loadparm.c - external_rsync - Gitiles

 /*
  * 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.
  *
  * This is based on loadparm.c from Samba, written by Andrew Tridgell
  * and Karl Auer.  Some of the changes are:
  *
  * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
  * Copyright (C) 2003-2020 Wayne Davison
  */

 /* Load parameters.
  *
  *  This module provides suitable callback functions for the params
  *  module. It builds the internal table of section details which is
  *  then used by the rest of the server.
  *
  * To add a parameter:
  *
  * 1) add it to the global_vars or local_vars structure definition
  * 2) add it to the parm_table
  * 3) add it to the list of available functions (eg: using FN_GLOBAL_STRING())
  * 4) initialise it in the Defaults static structure
  *
  * Notes:
  *   The configuration file is processed sequentially for speed. For this
  *   reason, there is a fair bit of sequence-dependent code here - ie., code
  *   which assumes that certain things happen before others. In particular, the
  *   code which happens at the boundary between sections is delicately poised,
  *   so be careful!
  */

 #include "rsync.h"
 #include "itypes.h"
 #include "ifuncs.h"
 #include "default-dont-compress.h"

 extern item_list dparam_list;

 #define strequal(a, b) (strcasecmp(a, b)==0)

 #ifndef LOG_DAEMON
 #define LOG_DAEMON 0
 #endif

 /* the following are used by loadparm for option lists */
 typedef enum {
 	P_BOOL, P_BOOLREV, P_BOOL3, P_CHAR, P_INTEGER,
 	P_OCTAL, P_PATH, P_STRING, P_ENUM
 } parm_type;

 typedef enum {
 	P_LOCAL, P_GLOBAL, P_NONE
 } parm_class;

 struct enum_list {
 	int value;
 	char *name;
 };

 struct parm_struct {
 	char *label;
 	parm_type type;
 	parm_class class;
 	void *ptr;
 	struct enum_list *enum_list;
 	unsigned flags;
 };

 #ifndef GLOBAL_NAME
 #define GLOBAL_NAME "global"
 #endif

 /* some helpful bits */
 #define iSECTION(i) ((local_vars*)section_list.items)[i]
 #define LP_SNUM_OK(i) ((i) >= 0 && (i) < (int)section_list.count)
 #define SECTION_PTR(s, p) (((char*)(s)) + (ptrdiff_t)(((char*)(p))-(char*)&Vars.l))

 /* Stack of "Vars" values used by the &include directive. */
 static item_list Vars_stack = EMPTY_ITEM_LIST;

 /* The array of section values that holds all the defined modules. */
 static item_list section_list = EMPTY_ITEM_LIST;

 static int iSectionIndex = -1;
 static BOOL bInGlobalSection = True;

 static struct enum_list enum_syslog_facility[] = {
 #ifdef LOG_AUTH
 	{ LOG_AUTH, "auth" },
 #endif
 #ifdef LOG_AUTHPRIV
 	{ LOG_AUTHPRIV, "authpriv" },
 #endif
 #ifdef LOG_CRON
 	{ LOG_CRON, "cron" },
 #endif
 #ifdef LOG_DAEMON
 	{ LOG_DAEMON, "daemon" },
 #endif
 #ifdef LOG_FTP
 	{ LOG_FTP, "ftp" },
 #endif
 #ifdef LOG_KERN
 	{ LOG_KERN, "kern" },
 #endif
 #ifdef LOG_LPR
 	{ LOG_LPR, "lpr" },
 #endif
 #ifdef LOG_MAIL
 	{ LOG_MAIL, "mail" },
 #endif
 #ifdef LOG_NEWS
 	{ LOG_NEWS, "news" },
 #endif
 #ifdef LOG_AUTH
 	{ LOG_AUTH, "security" },
 #endif
 #ifdef LOG_SYSLOG
 	{ LOG_SYSLOG, "syslog" },
 #endif
 #ifdef LOG_USER
 	{ LOG_USER, "user" },
 #endif
 #ifdef LOG_UUCP
 	{ LOG_UUCP, "uucp" },
 #endif
 #ifdef LOG_LOCAL0
 	{ LOG_LOCAL0, "local0" },
 #endif
 #ifdef LOG_LOCAL1
 	{ LOG_LOCAL1, "local1" },
 #endif
 #ifdef LOG_LOCAL2
 	{ LOG_LOCAL2, "local2" },
 #endif
 #ifdef LOG_LOCAL3
 	{ LOG_LOCAL3, "local3" },
 #endif
 #ifdef LOG_LOCAL4
 	{ LOG_LOCAL4, "local4" },
 #endif
 #ifdef LOG_LOCAL5
 	{ LOG_LOCAL5, "local5" },
 #endif
 #ifdef LOG_LOCAL6
 	{ LOG_LOCAL6, "local6" },
 #endif
 #ifdef LOG_LOCAL7
 	{ LOG_LOCAL7, "local7" },
 #endif
 	{ -1, NULL }
 };

