1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2#ifndef __LINUX_NETLINK_H
3#define __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
37struct 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
44struct 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
76/* Flags for ACK message */
77#define NLM_F_CAPPED 0x100 /* request was capped */
78#define NLM_F_ACK_TLVS 0x200 /* extended ACK TVLs were included */
79
80/*
81 4.4BSD ADD NLM_F_CREATE|NLM_F_EXCL
82 4.4BSD CHANGE NLM_F_REPLACE
83
84 True CHANGE NLM_F_CREATE|NLM_F_REPLACE
85 Append NLM_F_CREATE
86 Check NLM_F_EXCL
87 */
88
89#define NLMSG_ALIGNTO 4U
90#define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
91#define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
92#define NLMSG_LENGTH(len) ((len) + NLMSG_HDRLEN)
93#define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
94#define NLMSG_DATA(nlh) ((void *)(((char *)nlh) + NLMSG_HDRLEN))
95#define NLMSG_NEXT(nlh,len) ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
96 (struct nlmsghdr *)(((char *)(nlh)) + \
97 NLMSG_ALIGN((nlh)->nlmsg_len)))
98#define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
99 (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
100 (nlh)->nlmsg_len <= (len))
101#define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
102
103#define NLMSG_NOOP 0x1 /* Nothing. */
104#define NLMSG_ERROR 0x2 /* Error */
105#define NLMSG_DONE 0x3 /* End of a dump */
106#define NLMSG_OVERRUN 0x4 /* Data lost */
107
108#define NLMSG_MIN_TYPE 0x10 /* < 0x10: reserved control messages */
109
110struct nlmsgerr {
111 int error;
112 struct nlmsghdr msg;
113 /*
114 * followed by the message contents unless NETLINK_CAP_ACK was set
115 * or the ACK indicates success (error == 0)
116 * message length is aligned with NLMSG_ALIGN()
117 */
118 /*
119 * followed by TLVs defined in enum nlmsgerr_attrs
120 * if NETLINK_EXT_ACK was set
121 */
122};
123
124/**
125 * enum nlmsgerr_attrs - nlmsgerr attributes
126 * @NLMSGERR_ATTR_UNUSED: unused
127 * @NLMSGERR_ATTR_MSG: error message string (string)
128 * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
129 * message, counting from the beginning of the header (u32)
130 * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
131 * be used - in the success case - to identify a created
132 * object or operation or similar (binary)
133 * @NLMSGERR_ATTR_POLICY: policy for a rejected attribute
134 * @__NLMSGERR_ATTR_MAX: number of attributes
135 * @NLMSGERR_ATTR_MAX: highest attribute number
136 */
137enum nlmsgerr_attrs {
138 NLMSGERR_ATTR_UNUSED,
139 NLMSGERR_ATTR_MSG,
140 NLMSGERR_ATTR_OFFS,
141 NLMSGERR_ATTR_COOKIE,
142 NLMSGERR_ATTR_POLICY,
143
144 __NLMSGERR_ATTR_MAX,
145 NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
146};
147
148#define NETLINK_ADD_MEMBERSHIP 1
149#define NETLINK_DROP_MEMBERSHIP 2
150#define NETLINK_PKTINFO 3
151#define NETLINK_BROADCAST_ERROR 4
152#define NETLINK_NO_ENOBUFS 5
153#define NETLINK_RX_RING 6
154#define NETLINK_TX_RING 7
155#define NETLINK_LISTEN_ALL_NSID 8
156#define NETLINK_LIST_MEMBERSHIPS 9
157#define NETLINK_CAP_ACK 10
158#define NETLINK_EXT_ACK 11
159#define NETLINK_GET_STRICT_CHK 12
160
161struct nl_pktinfo {
162 __u32 group;
163};
164
165struct nl_mmap_req {
166 unsigned int nm_block_size;
167 unsigned int nm_block_nr;
168 unsigned int nm_frame_size;
169 unsigned int nm_frame_nr;
170};
171
172struct nl_mmap_hdr {
173 unsigned int nm_status;
174 unsigned int nm_len;
175 __u32 nm_group;
176 /* credentials */
177 __u32 nm_pid;
178 __u32 nm_uid;
179 __u32 nm_gid;
180};
181
182enum nl_mmap_status {
