int uv__udp_recv_start(uv_udp_t* handle, uv_alloc_cb alloc_cb,
uv_udp_recv_cb recv_cb) {
uv_loop_t* loop = handle->loop;
int err;
if (handle->flags & UV_HANDLE_READING) {
return WSAEALREADY;
}
err = uv_udp_maybe_bind(handle,
(const struct sockaddr*) &uv_addr_ip4_any_,
sizeof(uv_addr_ip4_any_),
0);
if (err)
return err;
handle->flags |= UV_HANDLE_READING;
INCREASE_ACTIVE_COUNT(loop, handle);
loop->active_udp_streams++;
handle->recv_cb = recv_cb;
handle->alloc_cb = alloc_cb;
/* If reading was stopped and then started again, there could still be a recv
* request pending. */
if (!(handle->flags & UV_HANDLE_READ_PENDING))
uv_udp_queue_recv(loop, handle);
return 0;
}
int uv_udp_recv_start(uv_udp_t* handle, uv_alloc_cb alloc_cb,
uv_udp_recv_cb recv_cb) {
uv_loop_t* loop = handle->loop;
if (handle->flags & UV_HANDLE_READING) {
uv__set_sys_error(loop, WSAEALREADY);
return -1;
}
if (!(handle->flags & UV_HANDLE_BOUND) &&
uv_udp_bind(handle, uv_addr_ip4_any_, 0) < 0) {
return -1;
}
handle->flags |= UV_HANDLE_READING;
INCREASE_ACTIVE_COUNT(loop, handle);
loop->active_udp_streams++;
handle->recv_cb = recv_cb;
handle->alloc_cb = alloc_cb;
/* If reading was stopped and then started again, there could still be a */
/* recv request pending. */
if (!(handle->flags & UV_HANDLE_READ_PENDING))
uv_udp_queue_recv(loop, handle);
return 0;
}
void uv_process_udp_recv_req(uv_loop_t* loop, uv_udp_t* handle,
uv_req_t* req) {
uv_buf_t buf;
int partial;
assert(handle->type == UV_UDP);
handle->flags &= ~UV_HANDLE_READ_PENDING;
if (!REQ_SUCCESS(req)) {
DWORD err = GET_REQ_SOCK_ERROR(req);
if (err == WSAEMSGSIZE) {
/* Not a real error, it just indicates that the received packet */
/* was bigger than the receive buffer. */
} else if (err == WSAECONNRESET || err == WSAENETRESET) {
/* A previous sendto operation failed; ignore this error. If */
/* zero-reading we need to call WSARecv/WSARecvFrom _without_ the */
/* MSG_PEEK flag to clear out the error queue. For nonzero reads, */
/* immediately queue a new receive. */
if (!(handle->flags & UV_HANDLE_ZERO_READ)) {
goto done;
}
} else {
/* A real error occurred. Report the error to the user only if we're */
/* currently reading. */
if (handle->flags & UV_HANDLE_READING) {
uv__set_sys_error(loop, err);
uv_udp_recv_stop(handle);
buf = (handle->flags & UV_HANDLE_ZERO_READ) ?
