1 /* 2 * An opener for a "host" file provided via the C library. 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 <sys/stat.h> 23 24 #include <fsclient/client.h> 25 26 #include "host_directory_accessor.h" 27 #include "host_file_accessor.h" 28 #include "host_file_opener.h" 29 #include "resource_server.h" 30 31 32 33 HostFileOpener::~HostFileOpener() 34 { 35 } 36 37 bool HostFileOpener::accessing_directory(const char *path, flags_t flags, fileid_t fileid) 38 { 39 (void) flags; (void) fileid; 40 struct stat st; 41 42 if (stat(path, &st)) 43 return false; 44 45 return (st.st_mode & S_IFDIR) ? true : false; 46 } 47 48 bool HostFileOpener::accessing_file(const char *path, flags_t flags, fileid_t fileid) 49 { 50 (void) flags; (void) fileid; 51 struct stat st; 52 53 if (stat(path, &st)) 54 return false; 55 56 return (st.st_mode & S_IFREG) ? true : false; 57 } 58 59 /* Return a file identifier for the given 'path'. */ 60 61 long HostFileOpener::get_fileid(const char *path, flags_t flags, fileid_t *fileid) 62 { 63 (void) flags; 64 65 /* Test for a valid file. */ 66 67 FILE *fp = fopen(path, "r"); 68 69 if (fp == NULL) 70 return -L4_ENOENT; 71 72 fclose(fp); 73 74 *fileid = _get_fileid(path, true); 75 return L4_EOK; 76 } 77 78 fileid_t HostFileOpener::_get_fileid(const char *path, bool create) 79 { 80 std::lock_guard<std::mutex> guard(_lock); 81 82 /* The inode number would be a good choice, but the L4Re read-only file 83 implementation just provides the value of a counter! 84 85 See: pkg/l4re-core/l4re_vfs/include/impl/ro_file_impl.h */ 86 87 std::string s(path); 88 89 HostFileIdentifiers::iterator it = _fileids.find(s); 90 91 if (it != _fileids.end()) 92 return it->second; 93 94 if (!create) 95 return FILEID_INVALID; 96 97 fileid_t fileid = _fileids.size(); 98 99 _fileids[s] = fileid; 100 101 return fileid; 102 } 103 104 /* Return a new accessor for 'fileid'. */ 105 106 long HostFileOpener::make_accessor(const char *path, flags_t flags, 107 fileid_t fileid, Accessor **accessor) 108 { 109 // NOTE: Not testing for create or write flags. 110 111 (void) flags; 112 113 FILE *fp = fopen(path, "r"); 114 115 if (fp == NULL) 116 return -L4_ENOENT; 117 118 *accessor = new HostFileAccessor(fp, fileid); 119 return L4_EOK; 120 } 121 122 /* Return a directory accessor for 'fileid'. */ 123 124 long HostFileOpener::make_directory_accessor(const char *path, flags_t flags, 125 fileid_t fileid, 126 DirectoryAccessor **accessor) 127 { 128 (void) flags; (void) fileid; 129 130 *accessor = new HostDirectoryAccessor(path); 131 return L4_EOK; 132 } 133 134 // vim: tabstop=4 expandtab shiftwidth=4