]> git.saurik.com Git - apple/xnu.git/blobdiff - libsyscall/mach/mach_msg.c
xnu-2782.10.72.tar.gz
[apple/xnu.git] / libsyscall / mach / mach_msg.c
index 87f6cb573949a440a11f5942b22afa9239df30ba..676a5392c33dcc8b3db0f1a6df2dc02f7401fe1c 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2007 Apple Inc. All rights reserved.
+ * Copyright (c) 1999-2013 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
 #include <mach/message.h>
 #include <mach/mig_errors.h>
 #include <mach/vm_statistics.h>
+#include <TargetConditionals.h>
+
+extern int proc_importance_assertion_begin_with_msg(mach_msg_header_t * msg, mach_msg_trailer_t * trailer, uint64_t * assertion_handlep);
+extern int proc_importance_assertion_complete(uint64_t assertion_handle);
 
 #define MACH_MSG_TRAP(msg, opt, ssize, rsize, rname, to, not) \
         mach_msg_trap((msg), (opt), (ssize), (rsize), (rname), (to), (not))
@@ -271,6 +275,7 @@ mach_msg_destroy(mach_msg_header_t *msg)
      */
 
     mach_msg_destroy_port(msg->msgh_remote_port, MACH_MSGH_BITS_REMOTE(mbits));
+    mach_msg_destroy_port(msg->msgh_voucher_port, MACH_MSGH_BITS_VOUCHER(mbits));
 
     if (mbits & MACH_MSGH_BITS_COMPLEX) {
        mach_msg_base_t         *base;
@@ -378,16 +383,17 @@ mach_msg_server_once(
        mach_msg_return_t mr;
        kern_return_t kr;
        mach_port_t self = mach_task_self_;
+       voucher_mach_msg_state_t old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
 
-       options &= ~(MACH_SEND_MSG|MACH_RCV_MSG);
+       options &= ~(MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_VOUCHER);
 
        trailer_alloc = REQUESTED_TRAILER_SIZE(options);
-       request_alloc = round_page(max_size + trailer_alloc);
+       request_alloc = (mach_msg_size_t)round_page(max_size + trailer_alloc);
 
        request_size = (options & MACH_RCV_LARGE) ?
                   request_alloc : max_size + trailer_alloc;
 
-       reply_alloc = round_page((options & MACH_SEND_TRAILER) ? 
+       reply_alloc = (mach_msg_size_t)round_page((options & MACH_SEND_TRAILER) ? 
                             (max_size + MAX_TRAILER_SIZE) :
                             max_size);
 
@@ -412,14 +418,14 @@ mach_msg_server_once(
                        return kr;
                }    
        
-               mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|options,
+               mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|MACH_RCV_VOUCHER|options,
                                          0, request_size, rcv_name,
                                          MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
        
                if (!((mr == MACH_RCV_TOO_LARGE) && (options & MACH_RCV_LARGE)))
                        break;
 
-               new_request_alloc = round_page(bufRequest->Head.msgh_size +
+               new_request_alloc = (mach_msg_size_t)round_page(bufRequest->Head.msgh_size +
                                                                           trailer_alloc);
                vm_deallocate(self,
                                (vm_address_t) bufRequest,
@@ -430,6 +436,8 @@ mach_msg_server_once(
        if (mr == MACH_MSG_SUCCESS) {
        /* we have a request message */
 
+               old_state = voucher_mach_msg_adopt(&bufRequest->Head);
+
                (void) (*demux)(&bufRequest->Head, &bufReply->Head);
 
                if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
@@ -472,6 +480,8 @@ mach_msg_server_once(
        }
 
  done_once:
+       voucher_mach_msg_revert(old_state);
+
        (void)vm_deallocate(self,
                        (vm_address_t) bufRequest,
                        request_alloc);
@@ -503,55 +513,60 @@ mach_msg_server(
        mach_msg_return_t mr;
        kern_return_t kr;
        mach_port_t self = mach_task_self_;
+       voucher_mach_msg_state_t old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
+       boolean_t buffers_swapped = FALSE;
 
-       options &= ~(MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_OVERWRITE);
+       options &= ~(MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_VOUCHER|MACH_RCV_OVERWRITE);
 
