xref: /linux-6.15/include/uapi/linux/netlink.h (revision 738136a0)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _UAPI__LINUX_NETLINK_H
3 #define _UAPI__LINUX_NETLINK_H
4 
5 #include <linux/const.h>
6 #include <linux/socket.h> /* for __kernel_sa_family_t */
7 #include <linux/types.h>
8 
9 #define NETLINK_ROUTE		0	/* Routing/device hook				*/
10 #define NETLINK_UNUSED		1	/* Unused number				*/
11 #define NETLINK_USERSOCK	2	/* Reserved for user mode socket protocols 	*/
12 #define NETLINK_FIREWALL	3	/* Unused number, formerly ip_queue		*/
13 #define NETLINK_SOCK_DIAG	4	/* socket monitoring				*/
14 #define NETLINK_NFLOG		5	/* netfilter/iptables ULOG */
15 #define NETLINK_XFRM		6	/* ipsec */
16 #define NETLINK_SELINUX		7	/* SELinux event notifications */
17 #define NETLINK_ISCSI		8	/* Open-iSCSI */
18 #define NETLINK_AUDIT		9	/* auditing */
19 #define NETLINK_FIB_LOOKUP	10
20 #define NETLINK_CONNECTOR	11
21 #define NETLINK_NETFILTER	12	/* netfilter subsystem */
22 #define NETLINK_IP6_FW		13
23 #define NETLINK_DNRTMSG		14	/* DECnet routing messages (obsolete) */
24 #define NETLINK_KOBJECT_UEVENT	15	/* Kernel messages to userspace */
25 #define NETLINK_GENERIC		16
26 /* leave room for NETLINK_DM (DM Events) */
27 #define NETLINK_SCSITRANSPORT	18	/* SCSI Transports */
28 #define NETLINK_ECRYPTFS	19
29 #define NETLINK_RDMA		20
30 #define NETLINK_CRYPTO		21	/* Crypto layer */
31 #define NETLINK_SMC		22	/* SMC monitoring */
32 
33 #define NETLINK_INET_DIAG	NETLINK_SOCK_DIAG
34 
35 #define MAX_LINKS 32
36 
37 struct sockaddr_nl {
38 	__kernel_sa_family_t	nl_family;	/* AF_NETLINK	*/
39 	unsigned short	nl_pad;		/* zero		*/
40 	__u32		nl_pid;		/* port ID	*/
41        	__u32		nl_groups;	/* multicast groups mask */
42 };
43 
44 /**
45  * struct nlmsghdr - fixed format metadata header of Netlink messages
46  * @nlmsg_len:   Length of message including header
47  * @nlmsg_type:  Message content type
48  * @nlmsg_flags: Additional flags
49  * @nlmsg_seq:   Sequence number
50  * @nlmsg_pid:   Sending process port ID
51  * @nlmsg_data:  Message payload
52  */
53 struct nlmsghdr {
54 	__u32		nlmsg_len;
55 	__u16		nlmsg_type;
56 	__u16		nlmsg_flags;
57 	__u32		nlmsg_seq;
58 	__u32		nlmsg_pid;
59 	__u8		nlmsg_data[];
60 };
61 
62 /* Flags values */
63 
64 #define NLM_F_REQUEST		0x01	/* It is request message. 	*/
65 #define NLM_F_MULTI		0x02	/* Multipart message, terminated by NLMSG_DONE */
66 #define NLM_F_ACK		0x04	/* Reply with ack, with zero or error code */
67 #define NLM_F_ECHO		0x08	/* Receive resulting notifications */
68 #define NLM_F_DUMP_INTR		0x10	/* Dump was inconsistent due to sequence change */
69 #define NLM_F_DUMP_FILTERED	0x20	/* Dump was filtered as requested */
70 
71 /* Modifiers to GET request */
72 #define NLM_F_ROOT	0x100	/* specify tree	root	*/
73 #define NLM_F_MATCH	0x200	/* return all matching	*/
74 #define NLM_F_ATOMIC	0x400	/* atomic GET		*/
75 #define NLM_F_DUMP	(NLM_F_ROOT|NLM_F_MATCH)
76 
77 /* Modifiers to NEW request */
78 #define NLM_F_REPLACE	0x100	/* Override existing		*/
79 #define NLM_F_EXCL	0x200	/* Do not touch, if it exists	*/
80 #define NLM_F_CREATE	0x400	/* Create, if it does not exist	*/
81 #define NLM_F_APPEND	0x800	/* Add to end of list		*/
82 
83 /* Modifiers to DELETE request */
84 #define NLM_F_NONREC	0x100	/* Do not delete recursively	*/
85 #define NLM_F_BULK	0x200	/* Delete multiple objects	*/
86 
87 /* Flags for ACK message */
88 #define NLM_F_CAPPED	0x100	/* request was capped */
89 #define NLM_F_ACK_TLVS	0x200	/* extended ACK TVLs were included */
