2 * Copyright (c) 2017 Netflix, Inc.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
29 #include <sys/param.h>
30 #include <sys/ucred.h>
31 #include <sys/mount.h>
46 #include "efi-osdep.h"
47 #include "efivar-dp.h"
49 #include "uefi-dplib.h"
51 #define MAX_DP_SANITY 4096 /* Biggest device path in bytes */
52 #define MAX_DP_TEXT_LEN 4096 /* Longest string rep of dp */
54 #define ValidLen(dp) (DevicePathNodeLength(dp) >= sizeof(EFI_DEVICE_PATH_PROTOCOL) && \
55 DevicePathNodeLength(dp) < MAX_DP_SANITY)
58 #define G_LABEL "LABEL"
62 geom_pp_attr(struct gmesh *mesh, struct gprovider *pp, const char *attr)
66 LIST_FOREACH(conf, &pp->lg_config, lg_config) {
67 if (strcmp(conf->lg_name, attr) != 0)
69 return (conf->lg_val);
74 static struct gprovider *
75 find_provider_by_efimedia(struct gmesh *mesh, const char *efimedia)
77 struct gclass *classp;
83 * Find the partition class so we can search it...
85 LIST_FOREACH(classp, &mesh->lg_class, lg_class) {
86 if (strcasecmp(classp->lg_name, G_PART) == 0)
93 * Each geom will have a number of providers, search each
94 * one of them for the efimedia that matches.
96 /* XXX just used gpart class since I know it's the only one, but maybe I should search all classes */
97 LIST_FOREACH(gp, &classp->lg_geom, lg_geom) {
98 LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
99 val = geom_pp_attr(mesh, pp, "efimedia");
102 if (strcasecmp(efimedia, val) == 0)
110 static struct gprovider *
111 find_provider_by_name(struct gmesh *mesh, const char *name)
113 struct gclass *classp;
115 struct gprovider *pp;
117 LIST_FOREACH(classp, &mesh->lg_class, lg_class) {
118 LIST_FOREACH(gp, &classp->lg_geom, lg_geom) {
119 LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
120 if (strcmp(pp->lg_name, name) == 0)
131 efi_hd_to_unix(struct gmesh *mesh, const_efidp dp, char **dev, char **relpath, char **abspath)
134 const_efidp media, file, walker;
136 char buf[MAX_DP_TEXT_LEN];
138 struct gprovider *pp, *provider;
139 struct gconsumer *cp;
145 * Now, we can either have a filepath node next, or the end.
146 * Otherwise, it's an error.
148 if (!ValidLen(walker))
150 walker = (const_efidp)NextDevicePathNode(walker);
151 if ((uintptr_t)walker - (uintptr_t)dp > MAX_DP_SANITY)
153 if (DevicePathType(walker) == MEDIA_DEVICE_PATH &&
154 DevicePathSubType(walker) == MEDIA_FILEPATH_DP)
156 else if (DevicePathType(walker) == MEDIA_DEVICE_PATH &&
157 DevicePathType(walker) == END_DEVICE_PATH_TYPE)
163 * Format this node. We're going to look for it as a efimedia
164 * attribute of some geom node. Once we find that node, we use it
165 * as the device it comes from, at least provisionally.
167 len = efidp_format_device_path_node(buf, sizeof(buf), media);
168 if (len > sizeof(buf))
171 pp = find_provider_by_efimedia(mesh, buf);
177 *dev = strdup(pp->lg_name);
184 * No file specified, just return the device. Don't even look
185 * for a mountpoint. XXX Sane?
191 * Now extract the relative path. The next node in the device path should
192 * be a filesystem node. If not, we have issues.
194 *relpath = efidp_extract_file_path(file);
195 if (*relpath == NULL) {
199 for (pwalk = *relpath; *pwalk; pwalk++)
204 * To find the absolute path, we have to look for where we're mounted.
205 * We only look a little hard, since looking too hard can come up with
206 * false positives (imagine a graid, one of whose devices is *dev).
208 n = getfsstat(NULL, 0, MNT_NOWAIT) + 1;
213 mntlen = sizeof(struct statfs) * n;
214 mnt = malloc(mntlen);
215 n = getfsstat(mnt, mntlen, MNT_NOWAIT);
221 for (i = 0; i < n; i++) {
223 * Skip all pseudo filesystems. This also skips the real filesytsem
224 * of ZFS. There's no EFI designator for ZFS in the standard, so
225 * we'll need to invent one, but its decoding will be handled in
226 * a separate function.
