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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - include/linux/netlink.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_NETLINK_H
3 #define __LINUX_NETLINK_H
6 #include <linux/capability.h>
7 #include <linux/skbuff.h>
8 #include <linux/export.h>
10 #include <uapi/linux/netlink.h>
14 void do_trace_netlink_extack(const char *msg
);
16 static inline struct nlmsghdr
*nlmsg_hdr(const struct sk_buff
*skb
)
18 return (struct nlmsghdr
*)skb
->data
;
21 enum netlink_skb_flags
{
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 void netlink_table_grab(void);
40 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 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 * @policy: policy for a bad attribute
74 * @cookie: cookie data to return to userspace (for success)
75 * @cookie_len: actual cookie data length
77 struct netlink_ext_ack
{
79 const struct nlattr
*bad_attr
;
80 const struct nla_policy
*policy
;
81 u8 cookie
[NETLINK_MAX_COOKIE_LEN
];
85 /* Always use this macro, this allows later putting the
86 * message into a separate section or such for things
87 * like translation or listing all possible messages.
88 * Currently string formatting is not supported (due
89 * to the lack of an output buffer.)
91 #define NL_SET_ERR_MSG(extack, msg) do { \
92 static const char __msg[] = msg; \
93 struct netlink_ext_ack *__extack = (extack); \
95 do_trace_netlink_extack(__msg); \
98 __extack->_msg = __msg; \
101 #define NL_SET_ERR_MSG_MOD(extack, msg) \
102 NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)
104 #define NL_SET_BAD_ATTR_POLICY(extack, attr, pol) do { \
106 (extack)->bad_attr = (attr); \
107 (extack)->policy = (pol); \
111 #define NL_SET_BAD_ATTR(extack, attr) NL_SET_BAD_ATTR_POLICY(extack, attr, NULL)
113 #define NL_SET_ERR_MSG_ATTR_POL(extack, attr, pol, msg) do { \
114 static const char __msg[] = msg; \
115 struct netlink_ext_ack *__extack = (extack); \
117 do_trace_netlink_extack(__msg); \
120 __extack->_msg = __msg; \
121 __extack->bad_attr = (attr); \
122 __extack->policy = (pol); \
126 #define NL_SET_ERR_MSG_ATTR(extack, attr, msg) \
127 NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg)
129 static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack
*extack
,
134 memcpy(extack
->cookie
, &cookie
, sizeof(cookie
));
135 extack
->cookie_len
= sizeof(cookie
);
138 static inline void nl_set_extack_cookie_u32(struct netlink_ext_ack
*extack
,
143 memcpy(extack
->cookie
, &cookie
, sizeof(cookie
));
144 extack
->cookie_len
= sizeof(cookie
);
147 void netlink_kernel_release(struct sock
*sk
);
148 int __netlink_change_ngroups(struct sock
*sk
, unsigned int groups
);
149 int netlink_change_ngroups(struct sock
*sk
, unsigned int groups
);
150 void __netlink_clear_multicast_users(struct sock
*sk
, unsigned int group
);
151 void netlink_ack(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, int err
,
152 const struct netlink_ext_ack
*extack
);
153 int netlink_has_listeners(struct sock
*sk
, unsigned int group
);
154 bool netlink_strict_get_check(struct sk_buff
*skb
);
156 int netlink_unicast(struct sock
*ssk
, struct sk_buff
*skb
, __u32 portid
, int nonblock
);
157 int netlink_broadcast(struct sock
*ssk
, struct sk_buff
*skb
, __u32 portid
,
158 __u32 group
, gfp_t allocation
);
159 int netlink_broadcast_filtered(struct sock
*ssk
, struct sk_buff
*skb
,
160 __u32 portid
, __u32 group
, gfp_t allocation
,
161 int (*filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
),
163 int netlink_set_err(struct sock
*ssk
, __u32 portid
, __u32 group
, int code
);
164 int netlink_register_notifier(struct notifier_block
*nb
);
165 int netlink_unregister_notifier(struct notifier_block
*nb
);
167 /* finegrained unicast helpers: */
168 struct sock
*netlink_getsockbyfilp(struct file
*filp
);
169 int netlink_attachskb(struct sock
*sk
, struct sk_buff
*skb
,
170 long *timeo
, struct sock
*ssk
);
171 void netlink_detachskb(struct sock
*sk
, struct sk_buff
*skb
);
172 int netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
);
174 static inline struct sk_buff
*
175 netlink_skb_clone(struct sk_buff
*skb
, gfp_t gfp_mask
)
177 struct sk_buff
*nskb
;
179 nskb
= skb_clone(skb
, gfp_mask
);
183 /* This is a large skb, set destructor callback to release head */
184 if (is_vmalloc_addr(skb
->head
))
185 nskb
->destructor
= skb
->destructor
;
191 * skb should fit one page. This choice is good for headerless malloc.
192 * But we should limit to 8K so that userspace does not have to
193 * use enormous buffer sizes on recvmsg() calls just to avoid
194 * MSG_TRUNC when PAGE_SIZE is very large.
196 #if PAGE_SIZE < 8192UL
197 #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
199 #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
202 #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
205 struct netlink_callback
{
207 const struct nlmsghdr
*nlh
;
208 int (*dump
)(struct sk_buff
* skb
,
209 struct netlink_callback
*cb
);
210 int (*done
)(struct netlink_callback
*cb
);
212 /* the module that dump function belong to */
213 struct module
*module
;
214 struct netlink_ext_ack
*extack
;
218 unsigned int prev_seq
, seq
;
223 /* args is deprecated. Cast a struct over ctx instead
224 * for proper type safety.
230 struct netlink_notify
{
237 __nlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
, int type
, int len
, int flags
);
239 struct netlink_dump_control
{
240 int (*start
)(struct netlink_callback
*);
241 int (*dump
)(struct sk_buff
*skb
, struct netlink_callback
*);
242 int (*done
)(struct netlink_callback
*);
244 struct module
*module
;
248 int __netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
249 const struct nlmsghdr
*nlh
,
250 struct netlink_dump_control
*control
);
251 static inline int netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
252 const struct nlmsghdr
*nlh
,
253 struct netlink_dump_control
*control
)
255 if (!control
->module
)
256 control
->module
= THIS_MODULE
;
258 return __netlink_dump_start(ssk
, skb
, nlh
, control
);
262 struct net_device
*dev
;
263 struct module
*module
;
264 struct list_head list
;
267 int netlink_add_tap(struct netlink_tap
*nt
);
268 int netlink_remove_tap(struct netlink_tap
*nt
);
270 bool __netlink_ns_capable(const struct netlink_skb_parms
*nsp
,
271 struct user_namespace
*ns
, int cap
);
272 bool netlink_ns_capable(const struct sk_buff
*skb
,
273 struct user_namespace
*ns
, int cap
);
274 bool netlink_capable(const struct sk_buff
*skb
, int cap
);
275 bool netlink_net_capable(const struct sk_buff
*skb
, int cap
);
277 #endif /* __LINUX_NETLINK_H */