diff options
Diffstat (limited to 'lib/tsocket/tsocket_readv.c')
| -rw-r--r-- | lib/tsocket/tsocket_readv.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/lib/tsocket/tsocket_readv.c b/lib/tsocket/tsocket_readv.c new file mode 100644 index 0000000000..2c8483ec7e --- /dev/null +++ b/lib/tsocket/tsocket_readv.c @@ -0,0 +1,222 @@ +/* + Unix SMB/CIFS implementation. + + Copyright (C) Stefan Metzmacher 2009 + + ** NOTE! The following LGPL license applies to the tevent + ** library. This does NOT imply that all of Samba is released + ** under the LGPL + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see <http://www.gnu.org/licenses/>. +*/ + +#include "replace.h" +#include "system/network.h" +#include "tsocket.h" +#include "tsocket_internal.h" + +struct tsocket_readv_state { + /* this structs are owned by the caller */ + struct { + struct tsocket_context *sock; + tsocket_readv_next_iovec_t next_iovec_fn; + void *private_data; + } caller; + + /* + * Each call to the callback resets iov and count + * the callback allocated the iov as child of our state, + * that means we are allowed to modify and free it. + * + * we should call the callback every time we filled the given + * vector and ask for a new vector. We return if the callback + * ask for 0 bytes. + */ + struct iovec *iov; + size_t count; + + /* + * the total number of bytes we read, + * the return value of the _recv function + */ + int total_read; +}; + +static int tsocket_readv_state_destructor(struct tsocket_readv_state *state) +{ + if (state->caller.sock) { + tsocket_set_readable_handler(state->caller.sock, NULL, NULL); + } + ZERO_STRUCT(state->caller); + + return 0; +} + +static bool tsocket_readv_ask_for_next_vector(struct tevent_req *req, + struct tsocket_readv_state *state) +{ + int ret; + int err; + bool dummy; + size_t to_read = 0; + size_t i; + + talloc_free(state->iov); + state->iov = NULL; + state->count = 0; + + ret = state->caller.next_iovec_fn(state->caller.sock, + state->caller.private_data, + state, &state->iov, &state->count); + err = tsocket_error_from_errno(ret, errno, &dummy); + if (tevent_req_error(req, err)) { + return false; + } + + for (i=0; i < state->count; i++) { + size_t tmp = to_read; + tmp += state->iov[i].iov_len; + + if (tmp < to_read) { + tevent_req_error(req, EMSGSIZE); + return false; + } + + to_read = tmp; + } + + if (to_read == 0) { + tevent_req_done(req); + return false; + } + + if (state->total_read + to_read < state->total_read) { + tevent_req_error(req, EMSGSIZE); + return false; + } + + return true; +} + +static void tsocket_readv_handler(struct tsocket_context *sock, + void *private_data); + +struct tevent_req *tsocket_readv_send(struct tsocket_context *sock, + TALLOC_CTX *mem_ctx, + tsocket_readv_next_iovec_t next_iovec_fn, + void *private_data) +{ + struct tevent_req *req; + struct tsocket_readv_state *state; + int ret; + int err; + bool dummy; + + req = tevent_req_create(mem_ctx, &state, + struct tsocket_readv_state); + if (!req) { + return NULL; + } + + state->caller.sock = sock; + state->caller.next_iovec_fn = next_iovec_fn; + state->caller.private_data = private_data; + + state->iov = NULL; + state->count = 0; + state->total_read = 0; + + if (!tsocket_readv_ask_for_next_vector(req, state)) { + goto post; + } + + talloc_set_destructor(state, tsocket_readv_state_destructor); + + ret = tsocket_set_readable_handler(sock, + tsocket_readv_handler, + req); + err = tsocket_error_from_errno(ret, errno, &dummy); + if (tevent_req_error(req, err)) { + goto post; + } + + return req; + + post: + return tevent_req_post(req, sock->event.ctx); +} + +static void tsocket_readv_handler(struct tsocket_context *sock, + void *private_data) +{ + struct tevent_req *req = talloc_get_type(private_data, + struct tevent_req); + struct tsocket_readv_state *state = tevent_req_data(req, + struct tsocket_readv_state); + ssize_t ret; + int err; + bool retry; + + ret = tsocket_readv(state->caller.sock, + state->iov, + state->count); + err = tsocket_error_from_errno(ret, errno, &retry); + if (retry) { + /* retry later */ + return; + } + if (tevent_req_error(req, err)) { + return; + } + + state->total_read += ret; + + while (ret > 0) { + if (ret < state->iov[0].iov_len) { + uint8_t *base; + base = (uint8_t *)state->iov[0].iov_base; + base += ret; + state->iov[0].iov_base = base; + state->iov[0].iov_len -= ret; + break; + } + ret -= state->iov[0].iov_len; + state->iov += 1; + state->count -= 1; + } + + if (state->count) { + /* we have more to read */ + return; + } + + /* ask the callback for a new vector we should fill */ + tsocket_readv_ask_for_next_vector(req, state); +} + +int tsocket_readv_recv(struct tevent_req *req, int *perrno) +{ + struct tsocket_readv_state *state = tevent_req_data(req, + struct tsocket_readv_state); + int ret; + + ret = tsocket_simple_int_recv(req, perrno); + if (ret == 0) { + ret = state->total_read; + } + + tevent_req_received(req); + return ret; +} + |