183 NL_MMAP_STATUS_UNUSED,
184 NL_MMAP_STATUS_RESERVED,
185 NL_MMAP_STATUS_VALID,
186 NL_MMAP_STATUS_COPY,
187 NL_MMAP_STATUS_SKIP,
188};
189
190#define NL_MMAP_MSG_ALIGNMENT NLMSG_ALIGNTO
191#define NL_MMAP_MSG_ALIGN(sz) __ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
192#define NL_MMAP_HDRLEN NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
193
194#define NET_MAJOR 36 /* Major 36 is reserved for networking */
195
196enum {
197 NETLINK_UNCONNECTED = 0,
198 NETLINK_CONNECTED,
199};
200
201/*
202 * <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
203 * +---------------------+- - -+- - - - - - - - - -+- - -+
204 * | Header | Pad | Payload | Pad |
205 * | (struct nlattr) | ing | | ing |
206 * +---------------------+- - -+- - - - - - - - - -+- - -+
207 * <-------------- nlattr->nla_len -------------->
208 */
209
210struct nlattr {
211 __u16 nla_len;
212 __u16 nla_type;
213};
214
215/*
216 * nla_type (16 bits)
217 * +---+---+-------------------------------+
218 * | N | O | Attribute Type |
219 * +---+---+-------------------------------+
220 * N := Carries nested attributes
221 * O := Payload stored in network byte order
222 *
223 * Note: The N and O flag are mutually exclusive.
224 */
225#define NLA_F_NESTED (1 << 15)
226#define NLA_F_NET_BYTEORDER (1 << 14)
227#define NLA_TYPE_MASK ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
228
229#define NLA_ALIGNTO 4
230#define NLA_ALIGN(len) (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
231#define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))
232
233/* Generic 32 bitflags attribute content sent to the kernel.
234 *
235 * The value is a bitmap that defines the values being set
236 * The selector is a bitmask that defines which value is legit
237 *
238 * Examples:
239 * value = 0x0, and selector = 0x1
240 * implies we are selecting bit 1 and we want to set its value to 0.
241 *
242 * value = 0x2, and selector = 0x2
243 * implies we are selecting bit 2 and we want to set its value to 1.
244 *
245 */
246struct nla_bitfield32 {
247 __u32 value;
248 __u32 selector;
249};
250
251/*
252 * policy descriptions - it's specific to each family how this is used
253 * Normally, it should be retrieved via a dump inside another attribute
254 * specifying where it applies.
255 */
256
257/**
258 * enum netlink_attribute_type - type of an attribute
259 * @NL_ATTR_TYPE_INVALID: unused
260 * @NL_ATTR_TYPE_FLAG: flag attribute (present/not present)
261 * @NL_ATTR_TYPE_U8: 8-bit unsigned attribute
262 * @NL_ATTR_TYPE_U16: 16-bit unsigned attribute
263 * @NL_ATTR_TYPE_U32: 32-bit unsigned attribute
264 * @NL_ATTR_TYPE_U64: 64-bit unsigned attribute
265 * @NL_ATTR_TYPE_S8: 8-bit signed attribute
266 * @NL_ATTR_TYPE_S16: 16-bit signed attribute
267 * @NL_ATTR_TYPE_S32: 32-bit signed attribute
268 * @NL_ATTR_TYPE_S64: 64-bit signed attribute
269 * @NL_ATTR_TYPE_BINARY: binary data, min/max length may be specified
270 * @NL_ATTR_TYPE_STRING: string, min/max length may be specified
271 * @NL_ATTR_TYPE_NUL_STRING: NUL-terminated string,
272 * min/max length may be specified
273 * @NL_ATTR_TYPE_NESTED: nested, i.e. the content of this attribute
274 * consists of sub-attributes. The nested policy and maxtype
275 * inside may be specified.
276 * @NL_ATTR_TYPE_NESTED_ARRAY: nested array, i.e. the content of this
277 * attribute contains sub-attributes whose type is irrelevant
278 * (just used to separate the array entries) and each such array
279 * entry has attributes again, the policy for those inner ones
280 * and the corresponding maxtype may be specified.