228 if (mnt[i].f_mntfromname[0] != '/')
232 * First see if it is directly attached
234 if (strcmp(provider->lg_name, mnt[i].f_mntfromname + 5) == 0)
238 * Next see if it is attached via one of the physical disk's
241 LIST_FOREACH(cp, &provider->lg_consumers, lg_consumer) {
242 pp = cp->lg_provider;
243 if (strcmp(pp->lg_geom->lg_class->lg_name, G_LABEL) != 0)
245 if (strcmp(g_device_path(pp->lg_name), mnt[i].f_mntfromname) == 0)
248 /* Not the one, try the next mount point */
253 * No mountpoint found, no absolute path possible
259 * Construct absolute path and we're finally done.
261 if (strcmp(mnt[i].f_mntonname, "/") == 0)
262 asprintf(abspath, "/%s", *relpath);
264 asprintf(abspath, "%s/%s", mnt[i].f_mntonname, *relpath);
277 * Translate the passed in device_path to a unix path via the following
280 * If dp, dev or path NULL, return EDOOFUS. XXX wise?
282 * Set *path = NULL; *dev = NULL;
284 * Walk through the device_path until we find either a media device path.
285 * Return EINVAL if not found. Return EINVAL if walking dp would
286 * land us more than sanity size away from the start (4k).
288 * If we find a media descriptor, we search through the geom mesh to see if we
289 * can find a matching node. If no match is found in the mesh that matches,
292 * Once we find a matching node, we search to see if there is a filesystem
293 * mounted on it. If we find nothing, then search each of the devices that are
294 * mounted to see if we can work up the geom tree to find the matching node. if
295 * we still can't find anything, *dev = sprintf("/dev/%s", provider_name
296 * of the original node we found), but return ENOTBLK.
298 * Record the dev of the mountpoint in *dev.
300 * Once we find something, check to see if the next node in the device path is
301 * the end of list. If so, return the mountpoint.
303 * If the next node isn't a File path node, return EFTYPE.
305 * Extract the path from the File path node(s). translate any \ file separators
306 * to /. Append the result to the mount point. Copy the resulting path into
307 * *path. Stat that path. If it is not found, return the errorr from stat.
309 * Finally, check to make sure the resulting path is still on the same
310 * device. If not, return ENODEV.
312 * Otherwise return 0.
314 * The dev or full path that's returned is malloced, so needs to be freed when
315 * the caller is done about it. Unlike many other functions, we can return data
316 * with an error code, so pay attention.
319 efivar_device_path_to_unix_path(const_efidp dp, char **dev, char **relpath, char **abspath)
326 * Sanity check args, fail early
328 if (dp == NULL || dev == NULL || relpath == NULL || abspath == NULL)
336 * Find the first media device path we can. If we go too far,
337 * assume the passed in device path is bogus. If we hit the end
338 * then we didn't find a media device path, so signal that error.
341 if (!ValidLen(walker))
343 while (DevicePathType(walker) != MEDIA_DEVICE_PATH &&
344 DevicePathType(walker) != END_DEVICE_PATH_TYPE) {
345 walker = (const_efidp)NextDevicePathNode(walker);
346 if ((uintptr_t)walker - (uintptr_t)dp > MAX_DP_SANITY)
348 if (!ValidLen(walker))
351 if (DevicePathType(walker) != MEDIA_DEVICE_PATH)
355 * There's several types of media paths. We're only interested in the
356 * hard disk path, as it's really the only relevant one to booting. The
357 * CD path just might also be relevant, and would be easy to add, but
358 * isn't supported. A file path too is relevant, but at this stage, it's
359 * premature because we're trying to translate a specification for a device
360 * and path on that device into a unix path, or at the very least, a
361 * geom device : path-on-device.
363 * Also, ZFS throws a bit of a monkey wrench in here since it doesn't have
364 * a device path type (it creates a new virtual device out of one or more
367 * For all of them, we'll need to know the geoms, so allocate / free the
368 * geom mesh here since it's safer than doing it in each sub-function
369 * which may have many error exits.
