linkconfig.c   [plain text]

/*
 * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

/*
 * Modification History
 *
 * October 21, 2000		Allan Nathanson <ajn@apple.com>
 * - initial revision
 */


#include <stdio.h>
#include <unistd.h>
//#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>

#include <SystemConfiguration/SystemConfiguration.h>
#include <SystemConfiguration/SCPrivate.h>
#include <SystemConfiguration/SCValidation.h>
#include <SystemConfiguration/LinkConfiguration.h>


static CFMutableDictionaryRef	baseSettings	= NULL;
static SCDynamicStoreRef	store		= NULL;
static CFRunLoopSourceRef	rls		= NULL;

static Boolean			_verbose	= FALSE;


/* in SystemConfiguration/LinkConfiguration.c */
int
__createMediaOptions(CFDictionaryRef media_options);


static char *
cfstring_to_cstring(CFStringRef cfstr, char *buf, int bufLen)
{
	CFIndex	len	= CFStringGetLength(cfstr);

	if (!buf) {
		bufLen = len + 1;
		buf = CFAllocatorAllocate(NULL, bufLen, 0);
	}

	if (len >= bufLen) {
		len = bufLen - 1;
	}

	(void)CFStringGetBytes(cfstr,
			       CFRangeMake(0, len),
			       kCFStringEncodingASCII,
			       0,
			       FALSE,
			       buf,
			       bufLen,
			       NULL);
	buf[len] = '\0';

	return buf;
}



Boolean
_NetworkInterfaceSetMediaOptions(CFStringRef		interface,
				 CFDictionaryRef	options)
{
	CFArrayRef		available	= NULL;
	CFDictionaryRef		current		= NULL;
	struct ifmediareq	ifm;
	struct ifreq		ifr;
	Boolean			ok		= FALSE;
	int			newOptions;
	CFMutableDictionaryRef	requested	= NULL;
	int			sock		= -1;
	CFTypeRef		val;

	/* get current & available options */
	if (!NetworkInterfaceCopyMediaOptions(interface, &current, NULL, &available, FALSE)) {
		return FALSE;
	}

	/* extract just the dictionary key/value pairs of interest */
	requested = CFDictionaryCreateMutable(NULL,
					      0,
					      &kCFTypeDictionaryKeyCallBacks,
					      &kCFTypeDictionaryValueCallBacks);

	val = CFDictionaryGetValue(options, kSCPropNetEthernetMediaSubType);
	if (!val) {
		val = CFDictionaryGetValue(current, kSCPropNetEthernetMediaSubType);
	}
	if (isA_CFString(val)) {
		CFDictionaryAddValue(requested, kSCPropNetEthernetMediaSubType, val);
	} else {
		/* if garbage */;
		goto done;
	}

	val = CFDictionaryGetValue(options, kSCPropNetEthernetMediaOptions);
	if (!val) {
		val = CFDictionaryGetValue(current, kSCPropNetEthernetMediaOptions);
	}
	if (isA_CFArray(val)) {
		CFDictionaryAddValue(requested, kSCPropNetEthernetMediaOptions, val);
	} else {
		/* if garbage */;
		goto done;
	}

	if (current && CFEqual(current, requested)) {
		/* if current settings are as requested */
		ok = TRUE;
		goto done;
	}

	if (!CFArrayContainsValue(available, CFRangeMake(0, CFArrayGetCount(available)), requested)) {
		/* if requested settings not currently available */
		SCLog(TRUE, LOG_DEBUG, CFSTR("requested media settings unavailable"));
		goto done;
	}

	newOptions = __createMediaOptions(requested);
	if (newOptions == -1) {
		/* since we have just validated, this should never happen */
		goto done;
	}

	sock = socket(AF_INET, SOCK_DGRAM, 0);
	if (sock < 0) {
		SCLog(TRUE, LOG_ERR, CFSTR("socket() failed: %s"), strerror(errno));
		goto done;
	}

	bzero((char *)&ifm, sizeof(ifm));
	(void)cfstring_to_cstring(interface, ifm.ifm_name, sizeof(ifm.ifm_name));

	if (ioctl(sock, SIOCGIFMEDIA, (caddr_t)&ifm) < 0) {
		SCLog(TRUE, LOG_DEBUG, CFSTR("ioctl(SIOCGIFMEDIA) failed: %s"), strerror(errno));
		goto done;
	}

	bzero((char *)&ifr, sizeof(ifr));
	bcopy(ifm.ifm_name, ifr.ifr_name, sizeof(ifr.ifr_name));
	ifr.ifr_media =  ifm.ifm_current & ~(IFM_NMASK|IFM_TMASK|IFM_OMASK|IFM_GMASK);
	ifr.ifr_media |= newOptions;

