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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/kernel.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 
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_LENGTH(0)))
95 #define NLMSG_NEXT(nlh,len)	 ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
96 				  (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
97 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
98 			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
99 			   (nlh)->nlmsg_len <= (len))
100 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
101 
102 #define NLMSG_NOOP		0x1	/* Nothing.		*/
103 #define NLMSG_ERROR		0x2	/* Error		*/
104 #define NLMSG_DONE		0x3	/* End of a dump	*/
105 #define NLMSG_OVERRUN		0x4	/* Data lost		*/
106 
107 #define NLMSG_MIN_TYPE		0x10	/* < 0x10: reserved control messages */
108 
109 struct nlmsgerr {
110 	int		error;
111 	struct nlmsghdr msg;
112 	/*
113 	 * followed by the message contents unless NETLINK_CAP_ACK was set
114 	 * or the ACK indicates success (error == 0)
115 	 * message length is aligned with NLMSG_ALIGN()
116 	 */
117 	/*
118 	 * followed by TLVs defined in enum nlmsgerr_attrs
119 	 * if NETLINK_EXT_ACK was set
120 	 */
121 };
122 
123 /**
124  * enum nlmsgerr_attrs - nlmsgerr attributes
125  * @NLMSGERR_ATTR_UNUSED: unused
126  * @NLMSGERR_ATTR_MSG: error message string (string)
127  * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
128  *	 message, counting from the beginning of the header (u32)
129  * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
130  *	be used - in the success case - to identify a created
131  *	object or operation or similar (binary)
132  * @__NLMSGERR_ATTR_MAX: number of attributes
133  * @NLMSGERR_ATTR_MAX: highest attribute number
134  */
135 enum nlmsgerr_attrs {
136 	NLMSGERR_ATTR_UNUSED,
137 	NLMSGERR_ATTR_MSG,
138 	NLMSGERR_ATTR_OFFS,
139 	NLMSGERR_ATTR_COOKIE,
140 
141 	__NLMSGERR_ATTR_MAX,
142 	NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
143 };
144 
145 #define NETLINK_ADD_MEMBERSHIP		1
146 #define NETLINK_DROP_MEMBERSHIP		2
147 #define NETLINK_PKTINFO			3
148 #define NETLINK_BROADCAST_ERROR		4
149 #define NETLINK_NO_ENOBUFS		5
150 #define NETLINK_RX_RING			6
151 #define NETLINK_TX_RING			7
152 #define NETLINK_LISTEN_ALL_NSID		8
153 #define NETLINK_LIST_MEMBERSHIPS	9
154 #define NETLINK_CAP_ACK			10
155 #define NETLINK_EXT_ACK			11
156 
157 struct nl_pktinfo {
158 	__u32	group;
159 };
160 
161 struct nl_mmap_req {
162 	unsigned int	nm_block_size;
163 	unsigned int	nm_block_nr;
164 	unsigned int	nm_frame_size;
165 	unsigned int	nm_frame_nr;
166 };
167 
168 struct nl_mmap_hdr {
169 	unsigned int	nm_status;
170 	unsigned int	nm_len;
171 	__u32		nm_group;
172 	/* credentials */
173 	__u32		nm_pid;
174 	__u32		nm_uid;
175 	__u32		nm_gid;
176 };
177 
178 enum nl_mmap_status {
179 	NL_MMAP_STATUS_UNUSED,
180 	NL_MMAP_STATUS_RESERVED,
181 	NL_MMAP_STATUS_VALID,
182 	NL_MMAP_STATUS_COPY,
183 	NL_MMAP_STATUS_SKIP,
184 };
185 
186 #define NL_MMAP_MSG_ALIGNMENT		NLMSG_ALIGNTO
187 #define NL_MMAP_MSG_ALIGN(sz)		__ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
188 #define NL_MMAP_HDRLEN			NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
189 
190 #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
191 
192 enum {
193 	NETLINK_UNCONNECTED = 0,
194 	NETLINK_CONNECTED,
195 };
196 
197 /*
198  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
199  * +---------------------+- - -+- - - - - - - - - -+- - -+
200  * |        Header       | Pad |     Payload       | Pad |
201  * |   (struct nlattr)   | ing |                   | ing |
202  * +---------------------+- - -+- - - - - - - - - -+- - -+
203  *  <-------------- nlattr->nla_len -------------->
204  */
205 
206 struct nlattr {
207 	__u16           nla_len;
208 	__u16           nla_type;
209 };
210 
211 /*
212  * nla_type (16 bits)
213  * +---+---+-------------------------------+
214  * | N | O | Attribute Type                |
215  * +---+---+-------------------------------+
216  * N := Carries nested attributes
217  * O := Payload stored in network byte order
218  *
219  * Note: The N and O flag are mutually exclusive.
220  */
221 #define NLA_F_NESTED		(1 << 15)
222 #define NLA_F_NET_BYTEORDER	(1 << 14)
223 #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
224 
225 #define NLA_ALIGNTO		4
226 #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
227 #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))
228 
229 /* Generic 32 bitflags attribute content sent to the kernel.
230  *
231  * The value is a bitmap that defines the values being set
232  * The selector is a bitmask that defines which value is legit
233  *
234  * Examples:
235  *  value = 0x0, and selector = 0x1
236  *  implies we are selecting bit 1 and we want to set its value to 0.
237  *
238  *  value = 0x2, and selector = 0x2
239  *  implies we are selecting bit 2 and we want to set its value to 1.
240  *
241  */
242 struct nla_bitfield32 {
243 	__u32 value;
244 	__u32 selector;
245 };
246 
247 #endif /* __LINUX_NETLINK_H */
248