projects/linux·blob v4.8 · refs

184 lines · 5.5 KiB

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
11struct net;
12
13static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
14{
15 return (struct nlmsghdr *)skb->data;
16}
17
18enum 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
25struct 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 bool nsid_is_set;
32 int nsid;
33};
34
35#define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb))
36#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
37
38
39extern void netlink_table_grab(void);
40extern void netlink_table_ungrab(void);
41
42#define NL_CFG_F_NONROOT_RECV (1 << 0)
43#define NL_CFG_F_NONROOT_SEND (1 << 1)
44
45/* optional Netlink kernel configuration parameters */
46struct netlink_kernel_cfg {
47 unsigned int groups;
48 unsigned int flags;
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);
54};
55
56extern struct sock *__netlink_kernel_create(struct net *net, int unit,
57 struct module *module,
58 struct netlink_kernel_cfg *cfg);
59static inline struct sock *
60netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
61{
62 return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
63}
64
65extern void netlink_kernel_release(struct sock *sk);
66extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
67extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
68extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
69extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
70extern int netlink_has_listeners(struct sock *sk, unsigned int group);
71
72extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
73extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
74 __u32 group, gfp_t allocation);
75extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
76 __u32 portid, __u32 group, gfp_t allocation,
77 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
78 void *filter_data);
79extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
80extern int netlink_register_notifier(struct notifier_block *nb);
81extern int netlink_unregister_notifier(struct notifier_block *nb);
82
83/* finegrained unicast helpers: */
84struct sock *netlink_getsockbyfilp(struct file *filp);
85int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
86 long *timeo, struct sock *ssk);
87void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
88int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
89
90static inline struct sk_buff *
91netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
92{
93 struct sk_buff *nskb;
94
95 nskb = skb_clone(skb, gfp_mask);
96 if (!nskb)
97 return NULL;
98
99 /* This is a large skb, set destructor callback to release head */
100 if (is_vmalloc_addr(skb->head))
101 nskb->destructor = skb->destructor;
102
103 return nskb;
104}
105
106/*
107 * skb should fit one page. This choice is good for headerless malloc.
108 * But we should limit to 8K so that userspace does not have to
109 * use enormous buffer sizes on recvmsg() calls just to avoid
110 * MSG_TRUNC when PAGE_SIZE is very large.
111 */
112#if PAGE_SIZE < 8192UL
113#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
114#else
115#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
116#endif
117
118#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
119
120
121struct netlink_callback {
122 struct sk_buff *skb;
123 const struct nlmsghdr *nlh;
124 int (*start)(struct netlink_callback *);
125 int (*dump)(struct sk_buff * skb,
126 struct netlink_callback *cb);
127 int (*done)(struct netlink_callback *cb);
128 void *data;
129 /* the module that dump function belong to */
130 struct module *module;
131 u16 family;
132 u16 min_dump_alloc;
133 unsigned int prev_seq, seq;
134 long args[6];
135};
136
137struct netlink_notify {
138 struct net *net;
139 u32 portid;
140 int protocol;
141};
142
143struct nlmsghdr *
144__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
145
146struct netlink_dump_control {
147 int (*start)(struct netlink_callback *);
148 int (*dump)(struct sk_buff *skb, struct netlink_callback *);
149 int (*done)(struct netlink_callback *);
150 void *data;
151 struct module *module;
152 u16 min_dump_alloc;
153};
154
155extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
156 const struct nlmsghdr *nlh,
157 struct netlink_dump_control *control);
158static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
159 const struct nlmsghdr *nlh,
160 struct netlink_dump_control *control)
161{
162 if (!control->module)
163 control->module = THIS_MODULE;
164
165 return __netlink_dump_start(ssk, skb, nlh, control);
166}
167
168struct netlink_tap {
169 struct net_device *dev;
170 struct module *module;
171 struct list_head list;
172};
173
174extern int netlink_add_tap(struct netlink_tap *nt);
175extern int netlink_remove_tap(struct netlink_tap *nt);
176
177bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
178 struct user_namespace *ns, int cap);
179bool netlink_ns_capable(const struct sk_buff *skb,
180 struct user_namespace *ns, int cap);
181bool netlink_capable(const struct sk_buff *skb, int cap);
182bool netlink_net_capable(const struct sk_buff *skb, int cap);
183
184#endif /* __LINUX_NETLINK_H */