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Diffstat (limited to 'grammar/lexer.l')
| -rw-r--r-- | grammar/lexer.l | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/grammar/lexer.l b/grammar/lexer.l new file mode 100644 index 00000000..a3f8bedd --- /dev/null +++ b/grammar/lexer.l @@ -0,0 +1,316 @@ + /* Lex file for rsyslog config format v2 (RainerScript). + * Please note: this file introduces the new config format, but maintains + * backward compatibility. In order to do so, the grammar is not 100% clean, + * but IMHO still sufficiently easy both to understand for programmers + * maitaining the code as well as users writing the config file. Users are, + * of course, encouraged to use new constructs only. But it needs to be noted + * that some of the legacy constructs (specifically the in-front-of-action + * PRI filter) are very hard to beat in ease of use, at least for simpler + * cases. So while we hope that cfsysline support can be dropped some time in + * the future, we will probably keep these useful constructs. + * + * Copyright 2011 Rainer Gerhards and Adiscon GmbH. + * + * This file is part of the rsyslog runtime library. + * + * The rsyslog runtime library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * The rsyslog runtime library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with the rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution. + */ + +%option noyywrap nodefault case-insensitive yylineno + /*%option noyywrap nodefault case-insensitive */ + +/* avoid compiler warning: `yyunput' defined but not used */ +%option nounput noinput + + +%x INOBJ + /* INOBJ is selected if we are inside an object (name/value pairs!) */ +%x COMMENT + /* COMMENT is "the usual trick" to handle C-style comments */ +%x INCL + /* INCL is in $IncludeConfig processing (skip to include file) */ +%x LINENO + /* LINENO: support for setting the linenumber */ +%x EXPR + /* EXPR is a bit ugly, but we need it to support pre v6-syntax. The problem + * is that cfsysline statement start with $..., the same like variables in + * an expression. However, cfsysline statements can never appear inside an + * expression. So we create a specific expr mode, which is turned on after + * we lexed a keyword that needs to be followed by an expression (using + * knowledge from the upper layer...). In expr mode, we strictly do + * expression-based parsing. Expr mode is stopped when we reach a token + * that can not be part of an expression (currently only "then"). As I + * wrote this ugly, but the price needed to pay in order to remain + * compatible to the previous format. + */ +%{ +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <strings.h> +#include <libestr.h> +#include "rainerscript.h" +#include "parserif.h" +#include "grammar.h" +static int preCommentState; /* save for lex state before a comment */ + +struct bufstack { + struct bufstack *prev; + YY_BUFFER_STATE bs; + int lineno; + char *fn; + es_str_t *estr; +} *currbs = NULL; + +char *cnfcurrfn; /* name of currently processed file */ + +int popfile(void); +int cnfSetLexFile(char *fname); + +extern int yydebug; + +/* somehow, I need these prototype even though the headers are + * included. I guess