uv_buf_init(NULL, 0) : handle->recv_buffer;
handle->recv_cb(handle, -1, buf, NULL, 0);
}
goto done;
}
}
if (!(handle->flags & UV_HANDLE_ZERO_READ)) {
/* Successful read */
partial = !REQ_SUCCESS(req);
handle->recv_cb(handle,
req->overlapped.InternalHigh,
handle->recv_buffer,
(struct sockaddr*) &handle->recv_from,
partial ? UV_UDP_PARTIAL : 0);
} else if (handle->flags & UV_HANDLE_READING) {
DWORD bytes, err, flags;
struct sockaddr_storage from;
int from_len;
/* Do a nonblocking receive */
/* TODO: try to read multiple datagrams at once. FIONREAD maybe? */
buf = handle->alloc_cb((uv_handle_t*) handle, 65536);
assert(buf.len > 0);
memset(&from, 0, sizeof from);
from_len = sizeof from;
flags = 0;
if (WSARecvFrom(handle->socket,
(WSABUF*)&buf,
1,
&bytes,
&flags,
(struct sockaddr*) &from,
&from_len,
NULL,
NULL) != SOCKET_ERROR) {
/* Message received */
handle->recv_cb(handle, bytes, buf, (struct sockaddr*) &from, 0);
} else {
err = WSAGetLastError();
if (err == WSAEMSGSIZE) {
/* Message truncated */
handle->recv_cb(handle,
bytes,
buf,
(struct sockaddr*) &from,
UV_UDP_PARTIAL);
} if (err == WSAEWOULDBLOCK) {
/* Kernel buffer empty */
uv__set_sys_error(loop, WSAEWOULDBLOCK);
handle->recv_cb(handle, 0, buf, NULL, 0);
} else if (err != WSAECONNRESET && err != WSAENETRESET) {
/* Serious error. WSAECONNRESET/WSANETRESET is ignored because this */
/* just indicates that a previous sendto operation failed. */
uv_udp_recv_stop(handle);
uv__set_sys_error(loop, err);
handle->recv_cb(handle, -1, buf, NULL, 0);
}
}
}
done:
/* Post another read if still reading and not closing. */
if ((handle->flags & UV_HANDLE_READING) &&
!(handle->flags & UV_HANDLE_READ_PENDING)) {
uv_udp_queue_recv(loop, handle);
}
DECREASE_PENDING_REQ_COUNT(handle);
}
void uv_process_udp_recv_req(uv_loop_t* loop, uv_udp_t* handle,
uv_req_t* req) {
uv_buf_t buf;
int partial;
assert(handle->type == UV_UDP);
handle->flags &= ~UV_HANDLE_READ_PENDING;
if (!REQ_SUCCESS(req) &&
GET_REQ_STATUS(req) != STATUS_RECEIVE_EXPEDITED) {
/* An error occurred doing the read. */
if ((handle->flags & UV_HANDLE_READING)) {
uv__set_sys_error(loop, GET_REQ_SOCK_ERROR(req));
uv_udp_recv_stop(handle);
#if 0
buf = (handle->flags & UV_HANDLE_ZERO_READ) ?
uv_buf_init(NULL, 0) : handle->recv_buffer;
#else
buf = handle->recv_buffer;
#endif
handle->recv_cb(handle, -1, buf, NULL, 0);
}
goto done;
}
#if 0
if (!(handle->flags & UV_HANDLE_ZERO_READ)) {
#endif
/* Successful read */
partial = (GET_REQ_STATUS(req) == STATUS_RECEIVE_EXPEDITED);
handle->recv_cb(handle,
req->overlapped.InternalHigh,
handle->recv_buffer,
(struct sockaddr*) &handle->recv_from,
partial ? UV_UDP_PARTIAL : 0);
#if 0
} else {
DWORD bytes, err, flags;
struct sockaddr_storage from;
int from_len;
/* Do a nonblocking receive */
/* TODO: try to read multiple datagrams at once. FIONREAD maybe? */
buf = handle->alloc_cb((uv_handle_t*) handle, 65536);
assert(buf.len > 0);
memset(&from, 0, sizeof from);
from_len = sizeof from;
flags = MSG_PARTIAL;
if (WSARecvFrom(handle->socket,
(WSABUF*)&buf,
1,
&bytes,
&flags,
(struct sockaddr*) &from,
&from_len,
NULL,
NULL) != SOCKET_ERROR) {
/* Message received */
handle->recv_cb(handle,
bytes,
buf,
(struct sockaddr*) &from,
(flags & MSG_PARTIAL) ? UV_UDP_PARTIAL : 0);
} else {
err = WSAGetLastError();
if (err == WSAEWOULDBLOCK) {
uv__set_sys_error(loop, WSAEWOULDBLOCK);
handle->recv_cb(handle, 0, buf, NULL, 0);
} else {
/* Ouch! serious error. */
uv__set_sys_error(loop, err);
handle->recv_cb(handle, -1, buf, NULL, 0);
}
}
}
#endif
done:
/* Post another read if still reading and not closing. */
if ((handle->flags & UV_HANDLE_READING) &&
!(handle->flags & UV_HANDLE_READ_PENDING)) {
uv_udp_queue_recv(loop, handle);
}
DECREASE_PENDING_REQ_COUNT(handle);
}
