1 /* Copyright (c) 2017, The Linux Foundation. All rights reserved.
2  *
3  * Redistribution and use in source and binary forms, with or without
4  * modification, are permitted provided that the following conditions are
5  * met:
6  *     * Redistributions of source code must retain the above copyright
7  *       notice, this list of conditions and the following disclaimer.
8  *     * Redistributions in binary form must reproduce the above
9  *       copyright notice, this list of conditions and the following
10  *       disclaimer in the documentation and/or other materials provided
11  *       with the distribution.
12  *     * Neither the name of The Linux Foundation nor the names of its
13  *       contributors may be used to endorse or promote products derived
14  *       from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
23  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
25  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
26  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  */
29 
30 #ifndef CLD80211_LIB_H
31 #define CLD80211_LIB_H
32 
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36 #include <netlink/genl/genl.h>
37 #include <stdbool.h>
38 
39 #ifndef UNUSED
40 #define UNUSED(x)    (void)(x)
41 #endif
42 
43 struct cld80211_ctx {
44 	struct nl_sock *sock;
45 	int netlink_familyid;
46 	/* socket pair used to exit from blocking poll*/
47 	int exit_sockets[2];
48 	int sock_buf_size;
49 	int nlctrl_familyid;
50 };
51 
52 /**
53  * enum cld80211_attr - Driver/Application embeds the data in nlmsg with the
54  *                      help of below attributes
55  * CLD80211_ATTR_VENDOR_DATA: Embed all other attributes in this nested
56  *                            attribute.
57  * CLD80211_ATTR_DATA: Embed driver/application data in this attribute
58  * Any new message in future can be added as another attribute
59  */
60 enum cld80211_attr {
61 	CLD80211_ATTR_VENDOR_DATA = 1,
62 	CLD80211_ATTR_DATA,
63 
64 	__CLD80211_ATTR_AFTER_LAST,
65 	CLD80211_ATTR_MAX = __CLD80211_ATTR_AFTER_LAST - 1
66 };
67 
68 /**
69  * Create socket of type NETLINK_GENERIC
70  * Retuns valid sock only if socket creation is succesful and cld80211
71  * family is present, returns NULL otherwise
72  */
73 struct cld80211_ctx *cld80211_init();
74 
75 /**
76  * free the socket created in cld80211_init()
77  */
78 void cld80211_deinit(struct cld80211_ctx *ctx);
79 
80 /**
81  * Allocate nl_msg and populate family and genl header details
82  */
83 struct nl_msg *cld80211_msg_alloc(struct cld80211_ctx *ctx, int cmd,
84 				  struct nlattr **nla_data, int pid);
85 
86 /**
87  * Send nlmsg to driver and return; It doesn't wait for response
88  */
89 int cld80211_send_msg(struct cld80211_ctx *ctx, struct nl_msg *nlmsg);
90 
91 /**
92  * Send nlmsg to driver and get response, if any
93  */
94 int cld80211_send_recv_msg(struct cld80211_ctx *ctx, struct nl_msg *nlmsg,
95 		      int (*valid_handler)(struct nl_msg *, void *),
96 		      void *valid_data);
97 
98 /**
99  * Add membership for multicast group "mcgroup" to receive the messages
100  * sent to this group from driver
101  */
102 int cld80211_add_mcast_group(struct cld80211_ctx *ctx, const char* mcgroup);
103 
104 /**
105  * Remove membership of multicast group "mcgroup" to stop receiving messages
106  * sent to this group from driver
107  */
108 int cld80211_remove_mcast_group(struct cld80211_ctx *ctx, const char* mcgroup);
109 
110 /**
111  * Receive messages from driver on cld80211 family. Client can do
112  * a select()/poll() on the socket before calling this API.
113  * sock: nl_sock created for communication
114  * cb: nl callback context provided by client
115  * Returns corresponding errno when a failure happens while receiving nl msg
116  */
117 int cld80211_recv_msg(struct nl_sock *sock, struct nl_cb *cb);
118 
119 /**
120  * Receive messages from driver on cld80211 family from the
121  * multicast groups subscribed
122  * timeout: Timeout in milliseconds for poll(); -1 is for infinite timeout.
123  * recv_multi_msg: Boolean flag to be sent false/true from client to indicate
124  *                 whether it wants to receive only one message or multiple
125  *                 messages from timeoutblock.
126  *                 false: Receive only one message and return
127  *                 true: Continue in the loop to receive multiple message till
128  *                       client explicitly sends exit via exit_cld80211_recv().
129  * cbctx: Context provided by client, which is to be used when an
130  *        nlmsg is received
131  * Returns corresponding errno when a failure happens while receiving nl msg
132  */
133 int cld80211_recv(struct cld80211_ctx *ctx, int timeout, bool recv_multi_msg,
134 		  int (*valid_handler)(struct nl_msg *, void *),
135 		  void *cbctx);
136 
137 /**
138  * poll() is a blocking call on sock. Client has to unblock the poll()
139  * first to exit gracefully.
140  */
141 void exit_cld80211_recv(struct cld80211_ctx *ctx);
142 #ifdef __cplusplus
143 }
144 #endif
145 
146 #endif
147