xref: /linux-6.15/include/uapi/linux/netlink.h (revision be2e2cb1)
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 */
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 struct nlmsghdr {
45 	__u32		nlmsg_len;	/* Length of message including header */
46 	__u16		nlmsg_type;	/* Message content */
47 	__u16		nlmsg_flags;	/* Additional flags */
48 	__u32		nlmsg_seq;	/* Sequence number */
49 	__u32		nlmsg_pid;	/* Sending process port ID */
50 };
51 
52 /* Flags values */
53 
54 #define NLM_F_REQUEST		0x01	/* It is request message. 	*/
55 #define NLM_F_MULTI		0x02	/* Multipart message, terminated by NLMSG_DONE */
56 #define NLM_F_ACK		0x04	/* Reply with ack, with zero or error code */
57 #define NLM_F_ECHO		0x08	/* Echo this request 		*/
58 #define NLM_F_DUMP_INTR		0x10	/* Dump was inconsistent due to sequence change */
59 #define NLM_F_DUMP_FILTERED	0x20	/* Dump was filtered as requested */
60 
61 /* Modifiers to GET request */
62 #define NLM_F_ROOT	0x100	/* specify tree	root	*/
63 #define NLM_F_MATCH	0x200	/* return all matching	*/
64 #define NLM_F_ATOMIC	0x400	/* atomic GET		*/
65 #define NLM_F_DUMP	(NLM_F_ROOT|NLM_F_MATCH)
66 
67 /* Modifiers to NEW request */
68 #define NLM_F_REPLACE	0x100	/* Override existing		*/
69 #define NLM_F_EXCL	0x200	/* Do not touch, if it exists	*/
70 #define NLM_F_CREATE	0x400	/* Create, if it does not exist	*/
71 #define NLM_F_APPEND	0x800	/* Add to end of list		*/
72 
73 /* Modifiers to DELETE request */
74 #define NLM_F_NONREC	0x100	/* Do not delete recursively	*/
75 #define NLM_F_BULK	0x200	/* Delete multiple objects	*/
76 
77 /* Flags for ACK message */
78 #define NLM_F_CAPPED	0x100	/* request was capped */
79 #define NLM_F_ACK_TLVS	0x200	/* extended ACK TVLs were included */
80 
81 /*
82    4.4BSD ADD		NLM_F_CREATE|NLM_F_EXCL
83    4.4BSD CHANGE	NLM_F_REPLACE
84 
85    True CHANGE		NLM_F_CREATE|NLM_F_REPLACE
86    Append		NLM_F_CREATE
87    Check		NLM_F_EXCL
88  */
89 
90 #define NLMSG_ALIGNTO	4U
91 #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
92 #define NLMSG_HDRLEN	 ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
93 #define NLMSG_LENGTH(len) ((len) + NLMSG_HDRLEN)
94 #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
95 #define NLMSG_DATA(nlh)  ((void *)(((char *)nlh) + NLMSG_HDRLEN))
96 #define NLMSG_NEXT(nlh,len)	 ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
97 				  (struct nlmsghdr *)(((char *)(nlh)) + \
98 				  NLMSG_ALIGN((nlh)->nlmsg_len)))
99 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
100 			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
101 			   (nlh)->nlmsg_len <= (len))
102 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
103 
104 #define NLMSG_NOOP		0x1	/* Nothing.		*/
105 #define NLMSG_ERROR		0x2	/* Error		*/
106 #define NLMSG_DONE		0x3	/* End of a dump	*/
107 #define NLMSG_OVERRUN		0x4	/* Data lost		*/
108 
109 #define NLMSG_MIN_TYPE		0x10	/* < 0x10: reserved control messages */
110 
111 struct nlmsgerr {
112 	int		error;
113 	struct nlmsghdr msg;
114 	/*
115 	 * followed by the message contents unless NETLINK_CAP_ACK was set
116 	 * or the ACK indicates success (error == 0)
117 	 * message length is aligned with NLMSG_ALIGN()
118 	 */
119 	/*
120 	 * followed by TLVs defined in enum nlmsgerr_attrs
121 	 * if NETLINK_EXT_ACK was set
122 	 */
123 };
124 
125 /**
126  * enum nlmsgerr_attrs - nlmsgerr attributes
127  * @NLMSGERR_ATTR_UNUSED: unused
128  * @NLMSGERR_ATTR_MSG: error message string (string)
129  * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
130  *	 message, counting from the beginning of the header (u32)
131  * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
132  *	be used - in the success case - to identify a created
133  *	object or operation or similar (binary)
134  * @NLMSGERR_ATTR_POLICY: policy for a rejected attribute
135  * @__NLMSGERR_ATTR_MAX: number of attributes
136  * @NLMSGERR_ATTR_MAX: highest attribute number
137  */
138 enum nlmsgerr_attrs {
139 	NLMSGERR_ATTR_UNUSED,
140 	NLMSGERR_ATTR_MSG,
141 	NLMSGERR_ATTR_OFFS,
142 	NLMSGERR_ATTR_COOKIE,
143 	NLMSGERR_ATTR_POLICY,
144 
145 	__NLMSGERR_ATTR_MAX,
146 	NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
147 };
148 
149 #define NETLINK_ADD_MEMBERSHIP		1
150 #define NETLINK_DROP_MEMBERSHIP		2
