configd.tproj/configd_server.c

   1 /*
   2  * Copyright (c) 2000-2011, 2013, 2015-2017 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 #pragma unused(port)
 102 #pragma unused(size)
 103 #pragma unused(info)
 104         mig_reply_error_t *     bufRequest      = msg;
 105         uint32_t                bufReply_q[MACH_MSG_BUFFER_SIZE/sizeof(uint32_t)];
 106         mig_reply_error_t *     bufReply        = (mig_reply_error_t *)bufReply_q;
 107         static size_t           bufSize         = 0;
 108         mach_msg_return_t       mr;
 109         int                     options;
 110
 111         if (bufSize == 0) {
 112                 // get max size for MiG reply buffers
 113                 bufSize = _config_subsystem.maxsize;
 114
 115                 // check if our on-the-stack reply buffer will be big enough
 116                 if (bufSize > sizeof(bufReply_q)) {
 117                         SC_log(LOG_NOTICE, "buffer size should be increased > %d",
 118                                _config_subsystem.maxsize);
 119                 }
 120         }
 121
 122         if (bufSize > sizeof(bufReply_q)) {
 123                 bufReply = CFAllocatorAllocate(NULL, _config_subsystem.maxsize, 0);
 124         }
 125         bufReply->RetCode = 0;
 126
 127         /* we have a request message */
 128         (void) config_demux(&bufRequest->Head, &bufReply->Head);
 129
 130         if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
 131                 if (bufReply->RetCode == MIG_NO_REPLY) {
 132                         bufReply->Head.msgh_remote_port = MACH_PORT_NULL;
 133                 } else if ((bufReply->RetCode != KERN_SUCCESS) &&
 134                            (bufRequest->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
 135                         /*
 136                          * destroy the request - but not the reply port
 137                          */
 138                         bufRequest->Head.msgh_remote_port = MACH_PORT_NULL;
 139                         mach_msg_destroy(&bufRequest->Head);
 140                 }
 141         }
 142
 143         if (bufReply->Head.msgh_remote_port != MACH_PORT_NULL) {
 144                 /*
 145                  * send reply.
 146                  *
 147                  * We don't want to block indefinitely because the client
 148                  * isn't receiving messages from the reply port.
 149                  * If we have a send-once right for the reply port, then
 150                  * this isn't a concern because the send won't block.
 151                  * If we have a send right, we need to use MACH_SEND_TIMEOUT.
 152                  * To avoid falling off the kernel's fast RPC path unnecessarily,
 153                  * we only supply MACH_SEND_TIMEOUT when absolutely necessary.
 154                  */
 155
 156                 options = MACH_SEND_MSG;
 157                 if (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) != MACH_MSG_TYPE_MOVE_SEND_ONCE) {
 158                         options |= MACH_SEND_TIMEOUT;
 159                 }
 160                 mr = mach_msg(&bufReply->Head,          /* msg */
 161                               options,                  /* option */
 162                               bufReply->Head.msgh_size, /* send_size */
 163                               0,                        /* rcv_size */
 164                               MACH_PORT_NULL,           /* rcv_name */
 165                               MACH_MSG_TIMEOUT_NONE,    /* timeout */
 166                               MACH_PORT_NULL);          /* notify */
 167
 168                 /* Has a message error occurred? */
 169                 switch (mr) {
 170                         case MACH_SEND_INVALID_DEST:
 171                         case MACH_SEND_TIMED_OUT:
 172                                 break;
 173                         default :
 174                                 /* Includes success case.  */
 175                                 goto done;
 176                 }
 177         }
 178
 179         if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
 180                 mach_msg_destroy(&bufReply->Head);
 181         }
 182
 183     done :
 184
 185         if (bufReply != (mig_reply_error_t *)bufReply_q)
