scanner.l - master - githubmirror/libpcap

scanner.l
665 строк18 KB
Denis Ovsienko
scanner: Do not try including grammar.h twice.
06 мар 2026, 18:55
06 мар 2026, 18:5513c0251
%top {
/* Must come first for _LARGE_FILE_API on AIX. */
#include <config.h>

/*
 * Must come first to avoid warnings on Windows.
 *
 * Flex-generated scanners may only include <inttypes.h> if __STDC_VERSION__
 * is defined with a value >= 199901, meaning "full C99", and MSVC may not
 * define it with that value, because it isn't 100% C99-compliant, even
 * though it has an <inttypes.h> capable of defining everything the Flex
 * scanner needs.
 *
 * We, however, will include it if we know we have an MSVC version that has
 * it; this means that we may define the INTn_MAX and UINTn_MAX values in
 * scanner.c, and then include <stdint.h>, which may define them differently
 * (same value, but different string of characters), causing compiler warnings.
 *
 * If we include it here, and they're defined, that'll prevent scanner.c
 * from defining them.  So we include <pcap/pcap-inttypes.h>, to get
 * <inttypes.h> if we have it.
 */
#include <pcap/pcap-inttypes.h>

/*
 * grammar.h requires gencode.h and sometimes breaks in a polluted namespace
 * (see ftmacros.h), so include it early.
 */
#include "gencode.h"
#include "grammar.h"

#include "diag-control.h"

/*
 * Convert string to 32-bit unsigned integer; the string starts at
 * string and is string_len bytes long.
 *
 * On success, sets *val to the value and returns 1.
 * On failure, sets the BPF error string and returns 0.
 *
 * Also used in gencode.c
 */
typedef enum {
	STOULEN_OK,
	STOULEN_NOT_HEX_NUMBER,
	STOULEN_NOT_OCTAL_NUMBER,
	STOULEN_NOT_DECIMAL_NUMBER,
	STOULEN_ERROR
} stoulen_ret;

stoulen_ret stoulen(const char *, const size_t, bpf_u_int32 *,
    compiler_state_t *);
}

/*
 * We want a reentrant scanner.
 */
%option reentrant

/*
 * And we need to pass the compiler state to the scanner.
 */
%option extra-type="compiler_state_t *"

/*
 * We don't use input, so don't generate code for it.
 */
%option noinput

/*
 * We don't use unput, so don't generate code for it.
 */
%option nounput

/*
 * We don't read from the terminal.
 */
%option never-interactive

/*
 * We want to stop processing when we get to the end of the input.
 */
%option noyywrap

/*
 * We want to generate code that can be used by a reentrant parser
 * generated by Bison or Berkeley YACC.
 */
%option bison-bridge

%{
/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
 *	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.
 */

#include <string.h>

#include "pcap-int.h"

/*
 * Earlier versions of Flex don't declare these, so we declare them
 * ourselves to squelch warnings.
 */
int pcap_get_column(yyscan_t);
void pcap_set_column(int, yyscan_t);

#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#else /* _WIN32 */
#include <sys/socket.h>	/* for "struct sockaddr" in "struct addrinfo" */
#include <netdb.h>	/* for "struct addrinfo" */
#endif /* _WIN32 */

#include <pcap/namedb.h>

#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif

static int stou(const char *, YYSTYPE *, compiler_state_t *);

/*
 * Disable diagnostics in the code generated by Flex.
 */
DIAG_OFF_FLEX

%}

N		([0-9]+|(0X|0x)[0-9A-Fa-f]+)
B		([0-9A-Fa-f][0-9A-Fa-f]?)
B2		([0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f])
W		([0-9A-Fa-f][0-9A-Fa-f]?[0-9A-Fa-f]?[0-9A-Fa-f]?)

