Plugins/KernelEventMonitor/ev_extra.m

   1 /*
   2  * Copyright (c) 2013-2016, 2018, 2020 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 #if     TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
  38 static Boolean
  39 haveMobileWiFi()
  40 {
  41         void * volatile fn_WeakFunction = (void *)&(WiFiManagerClientCreate);
  42         Boolean         haveFramework;
  43
  44         haveFramework = (fn_WeakFunction != NULL) ? TRUE : FALSE;
  45         return haveFramework;
  46 }
  47 #endif  // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
  48
  49
  50 static CFBooleanRef
  51 is_expensive(SCNetworkInterfaceRef _Nonnull interface)
  52 {
  53         CFBooleanRef    expensive;
  54         CFStringRef     interfaceType;
  55
  56         while (interface != NULL) {
  57                 SCNetworkInterfaceRef   child;
  58
  59                 child = SCNetworkInterfaceGetInterface(interface);
  60                 if (child == NULL) {
  61                         break;
  62                 }
  63
  64                 interface = child;
  65         }
  66         // by default, don't set/clear expensive
  67         expensive = NULL;
  68         interfaceType = SCNetworkInterfaceGetInterfaceType(interface);
  69         if (_SCNetworkInterfaceIsTethered(interface)) {
  70                 // if tethered (to iOS) interface
  71                 expensive = kCFBooleanTrue;
  72         } else if (_SCNetworkInterfaceIsBluetoothPAN(interface)) {
  73                 // if BT-PAN interface
  74                 expensive = kCFBooleanTrue;
  75         } else if (CFEqual(interfaceType, kSCNetworkInterfaceTypeWWAN)) {
  76                 // if WWAN [Ethernet] interface
  77                 expensive = kCFBooleanTrue;
  78         }
  79
  80         return expensive;
  81 }
  82
  83
  84 static int
  85 ifexpensive_set(int s, const char * name, uint32_t expensive)
  86 {
  87 #if     defined(SIOCGIFEXPENSIVE) && defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
  88         struct ifreq    ifr;
  89         int             ret;
  90
  91         memset(&ifr, 0, sizeof(ifr));
  92         strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
  93         ret = ioctl(s, SIOCGIFEXPENSIVE, &ifr);
  94         if ((ret == -1) && (errno != EPERM)) {
  95                 SC_log(LOG_ERR, "%s: ioctl(SIOCGIFEXPENSIVE) failed: %s", name, strerror(errno));
  96                 return ret;
  97         }
  98
  99         if (ifr.ifr_expensive == expensive) {
 100                 // if no change
 101                 return ret;
 102         }
 103
 104         ifr.ifr_expensive = expensive;
 105         ret = ioctl(s, SIOCSIFEXPENSIVE, &ifr);
 106         if ((ret == -1) && (errno != EPERM)) {
 107                 SC_log(LOG_ERR, "%s: ioctl(SIOCSIFEXPENSIVE) failed: %s", name, strerror(errno));
 108         }
 109
 110         return ret;
 111 #else   // defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
 112         return 0;
 113 #endif  // defined(SIOCSIFEXPENSIVE) && !defined(MAIN)
 114 }
 115
 116
 117 __private_extern__
 118 CFBooleanRef
 119 interface_update_expensive(const char *if_name)
 120 {
 121         CFBooleanRef            expensive;
 122         SCNetworkInterfaceRef   interface;
 123         CFStringRef             interface_name;
 124         int                     s;
 125
 126         interface_name = CFStringCreateWithCString(NULL, if_name, kCFStringEncodingUTF8);
 127         interface = _SCNetworkInterfaceCreateWithBSDName(NULL, interface_name, kIncludeNoVirtualInterfaces);
 128         CFRelease(interface_name);
 129         if (interface == NULL) {
 130                 return NULL;
 131         }
 132         expensive = is_expensive(interface);
 133         CFRelease(interface);
 134         if (expensive == NULL) {
 135                 return NULL;
 136         }
 137         // mark ... or clear ... the [if_name] interface as "expensive"
 138         s = dgram_socket(AF_INET);
 139         if (s != -1) {
 140                 ifexpensive_set(s,
 141                                 if_name,
 142                                 CFBooleanGetValue(expensive) ? 1 : 0);
 143                 close(s);
 144         }
 145
 146         return expensive;
 147 }
 148
 149
 150 #ifdef  MAIN
 151
 152 int
 153 dgram_socket(int domain)
 154 {
 155         int     s;
 156
 157         s = socket(domain, SOCK_DGRAM, 0);
 158         if (s == -1) {
 159                 SC_log(LOG_ERR, "socket() failed: %s", strerror(errno));
 160         }
 161
 162         return s;
 163 }
 164
 165 int
 166 main(int argc, char **argv)
 167 {
 168         CFBooleanRef    expensive;
 169
 170         if (argc < 1 + 1) {
 171                 SCPrint(TRUE, stderr, CFSTR("usage: %s <interface>\n"), argv[0]);
 172                 exit(1);
 173         }
 174
 175         expensive = interface_update_expensive(argv[1]);
 176         if (expensive != NULL) {
 177                 SCPrint(TRUE, stdout, CFSTR("%s: set expensive to %@\n"), argv[1], expensive);
 178         } else {
 179                 SCPrint(TRUE, stdout, CFSTR("%s: not changing expensive\n"), argv[1]);
 180         }
 181
 182         exit(0);
 183 }
 184 #endif  // MAIN