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      1 #ifndef __LINUX_NETLINK_H
      2 #define __LINUX_NETLINK_H
      3 
      4 #include <linux/socket.h> /* for sa_family_t */
      5 #include <linux/types.h>
      6 
      7 #define NETLINK_ROUTE		0	/* Routing/device hook				*/
      8 #define NETLINK_UNUSED		1	/* Unused number				*/
      9 #define NETLINK_USERSOCK	2	/* Reserved for user mode socket protocols 	*/
     10 #define NETLINK_FIREWALL	3	/* Firewalling hook				*/
     11 #define NETLINK_INET_DIAG	4	/* INET socket monitoring			*/
     12 #define NETLINK_NFLOG		5	/* netfilter/iptables ULOG */
     13 #define NETLINK_XFRM		6	/* ipsec */
     14 #define NETLINK_SELINUX		7	/* SELinux event notifications */
     15 #define NETLINK_ISCSI		8	/* Open-iSCSI */
     16 #define NETLINK_AUDIT		9	/* auditing */
     17 #define NETLINK_FIB_LOOKUP	10
     18 #define NETLINK_CONNECTOR	11
     19 #define NETLINK_NETFILTER	12	/* netfilter subsystem */
     20 #define NETLINK_IP6_FW		13
     21 #define NETLINK_DNRTMSG		14	/* DECnet routing messages */
     22 #define NETLINK_KOBJECT_UEVENT	15	/* Kernel messages to userspace */
     23 #define NETLINK_GENERIC		16
     24 /* leave room for NETLINK_DM (DM Events) */
     25 #define NETLINK_SCSITRANSPORT	18	/* SCSI Transports */
     26 #define NETLINK_ECRYPTFS	19
     27 #define NETLINK_RDMA		20
     28 #define NETLINK_IDLETIMER	21
     29 
     30 #define MAX_LINKS 32
     31 
     32 struct sockaddr_nl {
     33 	sa_family_t	nl_family;	/* AF_NETLINK	*/
     34 	unsigned short	nl_pad;		/* zero		*/
     35 	__u32		nl_pid;		/* port ID	*/
     36        	__u32		nl_groups;	/* multicast groups mask */
     37 };
     38 
     39 struct nlmsghdr {
     40 	__u32		nlmsg_len;	/* Length of message including header */
     41 	__u16		nlmsg_type;	/* Message content */
     42 	__u16		nlmsg_flags;	/* Additional flags */
     43 	__u32		nlmsg_seq;	/* Sequence number */
     44 	__u32		nlmsg_pid;	/* Sending process port ID */
     45 };
     46 
     47 /* Flags values */
     48 
     49 #define NLM_F_REQUEST		1	/* It is request message. 	*/
     50 #define NLM_F_MULTI		2	/* Multipart message, terminated by NLMSG_DONE */
     51 #define NLM_F_ACK		4	/* Reply with ack, with zero or error code */
     52 #define NLM_F_ECHO		8	/* Echo this request 		*/
     53 
     54 /* Modifiers to GET request */
     55 #define NLM_F_ROOT	0x100	/* specify tree	root	*/
     56 #define NLM_F_MATCH	0x200	/* return all matching	*/
     57 #define NLM_F_ATOMIC	0x400	/* atomic GET		*/
     58 #define NLM_F_DUMP	(NLM_F_ROOT|NLM_F_MATCH)
     59 
     60 /* Modifiers to NEW request */
     61 #define NLM_F_REPLACE	0x100	/* Override existing		*/
     62 #define NLM_F_EXCL	0x200	/* Do not touch, if it exists	*/
     63 #define NLM_F_CREATE	0x400	/* Create, if it does not exist	*/
     64 #define NLM_F_APPEND	0x800	/* Add to end of list		*/
     65 
     66 /*
     67    4.4BSD ADD		NLM_F_CREATE|NLM_F_EXCL
     68    4.4BSD CHANGE	NLM_F_REPLACE
     69 
     70    True CHANGE		NLM_F_CREATE|NLM_F_REPLACE
     71    Append		NLM_F_CREATE
     72    Check		NLM_F_EXCL
     73  */
     74 
     75 #define NLMSG_ALIGNTO	4U
     76 #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
     77 #define NLMSG_HDRLEN	 ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
     78 #define NLMSG_LENGTH(len) ((len)+NLMSG_ALIGN(NLMSG_HDRLEN))
     79 #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
     80 #define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
     81 #define NLMSG_NEXT(nlh,len)	 ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
     82 				  (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
     83 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
     84 			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
     85 			   (nlh)->nlmsg_len <= (len))
     86 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
     87 
     88 #define NLMSG_NOOP		0x1	/* Nothing.		*/
     89 #define NLMSG_ERROR		0x2	/* Error		*/
     90 #define NLMSG_DONE		0x3	/* End of a dump	*/
     91 #define NLMSG_OVERRUN		0x4	/* Data lost		*/
     92 
     93 #define NLMSG_MIN_TYPE		0x10	/* < 0x10: reserved control messages */
     94 
     95 struct nlmsgerr {
     96 	int		error;
     97 	struct nlmsghdr msg;
     98 };
     99 
    100 #define NETLINK_ADD_MEMBERSHIP	1
    101 #define NETLINK_DROP_MEMBERSHIP	2
    102 #define NETLINK_PKTINFO		3
    103 #define NETLINK_BROADCAST_ERROR	4
    104 #define NETLINK_NO_ENOBUFS	5
    105 
    106 struct nl_pktinfo {
    107 	__u32	group;
    108 };
    109 
    110 #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
    111 
    112 enum {
    113 	NETLINK_UNCONNECTED = 0,
    114 	NETLINK_CONNECTED,
    115 };
    116 
    117 /*
    118  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
    119  * +---------------------+- - -+- - - - - - - - - -+- - -+
    120  * |        Header       | Pad |     Payload       | Pad |
    121  * |   (struct nlattr)   | ing |                   | ing |
    122  * +---------------------+- - -+- - - - - - - - - -+- - -+
    123  *  <-------------- nlattr->nla_len -------------->
    124  */
    125 
    126 struct nlattr {
    127 	__u16           nla_len;
    128 	__u16           nla_type;
    129 };
    130 
    131 /*
    132  * nla_type (16 bits)
    133  * +---+---+-------------------------------+
    134  * | N | O | Attribute Type                |
    135  * +---+---+-------------------------------+
    136  * N := Carries nested attributes
    137  * O := Payload stored in network byte order
    138  *
    139  * Note: The N and O flag are mutually exclusive.
