Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef __LINUX_NETLINK_H |
3 | #define __LINUX_NETLINK_H | |
4 | ||
1da177e4 LT |
5 | |
6 | #include <linux/capability.h> | |
7 | #include <linux/skbuff.h> | |
abb17e6c | 8 | #include <linux/export.h> |
dbe9a417 | 9 | #include <net/scm.h> |
607ca46e | 10 | #include <uapi/linux/netlink.h> |
1da177e4 | 11 | |
56b49f4b OW |
12 | struct net; |
13 | ||
b529ccf2 ACM |
14 | static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb) |
15 | { | |
16 | return (struct nlmsghdr *)skb->data; | |
17 | } | |
18 | ||
9652e931 | 19 | enum netlink_skb_flags { |
2d7a85f4 | 20 | NETLINK_SKB_DST = 0x8, /* Dst set in sendto or sendmsg */ |
9652e931 PM |
21 | }; |
22 | ||
d94d9fee | 23 | struct netlink_skb_parms { |
dbe9a417 | 24 | struct scm_creds creds; /* Skb credentials */ |
15e47304 | 25 | __u32 portid; |
d629b836 | 26 | __u32 dst_group; |
9652e931 | 27 | __u32 flags; |
e32123e5 | 28 | struct sock *sk; |
59324cf3 ND |
29 | bool nsid_is_set; |
30 | int nsid; | |
1da177e4 LT |
31 | }; |
32 | ||
33 | #define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb)) | |
34 | #define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds) | |
35 | ||
36 | ||
d136f1bd JB |
37 | extern void netlink_table_grab(void); |
38 | extern void netlink_table_ungrab(void); | |
39 | ||
9785e10a PNA |
40 | #define NL_CFG_F_NONROOT_RECV (1 << 0) |
41 | #define NL_CFG_F_NONROOT_SEND (1 << 1) | |
42 | ||
a31f2d17 PNA |
43 | /* optional Netlink kernel configuration parameters */ |
44 | struct netlink_kernel_cfg { | |
45 | unsigned int groups; | |
c9d2ea96 | 46 | unsigned int flags; |
a31f2d17 PNA |
47 | void (*input)(struct sk_buff *skb); |
48 | struct mutex *cb_mutex; | |
023e2cfa JB |
49 | int (*bind)(struct net *net, int group); |
50 | void (*unbind)(struct net *net, int group); | |
da12c90e | 51 | bool (*compare)(struct net *net, struct sock *sk); |
a31f2d17 PNA |
52 | }; |
53 | ||
9f00d977 PNA |
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 * | |
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 | ||
ba0dc5f6 JB |
63 | /* this can be increased when necessary - don't expose to userland */ |
64 | #define NETLINK_MAX_COOKIE_LEN 20 | |
65 | ||
2d4bc933 JB |
66 | /** |
67 | * struct netlink_ext_ack - netlink extended ACK report struct | |
68 | * @_msg: message string to report - don't access directly, use | |
69 | * %NL_SET_ERR_MSG | |
70 | * @bad_attr: attribute with error | |
ba0dc5f6 JB |
71 | * @cookie: cookie data to return to userspace (for success) |
72 | * @cookie_len: actual cookie data length | |
2d4bc933 JB |
73 | */ |
74 | struct netlink_ext_ack { | |
75 | const char *_msg; | |
76 | const struct nlattr *bad_attr; | |
ba0dc5f6 JB |
77 | u8 cookie[NETLINK_MAX_COOKIE_LEN]; |
78 | u8 cookie_len; | |
2d4bc933 JB |
79 | }; |
80 | ||
81 | /* Always use this macro, this allows later putting the | |
82 | * message into a separate section or such for things | |
83 | * like translation or listing all possible messages. | |
84 | * Currently string formatting is not supported (due | |
85 | * to the lack of an output buffer.) | |
86 | */ | |
4d463c4d DB |
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; \ | |
2d4bc933 JB |
93 | } while (0) |
94 | ||
4d463c4d DB |
95 | #define NL_SET_ERR_MSG_MOD(extack, msg) \ |
96 | NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg) | |
45d9b378 | 97 | |
c3ab2b4e DA |
98 | #define NL_SET_BAD_ATTR(extack, attr) do { \ |
99 | if ((extack)) \ | |
100 | (extack)->bad_attr = (attr); \ | |
101 | } while (0) | |
102 | ||
9ae28727 DA |
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 | ||
b7c6ba6e | 113 | extern void netlink_kernel_release(struct sock *sk); |
d136f1bd | 114 | extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups); |
b4ff4f04 | 115 | extern int netlink_change_ngroups(struct sock *sk, unsigned int groups); |
b8273570 | 116 | extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group); |
2d4bc933 JB |
117 | extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, |
118 | const struct netlink_ext_ack *extack); | |
4277a083 | 119 | extern int netlink_has_listeners(struct sock *sk, unsigned int group); |
6bb0fef4 | 120 | |
15e47304 EB |
121 | extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); |
122 | extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, | |