%a 18400
%o 21500
%e 7600
%k 4550
%p 27600
%n 2000

V680		{W}:{W}:{W}:{W}:{W}:{W}:{W}:{W}

V670		::{W}:{W}:{W}:{W}:{W}:{W}:{W}
V671		{W}::{W}:{W}:{W}:{W}:{W}:{W}
V672		{W}:{W}::{W}:{W}:{W}:{W}:{W}
V673		{W}:{W}:{W}::{W}:{W}:{W}:{W}
V674		{W}:{W}:{W}:{W}::{W}:{W}:{W}
V675		{W}:{W}:{W}:{W}:{W}::{W}:{W}
V676		{W}:{W}:{W}:{W}:{W}:{W}::{W}
V677		{W}:{W}:{W}:{W}:{W}:{W}:{W}::

V660		::{W}:{W}:{W}:{W}:{W}:{W}
V661		{W}::{W}:{W}:{W}:{W}:{W}
V662		{W}:{W}::{W}:{W}:{W}:{W}
V663		{W}:{W}:{W}::{W}:{W}:{W}
V664		{W}:{W}:{W}:{W}::{W}:{W}
V665		{W}:{W}:{W}:{W}:{W}::{W}
V666		{W}:{W}:{W}:{W}:{W}:{W}::

V650		::{W}:{W}:{W}:{W}:{W}
V651		{W}::{W}:{W}:{W}:{W}
V652		{W}:{W}::{W}:{W}:{W}
V653		{W}:{W}:{W}::{W}:{W}
V654		{W}:{W}:{W}:{W}::{W}
V655		{W}:{W}:{W}:{W}:{W}::

V640		::{W}:{W}:{W}:{W}
V641		{W}::{W}:{W}:{W}
V642		{W}:{W}::{W}:{W}
V643		{W}:{W}:{W}::{W}
V644		{W}:{W}:{W}:{W}::

V630		::{W}:{W}:{W}
V631		{W}::{W}:{W}
V632		{W}:{W}::{W}
V633		{W}:{W}:{W}::

V620		::{W}:{W}
V621		{W}::{W}
V622		{W}:{W}::

V610		::{W}
V611		{W}::

V600		::

V6604		{W}:{W}:{W}:{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}

V6504		::{W}:{W}:{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}
V6514		{W}::{W}:{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}
V6524		{W}:{W}::{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}
V6534		{W}:{W}:{W}::{W}:{W}:{N}\.{N}\.{N}\.{N}
V6544		{W}:{W}:{W}:{W}::{W}:{N}\.{N}\.{N}\.{N}
V6554		{W}:{W}:{W}:{W}:{W}::{N}\.{N}\.{N}\.{N}

V6404		::{W}:{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}
V6414		{W}::{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}
V6424		{W}:{W}::{W}:{W}:{N}\.{N}\.{N}\.{N}
V6434		{W}:{W}:{W}::{W}:{N}\.{N}\.{N}\.{N}
V6444		{W}:{W}:{W}:{W}::{N}\.{N}\.{N}\.{N}

V6304		::{W}:{W}:{W}:{N}\.{N}\.{N}\.{N}
V6314		{W}::{W}:{W}:{N}\.{N}\.{N}\.{N}
V6324		{W}:{W}::{W}:{N}\.{N}\.{N}\.{N}
V6334		{W}:{W}:{W}::{N}\.{N}\.{N}\.{N}

V6204		::{W}:{W}:{N}\.{N}\.{N}\.{N}
V6214		{W}::{W}:{N}\.{N}\.{N}\.{N}
V6224		{W}:{W}::{N}\.{N}\.{N}\.{N}

V6104		::{W}:{N}\.{N}\.{N}\.{N}
V6114		{W}::{N}\.{N}\.{N}\.{N}

V6004		::{N}\.{N}\.{N}\.{N}


V6		({V680}|{V670}|{V671}|{V672}|{V673}|{V674}|{V675}|{V676}|{V677}|{V660}|{V661}|{V662}|{V663}|{V664}|{V665}|{V666}|{V650}|{V651}|{V652}|{V653}|{V654}|{V655}|{V640}|{V641}|{V642}|{V643}|{V644}|{V630}|{V631}|{V632}|{V633}|{V620}|{V621}|{V622}|{V610}|{V611}|{V600}|{V6604}|{V6504}|{V6514}|{V6524}|{V6534}|{V6544}|{V6554}|{V6404}|{V6414}|{V6424}|{V6434}|{V6444}|{V6304}|{V6314}|{V6324}|{V6334}|{V6204}|{V6214}|{V6224}|{V6104}|{V6114}|{V6004})

