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|
/*
* Copyright (C) 2003 by Darren Reed.
*
* See the IPFILTER.LICENCE file for details on licencing.
*/
#include <ctype.h>
#include "ipf.h"
#ifdef IPFILTER_SCAN
# include "netinet/ip_scan.h"
#endif
#include <sys/ioctl.h>
#include <syslog.h>
#ifdef TEST_LEXER
# define NO_YACC
union {
int num;
char *str;
struct in_addr ipa;
i6addr_t ip6;
} yylval;
#endif
#include "lexer.h"
#include "y.tab.h"
FILE *yyin;
#define ishex(c) (ISDIGIT(c) || ((c) >= 'a' && (c) <= 'f') || \
((c) >= 'A' && (c) <= 'F'))
#define TOOLONG -3
extern int string_start;
extern int string_end;
extern char *string_val;
extern int pos;
extern int yydebug;
char *yystr = NULL;
int yytext[YYBUFSIZ+1];
int yylineNum = 1;
int yypos = 0;
int yylast = -1;
int yyexpectaddr = 0;
int yybreakondot = 0;
int yyvarnext = 0;
int yytokentype = 0;
wordtab_t *yywordtab = NULL;
int yysavedepth = 0;
wordtab_t *yysavewords[30];
static wordtab_t *yyfindkey __P((char *));
static int yygetc __P((void));
static void yyunputc __P((int));
static int yyswallow __P((int));
static char *yytexttostr __P((int, int));
static void yystrtotext __P((char *));
static int yygetc()
{
int c;
if (yypos < yylast) {
c = yytext[yypos++];
if (c == '\n')
yylineNum++;
return c;
}
if (yypos == YYBUFSIZ)
return TOOLONG;
if (pos >= string_start && pos <= string_end) {
c = string_val[pos - string_start];
yypos++;
} else {
c = fgetc(yyin);
}
if (c == '\n')
yylineNum++;
yytext[yypos++] = c;
yylast = yypos;
yytext[yypos] = '\0';
return c;
}
static void yyunputc(c)
int c;
{
if (c == '\n')
yylineNum--;
yytext[--yypos] = c;
}
static int yyswallow(last)
int last;
{
int c;
while (((c = yygetc()) > '\0') && (c != last))
;
if (c != EOF)
yyunputc(c);
if (c == last)
return 0;
return -1;
}
static void yystrtotext(str)
char *str;
{
int len;
char *s;
len = strlen(str);
if (len > YYBUFSIZ)
len = YYBUFSIZ;
for (s = str; *s != '\0' && len > 0; s++, len--)
yytext[yylast++] = *s;
yytext[yylast] = '\0';
}
static char *yytexttostr(offset, max)
int offset, max;
{
char *str;
int i;
if ((yytext[offset] == '\'' || yytext[offset] == '"') &&
(yytext[offset] == yytext[offset + max - 1])) {
offset++;
max--;
}
if (max > yylast)
max = yylast;
str = malloc(max + 1);
if (str != NULL) {
for (i = offset; i < max; i++)
str[i - offset] = (char)(yytext[i] & 0xff);
str[i - offset] = '\0';
}
return str;
}
int yylex()
{
int c, n, isbuilding, rval, lnext, nokey = 0;
char *name;
isbuilding = 0;
lnext = 0;
rval = 0;
if (yystr != NULL) {
free(yystr);
yystr = NULL;
}
nextchar:
c = yygetc();
switch (c)
{
case '\n' :
lnext = 0;
nokey = 0;
case '\t' :
case '\r' :
case ' ' :
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
if (yylast > yypos) {
bcopy(yytext + yypos, yytext,
sizeof(yytext[0]) * (yylast - yypos + 1));
}
yylast -= yypos;
yypos = 0;
lnext = 0;
nokey = 0;
goto nextchar;
case '\\' :
if (lnext == 0) {
lnext = 1;
if (yylast == yypos) {
yylast--;
yypos--;
} else
yypos--;
if (yypos == 0)
nokey = 1;
goto nextchar;
}
break;
}
if (lnext == 1) {
lnext = 0;
if ((isbuilding == 0) && !ISALNUM(c)) {
return c;
}
goto nextchar;
}
switch (c)
{
case '#' :
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
