contrib/ipfilter/ipsd/slinux.c

   1 /*
   2  * (C)opyright 1992-1998 Darren Reed. (from tcplog)
   3  *
   4  * See the IPFILTER.LICENCE file for details on licencing.
   5  *
   6  *   The author of this software makes no garuntee about the
   7  * performance of this package or its suitability to fulfill any purpose.
   8  *
   9  */
  10
  11 #include <stdio.h>
  12 #include <netdb.h>
  13 #include <ctype.h>
  14 #include <signal.h>
  15 #include <errno.h>
  16 #include <sys/types.h>
  17 #include <sys/time.h>
  18 #include <sys/timeb.h>
  19 #include <sys/socket.h>
  20 #include <sys/file.h>
  21 #include <sys/ioctl.h>
  22 #include <sys/dirent.h>
  23 #include <linux/netdevice.h>
  24 #include <net/if.h>
  25 #include <netinet/in.h>
  26 #include <netinet/ip.h>
  27 #include <netinet/tcp.h>
  28 #include "ip_compat.h"
  29 #include "tcpip.h"
  30
  31 #ifndef lint
  32 static const char sccsid[] = "@(#)slinux.c      1.1 12/3/95 (C) 1995 Darren Reed";
  33 #endif
  34
  35 #define BUFSPACE        32768
  36
  37 /*
  38  * Be careful to only include those defined in the flags option for the
  39  * interface are included in the header size.
  40  */
  41
  42 static  int     timeout;
  43 static  char    *eth_dev = NULL;
  44
  45
  46 int     ack_recv(bp)
  47 char    *bp;
  48 {
  49         struct  tcpip   tip;
  50         tcphdr_t        *tcp;
  51         ip_t    *ip;
  52
  53         ip = (struct ip *)&tip;
  54         tcp = (tcphdr_t *)(ip + 1);
  55
  56         bcopy(bp, (char *)&tip, sizeof(tip));
  57         bcopy(bp + (ip.ip_hl << 2), (char *)tcp, sizeof(*tcp));
  58         if (0 == detect(ip, tcp))
  59                 return 1;
  60         return 0;
  61 }
  62
  63
  64 void    readloop(fd, port, dst)
  65 int     fd, port;
  66 struct  in_addr dst;
  67 {
  68         static  u_char  buf[BUFSPACE];
  69         struct  sockaddr dest;
  70         register u_char *bp = buf;
  71         register int    cc;
  72         int     dlen, done = 0;
  73         time_t  now = time(NULL);
  74
  75         do {
  76                 fflush(stdout);
  77                 dlen = sizeof(dest);
  78                 bzero((char *)&dest, dlen);
  79                 cc = recvfrom(fd, buf, BUFSPACE, 0, &dest, &dlen);
  80                 if (!cc)
  81                         if ((time(NULL) - now) > timeout)
  82                                 return done;
  83                         else
  84                                 continue;
  85
  86                 if (bp[12] != 0x8 || bp[13] != 0)
  87                         continue;       /* not ip */
  88
  89                 /*
  90                  * get rid of non-tcp or fragmented packets here.
  91                  */
  92                 if (cc >= sizeof(struct tcpiphdr))
  93                     {
  94                         if (((bp[14+9] != IPPROTO_TCP) &&
  95                              (bp[14+9] != IPPROTO_UDP)) ||
  96                             (bp[14+6] & 0x1f) || (bp[14+6] & 0xff))
  97                                 continue;
  98                         done += ack_recv(bp + 14);
  99                     }
 100         } while (cc >= 0);
 101         perror("read");
 102         exit(-1);
 103 }
 104
 105 int     initdevice(dev, tout)
 106 char    *dev;
 107 int     tout;
 108 {
 109         int fd;
 110
 111         eth_dev = strdup(dev);
 112         if ((fd = socket(AF_INET, SOCK_PACKET, htons(ETHERTYPE_IP))) == -1)
 113             {
 114                 perror("socket(SOCK_PACKET)");
 115                 exit(-1);
 116             }
 117
 118         return fd;
 119 }