1 #ifndef __LINUX_NETLINK_H
2 #define __LINUX_NETLINK_H
3
4
5 #include <linux/capability.h>
6 #include <linux/skbuff.h>
7 #include <linux/export.h>
8 #include <net/scm.h>
9 #include <uapi/linux/netlink.h>
10
11 struct net;
12
nlmsg_hdr(const struct sk_buff * skb)13 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
14 {
15 return (struct nlmsghdr *)skb->data;
16 }
17
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 */
23 };
24
25 struct netlink_skb_parms {
26 struct scm_creds creds; /* Skb credentials */
27 __u32 portid;
28 __u32 dst_group;
29 __u32 flags;
30 struct sock *sk;
31 };
32
33 #define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb))
34 #define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
35
36
37 extern void netlink_table_grab(void);
38 extern 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 /* optional Netlink kernel configuration parameters */
44 struct 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
54 extern struct sock *__netlink_kernel_create(struct net *net, int unit,
55 struct module *module,
56 struct netlink_kernel_cfg *cfg);
57 static inline struct sock *
netlink_kernel_create(struct net * net,int unit,struct netlink_kernel_cfg * cfg)58 netlink_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 extern void netlink_kernel_release(struct sock *sk);
64 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
65 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
66 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
67 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
68 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
69 extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
70 u32 dst_portid, gfp_t gfp_mask);
71 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
72 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
73 __u32 group, gfp_t allocation);
74 extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
75 __u32 portid, __u32 group, gfp_t allocation,
76 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
77 void *filter_data);
78 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
79 extern int netlink_register_notifier(struct notifier_block *nb);
80 extern int netlink_unregister_notifier(struct notifier_block *nb);
81
82 /* finegrained unicast helpers: */
83 struct sock *netlink_getsockbyfilp(struct file *filp);
84 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
85 long *timeo, struct sock *ssk);
86 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
87 int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
88
89 static inline struct sk_buff *
netlink_skb_clone(struct sk_buff * skb,gfp_t gfp_mask)90 netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
91 {
92 struct sk_buff *nskb;
93
94 nskb = skb_clone(skb, gfp_mask);
95 if (!nskb)
96 return NULL;
97
98 /* This is a large skb, set destructor callback to release head */
99 if (is_vmalloc_addr(skb->head))
100 nskb->destructor = skb->destructor;
101
102 return nskb;
103 }
104
105 /*
106 * skb should fit one page. This choice is good for headerless malloc.
107 * But we should limit to 8K so that userspace does not have to
108 * use enormous buffer sizes on recvmsg() calls just to avoid
109 * MSG_TRUNC when PAGE_SIZE is very large.
110 */
111 #if PAGE_SIZE < 8192UL
112 #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
113 #else
114 #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
115 #endif
116
117 #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
118
119
120 struct netlink_callback {
121 struct sk_buff *skb;
122 const struct nlmsghdr *nlh;
123 int (*dump)(struct sk_buff * skb,
124 struct netlink_callback *cb);
125 int (*done)(struct netlink_callback *cb);
126 void *data;
127 /* the module that dump function belong to */
128 struct module *module;
129 u16 family;
130 u16 min_dump_alloc;
131 unsigned int prev_seq, seq;
132 long args[6];
133 };
134
135 struct netlink_notify {
136 struct net *net;
137 u32 portid;
138 int protocol;
139 };
140
141 struct nlmsghdr *
142 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
143
144 struct netlink_dump_control {
145 int (*dump)(struct sk_buff *skb, struct netlink_callback *);
146 int (*done)(struct netlink_callback *);
147 void *data;
148 struct module *module;
149 u16 min_dump_alloc;
150 };
151
152 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
153 const struct nlmsghdr *nlh,
154 struct netlink_dump_control *control);
netlink_dump_start(struct sock * ssk,struct sk_buff * skb,const struct nlmsghdr * nlh,struct netlink_dump_control * control)155 static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
156 const struct nlmsghdr *nlh,
157 struct netlink_dump_control *control)
158 {
159 if (!control->module)
160 control->module = THIS_MODULE;
161
162 return __netlink_dump_start(ssk, skb, nlh, control);
163 }
164
165 struct netlink_tap {
166 struct net_device *dev;
167 struct module *module;
168 struct list_head list;
169 };
170
171 extern int netlink_add_tap(struct netlink_tap *nt);
172 extern int netlink_remove_tap(struct netlink_tap *nt);
173
174 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
175 struct user_namespace *ns, int cap);
176 bool netlink_ns_capable(const struct sk_buff *skb,
177 struct user_namespace *ns, int cap);
178 bool netlink_capable(const struct sk_buff *skb, int cap);
179 bool netlink_net_capable(const struct sk_buff *skb, int cap);
180
181 #endif /* __LINUX_NETLINK_H */
182