 /* Expand %VAR% references.  Any unknown vars or unrecognized
  * syntax leaves the raw chars unchanged. */
 static char *expand_vars(const char *str)
 {
 	char *buf, *t;
 	const char *f;
 	int bufsize;

 	if (!str || !strchr(str, '%'))
 		return (char *)str; /* TODO change return value to const char* at some point. */

 	bufsize = strlen(str) + 2048;
 	buf = new_array(char, bufsize+1); /* +1 for trailing '\0' */

 	for (t = buf, f = str; bufsize && *f; ) {
 		if (*f == '%' && isUpper(f+1)) {
 			char *percent = strchr(f+1, '%');
 			if (percent && percent - f < bufsize) {
 				char *val;
 				strlcpy(t, f+1, percent - f);
 				val = getenv(t);
 				if (val) {
 					int len = strlcpy(t, val, bufsize+1);
 					if (len > bufsize)
 						break;
 					bufsize -= len;
 					t += len;
 					f = percent + 1;
 					continue;
 				}
 			}
 		}
 		*t++ = *f++;
 		bufsize--;
 	}
 	*t = '\0';

 	if (*f) {
 		rprintf(FLOG, "Overflowed buf in expand_vars() trying to expand: %s\n", str);
 		exit_cleanup(RERR_MALLOC);
 	}

 	if (bufsize && (buf = realloc(buf, t - buf + 1)) == NULL)
 		out_of_memory("expand_vars");

 	return buf;
 }

 /* Each "char* foo" has an associated "BOOL foo_EXP" that tracks if the string has been expanded yet or not. */

 /* NOTE: use this function and all the FN_{GLOBAL,LOCAL} ones WITHOUT a trailing semicolon! */
 #define RETURN_EXPANDED(val) {if (!val ## _EXP) {val = expand_vars(val); val ## _EXP = True;} return val ? val : "";}

 /* In this section all the functions that are used to access the
  * parameters from the rest of the program are defined. */

 #define FN_GLOBAL_STRING(fn_name, val) \
  char *fn_name(void) RETURN_EXPANDED(Vars.g.val)
 #define FN_GLOBAL_BOOL(fn_name, val) \
  BOOL fn_name(void) {return Vars.g.val;}
 #define FN_GLOBAL_CHAR(fn_name, val) \
  char fn_name(void) {return Vars.g.val;}
 #define FN_GLOBAL_INTEGER(fn_name, val) \
  int fn_name(void) {return Vars.g.val;}

 #define FN_LOCAL_STRING(fn_name, val) \
  char *fn_name(int i) {if (LP_SNUM_OK(i) && iSECTION(i).val) RETURN_EXPANDED(iSECTION(i).val) else RETURN_EXPANDED(Vars.l.val)}
 #define FN_LOCAL_BOOL(fn_name, val) \
  BOOL fn_name(int i) {return LP_SNUM_OK(i)? iSECTION(i).val : Vars.l.val;}
 #define FN_LOCAL_CHAR(fn_name, val) \
  char fn_name(int i) {return LP_SNUM_OK(i)? iSECTION(i).val : Vars.l.val;}
 #define FN_LOCAL_INTEGER(fn_name, val) \
  int fn_name(int i) {return LP_SNUM_OK(i)? iSECTION(i).val : Vars.l.val;}

 /* The following include file contains:
  *
  * typedef global_vars - describes global (ie., server-wide) parameters.
  * typedef local_vars - describes a single section.
  * typedef all_vars - a combination of global_vars & local_vars.
  * all_vars Defaults - the default values for all the variables.
  * all_vars Vars - the currently configured values for all the variables.
  * struct parm_struct parm_table - the strings & variables for the parser.
  * FN_{LOCAL,GLOBAL}_{TYPE}() definition for all the lp_var_name() accessors.
  */

 #include "daemon-parm.h"

 /* Initialise the Default all_vars structure. */
 void reset_daemon_vars(void)
 {
 	memcpy(&Vars, &Defaults, sizeof Vars);
 }

 /* Assign a copy of v to *s.  Handles NULL strings.  We don't worry
  * about overwriting a malloc'd string because the long-running
  * (port-listening) daemon only loads the config file once, and the
  * per-job (forked or xinitd-ran) daemon only re-reads the file at
  * the start, so any lost memory is inconsequential. */
 static inline void string_set(char **s, const char *v)
 {
 	*s = v ? strdup(v) : NULL;
 }

