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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 | ||
7e3ce05e MRL |
14 | void do_trace_netlink_extack(const char *msg); |
15 | ||
b529ccf2 ACM |
16 | static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb) |
17 | { | |
18 | return (struct nlmsghdr *)skb->data; | |
19 | } | |
20 | ||
9652e931 | 21 | enum netlink_skb_flags { |
2d7a85f4 | 22 | NETLINK_SKB_DST = 0x8, /* Dst set in sendto or sendmsg */ |
9652e931 PM |
23 | }; |
24 | ||
d94d9fee | 25 | struct netlink_skb_parms { |
dbe9a417 | 26 | struct scm_creds creds; /* Skb credentials */ |
15e47304 | 27 | __u32 portid; |
d629b836 | 28 | __u32 dst_group; |
9652e931 | 29 | __u32 flags; |
e32123e5 | 30 | struct sock *sk; |
59324cf3 ND |
31 | bool nsid_is_set; |
32 | int nsid; | |
1da177e4 LT |
33 | }; |
34 | ||
35 | #define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb)) | |
36 | #define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds) | |
37 | ||
38 | ||
aa9d6e0f SH |
39 | void netlink_table_grab(void); |
40 | void netlink_table_ungrab(void); | |
d136f1bd | 41 | |
9785e10a PNA |
42 | #define NL_CFG_F_NONROOT_RECV (1 << 0) |
43 | #define NL_CFG_F_NONROOT_SEND (1 << 1) | |
44 | ||
a31f2d17 PNA |
45 | /* optional Netlink kernel configuration parameters */ |
46 | struct netlink_kernel_cfg { | |
47 | unsigned int groups; | |
c9d2ea96 | 48 | unsigned int flags; |
a31f2d17 PNA |
49 | void (*input)(struct sk_buff *skb); |
50 | struct mutex *cb_mutex; | |
023e2cfa JB |
51 | int (*bind)(struct net *net, int group); |
52 | void (*unbind)(struct net *net, int group); | |
da12c90e | 53 | bool (*compare)(struct net *net, struct sock *sk); |
a31f2d17 PNA |
54 | }; |
55 | ||
aa9d6e0f | 56 | struct sock *__netlink_kernel_create(struct net *net, int unit, |
9f00d977 PNA |
57 | struct module *module, |
58 | struct netlink_kernel_cfg *cfg); | |
59 | static inline struct sock * | |
60 | netlink_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 | ||
ba0dc5f6 JB |
65 | /* this can be increased when necessary - don't expose to userland */ |
66 | #define NETLINK_MAX_COOKIE_LEN 20 | |
67 | ||
2d4bc933 JB |
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 | |
44f3625b | 73 | * @policy: policy for a bad attribute |
ba0dc5f6 JB |
74 | * @cookie: cookie data to return to userspace (for success) |
75 | * @cookie_len: actual cookie data length | |
2d4bc933 JB |
76 | */ |
77 | struct netlink_ext_ack { | |
78 | const char *_msg; | |
79 | const struct nlattr *bad_attr; | |
44f3625b | 80 | const struct nla_policy *policy; |
ba0dc5f6 JB |
81 | u8 cookie[NETLINK_MAX_COOKIE_LEN]; |
82 | u8 cookie_len; | |
2d4bc933 JB |
83 | }; |
84 | ||
85 | /* Always use this macro, this allows later putting the | |
86 | * message into a separate section or such for things | |
87 | * like translation or listing all possible messages. | |
88 | * Currently string formatting is not supported (due | |
89 | * to the lack of an output buffer.) | |
90 | */ | |
4d463c4d | 91 | #define NL_SET_ERR_MSG(extack, msg) do { \ |
6311b7ce | 92 | static const char __msg[] = msg; \ |
4d463c4d DB |
93 | struct netlink_ext_ack *__extack = (extack); \ |
94 | \ | |
7e3ce05e MRL |
95 | do_trace_netlink_extack(__msg); \ |
96 | \ | |
4d463c4d DB |
97 | if (__extack) \ |
98 | __extack->_msg = __msg; \ | |
2d4bc933 JB |
99 | } while (0) |
100 | ||
4d463c4d DB |
101 | #define NL_SET_ERR_MSG_MOD(extack, msg) \ |
102 | NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg) | |
45d9b378 | 103 | |
44f3625b JB |
104 | #define NL_SET_BAD_ATTR_POLICY(extack, attr, pol) do { \ |
