xref: /linux/include/uapi/linux/netlink.h (revision ab1c247094e323177a578b38f0325bf79f0317ac)
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  */
52 struct nlmsghdr {
53 	__u32		nlmsg_len;
54 	__u16		nlmsg_type;
55 	__u16		nlmsg_flags;
56 	__u32		nlmsg_seq;
57 	__u32		nlmsg_pid;
58 };
59 
60 /* Flags values */
61 
62 #define NLM_F_REQUEST		0x01	/* It is request message. 	*/
63 #define NLM_F_MULTI		0x02	/* Multipart message, terminated by NLMSG_DONE */
64 #define NLM_F_ACK		0x04	/* Reply with ack, with zero or error code */
65 #define NLM_F_ECHO		0x08	/* Receive resulting notifications */
66 #define NLM_F_DUMP_INTR		0x10	/* Dump was inconsistent due to sequence change */
67 #define NLM_F_DUMP_FILTERED	0x20	/* Dump was filtered as requested */
68 
69 /* Modifiers to GET request */
70 #define NLM_F_ROOT	0x100	/* specify tree	root	*/
71 #define NLM_F_MATCH	0x200	/* return all matching	*/
72 #define NLM_F_ATOMIC	0x400	/* atomic GET		*/
73 #define NLM_F_DUMP	(NLM_F_ROOT|NLM_F_MATCH)
74 
75 /* Modifiers to NEW request */
76 #define NLM_F_REPLACE	0x100	/* Override existing		*/
77 #define NLM_F_EXCL	0x200	/* Do not touch, if it exists	*/
78 #define NLM_F_CREATE	0x400	/* Create, if it does not exist	*/
79 #define NLM_F_APPEND	0x800	/* Add to end of list		*/
80 
81 /* Modifiers to DELETE request */
82 #define NLM_F_NONREC	0x100	/* Do not delete recursively	*/
83 #define NLM_F_BULK	0x200	/* Delete multiple objects	*/
84 
85 /* Flags for ACK message */
86 #define NLM_F_CAPPED	0x100	/* request was capped */
87 #define NLM_F_ACK_TLVS	0x200	/* extended ACK TVLs were included */
88 
89 /*
90    4.4BSD ADD		NLM_F_CREATE|NLM_F_EXCL
91    4.4BSD CHANGE	NLM_F_REPLACE
92 
93    True CHANGE		NLM_F_CREATE|NLM_F_REPLACE
94    Append		NLM_F_CREATE
95    Check		NLM_F_EXCL
96  */
97 
98 #define NLMSG_ALIGNTO	4U
99 #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
100 #define NLMSG_HDRLEN	 ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
101 #define NLMSG_LENGTH(len) ((len) + NLMSG_HDRLEN)
102 #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
103 #define NLMSG_DATA(nlh)  ((void *)(((char *)nlh) + NLMSG_HDRLEN))
104 #define NLMSG_NEXT(nlh,len)	 ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
105 				  (struct nlmsghdr *)(((char *)(nlh)) + \
106 				  NLMSG_ALIGN((nlh)->nlmsg_len)))
107 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
108 			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
109 			   (nlh)->nlmsg_len <= (len))
110 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
111 
112 #define NLMSG_NOOP		0x1	/* Nothing.		*/
113 #define NLMSG_ERROR		0x2	/* Error		*/
114 #define NLMSG_DONE		0x3	/* End of a dump	*/
115 #define NLMSG_OVERRUN		0x4	/* Data lost		*/
116 
117 #define NLMSG_MIN_TYPE		0x10	/* < 0x10: reserved control messages */
118 
119 struct nlmsgerr {
120 	int		error;
121 	struct nlmsghdr msg;
122 	/*
123 	 * followed by the message contents unless NETLINK_CAP_ACK was set
124 	 * or the ACK indicates success (error == 0)
125 	 * message length is aligned with NLMSG_ALIGN()
126 	 */
127 	/*
128 	 * followed by TLVs defined in enum nlmsgerr_attrs
129 	 * if NETLINK_EXT_ACK was set
130 	 */
131 };
132 
133 /**
134  * enum nlmsgerr_attrs - nlmsgerr attributes
135  * @NLMSGERR_ATTR_UNUSED: unused
136  * @NLMSGERR_ATTR_MSG: error message string (string)
137  * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
138  *	 message, counting from the beginning of the header (u32)
139  * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
140  *	be used - in the success case - to identify a created
141  *	object or operation or similar (binary)
142  * @NLMSGERR_ATTR_POLICY: policy for a rejected attribute
143  * @NLMSGERR_ATTR_MISS_TYPE: type of a missing required attribute,
144  *	%NLMSGERR_ATTR_MISS_NEST will not be present if the attribute was