//SCLog(TRUE, LOG_INFO, CFSTR("old media settings: 0x%8.8x (0x%8.8x)"), ifm.ifm_current, ifm.ifm_active);
//SCLog(TRUE, LOG_INFO, CFSTR("new media settings: 0x%8.8x"), ifr.ifr_media);

	if (ioctl(sock, SIOCSIFMEDIA, (caddr_t)&ifr) < 0) {
		SCLog(TRUE, LOG_DEBUG, CFSTR("ioctl(SIOCSIFMEDIA) failed: %s"), strerror(errno));
		goto done;
	}

	ok = TRUE;

    done :

	if (available)	CFRelease(available);
	if (current)	CFRelease(current);
	if (requested)	CFRelease(requested);
	if (sock >= 0)	(void)close(sock);

	return ok;
}


Boolean
_NetworkInterfaceSetMTU(CFStringRef	interface,
			CFDictionaryRef	options)
{
	struct ifreq	ifr;
	int		mtu_cur		= -1;
	int		mtu_max		= -1;
	int		mtu_min		= -1;
	Boolean		ok		= FALSE;
	int		requested;
	int		sock		= -1;
	CFNumberRef	val;

	if (!NetworkInterfaceCopyMTU(interface, &mtu_cur, &mtu_min, &mtu_max)) {
		/* could not get current MTU */
		return FALSE;
	}

	val = CFDictionaryGetValue(options, kSCPropNetEthernetMTU);
	if (val) {
		if (isA_CFNumber(val)) {
			CFNumberGetValue(val, kCFNumberIntType, &requested);
		} else {
			goto done;
		}
	} else {
		requested = mtu_cur;
	}

	if (requested == mtu_cur) {
		/* if current setting is as requested */
		ok = TRUE;
		goto done;
	}

	if (((mtu_min >= 0) && (requested < mtu_min)) ||
	    ((mtu_max >= 0) && (requested > mtu_max))) {
		/* if requested MTU outside of the valid range */
		goto done;
	}

	bzero((char *)&ifr, sizeof(ifr));
	(void)cfstring_to_cstring(interface, ifr.ifr_name, sizeof(ifr.ifr_name));
	ifr.ifr_mtu = requested;

	sock = socket(AF_INET, SOCK_DGRAM, 0);
	if (sock < 0) {
		SCLog(TRUE, LOG_ERR, CFSTR("socket() failed: %s"), strerror(errno));
		goto done;
	}

	if (ioctl(sock, SIOCSIFMTU, (caddr_t)&ifr) < 0) {
		SCLog(TRUE, LOG_DEBUG, CFSTR("ioctl(SIOCSIFMTU) failed: %s"), strerror(errno));
		goto done;
	}

	ok = TRUE;

    done :

	if (sock >= 0)	(void)close(sock);
	return ok;
}


/*
 * Function: parse_component
 * Purpose:
 *   Given a string 'key' and a string prefix 'prefix',
 *   return the next component in the slash '/' separated
 *   key.
 *
 * Examples:
 * 1. key = "a/b/c" prefix = "a/"
 *    returns "b"
 * 2. key = "a/b/c" prefix = "a/b/"
 *    returns "c"
 */
static CFStringRef
parse_component(CFStringRef key, CFStringRef prefix)
{
	CFMutableStringRef	comp;
	CFRange			range;

	if (CFStringHasPrefix(key, prefix) == FALSE) {
		return NULL;
	}
	comp = CFStringCreateMutableCopy(NULL, 0, key);
	CFStringDelete(comp, CFRangeMake(0, CFStringGetLength(prefix)));
	range = CFStringFind(comp, CFSTR("/"), 0);
	if (range.location == kCFNotFound) {
		return comp;
	}
	range.length = CFStringGetLength(comp) - range.location;
	CFStringDelete(comp, range);
	return comp;
}


static void
updateLink(CFStringRef ifKey, CFDictionaryRef options)
{
	CFStringRef		interface	= NULL;
	static CFStringRef	prefix		= NULL;

	if (!prefix) {
		prefix = SCDynamicStoreKeyCreate(NULL,
						 CFSTR("%@/%@/%@/"),
						 kSCDynamicStoreDomainSetup,
						 kSCCompNetwork,
						 kSCCompInterface);
	}

	interface = parse_component(ifKey, prefix);
	if (!interface) {
		goto done;
	}

	if (options) {
		if (!CFDictionaryContainsKey(baseSettings, interface)) {
			CFDictionaryRef		cur_media	= NULL;
			CFMutableDictionaryRef	new_media	= NULL;
			int			cur_mtu		= -1;
			CFNumberRef		num;

			if (!NetworkInterfaceCopyMediaOptions(interface, &cur_media, NULL, NULL, FALSE)) {
				/* could not determine current settings */
				goto done;
			}

			if (!cur_media) {
				/* could not determine current settings */
				goto done;
			}

			if (!NetworkInterfaceCopyMTU(interface, &cur_mtu, NULL, NULL)) {
				/* could not determine current MTU */
				CFRelease(cur_media);
				goto done;
			}

			if (cur_mtu < 0) {
				/* could not determine current MTU */
				CFRelease(cur_media);
				goto done;
			}

			new_media = CFDictionaryCreateMutableCopy(NULL, 0, cur_media);
			CFRelease(cur_media);

			num = CFNumberCreate(NULL, kCFNumberIntType, &cur_mtu);
			CFDictionaryAddValue(new_media, kSCPropNetEthernetMTU, num);
			CFRelease(num);

