target/linux/etrax-2.6/image/e100boot/src/libpcap-0.4/pcap-enet.c

   1 /*
   2  * Stanford Enetfilter subroutines for tcpdump
   3  *
   4  * Based on the MERIT NNstat etherifrt.c and the Ultrix pcap-pf.c
   5  * subroutines.
   6  *
   7  * Rayan Zachariassen, CA*Net
   8  */
   9
  10 #include <sys/types.h>
  11 #include <sys/time.h>
  12 #include <sys/file.h>
  13 #include <sys/ioctl.h>
  14 #include <sys/socket.h>
  15
  16 #include <net/if.h>
  17 #include <net/bpf.h>
  18 #include <net/enet.h>
  19
  20 #include <netinet/in.h>
  21 #include <netinet/if_ether.h>
  22
  23 #include <stdio.h>
  24 #include <errno.h>
  25
  26 #include "interface.h"
  27
  28 struct packet_header {
  29 #ifdef  IBMRTPC
  30         struct LengthWords      length;
  31         struct tap_header       tap;
  32 #endif  /* IBMRTPC */
  33         u_char                  packet[8]
  34 };
  35
  36 extern int errno;
  37
  38 #define BUFSPACE (4*1024)
  39
  40 /* Forwards */
  41 static void efReadError(int, char *);
  42
  43 void
  44 readloop(int cnt, int if_fd, struct bpf_program *fp, printfunc printit)
  45 {
  46 #ifdef  IBMRTPC
  47         register struct packet_header *ph;
  48         register u_char *bp;
  49         register int inc;
  50 #else   /* !IBMRTPC */
  51         static struct timeval tv = { 0 };
  52 #endif  /* IBMRTPC */
  53         register int cc, caplen;
  54         register struct bpf_insn *fcode = fp->bf_insns;
  55         union {
  56                 struct packet_header hdr;
  57                 u_char  p[BUFSPACE];
  58                 u_short s;
  59         } buf;
  60
  61         while (1) {
  62                 if ((cc = read(if_fd, (char *)buf.p, sizeof(buf))) < 0)
  63                         efReadError(if_fd, "reader");
  64
  65 #ifdef  IBMRTPC
  66                 /*
  67                  * Loop through each packet.
  68                  */
  69                 bp = buf.p;
  70                 while (cc > 0) {
  71                         ph = (struct packet_header *)bp;
  72                         caplen = ph->tap.th_wirelen > snaplen ? snaplen : ph->tap
  73 .th_wirelen ;
  74                         if (bpf_filter(fcode, (char *)ph->packet,
  75                                                 ph->tap.th_wirelen, caplen)) {
  76                                 if (cnt >= 0 && --cnt < 0)
  77                                         goto out;
  78                                 (*printit)((char *)ph->packet,
  79                                         (struct timeval *)ph->tap.th_timestamp,
  80                                         ph->tap.th_wirelen, caplen);
  81                         }
  82                         inc = ph->length.PacketOffset;
  83                         cc -= inc;
  84                         bp += inc;
  85                 }
  86 #else   /* !IBMRTPC */
  87                 caplen = cc > snaplen ? snaplen : cc ;
  88                 if (bpf_filter(fcode, buf.hdr.packet, cc, caplen)) {
  89                         if (cnt >= 0 && --cnt < 0)
  90                                 goto out;
  91                         (*printit)(buf.hdr.packet, &tv, cc, caplen);
  92                 }
  93 #endif  /* IBMRTPC */
  94         }
  95  out:
  96         wrapup(if_fd);
  97 }
  98
  99 /* Call ONLY if read() has returned an error on packet filter */
 100 static void
 101 efReadError(int fid, char *msg)
 102 {
 103         if (errno == EINVAL) {  /* read MAXINT bytes already! */
 104                 if (lseek(fid, 0, 0) < 0) {
 105                         perror("tcpdump: efReadError/lseek");
 106                         exit(-1);
 107                 }
 108                 else
 109                         return;
 110         }
 111         else {
 112                 (void) fprintf(stderr, "tcpdump: ");
