/* -------------------------------------------------------------------------- ** * Microsoft Network Services for Unix, AKA., Andrew Tridgell's SAMBA. * * This module Copyright (C) 1990-1998 Karl Auer * * Rewritten almost completely by Christopher R. Hertel * at the University of Minnesota, September, 1997. * This module Copyright (C) 1997-1998 by the University of Minnesota * -------------------------------------------------------------------------- ** * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * -------------------------------------------------------------------------- ** * * Module name: params * * -------------------------------------------------------------------------- ** * * This module performs lexical analysis and initial parsing of a * Windows-like parameter file. It recognizes and handles four token * types: section-name, parameter-name, parameter-value, and * end-of-file. Comments and line continuation are handled * internally. * * The entry point to the module is function pm_process(). This * function opens the source file, calls the Parse() function to parse * the input, and then closes the file when either the EOF is reached * or a fatal error is encountered. * * A sample parameter file might look like this: * * [section one] * parameter one = value string * parameter two = another value * [section two] * new parameter = some value or t'other * * The parameter file is divided into sections by section headers: * section names enclosed in square brackets (eg. [section one]). * Each section contains parameter lines, each of which consist of a * parameter name and value delimited by an equal sign. Roughly, the * syntax is: * * <file> :== { <section> } EOF * * <section> :== <section header> { <parameter line> } * * <section header> :== '[' NAME ']' * * <parameter line> :== NAME '=' VALUE '\n' * * Blank lines and comment lines are ignored. Comment lines are lines * beginning with either a semicolon (';') or a pound sign ('#'). * * All whitespace in section names and parameter names is compressed * to single spaces. Leading and trailing whitespace is stipped from * both names and values. * * Only the first equals sign in a parameter line is significant. * Parameter values may contain equals signs, square brackets and * semicolons. Internal whitespace is retained in parameter values, * with the exception of the '\r' character, which is stripped for * historic reasons. Parameter names may not start with a left square * bracket, an equal sign, a pound sign, or a semicolon, because these * are used to identify other tokens. * * -------------------------------------------------------------------------- ** */ #include "includes.h" /* -------------------------------------------------------------------------- ** * Constants... */ #define BUFR_INC 1024 /* -------------------------------------------------------------------------- ** * Variables... * * DEBUGLEVEL - The ubiquitous DEBUGLEVEL. This determines which DEBUG() * messages will be produced. * bufr - pointer to a global buffer. This is probably a kludge, * but it was the nicest kludge I could think of (for now). * bSize - The size of the global buffer <bufr>. */ static char *bufr = NULL; static int bSize = 0; /* we can't use FILE* due to the 256 fd limit - use this cheap hack instead */ typedef struct { char *buf; char *p; size_t size; } myFILE; static int mygetc(myFILE *f) { if (f->p >= f->buf+f->size) return EOF; /* be sure to return chars >127 as positive values */ return (int)( *(f->p++) & 0x00FF ); } static void myfile_close(myFILE *f) { if (!f) return; SAFE_FREE(f->buf); SAFE_FREE(f); } /* -------------------------------------------------------------------------- ** * Functions... */ static int EatWhitespace( myFILE *InFile ) /* ------------------------------------------------------------------------ ** * Scan past whitespace (see ctype(3C)) and return the first non-whitespace * character, or newline, or EOF. * * Input: InFile - Input source. * * Output: The next non-whitespace character in the input stream. * * Notes: Because the config files use a line-oriented