1/*
2 * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19FILE_LICENCE ( GPL2_OR_LATER );
20
21#include <stdint.h>
22#include <stdlib.h>
23#include <stdio.h>
24#include <string.h>
25#include <strings.h>
26#include <byteswap.h>
27#include <errno.h>
28#include <assert.h>
29#include <gpxe/in.h>
30#include <gpxe/vsprintf.h>
31#include <gpxe/dhcp.h>
32#include <gpxe/uuid.h>
33#include <gpxe/uri.h>
34#include <gpxe/settings.h>
35
36/** @file
37 *
38 * Configuration settings
39 *
40 */
41
42/******************************************************************************
43 *
44 * Generic settings blocks
45 *
46 ******************************************************************************
47 */
48
49/**
50 * A generic setting
51 *
52 */
53struct generic_setting {
54	/** List of generic settings */
55	struct list_head list;
56	/** Setting */
57	struct setting setting;
58	/** Size of setting name */
59	size_t name_len;
60	/** Size of setting data */
61	size_t data_len;
62};
63
64/**
65 * Get generic setting name
66 *
67 * @v generic		Generic setting
68 * @ret name		Generic setting name
69 */
70static inline void * generic_setting_name ( struct generic_setting *generic ) {
71	return ( ( ( void * ) generic ) + sizeof ( *generic ) );
72}
73
74/**
75 * Get generic setting data
76 *
77 * @v generic		Generic setting
78 * @ret data		Generic setting data
79 */
80static inline void * generic_setting_data ( struct generic_setting *generic ) {
81	return ( ( ( void * ) generic ) + sizeof ( *generic ) +
82		 generic->name_len );
83}
84
85/**
86 * Find generic setting
87 *
88 * @v generics		Generic settings block
89 * @v setting		Setting to find
90 * @ret generic		Generic setting, or NULL
91 */
92static struct generic_setting *
93find_generic_setting ( struct generic_settings *generics,
94		       struct setting *setting ) {
95	struct generic_setting *generic;
96
97	list_for_each_entry ( generic, &generics->list, list ) {
98		if ( setting_cmp ( &generic->setting, setting ) == 0 )
99			return generic;
100	}
101	return NULL;
102}
103
104/**
105 * Store value of generic setting
106 *
107 * @v settings		Settings block
108 * @v setting		Setting to store
109 * @v data		Setting data, or NULL to clear setting
110 * @v len		Length of setting data
111 * @ret rc		Return status code
112 */
113int generic_settings_store ( struct settings *settings,
114			     struct setting *setting,
115			     const void *data, size_t len ) {
116	struct generic_settings *generics =
117		container_of ( settings, struct generic_settings, settings );
118	struct generic_setting *old;
119	struct generic_setting *new = NULL;
120	size_t name_len;
121
122	/* Identify existing generic setting, if any */
123	old = find_generic_setting ( generics, setting );
124
125	/* Create new generic setting, if required */
126	if ( len ) {
127		/* Allocate new generic setting */
128		name_len = ( strlen ( setting->name ) + 1 );
129		new = zalloc ( sizeof ( *new ) + name_len + len );
130		if ( ! new )
131			return -ENOMEM;
132
133		/* Populate new generic setting */
134		new->name_len = name_len;
135		new->data_len = len;
136		memcpy ( &new->setting, setting, sizeof ( new->setting ) );
137		new->setting.name = generic_setting_name ( new );
138		memcpy ( generic_setting_name ( new ),
139			 setting->name, name_len );
140		memcpy ( generic_setting_data ( new ), data, len );
141	}
142
143	/* Delete existing generic setting, if any */
144	if ( old ) {
145		list_del ( &old->list );
146		free ( old );
147	}
148
149	/* Add new setting to list, if any */
150	if ( new )
151		list_add ( &new->list, &generics->list );
152
153	return 0;
154}
155
156/**
157 * Fetch value of generic setting
158 *
159 * @v settings		Settings block
160 * @v setting		Setting to fetch
161 * @v data		Buffer to fill with setting data
162 * @v len		Length of buffer
163 * @ret len		Length of setting data, or negative error
164 */
165int generic_settings_fetch ( struct settings *settings,
166			     struct setting *setting,
167			     void *data, size_t len ) {
168	struct generic_settings *generics =
169		container_of ( settings, struct generic_settings, settings );
170	struct generic_setting *generic;
171
172	/* Find generic setting */
173	generic = find_generic_setting ( generics, setting );
174	if ( ! generic )
175		return -ENOENT;
176
177	/* Copy out generic setting data */
178	if ( len > generic->data_len )
179		len = generic->data_len;
180	memcpy ( data, generic_setting_data ( generic ), len );
181	return generic->data_len;
182}
183
184/**
185 * Clear generic settings block
186 *
187 * @v settings		Settings block
188 */
189void generic_settings_clear ( struct settings *settings ) {
190	struct generic_settings *generics =
191		container_of ( settings, struct generic_settings, settings );
192	struct generic_setting *generic;
193	struct generic_setting *tmp;
194
195	list_for_each_entry_safe ( generic, tmp, &generics->list, list ) {
196		list_del ( &generic->list );
197		free ( generic );
198	}
199	assert ( list_empty ( &generics->list ) );
200}
201
202/** Generic settings operations */
203struct settings_operations generic_settings_operations = {
204	.store = generic_settings_store,
205	.fetch = generic_settings_fetch,
