1
2#ifndef __LINUX_NETLINK_H
3#define __LINUX_NETLINK_H
4
5
6#include <linux/capability.h>
7#include <linux/skbuff.h>
8#include <linux/export.h>
9#include <net/scm.h>
10#include <uapi/linux/netlink.h>
11
12struct net;
13
14static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
15{
16 return (struct nlmsghdr *)skb->data;
17}
18
19enum netlink_skb_flags {
20 NETLINK_SKB_DST = 0x8,
21};
22
23struct netlink_skb_parms {
24 struct scm_creds creds;
25 __u32 portid;
26 __u32 dst_group;
27 __u32 flags;
28 struct sock *sk;
29 bool nsid_is_set;
30 int nsid;
31};
32
33#define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb))
34#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
35
36
37extern void netlink_table_grab(void);
38extern void netlink_table_ungrab(void);
39
40#define NL_CFG_F_NONROOT_RECV (1 << 0)
41#define NL_CFG_F_NONROOT_SEND (1 << 1)
42
43
44struct netlink_kernel_cfg {
45 unsigned int groups;
46 unsigned int flags;
47 void (*input)(struct sk_buff *skb);
48 struct mutex *cb_mutex;
49 int (*bind)(struct net *net, int group);
50 void (*unbind)(struct net *net, int group);
51 bool (*compare)(struct net *net, struct sock *sk);
52};
53
54extern struct sock *__netlink_kernel_create(struct net *net, int unit,
55 struct module *module,
56 struct netlink_kernel_cfg *cfg);
57static inline struct sock *
58netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
59{
60 return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
61}
62
63
64#define NETLINK_MAX_COOKIE_LEN 20
65
66
67
68
69
70
71
72
73
74struct netlink_ext_ack {
75 const char *_msg;
76 const struct nlattr *bad_attr;
77 u8 cookie[NETLINK_MAX_COOKIE_LEN];
78 u8 cookie_len;
79};
80
81
82
83
84
85
86
87#define NL_SET_ERR_MSG(extack, msg) do { \
88 static const char __msg[] = msg; \
89 struct netlink_ext_ack *__extack = (extack); \
90 \
91 if (__extack) \
92 __extack->_msg = __msg; \
93} while (0)
94
95#define NL_SET_ERR_MSG_MOD(extack, msg) \
96 NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)
97
98#define NL_SET_BAD_ATTR(extack, attr) do { \
99 if ((extack)) \
100 (extack)->bad_attr = (attr); \
101} while (0)
102
103#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do { \
104 static const char __msg[] = msg; \
105 struct netlink_ext_ack *__extack = (extack); \
106 \
107 if (__extack) { \
108 __extack->_msg = __msg; \
109 __extack->bad_attr = (attr); \
110 } \
111} while (0)
112
113extern void netlink_kernel_release(struct sock *sk);
114extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
115extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
116extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
117extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
118 const struct netlink_ext_ack *extack);
119extern int netlink_has_listeners(struct sock *sk, unsigned int group);
120
121extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
122extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
123 __u32 group, gfp_t allocation);
124extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
125 __u32 portid, __u32 group, gfp_t allocation,
126 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
127 void *filter_data);
128extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
129extern int netlink_register_notifier(struct notifier_block *nb);
130extern int netlink_unregister_notifier(struct notifier_block *nb);
131
132
133struct sock *netlink_getsockbyfilp(struct file *filp);
134int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
135 long *timeo, struct sock *ssk);
136void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
137int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
138
139static inline struct sk_buff *
140netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
141{
142 struct sk_buff *nskb;
143
144 nskb = skb_clone(skb, gfp_mask);
145 if (!nskb)
146 return NULL;
147
148
149 if (is_vmalloc_addr(skb->head))
150 nskb->destructor = skb->destructor;
151
152 return nskb;
153}
154
155
156
157
158
159
160
161#if PAGE_SIZE < 8192UL
162#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
163#else
164#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
165#endif
166
167#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
168
169
170struct netlink_callback {
171 struct sk_buff *skb;
172 const struct nlmsghdr *nlh;
173 int (*dump)(struct sk_buff * skb,
174 struct netlink_callback *cb);
175 int (*done)(struct netlink_callback *cb);
176 void *data;
177
178 struct module *module;
179 u16 family;
180 u16 min_dump_alloc;
181 unsigned int prev_seq, seq;
182 long args[6];
183};
184
185struct netlink_notify {
186 struct net *net;
187 u32 portid;
188 int protocol;
189};
190
191struct nlmsghdr *
192__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
193
194struct netlink_dump_control {
195 int (*start)(struct netlink_callback *);
196 int (*dump)(struct sk_buff *skb, struct netlink_callback *);
197 int (*done)(struct netlink_callback *);
198 void *data;
199 struct module *module;
200 u16 min_dump_alloc;
201};
202
203extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
204 const struct nlmsghdr *nlh,
205 struct netlink_dump_control *control);
206static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
207 const struct nlmsghdr *nlh,
208 struct netlink_dump_control *control)
209{
210 if (!control->module)
211 control->module = THIS_MODULE;
212
213 return __netlink_dump_start(ssk, skb, nlh, control);
214}
215
216struct netlink_tap {
217 struct net_device *dev;
218 struct module *module;
219 struct list_head list;
220};
221
222extern int netlink_add_tap(struct netlink_tap *nt);
223extern int netlink_remove_tap(struct netlink_tap *nt);
224
225bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
226 struct user_namespace *ns, int cap);
227bool netlink_ns_capable(const struct sk_buff *skb,
228 struct user_namespace *ns, int cap);
229bool netlink_capable(const struct sk_buff *skb, int cap);
230bool netlink_net_capable(const struct sk_buff *skb, int cap);
231
232#endif
233