xref: /linux-6.15/include/uapi/linux/netlink.h (revision 30b60554)
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	/* Echo this request 		*/
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_MAX: number of attributes
144  * @NLMSGERR_ATTR_MAX: highest attribute number
145  */
146 enum nlmsgerr_attrs {
147 	NLMSGERR_ATTR_UNUSED,
148 	NLMSGERR_ATTR_MSG,
149 	NLMSGERR_ATTR_OFFS,
150 	NLMSGERR_ATTR_COOKIE,
151 	NLMSGERR_ATTR_POLICY,
152 
153 	__NLMSGERR_ATTR_MAX,
154 	NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
155 };
156 
157 #define NETLINK_ADD_MEMBERSHIP		1
158 #define NETLINK_DROP_MEMBERSHIP		2
159 #define NETLINK_PKTINFO			3
160 #define NETLINK_BROADCAST_ERROR		4
161 #define NETLINK_NO_ENOBUFS		5
162 #ifndef __KERNEL__
163 #define NETLINK_RX_RING			6
164 #define NETLINK_TX_RING			7
165 #endif
166 #define NETLINK_LISTEN_ALL_NSID		8
167 #define NETLINK_LIST_MEMBERSHIPS	9
168 #define NETLINK_CAP_ACK			10
169 #define NETLINK_EXT_ACK			11
170 #define NETLINK_GET_STRICT_CHK		12
171 
172 struct nl_pktinfo {
173 	__u32	group;
174 };
175 
176 struct nl_mmap_req {
177 	unsigned int	nm_block_size;
178 	unsigned int	nm_block_nr;
179 	unsigned int	nm_frame_size;
180 	unsigned int	nm_frame_nr;
181 };
182 
183 struct nl_mmap_hdr {
184 	unsigned int	nm_status;
185 	unsigned int	nm_len;
186 	__u32		nm_group;
187 	/* credentials */
188 	__u32		nm_pid;
189 	__u32		nm_uid;
190 	__u32		nm_gid;
191 };
192 
193 #ifndef __KERNEL__
194 enum nl_mmap_status {
195 	NL_MMAP_STATUS_UNUSED,
196 	NL_MMAP_STATUS_RESERVED,
197 	NL_MMAP_STATUS_VALID,
198 	NL_MMAP_STATUS_COPY,
199 	NL_MMAP_STATUS_SKIP,
200 };
201 
202 #define NL_MMAP_MSG_ALIGNMENT		NLMSG_ALIGNTO
203 #define NL_MMAP_MSG_ALIGN(sz)		__ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
204 #define NL_MMAP_HDRLEN			NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
205 #endif
206 
207 #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
208 
209 enum {
210 	NETLINK_UNCONNECTED = 0,
211 	NETLINK_CONNECTED,
212 };
213 
214 /*
215  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
216  * +---------------------+- - -+- - - - - - - - - -+- - -+
217  * |        Header       | Pad |     Payload       | Pad |
218  * |   (struct nlattr)   | ing |                   | ing |
219  * +---------------------+- - -+- - - - - - - - - -+- - -+
220  *  <-------------- nlattr->nla_len -------------->
221  */
222 
223 struct nlattr {
224 	__u16           nla_len;
225 	__u16           nla_type;
226 };
227 
228 /*
229  * nla_type (16 bits)
230  * +---+---+-------------------------------+
231  * | N | O | Attribute Type                |
232  * +---+---+-------------------------------+
233  * N := Carries nested attributes
234  * O := Payload stored in network byte order
235  *
236  * Note: The N and O flag are mutually exclusive.
237  */
238 #define NLA_F_NESTED		(1 << 15)
239 #define NLA_F_NET_BYTEORDER	(1 << 14)
240 #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
241 
242 #define NLA_ALIGNTO		4
243 #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
244 #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))
245 
246 /* Generic 32 bitflags attribute content sent to the kernel.
247  *
248  * The value is a bitmap that defines the values being set
249  * The selector is a bitmask that defines which value is legit
250  *
251  * Examples:
252  *  value = 0x0, and selector = 0x1
253  *  implies we are selecting bit 1 and we want to set its value to 0.
254  *
255  *  value = 0x2, and selector = 0x2
256  *  implies we are selecting bit 2 and we want to set its value to 1.
257  *
258  */
259 struct nla_bitfield32 {
260 	__u32 value;
261 	__u32 selector;
262 };
263 
264 /*
265  * policy descriptions - it's specific to each family how this is used
266  * Normally, it should be retrieved via a dump inside another attribute
267  * specifying where it applies.
