/* * @OSF_COPYRIGHT@ */ /* * Mach Operating System * Copyright (c) 1991,1990 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ #include #include #include #include #include #include #include /* * Routine: mach_msg_server_once * Purpose: * A simple generic server function. It allows more flexibility * than mach_msg_server by processing only one message request * and then returning to the user. Note that more in the way * of error codes are returned to the user; specifically, any * failing error from mach_msg_overwrite_trap will be returned * (though errors from the demux routine or the routine it calls * will not be). */ mach_msg_return_t mach_msg_server_once( 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 = 0, *bufReply = 0, *bufTemp; register mach_msg_return_t mr; register kern_return_t kr; if ((kr = vm_allocate(mach_task_self(), (vm_address_t *)&bufRequest, max_size + MAX_TRAILER_SIZE, VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE)) != KERN_SUCCESS) return kr; if ((kr = vm_allocate(mach_task_self(), (vm_address_t *)&bufReply, max_size + MAX_TRAILER_SIZE, VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE)) != KERN_SUCCESS) return kr; mr = mach_msg_overwrite_trap(&bufRequest->Head, MACH_RCV_MSG|options, 0, max_size, rcv_name, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL, (mach_msg_header_t *) 0, 0); if (mr == MACH_MSG_SUCCESS) { /* we have a request message */ (void) (*demux)(&bufRequest->Head, &bufReply->Head); if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) && bufReply->RetCode != KERN_SUCCESS) { if (bufReply->RetCode == MIG_NO_REPLY) /* * This return code is a little tricky-- * it appears that the demux routine found an * error of some sort, but since that error * would not normally get returned either to * the local user or the remote one, we pretend it's * ok. */ return KERN_SUCCESS; /* don't destroy the reply port right, so we can send an error message */ bufRequest->Head.msgh_remote_port = MACH_PORT_NULL; mach_msg_destroy(&bufRequest->Head); } if (bufReply->Head.msgh_remote_port == MACH_PORT_NULL) { /* no reply port, so destroy the reply */ if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) mach_msg_destroy(&bufReply->Head); return KERN_SUCCESS; } /* send reply. */ bufTemp = bufRequest; bufRequest = bufReply; bufReply = bufTemp; /* * 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 unnecessarily, * we only supply MACH_SEND_TIMEOUT when absolutely necessary. */ mr = mach_msg_overwrite_trap(&bufRequest->Head, (MACH_MSGH_BITS_REMOTE(bufRequest->Head.msgh_bits) == MACH_MSG_TYPE_MOVE_SEND_ONCE) ? MACH_SEND_MSG|options : MACH_SEND_MSG|MACH_SEND_TIMEOUT|options, bufRequest->Head.msgh_size, 0, MACH_PORT_NULL, 0, MACH_PORT_NULL, (mach_msg_header_t *) 0, 0); } /* Has a message error occurred? */ switch (mr) { case MACH_SEND_INVALID_DEST: case MACH_SEND_TIMED_OUT: /* the reply can't be delivered, so destroy it */ mach_msg_destroy(&bufRequest->Head); return KERN_SUCCESS; /* Matches error hiding behavior in mach_msg_server. */ case MACH_RCV_TOO_LARGE: return KERN_SUCCESS; /* Matches error hiding behavior in mach_msg_server. */ default: /* Includes success case. */ (void)vm_deallocate(mach_task_self(), (vm_address_t) bufRequest, max_size + MAX_TRAILER_SIZE); (void)vm_deallocate(mach_task_self(), (vm_address_t) bufReply, max_size + MAX_TRAILER_SIZE); return mr; } } /* * Routine: mach_msg_server * Purpose: * A simple generic server function. Note that changes here * should be considered for duplication above. */ mach_msg_return_t mach_msg_server( 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 = 0, *bufReply = 0, *bufTemp; register mach_msg_return_t mr; register kern_return_t kr; if ((kr = vm_allocate(mach_task_self(), (vm_address_t *)&bufRequest, max_size + MAX_TRAILER_SIZE, VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE)) != KERN_SUCCESS) return kr; if ((kr = vm_allocate(mach_task_self(), (vm_address_t *)&bufReply, max_size + MAX_TRAILER_SIZE, VM_MAKE_TAG(VM_MEMORY_MACH_MSG)|TRUE)) != KERN_SUCCESS) return kr; for (;;) { get_request: mr = mach_msg_overwrite_trap(&bufRequest->Head, MACH_RCV_MSG|options, 0, max_size, rcv_name, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL, (mach_msg_header_t *) 0, 0); while (mr == MACH_MSG_SUCCESS) { /* we have a request message */ (void) (*demux)(&bufRequest->Head, &bufReply->Head); if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) && bufReply->RetCode != KERN_SUCCESS) { if (bufReply->RetCode == MIG_NO_REPLY) goto get_request; /* don't destroy the reply port right, so we can send an error message */ bufRequest->Head.msgh_remote_port = MACH_PORT_NULL; mach_msg_destroy(&bufRequest->Head); } if (bufReply->Head.msgh_remote_port == MACH_PORT_NULL) { /* no reply port, so destroy the reply */ if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) mach_msg_destroy(&bufReply->Head); goto get_request; } /* send reply and get next request */ bufTemp = bufRequest; bufRequest = bufReply; bufReply = bufTemp; /* * 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 unnecessarily, * we only supply MACH_SEND_TIMEOUT when absolutely necessary. */ mr = mach_msg_overwrite_trap(&bufRequest->Head, (MACH_MSGH_BITS_REMOTE(bufRequest->Head.msgh_bits) == MACH_MSG_TYPE_MOVE_SEND_ONCE) ? MACH_SEND_MSG|MACH_RCV_MSG|options : MACH_SEND_MSG|MACH_SEND_TIMEOUT|MACH_RCV_MSG|options, bufRequest->Head.msgh_size, max_size, rcv_name, 0, MACH_PORT_NULL, (mach_msg_header_t *) 0, 0); } /* a message error occurred */ switch (mr) { case MACH_SEND_INVALID_DEST: case MACH_SEND_TIMED_OUT: /* the reply can't be delivered, so destroy it */ mach_msg_destroy(&bufRequest->Head); break; case MACH_RCV_TOO_LARGE: /* the kernel destroyed the request */ break; default: /* should only happen if the server is buggy */ (void)vm_deallocate(mach_task_self(), (vm_address_t) bufRequest, max_size + MAX_TRAILER_SIZE); (void)vm_deallocate(mach_task_self(), (vm_address_t) bufReply, max_size + MAX_TRAILER_SIZE); return mr; } } }