-/*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * "Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
- * Reserved. This file contains Original Code and/or Modifications of
- * Original Code as defined in and that are subject to the Apple Public
- * Source License Version 1.0 (the 'License'). You may not use this file
- * except in compliance with the License. Please obtain a copy of the
- * License at http://www.apple.com/publicsource and read it before using
- * this file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License."
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-/* $OpenBSD: gencode.c,v 1.5 1996/09/16 02:33:05 tholo Exp $ */
-
-/*
- * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
- * The Regents of the University of California. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that: (1) source code distributions
- * retain the above copyright notice and this paragraph in its entirety, (2)
- * distributions including binary code include the above copyright notice and
- * this paragraph in its entirety in the documentation or other materials
- * provided with the distribution, and (3) all advertising materials mentioning
- * features or use of this software display the following acknowledgement:
- * ``This product includes software developed by the University of California,
- * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
- * the University nor the names of its contributors may be used to endorse
- * or promote products derived from this software without specific prior
- * written permission.
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
- */
-#ifndef lint
-static char rcsid[] =
- "@(#) Header: gencode.c,v 1.81 96/06/19 23:09:09 leres Exp (LBL)";
-#endif
-
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/time.h>
-
-#if __STDC__
-struct mbuf;
-struct rtentry;
-#endif
-
-#include <net/if.h>
-#include <net/bpf.h>
-
-#include <netinet/in.h>
-#include <netinet/if_ether.h>
-
-#include <stdlib.h>
-#include <memory.h>
-#include <pcap.h>
-#include <pcap-namedb.h>
-#include <setjmp.h>
-#if __STDC__
-#include <stdarg.h>
-#else
-#include <varargs.h>
-#endif
-
-#ifdef HAVE_OS_PROTO_H
-#include "os-proto.h"
-#endif
-
-#include "pcap-int.h"
-
-#include "gencode.h"
-
-#ifndef ETHERTYPE_REVARP
-#define ETHERTYPE_REVARP 0x8035
-#endif
-#ifndef ETHERTYPE_MOPDL
-#define ETHERTYPE_MOPDL 0x6001
-#endif
-#ifndef ETHERTYPE_MOPRC
-#define ETHERTYPE_MOPRC 0x6002
-#endif
-#ifndef ETHERTYPE_DN
-#define ETHERTYPE_DN 0x6003
-#endif
-#ifndef ETHERTYPE_LAT
-#define ETHERTYPE_LAT 0x6004
-#endif
-
-#define JMP(c) ((c)|BPF_JMP|BPF_K)
-
-/* Locals */
-static jmp_buf top_ctx;
-static pcap_t *bpf_pcap;
-
-/* XXX */
-#ifdef PCAP_FDDIPAD
-int pcap_fddipad = PCAP_FDDIPAD;
-#else
-int pcap_fddipad;
-#endif
-#ifndef DLT_ATM_RFC1483
-#define DLT_ATM_RFC1483 11
-#endif
-
-
-/* VARARGS */
-__dead void
-#if __STDC__
-bpf_error(const char *fmt, ...)
-#else
-bpf_error(fmt, va_alist)
- const char *fmt;
- va_dcl
-#endif
-{
- va_list ap;
-
-#if __STDC__
- va_start(ap, fmt);
-#else
- va_start(ap);
-#endif
- if (bpf_pcap != NULL)
- (void)vsprintf(pcap_geterr(bpf_pcap), fmt, ap);
- va_end(ap);
- longjmp(top_ctx, 1);
- /* NOTREACHED */
-}
-
-static void init_linktype(int);
-
-static int alloc_reg(void);
-static void free_reg(int);
-
-static struct block *root;
-
-/*
- * We divy out chunks of memory rather than call malloc each time so
- * we don't have to worry about leaking memory. It's probably
- * not a big deal if all this memory was wasted but it this ever
- * goes into a library that would probably not be a good idea.
- */
-#define NCHUNKS 16
-#define CHUNK0SIZE 1024
-struct chunk {
- u_int n_left;
- void *m;
-};
-
-static struct chunk chunks[NCHUNKS];
-static int cur_chunk;
-
-static void *newchunk(u_int);
-static void freechunks(void);
-static __inline struct block *new_block(int);
-static __inline struct slist *new_stmt(int);
-static struct block *gen_retblk(int);
-static __inline void syntax(void);
-
-static void backpatch(struct block *, struct block *);
-static void merge(struct block *, struct block *);
-static struct block *gen_cmp(u_int, u_int, bpf_int32);
-static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32);
-static struct block *gen_bcmp(u_int, u_int, u_char *);
-static struct block *gen_uncond(int);
-static __inline struct block *gen_true(void);
-static __inline struct block *gen_false(void);
-static struct block *gen_linktype(int);
-static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int);
-static struct block *gen_ehostop(u_char *, int);
-static struct block *gen_fhostop(u_char *, int);
-static struct block *gen_dnhostop(bpf_u_int32, int, u_int);
-static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int);
-static struct block *gen_gateway(u_char *, bpf_u_int32 **, int, int);
-static struct block *gen_ipfrag(void);
-static struct block *gen_portatom(int, bpf_int32);
-struct block *gen_portop(int, int, int);
-static struct block *gen_port(int, int, int);
-static int lookup_proto(char *, int);
-static struct block *gen_proto(int, int, int);
-static bpf_u_int32 net_mask(bpf_u_int32 *);
-static struct slist *xfer_to_x(struct arth *);
-static struct slist *xfer_to_a(struct arth *);
-static struct block *gen_len(int, int);
-
-static void *
-newchunk(n)
- u_int n;
-{
- struct chunk *cp;
- int k, size;
-
- /* XXX Round up to nearest long. */
- n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1);
-
- cp = &chunks[cur_chunk];
- if (n > cp->n_left) {
- ++cp, k = ++cur_chunk;
- if (k >= NCHUNKS)
- bpf_error("out of memory");
- size = CHUNK0SIZE << k;
- cp->m = (void *)malloc(size);
- memset((char *)cp->m, 0, size);
- cp->n_left = size;
- if (n > size)
- bpf_error("out of memory");
- }
- cp->n_left -= n;
- return (void *)((char *)cp->m + cp->n_left);
-}
-
-static void
-freechunks()
-{
- int i;
-
- cur_chunk = 0;
- for (i = 0; i < NCHUNKS; ++i)
- if (chunks[i].m != NULL) {
- free(chunks[i].m);
- chunks[i].m = NULL;
- }
-}
-
-/*
- * A strdup whose allocations are freed after code generation is over.