281 * @NL_ATTR_TYPE_BITFIELD32: &struct nla_bitfield32 attribute
282 */
283enum netlink_attribute_type {
284 NL_ATTR_TYPE_INVALID,
285
286 NL_ATTR_TYPE_FLAG,
287
288 NL_ATTR_TYPE_U8,
289 NL_ATTR_TYPE_U16,
290 NL_ATTR_TYPE_U32,
291 NL_ATTR_TYPE_U64,
292
293 NL_ATTR_TYPE_S8,
294 NL_ATTR_TYPE_S16,
295 NL_ATTR_TYPE_S32,
296 NL_ATTR_TYPE_S64,
297
298 NL_ATTR_TYPE_BINARY,
299 NL_ATTR_TYPE_STRING,
300 NL_ATTR_TYPE_NUL_STRING,
301
302 NL_ATTR_TYPE_NESTED,
303 NL_ATTR_TYPE_NESTED_ARRAY,
304
305 NL_ATTR_TYPE_BITFIELD32,
306};
307
308/**
309 * enum netlink_policy_type_attr - policy type attributes
310 * @NL_POLICY_TYPE_ATTR_UNSPEC: unused
311 * @NL_POLICY_TYPE_ATTR_TYPE: type of the attribute,
312 * &enum netlink_attribute_type (U32)
313 * @NL_POLICY_TYPE_ATTR_MIN_VALUE_S: minimum value for signed
314 * integers (S64)
315 * @NL_POLICY_TYPE_ATTR_MAX_VALUE_S: maximum value for signed
316 * integers (S64)
317 * @NL_POLICY_TYPE_ATTR_MIN_VALUE_U: minimum value for unsigned
318 * integers (U64)
319 * @NL_POLICY_TYPE_ATTR_MAX_VALUE_U: maximum value for unsigned
320 * integers (U64)
321 * @NL_POLICY_TYPE_ATTR_MIN_LENGTH: minimum length for binary
322 * attributes, no minimum if not given (U32)
323 * @NL_POLICY_TYPE_ATTR_MAX_LENGTH: maximum length for binary
324 * attributes, no maximum if not given (U32)
325 * @NL_POLICY_TYPE_ATTR_POLICY_IDX: sub policy for nested and
326 * nested array types (U32)
327 * @NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE: maximum sub policy
328 * attribute for nested and nested array types, this can
329 * in theory be < the size of the policy pointed to by
330 * the index, if limited inside the nesting (U32)
331 * @NL_POLICY_TYPE_ATTR_BITFIELD32_MASK: valid mask for the
332 * bitfield32 type (U32)
333 * @NL_POLICY_TYPE_ATTR_MASK: mask of valid bits for unsigned integers (U64)
334 * @NL_POLICY_TYPE_ATTR_PAD: pad attribute for 64-bit alignment
335 */
336enum netlink_policy_type_attr {
337 NL_POLICY_TYPE_ATTR_UNSPEC,
338 NL_POLICY_TYPE_ATTR_TYPE,
339 NL_POLICY_TYPE_ATTR_MIN_VALUE_S,
340 NL_POLICY_TYPE_ATTR_MAX_VALUE_S,
341 NL_POLICY_TYPE_ATTR_MIN_VALUE_U,
342 NL_POLICY_TYPE_ATTR_MAX_VALUE_U,
343 NL_POLICY_TYPE_ATTR_MIN_LENGTH,
344 NL_POLICY_TYPE_ATTR_MAX_LENGTH,
345 NL_POLICY_TYPE_ATTR_POLICY_IDX,
346 NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
347 NL_POLICY_TYPE_ATTR_BITFIELD32_MASK,
348 NL_POLICY_TYPE_ATTR_PAD,
349 NL_POLICY_TYPE_ATTR_MASK,
350
351 /* keep last */
352 __NL_POLICY_TYPE_ATTR_MAX,
353 NL_POLICY_TYPE_ATTR_MAX = __NL_POLICY_TYPE_ATTR_MAX - 1
354};
355
356#endif /* __LINUX_NETLINK_H */
357

source code of include/linux/netlink.h