 /* Copy local_vars into a new section. No need to strdup since we don't free. */
 static void copy_section(local_vars *psectionDest, local_vars *psectionSource)
 {
 	memcpy(psectionDest, psectionSource, sizeof psectionDest[0]);
 }

 /* Initialise a section to the defaults. */
 static void init_section(local_vars *psection)
 {
 	memset(psection, 0, sizeof (local_vars));
 	copy_section(psection, &Vars.l);
 }

 /* Do a case-insensitive, whitespace-ignoring string equality check. */
 static int strwiEQ(char *psz1, char *psz2)
 {
 	/* If one or both strings are NULL, we return equality right away. */
 	if (psz1 == psz2)
 		return 1;
 	if (psz1 == NULL || psz2 == NULL)
 		return 0;

 	/* sync the strings on first non-whitespace */
 	while (1) {
 		while (isSpace(psz1))
 			psz1++;
 		while (isSpace(psz2))
 			psz2++;
 		if (*psz1 == '\0' || *psz2 == '\0')
 			break;
 		if (toUpper(psz1) != toUpper(psz2))
 			break;
 		psz1++;
 		psz2++;
 	}
 	return *psz1 == *psz2;
 }

 /* Find a section by name. Otherwise works like get_section. */
 static int getsectionbyname(char *name)
 {
 	int i;

 	for (i = section_list.count - 1; i >= 0; i--) {
 		if (strwiEQ(iSECTION(i).name, name))
 			break;
 	}

 	return i;
 }

 /* Add a new section to the sections array w/the default values. */
 static int add_a_section(char *name)
 {
 	int i;
 	local_vars *s;

 	/* it might already exist */
 	if (name) {
 		i = getsectionbyname(name);
 		if (i >= 0)
 			return i;
 	}

 	i = section_list.count;
 	s = EXPAND_ITEM_LIST(&section_list, local_vars, 2);

 	init_section(s);
 	if (name)
 		string_set(&s->name, name);

 	return i;
 }

 /* Map a parameter's string representation to something we can use.
  * Returns False if the parameter string is not recognised, else TRUE. */
 static int map_parameter(char *parmname)
 {
 	int iIndex;

 	if (*parmname == '-')
 		return -1;

 	for (iIndex = 0; parm_table[iIndex].label; iIndex++) {
 		if (strwiEQ(parm_table[iIndex].label, parmname))
 			return iIndex;
 	}

 	rprintf(FLOG, "Unknown Parameter encountered: \"%s\"\n", parmname);
 	return -1;
 }

 /* Set a boolean variable from the text value stored in the passed string.
  * Returns True in success, False if the passed string does not correctly
  * represent a boolean. */
 static BOOL set_boolean(BOOL *pb, char *parmvalue, int allow_unset)
 {
 	if (strwiEQ(parmvalue, "yes") || strwiEQ(parmvalue, "true") || strwiEQ(parmvalue, "1"))
 		*pb = True;
 	else if (strwiEQ(parmvalue, "no") || strwiEQ(parmvalue, "false") || strwiEQ(parmvalue, "0"))
 		*pb = False;
 	else if (allow_unset && (strwiEQ(parmvalue, "unset") || strwiEQ(parmvalue, "-1")))
 		*pb = Unset;
 	else {
 		rprintf(FLOG, "Badly formed boolean in configuration file: \"%s\".\n", parmvalue);
 		return False;
 	}
 	return True;
 }

 /* Process a parameter. */
 static BOOL do_parameter(char *parmname, char *parmvalue)
 {
 	int parmnum, i;
 	void *parm_ptr; /* where we are going to store the result */
 	void *def_ptr;
 	char *cp;

 	parmnum = map_parameter(parmname);

 	if (parmnum < 0) {
 		rprintf(FLOG, "IGNORING unknown parameter \"%s\"\n", parmname);
 		return True;
 	}

 	def_ptr = parm_table[parmnum].ptr;

 	if (bInGlobalSection)
 		parm_ptr = def_ptr;
 	else {
 		if (parm_table[parmnum].class == P_GLOBAL) {
 			rprintf(FLOG, "Global parameter %s found in module section!\n", parmname);
 			return True;
 		}
 		parm_ptr = SECTION_PTR(&iSECTION(iSectionIndex), def_ptr);
 	}

