1/*
2 * Copyright (c) 2013, 2014 Apple Inc. All rights reserved.
3 *
4 * @APPLE_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. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24/*
25 * Modification History
26 *
27 * October 7, 2013	Allan Nathanson <ajn@apple.com>
28 * - initial revision
29 */
30
31
32#include <CoreFoundation/CoreFoundation.h>
33#include <SystemConfiguration/SystemConfiguration.h>
34#include <SystemConfiguration/SCPrivate.h>
35
36#include "eventmon.h"
37#include "ev_extra.h"
38
39
40static CFBooleanRef
41is_expensive(SCNetworkInterfaceRef interface)
42{
43	CFBooleanRef	expensive	= NULL;
44	CFStringRef	interfaceType;
45
46	while (interface != NULL) {
47		SCNetworkInterfaceRef	child;
48
49		child = SCNetworkInterfaceGetInterface(interface);
50		if (child == NULL) {
51			break;
52		}
53
54		interface = child;
55	}
56
57	// assume NOT expensive
58	expensive = kCFBooleanFalse;
59
60	interfaceType = SCNetworkInterfaceGetInterfaceType(interface);
61	if (_SCNetworkInterfaceIsTethered(interface)) {
62		// if tethered (to iOS) interface
63		expensive = kCFBooleanTrue;
64	} else if (_SCNetworkInterfaceIsBluetoothPAN(interface)) {
65		// if BT-PAN interface
66		expensive = kCFBooleanTrue;
67	} else if (CFEqual(interfaceType, kSCNetworkInterfaceTypeWWAN)) {
68		// if WWAN [Ethernet] interface
69		expensive = kCFBooleanTrue;
70	}
71
72	return expensive;
73}
74
75
76static int
77ifexpensive_set(int s, const char * name, uint32_t expensive)
78{
79#if	defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
80	struct ifreq	ifr;
81
82	bzero(&ifr, sizeof(ifr));
83	strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
84	ifr.ifr_expensive = expensive;
85	return (ioctl(s, SIOCSIFEXPENSIVE, &ifr));
86#else	// defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
87	return 0;
88#endif	// defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
89}
90
91
92__private_extern__
93CFBooleanRef
94interface_update_expensive(const char *if_name)
95{
96	CFBooleanRef		expensive	= NULL;
97	SCNetworkInterfaceRef	interface;
98	CFStringRef		interface_name;
99	int			s;
100
101	interface_name = CFStringCreateWithCString(NULL, if_name, kCFStringEncodingMacRoman);
102	interface = _SCNetworkInterfaceCreateWithBSDName(NULL, interface_name, kIncludeNoVirtualInterfaces);
103	CFRelease(interface_name);
104
105	if (interface != NULL) {
106		expensive = is_expensive(interface);
107		CFRelease(interface);
108	}
109
110	// mark ... or clear ... the [if_name] interface as "expensive"
111	s = dgram_socket(AF_INET);
112	if (s != -1) {
113		ifexpensive_set(s,
114				if_name,
115				((expensive != NULL) && CFBooleanGetValue(expensive)) ? 1 : 0);
116		close(s);
117	}
118
119	return expensive;
120}
121
122
123#ifdef	MAIN
124
125int
126dgram_socket(int domain)
127{
128	return (socket(domain, SOCK_DGRAM, 0));
129}
130
131int
132main(int argc, char **argv)
133{
134	CFBooleanRef	expensive;
135
136	if (argc < 1 + 1) {
137		SCPrint(TRUE, stderr, CFSTR("usage: %s <interface>\n"), argv[0]);
138		exit(1);
139	}
140
141	expensive = interface_update_expensive(argv[1]);
142	if (expensive != NULL) {
143		SCPrint(TRUE, stdout, CFSTR("interface \"%s\": %@\n"), argv[1], expensive);
144	} else {
145		SCPrint(TRUE, stdout, CFSTR("interface \"%s\": could not determine \"expensive\" status\n"), argv[1]);
146	}
147
148	exit(0);
149}
150#endif	// MAIN
151