-       reply_alloc = round_page((options & MACH_SEND_TRAILER) ? 
-                            (max_size + MAX_TRAILER_SIZE) : max_size);
+       reply_alloc = (mach_msg_size_t)round_page((options & MACH_SEND_TRAILER) ?
+                                                 (max_size + MAX_TRAILER_SIZE) : max_size);
 
        kr = vm_allocate(self,
-                    (vm_address_t *)&bufReply,
-                    reply_alloc,
-                    VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE);
-       if (kr != KERN_SUCCESS) 
+                        (vm_address_t *)&bufReply,
+                        reply_alloc,
+                        VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE);
+       if (kr != KERN_SUCCESS)
                return kr;
 
        request_alloc = 0;
        trailer_alloc = REQUESTED_TRAILER_SIZE(options);
-       new_request_alloc = round_page(max_size + trailer_alloc);
+       new_request_alloc = (mach_msg_size_t)round_page(max_size + trailer_alloc);
 
        request_size = (options & MACH_RCV_LARGE) ?
-                  new_request_alloc : max_size + trailer_alloc;
+       new_request_alloc : max_size + trailer_alloc;
 
        for (;;) {
                if (request_alloc < new_request_alloc) {
                        request_alloc = new_request_alloc;
                        kr = vm_allocate(self,
-                               (vm_address_t *)&bufRequest,
-                               request_alloc,
-                               VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE);
+                                        (vm_address_t *)&bufRequest,
+                                        request_alloc,
+                                        VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE);
                        if (kr != KERN_SUCCESS) {
                                vm_deallocate(self,
-                                               (vm_address_t)bufReply,
-                                               reply_alloc);
+                                             (vm_address_t)bufReply,
+                                             reply_alloc);
                                return kr;
                        }
                }
-               
-               mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|options,
-                               0, request_size, rcv_name,
-                               MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
-       
+
+               mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|MACH_RCV_VOUCHER|options,
+                             0, request_size, rcv_name,
+                             MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+
                while (mr == MACH_MSG_SUCCESS) {
                        /* we have another request message */
 
+                       buffers_swapped = FALSE;
+                       old_state = voucher_mach_msg_adopt(&bufRequest->Head);
+
                        (void) (*demux)(&bufRequest->Head, &bufReply->Head);
 
                        if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
                                if (bufReply->RetCode == MIG_NO_REPLY)
                                        bufReply->Head.msgh_remote_port = MACH_PORT_NULL;
                                else if ((bufReply->RetCode != KERN_SUCCESS) &&
-                                       (bufRequest->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
+                                        (bufRequest->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
                                        /* destroy the request - but not the reply port */
                                        bufRequest->Head.msgh_remote_port = MACH_PORT_NULL;
                                        mach_msg_destroy(&bufRequest->Head);
@@ -572,55 +587,226 @@ mach_msg_server(
                                        mig_reply_error_t *bufTemp;
 
                                        mr = mach_msg(
-                                               &bufReply->Head,
-                                               (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) ==
-                                                MACH_MSG_TYPE_MOVE_SEND_ONCE) ?
-                                                MACH_SEND_MSG|MACH_RCV_MSG|options :
-                                                MACH_SEND_MSG|MACH_RCV_MSG|MACH_SEND_TIMEOUT|options,
-                                               bufReply->Head.msgh_size, request_size, rcv_name,
-                                               MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+                                             &bufReply->Head,
+                                             (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) ==
+                                              MACH_MSG_TYPE_MOVE_SEND_ONCE) ?
+                                             MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_VOUCHER|options :
+                                             MACH_SEND_MSG|MACH_RCV_MSG|MACH_SEND_TIMEOUT|MACH_RCV_TIMEOUT|MACH_RCV_VOUCHER|options,
+                                             bufReply->Head.msgh_size, request_size, rcv_name,
+                                             MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
 
