2 * Copyright (c) 2017 Netflix, Inc.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
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14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/ucred.h>
32 #include <sys/mount.h>
47 #include "efi-osdep.h"
48 #include "efivar-dp.h"
50 #include "uefi-dplib.h"
52 #define MAX_DP_SANITY 4096 /* Biggest device path in bytes */
53 #define MAX_DP_TEXT_LEN 4096 /* Longest string rep of dp */
56 #define G_LABEL "LABEL"
60 geom_pp_attr(struct gmesh *mesh, struct gprovider *pp, const char *attr)
64 LIST_FOREACH(conf, &pp->lg_config, lg_config) {
65 if (strcmp(conf->lg_name, attr) != 0)
67 return (conf->lg_val);
72 static struct gprovider *
73 find_provider_by_efimedia(struct gmesh *mesh, const char *efimedia)
75 struct gclass *classp;
81 * Find the partition class so we can search it...
83 LIST_FOREACH(classp, &mesh->lg_class, lg_class) {
84 if (strcasecmp(classp->lg_name, G_PART) == 0)
91 * Each geom will have a number of providers, search each
92 * one of them for the efimedia that matches.
94 /* XXX just used gpart class since I know it's the only one, but maybe I should search all classes */
95 LIST_FOREACH(gp, &classp->lg_geom, lg_geom) {
96 LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
97 val = geom_pp_attr(mesh, pp, "efimedia");
100 if (strcasecmp(efimedia, val) == 0)
108 static struct gprovider *
109 find_provider_by_name(struct gmesh *mesh, const char *name)
111 struct gclass *classp;
113 struct gprovider *pp;
115 LIST_FOREACH(classp, &mesh->lg_class, lg_class) {
116 LIST_FOREACH(gp, &classp->lg_geom, lg_geom) {
117 LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
118 if (strcmp(pp->lg_name, name) == 0)
129 efi_hd_to_unix(struct gmesh *mesh, const_efidp dp, char **dev, char **relpath, char **abspath)
132 const_efidp media, file, walker;
134 char buf[MAX_DP_TEXT_LEN];
136 struct gprovider *pp, *provider;
137 struct gconsumer *cp;
143 * Now, we can either have a filepath node next, or the end.
144 * Otherwise, it's an error.
146 walker = (const_efidp)NextDevicePathNode(walker);
147 if ((uintptr_t)walker - (uintptr_t)dp > MAX_DP_SANITY)
149 if (DevicePathType(walker) == MEDIA_DEVICE_PATH &&
150 DevicePathSubType(walker) == MEDIA_FILEPATH_DP)
152 else if (DevicePathType(walker) == MEDIA_DEVICE_PATH &&
153 DevicePathType(walker) == END_DEVICE_PATH_TYPE)
159 * Format this node. We're going to look for it as a efimedia
160 * attribute of some geom node. Once we find that node, we use it
161 * as the device it comes from, at least provisionally.
163 len = efidp_format_device_path_node(buf, sizeof(buf), media);
164 if (len > sizeof(buf))
167 pp = find_provider_by_efimedia(mesh, buf);
173 *dev = strdup(pp->lg_name);
180 * No file specified, just return the device. Don't even look
181 * for a mountpoint. XXX Sane?
187 * Now extract the relative path. The next node in the device path should
188 * be a filesystem node. If not, we have issues.
190 *relpath = efidp_extract_file_path(file);
191 if (*relpath == NULL) {
195 for (pwalk = *relpath; *pwalk; pwalk++)
200 * To find the absolute path, we have to look for where we're mounted.
201 * We only look a little hard, since looking too hard can come up with
202 * false positives (imagine a graid, one of whose devices is *dev).
204 n = getfsstat(NULL, 0, MNT_NOWAIT) + 1;
209 mntlen = sizeof(struct statfs) * n;
210 mnt = malloc(mntlen);
211 n = getfsstat(mnt, mntlen, MNT_NOWAIT);
217 for (i = 0; i < n; i++) {
219 * Skip all pseudo filesystems. This also skips the real filesytsem
220 * of ZFS. There's no EFI designator for ZFS in the standard, so
221 * we'll need to invent one, but its decoding will be handled in
222 * a separate function.
