int main(void) {
struct UDPsopa sopa = {
.sop = NULL,
.pap = NULL,
.port = 0, // 0 = pick unused port
.packet_size = 512,
.packet_num = 0,
.host_port = 4444
};
strcpy(sopa.host_name, "127.0.0.1");
if (udp_setup(&sopa) != 0) {
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
}
// additional client setup
if (SDLNet_ResolveHost(&(sopa.pap->address), sopa.host_name, sopa.host_port) != 0) {
printf("SDLNet_ResolveHost(&(sopa.pap->address), sopa.host_name, sopa.host_port) != 0\n");
printf("SDLNet_GetError() = '%s'\n", SDLNet_GetError());
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
}
srand(123);
for (;;) {
sleep(1); // 1 second
sprintf((char*)sopa.pap->data, "rand_num = %d", rand());
sopa.pap->len = strlen((char*)sopa.pap->data) + 1;
const int channel = -1; // -1 = use packet's address as destination
if (SDLNet_UDP_Send(sopa.sop, channel, sopa.pap) == 0) {
printf("SDLNet_UDP_Send(sopa.sop, channel, sopa.pap) == 0\n");
printf("SDLNet_GetError() = '%s'\n", SDLNet_GetError());
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
}
switch (SDLNet_UDP_Recv(sopa.sop, sopa.pap)) {
case -1:
printf("SDLNet_UDP_Recv(sopa.sop, sopa.pap) == -1\n");
printf("SDLNet_GetError() = '%s'\n", SDLNet_GetError());
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
case 0:
printf("SDLNet_UDP_Recv(sopa.sop, sopa.pap) == 0 // no packets received\n");
break;
case 1:
sopa.packet_num++;
udp_print(&sopa);
break;
}
} // for(;;)
udp_cleanup(&sopa);
exit(EXIT_SUCCESS);
}
void send_test(void)
{
u32 ip = ((u32)192 << 24) | ((u32)168 << 16) | ((u32)1 << 8) | 20;
u16 src_port;
u16 port = 8888;
char data[] = "hello world!";
u16 len;
udp_close(0);
if (udp_setup(ip, port, port) < 0)
err_log("udp_setup");
send_data(ip, port, port, data, strlen(data));
recv_data(&ip, &src_port, data_i, &len);
}
int main(int argc, char **argv)
{
int udp_socket;
int tcp_socket;
int tcp_port;
int client_socket;
struct sockaddr_in addr;
int addr_size;
char buffer[1025];
struct client *clients;
int num_clients;
int max_clients;
int i, j;
int len;
char* temp_str;
fd_set read_fds_master;
fd_set read_fds_copy;
int fd_max;
FD_ZERO(&read_fds_master);
FD_ZERO(&read_fds_copy);
clients = malloc(BACKLOG * sizeof(struct client));
num_clients = 0;
max_clients = BACKLOG;
/* signal(SIGINT, handle_sigint); */
if ((udp_socket = udp_setup(UDP_PORT)) == -1) exit(1);
/* make udp socket "select()able" */
FD_SET(udp_socket, &read_fds_master);
fd_max = udp_socket;
if((tcp_socket = tcp_setup(&tcp_port)) == -1) exit(1);
printf("Listening on tcp port: %d\n", tcp_port);
/* make tcp socket "select()able" */
FD_SET(tcp_socket, &read_fds_master);
fd_max = tcp_socket;
/* main loop */
for (;;)
{
/* handle readable sockets */
read_fds_copy = read_fds_master; // make a copy that select() can modify
if (select(fd_max + 1, &read_fds_copy, NULL, NULL, NULL) == -1)
{
fprintf(stderr, "Error during select().\n");
close(udp_socket);
exit(1);
}
for (i = 0; i <= fd_max; i++)
{
if (FD_ISSET(i, &read_fds_copy))
{
if (i == udp_socket)
{
/* answer a multicast message */
memset(buffer, 0, sizeof(buffer));
addr_size = sizeof(addr);
if (recvfrom(udp_socket, buffer, sizeof(buffer), 0, (struct sockaddr*)&addr, &addr_size) == -1)
{
fprintf(stderr, "Error receiving multicast message.\n");
close(udp_socket);
exit(1);
}
if (strncmp(buffer, "server_discovery", 16) == 0)
{
printf("%s:%d - discovery request\n", inet_ntoa(addr.sin_addr.s_addr), ntohs(addr.sin_port));
len = sprintf(buffer, "discovery_reply %d\n", tcp_port);
addr_size = sizeof(addr);
if (sendto(udp_socket, buffer, len, 0, (struct sockaddr*)&addr, addr_size) == -1)
{
perror("Error answering multicast message.\n");
close(udp_socket);
exit(1);
}
}
}
if (i == tcp_socket)
{
for (j = 0; j < num_clients; j++)
{
if (clients[j].status == 'd') break; /* the value of j at this point is used as a side effect later */
}
/* j is now ALWAYS the first unused index of the clients array */
if (j == num_clients) num_clients++;
if (num_clients > max_clients)
{
max_clients = max_clients + BACKLOG;
