client.c

ipp打印机服务器原代码 注意：请将ipp.gz改为ipp.tar.gz 然后使用tar zxvf ipp.tar.gz解压 站长注意

/*
 * "$Id: client.c,v 1.197 2005/01/03 19:29:59 mike Exp $"
 *
 *   Client routines for the Common UNIX Printing System (CUPS) scheduler.
 *
 *   Copyright 1997-2005 by Easy Software Products, all rights reserved.
 *
 *   These coded instructions, statements, and computer programs are the
 *   property of Easy Software Products and are protected by Federal
 *   copyright law.  Distribution and use rights are outlined in the file
 *   "LICENSE.txt" which should have been included with this file.  If this
 *   file is missing or damaged please contact Easy Software Products
 *   at:
 *
 *       Attn: CUPS Licensing Information
 *       Easy Software Products
 *       44141 Airport View Drive, Suite 204
 *       Hollywood, Maryland 20636 USA
 *
 *       Voice: [phone]
 *       EMail: [e-mail]
 *         WWW: http://www.cups.org
 *
 * Contents:
 *
 *   AcceptClient()        - Accept a new client.
 *   CloseAllClients()     - Close all remote clients immediately.
 *   CloseClient()         - Close a remote client.
 *   EncryptClient()       - Enable encryption for the client...
 *   IsCGI()               - Is the resource a CGI script/program?
 *   ReadClient()          - Read data from a client.
 *   SendCommand()         - Send output from a command via HTTP.
 *   SendError()           - Send an error message via HTTP.
 *   SendFile()            - Send a file via HTTP.
 *   SendHeader()          - Send an HTTP request.
 *   UpdateCGI()           - Read status messages from CGI scripts and programs.
 *   WriteClient()         - Write data to a client as needed.
 *   check_if_modified()   - Decode an "If-Modified-Since" line.
 *   decode_auth()         - Decode an authorization string.
 *   get_file()            - Get a filename and state info.
 *   install_conf_file()   - Install a configuration file.
 *   is_path_absolute()    - Is a path absolute and free of relative elements.
 *   pipe_command()        - Pipe the output of a command to the remote client.
 *   CDSAReadFunc()        - Read function for CDSA decryption code.
 *   CDSAWriteFunc()       - Write function for CDSA encryption code.
 */

/*
 * Include necessary headers...
 */

#if	0
#include <cups/http-private.h>
#endif

#include "cupsd.h"
#include <grp.h>


/*
 * Local functions...
 */
#if	0
static int		check_if_modified(client_t *con,
			                  struct stat *filestats);
static void		decode_auth(client_t *con);
static char		*get_file(client_t *con, struct stat *filestats, 
			          char *filename, int len);
static http_status_t	install_conf_file(client_t *con);
static int		is_path_absolute(const char *path);
static int		pipe_command(client_t *con, int infile, int *outfile,
			             char *command, char *options);
#ifdef HAVE_CDSASSL
static OSStatus		CDSAReadFunc(SSLConnectionRef connection, void *data,
			             size_t *dataLength);
static OSStatus		CDSAWriteFunc(SSLConnectionRef connection,
			              const void *data, size_t *dataLength);
#endif /* HAVE_CDSASSL */
#endif

int	SFD = -1;
static int printer_get(client_t* con, char* dev);


/*
 * 'AcceptClient()' - Accept a new client.
 */

void
AcceptClient(listener_t *lis)	/* I - Listener socket */
{
  int			i;	/* Looping var */
  int			count;	/* Count of connections on a host */
  int			val;	/* Parameter value */
  client_t		*con;	/* New client pointer */
  unsigned		address;/* Address of client */
  struct hostent	*host;	/* Host entry for address */
  static time_t		last_dos = 0;
				/* Time of last DoS attack */

  DEBUG_printf(("\nFunction AcceptClient()  START...... \n")); 
  LogMessage(L_DEBUG2, "AcceptClient(lis=%p) %d NumClients = %d",
             lis, lis->fd, NumClients);

 /*
  * Make sure we don't have a full set of clients already...
  */


  if (NumClients == MaxClients)
    return;

 /*
  * Get a pointer to the next available client...
  */

  con = Clients + NumClients;

  memset(con, 0, sizeof(client_t));
  con->http.activity = time(NULL);
  con->file          = -1;

 /*
  * Accept the client and get the remote address...
  */

  val = sizeof(struct sockaddr_in);

  if ((con->http.fd = accept(lis->fd, (struct sockaddr *)&(con->http.hostaddr),
                             &val)) < 0)
  {
    DEBUG_printf(("Unable to accept client connection - %s.",
               strerror(errno)));
    LogMessage(L_ERROR, "Unable to accept client connection - %s.",
               strerror(errno));
    return;
  }

  con->http.hostaddr.sin_port = lis->address.sin_port;

