1// SPDX-License-Identifier: GPL-2.0-only
2
3#include <linux/ethtool_netlink.h>
4#include <linux/bitmap.h>
5#include "netlink.h"
6#include "bitset.h"
7
8/* Some bitmaps are internally represented as an array of unsigned long, some
9 * as an array of u32 (some even as single u32 for now). To avoid the need of
10 * wrappers on caller side, we provide two set of functions: those with "32"
11 * suffix in their names expect u32 based bitmaps, those without it expect
12 * unsigned long bitmaps.
13 */
14
15static u32 ethnl_lower_bits(unsigned int n)
16{
17	return ~(u32)0 >> (32 - n % 32);
18}
19
20static u32 ethnl_upper_bits(unsigned int n)
21{
22	return ~(u32)0 << (n % 32);
23}
24
25/**
26 * ethnl_bitmap32_clear() - Clear u32 based bitmap
27 * @dst:   bitmap to clear
28 * @start: beginning of the interval
29 * @end:   end of the interval
30 * @mod:   set if bitmap was modified
31 *
32 * Clear @nbits bits of a bitmap with indices @start <= i < @end
33 */
34static void ethnl_bitmap32_clear(u32 *dst, unsigned int start, unsigned int end,
35				 bool *mod)
36{
37	unsigned int start_word = start / 32;
38	unsigned int end_word = end / 32;
39	unsigned int i;
40	u32 mask;
41
42	if (end <= start)
43		return;
44
45	if (start % 32) {
46		mask = ethnl_upper_bits(start);
47		if (end_word == start_word) {
48			mask &= ethnl_lower_bits(end);
49			if (dst[start_word] & mask) {
50				dst[start_word] &= ~mask;
51				*mod = true;
52			}
53			return;
54		}
55		if (dst[start_word] & mask) {
56			dst[start_word] &= ~mask;
57			*mod = true;
58		}
59		start_word++;
60	}
61
62	for (i = start_word; i < end_word; i++) {
63		if (dst[i]) {
64			dst[i] = 0;
65			*mod = true;
66		}
67	}
68	if (end % 32) {
69		mask = ethnl_lower_bits(end);
70		if (dst[end_word] & mask) {
71			dst[end_word] &= ~mask;
72			*mod = true;
73		}
74	}
75}
76
77/**
78 * ethnl_bitmap32_not_zero() - Check if any bit is set in an interval
79 * @map:   bitmap to test
80 * @start: beginning of the interval
81 * @end:   end of the interval
82 *
83 * Return: true if there is non-zero bit with  index @start <= i < @end,
84 *         false if the whole interval is zero
85 */
86static bool ethnl_bitmap32_not_zero(const u32 *map, unsigned int start,
87				    unsigned int end)
88{
89	unsigned int start_word = start / 32;
90	unsigned int end_word = end / 32;
91	u32 mask;
92
93	if (end <= start)
94		return true;
95
96	if (start % 32) {
97		mask = ethnl_upper_bits(start);
98		if (end_word == start_word) {
99			mask &= ethnl_lower_bits(end);
100			return map[start_word] & mask;
101		}
102		if (map[start_word] & mask)
103			return true;
104		start_word++;
105	}
106
107	if (!memchr_inv(map + start_word, '\0',
108			(end_word - start_word) * sizeof(u32)))
109		return true;
110	if (end % 32 == 0)
111		return true;
112	return map[end_word] & ethnl_lower_bits(end);
113}
114
115/**
116 * ethnl_bitmap32_update() - Modify u32 based bitmap according to value/mask
117 *			     pair
118 * @dst:   bitmap to update
119 * @nbits: bit size of the bitmap
120 * @value: values to set
121 * @mask:  mask of bits to set
122 * @mod:   set to true if bitmap is modified, preserve if not
123 *
124 * Set bits in @dst bitmap which are set in @mask to values from @value, leave
125 * the rest untouched. If destination bitmap was modified, set @mod to true,
126 * leave as it is if not.
