| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <errno.h> |
| |
| #include "sd-device.h" |
| |
| #include "acl-util.h" |
| #include "alloc-util.h" |
| #include "device-util.h" |
| #include "devnode-acl.h" |
| #include "dirent-util.h" |
| #include "escape.h" |
| #include "fd-util.h" |
| #include "format-util.h" |
| #include "set.h" |
| #include "string-util.h" |
| #include "util.h" |
| |
| static int flush_acl(acl_t acl) { |
| acl_entry_t i; |
| int found; |
| bool changed = false; |
| |
| assert(acl); |
| |
| for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i); |
| found > 0; |
| found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) { |
| |
| acl_tag_t tag; |
| |
| if (acl_get_tag_type(i, &tag) < 0) |
| return -errno; |
| |
| if (tag != ACL_USER) |
| continue; |
| |
| if (acl_delete_entry(acl, i) < 0) |
| return -errno; |
| |
| changed = true; |
| } |
| |
| if (found < 0) |
| return -errno; |
| |
| return changed; |
| } |
| |
| int devnode_acl(const char *path, |
| bool flush, |
| bool del, uid_t old_uid, |
| bool add, uid_t new_uid) { |
| |
| _cleanup_(acl_freep) acl_t acl = NULL; |
| int r; |
| bool changed = false; |
| |
| assert(path); |
| |
| acl = acl_get_file(path, ACL_TYPE_ACCESS); |
| if (!acl) |
| return -errno; |
| |
| if (flush) { |
| |
| r = flush_acl(acl); |
| if (r < 0) |
| return r; |
| if (r > 0) |
| changed = true; |
| |
| } else if (del && old_uid > 0) { |
| acl_entry_t entry; |
| |
| r = acl_find_uid(acl, old_uid, &entry); |
| if (r < 0) |
| return r; |
| |
| if (r > 0) { |
| if (acl_delete_entry(acl, entry) < 0) |
| return -errno; |
| |
| changed = true; |
| } |
| } |
| |
| if (add && new_uid > 0) { |
| acl_entry_t entry; |
| acl_permset_t permset; |
| int rd, wt; |
| |
| r = acl_find_uid(acl, new_uid, &entry); |
| if (r < 0) |
| return r; |
| |
| if (r == 0) { |
| if (acl_create_entry(&acl, &entry) < 0) |
| return -errno; |
| |
| if (acl_set_tag_type(entry, ACL_USER) < 0 || |
| acl_set_qualifier(entry, &new_uid) < 0) |
| return -errno; |
| } |
| |
| if (acl_get_permset(entry, &permset) < 0) |
| return -errno; |
| |
| rd = acl_get_perm(permset, ACL_READ); |
| if (rd < 0) |
| return -errno; |
| |
| wt = acl_get_perm(permset, ACL_WRITE); |
| if (wt < 0) |
| return -errno; |
| |
| if (!rd || !wt) { |
| |
| if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0) |
| return -errno; |
| |
| changed = true; |
| } |
| } |
| |
| if (!changed) |
| return 0; |
| |
| if (acl_calc_mask(&acl) < 0) |
| return -errno; |
| |
| if (acl_set_file(path, ACL_TYPE_ACCESS, acl) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| int devnode_acl_all(const char *seat, |
| bool flush, |
| bool del, uid_t old_uid, |
| bool add, uid_t new_uid) { |
| |
| _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; |
| _cleanup_set_free_free_ Set *nodes = NULL; |
| _cleanup_closedir_ DIR *dir = NULL; |
| struct dirent *dent; |
| sd_device *d; |
| char *n; |
| int r; |
| |
| nodes = set_new(&path_hash_ops); |
| if (!nodes) |
| return -ENOMEM; |
| |
| r = sd_device_enumerator_new(&e); |
| if (r < 0) |
| return r; |
| |
| if (isempty(seat)) |
| seat = "seat0"; |
| |
| /* We can only match by one tag in libudev. We choose |
| * "uaccess" for that. If we could match for two tags here we |
| * could add the seat name as second match tag, but this would |
| * be hardly optimizable in libudev, and hence checking the |
| * second tag manually in our loop is a good solution. */ |
| r = sd_device_enumerator_add_match_tag(e, "uaccess"); |
| if (r < 0) |
| return r; |
| |
| FOREACH_DEVICE(e, d) { |
| const char *node, *sn; |
| |
| /* Make sure the tag is still in place */ |
| if (sd_device_has_current_tag(d, "uaccess") <= 0) |
| continue; |
| |
| if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn)) |
| sn = "seat0"; |
| |
| if (!streq(seat, sn)) |
| continue; |
| |
| /* In case people mistag devices with nodes, we need to ignore this */ |
| if (sd_device_get_devname(d, &node) < 0) |
| continue; |
| |
| log_device_debug(d, "Found udev node %s for seat %s", node, seat); |
| r = set_put_strdup(&nodes, node); |
| if (r < 0) |
| return r; |
| } |
| |
| /* udev exports "dead" device nodes to allow module on-demand loading, |
| * these devices are not known to the kernel at this moment */ |
| dir = opendir("/run/udev/static_node-tags/uaccess"); |
| if (dir) { |
| FOREACH_DIRENT(dent, dir, return -errno) { |
| _cleanup_free_ char *unescaped_devname = NULL; |
| |
| if (cunescape(dent->d_name, UNESCAPE_RELAX, &unescaped_devname) < 0) |
| return -ENOMEM; |
| |
| n = path_join("/dev", unescaped_devname); |
| if (!n) |
| return -ENOMEM; |
| |
| log_debug("Found static node %s for seat %s", n, seat); |
| r = set_consume(nodes, n); |
| if (r == -EEXIST) |
| continue; |
| if (r < 0) |
| return r; |
| } |
| } |
| |
| r = 0; |
| SET_FOREACH(n, nodes) { |
| int k; |
| |
| log_debug("Changing ACLs at %s for seat %s (uid "UID_FMT"→"UID_FMT"%s%s)", |
| n, seat, old_uid, new_uid, |
| del ? " del" : "", add ? " add" : ""); |
| |
| k = devnode_acl(n, flush, del, old_uid, add, new_uid); |
| if (k == -ENOENT) |
| log_debug("Device %s disappeared while setting ACLs", n); |
| else if (k < 0 && r == 0) |
| r = k; |
| } |
| |
| return r; |
| } |