 /*
  * Check the number of clients on the same address...
  */

  for (i = 0, count = 0; i < NumClients; i ++)
    if (memcmp(&(Clients[i].http.hostaddr), &(con->http.hostaddr),
               sizeof(con->http.hostaddr)) == 0)
    {
      count ++;
      if (count >= MaxClientsPerHost)
        break;
    }

  if (count >= MaxClientsPerHost)
  {
    if ((time(NULL) - last_dos) >= 60)
    {
      last_dos = time(NULL);
      LogMessage(L_WARN, "Possible DoS attack - more than %d clients connecting from %s!",
        	 MaxClientsPerHost, Clients[i].http.hostname);
    }

#ifdef WIN32
    closesocket(con->http.fd);
#else
    close(con->http.fd);
#endif /* WIN32 */

    return;
  }

 /*
  * Get the hostname or format the IP address as needed...
  */

  address = ntohl(con->http.hostaddr.sin_addr.s_addr);

  if (HostNameLookups)
#ifndef __sgi
    host = gethostbyaddr((char *)&(con->http.hostaddr.sin_addr),
                         sizeof(struct in_addr), AF_INET);
#else
    host = gethostbyaddr(&(con->http.hostaddr.sin_addr),
                         sizeof(struct in_addr), AF_INET);
#endif /* !__sgi */
  else
    host = NULL;

  if (address == 0x7f000001)
  {
   /*
    * Map accesses from the loopback interface to "localhost"...
    */

    strlcpy(con->http.hostname, "localhost", sizeof(con->http.hostname));
  }
  else if (con->http.hostaddr.sin_addr.s_addr == ServerAddr.sin_addr.s_addr)
  {
   /*
    * Map accesses from the same host to the server name.
    */

    strlcpy(con->http.hostname, ServerName, sizeof(con->http.hostname));
  }
  else if (host == NULL)
  {
    sprintf(con->http.hostname, "%d.%d.%d.%d", (address >> 24) & 255,
            (address >> 16) & 255, (address >> 8) & 255, address & 255);

    if (HostNameLookups == 2)
    {
     /*
      * Can't have an unresolved IP address with double-lookups enabled...
      */

#ifdef WIN32
      closesocket(con->http.fd);
#else
      close(con->http.fd);
#endif /* WIN32 */

      LogMessage(L_WARN, "Name lookup failed - connection from %s closed!",
                 con->http.hostname);
      return;
    }
  }
  else
    strlcpy(con->http.hostname, host->h_name, sizeof(con->http.hostname));

  if (HostNameLookups == 2)
  {
   /*
    * Do double lookups as needed...
    */

    if ((host = httpGetHostByName(con->http.hostname)) != NULL)
    {
     /*
      * See if the hostname maps to the IP address...
      */

      if (host->h_length != 4 || host->h_addrtype != AF_INET)
      {
       /*
        * Not an IPv4 address...
	*/

	host = NULL;
      }
      else
      {
       /*
        * Compare all of the addresses against this one...
	*/

	for (i = 0; host->h_addr_list[i]; i ++)
          if (memcmp(&(con->http.hostaddr.sin_addr), host->h_addr_list[i], 4) == 0)
	    break;

        if (!host->h_addr_list[i])
	  host = NULL;
      }
    }

    if (host == NULL)
    {
     /*
      * Can't have a hostname that doesn't resolve to the same IP address
      * with double-lookups enabled...
      */

#ifdef WIN32
      closesocket(con->http.fd);
#else
      close(con->http.fd);
#endif /* WIN32 */

      LogMessage(L_WARN, "IP lookup failed - connection from %s closed!",
                 con->http.hostname);
      return;
    }
  }

  LogMessage(L_DEBUG, "AcceptClient: %d from %s:%d.", con->http.fd,
             con->http.hostname, ntohs(con->http.hostaddr.sin_port));

 /*
  * Using TCP_NODELAY improves responsiveness, especially on systems
  * with a slow loopback interface...  Since we write large buffers
  * when sending print files and requests, there shouldn't be any
  * performance penalty for this...
  */

  val = 1;
  setsockopt(con->http.fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val)); 

 /*
  * Close this file on all execs...
  */

  fcntl(con->http.fd, F_SETFD, fcntl(con->http.fd, F_GETFD) | FD_CLOEXEC);

 /*
  * Add the socket to the select() input mask.
  */

  LogMessage(L_DEBUG2, "AcceptClient: Adding fd %d to InputSet...",
             con->http.fd);
  FD_SET(con->http.fd, InputSet);

  NumClients ++;

 /*
  * Temporarily suspend accept()'s until we lose a client...
  */

  if (NumClients == MaxClients)
    PauseListening();

#if	0
#ifdef HAVE_SSL
 /*
  * See if we are connecting on a secure port...
  */

  if (lis->encryption == HTTP_ENCRYPT_ALWAYS)
  {
   /*
    * https connection; go secure...
    */

    con->http.encryption = HTTP_ENCRYPT_ALWAYS;