grammar, we * explicitly exclude the newline character from the list of * whitespace characters. * - Note that both EOF (-1) and the nul character ('\0') are * considered end-of-file markers. * * ------------------------------------------------------------------------ ** */ { int c; for( c = mygetc( InFile ); isspace( c ) && ('\n' != c); c = mygetc( InFile ) ) ; return( c ); } /* EatWhitespace */ static int EatComment( myFILE *InFile ) /* ------------------------------------------------------------------------ ** * Scan to the end of a comment. * * Input: InFile - Input source. * * Output: The character that marks the end of the comment. Normally, * this will be a newline, but it *might* be an EOF. * * Notes: Because the config files use a line-oriented grammar, we * explicitly exclude the newline character from the list of * whitespace characters. * - Note that both EOF (-1) and the nul character ('\0') are * considered end-of-file markers. * * ------------------------------------------------------------------------ ** */ { int c; for( c = mygetc( InFile ); ('\n'!=c) && (EOF!=c) && (c>0); c = mygetc( InFile ) ) ; return( c ); } /* EatComment */ /***************************************************************************** * Scan backards within a string to discover if the last non-whitespace * character is a line-continuation character ('\\'). * * Input: line - A pointer to a buffer containing the string to be * scanned. * pos - This is taken to be the offset of the end of the * string. This position is *not* scanned. * * Output: The offset of the '\\' character if it was found, or -1 to * indicate that it was not. * *****************************************************************************/ static int Continuation( char *line, int pos ) { int pos2 = 0; pos--; while( (pos >= 0) && isspace((int)line[pos]) ) pos--; /* we should recognize if `\` is part of a multibyte character or not. */ while(pos2 <= pos) { size_t skip = 0; skip = get_character_len(line[pos2]); if (skip) { pos2 += skip; } else if (pos == pos2) { return( ((pos >= 0) && ('\\' == line[pos])) ? pos : -1 ); } else { pos2++; } } return (-1); } static BOOL Section( myFILE *InFile, BOOL (*sfunc)(char *) ) /* ------------------------------------------------------------------------ ** * Scan a section name, and pass the name to function sfunc(). * * Input: InFile - Input source. * sfunc - Pointer to the function to be called if the section * name is successfully read. * * Output: True if the section name was read and True was returned from * <sfunc>. False if <sfunc> failed or if a lexical error was * encountered. * * ------------------------------------------------------------------------ ** */ { int c; int i; int end; char *func = "params.c:Section() -"; i = 0; /* <i> is the offset of the next free byte in bufr[] and */ end = 0; /* <end> is the current "end of string" offset. In most */ /* cases these will be the same, but if the last */ /* character written to bufr[] is a space, then <end> */ /* will be one less than <i>. */ c = EatWhitespace( InFile ); /* We've already got the '['. Scan */ /* past initial white space. */ while( (EOF != c) && (c > 0) ) { /* Check that the buffer is big enough for the next character. */ if( i > (bSize - 2) ) { char *tb; tb = Realloc( bufr, bSize +BUFR_INC ); if( NULL == tb ) { DEBUG(0, ("%s Memory re-allocation failure.", func) ); return( False ); } bufr = tb; bSize += BUFR_INC; } /* Handle a single character. */ switch( c ) { case ']': /* Found the closing bracket. */ bufr[end] = '\0'; if( 0 == end ) /* Don't allow an empty name. */ { DEBUG(0, ("%s Empty section name in configuration file.