server.c

   1 #include <assert.h>
   2 #include <signal.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #ifdef _WIN32 /* Windows */
   7 #include <winsock2.h>
   8 #include <ws2tcpip.h>
   9 #else /* Posix */
  10 #include <errno.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <netinet/ip.h>
  14 #include <netinet/tcp.h>
  15 #include <sys/select.h>
  16 #endif
  17 #include <unistd.h>
  18
  19 #include "debug.h"
  20
  21 #include "server.h"
  22
  23 /* types */
  24
  25 #ifdef _WIN32 /* Windows */
  26 typedef SOCKET socket_t;
  27 #else /* Posix */
  28 typedef int socket_t;
  29 #endif
  30
  31 /* constants */
  32
  33 #define BACKLOG 5
  34 #define BUFFER_SIZE 4096
  35 #define TIMEOUT 100000
  36
  37 /* macros */
  38
  39 #ifdef _WIN32 /* Windows */
  40 #define PF_INET AF_INET
  41 #define ERRNO (WSAGetLastError ())
  42 #else /* Posix */
  43 #define closesocket close
  44 #define ERRNO errno
  45 #define SOCKET_ERROR -1
  46 #define INVALID_SOCKET -1
  47 #endif
  48
  49 /* gobal variables */
  50
  51 socket_t sock = INVALID_SOCKET;
  52 socket_t conn = INVALID_SOCKET;
  53
  54 /* stop server */
  55
  56 void stop_server (int sig)
  57 {
  58     VERBOSE (INFO, PRINT ("Signal: %d\n", sig));
  59     terminate_network_context ();
  60     exit (0);
  61 }
  62
  63 /* init network context */
  64
  65 void init_network_context (void)
  66 {
  67 #ifdef _WIN32 /* Windows */
  68     WSADATA WSAData;
  69     WSAStartup (MAKEWORD(2,0), &WSAData);
  70
  71     assert (INVALID_SOCKET == (socket_t)-1);
  72     assert (SOCKET_ERROR == -1);
  73 #endif
  74
  75     signal (SIGINT, &stop_server);
  76     signal (SIGQUIT, &stop_server);
  77     signal (SIGABRT, &stop_server);
  78     signal (SIGSEGV, &stop_server);
  79     signal (SIGTERM, &stop_server);
  80 }
  81
  82 /* terminate network context */
  83
  84 void terminate_network_context (void)
  85 {
  86     closesocket (sock);
  87     closesocket (conn);
  88 #ifdef _WIN32 /* Windows */
  89     WSACleanup ();
  90 #endif
  91 }
  92
  93 /* open listening socket */
  94
  95 int open_listening_socket (int port)
  96 {
  97     int val = 1;
  98
  99     VERBOSE (DEBUG, PRINT ("Opening socket\n"));
 100     //socket_t sock = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
 101     if (sock != INVALID_SOCKET) {
 102         int rc = closesocket (sock);
 103         if (rc == SOCKET_ERROR) {
 104             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 105         }
 106         sock = INVALID_SOCKET;
 107     }
 108     sock = socket (AF_INET, SOCK_STREAM, 0);
 109     if (sock == INVALID_SOCKET) {
 110         return 0;
 111     }
 112
 113     struct sockaddr_in addr = {0};
 114     //bzero (&addr, sizeof (addr));
 115     //addr.sin_family = PF_INET;
 116     addr.sin_family = AF_INET;
 117     addr.sin_port = htons (port);
 118     addr.sin_addr.s_addr = htonl (INADDR_ANY);
 119
 120     VERBOSE (DEBUG, PRINT ("Binding socket\n"));
 121     //setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof (val));
 122     int rc = bind (sock, (struct sockaddr *)&addr, sizeof (addr));
 123     if (rc == SOCKET_ERROR) {
 124         VERBOSE (ERROR, PERROR ("error: bind %d\n", ERRNO));
 125         rc = closesocket (sock);
 126         if (rc == SOCKET_ERROR) {
 127             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 128         }
 129         sock = INVALID_SOCKET;
 130         return 0;
 131     }
 132
 133     VERBOSE (DEBUG, PRINT ("Configuring socket\n"));
 134 #ifndef _WIN32 /* Posix */
 135     fcntl (sock, F_SETFL, O_NONBLOCK);
 136 #endif
 137     rc = setsockopt (sock, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof (val));
 138     if (rc < 0) {
 139         VERBOSE (ERROR, PERROR ("error: %s\n", "setsockopt/TCP_NODELAY"));
 140         closesocket (sock);
 141         if (rc == SOCKET_ERROR) {
 142             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 143         }
 144         sock = INVALID_SOCKET;
 145         return 0;
 146     }
 147
 148     rc = listen (sock, BACKLOG);
 149     if (rc < 0) {
