Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
65/* this can be increased when necessary - don't expose to userland */
66#define NETLINK_MAX_COOKIE_LEN 20
67
68/**
69 * struct netlink_ext_ack - netlink extended ACK report struct
70 * @_msg: message string to report - don't access directly, use
71 * %NL_SET_ERR_MSG
72 * @bad_attr: attribute with error
73 * @cookie: cookie data to return to userspace (for success)
74 * @cookie_len: actual cookie data length
75 */
76struct netlink_ext_ack {
77 const char *_msg;
78 const struct nlattr *bad_attr;
79 u8 cookie[NETLINK_MAX_COOKIE_LEN];
80 u8 cookie_len;
81};
82
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.)
88 */
89#define NL_SET_ERR_MSG(extack, msg) do { \
90 static const char __msg[] = (msg); \
91 struct netlink_ext_ack *__extack = (extack); \
92 \
93 if (__extack) \
94 __extack->_msg = __msg; \
95} while (0)
96
97#define NL_SET_ERR_MSG_MOD(extack, msg) \
98 NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)
99
100#define NL_SET_BAD_ATTR(extack, attr) do { \
101 if ((extack)) \
102 (extack)->bad_attr = (attr); \
103} while (0)
104
105#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do { \
106 static const char __msg[] = (msg); \
107 struct netlink_ext_ack *__extack = (extack); \
108 \
109 if (__extack) { \
110 __extack->_msg = __msg; \
111 __extack->bad_attr = (attr); \
112 } \
113} while (0)
114
115extern void netlink_kernel_release(struct sock *sk);
116extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
117extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
118extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
119extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
120 const struct netlink_ext_ack *extack);
121extern int netlink_has_listeners(struct sock *sk, unsigned int group);
122
123extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
124extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
125 __u32 group, gfp_t allocation);
126extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
127 __u32 portid, __u32 group, gfp_t allocation,
128 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
129 void *filter_data);
130extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
131extern int netlink_register_notifier(struct notifier_block *nb);
132extern int netlink_unregister_notifier(struct notifier_block *nb);
133
134/* finegrained unicast helpers: */
135struct sock *netlink_getsockbyfilp(struct file *filp);
136int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
137 long *timeo, struct sock *ssk);
138void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
139int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
140
141static inline struct sk_buff *
142netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
143{
144 struct sk_buff *nskb;
145
146 nskb = skb_clone(skb, gfp_mask);
147 if (!nskb)
148 return NULL;
149
150 /* This is a large skb, set destructor callback to release head */
151 if (is_vmalloc_addr(skb->head))
152 nskb->destructor = skb->destructor;
153
154 return nskb;
155}
156
157/*
158 * skb should fit one page. This choice is good for headerless malloc.
159 * But we should limit to 8K so that userspace does not have to
160 * use enormous buffer sizes on recvmsg() calls just to avoid
161 * MSG_TRUNC when PAGE_SIZE is very large.
162 */
163#if PAGE_SIZE < 8192UL
164#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
165#else
166#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
167#endif
168
169#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
170
171
172struct netlink_callback {
173 struct sk_buff *skb;
174 const struct nlmsghdr *nlh;
175 int (*start)(struct netlink_callback *);
176 int (*dump)(struct sk_buff * skb,
177 struct netlink_callback *cb);
178 int (*done)(struct netlink_callback *cb);
179 void *data;
180 /* the module that dump function belong to */
181 struct module *module;
182 u16 family;
183 u16 min_dump_alloc;
184 unsigned int prev_seq, seq;
185 long args[6];
186};
187
188struct netlink_notify {
189 struct net *net;
190 u32 portid;
191 int protocol;
192};
193
194struct nlmsghdr *
195__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
196
197struct netlink_dump_control {
198 int (*start)(struct netlink_callback *);
199 int (*dump)(struct sk_buff *skb, struct netlink_callback *);
200 int (*done)(struct netlink_callback *);
201 void *data;
202 struct module *module;
203 u16 min_dump_alloc;
204};
205
206extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
207 const struct nlmsghdr *nlh,
208 struct netlink_dump_control *control);
209static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
210 const struct nlmsghdr *nlh,
211 struct netlink_dump_control *control)
212{
213 if (!control->module)
214 control->module = THIS_MODULE;
215
216 return __netlink_dump_start(ssk, skb, nlh, control);
217}
218
219struct netlink_tap {
220 struct net_device *dev;
221 struct module *module;
222 struct list_head list;
223};
224
225extern int netlink_add_tap(struct netlink_tap *nt);
226extern int netlink_remove_tap(struct netlink_tap *nt);
227
228bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
229 struct user_namespace *ns, int cap);
230bool netlink_ns_capable(const struct sk_buff *skb,
231 struct user_namespace *ns, int cap);
232bool netlink_capable(const struct sk_buff *skb, int cap);
233bool netlink_net_capable(const struct sk_buff *skb, int cap);
234
235#endif /* __LINUX_NETLINK_H */