	/*
	 * In the regexp below the "{B2}{3}" form matches all octal numbers in
	 * the [010000000000 .. 077777777777] interval that use a single leading
	 * zero.  The interval includes both integer values that fit into 32
	 * bits and values that don't.
	 */
MAC		({B}:{B}:{B}:{B}:{B}:{B}|{B}\-{B}\-{B}\-{B}\-{B}\-{B}|{B}\.{B}\.{B}\.{B}\.{B}\.{B}|{B2}\.{B2}\.{B2}|{B2}{3})



%%
dst		return DST;
src		return SRC;

link|ether|ppp|slip  return LINK;
fddi|tr|wlan	return LINK;
arp		return ARP;
rarp		return RARP;
ip		return IP;
sctp		return SCTP;
tcp		return TCP;
udp		return UDP;
icmp		return ICMP;
igmp		return IGMP;
igrp		return IGRP;
pim		return PIM;
vrrp		return VRRP;
carp		return CARP;
radio		return RADIO;

ip6		return IPV6;
icmp6		return ICMPV6;
ah		return AH;
esp		return ESP;

atalk		return ATALK;
aarp		return AARP;
decnet		return DECNET;
lat		return LAT;
sca		return SCA;
moprc		return MOPRC;
mopdl		return MOPDL;

iso		return ISO;
esis		return ESIS;
es-is		return ESIS;
isis		return ISIS;
is-is		return ISIS;
l1              return L1;
l2              return L2;
iih             return IIH;
lsp             return LSP;
snp             return SNP;
csnp            return CSNP;
psnp            return PSNP;

clnp		return CLNP;

stp		return STP;

ipx		return IPX;

netbeui		return NETBEUI;

host		return HOST;
net		return NET;
mask		return NETMASK;
port		return PORT;
portrange	return PORTRANGE;
proto		return PROTO;
protochain	return PROTOCHAIN;

gateway		return GATEWAY;

type		return TYPE;
subtype		return SUBTYPE;
direction|dir	return DIR;
address1|addr1	return ADDR1;
address2|addr2	return ADDR2;
address3|addr3	return ADDR3;
address4|addr4	return ADDR4;
ra		return RA;
ta		return TA;

less		return LESS;
greater		return GREATER;
byte		return CBYTE;
broadcast	return TK_BROADCAST;
multicast	return TK_MULTICAST;

and|"&&"	return AND;
or|"||"		return OR;
not		return '!';

len|length	return LEN;
inbound		return INBOUND;
outbound	return OUTBOUND;

ifindex		return IFINDEX;

vlan		return VLAN;
mpls		return MPLS;
pppoed		return PPPOED;
pppoes		return PPPOES;
geneve		return GENEVE;
vxlan		return VXLAN;

lane		return LANE;
llc		return LLC;
metac		return METAC;
bcc		return BCC;
oam		return OAM;
oamf4		return OAMF4;
oamf4ec		return OAMF4EC;
oamf4sc		return OAMF4SC;
sc		return SC;
ilmic		return ILMIC;
vpi		return VPI;
vci		return VCI;
connectmsg	return CONNECTMSG;
metaconnect	return METACONNECT;

on|ifname	return PF_IFNAME;
rset|ruleset	return PF_RSET;
rnr|rulenum	return PF_RNR;
srnr|subrulenum	return PF_SRNR;
reason		return PF_REASON;
action		return PF_ACTION;

fisu		return FISU;
lssu		return LSSU;
lsu		return LSSU;
msu		return MSU;
hfisu		return HFISU;
hlssu		return HLSSU;
hmsu		return HMSU;
sio		return SIO;
opc		return OPC;
dpc		return DPC;
sls		return SLS;
hsio		return HSIO;
hopc		return HOPC;
hdpc		return HDPC;
hsls		return HSLS;