\n", func )); return( False ); } if( !sfunc( unix_to_dos(bufr,True) ) ) /* Got a valid name. Deal with it. */ return( False ); (void)EatComment( InFile ); /* Finish off the line. */ return( True ); case '\n': /* Got newline before closing ']'. */ i = Continuation( bufr, i ); /* Check for line continuation. */ if( i < 0 ) { bufr[end] = '\0'; DEBUG(0, ("%s Badly formed line in configuration file: %s\n", func, bufr )); return( False ); } end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i); c = mygetc( InFile ); /* Continue with next line. */ break; default: /* All else are a valid name chars. */ if( isspace( c ) ) /* One space per whitespace region. */ { bufr[end] = ' '; i = end + 1; c = EatWhitespace( InFile ); } else /* All others copy verbatim. */ { bufr[i++] = c; end = i; c = mygetc( InFile ); } } } /* We arrive here if we've met the EOF before the closing bracket. */ DEBUG(0, ("%s Unexpected EOF in the configuration file: %s\n", func, bufr )); return( False ); } /* Section */ static BOOL Parameter( myFILE *InFile, BOOL (*pfunc)(char *, char *), int c ) /* ------------------------------------------------------------------------ ** * Scan a parameter name and value, and pass these two fields to pfunc(). * * Input: InFile - The input source. * pfunc - A pointer to the function that will be called to * process the parameter, once it has been scanned. * c - The first character of the parameter name, which * would have been read by Parse(). Unlike a comment * line or a section header, there is no lead-in * character that can be discarded. * * Output: True if the parameter name and value were scanned and processed * successfully, else False. * * Notes: This function is in two parts. The first loop scans the * parameter name. Internal whitespace is compressed, and an * equal sign (=) terminates the token. Leading and trailing * whitespace is discarded. The second loop scans the parameter * value. When both have been successfully identified, they are * passed to pfunc() for processing. * * ------------------------------------------------------------------------ ** */ { int i = 0; /* Position within bufr. */ int end = 0; /* bufr[end] is current end-of-string. */ int vstart = 0; /* Starting position of the parameter value. */ char *func = "params.c:Parameter() -"; /* Read the parameter name. */ while( 0 == vstart ) /* Loop until we've found the start of the value. */ { if( i > (bSize - 2) ) /* Ensure there's space for next char. */ { char *tb; tb = Realloc( bufr, bSize + BUFR_INC ); if( NULL == tb ) { DEBUG(0, ("%s Memory re-allocation failure.", func) ); return( False ); } bufr = tb; bSize += BUFR_INC; } switch( c ) { case '=': /* Equal sign marks end of param name. */ if( 0 == end ) /* Don't allow an empty name. */ { DEBUG(0, ("%s Invalid parameter name in config. file.\n", func )); return( False ); } bufr[end++] = '\0'; /* Mark end of string & advance. */ i = end; /* New string starts here. */ vstart = end; /* New string is parameter value. */ bufr[i] = '\0'; /* New string is nul, for now. */ break; case '\n': /* Find continuation char, else error. */ i = Continuation( bufr, i ); if( i < 0 ) { bufr[end] = '\0'; DEBUG(1,("%s Ignoring badly formed line in configuration file: %s\n", func, bufr )); return( True ); } end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i); c = mygetc( InFile ); /* Read past eoln. */ break; case '\0': /* Shouldn't have EOF within param name. */ case EOF: bufr[i] = '\0'; DEBUG(1,("%s Unexpected end-of-file at: %s\n", func, bufr )); return( True ); default: if( isspace( c ) ) /* One ' ' per whitespace region. */ { bufr[end] = ' '; i = end + 1; c = EatWhitespace( InFile ); } else /* All others verbatim. */ { bufr[i++] = c; end = i; c = mygetc( InFile ); } } } /* Now parse the value. */ c = EatWhitespace( InFile ); /* Again, trim leading whitespace. */ while( (EOF !=c) && (c > 0) ) { if( i > (bSize - 2) ) /* Make sure there's enough room. */ { bSize += BUFR_INC; bufr = Realloc( bufr, bSize ); if( NULL == bufr ) { DEBUG(0, ("%s Memory re-allocation failure.", func) ); return( False ); } } switch( c ) { case '\r': /* Explicitly remove '\r' because the older */ c = mygetc( InFile ); /* version called fgets_slash() which also */ break; /* removes them. */ case '\n': /* Marks end of value unless there's a '\'. */ i = Continuation( bufr, i ); if( i < 0 ) c = 0; else { for( end = i; (end >= 0) && isspace((int)bufr[end]); end-- ) ; c = mygetc( InFile ); } break; default: /* All others verbatim. Note that spaces do */ bufr[i++] = c; /* not advance <end>. This allows