| paul@93 | 1 | /* |
| paul@93 | 2 | * An opener for a "host" file provided via the C library. |
| paul@93 | 3 | * |
| paul@236 | 4 | * Copyright (C) 2021, 2022 Paul Boddie <paul@boddie.org.uk> |
| paul@93 | 5 | * |
| paul@93 | 6 | * This program is free software; you can redistribute it and/or |
| paul@93 | 7 | * modify it under the terms of the GNU General Public License as |
| paul@93 | 8 | * published by the Free Software Foundation; either version 2 of |
| paul@93 | 9 | * the License, or (at your option) any later version. |
| paul@93 | 10 | * |
| paul@93 | 11 | * This program is distributed in the hope that it will be useful, |
| paul@93 | 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| paul@93 | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| paul@93 | 14 | * GNU General Public License for more details. |
| paul@93 | 15 | * |
| paul@93 | 16 | * You should have received a copy of the GNU General Public License |
| paul@93 | 17 | * along with this program; if not, write to the Free Software |
| paul@93 | 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| paul@93 | 19 | * Boston, MA 02110-1301, USA |
| paul@93 | 20 | */ |
| paul@93 | 21 | |
| paul@236 | 22 | #include <stdio.h> |
| paul@156 | 23 | #include <sys/stat.h> |
| paul@232 | 24 | #include <unistd.h> |
| paul@156 | 25 | |
| paul@160 | 26 | #include <fsclient/client.h> |
| paul@160 | 27 | |
| paul@202 | 28 | #include "host_directory_accessor.h" |
| paul@12 | 29 | #include "host_file_accessor.h" |
| paul@12 | 30 | #include "host_file_opener.h" |
| paul@202 | 31 | #include "resource_server.h" |
| paul@160 | 32 | |
| paul@160 | 33 | |
| paul@160 | 34 | |
| paul@156 | 35 | HostFileOpener::~HostFileOpener() |
| paul@156 | 36 | { |
| paul@156 | 37 | } |
| paul@156 | 38 | |
| paul@240 | 39 | bool HostFileOpener::accessing_directory(flags_t flags, fileid_t fileid) |
| paul@156 | 40 | { |
| paul@240 | 41 | (void) flags; |
| paul@240 | 42 | |
| paul@240 | 43 | const char *path = _get_path(fileid); |
| paul@240 | 44 | |
| paul@240 | 45 | if (path == NULL) |
| paul@240 | 46 | return false; |
| paul@240 | 47 | |
| paul@156 | 48 | struct stat st; |
| paul@156 | 49 | |
| paul@156 | 50 | if (stat(path, &st)) |
| paul@156 | 51 | return false; |
| paul@156 | 52 | |
| paul@156 | 53 | return (st.st_mode & S_IFDIR) ? true : false; |
| paul@156 | 54 | } |
| paul@156 | 55 | |
| paul@240 | 56 | bool HostFileOpener::accessing_file(flags_t flags, fileid_t fileid) |
| paul@156 | 57 | { |
| paul@240 | 58 | (void) flags; |
| paul@156 | 59 | struct stat st; |
| paul@156 | 60 | |
| paul@240 | 61 | const char *path = _get_path(fileid); |
| paul@240 | 62 | |
| paul@240 | 63 | if (path == NULL) |
| paul@240 | 64 | return false; |
| paul@240 | 65 | |
| paul@156 | 66 | if (stat(path, &st)) |
| paul@156 | 67 | return false; |
| paul@156 | 68 | |
| paul@156 | 69 | return (st.st_mode & S_IFREG) ? true : false; |
| paul@156 | 70 | } |
| paul@156 | 71 | |
| paul@12 | 72 | /* Return a file identifier for the given 'path'. */ |