 113                 perror(msg);
 114                 exit(-1);
 115         }
 116 }
 117
 118 void
 119 wrapup(int fd)
 120 {
 121 #ifdef  IBMRTPC
 122         struct enstats es;
 123
 124         if (ioctl(fd, EIOSTATS, &es) == -1) {
 125                 perror("tcpdump: enet ioctl EIOSTATS error");
 126                 exit(-1);
 127         }
 128
 129         fprintf(stderr, "%d packets queued", es.enStat_Rcnt);
 130         if (es.enStat_Rdrops > 0)
 131                 fprintf(stderr, ", %d dropped", es.enStat_Rdrops);
 132         if (es.enStat_Reads > 0)
 133                 fprintf(stderr, ", %d tcpdump %s", es.enStat_Reads,
 134                                 es.enStat_Reads > 1 ? "reads" : "read");
 135         if (es.enStat_MaxRead > 1)
 136                 fprintf(stderr, ", %d packets in largest read",
 137                         es.enStat_MaxRead);
 138         putc('\n', stderr);
 139 #endif  /* IBMRTPC */
 140         close(fd);
 141 }
 142
 143 int
 144 initdevice(char *device, int pflag, int *linktype)
 145 {
 146         struct eniocb ctl;
 147         struct enfilter filter;
 148         u_int maxwaiting;
 149         int if_fd;
 150
 151 #ifdef  IBMRTPC
 152         GETENETDEVICE(0, O_RDONLY, &if_fd);
 153 #else   /* !IBMRTPC */
 154         if_fd = open("/dev/enet", O_RDONLY, 0);
 155 #endif  /* IBMRTPC */
 156
 157         if (if_fd == -1) {
 158                 perror("tcpdump: enet open error");
 159                 error(
 160 "your system may not be properly configured; see \"man enet(4)\"");
 161                 exit(-1);
 162         }
 163
 164         /*  Get operating parameters. */
 165
 166         if (ioctl(if_fd, EIOCGETP, (char *)&ctl) == -1) {
 167                 perror("tcpdump: enet ioctl EIOCGETP error");
 168                 exit(-1);
 169         }
 170
 171         /*  Set operating parameters. */
 172
 173 #ifdef  IBMRTPC
 174         ctl.en_rtout = 1 * ctl.en_hz;
 175         ctl.en_tr_etherhead = 1;
 176         ctl.en_tap_network = 1;
 177         ctl.en_multi_packet = 1;
 178         ctl.en_maxlen = BUFSPACE;
 179 #else   /* !IBMRTPC */
 180         ctl.en_rtout = 64;      /* randomly picked value for HZ */
 181 #endif  /* IBMRTPC */
 182         if (ioctl(if_fd, EIOCSETP, &ctl) == -1) {
 183                 perror("tcpdump: enet ioctl EIOCSETP error");
 184                 exit(-1);
 185         }
 186
 187         /*  Flush the receive queue, since we've changed
 188             the operating parameters and we otherwise might
 189             receive data without headers. */
 190
 191         if (ioctl(if_fd, EIOCFLUSH) == -1) {
 192                 perror("tcpdump: enet ioctl EIOCFLUSH error");
 193                 exit(-1);
 194         }
 195
 196         /*  Set the receive queue depth to its maximum. */
 197
 198         maxwaiting = ctl.en_maxwaiting;
 199         if (ioctl(if_fd, EIOCSETW, &maxwaiting) == -1) {
 200                 perror("tcpdump: enet ioctl EIOCSETW error");
 201                 exit(-1);
 202         }
 203
 204 #ifdef  IBMRTPC
 205         /*  Clear statistics. */
 206
 207         if (ioctl(if_fd, EIOCLRSTAT, 0) == -1) {
 208                 perror("tcpdump: enet ioctl EIOCLRSTAT error");
 209                 exit(-1);
 210         }
 211 #endif  /* IBMRTPC */
 212
 213         /*  Set the filter (accept all packets). */
 214
 215         filter.enf_Priority = 3;
 216         filter.enf_FilterLen = 0;
 217         if (ioctl(if_fd, EIOCSETF, &filter) == -1) {
 218                 perror("tcpdump: enet ioctl EIOCSETF error");
 219                 exit(-1);
 220         }
 221         /*
 222          * "enetfilter" supports only ethernets.
 223          */
 224         *linktype = DLT_EN10MB;
 225
 226         return(if_fd);
 227 }