configd.tproj/configd_server.c

   1 /*
   2  * Copyright (c) 2000-2011, 2013, 2015, 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  * March 9, 2004                Allan Nathanson <ajn@apple.com>
  28  * - add DNS configuration server
  29  *
  30  * June 1, 2001                 Allan Nathanson <ajn@apple.com>
  31  * - public API conversion
  32  *
  33  * March 24, 2000               Allan Nathanson <ajn@apple.com>
  34  * - initial revision
  35  */
  36
  37 #include <TargetConditionals.h>
  38 #include <sysexits.h>
  39 #include <unistd.h>
  40 #include <sys/types.h>
  41 #include <servers/bootstrap.h>
  42
  43 #include "configd.h"
  44 #include "configd_server.h"
  45 #include "notify_server.h"
  46 #include "session.h"
  47
  48 /* MiG generated externals and functions */
  49 extern struct mig_subsystem     _config_subsystem;
  50 extern boolean_t                config_server(mach_msg_header_t *, mach_msg_header_t *);
  51
  52 /* configd server port (for new session requests) */
  53 static CFMachPortRef            configd_port            = NULL;
  54
  55
  56 __private_extern__
  57 boolean_t
  58 config_demux(mach_msg_header_t *request, mach_msg_header_t *reply)
  59 {
  60         Boolean                         processed = FALSE;
  61
  62         /*
  63          * (attempt to) process SCDynamicStore requests.
  64          */
  65         processed = config_server(request, reply);
  66         if (processed) {
  67                 return TRUE;
  68         }
  69
  70         /*
  71          * (attempt to) process (NO MORE SENDERS) notification messages.
  72          */
  73         processed = notify_server(request, reply);
  74         if (processed) {
  75                 return TRUE;
  76         }
  77
  78         /*
  79          * unknown message ID, log and return an error.
  80          */
  81         SC_log(LOG_ERR, "unknown message ID (%d) received", request->msgh_id);
  82         reply->msgh_bits        = MACH_MSGH_BITS(MACH_MSGH_BITS_REMOTE(request->msgh_bits), 0);
  83         reply->msgh_remote_port = request->msgh_remote_port;
  84         reply->msgh_size        = sizeof(mig_reply_error_t);    /* Minimal size */
  85         reply->msgh_local_port  = MACH_PORT_NULL;
  86         reply->msgh_id          = request->msgh_id + 100;
  87         ((mig_reply_error_t *)reply)->NDR = NDR_record;
  88         ((mig_reply_error_t *)reply)->RetCode = MIG_BAD_ID;
  89
  90         return FALSE;
  91 }
  92
  93
  94 #define MACH_MSG_BUFFER_SIZE    128
  95
  96
  97 __private_extern__
  98 void
  99 configdCallback(CFMachPortRef port, void *msg, CFIndex size, void *info)
 100 {
 101         mig_reply_error_t *     bufRequest      = msg;
 102         uint32_t                bufReply_q[MACH_MSG_BUFFER_SIZE/sizeof(uint32_t)];
 103         mig_reply_error_t *     bufReply        = (mig_reply_error_t *)bufReply_q;
 104         static CFIndex          bufSize         = 0;
 105         mach_msg_return_t       mr;
 106         int                     options;
 107
 108         if (bufSize == 0) {
 109                 // get max size for MiG reply buffers
 110                 bufSize = _config_subsystem.maxsize;
 111
 112                 // check if our on-the-stack reply buffer will be big enough
 113                 if (bufSize > sizeof(bufReply_q)) {
 114                         SC_log(LOG_NOTICE, "buffer size should be increased > %d",
 115                                _config_subsystem.maxsize);
 116                 }
 117         }
 118
 119         if (bufSize > sizeof(bufReply_q)) {
 120                 bufReply = CFAllocatorAllocate(NULL, _config_subsystem.maxsize, 0);
 121         }
 122         bufReply->RetCode = 0;
 123
 124         /* we have a request message */
 125         (void) config_demux(&bufRequest->Head, &bufReply->Head);
 126
 127         if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
 128                 if (bufReply->RetCode == MIG_NO_REPLY) {
 129                         bufReply->Head.msgh_remote_port = MACH_PORT_NULL;
 130                 } else if ((bufReply->RetCode != KERN_SUCCESS) &&
 131                            (bufRequest->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
 132                         /*
 133                          * destroy the request - but not the reply port
 134                          */
 135                         bufRequest->Head.msgh_remote_port = MACH_PORT_NULL;
 136                         mach_msg_destroy(&bufRequest->Head);
 137                 }
 138         }
 139
 140         if (bufReply->Head.msgh_remote_port != MACH_PORT_NULL) {
 141                 /*
 142                  * send reply.
 143                  *
 144                  * We don't want to block indefinitely because the client
 145                  * isn't receiving messages from the reply port.
 146                  * If we have a send-once right for the reply port, then
 147                  * this isn't a concern because the send won't block.
 148                  * If we have a send right, we need to use MACH_SEND_TIMEOUT.
 149                  * To avoid falling off the kernel's fast RPC path unnecessarily,
 150                  * we only supply MACH_SEND_TIMEOUT when absolutely necessary.
