mDNSMacOSX/uDNSPathEvalulation.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2013, 2015 Apple Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include "mDNSMacOSX.h"
  19 #include <libproc.h>
  20
  21 #if __has_include(<nw/private.h>)
  22     #include <nw/private.h>
  23 #else
  24     #include <network/private.h>
  25 #endif
  26
  27 #include "dns_sd_internal.h"
  28
  29 //Gets the DNSPolicy from NW PATH EVALUATOR
  30 mDNSexport void mDNSPlatformGetDNSRoutePolicy(DNSQuestion *q, mDNSBool *isBlocked)
  31 {
  32     q->ServiceID = -1; // initialize the ServiceID to default value of -1
  33
  34     // Return for non-unicast DNS queries, invalid pid, if NWPathEvaluation is already done by the client, or NWPathEvaluation not available on this OS
  35     if (mDNSOpaque16IsZero(q->TargetQID) || (q->pid < 0) || (q->flags & kDNSServiceFlagsPathEvaluationDone) || !nw_endpoint_create_host)
  36     {
  37         *isBlocked = mDNSfalse;
  38         return;
  39     }
  40
  41     mDNSs32 service_id;
  42     mDNSu32 client_ifindex, dnspol_ifindex;
  43     int retval;
  44     struct proc_uniqidentifierinfo info;
  45     mDNSBool isUUIDSet;
  46
  47     char unenc_name[MAX_ESCAPED_DOMAIN_NAME];
  48     ConvertDomainNameToCString(&q->qname, unenc_name);
  49
  50     nw_endpoint_t host = nw_endpoint_create_host(unenc_name, "0");
  51     if (host == NULL)
  52         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_endpoint_t host is NULL", q->qname.c,
  53                DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
  54
  55     nw_parameters_t parameters = nw_parameters_create();
  56     if (parameters == NULL)
  57         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_endpoint_t parameters is NULL", q->qname.c,
  58                DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
  59
  60     // Check for all the special (negative) internal value interface indices before initializing client_ifindex
  61     if (   (q->InterfaceID == mDNSInterface_Any)
  62         || (q->InterfaceID == mDNSInterface_Unicast)
  63         || (q->InterfaceID == mDNSInterface_LocalOnly)
  64         || (q->InterfaceID == mDNSInterfaceMark)
  65         || (q->InterfaceID == mDNSInterface_P2P)
  66         || (q->InterfaceID == mDNSInterface_BLE)
  67         || (q->InterfaceID == uDNSInterfaceMark))
  68     {
  69         client_ifindex = 0;
  70     }
  71     else
  72     {
  73         client_ifindex = (mDNSu32)(uintptr_t)q->InterfaceID;
  74     }
  75
  76
  77     if (client_ifindex > 0)
  78     {
  79         nw_interface_t client_intf = nw_interface_create_with_index(client_ifindex);
  80         nw_parameters_require_interface(parameters, client_intf);
  81         if (client_intf != NULL)
  82             network_release(client_intf);
  83         else
  84             LogInfo("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: client_intf returned by nw_interface_create_with_index() is NULL");
  85     }
  86
  87     nw_parameters_set_uid(parameters,(uid_t)q->euid);
  88
  89     if (q->pid != 0)
  90     {
  91         nw_parameters_set_pid(parameters, q->pid);
  92         retval = proc_pidinfo(q->pid, PROC_PIDUNIQIDENTIFIERINFO, 1, &info, sizeof(info));
  93         if (retval == (int)sizeof(info))
  94         {
  95             nw_parameters_set_e_proc_uuid(parameters, info.p_uuid);
  96             isUUIDSet = mDNStrue;
  97         }
  98         else
  99         {
 100             debugf("mDNSPlatformGetDNSRoutePolicy: proc_pidinfo returned %d", retval);
 101             isUUIDSet = mDNSfalse;
 102         }
 103     }
 104     else
 105     {
 106         nw_parameters_set_e_proc_uuid(parameters, q->uuid);
 107         isUUIDSet = mDNStrue;
 108     }
 109
 110     nw_path_evaluator_t evaluator = nw_path_create_evaluator_for_endpoint(host, parameters);
 111     if (evaluator == NULL)
 112         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_path_evaluator_t evaluator is NULL", q->qname.c,
 113                 DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
 114
 115     if (host != NULL)
 116         network_release(host);
 117     if (parameters != NULL)
 118         network_release(parameters);
 119
 120     nw_path_t path = nw_path_evaluator_copy_path(evaluator);
 121     if (path == NULL)
 122         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_path_t path is NULL", q->qname.c,
 123                DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
 124
 125     service_id = nw_path_get_flow_divert_unit(path);
 126     if (service_id != 0)
 127     {
 128         q->ServiceID = service_id;
 129         LogInfo("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s service ID is set ->service_ID:[%d] ", q->qname.c, service_id);
 130     }
 131     else
 132     {
 133         nw_interface_t nwpath_intf = nw_path_copy_scoped_interface(path);
 134         if (nwpath_intf != NULL)
 135         {
 136             // Use the new scoped interface given by NW PATH EVALUATOR
 137             dnspol_ifindex = nw_interface_get_index(nwpath_intf);
 138             q->InterfaceID = (mDNSInterfaceID)(uintptr_t)dnspol_ifindex;
 139
 140             network_release(nwpath_intf);
 141
 142             if (dnspol_ifindex != client_ifindex)
 143                 LogInfo("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy has changed the scoped ifindex from [%d] to [%d]",
 144                         client_ifindex, dnspol_ifindex);
 145         }
 146         else
 147         {
 148             debugf("mDNSPlatformGetDNSRoutePolicy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_interface_t nwpath_intf is NULL ", q->qname.c, DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
 149         }
 150     }
 151
 152     if (isUUIDSet && (nw_path_get_status(path) == nw_path_status_unsatisfied) && (nw_path_get_reason(path) == nw_path_reason_policy_drop))
 153         *isBlocked = mDNStrue;
 154     else
 155         *isBlocked = mDNSfalse;
 156
 157     if (path != NULL)
 158         network_release(path);
 159     if (evaluator != NULL)
 160         network_release(evaluator);
 161
 162 }