1 /* 2 * A context resource offering support for opening files. 3 * 4 * Copyright (C) 2021 Paul Boddie <paul@boddie.org.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA 20 */ 21 22 #include <ipc/cap_alloc.h> 23 24 #include "opener_context_resource.h" 25 #include "opener_context_object_server.h" 26 #include "opener_resource.h" 27 28 #include <string.h> 29 30 31 32 /* Support for providing access to files. */ 33 34 OpenerContextResource::OpenerContextResource(OpenerResource *opener, Memory *memory) 35 : SimplePager(memory), _opener(opener) 36 { 37 } 38 39 int OpenerContextResource::expected_items() 40 { 41 return OpenerContextObject_expected_items; 42 } 43 44 ipc_server_handler_type OpenerContextResource::handler() 45 { 46 return (ipc_server_handler_type) handle_OpenerContextObject; 47 } 48 49 50 51 /* Data access methods. */ 52 53 char *OpenerContextResource::get_path() 54 { 55 char *buffer = _region->read(); 56 offset_t size = _region->size(); 57 58 /* Confine the path to the limit of the buffer. */ 59 60 if ((buffer != NULL) && (strnlen(buffer, size) < size)) 61 return buffer; 62 else 63 return NULL; 64 } 65 66 67 68 /* Opener context interface methods. */ 69 70 long OpenerContextResource::open(flags_t flags, offset_t *size, l4_cap_idx_t *file) 71 { 72 char *path = get_path(); 73 74 if (path == NULL) 75 return -L4_EINVAL; 76 77 long err = _opener->open(path, flags, size, file); 78 79 /* Handle propagated capabilities. By indicating the special status, the 80 operation is first completed and then the capability is discarded. */ 81 82 if (err == IPC_MESSAGE_SENT) 83 { 84 complete_OpenerContext_open(*size, *file); 85 ipc_cap_free_um(*file); 86 return IPC_MESSAGE_SENT; 87 } 88 89 return err; 90 } 91 92 // vim: tabstop=4 expandtab shiftwidth=4