145  *	missing at the message level
146  * @NLMSGERR_ATTR_MISS_NEST: offset of the nest where attribute was missing
147  * @__NLMSGERR_ATTR_MAX: number of attributes
148  * @NLMSGERR_ATTR_MAX: highest attribute number
149  */
150 enum nlmsgerr_attrs {
151 	NLMSGERR_ATTR_UNUSED,
152 	NLMSGERR_ATTR_MSG,
153 	NLMSGERR_ATTR_OFFS,
154 	NLMSGERR_ATTR_COOKIE,
155 	NLMSGERR_ATTR_POLICY,
156 	NLMSGERR_ATTR_MISS_TYPE,
157 	NLMSGERR_ATTR_MISS_NEST,
158 
159 	__NLMSGERR_ATTR_MAX,
160 	NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
161 };
162 
163 #define NETLINK_ADD_MEMBERSHIP		1
164 #define NETLINK_DROP_MEMBERSHIP		2
165 #define NETLINK_PKTINFO			3
166 #define NETLINK_BROADCAST_ERROR		4
167 #define NETLINK_NO_ENOBUFS		5
168 #ifndef __KERNEL__
169 #define NETLINK_RX_RING			6
170 #define NETLINK_TX_RING			7
171 #endif
172 #define NETLINK_LISTEN_ALL_NSID		8
173 #define NETLINK_LIST_MEMBERSHIPS	9
174 #define NETLINK_CAP_ACK			10
175 #define NETLINK_EXT_ACK			11
176 #define NETLINK_GET_STRICT_CHK		12
177 
178 struct nl_pktinfo {
179 	__u32	group;
180 };
181 
182 struct nl_mmap_req {
183 	unsigned int	nm_block_size;
184 	unsigned int	nm_block_nr;
185 	unsigned int	nm_frame_size;
186 	unsigned int	nm_frame_nr;
187 };
188 
189 struct nl_mmap_hdr {
190 	unsigned int	nm_status;
191 	unsigned int	nm_len;
192 	__u32		nm_group;
193 	/* credentials */
194 	__u32		nm_pid;
195 	__u32		nm_uid;
196 	__u32		nm_gid;
197 };
198 
199 #ifndef __KERNEL__
200 enum nl_mmap_status {
201 	NL_MMAP_STATUS_UNUSED,
202 	NL_MMAP_STATUS_RESERVED,
203 	NL_MMAP_STATUS_VALID,
204 	NL_MMAP_STATUS_COPY,
205 	NL_MMAP_STATUS_SKIP,
206 };
207 
208 #define NL_MMAP_MSG_ALIGNMENT		NLMSG_ALIGNTO
209 #define NL_MMAP_MSG_ALIGN(sz)		__ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
210 #define NL_MMAP_HDRLEN			NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
211 #endif
212 
213 #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
214 
215 enum {
216 	NETLINK_UNCONNECTED = 0,
217 	NETLINK_CONNECTED,
218 };
219 
220 /*
221  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
222  * +---------------------+- - -+- - - - - - - - - -+- - -+
223  * |        Header       | Pad |     Payload       | Pad |
224  * |   (struct nlattr)   | ing |                   | ing |
225  * +---------------------+- - -+- - - - - - - - - -+- - -+
226  *  <-------------- nlattr->nla_len -------------->
227  */
228 
229 struct nlattr {
230 	__u16           nla_len;
231 	__u16           nla_type;
232 };
233 
234 /*
235  * nla_type (16 bits)
236  * +---+---+-------------------------------+
237  * | N | O | Attribute Type                |
238  * +---+---+-------------------------------+
239  * N := Carries nested attributes
240  * O := Payload stored in network byte order
241  *
242  * Note: The N and O flag are mutually exclusive.
243  */
244 #define NLA_F_NESTED		(1 << 15)
245 #define NLA_F_NET_BYTEORDER	(1 << 14)
246 #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
247 
248 #define NLA_ALIGNTO		4
249 #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
250 #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))
251 
252 /* Generic 32 bitflags attribute content sent to the kernel.
253  *
254  * The value is a bitmap that defines the values being set
255  * The selector is a bitmask that defines which value is legit
256  *
257  * Examples:
258  *  value = 0x0, and selector = 0x1
259  *  implies we are selecting bit 1 and we want to set its value to 0.
260  *
261  *  value = 0x2, and selector = 0x2
262  *  implies we are selecting bit 2 and we want to set its value to 1.
263  *
264  */
265 struct nla_bitfield32 {
266 	__u32 value;
267 	__u32 selector;
268 };
269 
270 /*
271  * policy descriptions - it's specific to each family how this is used
272  * Normally, it should be retrieved via a dump inside another attribute
273  * specifying where it applies.