371 if (geom_gettree(&mesh))
375 if (DevicePathSubType(walker) == MEDIA_HARDDRIVE_DP)
376 rv = efi_hd_to_unix(&mesh, walker, dev, relpath, abspath);
378 else if (is_cdrom_device(walker))
379 rv = efi_cdrom_to_unix(&mesh, walker, dev, relpath, abspath);
380 else if (is_floppy_device(walker))
381 rv = efi_floppy_to_unix(&mesh, walker, dev, relpath, abspath);
382 else if (is_zpool_device(walker))
383 rv = efi_zpool_to_unix(&mesh, walker, dev, relpath, abspath);
385 geom_deletetree(&mesh);
391 * Construct the EFI path to a current unix path as follows.
393 * The path may be of one of three forms:
394 * 1) /path/to/file -- full path to a file. The file need not be present,
395 * but /path/to must be. It must reside on a local filesystem
396 * mounted on a GPT or MBR partition.
397 * 2) //path/to/file -- Shorthand for 'On the EFI partition, \path\to\file'
398 * where 'The EFI Partition' is a partition that's type is 'efi'
399 * on the same disk that / is mounted from. If there are multiple
400 * or no 'efi' parittions on that disk, or / isn't on a disk that
401 * we can trace back to a physical device, an error will result
402 * 3) [/dev/]geom-name:/path/to/file -- Use the specified partition
403 * (and it must be a GPT or MBR partition) with the specified
404 * path. The latter is not authenticated.
405 * all path forms translate any \ characters to / before further processing.
406 * When a file path node is created, all / characters are translated back
409 * For paths of the first form:
410 * find where the filesystem is mount (either the file directly, or
411 * its parent directory).
412 * translate any logical device name (eg lable) to a physical one
413 * If not possible, return ENXIO
414 * If the physical path is unsupported (Eg not on a GPT or MBR disk),
416 * Create a media device path node.
417 * append the relative path from the mountpoint to the media device node
420 * For paths matching the second form:
421 * find the EFI partition corresponding to the root fileystem.
422 * If none found, return ENXIO
423 * Create a media device path node for the found partition
424 * Append a File Path to the end for the rest of the file.
426 * For paths of the third form
427 * Translate the geom-name passed in into a physical partition
429 * Return ENXIO if the translation fails
430 * Make a media device path for it
431 * append the part after the : as a File path node.
435 path_to_file_dp(const char *relpath)
439 asprintf(&rv, "File(%s)", relpath);
444 find_geom_efi_on_root(struct gmesh *mesh)
448 struct gprovider *pp;
449 // struct ggeom *disk;
450 struct gconsumer *cp;
453 * Find /'s geom. Assume it's mounted on /dev/ and filter out all the
454 * filesystems that aren't.
456 if (statfs("/", &buf) != 0)
458 dev = buf.f_mntfromname;
459 if (*dev != '/' || strncmp(dev, _PATH_DEV, sizeof(_PATH_DEV) - 1) != 0)
461 dev += sizeof(_PATH_DEV) -1;
462 pp = find_provider_by_name(mesh, dev);
467 * If the provider is a LABEL, find it's outer PART class, if any. We
468 * only operate on partitions.
470 if (strcmp(pp->lg_geom->lg_class->lg_name, G_LABEL) == 0) {
471 LIST_FOREACH(cp, &pp->lg_consumers, lg_consumer) {
472 if (strcmp(cp->lg_provider->lg_geom->lg_class->lg_name, G_PART) == 0) {
473 pp = cp->lg_provider;
478 if (strcmp(pp->lg_geom->lg_class->lg_name, G_PART) != 0)
482 /* This doesn't work because we can't get the data to walk UP the tree it seems */
485 * Now that we've found the PART that we have mounted as root, find the
486 * first efi typed partition that's a peer, if any.
488 LIST_FOREACH(cp, &pp->lg_consumers, lg_consumer) {
489 if (strcmp(cp->lg_provider->lg_geom->lg_class->lg_name, G_DISK) == 0) {
490 disk = cp->lg_provider->lg_geom;
494 if (disk == NULL) /* This is very bad -- old nested partitions -- no support ? */
499 /* This doesn't work because we can't get the data to walk UP the tree it seems */
502 * With the disk provider, we can look for its consumers to see if any are the proper type.