yyswallow('\n');
rval = YY_COMMENT;
goto nextchar;
case '$' :
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
n = yygetc();
if (n == '{') {
if (yyswallow('}') == -1) {
rval = -2;
goto done;
}
(void) yygetc();
} else {
if (!ISALPHA(n)) {
yyunputc(n);
break;
}
do {
n = yygetc();
} while (ISALPHA(n) || ISDIGIT(n) || n == '_');
yyunputc(n);
}
name = yytexttostr(1, yypos); /* skip $ */
if (name != NULL) {
string_val = get_variable(name, NULL, yylineNum);
free(name);
if (string_val != NULL) {
name = yytexttostr(yypos, yylast);
if (name != NULL) {
yypos = 0;
yylast = 0;
yystrtotext(string_val);
yystrtotext(name);
free(string_val);
free(name);
goto nextchar;
}
free(string_val);
}
}
break;
case '\'':
case '"' :
if (isbuilding == 1) {
goto done;
}
do {
n = yygetc();
if (n == EOF || n == TOOLONG) {
rval = -2;
goto done;
}
if (n == '\n') {
yyunputc(' ');
yypos++;
}
} while (n != c);
yyunputc(n);
break;
case EOF :
yylineNum = 1;
yypos = 0;
yylast = -1;
yyexpectaddr = 0;
yybreakondot = 0;
yyvarnext = 0;
yytokentype = 0;
return 0;
}
if (strchr("=,/;{}()@", c) != NULL) {
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
rval = c;
goto done;
} else if (c == '.') {
if (isbuilding == 0) {
rval = c;
goto done;
}
if (yybreakondot != 0) {
yyunputc(c);
goto done;
}
}
switch (c)
{
case '-' :
if (yyexpectaddr)
break;
if (isbuilding == 1)
break;
n = yygetc();
if (n == '>') {
isbuilding = 1;
goto done;
}
yyunputc(n);
rval = '-';
goto done;
case '!' :
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
n = yygetc();
if (n == '=') {
rval = YY_CMP_NE;
goto done;
}
yyunputc(n);
rval = '!';
goto done;
case '<' :
if (yyexpectaddr)
break;
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
n = yygetc();
if (n == '=') {
rval = YY_CMP_LE;
goto done;
}
if (n == '>') {
rval = YY_RANGE_OUT;
goto done;
}
yyunputc(n);
rval = YY_CMP_LT;
goto done;
case '>' :
if (yyexpectaddr)
break;
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
n = yygetc();
if (n == '=') {
rval = YY_CMP_GE;
goto done;
}
if (n == '<') {
rval = YY_RANGE_IN;
goto done;
}
yyunputc(n);
rval = YY_CMP_GT;
goto done;
}
/*
* Now for the reason this is here...IPv6 address parsing.
* The longest string we can expect is of this form:
* 0000:0000:0000:0000:0000:0000:000.000.000.000
* not:
* 0000:0000:0000:0000:0000:0000:0000:0000
*/
#ifdef USE_INET6
if (yyexpectaddr == 1 && isbuilding == 0 && (ishex(c) || c == ':')) {
char ipv6buf[45 + 1], *s, oc;
int start;
start = yypos;
s = ipv6buf;
oc = c;
/*
* Perhaps we should implement stricter controls on what we
* swallow up here, but surely it would just be duplicating
* the code in inet_pton() anyway.
*/
do {
*s++ = c;
c = yygetc();
} while ((ishex(c) || c == ':' || c == '.') &&
(s - ipv6buf < 46));
yyunputc(c);
*s = '\0';
if (inet_pton(AF_INET6, ipv6buf, &yylval.ip6) == 1) {
rval = YY_IPV6;
yyexpectaddr = 0;
goto done;
}
yypos = start;
c = oc;
}
#endif
if (c == ':') {
if (isbuilding == 1) {
yyunputc(c);
goto done;
}
rval = ':';
goto done;
}
if (isbuilding == 0 && c == '0') {
n = yygetc();
if (n == 'x') {
do {
n = yygetc();
} while (ishex(n));
yyunputc(n);
rval = YY_HEX;
goto done;
}
yyunputc(n);
}
/*
* No negative numbers with leading - sign..