 150         VERBOSE (ERROR, PERROR ("error: %s\n", "listen"));
 151         closesocket (sock);
 152         if (rc == SOCKET_ERROR) {
 153             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 154         }
 155         sock = INVALID_SOCKET;
 156         return 0;
 157     }
 158
 159     return 1;
 160 }
 161
 162 /* accept incomming connection */
 163
 164 int accept_incoming_connection (void)
 165 {
 166     if (sock == INVALID_SOCKET) {
 167         VERBOSE (ERROR, PERROR ("Can't accept connection from closed socket\n"));
 168         return 0;
 169     }
 170
 171     if (conn != INVALID_SOCKET) {
 172         int rc = closesocket (conn);
 173         if (rc == SOCKET_ERROR) {
 174             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 175         }
 176         conn = INVALID_SOCKET;
 177     }
 178     conn = accept (sock, NULL, 0);
 179     if (conn == INVALID_SOCKET) {
 180         return 0;
 181     }
 182
 183 #ifndef _WIN32 /* POSIX */
 184     fcntl (conn, F_SETFL, O_NONBLOCK);
 185 #endif
 186     int val = 1;
 187     int rc = setsockopt (conn, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof (val));
 188     if (rc < 0) {
 189         VERBOSE (ERROR, PERROR ("error: %s\n", "setsockopt/TCP_NODELAY"));
 190         closesocket (conn);
 191         if (rc == SOCKET_ERROR) {
 192             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 193         }
 194         conn = INVALID_SOCKET;
 195         return 0;
 196     }
 197
 198     return 1;
 199 }
 200
 201 /* close connection socket */
 202
 203 void close_connection (void)
 204 {
 205     int rc = closesocket (conn);
 206     if (rc == SOCKET_ERROR) {
 207         VERBOSE (ERROR, PERROR ("error: %d\n", ERRNO));
 208     }
 209     conn = INVALID_SOCKET;
 210 }
 211
 212 /* receive data from socket */
 213
 214 int receive_data (unsigned char **pdata)
 215 {
 216     unsigned char buffer[BUFFER_SIZE] = {0};
 217     unsigned char *data = NULL;
 218     int len = 0;
 219
 220     if (conn == INVALID_SOCKET) {
 221         VERBOSE (ERROR, PERROR ("Can't read data from closed socket\n"));
 222         return 0;
 223     }
 224
 225     while (1) {
 226
 227         /* timeout management */
 228         fd_set rfds;
 229         struct timeval tv = { 0, TIMEOUT };
 230         FD_ZERO (&rfds);
 231         FD_SET (conn, &rfds);
 232
 233         int retval = select (conn + 1, &rfds, NULL, NULL, &tv);
 234         if (retval != 1) { /* 0 or SOCKET_ERROR */
 235             break;
 236         }
 237
 238         /* read from socket */
 239         int rc = read (conn, buffer, BUFFER_SIZE);
 240
 241         if (rc == 0) { /* sock closed */
 242             if (data) {
 243                 free (data);
 244                 data = NULL;
 245                 len  = 0;
 246             }
 247             break;
 248
 249         } else if ((rc < 0) && (ERRNO != EAGAIN)) { /* error */
 250             if (data) {
 251                 free (data);
 252                 data = NULL;
 253             }
 254             len  = -1;
 255             break;
 256
 257         } else if (rc > 0) {
 258             data = realloc (data, len + rc);
 259             memcpy (data + len, buffer, rc);
 260             len += rc;
 261         }
 262     }
 263
 264     if (pdata != NULL) {
 265         *pdata = data;
 266     }
 267     return len;
 268 }
 269
 270 /* send data onto socket */
 271
 272 int send_data (unsigned char *data, int len)
 273 {
 274     int index = 0;
 275
 276     if (conn == INVALID_SOCKET) {
 277         VERBOSE (ERROR, PERROR ("Can't read data from closed socket\n"));
 278         return 0;
 279     }
 280
 281     while (index < len) {
 282         int rc = write (conn, data + index, len - index);
 283
 284         if (rc == 0) { /* sock closed */
 285             index = 0;
 286             break;
 287         } else if ((rc < 0) && (ERRNO != EAGAIN)) { /* error */
 288             index = -1;
 289             break;
 290         } else if (rc > 0) {
 291             index += rc;
 292         }
 293     }
 294
 295     return index;
 296 }
 297
 298 /* vim: set ts=4 sw=4 et: */