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-rw-r--r--lib/tsocket/tsocket_readv.c222
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;
+}
+