clients = realloc(clients, max_clients * sizeof(struct client));
}
addr_size = sizeof(addr);
clients[j].socket = accept(tcp_socket, (struct sockaddr*)&addr, &addr_size);
clients[j].status = 'c';
/* save source as string for logging and debugging */
strncpy(clients[j].socket_addr, (const char*)inet_ntoa(addr.sin_addr.s_addr), 15);
clients[j].socket_port = ntohs(addr.sin_port);
printf("%s:%d - new connection.\n", clients[j].socket_addr, clients[j].socket_port);
FD_SET(clients[j].socket, &read_fds_master);
if (clients[j].socket > fd_max) fd_max = clients[j].socket;
}
for (j = 0; j < num_clients; j++)
{
if (i == clients[j].socket)
{
memset(buffer, 0, sizeof(buffer));
len = recv(clients[j].socket, buffer, sizeof(buffer) - 1 - strlen(clients[j].line_buffer), 0);
switch (len)
{
case 0:
printf("%s:%d - disconnected.\n", clients[j].socket_addr, clients[j].socket_port);
FD_CLR(clients[j].socket, &read_fds_master);
clients[j].status = 'd';
push_global_filelist(clients, num_clients);
break;
case -1:
/* TODO: handle gracefully. this is usually a "connection reset by peer" */
perror("recv");
break;
default:
strncat(clients[j].line_buffer, buffer, len);
while (strchr(clients[j].line_buffer, '\n') != NULL)
{
switch (clients[j].status)
{
case 'c':
//printf("status: connected\n");
if (sscanf(clients[j].line_buffer, "register %d", &(clients[j].download_port)) == 1)
{
printf("%s:%d - registered port %d for downloads.\n", clients[j].socket_addr, clients[j].socket_port, clients[j].download_port);
clients[j].status = 'r';
break;
}
printf("%s:%d - sent %d unrecognized bytes: %s\n", clients[j].socket_addr, clients[j].socket_port, strlen(clients[j].line_buffer), clients[j].line_buffer);
break;
case 'r':
//printf("status: registered\n");
//printf("buffer: %s", clients[j].line_buffer);
if (sscanf(clients[j].line_buffer, "send_filelist %d\n", &(clients[j].filelist_size)) == 1)
{
if (clients[j].filelist_size > 0)
{
printf("%s:%d - will send %d file list entries next.\n", clients[j].socket_addr, clients[j].socket_port, clients[j].filelist_size);
if (clients[j].file_list != NULL) free(clients[j].file_list);
clients[j].file_list = malloc(clients[j].filelist_size * sizeof(struct filelist_entry));
}
clients[j].status = 's';
clients[j].filelist_len = 0;
break;
}
if (strncmp(clients[j].line_buffer, "unregister", 10) == 0)
{
printf("%s:%d - unregistered download port.\n", clients[j].socket_addr, clients[j].socket_port);
clients[j].status = 'c';
break;
}
printf("%s:%d - sent %d unrecognized bytes: %s\n", clients[j].socket_addr, clients[j].socket_port, strlen(clients[j].line_buffer), clients[j].line_buffer);
break;
case 's':
//printf("status: sending file list\n");
if (clients[j].filelist_len < clients[j].filelist_size)
{
len = clients[j].filelist_len;
if (sscanf(clients[j].line_buffer , "%d %1000s", &(clients[j].file_list[len].size), clients[j].file_list[len].name) == 2)
{
clients[j].filelist_len = clients[j].filelist_len + 1;
printf("%s:%d - sent a file list entry: %s (%d bytes)\n", clients[j].socket_addr, clients[j].socket_port, clients[j].file_list[len].name, clients[j].file_list[len].size);
}
else
{
printf("%s:%d - sent %d unrecognized bytes: %s\n", clients[j].socket_addr, clients[j].socket_port, strlen(clients[j].line_buffer), clients[j].line_buffer);
}
}
if (clients[j].filelist_len == clients[j].filelist_size)
{
clients[j].status = 'r';
push_global_filelist(clients, num_clients);
}
break;
default:
break;
}
/* consume part of buffer */
temp_str = strchr(clients[j].line_buffer, '\n');
//printf("bytes left: %d\n", strlen(temp_str));
if (strlen(temp_str) > 1)
{
memset(buffer, 0, sizeof(buffer));
strncpy(buffer, temp_str + 1, strlen(temp_str) - 1);
//printf("bytes left: %d\n", strlen(buffer));
memset(clients[j].line_buffer, 0, sizeof(clients[j].line_buffer));
strncpy(clients[j].line_buffer, buffer, strlen(buffer));
//printf("line buffer: %s", clients[j].line_buffer);
}
else
{
memset(clients[j].line_buffer, 0, sizeof(clients[j].line_buffer));
}
}
}
}
}
}
}
}
}