105 | if ((extack)) { \ | |
c3ab2b4e | 106 | (extack)->bad_attr = (attr); \ |
44f3625b JB |
107 | (extack)->policy = (pol); \ |
108 | } \ | |
c3ab2b4e DA |
109 | } while (0) |
110 | ||
44f3625b JB |
111 | #define NL_SET_BAD_ATTR(extack, attr) NL_SET_BAD_ATTR_POLICY(extack, attr, NULL) |
112 | ||
113 | #define NL_SET_ERR_MSG_ATTR_POL(extack, attr, pol, msg) do { \ | |
114 | static const char __msg[] = msg; \ | |
115 | struct netlink_ext_ack *__extack = (extack); \ | |
116 | \ | |
7e3ce05e MRL |
117 | do_trace_netlink_extack(__msg); \ |
118 | \ | |
44f3625b JB |
119 | if (__extack) { \ |
120 | __extack->_msg = __msg; \ | |
121 | __extack->bad_attr = (attr); \ | |
122 | __extack->policy = (pol); \ | |
123 | } \ | |
9ae28727 DA |
124 | } while (0) |
125 | ||
44f3625b JB |
126 | #define NL_SET_ERR_MSG_ATTR(extack, attr, msg) \ |
127 | NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg) | |
128 | ||
801f8746 JB |
129 | static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack *extack, |
130 | u64 cookie) | |
131 | { | |
55b474c4 MK |
132 | if (!extack) |
133 | return; | |
c6400e3f AD |
134 | memcpy(extack->cookie, &cookie, sizeof(cookie)); |
135 | extack->cookie_len = sizeof(cookie); | |
801f8746 JB |
136 | } |
137 | ||
f1388ec4 MK |
138 | static inline void nl_set_extack_cookie_u32(struct netlink_ext_ack *extack, |
139 | u32 cookie) | |
140 | { | |
55b474c4 MK |
141 | if (!extack) |
142 | return; | |
c6400e3f AD |
143 | memcpy(extack->cookie, &cookie, sizeof(cookie)); |
144 | extack->cookie_len = sizeof(cookie); | |
801f8746 JB |
145 | } |
146 | ||
aa9d6e0f SH |
147 | void netlink_kernel_release(struct sock *sk); |
148 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups); | |
149 | int netlink_change_ngroups(struct sock *sk, unsigned int groups); | |
150 | void __netlink_clear_multicast_users(struct sock *sk, unsigned int group); | |
151 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, | |
152 | const struct netlink_ext_ack *extack); | |
153 | int netlink_has_listeners(struct sock *sk, unsigned int group); | |
59c28058 | 154 | bool netlink_strict_get_check(struct sk_buff *skb); |
aa9d6e0f SH |
155 | |
156 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); | |
157 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, | |
158 | __u32 group, gfp_t allocation); | |
159 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, | |
160 | __u32 portid, __u32 group, gfp_t allocation, | |
161 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
162 | void *filter_data); | |
163 | int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code); | |
164 | int netlink_register_notifier(struct notifier_block *nb); | |
165 | int netlink_unregister_notifier(struct notifier_block *nb); | |
1da177e4 LT |
166 | |
167 | /* finegrained unicast helpers: */ | |
168 | struct sock *netlink_getsockbyfilp(struct file *filp); | |
9457afee | 169 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 170 | long *timeo, struct sock *ssk); |
1da177e4 | 171 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb); |
7ee015e0 | 172 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb); |
1da177e4 | 173 | |
3a36515f PN |
174 | static inline struct sk_buff * |
175 | netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask) | |
176 | { | |
177 | struct sk_buff *nskb; | |
178 | ||
179 | nskb = skb_clone(skb, gfp_mask); | |
180 | if (!nskb) | |
181 | return NULL; | |
182 | ||
183 | /* This is a large skb, set destructor callback to release head */ | |
184 | if (is_vmalloc_addr(skb->head)) | |