206	.clear = generic_settings_clear,
207};
208
209/******************************************************************************
210 *
211 * Registered settings blocks
212 *
213 ******************************************************************************
214 */
215
216/** Root generic settings block */
217struct generic_settings generic_settings_root = {
218	.settings = {
219		.refcnt = NULL,
220		.name = "",
221		.siblings =
222		    LIST_HEAD_INIT ( generic_settings_root.settings.siblings ),
223		.children =
224		    LIST_HEAD_INIT ( generic_settings_root.settings.children ),
225		.op = &generic_settings_operations,
226	},
227	.list = LIST_HEAD_INIT ( generic_settings_root.list ),
228};
229
230/** Root settings block */
231#define settings_root generic_settings_root.settings
232
233/**
234 * Find child named settings block
235 *
236 * @v parent		Parent settings block
237 * @v name		Name within this parent
238 * @ret settings	Settings block, or NULL
239 */
240static struct settings * find_child_settings ( struct settings *parent,
241					       const char *name ) {
242	struct settings *settings;
243
244	/* Treat empty name as meaning "this block" */
245	if ( ! *name )
246		return parent;
247
248	/* Look for child with matching name */
249	list_for_each_entry ( settings, &parent->children, siblings ) {
250		if ( strcmp ( settings->name, name ) == 0 )
251			return settings;
252	}
253
254	return NULL;
255}
256
257/**
258 * Find or create child named settings block
259 *
260 * @v parent		Parent settings block
261 * @v name		Name within this parent
262 * @ret settings	Settings block, or NULL
263 */
264static struct settings * autovivify_child_settings ( struct settings *parent,
265						     const char *name ) {
266	struct {
267		struct generic_settings generic;
268		char name[ strlen ( name ) + 1 /* NUL */ ];
269	} *new_child;
270	struct settings *settings;
271
272	/* Return existing settings, if existent */
273	if ( ( settings = find_child_settings ( parent, name ) ) != NULL )
274		return settings;
275
276	/* Create new generic settings block */
277	new_child = zalloc ( sizeof ( *new_child ) );
278	if ( ! new_child ) {
279		DBGC ( parent, "Settings %p could not create child %s\n",
280		       parent, name );
281		return NULL;
282	}
283	memcpy ( new_child->name, name, sizeof ( new_child->name ) );
284	generic_settings_init ( &new_child->generic, NULL, new_child->name );
285	settings = &new_child->generic.settings;
286	register_settings ( settings, parent );
287	return settings;
288}
289
290/**
291 * Return settings block name (for debug only)
292 *
293 * @v settings		Settings block
294 * @ret name		Settings block name
295 */
296static const char * settings_name ( struct settings *settings ) {
297	static char buf[64];
298	char tmp[ sizeof ( buf ) ];
299	int count;
300
301	for ( count = 0 ; settings ; settings = settings->parent ) {
302		memcpy ( tmp, buf, sizeof ( tmp ) );
303		snprintf ( buf, sizeof ( buf ), "%s%c%s", settings->name,
304			   ( count++ ? '.' : '\0' ), tmp );
305	}
306	return ( buf + 1 );
307}
308
309/**
310 * Parse settings block name
311 *
312 * @v name		Name
313 * @v get_child		Function to find or create child settings block
314 * @ret settings	Settings block, or NULL
315 */
316static struct settings *
317parse_settings_name ( const char *name,
318		      struct settings * ( * get_child ) ( struct settings *,
319							  const char * ) ) {
320	struct settings *settings = &settings_root;
321	char name_copy[ strlen ( name ) + 1 ];
322	char *subname;
323	char *remainder;
324
325	/* Create modifiable copy of name */
326	memcpy ( name_copy, name, sizeof ( name_copy ) );
327	remainder = name_copy;
328
329	/* Parse each name component in turn */
330	while ( remainder ) {
331		struct net_device *netdev;
332
333		subname = remainder;
334		remainder = strchr ( subname, '.' );
335		if ( remainder )
336			*(remainder++) = '\0';
337
338		/* Special case "netX" root settings block */
339		if ( ( subname == name_copy ) && ! strcmp ( subname, "netX" ) &&
340		     ( ( netdev = last_opened_netdev() ) != NULL ) )
341			settings = get_child ( settings, netdev->name );
342		else
343			settings = get_child ( settings, subname );
344
345		if ( ! settings )
346			break;
347	}
348
349	return settings;
350}
351
352/**
353 * Find named settings block
354 *
355 * @v name		Name
356 * @ret settings	Settings block, or NULL
357 */
358struct settings * find_settings ( const char *name ) {
359
360	return parse_settings_name ( name, find_child_settings );
361}
362
363/**
364 * Apply all settings
365 *
366 * @ret rc		Return status code
367 */
368static int apply_settings ( void ) {
369	struct settings_applicator *applicator;
370	int rc;
371
372	/* Call all settings applicators */
373	for_each_table_entry ( applicator, SETTINGS_APPLICATORS ) {
374		if ( ( rc = applicator->apply() ) != 0 ) {
375			DBG ( "Could not apply settings using applicator "
376			      "%p: %s\n", applicator, strerror ( rc ) );
377			return rc;
378		}
379	}
380
381	return 0;
382}
383
384/**
385 * Reprioritise settings
386 *
387 * @v settings		Settings block
388 *
389 * Reorders the settings block amongst its siblings according to its
390 * priority.
