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#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <stdint.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <arpa/inet.h>
#define _DEF_MAX_BACKLOG 20
#define _DEF_PORT 23
#define _DEF_IP 0
#define _DEF_CONFIG_FILE "/etc/bbs.conf"
#ifdef _DEBUG
//DEBUG Macros
#warning "Compiling in DEBUG mode"
#define DEBUG_PRINTF( ... ) { \
printf("%s:%d: ", __FILE__, __LINE__); \
printf(__VA_ARGS__ ); }
#define PRINT_ERROR( str ) { \
printf("%s:%d: %s: %s\n", __FILE__, __LINE__, str, strerror(errno)); }
#else
//Release Macros
#define DEBUG_PRINTF( ... ) { }
#define PRINT_ERROR( str ) { printf("%s: %s\n", str, strerror(errno)); }
#endif
struct prog_params
{
uint8_t telnet;
uint16_t port;
uint16_t backlog;
char* ip;
char** run_argv;
int run_argc;
uint8_t serial;
char* serial_port;
};
struct prog_params parse_args(int argc, char* argv[])
{
struct prog_params ret;
memset(&ret, 0, sizeof(ret));
for (int i = 1; i < argc; i++)
{
int i_cpy = i; //i might be changed in loop
if(argv[i_cpy][0] == '-')
{
for (int o = 1; o < strlen(argv[i_cpy]); o++)
{
switch (argv[i_cpy][o])
{
case 'h':
printf("Help goes here\n");
break;
case 'p':
ret.telnet = 1;
ret.port = atoi(argv[i_cpy + 1]);
i++;
break;
case 'i':
ret.telnet = 1;
ret.ip = argv[i_cpy + 1];
i++;
break;
case 's'://Serial modem
ret.serial = 1;
ret.serial_port = argv[i_cpy + 1];
i++;
break;
default:
printf("Unrecognized Option: '%c'\n", argv[i_cpy][o]);
break;
};//switch
}//for
}//if
else
{
//Copy the rest as arguments for prog to exec
ret.run_argc = argc - i_cpy;
ret.run_argv = &(argv[i_cpy]);
}//else
}//for
return ret;
}
void handle_connection(int _socket, struct sockaddr_in _addr)
{
pid_t pid = fork();
if( pid > 0 )
{
close(_socket);
return;
}
else if ( pid < 0 )
return;
//This is here for later
//This should handle a premature closed socket from client to not create unused processes
pid = fork();
if(pid > 0)
{
close(_socket);
//Instead of waiting for pid, check if process is running AND socket is still open
wait(0);
exit(0);
}
else if(pid < 0)
exit(1);
//Redirect STDIO to socket
close(STDIN_FILENO);
dup(_socket);
close(STDOUT_FILENO);
dup(_socket);
//RUUNNNN!
execl("/usr/bin/whoami", "/usr/bin/whoami", NULL);
close(_socket);
exit(0);
}
int main(int argc, char* argv[])
{
signal(SIGCHLD,SIG_IGN); //Ignore sigchld
struct prog_params params = parse_args(argc, argv);
int server_socket, client_socket;
struct sockaddr_in socket_address, client_address;
size_t claddrsize = sizeof(client_address);
if ( (server_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1 )
{
printf("Error creating socket: %i: %s\n", errno, strerror(errno));
exit(1);
}
memset (&socket_address, 0, sizeof(socket_address));
socket_address.sin_family = AF_INET;
socket_address.sin_port = htons( 1111 );
if ( (bind(server_socket, &socket_address, sizeof(socket_address))) == -1 )
{
printf("Error binding socket: %i: %s\n", errno, strerror(errno));
exit(1);
}
if ( (listen(server_socket, 10)) == -1 )
{
printf("Error listening socket: %i: %s\n", errno, strerror(errno));
exit(1);
}
while(1)
{
client_socket = accept(server_socket, &client_address, &claddrsize);
DEBUG_PRINTF("Connection: %s\n", inet_ntoa(client_address.sin_addr));
handle_connection(client_socket, client_address);
}
return 0;
}
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