90 
91 /*
92    4.4BSD ADD		NLM_F_CREATE|NLM_F_EXCL
93    4.4BSD CHANGE	NLM_F_REPLACE
94 
95    True CHANGE		NLM_F_CREATE|NLM_F_REPLACE
96    Append		NLM_F_CREATE
97    Check		NLM_F_EXCL
98  */
99 
100 #define NLMSG_ALIGNTO	4U
101 #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
102 #define NLMSG_HDRLEN	 ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
103 #define NLMSG_LENGTH(len) ((len) + NLMSG_HDRLEN)
104 #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
105 #define NLMSG_DATA(nlh)  ((void *)(((char *)nlh) + NLMSG_HDRLEN))
106 #define NLMSG_NEXT(nlh,len)	 ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
107 				  (struct nlmsghdr *)(((char *)(nlh)) + \
108 				  NLMSG_ALIGN((nlh)->nlmsg_len)))
109 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
110 			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
111 			   (nlh)->nlmsg_len <= (len))
112 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
113 
114 #define NLMSG_NOOP		0x1	/* Nothing.		*/
115 #define NLMSG_ERROR		0x2	/* Error		*/
116 #define NLMSG_DONE		0x3	/* End of a dump	*/
117 #define NLMSG_OVERRUN		0x4	/* Data lost		*/
118 
119 #define NLMSG_MIN_TYPE		0x10	/* < 0x10: reserved control messages */
120 
121 struct nlmsgerr {
122 	int		error;
123 	struct nlmsghdr msg;
124 	/*
125 	 * followed by the message contents unless NETLINK_CAP_ACK was set
126 	 * or the ACK indicates success (error == 0)
127 	 * message length is aligned with NLMSG_ALIGN()
128 	 */
129 	/*
130 	 * followed by TLVs defined in enum nlmsgerr_attrs
131 	 * if NETLINK_EXT_ACK was set
132 	 */
133 };
134 
135 /**
136  * enum nlmsgerr_attrs - nlmsgerr attributes
137  * @NLMSGERR_ATTR_UNUSED: unused
138  * @NLMSGERR_ATTR_MSG: error message string (string)
139  * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
140  *	 message, counting from the beginning of the header (u32)
141  * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
142  *	be used - in the success case - to identify a created
143  *	object or operation or similar (binary)
144  * @NLMSGERR_ATTR_POLICY: policy for a rejected attribute
145  * @NLMSGERR_ATTR_MISS_TYPE: type of a missing required attribute,
146  *	%NLMSGERR_ATTR_MISS_NEST will not be present if the attribute was
147  *	missing at the message level
148  * @NLMSGERR_ATTR_MISS_NEST: offset of the nest where attribute was missing
149  * @__NLMSGERR_ATTR_MAX: number of attributes
150  * @NLMSGERR_ATTR_MAX: highest attribute number
151  */
152 enum nlmsgerr_attrs {
153 	NLMSGERR_ATTR_UNUSED,
154 	NLMSGERR_ATTR_MSG,
155 	NLMSGERR_ATTR_OFFS,
156 	NLMSGERR_ATTR_COOKIE,
157 	NLMSGERR_ATTR_POLICY,
158 	NLMSGERR_ATTR_MISS_TYPE,
159 	NLMSGERR_ATTR_MISS_NEST,
160 
161 	__NLMSGERR_ATTR_MAX,
162 	NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
163 };
164 
165 #define NETLINK_ADD_MEMBERSHIP		1
166 #define NETLINK_DROP_MEMBERSHIP		2
167 #define NETLINK_PKTINFO			3
168 #define NETLINK_BROADCAST_ERROR		4
169 #define NETLINK_NO_ENOBUFS		5
170 #ifndef __KERNEL__
171 #define NETLINK_RX_RING			6
172 #define NETLINK_TX_RING			7
173 #endif
174 #define NETLINK_LISTEN_ALL_NSID		8
175 #define NETLINK_LIST_MEMBERSHIPS	9
176 #define NETLINK_CAP_ACK			10
177 #define NETLINK_EXT_ACK			11
178 #define NETLINK_GET_STRICT_CHK		12
179 
180 struct nl_pktinfo {
181 	__u32	group;
182 };
183 
184 struct nl_mmap_req {
185 	unsigned int	nm_block_size;
186 	unsigned int	nm_block_nr;
187 	unsigned int	nm_frame_size;
188 	unsigned int	nm_frame_nr;
189 };
190 
191 struct nl_mmap_hdr {
192 	unsigned int	nm_status;
193 	unsigned int	nm_len;