224 if (mnt[i].f_mntfromname[0] != '/')
228 * First see if it is directly attached
230 if (strcmp(provider->lg_name, mnt[i].f_mntfromname + 5) == 0)
234 * Next see if it is attached via one of the physical disk's
237 LIST_FOREACH(cp, &provider->lg_consumers, lg_consumer) {
238 pp = cp->lg_provider;
239 if (strcmp(pp->lg_geom->lg_class->lg_name, G_LABEL) != 0)
241 if (strcmp(g_device_path(pp->lg_name), mnt[i].f_mntfromname) == 0)
244 /* Not the one, try the next mount point */
249 * No mountpoint found, no absolute path possible
255 * Construct absolute path and we're finally done.
257 if (strcmp(mnt[i].f_mntonname, "/") == 0)
258 asprintf(abspath, "/%s", *relpath);
260 asprintf(abspath, "%s/%s", mnt[i].f_mntonname, *relpath);
273 * Translate the passed in device_path to a unix path via the following
276 * If dp, dev or path NULL, return EDOOFUS. XXX wise?
278 * Set *path = NULL; *dev = NULL;
280 * Walk through the device_path until we find either a media device path.
281 * Return EINVAL if not found. Return EINVAL if walking dp would
282 * land us more than sanity size away from the start (4k).
284 * If we find a media descriptor, we search through the geom mesh to see if we
285 * can find a matching node. If no match is found in the mesh that matches,
288 * Once we find a matching node, we search to see if there is a filesystem
289 * mounted on it. If we find nothing, then search each of the devices that are
290 * mounted to see if we can work up the geom tree to find the matching node. if
291 * we still can't find anything, *dev = sprintf("/dev/%s", provider_name
292 * of the original node we found), but return ENOTBLK.
294 * Record the dev of the mountpoint in *dev.
296 * Once we find something, check to see if the next node in the device path is
297 * the end of list. If so, return the mountpoint.
299 * If the next node isn't a File path node, return EFTYPE.
301 * Extract the path from the File path node(s). translate any \ file separators
302 * to /. Append the result to the mount point. Copy the resulting path into
303 * *path. Stat that path. If it is not found, return the errorr from stat.
305 * Finally, check to make sure the resulting path is still on the same
306 * device. If not, return ENODEV.
308 * Otherwise return 0.
310 * The dev or full path that's returned is malloced, so needs to be freed when
311 * the caller is done about it. Unlike many other functions, we can return data
312 * with an error code, so pay attention.
315 efivar_device_path_to_unix_path(const_efidp dp, char **dev, char **relpath, char **abspath)
322 * Sanity check args, fail early
324 if (dp == NULL || dev == NULL || relpath == NULL || abspath == NULL)
332 * Find the first media device path we can. If we go too far,
333 * assume the passed in device path is bogus. If we hit the end
334 * then we didn't find a media device path, so signal that error.
337 while (DevicePathType(walker) != MEDIA_DEVICE_PATH &&
338 DevicePathType(walker) != END_DEVICE_PATH_TYPE) {
339 walker = (const_efidp)NextDevicePathNode(walker);
340 if ((uintptr_t)walker - (uintptr_t)dp > MAX_DP_SANITY)
343 if (DevicePathType(walker) != MEDIA_DEVICE_PATH)
347 * There's several types of media paths. We're only interested in the
348 * hard disk path, as it's really the only relevant one to booting. The
349 * CD path just might also be relevant, and would be easy to add, but
350 * isn't supported. A file path too is relevant, but at this stage, it's
351 * premature because we're trying to translate a specification for a device
352 * and path on that device into a unix path, or at the very least, a
353 * geom device : path-on-device.
355 * Also, ZFS throws a bit of a monkey wrench in here since it doesn't have
356 * a device path type (it creates a new virtual device out of one or more
359 * For all of them, we'll need to know the geoms, so allocate / free the
360 * geom mesh here since it's safer than doing it in each sub-function
361 * which may have many error exits.
