dist/ipf/ipsd/snit.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * (C)opyright 1992-1998 Darren Reed. (from tcplog)
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  */
   9
  10 #include <stdio.h>
  11 #include <netdb.h>
  12 #include <ctype.h>
  13 #include <signal.h>
  14 #include <errno.h>
  15 #include <sys/types.h>
  16 #include <sys/time.h>
  17 #include <sys/timeb.h>
  18 #include <sys/socket.h>
  19 #include <sys/file.h>
  20 #include <sys/ioctl.h>
  21 #include <net/nit.h>
  22 #include <sys/fcntlcom.h>
  23 #include <sys/dir.h>
  24 #include <net/nit_if.h>
  25 #include <net/nit_pf.h>
  26 #include <net/nit_buf.h>
  27 #include <net/packetfilt.h>
  28 #include <sys/stropts.h>
  29
  30 #include <net/if.h>
  31 #include <netinet/in.h>
  32 #include <netinet/in_systm.h>
  33 #include <netinet/ip.h>
  34 #include <netinet/if_ether.h>
  35 #include <netinet/ip_var.h>
  36 #include <netinet/udp.h>
  37 #include <netinet/udp_var.h>
  38 #include <netinet/tcp.h>
  39 #include <netinet/tcpip.h>
  40
  41 #ifndef lint
  42 static  char    snitid[] = "@(#)snit.c  1.2 12/3/95 (C)1995 Darren Reed";
  43 #endif
  44
  45 #define BUFSPACE        32768
  46
  47 /*
  48  * Be careful to only include those defined in the flags option for the
  49  * interface are included in the header size.
  50  */
  51 #define BUFHDR_SIZE  (sizeof(struct nit_bufhdr))
  52 #define NIT_HDRSIZE  (BUFHDR_SIZE)
  53
  54 static  int     timeout;
  55
  56
  57 int     ack_recv(ep)
  58 char    *ep;
  59 {
  60         struct  tcpiphdr        tip;
  61         struct  tcphdr  *tcp;
  62         struct  ip      *ip;
  63
  64         ip = (struct ip *)&tip;
  65         tcp = (struct tcphdr *)(ip + 1);
  66         bcopy(ep + 14, (char *)ip, sizeof(*ip));
  67         bcopy(ep + 14 + (ip->ip_hl << 2), (char *)tcp, sizeof(*tcp));
  68         if (ip->ip_off & 0x1fff != 0)
  69                 return 0;
  70         if (0 == detect(ip, tcp))
  71                 return 1;
  72         return 0;
  73 }
  74
  75
  76 int     readloop(fd, dst)
  77 int     fd;
  78 struct  in_addr dst;
  79 {
  80         static  u_char  buf[BUFSPACE];
  81         register u_char *bp, *cp, *bufend;
  82         register struct nit_bufhdr      *hp;
  83         register int    cc;
  84         time_t  now = time(NULL);
  85         int     done = 0;
  86
  87         while ((cc = read(fd, buf, BUFSPACE-1)) >= 0) {
  88                 if (!cc)
  89                         if ((time(NULL) - now) > timeout)
  90                                 return done;
  91                         else
  92                                 continue;
  93                 bp = buf;
  94                 bufend = buf + cc;
  95                 /*
  96                  * loop through each snapshot in the chunk
  97                  */
  98                 while (bp < bufend) {
  99                         cp = (u_char *)((char *)bp + NIT_HDRSIZE);
 100                         /*
 101                          * get past NIT buffer
 102                          */
 103                         hp = (struct nit_bufhdr *)bp;
 104                         /*
 105                          * next snapshot
 106                          */
 107                         bp += hp->nhb_totlen;
 108                         done += ack_recv(cp);
 109                 }
 110                 return done;
 111         }
 112         perror("read");
 113         exit(-1);
 114 }
 115
 116 int     initdevice(device, tout)
 117 char    *device;
 118 int     tout;
 119 {
 120         struct  strioctl si;
 121         struct  timeval to;
 122         struct  ifreq ifr;
 123         struct  packetfilt pfil;
 124         u_long  if_flags;
 125         u_short *fwp = pfil.Pf_Filter;
 126         int     ret, offset, fd, snaplen= 76, chunksize = BUFSPACE;
 127
 128         if ((fd = open("/dev/nit", O_RDWR)) < 0)
 129             {
 130                 perror("/dev/nit");
 131                 exit(-1);
 132             }
 133
 134         /*
 135          * Create some filter rules for our TCP watcher. We only want ethernet
 136          * pacets which are IP protocol and only the TCP packets from IP.
