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| -rw-r--r-- | source4/lib/util/params.c | 587 |
1 files changed, 587 insertions, 0 deletions
diff --git a/source4/lib/util/params.c b/source4/lib/util/params.c new file mode 100644 index 0000000000..3a9e2b9505 --- /dev/null +++ b/source4/lib/util/params.c @@ -0,0 +1,587 @@ +/* -------------------------------------------------------------------------- ** + * 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 3 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, see <http://www.gnu.org/licenses/>. + * + * -------------------------------------------------------------------------- ** + * + * 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" +#include "system/locale.h" + +/* -------------------------------------------------------------------------- ** + * Constants... + */ + +#define BUFR_INC 1024 + + +/* 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; + char *bufr; + int bSize; +} 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) +{ + talloc_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 ) +{ + pos--; + while( (pos >= 0) && isspace((int)line[pos])) + pos--; + + return (((pos >= 0) && ('\\' == line[pos])) ? pos : -1 ); +} + + +static bool Section( myFILE *InFile, bool (*sfunc)(const char *, void *), void *userdata ) + /* ------------------------------------------------------------------------ ** + * 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; + const 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 > (InFile->bSize - 2) ) + { + char *tb; + + tb = talloc_realloc(InFile, InFile->bufr, char, InFile->bSize + BUFR_INC); + if( NULL == tb ) + { + DEBUG(0, ("%s Memory re-allocation failure.", func) ); + return( false ); + } + InFile->bufr = tb; + InFile->bSize += BUFR_INC; + } + + /* Handle a single character. */ + switch( c ) + { + case ']': /* Found the closing bracket. */ + InFile->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(InFile->bufr,userdata) ) /* 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( InFile->bufr, i ); /* Check for line continuation. */ + if( i < 0 ) + { + InFile->bufr[end] = '\0'; + DEBUG(0, ("%s Badly formed line in configuration file: %s\n", + func, InFile->bufr )); + return( false ); + } + end = ( (i > 0) && (' ' == InFile->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. */ + { + InFile->bufr[end] = ' '; + i = end + 1; + c = EatWhitespace( InFile ); + } + else /* All others copy verbatim. */ + { + InFile->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\n", func)); + return( false ); + } /* Section */ + +static bool Parameter( myFILE *InFile, bool (*pfunc)(const char *, const char *, void *), int c, void *userdata ) + /* ------------------------------------------------------------------------ ** + * 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. */ + const char *func = "params.c:Parameter() -"; + + /* Read the parameter name. */ + while( 0 == vstart ) /* Loop until we've found the start of the value. */ + { + + if( i > (InFile->bSize - 2) ) /* Ensure there's space for next char. */ + { + char *tb; + + tb = talloc_realloc(InFile, InFile->bufr, char, InFile->bSize + BUFR_INC ); + if( NULL == tb ) + { + DEBUG(0, ("%s Memory re-allocation failure.", func) ); + return( false ); + } + InFile->bufr = tb; + InFile->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 ); + } + InFile->bufr[end++] = '\0'; /* Mark end of string & advance. */ + i = end; /* New string starts here. */ + vstart = end; /* New string is parameter value. */ + InFile->bufr[i] = '\0'; /* New string is nul, for now. */ + break; + + case '\n': /* Find continuation char, else error. */ + i = Continuation( InFile->bufr, i ); + if( i < 0 ) + { + InFile->bufr[end] = '\0'; + DEBUG(1,("%s Ignoring badly formed line in configuration file: %s\n", + func, InFile->bufr )); + return( true ); + } + end = ( (i > 0) && (' ' == InFile->bufr[i - 1]) ) ? (i - 1) : (i); + c = mygetc( InFile ); /* Read past eoln. */ + break; + + case '\0': /* Shouldn't have EOF within param name. */ + case EOF: + InFile->bufr[i] = '\0'; + DEBUG(1,("%s Unexpected end-of-file at: %s\n", func, InFile->bufr )); + return( true ); + + default: + if( isspace( c ) ) /* One ' ' per whitespace region. */ + { + InFile->bufr[end] = ' '; + i = end + 1; + c = EatWhitespace( InFile ); + } + else /* All others verbatim. */ + { + InFile->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 > (InFile->bSize - 2) ) /* Make sure there's enough room. */ + { + char *tb; + + tb = talloc_realloc(InFile, InFile->bufr, char, InFile->bSize + BUFR_INC ); + if( NULL == tb ) + { + DEBUG(0, ("%s Memory re-allocation failure.", func) ); + return( false ); + } + InFile->bufr = tb; + InFile->bSize += BUFR_INC; + } + + 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( InFile->bufr, i ); + if( i < 0 ) + c = 0; + else + { + for( end = i; (end >= 0) && isspace((int)InFile->bufr[end]); end-- ) + ; + c = mygetc( InFile ); + } + break; + + default: /* All others verbatim. Note that spaces do */ + InFile->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; + } + } + InFile->bufr[end] = '\0'; /* End of value. */ + + return( pfunc( InFile->bufr, &InFile->bufr[vstart], userdata ) ); /* Pass name & value to pfunc(). */ + } /* Parameter */ + +static bool Parse( myFILE *InFile, + bool (*sfunc)(const char *, void *), + bool (*pfunc)(const char *, const char *, void *), + void *userdata ) + /* ------------------------------------------------------------------------ ** + * 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, userdata ) ) + return( false ); + c = EatWhitespace( InFile ); + break; + + case '\\': /* Bogus backslash. */ + c = EatWhitespace( InFile ); + break; + + default: /* Parameter line. */ + if( !Parameter( InFile, pfunc, c, userdata ) ) + return( false ); + c = EatWhitespace( InFile ); + break; + } + } + return( true ); + } /* Parse */ + +static myFILE *OpenConfFile( const 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 + * + * ------------------------------------------------------------------------ ** + */ + { + const char *func = "params.c:OpenConfFile() -"; + myFILE *ret; + + ret = talloc(talloc_autofree_context(), myFILE); + if (!ret) return NULL; + + ret->buf = file_load(FileName, &ret->size, ret); + if( NULL == ret->buf ) + { + DEBUG( 1, + ("%s Unable to open configuration file \"%s\":\n\t%s\n", + func, FileName, strerror(errno)) ); + talloc_free(ret); + return NULL; + } + + ret->p = ret->buf; + ret->bufr = NULL; + ret->bSize = 0; + return( ret ); + } /* OpenConfFile */ + +bool pm_process( const char *FileName, + bool (*sfunc)(const char *, void *), + bool (*pfunc)(const char *, const char *, void *), + void *userdata) + /* ------------------------------------------------------------------------ ** + * 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; + const 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 != InFile->bufr ) /* If we already have a buffer */ + result = Parse( InFile, sfunc, pfunc, userdata ); /* (recursive call), then just */ + /* use it. */ + + else /* If we don't have a buffer */ + { /* allocate one, then parse, */ + InFile->bSize = BUFR_INC; /* then free. */ + InFile->bufr = talloc_array(InFile, char, InFile->bSize ); + if( NULL == InFile->bufr ) + { + DEBUG(0,("%s memory allocation failure.\n", func)); + myfile_close(InFile); + return( false ); + } + result = Parse( InFile, sfunc, pfunc, userdata ); + InFile->bufr = NULL; + InFile->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 */ + +/* -------------------------------------------------------------------------- */ |