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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_NETLINK_H
3#define __NET_NETLINK_H
4
5#include <linux/types.h>
6#include <linux/netlink.h>
7#include <linux/jiffies.h>
8#include <linux/in6.h>
9
10/* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
13 * Messages Interface
14 * ------------------------------------------------------------------------
15 *
16 * Message Format:
17 * <--- nlmsg_total_size(payload) --->
18 * <-- nlmsg_msg_size(payload) ->
19 * +----------+- - -+-------------+- - -+-------- - -
20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
21 * +----------+- - -+-------------+- - -+-------- - -
22 * nlmsg_data(nlh)---^ ^
23 * nlmsg_next(nlh)-----------------------+
24 *
25 * Payload Format:
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
32 *
33 * Data Structures:
34 * struct nlmsghdr netlink message header
35 *
36 * Message Construction:
37 * nlmsg_new() create a new netlink message
38 * nlmsg_put() add a netlink message to an skb
39 * nlmsg_put_answer() callback based nlmsg_put()
40 * nlmsg_end() finalize netlink message
41 * nlmsg_get_pos() return current position in message
42 * nlmsg_trim() trim part of message
43 * nlmsg_cancel() cancel message construction
44 * nlmsg_free() free a netlink message
45 *
46 * Message Sending:
47 * nlmsg_multicast() multicast message to several groups
48 * nlmsg_unicast() unicast a message to a single socket
49 * nlmsg_notify() send notification message
50 *
51 * Message Length Calculations:
52 * nlmsg_msg_size(payload) length of message w/o padding
53 * nlmsg_total_size(payload) length of message w/ padding
54 * nlmsg_padlen(payload) length of padding at tail
55 *
56 * Message Payload Access:
57 * nlmsg_data(nlh) head of message payload
58 * nlmsg_len(nlh) length of message payload
59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
61 *
62 * Message Parsing:
63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
64 * nlmsg_next(nlh, remaining) get next netlink message
65 * nlmsg_parse() parse attributes of a message
66 * nlmsg_find_attr() find an attribute in a message
67 * nlmsg_for_each_msg() loop over all messages
68 * nlmsg_validate() validate netlink message incl. attrs
69 * nlmsg_for_each_attr() loop over all attributes
70 *
71 * Misc:
72 * nlmsg_report() report back to application?
73 *
74 * ------------------------------------------------------------------------
75 * Attributes Interface
76 * ------------------------------------------------------------------------
77 *
78 * Attribute Format:
79 * <------- nla_total_size(payload) ------->
80 * <---- nla_attr_size(payload) ----->
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * | Header | Pad | Payload | Pad | Header
83 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
84 * <- nla_len(nla) -> ^
85 * nla_data(nla)----^ |
86 * nla_next(nla)-----------------------------'
87 *
88 * Data Structures:
89 * struct nlattr netlink attribute header
90 *
91 * Attribute Construction:
92 * nla_reserve(skb, type, len) reserve room for an attribute
93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
94 * nla_put(skb, type, len, data) add attribute to skb
95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
96 * nla_append(skb, len, data) append data to skb
97 *
98 * Attribute Construction for Basic Types:
99 * nla_put_u8(skb, type, value) add u8 attribute to skb
100 * nla_put_u16(skb, type, value) add u16 attribute to skb
101 * nla_put_u32(skb, type, value) add u32 attribute to skb
102 * nla_put_u64_64bit(skb, type,
103 * value, padattr) add u64 attribute to skb
104 * nla_put_s8(skb, type, value) add s8 attribute to skb
105 * nla_put_s16(skb, type, value) add s16 attribute to skb
106 * nla_put_s32(skb, type, value) add s32 attribute to skb
107 * nla_put_s64(skb, type, value,
108 * padattr) add s64 attribute to skb
109 * nla_put_string(skb, type, str) add string attribute to skb
110 * nla_put_flag(skb, type) add flag attribute to skb
111 * nla_put_msecs(skb, type, jiffies,
112 * padattr) add msecs attribute to skb
113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
115 *
116 * Nested Attributes Construction:
117 * nla_nest_start(skb, type) start a nested attribute
118 * nla_nest_end(skb, nla) finalize a nested attribute
119 * nla_nest_cancel(skb, nla) cancel nested attribute construction
120 *
121 * Attribute Length Calculations:
122 * nla_attr_size(payload) length of attribute w/o padding
123 * nla_total_size(payload) length of attribute w/ padding
124 * nla_padlen(payload) length of padding
125 *
126 * Attribute Payload Access:
127 * nla_data(nla) head of attribute payload
128 * nla_len(nla) length of attribute payload
129 *
130 * Attribute Payload Access for Basic Types:
131 * nla_get_u8(nla) get payload for a u8 attribute
132 * nla_get_u16(nla) get payload for a u16 attribute
133 * nla_get_u32(nla) get payload for a u32 attribute
134 * nla_get_u64(nla) get payload for a u64 attribute
135 * nla_get_s8(nla) get payload for a s8 attribute
136 * nla_get_s16(nla) get payload for a s16 attribute
137 * nla_get_s32(nla) get payload for a s32 attribute
138 * nla_get_s64(nla) get payload for a s64 attribute
139 * nla_get_flag(nla) return 1 if flag is true
140 * nla_get_msecs(nla) get payload for a msecs attribute
141 *
142 * Attribute Misc:
143 * nla_memcpy(dest, nla, count) copy attribute into memory
144 * nla_memcmp(nla, data, size) compare attribute with memory area
145 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
146 * nla_strcmp(nla, str) compare attribute with string
147 *
148 * Attribute Parsing:
149 * nla_ok(nla, remaining) does nla fit into remaining bytes?
150 * nla_next(nla, remaining) get next netlink attribute
151 * nla_validate() validate a stream of attributes
152 * nla_validate_nested() validate a stream of nested attributes
153 * nla_find() find attribute in stream of attributes
154 * nla_find_nested() find attribute in nested attributes
155 * nla_parse() parse and validate stream of attrs
156 * nla_parse_nested() parse nested attribuets
157 * nla_for_each_attr() loop over all attributes
158 * nla_for_each_nested() loop over the nested attributes
159 *=========================================================================
160 */
161
162 /**
163 * Standard attribute types to specify validation policy
164 */
165enum {
166 NLA_UNSPEC,
167 NLA_U8,
168 NLA_U16,
169 NLA_U32,
170 NLA_U64,
171 NLA_STRING,
172 NLA_FLAG,
173 NLA_MSECS,
174 NLA_NESTED,
175 NLA_NESTED_COMPAT,
176 NLA_NUL_STRING,
177 NLA_BINARY,
178 NLA_S8,
179 NLA_S16,
180 NLA_S32,
181 NLA_S64,
182 NLA_BITFIELD32,
183 __NLA_TYPE_MAX,
184};
185
186#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
187
188/**
189 * struct nla_policy - attribute validation policy
190 * @type: Type of attribute or NLA_UNSPEC
191 * @len: Type specific length of payload
192 *
193 * Policies are defined as arrays of this struct, the array must be
194 * accessible by attribute type up to the highest identifier to be expected.
195 *
196 * Meaning of `len' field:
197 * NLA_STRING Maximum length of string
198 * NLA_NUL_STRING Maximum length of string (excluding NUL)
199 * NLA_FLAG Unused
200 * NLA_BINARY Maximum length of attribute payload
201 * NLA_NESTED Don't use `len' field -- length verification is
202 * done by checking len of nested header (or empty)
203 * NLA_NESTED_COMPAT Minimum length of structure payload
204 * NLA_U8, NLA_U16,
205 * NLA_U32, NLA_U64,
206 * NLA_S8, NLA_S16,
207 * NLA_S32, NLA_S64,
208 * NLA_MSECS Leaving the length field zero will verify the
209 * given type fits, using it verifies minimum length
210 * just like "All other"
211 * NLA_BITFIELD32 A 32-bit bitmap/bitselector attribute
212 * All other Minimum length of attribute payload
213 *
214 * Example:
215 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
216 * [ATTR_FOO] = { .type = NLA_U16 },
217 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
218 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
219 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags },
220 * };
221 */
222struct nla_policy {
223 u16 type;
224 u16 len;
225 void *validation_data;
226};
227
228/**
229 * struct nl_info - netlink source information
230 * @nlh: Netlink message header of original request
231 * @portid: Netlink PORTID of requesting application
232 */
233struct nl_info {
234 struct nlmsghdr *nlh;
235 struct net *nl_net;
236 u32 portid;
237 bool skip_notify;
238};
239
240int netlink_rcv_skb(struct sk_buff *skb,
241 int (*cb)(struct sk_buff *, struct nlmsghdr *,
242 struct netlink_ext_ack *));
243int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
244 unsigned int group, int report, gfp_t flags);
245
246int nla_validate(const struct nlattr *head, int len, int maxtype,
247 const struct nla_policy *policy,
248 struct netlink_ext_ack *extack);
249int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
250 int len, const struct nla_policy *policy,
251 struct netlink_ext_ack *extack);
252int nla_policy_len(const struct nla_policy *, int);
253struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
254size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
255char *nla_strdup(const struct nlattr *nla, gfp_t flags);
256int nla_memcpy(void *dest, const struct nlattr *src, int count);
257int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
258int nla_strcmp(const struct nlattr *nla, const char *str);
259struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
260struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
261 int attrlen, int padattr);
262void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
263struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
264struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
265 int attrlen, int padattr);
266void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
267void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
268 const void *data);
269void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
270 const void *data, int padattr);
271void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
272int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
273int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
274 const void *data, int padattr);
275int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
276int nla_append(struct sk_buff *skb, int attrlen, const void *data);
277
278/**************************************************************************
279 * Netlink Messages
280 **************************************************************************/
281
282/**
283 * nlmsg_msg_size - length of netlink message not including padding
284 * @payload: length of message payload
285 */
286static inline int nlmsg_msg_size(int payload)
287{
288 return NLMSG_HDRLEN + payload;
289}
290
291/**
292 * nlmsg_total_size - length of netlink message including padding
293 * @payload: length of message payload
294 */
295static inline int nlmsg_total_size(int payload)
296{
297 return NLMSG_ALIGN(nlmsg_msg_size(payload));
298}
299
300/**
301 * nlmsg_padlen - length of padding at the message's tail
302 * @payload: length of message payload
303 */
304static inline int nlmsg_padlen(int payload)
305{
306 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
307}
308
309/**
310 * nlmsg_data - head of message payload
311 * @nlh: netlink message header
312 */
313static inline void *nlmsg_data(const struct nlmsghdr *nlh)
314{
315 return (unsigned char *) nlh + NLMSG_HDRLEN;
316}
317
318/**
319 * nlmsg_len - length of message payload
320 * @nlh: netlink message header
321 */
322static inline int nlmsg_len(const struct nlmsghdr *nlh)
323{
324 return nlh->nlmsg_len - NLMSG_HDRLEN;
325}
326
327/**
328 * nlmsg_attrdata - head of attributes data
329 * @nlh: netlink message header
330 * @hdrlen: length of family specific header
331 */
332static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
333 int hdrlen)
334{
335 unsigned char *data = nlmsg_data(nlh);
336 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
337}
338
339/**
340 * nlmsg_attrlen - length of attributes data
341 * @nlh: netlink message header
342 * @hdrlen: length of family specific header
343 */
344static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
345{
346 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
347}
348
349/**
350 * nlmsg_ok - check if the netlink message fits into the remaining bytes
351 * @nlh: netlink message header
352 * @remaining: number of bytes remaining in message stream
353 */
354static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
355{
356 return (remaining >= (int) sizeof(struct nlmsghdr) &&
357 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
358 nlh->nlmsg_len <= remaining);
359}
360
361/**
362 * nlmsg_next - next netlink message in message stream
363 * @nlh: netlink message header
364 * @remaining: number of bytes remaining in message stream
365 *
366 * Returns the next netlink message in the message stream and
367 * decrements remaining by the size of the current message.