- */
-char *
-sdup(s)
- char *s;
-{
- int n = strlen(s) + 1;
- char *cp = newchunk(n);
- strcpy(cp, s);
- return (cp);
-}
-
-static __inline struct block *
-new_block(code)
- int code;
-{
- struct block *p;
-
- p = (struct block *)newchunk(sizeof(*p));
- p->s.code = code;
- p->head = p;
-
- return p;
-}
-
-static __inline struct slist *
-new_stmt(code)
- int code;
-{
- struct slist *p;
-
- p = (struct slist *)newchunk(sizeof(*p));
- p->s.code = code;
-
- return p;
-}
-
-static struct block *
-gen_retblk(v)
- int v;
-{
- struct block *b = new_block(BPF_RET|BPF_K);
-
- b->s.k = v;
- return b;
-}
-
-static __inline void
-syntax()
-{
- bpf_error("syntax error in filter expression");
-}
-
-static bpf_u_int32 netmask;
-static int snaplen;
-
-int
-pcap_compile(pcap_t *p, struct bpf_program *program,
- char *buf, int optimize, bpf_u_int32 mask)
-{
- extern int n_errors;
- int len;
-
- n_errors = 0;
- root = NULL;
- bpf_pcap = p;
- if (setjmp(top_ctx)) {
- freechunks();
- return (-1);
- }
-
- netmask = mask;
- snaplen = pcap_snapshot(p);
-
- lex_init(buf ? buf : "");
- init_linktype(pcap_datalink(p));
- (void)pcap_parse();
-
- if (n_errors)
- syntax();
-
- if (root == NULL)
- root = gen_retblk(snaplen);
-
- if (optimize) {
- bpf_optimize(&root);
- if (root == NULL ||
- (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0))
- bpf_error("expression rejects all packets");
- }
- program->bf_insns = icode_to_fcode(root, &len);
- program->bf_len = len;
-
- freechunks();
- return (0);
-}
-
-/*
- * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
- * which of the jt and jf fields has been resolved and which is a pointer
- * back to another unresolved block (or nil). At least one of the fields
- * in each block is already resolved.
- */
-static void
-backpatch(list, target)
- struct block *list, *target;
-{
- struct block *next;
-
- while (list) {
- if (!list->sense) {
- next = JT(list);
- JT(list) = target;
- } else {
- next = JF(list);
- JF(list) = target;
- }
- list = next;
- }
-}
-
-/*
- * Merge the lists in b0 and b1, using the 'sense' field to indicate
- * which of jt and jf is the link.
- */
-static void
-merge(b0, b1)
- struct block *b0, *b1;
-{
- register struct block **p = &b0;
-
- /* Find end of list. */
- while (*p)
- p = !((*p)->sense) ? &JT(*p) : &JF(*p);
-
- /* Concatenate the lists. */
- *p = b1;
-}
-
-void
-finish_parse(p)
- struct block *p;
-{
- backpatch(p, gen_retblk(snaplen));
- p->sense = !p->sense;
- backpatch(p, gen_retblk(0));
- root = p->head;
-}
-
-void
-gen_and(b0, b1)
- struct block *b0, *b1;
-{
- backpatch(b0, b1->head);
- b0->sense = !b0->sense;
- b1->sense = !b1->sense;
- merge(b1, b0);
- b1->sense = !b1->sense;
- b1->head = b0->head;
-}
-
-void
-gen_or(b0, b1)
- struct block *b0, *b1;
-{
- b0->sense = !b0->sense;
- backpatch(b0, b1->head);
- b0->sense = !b0->sense;
- merge(b1, b0);
- b1->head = b0->head;
-}
-
-void
-gen_not(b)
- struct block *b;
-{
- b->sense = !b->sense;
-}
-
-static struct block *
-gen_cmp(offset, size, v)
- u_int offset, size;
- bpf_int32 v;
-{
- struct slist *s;
- struct block *b;
-
- s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = offset;
-
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
- b->s.k = v;
-
- return b;
-}
-
-static struct block *
-gen_mcmp(offset, size, v, mask)
- u_int offset, size;
- bpf_int32 v;
- bpf_u_int32 mask;
-{
- struct block *b = gen_cmp(offset, size, v);
- struct slist *s;
-
- if (mask != 0xffffffff) {
- s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
- s->s.k = mask;
- b->stmts->next = s;
- }
- return b;
-}
-
-static struct block *
-gen_bcmp(offset, size, v)
- u_int offset, size;
- u_char *v;
-{
- struct block *b, *tmp;
-
- b = NULL;
- while (size >= 4) {
- u_char *p = &v[size - 4];
- bpf_int32 w = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
- tmp = gen_cmp(offset + size - 4, BPF_W, w);
- if (b != NULL)
- gen_and(b, tmp);
- b = tmp;
- size -= 4;
- }
- while (size >= 2) {
- u_char *p = &v[size - 2];
- bpf_int32 w = (p[0] << 8) | p[1];
- tmp = gen_cmp(offset + size - 2, BPF_H, w);
- if (b != NULL)
- gen_and(b, tmp);
- b = tmp;
- size -= 2;
- }
- if (size > 0) {
- tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]);
- if (b != NULL)
- gen_and(b, tmp);
- b = tmp;
- }
- return b;
-}
-
-/*
- * Various code constructs need to know the layout of the data link
- * layer. These variables give the necessary offsets. off_linktype
- * is set to -1 for no encapsulation, in which case, IP is assumed.