dd0fc66f | 123 | __u32 group, gfp_t allocation); |
910a7e90 | 124 | extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, |
15e47304 | 125 | __u32 portid, __u32 group, gfp_t allocation, |
910a7e90 EB |
126 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), |
127 | void *filter_data); | |
15e47304 | 128 | extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code); |
1da177e4 LT |
129 | extern int netlink_register_notifier(struct notifier_block *nb); |
130 | extern int netlink_unregister_notifier(struct notifier_block *nb); | |
131 | ||
132 | /* finegrained unicast helpers: */ | |
133 | struct sock *netlink_getsockbyfilp(struct file *filp); | |
9457afee | 134 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 135 | long *timeo, struct sock *ssk); |
1da177e4 | 136 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb); |
7ee015e0 | 137 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb); |
1da177e4 | 138 | |
3a36515f PN |
139 | static inline struct sk_buff * |
140 | netlink_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 | /* This is a large skb, set destructor callback to release head */ | |
149 | if (is_vmalloc_addr(skb->head)) | |
150 | nskb->destructor = skb->destructor; | |
151 | ||
152 | return nskb; | |
153 | } | |
154 | ||
1da177e4 LT |
155 | /* |
156 | * skb should fit one page. This choice is good for headerless malloc. | |
fc910a27 DM |
157 | * But we should limit to 8K so that userspace does not have to |
158 | * use enormous buffer sizes on recvmsg() calls just to avoid | |
159 | * MSG_TRUNC when PAGE_SIZE is very large. | |
1da177e4 | 160 | */ |
fc910a27 DM |
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 | ||
339bf98f | 167 | #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN) |
1da177e4 LT |
168 | |
169 | ||
d94d9fee | 170 | struct netlink_callback { |
3a6c2b41 PM |
171 | struct sk_buff *skb; |
172 | const struct nlmsghdr *nlh; | |
fc9e50f5 | 173 | int (*start)(struct netlink_callback *); |
3a6c2b41 PM |
174 | int (*dump)(struct sk_buff * skb, |
175 | struct netlink_callback *cb); | |
176 | int (*done)(struct netlink_callback *cb); | |
7175c883 | 177 | void *data; |
6dc878a8 G |
178 | /* the module that dump function belong to */ |
179 | struct module *module; | |
c7ac8679 GR |
180 | u16 family; |
181 | u16 min_dump_alloc; | |
670dc283 | 182 | unsigned int prev_seq, seq; |
3a6c2b41 | 183 | long args[6]; |
1da177e4 LT |
184 | }; |
185 | ||
d94d9fee | 186 | struct netlink_notify { |
b4b51029 | 187 | struct net *net; |
0392d099 | 188 | u32 portid; |
1da177e4 LT |
189 | int protocol; |
190 | }; | |
191 | ||
a46621a3 | 192 | struct nlmsghdr * |
15e47304 | 193 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags); |
1da177e4 | 194 | |
80d326fa | 195 | struct netlink_dump_control { |
fc9e50f5 | 196 | int (*start)(struct netlink_callback *); |
80d326fa | 197 | int (*dump)(struct sk_buff *skb, struct netlink_callback *); |
6dc878a8 | 198 | int (*done)(struct netlink_callback *); |
7175c883 | 199 | void *data; |
6dc878a8 | 200 | struct module *module; |
80d326fa PNA |
201 | u16 min_dump_alloc; |
202 | }; | |
203 | ||
6dc878a8 G |
204 | extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
205 | const struct nlmsghdr *nlh, | |
206 | struct netlink_dump_control *control); | |
207 | static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
208 | const struct nlmsghdr *nlh, | |
209 | struct netlink_dump_control *control) | |
210 | { | |
211 | if (!control->module) | |
212 | control->module = THIS_MODULE; | |
213 | ||
214 | return __netlink_dump_start(ssk, skb, nlh, control); | |
215 | } | |
1da177e4 | 216 | |
bcbde0d4 DB |
217 | struct netlink_tap { |
218 | struct net_device *dev; | |
219 | struct module *module; | |
220 | struct list_head list; | |
221 | }; | |
222 | ||
223 | extern int netlink_add_tap(struct netlink_tap *nt); | |
bcbde0d4 DB |
224 | extern int netlink_remove_tap(struct netlink_tap *nt); |
225 | ||
aa4cf945 EB |
226 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, |
227 | struct user_namespace *ns, int cap); | |
228 | bool netlink_ns_capable(const struct sk_buff *skb, | |
229 | struct user_namespace *ns, int cap); | |
230 | bool netlink_capable(const struct sk_buff *skb, int cap); | |
231 | bool netlink_net_capable(const struct sk_buff *skb, int cap); | |
232 | ||
1da177e4 | 233 | #endif /* __LINUX_NETLINK_H */ |