+++ /dev/null
-/* $Id: bpf_filter.c,v 1.1 1996/04/04 04:22:23 paulus Exp $ */
-/* From: NetBSD: bpf_filter.c,v 1.11 1995/04/22 13:26:39 cgd Exp $ */
-
-/*
- * Copyright (c) 1990, 1991, 1992, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * This code is derived from the Stanford/CMU enet packet filter,
- * (net/enet.c) distributed as part of 4.3BSD, and code contributed
- * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
- * Berkeley Laboratory.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * @(#)bpf_filter.c 8.1 (Berkeley) 6/10/93
- */
-
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/time.h>
-#include <net/ppp_defs.h>
-
-#if !defined(i386) && !defined(m68k)
-#define BPF_ALIGN
-#endif
-
-/* XXX we assume ints are 32 bits, shorts are 16 bits. */
-
-#ifndef BPF_ALIGN
-#define EXTRACT_SHORT(p) ((unsigned short)ntohs(*(unsigned short *)p))
-#define EXTRACT_LONG(p) (ntohl(*(u_int32_t *)p))
-#else
-#define EXTRACT_SHORT(p)\
- ((unsigned short)\
- ((unsigned short)*((u_char *)p+0)<<8|\
- (unsigned short)*((u_char *)p+1)<<0))
-#define EXTRACT_LONG(p)\
- ((u_int32_t)*((u_char *)p+0)<<24|\
- (u_int32_t)*((u_char *)p+1)<<16|\
- (u_int32_t)*((u_char *)p+2)<<8|\
- (u_int32_t)*((u_char *)p+3)<<0)
-#endif
-
-#include <net/bpf.h>
-
-/*
- * Execute the filter program starting at pc on the packet p
- * wirelen is the length of the original packet
- * buflen is the amount of data present
- */
-u_int
-bpf_filter(pc, p, wirelen, buflen)
- register struct bpf_insn *pc;
- register u_char *p;
- u_int wirelen;
- register u_int buflen;
-{
- register u_int32_t A, X;
- register int k;
- int mem[BPF_MEMWORDS];
-
- if (pc == 0)
- /*
- * No filter means accept all.
- */
- return (u_int)-1;
-#ifdef lint
- A = 0;
- X = 0;
-#endif
- --pc;
- while (1) {
- ++pc;
- switch (pc->code) {
-
- default:
- return 0; /* gak! */
-
- case BPF_RET|BPF_K:
- return (u_int)pc->k;
-
- case BPF_RET|BPF_A:
- return (u_int)A;
-
- case BPF_LD|BPF_W|BPF_ABS:
- k = pc->k;
- if (k + sizeof(int) > buflen) {
- return 0;
- }
- A = EXTRACT_LONG(&p[k]);
- continue;
-
- case BPF_LD|BPF_H|BPF_ABS:
- k = pc->k;
- if (k + sizeof(short int) > buflen) {
- return 0;
- }
- A = EXTRACT_SHORT(&p[k]);
- continue;
-
- case BPF_LD|BPF_B|BPF_ABS:
- k = pc->k;
- if (k >= buflen) {
- return 0;
- }
- A = p[k];
- continue;
-
- case BPF_LD|BPF_W|BPF_LEN:
- A = wirelen;
- continue;
-
- case BPF_LDX|BPF_W|BPF_LEN:
- X = wirelen;
- continue;
-
- case BPF_LD|BPF_W|BPF_IND:
- k = X + pc->k;
- if (k + sizeof(int) > buflen) {
- return 0;
- }
- A = EXTRACT_LONG(&p[k]);
- continue;
-
- case BPF_LD|BPF_H|BPF_IND:
- k = X + pc->k;
- if (k + sizeof(short int) > buflen) {
- return 0;
- }
- A = EXTRACT_SHORT(&p[k]);
- continue;
-
- case BPF_LD|BPF_B|BPF_IND:
- k = X + pc->k;
- if (k >= buflen) {
- return 0;
- }
- A = p[k];
- continue;
-
- case BPF_LDX|BPF_MSH|BPF_B:
- k = pc->k;
- if (k >= buflen) {
- return 0;
- }
- X = (p[pc->k] & 0xf) << 2;
- continue;
-
- case BPF_LD|BPF_IMM:
- A = pc->k;
- continue;
-
- case BPF_LDX|BPF_IMM:
- X = pc->k;
- continue;
-
- case BPF_LD|BPF_MEM:
- A = mem[pc->k];
- continue;
-
- case BPF_LDX|BPF_MEM:
- X = mem[pc->k];
- continue;
-
- case BPF_ST:
- mem[pc->k] = A;
- continue;
-
- case BPF_STX:
- mem[pc->k] = X;
- continue;
-
- case BPF_JMP|BPF_JA:
- pc += pc->k;
- continue;
-
- case BPF_JMP|BPF_JGT|BPF_K:
- pc += (A > pc->k) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JGE|BPF_K:
- pc += (A >= pc->k) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JEQ|BPF_K:
- pc += (A == pc->k) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JSET|BPF_K:
- pc += (A & pc->k) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JGT|BPF_X:
- pc += (A > X) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JGE|BPF_X:
- pc += (A >= X) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JEQ|BPF_X:
- pc += (A == X) ? pc->jt : pc->jf;
- continue;
-
- case BPF_JMP|BPF_JSET|BPF_X:
- pc += (A & X) ? pc->jt : pc->jf;
- continue;
-
- case BPF_ALU|BPF_ADD|BPF_X:
- A += X;
- continue;
-
- case BPF_ALU|BPF_SUB|BPF_X:
- A -= X;
- continue;
-
- case BPF_ALU|BPF_MUL|BPF_X:
- A *= X;
- continue;
-
- case BPF_ALU|BPF_DIV|BPF_X:
- if (X == 0)
- return 0;
- A /= X;
- continue;
-
- case BPF_ALU|BPF_AND|BPF_X:
- A &= X;
- continue;
-
- case BPF_ALU|BPF_OR|BPF_X:
- A |= X;
- continue;
-
- case BPF_ALU|BPF_LSH|BPF_X:
- A <<= X;
- continue;
-
- case BPF_ALU|BPF_RSH|BPF_X:
- A >>= X;
- continue;
-
- case BPF_ALU|BPF_ADD|BPF_K:
- A += pc->k;
- continue;
-
- case BPF_ALU|BPF_SUB|BPF_K:
- A -= pc->k;
- continue;
-
- case BPF_ALU|BPF_MUL|BPF_K:
- A *= pc->k;
- continue;
-
- case BPF_ALU|BPF_DIV|BPF_K:
- A /= pc->k;
- continue;
-
- case BPF_ALU|BPF_AND|BPF_K:
- A &= pc->k;
- continue;
-
- case BPF_ALU|BPF_OR|BPF_K:
- A |= pc->k;
- continue;
-
- case BPF_ALU|BPF_LSH|BPF_K:
- A <<= pc->k;
- continue;
-
- case BPF_ALU|BPF_RSH|BPF_K:
- A >>= pc->k;
- continue;
-
- case BPF_ALU|BPF_NEG:
- A = -A;
- continue;
-
- case BPF_MISC|BPF_TAX:
- X = A;
- continue;
-
- case BPF_MISC|BPF_TXA:
- A = X;
- continue;
- }
- }
-}
projects / ppp.git / blobdiff