/* * NetLabel Unlabeled Support * * This file defines functions for dealing with unlabeled packets for the * NetLabel system. The NetLabel system manages static and dynamic label * mappings for network protocols such as CIPSO and RIPSO. * * Author: Paul Moore <paul@paul-moore.com> * */ /* * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 - 2008 * * 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 <http://www.gnu.org/licenses/>. * */ #include <linux/types.h> #include <linux/rcupdate.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/socket.h> #include <linux/string.h> #include <linux/skbuff.h> #include <linux/audit.h> #include <linux/in.h> #include <linux/in6.h> #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/notifier.h> #include <linux/netdevice.h> #include <linux/security.h> #include <linux/slab.h> #include <net/sock.h> #include <net/netlink.h> #include <net/genetlink.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/net_namespace.h> #include <net/netlabel.h> #include <asm/bug.h> #include <linux/atomic.h> #include "netlabel_user.h" #include "netlabel_addrlist.h" #include "netlabel_domainhash.h" #include "netlabel_unlabeled.h" #include "netlabel_mgmt.h" /* NOTE: at present we always use init's network namespace since we don't * presently support different namespaces even though the majority of * the functions in this file are "namespace safe" */ /* The unlabeled connection hash table which we use to map network interfaces * and addresses of unlabeled packets to a user specified secid value for the * LSM. The hash table is used to lookup the network interface entry * (struct netlbl_unlhsh_iface) and then the interface entry is used to * lookup an IP address match from an ordered list. If a network interface * match can not be found in the hash table then the default entry * (netlbl_unlhsh_def) is used. The IP address entry list * (struct netlbl_unlhsh_addr) is ordered such that the entries with a * larger netmask come first. */ struct netlbl_unlhsh_tbl { struct list_head *tbl; u32 size; }; #define netlbl_unlhsh_addr4_entry(iter) \ container_of(iter, struct netlbl_unlhsh_addr4, list) struct netlbl_unlhsh_addr4 { u32 secid; struct netlbl_af4list list; struct rcu_head rcu; }; #define netlbl_unlhsh_addr6_entry(iter) \ container_of(iter, struct netlbl_unlhsh_addr6, list) struct netlbl_unlhsh_addr6 { u32 secid; struct netlbl_af6list list; struct rcu_head rcu; }; struct netlbl_unlhsh_iface { int ifindex; struct list_head addr4_list; struct list_head addr6_list; u32 valid; struct list_head list; struct rcu_head rcu; }; /* Argument struct for netlbl_unlhsh_walk() */ struct netlbl_unlhsh_walk_arg { struct netlink_callback *nl_cb; struct sk_buff *skb; u32 seq; }; /* Unlabeled connection hash table */ /* updates should be so rare that having one spinlock for the entire * hash table should be okay */ static DEFINE_SPINLOCK(netlbl_unlhsh_lock); #define netlbl_unlhsh_rcu_deref(p) \ rcu_dereference_check(p, lockdep_is_held(&netlbl_unlhsh_lock)) static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL; static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL; /* Accept unlabeled packets flag */ static u8 netlabel_unlabel_acceptflg = 0; /* NetLabel Generic NETLINK unlabeled family */ static struct genl_family netlbl_unlabel_gnl_family = { .id = GENL_ID_GENERATE, .hdrsize = 0, .name = NETLBL_NLTYPE_UNLABELED_NAME, .version = NETLBL_PROTO_VERSION, .maxattr = NLBL_UNLABEL_A_MAX, }; /* NetLabel Netlink attribute policy */ static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = { [NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 }, [NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY, .len = sizeof(struct in6_addr) }, [NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY, .len = sizeof(struct in6_addr) }, [NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY, .len = sizeof(struct in_addr) }, [NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY, .len = sizeof(struct in_addr) }, [NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 }, [NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY } }; /* * Unlabeled Connection Hash Table Functions */ /** * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table * @entry: the entry's RCU field * * Description: * This function is designed to be used as a callback to the call_rcu() * function so that memory allocated to a hash table interface entry can be * released safely. It is important to note that this function does not free * the IPv4 