127 */
128static void ethnl_bitmap32_update(u32 *dst, unsigned int nbits,
129				  const u32 *value, const u32 *mask, bool *mod)
130{
131	while (nbits > 0) {
132		u32 real_mask = mask ? *mask : ~(u32)0;
133		u32 new_value;
134
135		if (nbits < 32)
136			real_mask &= ethnl_lower_bits(nbits);
137		new_value = (*dst & ~real_mask) | (*value & real_mask);
138		if (new_value != *dst) {
139			*dst = new_value;
140			*mod = true;
141		}
142
143		if (nbits <= 32)
144			break;
145		dst++;
146		nbits -= 32;
147		value++;
148		if (mask)
149			mask++;
150	}
151}
152
153static bool ethnl_bitmap32_test_bit(const u32 *map, unsigned int index)
154{
155	return map[index / 32] & (1U << (index % 32));
156}
157
158/**
159 * ethnl_bitset32_size() - Calculate size of bitset nested attribute
160 * @val:     value bitmap (u32 based)
161 * @mask:    mask bitmap (u32 based, optional)
162 * @nbits:   bit length of the bitset
163 * @names:   array of bit names (optional)
164 * @compact: assume compact format for output
165 *
166 * Estimate length of netlink attribute composed by a later call to
167 * ethnl_put_bitset32() call with the same arguments.
168 *
169 * Return: negative error code or attribute length estimate
170 */
171int ethnl_bitset32_size(const u32 *val, const u32 *mask, unsigned int nbits,
172			ethnl_string_array_t names, bool compact)
173{
174	unsigned int len = 0;
175
176	/* list flag */
177	if (!mask)
178		len += nla_total_size(sizeof(u32));
179	/* size */
180	len += nla_total_size(sizeof(u32));
181
182	if (compact) {
183		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
184
185		/* value, mask */
186		len += (mask ? 2 : 1) * nla_total_size(nwords * sizeof(u32));
187	} else {
188		unsigned int bits_len = 0;
189		unsigned int bit_len, i;
190
191		for (i = 0; i < nbits; i++) {
192			const char *name = names ? names[i] : NULL;
193
194			if (!ethnl_bitmap32_test_bit(mask ?: val, i))
195				continue;
196			/* index */
197			bit_len = nla_total_size(sizeof(u32));
198			/* name */
199			if (name)
200				bit_len += ethnl_strz_size(name);
201			/* value */
202			if (mask && ethnl_bitmap32_test_bit(val, i))
203				bit_len += nla_total_size(0);
204
205			/* bit nest */
206			bits_len += nla_total_size(bit_len);
207		}
208		/* bits nest */
209		len += nla_total_size(bits_len);
210	}
211
212	/* outermost nest */
213	return nla_total_size(len);
214}
215
216/**
217 * ethnl_put_bitset32() - Put a bitset nest into a message
218 * @skb:      skb with the message
219 * @attrtype: attribute type for the bitset nest
220 * @val:      value bitmap (u32 based)
221 * @mask:     mask bitmap (u32 based, optional)
222 * @nbits:    bit length of the bitset
223 * @names:    array of bit names (optional)
224 * @compact:  use compact format for the output
225 *
226 * Compose a nested attribute representing a bitset. If @mask is null, simple
227 * bitmap (bit list) is created, if @mask is provided, represent a value/mask
228 * pair. Bit names are only used in verbose mode and when provided by calller.
