scheduler/listen.c

   1 /*
   2  * "$Id$"
   3  *
   4  *   Server listening routines for the Common UNIX Printing System (CUPS)
   5  *   scheduler.
   6  *
   7  *   Copyright 1997-2001 by Easy Software Products, all rights reserved.
   8  *
   9  *   These coded instructions, statements, and computer programs are the
  10  *   property of Easy Software Products and are protected by Federal
  11  *   copyright law.  Distribution and use rights are outlined in the file
  12  *   "LICENSE.txt" which should have been included with this file.  If this
  13  *   file is missing or damaged please contact Easy Software Products
  14  *   at:
  15  *
  16  *       Attn: CUPS Licensing Information
  17  *       Easy Software Products
  18  *       44141 Airport View Drive, Suite 204
  19  *       Hollywood, Maryland 20636-3111 USA
  20  *
  21  *       Voice: (301) 373-9603
  22  *       EMail: cups-info@cups.org
  23  *         WWW: http://www.cups.org
  24  *
  25  * Contents:
  26  *
  27  *   PauseListening()  - Clear input polling on all listening sockets...
  28  *   ResumeListening() - Set input polling on all listening sockets...
  29  *   StartListening()  - Create all listening sockets...
  30  *   StopListening()   - Close all listening sockets...
  31  */
  32
  33 /*
  34  * Include necessary headers...
  35  */
  36
  37 #include "cupsd.h"
  38
  39
  40 /*
  41  * 'PauseListening()' - Clear input polling on all listening sockets...
  42  */
  43
  44 void
  45 PauseListening(void)
  46 {
  47   int           i;              /* Looping var */
  48   listener_t    *lis;           /* Current listening socket */
  49
  50
  51   if (!FD_ISSET(Listeners[0].fd, &InputSet))
  52     return;
  53
  54   if (NumClients == MaxClients)
  55     LogMessage(L_WARN, "Max clients reached, holding new connections...");
  56
  57   LogMessage(L_DEBUG, "PauseListening: clearing input bits...");
  58
  59   for (i = NumListeners, lis = Listeners; i > 0; i --, lis ++)
  60   {
  61     LogMessage(L_DEBUG2, "PauseListening: Removing fd %d from InputSet...",
  62                lis->fd);
  63
  64     FD_CLR(lis->fd, &InputSet);
  65   }
  66 }
  67
  68
  69 /*
  70  * 'ResumeListening()' - Set input polling on all listening sockets...
  71  */
  72
  73 void
  74 ResumeListening(void)
  75 {
  76   int           i;              /* Looping var */
  77   listener_t    *lis;           /* Current listening socket */
  78
  79
  80   if (FD_ISSET(Listeners[0].fd, &InputSet))
  81     return;
  82
  83   if (NumClients >= (MaxClients - 1))
  84     LogMessage(L_WARN, "Resuming new connection processing...");
  85
  86   LogMessage(L_DEBUG, "ResumeListening: setting input bits...");
  87
  88   for (i = NumListeners, lis = Listeners; i > 0; i --, lis ++)
  89   {
  90     LogMessage(L_DEBUG2, "ResumeListening: Adding fd %d to InputSet...",
  91                lis->fd);
  92
  93     FD_SET(lis->fd, &InputSet);
  94   }
  95 }
  96
  97
  98 /*
  99  * 'StartListening()' - Create all listening sockets...
 100  */
 101
 102 void
 103 StartListening(void)
 104 {
 105   int           i,              /* Looping var */
 106                 val;            /* Parameter value */
 107   listener_t    *lis;           /* Current listening socket */
 108   struct hostent *host;         /* Host entry for server address */
 109
 110
 111   LogMessage(L_DEBUG, "StartListening: NumListeners=%d", NumListeners);
 112
 113  /*
 114   * Get the server's IP address...
 115   */
 116
 117   memset(&ServerAddr, 0, sizeof(ServerAddr));
 118
 119   if ((host = gethostbyname(ServerName)) != NULL)
 120   {
 121    /*
 122     * Found the server's address!
 123     */
 124
 125     memcpy((char *)&(ServerAddr.sin_addr), host->h_addr, host->h_length);
 126     ServerAddr.sin_family = host->h_addrtype;
 127   }
 128   else
 129   {
 130    /*
 131     * Didn't find it!  Use an address of 0...
 132     */
 133
 134     LogMessage(L_ERROR, "StartListening: Unable to find IP address for server name \"%s\"!\n",
 135                ServerName);
 136
 137     ServerAddr.sin_family = AF_INET;
 138   }
 139
 140  /*
 141   * Setup socket listeners...
 142   */
 143
 144   for (i = NumListeners, lis = Listeners; i > 0; i --, lis ++)
 145   {
 146     LogMessage(L_DEBUG, "StartListening: address=%08x port=%d",
 147                ntohl(lis->address.sin_addr.s_addr),
 148                ntohs(lis->address.sin_port));
 149
 150     if ((lis->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 151     {
 152       LogMessage(L_ERROR, "StartListening: Unable to open listen socket - %s.",
 153                  strerror(errno));
 154       exit(errno);
 155     }
 156
 157     fcntl(lis->fd, F_SETFD, fcntl(lis->fd, F_GETFD) | FD_CLOEXEC);
 158
 159    /*
 160     * Set things up to reuse the local address for this port.
 161     */
 162
 163     val = 1;
 164 #ifdef __sun
 165     setsockopt(lis->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&val, sizeof(val));
 166 #else
 167     setsockopt(lis->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 168 #endif /* __sun */
 169
 170    /*
 171     * Bind to the port we found...
 172     */
 173
 174     if (bind(lis->fd, (struct sockaddr *)&(lis->address), sizeof(lis->address)) < 0)
 175     {
 176       LogMessage(L_ERROR, "StartListening: Unable to bind socket - %s.", strerror(errno));
 177       exit(errno);
 178     }
 179
 180    /*
 181     * Listen for new clients.
 182     */
 183
 184     if (listen(lis->fd, ListenBackLog) < 0)
 185     {
 186       LogMessage(L_ERROR, "StartListening: Unable to listen for clients - %s.",
 187                  strerror(errno));
 188       exit(errno);
 189     }
 190   }
 191
 192   ResumeListening();
 193 }
 194
 195
 196 /*
 197  * 'StopListening()' - Close all listening sockets...
 198  */
 199
 200 void
 201 StopListening(void)
 202 {
 203   int           i;              /* Looping var */
 204   listener_t    *lis;           /* Current listening socket */
 205
 206
 207   LogMessage(L_DEBUG, "StopListening: closing all listen sockets.");
 208
 209   PauseListening();
 210
 211   for (i = NumListeners, lis = Listeners; i > 0; i --, lis ++)
 212 #if defined(WIN32) || defined(__EMX__)
 213     closesocket(lis->fd);
 214 #else
 215     close(lis->fd);
 216 #endif /* WIN32 || __EMX__ */
 217 }
 218
 219
 220 /*
 221  * End of "$Id$".
 222  */