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Diffstat (limited to 'package/etrax-tools/src/e100boot/libpcap-0.4/gencode.c')
| -rw-r--r-- | package/etrax-tools/src/e100boot/libpcap-0.4/gencode.c | 1944 |
1 files changed, 1944 insertions, 0 deletions
diff --git a/package/etrax-tools/src/e100boot/libpcap-0.4/gencode.c b/package/etrax-tools/src/e100boot/libpcap-0.4/gencode.c new file mode 100644 index 000000000..f3fc5a60f --- /dev/null +++ b/package/etrax-tools/src/e100boot/libpcap-0.4/gencode.c @@ -0,0 +1,1944 @@ +/* + * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998 + * 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 const char rcsid[] = + "@(#) $Header: /usr/local/cvs/linux/tools/build/e100boot/libpcap-0.4/gencode.c,v 1.1 1999/08/26 10:05:22 johana 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 <netinet/in.h> +#include <netinet/if_ether.h> + +#include <stdlib.h> +#include <memory.h> +#include <setjmp.h> +#if __STDC__ +#include <stdarg.h> +#else +#include <varargs.h> +#endif + +#include "pcap-int.h" + +#include "ethertype.h" +#include "gencode.h" +#include "ppp.h" +#include <pcap-namedb.h> + +#include "gnuc.h" +#ifdef HAVE_OS_PROTO_H +#include "os-proto.h" +#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 + +/* 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, const 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(const u_char *, int); +static struct block *gen_fhostop(const 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(const 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(const char *, int); +static struct block *gen_proto(int, int, int); +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) + register const 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) + register u_int offset, size; + register const u_char *v; +{ + register struct block *b, *tmp; + + b = NULL; + while (size >= 4) { + register const u_char *p = &v[size - 4]; + bpf_int32 w = ((bpf_int32)p[0] << 24) | + ((bpf_int32)p[1] << 16) | ((bpf_int32)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) { + register const u_char *p = &v[size - 2]; + bpf_int32 w = ((bpf_int32)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_SLIP_BSDOS: + /* XXX this may be the same as the DLT_PPP_BSDOS case */ + off_linktype = -1; + /* XXX end */ + off_nl = 24; + return; + + case DLT_NULL: + off_linktype = 0; + off_nl = 4; + return; + + case DLT_PPP: + off_linktype = 2; + off_nl = 4; + return; + + case DLT_PPP_BSDOS: + off_linktype = 5; + off_nl = 24; + 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; + + case DLT_RAW: + off_linktype = -1; + off_nl = 0; + 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) + register int proto; +{ + struct block *b0, *b1; + + /* If we're not using encapsulation and checking for IP, we're done */ + if (off_linktype == -1 && proto == ETHERTYPE_IP) + return gen_true(); + + switch (linktype) { + + case DLT_SLIP: + return gen_false(); + + case DLT_PPP: + if (proto == ETHERTYPE_IP) + proto = PPP_IP; /* XXX was 0x21 */ + break; + + case DLT_PPP_BSDOS: + switch (proto) { + + case ETHERTYPE_IP: + b0 = gen_cmp(off_linktype, BPF_H, PPP_IP); + b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC); + gen_or(b0, b1); + b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC); + gen_or(b1, b0); + return b0; + + case ETHERTYPE_DN: + proto = PPP_DECNET; + break; + + case ETHERTYPE_ATALK: + proto = PPP_APPLE; + break; + + case ETHERTYPE_NS: + proto = PPP_NS; + break; + } + break; + + case DLT_NULL: + /* XXX */ + if (proto == ETHERTYPE_IP) + return (gen_cmp(0, BPF_W, (bpf_int32)htonl(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) + register const u_char *eaddr; + register int dir; +{ + register 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) + register const u_char *eaddr; + register 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_IGRP: + bpf_error("'igrp' modifier