that's some autotools magic I don't understand... + */ +//char *strdup(char*); +int fileno(FILE *stream); + +%} + +%% + + /* keywords */ +"if" { BEGIN EXPR; return IF; } +<EXPR>"then" { BEGIN INITIAL; return THEN; } +<EXPR>"or" { return OR; } +<EXPR>"and" { return AND; } +<EXPR>"not" { return NOT; } +<EXPR>"," | +<EXPR>"*" | +<EXPR>"/" | +<EXPR>"%" | +<EXPR>"+" | +<EXPR>"-" | +<EXPR>"(" | +<EXPR>")" { return yytext[0]; } +<EXPR>"==" { return CMP_EQ; } +<EXPR>"<=" { return CMP_LE; } +<EXPR>">=" { return CMP_GE; } +<EXPR>"!=" | +<EXPR>"<>" { return CMP_NE; } +<EXPR>"<" { return CMP_LT; } +<EXPR>">" { return CMP_GT; } +<EXPR>"contains" { return CMP_CONTAINS; } +<EXPR>"contains_i" { return CMP_CONTAINSI; } +<EXPR>"startswith" { return CMP_STARTSWITH; } +<EXPR>"startswith_i" { return CMP_STARTSWITHI; } +<EXPR>0[0-7]+ | /* octal number */ +<EXPR>0x[0-7a-f] | /* hex number, following rule is dec; strtoll handles all! */ +<EXPR>([1-9][0-9]*|0) { yylval.n = strtoll(yytext, NULL, 0); return NUMBER; } +<EXPR>\$[$!]{0,1}[a-z][a-z0-9\-_\.]* { yylval.s = strdup(yytext); return VAR; } +<EXPR>\'([^'\\]|\\['])*\' { yylval.estr = es_newStrFromBuf(yytext+1, yyleng-2); + return STRING; } +<EXPR>\"([^"\\]|\\["])*\" { yylval.estr = es_newStrFromBuf(yytext+1, yyleng-2); + return STRING; } +<EXPR>[ \t\n] +<EXPR>[a-z][a-z0-9_]* { yylval.estr = es_newStrFromCStr(yytext, yyleng); + return FUNC; } +<EXPR>. { dbgprintf("invalid char in expr: %s\n", yytext); } +"&" { return '&'; } +"{" { return '{'; } +"}" { return '}'; } +"ruleset" { dbgprintf("RULESET\n"); } + /* line number support because the "preprocessor" combines lines and so needs + * to tell us the real source line. + */ +"stop" { dbgprintf("STOP\n"); return STOP; } +"preprocfilelinenumber(" { BEGIN LINENO; } +<LINENO>[0-9]+ { yylineno = atoi(yytext) - 1; } +<LINENO>")" { BEGIN INITIAL; } +<LINENO>.|\n + /* $IncludeConfig must be detected as part of CFSYSLINE, because this is + * always the longest match :-( + */ +<INCL>.|\n +<INCL>[^ \t\n]+ { if(cnfDoInclude(yytext) != 0) + yyterminate(); + BEGIN INITIAL; } +"global"[ \n\t]*"(" { yylval.objType = CNFOBJ_GLOBAL; + BEGIN INOBJ; return BEGINOBJ; } +"input"[ \n\t]*"(" { yylval.objType = CNFOBJ_INPUT; + BEGIN INOBJ; return BEGINOBJ; } +"module"[ \n\t]*"(" { yylval.objType = CNFOBJ_MODULE; + BEGIN INOBJ; return BEGINOBJ; } +"action"[ \n\t]*"(" { BEGIN INOBJ; return BEGIN_ACTION; } +^[ \t]*:\$?[a-z\-]+[ ]*,[ ]*!?[a-z]+[ ]*,[ ]*\".*\" { + yylval.s = strdup(yytext); return PROPFILT; } +^[ \t]*[\*a-z][,\*a-z]*[0-7]*\.[,!=;\.\*a-z0-7]+ { yylval.s = strdup(yytext); return PRIFILT; } +"~" | +"*" | +\-\/[^*][^\n]* | +\/[^*][^\n]* | +:[a-z0-9]+:[^\n]* | +[\|\.\-\@\^?~>][^\n]+ | +[a-z0-9_][a-z0-9_\-\+,;]* { yylval.s = strdup(yytext); + // printf("lex: LEGA ACT: '%s'\n", yytext); + return LEGACY_ACTION; } +<INOBJ>")" { BEGIN INITIAL; return ENDOBJ; } +<INOBJ>[a-z][a-z0-9_\.]* { yylval.estr = es_newStrFromCStr(yytext, yyleng); + return NAME; } +<INOBJ>"=" { return(yytext[0]); } +<INOBJ>\"([^"\\]|\\['"?\\abfnrtv]|\\[0-7]{1,3})*\" { + yylval.estr = es_newStrFromBuf(yytext+1, yyleng-2); + return VALUE; } +"/*" { preCommentState = YY_START; BEGIN COMMENT; } +<EXPR>"/*" { preCommentState = YY_START; BEGIN COMMENT; } +<COMMENT>"*/" { BEGIN preCommentState; } +<COMMENT>([^*]|\n)+|. +<INOBJ>#.