    EncryptClient(con);
  }
#endif /* HAVE_SSL */
#endif

  DEBUG_printf(("Function AcceptClient()\n\n")); 
}


/*
 * 'CloseAllClients()' - Close all remote clients immediately.
 */

void
CloseAllClients(void)
{
  while (NumClients > 0)
    CloseClient(Clients);
}


/*
 * 'CloseClient()' - Close a remote client.
 */

int				/* O - 1 if partial close, 0 if fully closed */
CloseClient(client_t *con)	/* I - Client to close */
{
  int		partial;	/* Do partial close for SSL? */
#if defined(HAVE_LIBSSL)
  SSL_CTX	*context;	/* Context for encryption */
  SSL		*conn;		/* Connection for encryption */
  unsigned long	error;		/* Error code */
#elif defined(HAVE_GNUTLS)
  http_tls_t     *conn;		/* TLS connection information */
  int            error;		/* Error code */
  gnutls_certificate_server_credentials *credentials;
				/* TLS credentials */
#endif /* HAVE_GNUTLS */


  LogMessage(L_DEBUG, "CloseClient: %d", con->http.fd);

  partial = 0;

#if	0
#ifdef HAVE_SSL
 /*
  * Shutdown encryption as needed...
  */

  if (con->http.tls)
  {
    partial = 1;

#  ifdef HAVE_LIBSSL
    conn    = (SSL *)(con->http.tls);
    context = SSL_get_SSL_CTX(conn);

    switch (SSL_shutdown(conn))
    {
      case 1 :
          LogMessage(L_INFO, "CloseClient: SSL shutdown successful!");
	  break;
      case -1 :
          LogMessage(L_ERROR, "CloseClient: Fatal error during SSL shutdown!");
      default :
	  while ((error = ERR_get_error()) != 0)
	    LogMessage(L_ERROR, "CloseClient: %s", ERR_error_string(error, NULL));
          break;
    }

    SSL_CTX_free(context);
    SSL_free(conn);

#  elif defined(HAVE_GNUTLS)
    conn        = (http_tls_t *)(con->http.tls);
    credentials = (gnutls_certificate_server_credentials *)(conn->credentials);

    error = gnutls_bye(conn->session, GNUTLS_SHUT_WR);
    switch (error)
    {
      case GNUTLS_E_SUCCESS:
	LogMessage(L_INFO, "CloseClient: SSL shutdown successful!");
	break;
      default:
	LogMessage(L_ERROR, "CloseClient: %s", gnutls_strerror(error));
	break;
    }

    gnutls_deinit(conn->session);
    gnutls_certificate_free_credentials(*credentials);
    free(credentials);
    free(conn);

#  elif defined(HAVE_CDSASSL)
    status = SSLClose((SSLContextRef)con->http.tls);
    SSLDisposeContext((SSLContextRef)con->http.tls);
#  endif /* HAVE_LIBSSL */

    con->http.tls = NULL;
  }
#endif /* HAVE_SSL */
#endif

 /*
  * Close the socket and clear the file from the input set for select()...
  */

  if (con->http.fd > 0)
  {
    if (partial)
    {
     /*
      * Only do a partial close so that the encrypted client gets everything.
      */

      LogMessage(L_DEBUG2, "CloseClient: Removing fd %d from OutputSet...",
        	 con->http.fd);
      shutdown(con->http.fd, 0);
      FD_CLR(con->http.fd, OutputSet);
    }
    else
    {
     /*
      * Shut the socket down fully...
      */

      LogMessage(L_DEBUG2, "CloseClient: Removing fd %d from InputSet and OutputSet...",
        	 con->http.fd);
      close(con->http.fd);
      FD_CLR(con->http.fd, InputSet);
      FD_CLR(con->http.fd, OutputSet);
      con->http.fd = 0;
    }
  }

  if (con->pipe_pid != 0)
  {
   /*
    * Stop any CGI process...
    */

    LogMessage(L_DEBUG2, "CloseClient: %d Killing process ID %d...",
               con->http.fd, con->pipe_pid);
    kill(con->pipe_pid, SIGKILL);
  }

  if (con->file >= 0)
  {
    if (FD_ISSET(con->file, InputSet))
    {
      LogMessage(L_DEBUG2, "CloseClient: %d Removing fd %d from InputSet...",
        	 con->http.fd, con->file);
      FD_CLR(con->file, InputSet);
    }

    LogMessage(L_DEBUG2, "CloseClient: %d Closing data file %d.",
               con->http.fd, con->file);

    close(con->file);
    con->file = -1;
  }

  if (!partial)
  {
   /*
    * Free memory...
    */

    if (con->http.input_set)
      free(con->http.input_set);

    httpClearCookie(HTTP(con));

    ClearString(&con->filename);
    ClearString(&con->command);
    ClearString(&con->options);

    if (con->request)
    {
      ippDelete(con->request);
      con->request = NULL;
    }

    if (con->response)
    {
      ippDelete(con->response);
      con->response = NULL;
    }

    if (con->language)
    {
      cupsLangFree(con->language);
      con->language = NULL;
    }

   /*
    * Re-enable new client connections if we are going back under the