- */
-static u_int off_linktype;
-static u_int off_nl;
-static int linktype;
-
-static void
-init_linktype(type)
- int type;
-{
- linktype = type;
-
- switch (type) {
-
- case DLT_EN10MB:
- off_linktype = 12;
- off_nl = 14;
- return;
-
- case DLT_SLIP:
- /*
- * SLIP doesn't have a link level type. The 16 byte
- * header is hacked into our SLIP driver.
- */
- off_linktype = -1;
- off_nl = 16;
- return;
-
- case DLT_NULL:
- off_linktype = -1;
- off_nl = 0;
- return;
-
- case DLT_PPP:
- off_linktype = 2;
- off_nl = 4;
- return;
-
- case DLT_FDDI:
- /*
- * FDDI doesn't really have a link-level type field.
- * We assume that SSAP = SNAP is being used and pick
- * out the encapsulated Ethernet type.
- */
- off_linktype = 19;
-#ifdef PCAP_FDDIPAD
- off_linktype += pcap_fddipad;
-#endif
- off_nl = 21;
-#ifdef PCAP_FDDIPAD
- off_nl += pcap_fddipad;
-#endif
- return;
-
- case DLT_IEEE802:
- off_linktype = 20;
- off_nl = 22;
- return;
-
- case DLT_ATM_RFC1483:
- /*
- * assume routed, non-ISO PDUs
- * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
- */
- off_linktype = 6;
- off_nl = 8;
- return;
- }
- bpf_error("unknown data link type 0x%x", linktype);
- /* NOTREACHED */
-}
-
-static struct block *
-gen_uncond(rsense)
- int rsense;
-{
- struct block *b;
- struct slist *s;
-
- s = new_stmt(BPF_LD|BPF_IMM);
- s->s.k = !rsense;
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
-
- return b;
-}
-
-static __inline struct block *
-gen_true()
-{
- return gen_uncond(1);
-}
-
-static __inline struct block *
-gen_false()
-{
- return gen_uncond(0);
-}
-
-static struct block *
-gen_linktype(proto)
- int proto;
-{
- switch (linktype) {
- case DLT_SLIP:
- if (proto == ETHERTYPE_IP)
- return gen_true();
- else
- return gen_false();
-
- case DLT_PPP:
- if (proto == ETHERTYPE_IP)
- proto = 0x0021; /* XXX - need ppp.h defs */
- break;
-
- case DLT_NULL:
- /* XXX */
- if (proto == ETHERTYPE_IP)
- return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET));
- else
- return gen_false();
- }
- return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto);
-}
-
-static struct block *
-gen_hostop(addr, mask, dir, proto, src_off, dst_off)
- bpf_u_int32 addr;
- bpf_u_int32 mask;
- int dir, proto;
- u_int src_off, dst_off;
-{
- struct block *b0, *b1;
- u_int offset;
-
- switch (dir) {
-
- case Q_SRC:
- offset = src_off;
- break;
-
- case Q_DST:
- offset = dst_off;
- break;
-
- case Q_AND:
- b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
- b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
- gen_and(b0, b1);
- return b1;
-
- case Q_OR:
- case Q_DEFAULT:
- b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
- b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
- gen_or(b0, b1);
- return b1;
-
- default:
- abort();
- }
- b0 = gen_linktype(proto);
- b1 = gen_mcmp(offset, BPF_W, (bpf_int32)addr, mask);
- gen_and(b0, b1);
- return b1;
-}
-
-static struct block *
-gen_ehostop(eaddr, dir)
- u_char *eaddr;
- int dir;
-{
- struct block *b0, *b1;
-
- switch (dir) {
- case Q_SRC:
- return gen_bcmp(6, 6, eaddr);
-
- case Q_DST:
- return gen_bcmp(0, 6, eaddr);
-
- case Q_AND:
- b0 = gen_ehostop(eaddr, Q_SRC);
- b1 = gen_ehostop(eaddr, Q_DST);
- gen_and(b0, b1);
- return b1;
-
- case Q_DEFAULT:
- case Q_OR:
- b0 = gen_ehostop(eaddr, Q_SRC);
- b1 = gen_ehostop(eaddr, Q_DST);
- gen_or(b0, b1);
- return b1;
- }
- abort();
- /* NOTREACHED */
-}
-
-/*
- * Like gen_ehostop, but for DLT_FDDI
- */
-static struct block *
-gen_fhostop(eaddr, dir)
- u_char *eaddr;
- int dir;
-{
- struct block *b0, *b1;
-
- switch (dir) {
- case Q_SRC:
-#ifdef PCAP_FDDIPAD
- return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr);
-#else
- return gen_bcmp(6 + 1, 6, eaddr);
-#endif
-
- case Q_DST:
-#ifdef PCAP_FDDIPAD
- return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr);
-#else
- return gen_bcmp(0 + 1, 6, eaddr);
-#endif
-
- case Q_AND:
- b0 = gen_fhostop(eaddr, Q_SRC);
- b1 = gen_fhostop(eaddr, Q_DST);
- gen_and(b0, b1);
- return b1;
-
- case Q_DEFAULT:
- case Q_OR:
- b0 = gen_fhostop(eaddr, Q_SRC);
- b1 = gen_fhostop(eaddr, Q_DST);
- gen_or(b0, b1);
- return b1;
- }
- abort();
- /* NOTREACHED */
-}
-
-/*
- * This is quite tricky because there may be pad bytes in front of the
- * DECNET header, and then there are two possible data packet formats that
- * carry both src and dst addresses, plus 5 packet types in a format that
- * carries only the src node, plus 2 types that use a different format and
- * also carry just the src node.
