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/* SPDX-License-Identifier: Unlicense */
#include "proto_io.h"
#include <arpa/inet.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <stdio.h>
static unsigned char g_udp_buffer[UINT16_MAX + 1u];
int ReceiveFrame(int fd, struct frame *frame)
{
frame->type = FT_NONE;
struct sockaddr_in source_address;
socklen_t source_address_len = sizeof(source_address);
int const length = recvfrom(
fd,
g_udp_buffer,
sizeof(g_udp_buffer) - 1,
0,
(struct sockaddr*)&source_address,
&source_address_len);
if (length == 0) {
return -EWOULDBLOCK;
}
if (length < 0) {
int const err = errno;
if (err != EWOULDBLOCK) {
perror("recvfrom failed");
}
return -err;
}
uint32_t const addr = ntohl(source_address.sin_addr.s_addr);
uint16_t const port = ntohs(source_address.sin_port);
if (length) {
*frame = ParseFrame(g_udp_buffer, length);
frame->addr = addr;
frame->port = port;
}
if (LOG_TRACE) {
uint8_t const a0 = addr >> 24;
uint8_t const a1 = addr >> 16;
uint8_t const a2 = addr >> 8;
uint8_t const a3 = addr;
fprintf(stderr, "Received from %u.%u.%u.%u:%u\n", a0, a1, a2, a3, port);
}
return 0;
}
int SendFrame(int const fd, struct frame const *const frame)
{
g_udp_buffer[0] = frame->type;
struct sockaddr_in const sockaddr = {
.sin_family = AF_INET,
.sin_port = htons(frame->port),
.sin_addr.s_addr = htonl(frame->addr),
};
if (LOG_TRACE) {
uint32_t const addr = frame->addr;
uint16_t const port = frame->port;
uint8_t const a0 = addr >> 24;
uint8_t const a1 = addr >> 16;
uint8_t const a2 = addr >> 8;
uint8_t const a3 = addr;
fprintf(stderr, "Sending to %u.%u.%u.%u:%u\n", a0, a1, a2, a3, port);
}
size_t const size = SerializeFrame(g_udp_buffer, UINT16_MAX + 1u, frame);
ssize_t const ret = sendto(
fd, g_udp_buffer, size, 0, (struct sockaddr const *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
int const err = errno;
perror("sendto failed");
return -err;
}
return 0;
}
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