229 *
230 * Return: 0 on success, negative error value on error
231 */
232int ethnl_put_bitset32(struct sk_buff *skb, int attrtype, const u32 *val,
233		       const u32 *mask, unsigned int nbits,
234		       ethnl_string_array_t names, bool compact)
235{
236	struct nlattr *nest;
237	struct nlattr *attr;
238
239	nest = nla_nest_start(skb, attrtype);
240	if (!nest)
241		return -EMSGSIZE;
242
243	if (!mask && nla_put_flag(skb, ETHTOOL_A_BITSET_NOMASK))
244		goto nla_put_failure;
245	if (nla_put_u32(skb, ETHTOOL_A_BITSET_SIZE, nbits))
246		goto nla_put_failure;
247	if (compact) {
248		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
249		unsigned int nbytes = nwords * sizeof(u32);
250		u32 *dst;
251
252		attr = nla_reserve(skb, ETHTOOL_A_BITSET_VALUE, nbytes);
253		if (!attr)
254			goto nla_put_failure;
255		dst = nla_data(attr);
256		memcpy(dst, val, nbytes);
257		if (nbits % 32)
258			dst[nwords - 1] &= ethnl_lower_bits(nbits);
259
260		if (mask) {
261			attr = nla_reserve(skb, ETHTOOL_A_BITSET_MASK, nbytes);
262			if (!attr)
263				goto nla_put_failure;
264			dst = nla_data(attr);
265			memcpy(dst, mask, nbytes);
266			if (nbits % 32)
267				dst[nwords - 1] &= ethnl_lower_bits(nbits);
268		}
269	} else {
270		struct nlattr *bits;
271		unsigned int i;
272
273		bits = nla_nest_start(skb, ETHTOOL_A_BITSET_BITS);
274		if (!bits)
275			goto nla_put_failure;
276		for (i = 0; i < nbits; i++) {
277			const char *name = names ? names[i] : NULL;
278
279			if (!ethnl_bitmap32_test_bit(mask ?: val, i))
280				continue;
281			attr = nla_nest_start(skb, ETHTOOL_A_BITSET_BITS_BIT);
282			if (!attr)
283				goto nla_put_failure;
284			if (nla_put_u32(skb, ETHTOOL_A_BITSET_BIT_INDEX, i))
285				goto nla_put_failure;
286			if (name &&
287			    ethnl_put_strz(skb, ETHTOOL_A_BITSET_BIT_NAME, name))
288				goto nla_put_failure;
289			if (mask && ethnl_bitmap32_test_bit(val, i) &&
290			    nla_put_flag(skb, ETHTOOL_A_BITSET_BIT_VALUE))
291				goto nla_put_failure;
292			nla_nest_end(skb, attr);
293		}
294		nla_nest_end(skb, bits);
295	}
296
297	nla_nest_end(skb, nest);
298	return 0;
299
300nla_put_failure:
301	nla_nest_cancel(skb, nest);
302	return -EMSGSIZE;
303}
304
305static const struct nla_policy bitset_policy[] = {
306	[ETHTOOL_A_BITSET_NOMASK]	= { .type = NLA_FLAG },
307	[ETHTOOL_A_BITSET_SIZE]		= NLA_POLICY_MAX(NLA_U32,
308							 ETHNL_MAX_BITSET_SIZE),
309	[ETHTOOL_A_BITSET_BITS]		= { .type = NLA_NESTED },
310	[ETHTOOL_A_BITSET_VALUE]	= { .type = NLA_BINARY },
311	[ETHTOOL_A_BITSET_MASK]		= { .type = NLA_BINARY },
312};
313
314static const struct nla_policy bit_policy[] = {
315	[ETHTOOL_A_BITSET_BIT_INDEX]	= { .type = NLA_U32 },
316	[ETHTOOL_A_BITSET_BIT_NAME]	= { .type = NLA_NUL_STRING },
317	[ETHTOOL_A_BITSET_BIT_VALUE]	= { .type = NLA_FLAG },
318};
319
320/**
321 * ethnl_bitset_is_compact() - check if bitset attribute represents a compact
322 *			       bitset
323 * @bitset:  nested attribute representing a bitset
324 * @compact: pointer for return value
325 *
326 * Return: 0 on success, negative error code on failure
327 */
328int ethnl_bitset_is_compact(const struct nlattr *bitset, bool *compact)
329{
330	struct nlattr *tb[ARRAY_SIZE(bitset_policy)];
331	int ret;
332
333	ret = nla_parse_nested(tb, ARRAY_SIZE(bitset_policy) - 1, bitset,
334			       bitset_policy, NULL);
335	if (ret < 0)
336		return ret;
337
338	if (tb[ETHTOOL_A_BITSET_BITS]) {