 	/* now switch on the type of variable it is */
 	switch (parm_table[parmnum].type) {
 	case P_PATH:
 	case P_STRING:
 		/* delay expansion of %VAR% strings */
 		break;
 	default:
 		/* expand any %VAR% strings now */
 		parmvalue = expand_vars(parmvalue);
 		break;
 	}

 	switch (parm_table[parmnum].type) {
 	case P_BOOL:
 		set_boolean(parm_ptr, parmvalue, False);
 		break;

 	case P_BOOL3:
 		set_boolean(parm_ptr, parmvalue, True);
 		break;

 	case P_BOOLREV:
 		set_boolean(parm_ptr, parmvalue, False);
 		*(BOOL *)parm_ptr = ! *(BOOL *)parm_ptr;
 		break;

 	case P_INTEGER:
 		*(int *)parm_ptr = atoi(parmvalue);
 		break;

 	case P_CHAR:
 		*(char *)parm_ptr = *parmvalue;
 		break;

 	case P_OCTAL:
 		sscanf(parmvalue, "%o", (unsigned int *)parm_ptr);
 		break;

 	case P_PATH:
 		string_set(parm_ptr, parmvalue);
 		if ((cp = *(char**)parm_ptr) != NULL) {
 			int len = strlen(cp);
 			while (len > 1 && cp[len-1] == '/') len--;
 			cp[len] = '\0';
 		}
 		break;

 	case P_STRING:
 		string_set(parm_ptr, parmvalue);
 		break;

 	case P_ENUM:
 		for (i=0; parm_table[parmnum].enum_list[i].name; i++) {
 			if (strequal(parmvalue, parm_table[parmnum].enum_list[i].name)) {
 				*(int *)parm_ptr = parm_table[parmnum].enum_list[i].value;
 				break;
 			}
 		}
 		if (!parm_table[parmnum].enum_list[i].name) {
 			if (atoi(parmvalue) > 0)
 				*(int *)parm_ptr = atoi(parmvalue);
 		}
 		break;
 	}

 	return True;
 }

 /* Process a new section (rsync module).
  * Returns True on success, False on failure. */
 static BOOL do_section(char *sectionname)
 {
 	BOOL isglobal;

 	if (*sectionname == ']') { /* A special push/pop/reset directive from params.c */
 		bInGlobalSection = 1;
 		if (strcmp(sectionname+1, "push") == 0) {
 			all_vars *vp = EXPAND_ITEM_LIST(&Vars_stack, all_vars, 2);
 			memcpy(vp, &Vars, sizeof Vars);
 		} else if (strcmp(sectionname+1, "pop") == 0
 		 || strcmp(sectionname+1, "reset") == 0) {
 			all_vars *vp = ((all_vars*)Vars_stack.items) + Vars_stack.count - 1;
 			if (!Vars_stack.count)
 				return False;
 			memcpy(&Vars, vp, sizeof Vars);
 			if (sectionname[1] == 'p')
 				Vars_stack.count--;
 		} else
 			return False;
 		return True;
 	}

 	isglobal = strwiEQ(sectionname, GLOBAL_NAME);

 	/* At the end of the global section, add any --dparam items. */
 	if (bInGlobalSection && !isglobal) {
 		if (!section_list.count)
 			set_dparams(0);
 	}

 	/* if we've just struck a global section, note the fact. */
 	bInGlobalSection = isglobal;

 	/* check for multiple global sections */
 	if (bInGlobalSection)
 		return True;

 #if 0
 	/* If we have a current section, tidy it up before moving on. */
 	if (iSectionIndex >= 0) {
 		/* Add any tidy work as needed ... */
 		if (problem)
 			return False;
 	}
 #endif

 	if (strchr(sectionname, '/') != NULL) {
 		rprintf(FLOG, "Warning: invalid section name in configuration file: %s\n", sectionname);
 		return False;
 	}

 	if ((iSectionIndex = add_a_section(sectionname)) < 0) {
 		rprintf(FLOG, "Failed to add a new module\n");
 		bInGlobalSection = True;
 		return False;
 	}

 	return True;
 }

 /* Load the modules from the config file. Return True on success,
  * False on failure. */
 int lp_load(char *pszFname, int globals_only)
 {
 	bInGlobalSection = True;

 	reset_daemon_vars();

 	/* We get sections first, so have to start 'behind' to make up. */
 	iSectionIndex = -1;
 	return pm_process(pszFname, globals_only ? NULL : do_section, do_parameter);
 }

 BOOL set_dparams(int syntax_check_only)
 {
 	char *equal, *val, **params = dparam_list.items;
 	unsigned j;

 	for (j = 0; j < dparam_list.count; j++) {
 		equal = strchr(params[j], '='); /* options.c verified this */
 		*equal = '\0';
 		if (syntax_check_only) {
 			if (map_parameter(params[j]) < 0) {
 				rprintf(FERROR, "Unknown parameter \"%s\"\n", params[j]);
 				*equal = '=';
 				return False;
 			}
 		} else {
 			for (val = equal+1; isSpace(val); val++) {}
 			do_parameter(params[j], val);
 		}
 		*equal = '=';
 	}

 	return True;
 }

 /* Return the max number of modules (sections). */
 int lp_num_modules(void)
 {
 	return section_list.count;
 }

