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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *	http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 /* NOTICE: This is a clean room re-implementation of libnl */
     18 
     19 #include <errno.h>
     20 #include <unistd.h>
     21 #include <malloc.h>
     22 #include <sys/time.h>
     23 #include <sys/socket.h>
     24 #include "netlink-types.h"
     25 
     26 /* Join group */
     27 int nl_socket_add_membership(struct nl_sock *sk, int group)
     28 {
     29 	return setsockopt(sk->s_fd, SOL_NETLINK,
     30 			NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
     31 }
     32 
     33 /* Allocate new netlink socket. */
     34 struct nl_sock *nl_socket_alloc(void)
     35 {
     36 	struct nl_sock *sk;
     37 	struct timeval tv;
     38 	struct nl_cb *cb;
     39 
     40 	sk = (struct nl_sock *) malloc(sizeof(struct nl_sock));
     41 	if (!sk)
     42 		goto fail;
     43 	memset(sk, 0, sizeof(*sk));
     44 
     45 	/* Get current time */
     46 
     47 	if (gettimeofday(&tv, NULL))
     48 		return NULL;
     49 	else
     50 		sk->s_seq_next = (int) tv.tv_sec;
     51 
     52 	/* Create local socket */
     53 	sk->s_local.nl_family = AF_NETLINK;
     54 	sk->s_local.nl_pid = 0; /* Kernel fills in pid */
     55 	sk->s_local.nl_groups = 0; /* No groups */
     56 
     57 	/* Create peer socket */
     58 	sk->s_peer.nl_family = AF_NETLINK;
     59 	sk->s_peer.nl_pid = 0; /* Kernel */
     60 	sk->s_peer.nl_groups = 0; /* No groups */
     61 
     62 	cb = (struct nl_cb *) malloc(sizeof(struct nl_cb));
     63 	if (!cb)
     64 		goto cb_fail;
     65 	memset(cb, 0, sizeof(*cb));
     66 	sk->s_cb = nl_cb_alloc(NL_CB_DEFAULT);
     67 
     68 
     69 	return sk;
     70 cb_fail:
     71 	free(sk);
     72 fail:
     73 	return NULL;
     74 }
     75 
     76 /* Allocate new socket with custom callbacks. */
     77 struct nl_sock *nl_socket_alloc_cb(struct nl_cb *cb)
     78 {
     79 	struct nl_sock *sk = nl_socket_alloc();
     80 	if (!sk)
     81 		return NULL;
     82 
     83 	sk->s_cb = cb;
     84 	nl_cb_get(cb);
     85 
     86 	return sk;
     87 
     88 }
     89 
     90 /* Free a netlink socket. */
     91 void nl_socket_free(struct nl_sock *sk)
     92 {
     93 	nl_cb_put(sk->s_cb);
     94 	close(sk->s_fd);
     95 	free(sk);
     96 }
     97 
     98 /* Sets socket buffer size of netlink socket */
     99 int nl_socket_set_buffer_size(struct nl_sock *sk, int rxbuf, int txbuf)
    100 {
    101 	if (setsockopt(sk->s_fd, SOL_SOCKET, SO_SNDBUF, \
    102 			&rxbuf, (socklen_t) sizeof(rxbuf)))
    103 		goto error;
    104 
    105 	if (setsockopt(sk->s_fd, SOL_SOCKET, SO_RCVBUF, \
    106 			&txbuf, (socklen_t) sizeof(txbuf)))
    107 		goto error;
    108 
    109 	return 0;
    110 error:
    111 	return -errno;
    112 
    113 }
    114 
    115 int nl_socket_get_fd(struct nl_sock *sk)
    116 {
    117 	return sk->s_fd;
    118 }
    119 
    120 
    121