 137          */
 138         offset = 6;
 139         *fwp++ = ENF_PUSHWORD + offset;
 140         *fwp++ = ENF_PUSHLIT | ENF_CAND;
 141         *fwp++ = htons(ETHERTYPE_IP);
 142         *fwp++ = ENF_PUSHWORD + sizeof(struct ether_header)/sizeof(short)+4;
 143         *fwp++ = ENF_PUSHLIT | ENF_AND;
 144         *fwp++ = htons(0x00ff);
 145         *fwp++ = ENF_PUSHLIT | ENF_COR;
 146         *fwp++ = htons(IPPROTO_TCP);
 147         *fwp++ = ENF_PUSHWORD + sizeof(struct ether_header)/sizeof(short)+4;
 148         *fwp++ = ENF_PUSHLIT | ENF_AND;
 149         *fwp++ = htons(0x00ff);
 150         *fwp++ = ENF_PUSHLIT | ENF_CAND;
 151         *fwp++ = htons(IPPROTO_UDP);
 152         pfil.Pf_FilterLen = fwp - &pfil.Pf_Filter[0];
 153         /*
 154          * put filter in place.
 155          */
 156         if (ioctl(fd, I_PUSH, "pf") == -1)
 157             {
 158                 perror("ioctl: I_PUSH pf");
 159                 exit(1);
 160             }
 161         if (ioctl(fd, NIOCSETF, &pfil) == -1)
 162             {
 163                 perror("ioctl: NIOCSETF");
 164                 exit(1);
 165             }
 166         /*
 167          * arrange to get messages from the NIT STREAM and use NIT_BUF option
 168          */
 169         ioctl(fd, I_SRDOPT, (char*)RMSGD);
 170         ioctl(fd, I_PUSH, "nbuf");
 171         /*
 172          * set the timeout
 173          */
 174         timeout = tout;
 175         si.ic_timout = 1;
 176         to.tv_sec = 1;
 177         to.tv_usec = 0;
 178         si.ic_cmd = NIOCSTIME;
 179         si.ic_len = sizeof(to);
 180         si.ic_dp = (char*)&to;
 181         if (ioctl(fd, I_STR, (char*)&si) == -1)
 182             {
 183                 perror("ioctl: NIT timeout");
 184                 exit(-1);
 185             }
 186         /*
 187          * set the chunksize
 188          */
 189         si.ic_cmd = NIOCSCHUNK;
 190         si.ic_len = sizeof(chunksize);
 191         si.ic_dp = (char*)&chunksize;
 192         if (ioctl(fd, I_STR, (char*)&si) == -1)
 193                 perror("ioctl: NIT chunksize");
 194         if (ioctl(fd, NIOCGCHUNK, (char*)&chunksize) == -1)
 195             {
 196                 perror("ioctl: NIT chunksize");
 197                 exit(-1);
 198             }
 199         printf("NIT buffer size: %d\n", chunksize);
 200
 201         /*
 202          * request the interface
 203          */
 204         strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 205         ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
 206         si.ic_cmd = NIOCBIND;
 207         si.ic_len = sizeof(ifr);
 208         si.ic_dp = (char*)&ifr;
 209         if (ioctl(fd, I_STR, (char*)&si) == -1)
 210             {
 211                 perror(ifr.ifr_name);
 212                 exit(1);
 213             }
 214
 215         /*
 216          * set the snapshot length
 217          */
 218         si.ic_cmd = NIOCSSNAP;
 219         si.ic_len = sizeof(snaplen);
 220         si.ic_dp = (char*)&snaplen;
 221         if (ioctl(fd, I_STR, (char*)&si) == -1)
 222             {
 223                 perror("ioctl: NIT snaplen");
 224                 exit(1);
 225             }
 226         (void) ioctl(fd, I_FLUSH, (char*)FLUSHR);
 227         return fd;
 228 }