| paul@12 | 73 | |
| paul@146 | 74 | long HostFileOpener::get_fileid(const char *path, flags_t flags, fileid_t *fileid) |
| paul@143 | 75 | { |
| paul@143 | 76 | (void) flags; |
| paul@143 | 77 | |
| paul@146 | 78 | /* Test for a valid file. */ |
| paul@143 | 79 | |
| paul@143 | 80 | FILE *fp = fopen(path, "r"); |
| paul@143 | 81 | |
| paul@143 | 82 | if (fp == NULL) |
| paul@146 | 83 | return -L4_ENOENT; |
| paul@143 | 84 | |
| paul@143 | 85 | fclose(fp); |
| paul@143 | 86 | |
| paul@146 | 87 | *fileid = _get_fileid(path, true); |
| paul@146 | 88 | return L4_EOK; |
| paul@143 | 89 | } |
| paul@143 | 90 | |
| paul@143 | 91 | fileid_t HostFileOpener::_get_fileid(const char *path, bool create) |
| paul@12 | 92 | { |
| paul@139 | 93 | std::lock_guard<std::mutex> guard(_lock); |
| paul@139 | 94 | |
| paul@139 | 95 | /* The inode number would be a good choice, but the L4Re read-only file |
| paul@139 | 96 | implementation just provides the value of a counter! |
| paul@139 | 97 | |
| paul@139 | 98 | See: pkg/l4re-core/l4re_vfs/include/impl/ro_file_impl.h */ |
| paul@139 | 99 | |
| paul@139 | 100 | std::string s(path); |
| paul@12 | 101 | |
| paul@139 | 102 | HostFileIdentifiers::iterator it = _fileids.find(s); |
| paul@139 | 103 | |
| paul@139 | 104 | if (it != _fileids.end()) |
| paul@139 | 105 | return it->second; |
| paul@12 | 106 | |
| paul@143 | 107 | if (!create) |
| paul@143 | 108 | return FILEID_INVALID; |
| paul@143 | 109 | |
| paul@139 | 110 | fileid_t fileid = _fileids.size(); |
| paul@12 | 111 | |
| paul@139 | 112 | _fileids[s] = fileid; |
| paul@240 | 113 | _paths[fileid] = s; |
| paul@139 | 114 | |
| paul@139 | 115 | return fileid; |
| paul@12 | 116 | } |
| paul@12 | 117 | |
| paul@240 | 118 | const char *HostFileOpener::_get_path(fileid_t fileid) |
| paul@240 | 119 | { |
| paul@240 | 120 | std::lock_guard<std::mutex> guard(_lock); |
| paul@240 | 121 | |
| paul@240 | 122 | HostFilePaths::iterator it = _paths.find(fileid); |
| paul@240 | 123 | |
| paul@240 | 124 | if (it != _paths.end()) |
| paul@240 | 125 | return it->second.c_str(); |
| paul@240 | 126 | else |
| paul@240 | 127 | return NULL; |
| paul@240 | 128 | } |
| paul@240 | 129 | |
| paul@12 | 130 | /* Return a new accessor for 'fileid'. */ |
| paul@12 | 131 | |
| paul@240 | 132 | long HostFileOpener::make_accessor(flags_t flags, fileid_t fileid, |
| paul@240 | 133 | Accessor **accessor) |
| paul@12 | 134 | { |
| paul@143 | 135 | // NOTE: Not testing for create or write flags. |
| paul@143 | 136 | |
| paul@143 | 137 | (void) flags; |
| paul@143 | 138 | |
| paul@240 | 139 | const char *path = _get_path(fileid); |
| paul@240 | 140 | |
| paul@240 | 141 | if (path == NULL) |
| paul@240 | 142 | return -L4_ENOENT; |
| paul@240 | 143 | |
| paul@106 | 144 | FILE *fp = fopen(path, "r"); |
| paul@12 | 145 | |
| paul@106 | 146 | if (fp == NULL) |
| paul@143 | 147 | return -L4_ENOENT; |
| paul@106 | 148 | |
| paul@143 | 149 | *accessor = new HostFileAccessor(fp, fileid); |