504 LIST_FOREACH(pp, &disk->lg_consumer, lg_consumer) {
505 type = geom_pp_attr(mesh, pp, "type");
508 if (strcmp(type, "efi") != 0)
510 efimedia = geom_pp_attr(mesh, pp, "efimedia");
511 if (efimedia == NULL)
513 return strdup(efimedia);
521 find_geom_efimedia(struct gmesh *mesh, const char *dev)
523 struct gprovider *pp;
524 const char *efimedia;
526 pp = find_provider_by_name(mesh, dev);
529 efimedia = geom_pp_attr(mesh, pp, "efimedia");
530 if (efimedia == NULL)
532 return strdup(efimedia);
536 build_dp(const char *efimedia, const char *relpath, efidp *dp)
538 char *fp, *dptxt = NULL, *cp, *rp;
543 rp = strdup(relpath);
544 for (cp = rp; *cp; cp++)
547 fp = path_to_file_dp(rp);
554 asprintf(&dptxt, "%s/%s", efimedia, fp);
556 len = efidp_parse_device_path(dptxt, out, 8192);
577 /* Handles //path/to/file */
579 * Which means: find the disk that has /. Then look for a EFI partition
580 * and use that for the efimedia and /path/to/file as relative to that.
581 * Not sure how ZFS will work here since we can't easily make the leap
582 * to the geom from the zpool.
585 efipart_to_dp(struct gmesh *mesh, char *path, efidp *dp)
587 char *efimedia = NULL;
590 efimedia = find_geom_efi_on_root(mesh);
592 if (efimedia == NULL)
593 efimedia = find_efi_on_zfsroot(dev);
595 if (efimedia == NULL) {
600 rv = build_dp(efimedia, path + 1, dp);
607 /* Handles [/dev/]geom:[/]path/to/file */
608 /* Handles zfs-dataset:[/]path/to/file (this may include / ) */
610 dev_path_to_dp(struct gmesh *mesh, char *path, efidp *dp)
612 char *relpath, *dev, *efimedia = NULL;
615 relpath = strchr(path, ':');
616 assert(relpath != NULL);
620 if (strncmp(dev, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
621 dev += sizeof(_PATH_DEV) -1;
623 efimedia = find_geom_efimedia(mesh, dev);
625 if (efimedia == NULL)
626 find_zfs_efi_media(dev);
628 if (efimedia == NULL) {
632 rv = build_dp(efimedia, relpath, dp);
639 /* Handles /path/to/file */
641 path_to_dp(struct gmesh *mesh, char *path, efidp *dp)
644 char *rp = NULL, *ep, *dev, *efimedia = NULL;
647 rp = realpath(path, NULL);
653 if (statfs(rp, &buf) != 0) {
658 dev = buf.f_mntfromname;
659 if (strncmp(dev, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
660 dev += sizeof(_PATH_DEV) -1;
661 ep = rp + strlen(buf.f_mntonname);
663 efimedia = find_geom_efimedia(mesh, dev);
665 if (efimedia == NULL)
666 find_zfs_efi_media(dev);
668 if (efimedia == NULL) {
673 rv = build_dp(efimedia, ep, dp);
685 efivar_unix_path_to_device_path(const char *path, efidp *dp)
687 char *modpath = NULL, *cp;
692 * Fail early for clearly bogus things
694 if (path == NULL || dp == NULL)
698 * We'll need the goem mesh to grovel through it to find the
699 * efimedia attribute for any devices we find. Grab it here
700 * and release it to simplify the error paths out of the
701 * subordinate functions
703 if (geom_gettree(&mesh))
707 * Convert all \ to /. We'll convert them back again when
708 * we encode the file. Boot loaders are expected to cope.
710 modpath = strdup(path);
713 for (cp = modpath; *cp; cp++)
717 if (modpath[0] == '/' && modpath[1] == '/') /* Handle //foo/bar/baz */
718 rv = efipart_to_dp(&mesh, modpath, dp);
719 else if (strchr(modpath, ':')) /* Handle dev:/bar/baz */
720 rv = dev_path_to_dp(&mesh, modpath, dp);
721 else /* Handle /a/b/c */
722 rv = path_to_dp(&mesh, modpath, dp);
725 geom_deletetree(&mesh);