[ \r\n\t]		;
[+\-*/%:\[\]!<>()&|\^=]	return yytext[0];
">="			return GEQ;
"<="			return LEQ;
"!="			return NEQ;
"=="			return '=';
"<<"			return LSH;
">>"			return RSH;
${B}			{ yylval->s = sdup(yyextra, yytext); return AID; }
{MAC}			{ yylval->s = sdup(yyextra, yytext); return EID; }
{N}			{ return stou(yytext, yylval, yyextra); }
({N}\.{N})|({N}\.{N}\.{N})|({N}\.{N}\.{N}\.{N})	{
			yylval->s = sdup(yyextra, (char *)yytext); return HID; }
{V6}			{
			  struct in6_addr addr;
			  if (1 != inet_pton(AF_INET6, yytext, &addr)) {
				bpf_set_error(yyextra, "invalid IPv6 address %s", yytext);
				yylval->s = NULL;
			  } else {
				yylval->s = sdup(yyextra, (char *)yytext);
			  }
			  return HID6;
			}
{B}:+({B}:+)+		{ bpf_set_error(yyextra, "invalid Ethernet address %s", yytext); yylval->s = NULL; return EID; }
icmptype		{ yylval->h = 0; return NUM; }
icmpcode		{ yylval->h = 1; return NUM; }
icmp-echoreply		{ yylval->h = 0; return NUM; }
icmp-unreach		{ yylval->h = 3; return NUM; }
icmp-sourcequench	{ yylval->h = 4; return NUM; }
icmp-redirect		{ yylval->h = 5; return NUM; }
icmp-echo		{ yylval->h = 8; return NUM; }
icmp-routeradvert	{ yylval->h = 9; return NUM; }
icmp-routersolicit	{ yylval->h = 10; return NUM; }
icmp-timxceed		{ yylval->h = 11; return NUM; }
icmp-paramprob		{ yylval->h = 12; return NUM; }
icmp-tstamp		{ yylval->h = 13; return NUM; }
icmp-tstampreply	{ yylval->h = 14; return NUM; }
icmp-ireq		{ yylval->h = 15; return NUM; }
icmp-ireqreply		{ yylval->h = 16; return NUM; }
icmp-maskreq		{ yylval->h = 17; return NUM; }
icmp-maskreply		{ yylval->h = 18; return NUM; }

icmp6type       { yylval->h = 0; return NUM; }
icmp6code       { yylval->h = 1; return NUM; }

icmp6-destinationunreach	{ yylval->h = 1; return NUM; }
icmp6-packettoobig		{ yylval->h = 2; return NUM; }
icmp6-timeexceeded		{ yylval->h = 3; return NUM; }
icmp6-parameterproblem		{ yylval->h = 4; return NUM; }
icmp6-echo      { yylval->h = 128; return NUM; }
icmp6-echoreply { yylval->h = 129; return NUM; }
icmp6-multicastlistenerquery    { yylval->h = 130; return NUM; }
icmp6-multicastlistenerreportv1 { yylval->h = 131; return NUM; }
icmp6-multicastlistenerdone     { yylval->h = 132; return NUM; }
icmp6-routersolicit   { yylval->h = 133; return NUM; }
icmp6-routeradvert    { yylval->h = 134; return NUM; }
icmp6-neighborsolicit { yylval->h = 135; return NUM; }
icmp6-neighboradvert  { yylval->h = 136; return NUM; }
icmp6-redirect    { yylval->h = 137; return NUM; }
icmp6-routerrenum { yylval->h = 138; return NUM; }
icmp6-nodeinformationquery      { yylval->h = 139; return NUM; }
icmp6-nodeinformationresponse   { yylval->h = 140; return NUM; }
icmp6-ineighbordiscoverysolicit { yylval->h = 141; return NUM; }
icmp6-ineighbordiscoveryadvert  { yylval->h = 142; return NUM; }
icmp6-multicastlistenerreportv2 { yylval->h = 143; return NUM; }
icmp6-homeagentdiscoveryrequest { yylval->h = 144; return NUM; }
icmp6-homeagentdiscoveryreply   { yylval->h = 145; return NUM; }
icmp6-mobileprefixsolicit       { yylval->h = 146; return NUM; }
icmp6-mobileprefixadvert        { yylval->h = 147; return NUM; }
icmp6-certpathsolicit           { yylval->h = 148; return NUM; }
icmp6-certpathadvert            { yylval->h = 149; return NUM; }
icmp6-multicastrouteradvert     { yylval->h = 151; return NUM; }
icmp6-multicastroutersolicit    { yylval->h = 152; return NUM; }
icmp6-multicastrouterterm       { yylval->h = 153; return NUM; }

