bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 1 | /* |
| 2 | CUSE: Character device in Userspace |
| 3 | Copyright (C) 2008 SUSE Linux Products GmbH |
| 4 | Copyright (C) 2008 Tejun Heo <teheo@suse.de> |
| 5 | |
| 6 | This program can be distributed under the terms of the GNU LGPLv2. |
| 7 | See the file COPYING.LIB. |
| 8 | */ |
| 9 | |
| 10 | #include "cuse_lowlevel.h" |
| 11 | #include "fuse_kernel.h" |
| 12 | #include "fuse_i.h" |
| 13 | #include "fuse_opt.h" |
| 14 | #include "fuse_misc.h" |
| 15 | |
| 16 | #include <stdio.h> |
| 17 | #include <string.h> |
| 18 | #include <stdlib.h> |
| 19 | #include <stddef.h> |
| 20 | #include <errno.h> |
| 21 | #include <unistd.h> |
| 22 | |
| 23 | struct cuse_data { |
| 24 | struct cuse_lowlevel_ops clop; |
| 25 | unsigned max_read; |
| 26 | unsigned dev_major; |
| 27 | unsigned dev_minor; |
| 28 | unsigned flags; |
| 29 | unsigned dev_info_len; |
| 30 | char dev_info[]; |
| 31 | }; |
| 32 | |
| 33 | static struct cuse_lowlevel_ops *req_clop(fuse_req_t req) |
| 34 | { |
| 35 | return &req->f->cuse_data->clop; |
| 36 | } |
| 37 | |
| 38 | static void cuse_fll_open(fuse_req_t req, fuse_ino_t ino, |
| 39 | struct fuse_file_info *fi) |
| 40 | { |
| 41 | (void)ino; |
| 42 | req_clop(req)->open(req, fi); |
| 43 | } |
| 44 | |
| 45 | static void cuse_fll_read(fuse_req_t req, fuse_ino_t ino, size_t size, |
Matt Mower | 523a059 | 2015-12-13 11:31:00 -0600 | [diff] [blame^] | 46 | loff_t off, struct fuse_file_info *fi) |
bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 47 | { |
| 48 | (void)ino; |
| 49 | req_clop(req)->read(req, size, off, fi); |
| 50 | } |
| 51 | |
| 52 | static void cuse_fll_write(fuse_req_t req, fuse_ino_t ino, const char *buf, |
Matt Mower | 523a059 | 2015-12-13 11:31:00 -0600 | [diff] [blame^] | 53 | size_t size, loff_t off, struct fuse_file_info *fi) |
bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 54 | { |
| 55 | (void)ino; |
| 56 | req_clop(req)->write(req, buf, size, off, fi); |
| 57 | } |
| 58 | |
| 59 | static void cuse_fll_flush(fuse_req_t req, fuse_ino_t ino, |
| 60 | struct fuse_file_info *fi) |
| 61 | { |
| 62 | (void)ino; |
| 63 | req_clop(req)->flush(req, fi); |
| 64 | } |
| 65 | |
| 66 | static void cuse_fll_release(fuse_req_t req, fuse_ino_t ino, |
| 67 | struct fuse_file_info *fi) |
| 68 | { |
| 69 | (void)ino; |
| 70 | req_clop(req)->release(req, fi); |
| 71 | } |
| 72 | |
| 73 | static void cuse_fll_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, |
| 74 | struct fuse_file_info *fi) |
| 75 | { |
| 76 | (void)ino; |
| 77 | req_clop(req)->fsync(req, datasync, fi); |
| 78 | } |
| 79 | |
| 80 | static void cuse_fll_ioctl(fuse_req_t req, fuse_ino_t ino, int cmd, void *arg, |
| 81 | struct fuse_file_info *fi, unsigned int flags, |
| 82 | const void *in_buf, size_t in_bufsz, size_t out_bufsz) |
| 83 | { |
| 84 | (void)ino; |
| 85 | req_clop(req)->ioctl(req, cmd, arg, fi, flags, in_buf, in_bufsz, |
| 86 | out_bufsz); |
| 87 | } |
| 88 | |
| 89 | static void cuse_fll_poll(fuse_req_t req, fuse_ino_t ino, |
| 90 | struct fuse_file_info *fi, struct fuse_pollhandle *ph) |
| 91 | { |
| 92 | (void)ino; |