194 	__u32		nm_group;
195 	/* credentials */
196 	__u32		nm_pid;
197 	__u32		nm_uid;
198 	__u32		nm_gid;
199 };
200 
201 #ifndef __KERNEL__
202 enum nl_mmap_status {
203 	NL_MMAP_STATUS_UNUSED,
204 	NL_MMAP_STATUS_RESERVED,
205 	NL_MMAP_STATUS_VALID,
206 	NL_MMAP_STATUS_COPY,
207 	NL_MMAP_STATUS_SKIP,
208 };
209 
210 #define NL_MMAP_MSG_ALIGNMENT		NLMSG_ALIGNTO
211 #define NL_MMAP_MSG_ALIGN(sz)		__ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
212 #define NL_MMAP_HDRLEN			NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
213 #endif
214 
215 #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
216 
217 enum {
218 	NETLINK_UNCONNECTED = 0,
219 	NETLINK_CONNECTED,
220 };
221 
222 /*
223  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
224  * +---------------------+- - -+- - - - - - - - - -+- - -+
225  * |        Header       | Pad |     Payload       | Pad |
226  * |   (struct nlattr)   | ing |                   | ing |
227  * +---------------------+- - -+- - - - - - - - - -+- - -+
228  *  <-------------- nlattr->nla_len -------------->
229  */
230 
231 struct nlattr {
232 	__u16           nla_len;
233 	__u16           nla_type;
234 };
235 
236 /*
237  * nla_type (16 bits)
238  * +---+---+-------------------------------+
239  * | N | O | Attribute Type                |
240  * +---+---+-------------------------------+
241  * N := Carries nested attributes
242  * O := Payload stored in network byte order
243  *
244  * Note: The N and O flag are mutually exclusive.
245  */
246 #define NLA_F_NESTED		(1 << 15)
247 #define NLA_F_NET_BYTEORDER	(1 << 14)
248 #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
249 
250 #define NLA_ALIGNTO		4
251 #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
252 #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))
253 
254 /* Generic 32 bitflags attribute content sent to the kernel.
255  *
256  * The value is a bitmap that defines the values being set
257  * The selector is a bitmask that defines which value is legit
258  *
259  * Examples:
260  *  value = 0x0, and selector = 0x1
261  *  implies we are selecting bit 1 and we want to set its value to 0.
262  *
263  *  value = 0x2, and selector = 0x2
264  *  implies we are selecting bit 2 and we want to set its value to 1.
265  *
266  */
267 struct nla_bitfield32 {
268 	__u32 value;
269 	__u32 selector;
270 };
271 
272 /*
273  * policy descriptions - it's specific to each family how this is used
274  * Normally, it should be retrieved via a dump inside another attribute
275  * specifying where it applies.
276  */
277 
278 /**
279  * enum netlink_attribute_type - type of an attribute
280  * @NL_ATTR_TYPE_INVALID: unused
281  * @NL_ATTR_TYPE_FLAG: flag attribute (present/not present)
282  * @NL_ATTR_TYPE_U8: 8-bit unsigned attribute
283  * @NL_ATTR_TYPE_U16: 16-bit unsigned attribute
284  * @NL_ATTR_TYPE_U32: 32-bit unsigned attribute
285  * @NL_ATTR_TYPE_U64: 64-bit unsigned attribute
286  * @NL_ATTR_TYPE_S8: 8-bit signed attribute
287  * @NL_ATTR_TYPE_S16: 16-bit signed attribute
288  * @NL_ATTR_TYPE_S32: 32-bit signed attribute
289  * @NL_ATTR_TYPE_S64: 64-bit signed attribute
290  * @NL_ATTR_TYPE_BINARY: binary data, min/max length may be specified
291  * @NL_ATTR_TYPE_STRING: string, min/max length may be specified
292  * @NL_ATTR_TYPE_NUL_STRING: NUL-terminated string,
293  *	min/max length may be specified
294  * @NL_ATTR_TYPE_NESTED: nested, i.e. the content of this attribute
295  *	consists of sub-attributes. The nested policy and maxtype
296  *	inside may be specified.
