/* $NetBSD: sbpf.c,v 1.1.1.1 2012/03/23 21:20:06 christos Exp $ */ /* * (C)opyright 1995-1998 Darren Reed. (from tcplog) * * See the IPFILTER.LICENCE file for details on licencing. * */ #include #include #include #include #include #ifdef __NetBSD__ # include #endif #include #include #include #include #include #include #include #include #if BSD < 199103 #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include "ip_compat.h" #ifndef lint static char sbpf[] = "@(#)sbpf.c 1.2 12/3/95 (C)1995 Darren Reed"; #endif /* (000) ldh [12] (001) jeq #0x800 jt 2 jf 5 (002) ldb [23] (003) jeq #0x6 jt 4 jf 5 (004) ret #68 (005) ret #0 */ struct bpf_insn filter[] = { /* 0. */ { BPF_LD|BPF_H|BPF_ABS, 0, 0, 12 }, /* 1. */ { BPF_JMP|BPF_JEQ, 0, 3, 0x0800 }, /* 2. */ { BPF_LD|BPF_B|BPF_ABS, 0, 0, 23 }, /* 3. */ { BPF_JMP|BPF_JEQ, 0, 1, 0x06 }, /* 4. */ { BPF_RET, 0, 0, 68 }, /* 5. */ { BPF_RET, 0, 0, 0 } }; /* * the code herein is dervied from libpcap. */ static u_char *buf = NULL; static u_int bufsize = 32768, timeout = 1; int ack_recv(ep) char *ep; { struct tcpiphdr tip; tcphdr_t *tcp; ip_t *ip; ip = (ip_t *)&tip; tcp = (tcphdr_t *)(ip + 1); bcopy(ep + 14, (char *)ip, sizeof(*ip)); bcopy(ep + 14 + (ip->ip_hl << 2), (char *)tcp, sizeof(*tcp)); if (ip->ip_p != IPPROTO_TCP && ip->ip_p != IPPROTO_UDP) return -1; if (ip->ip_p & 0x1fff != 0) return 0; if (0 == detect(ip, tcp)) return 1; return 0; } int readloop(fd, port, dst) int fd, port; struct in_addr dst; { register u_char *bp, *cp, *bufend; register struct bpf_hdr *bh; register int cc; time_t in = time(NULL); int done = 0; while ((cc = read(fd, buf, bufsize)) >= 0) { if (!cc && (time(NULL) - in) > timeout) return done; bp = buf; bufend = buf + cc; /* * loop through each snapshot in the chunk */ while (bp < bufend) { bh = (struct bpf_hdr *)bp; cp = bp + bh->bh_hdrlen; done += ack_recv(cp); bp += BPF_WORDALIGN(bh->bh_caplen + bh->bh_hdrlen); } return done; } perror("read"); exit(-1); } int initdevice(device, tout) char *device; int tout; { struct bpf_program prog; struct bpf_version bv; struct timeval to; struct ifreq ifr; #ifdef _PATH_BPF char *bpfname = _PATH_BPF; int fd; if ((fd = open(bpfname, O_RDWR)) < 0) { fprintf(stderr, "no bpf devices available as /dev/bpfxx\n"); return -1; } #else char bpfname[16]; int fd = -1, i; for (i = 0; i < 16; i++) { (void) sprintf(bpfname, "/dev/bpf%d", i); if ((fd = open(bpfname, O_RDWR)) >= 0) break; } if (i == 16) { fprintf(stderr, "no bpf devices available as /dev/bpfxx\n"); return -1; } #endif if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { perror("BIOCVERSION"); return -1; } if (bv.bv_major != BPF_MAJOR_VERSION || bv.bv_minor < BPF_MINOR_VERSION) { fprintf(stderr, "kernel bpf (v%d.%d) filter out of date:\n", bv.bv_major, bv.bv_minor); fprintf(stderr, "current version: %d.%d\n", BPF_MAJOR_VERSION, BPF_MINOR_VERSION); return -1; } (void) strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); if (ioctl(fd, BIOCSETIF, &ifr) == -1) { fprintf(stderr, "%s(%d):", ifr.ifr_name, fd); perror("BIOCSETIF"); exit(1); } /* * set the timeout */ timeout = tout; to.tv_sec = 1; to.tv_usec = 0; if (ioctl(fd, BIOCSRTIMEOUT, (caddr_t)&to) == -1) { perror("BIOCSRTIMEOUT"); exit(-1); } /* * get kernel buffer size */ if (ioctl(fd, BIOCSBLEN, &bufsize) == -1) perror("BIOCSBLEN"); if (ioctl(fd, BIOCGBLEN, &bufsize) == -1) { perror("BIOCGBLEN"); exit(-1); } printf("BPF buffer size: %d\n", bufsize); buf = (u_char*)malloc(bufsize); prog.bf_len = sizeof(filter) / sizeof(struct bpf_insn); prog.bf_insns = filter; if (ioctl(fd, BIOCSETF, (caddr_t)&prog) == -1) { perror("BIOCSETF"); exit(-1); } (void) ioctl(fd, BIOCFLUSH, 0); return fd; }