/* This modules is based on the params.c module from Samba, written by Karl Auer
and much modified by Christopher Hertel. */
/*
* 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, visit the http://fsf.org website.
*/
/* -------------------------------------------------------------------------- **
*
* 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 stripped 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 "rsync.h"
#include "ifuncs.h"
#include "itypes.h"
/* -------------------------------------------------------------------------- **
* Constants...
*/
#define BUFR_INC 1024
/* -------------------------------------------------------------------------- **
* Variables...
*
* 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;
static BOOL (*the_sfunc)(char *);
static BOOL (*the_pfunc)(char *, char *);
/* -------------------------------------------------------------------------- **
* Functions...
*/
static int EatWhitespace( FILE *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 = getc( InFile ); isspace( c ) && ('\n' != c); c = getc( InFile ) )
;
return( c );
} /* EatWhitespace */
static int EatComment( FILE *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 = getc( InFile ); ('\n'!=c) && (EOF!=c) && (c>0); c = getc( InFile ) )
;
return( c );
} /* EatComment */
static int Continuation( char *line, int pos )
/* ------------------------------------------------------------------------ **
* Scan backwards 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.
*
* ------------------------------------------------------------------------ **
*/
{
pos--;
while( pos >= 0 && isSpace(line + pos) )
pos--;
return( ((pos >= 0) && ('\\' == line[pos])) ? pos : -1 );
} /* Continuation */
static BOOL Section( FILE *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) )
{
bSize += BUFR_INC;
bufr = realloc_array( bufr, char, bSize );
}
/* Handle a single character. */
switch( c )
{
case ']': /* Found the closing bracket. */
bufr[end] = '\0';
if( 0 == end ) /* Don't allow an empty name. */
{
rprintf(FLOG, "%s Empty section name in config file.\n", func );
return( False );
}
if( !sfunc( bufr ) ) /* 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';
rprintf(FLOG, "%s Badly formed line in config file: %s\n",
func, bufr );
return( False );
}
end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i);
c = getc( 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 = getc( InFile );
}
}
}
/* We arrive here if we've met the EOF before the closing bracket. */
rprintf(FLOG, "%s Unexpected EOF in the config file: %s\n", func, bufr );
return( False );
} /* Section */
static BOOL Parameter( FILE *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. */
{
bSize += BUFR_INC;
bufr = realloc_array( bufr, char, bSize );
}
switch( c )
{
case '=': /* Equal sign marks end of param name. */
if( 0 == end ) /* Don't allow an empty name. */
{
rprintf(FLOG, "%s Invalid parameter name in config file.\n", func );
return( False );
}
bufr[end++] = '\0'; /* Mark end of string & advance. */
i = vstart = end; /* New string starts here. */
c = EatWhitespace(InFile);
break;
case '\n': /* Find continuation char, else error. */
i = Continuation( bufr, i );
if( i < 0 )
{
bufr[end] = '\0';
rprintf(FLOG, "%s Ignoring badly formed line in config file: %s\n",
func, bufr );
return( True );
}
end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i);
c = getc( InFile ); /* Read past eoln. */
break;
case '\0': /* Shouldn't have EOF within param name. */
case EOF:
bufr[i] = '\0';
rprintf(FLOG, "%s Unexpected end-of-file at: %s\n", func, bufr );
return( True );
case ' ':
case '\t':
/* A directive divides at the first space or tab. */
if (*bufr == '&') {
bufr[end++] = '\0';
i = vstart = end;
c = EatWhitespace(InFile);
if (c == '=')
c = EatWhitespace(InFile);
break;
}
/* FALL THROUGH */
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 = getc( InFile );
}
}
}
/* Now parse the value. */
while( (EOF !=c) && (c > 0) )
{
if( i > (bSize - 2) ) /* Make sure there's enough room. */
{
bSize += BUFR_INC;
bufr = realloc_array( bufr, char, bSize );
}
switch( c )
{
case '\r': /* Explicitly remove '\r' because the older */
c = getc( 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(bufr + end); end-- )
;
c = getc( 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 = getc( InFile );