 /* Return the number of the module with the given name, or -1 if it doesn't
  * exist. Note that this is a DIFFERENT ANIMAL from the internal function
  * getsectionbyname()! This works ONLY if all sections have been loaded,
  * and does not copy the found section. */
 int lp_number(char *name)
 {
 	int i;

 	for (i = section_list.count - 1; i >= 0; i--) {
 		if (strcmp(lp_name(i), name) == 0)
 			break;
 	}

 	return i;
 }
	/*
	* 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.
	*
	* This is based on loadparm.c from Samba, written by Andrew Tridgell
	* and Karl Auer. Some of the changes are:
	*
	* Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
	* Copyright (C) 2003-2020 Wayne Davison
	*/

	/* Load parameters.
	*
	* This module provides suitable callback functions for the params
	* module. It builds the internal table of section details which is
	* then used by the rest of the server.
	*
	* To add a parameter:
	*
	* 1) add it to the global_vars or local_vars structure definition
	* 2) add it to the parm_table
	* 3) add it to the list of available functions (eg: using FN_GLOBAL_STRING())
	* 4) initialise it in the Defaults static structure
	*
	* Notes:
	* The configuration file is processed sequentially for speed. For this
	* reason, there is a fair bit of sequence-dependent code here - ie., code
	* which assumes that certain things happen before others. In particular, the
	* code which happens at the boundary between sections is delicately poised,
	* so be careful!
	*/

	#include "rsync.h"
	#include "itypes.h"
	#include "ifuncs.h"
	#include "default-dont-compress.h"

	extern item_list dparam_list;

	#define strequal(a, b) (strcasecmp(a, b)==0)

	#ifndef LOG_DAEMON
	#define LOG_DAEMON 0
	#endif

	/* the following are used by loadparm for option lists */
	typedef enum {
	P_BOOL, P_BOOLREV, P_BOOL3, P_CHAR, P_INTEGER,
	P_OCTAL, P_PATH, P_STRING, P_ENUM
	} parm_type;

	typedef enum {
	P_LOCAL, P_GLOBAL, P_NONE
	} parm_class;

	struct enum_list {
	int value;
	char *name;
	};

	struct parm_struct {
	char *label;
	parm_type type;
	parm_class class;
	void *ptr;
	struct enum_list *enum_list;
	unsigned flags;
	};

	#ifndef GLOBAL_NAME
	#define GLOBAL_NAME "global"
	#endif

	/* some helpful bits */
	#define iSECTION(i) ((local_vars*)section_list.items)[i]
	#define LP_SNUM_OK(i) ((i) >= 0 && (i) < (int)section_list.count)
	#define SECTION_PTR(s, p) (((char)(s)) + (ptrdiff_t)(((char)(p))-(char*)&Vars.l))

	/* Stack of "Vars" values used by the &include directive. */
	static item_list Vars_stack = EMPTY_ITEM_LIST;

	/* The array of section values that holds all the defined modules. */
	static item_list section_list = EMPTY_ITEM_LIST;

	static int iSectionIndex = -1;
	static BOOL bInGlobalSection = True;

	static struct enum_list enum_syslog_facility[] = {
	#ifdef LOG_AUTH
	{ LOG_AUTH, "auth" },
	#endif
	#ifdef LOG_AUTHPRIV
	{ LOG_AUTHPRIV, "authpriv" },
	#endif
	#ifdef LOG_CRON
	{ LOG_CRON, "cron" },
	#endif
	#ifdef LOG_DAEMON
	{ LOG_DAEMON, "daemon" },
	#endif
	#ifdef LOG_FTP
	{ LOG_FTP, "ftp" },
	#endif
	#ifdef LOG_KERN
	{ LOG_KERN, "kern" },
	#endif
	#ifdef LOG_LPR
	{ LOG_LPR, "lpr" },
	#endif
	#ifdef LOG_MAIL
	{ LOG_MAIL, "mail" },
	#endif
	#ifdef LOG_NEWS
	{ LOG_NEWS, "news" },
	#endif
	#ifdef LOG_AUTH
	{ LOG_AUTH, "security" },
	#endif
	#ifdef LOG_SYSLOG
	{ LOG_SYSLOG, "syslog" },
	#endif
	#ifdef LOG_USER
	{ LOG_USER, "user" },
	#endif
	#ifdef LOG_UUCP
	{ LOG_UUCP, "uucp" },
	#endif
	#ifdef LOG_LOCAL0
	{ LOG_LOCAL0, "local0" },
	#endif
	#ifdef LOG_LOCAL1
	{ LOG_LOCAL1, "local1" },
	#endif
	#ifdef LOG_LOCAL2
	{ LOG_LOCAL2, "local2" },
	#endif
	#ifdef LOG_LOCAL3
	{ LOG_LOCAL3, "local3" },
	#endif
	#ifdef LOG_LOCAL4
	{ LOG_LOCAL4, "local4" },
	#endif
	#ifdef LOG_LOCAL5
	{ LOG_LOCAL5, "local5" },
	#endif
	#ifdef LOG_LOCAL6
	{ LOG_LOCAL6, "local6" },
	#endif
	#ifdef LOG_LOCAL7
	{ LOG_LOCAL7, "local7" },
	#endif
	{ -1, NULL }
	};