339		if (tb[ETHTOOL_A_BITSET_VALUE] || tb[ETHTOOL_A_BITSET_MASK])
340			return -EINVAL;
341		*compact = false;
342		return 0;
343	}
344	if (!tb[ETHTOOL_A_BITSET_SIZE] || !tb[ETHTOOL_A_BITSET_VALUE])
345		return -EINVAL;
346
347	*compact = true;
348	return 0;
349}
350
351/**
352 * ethnl_name_to_idx() - look up string index for a name
353 * @names:   array of ETH_GSTRING_LEN sized strings
354 * @n_names: number of strings in the array
355 * @name:    name to look up
356 *
357 * Return: index of the string if found, -ENOENT if not found
358 */
359static int ethnl_name_to_idx(ethnl_string_array_t names, unsigned int n_names,
360			     const char *name)
361{
362	unsigned int i;
363
364	if (!names)
365		return -ENOENT;
366
367	for (i = 0; i < n_names; i++) {
368		/* names[i] may not be null terminated */
369		if (!strncmp(names[i], name, ETH_GSTRING_LEN) &&
370		    strlen(name) <= ETH_GSTRING_LEN)
371			return i;
372	}
373
374	return -ENOENT;
375}
376
377static int ethnl_parse_bit(unsigned int *index, bool *val, unsigned int nbits,
378			   const struct nlattr *bit_attr, bool no_mask,
379			   ethnl_string_array_t names,
380			   struct netlink_ext_ack *extack)
381{
382	struct nlattr *tb[ARRAY_SIZE(bit_policy)];
383	int ret, idx;
384
385	ret = nla_parse_nested(tb, ARRAY_SIZE(bit_policy) - 1, bit_attr,
386			       bit_policy, extack);
387	if (ret < 0)
388		return ret;
389
390	if (tb[ETHTOOL_A_BITSET_BIT_INDEX]) {
391		const char *name;
392
393		idx = nla_get_u32(tb[ETHTOOL_A_BITSET_BIT_INDEX]);
394		if (idx >= nbits) {
395			NL_SET_ERR_MSG_ATTR(extack,
396					    tb[ETHTOOL_A_BITSET_BIT_INDEX],
397					    "bit index too high");
398			return -EOPNOTSUPP;
399		}
400		name = names ? names[idx] : NULL;
401		if (tb[ETHTOOL_A_BITSET_BIT_NAME] && name &&
402		    strncmp(nla_data(tb[ETHTOOL_A_BITSET_BIT_NAME]), name,
403			    nla_len(tb[ETHTOOL_A_BITSET_BIT_NAME]))) {
404			NL_SET_ERR_MSG_ATTR(extack, bit_attr,
405					    "bit index and name mismatch");
406			return -EINVAL;
407		}
408	} else if (tb[ETHTOOL_A_BITSET_BIT_NAME]) {
409		idx = ethnl_name_to_idx(names, nbits,
410					nla_data(tb[ETHTOOL_A_BITSET_BIT_NAME]));
411		if (idx < 0) {
412			NL_SET_ERR_MSG_ATTR(extack,
413					    tb[ETHTOOL_A_BITSET_BIT_NAME],
414					    "bit name not found");
415			return -EOPNOTSUPP;
416		}
417	} else {
418		NL_SET_ERR_MSG_ATTR(extack, bit_attr,
419				    "neither bit index nor name specified");
420		return -EINVAL;
421	}
422
423	*index = idx;
424	*val = no_mask || tb[ETHTOOL_A_BITSET_BIT_VALUE];
425	return 0;
426}
427
428static int
429ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits,
430			      const struct nlattr *attr, struct nlattr **tb,
431			      ethnl_string_array_t names,
432			      struct netlink_ext_ack *extack, bool *mod)
433{
434	struct nlattr *bit_attr;
435	bool no_mask;
436	int rem;
437	int ret;
438
439	if (tb[ETHTOOL_A_BITSET_VALUE]) {
440		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
441				    "value only allowed in compact bitset");
442		return -EINVAL;
443	}
444	if (tb[ETHTOOL_A_BITSET_MASK]) {
445		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
446				    "mask only allowed in compact bitset");
447		return -EINVAL;
448	}
449
450	no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
451	if (no_mask)
452		ethnl_bitmap32_clear(bitmap, 0, nbits, mod);
453
454	nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