391 */
392static void reprioritise_settings ( struct settings *settings ) {
393	struct settings *parent = settings->parent;
394	long priority;
395	struct settings *tmp;
396	long tmp_priority;
397
398	/* Stop when we reach the top of the tree */
399	if ( ! parent )
400		return;
401
402	/* Read priority, if present */
403	priority = fetch_intz_setting ( settings, &priority_setting );
404
405	/* Remove from siblings list */
406	list_del ( &settings->siblings );
407
408	/* Reinsert after any existing blocks which have a higher priority */
409	list_for_each_entry ( tmp, &parent->children, siblings ) {
410		tmp_priority = fetch_intz_setting ( tmp, &priority_setting );
411		if ( priority > tmp_priority )
412			break;
413	}
414	list_add_tail ( &settings->siblings, &tmp->siblings );
415
416	/* Recurse up the tree */
417	reprioritise_settings ( parent );
418}
419
420/**
421 * Register settings block
422 *
423 * @v settings		Settings block
424 * @v parent		Parent settings block, or NULL
425 * @ret rc		Return status code
426 */
427int register_settings ( struct settings *settings, struct settings *parent ) {
428	struct settings *old_settings;
429
430	/* NULL parent => add to settings root */
431	assert ( settings != NULL );
432	if ( parent == NULL )
433		parent = &settings_root;
434
435	/* Remove any existing settings with the same name */
436	if ( ( old_settings = find_child_settings ( parent, settings->name ) ))
437		unregister_settings ( old_settings );
438
439	/* Add to list of settings */
440	ref_get ( settings->refcnt );
441	ref_get ( parent->refcnt );
442	settings->parent = parent;
443	list_add_tail ( &settings->siblings, &parent->children );
444	DBGC ( settings, "Settings %p (\"%s\") registered\n",
445	       settings, settings_name ( settings ) );
446
447	/* Fix up settings priority */
448	reprioritise_settings ( settings );
449
450	/* Apply potentially-updated settings */
451	apply_settings();
452
453	return 0;
454}
455
456/**
457 * Unregister settings block
458 *
459 * @v settings		Settings block
460 */
461void unregister_settings ( struct settings *settings ) {
462
463	DBGC ( settings, "Settings %p (\"%s\") unregistered\n",
464	       settings, settings_name ( settings ) );
465
466	/* Remove from list of settings */
467	ref_put ( settings->refcnt );
468	ref_put ( settings->parent->refcnt );
469	settings->parent = NULL;
470	list_del ( &settings->siblings );
471
472	/* Apply potentially-updated settings */
473	apply_settings();
474}
475
476/******************************************************************************
477 *
478 * Core settings routines
479 *
480 ******************************************************************************
481 */
482
483/**
484 * Store value of setting
485 *
486 * @v settings		Settings block, or NULL
487 * @v setting		Setting to store
488 * @v data		Setting data, or NULL to clear setting
489 * @v len		Length of setting data
490 * @ret rc		Return status code
491 */
492int store_setting ( struct settings *settings, struct setting *setting,
493		    const void *data, size_t len ) {
494	int rc;
495
496	/* NULL settings implies storing into the global settings root */
497	if ( ! settings )
498		settings = &settings_root;
499
500	/* Sanity check */
501	if ( ! settings->op->store )
502		return -ENOTSUP;
503
504	/* Store setting */
505	if ( ( rc = settings->op->store ( settings, setting,
506					  data, len ) ) != 0 )
507		return rc;
508
509	/* Reprioritise settings if necessary */
510	if ( setting_cmp ( setting, &priority_setting ) == 0 )
511		reprioritise_settings ( settings );
512
513	/* If these settings are registered, apply potentially-updated
514	 * settings
515	 */
516	for ( ; settings ; settings = settings->parent ) {
517		if ( settings == &settings_root ) {
518			if ( ( rc = apply_settings() ) != 0 )
519				return rc;
520			break;
521		}
522	}
523
524	return 0;
525}
526
527/**
528 * Fetch value of setting
529 *
530 * @v settings		Settings block, or NULL to search all blocks
531 * @v setting		Setting to fetch
532 * @v data		Buffer to fill with setting data
533 * @v len		Length of buffer
534 * @ret len		Length of setting data, or negative error
535 *
536 * The actual length of the setting will be returned even if
537 * the buffer was too small.
538 */
539int fetch_setting ( struct settings *settings, struct setting *setting,
540		    void *data, size_t len ) {
541	struct settings *child;
542	int ret;
543
544	/* Avoid returning uninitialised data on error */
545	memset ( data, 0, len );
546
547	/* NULL settings implies starting at the global settings root */
548	if ( ! settings )
549		settings = &settings_root;
550
551	/* Sanity check */
552	if ( ! settings->op->fetch )
553		return -ENOTSUP;
554
555	/* Try this block first */
556	if ( ( ret = settings->op->fetch ( settings, setting,
557					   data, len ) ) >= 0 )
558		return ret;
559
560	/* Recurse into each child block in turn */
561	list_for_each_entry ( child, &settings->children, siblings ) {
562		if ( ( ret = fetch_setting ( child, setting,
563					     data, len ) ) >= 0 )
564			return ret;
565	}
566
567	return -ENOENT;
568}
569
570/**
571 * Fetch length of setting
572 *
573 * @v settings		Settings block, or NULL to search all blocks
574 * @v setting		Setting to fetch
575 * @ret len		Length of setting data, or negative error
576 *
577 * This function can also be used as an existence check for the
578 * setting.
579 */
580int fetch_setting_len ( struct settings *settings, struct setting *setting ) {
581	return fetch_setting ( settings, setting, NULL, 0 );
582}
583
584/**
585 * Fetch value of string setting
586 *
587 * @v settings		Settings block, or NULL to search all blocks
588 * @v setting		Setting to fetch
589 * @v data		Buffer to fill with setting string data
590 * @v len		Length of buffer
591 * @ret len		Length of string setting, or negative error
592 *
593 * The resulting string is guaranteed to be correctly NUL-terminated.
