Introduce the digest_query interface, which allows to write a query in the format <algo>-<digest> and to obtain all digest lists that include that digest.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com --- security/integrity/diglim/fs.c | 154 +++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+)
diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c index 8958e987f708..f1c1fc56448a 100644 --- a/security/integrity/diglim/fs.c +++ b/security/integrity/diglim/fs.c @@ -43,6 +43,13 @@ static struct dentry *digest_lists_loaded_dir; * list (buffer) loaded through digest_list_add. */ static struct dentry *digest_label_dentry; +/** + * DOC: digest_query + * + * digest_query allows to write a query in the format <algo>-<digest> and + * to obtain all digest lists that include that digest. + */ +static struct dentry *digest_query_dentry; /** * DOC: digest_list_add * @@ -63,6 +70,7 @@ static struct dentry *digest_list_add_dentry; * described for digest_list_add. */ static struct dentry *digest_list_del_dentry; +char digest_query[CRYPTO_MAX_ALG_NAME + 1 + IMA_MAX_DIGEST_SIZE * 2 + 1]; char digest_label[NAME_MAX + 1];
static int parse_digest_list_filename(const char *digest_list_filename, @@ -253,6 +261,84 @@ static const struct file_operations digest_list_ascii_ops = { .release = seq_release, };
+/* + * *pos is the n-th reference to show among all the references in all digest + * items found with the query. + */ +static void *digest_query_start(struct seq_file *m, loff_t *pos) +{ + struct digest_item *d; + u8 digest[IMA_MAX_DIGEST_SIZE]; + enum hash_algo algo; + loff_t count = 0; + enum compact_types type = 0; + struct digest_list_item_ref *ref; + int ret; + + ret = parse_digest_list_filename(digest_query, digest, &algo); + if (ret < 0) + return NULL; + + for (type = 0; type < COMPACT__LAST; type++) { + d = __digest_lookup(digest, algo, type, NULL, NULL); + if (!d) + continue; + + list_for_each_entry(ref, &d->refs, list) { + if (count++ == *pos) { + m->private = d; + return ref; + } + } + } + + return NULL; +} + +static void *digest_query_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct digest_item *d = (struct digest_item *)m->private; + struct digest_list_item_ref *cur_ref = (struct digest_list_item_ref *)v; + struct digest_list_item_ref *ref; + + (*pos)++; + + list_for_each_entry(ref, &d->refs, list) { + if (ref != cur_ref) + continue; + + if (!list_is_last(&cur_ref->list, &d->refs)) + return list_next_entry(cur_ref, list); + } + + return NULL; +} + +static void digest_query_stop(struct seq_file *m, void *v) +{ +} + +static int digest_query_show(struct seq_file *m, void *v) +{ + struct digest_list_item_ref *ref = (struct digest_list_item_ref *)v; + struct digest_list_item *digest_list = ref->digest_list; + struct compact_list_hdr *hdr = get_hdr_ref(ref); + + if (!ref->digest_offset) { + seq_printf(m, "%s (actions: %d): type: %d, size: %lld\n", + digest_list->label, digest_list->actions, + COMPACT_DIGEST_LIST, digest_list->size); + return 0; + } + + seq_printf(m, + "%s (actions: %d): version: %d, algo: %s, type: %d, modifiers: %d, count: %d, datalen: %d\n", + digest_list->label, digest_list->actions, hdr->version, + hash_algo_name[hdr->algo], hdr->type, hdr->modifiers, + hdr->count, hdr->datalen); + return 0; +} + static int digest_list_get_secfs_files(char *label, u8 *digest, enum hash_algo algo, enum ops op, struct dentry **dentry, @@ -538,6 +624,67 @@ static const struct file_operations digest_label_ops = { .llseek = generic_file_llseek, };
+static const struct seq_operations digest_query_seqops = { + .start = digest_query_start, + .next = digest_query_next, + .stop = digest_query_stop, + .show = digest_query_show, +}; + +/* + * digest_query_open: sequentialize access to the add/del/query files + */ +static int digest_query_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &flags)) + return -EBUSY; + + if (file->f_flags & O_WRONLY) + return 0; + + return seq_open(file, &digest_query_seqops); +} + +/* + * digest_query_write: write digest query (<algo>-<digest>). + */ +static ssize_t digest_query_write(struct file *file, const char __user *buf, + size_t datalen, loff_t *ppos) +{ + int rc; + + if (datalen >= sizeof(digest_query)) + return -EINVAL; + + rc = copy_from_user(digest_query, buf, datalen); + if (rc) + return -EFAULT; + + digest_query[datalen] = '\0'; + return datalen; +} + +/* + * digest_query_release - release the query file + */ +static int digest_query_release(struct inode *inode, struct file *file) +{ + clear_bit(0, &flags); + + if (file->f_flags & O_WRONLY) + return 0; + + return seq_release(inode, file); +} + +static const struct file_operations digest_query_ops = { + .open = digest_query_open, + .write = digest_query_write, + .read = seq_read, + .release = digest_query_release, + .llseek = generic_file_llseek, +}; + static int __init diglim_fs_init(void) { diglim_dir = securityfs_create_dir("diglim", integrity_dir); @@ -567,8 +714,15 @@ static int __init diglim_fs_init(void) if (IS_ERR(digest_label_dentry)) goto out;
+ digest_query_dentry = securityfs_create_file("digest_query", 0600, + diglim_dir, NULL, + &digest_query_ops); + if (IS_ERR(digest_query_dentry)) + goto out; + return 0; out: + securityfs_remove(digest_query_dentry); securityfs_remove(digest_label_dentry); securityfs_remove(digest_list_del_dentry); securityfs_remove(digest_list_add_dentry);