 151                  */
 152
 153                 options = MACH_SEND_MSG;
 154                 if (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) != MACH_MSG_TYPE_MOVE_SEND_ONCE) {
 155                         options |= MACH_SEND_TIMEOUT;
 156                 }
 157                 mr = mach_msg(&bufReply->Head,          /* msg */
 158                               options,                  /* option */
 159                               bufReply->Head.msgh_size, /* send_size */
 160                               0,                        /* rcv_size */
 161                               MACH_PORT_NULL,           /* rcv_name */
 162                               MACH_MSG_TIMEOUT_NONE,    /* timeout */
 163                               MACH_PORT_NULL);          /* notify */
 164
 165                 /* Has a message error occurred? */
 166                 switch (mr) {
 167                         case MACH_SEND_INVALID_DEST:
 168                         case MACH_SEND_TIMED_OUT:
 169                                 break;
 170                         default :
 171                                 /* Includes success case.  */
 172                                 goto done;
 173                 }
 174         }
 175
 176         if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
 177                 mach_msg_destroy(&bufReply->Head);
 178         }
 179
 180     done :
 181
 182         if (bufReply != (mig_reply_error_t *)bufReply_q)
 183                 CFAllocatorDeallocate(NULL, bufReply);
 184
 185         return;
 186 }
 187
 188
 189 static CFStringRef
 190 serverMPCopyDescription(const void *info)
 191 {
 192         return CFStringCreateWithFormat(NULL, NULL, CFSTR("<main DynamicStore MP>"));
 193 }
 194
 195
 196 __private_extern__
 197 void
 198 server_init()
 199 {
 200         serverSessionRef        mySession;
 201         int                     ret;
 202         CFRunLoopSourceRef      rls;
 203         char                    *service_name;
 204         mach_port_t             service_port    = MACH_PORT_NULL;
 205         kern_return_t           status;
 206
 207         service_name = getenv("SCD_SERVER");
 208         if (service_name == NULL) {
 209                 service_name = SCD_SERVER;
 210         }
 211
 212         /* Check "configd" server status */
 213         status = bootstrap_check_in(bootstrap_port, service_name, &service_port);
 214         switch (status) {
 215                 case BOOTSTRAP_SUCCESS :
 216                         /* if we are being [re-]started by launchd */
 217                         break;
 218                 case BOOTSTRAP_NOT_PRIVILEGED :
 219                         /* if another instance of the server is starting */
 220                         SC_log(LOG_ERR, "'%s' server already starting", service_name);
 221                         exit (EX_UNAVAILABLE);
 222                 case BOOTSTRAP_SERVICE_ACTIVE :
 223                         /* if another instance of the server is active */
 224                         SC_log(LOG_ERR, "'%s' server already active", service_name);
 225                         exit (EX_UNAVAILABLE);
 226                 default :
 227                         SC_log(LOG_ERR, "server_init bootstrap_check_in(..., '%s', ...) failed: %s",
 228                                service_name,
 229                                bootstrap_strerror(status));
 230                         exit (EX_UNAVAILABLE);
 231         }
 232
 233         /* Create the primary / new connection port and backing session */
 234         mySession = addSession(service_port, serverMPCopyDescription);
 235         configd_port = mySession->serverPort;
 236
 237         /*
 238          * Create and add a run loop source for the port and add this source
 239          * to the default run loop mode.
 240          */
 241         rls = CFMachPortCreateRunLoopSource(NULL, configd_port, 0);
 242         CFRunLoopAddSource(CFRunLoopGetCurrent(), rls, kCFRunLoopDefaultMode);
 243         CFRelease(rls);
 244
 245         // bump thread QoS priority
 246         ret = pthread_set_qos_class_self_np(QOS_CLASS_USER_INITIATED, 0);
 247         if (ret != 0) {
 248                 SC_log(LOG_ERR, "pthread_set_qos_class_self_np() failed: %s", strerror(errno));
 249         }
 250
 251         return;
 252 }
 253
 254
 255 __private_extern__
 256 int
 257 server_shutdown()
 258 {
 259         if (configd_port != NULL) {
 260                 mach_port_t     service_port    = CFMachPortGetPort(configd_port);
 261
 262                 CFMachPortInvalidate(configd_port);
 263                 CFRelease(configd_port);
 264                 configd_port = NULL;
 265
 266                 if (service_port != MACH_PORT_NULL) {
 267                         (void) mach_port_mod_refs(mach_task_self(),
 268                                                   service_port,
 269                                                   MACH_PORT_RIGHT_RECEIVE,
 270                                                   -1);
 271                 }
 272         }
 273
 274         return EX_OK;
 275 }
 276
 277
 278 __private_extern__
 279 void
 280 server_loop()
 281 {
 282         pthread_setname_np("SCDynamicStore");
 283
 284         while (TRUE) {
 285                 /*
 286                  * process one run loop event
 287                  */
 288                 CFRunLoopRunInMode(kCFRunLoopDefaultMode, 1.0e10, TRUE);
 289
 290                 /*
 291                  * check for, and if necessary, push out change notifications
 292                  * to other processes.
 293                  */
 294                 pushNotifications();
 295         }
 296 }