libwebsockets/lib/plat/freertos/freertos-pipe.c
2024-11-03 07:59:12 +00:00

137 lines
4.0 KiB
C

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "private-lib-core.h"
#include <lwip/sockets.h>
int
lws_plat_pipe_create(struct lws *wsi)
{
struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
struct sockaddr_in *si = &wsi->a.context->frt_pipe_si;
lws_sockfd_type *fd = pt->dummy_pipe_fds;
socklen_t sl;
/*
* There's no pipe abstraction on lwip / freertos... use a UDP socket
* listening on 127.0.0.1:xxxx and send a byte to it from a second UDP
* socket to cancel the wait.
*
* Set the port to 0 at the bind, so lwip will choose a free one in the
* ephemeral range for us.
*/
fd[0] = lwip_socket(AF_INET, SOCK_DGRAM, 0);
if (fd[0] < 0)
goto bail;
fd[1] = lwip_socket(AF_INET, SOCK_DGRAM, 0);
if (fd[1] < 0)
goto bail;
/*
* No need for memset since it's in zalloc'd context... it's in the
* context so we can reuse the prepared sockaddr to send tp fd[0] whem
* we want to cancel the wait
*/
si->sin_family = AF_INET;
si->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
si->sin_port = 0;
if (lwip_bind(fd[0], (const struct sockaddr *)si, sizeof(*si)) < 0)
goto bail;
/*
* Query the socket to set context->frt_pipe_si to the full sockaddr it
* wants to be addressed by, including the port that lwip chose.
*
* Afterwards, we can use this prepared sockaddr stashed in the context
* to trigger the "pipe" without any other preliminaries.
*/
sl = sizeof(*si);
if (lwip_getsockname(fd[0], (struct sockaddr *)si, &sl))
goto bail;
lwsl_info("%s: cancel UDP skt port %d\n", __func__,
ntohs(si->sin_port));
return 0;
bail:
lwsl_err("%s: failed\n", __func__);
return 1;
}
int
lws_plat_pipe_signal(struct lws_context *ctx, int tsi)
{
struct lws_context_per_thread *pt = &ctx->pt[tsi];
struct sockaddr_in *si = &ctx->frt_pipe_si;
lws_sockfd_type *fd = pt->dummy_pipe_fds;
uint8_t u = 0;
int n;
/*
* Send a single UDP byte payload to the listening socket fd[0], forcing
* the event loop wait to wake. fd[1] and context->frt_pipe_si are
* set at context creation and are static, the UDP sendto is supposed to
* be threadsafe for lwip:
*
* https://lwip.fandom.com/wiki/LwIP_and_multithreading
*
* Sockets generally can't be used by more than one application thread
* (on udp/raw netconn, doing a sendto/recv is currently possible).
*/
n = lwip_sendto(fd[1], &u, 1, 0, (struct sockaddr *)si, sizeof(*si));
return n != 1;
}
void
lws_plat_pipe_close(struct lws *wsi)
{
struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
lws_sockfd_type *fd = pt->dummy_pipe_fds;
if (fd[0] && fd[0] != -1)
close(fd[0]);
if (fd[1] && fd[1] != -1)
close(fd[1]);
fd[0] = fd[1] = -1;
}
int
lws_plat_pipe_is_fd_assocated(struct lws_context *cx, int tsi, lws_sockfd_type fd)
{
struct lws_context_per_thread *pt = &cx->pt[tsi];
return fd == pt->dummy_pipe_fds[0] || fd == pt->dummy_pipe_fds[1];
}