455		bool old_val, new_val;
456		unsigned int idx;
457
458		if (nla_type(bit_attr) != ETHTOOL_A_BITSET_BITS_BIT) {
459			NL_SET_ERR_MSG_ATTR(extack, bit_attr,
460					    "only ETHTOOL_A_BITSET_BITS_BIT allowed in ETHTOOL_A_BITSET_BITS");
461			return -EINVAL;
462		}
463		ret = ethnl_parse_bit(&idx, &new_val, nbits, bit_attr, no_mask,
464				      names, extack);
465		if (ret < 0)
466			return ret;
467		old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32));
468		if (new_val != old_val) {
469			if (new_val)
470				bitmap[idx / 32] |= ((u32)1 << (idx % 32));
471			else
472				bitmap[idx / 32] &= ~((u32)1 << (idx % 32));
473			*mod = true;
474		}
475	}
476
477	return 0;
478}
479
480static int ethnl_compact_sanity_checks(unsigned int nbits,
481				       const struct nlattr *nest,
482				       struct nlattr **tb,
483				       struct netlink_ext_ack *extack)
484{
485	bool no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
486	unsigned int attr_nbits, attr_nwords;
487	const struct nlattr *test_attr;
488
489	if (no_mask && tb[ETHTOOL_A_BITSET_MASK]) {
490		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
491				    "mask not allowed in list bitset");
492		return -EINVAL;
493	}
494	if (!tb[ETHTOOL_A_BITSET_SIZE]) {
495		NL_SET_ERR_MSG_ATTR(extack, nest,
496				    "missing size in compact bitset");
497		return -EINVAL;
498	}
499	if (!tb[ETHTOOL_A_BITSET_VALUE]) {
500		NL_SET_ERR_MSG_ATTR(extack, nest,
501				    "missing value in compact bitset");
502		return -EINVAL;
503	}
504	if (!no_mask && !tb[ETHTOOL_A_BITSET_MASK]) {
505		NL_SET_ERR_MSG_ATTR(extack, nest,
506				    "missing mask in compact nonlist bitset");
507		return -EINVAL;
508	}
509
510	attr_nbits = nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]);
511	attr_nwords = DIV_ROUND_UP(attr_nbits, 32);
512	if (nla_len(tb[ETHTOOL_A_BITSET_VALUE]) != attr_nwords * sizeof(u32)) {
513		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
514				    "bitset value length does not match size");
515		return -EINVAL;
516	}
517	if (tb[ETHTOOL_A_BITSET_MASK] &&
518	    nla_len(tb[ETHTOOL_A_BITSET_MASK]) != attr_nwords * sizeof(u32)) {
519		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
520				    "bitset mask length does not match size");
521		return -EINVAL;
522	}
523	if (attr_nbits <= nbits)
524		return 0;
525
526	test_attr = no_mask ? tb[ETHTOOL_A_BITSET_VALUE] :
527			      tb[ETHTOOL_A_BITSET_MASK];
528	if (ethnl_bitmap32_not_zero(nla_data(test_attr), nbits, attr_nbits)) {
529		NL_SET_ERR_MSG_ATTR(extack, test_attr,
530				    "cannot modify bits past kernel bitset size");
531		return -EINVAL;
532	}
533	return 0;
534}
535
536/**
537 * ethnl_update_bitset32() - Apply a bitset nest to a u32 based bitmap
538 * @bitmap:  bitmap to update
539 * @nbits:   size of the updated bitmap in bits
540 * @attr:    nest attribute to parse and apply
541 * @names:   array of bit names; may be null for compact format
542 * @extack:  extack for error reporting
543 * @mod:     set this to true if bitmap is modified, leave as it is if not
544 *
545 * Apply bitset netsted attribute to a bitmap. If the attribute represents
546 * a bit list, @bitmap is set to its contents; otherwise, bits in mask are
547 * set to values from value. Bitmaps in the attribute may be longer than
548 * @nbits but the message must not request modifying any bits past @nbits.
