1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#include <kern/kalloc.h>
30#include <libkern/OSAtomic.h>
31#include <sys/errno.h>
32#include <net/init.h>
33#include <libkern/libkern.h>
34#include <string.h>
35
36struct init_list_entry {
37	struct init_list_entry	*next;
38	net_init_func_ptr		func;
39};
40
41#define LIST_RAN ((struct init_list_entry*)0xffffffff)
42static struct init_list_entry	*list_head = 0;
43
44errno_t
45net_init_add(
46	net_init_func_ptr init_func)
47{
48	struct init_list_entry	*entry;
49
50	if (init_func == 0) {
51		return EINVAL;
52	}
53
54	/* Check if we've already started */
55	if (list_head == LIST_RAN) {
56		return EALREADY;
57	}
58
59	entry = kalloc(sizeof(*entry));
60	if (entry == 0) {
61		printf("net_init_add: no memory\n");
62		return ENOMEM;
63	}
64
65	bzero(entry, sizeof(*entry));
66	entry->func = init_func;
67
68	do {
69		entry->next = list_head;
70
71		if (entry->next == LIST_RAN) {
72			/* List already ran, cleanup and call the function */
73			kfree(entry, sizeof(*entry));
74			return EALREADY;
75		}
76	} while(!OSCompareAndSwapPtr(entry->next, entry, &list_head));
77
78	return 0;
79}
80
81__private_extern__ void
82net_init_run(void)
83{
84	struct init_list_entry	*backward_head = 0;
85	struct init_list_entry	*forward_head = 0;
86	struct init_list_entry	*current = 0;
87
88	/*
89	 * Grab the list, replacing the head with 0xffffffff to indicate
90	 * that we've already run.
91	 */
92	do {
93		backward_head = list_head;
94	} while (!OSCompareAndSwapPtr(backward_head, LIST_RAN, &list_head));
95
96	/* Reverse the order of the list */
97	while (backward_head != 0) {
98		current = backward_head;
99		backward_head = current->next;
100		current->next = forward_head;
101		forward_head = current;
102	}
103
104	/* Call each function pointer registered */
105	while (forward_head != 0) {
106		current = forward_head;
107		forward_head = current->next;
108		current->func();
109		kfree(current, sizeof(*current));
110	}
111}
112