363 if (geom_gettree(&mesh))
367 if (DevicePathSubType(walker) == MEDIA_HARDDRIVE_DP)
368 rv = efi_hd_to_unix(&mesh, walker, dev, relpath, abspath);
370 else if (is_cdrom_device(walker))
371 rv = efi_cdrom_to_unix(&mesh, walker, dev, relpath, abspath);
372 else if (is_floppy_device(walker))
373 rv = efi_floppy_to_unix(&mesh, walker, dev, relpath, abspath);
374 else if (is_zpool_device(walker))
375 rv = efi_zpool_to_unix(&mesh, walker, dev, relpath, abspath);
377 geom_deletetree(&mesh);
383 * Construct the EFI path to a current unix path as follows.
385 * The path may be of one of three forms:
386 * 1) /path/to/file -- full path to a file. The file need not be present,
387 * but /path/to must be. It must reside on a local filesystem
388 * mounted on a GPT or MBR partition.
389 * 2) //path/to/file -- Shorthand for 'On the EFI partition, \path\to\file'
390 * where 'The EFI Partition' is a partiton that's type is 'efi'
391 * on the same disk that / is mounted from. If there are multiple
392 * or no 'efi' parittions on that disk, or / isn't on a disk that
393 * we can trace back to a physical device, an error will result
394 * 3) [/dev/]geom-name:/path/to/file -- Use the specified partition
395 * (and it must be a GPT or MBR partition) with the specified
396 * path. The latter is not authenticated.
397 * all path forms translate any \ characters to / before further processing.
398 * When a file path node is created, all / characters are translated back
401 * For paths of the first form:
402 * find where the filesystem is mount (either the file directly, or
403 * its parent directory).
404 * translate any logical device name (eg lable) to a physical one
405 * If not possible, return ENXIO
406 * If the physical path is unsupported (Eg not on a GPT or MBR disk),
408 * Create a media device path node.
409 * append the relative path from the mountpoint to the media device node
412 * For paths matching the second form:
413 * find the EFI partition corresponding to the root fileystem.
414 * If none found, return ENXIO
415 * Create a media device path node for the found partition
416 * Append a File Path to the end for the rest of the file.
418 * For paths of the third form
419 * Translate the geom-name passed in into a physical partition
421 * Return ENXIO if the translation fails
422 * Make a media device path for it
423 * append the part after the : as a File path node.
427 path_to_file_dp(const char *relpath)
431 asprintf(&rv, "File(%s)", relpath);
436 find_geom_efi_on_root(struct gmesh *mesh)
440 struct gprovider *pp;
441 // struct ggeom *disk;
442 struct gconsumer *cp;
445 * Find /'s geom. Assume it's mounted on /dev/ and filter out all the
446 * filesystems that aren't.
448 if (statfs("/", &buf) != 0)
450 dev = buf.f_mntfromname;
451 if (*dev != '/' || strncmp(dev, _PATH_DEV, sizeof(_PATH_DEV) - 1) != 0)
453 dev += sizeof(_PATH_DEV) -1;
454 pp = find_provider_by_name(mesh, dev);
459 * If the provider is a LABEL, find it's outer PART class, if any. We
460 * only operate on partitions.
462 if (strcmp(pp->lg_geom->lg_class->lg_name, G_LABEL) == 0) {
463 LIST_FOREACH(cp, &pp->lg_consumers, lg_consumer) {
464 if (strcmp(cp->lg_provider->lg_geom->lg_class->lg_name, G_PART) == 0) {
465 pp = cp->lg_provider;
470 if (strcmp(pp->lg_geom->lg_class->lg_name, G_PART) != 0)
474 /* This doesn't work because we can't get the data to walk UP the tree it seems */
477 * Now that we've found the PART that we have mounted as root, find the
478 * first efi typed partition that's a peer, if any.
480 LIST_FOREACH(cp, &pp->lg_consumers, lg_consumer) {
481 if (strcmp(cp->lg_provider->lg_geom->lg_class->lg_name, G_DISK) == 0) {
482 disk = cp->lg_provider->lg_geom;
486 if (disk == NULL) /* This is very bad -- old nested partitions -- no support ? */
491 /* This doesn't work because we can't get the data to walk UP the tree it seems */
494 * With the disk provider, we can look for its consumers to see if any are the proper type.