trimming */ if( !isspace( c ) ) /* of whitespace at the end of the line. */ end = i; c = mygetc( InFile ); break; } } bufr[end] = '\0'; /* End of value. */ return( pfunc( bufr, &bufr[vstart] ) ); /* Pass name & value to pfunc(). */ } /* Parameter */ static BOOL Parse( myFILE *InFile, BOOL (*sfunc)(char *), BOOL (*pfunc)(char *, char *) ) /* ------------------------------------------------------------------------ ** * Scan & parse the input. * * Input: InFile - Input source. * sfunc - Function to be called when a section name is scanned. * See Section(). * pfunc - Function to be called when a parameter is scanned. * See Parameter(). * * Output: True if the file was successfully scanned, else False. * * Notes: The input can be viewed in terms of 'lines'. There are four * types of lines: * Blank - May contain whitespace, otherwise empty. * Comment - First non-whitespace character is a ';' or '#'. * The remainder of the line is ignored. * Section - First non-whitespace character is a '['. * Parameter - The default case. * * ------------------------------------------------------------------------ ** */ { int c; c = EatWhitespace( InFile ); while( (EOF != c) && (c > 0) ) { switch( c ) { case '\n': /* Blank line. */ c = EatWhitespace( InFile ); break; case ';': /* Comment line. */ case '#': c = EatComment( InFile ); break; case '[': /* Section Header. */ if( !Section( InFile, sfunc ) ) return( False ); c = EatWhitespace( InFile ); break; case '\\': /* Bogus backslash. */ c = EatWhitespace( InFile ); break; default: /* Parameter line. */ if( !Parameter( InFile, pfunc, c ) ) return( False ); c = EatWhitespace( InFile ); break; } } return( True ); } /* Parse */ static myFILE *OpenConfFile( char *FileName ) /* ------------------------------------------------------------------------ ** * Open a configuration file. * * Input: FileName - The pathname of the config file to be opened. * * Output: A pointer of type (char **) to the lines of the file * * ------------------------------------------------------------------------ ** */ { char *func = "params.c:OpenConfFile() -"; extern BOOL in_client; int lvl = in_client?1:0; myFILE *ret; ret = (myFILE *)malloc(sizeof(*ret)); if (!ret) return NULL; ret->buf = file_load(FileName, &ret->size); if( NULL == ret->buf ) { DEBUG( lvl, ("%s Unable to open configuration file \"%s\":\n\t%s\n", func, FileName, strerror(errno)) ); SAFE_FREE(ret); return NULL; } ret->p = ret->buf; return( ret ); } /* OpenConfFile */ BOOL pm_process( char *FileName, BOOL (*sfunc)(char *), BOOL (*pfunc)(char *, char *) ) /* ------------------------------------------------------------------------ ** * Process the named parameter file. * * Input: FileName - The pathname of the parameter file to be opened. * sfunc - A pointer to a function that will be called when * a section name is discovered. * pfunc - A pointer to a function that will be called when * a parameter name and value are discovered. * * Output: TRUE if the file was successfully parsed, else FALSE. * * ------------------------------------------------------------------------ ** */ { int result; myFILE *InFile; char *func = "params.c:pm_process() -"; InFile = OpenConfFile( FileName ); /* Open the config file. */ if( NULL == InFile ) return( False ); DEBUG( 3, ("%s Processing configuration file \"%s\"\n", func, FileName) ); if( NULL != bufr ) /* If we already have a buffer */ result = Parse( InFile, sfunc, pfunc ); /* (recursive call), then just */ /* use it. */ else /* If we don't have a buffer */ { /* allocate one, then parse, */ bSize = BUFR_INC; /* then free. */ bufr = (char *)malloc( bSize ); if( NULL == bufr ) { DEBUG(0,("%s memory allocation failure.\n", func)); myfile_close(InFile); return( False ); } result = Parse( InFile, sfunc, pfunc ); SAFE_FREE( bufr ); bufr = NULL; bSize = 0; } myfile_close(InFile); if( !result ) /* Generic failure. */ { DEBUG(0,("%s Failed. Error returned from params.c:parse().\n", func)); return( False ); } return( True ); /* Generic success. */ } /* pm_process */ /* -------------------------------------------------------------------------- */