 186                 CFAllocatorDeallocate(NULL, bufReply);
 187
 188         return;
 189 }
 190
 191
 192 static CFStringRef
 193 serverMPCopyDescription(const void *info)
 194 {
 195 #pragma unused(info)
 196         return CFStringCreateWithFormat(NULL, NULL, CFSTR("<main DynamicStore MP>"));
 197 }
 198
 199
 200 __private_extern__
 201 void
 202 server_init()
 203 {
 204         serverSessionRef        mySession;
 205         int                     ret;
 206         CFRunLoopSourceRef      rls;
 207         char                    *service_name;
 208         mach_port_t             service_port    = MACH_PORT_NULL;
 209         kern_return_t           status;
 210
 211         service_name = getenv("SCD_SERVER");
 212         if (service_name == NULL) {
 213                 service_name = SCD_SERVER;
 214         }
 215
 216         /* Check "configd" server status */
 217         status = bootstrap_check_in(bootstrap_port, service_name, &service_port);
 218         switch (status) {
 219                 case BOOTSTRAP_SUCCESS :
 220                         /* if we are being [re-]started by launchd */
 221                         break;
 222                 case BOOTSTRAP_NOT_PRIVILEGED :
 223                         /* if another instance of the server is starting */
 224                         SC_log(LOG_ERR, "'%s' server already starting", service_name);
 225                         exit (EX_UNAVAILABLE);
 226                 case BOOTSTRAP_SERVICE_ACTIVE :
 227                         /* if another instance of the server is active */
 228                         SC_log(LOG_ERR, "'%s' server already active", service_name);
 229                         exit (EX_UNAVAILABLE);
 230                 default :
 231                         SC_log(LOG_ERR, "server_init bootstrap_check_in(..., '%s', ...) failed: %s",
 232                                service_name,
 233                                bootstrap_strerror(status));
 234                         exit (EX_UNAVAILABLE);
 235         }
 236
 237         /* Create the primary / new connection port and backing session */
 238         mySession = addSession(service_port, serverMPCopyDescription);
 239         configd_port = mySession->serverPort;
 240
 241         /*
 242          * Create and add a run loop source for the port and add this source
 243          * to the default run loop mode.
 244          */
 245         rls = CFMachPortCreateRunLoopSource(NULL, configd_port, 0);
 246         CFRunLoopAddSource(CFRunLoopGetCurrent(), rls, kCFRunLoopDefaultMode);
 247         CFRelease(rls);
 248
 249         // bump thread QoS priority
 250         ret = pthread_set_qos_class_self_np(QOS_CLASS_USER_INITIATED, 0);
 251         if (ret != 0) {
 252                 SC_log(LOG_ERR, "pthread_set_qos_class_self_np() failed: %s", strerror(errno));
 253         }
 254
 255         return;
 256 }
 257
 258
 259 __private_extern__
 260 int
 261 server_shutdown()
 262 {
 263         if (configd_port != NULL) {
 264                 mach_port_t     service_port    = CFMachPortGetPort(configd_port);
 265
 266                 CFMachPortInvalidate(configd_port);
 267                 CFRelease(configd_port);
 268                 configd_port = NULL;
 269
 270                 if (service_port != MACH_PORT_NULL) {
 271                         (void) mach_port_mod_refs(mach_task_self(),
 272                                                   service_port,
 273                                                   MACH_PORT_RIGHT_RECEIVE,
 274                                                   -1);
 275                 }
 276         }
 277
 278         return EX_OK;
 279 }
 280
 281
 282 __private_extern__
 283 void
 284 server_loop()
 285 {
 286         pthread_setname_np("SCDynamicStore");
 287
 288         while (TRUE) {
 289                 /*
 290                  * process one run loop event
 291                  */
 292                 CFRunLoopRunInMode(kCFRunLoopDefaultMode, 1.0e10, TRUE);
 293
 294                 /*
 295                  * check for, and if necessary, push out change notifications
 296                  * to other processes.
 297                  */
 298                 pushNotifications();
 299         }
 300 }