	/* Expand %VAR% references. Any unknown vars or unrecognized
	* syntax leaves the raw chars unchanged. */
	static char expand_vars(const char str)
	{
	char buf, t;
	const char *f;
	int bufsize;

	if (!str \|\| !strchr(str, '%'))
	return (char )str; / TODO change return value to const char* at some point. */

	bufsize = strlen(str) + 2048;
	buf = new_array(char, bufsize+1); /* +1 for trailing '\0' */

	for (t = buf, f = str; bufsize && *f; ) {
	if (*f == '%' && isUpper(f+1)) {
	char *percent = strchr(f+1, '%');
	if (percent && percent - f < bufsize) {
	char *val;
	strlcpy(t, f+1, percent - f);
	val = getenv(t);
	if (val) {
	int len = strlcpy(t, val, bufsize+1);
	if (len > bufsize)
	break;
	bufsize -= len;
	t += len;
	f = percent + 1;
	continue;
	}
	}
	}
	t++ = f++;
	bufsize--;
	}
	*t = '\0';

	if (*f) {
	rprintf(FLOG, "Overflowed buf in expand_vars() trying to expand: %s\n", str);
	exit_cleanup(RERR_MALLOC);
	}

	if (bufsize && (buf = realloc(buf, t - buf + 1)) == NULL)
	out_of_memory("expand_vars");

	return buf;
	}

	/* Each "char* foo" has an associated "BOOL foo_EXP" that tracks if the string has been expanded yet or not. */

	/* NOTE: use this function and all the FN_{GLOBAL,LOCAL} ones WITHOUT a trailing semicolon! */
	#define RETURN_EXPANDED(val) {if (!val ## _EXP) {val = expand_vars(val); val ## _EXP = True;} return val ? val : "";}

	/* In this section all the functions that are used to access the
	* parameters from the rest of the program are defined. */

	#define FN_GLOBAL_STRING(fn_name, val) \
	char *fn_name(void) RETURN_EXPANDED(Vars.g.val)
	#define FN_GLOBAL_BOOL(fn_name, val) \
	BOOL fn_name(void) {return Vars.g.val;}
	#define FN_GLOBAL_CHAR(fn_name, val) \
	char fn_name(void) {return Vars.g.val;}
	#define FN_GLOBAL_INTEGER(fn_name, val) \
	int fn_name(void) {return Vars.g.val;}

	#define FN_LOCAL_STRING(fn_name, val) \
	char *fn_name(int i) {if (LP_SNUM_OK(i) && iSECTION(i).val) RETURN_EXPANDED(iSECTION(i).val) else RETURN_EXPANDED(Vars.l.val)}
	#define FN_LOCAL_BOOL(fn_name, val) \
	BOOL fn_name(int i) {return LP_SNUM_OK(i)? iSECTION(i).val : Vars.l.val;}
	#define FN_LOCAL_CHAR(fn_name, val) \
	char fn_name(int i) {return LP_SNUM_OK(i)? iSECTION(i).val : Vars.l.val;}
	#define FN_LOCAL_INTEGER(fn_name, val) \
	int fn_name(int i) {return LP_SNUM_OK(i)? iSECTION(i).val : Vars.l.val;}

	/* The following include file contains:
	*
	* typedef global_vars - describes global (ie., server-wide) parameters.
	* typedef local_vars - describes a single section.
	* typedef all_vars - a combination of global_vars & local_vars.
	* all_vars Defaults - the default values for all the variables.
	* all_vars Vars - the currently configured values for all the variables.
	* struct parm_struct parm_table - the strings & variables for the parser.
	* FN_{LOCAL,GLOBAL}_{TYPE}() definition for all the lp_var_name() accessors.
	*/

	#include "daemon-parm.h"

	/* Initialise the Default all_vars structure. */
	void reset_daemon_vars(void)
	{
	memcpy(&Vars, &Defaults, sizeof Vars);
	}

	/* Assign a copy of v to *s. Handles NULL strings. We don't worry
	* about overwriting a malloc'd string because the long-running
	* (port-listening) daemon only loads the config file once, and the
	* per-job (forked or xinitd-ran) daemon only re-reads the file at
	* the start, so any lost memory is inconsequential. */
	static inline void string_set(char *s, const char v)
	{
	*s = v ? strdup(v) : NULL;
	}

