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 #ifndef _WIN32 /* Posix */
  76     signal (SIGINT, &stop_server);
  77 #endif
  78     signal (SIGABRT, &stop_server);
  79     signal (SIGSEGV, &stop_server);
  80     signal (SIGTERM, &stop_server);
  81 }
  82
  83 /* terminate network context */
  84
  85 void terminate_network_context (void)
  86 {
  87     closesocket (sock);
  88     closesocket (conn);
  89 #ifdef _WIN32 /* Windows */
  90     WSACleanup ();
  91 #endif
  92 }
  93
  94 /* open listening socket */
  95
  96 int open_listening_socket (int port)
  97 {
  98     int val = 1;
  99
 100     VERBOSE (DEBUG, PRINT ("Opening socket\n"));
 101     //socket_t sock = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
 102     if (sock != INVALID_SOCKET) {
 103         int rc = closesocket (sock);
 104         if (rc == SOCKET_ERROR) {
 105             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 106         }
 107         sock = INVALID_SOCKET;
 108     }
 109     sock = socket (AF_INET, SOCK_STREAM, 0);
 110     if (sock == INVALID_SOCKET) {
 111         return 0;
 112     }
 113
 114     struct sockaddr_in addr = {0};
 115     //bzero (&addr, sizeof (addr));
 116     //addr.sin_family = PF_INET;
 117     addr.sin_family = AF_INET;
 118     addr.sin_port = htons (port);
 119     addr.sin_addr.s_addr = htonl (INADDR_ANY);
 120
 121     VERBOSE (DEBUG, PRINT ("Binding socket\n"));
 122     //setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof (val));
 123     int rc = bind (sock, (struct sockaddr *)&addr, sizeof (addr));
 124     if (rc == SOCKET_ERROR) {
 125         VERBOSE (ERROR, PERROR ("error: bind %d\n", ERRNO));
 126         rc = closesocket (sock);
 127         if (rc == SOCKET_ERROR) {
 128             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 129         }
 130         sock = INVALID_SOCKET;
 131         return 0;
 132     }
 133
 134     VERBOSE (DEBUG, PRINT ("Configuring socket\n"));
 135 #ifndef _WIN32 /* Posix */
 136     fcntl (sock, F_SETFL, O_NONBLOCK);
 137 #endif
 138     rc = setsockopt (sock, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof (val));
 139     if (rc < 0) {
 140         VERBOSE (ERROR, PERROR ("error: %s\n", "setsockopt/TCP_NODELAY"));
 141         closesocket (sock);
 142         if (rc == SOCKET_ERROR) {
 143             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 144         }
 145         sock = INVALID_SOCKET;
 146         return 0;
 147     }
 148
 149     rc = listen (sock, BACKLOG);
 150     if (rc < 0) {
 151         VERBOSE (ERROR, PERROR ("error: %s\n", "listen"));
 152         closesocket (sock);
 153         if (rc == SOCKET_ERROR) {
 154             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 155         }
 156         sock = INVALID_SOCKET;
 157         return 0;
 158     }
 159
 160     return 1;
 161 }
 162
 163 /* accept incomming connection */
 164
 165 int accept_incoming_connection (void)
 166 {
 167     if (sock == INVALID_SOCKET) {
 168         VERBOSE (ERROR, PERROR ("Can't accept connection from closed socket\n"));
 169         return 0;
 170     }
 171
 172     if (conn != INVALID_SOCKET) {
 173         int rc = closesocket (conn);
 174         if (rc == SOCKET_ERROR) {
 175             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 176         }
 177         conn = INVALID_SOCKET;
 178     }
 179     conn = accept (sock, NULL, 0);
 180     if (conn == INVALID_SOCKET) {
 181         return 0;
 182     }
 183
 184 #ifndef _WIN32 /* POSIX */
 185     fcntl (conn, F_SETFL, O_NONBLOCK);
 186 #endif
 187     int val = 1;
 188     int rc = setsockopt (conn, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof (val));
 189     if (rc < 0) {
 190         VERBOSE (ERROR, PERROR ("error: %s\n", "setsockopt/TCP_NODELAY"));
 191         closesocket (conn);
 192         if (rc == SOCKET_ERROR) {
 193             VERBOSE (ERROR, PERROR ("error: close %d\n", ERRNO));
 194         }
 195         conn = INVALID_SOCKET;
 196         return 0;
 197     }
 198
 199     return 1;
 200 }
 201
 202 /* close connection socket */
 203
 204 void close_connection (void)
 205 {
 206     int rc = closesocket (conn);
 207     if (rc == SOCKET_ERROR) {
 208         VERBOSE (ERROR, PERROR ("error: %d\n", ERRNO));
 209     }
 210     conn = INVALID_SOCKET;
 211 }
 212
 213 /* receive data from socket */
 214
 215 int receive_data (char **pdata)
 216 {
 217     char buffer[BUFFER_SIZE] = {0};
 218     char *data = NULL;
 219     int len = 0;
 220
 221     if (conn == INVALID_SOCKET) {
 222         VERBOSE (ERROR, PERROR ("Can't read data from closed socket\n"));
 223         return 0;
 224     }
 225
 226     while (1) {
 227
 228         /* timeout management */
 229         fd_set rfds;
 230         struct timeval tv = { 0, TIMEOUT };
 231         FD_ZERO (&rfds);
 232         FD_SET (conn, &rfds);
 233
 234         int retval = select (conn + 1, &rfds, NULL, NULL, &tv);
 235         if (retval != 1) { /* 0 or SOCKET_ERROR */
 236             break;
 237         }
 238
 239         /* read from socket */
 240         int rc = recv (conn, buffer, BUFFER_SIZE, 0);
 241         VERBOSE (DEBUG, PRINT ("rc: %d\nerrno: %d\n", rc, ERRNO));
 242
 243         if (rc == 0) { /* sock closed */
 244             if (data) {
 245                 free (data);
 246                 data = NULL;
 247                 len  = 0;
 248             }
 249             break;
 250
 251         } else if ((rc < 0) && (ERRNO != EAGAIN)) { /* error */
 252             if (data) {
 253                 free (data);
 254                 data = NULL;
 255             }
 256             len  = -1;
 257             break;
 258
 259         } else if (rc > 0) {
 260             data = realloc (data, len + rc);
 261             memcpy (data + len, buffer, rc);
 262             len += rc;
 263         }
 264     }
 265
 266     if (pdata != NULL) {
 267         *pdata = data;
 268     }
 269     return len;
 270 }
 271
 272 /* send data onto socket */
 273
 274 int send_data (char *data, int len)
 275 {
 276     int index = 0;
 277
 278     if (conn == INVALID_SOCKET) {
 279         VERBOSE (ERROR, PERROR ("Can't read data from closed socket\n"));
 280         return 0;
 281     }
 282
 283     while (index < len) {
 284         int rc = write (conn, data + index, len - index);
 285
 286         if (rc == 0) { /* sock closed */
 287             index = 0;
 288             break;
 289         } else if ((rc < 0) && (ERRNO != EAGAIN)) { /* error */
 290             index = -1;
 291             break;
 292         } else if (rc > 0) {
 293             index += rc;
 294         }
 295     }
 296
 297     return index;
 298 }
 299
 300 /* vim: set ts=4 sw=4 et: */