549 *
550 * Return: negative error code on failure, 0 on success
551 */
552int ethnl_update_bitset32(u32 *bitmap, unsigned int nbits,
553			  const struct nlattr *attr, ethnl_string_array_t names,
554			  struct netlink_ext_ack *extack, bool *mod)
555{
556	struct nlattr *tb[ARRAY_SIZE(bitset_policy)];
557	unsigned int change_bits;
558	bool no_mask;
559	int ret;
560
561	if (!attr)
562		return 0;
563	ret = nla_parse_nested(tb, ARRAY_SIZE(bitset_policy) - 1, attr,
564			       bitset_policy, extack);
565	if (ret < 0)
566		return ret;
567
568	if (tb[ETHTOOL_A_BITSET_BITS])
569		return ethnl_update_bitset32_verbose(bitmap, nbits, attr, tb,
570						     names, extack, mod);
571	ret = ethnl_compact_sanity_checks(nbits, attr, tb, extack);
572	if (ret < 0)
573		return ret;
574
575	no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
576	change_bits = min_t(unsigned int,
577			    nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]), nbits);
578	ethnl_bitmap32_update(bitmap, change_bits,
579			      nla_data(tb[ETHTOOL_A_BITSET_VALUE]),
580			      no_mask ? NULL :
581					nla_data(tb[ETHTOOL_A_BITSET_MASK]),
582			      mod);
583	if (no_mask && change_bits < nbits)
584		ethnl_bitmap32_clear(bitmap, change_bits, nbits, mod);
585
586	return 0;
587}
588
589/**
590 * ethnl_parse_bitset() - Compute effective value and mask from bitset nest
591 * @val:     unsigned long based bitmap to put value into
592 * @mask:    unsigned long based bitmap to put mask into
593 * @nbits:   size of @val and @mask bitmaps
594 * @attr:    nest attribute to parse and apply
595 * @names:   array of bit names; may be null for compact format
596 * @extack:  extack for error reporting
597 *
598 * Provide @nbits size long bitmaps for value and mask so that
599 * x = (val & mask) | (x & ~mask) would modify any @nbits sized bitmap x
600 * the same way ethnl_update_bitset() with the same bitset attribute would.