368 */
369static inline struct nlmsghdr *
370nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
371{
372 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
373
374 *remaining -= totlen;
375
376 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
377}
378
379/**
380 * nlmsg_parse - parse attributes of a netlink message
381 * @nlh: netlink message header
382 * @hdrlen: length of family specific header
383 * @tb: destination array with maxtype+1 elements
384 * @maxtype: maximum attribute type to be expected
385 * @policy: validation policy
386 * @extack: extended ACK report struct
387 *
388 * See nla_parse()
389 */
390static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
391 struct nlattr *tb[], int maxtype,
392 const struct nla_policy *policy,
393 struct netlink_ext_ack *extack)
394{
395 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
396 return -EINVAL;
397
398 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
399 nlmsg_attrlen(nlh, hdrlen), policy, extack);
400}
401
402/**
403 * nlmsg_find_attr - find a specific attribute in a netlink message
404 * @nlh: netlink message header
405 * @hdrlen: length of familiy specific header
406 * @attrtype: type of attribute to look for
407 *
408 * Returns the first attribute which matches the specified type.
409 */
410static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
411 int hdrlen, int attrtype)
412{
413 return nla_find(nlmsg_attrdata(nlh, hdrlen),
414 nlmsg_attrlen(nlh, hdrlen), attrtype);
415}
416
417/**
418 * nlmsg_validate - validate a netlink message including attributes
419 * @nlh: netlinket message header
420 * @hdrlen: length of familiy specific header
421 * @maxtype: maximum attribute type to be expected
422 * @policy: validation policy
423 * @extack: extended ACK report struct
424 */
425static inline int nlmsg_validate(const struct nlmsghdr *nlh,
426 int hdrlen, int maxtype,
427 const struct nla_policy *policy,
428 struct netlink_ext_ack *extack)
429{
430 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
431 return -EINVAL;
432
433 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
434 nlmsg_attrlen(nlh, hdrlen), maxtype, policy,
435 extack);
436}
437
438/**
439 * nlmsg_report - need to report back to application?
440 * @nlh: netlink message header
441 *
442 * Returns 1 if a report back to the application is requested.
443 */
444static inline int nlmsg_report(const struct nlmsghdr *nlh)
445{
446 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
447}
448
449/**
450 * nlmsg_for_each_attr - iterate over a stream of attributes
451 * @pos: loop counter, set to current attribute
452 * @nlh: netlink message header
453 * @hdrlen: length of familiy specific header
454 * @rem: initialized to len, holds bytes currently remaining in stream
455 */
456#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
457 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
458 nlmsg_attrlen(nlh, hdrlen), rem)
459
460/**
461 * nlmsg_put - Add a new netlink message to an skb
462 * @skb: socket buffer to store message in
463 * @portid: netlink PORTID of requesting application
464 * @seq: sequence number of message
465 * @type: message type
466 * @payload: length of message payload
467 * @flags: message flags
468 *
469 * Returns NULL if the tailroom of the skb is insufficient to store
470 * the message header and payload.
471 */
472static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
473 int type, int payload, int flags)
474{
475 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
476 return NULL;
477
478 return __nlmsg_put(skb, portid, seq, type, payload, flags);
479}
480
481/**
482 * nlmsg_put_answer - Add a new callback based netlink message to an skb
483 * @skb: socket buffer to store message in
484 * @cb: netlink callback
485 * @type: message type
486 * @payload: length of message payload
487 * @flags: message flags
488 *
489 * Returns NULL if the tailroom of the skb is insufficient to store
490 * the message header and payload.
491 */
492static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
493 struct netlink_callback *cb,
494 int type, int payload,
495 int flags)
496{
497 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
498 type, payload, flags);
499}
500
501/**
502 * nlmsg_new - Allocate a new netlink message
503 * @payload: size of the message payload
504 * @flags: the type of memory to allocate.
505 *
506 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
507 * and a good default is needed.
508 */
509static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
510{
511 return alloc_skb(nlmsg_total_size(payload), flags);
512}
513
514/**
515 * nlmsg_end - Finalize a netlink message
516 * @skb: socket buffer the message is stored in
517 * @nlh: netlink message header
518 *
519 * Corrects the netlink message header to include the appeneded
520 * attributes. Only necessary if attributes have been added to
521 * the message.
522 */
523static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
524{
525 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
526}
527
528/**
529 * nlmsg_get_pos - return current position in netlink message
530 * @skb: socket buffer the message is stored in
531 *
532 * Returns a pointer to the current tail of the message.
533 */
534static inline void *nlmsg_get_pos(struct sk_buff *skb)
535{
536 return skb_tail_pointer(skb);
537}
538
539/**
540 * nlmsg_trim - Trim message to a mark
541 * @skb: socket buffer the message is stored in
542 * @mark: mark to trim to
543 *
544 * Trims the message to the provided mark.
545 */
546static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
547{
548 if (mark) {
549 WARN_ON((unsigned char *) mark < skb->data);
550 skb_trim(skb, (unsigned char *) mark - skb->data);
551 }
552}
553
554/**
555 * nlmsg_cancel - Cancel construction of a netlink message
556 * @skb: socket buffer the message is stored in
557 * @nlh: netlink message header
558 *
559 * Removes the complete netlink message including all
560 * attributes from the socket buffer again.
561 */
562static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
563{
564 nlmsg_trim(skb, nlh);
565}
566
567/**
568 * nlmsg_free - free a netlink message
569 * @skb: socket buffer of netlink message
570 */
571static inline void nlmsg_free(struct sk_buff *skb)
572{
573 kfree_skb(skb);
574}
575
576/**
577 * nlmsg_multicast - multicast a netlink message
578 * @sk: netlink socket to spread messages to
579 * @skb: netlink message as socket buffer
580 * @portid: own netlink portid to avoid sending to yourself
581 * @group: multicast group id
582 * @flags: allocation flags
583 */
584static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
585 u32 portid, unsigned int group, gfp_t flags)
586{
587 int err;
588
589 NETLINK_CB(skb).dst_group = group;
590
591 err = netlink_broadcast(sk, skb, portid, group, flags);
592 if (err > 0)
593 err = 0;
594
595 return err;
596}
597
598/**
599 * nlmsg_unicast - unicast a netlink message
600 * @sk: netlink socket to spread message to
601 * @skb: netlink message as socket buffer
602 * @portid: netlink portid of the destination socket
603 */
604static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
605{
606 int err;
607
608 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
609 if (err > 0)
610 err = 0;
611
612 return err;
613}
614
615/**
616 * nlmsg_for_each_msg - iterate over a stream of messages
617 * @pos: loop counter, set to current message
618 * @head: head of message stream
619 * @len: length of message stream
620 * @rem: initialized to len, holds bytes currently remaining in stream
621 */
622#define nlmsg_for_each_msg(pos, head, len, rem) \
623 for (pos = head, rem = len; \
624 nlmsg_ok(pos, rem); \
625 pos = nlmsg_next(pos, &(rem)))
626
627/**
628 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
629 * @cb: netlink callback structure that stores the sequence number
630 * @nlh: netlink message header to write the flag to
631 *
632 * This function checks if the sequence (generation) number changed during dump
633 * and if it did, advertises it in the netlink message header.
634 *
635 * The correct way to use it is to set cb->seq to the generation counter when
636 * all locks for dumping have been acquired, and then call this function for
637 * each message that is generated.
638 *
639 * Note that due to initialisation concerns, 0 is an invalid sequence number
640 * and must not be used by code that uses this functionality.
641 */
642static inline void
643nl_dump_check_consistent(struct netlink_callback *cb,
644 struct nlmsghdr *nlh)
645{
646 if (cb->prev_seq && cb->seq != cb->prev_seq)
647 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
648 cb->prev_seq = cb->seq;
649}
650
651/**************************************************************************
652 * Netlink Attributes
653 **************************************************************************/
654
655/**
656 * nla_attr_size - length of attribute not including padding
657 * @payload: length of payload
658 */
659static inline int nla_attr_size(int payload)
660{
661 return NLA_HDRLEN + payload;
662}
663
664/**
665 * nla_total_size - total length of attribute including padding
666 * @payload: length of payload
667 */
668static inline int nla_total_size(int payload)
669{
670 return NLA_ALIGN(nla_attr_size(payload));
671}
672
673/**
674 * nla_padlen - length of padding at the tail of attribute
675 * @payload: length of payload
676 */
677static inline int nla_padlen(int payload)
678{
679 return nla_total_size(payload) - nla_attr_size(payload);
680}
681
682/**
683 * nla_type - attribute type
684 * @nla: netlink attribute
685 */
686static inline int nla_type(const struct nlattr *nla)
687{
688 return nla->nla_type & NLA_TYPE_MASK;
689}
690
691/**
692 * nla_data - head of payload
693 * @nla: netlink attribute
694 */
695static inline void *nla_data(const struct nlattr *nla)
696{
697 return (char *) nla + NLA_HDRLEN;
698}
699
700/**
701 * nla_len - length of payload
702 * @nla: netlink attribute
703 */
704static inline int nla_len(const struct nlattr *nla)
705{
706 return nla->nla_len - NLA_HDRLEN;
707}
708
709/**
710 * nla_ok - check if the netlink attribute fits into the remaining bytes
711 * @nla: netlink attribute
712 * @remaining: number of bytes remaining in attribute stream
713 */
714static inline int nla_ok(const struct nlattr *nla, int remaining)
715{
716 return remaining >= (int) sizeof(*nla) &&
717 nla->nla_len >= sizeof(*nla) &&
718 nla->nla_len <= remaining;
719}
720
721/**
722 * nla_next - next netlink attribute in attribute stream
723 * @nla: netlink attribute
724 * @remaining: number of bytes remaining in attribute stream
725 *
726 * Returns the next netlink attribute in the attribute stream and
727 * decrements remaining by the size of the current attribute.
728 */
729static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
730{
731 unsigned int totlen = NLA_ALIGN(nla->nla_len);
732
733 *remaining -= totlen;
734 return (struct nlattr *) ((char *) nla + totlen);
735}
736
737/**
738 * nla_find_nested - find attribute in a set of nested attributes
739 * @nla: attribute containing the nested attributes
740 * @attrtype: type of attribute to look for
741 *
742 * Returns the first attribute which matches the specified type.
