diff options
Diffstat (limited to 'source3/libsmb/async_smb.c')
| -rw-r--r-- | source3/libsmb/async_smb.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/source3/libsmb/async_smb.c b/source3/libsmb/async_smb.c new file mode 100644 index 0000000000..21bcd5b9b1 --- /dev/null +++ b/source3/libsmb/async_smb.c @@ -0,0 +1,483 @@ +/* + Unix SMB/CIFS implementation. + Infrastructure for async SMB client requests + Copyright (C) Volker Lendecke 2008 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" + +/* + * Fetch an error out of a NBT packet + */ + +NTSTATUS cli_pull_error(char *buf) +{ + uint32_t flags2 = SVAL(buf, smb_flg2); + + if (flags2 & FLAGS2_32_BIT_ERROR_CODES) { + return NT_STATUS(IVAL(buf, smb_rcls)); + } + + return NT_STATUS_DOS(CVAL(buf, smb_rcls), SVAL(buf,smb_err)); +} + +/* + * Compatibility helper for the sync APIs: Fake NTSTATUS in cli->inbuf + */ + +void cli_set_error(struct cli_state *cli, NTSTATUS status) +{ + uint32_t flags2 = SVAL(cli->inbuf, smb_flg2); + + if (NT_STATUS_IS_DOS(status)) { + SSVAL(cli->inbuf, smb_flg2, + flags2 & ~FLAGS2_32_BIT_ERROR_CODES); + SCVAL(cli->inbuf, smb_rcls, NT_STATUS_DOS_CLASS(status)); + SSVAL(cli->inbuf, smb_err, NT_STATUS_DOS_CODE(status)); + return; + } + + SSVAL(cli->inbuf, smb_flg2, flags2 | FLAGS2_32_BIT_ERROR_CODES); + SIVAL(cli->inbuf, smb_rcls, NT_STATUS_V(status)); + return; +} + +/* + * Allocate a new mid + */ + +static uint16_t cli_new_mid(struct cli_state *cli) +{ + uint16_t result; + struct cli_request *req; + + while (true) { + result = cli->mid++; + if (result == 0) { + continue; + } + + for (req = cli->outstanding_requests; req; req = req->next) { + if (result == req->mid) { + break; + } + } + + if (req == NULL) { + return result; + } + } +} + +static char *cli_request_print(TALLOC_CTX *mem_ctx, struct async_req *req) +{ + char *result = async_req_print(mem_ctx, req); + struct cli_request *cli_req = cli_request_get(req); + + if (result == NULL) { + return NULL; + } + + return talloc_asprintf_append_buffer( + result, "mid=%d\n", cli_req->mid); +} + +static int cli_request_destructor(struct cli_request *req) +{ + if (req->enc_state != NULL) { + common_free_enc_buffer(req->enc_state, req->outbuf); + } + DLIST_REMOVE(req->cli->outstanding_requests, req); + return 0; +} + +/* + * Create a fresh async smb request + */ + +struct async_req *cli_request_new(TALLOC_CTX *mem_ctx, + struct event_context *ev, + struct cli_state *cli, + uint8_t num_words, size_t num_bytes, + struct cli_request **preq) +{ + struct async_req *result; + struct cli_request *cli_req; + size_t bufsize = smb_size + num_words * 2 + num_bytes; + + result = async_req_new(mem_ctx, ev); + if (result == NULL) { + return NULL; + } + + cli_req = (struct cli_request *)talloc_size( + result, sizeof(*cli_req) + bufsize); + if (cli_req == NULL) { + TALLOC_FREE(result); + return NULL; + } + talloc_set_name_const(cli_req, "struct cli_request"); + result->private_data = cli_req; + result->print = cli_request_print; + + cli_req->async = result; + cli_req->cli = cli; + cli_req->outbuf = ((char *)cli_req + sizeof(*cli_req)); + cli_req->sent = 0; + cli_req->mid = cli_new_mid(cli); + cli_req->inbuf = NULL; + cli_req->enc_state = NULL; + + SCVAL(cli_req->outbuf, smb_wct, num_words); + SSVAL(cli_req->outbuf, smb_vwv + num_words * 2, num_bytes); + + DLIST_ADD_END(cli->outstanding_requests, cli_req, + struct cli_request *); + talloc_set_destructor(cli_req, cli_request_destructor); + + DEBUG(10, ("cli_request_new: mid=%d\n", cli_req->mid)); + + *preq = cli_req; + return result; +} + +/* + * Convenience function to get the SMB part out of