- *
- * Yuck.
- *
- * Instead of doing those all right, we just look for data packets with
- * 0 or 1 bytes of padding. If you want to look at other packets, that
- * will require a lot more hacking.
- *
- * To add support for filtering on DECNET "areas" (network numbers)
- * one would want to add a "mask" argument to this routine. That would
- * make the filter even more inefficient, although one could be clever
- * and not generate masking instructions if the mask is 0xFFFF.
- */
-static struct block *
-gen_dnhostop(addr, dir, base_off)
- bpf_u_int32 addr;
- int dir;
- u_int base_off;
-{
- struct block *b0, *b1, *b2, *tmp;
- u_int offset_lh; /* offset if long header is received */
- u_int offset_sh; /* offset if short header is received */
-
- switch (dir) {
-
- case Q_DST:
- offset_sh = 1; /* follows flags */
- offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
- break;
-
- case Q_SRC:
- offset_sh = 3; /* follows flags, dstnode */
- offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
- break;
-
- case Q_AND:
- /* Inefficient because we do our Calvinball dance twice */
- b0 = gen_dnhostop(addr, Q_SRC, base_off);
- b1 = gen_dnhostop(addr, Q_DST, base_off);
- gen_and(b0, b1);
- return b1;
-
- case Q_OR:
- case Q_DEFAULT:
- /* Inefficient because we do our Calvinball dance twice */
- b0 = gen_dnhostop(addr, Q_SRC, base_off);
- b1 = gen_dnhostop(addr, Q_DST, base_off);
- gen_or(b0, b1);
- return b1;
-
- default:
- abort();
- }
- b0 = gen_linktype(ETHERTYPE_DN);
- /* Check for pad = 1, long header case */
- tmp = gen_mcmp(base_off + 2, BPF_H,
- (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
- b1 = gen_cmp(base_off + 2 + 1 + offset_lh,
- BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b1);
- /* Check for pad = 0, long header case */
- tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
- b2 = gen_cmp(base_off + 2 + offset_lh, BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b2);
- gen_or(b2, b1);
- /* Check for pad = 1, short header case */
- tmp = gen_mcmp(base_off + 2, BPF_H,
- (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
- b2 = gen_cmp(base_off + 2 + 1 + offset_sh,
- BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b2);
- gen_or(b2, b1);
- /* Check for pad = 0, short header case */
- tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
- b2 = gen_cmp(base_off + 2 + offset_sh, BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b2);
- gen_or(b2, b1);
-
- /* Combine with test for linktype */
- gen_and(b0, b1);
- return b1;
-}
-
-static struct block *
-gen_host(addr, mask, proto, dir)
- bpf_u_int32 addr;
- bpf_u_int32 mask;
- int proto;
- int dir;
-{
- struct block *b0, *b1;
-
- switch (proto) {
-
- case Q_DEFAULT:
- b0 = gen_host(addr, mask, Q_IP, dir);
- b1 = gen_host(addr, mask, Q_ARP, dir);
- gen_or(b0, b1);
- b0 = gen_host(addr, mask, Q_RARP, dir);
- gen_or(b1, b0);
- return b0;
-
- case Q_IP:
- return gen_hostop(addr, mask, dir, ETHERTYPE_IP,
- off_nl + 12, off_nl + 16);
-
- case Q_RARP:
- return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP,
- off_nl + 14, off_nl + 24);
-
- case Q_ARP:
- return gen_hostop(addr, mask, dir, ETHERTYPE_ARP,
- off_nl + 14, off_nl + 24);
-
- case Q_TCP:
- bpf_error("'tcp' modifier applied to host");
-
- case Q_UDP:
- bpf_error("'udp' modifier applied to host");
-
- case Q_ICMP:
- bpf_error("'icmp' modifier applied to host");
-
- case Q_IGMP:
- bpf_error("'igmp' modifier applied to host");
-
- case Q_DECNET:
- return gen_dnhostop(addr, dir, off_nl);
-
- case Q_LAT:
- bpf_error("LAT host filtering not implemented");
-
- case Q_MOPDL:
- bpf_error("MOPDL host filtering not implemented");
-
- case Q_MOPRC:
- bpf_error("MOPRC host filtering not implemented");
-
- default:
- abort();
- }
- /* NOTREACHED */
-}
-
-static struct block *
-gen_gateway(eaddr, alist, proto, dir)
- u_char *eaddr;
- bpf_u_int32 **alist;
- int proto;
- int dir;
-{
- struct block *b0, *b1, *tmp;
-
- if (dir != 0)
- bpf_error("direction applied to 'gateway'");
-
- switch (proto) {
- case Q_DEFAULT:
- case Q_IP:
- case Q_ARP:
- case Q_RARP:
- if (linktype == DLT_EN10MB)
- b0 = gen_ehostop(eaddr, Q_OR);
- else if (linktype == DLT_FDDI)
- b0 = gen_fhostop(eaddr, Q_OR);
- else
- bpf_error(
- "'gateway' supported only on ethernet or FDDI");
-
- b1 = gen_host(**alist++, 0xffffffffL, proto, Q_OR);
- while (*alist) {
- tmp = gen_host(**alist++, 0xffffffffL, proto, Q_OR);
- gen_or(b1, tmp);
- b1 = tmp;
- }
- gen_not(b1);
- gen_and(b0, b1);
- return b1;
- }
- bpf_error("illegal modifier of 'gateway'");
- /* NOTREACHED */
-}
-
-struct block *
-gen_proto_abbrev(proto)
- int proto;
-{
- struct block *b0, *b1;
-
- switch (proto) {
-