                                        /* swap request and reply */
                                        bufTemp = bufRequest;
                                        bufRequest = bufReply;
                                        bufReply = bufTemp;
-
+                                       buffers_swapped = TRUE;
                                } else {
                                        mr = mach_msg_overwrite(
                                                &bufReply->Head,
                                                (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) ==
                                                 MACH_MSG_TYPE_MOVE_SEND_ONCE) ?
-                                                MACH_SEND_MSG|MACH_RCV_MSG|options :
-                                                MACH_SEND_MSG|MACH_RCV_MSG|MACH_SEND_TIMEOUT|options,
+                                                MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_VOUCHER|options :
+                                                MACH_SEND_MSG|MACH_RCV_MSG|MACH_SEND_TIMEOUT|MACH_RCV_TIMEOUT|MACH_RCV_VOUCHER|options,
                                                bufReply->Head.msgh_size, request_size, rcv_name,
                                                MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL,
                                                &bufRequest->Head, 0);
                                }
-                               
+
                                if ((mr != MACH_SEND_INVALID_DEST) &&
-                                       (mr != MACH_SEND_TIMED_OUT))
+                                   (mr != MACH_SEND_TIMED_OUT) &&
+                                   (mr != MACH_RCV_TIMED_OUT)) {
+
+                                       voucher_mach_msg_revert(old_state);
+                                       old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
+
                                        continue;
+                               }
+                       }
+                       /* 
+                        * Need to destroy the reply msg in case if there was a send timeout or
+                        * invalid destination. The reply msg would be swapped with request msg
+                        * if buffers_swapped is true, thus destroy request msg instead of
+                        * reply msg in such cases.
+                        */
+                       if (mr != MACH_RCV_TIMED_OUT) {
+                               if (buffers_swapped) {
+                                       if (bufRequest->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
+                                               mach_msg_destroy(&bufRequest->Head);
+                               } else {
+                                       if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
+                                               mach_msg_destroy(&bufReply->Head);
+                               }
+                       }
+                       voucher_mach_msg_revert(old_state);
+                       old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
+
+                       mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|MACH_RCV_VOUCHER|options,
+                                       0, request_size, rcv_name,
+                                       MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+
+               } /* while (mr == MACH_MSG_SUCCESS) */
+
+               if ((mr == MACH_RCV_TOO_LARGE) && (options & MACH_RCV_LARGE)) {
+                       new_request_alloc = (mach_msg_size_t)round_page(bufRequest->Head.msgh_size +
+                                                                       trailer_alloc);
+                       request_size = new_request_alloc;
+                       vm_deallocate(self,
+                                     (vm_address_t) bufRequest,
+                                     request_alloc);
+                       continue;
+               }
+
+               break;
+
+       } /* for(;;) */
+
+       (void)vm_deallocate(self,
+                           (vm_address_t) bufRequest,
+                           request_alloc);
+       (void)vm_deallocate(self,
+                           (vm_address_t) bufReply,
+                           reply_alloc);
+       return mr;
+}
+
+/*
+ *     Routine:        mach_msg_server_importance
+ *     Purpose:
+ *             A simple generic server function which handles importance
+ *             promotion assertions for adaptive daemons.
+ */
+mach_msg_return_t
+mach_msg_server_importance(
+       boolean_t (*demux)(mach_msg_header_t *, mach_msg_header_t *),
+       mach_msg_size_t max_size,
+       mach_port_t rcv_name,
+       mach_msg_options_t options)
+{
+       mig_reply_error_t *bufRequest, *bufReply;
+       mach_msg_size_t request_size;
+       mach_msg_size_t new_request_alloc;
+       mach_msg_size_t request_alloc;
+       mach_msg_size_t trailer_alloc;
+       mach_msg_size_t reply_alloc;
+       mach_msg_return_t mr;
+       kern_return_t kr;
+       mach_port_t self = mach_task_self_;
+       int retval = 1;
+       uint64_t token;
+       voucher_mach_msg_state_t old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
+
+       options &= ~(MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_VOUCHER|MACH_RCV_OVERWRITE);
+
+       reply_alloc = (mach_msg_size_t)round_page((options & MACH_SEND_TRAILER) ? 
+                            (max_size + MAX_TRAILER_SIZE) : max_size);
+
+       kr = vm_allocate(self,
+                    (vm_address_t *)&bufReply,
+                    reply_alloc,
+                    VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE);
+       if (kr != KERN_SUCCESS) 
+               return kr;
+
+       request_alloc = 0;
+       trailer_alloc = REQUESTED_TRAILER_SIZE(options);
+       new_request_alloc = (mach_msg_size_t)round_page(max_size + trailer_alloc);
+
+       request_size = (options & MACH_RCV_LARGE) ?
+                  new_request_alloc : max_size + trailer_alloc;
+
+       for (;;) {
+               if (request_alloc < new_request_alloc) {
+                       request_alloc = new_request_alloc;
+                       kr = vm_allocate(self,
+                               (vm_address_t *)&bufRequest,
+                               request_alloc,
+                               VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE);
+                       if (kr != KERN_SUCCESS) {
+                               vm_deallocate(self,
+                                               (vm_address_t)bufReply,
+                                               reply_alloc);
+                               return kr;
+                       }
+               }
+               
+               mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|MACH_RCV_VOUCHER|options,
+                               0, request_size, rcv_name,
+                               MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+       
+               if (mr == MACH_MSG_SUCCESS) {
+                       /* we have another request message */
+
+                       old_state = voucher_mach_msg_adopt(&bufRequest->Head);
+
+                       retval = proc_importance_assertion_begin_with_msg(&bufRequest->Head, NULL, &token);
+
+                       (void) (*demux)(&bufRequest->Head, &bufReply->Head);
+
+                       if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
+                               if (bufReply->RetCode == MIG_NO_REPLY)
+                                       bufReply->Head.msgh_remote_port = MACH_PORT_NULL;
+                               else if ((bufReply->RetCode != KERN_SUCCESS) &&
+                                       (bufRequest->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
+                                       /* destroy the request - but not the reply port */
+                                       bufRequest->Head.msgh_remote_port = MACH_PORT_NULL;
+                                       mach_msg_destroy(&bufRequest->Head);
+                               }
+                       }
+
+                       /*
+                        * We don't want to block indefinitely because the client
+                        * isn't receiving messages from the reply port.
+                        * If we have a send-once right for the reply port, then
+                        * this isn't a concern because the send won't block.
+                        * If we have a send right, we need to use MACH_SEND_TIMEOUT.
+                        * To avoid falling off the kernel's fast RPC path,
+                        * we only supply MACH_SEND_TIMEOUT when absolutely necessary.
+                        */
+                       if (bufReply->Head.msgh_remote_port != MACH_PORT_NULL) {
+
+                               mr = mach_msg(
+                                       &bufReply->Head,
+                                       (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) ==
+                                        MACH_MSG_TYPE_MOVE_SEND_ONCE) ?
+                                        MACH_SEND_MSG|options :
+                                        MACH_SEND_MSG|MACH_SEND_TIMEOUT|options,
+                                       bufReply->Head.msgh_size, 0, MACH_PORT_NULL,
+                                       MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+
+                               if ((mr != MACH_SEND_INVALID_DEST) &&
+                                       (mr != MACH_SEND_TIMED_OUT)) {
+                                       if (retval == 0)
+                                               proc_importance_assertion_complete(token);
+
+                                       voucher_mach_msg_revert(old_state);
+                                       old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
+
+                                       continue;
+                               }
+                               mr = MACH_MSG_SUCCESS;
                        }
                        if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
                                mach_msg_destroy(&bufReply->Head);
+                       if (retval == 0)
+                               proc_importance_assertion_complete(token);
 