496 LIST_FOREACH(pp, &disk->lg_consumer, lg_consumer) {
497 type = geom_pp_attr(mesh, pp, "type");
500 if (strcmp(type, "efi") != 0)
502 efimedia = geom_pp_attr(mesh, pp, "efimedia");
503 if (efimedia == NULL)
505 return strdup(efimedia);
513 find_geom_efimedia(struct gmesh *mesh, const char *dev)
515 struct gprovider *pp;
516 const char *efimedia;
518 pp = find_provider_by_name(mesh, dev);
521 efimedia = geom_pp_attr(mesh, pp, "efimedia");
522 if (efimedia == NULL)
524 return strdup(efimedia);
528 build_dp(const char *efimedia, const char *relpath, efidp *dp)
530 char *fp, *dptxt = NULL, *cp, *rp;
535 rp = strdup(relpath);
536 for (cp = rp; *cp; cp++)
539 fp = path_to_file_dp(rp);
546 asprintf(&dptxt, "%s/%s", efimedia, fp);
548 len = efidp_parse_device_path(dptxt, out, 8192);
569 /* Handles //path/to/file */
571 * Which means: find the disk that has /. Then look for a EFI partition
572 * and use that for the efimedia and /path/to/file as relative to that.
573 * Not sure how ZFS will work here since we can't easily make the leap
574 * to the geom from the zpool.
577 efipart_to_dp(struct gmesh *mesh, char *path, efidp *dp)
579 char *efimedia = NULL;
582 efimedia = find_geom_efi_on_root(mesh);
584 if (efimedia == NULL)
585 efimedia = find_efi_on_zfsroot(dev);
587 if (efimedia == NULL) {
592 rv = build_dp(efimedia, path + 1, dp);
599 /* Handles [/dev/]geom:[/]path/to/file */
600 /* Handles zfs-dataset:[/]path/to/file (this may include / ) */
602 dev_path_to_dp(struct gmesh *mesh, char *path, efidp *dp)
604 char *relpath, *dev, *efimedia = NULL;
607 relpath = strchr(path, ':');
608 assert(relpath != NULL);
612 if (strncmp(dev, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
613 dev += sizeof(_PATH_DEV) -1;
615 efimedia = find_geom_efimedia(mesh, dev);
617 if (efimedia == NULL)
618 find_zfs_efi_media(dev);
620 if (efimedia == NULL) {
624 rv = build_dp(efimedia, relpath, dp);
631 /* Handles /path/to/file */
633 path_to_dp(struct gmesh *mesh, char *path, efidp *dp)
636 char *rp = NULL, *ep, *dev, *efimedia = NULL;
639 rp = realpath(path, NULL);
645 if (statfs(rp, &buf) != 0) {
650 dev = buf.f_mntfromname;
651 if (strncmp(dev, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
652 dev += sizeof(_PATH_DEV) -1;
653 ep = rp + strlen(buf.f_mntonname);
655 efimedia = find_geom_efimedia(mesh, dev);
657 if (efimedia == NULL)
658 find_zfs_efi_media(dev);
660 if (efimedia == NULL) {
665 rv = build_dp(efimedia, ep, dp);
677 efivar_unix_path_to_device_path(const char *path, efidp *dp)
679 char *modpath = NULL, *cp;
684 * Fail early for clearly bogus things
686 if (path == NULL || dp == NULL)
690 * We'll need the goem mesh to grovel through it to find the
691 * efimedia attribute for any devices we find. Grab it here
692 * and release it to simplify the error paths out of the
693 * subordinate functions
695 if (geom_gettree(&mesh))
699 * Convert all \ to /. We'll convert them back again when
700 * we encode the file. Boot loaders are expected to cope.
702 modpath = strdup(path);
705 for (cp = modpath; *cp; cp++)
709 if (modpath[0] == '/' && modpath[1] == '/') /* Handle //foo/bar/baz */
710 rv = efipart_to_dp(&mesh, modpath, dp);
711 else if (strchr(modpath, ':')) /* Handle dev:/bar/baz */
712 rv = dev_path_to_dp(&mesh, modpath, dp);
713 else /* Handle /a/b/c */
714 rv = path_to_dp(&mesh, modpath, dp);
717 geom_deletetree(&mesh);