601 *
602 * Return:   negative error code on failure, 0 on success
603 */
604int ethnl_parse_bitset(unsigned long *val, unsigned long *mask,
605		       unsigned int nbits, const struct nlattr *attr,
606		       ethnl_string_array_t names,
607		       struct netlink_ext_ack *extack)
608{
609	struct nlattr *tb[ARRAY_SIZE(bitset_policy)];
610	const struct nlattr *bit_attr;
611	bool no_mask;
612	int rem;
613	int ret;
614
615	if (!attr)
616		return 0;
617	ret = nla_parse_nested(tb, ARRAY_SIZE(bitset_policy) - 1, attr,
618			       bitset_policy, extack);
619	if (ret < 0)
620		return ret;
621	no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
622
623	if (!tb[ETHTOOL_A_BITSET_BITS]) {
624		unsigned int change_bits;
625
626		ret = ethnl_compact_sanity_checks(nbits, attr, tb, extack);
627		if (ret < 0)
628			return ret;
629
630		change_bits = nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]);
631		if (change_bits > nbits)
632			change_bits = nbits;
633		bitmap_from_arr32(val, nla_data(tb[ETHTOOL_A_BITSET_VALUE]),
634				  change_bits);
635		if (change_bits < nbits)
636			bitmap_clear(val, change_bits, nbits - change_bits);
637		if (no_mask) {
638			bitmap_fill(mask, nbits);
639		} else {
640			bitmap_from_arr32(mask,
641					  nla_data(tb[ETHTOOL_A_BITSET_MASK]),
642					  change_bits);
643			if (change_bits < nbits)
644				bitmap_clear(mask, change_bits,
645					     nbits - change_bits);
646		}
647
648		return 0;
649	}
650
651	if (tb[ETHTOOL_A_BITSET_VALUE]) {
652		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
653				    "value only allowed in compact bitset");
654		return -EINVAL;
655	}
656	if (tb[ETHTOOL_A_BITSET_MASK]) {
657		NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
658				    "mask only allowed in compact bitset");
659		return -EINVAL;
660	}
661
662	bitmap_zero(val, nbits);
663	if (no_mask)
664		bitmap_fill(mask, nbits);
665	else
666		bitmap_zero(mask, nbits);
667
668	nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
669		unsigned int idx;
670		bool bit_val;
671
672		ret = ethnl_parse_bit(&idx, &bit_val, nbits, bit_attr, no_mask,
673				      names, extack);
674		if (ret < 0)
675			return ret;
676		if (bit_val)
677			__set_bit(idx, val);
678		if (!no_mask)
679			__set_bit(idx, mask);
680	}
681
682	return 0;
683}
684
685#if BITS_PER_LONG == 64 && defined(__BIG_ENDIAN)
686
687/* 64-bit big endian architectures are the only case when u32 based bitmaps
688 * and unsigned long based bitmaps have different memory layout so that we
689 * cannot simply cast the latter to the former and need actual wrappers
690 * converting the latter to the former.
691 *
692 * To reduce the number of slab allocations, the wrappers use fixed size local
693 * variables for bitmaps up to ETHNL_SMALL_BITMAP_BITS bits which is the
694 * majority of bitmaps used by ethtool.
695 */
696#define ETHNL_SMALL_BITMAP_BITS 128
697#define ETHNL_SMALL_BITMAP_WORDS DIV_ROUND_UP(ETHNL_SMALL_BITMAP_BITS, 32)
698
699int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask,
700		      unsigned int nbits, ethnl_string_array_t names,
701		      bool compact)
702{
703	u32 small_mask32[ETHNL_SMALL_BITMAP_WORDS];
704	u32 small_val32[ETHNL_SMALL_BITMAP_WORDS];
705	u32 *mask32;
706	u32 *val32;
707	int ret;
708
709	if (nbits > ETHNL_SMALL_BITMAP_BITS) {
710		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
711
712		val32 = kmalloc_array(2 * nwords, sizeof(u32), GFP_KERNEL);