594 * The returned length will be the length of the underlying setting
595 * data.
596 */
597int fetch_string_setting ( struct settings *settings, struct setting *setting,
598			   char *data, size_t len ) {
599	memset ( data, 0, len );
600	return fetch_setting ( settings, setting, data,
601			       ( ( len > 0 ) ? ( len - 1 ) : 0 ) );
602}
603
604/**
605 * Fetch value of string setting
606 *
607 * @v settings		Settings block, or NULL to search all blocks
608 * @v setting		Setting to fetch
609 * @v data		Buffer to allocate and fill with setting string data
610 * @ret len		Length of string setting, or negative error
611 *
612 * The resulting string is guaranteed to be correctly NUL-terminated.
613 * The returned length will be the length of the underlying setting
614 * data.  The caller is responsible for eventually freeing the
615 * allocated buffer.
616 */
617int fetch_string_setting_copy ( struct settings *settings,
618				struct setting *setting,
619				char **data ) {
620	int len;
621	int check_len = 0;
622
623	len = fetch_setting_len ( settings, setting );
624	if ( len < 0 )
625		return len;
626
627	*data = malloc ( len + 1 );
628	if ( ! *data )
629		return -ENOMEM;
630
631	check_len = fetch_string_setting ( settings, setting, *data,
632					   ( len + 1 ) );
633	assert ( check_len == len );
634	return len;
635}
636
637/**
638 * Fetch value of IPv4 address setting
639 *
640 * @v settings		Settings block, or NULL to search all blocks
641 * @v setting		Setting to fetch
642 * @v inp		IPv4 address to fill in
643 * @ret len		Length of setting, or negative error
644 */
645int fetch_ipv4_setting ( struct settings *settings, struct setting *setting,
646			 struct in_addr *inp ) {
647	int len;
648
649	len = fetch_setting ( settings, setting, inp, sizeof ( *inp ) );
650	if ( len < 0 )
651		return len;
652	if ( len < ( int ) sizeof ( *inp ) )
653		return -ERANGE;
654	return len;
655}
656
657/**
658 * Fetch value of signed integer setting
659 *
660 * @v settings		Settings block, or NULL to search all blocks
661 * @v setting		Setting to fetch
662 * @v value		Integer value to fill in
663 * @ret len		Length of setting, or negative error
664 */
665int fetch_int_setting ( struct settings *settings, struct setting *setting,
666			long *value ) {
667	union {
668		uint8_t u8[ sizeof ( long ) ];
669		int8_t s8[ sizeof ( long ) ];
670	} buf;
671	int len;
672	int i;
673
674	/* Avoid returning uninitialised data on error */
675	*value = 0;
676
677	/* Fetch raw (network-ordered, variable-length) setting */
678	len = fetch_setting ( settings, setting, &buf, sizeof ( buf ) );
679	if ( len < 0 )
680		return len;
681	if ( len > ( int ) sizeof ( buf ) )
682		return -ERANGE;
683
684	/* Convert to host-ordered signed long */
685	*value = ( ( buf.s8[0] >= 0 ) ? 0 : -1L );
686	for ( i = 0 ; i < len ; i++ ) {
687		*value = ( ( *value << 8 ) | buf.u8[i] );
688	}
689
690	return len;
691}
692
693/**
694 * Fetch value of unsigned integer setting
695 *
696 * @v settings		Settings block, or NULL to search all blocks
697 * @v setting		Setting to fetch
698 * @v value		Integer value to fill in
699 * @ret len		Length of setting, or negative error
700 */
701int fetch_uint_setting ( struct settings *settings, struct setting *setting,
702			 unsigned long *value ) {
703	long svalue;
704	int len;
705
706	/* Avoid returning uninitialised data on error */
707	*value = 0;
708
709	/* Fetch as a signed long */
710	len = fetch_int_setting ( settings, setting, &svalue );
711	if ( len < 0 )
712		return len;
713
714	/* Mask off sign-extended bits */
715	assert ( len <= ( int ) sizeof ( long ) );
716	*value = ( svalue & ( -1UL >> ( 8 * ( sizeof ( long ) - len ) ) ) );
717
718	return len;
719}
720
721/**
722 * Fetch value of signed integer setting, or zero
723 *
724 * @v settings		Settings block, or NULL to search all blocks
725 * @v setting		Setting to fetch
726 * @ret value		Setting value, or zero
727 */
728long fetch_intz_setting ( struct settings *settings, struct setting *setting ){
729	long value;
730
731	fetch_int_setting ( settings, setting, &value );
732	return value;
733}
734
735/**
736 * Fetch value of unsigned integer setting, or zero
737 *
738 * @v settings		Settings block, or NULL to search all blocks
739 * @v setting		Setting to fetch
740 * @ret value		Setting value, or zero
741 */
742unsigned long fetch_uintz_setting ( struct settings *settings,
743				    struct setting *setting ) {
744	unsigned long value;
745
746	fetch_uint_setting ( settings, setting, &value );
747	return value;
748}
749
750/**
751 * Fetch value of UUID setting
752 *
753 * @v settings		Settings block, or NULL to search all blocks
754 * @v setting		Setting to fetch
755 * @v uuid		UUID to fill in
756 * @ret len		Length of setting, or negative error
757 */
758int fetch_uuid_setting ( struct settings *settings, struct setting *setting,
759			 union uuid *uuid ) {
760	int len;
761
762	len = fetch_setting ( settings, setting, uuid, sizeof ( *uuid ) );
763	if ( len < 0 )
764		return len;
765	if ( len != sizeof ( *uuid ) )
766		return -ERANGE;
767	return len;
768}
769
770/**
771 * Clear settings block
772 *
773 * @v settings		Settings block
774 */
775void clear_settings ( struct settings *settings ) {
776	if ( settings->op->clear )
777		settings->op->clear ( settings );
778}
779
780/**
781 * Compare two settings
782 *
783 * @v a			Setting to compare
784 * @v b			Setting to compare
785 * @ret 0		Settings are the same
786 * @ret non-zero	Settings are not the same
787 */
788int setting_cmp ( struct setting *a, struct setting *b ) {
789
790	/* If the settings have tags, compare them */
791	if ( a->tag && ( a->tag == b->tag ) )
792		return 0;
793
794	/* Otherwise, if the settings have names, compare them */
795	if ( a->name && b->name && a->name[0] )
796		return strcmp ( a->name, b->name );
797
798	/* Otherwise, return a non-match */
799	return ( ! 0 );
800}
801
802/******************************************************************************
803 *
804 * Formatted setting routines
805 *
806 ******************************************************************************
807 */
808
809/**
810 * Store value of typed setting
811 *
812 * @v settings		Settings block
813 * @v setting		Setting to store
814 * @v type		Settings type
815 * @v value		Formatted setting data, or NULL
816 * @ret rc		Return status code
817 */
818int storef_setting ( struct settings *settings, struct setting *setting,
819		     const char *value ) {
820
821	/* NULL value implies deletion.  Avoid imposing the burden of
822	 * checking for NULL values on each typed setting's storef()
823	 * method.