- case Q_TCP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)IPPROTO_TCP);
- gen_and(b0, b1);
- break;
-
- case Q_UDP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)IPPROTO_UDP);
- gen_and(b0, b1);
- break;
-
- case Q_ICMP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)IPPROTO_ICMP);
- gen_and(b0, b1);
- break;
-
- case Q_IGMP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)2);
- gen_and(b0, b1);
- break;
-
- case Q_IP:
- b1 = gen_linktype(ETHERTYPE_IP);
- break;
-
- case Q_ARP:
- b1 = gen_linktype(ETHERTYPE_ARP);
- break;
-
- case Q_RARP:
- b1 = gen_linktype(ETHERTYPE_REVARP);
- break;
-
- case Q_LINK:
- bpf_error("link layer applied in wrong context");
-
- case Q_DECNET:
- b1 = gen_linktype(ETHERTYPE_DN);
- break;
-
- case Q_LAT:
- b1 = gen_linktype(ETHERTYPE_LAT);
- break;
-
- case Q_MOPDL:
- b1 = gen_linktype(ETHERTYPE_MOPDL);
- break;
-
- case Q_MOPRC:
- b1 = gen_linktype(ETHERTYPE_MOPRC);
- break;
-
- default:
- abort();
- }
- return b1;
-}
-
-static struct block *
-gen_ipfrag()
-{
- struct slist *s;
- struct block *b;
-
- /* not ip frag */
- s = new_stmt(BPF_LD|BPF_H|BPF_ABS);
- s->s.k = off_nl + 6;
- b = new_block(JMP(BPF_JSET));
- b->s.k = 0x1fff;
- b->stmts = s;
- gen_not(b);
-
- return b;
-}
-
-static struct block *
-gen_portatom(off, v)
- int off;
- bpf_int32 v;
-{
- struct slist *s;
- struct block *b;
-
- s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
- s->s.k = off_nl;
-
- s->next = new_stmt(BPF_LD|BPF_IND|BPF_H);
- s->next->s.k = off_nl + off;
-
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
- b->s.k = v;
-
- return b;
-}
-
-struct block *
-gen_portop(port, proto, dir)
- int port, proto, dir;
-{
- struct block *b0, *b1, *tmp;
-
- /* ip proto 'proto' */
- tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto);
- b0 = gen_ipfrag();
- gen_and(tmp, b0);
-
- switch (dir) {
- case Q_SRC:
- b1 = gen_portatom(0, (bpf_int32)port);
- break;
-
- case Q_DST:
- b1 = gen_portatom(2, (bpf_int32)port);
- break;
-
- case Q_OR:
- case Q_DEFAULT:
- tmp = gen_portatom(0, (bpf_int32)port);
- b1 = gen_portatom(2, (bpf_int32)port);
- gen_or(tmp, b1);
- break;
-
- case Q_AND:
- tmp = gen_portatom(0, (bpf_int32)port);
- b1 = gen_portatom(2, (bpf_int32)port);
- gen_and(tmp, b1);
- break;
-
- default:
- abort();
- }
- gen_and(b0, b1);
-
- return b1;
-}
-
-static struct block *
-gen_port(port, ip_proto, dir)
- int port;
- int ip_proto;
- int dir;
-{
- struct block *b0, *b1, *tmp;
-
- /* ether proto ip */
- b0 = gen_linktype(ETHERTYPE_IP);
-
- switch (ip_proto) {
- case IPPROTO_UDP:
- case IPPROTO_TCP:
- b1 = gen_portop(port, ip_proto, dir);
- break;
-
- case PROTO_UNDEF:
- tmp = gen_portop(port, IPPROTO_TCP, dir);
- b1 = gen_portop(port, IPPROTO_UDP, dir);
- gen_or(tmp, b1);
- break;
-
- default:
- abort();
- }
- gen_and(b0, b1);
- return b1;
-}
-
-static int
-lookup_proto(name, proto)
- char *name;
- int proto;
-{
- int v;
-
- switch (proto) {
- case Q_DEFAULT:
- case Q_IP:
- v = pcap_nametoproto(name);
- if (v == PROTO_UNDEF)
- bpf_error("unknown ip proto '%s'", name);
- break;
-
- case Q_LINK:
- /* XXX should look up h/w protocol type based on linktype */
- v = pcap_nametoeproto(name);
- if (v == PROTO_UNDEF)
- bpf_error("unknown ether proto '%s'", name);
- break;
-
- default:
- v = PROTO_UNDEF;
- break;
- }
- return v;
-}
-
-static struct block *
-gen_proto(v, proto, dir)
- int v;
- int proto;
- int dir;
-{
- struct block *b0, *b1;
-
- if (dir != Q_DEFAULT)
- bpf_error("direction applied to 'proto'");
-
- switch (proto) {
- case Q_DEFAULT:
- case Q_IP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v);
- gen_and(b0, b1);
- return b1;
-
- case Q_ARP:
- bpf_error("arp does not encapsulate another protocol");
- /* NOTREACHED */
-
- case Q_RARP:
- bpf_error("rarp does not encapsulate another protocol");
- /* NOTREACHED */
-
- case Q_DECNET:
- bpf_error("decnet encapsulation is not specifiable");
- /* NOTREACHED */
-
- case Q_LAT:
- bpf_error("lat does not encapsulate another protocol");
- /* NOTREACHED */
-
- case Q_MOPRC:
- bpf_error("moprc does not encapsulate another protocol");
- /* NOTREACHED */
-
- case Q_MOPDL:
- bpf_error("mopdl does not encapsulate another protocol");
- /* NOTREACHED */
-
- case Q_LINK:
- return gen_linktype(v);
-
- case Q_UDP:
- bpf_error("'udp proto' is bogus");
- /* NOTREACHED */
-
- case Q_TCP:
- bpf_error("'tcp proto' is bogus");
- /* NOTREACHED */
-
- case Q_ICMP:
- bpf_error("'icmp proto' is bogus");
- /* NOTREACHED */
-
- case Q_IGMP:
- bpf_error("'igmp proto' is bogus");
- /* NOTREACHED */
-
- default:
- abort();
- /* NOTREACHED */
- }
- /* NOTREACHED */
-}
-
-/*
- * Left justify 'addr' and return its resulting network mask.