743 */
744static inline struct nlattr *
745nla_find_nested(const struct nlattr *nla, int attrtype)
746{
747 return nla_find(nla_data(nla), nla_len(nla), attrtype);
748}
749
750/**
751 * nla_parse_nested - parse nested attributes
752 * @tb: destination array with maxtype+1 elements
753 * @maxtype: maximum attribute type to be expected
754 * @nla: attribute containing the nested attributes
755 * @policy: validation policy
756 * @extack: extended ACK report struct
757 *
758 * See nla_parse()
759 */
760static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
761 const struct nlattr *nla,
762 const struct nla_policy *policy,
763 struct netlink_ext_ack *extack)
764{
765 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
766 extack);
767}
768
769/**
770 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
771 * @skb: socket buffer to add attribute to
772 * @attrtype: attribute type
773 * @value: numeric value
774 */
775static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
776{
777 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
778 u8 tmp = value;
779
780 return nla_put(skb, attrtype, sizeof(u8), &tmp);
781}
782
783/**
784 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
785 * @skb: socket buffer to add attribute to
786 * @attrtype: attribute type
787 * @value: numeric value
788 */
789static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
790{
791 u16 tmp = value;
792
793 return nla_put(skb, attrtype, sizeof(u16), &tmp);
794}
795
796/**
797 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
798 * @skb: socket buffer to add attribute to
799 * @attrtype: attribute type
800 * @value: numeric value
801 */
802static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
803{
804 __be16 tmp = value;
805
806 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
807}
808
809/**
810 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
811 * @skb: socket buffer to add attribute to
812 * @attrtype: attribute type
813 * @value: numeric value
814 */
815static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
816{
817 __be16 tmp = value;
818
819 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
820}
821
822/**
823 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
824 * @skb: socket buffer to add attribute to
825 * @attrtype: attribute type
826 * @value: numeric value
827 */
828static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
829{
830 __le16 tmp = value;
831
832 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
833}
834
835/**
836 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
837 * @skb: socket buffer to add attribute to
838 * @attrtype: attribute type
839 * @value: numeric value
840 */
841static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
842{
843 u32 tmp = value;
844
845 return nla_put(skb, attrtype, sizeof(u32), &tmp);
846}
847
848/**
849 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
850 * @skb: socket buffer to add attribute to
851 * @attrtype: attribute type
852 * @value: numeric value
853 */
854static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
855{
856 __be32 tmp = value;
857
858 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
859}
860
861/**
862 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
863 * @skb: socket buffer to add attribute to
864 * @attrtype: attribute type
865 * @value: numeric value
866 */
867static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
868{
869 __be32 tmp = value;
870
871 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
872}
873
874/**
875 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
876 * @skb: socket buffer to add attribute to
877 * @attrtype: attribute type
878 * @value: numeric value
879 */
880static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
881{
882 __le32 tmp = value;
883
884 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
885}
886
887/**
888 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
889 * @skb: socket buffer to add attribute to
890 * @attrtype: attribute type
891 * @value: numeric value
892 * @padattr: attribute type for the padding
893 */
894static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
895 u64 value, int padattr)
896{
897 u64 tmp = value;
898
899 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
900}
901
902/**
903 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
904 * @skb: socket buffer to add attribute to
905 * @attrtype: attribute type
906 * @value: numeric value
907 * @padattr: attribute type for the padding
908 */
909static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
910 int padattr)
911{
912 __be64 tmp = value;
913
914 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
915}
916
917/**
918 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
919 * @skb: socket buffer to add attribute to
920 * @attrtype: attribute type
921 * @value: numeric value
922 * @padattr: attribute type for the padding
923 */
924static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
925 int padattr)
926{
927 __be64 tmp = value;
928
929 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
930 padattr);
931}
932
933/**
934 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
935 * @skb: socket buffer to add attribute to
936 * @attrtype: attribute type
937 * @value: numeric value
938 * @padattr: attribute type for the padding
939 */
940static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
941 int padattr)
942{
943 __le64 tmp = value;
944
945 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
946}
947
948/**
949 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
950 * @skb: socket buffer to add attribute to
951 * @attrtype: attribute type
952 * @value: numeric value
953 */
954static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
955{
956 s8 tmp = value;
957
958 return nla_put(skb, attrtype, sizeof(s8), &tmp);
959}
960
961/**
962 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
963 * @skb: socket buffer to add attribute to
964 * @attrtype: attribute type
965 * @value: numeric value
966 */
967static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
968{
969 s16 tmp = value;
970
971 return nla_put(skb, attrtype, sizeof(s16), &tmp);
972}
973
974/**
975 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
976 * @skb: socket buffer to add attribute to
977 * @attrtype: attribute type
978 * @value: numeric value
979 */
980static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
981{
982 s32 tmp = value;
983
984 return nla_put(skb, attrtype, sizeof(s32), &tmp);
985}
986
987/**
988 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
989 * @skb: socket buffer to add attribute to
990 * @attrtype: attribute type
991 * @value: numeric value
992 * @padattr: attribute type for the padding
993 */
994static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
995 int padattr)
996{
997 s64 tmp = value;
998
999 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1000}
1001
1002/**
1003 * nla_put_string - Add a string netlink attribute to a socket buffer
1004 * @skb: socket buffer to add attribute to
1005 * @attrtype: attribute type
1006 * @str: NUL terminated string
1007 */
1008static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1009 const char *str)
1010{
1011 return nla_put(skb, attrtype, strlen(str) + 1, str);
1012}
1013
1014/**
1015 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1016 * @skb: socket buffer to add attribute to
1017 * @attrtype: attribute type
1018 */
1019static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1020{
1021 return nla_put(skb, attrtype, 0, NULL);
1022}
1023
1024/**
1025 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1026 * @skb: socket buffer to add attribute to
1027 * @attrtype: attribute type
1028 * @njiffies: number of jiffies to convert to msecs
1029 * @padattr: attribute type for the padding
1030 */
1031static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1032 unsigned long njiffies, int padattr)
1033{
1034 u64 tmp = jiffies_to_msecs(njiffies);
1035
1036 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1037}
1038
1039/**
1040 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1041 * buffer
1042 * @skb: socket buffer to add attribute to
1043 * @attrtype: attribute type
1044 * @addr: IPv4 address
1045 */
1046static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1047 __be32 addr)
1048{
1049 __be32 tmp = addr;
1050
1051 return nla_put_be32(skb, attrtype, tmp);
1052}
1053
1054/**
1055 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1056 * buffer
1057 * @skb: socket buffer to add attribute to
1058 * @attrtype: attribute type
1059 * @addr: IPv6 address
1060 */
1061static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1062 const struct in6_addr *addr)
1063{
1064 return nla_put(skb, attrtype, sizeof(*addr), addr);
1065}
1066
1067/**
1068 * nla_get_u32 - return payload of u32 attribute
1069 * @nla: u32 netlink attribute
1070 */
1071static inline u32 nla_get_u32(const struct nlattr *nla)
1072{
1073 return *(u32 *) nla_data(nla);
1074}
1075
1076/**
1077 * nla_get_be32 - return payload of __be32 attribute
1078 * @nla: __be32 netlink attribute
1079 */
1080static inline __be32 nla_get_be32(const struct nlattr *nla)
1081{
1082 return *(__be32 *) nla_data(nla);
1083}
1084
1085/**
1086 * nla_get_le32 - return payload of __le32 attribute
1087 * @nla: __le32 netlink attribute
1088 */
1089static inline __le32 nla_get_le32(const struct nlattr *nla)
1090{
1091 return *(__le32 *) nla_data(nla);
1092}
1093
1094/**
1095 * nla_get_u16 - return payload of u16 attribute
1096 * @nla: u16 netlink attribute
1097 */
1098static inline u16 nla_get_u16(const struct nlattr *nla)
1099{
1100 return *(u16 *) nla_data(nla);
1101}
1102
1103/**
1104 * nla_get_be16 - return payload of __be16 attribute
1105 * @nla: __be16 netlink attribute
1106 */
1107static inline __be16 nla_get_be16(const struct nlattr *nla)
1108{
1109 return *(__be16 *) nla_data(nla);
1110}
1111
1112/**
1113 * nla_get_le16 - return payload of __le16 attribute
1114 * @nla: __le16 netlink attribute
1115 */
1116static inline __le16 nla_get_le16(const struct nlattr *nla)
1117{
1118 return *(__le16 *) nla_data(nla);
1119}
1120
1121/**
1122 * nla_get_u8 - return payload of u8 attribute
1123 * @nla: u8 netlink attribute
1124 */
1125static inline u8 nla_get_u8(const struct nlattr *nla)
1126{
1127 return *(u8 *) nla_data(nla);
1128}
1129
1130/**
1131 * nla_get_u64 - return payload of u64 attribute
1132 * @nla: u64 netlink attribute
1133 */
1134static inline u64 nla_get_u64(const struct nlattr *nla)
1135{
1136 u64 tmp;
1137
1138 nla_memcpy(&tmp, nla, sizeof(tmp));
1139
1140 return tmp;
1141}
1142
1143/**
1144 * nla_get_be64 - return payload of __be64 attribute
1145 * @nla: __be64 netlink attribute
1146 */
1147static inline __be64 nla_get_be64(const struct nlattr *nla)
1148{
1149 __be64 tmp;
1150
1151 nla_memcpy(&tmp, nla, sizeof(tmp));
1152
1153 return tmp;
1154}
1155
1156/**
1157 * nla_get_le64 - return payload of __le64 attribute
1158 * @nla: __le64 netlink attribute
1159 */
1160static inline __le64 nla_get_le64(const struct nlattr *nla)
1161{
1162 return *(__le64 *) nla_data(nla);
1163}
1164
1165/**
1166 * nla_get_s32 - return payload of s32 attribute
1167 * @nla: s32 netlink attribute
1168 */
1169static inline s32 nla_get_s32(const struct nlattr *nla)
1170{
1171 return *(s32 *) nla_data(nla);
1172}
1173
1174/**
1175 * nla_get_s16 - return payload of s16 attribute
1176 * @nla: s16 netlink attribute
1177 */
1178static inline s16 nla_get_s16(const struct nlattr *nla)
1179{
1180 return *(s16 *) nla_data(nla);
1181}
1182
1183/**
1184 * nla_get_s8 - return payload of s8 attribute
1185 * @nla: s8 netlink attribute
1186 */
1187static inline s8 nla_get_s8(const struct nlattr *nla)
1188{
1189 return *(s8 *) nla_data(nla);
1190}
1191
1192/**
1193 * nla_get_s64 - return payload of s64 attribute
1194 * @nla: s64 netlink attribute
1195 */
1196static inline s64 nla_get_s64(const struct nlattr *nla)
1197{
1198 s64 tmp;
1199
1200 nla_memcpy(&tmp, nla, sizeof(tmp));
1201
1202 return tmp;
1203}
1204
1205/**
1206 * nla_get_flag - return payload of flag attribute
1207 * @nla: flag netlink attribute
1208 */
1209static inline int nla_get_flag(const struct nlattr *nla)
1210{
1211 return !!nla;
1212}
1213
1214/**
1215 * nla_get_msecs - return payload of msecs attribute
1216 * @nla: msecs netlink attribute
1217 *
1218 * Returns the number of milliseconds in jiffies.
1219 */
1220static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1221{
1222 u64 msecs = nla_get_u64(nla);
1223
1224 return msecs_to_jiffies((unsigned long) msecs);
1225}
1226
1227/**
1228 * nla_get_in_addr - return payload of IPv4 address attribute
1229 * @nla: IPv4 address netlink attribute
1230 */
1231static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1232{
1233 return *(__be32 *) nla_data(nla);
1234}
1235
1236/**
1237 * nla_get_in6_addr - return payload of IPv6 address attribute
1238 * @nla: IPv6 address netlink attribute
1239 */
1240static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1241{
1242 struct in6_addr tmp;
1243
1244 nla_memcpy(&tmp, nla, sizeof(tmp));
1245 return tmp;
1246}
1247
1248/**
1249 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1250 * @nla: nla_bitfield32 attribute
1251 */
1252static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1253{
1254 struct nla_bitfield32 tmp;
1255
1256 nla_memcpy(&tmp, nla, sizeof(tmp));
1257 return tmp;
1258}
1259
1260/**
1261 * nla_memdup - duplicate attribute memory (kmemdup)
1262 * @src: netlink attribute to duplicate from
1263 * @gfp: GFP mask
1264 */
1265static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1266{
1267 return kmemdup(nla_data(src), nla_len(src), gfp);
1268}
1269
1270/**
1271 * nla_nest_start - Start a new level of nested attributes
1272 * @skb: socket buffer to add attributes to
1273 * @attrtype: attribute type of container
1274 *
1275 * Returns the container attribute
1276 */
1277static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1278{
1279 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1280
1281 if (nla_put(skb, attrtype, 0, NULL) < 0)
1282 return NULL;
1283
1284 return start;
1285}
1286
1287/**
1288 * nla_nest_end - Finalize nesting of attributes
1289 * @skb: socket buffer the attributes are stored in
1290 * @start: container attribute
1291 *
1292 * Corrects the container attribute header to include the all
1293 * appeneded attributes.
1294 *
1295 * Returns the total data length of the skb.
1296 */
1297static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1298{
1299 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1300 return skb->len;
1301}
1302
1303/**
1304 * nla_nest_cancel - Cancel nesting of attributes
1305 * @skb: socket buffer the message is stored in
1306 * @start: container attribute
1307 *
1308 * Removes the container attribute and including all nested
1309 * attributes. Returns -EMSGSIZE
1310 */
1311static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1312{
1313 nlmsg_trim(skb, start);
1314}
1315
1316/**
1317 * nla_validate_nested - Validate a stream of nested attributes
1318 * @start: container attribute
1319 * @maxtype: maximum attribute type to be expected
1320 * @policy: validation policy
1321 * @extack: extended ACK report struct
1322 *
1323 * Validates all attributes in the nested attribute stream against the
1324 * specified policy. Attributes with a type exceeding maxtype will be
1325 * ignored. See documenation of struct nla_policy for more details.