| 93 | req_clop(req)->poll(req, fi, ph); |
| 94 | } |
| 95 | |
| 96 | static size_t cuse_pack_info(int argc, const char **argv, char *buf) |
| 97 | { |
| 98 | size_t size = 0; |
| 99 | int i; |
| 100 | |
| 101 | for (i = 0; i < argc; i++) { |
| 102 | size_t len; |
| 103 | |
| 104 | len = strlen(argv[i]) + 1; |
| 105 | size += len; |
| 106 | if (buf) { |
| 107 | memcpy(buf, argv[i], len); |
| 108 | buf += len; |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | return size; |
| 113 | } |
| 114 | |
| 115 | static struct cuse_data *cuse_prep_data(const struct cuse_info *ci, |
| 116 | const struct cuse_lowlevel_ops *clop) |
| 117 | { |
| 118 | struct cuse_data *cd; |
| 119 | size_t dev_info_len; |
| 120 | |
| 121 | dev_info_len = cuse_pack_info(ci->dev_info_argc, ci->dev_info_argv, |
| 122 | NULL); |
| 123 | |
| 124 | if (dev_info_len > CUSE_INIT_INFO_MAX) { |
| 125 | fprintf(stderr, "cuse: dev_info (%zu) too large, limit=%u\n", |
| 126 | dev_info_len, CUSE_INIT_INFO_MAX); |
| 127 | return NULL; |
| 128 | } |
| 129 | |
| 130 | cd = calloc(1, sizeof(*cd) + dev_info_len); |
| 131 | if (!cd) { |
| 132 | fprintf(stderr, "cuse: failed to allocate cuse_data\n"); |
| 133 | return NULL; |
| 134 | } |
| 135 | |
| 136 | memcpy(&cd->clop, clop, sizeof(cd->clop)); |
| 137 | cd->max_read = 131072; |
| 138 | cd->dev_major = ci->dev_major; |
| 139 | cd->dev_minor = ci->dev_minor; |
| 140 | cd->dev_info_len = dev_info_len; |
| 141 | cd->flags = ci->flags; |
| 142 | cuse_pack_info(ci->dev_info_argc, ci->dev_info_argv, cd->dev_info); |
| 143 | |
| 144 | return cd; |
| 145 | } |
| 146 | |
| 147 | struct fuse_session *cuse_lowlevel_new(struct fuse_args *args, |
| 148 | const struct cuse_info *ci, |
| 149 | const struct cuse_lowlevel_ops *clop, |
| 150 | void *userdata) |
| 151 | { |
| 152 | struct fuse_lowlevel_ops lop; |
| 153 | struct cuse_data *cd; |
| 154 | struct fuse_session *se; |
| 155 | struct fuse_ll *ll; |
| 156 | |
| 157 | cd = cuse_prep_data(ci, clop); |
| 158 | if (!cd) |
| 159 | return NULL; |
| 160 | |
| 161 | memset(&lop, 0, sizeof(lop)); |
| 162 | lop.init = clop->init; |
| 163 | lop.destroy = clop->destroy; |
| 164 | lop.open = clop->open ? cuse_fll_open : NULL; |
| 165 | lop.read = clop->read ? cuse_fll_read : NULL; |
| 166 | lop.write = clop->write ? cuse_fll_write : NULL; |
| 167 | lop.flush = clop->flush ? cuse_fll_flush : NULL; |
| 168 | lop.release = clop->release ? cuse_fll_release : NULL; |
| 169 | lop.fsync = clop->fsync ? cuse_fll_fsync : NULL; |
| 170 | lop.ioctl = clop->ioctl ? cuse_fll_ioctl : NULL; |
| 171 | lop.poll = clop->poll ? cuse_fll_poll : NULL; |
| 172 | |
| 173 | se = fuse_lowlevel_new_common(args, &lop, sizeof(lop), userdata); |
| 174 | if (!se) { |
| 175 | free(cd); |
| 176 | return NULL; |
| 177 | } |
| 178 | ll = se->data; |
| 179 | ll->cuse_data = cd; |
| 180 | |
| 181 | return se; |
| 182 | } |
| 183 | |
| 184 | static int cuse_reply_init(fuse_req_t req, struct cuse_init_out *arg, |
| 185 | char *dev_info, unsigned dev_info_len) |
| 186 | { |
| 187 | struct iovec iov[3]; |
| 188 | |
| 189 | iov[1].iov_base = arg; |
| 190 | iov[1].iov_len = sizeof(struct cuse_init_out); |