tcpflags		{ yylval->h = 13; return NUM; }
tcp-fin			{ yylval->h = 0x01; return NUM; }
tcp-syn			{ yylval->h = 0x02; return NUM; }
tcp-rst			{ yylval->h = 0x04; return NUM; }
tcp-push		{ yylval->h = 0x08; return NUM; }
tcp-ack			{ yylval->h = 0x10; return NUM; }
tcp-urg			{ yylval->h = 0x20; return NUM; }
tcp-ece			{ yylval->h = 0x40; return NUM; }
tcp-cwr			{ yylval->h = 0x80; return NUM; }
[A-Za-z0-9]([-_.A-Za-z0-9]*[.A-Za-z0-9])? {
			 yylval->s = sdup(yyextra, (char *)yytext); return ID; }
"\\"[^ !()\n\t]+	{ yylval->s = sdup(yyextra, (char *)yytext + 1); return ID; }
.			{ return LEX_ERROR; }
%%

/*
 * Turn diagnostics back on, so we check the code that we've written.
 */
DIAG_ON_FLEX

#define FORMAT_OVERFLOWS_32_BITS "%s number %.*s overflows 32 bits"

stoulen_ret
stoulen(const char *string, const size_t orig_string_len, bpf_u_int32 *val,
    compiler_state_t *cstate)
{
	bpf_u_int32 n = 0;
	unsigned int digit;
	const char *s = string;
	size_t string_len = orig_string_len;

	/*
	 * string is guaranteed either to be a string of decimal digits
	 * or 0[xX] followed by a string of hex digits.
	 */
	if (string_len >= 1 && *s == '0') {
		if (string_len >= 2  && (s[1] == 'x' || s[1] == 'X')) {
			/*
			 * Begins with 0x or 0X, so hex.
			 * Guaranteed to be all hex digits following the
			 * prefix, so anything that's not 0-9 or a-f is
			 * A-F.
			 */
			s += 2;	/* skip the prefix */
			string_len -= 2;
			while (string_len != 0) {
				digit = *s++;
				string_len--;
				if (digit >= '0' && digit <= '9')
					digit = digit - '0';
				else if (digit >= 'a' && digit <= 'f')
					digit = digit - 'a' + 10;
				else if (digit >= 'A' && digit <= 'F')
					digit = digit - 'A' + 10;
				else {
					/*
					 * Not a valid hex number.
					 * Don't treat this as an error,
					 * in case the caller wants to
					 * interpret it as something else.
					 */
					return STOULEN_NOT_HEX_NUMBER;
				}