824	 */
825	if ( ! value )
826		return delete_setting ( settings, setting );
827
828	return setting->type->storef ( settings, setting, value );
829}
830
831/**
832 * Find named setting
833 *
834 * @v name		Name
835 * @ret setting		Named setting, or NULL
836 */
837static struct setting * find_setting ( const char *name ) {
838	struct setting *setting;
839
840	for_each_table_entry ( setting, SETTINGS ) {
841		if ( strcmp ( name, setting->name ) == 0 )
842			return setting;
843	}
844	return NULL;
845}
846
847/**
848 * Parse setting name as tag number
849 *
850 * @v name		Name
851 * @ret tag		Tag number, or 0 if not a valid number
852 */
853static unsigned int parse_setting_tag ( const char *name ) {
854	char *tmp = ( ( char * ) name );
855	unsigned int tag = 0;
856
857	while ( 1 ) {
858		tag = ( ( tag << 8 ) | strtoul ( tmp, &tmp, 0 ) );
859		if ( *tmp == 0 )
860			return tag;
861		if ( *tmp != '.' )
862			return 0;
863		tmp++;
864	}
865}
866
867/**
868 * Find setting type
869 *
870 * @v name		Name
871 * @ret type		Setting type, or NULL
872 */
873static struct setting_type * find_setting_type ( const char *name ) {
874	struct setting_type *type;
875
876	for_each_table_entry ( type, SETTING_TYPES ) {
877		if ( strcmp ( name, type->name ) == 0 )
878			return type;
879	}
880	return NULL;
881}
882
883/**
884 * Parse setting name
885 *
886 * @v name		Name of setting
887 * @v get_child		Function to find or create child settings block
888 * @v settings		Settings block to fill in
889 * @v setting		Setting to fill in
890 * @v tmp_name		Buffer for copy of setting name
891 * @ret rc		Return status code
892 *
893 * Interprets a name of the form
894 * "[settings_name/]tag_name[:type_name]" and fills in the appropriate
895 * fields.
896 *
897 * The @c tmp_name buffer must be large enough to hold a copy of the
898 * setting name.
899 */
900static int
901parse_setting_name ( const char *name,
902		     struct settings * ( * get_child ) ( struct settings *,
903							 const char * ),
904		     struct settings **settings, struct setting *setting,
905		     char *tmp_name ) {
906	char *settings_name;
907	char *setting_name;
908	char *type_name;
909	struct setting *named_setting;
910
911	/* Set defaults */
912	*settings = &settings_root;
913	memset ( setting, 0, sizeof ( *setting ) );
914	setting->name = "";
915	setting->type = &setting_type_string;
916
917	/* Split name into "[settings_name/]setting_name[:type_name]" */
918	strcpy ( tmp_name, name );
919	if ( ( setting_name = strchr ( tmp_name, '/' ) ) != NULL ) {
920		*(setting_name++) = 0;
921		settings_name = tmp_name;
922	} else {
923		setting_name = tmp_name;
924		settings_name = NULL;
925	}
926	if ( ( type_name = strchr ( setting_name, ':' ) ) != NULL )
927		*(type_name++) = 0;
928
929	/* Identify settings block, if specified */
930	if ( settings_name ) {
931		*settings = parse_settings_name ( settings_name, get_child );
932		if ( *settings == NULL ) {
933			DBG ( "Unrecognised settings block \"%s\" in \"%s\"\n",
934			      settings_name, name );
935			return -ENODEV;
936		}
937	}
938
939	/* Identify setting */
940	if ( ( named_setting = find_setting ( setting_name ) ) != NULL ) {
941		/* Matches a defined named setting; use that setting */
942		memcpy ( setting, named_setting, sizeof ( *setting ) );
943	} else if ( ( setting->tag = parse_setting_tag ( setting_name ) ) !=0){
944		/* Is a valid numeric tag; use the tag */
945		setting->tag |= (*settings)->tag_magic;
946	} else {
947		/* Use the arbitrary name */
948		setting->name = setting_name;
949	}
950
951	/* Identify setting type, if specified */
952	if ( type_name ) {
953		setting->type = find_setting_type ( type_name );
954		if ( setting->type == NULL ) {
955			DBG ( "Invalid setting type \"%s\" in \"%s\"\n",