185 | nskb->destructor = skb->destructor; | |
186 | ||
187 | return nskb; | |
188 | } | |
189 | ||
1da177e4 LT |
190 | /* |
191 | * skb should fit one page. This choice is good for headerless malloc. | |
fc910a27 DM |
192 | * But we should limit to 8K so that userspace does not have to |
193 | * use enormous buffer sizes on recvmsg() calls just to avoid | |
194 | * MSG_TRUNC when PAGE_SIZE is very large. | |
1da177e4 | 195 | */ |
fc910a27 DM |
196 | #if PAGE_SIZE < 8192UL |
197 | #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE) | |
198 | #else | |
199 | #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL) | |
200 | #endif | |
201 | ||
339bf98f | 202 | #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN) |
1da177e4 LT |
203 | |
204 | ||
d94d9fee | 205 | struct netlink_callback { |
3a6c2b41 PM |
206 | struct sk_buff *skb; |
207 | const struct nlmsghdr *nlh; | |
208 | int (*dump)(struct sk_buff * skb, | |
209 | struct netlink_callback *cb); | |
210 | int (*done)(struct netlink_callback *cb); | |
7175c883 | 211 | void *data; |
6dc878a8 G |
212 | /* the module that dump function belong to */ |
213 | struct module *module; | |
4a19edb6 | 214 | struct netlink_ext_ack *extack; |
c7ac8679 | 215 | u16 family; |
22e6c58b | 216 | u16 answer_flags; |
085c20ca | 217 | u32 min_dump_alloc; |
670dc283 | 218 | unsigned int prev_seq, seq; |
085c20ca | 219 | bool strict_check; |
362b87f5 JD |
220 | union { |
221 | u8 ctx[48]; | |
222 | ||
223 | /* args is deprecated. Cast a struct over ctx instead | |
224 | * for proper type safety. | |
225 | */ | |
226 | long args[6]; | |
227 | }; | |
1da177e4 LT |
228 | }; |
229 | ||
d94d9fee | 230 | struct netlink_notify { |
b4b51029 | 231 | struct net *net; |
0392d099 | 232 | u32 portid; |
1da177e4 LT |
233 | int protocol; |
234 | }; | |
235 | ||
a46621a3 | 236 | struct nlmsghdr * |
15e47304 | 237 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags); |
1da177e4 | 238 | |
80d326fa | 239 | struct netlink_dump_control { |
fc9e50f5 | 240 | int (*start)(struct netlink_callback *); |
80d326fa | 241 | int (*dump)(struct sk_buff *skb, struct netlink_callback *); |
6dc878a8 | 242 | int (*done)(struct netlink_callback *); |
7175c883 | 243 | void *data; |
6dc878a8 | 244 | struct module *module; |
ebfe3c51 | 245 | u32 min_dump_alloc; |
80d326fa PNA |
246 | }; |
247 | ||
aa9d6e0f | 248 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
6dc878a8 G |
249 | const struct nlmsghdr *nlh, |
250 | struct netlink_dump_control *control); | |
251 | static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
252 | const struct nlmsghdr *nlh, | |
253 | struct netlink_dump_control *control) | |
254 | { | |
255 | if (!control->module) | |
256 | control->module = THIS_MODULE; | |
257 | ||
258 | return __netlink_dump_start(ssk, skb, nlh, control); | |
259 | } | |
1da177e4 | 260 | |
bcbde0d4 DB |
261 | struct netlink_tap { |
262 | struct net_device *dev; | |
263 | struct module *module; | |
264 | struct list_head list; | |
265 | }; | |
266 | ||
aa9d6e0f SH |
267 | int netlink_add_tap(struct netlink_tap *nt); |
268 | int netlink_remove_tap(struct netlink_tap *nt); | |
bcbde0d4 | 269 | |
aa4cf945 EB |
270 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, |
271 | struct user_namespace *ns, int cap); | |
272 | bool netlink_ns_capable(const struct sk_buff *skb, | |
273 | struct user_namespace *ns, int cap); | |
274 | bool netlink_capable(const struct sk_buff *skb, int cap); | |
275 | bool netlink_net_capable(const struct sk_buff *skb, int cap); | |
276 | ||
1da177e4 | 277 | #endif /* __LINUX_NETLINK_H */ |