an async_req + */ + +struct cli_request *cli_request_get(struct async_req *req) +{ + if (req == NULL) { + return NULL; + } + return talloc_get_type_abort(req->private_data, struct cli_request); +} + +/* + * A PDU has arrived on cli->evt_inbuf + */ + +static void handle_incoming_pdu(struct cli_state *cli) +{ + struct cli_request *req; + uint16_t mid; + size_t raw_pdu_len, buf_len, pdu_len; + size_t rest_len; + NTSTATUS status; + + /* + * The encrypted PDU len might differ from the unencrypted one + */ + raw_pdu_len = smb_len(cli->evt_inbuf) + 4; + + /* + * TODO: Handle oplock break requests + */ + + if (cli_encryption_on(cli) && CVAL(cli->evt_inbuf, 0) == 0) { + uint16_t enc_ctx_num; + + status = get_enc_ctx_num((uint8_t *)cli->evt_inbuf, + &enc_ctx_num); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(10, ("get_enc_ctx_num returned %s\n", + nt_errstr(status))); + goto invalidate_requests; + } + + if (enc_ctx_num != cli->trans_enc_state->enc_ctx_num) { + DEBUG(10, ("wrong enc_ctx %d, expected %d\n", + enc_ctx_num, + cli->trans_enc_state->enc_ctx_num)); + status = NT_STATUS_INVALID_HANDLE; + goto invalidate_requests; + } + + status = common_decrypt_buffer(cli->trans_enc_state, + cli->evt_inbuf); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(10, ("common_decrypt_buffer returned %s\n", + nt_errstr(status))); + goto invalidate_requests; + } + } + + if (!cli_check_sign_mac(cli, cli->evt_inbuf)) { + DEBUG(10, ("cli_check_sign_mac failed\n")); + status = NT_STATUS_ACCESS_DENIED; + goto invalidate_requests; + } + + mid = SVAL(cli->evt_inbuf, smb_mid); + + DEBUG(10, ("handle_incoming_pdu: got mid %d\n", mid)); + + for (req = cli->outstanding_requests; req; req = req->next) { + if (req->mid == mid) { + break; + } + } + + buf_len = talloc_get_size(cli->evt_inbuf); + pdu_len = smb_len(cli->evt_inbuf) + 4; + rest_len = buf_len - raw_pdu_len; + + if (req == NULL) { + DEBUG(3, ("Request for mid %d not found, dumping PDU\n", mid)); + + memmove(cli->evt_inbuf, cli->evt_inbuf + raw_pdu_len, + buf_len - raw_pdu_len); + + cli->evt_inbuf = TALLOC_REALLOC_ARRAY(NULL, cli->evt_inbuf, + char, rest_len); + return; + } + + if (buf_len == pdu_len) { + /* + * Optimal case: Exactly one PDU was in the socket buffer + */ + req->inbuf = talloc_move(req, &cli->evt_inbuf); + goto done; + } + + DEBUG(11, ("buf_len = %d, pdu_len = %d, splitting buffer\n", + (int)buf_len, (int)pdu_len)); + + if (pdu_len < rest_len) { + /* + * The PDU is shorter, talloc_memdup that one. + */ + req->inbuf = (char *)talloc_memdup( + req, cli->evt_inbuf, pdu_len); + + memmove(cli->evt_inbuf, + cli->evt_inbuf + raw_pdu_len, + buf_len - raw_pdu_len); + + cli->evt_inbuf = TALLOC_REALLOC_ARRAY( + NULL, cli->evt_inbuf, char, rest_len); + } + else { + /* + * The PDU is larger than the rest, + * talloc_memdup the rest + */ + req->inbuf = talloc_move(req, &cli->evt_inbuf); + + cli->evt_inbuf = (char *)talloc_memdup( + cli, req->inbuf + raw_pdu_len, + rest_len); + } + + if ((req->inbuf == NULL) || (cli->evt_inbuf == NULL)) { + status = NT_STATUS_NO_MEMORY; + goto invalidate_requests; + } + + done: + async_req_done(req->async); + return; + + invalidate_requests: + + DEBUG(10, ("handle_incoming_pdu: Aborting with %s\n", + nt_errstr(status))); + + for (req = cli->outstanding_requests; req; req = req->next) { + async_req_error(req->async, status); + } + return; +} + +/* + * fd event callback. This is the basic connection to the socket + */ + +static void cli_state_handler(struct event_context *event_ctx, + struct fd_event *event, uint16 flags, void *p) +{ + struct cli_state *cli = (struct cli_state *)p; + struct