*/
if (isbuilding == 0 && ISDIGIT(c)) {
do {
n = yygetc();
} while (ISDIGIT(n));
yyunputc(n);
rval = YY_NUMBER;
goto done;
}
isbuilding = 1;
goto nextchar;
done:
yystr = yytexttostr(0, yypos);
if (isbuilding == 1) {
wordtab_t *w;
w = NULL;
isbuilding = 0;
if ((yyvarnext == 0) && (nokey == 0)) {
w = yyfindkey(yystr);
if (w == NULL && yywordtab != NULL) {
yyresetdict();
w = yyfindkey(yystr);
}
} else
yyvarnext = 0;
if (w != NULL)
rval = w->w_value;
else
rval = YY_STR;
}
if (rval == YY_STR && yysavedepth > 0)
yyresetdict();
yytokentype = rval;
if (yydebug)
printf("lexed(%s) [%d,%d,%d] => %d\n", yystr, string_start,
string_end, pos, rval);
switch (rval)
{
case YY_NUMBER :
sscanf(yystr, "%u", &yylval.num);
break;
case YY_HEX :
sscanf(yystr, "0x%x", (u_int *)&yylval.num);
break;
case YY_STR :
yylval.str = strdup(yystr);
break;
default :
break;
}
if (yylast > 0) {
bcopy(yytext + yypos, yytext,
sizeof(yytext[0]) * (yylast - yypos + 1));
yylast -= yypos;
yypos = 0;
}
return rval;
}
static wordtab_t *yyfindkey(key)
char *key;
{
wordtab_t *w;
if (yywordtab == NULL)
return NULL;
for (w = yywordtab; w->w_word != 0; w++)
if (strcasecmp(key, w->w_word) == 0)
return w;
return NULL;
}
char *yykeytostr(num)
int num;
{
wordtab_t *w;
if (yywordtab == NULL)
return "<unknown>";
for (w = yywordtab; w->w_word; w++)
if (w->w_value == num)
return w->w_word;
return "<unknown>";
}
wordtab_t *yysettab(words)
wordtab_t *words;
{
wordtab_t *save;
save = yywordtab;
yywordtab = words;
return save;
}
void yyerror(msg)
char *msg;
{
char *txt, letter[2];
int freetxt = 0;
if (yytokentype < 256) {
letter[0] = yytokentype;
letter[1] = '\0';
txt = letter;
} else if (yytokentype == YY_STR || yytokentype == YY_HEX ||
yytokentype == YY_NUMBER) {
if (yystr == NULL) {
txt = yytexttostr(yypos, YYBUFSIZ);
freetxt = 1;
} else
txt = yystr;
} else {
txt = yykeytostr(yytokentype);
}
fprintf(stderr, "%s error at \"%s\", line %d\n", msg, txt, yylineNum);
if (freetxt == 1)
free(txt);
exit(1);
}
void yysetdict(newdict)
wordtab_t *newdict;
{
if (yysavedepth == sizeof(yysavewords)/sizeof(yysavewords[0])) {
fprintf(stderr, "%d: at maximum dictionary depth\n",
yylineNum);
return;
}
yysavewords[yysavedepth++] = yysettab(newdict);
if (yydebug)
printf("yysavedepth++ => %d\n", yysavedepth);
}
void yyresetdict()
{
if (yysavedepth > 0) {
yysettab(yysavewords[--yysavedepth]);
if (yydebug)
printf("yysavedepth-- => %d\n", yysavedepth);
}
}
#ifdef TEST_LEXER
int main(argc, argv)
int argc;
char *argv[];
{
int n;
yyin = stdin;
while ((n = yylex()) != 0)
printf("%d.n = %d [%s] %d %d\n",
yylineNum, n, yystr, yypos, yylast);
}
#endif
|