- */
-static bpf_u_int32
-net_mask(addr)
- bpf_u_int32 *addr;
-{
- register bpf_u_int32 m = 0xffffffff;
-
- if (*addr)
- while ((*addr & 0xff000000) == 0)
- *addr <<= 8, m <<= 8;
-
- return m;
-}
-
-struct block *
-gen_scode(name, q)
- char *name;
- struct qual q;
-{
- int proto = q.proto;
- int dir = q.dir;
- u_char *eaddr;
- bpf_u_int32 mask, addr, **alist;
- struct block *b, *tmp;
- int port, real_proto;
-
- switch (q.addr) {
-
- case Q_NET:
- addr = pcap_nametonetaddr(name);
- if (addr == 0)
- bpf_error("unknown network '%s'", name);
- mask = net_mask(&addr);
- return gen_host(addr, mask, proto, dir);
-
- case Q_DEFAULT:
- case Q_HOST:
- if (proto == Q_LINK) {
- switch (linktype) {
-
- case DLT_EN10MB:
- eaddr = pcap_ether_hostton(name);
- if (eaddr == NULL)
- bpf_error(
- "unknown ether host '%s'", name);
- return gen_ehostop(eaddr, dir);
-
- case DLT_FDDI:
- eaddr = pcap_ether_hostton(name);
- if (eaddr == NULL)
- bpf_error(
- "unknown FDDI host '%s'", name);
- return gen_fhostop(eaddr, dir);
-
- default:
- bpf_error(
- "only ethernet/FDDI supports link-level host name");
- break;
- }
- } else if (proto == Q_DECNET) {
- unsigned short dn_addr = __pcap_nametodnaddr(name);
- /*
- * I don't think DECNET hosts can be multihomed, so
- * there is no need to build up a list of addresses
- */
- return (gen_host(dn_addr, 0, proto, dir));
- } else {
- alist = pcap_nametoaddr(name);
- if (alist == NULL || *alist == NULL)
- bpf_error("unknown host '%s'", name);
- b = gen_host(**alist++, 0xffffffffL, proto, dir);
- while (*alist) {
- tmp = gen_host(**alist++, 0xffffffffL,
- proto, dir);
- gen_or(b, tmp);
- b = tmp;
- }
- return b;
- }
-
- case Q_PORT:
- if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP)
- bpf_error("illegal qualifier of 'port'");
- if (pcap_nametoport(name, &port, &real_proto) == 0)
- bpf_error("unknown port '%s'", name);
- if (proto == Q_UDP) {
- if (real_proto == IPPROTO_TCP)
- bpf_error("port '%s' is tcp", name);
- else
- /* override PROTO_UNDEF */
- real_proto = IPPROTO_UDP;
- }
- if (proto == Q_TCP) {
- if (real_proto == IPPROTO_UDP)
- bpf_error("port '%s' is udp", name);
- else
- /* override PROTO_UNDEF */
- real_proto = IPPROTO_TCP;
- }
- return gen_port(port, real_proto, dir);
-
- case Q_GATEWAY:
- eaddr = pcap_ether_hostton(name);
- if (eaddr == NULL)
- bpf_error("unknown ether host: %s", name);
-
- alist = pcap_nametoaddr(name);
- if (alist == NULL || *alist == NULL)
- bpf_error("unknown host '%s'", name);
- return gen_gateway(eaddr, alist, proto, dir);
-
- case Q_PROTO:
- real_proto = lookup_proto(name, proto);
- if (real_proto >= 0)
- return gen_proto(real_proto, proto, dir);
- else
- bpf_error("unknown protocol: %s", name);
-
- case Q_UNDEF:
- syntax();
- /* NOTREACHED */
- }
- abort();
- /* NOTREACHED */
-}
-
-struct block *
-gen_ncode(v, q)
- bpf_u_int32 v;
- struct qual q;
-{
- bpf_u_int32 mask;
- int proto = q.proto;
- int dir = q.dir;
-
- switch (q.addr) {
-
- case Q_DEFAULT:
- case Q_HOST:
- case Q_NET:
- if (proto == Q_DECNET)
- return gen_host(v, 0, proto, dir);
- else if (proto == Q_LINK) {
- bpf_error("illegal link layer address");
- } else {
- mask = net_mask(&v);
- return gen_host(v, mask, proto, dir);
- }
-
- case Q_PORT:
- if (proto == Q_UDP)
- proto = IPPROTO_UDP;
- else if (proto == Q_TCP)
- proto = IPPROTO_TCP;
- else if (proto == Q_DEFAULT)
- proto = PROTO_UNDEF;
- else
- bpf_error("illegal qualifier of 'port'");
-
- return gen_port((int)v, proto, dir);
-
- case Q_GATEWAY:
- bpf_error("'gateway' requires a name");
- /* NOTREACHED */
-
- case Q_PROTO:
- return gen_proto((int)v, proto, dir);
-
- case Q_UNDEF:
- syntax();
- /* NOTREACHED */
-
- default:
- abort();
- /* NOTREACHED */
- }
- /* NOTREACHED */
-}
-
-struct block *
-gen_ecode(eaddr, q)
- u_char *eaddr;
- struct qual q;
-{
- if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
- if (linktype == DLT_EN10MB)
- return gen_ehostop(eaddr, (int)q.dir);
- if (linktype == DLT_FDDI)
- return gen_fhostop(eaddr, (int)q.dir);
- }
- bpf_error("ethernet address used in non-ether expression");
- /* NOTREACHED */
-}
-
-void
-sappend(s0, s1)
- struct slist *s0, *s1;
-{
- /*
- * This is definitely not the best way to do this, but the
- * lists will rarely get long.