    140  */
    141 #define NLA_F_NESTED		(1 << 15)
    142 #define NLA_F_NET_BYTEORDER	(1 << 14)
    143 #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
    144 
    145 #define NLA_ALIGNTO		4
    146 #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
    147 #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))
    148 
    149 #ifdef __KERNEL__
    150 
    151 #include <linux/capability.h>
    152 #include <linux/skbuff.h>
    153 
    154 struct net;
    155 
    156 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
    157 {
    158 	return (struct nlmsghdr *)skb->data;
    159 }
    160 
    161 struct netlink_skb_parms {
    162 	struct ucred		creds;		/* Skb credentials	*/
    163 	__u32			pid;
    164 	__u32			dst_group;
    165 };
    166 
    167 #define NETLINK_CB(skb)		(*(struct netlink_skb_parms*)&((skb)->cb))
    168 #define NETLINK_CREDS(skb)	(&NETLINK_CB((skb)).creds)
    169 
    170 
    171 extern void netlink_table_grab(void);
    172 extern void netlink_table_ungrab(void);
    173 
    174 extern struct sock *netlink_kernel_create(struct net *net,
    175 					  int unit,unsigned int groups,
    176 					  void (*input)(struct sk_buff *skb),
    177 					  struct mutex *cb_mutex,
    178 					  struct module *module);
    179 extern void netlink_kernel_release(struct sock *sk);
    180 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
    181 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
    182 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
    183 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
    184 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
    185 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
    186 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
    187 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
    188 			     __u32 group, gfp_t allocation);
    189 extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
    190 	__u32 pid, __u32 group, gfp_t allocation,
    191 	int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
    192 	void *filter_data);
    193 extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
    194 extern int netlink_register_notifier(struct notifier_block *nb);
    195 extern int netlink_unregister_notifier(struct notifier_block *nb);
    196 
    197 /* finegrained unicast helpers: */
    198 struct sock *netlink_getsockbyfilp(struct file *filp);
    199 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
    200 		      long *timeo, struct sock *ssk);
    201 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
    202 int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
    203 
    204 /*
    205  *	skb should fit one page. This choice is good for headerless malloc.
    206  *	But we should limit to 8K so that userspace does not have to
    207  *	use enormous buffer sizes on recvmsg() calls just to avoid
    208  *	MSG_TRUNC when PAGE_SIZE is very large.
    209  */
    210 #if PAGE_SIZE < 8192UL
    211 #define NLMSG_GOODSIZE	SKB_WITH_OVERHEAD(PAGE_SIZE)
    212 #else
    213 #define NLMSG_GOODSIZE	SKB_WITH_OVERHEAD(8192UL)
    214 #endif
    215 
    216 #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
    217 
    218 
    219 struct netlink_callback {
    220 	struct sk_buff		*skb;
    221 	const struct nlmsghdr	*nlh;
    222 	int			(*dump)(struct sk_buff * skb,
    223 					struct netlink_callback *cb);
    224 	int			(*done)(struct netlink_callback *cb);
    225 	int			family;
    226 	long			args[6];
    227 };
    228 
    229 struct netlink_notify {
    230 	struct net *net;
    231 	int pid;
    232 	int protocol;
    233 };
    234 
    235 static __inline__ struct nlmsghdr *
    236 __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
    237 {
    238 	struct nlmsghdr *nlh;
    239 	int size = NLMSG_LENGTH(len);
    240 
    241 	nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
    242 	nlh->nlmsg_type = type;
    243 	nlh->nlmsg_len = size;
    244 	nlh->nlmsg_flags = flags;
    245 	nlh->nlmsg_pid = pid;
    246 	nlh->nlmsg_seq = seq;
    247 	if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
    248 		memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
    249 	return nlh;
    250 }
    251 
    252 #define NLMSG_NEW(skb, pid, seq, type, len, flags) \
    253 ({	if (unlikely(skb_tailroom(skb) < (int)NLMSG_SPACE(len))) \
    254 		goto nlmsg_failure; \
    255 	__nlmsg_put(skb, pid, seq, type, len, flags); })
    256 
    257 #define NLMSG_PUT(skb, pid, seq, type, len) \
    258 	NLMSG_NEW(skb, pid, seq, type, len, 0)
    259 
    260 extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
    261 			      const struct nlmsghdr *nlh,
    262 			      int (*dump)(struct sk_buff *skb, struct netlink_callback*),
    263 			      int (*done)(struct netlink_callback*));
    264 
    265 
    266 #define NL_NONROOT_RECV 0x1
    267 #define NL_NONROOT_SEND 0x2
    268 extern void netlink_set_nonroot(int protocol, unsigned flag);
    269 
    270 #endif /* __KERNEL__ */
    271 
    272 #endif	/* __LINUX_NETLINK_H */
    273