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(!OSCompareAndSwap((UInt32)entry->next, (UInt32)entry,
77							  (UInt32*)&list_head));
78
79	return 0;
80}
81
82__private_extern__ void
83net_init_run(void)
84{
85	struct init_list_entry	*backward_head = 0;
86	struct init_list_entry	*forward_head = 0;
87	struct init_list_entry	*current = 0;
88
89	/*
90	 * Grab the list, replacing the head with 0xffffffff to indicate
91	 * that we've already run.
92	 */
93	do {
94		backward_head = list_head;
95	} while (!OSCompareAndSwap((UInt32)backward_head, (UInt32)LIST_RAN,
96							   (UInt32*)&list_head));
97
98	/* Reverse the order of the list */
99	while (backward_head != 0) {
100		current = backward_head;
101		backward_head = current->next;
102		current->next = forward_head;
103		forward_head = current;
104	}
105
106	/* Call each function pointer registered */
107	while (forward_head != 0) {
108		current = forward_head;
109		forward_head = current->next;
110		current->func();
111		kfree(current, sizeof(*current));
112	}
113}
114