- */
- while (s0->next)
- s0 = s0->next;
- s0->next = s1;
-}
-
-static struct slist *
-xfer_to_x(a)
- struct arth *a;
-{
- struct slist *s;
-
- s = new_stmt(BPF_LDX|BPF_MEM);
- s->s.k = a->regno;
- return s;
-}
-
-static struct slist *
-xfer_to_a(a)
- struct arth *a;
-{
- struct slist *s;
-
- s = new_stmt(BPF_LD|BPF_MEM);
- s->s.k = a->regno;
- return s;
-}
-
-struct arth *
-gen_load(proto, index, size)
- int proto;
- struct arth *index;
- int size;
-{
- struct slist *s, *tmp;
- struct block *b;
- int regno = alloc_reg();
-
- free_reg(index->regno);
- switch (size) {
-
- default:
- bpf_error("data size must be 1, 2, or 4");
-
- case 1:
- size = BPF_B;
- break;
-
- case 2:
- size = BPF_H;
- break;
-
- case 4:
- size = BPF_W;
- break;
- }
- switch (proto) {
- default:
- bpf_error("unsupported index operation");
-
- case Q_LINK:
- s = xfer_to_x(index);
- tmp = new_stmt(BPF_LD|BPF_IND|size);
- sappend(s, tmp);
- sappend(index->s, s);
- break;
-
- case Q_IP:
- case Q_ARP:
- case Q_RARP:
- case Q_DECNET:
- case Q_LAT:
- case Q_MOPRC:
- case Q_MOPDL:
- /* XXX Note that we assume a fixed link link header here. */
- s = xfer_to_x(index);
- tmp = new_stmt(BPF_LD|BPF_IND|size);
- tmp->s.k = off_nl;
- sappend(s, tmp);
- sappend(index->s, s);
-
- b = gen_proto_abbrev(proto);
- if (index->b)
- gen_and(index->b, b);
- index->b = b;
- break;
-
- case Q_TCP:
- case Q_UDP:
- case Q_ICMP:
- case Q_IGMP:
- s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
- s->s.k = off_nl;
- sappend(s, xfer_to_a(index));
- sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
- sappend(s, new_stmt(BPF_MISC|BPF_TAX));
- sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size));
- tmp->s.k = off_nl;
- sappend(index->s, s);
-
- gen_and(gen_proto_abbrev(proto), b = gen_ipfrag());
- if (index->b)
- gen_and(index->b, b);
- index->b = b;
- break;
- }
- index->regno = regno;
- s = new_stmt(BPF_ST);
- s->s.k = regno;
- sappend(index->s, s);
-
- return index;
-}
-
-struct block *
-gen_relation(code, a0, a1, reversed)
- int code;
- struct arth *a0, *a1;
- int reversed;
-{
- struct slist *s0, *s1, *s2;
- struct block *b, *tmp;
-
- s0 = xfer_to_x(a1);
- s1 = xfer_to_a(a0);
- s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X);
- b = new_block(JMP(code));
- if (code == BPF_JGT || code == BPF_JGE) {
- reversed = !reversed;
- b->s.k = 0x80000000;
- }
- if (reversed)
- gen_not(b);
-
- sappend(s1, s2);
- sappend(s0, s1);
- sappend(a1->s, s0);
- sappend(a0->s, a1->s);
-
- b->stmts = a0->s;
-
- free_reg(a0->regno);
- free_reg(a1->regno);
-
- /* 'and' together protocol checks */
- if (a0->b) {
- if (a1->b) {
- gen_and(a0->b, tmp = a1->b);
- }
- else
- tmp = a0->b;
- } else
- tmp = a1->b;
-
- if (tmp)
- gen_and(tmp, b);
-
- return b;
-}
-
-struct arth *
-gen_loadlen()
-{
- int regno = alloc_reg();
- struct arth *a = (struct arth *)newchunk(sizeof(*a));
- struct slist *s;
-
- s = new_stmt(BPF_LD|BPF_LEN);
- s->next = new_stmt(BPF_ST);
- s->next->s.k = regno;
- a->s = s;
- a->regno = regno;
-
- return a;
-}
-
-struct arth *
-gen_loadi(val)
- int val;
-{
- struct arth *a;
- struct slist *s;
- int reg;
-
- a = (struct arth *)newchunk(sizeof(*a));
-
- reg = alloc_reg();
-
- s = new_stmt(BPF_LD|BPF_IMM);
- s->s.k = val;
- s->next = new_stmt(BPF_ST);
- s->next->s.k = reg;
- a->s = s;
- a->regno = reg;
-
- return a;
-}
-
-struct arth *
-gen_neg(a)
- struct arth *a;
-{
- struct slist *s;
-
- s = xfer_to_a(a);
- sappend(a->s, s);
- s = new_stmt(BPF_ALU|BPF_NEG);
- s->s.k = 0;
- sappend(a->s, s);
- s = new_stmt(BPF_ST);
- s->s.k = a->regno;
- sappend(a->s, s);
-
- return a;
-}
-
-struct arth *
-gen_arth(code, a0, a1)
- int code;
- struct arth *a0, *a1;
-{
- struct slist *s0, *s1, *s2;
-
- s0 = xfer_to_x(a1);
- s1 = xfer_to_a(a0);
- s2 = new_stmt(BPF_ALU|BPF_X|code);
-
- sappend(s1, s2);
- sappend(s0, s1);
- sappend(a1->s, s0);
- sappend(a0->s, a1->s);
-
- free_reg(a1->regno);
-
- s0 = new_stmt(BPF_ST);
- a0->regno = s0->s.k = alloc_reg();
- sappend(a0->s, s0);
-
- return a0;
-}
-
-/*
- * Here we handle simple allocation of the scratch registers.
