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         int             ret;
  79
  80         bzero(&ifr, sizeof(ifr));
  81         strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
  82         ifr.ifr_expensive = expensive;
  83         ret = ioctl(s, SIOCSIFEXPENSIVE, &ifr);
  84         if (ret == -1) {
  85                 SC_log(LOG_ERR, "%s: ioctl(SIOCSIFEXPENSIVE) failed: %s", name, strerror(errno));
  86         }
  87
  88         return ret;
  89 #else   // defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
  90         return 0;
  91 #endif  // defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
  92 }
  93
  94
  95 __private_extern__
  96 CFBooleanRef
  97 interface_update_expensive(const char *if_name)
  98 {
  99         CFBooleanRef            expensive       = NULL;
 100         SCNetworkInterfaceRef   interface;
 101         CFStringRef             interface_name;
 102         int                     s;
 103
 104         interface_name = CFStringCreateWithCString(NULL, if_name, kCFStringEncodingMacRoman);
 105         interface = _SCNetworkInterfaceCreateWithBSDName(NULL, interface_name, kIncludeNoVirtualInterfaces);
 106         CFRelease(interface_name);
 107
 108         if (interface != NULL) {
 109                 expensive = is_expensive(interface);
 110                 CFRelease(interface);
 111         }
 112
 113         // mark ... or clear ... the [if_name] interface as "expensive"
 114         s = dgram_socket(AF_INET);
 115         if (s != -1) {
 116                 ifexpensive_set(s,
 117                                 if_name,
 118                                 ((expensive != NULL) && CFBooleanGetValue(expensive)) ? 1 : 0);
 119                 close(s);
 120         }
 121
 122         return expensive;
 123 }
 124
 125
 126 #ifdef  MAIN
 127
 128 int
 129 dgram_socket(int domain)
 130 {
 131         int     s;
 132
 133         s = socket(domain, SOCK_DGRAM, 0);
 134         if (s == -1) {
 135                 SC_log(LOG_ERR, "socket() failed: %s", strerror(errno));
 136         }
 137
 138         return s;
 139 }
 140
 141 int
 142 main(int argc, char **argv)
 143 {
 144         CFBooleanRef    expensive;
 145
 146         if (argc < 1 + 1) {
 147                 SCPrint(TRUE, stderr, CFSTR("usage: %s <interface>\n"), argv[0]);
 148                 exit(1);
 149         }
 150
 151         expensive = interface_update_expensive(argv[1]);
 152         if (expensive != NULL) {
 153                 SCPrint(TRUE, stdout, CFSTR("interface \"%s\": %@\n"), argv[1], expensive);
 154         } else {
 155                 SCPrint(TRUE, stdout, CFSTR("interface \"%s\": could not determine \"expensive\" status\n"), argv[1]);
 156         }
 157
 158         exit(0);
 159 }
 160 #endif  // MAIN