956			      type_name, name );
957			return -ENOTSUP;
958		}
959	}
960
961	return 0;
962}
963
964/**
965 * Parse and store value of named setting
966 *
967 * @v name		Name of setting
968 * @v value		Formatted setting data, or NULL
969 * @ret rc		Return status code
970 */
971int storef_named_setting ( const char *name, const char *value ) {
972	struct settings *settings;
973	struct setting setting;
974	char tmp_name[ strlen ( name ) + 1 ];
975	int rc;
976
977	if ( ( rc = parse_setting_name ( name, autovivify_child_settings,
978					 &settings, &setting, tmp_name )) != 0)
979		return rc;
980	return storef_setting ( settings, &setting, value );
981}
982
983/**
984 * Fetch and format value of named setting
985 *
986 * @v name		Name of setting
987 * @v buf		Buffer to contain formatted value
988 * @v len		Length of buffer
989 * @ret len		Length of formatted value, or negative error
990 */
991int fetchf_named_setting ( const char *name, char *buf, size_t len ) {
992	struct settings *settings;
993	struct setting setting;
994	char tmp_name[ strlen ( name ) + 1 ];
995	int rc;
996
997	if ( ( rc = parse_setting_name ( name, find_child_settings,
998					 &settings, &setting, tmp_name )) != 0)
999		return rc;
1000	return fetchf_setting ( settings, &setting, buf, len );
1001}
1002
1003/******************************************************************************
1004 *
1005 * Setting types
1006 *
1007 ******************************************************************************
1008 */
1009
1010/**
1011 * Parse and store value of string setting
1012 *
1013 * @v settings		Settings block
1014 * @v setting		Setting to store
1015 * @v value		Formatted setting data
1016 * @ret rc		Return status code
1017 */
1018static int storef_string ( struct settings *settings, struct setting *setting,
1019			   const char *value ) {
1020	return store_setting ( settings, setting, value, strlen ( value ) );
1021}
1022
1023/**
1024 * Fetch and format value of string setting
1025 *
1026 * @v settings		Settings block, or NULL to search all blocks
1027 * @v setting		Setting to fetch
1028 * @v buf		Buffer to contain formatted value
1029 * @v len		Length of buffer
1030 * @ret len		Length of formatted value, or negative error
1031 */
1032static int fetchf_string ( struct settings *settings, struct setting *setting,
1033			   char *buf, size_t len ) {
1034	return fetch_string_setting ( settings, setting, buf, len );
1035}
1036
1037/** A string setting type */
1038struct setting_type setting_type_string __setting_type = {
1039	.name = "string",
1040	.storef = storef_string,
1041	.fetchf = fetchf_string,
1042};
1043
1044/**
1045 * Parse and store value of URI-encoded string setting
1046 *
1047 * @v settings		Settings block
1048 * @v setting		Setting to store
1049 * @v value		Formatted setting data
1050 * @ret rc		Return status code
1051 */
1052static int storef_uristring ( struct settings *settings,
1053			      struct setting *setting,
1054			      const char *value ) {
1055	char buf[ strlen ( value ) + 1 ]; /* Decoding never expands string */
1056	size_t len;
1057
1058	len = uri_decode ( value, buf, sizeof ( buf ) );
1059	return store_setting ( settings, setting, buf, len );
1060}
1061
1062/**
1063 * Fetch and format value of URI-encoded string setting
1064 *
1065 * @v settings		Settings block, or NULL to search all blocks
1066 * @v setting		Setting to fetch
1067 * @v buf		Buffer to contain formatted value
1068 * @v len		Length of buffer
1069 * @ret len		Length of formatted value, or negative error
1070 */
1071static int fetchf_uristring ( struct settings *settings,
1072			      struct setting *setting,
1073			      char *buf, size_t len ) {
1074	ssize_t raw_len;
1075
1076	/* We need to always retrieve the full raw string to know the
1077	 * length of the encoded string.