713		if (!val32)
714			return -ENOMEM;
715		mask32 = val32 + nwords;
716	} else {
717		val32 = small_val32;
718		mask32 = small_mask32;
719	}
720
721	bitmap_to_arr32(val32, val, nbits);
722	if (mask)
723		bitmap_to_arr32(mask32, mask, nbits);
724	else
725		mask32 = NULL;
726	ret = ethnl_bitset32_size(val32, mask32, nbits, names, compact);
727
728	if (nbits > ETHNL_SMALL_BITMAP_BITS)
729		kfree(val32);
730
731	return ret;
732}
733
734int ethnl_put_bitset(struct sk_buff *skb, int attrtype,
735		     const unsigned long *val, const unsigned long *mask,
736		     unsigned int nbits, ethnl_string_array_t names,
737		     bool compact)
738{
739	u32 small_mask32[ETHNL_SMALL_BITMAP_WORDS];
740	u32 small_val32[ETHNL_SMALL_BITMAP_WORDS];
741	u32 *mask32;
742	u32 *val32;
743	int ret;
744
745	if (nbits > ETHNL_SMALL_BITMAP_BITS) {
746		unsigned int nwords = DIV_ROUND_UP(nbits, 32);
747
748		val32 = kmalloc_array(2 * nwords, sizeof(u32), GFP_KERNEL);
749		if (!val32)
750			return -ENOMEM;
751		mask32 = val32 + nwords;
752	} else {
753		val32 = small_val32;
754		mask32 = small_mask32;
755	}
756
757	bitmap_to_arr32(val32, val, nbits);
758	if (mask)
759		bitmap_to_arr32(mask32, mask, nbits);
760	else
761		mask32 = NULL;
762	ret = ethnl_put_bitset32(skb, attrtype, val32, mask32, nbits, names,
763				 compact);
764
765	if (nbits > ETHNL_SMALL_BITMAP_BITS)
766		kfree(val32);
767
768	return ret;
769}
770
771int ethnl_update_bitset(unsigned long *bitmap, unsigned int nbits,
772			const struct nlattr *attr, ethnl_string_array_t names,
773			struct netlink_ext_ack *extack, bool *mod)
774{
775	u32 small_bitmap32[ETHNL_SMALL_BITMAP_WORDS];
776	u32 *bitmap32 = small_bitmap32;
777	bool u32_mod = false;
778	int ret;
779
780	if (nbits > ETHNL_SMALL_BITMAP_BITS) {
781		unsigned int dst_words = DIV_ROUND_UP(nbits, 32);
782
783		bitmap32 = kmalloc_array(dst_words, sizeof(u32), GFP_KERNEL);
784		if (!bitmap32)
785			return -ENOMEM;
786	}
787
788	bitmap_to_arr32(bitmap32, bitmap, nbits);
789	ret = ethnl_update_bitset32(bitmap32, nbits, attr, names, extack,
790				    &u32_mod);
791	if (u32_mod) {
792		bitmap_from_arr32(bitmap, bitmap32, nbits);
793		*mod = true;
794	}
795
796	if (nbits > ETHNL_SMALL_BITMAP_BITS)
797		kfree(bitmap32);
798
799	return ret;
800}
801
802#else
803
804/* On little endian 64-bit and all 32-bit architectures, an unsigned long
805 * based bitmap can be interpreted as u32 based one using a simple cast.
806 */
807
808int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask,
809		      unsigned int nbits, ethnl_string_array_t names,
810		      bool compact)
811{
812	return ethnl_bitset32_size((const u32 *)val, (const u32 *)mask, nbits,
813				   names, compact);
814}
815
816int ethnl_put_bitset(struct sk_buff *skb, int attrtype,
817		     const unsigned long *val, const unsigned long *mask,
818		     unsigned int nbits, ethnl_string_array_t names,
819		     bool compact)
820{
821	return ethnl_put_bitset32(skb, attrtype, (const u32 *)val,
822				  (const u32 *)mask, nbits, names, compact);
823}
824
825int ethnl_update_bitset(unsigned long *bitmap, unsigned int nbits,
826			const struct nlattr *attr, ethnl_string_array_t names,
827			struct netlink_ext_ack *extack, bool *mod)
828{
829	return ethnl_update_bitset32((u32 *)bitmap, nbits, attr, names, extack,
830				     mod);
831}
832
833#endif /* BITS_PER_LONG == 64 && defined(__BIG_ENDIAN) */
834