151 #define NETLINK_PKTINFO			3
152 #define NETLINK_BROADCAST_ERROR		4
153 #define NETLINK_NO_ENOBUFS		5
154 #ifndef __KERNEL__
155 #define NETLINK_RX_RING			6
156 #define NETLINK_TX_RING			7
157 #endif
158 #define NETLINK_LISTEN_ALL_NSID		8
159 #define NETLINK_LIST_MEMBERSHIPS	9
160 #define NETLINK_CAP_ACK			10
161 #define NETLINK_EXT_ACK			11
162 #define NETLINK_GET_STRICT_CHK		12
163 
164 struct nl_pktinfo {
165 	__u32	group;
166 };
167 
168 struct nl_mmap_req {
169 	unsigned int	nm_block_size;
170 	unsigned int	nm_block_nr;
171 	unsigned int	nm_frame_size;
172 	unsigned int	nm_frame_nr;
173 };
174 
175 struct nl_mmap_hdr {
176 	unsigned int	nm_status;
177 	unsigned int	nm_len;
178 	__u32		nm_group;
179 	/* credentials */
180 	__u32		nm_pid;
181 	__u32		nm_uid;
182 	__u32		nm_gid;
183 };
184 
185 #ifndef __KERNEL__
186 enum nl_mmap_status {
187 	NL_MMAP_STATUS_UNUSED,
188 	NL_MMAP_STATUS_RESERVED,
189 	NL_MMAP_STATUS_VALID,
190 	NL_MMAP_STATUS_COPY,
191 	NL_MMAP_STATUS_SKIP,
192 };
193 
194 #define NL_MMAP_MSG_ALIGNMENT		NLMSG_ALIGNTO
195 #define NL_MMAP_MSG_ALIGN(sz)		__ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
196 #define NL_MMAP_HDRLEN			NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
197 #endif
198 
199 #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
200 
201 enum {
202 	NETLINK_UNCONNECTED = 0,
203 	NETLINK_CONNECTED,
204 };
205 
206 /*
207  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
208  * +---------------------+- - -+- - - - - - - - - -+- - -+
209  * |        Header       | Pad |     Payload       | Pad |
210  * |   (struct nlattr)   | ing |                   | ing |
211  * +---------------------+- - -+- - - - - - - - - -+- - -+
212  *  <-------------- nlattr->nla_len -------------->
213  */
214 
215 struct nlattr {
216 	__u16           nla_len;
217 	__u16           nla_type;
218 };
219 
220 /*
221  * nla_type (16 bits)
222  * +---+---+-------------------------------+
223  * | N | O | Attribute Type                |
224  * +---+---+-------------------------------+
225  * N := Carries nested attributes
226  * O := Payload stored in network byte order
227  *
228  * Note: The N and O flag are mutually exclusive.
229  */
230 #define NLA_F_NESTED		(1 << 15)
231 #define NLA_F_NET_BYTEORDER	(1 << 14)
232 #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
233 
234 #define NLA_ALIGNTO		4
235 #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
236 #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))
237 
238 /* Generic 32 bitflags attribute content sent to the kernel.
239  *
240  * The value is a bitmap that defines the values being set
241  * The selector is a bitmask that defines which value is legit
242  *
243  * Examples:
244  *  value = 0x0, and selector = 0x1
245  *  implies we are selecting bit 1 and we want to set its value to 0.
246  *
247  *  value = 0x2, and selector = 0x2
248  *  implies we are selecting bit 2 and we want to set its value to 1.
249  *
250  */
251 struct nla_bitfield32 {
252 	__u32 value;
253 	__u32 selector;
254 };
255 
256 /*
257  * policy descriptions - it's specific to each family how this is used
258  * Normally, it should be retrieved via a dump inside another attribute
259  * specifying where it applies.
260  */
261 
262 /**
263  * enum netlink_attribute_type - type of an attribute
264  * @NL_ATTR_TYPE_INVALID: unused
265  * @NL_ATTR_TYPE_FLAG: flag attribute (present/not present)
266  * @NL_ATTR_TYPE_U8: 8-bit unsigned attribute
267  * @NL_ATTR_TYPE_U16: 16-bit unsigned attribute
268  * @NL_ATTR_TYPE_U32: 32-bit unsigned attribute
269  * @NL_ATTR_TYPE_U64: 64-bit unsigned attribute
270  * @NL_ATTR_TYPE_S8: 8-bit signed attribute
271  * @NL_ATTR_TYPE_S16: 16-bit signed attribute
272  * @NL_ATTR_TYPE_S32: 32-bit signed attribute
273  * @NL_ATTR_TYPE_S64: 64-bit signed attribute
274  * @NL_ATTR_TYPE_BINARY: binary data, min/max length may be specified
275  * @NL_ATTR_TYPE_STRING: string, min/max length may be specified
276  * @NL_ATTR_TYPE_NUL_STRING: NUL-terminated string,
277  *	min/max length may be specified
278  * @NL_ATTR_TYPE_NESTED: nested, i.e. the content of this attribute
279  *	consists of sub-attributes. The nested policy and maxtype
280  *	inside may be specified.