			CFDictionarySetValue(baseSettings, interface, new_media);
			CFRelease(new_media);
		}

		/* establish new settings */
		(void)_NetworkInterfaceSetMediaOptions(interface, options);
		(void)_NetworkInterfaceSetMTU         (interface, options);
	} else {
		/* no requested settings */
		options = CFDictionaryGetValue(baseSettings, interface);
		if (options) {
			/* restore original settings */
			(void)_NetworkInterfaceSetMediaOptions(interface, options);
			(void)_NetworkInterfaceSetMTU         (interface, options);
			CFDictionaryRemoveValue(baseSettings, interface);
		}
	}

    done :

	if (interface)	CFRelease(interface);
	return;
}


static void
linkConfigChangedCallback(SCDynamicStoreRef store, CFArrayRef changedKeys, void *arg)
{
	CFIndex			i;
	CFIndex			n;
	CFDictionaryRef		linkInfo;

	linkInfo = SCDynamicStoreCopyMultiple(store, changedKeys, NULL);

	n = CFArrayGetCount(changedKeys);
	for (i = 0; i < n; i++) {
		CFStringRef	key;
		CFDictionaryRef	link;

		key  = CFArrayGetValueAtIndex(changedKeys, i);
		link = CFDictionaryGetValue(linkInfo, key);
		updateLink(key, link);
	}

	CFRelease(linkInfo);

	return;
}


void
load(CFBundleRef bundle, Boolean bundleVerbose)
{
	CFStringRef		key;
	CFMutableArrayRef	patterns	= NULL;

	if (bundleVerbose) {
		_verbose = TRUE;
	}

	SCLog(_verbose, LOG_DEBUG, CFSTR("load() called"));
	SCLog(_verbose, LOG_DEBUG, CFSTR("  bundle ID = %@"), CFBundleGetIdentifier(bundle));

	/* initialize a few globals */

	baseSettings = CFDictionaryCreateMutable(NULL,
						 0,
						 &kCFTypeDictionaryKeyCallBacks,
						 &kCFTypeDictionaryValueCallBacks);

	/* open a "configd" store to allow cache updates */
	store = SCDynamicStoreCreate(NULL,
				     CFSTR("Link Configuraton plug-in"),
				     linkConfigChangedCallback,
				     NULL);
	if (!store) {
		SCLog(TRUE, LOG_ERR, CFSTR("SCDynamicStoreCreate() failed: %s"), SCErrorString(SCError()));
		goto error;
	}

	/* establish notificaiton keys and patterns */

	patterns = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);

	/* ...watch for (per-interface) Ethernet configuration changes */
	key = SCDynamicStoreKeyCreateNetworkInterfaceEntity(NULL,
							    kSCDynamicStoreDomainSetup,
							    kSCCompAnyRegex,
							    kSCEntNetEthernet);
	CFArrayAppendValue(patterns, key);
	CFRelease(key);

	/* register the keys/patterns */
	if (!SCDynamicStoreSetNotificationKeys(store, NULL, patterns)) {
		SCLog(TRUE, LOG_ERR,
		      CFSTR("SCDynamicStoreSetNotificationKeys() failed: %s"),
		      SCErrorString(SCError()));
		goto error;
	}

	rls = SCDynamicStoreCreateRunLoopSource(NULL, store, 0);
	if (!rls) {
		SCLog(TRUE, LOG_ERR,
		      CFSTR("SCDynamicStoreCreateRunLoopSource() failed: %s"),
		      SCErrorString(SCError()));
		goto error;
	}

	CFRunLoopAddSource(CFRunLoopGetCurrent(), rls, kCFRunLoopDefaultMode);

	CFRelease(patterns);
	return;

    error :

	if (baseSettings)	CFRelease(baseSettings);
	if (store) 		CFRelease(store);
	if (patterns)		CFRelease(patterns);
	return;
}


#ifdef	MAIN
int
main(int argc, char **argv)
{
	_sc_log     = FALSE;
	_sc_verbose = (argc > 1) ? TRUE : FALSE;

	load(CFBundleGetMainBundle(), (argc > 1) ? TRUE : FALSE);
	CFRunLoopRun();
	/* not reached */
	exit(0);
	return 0;
}
#endif