1326 *
1327 * Returns 0 on success or a negative error code.
1328 */
1329static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1330 const struct nla_policy *policy,
1331 struct netlink_ext_ack *extack)
1332{
1333 return nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1334 extack);
1335}
1336
1337/**
1338 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1339 * @skb: socket buffer the message is stored in
1340 *
1341 * Return true if padding is needed to align the next attribute (nla_data()) to
1342 * a 64-bit aligned area.
1343 */
1344static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1345{
1346#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1347 /* The nlattr header is 4 bytes in size, that's why we test
1348 * if the skb->data _is_ aligned. A NOP attribute, plus
1349 * nlattr header for next attribute, will make nla_data()
1350 * 8-byte aligned.
1351 */
1352 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1353 return true;
1354#endif
1355 return false;
1356}
1357
1358/**
1359 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1360 * @skb: socket buffer the message is stored in
1361 * @padattr: attribute type for the padding
1362 *
1363 * Conditionally emit a padding netlink attribute in order to make
1364 * the next attribute we emit have a 64-bit aligned nla_data() area.
1365 * This will only be done in architectures which do not have
1366 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1367 *
1368 * Returns zero on success or a negative error code.
1369 */
1370static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1371{
1372 if (nla_need_padding_for_64bit(skb) &&
1373 !nla_reserve(skb, padattr, 0))
1374 return -EMSGSIZE;
1375
1376 return 0;
1377}
1378
1379/**
1380 * nla_total_size_64bit - total length of attribute including padding
1381 * @payload: length of payload
1382 */
1383static inline int nla_total_size_64bit(int payload)
1384{
1385 return NLA_ALIGN(nla_attr_size(payload))
1386#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1387 + NLA_ALIGN(nla_attr_size(0))
1388#endif
1389 ;
1390}
1391
1392/**
1393 * nla_for_each_attr - iterate over a stream of attributes
1394 * @pos: loop counter, set to current attribute
1395 * @head: head of attribute stream
1396 * @len: length of attribute stream
1397 * @rem: initialized to len, holds bytes currently remaining in stream
1398 */
1399#define nla_for_each_attr(pos, head, len, rem) \
1400 for (pos = head, rem = len; \
1401 nla_ok(pos, rem); \
1402 pos = nla_next(pos, &(rem)))
1403
1404/**
1405 * nla_for_each_nested - iterate over nested attributes
1406 * @pos: loop counter, set to current attribute
1407 * @nla: attribute containing the nested attributes
1408 * @rem: initialized to len, holds bytes currently remaining in stream
1409 */
1410#define nla_for_each_nested(pos, nla, rem) \
1411 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1412
1413/**
1414 * nla_is_last - Test if attribute is last in stream
1415 * @nla: attribute to test
1416 * @rem: bytes remaining in stream
1417 */
1418static inline bool nla_is_last(const struct nlattr *nla, int rem)
1419{
1420 return nla->nla_len == rem;
1421}
1422
1423#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_NETLINK_H
3#define __NET_NETLINK_H
4
5#include <linux/types.h>
6#include <linux/netlink.h>
7#include <linux/jiffies.h>
8#include <linux/in6.h>
9
10/* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
13 * Messages Interface
14 * ------------------------------------------------------------------------
15 *
16 * Message Format:
17 * <--- nlmsg_total_size(payload) --->
18 * <-- nlmsg_msg_size(payload) ->
19 * +----------+- - -+-------------+- - -+-------- - -
20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
21 * +----------+- - -+-------------+- - -+-------- - -
22 * nlmsg_data(nlh)---^ ^
23 * nlmsg_next(nlh)-----------------------+
24 *
25 * Payload Format:
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
32 *
33 * Data Structures:
34 * struct nlmsghdr netlink message header
35 *
36 * Message Construction:
37 * nlmsg_new() create a new netlink message
38 * nlmsg_put() add a netlink message to an skb
39 * nlmsg_put_answer() callback based nlmsg_put()
40 * nlmsg_end() finalize netlink message
41 * nlmsg_get_pos() return current position in message
42 * nlmsg_trim() trim part of message
43 * nlmsg_cancel() cancel message construction
44 * nlmsg_free() free a netlink message
45 *
46 * Message Sending:
47 * nlmsg_multicast() multicast message to several groups
48 * nlmsg_unicast() unicast a message to a single socket
49 * nlmsg_notify() send notification message
50 *
51 * Message Length Calculations:
52 * nlmsg_msg_size(payload) length of message w/o padding
53 * nlmsg_total_size(payload) length of message w/ padding
54 * nlmsg_padlen(payload) length of padding at tail
55 *
56 * Message Payload Access:
57 * nlmsg_data(nlh) head of message payload
58 * nlmsg_len(nlh) length of message payload
59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
61 *
62 * Message Parsing:
63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
64 * nlmsg_next(nlh, remaining) get next netlink message
65 * nlmsg_parse() parse attributes of a message
66 * nlmsg_find_attr() find an attribute in a message
67 * nlmsg_for_each_msg() loop over all messages
68 * nlmsg_validate() validate netlink message incl. attrs
69 * nlmsg_for_each_attr() loop over all attributes
70 *
71 * Misc:
72 * nlmsg_report() report back to application?
73 *
74 * ------------------------------------------------------------------------
75 * Attributes Interface
76 * ------------------------------------------------------------------------
77 *
78 * Attribute Format:
79 * <------- nla_total_size(payload) ------->
80 * <---- nla_attr_size(payload) ----->
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * | Header | Pad | Payload | Pad | Header
83 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
84 * <- nla_len(nla) -> ^
85 * nla_data(nla)----^ |
86 * nla_next(nla)-----------------------------'
87 *
88 * Data Structures:
89 * struct nlattr netlink attribute header
90 *
91 * Attribute Construction:
92 * nla_reserve(skb, type, len) reserve room for an attribute
93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
94 * nla_put(skb, type, len, data) add attribute to skb
95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
96 * nla_append(skb, len, data) append data to skb
97 *
98 * Attribute Construction for Basic Types:
99 * nla_put_u8(skb, type, value) add u8 attribute to skb
100 * nla_put_u16(skb, type, value) add u16 attribute to skb
101 * nla_put_u32(skb, type, value) add u32 attribute to skb
102 * nla_put_u64_64bit(skb, type,
103 * value, padattr) add u64 attribute to skb
104 * nla_put_s8(skb, type, value) add s8 attribute to skb
105 * nla_put_s16(skb, type, value) add s16 attribute to skb
106 * nla_put_s32(skb, type, value) add s32 attribute to skb
107 * nla_put_s64(skb, type, value,
108 * padattr) add s64 attribute to skb
109 * nla_put_string(skb, type, str) add string attribute to skb
110 * nla_put_flag(skb, type) add flag attribute to skb
111 * nla_put_msecs(skb, type, jiffies,
112 * padattr) add msecs attribute to skb
113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
115 *
116 * Nested Attributes Construction:
117 * nla_nest_start(skb, type) start a nested attribute
118 * nla_nest_end(skb, nla) finalize a nested attribute
119 * nla_nest_cancel(skb, nla) cancel nested attribute construction
120 *
121 * Attribute Length Calculations:
122 * nla_attr_size(payload) length of attribute w/o padding
123 * nla_total_size(payload) length of attribute w/ padding
124 * nla_padlen(payload) length of padding
125 *
126 * Attribute Payload Access:
127 * nla_data(nla) head of attribute payload
128 * nla_len(nla) length of attribute payload
129 *
130 * Attribute Payload Access for Basic Types:
131 * nla_get_u8(nla) get payload for a u8 attribute
132 * nla_get_u16(nla) get payload for a u16 attribute
133 * nla_get_u32(nla) get payload for a u32 attribute
134 * nla_get_u64(nla) get payload for a u64 attribute
135 * nla_get_s8(nla) get payload for a s8 attribute
136 * nla_get_s16(nla) get payload for a s16 attribute
137 * nla_get_s32(nla) get payload for a s32 attribute
138 * nla_get_s64(nla) get payload for a s64 attribute
139 * nla_get_flag(nla) return 1 if flag is true
140 * nla_get_msecs(nla) get payload for a msecs attribute
141 *
142 * Attribute Misc:
143 * nla_memcpy(dest, nla, count) copy attribute into memory
144 * nla_memcmp(nla, data, size) compare attribute with memory area
145 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
146 * nla_strcmp(nla, str) compare attribute with string
147 *
148 * Attribute Parsing:
149 * nla_ok(nla, remaining) does nla fit into remaining bytes?
150 * nla_next(nla, remaining) get next netlink attribute
151 * nla_validate() validate a stream of attributes
152 * nla_validate_nested() validate a stream of nested attributes
153 * nla_find() find attribute in stream of attributes
154 * nla_find_nested() find attribute in nested attributes
155 * nla_parse() parse and validate stream of attrs
156 * nla_parse_nested() parse nested attributes
157 * nla_for_each_attr() loop over all attributes
158 * nla_for_each_nested() loop over the nested attributes
159 *=========================================================================
160 */
161
162 /**
163 * Standard attribute types to specify validation policy
164 */
165enum {
166 NLA_UNSPEC,
167 NLA_U8,
168 NLA_U16,
169 NLA_U32,
170 NLA_U64,
171 NLA_STRING,
172 NLA_FLAG,
173 NLA_MSECS,
174 NLA_NESTED,
175 NLA_NESTED_ARRAY,
176 NLA_NUL_STRING,
177 NLA_BINARY,
178 NLA_S8,
179 NLA_S16,
180 NLA_S32,
181 NLA_S64,
182 NLA_BITFIELD32,
183 NLA_REJECT,
184 NLA_EXACT_LEN,
185 NLA_MIN_LEN,
186 __NLA_TYPE_MAX,
187};
188
189#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
190
191struct netlink_range_validation {
192 u64 min, max;
193};
194
195struct netlink_range_validation_signed {
196 s64 min, max;
197};
198
199enum nla_policy_validation {
200 NLA_VALIDATE_NONE,
201 NLA_VALIDATE_RANGE,
202 NLA_VALIDATE_MIN,
203 NLA_VALIDATE_MAX,
204 NLA_VALIDATE_RANGE_PTR,
205 NLA_VALIDATE_FUNCTION,
206 NLA_VALIDATE_WARN_TOO_LONG,
207};
208
209/**
210 * struct nla_policy - attribute validation policy
211 * @type: Type of attribute or NLA_UNSPEC
212 * @validation_type: type of attribute validation done in addition to
213 * type-specific validation (e.g. range, function call), see
214 * &enum nla_policy_validation
215 * @len: Type specific length of payload
216 *
217 * Policies are defined as arrays of this struct, the array must be
218 * accessible by attribute type up to the highest identifier to be expected.
219 *
220 * Meaning of `len' field:
221 * NLA_STRING Maximum length of string
222 * NLA_NUL_STRING Maximum length of string (excluding NUL)
223 * NLA_FLAG Unused
224 * NLA_BINARY Maximum length of attribute payload
225 * NLA_MIN_LEN Minimum length of attribute payload
226 * NLA_NESTED,
227 * NLA_NESTED_ARRAY Length verification is done by checking len of
228 * nested header (or empty); len field is used if
229 * nested_policy is also used, for the max attr
230 * number in the nested policy.
231 * NLA_U8, NLA_U16,
232 * NLA_U32, NLA_U64,
233 * NLA_S8, NLA_S16,
234 * NLA_S32, NLA_S64,
235 * NLA_MSECS Leaving the length field zero will verify the
236 * given type fits, using it verifies minimum length
237 * just like "All other"
238 * NLA_BITFIELD32 Unused
239 * NLA_REJECT Unused
240 * NLA_EXACT_LEN Attribute should have exactly this length, otherwise
241 * it is rejected or warned about, the latter happening
242 * if and only if the `validation_type' is set to
243 * NLA_VALIDATE_WARN_TOO_LONG.
