/* * CALIPSO - Common Architecture Label IPv6 Security Option * * This is an implementation of the CALIPSO protocol as specified in * RFC 5570. * * Authors: Paul Moore * Huw Davies * */ /* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 * (c) Copyright Huw Davies , 2015 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* List of available DOI definitions */ static DEFINE_SPINLOCK(calipso_doi_list_lock); static LIST_HEAD(calipso_doi_list); /* DOI List Functions */ /** * calipso_doi_search - Searches for a DOI definition * @doi: the DOI to search for * * Description: * Search the DOI definition list for a DOI definition with a DOI value that * matches @doi. The caller is responsible for calling rcu_read_[un]lock(). * Returns a pointer to the DOI definition on success and NULL on failure. */ static struct calipso_doi *calipso_doi_search(u32 doi) { struct calipso_doi *iter; list_for_each_entry_rcu(iter, &calipso_doi_list, list) if (iter->doi == doi && atomic_read(&iter->refcount)) return iter; return NULL; } /** * calipso_doi_add - Add a new DOI to the CALIPSO protocol engine * @doi_def: the DOI structure * @audit_info: NetLabel audit information * * Description: * The caller defines a new DOI for use by the CALIPSO engine and calls this * function to add it to the list of acceptable domains. The caller must * ensure that the mapping table specified in @doi_def->map meets all of the * requirements of the mapping type (see calipso.h for details). Returns * zero on success and non-zero on failure. * */ static int calipso_doi_add(struct calipso_doi *doi_def, struct netlbl_audit *audit_info) { int ret_val = -EINVAL; u32 doi; u32 doi_type; struct audit_buffer *audit_buf; doi = doi_def->doi; doi_type = doi_def->type; if (doi_def->doi == CALIPSO_DOI_UNKNOWN) goto doi_add_return; atomic_set(&doi_def->refcount, 1); spin_lock(&calipso_doi_list_lock); if (calipso_doi_search(doi_def->doi)) { spin_unlock(&calipso_doi_list_lock); ret_val = -EEXIST; goto doi_add_return; } list_add_tail_rcu(&doi_def->list, &calipso_doi_list); spin_unlock(&calipso_doi_list_lock); ret_val = 0; doi_add_return: audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_ADD, audit_info); if (audit_buf) { const char *type_str; switch (doi_type) { case CALIPSO_MAP_PASS: type_str = "pass"; break; default: type_str = "(unknown)"; } audit_log_format(audit_buf, " calipso_doi=%u calipso_type=%s res=%u", doi, type_str, ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); } return ret_val; } /** * calipso_doi_free - Frees a DOI definition * @doi_def: the DOI definition * * Description: * This function frees all of the memory associated with a DOI definition. * */ static void calipso_doi_free(struct calipso_doi *doi_def) { kfree(doi_def); } /** * calipso_doi_free_rcu - Frees a DOI definition via the RCU pointer * @entry: the entry's RCU field * * Description: * This function is designed to be used as a callback to the call_rcu() * function so that the memory allocated to the DOI definition can be released * safely. * */ static void calipso_doi_free_rcu(struct rcu_head *entry) { struct calipso_doi *doi_def; doi_def = container_of(entry, struct calipso_doi, rcu); calipso_doi_free(doi_def); } /** * calipso_doi_remove - Remove an existing DOI from the CALIPSO protocol engine * @doi: the DOI value * @audit_secid: the LSM secid to use in the audit message * * Description: * Removes a DOI definition from the CALIPSO engine. The NetLabel routines will * be called to release their own LSM domain mappings as well as our own * domain list. Returns zero on success and negative values on failure. * */ static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info) { int ret_val; struct calipso_doi *doi_def; struct audit_buffer *audit_buf; spin_lock(&calipso_doi_list_lock); doi_def = calipso_doi_search(doi); if (!doi_def) { spin_unlock(&calipso_doi_list_lock); ret_val = -ENOENT; goto doi_remove_return; } if (!atomic_dec_and_test(&doi_def->refcount)) { spin_unlock(&calipso_doi_list_lock); ret_val = -EBUSY; goto doi_remove_return; } list_del_rcu(&doi_def->list); spin_unlock(&calipso_doi_list_lock); call_rcu(&doi_def->rcu, calipso_doi_free_rcu); ret_val = 0; doi_remove_return: audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_DEL, audit_info); if (audit_buf) { audit_log_format(audit_buf, " calipso_doi=%u res=%u", doi, ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); } return ret_val; } /** * calipso_doi_getdef - Returns a reference to a valid DOI definition * @doi: the DOI value * * Description: * Searches for a valid DOI definition and if one is found it is returned to * the caller. Otherwise NULL is returned. The caller must ensure that * calipso_doi_putdef() is called when the caller is done. * */ static struct calipso_doi *calipso_doi_getdef(u32 doi) { struct calipso_doi *doi_def; rcu_read_lock(); doi_def = calipso_doi_search(doi); if (!doi_def) goto doi_getdef_return; if (!atomic_inc_not_zero(&doi_def->refcount)) doi_def = NULL; doi_getdef_return: rcu_read_unlock(); return doi_def; } /** * calipso_doi_putdef - Releases a reference for the given DOI definition * @doi_def: the DOI definition * * Description: * Releases a DOI definition reference obtained from calipso_doi_getdef(). * */ static void calipso_doi_putdef(struct calipso_doi *doi_def) { if (!doi_def) return; if (!atomic_dec_and_test(&doi_def->refcount)) return; spin_lock(&calipso_doi_list_lock); list_del_rcu(&doi_def->list); spin_unlock(&calipso_doi_list_lock); call_rcu(&doi_def->rcu, calipso_doi_free_rcu); } /** * calipso_doi_walk - Iterate through the DOI definitions * @skip_cnt: skip past this number of DOI definitions, updated * @callback: callback for each DOI definition * @cb_arg: argument for the callback function * * Description: * Iterate over the DOI definition list, skipping the first @skip_cnt entries. * For each entry call @callback, if @callback returns a negative value stop * 'walking' through the list and return. Updates the value in @skip_cnt upon * return. Returns zero on success, negative values on failure. * */ static int calipso_doi_walk(u32 *skip_cnt, int (*callback)(struct calipso_doi *doi_def, void *arg), void *cb_arg) { int ret_val = -ENOENT; u32 doi_cnt = 0; struct calipso_doi *iter_doi; rcu_read_lock(); list_for_each_entry_rcu(iter_doi, &calipso_doi_list, list) if (atomic_read(&iter_doi->refcount) > 0) { if (doi_cnt++ < *skip_cnt) continue; ret_val = callback(iter_doi, cb_arg); if (ret_val < 0) { doi_cnt--; goto doi_walk_return; } } doi_walk_return: rcu_read_unlock(); *skip_cnt = doi_cnt; return ret_val; } static const struct netlbl_calipso_ops ops = { .doi_add = calipso_doi_add, .doi_free = calipso_doi_free, .doi_remove = calipso_doi_remove, .doi_getdef = calipso_doi_getdef, .doi_putdef = calipso_doi_putdef, .doi_walk = calipso_doi_walk, }; /** * calipso_init - Initialize the CALIPSO module * * Description: * Initialize the CALIPSO module and prepare it for use. Returns zero on * success and negative values on failure. * */ int __init calipso_init(void) { netlbl_calipso_ops_register(&ops); return 0; } void calipso_exit(void) { netlbl_calipso_ops_register(NULL); }