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 #include <network/private.h>
  21
  22 //Gets the DNSPolicy from NW PATH EVALUATOR
  23 mDNSexport void mDNSPlatformGetDNSRoutePolicy(mDNS *const m, DNSQuestion *q, mDNSBool *isBlocked)
  24 {
  25     (void) m;
  26     q->ServiceID = -1; // initialize the ServiceID to default value of -1
  27
  28     // Return for non-unicast DNS queries, invalid pid, if NWPathEvaluation is already done by the client, or NWPathEvaluation not available on this OS
  29     if (mDNSOpaque16IsZero(q->TargetQID) || (q->pid < 0) || (q->flags & kDNSServiceFlagsPathEvaluationDone) || !nw_endpoint_create_host)
  30     {
  31         *isBlocked = mDNSfalse;
  32         return;
  33     }
  34
  35     mDNSs32 service_id;
  36     mDNSu32 client_ifindex, dnspol_ifindex;
  37     int retval;
  38     struct proc_uniqidentifierinfo info;
  39     mDNSBool isUUIDSet;
  40
  41     char unenc_name[MAX_ESCAPED_DOMAIN_NAME];
  42     ConvertDomainNameToCString(&q->qname, unenc_name);
  43
  44     nw_endpoint_t host = nw_endpoint_create_host(unenc_name, "0");
  45     if (host == NULL)
  46         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_endpoint_t host is NULL", q->qname.c,
  47                DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
  48
  49     nw_parameters_t parameters = nw_parameters_create();
  50     if (parameters == NULL)
  51         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_endpoint_t parameters is NULL", q->qname.c,
  52                DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
  53
  54     // Check for all the special (negative) internal value interface indices before initializing client_ifindex
  55     if (   (q->InterfaceID == mDNSInterface_Any)
  56         || (q->InterfaceID == mDNSInterface_Unicast)
  57         || (q->InterfaceID == mDNSInterface_LocalOnly)
  58         || (q->InterfaceID == mDNSInterfaceMark)
  59         || (q->InterfaceID == mDNSInterface_P2P)
  60         || (q->InterfaceID == uDNSInterfaceMark))
  61     {
  62         client_ifindex = 0;
  63     }
  64     else
  65     {
  66         client_ifindex = (mDNSu32)(uintptr_t)q->InterfaceID;
  67     }
  68
  69
  70     if (client_ifindex > 0)
  71     {
  72         nw_interface_t client_intf = nw_interface_create_with_index(client_ifindex);
  73         nw_parameters_require_interface(parameters, client_intf);
  74         if (client_intf != NULL)
  75             network_release(client_intf);
  76         else
  77             LogInfo("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: client_intf returned by nw_interface_create_with_index() is NULL");
  78     }
  79
  80     nw_parameters_set_uid(parameters,(uid_t)q->euid);
  81
  82     if (q->pid != 0)
  83     {
  84         nw_parameters_set_pid(parameters, q->pid);
  85         retval = proc_pidinfo(q->pid, PROC_PIDUNIQIDENTIFIERINFO, 1, &info, sizeof(info));
  86         if (retval == (int)sizeof(info))
  87         {
  88             nw_parameters_set_e_proc_uuid(parameters, info.p_uuid);
  89             isUUIDSet = mDNStrue;
  90         }
  91         else
  92         {
  93             debugf("mDNSPlatformGetDNSRoutePolicy: proc_pidinfo returned %d", retval);
  94             isUUIDSet = mDNSfalse;
  95         }
  96     }
  97     else
  98     {
  99         nw_parameters_set_e_proc_uuid(parameters, q->uuid);
 100         isUUIDSet = mDNStrue;
 101     }
 102
 103     nw_path_evaluator_t evaluator = nw_path_create_evaluator_for_endpoint(host, parameters);
 104     if (evaluator == NULL)
 105         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,
 106                 DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
 107
 108     if (host != NULL)
 109         network_release(host);
 110     if (parameters != NULL)
 111         network_release(parameters);
 112
 113     nw_path_t path = nw_path_evaluator_copy_path(evaluator);
 114     if (path == NULL)
 115         LogMsg("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] nw_path_t path is NULL", q->qname.c,
 116                DNSTypeName(q->qtype), q->pid, q->euid, q->ServiceID);
 117
 118     service_id = nw_path_get_flow_divert_unit(path);
 119     if (service_id != 0)
 120     {
 121         q->ServiceID = service_id;
 122         LogInfo("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy: Query for %##s service ID is set ->service_ID:[%d] ", q->qname.c, service_id);
 123     }
 124     else
 125     {
 126         nw_interface_t nwpath_intf = nw_path_copy_scoped_interface(path);
 127         if (nwpath_intf != NULL)
 128         {
 129             // Use the new scoped interface given by NW PATH EVALUATOR
 130             dnspol_ifindex = nw_interface_get_index(nwpath_intf);
 131             q->InterfaceID = (mDNSInterfaceID)(uintptr_t)dnspol_ifindex;
 132
 133             network_release(nwpath_intf);
 134
 135             if (dnspol_ifindex != client_ifindex)
 136                 LogInfo("mDNSPlatformGetDNSRoutePolicy: DNS Route Policy has changed the scoped ifindex from [%d] to [%d]",
 137                         client_ifindex, dnspol_ifindex);
 138         }
 139         else
 140         {
 141             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);
 142         }
 143     }
 144
 145     if (isUUIDSet && (nw_path_get_status(path) == nw_path_status_unsatisfied) && (nw_path_get_reason(path) == nw_path_reason_policy_drop))
 146         *isBlocked = mDNStrue;
 147     else
 148         *isBlocked = mDNSfalse;
 149
 150     if (path != NULL)
 151         network_release(path);
 152     if (evaluator != NULL)
 153         network_release(evaluator);
 154
 155 }