applied to host"); + + case Q_ATALK: + bpf_error("ATALK host filtering not implemented"); + + case Q_DECNET: + return gen_dnhostop(addr, dir, off_nl); + + case Q_SCA: + bpf_error("SCA host filtering not implemented"); + + 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) + const 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++, 0xffffffff, proto, Q_OR); + while (*alist) { + tmp = gen_host(**alist++, 0xffffffff, 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; + +#ifndef IPPROTO_IGRP +#define IPPROTO_IGRP 9 +#endif + case Q_IGRP: + b0 = gen_linktype(ETHERTYPE_IP); + b1 = gen_cmp(off_nl + 9, BPF_B, (long)IPPROTO_IGRP); + 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_ATALK: + b1 = gen_linktype(ETHERTYPE_ATALK); + break; + + case Q_DECNET: + b1 = gen_linktype(ETHERTYPE_DN); + break; + + case Q_SCA: + b1 = gen_linktype(ETHERTYPE_SCA); + 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) + register const char *name; + register int proto; +{ + register 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_ATALK: + bpf_error("atalk encapsulation is not specifiable"); + /* NOTREACHED */ + + case Q_DECNET: + bpf_error("decnet encapsulation is not specifiable"); + /* NOTREACHED */ + + case Q_SCA: + bpf_error("sca does not encapsulate another protocol"); + /* 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 */ + + case Q_IGRP: + bpf_error("'igrp proto' is bogus"); + /* NOTREACHED */ + + default: + abort(); + /* NOTREACHED */ + } + /* NOTREACHED */ +} + +struct block * +gen_scode(name, q) + register const char *name; + struct qual q; +{ + int proto = q.proto; + int dir = q.dir; + int tproto; + 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); + /* Left justify network addr and calculate its network mask */ + mask = 0xffffffff; + while (addr && (addr & 0xff000000) == 0) { + addr <<= 8; + mask <<= 8; + } + 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); + tproto = proto; + if (off_linktype == -1 && tproto == Q_DEFAULT) + tproto = Q_IP; + b = gen_host(**alist++, 0xffffffff, tproto, dir); + while (*alist) { + tmp = gen_host(**alist++, 0xffffffff, + tproto, 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_mcode(s1, s2, masklen, q) + register const char *s1, *s2; + register int masklen; + struct qual q; +{ + register int nlen, mlen; + bpf_u_int32 n, m; + + nlen = __pcap_atoin(s1, &n); + /* Promote short ipaddr */ + n <<= 32 - nlen; + + if (s2 != NULL) { + mlen = __pcap_atoin(s2, &m); + /* Promote short ipaddr */ + m <<= 32 - mlen; + if ((n & ~m) != 0) + bpf_error("non-network bits set in \"%s mask %s\"", + s1, s2); + } else { + /* Convert mask len to mask */ + if (masklen > 32) + bpf_error("mask length must be <= 32"); + m = 0xffffffff << (32 - masklen); + if ((n & ~m) != 0) + bpf_error("non-network bits set in \"%s/%d\"", + s1, masklen); + } + + switch (q.addr) { + + case Q_NET: + return gen_host(n, m, q.proto, q.dir); + + default: + bpf_error("Mask syntax for networks only"); + /* NOTREACHED */ + } +} + +struct block * +gen_ncode(s, v, q) + register const char *s; + bpf_u_int32 v; + struct qual q; +{ + bpf_u_int32 mask; + int proto = q.proto; + int dir = q.dir; + register int vlen; + + if (s == NULL) + vlen = 32; + else if (q.proto == Q_DECNET) + vlen = __pcap_atodn(s, &v); + else + vlen = __pcap_atoin(s, &v); + + 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 = 0xffffffff; + if (s == NULL && q.addr == Q_NET) { + /* Promote short net number */ + while (v && (v & 0xff000000) == 0) { + v <<= 8; + mask <<= 8; + } + } else { + /* Promote short ipaddr */ + v <<= 32 - vlen; + mask <<= 32 - vlen; + } + 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) + register const 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_ATALK: + case Q_DECNET: + case Q_SCA: + 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: + case Q_IGRP: + 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); +} |