274  */
275 
276 /**
277  * enum netlink_attribute_type - type of an attribute
278  * @NL_ATTR_TYPE_INVALID: unused
279  * @NL_ATTR_TYPE_FLAG: flag attribute (present/not present)
280  * @NL_ATTR_TYPE_U8: 8-bit unsigned attribute
281  * @NL_ATTR_TYPE_U16: 16-bit unsigned attribute
282  * @NL_ATTR_TYPE_U32: 32-bit unsigned attribute
283  * @NL_ATTR_TYPE_U64: 64-bit unsigned attribute
284  * @NL_ATTR_TYPE_S8: 8-bit signed attribute
285  * @NL_ATTR_TYPE_S16: 16-bit signed attribute
286  * @NL_ATTR_TYPE_S32: 32-bit signed attribute
287  * @NL_ATTR_TYPE_S64: 64-bit signed attribute
288  * @NL_ATTR_TYPE_BINARY: binary data, min/max length may be specified
289  * @NL_ATTR_TYPE_STRING: string, min/max length may be specified
290  * @NL_ATTR_TYPE_NUL_STRING: NUL-terminated string,
291  *	min/max length may be specified
292  * @NL_ATTR_TYPE_NESTED: nested, i.e. the content of this attribute
293  *	consists of sub-attributes. The nested policy and maxtype
294  *	inside may be specified.
295  * @NL_ATTR_TYPE_NESTED_ARRAY: nested array, i.e. the content of this
296  *	attribute contains sub-attributes whose type is irrelevant
297  *	(just used to separate the array entries) and each such array
298  *	entry has attributes again, the policy for those inner ones
299  *	and the corresponding maxtype may be specified.
300  * @NL_ATTR_TYPE_BITFIELD32: &struct nla_bitfield32 attribute
301  * @NL_ATTR_TYPE_SINT: 32-bit or 64-bit signed attribute, aligned to 4B
302  * @NL_ATTR_TYPE_UINT: 32-bit or 64-bit unsigned attribute, aligned to 4B
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 	NL_ATTR_TYPE_SINT,
329 	NL_ATTR_TYPE_UINT,
330 };
331 
332 /**
333  * enum netlink_policy_type_attr - policy type attributes
334  * @NL_POLICY_TYPE_ATTR_UNSPEC: unused
335  * @NL_POLICY_TYPE_ATTR_TYPE: type of the attribute,
336  *	&enum netlink_attribute_type (U32)
337  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_S: minimum value for signed
338  *	integers (S64)
339  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_S: maximum value for signed
340  *	integers (S64)
341  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_U: minimum value for unsigned
342  *	integers (U64)
343  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_U: maximum value for unsigned
344  *	integers (U64)
345  * @NL_POLICY_TYPE_ATTR_MIN_LENGTH: minimum length for binary
346  *	attributes, no minimum if not given (U32)
347  * @NL_POLICY_TYPE_ATTR_MAX_LENGTH: maximum length for binary
348  *	attributes, no maximum if not given (U32)
349  * @NL_POLICY_TYPE_ATTR_POLICY_IDX: sub policy for nested and
350  *	nested array types (U32)
351  * @NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE: maximum sub policy
352  *	attribute for nested and nested array types, this can
353  *	in theory be < the size of the policy pointed to by
354  *	the index, if limited inside the nesting (U32)
355  * @NL_POLICY_TYPE_ATTR_BITFIELD32_MASK: valid mask for the
356  *	bitfield32 type (U32)
357  * @NL_POLICY_TYPE_ATTR_MASK: mask of valid bits for unsigned integers (U64)
358  * @NL_POLICY_TYPE_ATTR_PAD: pad attribute for 64-bit alignment
359  *
360  * @__NL_POLICY_TYPE_ATTR_MAX: number of attributes
361  * @NL_POLICY_TYPE_ATTR_MAX: highest attribute number
362  */
363 enum netlink_policy_type_attr {
364 	NL_POLICY_TYPE_ATTR_UNSPEC,
365 	NL_POLICY_TYPE_ATTR_TYPE,
366 	NL_POLICY_TYPE_ATTR_MIN_VALUE_S,
367 	NL_POLICY_TYPE_ATTR_MAX_VALUE_S,
368 	NL_POLICY_TYPE_ATTR_MIN_VALUE_U,
369 	NL_POLICY_TYPE_ATTR_MAX_VALUE_U,
370 	NL_POLICY_TYPE_ATTR_MIN_LENGTH,
371 	NL_POLICY_TYPE_ATTR_MAX_LENGTH,
372 	NL_POLICY_TYPE_ATTR_POLICY_IDX,
373 	NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
374 	NL_POLICY_TYPE_ATTR_BITFIELD32_MASK,
375 	NL_POLICY_TYPE_ATTR_PAD,
376 	NL_POLICY_TYPE_ATTR_MASK,
377 
378 	/* keep last */
379 	__NL_POLICY_TYPE_ATTR_MAX,
380 	NL_POLICY_TYPE_ATTR_MAX = __NL_POLICY_TYPE_ATTR_MAX - 1
381 };
382 
383 #endif /* _UAPI__LINUX_NETLINK_H */
384