Plugins/KernelEventMonitor/ev_extra.m

   1 /*
   2  * Copyright (c) 2013-2016 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 "eventmon.h"
  33 #include "ev_extra.h"
  34
  35
  36
  37 static CFBooleanRef
  38 is_expensive(SCNetworkInterfaceRef _Nonnull interface)
  39 {
  40         CFBooleanRef    expensive       = NULL;
  41         CFStringRef     interfaceType;
  42
  43         while (interface != NULL) {
  44                 SCNetworkInterfaceRef   child;
  45
  46                 child = SCNetworkInterfaceGetInterface(interface);
  47                 if (child == NULL) {
  48                         break;
  49                 }
  50
  51                 interface = child;
  52         }
  53
  54         // assume NOT expensive
  55         expensive = kCFBooleanFalse;
  56
  57         interfaceType = SCNetworkInterfaceGetInterfaceType(interface);
  58         if (_SCNetworkInterfaceIsTethered(interface)) {
  59                 // if tethered (to iOS) interface
  60                 expensive = kCFBooleanTrue;
  61         } else if (_SCNetworkInterfaceIsBluetoothPAN(interface)) {
  62                 // if BT-PAN interface
  63                 expensive = kCFBooleanTrue;
  64         } else if (CFEqual(interfaceType, kSCNetworkInterfaceTypeWWAN)) {
  65                 // if WWAN [Ethernet] interface
  66                 expensive = kCFBooleanTrue;
  67         }
  68
  69         return expensive;
  70 }
  71
  72
  73 static int
  74 ifexpensive_set(int s, const char * name, uint32_t expensive)
  75 {
  76 #if     defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
  77         struct ifreq    ifr;
  78
  79         bzero(&ifr, sizeof(ifr));
  80         strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
  81         ifr.ifr_expensive = expensive;
  82         return (ioctl(s, SIOCSIFEXPENSIVE, &ifr));
  83 #else   // defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
  84         return 0;
  85 #endif  // defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
  86 }
  87
  88
  89 __private_extern__
  90 CFBooleanRef
  91 interface_update_expensive(const char *if_name)
  92 {
  93         CFBooleanRef            expensive       = NULL;
  94         SCNetworkInterfaceRef   interface;
  95         CFStringRef             interface_name;
  96         int                     s;
  97
  98         interface_name = CFStringCreateWithCString(NULL, if_name, kCFStringEncodingMacRoman);
  99         interface = _SCNetworkInterfaceCreateWithBSDName(NULL, interface_name, kIncludeNoVirtualInterfaces);
 100         CFRelease(interface_name);
 101
 102         if (interface != NULL) {
 103                 expensive = is_expensive(interface);
 104                 CFRelease(interface);
 105         }
 106
 107         // mark ... or clear ... the [if_name] interface as "expensive"
 108         s = dgram_socket(AF_INET);
 109         if (s != -1) {
 110                 ifexpensive_set(s,
 111                                 if_name,
 112                                 ((expensive != NULL) && CFBooleanGetValue(expensive)) ? 1 : 0);
 113                 close(s);
 114         }
 115
 116         return expensive;
 117 }
 118
 119
 120 #ifdef  MAIN
 121
 122 int
 123 dgram_socket(int domain)
 124 {
 125         int     s;
 126
 127         s = socket(domain, SOCK_DGRAM, 0);
 128         if (s == -1) {
 129                 SC_log(LOG_ERR, "socket() failed: %s", strerror(errno));
 130         }
 131
 132         return s;
 133 }
 134
 135 int
 136 main(int argc, char **argv)
 137 {
 138         CFBooleanRef    expensive;
 139
 140         if (argc < 1 + 1) {
 141                 SCPrint(TRUE, stderr, CFSTR("usage: %s <interface>\n"), argv[0]);
 142                 exit(1);
 143         }
 144
 145         expensive = interface_update_expensive(argv[1]);
 146         if (expensive != NULL) {
 147                 SCPrint(TRUE, stdout, CFSTR("interface \"%s\": %@\n"), argv[1], expensive);
 148         } else {
 149                 SCPrint(TRUE, stdout, CFSTR("interface \"%s\": could not determine \"expensive\" status\n"), argv[1]);
 150         }
 151
 152         exit(0);
 153 }
 154 #endif  // MAIN