244 * NLA_MIN_LEN Minimum length of attribute payload
245 * All other Minimum length of attribute payload
246 *
247 * Meaning of validation union:
248 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
249 * `bitfield32_valid' is the u32 value of valid flags
250 * NLA_REJECT This attribute is always rejected and `reject_message'
251 * may point to a string to report as the error instead
252 * of the generic one in extended ACK.
253 * NLA_NESTED `nested_policy' to a nested policy to validate, must
254 * also set `len' to the max attribute number. Use the
255 * provided NLA_POLICY_NESTED() macro.
256 * Note that nla_parse() will validate, but of course not
257 * parse, the nested sub-policies.
258 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
259 * must also set `len' to the max attribute number. Use
260 * the provided NLA_POLICY_NESTED_ARRAY() macro.
261 * The difference to NLA_NESTED is the structure:
262 * NLA_NESTED has the nested attributes directly inside
263 * while an array has the nested attributes at another
264 * level down and the attribute types directly in the
265 * nesting don't matter.
266 * NLA_U8,
267 * NLA_U16,
268 * NLA_U32,
269 * NLA_U64,
270 * NLA_S8,
271 * NLA_S16,
272 * NLA_S32,
273 * NLA_S64 The `min' and `max' fields are used depending on the
274 * validation_type field, if that is min/max/range then
275 * the min, max or both are used (respectively) to check
276 * the value of the integer attribute.
277 * Note that in the interest of code simplicity and
278 * struct size both limits are s16, so you cannot
279 * enforce a range that doesn't fall within the range
280 * of s16 - do that as usual in the code instead.
281 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
282 * NLA_POLICY_RANGE() macros.
283 * NLA_U8,
284 * NLA_U16,
285 * NLA_U32,
286 * NLA_U64 If the validation_type field instead is set to
287 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
288 * to a struct netlink_range_validation that indicates
289 * the min/max values.
290 * Use NLA_POLICY_FULL_RANGE().
291 * NLA_S8,
292 * NLA_S16,
293 * NLA_S32,
294 * NLA_S64 If the validation_type field instead is set to
295 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
296 * pointer to a struct netlink_range_validation_signed
297 * that indicates the min/max values.
298 * Use NLA_POLICY_FULL_RANGE_SIGNED().
299 * All other Unused - but note that it's a union
300 *
301 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
302 * NLA_BINARY Validation function called for the attribute.
303 * All other Unused - but note that it's a union
304 *
305 * Example:
306 *
307 * static const u32 myvalidflags = 0xff231023;
308 *
309 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
310 * [ATTR_FOO] = { .type = NLA_U16 },
311 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
312 * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) },
313 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
314 * };
315 */
316struct nla_policy {
317 u8 type;
318 u8 validation_type;
319 u16 len;
320 union {
321 const u32 bitfield32_valid;
322 const char *reject_message;
323 const struct nla_policy *nested_policy;
324 struct netlink_range_validation *range;
325 struct netlink_range_validation_signed *range_signed;
326 struct {
327 s16 min, max;
328 };
329 int (*validate)(const struct nlattr *attr,
330 struct netlink_ext_ack *extack);
331 /* This entry is special, and used for the attribute at index 0
332 * only, and specifies special data about the policy, namely it
333 * specifies the "boundary type" where strict length validation
334 * starts for any attribute types >= this value, also, strict
335 * nesting validation starts here.
336 *
337 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
338 * for any types >= this, so need to use NLA_MIN_LEN to get the
339 * previous pure { .len = xyz } behaviour. The advantage of this
340 * is that types not specified in the policy will be rejected.
341 *
342 * For completely new families it should be set to 1 so that the
343 * validation is enforced for all attributes. For existing ones
344 * it should be set at least when new attributes are added to
345 * the enum used by the policy, and be set to the new value that
346 * was added to enforce strict validation from thereon.
347 */
348 u16 strict_start_type;
349 };
350};
351
352#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len }
353#define NLA_POLICY_EXACT_LEN_WARN(_len) \
354 { .type = NLA_EXACT_LEN, .len = _len, \
355 .validation_type = NLA_VALIDATE_WARN_TOO_LONG, }
356#define NLA_POLICY_MIN_LEN(_len) { .type = NLA_MIN_LEN, .len = _len }
357
358#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
359#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
360
361#define _NLA_POLICY_NESTED(maxattr, policy) \
362 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
363#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
364 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
365#define NLA_POLICY_NESTED(policy) \
366 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
367#define NLA_POLICY_NESTED_ARRAY(policy) \
368 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
369#define NLA_POLICY_BITFIELD32(valid) \
370 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
371
372#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
373#define NLA_ENSURE_UINT_TYPE(tp) \
374 (__NLA_ENSURE(tp == NLA_U8 || tp == NLA_U16 || \
375 tp == NLA_U32 || tp == NLA_U64 || \
376 tp == NLA_MSECS) + tp)
377#define NLA_ENSURE_SINT_TYPE(tp) \
378 (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_S16 || \
379 tp == NLA_S32 || tp == NLA_S64) + tp)
380#define NLA_ENSURE_INT_TYPE(tp) \
381 (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \
382 tp == NLA_S16 || tp == NLA_U16 || \
383 tp == NLA_S32 || tp == NLA_U32 || \
384 tp == NLA_S64 || tp == NLA_U64 || \
385 tp == NLA_MSECS) + tp)
386#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
387 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
388 tp != NLA_REJECT && \
389 tp != NLA_NESTED && \
390 tp != NLA_NESTED_ARRAY) + tp)
391
392#define NLA_POLICY_RANGE(tp, _min, _max) { \
393 .type = NLA_ENSURE_INT_TYPE(tp), \
394 .validation_type = NLA_VALIDATE_RANGE, \
395 .min = _min, \
396 .max = _max \
397}
398
399#define NLA_POLICY_FULL_RANGE(tp, _range) { \
400 .type = NLA_ENSURE_UINT_TYPE(tp), \
401 .validation_type = NLA_VALIDATE_RANGE_PTR, \
402 .range = _range, \
403}
404
405#define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
406 .type = NLA_ENSURE_SINT_TYPE(tp), \
407 .validation_type = NLA_VALIDATE_RANGE_PTR, \
408 .range_signed = _range, \
409}
410
411#define NLA_POLICY_MIN(tp, _min) { \
412 .type = NLA_ENSURE_INT_TYPE(tp), \
413 .validation_type = NLA_VALIDATE_MIN, \
414 .min = _min, \
415}
416
417#define NLA_POLICY_MAX(tp, _max) { \
418 .type = NLA_ENSURE_INT_TYPE(tp), \
419 .validation_type = NLA_VALIDATE_MAX, \
420 .max = _max, \
421}
422
423#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
424 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
425 .validation_type = NLA_VALIDATE_FUNCTION, \
426 .validate = fn, \
427 .len = __VA_ARGS__ + 0, \
428}
429
430/**
431 * struct nl_info - netlink source information
432 * @nlh: Netlink message header of original request
433 * @nl_net: Network namespace
434 * @portid: Netlink PORTID of requesting application
435 * @skip_notify: Skip netlink notifications to user space
436 * @skip_notify_kernel: Skip selected in-kernel notifications
437 */
438struct nl_info {
439 struct nlmsghdr *nlh;
440 struct net *nl_net;
441 u32 portid;
442 u8 skip_notify:1,
443 skip_notify_kernel:1;
444};
445
446/**
447 * enum netlink_validation - netlink message/attribute validation levels
448 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
449 * extra data at the end of the message, attributes being longer than
450 * they should be, or unknown attributes being present.
451 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
452 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
453 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
454 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
455 * This can safely be set by the kernel when the given policy has no
456 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
457 * are enforced going forward.
458 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
459 * U8, U16, U32 must have exact size, etc.)
460 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
461 * and unset for other policies.
462 */
463enum netlink_validation {
464 NL_VALIDATE_LIBERAL = 0,
465 NL_VALIDATE_TRAILING = BIT(0),
466 NL_VALIDATE_MAXTYPE = BIT(1),
467 NL_VALIDATE_UNSPEC = BIT(2),
468 NL_VALIDATE_STRICT_ATTRS = BIT(3),
469 NL_VALIDATE_NESTED = BIT(4),
470};
471
472#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
473 NL_VALIDATE_MAXTYPE)
474#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
475 NL_VALIDATE_MAXTYPE |\
476 NL_VALIDATE_UNSPEC |\
477 NL_VALIDATE_STRICT_ATTRS |\
478 NL_VALIDATE_NESTED)
479
480int netlink_rcv_skb(struct sk_buff *skb,
481 int (*cb)(struct sk_buff *, struct nlmsghdr *,
482 struct netlink_ext_ack *));
483int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
484 unsigned int group, int report, gfp_t flags);
485
486int __nla_validate(const struct nlattr *head, int len, int maxtype,
487 const struct nla_policy *policy, unsigned int validate,
488 struct netlink_ext_ack *extack);
489int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
490 int len, const struct nla_policy *policy, unsigned int validate,
491 struct netlink_ext_ack *extack);
492int nla_policy_len(const struct nla_policy *, int);
493struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
494size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
495char *nla_strdup(const struct nlattr *nla, gfp_t flags);
496int nla_memcpy(void *dest, const struct nlattr *src, int count);
497int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
498int nla_strcmp(const struct nlattr *nla, const char *str);
499struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
500struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
501 int attrlen, int padattr);
502void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
503struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
504struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
505 int attrlen, int padattr);
506void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
507void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
508 const void *data);
509void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
510 const void *data, int padattr);
511void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
512int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
513int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
514 const void *data, int padattr);
515int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
516int nla_append(struct sk_buff *skb, int attrlen, const void *data);
517
518/**************************************************************************
519 * Netlink Messages
520 **************************************************************************/
521
522/**
523 * nlmsg_msg_size - length of netlink message not including padding
524 * @payload: length of message payload
525 */
526static inline int nlmsg_msg_size(int payload)
527{
528 return NLMSG_HDRLEN + payload;
529}
530
531/**
532 * nlmsg_total_size - length of netlink message including padding
533 * @payload: length of message payload
534 */
535static inline int nlmsg_total_size(int payload)
536{
537 return NLMSG_ALIGN(nlmsg_msg_size(payload));
538}
539
540/**
541 * nlmsg_padlen - length of padding at the message's tail
542 * @payload: length of message payload
543 */
544static inline int nlmsg_padlen(int payload)
545{
546 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
547}
548
549/**
550 * nlmsg_data - head of message payload
551 * @nlh: netlink message header
552 */
553static inline void *nlmsg_data(const struct nlmsghdr *nlh)
554{
555 return (unsigned char *) nlh + NLMSG_HDRLEN;
556}
557
558/**
559 * nlmsg_len - length of message payload
560 * @nlh: netlink message header
561 */
562static inline int nlmsg_len(const struct nlmsghdr *nlh)
563{
564 return nlh->nlmsg_len - NLMSG_HDRLEN;
565}
566
567/**
568 * nlmsg_attrdata - head of attributes data
569 * @nlh: netlink message header
570 * @hdrlen: length of family specific header
571 */
572static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
573 int hdrlen)
574{
575 unsigned char *data = nlmsg_data(nlh);
576 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
577}
578
579/**
580 * nlmsg_attrlen - length of attributes data
581 * @nlh: netlink message header
582 * @hdrlen: length of family specific header
583 */
584static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
585{
586 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
587}
588
589/**
590 * nlmsg_ok - check if the netlink message fits into the remaining bytes
591 * @nlh: netlink message header
592 * @remaining: number of bytes remaining in message stream
593 */
594static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
595{
596 return (remaining >= (int) sizeof(struct nlmsghdr) &&
597 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
598 nlh->nlmsg_len <= remaining);
599}
600
601/**
602 * nlmsg_next - next netlink message in message stream
603 * @nlh: netlink message header
604 * @remaining: number of bytes remaining in message stream
605 *
606 * Returns the next netlink message in the message stream and
607 * decrements remaining by the size of the current message.