1078	 */
1079	raw_len = fetch_setting ( settings, setting, NULL, 0 );
1080	if ( raw_len < 0 )
1081		return raw_len;
1082
1083	{
1084		char raw_buf[ raw_len + 1 ];
1085
1086		fetch_string_setting ( settings, setting, raw_buf,
1087				       sizeof ( raw_buf ) );
1088		return uri_encode ( raw_buf, buf, len, URI_FRAGMENT );
1089	}
1090}
1091
1092/** A URI-encoded string setting type */
1093struct setting_type setting_type_uristring __setting_type = {
1094	.name = "uristring",
1095	.storef = storef_uristring,
1096	.fetchf = fetchf_uristring,
1097};
1098
1099/**
1100 * Parse and store value of IPv4 address setting
1101 *
1102 * @v settings		Settings block
1103 * @v setting		Setting to store
1104 * @v value		Formatted setting data
1105 * @ret rc		Return status code
1106 */
1107static int storef_ipv4 ( struct settings *settings, struct setting *setting,
1108			 const char *value ) {
1109	struct in_addr ipv4;
1110
1111	if ( inet_aton ( value, &ipv4 ) == 0 )
1112		return -EINVAL;
1113	return store_setting ( settings, setting, &ipv4, sizeof ( ipv4 ) );
1114}
1115
1116/**
1117 * Fetch and format value of IPv4 address setting
1118 *
1119 * @v settings		Settings block, or NULL to search all blocks
1120 * @v setting		Setting to fetch
1121 * @v buf		Buffer to contain formatted value
1122 * @v len		Length of buffer
1123 * @ret len		Length of formatted value, or negative error
1124 */
1125static int fetchf_ipv4 ( struct settings *settings, struct setting *setting,
1126			 char *buf, size_t len ) {
1127	struct in_addr ipv4;
1128	int raw_len;
1129
1130	if ( ( raw_len = fetch_ipv4_setting ( settings, setting, &ipv4 ) ) < 0)
1131		return raw_len;
1132	return snprintf ( buf, len, "%s", inet_ntoa ( ipv4 ) );
1133}
1134
1135/** An IPv4 address setting type */
1136struct setting_type setting_type_ipv4 __setting_type = {
1137	.name = "ipv4",
1138	.storef = storef_ipv4,
1139	.fetchf = fetchf_ipv4,
1140};
1141
1142/**
1143 * Parse and store value of integer setting
1144 *
1145 * @v settings		Settings block
1146 * @v setting		Setting to store
1147 * @v value		Formatted setting data
1148 * @v size		Integer size, in bytes
1149 * @ret rc		Return status code
1150 */
1151static int storef_int ( struct settings *settings, struct setting *setting,
1152			const char *value, unsigned int size ) {
1153	union {
1154		uint32_t num;
1155		uint8_t bytes[4];
1156	} u;
1157	char *endp;
1158
1159	u.num = htonl ( strtoul ( value, &endp, 0 ) );
1160	if ( *endp )
1161		return -EINVAL;
1162	return store_setting ( settings, setting,
1163			       &u.bytes[ sizeof ( u ) - size ], size );
1164}
1165
1166/**
1167 * Parse and store value of 8-bit integer setting
1168 *
1169 * @v settings		Settings block
1170 * @v setting		Setting to store
1171 * @v value		Formatted setting data
1172 * @v size		Integer size, in bytes
1173 * @ret rc		Return status code
1174 */
1175static int storef_int8 ( struct settings *settings, struct setting *setting,
1176			 const char *value ) {
1177	return storef_int ( settings, setting, value, 1 );
1178}
1179
1180/**
1181 * Parse and store value of 16-bit integer setting
1182 *
1183 * @v settings		Settings block
1184 * @v setting		Setting to store
1185 * @v value		Formatted setting data
1186 * @v size		Integer size, in bytes
1187 * @ret rc		Return status code
1188 */
1189static int storef_int16 ( struct settings *settings, struct setting *setting,
1190			  const char *value ) {
1191	return storef_int ( settings, setting, value, 2 );
1192}
1193
1194/**
1195 * Parse and store value of 32-bit integer setting
1196 *
1197 * @v settings		Settings block
1198 * @v setting		Setting to store
1199 * @v value		Formatted setting data
1200 * @v size		Integer size, in bytes
1201 * @ret rc		Return status code
1202 */
1203static int storef_int32 ( struct settings *settings, struct setting *setting,
1204			  const char *value ) {
1205	return storef_int ( settings, setting, value, 4 );
1206}
1207
1208/**
1209 * Fetch and format value of signed integer setting
1210 *
1211 * @v settings		Settings block, or NULL to search all blocks
1212 * @v setting		Setting to fetch
1213 * @v buf		Buffer to contain formatted value
1214 * @v len		Length of buffer
1215 * @ret len		Length of formatted value, or negative error
1216 */
1217static int fetchf_int ( struct settings *settings, struct setting *setting,
1218			char *buf, size_t len ) {
1219	long value;
1220	int rc;
1221
1222	if ( ( rc = fetch_int_setting ( settings, setting, &value ) ) < 0 )
1223		return rc;
1224	return snprintf ( buf, len, "%ld", value );
1225}
1226
1227/**
1228 * Fetch and format value of unsigned integer setting
1229 *
1230 * @v settings		Settings block, or NULL to search all blocks
1231 * @v setting		Setting to fetch
1232 * @v buf		Buffer to contain formatted value
1233 * @v len		Length of buffer
1234 * @ret len		Length of formatted value, or negative error
1235 */
1236static int fetchf_uint ( struct settings *settings, struct setting *setting,
1237			 char *buf, size_t len ) {
1238	unsigned long value;
1239	int rc;
1240
1241	if ( ( rc = fetch_uint_setting ( settings, setting, &value ) ) < 0 )
1242		return rc;
1243	return snprintf ( buf, len, "%#lx", value );
1244}
1245
1246/** A signed 8-bit integer setting type */
1247struct setting_type setting_type_int8 __setting_type = {
1248	.name = "int8",
1249	.storef = storef_int8,
1250	.fetchf = fetchf_int,
1251};
1252
1253/** A signed 16-bit integer setting type */
1254struct setting_type setting_type_int16 __setting_type = {
1255	.name = "int16",
1256	.storef = storef_int16,
1257	.fetchf = fetchf_int,
1258};
1259