	/* Copy local_vars into a new section. No need to strdup since we don't free. */
	static void copy_section(local_vars psectionDest, local_vars psectionSource)
	{
	memcpy(psectionDest, psectionSource, sizeof psectionDest[0]);
	}

	/* Initialise a section to the defaults. */
	static void init_section(local_vars *psection)
	{
	memset(psection, 0, sizeof (local_vars));
	copy_section(psection, &Vars.l);
	}

	/* Do a case-insensitive, whitespace-ignoring string equality check. */
	static int strwiEQ(char psz1, char psz2)
	{
	/* If one or both strings are NULL, we return equality right away. */
	if (psz1 == psz2)
	return 1;
	if (psz1 == NULL \|\| psz2 == NULL)
	return 0;

	/* sync the strings on first non-whitespace */
	while (1) {
	while (isSpace(psz1))
	psz1++;
	while (isSpace(psz2))
	psz2++;
	if (psz1 == '\0' \|\| psz2 == '\0')
	break;
	if (toUpper(psz1) != toUpper(psz2))
	break;
	psz1++;
	psz2++;
	}
	return psz1 == psz2;
	}

	/* Find a section by name. Otherwise works like get_section. */
	static int getsectionbyname(char *name)
	{
	int i;

	for (i = section_list.count - 1; i >= 0; i--) {
	if (strwiEQ(iSECTION(i).name, name))
	break;
	}

	return i;
	}

	/* Add a new section to the sections array w/the default values. */
	static int add_a_section(char *name)
	{
	int i;
	local_vars *s;

	/* it might already exist */
	if (name) {
	i = getsectionbyname(name);
	if (i >= 0)
	return i;
	}

	i = section_list.count;
	s = EXPAND_ITEM_LIST(&section_list, local_vars, 2);

	init_section(s);
	if (name)
	string_set(&s->name, name);

	return i;
	}

	/* Map a parameter's string representation to something we can use.
	* Returns False if the parameter string is not recognised, else TRUE. */
	static int map_parameter(char *parmname)
	{
	int iIndex;

	if (*parmname == '-')
	return -1;

	for (iIndex = 0; parm_table[iIndex].label; iIndex++) {
	if (strwiEQ(parm_table[iIndex].label, parmname))
	return iIndex;
	}

	rprintf(FLOG, "Unknown Parameter encountered: \"%s\"\n", parmname);
	return -1;
	}

	/* Set a boolean variable from the text value stored in the passed string.
	* Returns True in success, False if the passed string does not correctly
	* represent a boolean. */
	static BOOL set_boolean(BOOL pb, char parmvalue, int allow_unset)
	{
	if (strwiEQ(parmvalue, "yes") \|\| strwiEQ(parmvalue, "true") \|\| strwiEQ(parmvalue, "1"))
	*pb = True;
	else if (strwiEQ(parmvalue, "no") \|\| strwiEQ(parmvalue, "false") \|\| strwiEQ(parmvalue, "0"))
	*pb = False;
	else if (allow_unset && (strwiEQ(parmvalue, "unset") \|\| strwiEQ(parmvalue, "-1")))
	*pb = Unset;
	else {
	rprintf(FLOG, "Badly formed boolean in configuration file: \"%s\".\n", parmvalue);
	return False;
	}
	return True;
	}

	/* Process a parameter. */
	static BOOL do_parameter(char parmname, char parmvalue)
	{
	int parmnum, i;
	void parm_ptr; / where we are going to store the result */
	void *def_ptr;
	char *cp;

	parmnum = map_parameter(parmname);

	if (parmnum < 0) {
	rprintf(FLOG, "IGNORING unknown parameter \"%s\"\n", parmname);
	return True;
	}

	def_ptr = parm_table[parmnum].ptr;

	if (bInGlobalSection)
	parm_ptr = def_ptr;
	else {
	if (parm_table[parmnum].class == P_GLOBAL) {
	rprintf(FLOG, "Global parameter %s found in module section!\n", parmname);
	return True;
	}
	parm_ptr = SECTION_PTR(&iSECTION(iSectionIndex), def_ptr);
	}