608 */
609static inline struct nlmsghdr *
610nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
611{
612 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
613
614 *remaining -= totlen;
615
616 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
617}
618
619/**
620 * nla_parse - Parse a stream of attributes into a tb buffer
621 * @tb: destination array with maxtype+1 elements
622 * @maxtype: maximum attribute type to be expected
623 * @head: head of attribute stream
624 * @len: length of attribute stream
625 * @policy: validation policy
626 * @extack: extended ACK pointer
627 *
628 * Parses a stream of attributes and stores a pointer to each attribute in
629 * the tb array accessible via the attribute type. Attributes with a type
630 * exceeding maxtype will be rejected, policy must be specified, attributes
631 * will be validated in the strictest way possible.
632 *
633 * Returns 0 on success or a negative error code.
634 */
635static inline int nla_parse(struct nlattr **tb, int maxtype,
636 const struct nlattr *head, int len,
637 const struct nla_policy *policy,
638 struct netlink_ext_ack *extack)
639{
640 return __nla_parse(tb, maxtype, head, len, policy,
641 NL_VALIDATE_STRICT, extack);
642}
643
644/**
645 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
646 * @tb: destination array with maxtype+1 elements
647 * @maxtype: maximum attribute type to be expected
648 * @head: head of attribute stream
649 * @len: length of attribute stream
650 * @policy: validation policy
651 * @extack: extended ACK pointer
652 *
653 * Parses a stream of attributes and stores a pointer to each attribute in
654 * the tb array accessible via the attribute type. Attributes with a type
655 * exceeding maxtype will be ignored and attributes from the policy are not
656 * always strictly validated (only for new attributes).
657 *
658 * Returns 0 on success or a negative error code.
659 */
660static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
661 const struct nlattr *head, int len,
662 const struct nla_policy *policy,
663 struct netlink_ext_ack *extack)
664{
665 return __nla_parse(tb, maxtype, head, len, policy,
666 NL_VALIDATE_LIBERAL, extack);
667}
668
669/**
670 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
671 * @tb: destination array with maxtype+1 elements
672 * @maxtype: maximum attribute type to be expected
673 * @head: head of attribute stream
674 * @len: length of attribute stream
675 * @policy: validation policy
676 * @extack: extended ACK pointer
677 *
678 * Parses a stream of attributes and stores a pointer to each attribute in
679 * the tb array accessible via the attribute type. Attributes with a type
680 * exceeding maxtype will be rejected as well as trailing data, but the
681 * policy is not completely strictly validated (only for new attributes).
682 *
683 * Returns 0 on success or a negative error code.
684 */
685static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
686 const struct nlattr *head,
687 int len,
688 const struct nla_policy *policy,
689 struct netlink_ext_ack *extack)
690{
691 return __nla_parse(tb, maxtype, head, len, policy,
692 NL_VALIDATE_DEPRECATED_STRICT, extack);
693}
694
695/**
696 * __nlmsg_parse - parse attributes of a netlink message
697 * @nlh: netlink message header
698 * @hdrlen: length of family specific header
699 * @tb: destination array with maxtype+1 elements
700 * @maxtype: maximum attribute type to be expected
701 * @policy: validation policy
702 * @validate: validation strictness
703 * @extack: extended ACK report struct
704 *
705 * See nla_parse()
706 */
707static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
708 struct nlattr *tb[], int maxtype,
709 const struct nla_policy *policy,
710 unsigned int validate,
711 struct netlink_ext_ack *extack)
712{
713 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
714 NL_SET_ERR_MSG(extack, "Invalid header length");
715 return -EINVAL;
716 }
717
718 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
719 nlmsg_attrlen(nlh, hdrlen), policy, validate,
720 extack);
721}
722
723/**
724 * nlmsg_parse - parse attributes of a netlink message
725 * @nlh: netlink message header
726 * @hdrlen: length of family specific header
727 * @tb: destination array with maxtype+1 elements
728 * @maxtype: maximum attribute type to be expected
729 * @extack: extended ACK report struct
730 *
731 * See nla_parse()
732 */
733static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
734 struct nlattr *tb[], int maxtype,
735 const struct nla_policy *policy,
736 struct netlink_ext_ack *extack)
737{
738 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
739 NL_VALIDATE_STRICT, extack);
740}
741
742/**
743 * nlmsg_parse_deprecated - parse attributes of a netlink message
744 * @nlh: netlink message header
745 * @hdrlen: length of family specific header
746 * @tb: destination array with maxtype+1 elements
747 * @maxtype: maximum attribute type to be expected
748 * @extack: extended ACK report struct
749 *
750 * See nla_parse_deprecated()
751 */
752static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
753 struct nlattr *tb[], int maxtype,
754 const struct nla_policy *policy,
755 struct netlink_ext_ack *extack)
756{
757 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
758 NL_VALIDATE_LIBERAL, extack);
759}
760
761/**
762 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
763 * @nlh: netlink message header
764 * @hdrlen: length of family specific header
765 * @tb: destination array with maxtype+1 elements
766 * @maxtype: maximum attribute type to be expected
767 * @extack: extended ACK report struct
768 *
769 * See nla_parse_deprecated_strict()
770 */
771static inline int
772nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
773 struct nlattr *tb[], int maxtype,
774 const struct nla_policy *policy,
775 struct netlink_ext_ack *extack)
776{
777 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
778 NL_VALIDATE_DEPRECATED_STRICT, extack);
779}
780
781/**
782 * nlmsg_find_attr - find a specific attribute in a netlink message
783 * @nlh: netlink message header
784 * @hdrlen: length of familiy specific header
785 * @attrtype: type of attribute to look for
786 *
787 * Returns the first attribute which matches the specified type.
788 */
789static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
790 int hdrlen, int attrtype)
791{
792 return nla_find(nlmsg_attrdata(nlh, hdrlen),
793 nlmsg_attrlen(nlh, hdrlen), attrtype);
794}
795
796/**
797 * nla_validate_deprecated - Validate a stream of attributes
798 * @head: head of attribute stream
799 * @len: length of attribute stream
800 * @maxtype: maximum attribute type to be expected
801 * @policy: validation policy
802 * @validate: validation strictness
803 * @extack: extended ACK report struct
804 *
805 * Validates all attributes in the specified attribute stream against the
806 * specified policy. Validation is done in liberal mode.
807 * See documenation of struct nla_policy for more details.
808 *
809 * Returns 0 on success or a negative error code.
810 */
811static inline int nla_validate_deprecated(const struct nlattr *head, int len,
812 int maxtype,
813 const struct nla_policy *policy,
814 struct netlink_ext_ack *extack)
815{
816 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
817 extack);
818}
819
820/**
821 * nla_validate - Validate a stream of attributes
822 * @head: head of attribute stream
823 * @len: length of attribute stream
824 * @maxtype: maximum attribute type to be expected
825 * @policy: validation policy
826 * @extack: extended ACK report struct
827 *
828 * Validates all attributes in the specified attribute stream against the
829 * specified policy. Validation is done in strict mode.
830 * See documenation of struct nla_policy for more details.
831 *
832 * Returns 0 on success or a negative error code.
833 */
834static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
835 const struct nla_policy *policy,
836 struct netlink_ext_ack *extack)
837{
838 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
839 extack);
840}
841
842/**
843 * nlmsg_validate_deprecated - validate a netlink message including attributes
844 * @nlh: netlinket message header
845 * @hdrlen: length of familiy specific header
846 * @maxtype: maximum attribute type to be expected
847 * @policy: validation policy
848 * @extack: extended ACK report struct
849 */
850static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
851 int hdrlen, int maxtype,
852 const struct nla_policy *policy,
853 struct netlink_ext_ack *extack)
854{
855 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
856 return -EINVAL;
857
858 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
859 nlmsg_attrlen(nlh, hdrlen), maxtype,
860 policy, NL_VALIDATE_LIBERAL, extack);
861}
862
863
864
865/**
866 * nlmsg_report - need to report back to application?
867 * @nlh: netlink message header
868 *
869 * Returns 1 if a report back to the application is requested.
870 */
871static inline int nlmsg_report(const struct nlmsghdr *nlh)
872{
873 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
874}
875
876/**
877 * nlmsg_for_each_attr - iterate over a stream of attributes
878 * @pos: loop counter, set to current attribute
879 * @nlh: netlink message header
880 * @hdrlen: length of familiy specific header
881 * @rem: initialized to len, holds bytes currently remaining in stream
882 */
883#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
884 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
885 nlmsg_attrlen(nlh, hdrlen), rem)
886
887/**
888 * nlmsg_put - Add a new netlink message to an skb
889 * @skb: socket buffer to store message in
890 * @portid: netlink PORTID of requesting application
891 * @seq: sequence number of message
892 * @type: message type
893 * @payload: length of message payload
894 * @flags: message flags
895 *
896 * Returns NULL if the tailroom of the skb is insufficient to store
897 * the message header and payload.
898 */
899static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
900 int type, int payload, int flags)
901{
902 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
903 return NULL;
904
905 return __nlmsg_put(skb, portid, seq, type, payload, flags);
906}
907
908/**
909 * nlmsg_put_answer - Add a new callback based netlink message to an skb
910 * @skb: socket buffer to store message in
911 * @cb: netlink callback
912 * @type: message type
913 * @payload: length of message payload
914 * @flags: message flags
915 *
916 * Returns NULL if the tailroom of the skb is insufficient to store
917 * the message header and payload.
918 */
919static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
920 struct netlink_callback *cb,
921 int type, int payload,
922 int flags)
923{
924 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
925 type, payload, flags);
926}
927
928/**
929 * nlmsg_new - Allocate a new netlink message
930 * @payload: size of the message payload
931 * @flags: the type of memory to allocate.
932 *
933 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
934 * and a good default is needed.
935 */
936static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
937{
938 return alloc_skb(nlmsg_total_size(payload), flags);
939}
940
941/**
942 * nlmsg_end - Finalize a netlink message
943 * @skb: socket buffer the message is stored in
944 * @nlh: netlink message header
945 *
946 * Corrects the netlink message header to include the appeneded
947 * attributes. Only necessary if attributes have been added to
948 * the message.
949 */
950static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
951{
952 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
953}
954
955/**
956 * nlmsg_get_pos - return current position in netlink message
957 * @skb: socket buffer the message is stored in
958 *
959 * Returns a pointer to the current tail of the message.
960 */
961static inline void *nlmsg_get_pos(struct sk_buff *skb)
962{
963 return skb_tail_pointer(skb);
964}
965
966/**
967 * nlmsg_trim - Trim message to a mark
968 * @skb: socket buffer the message is stored in
969 * @mark: mark to trim to
970 *
971 * Trims the message to the provided mark.
972 */
973static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
974{
975 if (mark) {
976 WARN_ON((unsigned char *) mark < skb->data);
977 skb_trim(skb, (unsigned char *) mark - skb->data);
978 }
979}
980
981/**
982 * nlmsg_cancel - Cancel construction of a netlink message
983 * @skb: socket buffer the message is stored in
984 * @nlh: netlink message header
985 *
986 * Removes the complete netlink message including all
987 * attributes from the socket buffer again.
988 */
989static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
990{
991 nlmsg_trim(skb, nlh);
992}
993
994/**
995 * nlmsg_free - free a netlink message
996 * @skb: socket buffer of netlink message
997 */
998static inline void nlmsg_free(struct sk_buff *skb)
999{
1000 kfree_skb(skb);
1001}
1002
1003/**
1004 * nlmsg_multicast - multicast a netlink message
1005 * @sk: netlink socket to spread messages to
1006 * @skb: netlink message as socket buffer
1007 * @portid: own netlink portid to avoid sending to yourself
1008 * @group: multicast group id
1009 * @flags: allocation flags
1010 */
1011static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1012 u32 portid, unsigned int group, gfp_t flags)
1013{
1014 int err;
1015
1016 NETLINK_CB(skb).dst_group = group;
1017
1018 err = netlink_broadcast(sk, skb, portid, group, flags);
1019 if (err > 0)
1020 err = 0;
1021
1022 return err;
1023}
1024
1025/**
1026 * nlmsg_unicast - unicast a netlink message
1027 * @sk: netlink socket to spread message to
1028 * @skb: netlink message as socket buffer
1029 * @portid: netlink portid of the destination socket
1030 */
1031static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1032{
1033 int err;
1034
1035 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1036 if (err > 0)
1037 err = 0;
1038
1039 return err;
1040}
1041
1042/**
1043 * nlmsg_for_each_msg - iterate over a stream of messages
1044 * @pos: loop counter, set to current message
1045 * @head: head of message stream
1046 * @len: length of message stream
1047 * @rem: initialized to len, holds bytes currently remaining in stream
1048 */
1049#define nlmsg_for_each_msg(pos, head, len, rem) \
1050 for (pos = head, rem = len; \
1051 nlmsg_ok(pos, rem); \
1052 pos = nlmsg_next(pos, &(rem)))
1053
1054/**
1055 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1056 * @cb: netlink callback structure that stores the sequence number
1057 * @nlh: netlink message header to write the flag to
1058 *
1059 * This function checks if the sequence (generation) number changed during dump
1060 * and if it did, advertises it in the netlink message header.
