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      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