268  */
269 
270 /**
271  * enum netlink_attribute_type - type of an attribute
272  * @NL_ATTR_TYPE_INVALID: unused
273  * @NL_ATTR_TYPE_FLAG: flag attribute (present/not present)
274  * @NL_ATTR_TYPE_U8: 8-bit unsigned attribute
275  * @NL_ATTR_TYPE_U16: 16-bit unsigned attribute
276  * @NL_ATTR_TYPE_U32: 32-bit unsigned attribute
277  * @NL_ATTR_TYPE_U64: 64-bit unsigned attribute
278  * @NL_ATTR_TYPE_S8: 8-bit signed attribute
279  * @NL_ATTR_TYPE_S16: 16-bit signed attribute
280  * @NL_ATTR_TYPE_S32: 32-bit signed attribute
281  * @NL_ATTR_TYPE_S64: 64-bit signed attribute
282  * @NL_ATTR_TYPE_BINARY: binary data, min/max length may be specified
283  * @NL_ATTR_TYPE_STRING: string, min/max length may be specified
284  * @NL_ATTR_TYPE_NUL_STRING: NUL-terminated string,
285  *	min/max length may be specified
286  * @NL_ATTR_TYPE_NESTED: nested, i.e. the content of this attribute
287  *	consists of sub-attributes. The nested policy and maxtype
288  *	inside may be specified.
289  * @NL_ATTR_TYPE_NESTED_ARRAY: nested array, i.e. the content of this
290  *	attribute contains sub-attributes whose type is irrelevant
291  *	(just used to separate the array entries) and each such array
292  *	entry has attributes again, the policy for those inner ones
293  *	and the corresponding maxtype may be specified.
294  * @NL_ATTR_TYPE_BITFIELD32: &struct nla_bitfield32 attribute
295  */
296 enum netlink_attribute_type {
297 	NL_ATTR_TYPE_INVALID,
298 
299 	NL_ATTR_TYPE_FLAG,
300 
301 	NL_ATTR_TYPE_U8,
302 	NL_ATTR_TYPE_U16,
303 	NL_ATTR_TYPE_U32,
304 	NL_ATTR_TYPE_U64,
305 
306 	NL_ATTR_TYPE_S8,
307 	NL_ATTR_TYPE_S16,
308 	NL_ATTR_TYPE_S32,
309 	NL_ATTR_TYPE_S64,
310 
311 	NL_ATTR_TYPE_BINARY,
312 	NL_ATTR_TYPE_STRING,
313 	NL_ATTR_TYPE_NUL_STRING,
314 
315 	NL_ATTR_TYPE_NESTED,
316 	NL_ATTR_TYPE_NESTED_ARRAY,
317 
318 	NL_ATTR_TYPE_BITFIELD32,
319 };
320 
321 /**
322  * enum netlink_policy_type_attr - policy type attributes
323  * @NL_POLICY_TYPE_ATTR_UNSPEC: unused
324  * @NL_POLICY_TYPE_ATTR_TYPE: type of the attribute,
325  *	&enum netlink_attribute_type (U32)
326  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_S: minimum value for signed
327  *	integers (S64)
328  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_S: maximum value for signed
329  *	integers (S64)
330  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_U: minimum value for unsigned
331  *	integers (U64)
332  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_U: maximum value for unsigned
333  *	integers (U64)
334  * @NL_POLICY_TYPE_ATTR_MIN_LENGTH: minimum length for binary
335  *	attributes, no minimum if not given (U32)
336  * @NL_POLICY_TYPE_ATTR_MAX_LENGTH: maximum length for binary
337  *	attributes, no maximum if not given (U32)
338  * @NL_POLICY_TYPE_ATTR_POLICY_IDX: sub policy for nested and
339  *	nested array types (U32)
340  * @NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE: maximum sub policy
341  *	attribute for nested and nested array types, this can
342  *	in theory be < the size of the policy pointed to by
343  *	the index, if limited inside the nesting (U32)
344  * @NL_POLICY_TYPE_ATTR_BITFIELD32_MASK: valid mask for the
345  *	bitfield32 type (U32)
346  * @NL_POLICY_TYPE_ATTR_MASK: mask of valid bits for unsigned integers (U64)
347  * @NL_POLICY_TYPE_ATTR_PAD: pad attribute for 64-bit alignment
348  *
349  * @__NL_POLICY_TYPE_ATTR_MAX: number of attributes
350  * @NL_POLICY_TYPE_ATTR_MAX: highest attribute number
351  */
352 enum netlink_policy_type_attr {
353 	NL_POLICY_TYPE_ATTR_UNSPEC,
354 	NL_POLICY_TYPE_ATTR_TYPE,
355 	NL_POLICY_TYPE_ATTR_MIN_VALUE_S,
356 	NL_POLICY_TYPE_ATTR_MAX_VALUE_S,
357 	NL_POLICY_TYPE_ATTR_MIN_VALUE_U,
358 	NL_POLICY_TYPE_ATTR_MAX_VALUE_U,
359 	NL_POLICY_TYPE_ATTR_MIN_LENGTH,
360 	NL_POLICY_TYPE_ATTR_MAX_LENGTH,
361 	NL_POLICY_TYPE_ATTR_POLICY_IDX,
362 	NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
363 	NL_POLICY_TYPE_ATTR_BITFIELD32_MASK,
364 	NL_POLICY_TYPE_ATTR_PAD,
365 	NL_POLICY_TYPE_ATTR_MASK,
366 
367 	/* keep last */
368 	__NL_POLICY_TYPE_ATTR_MAX,
369 	NL_POLICY_TYPE_ATTR_MAX = __NL_POLICY_TYPE_ATTR_MAX - 1
370 };
371 
372 #endif /* _UAPI__LINUX_NETLINK_H */
373