	/* now switch on the type of variable it is */
	switch (parm_table[parmnum].type) {
	case P_PATH:
	case P_STRING:
	/* delay expansion of %VAR% strings */
	break;
	default:
	/* expand any %VAR% strings now */
	parmvalue = expand_vars(parmvalue);
	break;
	}

	switch (parm_table[parmnum].type) {
	case P_BOOL:
	set_boolean(parm_ptr, parmvalue, False);
	break;

	case P_BOOL3:
	set_boolean(parm_ptr, parmvalue, True);
	break;

	case P_BOOLREV:
	set_boolean(parm_ptr, parmvalue, False);
	(BOOL )parm_ptr = ! (BOOL )parm_ptr;
	break;

	case P_INTEGER:
	(int )parm_ptr = atoi(parmvalue);
	break;

	case P_CHAR:
	(char )parm_ptr = *parmvalue;
	break;

	case P_OCTAL:
	sscanf(parmvalue, "%o", (unsigned int *)parm_ptr);
	break;

	case P_PATH:
	string_set(parm_ptr, parmvalue);
	if ((cp = (char*)parm_ptr) != NULL) {
	int len = strlen(cp);
	while (len > 1 && cp[len-1] == '/') len--;
	cp[len] = '\0';
	}
	break;

	case P_STRING:
	string_set(parm_ptr, parmvalue);
	break;

	case P_ENUM:
	for (i=0; parm_table[parmnum].enum_list[i].name; i++) {
	if (strequal(parmvalue, parm_table[parmnum].enum_list[i].name)) {
	(int )parm_ptr = parm_table[parmnum].enum_list[i].value;
	break;
	}
	}
	if (!parm_table[parmnum].enum_list[i].name) {
	if (atoi(parmvalue) > 0)
	(int )parm_ptr = atoi(parmvalue);
	}
	break;
	}

	return True;
	}

	/* Process a new section (rsync module).
	* Returns True on success, False on failure. */
	static BOOL do_section(char *sectionname)
	{
	BOOL isglobal;

	if (sectionname == ']') { / A special push/pop/reset directive from params.c */
	bInGlobalSection = 1;
	if (strcmp(sectionname+1, "push") == 0) {
	all_vars *vp = EXPAND_ITEM_LIST(&Vars_stack, all_vars, 2);
	memcpy(vp, &Vars, sizeof Vars);
	} else if (strcmp(sectionname+1, "pop") == 0
	\|\| strcmp(sectionname+1, "reset") == 0) {
	all_vars vp = ((all_vars)Vars_stack.items) + Vars_stack.count - 1;
	if (!Vars_stack.count)
	return False;
	memcpy(&Vars, vp, sizeof Vars);
	if (sectionname[1] == 'p')
	Vars_stack.count--;
	} else
	return False;
	return True;
	}

	isglobal = strwiEQ(sectionname, GLOBAL_NAME);

	/* At the end of the global section, add any --dparam items. */
	if (bInGlobalSection && !isglobal) {
	if (!section_list.count)
	set_dparams(0);
	}

	/* if we've just struck a global section, note the fact. */
	bInGlobalSection = isglobal;

	/* check for multiple global sections */
	if (bInGlobalSection)
	return True;

	#if 0
	/* If we have a current section, tidy it up before moving on. */
	if (iSectionIndex >= 0) {
	/* Add any tidy work as needed ... */
	if (problem)
	return False;
	}
	#endif

	if (strchr(sectionname, '/') != NULL) {
	rprintf(FLOG, "Warning: invalid section name in configuration file: %s\n", sectionname);
	return False;
	}

	if ((iSectionIndex = add_a_section(sectionname)) < 0) {
	rprintf(FLOG, "Failed to add a new module\n");
	bInGlobalSection = True;
	return False;
	}

	return True;
	}

	/* Load the modules from the config file. Return True on success,
	* False on failure. */
	int lp_load(char *pszFname, int globals_only)
	{
	bInGlobalSection = True;

	reset_daemon_vars();

	/* We get sections first, so have to start 'behind' to make up. */
	iSectionIndex = -1;
	return pm_process(pszFname, globals_only ? NULL : do_section, do_parameter);
	}

	BOOL set_dparams(int syntax_check_only)
	{
	char equal, val, **params = dparam_list.items;
	unsigned j;

	for (j = 0; j < dparam_list.count; j++) {
	equal = strchr(params[j], '='); /* options.c verified this */
	*equal = '\0';
	if (syntax_check_only) {
	if (map_parameter(params[j]) < 0) {
	rprintf(FERROR, "Unknown parameter \"%s\"\n", params[j]);
	*equal = '=';
	return False;
	}
	} else {
	for (val = equal+1; isSpace(val); val++) {}
	do_parameter(params[j], val);
	}
	*equal = '=';
	}

	return True;
	}

	/* Return the max number of modules (sections). */
	int lp_num_modules(void)
	{
	return section_list.count;
	}

	/* Return the number of the module with the given name, or -1 if it doesn't
	* exist. Note that this is a DIFFERENT ANIMAL from the internal function
	* getsectionbyname()! This works ONLY if all sections have been loaded,
	* and does not copy the found section. */
	int lp_number(char *name)
	{
	int i;

	for (i = section_list.count - 1; i >= 0; i--) {
	if (strcmp(lp_name(i), name) == 0)
	break;
	}

	return i;
	}