cli_request *req; + + DEBUG(11, ("cli_state_handler called with flags %d\n", flags)); + + if (flags & EVENT_FD_READ) { + int res, available; + size_t old_size, new_size; + char *tmp; + + res = ioctl(cli->fd, FIONREAD, &available); + if (res == -1) { + DEBUG(10, ("ioctl(FIONREAD) failed: %s\n", + strerror(errno))); + goto sock_error; + } + + if (available == 0) { + /* EOF */ + goto sock_error; + } + + old_size = talloc_get_size(cli->evt_inbuf); + new_size = old_size + available; + + if (new_size < old_size) { + /* wrap */ + goto sock_error; + } + + tmp = TALLOC_REALLOC_ARRAY(cli, cli->evt_inbuf, char, + new_size); + if (tmp == NULL) { + /* nomem */ + goto sock_error; + } + cli->evt_inbuf = tmp; + + res = recv(cli->fd, cli->evt_inbuf + old_size, available, 0); + if (res == -1) { + DEBUG(10, ("recv failed: %s\n", strerror(errno))); + goto sock_error; + } + + DEBUG(11, ("cli_state_handler: received %d bytes, " + "smb_len(evt_inbuf) = %d\n", (int)res, + smb_len(cli->evt_inbuf))); + + /* recv *might* have returned less than announced */ + new_size = old_size + res; + + /* shrink, so I don't expect errors here */ + cli->evt_inbuf = TALLOC_REALLOC_ARRAY(cli, cli->evt_inbuf, + char, new_size); + + while ((cli->evt_inbuf != NULL) + && ((smb_len(cli->evt_inbuf) + 4) <= new_size)) { + /* + * we've got a complete NBT level PDU in evt_inbuf + */ + handle_incoming_pdu(cli); + new_size = talloc_get_size(cli->evt_inbuf); + } + } + + if (flags & EVENT_FD_WRITE) { + size_t to_send; + ssize_t sent; + + for (req = cli->outstanding_requests; req; req = req->next) { + to_send = smb_len(req->outbuf)+4; + if (to_send > req->sent) { + break; + } + } + + if (req == NULL) { + event_fd_set_not_writeable(event); + return; + } + + sent = send(cli->fd, req->outbuf + req->sent, + to_send - req->sent, 0); + + if (sent < 0) { + goto sock_error; + } + + req->sent += sent; + + if (req->sent == to_send) { + return; + } + } + return; + + sock_error: + for (req = cli->outstanding_requests; req; req = req->next) { + req->async->state = ASYNC_REQ_ERROR; + req->async->status = map_nt_error_from_unix(errno); + } + TALLOC_FREE(cli->fd_event); + close(cli->fd); + cli->fd = -1; +} + +/* + * Holder for a talloc_destructor, we need to zero out the pointers in cli + * when deleting + */ +struct cli_tmp_event { + struct cli_state *cli; +}; + +static int cli_tmp_event_destructor(struct cli_tmp_event *e) +{ + TALLOC_FREE(e->cli->fd_event); + TALLOC_FREE(e->cli->event_ctx); + return 0; +} + +/* + * Create a temporary event context for use in the sync helper functions + */ + +struct cli_tmp_event *cli_tmp_event_ctx(TALLOC_CTX *mem_ctx, + struct cli_state *cli) +{ + struct cli_tmp_event *state; + + if (cli->event_ctx != NULL) { + return NULL; + } + + state = talloc(mem_ctx, struct cli_tmp_event); + if (state == NULL) { + return NULL; + } + state->cli = cli; + talloc_set_destructor(state, cli_tmp_event_destructor); + + cli->event_ctx = event_context_init(state); + if (cli->event_ctx == NULL) { + TALLOC_FREE(state); + return NULL; + } + + cli->fd_event = event_add_fd(cli->event_ctx, state, cli->fd, + EVENT_FD_READ, cli_state_handler, cli); + if (cli->fd_event == NULL) { + TALLOC_FREE(state); + return NULL; + } + return state; +} + +/* + * Attach an event context permanently to a cli_struct + */ + +NTSTATUS cli_add_event_ctx(struct cli_state *cli, + struct event_context *event_ctx) +{ + cli->event_ctx = event_ctx; + cli->fd_event = event_add_fd(event_ctx, cli, cli->fd, EVENT_FD_READ, + cli_state_handler, cli); + if (cli->fd_event == NULL) { + return NT_STATUS_NO_MEMORY; + } + return NT_STATUS_OK; +} |