- * If too many registers are alloc'd, the allocator punts.
- */
-static int regused[BPF_MEMWORDS];
-static int curreg;
-
-/*
- * Return the next free register.
- */
-static int
-alloc_reg()
-{
- int n = BPF_MEMWORDS;
-
- while (--n >= 0) {
- if (regused[curreg])
- curreg = (curreg + 1) % BPF_MEMWORDS;
- else {
- regused[curreg] = 1;
- return curreg;
- }
- }
- bpf_error("too many registers needed to evaluate expression");
- /* NOTREACHED */
-}
-
-/*
- * Return a register to the table so it can
- * be used later.
- */
-static void
-free_reg(n)
- int n;
-{
- regused[n] = 0;
-}
-
-static struct block *
-gen_len(jmp, n)
- int jmp, n;
-{
- struct slist *s;
- struct block *b;
-
- s = new_stmt(BPF_LD|BPF_LEN);
- b = new_block(JMP(jmp));
- b->stmts = s;
- b->s.k = n;
-
- return b;
-}
-
-struct block *
-gen_greater(n)
- int n;
-{
- return gen_len(BPF_JGE, n);
-}
-
-struct block *
-gen_less(n)
- int n;
-{
- struct block *b;
-
- b = gen_len(BPF_JGT, n);
- gen_not(b);
-
- return b;
-}
-
-struct block *
-gen_byteop(op, idx, val)
- int op, idx, val;
-{
- struct block *b;
- struct slist *s;
-
- switch (op) {
- default:
- abort();
-
- case '=':
- return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val);
-
- case '<':
- b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val);
- b->s.code = JMP(BPF_JGE);
- gen_not(b);
- return b;
-
- case '>':
- b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val);
- b->s.code = JMP(BPF_JGT);
- return b;
-
- case '|':
- s = new_stmt(BPF_ALU|BPF_OR|BPF_K);
- break;
-
- case '&':
- s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
- break;
- }
- s->s.k = val;
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
- gen_not(b);
-
- return b;
-}
-
-struct block *
-gen_broadcast(proto)
- int proto;
-{
- bpf_u_int32 hostmask;
- struct block *b0, *b1, *b2;
- static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
-
- switch (proto) {
-
- case Q_DEFAULT:
- case Q_LINK:
- if (linktype == DLT_EN10MB)
- return gen_ehostop(ebroadcast, Q_DST);
- if (linktype == DLT_FDDI)
- return gen_fhostop(ebroadcast, Q_DST);
- bpf_error("not a broadcast link");
- break;
-
- case Q_IP:
- b0 = gen_linktype(ETHERTYPE_IP);
- hostmask = ~netmask;
- b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask);
- b2 = gen_mcmp(off_nl + 16, BPF_W,
- (bpf_int32)(~0 & hostmask), hostmask);
- gen_or(b1, b2);
- gen_and(b0, b2);
- return b2;
- }
- bpf_error("only ether/ip broadcast filters supported");
-}
-
-struct block *
-gen_multicast(proto)
- int proto;
-{
- register struct block *b0, *b1;
- register struct slist *s;
-
- switch (proto) {
-
- case Q_DEFAULT:
- case Q_LINK:
- if (linktype == DLT_EN10MB) {
- /* ether[0] & 1 != 0 */
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 1;
- b0->stmts = s;
- return b0;
- }
-
- if (linktype == DLT_FDDI) {
- /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */
- /* fddi[1] & 1 != 0 */
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 1;
- b0->stmts = s;
- return b0;
- }
- /* Link not known to support multicasts */
- break;
-
- case Q_IP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224);
- b1->s.code = JMP(BPF_JGE);
- gen_and(b0, b1);
- return b1;
- }
- bpf_error("only IP multicast filters supported on ethernet/FDDI");
-}
-
-/*
- * generate command for inbound/outbound. It's here so we can
- * make it link-type specific. 'dir' = 0 implies "inbound",
- * = 1 implies "outbound".
- */
-struct block *
-gen_inbound(dir)
- int dir;
-{
- register struct block *b0;
-
- b0 = gen_relation(BPF_JEQ,
- gen_load(Q_LINK, gen_loadi(0), 1),
- gen_loadi(0),
- dir);
- return (b0);
-}
projects / apple / network_cmds.git / blobdiff