server.c

   1 /* depend: */
   2 /* cflags: */
   3 /* linker: color.o debug.o */
   4
   5 #include <assert.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #ifdef _WIN32 /* Windows */
  10 #include <winsock2.h>
  11 #include <ws2tcpip.h>
  12 #else /* Posix */
  13 #include <errno.h>
  14 #include <unistd.h>
  15 #include <fcntl.h>
  16 #include <netinet/ip.h>
  17 #include <netinet/tcp.h>
  18 //#include <sys/types.h>
  19 //#include <sys/socket.h>
  20 #include <sys/select.h>
  21 #endif
  22
  23 #include "debug.h"
  24
  25 #include "server.h"
  26
  27 /* compat */
  28
  29 #ifdef _WIN32 /* Windows */
  30 #define PF_INET AF_INET
  31 #define ERRNO (WSAGetLastError ())
  32 #else /* Posix */
  33 #define closesocket close
  34 #define ERRNO errno
  35 #define SOCKET_ERROR -1
  36 #endif
  37
  38 /* types */
  39
  40 /* constants */
  41
  42 #define BACKLOG 5
  43 #define BUFFER_SIZE 4096
  44 #define TIMEOUT 100000
  45
  46 /* macros */
  47
  48 /* gobal variables */
  49
  50 /* init network context */
  51
  52 void init_network_context (void)
  53 {
  54 #ifdef _WIN32 /* Windows */
  55     WSADATA WSAData;
  56     WSAStartup (MAKEWORD(2,0), &WSAData);
  57     assert (INVALID_SOCKET == (socket_t)-1);
  58     assert (SOCKET_ERROR == -1);
  59 #endif
  60 }
  61
  62 /* terminate network context */
  63
  64 void terminate_network_context (void)
  65 {
  66 #ifdef _WIN32 /* Windows */
  67     WSACleanup ();
  68 #endif
  69 }
  70
  71 /* open listening socket */
  72
  73 socket_t open_listening_socket (int port)
  74 {
  75     VERBOSE (DEBUG, fprintf (stdout, "Opening socket\n"));
  76     socket_t sock = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
  77     if (sock == INVALID_SOCKET) {
  78         return -1;
  79     }
  80
  81     struct sockaddr_in addr = {0};
  82     addr.sin_family = PF_INET;
  83     addr.sin_port = htons (port);
  84     addr.sin_addr.s_addr = htonl (INADDR_ANY);
  85
  86     VERBOSE (DEBUG, fprintf (stdout, "Binding socket\n"));
  87     int rc = bind (sock, (struct sockaddr *)&addr, sizeof (addr));
  88     if (rc == SOCKET_ERROR) {
  89         VERBOSE (ERROR, fprintf (stderr, "error: bind %d\n", ERRNO));
  90         rc = closesocket (sock);
  91         if (rc == SOCKET_ERROR) {
  92             VERBOSE (ERROR, fprintf (stderr, "error: close %d\n", ERRNO));
  93         }
  94         return -1;
  95     }
  96
  97     VERBOSE (DEBUG, fprintf (stdout, "Configuring socket\n"));
  98 #ifndef _WIN32 /* Posix */
  99     fcntl (sock, F_SETFL, O_NONBLOCK);
 100 #endif
 101     int val = 1;
 102     rc = setsockopt (sock, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof (val));
 103     if (rc < 0) {
 104         VERBOSE (ERROR, fprintf (stderr, "error: %s\n", "setsockopt/TCP_NODELAY"));
 105         closesocket (sock);
 106         if (rc == SOCKET_ERROR) {
 107             VERBOSE (ERROR, fprintf (stderr, "error: close %d\n", ERRNO));
 108         }
 109         return -1;
 110     }
 111
 112     rc = listen (sock, BACKLOG);
 113     if (rc < 0) {
 114         VERBOSE (ERROR, fprintf (stderr, "error: %s\n", "listen"));
 115         closesocket (sock);
 116         if (rc == SOCKET_ERROR) {
 117             VERBOSE (ERROR, fprintf (stderr, "error: close %d\n", ERRNO));
 118         }
 119         return -1;
 120     }
 121
 122     return sock;
 123 }
 124
 125 /* accept incomming connection */
 126
 127 socket_t accept_incoming_connection (socket_t sock)
 128 {
 129     socket_t connection = accept (sock, NULL, 0);
 130     if (connection < 0) {
 131         return INVALID_SOCKET;
 132     }
 133
 134 #ifndef _WIN32 /* POSIX */
 135     fcntl (connection, F_SETFL, O_NONBLOCK);
 136 #endif
 137     int val = 1;
 138     int rc = setsockopt (connection, IPPROTO_TCP, TCP_NODELAY, (char *)&val, sizeof (val));
 139     if (rc < 0) {
 140         VERBOSE (ERROR, fprintf (stderr, "error: %s\n", "setsockopt/TCP_NODELAY"));
 141         closesocket (connection);
 142         if (rc == SOCKET_ERROR) {
 143             VERBOSE (ERROR, fprintf (stderr, "error: close %d\n", ERRNO));
 144         }
 145         return INVALID_SOCKET;
 146     }
 147
 148     return connection;
 149 }
 150
 151 /* close listening socket */
 152
 153 void close_socket (socket_t sock)
 154 {
 155     int rc = closesocket (sock);
 156     if (rc == SOCKET_ERROR) {
 157         VERBOSE (ERROR, fprintf (stderr, "error: %d\n", ERRNO));
 158     }
 159 }
 160
 161 /* receive data from socket */
 162
 163 int receive_data (socket_t sock, unsigned char **pdata)
 164 {
 165     unsigned char buffer[BUFFER_SIZE] = {0};
 166     unsigned char *data = NULL;
 167     int len = 0;
 168
 169     while (1) {
 170
 171         /* timeout management */
 172         fd_set rfds;
 173         struct timeval tv = { 0, TIMEOUT };
 174         FD_ZERO (&rfds);
 175         FD_SET (sock, &rfds);
 176
 177         int retval = select (sock + 1, &rfds, NULL, NULL, &tv);
 178         if (retval != 1) { /* 0 or SOCKET_ERROR */
 179             break;
 180         }
 181
 182         /* read from socket */
 183         int rc = read (sock, buffer, BUFFER_SIZE);
 184
 185         if (rc == 0) { /* sock closed */
 186             if (data) {
 187                 free (data);
 188                 data = NULL;
 189                 len  = 0;
 190             }
 191             break;
 192
 193         } else if ((rc < 0) && (ERRNO != EAGAIN)) { /* error */
 194             if (data) {
 195                 free (data);
 196                 data = NULL;
 197             }
 198             len  = -1;
 199             break;
 200
 201         } else if (rc > 0) {
 202             data = realloc (data, len + rc);
 203             memcpy (data + len, buffer, rc);
 204             len += rc;
 205         }
 206     }
 207
 208     if (pdata != NULL) {
 209         *pdata = data;
 210     }
 211     return len;
 212 }
 213
 214 /* send data onto socket */
 215
 216 int send_data (socket_t sock, unsigned char *data, int len)
 217 {
 218     int index = 0;
 219
 220     while (index < len) {
 221         int rc = write (sock, data + index, len - index);
 222
 223         if (rc == 0) { /* sock closed */
 224             index = 0;
 225             break;
 226         } else if ((rc < 0) && (ERRNO != EAGAIN)) { /* error */
 227             index = -1;
 228             break;
 229         } else if (rc > 0) {
 230             index += rc;
 231         }
 232     }
 233
 234     return index;
 235 }
 236
 237 /* vim: set ts=4 sw=4 et: */