1 /* 2 * A resource offering support for creating contexts and 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 "opener_server.h" 23 #include "opener_resource.h" 24 #include "resource_server.h" 25 26 /* Support for providing access to files. */ 27 28 OpenerResource::OpenerResource(FilePaging *paging) 29 : _paging(paging) 30 { 31 } 32 33 OpenerResource::~OpenerResource() 34 { 35 } 36 37 int OpenerResource::expected_items() 38 { 39 return Opener_expected_items; 40 } 41 42 ipc_server_handler_type OpenerResource::handler() 43 { 44 return (ipc_server_handler_type) handle_Opener; 45 } 46 47 48 49 /* Return a pager object for the given path and flags. */ 50 51 long OpenerResource::open(const char *path, flags_t flags, offset_t *size, 52 l4_cap_idx_t *cap, object_flags_t *object_flags) 53 { 54 /* Obtain an identifier for the file, even for new files. */ 55 56 fileid_t fileid; 57 long err = get_fileid(path, flags, &fileid); 58 59 if (err) 60 return err; 61 62 /* Test for file and directory access. */ 63 64 if (accessing_directory(path, flags, fileid)) 65 return get_directory(path, flags, fileid, size, cap, object_flags); 66 else if (accessing_file(path, flags, fileid)) 67 return get_file(path, flags, fileid, size, cap, object_flags); 68 else 69 return -L4_EIO; 70 } 71 72 73 74 /* Return a directory object reference for the given file identifier. */ 75 76 long OpenerResource::get_directory(const char *path, flags_t flags, 77 fileid_t fileid, offset_t *size, 78 l4_cap_idx_t *cap, 79 object_flags_t *object_flags) 80 { 81 Resource *directory; 82 long err = _paging->get_directory(this, path, flags, fileid, &directory); 83 84 if (err) 85 return err; 86 87 /* Provide non-file values for certain outputs. */ 88 89 *size = 0; 90 *object_flags = 0; 91 92 return ResourceServer(directory).start_thread(cap); 93 } 94 95 /* Return a file pager. */ 96 97 long OpenerResource::get_file(const char *path, flags_t flags, fileid_t fileid, 98 offset_t *size, l4_cap_idx_t *cap, 99 object_flags_t *object_flags) 100 { 101 Pager *pager; 102 long err = _paging->get_pager(this, path, flags, fileid, &pager); 103 104 if (err) 105 return err; 106 107 /* Obtain the size details from the pager, also providing appropriate 108 flags. */ 109 110 *size = pager->get_data_size(); 111 *object_flags = OBJECT_SUPPORTS_MMAP | OBJECT_HAS_SIZE; 112 113 return ResourceServer(pager).start_thread(cap); 114 } 115 116 117 118 /* Opener interface methods. */ 119 120 long OpenerResource::context(l4_cap_idx_t *context) 121 { 122 OpenerContextResource *resource = new OpenerContextResource(this); 123 124 /* Complete the initialisation and start a server in a new thread. 125 If the thread does not start, the resource will be finalised. */ 126 127 return ResourceServer(resource).start_thread(context); 128 } 129 130 // vim: tabstop=4 expandtab shiftwidth=4