1061 *
1062 * The correct way to use it is to set cb->seq to the generation counter when
1063 * all locks for dumping have been acquired, and then call this function for
1064 * each message that is generated.
1065 *
1066 * Note that due to initialisation concerns, 0 is an invalid sequence number
1067 * and must not be used by code that uses this functionality.
1068 */
1069static inline void
1070nl_dump_check_consistent(struct netlink_callback *cb,
1071 struct nlmsghdr *nlh)
1072{
1073 if (cb->prev_seq && cb->seq != cb->prev_seq)
1074 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1075 cb->prev_seq = cb->seq;
1076}
1077
1078/**************************************************************************
1079 * Netlink Attributes
1080 **************************************************************************/
1081
1082/**
1083 * nla_attr_size - length of attribute not including padding
1084 * @payload: length of payload
1085 */
1086static inline int nla_attr_size(int payload)
1087{
1088 return NLA_HDRLEN + payload;
1089}
1090
1091/**
1092 * nla_total_size - total length of attribute including padding
1093 * @payload: length of payload
1094 */
1095static inline int nla_total_size(int payload)
1096{
1097 return NLA_ALIGN(nla_attr_size(payload));
1098}
1099
1100/**
1101 * nla_padlen - length of padding at the tail of attribute
1102 * @payload: length of payload
1103 */
1104static inline int nla_padlen(int payload)
1105{
1106 return nla_total_size(payload) - nla_attr_size(payload);
1107}
1108
1109/**
1110 * nla_type - attribute type
1111 * @nla: netlink attribute
1112 */
1113static inline int nla_type(const struct nlattr *nla)
1114{
1115 return nla->nla_type & NLA_TYPE_MASK;
1116}
1117
1118/**
1119 * nla_data - head of payload
1120 * @nla: netlink attribute
1121 */
1122static inline void *nla_data(const struct nlattr *nla)
1123{
1124 return (char *) nla + NLA_HDRLEN;
1125}
1126
1127/**
1128 * nla_len - length of payload
1129 * @nla: netlink attribute
1130 */
1131static inline int nla_len(const struct nlattr *nla)
1132{
1133 return nla->nla_len - NLA_HDRLEN;
1134}
1135
1136/**
1137 * nla_ok - check if the netlink attribute fits into the remaining bytes
1138 * @nla: netlink attribute
1139 * @remaining: number of bytes remaining in attribute stream
1140 */
1141static inline int nla_ok(const struct nlattr *nla, int remaining)
1142{
1143 return remaining >= (int) sizeof(*nla) &&
1144 nla->nla_len >= sizeof(*nla) &&
1145 nla->nla_len <= remaining;
1146}
1147
1148/**
1149 * nla_next - next netlink attribute in attribute stream
1150 * @nla: netlink attribute
1151 * @remaining: number of bytes remaining in attribute stream
1152 *
1153 * Returns the next netlink attribute in the attribute stream and
1154 * decrements remaining by the size of the current attribute.
1155 */
1156static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1157{
1158 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1159
1160 *remaining -= totlen;
1161 return (struct nlattr *) ((char *) nla + totlen);
1162}
1163
1164/**
1165 * nla_find_nested - find attribute in a set of nested attributes
1166 * @nla: attribute containing the nested attributes
1167 * @attrtype: type of attribute to look for
1168 *
1169 * Returns the first attribute which matches the specified type.
1170 */
1171static inline struct nlattr *
1172nla_find_nested(const struct nlattr *nla, int attrtype)
1173{
1174 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1175}
1176
1177/**
1178 * nla_parse_nested - parse nested attributes
1179 * @tb: destination array with maxtype+1 elements
1180 * @maxtype: maximum attribute type to be expected
1181 * @nla: attribute containing the nested attributes
1182 * @policy: validation policy
1183 * @extack: extended ACK report struct
1184 *
1185 * See nla_parse()
1186 */
1187static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1188 const struct nlattr *nla,
1189 const struct nla_policy *policy,
1190 struct netlink_ext_ack *extack)
1191{
1192 if (!(nla->nla_type & NLA_F_NESTED)) {
1193 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1194 return -EINVAL;
1195 }
1196
1197 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1198 NL_VALIDATE_STRICT, extack);
1199}
1200
1201/**
1202 * nla_parse_nested_deprecated - parse nested attributes
1203 * @tb: destination array with maxtype+1 elements
1204 * @maxtype: maximum attribute type to be expected
1205 * @nla: attribute containing the nested attributes
1206 * @policy: validation policy
1207 * @extack: extended ACK report struct
1208 *
1209 * See nla_parse_deprecated()
1210 */
1211static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1212 const struct nlattr *nla,
1213 const struct nla_policy *policy,
1214 struct netlink_ext_ack *extack)
1215{
1216 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1217 NL_VALIDATE_LIBERAL, extack);
1218}
1219
1220/**
1221 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1222 * @skb: socket buffer to add attribute to
1223 * @attrtype: attribute type
1224 * @value: numeric value
1225 */
1226static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1227{
1228 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1229 u8 tmp = value;
1230
1231 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1232}
1233
1234/**
1235 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1236 * @skb: socket buffer to add attribute to
1237 * @attrtype: attribute type
1238 * @value: numeric value
1239 */
1240static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1241{
1242 u16 tmp = value;
1243
1244 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1245}
1246
1247/**
1248 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1249 * @skb: socket buffer to add attribute to
1250 * @attrtype: attribute type
1251 * @value: numeric value
1252 */
1253static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1254{
1255 __be16 tmp = value;
1256
1257 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1258}
1259
1260/**
1261 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1262 * @skb: socket buffer to add attribute to
1263 * @attrtype: attribute type
1264 * @value: numeric value
1265 */
1266static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1267{
1268 __be16 tmp = value;
1269
1270 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1271}
1272
1273/**
1274 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1275 * @skb: socket buffer to add attribute to
1276 * @attrtype: attribute type
1277 * @value: numeric value
1278 */
1279static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1280{
1281 __le16 tmp = value;
1282
1283 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1284}
1285
1286/**
1287 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1288 * @skb: socket buffer to add attribute to
1289 * @attrtype: attribute type
1290 * @value: numeric value
1291 */
1292static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1293{
1294 u32 tmp = value;
1295
1296 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1297}
1298
1299/**
1300 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1301 * @skb: socket buffer to add attribute to
1302 * @attrtype: attribute type
1303 * @value: numeric value
1304 */
1305static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1306{
1307 __be32 tmp = value;
1308
1309 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1310}
1311
1312/**
1313 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1314 * @skb: socket buffer to add attribute to
1315 * @attrtype: attribute type
1316 * @value: numeric value
1317 */
1318static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1319{
1320 __be32 tmp = value;
1321
1322 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1323}
1324
1325/**
1326 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1327 * @skb: socket buffer to add attribute to
1328 * @attrtype: attribute type
1329 * @value: numeric value
1330 */
1331static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1332{
1333 __le32 tmp = value;
1334
1335 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1336}
1337
1338/**
1339 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1340 * @skb: socket buffer to add attribute to
1341 * @attrtype: attribute type
1342 * @value: numeric value
1343 * @padattr: attribute type for the padding
1344 */
1345static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1346 u64 value, int padattr)
1347{
1348 u64 tmp = value;
1349
1350 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1351}
1352
1353/**
1354 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1355 * @skb: socket buffer to add attribute to
1356 * @attrtype: attribute type
1357 * @value: numeric value
1358 * @padattr: attribute type for the padding
1359 */
1360static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1361 int padattr)
1362{
1363 __be64 tmp = value;
1364
1365 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1366}
1367
1368/**
1369 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1370 * @skb: socket buffer to add attribute to
1371 * @attrtype: attribute type
1372 * @value: numeric value
1373 * @padattr: attribute type for the padding
1374 */
1375static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1376 int padattr)
1377{
1378 __be64 tmp = value;
1379
1380 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1381 padattr);
1382}
1383
1384/**
1385 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1386 * @skb: socket buffer to add attribute to
1387 * @attrtype: attribute type
1388 * @value: numeric value
1389 * @padattr: attribute type for the padding
1390 */
1391static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1392 int padattr)
1393{
1394 __le64 tmp = value;
1395
1396 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1397}
1398
1399/**
1400 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1401 * @skb: socket buffer to add attribute to
1402 * @attrtype: attribute type
1403 * @value: numeric value
1404 */
1405static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1406{
1407 s8 tmp = value;
1408
1409 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1410}
1411
1412/**
1413 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1414 * @skb: socket buffer to add attribute to
1415 * @attrtype: attribute type
1416 * @value: numeric value
1417 */
1418static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1419{
1420 s16 tmp = value;
1421
1422 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1423}
1424
1425/**
1426 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1427 * @skb: socket buffer to add attribute to
1428 * @attrtype: attribute type
1429 * @value: numeric value
1430 */
1431static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1432{
1433 s32 tmp = value;
1434
1435 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1436}
1437
1438/**
1439 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1440 * @skb: socket buffer to add attribute to
1441 * @attrtype: attribute type
1442 * @value: numeric value
1443 * @padattr: attribute type for the padding
1444 */
1445static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1446 int padattr)
1447{
1448 s64 tmp = value;
1449
1450 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1451}
1452
1453/**
1454 * nla_put_string - Add a string netlink attribute to a socket buffer
1455 * @skb: socket buffer to add attribute to
1456 * @attrtype: attribute type
1457 * @str: NUL terminated string
1458 */
1459static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1460 const char *str)
1461{
1462 return nla_put(skb, attrtype, strlen(str) + 1, str);
1463}
1464
1465/**
1466 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1467 * @skb: socket buffer to add attribute to
1468 * @attrtype: attribute type
1469 */
1470static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1471{
1472 return nla_put(skb, attrtype, 0, NULL);
1473}
1474
1475/**
1476 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1477 * @skb: socket buffer to add attribute to
1478 * @attrtype: attribute type
1479 * @njiffies: number of jiffies to convert to msecs
1480 * @padattr: attribute type for the padding
1481 */
1482static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1483 unsigned long njiffies, int padattr)
1484{
1485 u64 tmp = jiffies_to_msecs(njiffies);
1486
1487 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1488}
1489
1490/**
1491 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1492 * buffer
1493 * @skb: socket buffer to add attribute to
1494 * @attrtype: attribute type
1495 * @addr: IPv4 address
1496 */
1497static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1498 __be32 addr)
1499{