| 191 | iov[2].iov_base = dev_info; |
| 192 | iov[2].iov_len = dev_info_len; |
| 193 | |
| 194 | return fuse_send_reply_iov_nofree(req, 0, iov, 3); |
| 195 | } |
| 196 | |
| 197 | void cuse_lowlevel_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) |
| 198 | { |
| 199 | struct fuse_init_in *arg = (struct fuse_init_in *) inarg; |
| 200 | struct cuse_init_out outarg; |
| 201 | struct fuse_ll *f = req->f; |
| 202 | struct cuse_data *cd = f->cuse_data; |
| 203 | size_t bufsize = fuse_chan_bufsize(req->ch); |
| 204 | struct cuse_lowlevel_ops *clop = req_clop(req); |
| 205 | |
| 206 | (void) nodeid; |
| 207 | if (f->debug) { |
| 208 | fprintf(stderr, "CUSE_INIT: %u.%u\n", arg->major, arg->minor); |
| 209 | fprintf(stderr, "flags=0x%08x\n", arg->flags); |
| 210 | } |
| 211 | f->conn.proto_major = arg->major; |
| 212 | f->conn.proto_minor = arg->minor; |
| 213 | f->conn.capable = 0; |
| 214 | f->conn.want = 0; |
| 215 | |
| 216 | if (arg->major < 7) { |
Dees_Troy | e34c133 | 2013-02-06 19:13:00 +0000 | [diff] [blame] | 217 | fprintf(stderr, "cuse: unsupported protocol version: %u.%u\n", |
bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 218 | arg->major, arg->minor); |
| 219 | fuse_reply_err(req, EPROTO); |
| 220 | return; |
| 221 | } |
| 222 | |
| 223 | if (bufsize < FUSE_MIN_READ_BUFFER) { |
Dees_Troy | e34c133 | 2013-02-06 19:13:00 +0000 | [diff] [blame] | 224 | fprintf(stderr, "cuse: warning: buffer size too small: %zu\n", |
bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 225 | bufsize); |
| 226 | bufsize = FUSE_MIN_READ_BUFFER; |
| 227 | } |
| 228 | |
| 229 | bufsize -= 4096; |
| 230 | if (bufsize < f->conn.max_write) |
| 231 | f->conn.max_write = bufsize; |
| 232 | |
| 233 | f->got_init = 1; |
| 234 | if (f->op.init) |
| 235 | f->op.init(f->userdata, &f->conn); |
| 236 | |
| 237 | memset(&outarg, 0, sizeof(outarg)); |
| 238 | outarg.major = FUSE_KERNEL_VERSION; |
| 239 | outarg.minor = FUSE_KERNEL_MINOR_VERSION; |
| 240 | outarg.flags = cd->flags; |
| 241 | outarg.max_read = cd->max_read; |
| 242 | outarg.max_write = f->conn.max_write; |
| 243 | outarg.dev_major = cd->dev_major; |
| 244 | outarg.dev_minor = cd->dev_minor; |
| 245 | |
| 246 | if (f->debug) { |
| 247 | fprintf(stderr, " CUSE_INIT: %u.%u\n", |
| 248 | outarg.major, outarg.minor); |
| 249 | fprintf(stderr, " flags=0x%08x\n", outarg.flags); |
| 250 | fprintf(stderr, " max_read=0x%08x\n", outarg.max_read); |
| 251 | fprintf(stderr, " max_write=0x%08x\n", outarg.max_write); |
| 252 | fprintf(stderr, " dev_major=%u\n", outarg.dev_major); |
| 253 | fprintf(stderr, " dev_minor=%u\n", outarg.dev_minor); |
| 254 | fprintf(stderr, " dev_info: %.*s\n", cd->dev_info_len, |
| 255 | cd->dev_info); |
| 256 | } |
| 257 | |
| 258 | cuse_reply_init(req, &outarg, cd->dev_info, cd->dev_info_len); |
| 259 | |
| 260 | if (clop->init_done) |
| 261 | clop->init_done(f->userdata); |
| 262 | |
| 263 | fuse_free_req(req); |
| 264 | } |
| 265 | |
| 266 | struct fuse_session *cuse_lowlevel_setup(int argc, char *argv[], |
| 267 | const struct cuse_info *ci, |
| 268 | const struct cuse_lowlevel_ops *clop, |
| 269 | int *multithreaded, void *userdata) |
| 270 | { |