-                       mr = mach_msg(&bufRequest->Head, MACH_RCV_MSG|options,
-                                                 0, request_size, rcv_name,
-                                                 MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+                       voucher_mach_msg_revert(old_state);
+                       old_state = VOUCHER_MACH_MSG_STATE_UNCHANGED;
 
-               } /* while (mr == MACH_MSG_SUCCESS) */
+               } /* if (mr == MACH_MSG_SUCCESS) */
                
                if ((mr == MACH_RCV_TOO_LARGE) && (options & MACH_RCV_LARGE)) {
-                       new_request_alloc = round_page(bufRequest->Head.msgh_size +
+                       new_request_alloc = (mach_msg_size_t)round_page(bufRequest->Head.msgh_size +
                                                                trailer_alloc);
                        request_size = new_request_alloc;
                        vm_deallocate(self,
                                                  (vm_address_t) bufRequest,
                                                  request_alloc);
                        continue;
-               }
-
-               break;
+               } else if (mr == MACH_MSG_SUCCESS)
+                       continue;
+               else
+                       break;
 
     } /* for(;;) */
 
@@ -632,3 +818,10 @@ mach_msg_server(
                        reply_alloc);
     return mr;
 }
+
+kern_return_t
+mach_voucher_deallocate(
+       mach_voucher_t  voucher)
+{
+       return mach_port_deallocate(mach_task_self(), voucher);
+}