diff options
Diffstat (limited to 'tools/lexer.c')
-rw-r--r-- | tools/lexer.c | 661 |
1 files changed, 661 insertions, 0 deletions
diff --git a/tools/lexer.c b/tools/lexer.c new file mode 100644 index 0000000..1ad00c4 --- /dev/null +++ b/tools/lexer.c @@ -0,0 +1,661 @@ +/* + * Copyright (C) 2002-2006 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]; +char yychars[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((int)); +static void yyunputc __P((int)); +static int yyswallow __P((int)); +static char *yytexttostr __P((int, int)); +static void yystrtotext __P((char *)); +static char *yytexttochar __P((void)); + +static int yygetc(docont) +int docont; +{ + 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 (docont && (c == '\\')) { + c = fgetc(yyin); + if (c == '\n') { + yylineNum++; + 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)) > '\0') && (c != last)) + ; + + if (c != EOF) + yyunputc(c); + if (c == last) + return 0; + return -1; +} + + +static char *yytexttochar() +{ + int i; + + for (i = 0; i < yypos; i++) + yychars[i] = (char)(yytext[i] & 0xff); + yychars[i] = '\0'; + return yychars; +} + + +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(0); + if (yydebug > 1) + printf("yygetc = (%x) %c [%*.*s]\n", c, c, yypos, yypos, yytexttochar()); + + 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(0); + if (n == '{') { + if (yyswallow('}') == -1) { + rval = -2; + goto done; + } + (void) yygetc(0); + } else { + if (!ISALPHA(n)) { + yyunputc(n); + break; + } + do { + n = yygetc(1); + } 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(1); + if (n == EOF || n == TOOLONG) { + rval = -2; + goto done; + } + if (n == '\n') { + yyunputc(' '); + yypos++; + } + } while (n != c); + rval = YY_STR; + goto done; + /* NOTREACHED */ + + 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(0); + if (n == '>') { + isbuilding = 1; + goto done; + } + yyunputc(n); + rval = '-'; + goto done; + + case '!' : + if (isbuilding == 1) { + yyunputc(c); + goto done; + } + n = yygetc(0); + 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(0); + 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(0); + 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(1); + } 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(0); + if (n == 'x') { + do { + n = yygetc(1); + } 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(1); + } while (ISDIGIT(n)); + yyunputc(n); + rval = YY_NUMBER; + goto done; + } + + isbuilding = 1; + goto nextchar; + +done: + yystr = yytexttostr(0, yypos); + + if (yydebug) + printf("isbuilding %d yyvarnext %d nokey %d\n", + isbuilding, yyvarnext, nokey); + 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 @%d\n", yystr, string_start, + string_end, pos, rval, yysavedepth); + + 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 (yydebug) + printf("yyresetdict(%d)\n", yysavedepth); + 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 |