/* * Stanford Enetfilter subroutines for tcpdump * * Based on the MERIT NNstat etherifrt.c and the Ultrix pcap-pf.c * subroutines. * * Rayan Zachariassen, CA*Net */ #ifndef lint static const char rcsid[] _U_ = "@(#) $Header: /tcpdump/master/libpcap/pcap-enet.c,v 1.7.2.1 2003/11/15 23:26:44 guy Exp $"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include "interface.h" struct packet_header { #ifdef IBMRTPC struct LengthWords length; struct tap_header tap; #endif /* IBMRTPC */ u_char packet[8] }; extern int errno; #define BUFSPACE (4*1024) /* Forwards */ static void efReadError(int, char *); void readloop(int cnt, int if_fd, struct bpf_program *fp, printfunc printit) { #ifdef IBMRTPC register struct packet_header *ph; register u_char *bp; register int inc; #else /* !IBMRTPC */ static struct timeval tv = { 0 }; #endif /* IBMRTPC */ register int cc, caplen; register struct bpf_insn *fcode = fp->bf_insns; union { struct packet_header hdr; u_char p[BUFSPACE]; u_short s; } buf; while (1) { if ((cc = read(if_fd, (char *)buf.p, sizeof(buf))) < 0) efReadError(if_fd, "reader"); #ifdef IBMRTPC /* * Loop through each packet. */ bp = buf.p; while (cc > 0) { ph = (struct packet_header *)bp; caplen = ph->tap.th_wirelen > snaplen ? snaplen : ph->tap .th_wirelen ; if (bpf_filter(fcode, (char *)ph->packet, ph->tap.th_wirelen, caplen)) { if (cnt >= 0 && --cnt < 0) goto out; (*printit)((char *)ph->packet, (struct timeval *)ph->tap.th_timestamp, ph->tap.th_wirelen, caplen); } inc = ph->length.PacketOffset; cc -= inc; bp += inc; } #else /* !IBMRTPC */ caplen = cc > snaplen ? snaplen : cc ; if (bpf_filter(fcode, buf.hdr.packet, cc, caplen)) { if (cnt >= 0 && --cnt < 0) goto out; (*printit)(buf.hdr.packet, &tv, cc, caplen); } #endif /* IBMRTPC */ } out: wrapup(if_fd); } /* Call ONLY if read() has returned an error on packet filter */ static void efReadError(int fid, char *msg) { if (errno == EINVAL) { /* read MAXINT bytes already! */ if (lseek(fid, 0, 0) < 0) { perror("tcpdump: efReadError/lseek"); exit(-1); } else return; } else { (void) fprintf(stderr, "tcpdump: "); perror(msg); exit(-1); } } void wrapup(int fd) { #ifdef IBMRTPC struct enstats es; if (ioctl(fd, EIOSTATS, &es) == -1) { perror("tcpdump: enet ioctl EIOSTATS error"); exit(-1); } fprintf(stderr, "%d packets queued", es.enStat_Rcnt); if (es.enStat_Rdrops > 0) fprintf(stderr, ", %d dropped", es.enStat_Rdrops); if (es.enStat_Reads > 0) fprintf(stderr, ", %d tcpdump %s", es.enStat_Reads, es.enStat_Reads > 1 ? "reads" : "read"); if (es.enStat_MaxRead > 1) fprintf(stderr, ", %d packets in largest read", es.enStat_MaxRead); putc('\n', stderr); #endif /* IBMRTPC */ close(fd); } int initdevice(char *device, int pflag, int *linktype) { struct eniocb ctl; struct enfilter filter; u_int maxwaiting; int if_fd; #ifdef IBMRTPC GETENETDEVICE(0, O_RDONLY, &if_fd); #else /* !IBMRTPC */ if_fd = open("/dev/enet", O_RDONLY, 0); #endif /* IBMRTPC */ if (if_fd == -1) { perror("tcpdump: enet open error"); error( "your system may not be properly configured; see \"man enet(4)\""); exit(-1); } /* Get operating parameters. */ if (ioctl(if_fd, EIOCGETP, (char *)&ctl) == -1) { perror("tcpdump: enet ioctl EIOCGETP error"); exit(-1); } /* Set operating parameters. */ #ifdef IBMRTPC ctl.en_rtout = 1 * ctl.en_hz; ctl.en_tr_etherhead = 1; ctl.en_tap_network = 1; ctl.en_multi_packet = 1; ctl.en_maxlen = BUFSPACE; #else /* !IBMRTPC */ ctl.en_rtout = 64; /* randomly picked value for HZ */ #endif /* IBMRTPC */ if (ioctl(if_fd, EIOCSETP, &ctl) == -1) { perror("tcpdump: enet ioctl EIOCSETP error"); exit(-1); } /* Flush the receive queue, since we've changed the operating parameters and we otherwise might receive data without headers. */ if (ioctl(if_fd, EIOCFLUSH) == -1) { perror("tcpdump: enet ioctl EIOCFLUSH error"); exit(-1); } /* Set the receive queue depth to its maximum. */ maxwaiting = ctl.en_maxwaiting; if (ioctl(if_fd, EIOCSETW, &maxwaiting) == -1) { perror("tcpdump: enet ioctl EIOCSETW error"); exit(-1); } #ifdef IBMRTPC /* Clear statistics. */ if (ioctl(if_fd, EIOCLRSTAT, 0) == -1) { perror("tcpdump: enet ioctl EIOCLRSTAT error"); exit(-1); } #endif /* IBMRTPC */ /* Set the filter (accept all packets). */ filter.enf_Priority = 3; filter.enf_FilterLen = 0; if (ioctl(if_fd, EIOCSETF, &filter) == -1) { perror("tcpdump: enet ioctl EIOCSETF error"); exit(-1); } /* * "enetfilter" supports only ethernets. */ *linktype = DLT_EN10MB; return(if_fd); }