				/*
				 * Check for overflow.
				 */
				if (n > 0xFFFFFFFU) {
					/*
					 * We have more than 28 bits of
					 * number, and are about to
					 * add 4 more; that won't fit
					 * in 32 bits.
					 */
					bpf_set_error(cstate,
					    FORMAT_OVERFLOWS_32_BITS,
					    "hexadecimal", (int)orig_string_len, string);
					return STOULEN_ERROR;
				}
				n = (n << 4) + digit;
			}
		} else {
			/*
			 * Begins with 0, but not 0x or 0X, so octal.
			 * Guaranteed to be all *decimal* digits following
			 * the prefix, so we need to catch 8 and 9 and
			 * report an error.
			 */
			s += 1;
			string_len -= 1;
			while (string_len != 0) {
				digit = *s++;
				string_len--;
				if (digit >= '0' && digit <= '7')
					digit = digit - '0';
				else {
					/*
					 * Not a valid octal number.
					 * Don't treat this as an error,
					 * in case the caller wants to
					 * interpret it as something else.
					 */
					return STOULEN_NOT_OCTAL_NUMBER;
				}
				if (n > 03777777777U) {
					/*
					 * We have more than 29 bits of
					 * number, and are about to add
					 * 3 more; that won't fit in
					 * 32 bits.
					 *
					 * This code path depends on using more
					 * than one leading zero for all values
					 * in the [040000000000 .. 077777777777]
					 * interval, otherwise the MAC regexp
					 * above consumes the string first.
					 */
					bpf_set_error(cstate,
					    FORMAT_OVERFLOWS_32_BITS,
					    "octal", (int)orig_string_len, string);
					return STOULEN_ERROR;
				}
				n = (n << 3) + digit;
			}
		}
	} else {
		/*
		 * Decimal.
		 */
		while (string_len != 0) {
			digit = *s++;
			string_len--;
			if (digit >= '0' && digit <= '9')
				digit = digit - '0';
			else {
				/*
				 * Not a valid decimal number.
				 * Don't treat this as an error,
				 * in case the caller wants to
				 * interpret it as something else.
				 */
				return STOULEN_NOT_DECIMAL_NUMBER;
			}
#define CUTOFF_DEC	(0xFFFFFFFFU / 10U)
#define CUTLIM_DEC	(0xFFFFFFFFU % 10U)
			if (n > CUTOFF_DEC ||
			    (n == CUTOFF_DEC && digit > CUTLIM_DEC)) {
				/*
				 * Adding that digit will result in a
				 * number that won't fit in 32 bits.
				 */
				bpf_set_error(cstate,
				    FORMAT_OVERFLOWS_32_BITS,
				    "decimal", (int)orig_string_len, string);
				return STOULEN_ERROR;
			}
			n = (n * 10) + digit;
		}
	}

	*val = n;
	return STOULEN_OK;
}

/*
 * Convert string to 32-bit unsigned integer.  Just like atoi(), but checks for
 * preceding 0x or 0 and uses hex or octal instead of decimal.
 *
 * On success, sets yylval->h to the value and returns NUM.
 * On failure, sets the BPF error string and returns LEX_ERROR, to force
 * the parse to stop.
 */
static int
stou(const char *yytext_arg, YYSTYPE *yylval_arg, compiler_state_t *yyextra_arg)
{
	stoulen_ret ret;

	ret = stoulen(yytext_arg, strlen(yytext_arg), &yylval_arg->h,
	    yyextra_arg);
	switch (ret) {

	case STOULEN_OK:
		return NUM;

	case STOULEN_NOT_OCTAL_NUMBER:
		bpf_set_error(yyextra_arg, "number %s contains non-octal digit",
		    yytext_arg);
		return LEX_ERROR;

	case STOULEN_NOT_HEX_NUMBER:
		bpf_set_error(yyextra_arg, "number %s contains non-hex digit",
		    yytext_arg);
		return LEX_ERROR;

	case STOULEN_NOT_DECIMAL_NUMBER:
		bpf_set_error(yyextra_arg, "number %s contains non-decimal digit",
		    yytext_arg);
		return LEX_ERROR;

	case STOULEN_ERROR:
		/* Error already set. */
		return LEX_ERROR;

	default:
		/* Should not happen */
		bpf_set_error(yyextra_arg, "stoulen returned %d - this should not happen", ret);
		return LEX_ERROR;
	}
}