| paul@143 | 150 | return L4_EOK; |
| paul@12 | 151 | } |
| paul@12 | 152 | |
| paul@202 | 153 | /* Return a directory accessor for 'fileid'. */ |
| paul@202 | 154 | |
| paul@240 | 155 | long HostFileOpener::make_directory_accessor(flags_t flags, fileid_t fileid, |
| paul@202 | 156 | DirectoryAccessor **accessor) |
| paul@202 | 157 | { |
| paul@240 | 158 | (void) flags; |
| paul@240 | 159 | |
| paul@240 | 160 | const char *path = _get_path(fileid); |
| paul@240 | 161 | |
| paul@240 | 162 | if (path == NULL) |
| paul@240 | 163 | return -L4_ENOENT; |
| paul@202 | 164 | |
| paul@202 | 165 | *accessor = new HostDirectoryAccessor(path); |
| paul@202 | 166 | return L4_EOK; |
| paul@202 | 167 | } |
| paul@202 | 168 | |
| paul@232 | 169 | /* Remove a filesystem object. */ |
| paul@232 | 170 | |
| paul@240 | 171 | long HostFileOpener::remove_object(fileid_t fileid) |
| paul@232 | 172 | { |
| paul@240 | 173 | (void) fileid; |
| paul@232 | 174 | return L4_EOK; |
| paul@232 | 175 | } |
| paul@232 | 176 | |
| paul@236 | 177 | /* Rename a filesystem object, placing source inside the parent of target. */ |
| paul@236 | 178 | |
| paul@240 | 179 | long HostFileOpener::rename_object(const char *source, const char *target) |
| paul@236 | 180 | { |
| paul@236 | 181 | /* NOTE: Should propagate a more meaningful error. */ |
| paul@236 | 182 | |
| paul@236 | 183 | if (rename(source, target)) |
| paul@236 | 184 | return -L4_EIO; |
| paul@236 | 185 | |
| paul@236 | 186 | return L4_EOK; |
| paul@236 | 187 | } |
| paul@236 | 188 | |
| paul@232 | 189 | /* Unlink a filesystem object. */ |
| paul@232 | 190 | |
| paul@240 | 191 | long HostFileOpener::unlink_object(fileid_t parent_fileid, fileid_t fileid) |
| paul@232 | 192 | { |
| paul@240 | 193 | /* Ignore the parent and always use the path. */ |
| paul@240 | 194 | |
| paul@240 | 195 | (void) parent_fileid; |
| paul@232 | 196 | |
| paul@240 | 197 | const char *path = _get_path(fileid); |
| paul@240 | 198 | |
| paul@240 | 199 | if (path == NULL) |
| paul@240 | 200 | return -L4_ENOENT; |
| paul@232 | 201 | |
| paul@232 | 202 | // NOTE: Return code may need converting. |
| paul@232 | 203 | |
| paul@232 | 204 | int err = unlink(path); |
| paul@232 | 205 | |
| paul@232 | 206 | if (err) |
| paul@232 | 207 | return err; |
| paul@232 | 208 | |
| paul@232 | 209 | /* Remove the file identifier mapping. */ |
| paul@232 | 210 | |
| paul@232 | 211 | std::string s(path); |
| paul@232 | 212 | |
| paul@232 | 213 | HostFileIdentifiers::iterator it = _fileids.find(s); |
| paul@232 | 214 | |
| paul@232 | 215 | if (it != _fileids.end()) |
| paul@232 | 216 | _fileids.erase(it); |
| paul@232 | 217 | |
| paul@240 | 218 | HostFilePaths::iterator pit = _paths.find(fileid); |
| paul@240 | 219 | |
| paul@240 | 220 | if (pit != _paths.end()) |
| paul@240 | 221 | _paths.erase(pit); |
| paul@240 | 222 | |
| paul@232 | 223 | return L4_EOK; |
| paul@232 | 224 | } |
| paul@232 | 225 | |
| paul@12 | 226 | // vim: tabstop=4 expandtab shiftwidth=4 |