| 271 | const char *devname = "/dev/cuse"; |
| 272 | static const struct fuse_opt kill_subtype_opts[] = { |
| 273 | FUSE_OPT_KEY("subtype=", FUSE_OPT_KEY_DISCARD), |
| 274 | FUSE_OPT_END |
| 275 | }; |
| 276 | struct fuse_args args = FUSE_ARGS_INIT(argc, argv); |
| 277 | struct fuse_session *se; |
| 278 | struct fuse_chan *ch; |
| 279 | int fd; |
| 280 | int foreground; |
| 281 | int res; |
| 282 | |
| 283 | res = fuse_parse_cmdline(&args, NULL, multithreaded, &foreground); |
| 284 | if (res == -1) |
| 285 | goto err_args; |
| 286 | |
| 287 | res = fuse_opt_parse(&args, NULL, kill_subtype_opts, NULL); |
| 288 | if (res == -1) |
| 289 | goto err_args; |
| 290 | |
| 291 | /* |
| 292 | * Make sure file descriptors 0, 1 and 2 are open, otherwise chaos |
| 293 | * would ensue. |
| 294 | */ |
| 295 | do { |
| 296 | fd = open("/dev/null", O_RDWR); |
| 297 | if (fd > 2) |
| 298 | close(fd); |
| 299 | } while (fd >= 0 && fd <= 2); |
| 300 | |
| 301 | se = cuse_lowlevel_new(&args, ci, clop, userdata); |
| 302 | fuse_opt_free_args(&args); |
| 303 | if (se == NULL) |
| 304 | goto err_args; |
| 305 | |
| 306 | fd = open(devname, O_RDWR); |
| 307 | if (fd == -1) { |
| 308 | if (errno == ENODEV || errno == ENOENT) |
Dees_Troy | e34c133 | 2013-02-06 19:13:00 +0000 | [diff] [blame] | 309 | fprintf(stderr, "cuse: device not found, try 'modprobe cuse' first\n"); |
bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 310 | else |
Dees_Troy | e34c133 | 2013-02-06 19:13:00 +0000 | [diff] [blame] | 311 | fprintf(stderr, "cuse: failed to open %s: %s\n", |
bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 312 | devname, strerror(errno)); |
| 313 | goto err_se; |
| 314 | } |
| 315 | |
| 316 | ch = fuse_kern_chan_new(fd); |
| 317 | if (!ch) { |
| 318 | close(fd); |
| 319 | goto err_se; |
| 320 | } |
| 321 | |
| 322 | fuse_session_add_chan(se, ch); |
| 323 | |
| 324 | res = fuse_set_signal_handlers(se); |
| 325 | if (res == -1) |
| 326 | goto err_se; |
| 327 | |
| 328 | res = fuse_daemonize(foreground); |
| 329 | if (res == -1) |
| 330 | goto err_sig; |
| 331 | |
| 332 | return se; |
| 333 | |
| 334 | err_sig: |
| 335 | fuse_remove_signal_handlers(se); |
| 336 | err_se: |
| 337 | fuse_session_destroy(se); |
| 338 | err_args: |
| 339 | fuse_opt_free_args(&args); |
| 340 | return NULL; |
| 341 | } |
| 342 | |
| 343 | void cuse_lowlevel_teardown(struct fuse_session *se) |
| 344 | { |
| 345 | fuse_remove_signal_handlers(se); |
| 346 | fuse_session_destroy(se); |
| 347 | } |
| 348 | |
| 349 | int cuse_lowlevel_main(int argc, char *argv[], const struct cuse_info *ci, |
| 350 | const struct cuse_lowlevel_ops *clop, void *userdata) |
| 351 | { |
| 352 | struct fuse_session *se; |
| 353 | int multithreaded; |
| 354 | int res; |
| 355 | |
| 356 | se = cuse_lowlevel_setup(argc, argv, ci, clop, &multithreaded, |
| 357 | userdata); |
| 358 | if (se == NULL) |
| 359 | return 1; |
| 360 | |
| 361 | if (multithreaded) |
| 362 | res = fuse_session_loop_mt(se); |
| 363 | else |
| 364 | res = fuse_session_loop(se); |
| 365 | |
| 366 | cuse_lowlevel_teardown(se); |
| 367 | if (res == -1) |
| 368 | return 1; |
| 369 | |
| 370 | return 0; |
| 371 | } |