break;
}
}
bufr[end] = '\0'; /* End of value. */
return( pfunc( bufr, &bufr[vstart] ) ); /* Pass name & value to pfunc(). */
} /* Parameter */
static int name_cmp(const void *n1, const void *n2)
{
return strcmp(*(char * const *)n1, *(char * const *)n2);
}
static int include_config(char *include, int manage_globals)
{
STRUCT_STAT sb;
char *match = manage_globals ? "*.conf" : "*.inc";
int ret;
if (do_stat(include, &sb) < 0) {
rsyserr(FLOG, errno, "unable to stat config file \"%s\"", include);
return 0;
}
if (S_ISREG(sb.st_mode)) {
if (manage_globals && the_sfunc)
the_sfunc("]push");
ret = pm_process(include, the_sfunc, the_pfunc);
if (manage_globals && the_sfunc)
the_sfunc("]pop");
} else if (S_ISDIR(sb.st_mode)) {
char buf[MAXPATHLEN], **bpp;
item_list conf_list;
struct dirent *di;
size_t j;
DIR *d;
if (!(d = opendir(include))) {
rsyserr(FLOG, errno, "unable to open config dir \"%s\"", include);
return 0;
}
memset(&conf_list, 0, sizeof conf_list);
while ((di = readdir(d)) != NULL) {
char *dname = d_name(di);
if (!wildmatch(match, dname))
continue;
bpp = EXPAND_ITEM_LIST(&conf_list, char *, 32);
pathjoin(buf, sizeof buf, include, dname);
*bpp = strdup(buf);
}
closedir(d);
if (!(bpp = conf_list.items))
return 1;
if (conf_list.count > 1)
qsort(bpp, conf_list.count, sizeof (char *), name_cmp);
for (j = 0, ret = 1; j < conf_list.count; j++) {
if (manage_globals && the_sfunc)
the_sfunc(j == 0 ? "]push" : "]reset");
if ((ret = pm_process(bpp[j], the_sfunc, the_pfunc)) != 1)
break;
}
if (manage_globals && the_sfunc)
the_sfunc("]pop");
for (j = 0; j < conf_list.count; j++)
free(bpp[j]);
free(bpp);
} else
ret = 0;
return ret;
}
static int parse_directives(char *name, char *val)
{
if (strcasecmp(name, "&include") == 0)
return include_config(val, 1);
if (strcasecmp(name, "&merge") == 0)
return include_config(val, 0);
rprintf(FLOG, "Unknown directive: %s.\n", name);
return 0;
}
static int Parse( FILE *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: 1 if the file was successfully scanned, 2 if the file was
* scanned until a section header with no section function, else 0.
*
* 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 (!sfunc)
return 2;
if( !Section( InFile, sfunc ) )
return 0;
c = EatWhitespace( InFile );
break;
case '\\': /* Bogus backslash. */
c = EatWhitespace( InFile );
break;
case '&': /* Handle directives */
the_sfunc = sfunc;
the_pfunc = pfunc;
c = Parameter( InFile, parse_directives, c );
if (c != 1)
return c;
c = EatWhitespace( InFile );
break;
default: /* Parameter line. */
if( !Parameter( InFile, pfunc, c ) )
return 0;
c = EatWhitespace( InFile );
break;
}
}
return 1;
} /* Parse */
static FILE *OpenConfFile( char *FileName )
/* ------------------------------------------------------------------------ **
* Open a config file.
*
* Input: FileName - The pathname of the config file to be opened.
*
* Output: A pointer of type (FILE *) to the opened file, or NULL if the
* file could not be opened.
*
* ------------------------------------------------------------------------ **
*/
{
FILE *OpenedFile;
char *func = "params.c:OpenConfFile() -";
if( NULL == FileName || 0 == *FileName )
{
rprintf(FLOG, "%s No config filename specified.\n", func);
return( NULL );
}
OpenedFile = fopen( FileName, "r" );
if( NULL == OpenedFile )
{
rsyserr(FLOG, errno, "unable to open config file \"%s\"",
FileName);
}
return( OpenedFile );
} /* OpenConfFile */
int 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: 1 if the file was successfully parsed, 2 if parsing ended at a
* section header w/o a section function, else 0.
*
* ------------------------------------------------------------------------ **
*/
{
int result;
FILE *InFile;
char *func = "params.c:pm_process() -";
InFile = OpenConfFile( FileName ); /* Open the config file. */
if( NULL == InFile )
return( False );
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 = new_array( char, bSize );
result = Parse( InFile, sfunc, pfunc );
free( bufr );
bufr = NULL;
bSize = 0;
}
fclose(InFile);
if( !result ) /* Generic failure. */
{
rprintf(FLOG, "%s Failed. Error returned from params.c:parse().\n", func);
return 0;
}
return result;
} /* pm_process */
/* -------------------------------------------------------------------------- */
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