1 #ifndef __LINUX_NETLINK_H
2 #define __LINUX_NETLINK_H
5 #include <linux/capability.h>
6 #include <linux/skbuff.h>
7 #include <linux/export.h>
9 #include <uapi/linux/netlink.h>
13 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
15 return (struct nlmsghdr *)skb->data;
18 enum netlink_skb_flags {
19 NETLINK_SKB_MMAPED = 0x1, /* Packet data is mmaped */
20 NETLINK_SKB_TX = 0x2, /* Packet was sent by userspace */
21 NETLINK_SKB_DELIVERED = 0x4, /* Packet was delivered */
22 NETLINK_SKB_DST = 0x8, /* Dst set in sendto or sendmsg */
25 struct netlink_skb_parms {
26 struct scm_creds creds; /* Skb credentials */
35 #define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb))
36 #define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
39 extern void netlink_table_grab(void);
40 extern void netlink_table_ungrab(void);
42 #define NL_CFG_F_NONROOT_RECV (1 << 0)
43 #define NL_CFG_F_NONROOT_SEND (1 << 1)
45 /* optional Netlink kernel configuration parameters */
46 struct netlink_kernel_cfg {
49 void (*input)(struct sk_buff *skb);
50 struct mutex *cb_mutex;
51 int (*bind)(struct net *net, int group);
52 void (*unbind)(struct net *net, int group);
53 bool (*compare)(struct net *net, struct sock *sk);
56 extern struct sock *__netlink_kernel_create(struct net *net, int unit,
57 struct module *module,
58 struct netlink_kernel_cfg *cfg);
59 static inline struct sock *
60 netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
62 return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
65 /* this can be increased when necessary - don't expose to userland */
66 #define NETLINK_MAX_COOKIE_LEN 20
69 * struct netlink_ext_ack - netlink extended ACK report struct
70 * @_msg: message string to report - don't access directly, use
72 * @bad_attr: attribute with error
73 * @cookie: cookie data to return to userspace (for success)
74 * @cookie_len: actual cookie data length
76 struct netlink_ext_ack {
78 const struct nlattr *bad_attr;
79 u8 cookie[NETLINK_MAX_COOKIE_LEN];
83 /* Always use this macro, this allows later putting the
84 * message into a separate section or such for things
85 * like translation or listing all possible messages.
86 * Currently string formatting is not supported (due
87 * to the lack of an output buffer.)
89 #define NL_SET_ERR_MSG(extack, msg) do { \
90 static const char _msg[] = (msg); \
92 (extack)->_msg = _msg; \
95 extern void netlink_kernel_release(struct sock *sk);
96 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
97 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
98 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
99 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
100 const struct netlink_ext_ack *extack);
101 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
103 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
104 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
105 __u32 group, gfp_t allocation);
106 extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
107 __u32 portid, __u32 group, gfp_t allocation,
108 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
110 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
111 extern int netlink_register_notifier(struct notifier_block *nb);
112 extern int netlink_unregister_notifier(struct notifier_block *nb);
114 /* finegrained unicast helpers: */
115 struct sock *netlink_getsockbyfilp(struct file *filp);
116 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
117 long *timeo, struct sock *ssk);
118 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
119 int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
121 static inline struct sk_buff *
122 netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
124 struct sk_buff *nskb;
126 nskb = skb_clone(skb, gfp_mask);
130 /* This is a large skb, set destructor callback to release head */
131 if (is_vmalloc_addr(skb->head))
132 nskb->destructor = skb->destructor;
138 * skb should fit one page. This choice is good for headerless malloc.
139 * But we should limit to 8K so that userspace does not have to
140 * use enormous buffer sizes on recvmsg() calls just to avoid
141 * MSG_TRUNC when PAGE_SIZE is very large.
143 #if PAGE_SIZE < 8192UL
144 #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
146 #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
149 #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
152 struct netlink_callback {
154 const struct nlmsghdr *nlh;
155 int (*start)(struct netlink_callback *);
156 int (*dump)(struct sk_buff * skb,
157 struct netlink_callback *cb);
158 int (*done)(struct netlink_callback *cb);
160 /* the module that dump function belong to */
161 struct module *module;
164 unsigned int prev_seq, seq;
168 struct netlink_notify {
175 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
177 struct netlink_dump_control {
178 int (*start)(struct netlink_callback *);
179 int (*dump)(struct sk_buff *skb, struct netlink_callback *);
180 int (*done)(struct netlink_callback *);
182 struct module *module;
186 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
187 const struct nlmsghdr *nlh,
188 struct netlink_dump_control *control);
189 static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
190 const struct nlmsghdr *nlh,
191 struct netlink_dump_control *control)
193 if (!control->module)
194 control->module = THIS_MODULE;
196 return __netlink_dump_start(ssk, skb, nlh, control);
200 struct net_device *dev;
201 struct module *module;
202 struct list_head list;
205 extern int netlink_add_tap(struct netlink_tap *nt);
206 extern int netlink_remove_tap(struct netlink_tap *nt);
208 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
209 struct user_namespace *ns, int cap);
210 bool netlink_ns_capable(const struct sk_buff *skb,
211 struct user_namespace *ns, int cap);
212 bool netlink_capable(const struct sk_buff *skb, int cap);
213 bool netlink_net_capable(const struct sk_buff *skb, int cap);
215 #endif /* __LINUX_NETLINK_H */