8_t smb_command,
+ uint8_t additional_flags,
+ uint8_t wct, const uint16_t *vwv,
+ uint16_t num_bytes, const uint8_t *bytes)
+{
+ struct async_req *result;
+ bool uncork = false;
+
+ if (cli->chain_accumulator == NULL) {
+ if (!cli_chain_cork(cli, ev,
+ wct * sizeof(uint16_t) + num_bytes + 3)) {
+ DEBUG(1, ("cli_chain_cork failed\n"));
+ return NULL;
+ }
+ uncork = true;
+ }
+
+ result = cli_request_chain(mem_ctx, ev, cli, smb_command,
+ additional_flags, wct, vwv,
+ num_bytes, bytes);
+
+ if (result == NULL) {
+ DEBUG(1, ("cli_request_chain failed\n"));
+ }
+
+ if (uncork) {
+ cli_chain_uncork(cli);
+ }
+
+ return result;
+}
+
+/**
+ * Figure out if there is an andx command behind the current one
+ * @param[in] buf The smb buffer to look at
+ * @param[in] ofs The offset to the wct field that is followed by the cmd
+ * @retval Is there a command following?
+ */
+
+static bool have_andx_command(const char *buf, uint16_t ofs)
+{
+ uint8_t wct;
+ size_t buflen = talloc_get_size(buf);
+
+ if ((ofs == buflen-1) || (ofs == buflen)) {
+ return false;
+ }
+
+ wct = CVAL(buf, ofs);
+ if (wct < 2) {
+ /*
+ * Not enough space for the command and a following pointer
+ */
+ return false;
+ }
+ return (CVAL(buf, ofs+1) != 0xff);
+}
+
+/**
+ * @brief Pull reply data out of a request
+ * @param[in] req The request that we just received a reply for
+ * @param[out] pwct How many words did the server send?
+ * @param[out] pvwv The words themselves
+ * @param[out] pnum_bytes How many bytes did the server send?
+ * @param[out] pbytes The bytes themselves
+ * @retval Was the reply formally correct?
+ */
+
+NTSTATUS cli_pull_reply(struct async_req *req,
+ uint8_t *pwct, uint16_t **pvwv,
+ uint16_t *pnum_bytes, uint8_t **pbytes)
+{
+ struct cli_request *cli_req = cli_request_get(req);
+ uint8_t wct, cmd;
+ uint16_t num_bytes;
+ size_t wct_ofs, bytes_offset;
+ int i, j;
+ NTSTATUS status;
+
+ for (i = 0; i < cli_req->num_async; i++) {
+ if (req == cli_req->async[i]) {
+ break;
+ }
+ }
+
+ if (i == cli_req->num_async) {
+ cli_set_error(cli_req->cli, NT_STATUS_INVALID_PARAMETER);
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ /**
+ * The status we pull here is only relevant for the last reply in the
+ * chain.
+ */
+
+ status = cli_pull_error(cli_req->inbuf);
+
+ if (i == 0) {
+ if (NT_STATUS_IS_ERR(status)
+ && !have_andx_command(cli_req->inbuf, smb_wct)) {
+ cli_set_error(cli_req->cli, status);
+ return status;
+ }
+ wct_ofs = smb_wct;
+ goto done;
+ }
+
+ cmd = CVAL(cli_req->inbuf, smb_com);
+ wct_ofs = smb_wct;
+
+ for (j = 0; j < i; j++) {
+ if (j < i-1) {
+ if (cmd == 0xff) {
+ return NT_STATUS_REQUEST_ABORTED;
+ }
+ if (!is_andx_req(cmd)) {
+ return NT_STATUS_INVALID_NETWORK_RESPONSE;
+ }
+ }
+
+ if (!have_andx_command(cli_req->inbuf, wct_ofs)) {
+ /*
+ * This request was not completed because a previous
+ * request in the chain had received an error.
+ */
+ return NT_STATUS_REQUEST_ABORTED;
+ }
+
+ wct_ofs = SVAL(cli_req->inbuf, wct_ofs + 3);
+
+ /*
+ * Skip the all-present length field. No overflow, we've just
+ * put a 16-bit value into a size_t.
+ */
+ wct_ofs += 4;
+
+ if (wct_ofs+2 > talloc_get_size(cli_req->inbuf)) {
+ return NT_STATUS_INVALID_NETWORK_RESPONSE;
+ }
+
+ cmd = CVAL(cli_req->inbuf, wct_ofs + 1);
+ }
+
+ if (!have_andx_command(cli_req->inbuf, wct_ofs)
+ && NT_STATUS_IS_ERR(status)) {
+ /*
+ * The last command takes the error code. All further commands
+ * down the requested chain will get a
+ * NT_STATUS_REQUEST_ABORTED.
+ */
+ return status;
+ }
+
+ done:
+ wct = CVAL(cli_req->inbuf, wct_ofs);
+
+ bytes_offset = wct_ofs + 1 + wct * sizeof(uint16_t);
+ num_bytes = SVAL(cli_req->inbuf, bytes_offset);
+
+ /*
+ * wct_ofs is a 16-bit value plus 4, wct is a 8-bit value, num_bytes
+ * is a 16-bit value. So bytes_offset being size_t should be far from
+ * wrapping.
+ */
+
+ if ((bytes_offset + 2 > talloc_get_size(cli_req->inbuf))
+ || (bytes_offset > 0xffff)) {
+ return NT_STATUS_INVALID_NETWORK_RESPONSE;
+ }
+
+ *pwct = wct;
+ *pvwv = (uint16_t *)(cli_req->inbuf + wct_ofs + 1);
+ *pnum_bytes = num_bytes;
+ *pbytes = (uint8_t *)cli_req->inbuf + bytes_offset + 2;
+
+ return NT_STATUS_OK;
+}
+
+#endif
+
/*
* Create a fresh async smb request
*/