1260/** A signed 32-bit integer setting type */
1261struct setting_type setting_type_int32 __setting_type = {
1262	.name = "int32",
1263	.storef = storef_int32,
1264	.fetchf = fetchf_int,
1265};
1266
1267/** An unsigned 8-bit integer setting type */
1268struct setting_type setting_type_uint8 __setting_type = {
1269	.name = "uint8",
1270	.storef = storef_int8,
1271	.fetchf = fetchf_uint,
1272};
1273
1274/** An unsigned 16-bit integer setting type */
1275struct setting_type setting_type_uint16 __setting_type = {
1276	.name = "uint16",
1277	.storef = storef_int16,
1278	.fetchf = fetchf_uint,
1279};
1280
1281/** An unsigned 32-bit integer setting type */
1282struct setting_type setting_type_uint32 __setting_type = {
1283	.name = "uint32",
1284	.storef = storef_int32,
1285	.fetchf = fetchf_uint,
1286};
1287
1288/**
1289 * Parse and store value of hex string setting
1290 *
1291 * @v settings		Settings block
1292 * @v setting		Setting to store
1293 * @v value		Formatted setting data
1294 * @ret rc		Return status code
1295 */
1296static int storef_hex ( struct settings *settings, struct setting *setting,
1297			const char *value ) {
1298	char *ptr = ( char * ) value;
1299	uint8_t bytes[ strlen ( value ) ]; /* cannot exceed strlen(value) */
1300	unsigned int len = 0;
1301
1302	while ( 1 ) {
1303		bytes[len++] = strtoul ( ptr, &ptr, 16 );
1304		switch ( *ptr ) {
1305		case '\0' :
1306			return store_setting ( settings, setting, bytes, len );
1307		case ':' :
1308			ptr++;
1309			break;
1310		default :
1311			return -EINVAL;
1312		}
1313	}
1314}
1315
1316/**
1317 * Fetch and format value of hex string setting
1318 *
1319 * @v settings		Settings block, or NULL to search all blocks
1320 * @v setting		Setting to fetch
1321 * @v buf		Buffer to contain formatted value
1322 * @v len		Length of buffer
1323 * @ret len		Length of formatted value, or negative error
1324 */
1325static int fetchf_hex ( struct settings *settings, struct setting *setting,
1326			char *buf, size_t len ) {
1327	int raw_len;
1328	int check_len;
1329	int used = 0;
1330	int i;
1331
1332	raw_len = fetch_setting_len ( settings, setting );
1333	if ( raw_len < 0 )
1334		return raw_len;
1335
1336	{
1337		uint8_t raw[raw_len];
1338
1339		check_len = fetch_setting ( settings, setting, raw,
1340					    sizeof ( raw ) );
1341		if ( check_len < 0 )
1342			return check_len;
1343		assert ( check_len == raw_len );
1344
1345		if ( len )
1346			buf[0] = 0; /* Ensure that a terminating NUL exists */
1347		for ( i = 0 ; i < raw_len ; i++ ) {
1348			used += ssnprintf ( ( buf + used ), ( len - used ),
1349					    "%s%02x", ( used ? ":" : "" ),
1350					    raw[i] );
1351		}
1352		return used;
1353	}
1354}
1355
1356/** A hex-string setting */
1357struct setting_type setting_type_hex __setting_type = {
1358	.name = "hex",
1359	.storef = storef_hex,
1360	.fetchf = fetchf_hex,
1361};
1362
1363/**
1364 * Parse and store value of UUID setting
1365 *
1366 * @v settings		Settings block
1367 * @v setting		Setting to store
1368 * @v value		Formatted setting data
1369 * @ret rc		Return status code
1370 */
1371static int storef_uuid ( struct settings *settings __unused,
1372			 struct setting *setting __unused,
1373			 const char *value __unused ) {
1374	return -ENOTSUP;
1375}
1376
1377/**
1378 * Fetch and format value of UUID setting
1379 *
1380 * @v settings		Settings block, or NULL to search all blocks
1381 * @v setting		Setting to fetch
1382 * @v buf		Buffer to contain formatted value
1383 * @v len		Length of buffer
1384 * @ret len		Length of formatted value, or negative error
1385 */
1386static int fetchf_uuid ( struct settings *settings, struct setting *setting,
1387			 char *buf, size_t len ) {
1388	union uuid uuid;
1389	int raw_len;
1390
1391	if ( ( raw_len = fetch_uuid_setting ( settings, setting, &uuid ) ) < 0)
1392		return raw_len;
1393	return snprintf ( buf, len, "%s", uuid_ntoa ( &uuid ) );
1394}
1395
1396/** UUID setting type */
1397struct setting_type setting_type_uuid __setting_type = {
1398	.name = "uuid",
1399	.storef = storef_uuid,
1400	.fetchf = fetchf_uuid,
1401};
1402
1403/******************************************************************************
1404 *
1405 * Settings
1406 *
1407 ******************************************************************************
1408 */
1409
1410/** Hostname setting */
1411struct setting hostname_setting __setting = {
1412	.name = "hostname",
1413	.description = "Host name",
1414	.tag = DHCP_HOST_NAME,
1415	.type = &setting_type_string,
1416};
1417
1418/** Filename setting */
1419struct setting filename_setting __setting = {
1420	.name = "filename",
1421	.description = "Boot filename",
1422	.tag = DHCP_BOOTFILE_NAME,
1423	.type = &setting_type_string,
1424};
1425
1426/** Root path setting */
1427struct setting root_path_setting __setting = {
1428	.name = "root-path",
1429	.description = "iSCSI root path",
1430	.tag = DHCP_ROOT_PATH,
1431	.type = &setting_type_string,
1432};
1433
1434/** Username setting */
1435struct setting username_setting __setting = {
1436	.name = "username",
1437	.description = "User name",
1438	.tag = DHCP_EB_USERNAME,
1439	.type = &setting_type_string,
1440};
1441
1442/** Password setting */
1443struct setting password_setting __setting = {
1444	.name = "password",
1445	.description = "Password",
1446	.tag = DHCP_EB_PASSWORD,
1447	.type = &setting_type_string,
1448};
1449
1450/** Priority setting */
1451struct setting priority_setting __setting = {
1452	.name = "priority",
1453	.description = "Priority of these settings",
1454	.tag = DHCP_EB_PRIORITY,
1455	.type = &setting_type_int8,
1456};
1457