diff options
Diffstat (limited to 'package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net')
| -rw-r--r-- | package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf.h | 264 | ||||
| -rw-r--r-- | package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf_filter.c | 532 |
2 files changed, 796 insertions, 0 deletions
diff --git a/package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf.h b/package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf.h new file mode 100644 index 000000000..9ff7ab704 --- /dev/null +++ b/package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf.h @@ -0,0 +1,264 @@ +/*- + * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 + * 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.h 7.1 (Berkeley) 5/7/91 + * + * @(#) $Header: /usr/local/cvs/linux/tools/build/e100boot/libpcap-0.4/bpf/net/bpf.h,v 1.1 1999/08/26 10:07:57 johana Exp $ (LBL) + */ + +#ifndef BPF_MAJOR_VERSION + +/* BSD style release date */ +#define BPF_RELEASE 199606 + +typedef int bpf_int32; +typedef u_int bpf_u_int32; + +/* + * Alignment macros. BPF_WORDALIGN rounds up to the next + * even multiple of BPF_ALIGNMENT. + */ +#define BPF_ALIGNMENT sizeof(bpf_int32) +#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) + +#define BPF_MAXINSNS 512 +#define BPF_MAXBUFSIZE 0x8000 +#define BPF_MINBUFSIZE 32 + +/* + * Structure for BIOCSETF. + */ +struct bpf_program { + u_int bf_len; + struct bpf_insn *bf_insns; +}; + +/* + * Struct returned by BIOCGSTATS. + */ +struct bpf_stat { + u_int bs_recv; /* number of packets received */ + u_int bs_drop; /* number of packets dropped */ +}; + +/* + * Struct return by BIOCVERSION. This represents the version number of + * the filter language described by the instruction encodings below. + * bpf understands a program iff kernel_major == filter_major && + * kernel_minor >= filter_minor, that is, if the value returned by the + * running kernel has the same major number and a minor number equal + * equal to or less than the filter being downloaded. Otherwise, the + * results are undefined, meaning an error may be returned or packets + * may be accepted haphazardly. + * It has nothing to do with the source code version. + */ +struct bpf_version { + u_short bv_major; + u_short bv_minor; +}; +/* Current version number of filter architecture. */ +#define BPF_MAJOR_VERSION 1 +#define BPF_MINOR_VERSION 1 + +/* + * BPF ioctls + * + * The first set is for compatibility with Sun's pcc style + * header files. If your using gcc, we assume that you + * have run fixincludes so the latter set should work. + */ +#if (defined(sun) || defined(ibm032)) && !defined(__GNUC__) +#define BIOCGBLEN _IOR(B,102, u_int) +#define BIOCSBLEN _IOWR(B,102, u_int) +#define BIOCSETF _IOW(B,103, struct bpf_program) +#define BIOCFLUSH _IO(B,104) +#define BIOCPROMISC _IO(B,105) +#define BIOCGDLT _IOR(B,106, u_int) +#define BIOCGETIF _IOR(B,107, struct ifreq) +#define BIOCSETIF _IOW(B,108, struct ifreq) +#define BIOCSRTIMEOUT _IOW(B,109, struct timeval) +#define BIOCGRTIMEOUT _IOR(B,110, struct timeval) +#define BIOCGSTATS _IOR(B,111, struct bpf_stat) +#define BIOCIMMEDIATE _IOW(B,112, u_int) +#define BIOCVERSION _IOR(B,113, struct bpf_version) +#define BIOCSTCPF _IOW(B,114, struct bpf_program) +#define BIOCSUDPF _IOW(B,115, struct bpf_program) +#else +#define BIOCGBLEN _IOR('B',102, u_int) +#define BIOCSBLEN _IOWR('B',102, u_int) +#define BIOCSETF _IOW('B',103, struct bpf_program) +#define BIOCFLUSH _IO('B',104) +#define BIOCPROMISC _IO('B',105) +#define BIOCGDLT _IOR('B',106, u_int) +#define BIOCGETIF _IOR('B',107, struct ifreq) +#define BIOCSETIF _IOW('B',108, struct ifreq) +#define BIOCSRTIMEOUT _IOW('B',109, struct timeval) +#define BIOCGRTIMEOUT _IOR('B',110, struct timeval) +#define BIOCGSTATS _IOR('B',111, struct bpf_stat) +#define BIOCIMMEDIATE _IOW('B',112, u_int) +#define BIOCVERSION _IOR('B',113, struct bpf_version) +#define BIOCSTCPF _IOW('B',114, struct bpf_program) +#define BIOCSUDPF _IOW('B',115, struct bpf_program) +#endif + +/* + * Structure prepended to each packet. + */ +struct bpf_hdr { + struct timeval bh_tstamp; /* time stamp */ + bpf_u_int32 bh_caplen; /* length of captured portion */ + bpf_u_int32 bh_datalen; /* original length of packet */ + u_short bh_hdrlen; /* length of bpf header (this struct + plus alignment padding) */ +}; +/* + * Because the structure above is not a multiple of 4 bytes, some compilers + * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work. + * Only the kernel needs to know about it; applications use bh_hdrlen. + */ +#ifdef KERNEL +#define SIZEOF_BPF_HDR 18 +#endif + +/* + * Data-link level type codes. + */ +#define DLT_NULL 0 /* no link-layer encapsulation */ +#define DLT_EN10MB 1 /* Ethernet (10Mb) */ +#define DLT_EN3MB 2 /* Experimental Ethernet (3Mb) */ +#define DLT_AX25 3 /* Amateur Radio AX.25 */ +#define DLT_PRONET 4 /* Proteon ProNET Token Ring */ +#define DLT_CHAOS 5 /* Chaos */ +#define DLT_IEEE802 6 /* IEEE 802 Networks */ +#define DLT_ARCNET 7 /* ARCNET */ +#define DLT_SLIP 8 /* Serial Line IP */ +#define DLT_PPP 9 /* Point-to-point Protocol */ +#define DLT_FDDI 10 /* FDDI */ +#define DLT_ATM_RFC1483 11 /* LLC/SNAP encapsulated atm */ +#define DLT_RAW 12 /* raw IP */ +#define DLT_SLIP_BSDOS 13 /* BSD/OS Serial Line IP */ +#define DLT_PPP_BSDOS 14 /* BSD/OS Point-to-point Protocol */ + +/* + * The instruction encondings. + */ +/* instruction classes */ +#define BPF_CLASS(code) ((code) & 0x07) +#define BPF_LD 0x00 +#define BPF_LDX 0x01 +#define BPF_ST 0x02 +#define BPF_STX 0x03 +#define BPF_ALU 0x04 +#define BPF_JMP 0x05 +#define BPF_RET 0x06 +#define BPF_MISC 0x07 + +/* ld/ldx fields */ +#define BPF_SIZE(code) ((code) & 0x18) +#define BPF_W 0x00 +#define BPF_H 0x08 +#define BPF_B 0x10 +#define BPF_MODE(code) ((code) & 0xe0) +#define BPF_IMM 0x00 +#define BPF_ABS 0x20 +#define BPF_IND 0x40 +#define BPF_MEM 0x60 +#define BPF_LEN 0x80 +#define BPF_MSH 0xa0 + +/* alu/jmp fields */ +#define BPF_OP(code) ((code) & 0xf0) +#define BPF_ADD 0x00 +#define BPF_SUB 0x10 +#define BPF_MUL 0x20 +#define BPF_DIV 0x30 +#define BPF_OR 0x40 +#define BPF_AND 0x50 +#define BPF_LSH 0x60 +#define BPF_RSH 0x70 +#define BPF_NEG 0x80 +#define BPF_JA 0x00 +#define BPF_JEQ 0x10 +#define BPF_JGT 0x20 +#define BPF_JGE 0x30 +#define BPF_JSET 0x40 +#define BPF_SRC(code) ((code) & 0x08) +#define BPF_K 0x00 +#define BPF_X 0x08 + +/* ret - BPF_K and BPF_X also apply */ +#define BPF_RVAL(code) ((code) & 0x18) +#define BPF_A 0x10 + +/* misc */ +#define BPF_MISCOP(code) ((code) & 0xf8) +#define BPF_TAX 0x00 +#define BPF_TXA 0x80 + +/* + * The instruction data structure. + */ +struct bpf_insn { + u_short code; + u_char jt; + u_char jf; + bpf_int32 k; +}; + +/* + * Macros for insn array initializers. + */ +#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } +#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } + +#ifdef