297  * @NL_ATTR_TYPE_NESTED_ARRAY: nested array, i.e. the content of this
298  *	attribute contains sub-attributes whose type is irrelevant
299  *	(just used to separate the array entries) and each such array
300  *	entry has attributes again, the policy for those inner ones
301  *	and the corresponding maxtype may be specified.
302  * @NL_ATTR_TYPE_BITFIELD32: &struct nla_bitfield32 attribute
303  */
304 enum netlink_attribute_type {
305 	NL_ATTR_TYPE_INVALID,
306 
307 	NL_ATTR_TYPE_FLAG,
308 
309 	NL_ATTR_TYPE_U8,
310 	NL_ATTR_TYPE_U16,
311 	NL_ATTR_TYPE_U32,
312 	NL_ATTR_TYPE_U64,
313 
314 	NL_ATTR_TYPE_S8,
315 	NL_ATTR_TYPE_S16,
316 	NL_ATTR_TYPE_S32,
317 	NL_ATTR_TYPE_S64,
318 
319 	NL_ATTR_TYPE_BINARY,
320 	NL_ATTR_TYPE_STRING,
321 	NL_ATTR_TYPE_NUL_STRING,
322 
323 	NL_ATTR_TYPE_NESTED,
324 	NL_ATTR_TYPE_NESTED_ARRAY,
325 
326 	NL_ATTR_TYPE_BITFIELD32,
327 };
328 
329 /**
330  * enum netlink_policy_type_attr - policy type attributes
331  * @NL_POLICY_TYPE_ATTR_UNSPEC: unused
332  * @NL_POLICY_TYPE_ATTR_TYPE: type of the attribute,
333  *	&enum netlink_attribute_type (U32)
334  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_S: minimum value for signed
335  *	integers (S64)
336  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_S: maximum value for signed
337  *	integers (S64)
338  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_U: minimum value for unsigned
339  *	integers (U64)
340  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_U: maximum value for unsigned
341  *	integers (U64)
342  * @NL_POLICY_TYPE_ATTR_MIN_LENGTH: minimum length for binary
343  *	attributes, no minimum if not given (U32)
344  * @NL_POLICY_TYPE_ATTR_MAX_LENGTH: maximum length for binary
345  *	attributes, no maximum if not given (U32)
346  * @NL_POLICY_TYPE_ATTR_POLICY_IDX: sub policy for nested and
347  *	nested array types (U32)
348  * @NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE: maximum sub policy
349  *	attribute for nested and nested array types, this can
350  *	in theory be < the size of the policy pointed to by
351  *	the index, if limited inside the nesting (U32)
352  * @NL_POLICY_TYPE_ATTR_BITFIELD32_MASK: valid mask for the
353  *	bitfield32 type (U32)
354  * @NL_POLICY_TYPE_ATTR_MASK: mask of valid bits for unsigned integers (U64)
355  * @NL_POLICY_TYPE_ATTR_PAD: pad attribute for 64-bit alignment
356  *
357  * @__NL_POLICY_TYPE_ATTR_MAX: number of attributes
358  * @NL_POLICY_TYPE_ATTR_MAX: highest attribute number
359  */
360 enum netlink_policy_type_attr {
361 	NL_POLICY_TYPE_ATTR_UNSPEC,
362 	NL_POLICY_TYPE_ATTR_TYPE,
363 	NL_POLICY_TYPE_ATTR_MIN_VALUE_S,
364 	NL_POLICY_TYPE_ATTR_MAX_VALUE_S,
365 	NL_POLICY_TYPE_ATTR_MIN_VALUE_U,
366 	NL_POLICY_TYPE_ATTR_MAX_VALUE_U,
367 	NL_POLICY_TYPE_ATTR_MIN_LENGTH,
368 	NL_POLICY_TYPE_ATTR_MAX_LENGTH,
369 	NL_POLICY_TYPE_ATTR_POLICY_IDX,
370 	NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
371 	NL_POLICY_TYPE_ATTR_BITFIELD32_MASK,
372 	NL_POLICY_TYPE_ATTR_PAD,
373 	NL_POLICY_TYPE_ATTR_MASK,
374 
375 	/* keep last */
376 	__NL_POLICY_TYPE_ATTR_MAX,
377 	NL_POLICY_TYPE_ATTR_MAX = __NL_POLICY_TYPE_ATTR_MAX - 1
378 };
379 
380 #endif /* _UAPI__LINUX_NETLINK_H */
381