*$ /* skip comments in input */ +<INOBJ>[ \n\t] +<INOBJ>. { dbgprintf("INOBJ: invalid char '%s'\n", yytext); } +\$[a-z]+.*$ { /* see comment on $IncludeConfig above */ + if(!strncasecmp(yytext, "$includeconfig ", 14)) { + yyless(14); + BEGIN INCL; + } else { + yylval.s = strdup(yytext); + return CFSYSLINE; + } + } +![^ \t\n]+[ \t]*$ { yylval.s = strdup(yytext); return BSD_TAG_SELECTOR; } +[+-]\*[ \t\n]*#.*$ { yylval.s = strdup(yytext); return BSD_HOST_SELECTOR; } +[+-]\*[ \t\n]*$ { yylval.s = strdup(yytext); return BSD_HOST_SELECTOR; } +^[ \t]*[+-][a-z0-9.:-]+[ \t]*$ { yylval.s = strdup(yytext); return BSD_HOST_SELECTOR; } +\#.*\n /* skip comments in input */ +[\n\t ] /* drop whitespace */ +. { dbgprintf("invalid char: %s\n", yytext); + } +<<EOF>> { if(popfile() != 0) yyterminate(); } + +%% +int +cnfParseBuffer(char *buf, unsigned lenBuf) +{ + struct bufstack *bs; + int r = 0; + yydebug = 1; + BEGIN INITIAL; + /* maintain stack */ + if((bs = malloc(sizeof(struct bufstack))) == NULL) { + r = 1; + goto done; + } + + if(currbs != NULL) + currbs->lineno = yylineno; + bs->prev = currbs; + bs->fn = strdup("*buffer*"); + bs->bs = yy_scan_buffer(buf, lenBuf); + bs->estr = NULL; + currbs = bs; + cnfcurrfn = bs->fn; + yylineno = 1; +done: return r; +} + +/* set a new buffers. Returns 0 on success, something else otherwise. */ +int +cnfSetLexFile(char *fname) +{ + es_str_t *str = NULL; + FILE *fp; + int r = 0; + struct bufstack *bs; + + if(fname == NULL) { + fp = stdin; + } else { + if((fp = fopen(fname, "r")) == NULL) { + r = 1; + goto done; + } + } + readConfFile(fp, &str); + if(fp != stdin) + fclose(fp); + + /* maintain stack */ + if((bs = malloc(sizeof(struct bufstack))) == NULL) { + r = 1; + goto done; + } + + if(currbs != NULL) + currbs->lineno = yylineno; + bs->prev = currbs; + bs->fn = strdup(fname == NULL ? "stdin" : fname); + bs->bs = yy_scan_buffer((char*)es_getBufAddr(str), es_strlen(str)); + bs->estr = str; /* needed so we can free it later */ + currbs = bs; + cnfcurrfn = bs->fn; + yylineno = 1; + +done: + if(r != 0) { + if(str != NULL) + es_deleteStr(str); + } + return r; +} + + +/* returns 0 on success, something else otherwise */ +int +popfile(void) +{ + struct bufstack *bs = currbs; + + if(bs == NULL) + return 1; + + /* delete current entry. But we must not free the file name if + * this is the top-level file, because then it may still be used + * in error messages for other processing steps. + * TODO: change this to another method which stores the file + * name inside the config objects. In the longer term, this is + * necessary, as otherwise we may provide wrong file name information + * at the end of include files as well. -- rgerhards, 2011-07-22 + */ + yy_delete_buffer(bs->bs); + if(bs->prev != NULL) + free(bs->fn); + free(bs->estr); + + /* switch back to previous */ + currbs = bs->prev; + free(bs); + + if(currbs == NULL) + return 1; /* all processed */ + + yy_switch_to_buffer(currbs->bs); + yylineno = currbs->lineno; + cnfcurrfn = currbs->fn; + return 0; +} + +void +tellLexEndParsing(void) +{ + free(cnfcurrfn); + cnfcurrfn= NULL; +} |