KERNEL +extern u_int bpf_filter(); +extern void bpfattach(); +extern void bpf_tap(); +extern void bpf_mtap(); +#else +#if __STDC__ +extern u_int bpf_filter(struct bpf_insn *, u_char *, u_int, u_int); +#endif +#endif + +/* + * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). + */ +#define BPF_MEMWORDS 16 + +#endif diff --git a/package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf_filter.c b/package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf_filter.c new file mode 100644 index 000000000..d3dcc689a --- /dev/null +++ b/package/etrax-tools/src/e100boot/libpcap-0.4/bpf/net/bpf_filter.c @@ -0,0 +1,532 @@ +/*- + * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 + * 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.c 7.5 (Berkeley) 7/15/91 + */ + +#if !(defined(lint) || defined(KERNEL)) +static const char rcsid[] = + "@(#) $Header: /usr/local/cvs/linux/tools/build/e100boot/libpcap-0.4/bpf/net/bpf_filter.c,v 1.1 1999/08/26 10:07:57 johana Exp $ (LBL)"; +#endif + +#include <sys/param.h> +#include <sys/types.h> +#include <sys/time.h> +#include <net/bpf.h> + +#ifndef KERNEL +#include <stdlib.h> +#endif + +#define int32 bpf_int32 +#define u_int32 bpf_u_int32 + +#ifndef LBL_ALIGN +#if defined(sparc) || defined(mips) || defined(ibm032) || \ + defined(__alpha) || defined(__hpux) +#define LBL_ALIGN +#endif +#endif + +#ifndef LBL_ALIGN +#include <netinet/in.h> + +#define EXTRACT_SHORT(p) ((u_short)ntohs(*(u_short *)p)) +#define EXTRACT_LONG(p) (ntohl(*(u_int32 *)p)) +#else +#define EXTRACT_SHORT(p)\ + ((u_short)\ + ((u_short)*((u_char *)p+0)<<8|\ + (u_short)*((u_char *)p+1)<<0)) +#define EXTRACT_LONG(p)\ + ((u_int32)*((u_char *)p+0)<<24|\ + (u_int32)*((u_char *)p+1)<<16|\ + (u_int32)*((u_char *)p+2)<<8|\ + (u_int32)*((u_char *)p+3)<<0) +#endif + +#ifdef KERNEL +#include <sys/mbuf.h> +#define MINDEX(len, m, k) \ +{ \ + len = m->m_len; \ + while (k >= len) { \ + k -= len; \ + m = m->m_next; \ + if (m == 0) \ + return 0; \ + len = m->m_len; \ + } \ +} + +static int +m_xword(m, k, err) + register struct mbuf *m; + register int k, *err; +{ + register int len; + register u_char *cp, *np; + register struct mbuf *m0; + + MINDEX(len, m, k); + cp = mtod(m, u_char *) + k; + if (len - k >= 4) { + *err = 0; + return EXTRACT_LONG(cp); + } + m0 = m->m_next; + if (m0 == 0 || m0->m_len + len - k < 4) + goto bad; + *err = 0; + np = mtod(m0, u_char *); + switch (len - k) { + + case 1: + return (cp[0] << 24) | (np[0] << 16) | (np[1] << 8) | np[2]; + + case 2: + return (cp[0] << 24) | (cp[1] << 16) | (np[0] << 8) | np[1]; + + default: + return (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | np[0]; + } + bad: + *err = 1; + return 0; +} + +static int +m_xhalf(m, k, err) + register struct mbuf *m; + register int k, *err; +{ + register int len; + register u_char *cp; + register struct mbuf *m0; + + MINDEX(len, m, k); + cp = mtod(m, u_char *) + k; + if (len - k >= 2) { + *err = 0; + return EXTRACT_SHORT(cp); + } + m0 = m->m_next; + if (m0 == 0) + goto bad; + *err = 0; + return (cp[0] << 8) | mtod(m0, u_char *)[0]; + bad: + *err = 1; + return 0; +} +#endif + +/* + * 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 A, X; + register int k; + int32 mem[BPF_MEMWORDS]; + + if (pc == 0) + /* + * No filter means accept all. + */ + return (u_int)-1; + A = 0; + X = 0; + --pc; + while (1) { + ++pc; + switch (pc->code) { + + default: +#ifdef KERNEL + return 0; +#else + abort(); +#endif + 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(int32) > buflen) { +#ifdef KERNEL + int merr; + + if (buflen != 0) + return 0; + A = m_xword((struct mbuf *)p, k, &merr); + if (merr != 0) + return 0; + continue; +#else + return 0; +#endif + } + A = EXTRACT_LONG(&p[k]); + continue; + + case BPF_LD|BPF_H|BPF_ABS: + k = pc->k; + if (k + sizeof(short) > buflen) { +#ifdef KERNEL + int merr; + + if (buflen != 0) + return 0; + A = m_xhalf((struct mbuf *)p, k, &merr); + continue; +#else + return 0; +#endif + } + A = EXTRACT_SHORT(&p[k]); + continue; + + case BPF_LD|BPF_B|BPF_ABS: + k = pc->k; + if (k >= buflen) { +#ifdef KERNEL + register struct mbuf *m; + register int len; + + if (buflen != 0) + return 0; + m = (struct mbuf *)p; + MINDEX(len, m, k); + A = mtod(m, u_char *)[k]; + continue; +#else + return 0; +#endif + } + 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(int32) > buflen) { +#ifdef KERNEL + int merr; + + if (buflen != 0) + return 0; + A = m_xword((struct mbuf *)p, k, &merr); + if (merr != 0) + return 0; + continue; +#else + return 0; +#endif + } + A = EXTRACT_LONG(&p[k]); + continue; + + case BPF_LD|BPF_H|BPF_IND: + k = X + pc->k; + if (k + sizeof(short) > buflen) { +#ifdef KERNEL + int merr; + + if (buflen != 0) + return 0; + A = m_xhalf((struct mbuf *)p, k, &merr); + if (merr != 0) + return 0; + continue; +#else + return 0; +#endif + } + A = EXTRACT_SHORT(&p[k]); + continue; + + case BPF_LD|BPF_B|BPF_IND: + k = X + pc->k; + if (k >= buflen) { +#ifdef KERNEL + register struct mbuf *m; + register int len; + + if (buflen != 0) + return 0; + m = (struct mbuf *)p; + MINDEX(len, m, k); + A = mtod(m, u_char *)[k]; + continue; +#else + return 0; +#endif + } + A = p[k]; + continue; + + case BPF_LDX|BPF_MSH|BPF_B: + k = pc->k; + if (k >= buflen) { +#ifdef KERNEL + register struct mbuf *m; + register int len; + + if (buflen != 0) + return 0; + m = (struct mbuf *)p; + MINDEX(len, m, k); + X = (mtod(m, char *)[k] & 0xf) << 2; + continue; +#else + return 0; +#endif + } + 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; + } + } +} + +#ifdef KERNEL +/* + * Return true if the 'fcode' is a valid filter program. + * The constraints are that each jump be forward and to a valid + * code. The code must terminate with either an accept or reject. + * 'valid' is an array for use by the routine (it must be at least + * 'len' bytes long). + * + * The kernel needs to be able to verify an application's filter code. + * Otherwise, a bogus program could easily crash the system. + */ +int +bpf_validate(f, len) + struct bpf_insn *f; + int len; +{ + register int i; + register struct bpf_insn *p; + + for (i = 0; i < len; ++i) { + /* + * Check that that jumps are forward, and within + * the code block. + */ + p = &f[i]; + if (BPF_CLASS(p->code) == BPF_JMP) { + register int from = i + 1; + + if (BPF_OP(p->code) == BPF_JA) { + if (from + p->k >= (unsigned)len) + return 0; + } + else if (from + p->jt >= len || from + p->jf >= len) + return 0; + } + /* + * Check that memory operations use valid addresses. + */ + if ((BPF_CLASS(p->code) == BPF_ST || + (BPF_CLASS(p->code) == BPF_LD && + (p->code & 0xe0) == BPF_MEM)) && + (p->k >= BPF_MEMWORDS || p->k < 0)) + return 0; + /* + * Check for constant division by 0. + */ + if (p->code == (BPF_ALU|BPF_DIV|BPF_K) && p->k == 0) + return 0; + } + return BPF_CLASS(f[len - 1].code) == BPF_RET; +} +#endif |