1500 __be32 tmp = addr;
1501
1502 return nla_put_be32(skb, attrtype, tmp);
1503}
1504
1505/**
1506 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1507 * buffer
1508 * @skb: socket buffer to add attribute to
1509 * @attrtype: attribute type
1510 * @addr: IPv6 address
1511 */
1512static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1513 const struct in6_addr *addr)
1514{
1515 return nla_put(skb, attrtype, sizeof(*addr), addr);
1516}
1517
1518/**
1519 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1520 * @skb: socket buffer to add attribute to
1521 * @attrtype: attribute type
1522 * @value: value carrying bits
1523 * @selector: selector of valid bits
1524 */
1525static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1526 __u32 value, __u32 selector)
1527{
1528 struct nla_bitfield32 tmp = { value, selector, };
1529
1530 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1531}
1532
1533/**
1534 * nla_get_u32 - return payload of u32 attribute
1535 * @nla: u32 netlink attribute
1536 */
1537static inline u32 nla_get_u32(const struct nlattr *nla)
1538{
1539 return *(u32 *) nla_data(nla);
1540}
1541
1542/**
1543 * nla_get_be32 - return payload of __be32 attribute
1544 * @nla: __be32 netlink attribute
1545 */
1546static inline __be32 nla_get_be32(const struct nlattr *nla)
1547{
1548 return *(__be32 *) nla_data(nla);
1549}
1550
1551/**
1552 * nla_get_le32 - return payload of __le32 attribute
1553 * @nla: __le32 netlink attribute
1554 */
1555static inline __le32 nla_get_le32(const struct nlattr *nla)
1556{
1557 return *(__le32 *) nla_data(nla);
1558}
1559
1560/**
1561 * nla_get_u16 - return payload of u16 attribute
1562 * @nla: u16 netlink attribute
1563 */
1564static inline u16 nla_get_u16(const struct nlattr *nla)
1565{
1566 return *(u16 *) nla_data(nla);
1567}
1568
1569/**
1570 * nla_get_be16 - return payload of __be16 attribute
1571 * @nla: __be16 netlink attribute
1572 */
1573static inline __be16 nla_get_be16(const struct nlattr *nla)
1574{
1575 return *(__be16 *) nla_data(nla);
1576}
1577
1578/**
1579 * nla_get_le16 - return payload of __le16 attribute
1580 * @nla: __le16 netlink attribute
1581 */
1582static inline __le16 nla_get_le16(const struct nlattr *nla)
1583{
1584 return *(__le16 *) nla_data(nla);
1585}
1586
1587/**
1588 * nla_get_u8 - return payload of u8 attribute
1589 * @nla: u8 netlink attribute
1590 */
1591static inline u8 nla_get_u8(const struct nlattr *nla)
1592{
1593 return *(u8 *) nla_data(nla);
1594}
1595
1596/**
1597 * nla_get_u64 - return payload of u64 attribute
1598 * @nla: u64 netlink attribute
1599 */
1600static inline u64 nla_get_u64(const struct nlattr *nla)
1601{
1602 u64 tmp;
1603
1604 nla_memcpy(&tmp, nla, sizeof(tmp));
1605
1606 return tmp;
1607}
1608
1609/**
1610 * nla_get_be64 - return payload of __be64 attribute
1611 * @nla: __be64 netlink attribute
1612 */
1613static inline __be64 nla_get_be64(const struct nlattr *nla)
1614{
1615 __be64 tmp;
1616
1617 nla_memcpy(&tmp, nla, sizeof(tmp));
1618
1619 return tmp;
1620}
1621
1622/**
1623 * nla_get_le64 - return payload of __le64 attribute
1624 * @nla: __le64 netlink attribute
1625 */
1626static inline __le64 nla_get_le64(const struct nlattr *nla)
1627{
1628 return *(__le64 *) nla_data(nla);
1629}
1630
1631/**
1632 * nla_get_s32 - return payload of s32 attribute
1633 * @nla: s32 netlink attribute
1634 */
1635static inline s32 nla_get_s32(const struct nlattr *nla)
1636{
1637 return *(s32 *) nla_data(nla);
1638}
1639
1640/**
1641 * nla_get_s16 - return payload of s16 attribute
1642 * @nla: s16 netlink attribute
1643 */
1644static inline s16 nla_get_s16(const struct nlattr *nla)
1645{
1646 return *(s16 *) nla_data(nla);
1647}
1648
1649/**
1650 * nla_get_s8 - return payload of s8 attribute
1651 * @nla: s8 netlink attribute
1652 */
1653static inline s8 nla_get_s8(const struct nlattr *nla)
1654{
1655 return *(s8 *) nla_data(nla);
1656}
1657
1658/**
1659 * nla_get_s64 - return payload of s64 attribute
1660 * @nla: s64 netlink attribute
1661 */
1662static inline s64 nla_get_s64(const struct nlattr *nla)
1663{
1664 s64 tmp;
1665
1666 nla_memcpy(&tmp, nla, sizeof(tmp));
1667
1668 return tmp;
1669}
1670
1671/**
1672 * nla_get_flag - return payload of flag attribute
1673 * @nla: flag netlink attribute
1674 */
1675static inline int nla_get_flag(const struct nlattr *nla)
1676{
1677 return !!nla;
1678}
1679
1680/**
1681 * nla_get_msecs - return payload of msecs attribute
1682 * @nla: msecs netlink attribute
1683 *
1684 * Returns the number of milliseconds in jiffies.
1685 */
1686static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1687{
1688 u64 msecs = nla_get_u64(nla);
1689
1690 return msecs_to_jiffies((unsigned long) msecs);
1691}
1692
1693/**
1694 * nla_get_in_addr - return payload of IPv4 address attribute
1695 * @nla: IPv4 address netlink attribute
1696 */
1697static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1698{
1699 return *(__be32 *) nla_data(nla);
1700}
1701
1702/**
1703 * nla_get_in6_addr - return payload of IPv6 address attribute
1704 * @nla: IPv6 address netlink attribute
1705 */
1706static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1707{
1708 struct in6_addr tmp;
1709
1710 nla_memcpy(&tmp, nla, sizeof(tmp));
1711 return tmp;
1712}
1713
1714/**
1715 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1716 * @nla: nla_bitfield32 attribute
1717 */
1718static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1719{
1720 struct nla_bitfield32 tmp;
1721
1722 nla_memcpy(&tmp, nla, sizeof(tmp));
1723 return tmp;
1724}
1725
1726/**
1727 * nla_memdup - duplicate attribute memory (kmemdup)
1728 * @src: netlink attribute to duplicate from
1729 * @gfp: GFP mask
1730 */
1731static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1732{
1733 return kmemdup(nla_data(src), nla_len(src), gfp);
1734}
1735
1736/**
1737 * nla_nest_start_noflag - Start a new level of nested attributes
1738 * @skb: socket buffer to add attributes to
1739 * @attrtype: attribute type of container
1740 *
1741 * This function exists for backward compatibility to use in APIs which never
1742 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1743 * nla_nest_start() which sets the flag.
1744 *
1745 * Returns the container attribute or NULL on error
1746 */
1747static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1748 int attrtype)
1749{
1750 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1751
1752 if (nla_put(skb, attrtype, 0, NULL) < 0)
1753 return NULL;
1754
1755 return start;
1756}
1757
1758/**
1759 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1760 * @skb: socket buffer to add attributes to
1761 * @attrtype: attribute type of container
1762 *
1763 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1764 * flag. This is the preferred function to use in new code.
1765 *
1766 * Returns the container attribute or NULL on error
1767 */
1768static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1769{
1770 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1771}
1772
1773/**
1774 * nla_nest_end - Finalize nesting of attributes
1775 * @skb: socket buffer the attributes are stored in
1776 * @start: container attribute
1777 *
1778 * Corrects the container attribute header to include the all
1779 * appeneded attributes.
1780 *
1781 * Returns the total data length of the skb.
1782 */
1783static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1784{
1785 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1786 return skb->len;
1787}
1788
1789/**
1790 * nla_nest_cancel - Cancel nesting of attributes
1791 * @skb: socket buffer the message is stored in
1792 * @start: container attribute
1793 *
1794 * Removes the container attribute and including all nested
1795 * attributes. Returns -EMSGSIZE
1796 */
1797static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1798{
1799 nlmsg_trim(skb, start);
1800}
1801
1802/**
1803 * __nla_validate_nested - Validate a stream of nested attributes
1804 * @start: container attribute
1805 * @maxtype: maximum attribute type to be expected
1806 * @policy: validation policy
1807 * @validate: validation strictness
1808 * @extack: extended ACK report struct
1809 *
1810 * Validates all attributes in the nested attribute stream against the
1811 * specified policy. Attributes with a type exceeding maxtype will be
1812 * ignored. See documenation of struct nla_policy for more details.
1813 *
1814 * Returns 0 on success or a negative error code.
1815 */
1816static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1817 const struct nla_policy *policy,
1818 unsigned int validate,
1819 struct netlink_ext_ack *extack)
1820{
1821 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1822 validate, extack);
1823}
1824
1825static inline int
1826nla_validate_nested(const struct nlattr *start, int maxtype,
1827 const struct nla_policy *policy,
1828 struct netlink_ext_ack *extack)
1829{
1830 return __nla_validate_nested(start, maxtype, policy,
1831 NL_VALIDATE_STRICT, extack);
1832}
1833
1834static inline int
1835nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1836 const struct nla_policy *policy,
1837 struct netlink_ext_ack *extack)
1838{
1839 return __nla_validate_nested(start, maxtype, policy,
1840 NL_VALIDATE_LIBERAL, extack);
1841}
1842
1843/**
1844 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1845 * @skb: socket buffer the message is stored in
1846 *
1847 * Return true if padding is needed to align the next attribute (nla_data()) to
1848 * a 64-bit aligned area.
1849 */
1850static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1851{
1852#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1853 /* The nlattr header is 4 bytes in size, that's why we test
1854 * if the skb->data _is_ aligned. A NOP attribute, plus
1855 * nlattr header for next attribute, will make nla_data()
1856 * 8-byte aligned.
1857 */
1858 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1859 return true;
1860#endif
1861 return false;
1862}
1863
1864/**
1865 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1866 * @skb: socket buffer the message is stored in
1867 * @padattr: attribute type for the padding
1868 *
1869 * Conditionally emit a padding netlink attribute in order to make
1870 * the next attribute we emit have a 64-bit aligned nla_data() area.
1871 * This will only be done in architectures which do not have
1872 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1873 *
1874 * Returns zero on success or a negative error code.
1875 */
1876static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1877{
1878 if (nla_need_padding_for_64bit(skb) &&
1879 !nla_reserve(skb, padattr, 0))
1880 return -EMSGSIZE;
1881
1882 return 0;
1883}
1884
1885/**
1886 * nla_total_size_64bit - total length of attribute including padding
1887 * @payload: length of payload
1888 */
1889static inline int nla_total_size_64bit(int payload)
1890{
1891 return NLA_ALIGN(nla_attr_size(payload))
1892#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1893 + NLA_ALIGN(nla_attr_size(0))
1894#endif
1895 ;
1896}
1897
1898/**
1899 * nla_for_each_attr - iterate over a stream of attributes
1900 * @pos: loop counter, set to current attribute
1901 * @head: head of attribute stream
1902 * @len: length of attribute stream
1903 * @rem: initialized to len, holds bytes currently remaining in stream
1904 */
1905#define nla_for_each_attr(pos, head, len, rem) \
1906 for (pos = head, rem = len; \
1907 nla_ok(pos, rem); \
1908 pos = nla_next(pos, &(rem)))
1909
1910/**
1911 * nla_for_each_nested - iterate over nested attributes
1912 * @pos: loop counter, set to current attribute
1913 * @nla: attribute containing the nested attributes
1914 * @rem: initialized to len, holds bytes currently remaining in stream
1915 */
1916#define nla_for_each_nested(pos, nla, rem) \
1917 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1918
1919/**
1920 * nla_is_last - Test if attribute is last in stream
1921 * @nla: attribute to test
1922 * @rem: bytes remaining in stream
1923 */
1924static inline bool nla_is_last(const struct nlattr *nla, int rem)
1925{
1926 return nla->nla_len == rem;
1927}
1928
1929void nla_get_range_unsigned(const struct nla_policy *pt,
1930 struct netlink_range_validation *range);
1931void nla_get_range_signed(const struct nla_policy *pt,
1932 struct netlink_range_validation_signed *range);
1933
1934int netlink_policy_dump_start(const struct nla_policy *policy,
1935 unsigned int maxtype,
1936 unsigned long *state);
1937bool netlink_policy_dump_loop(unsigned long state);
1938int netlink_policy_dump_write(struct sk_buff *skb, unsigned long state);
1939void netlink_policy_dump_free(unsigned long state);
1940
1941#endif