281  * @NL_ATTR_TYPE_NESTED_ARRAY: nested array, i.e. the content of this
282  *	attribute contains sub-attributes whose type is irrelevant
283  *	(just used to separate the array entries) and each such array
284  *	entry has attributes again, the policy for those inner ones
285  *	and the corresponding maxtype may be specified.
286  * @NL_ATTR_TYPE_BITFIELD32: &struct nla_bitfield32 attribute
287  */
288 enum netlink_attribute_type {
289 	NL_ATTR_TYPE_INVALID,
290 
291 	NL_ATTR_TYPE_FLAG,
292 
293 	NL_ATTR_TYPE_U8,
294 	NL_ATTR_TYPE_U16,
295 	NL_ATTR_TYPE_U32,
296 	NL_ATTR_TYPE_U64,
297 
298 	NL_ATTR_TYPE_S8,
299 	NL_ATTR_TYPE_S16,
300 	NL_ATTR_TYPE_S32,
301 	NL_ATTR_TYPE_S64,
302 
303 	NL_ATTR_TYPE_BINARY,
304 	NL_ATTR_TYPE_STRING,
305 	NL_ATTR_TYPE_NUL_STRING,
306 
307 	NL_ATTR_TYPE_NESTED,
308 	NL_ATTR_TYPE_NESTED_ARRAY,
309 
310 	NL_ATTR_TYPE_BITFIELD32,
311 };
312 
313 /**
314  * enum netlink_policy_type_attr - policy type attributes
315  * @NL_POLICY_TYPE_ATTR_UNSPEC: unused
316  * @NL_POLICY_TYPE_ATTR_TYPE: type of the attribute,
317  *	&enum netlink_attribute_type (U32)
318  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_S: minimum value for signed
319  *	integers (S64)
320  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_S: maximum value for signed
321  *	integers (S64)
322  * @NL_POLICY_TYPE_ATTR_MIN_VALUE_U: minimum value for unsigned
323  *	integers (U64)
324  * @NL_POLICY_TYPE_ATTR_MAX_VALUE_U: maximum value for unsigned
325  *	integers (U64)
326  * @NL_POLICY_TYPE_ATTR_MIN_LENGTH: minimum length for binary
327  *	attributes, no minimum if not given (U32)
328  * @NL_POLICY_TYPE_ATTR_MAX_LENGTH: maximum length for binary
329  *	attributes, no maximum if not given (U32)
330  * @NL_POLICY_TYPE_ATTR_POLICY_IDX: sub policy for nested and
331  *	nested array types (U32)
332  * @NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE: maximum sub policy
333  *	attribute for nested and nested array types, this can
334  *	in theory be < the size of the policy pointed to by
335  *	the index, if limited inside the nesting (U32)
336  * @NL_POLICY_TYPE_ATTR_BITFIELD32_MASK: valid mask for the
337  *	bitfield32 type (U32)
338  * @NL_POLICY_TYPE_ATTR_MASK: mask of valid bits for unsigned integers (U64)
339  * @NL_POLICY_TYPE_ATTR_PAD: pad attribute for 64-bit alignment
340  */
341 enum netlink_policy_type_attr {
342 	NL_POLICY_TYPE_ATTR_UNSPEC,
343 	NL_POLICY_TYPE_ATTR_TYPE,
344 	NL_POLICY_TYPE_ATTR_MIN_VALUE_S,
345 	NL_POLICY_TYPE_ATTR_MAX_VALUE_S,
346 	NL_POLICY_TYPE_ATTR_MIN_VALUE_U,
347 	NL_POLICY_TYPE_ATTR_MAX_VALUE_U,
348 	NL_POLICY_TYPE_ATTR_MIN_LENGTH,
349 	NL_POLICY_TYPE_ATTR_MAX_LENGTH,
350 	NL_POLICY_TYPE_ATTR_POLICY_IDX,
351 	NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
352 	NL_POLICY_TYPE_ATTR_BITFIELD32_MASK,
353 	NL_POLICY_TYPE_ATTR_PAD,
354 	NL_POLICY_TYPE_ATTR_MASK,
355 
356 	/* keep last */
357 	__NL_POLICY_TYPE_ATTR_MAX,
358 	NL_POLICY_TYPE_ATTR_MAX = __NL_POLICY_TYPE_ATTR_MAX - 1
359 };
360 
361 #endif /* _UAPI__LINUX_NETLINK_H */
362