and IPv6 address lists contained as part of an interface entry. It * is up to the rest of the code to make sure an interface entry is only freed * once it's address lists are empty. * */ static void netlbl_unlhsh_free_iface(struct rcu_head *entry) { struct netlbl_unlhsh_iface *iface; struct netlbl_af4list *iter4; struct netlbl_af4list *tmp4; #if IS_ENABLED(CONFIG_IPV6) struct netlbl_af6list *iter6; struct netlbl_af6list *tmp6; #endif /* IPv6 */ iface = container_of(entry, struct netlbl_unlhsh_iface, rcu); /* no need for locks here since we are the only one with access to this * structure */ netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) { netlbl_af4list_remove_entry(iter4); kfree(netlbl_unlhsh_addr4_entry(iter4)); } #if IS_ENABLED(CONFIG_IPV6) netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) { netlbl_af6list_remove_entry(iter6); kfree(netlbl_unlhsh_addr6_entry(iter6)); } #endif /* IPv6 */ kfree(iface); } /** * netlbl_unlhsh_hash - Hashing function for the hash table * @ifindex: the network interface/device to hash * * Description: * This is the hashing function for the unlabeled hash table, it returns the * bucket number for the given device/interface. The caller is responsible for * ensuring that the hash table is protected with either a RCU read lock or * the hash table lock. * */ static u32 netlbl_unlhsh_hash(int ifindex) { return ifindex & (netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->size - 1); } /** * netlbl_unlhsh_search_iface - Search for a matching interface entry * @ifindex: the network interface * * Description: * Searches the unlabeled connection hash table and returns a pointer to the * interface entry which matches @ifindex, otherwise NULL is returned. The * caller is responsible for ensuring that the hash table is protected with * either a RCU read lock or the hash table lock. * */ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex) { u32 bkt; struct list_head *bkt_list; struct netlbl_unlhsh_iface *iter; bkt = netlbl_unlhsh_hash(ifindex); bkt_list = &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]; list_for_each_entry_rcu(iter, bkt_list, list) if (iter->valid && iter->ifindex == ifindex) return iter; return NULL; } /** * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table * @iface: the associated interface entry * @addr: IPv4 address in network byte order * @mask: IPv4 address mask in network byte order * @secid: LSM secid value for entry * * Description: * Add a new address entry into the unlabeled connection hash table using the * interface entry specified by @iface. On success zero is returned, otherwise * a negative value is returned. * */ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface, const struct in_addr *addr, const struct in_addr *mask, u32 secid) { int ret_val; struct netlbl_unlhsh_addr4 *entry; entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (entry == NULL) return -ENOMEM; entry->list.addr = addr->s_addr & mask->s_addr; entry->list.mask = mask->s_addr; entry->list.valid = 1; entry->secid = secid; spin_lock(&netlbl_unlhsh_lock); ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list); spin_unlock(&netlbl_unlhsh_lock); if (ret_val != 0) kfree(entry); return ret_val; } #if IS_ENABLED(CONFIG_IPV6) /** * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table * @iface: the associated interface entry * @addr: IPv6 address in network byte order * @mask: IPv6 address mask in network byte order * @secid: LSM secid value for entry * * Description: * Add a new address entry into the unlabeled connection hash table using the * interface entry specified by @iface. On success zero is returned, otherwise * a negative value is returned. * */ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface, const struct in6_addr *addr, const struct in6_addr *mask, u32 secid) { int ret_val; struct netlbl_unlhsh_addr6 *entry; entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (entry == NULL) return -ENOMEM; entry->list.addr = *addr; entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0]; entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1]; entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2]; entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3]; entry->list.mask = *mask; entry->list.valid = 1; entry->secid = secid; spin_lock(&netlbl_unlhsh_lock); ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list); spin_unlock(&netlbl_unlhsh_lock); if (ret_val != 0) kfree(entry); return 0; } #endif /* IPv6 */ /** * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table * @ifindex: network interface * * Description: * Add a new, empty, interface entry into the unlabeled connection hash table. * On success a pointer to the new interface entry is returned, on failure NULL * is returned. * */ static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex) { u32 bkt; struct netlbl_unlhsh_iface *iface; iface = kzalloc(sizeof(*iface), GFP_ATOMIC); if (iface == NULL) return NULL; iface->ifindex = ifindex; INIT_LIST_HEAD(&iface->addr4_list); INIT_LIST_HEAD(&iface->addr6_list); iface->valid = 1; spin_lock(&netlbl_unlhsh_lock); if (ifindex > 0) { bkt = netlbl_unlhsh_hash(ifindex); if (netlbl_unlhsh_search_iface(ifindex) != NULL) goto add_iface_failure; list_add_tail_rcu(&iface->list, &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]); } else { INIT_LIST_HEAD(&iface->list); if (netlbl_unlhsh_rcu_deref(netlbl_unlhsh_def) != NULL) goto add_iface_failure; rcu_assign_pointer(netlbl_unlhsh_def, iface); } spin_unlock(&netlbl_unlhsh_lock); return iface; add_iface_failure: spin_unlock(&netlbl_unlhsh_lock); kfree(iface); return NULL; } /** * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table * @net: network namespace * @dev_name: interface name * @addr: IP address in network byte order * @mask: address mask in network byte order * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6) * @secid: LSM secid value for the entry * @audit_info: NetLabel audit information * * Description: * Adds a new entry to the unlabeled connection hash table. Returns zero on * success, negative values on failure. * */ int netlbl_unlhsh_add(struct net *net, const char *dev_name, const void *addr, const void *mask, u32 addr_len, u32 secid, struct netlbl_audit *audit_info) { int ret_val; int ifindex; struct net_device *dev; struct netlbl_unlhsh_iface *iface; struct audit_buffer *audit_buf = NULL; char *secctx = NULL; u32 secctx_len; if (addr_len != sizeof(struct in_addr) && addr_len != sizeof(struct in6_addr)) return -EINVAL; rcu_read_lock(); if (dev_name != NULL) { dev = dev_get_by_name_rcu(net, dev_name); if (dev == NULL) { ret_val = -ENODEV; goto unlhsh_add_return; } ifindex = dev->ifindex; iface = netlbl_unlhsh_search_iface(ifindex); } else { ifindex = 0; iface = rcu_dereference(netlbl_unlhsh_def); } if (iface == NULL) { iface = netlbl_unlhsh_add_iface(ifindex); if (iface == NULL) { ret_val = -ENOMEM; goto unlhsh_add_return; } } audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD, audit_info); switch (addr_len) { case sizeof(struct in_addr): { const struct in_addr *addr4 = addr; const struct in_addr *mask4 = mask; ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid); if (audit_buf != NULL) netlbl_af4list_audit_addr(audit_buf, 1, dev_name, addr4->s_addr, mask4->s_addr); break; } #if IS_ENABLED(CONFIG_IPV6) case sizeof(struct in6_addr): { const struct in6_addr *addr6 = addr; const struct in6_addr *mask6 = mask; ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid); if (audit_buf != NULL) netlbl_af6list_audit_addr(audit_buf, 1, dev_name, addr6, mask6); break; } #endif /* IPv6 */ default: ret_val = -EINVAL; } if (ret_val == 0) atomic_inc(&netlabel_mgmt_protocount); unlhsh_add_return: rcu_read_unlock(); if (audit_buf != NULL) { if (security_secid_to_secctx(secid, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); security_release_secctx(secctx, secctx_len); } audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); } return ret_val; } /** * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry * @net: network namespace * @iface: interface entry * @addr: IP address * @mask: IP address mask * @audit_info: NetLabel audit information * * Description: * Remove an IP address entry from the unlabeled connection hash table. * Returns zero on success, negative values on failure. * */ static int netlbl_unlhsh_remove_addr4(struct net *net, struct netlbl_unlhsh_iface *iface, const struct in_addr *addr, const struct in_addr *mask, struct netlbl_audit *audit_info) { struct netlbl_af4list *list_entry; struct netlbl_unlhsh_addr4 *entry; struct audit_buffer *audit_buf; struct net_device *dev; char *secctx; u32 secctx_len; spin_lock(&netlbl_unlhsh_lock); list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr, &iface->addr4_list); spin_unlock(&netlbl_unlhsh_lock); if (list_entry != NULL) entry = netlbl_unlhsh_addr4_entry(list_entry); else entry = NULL; audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL, audit_info); if (audit_buf != NULL) { dev = dev_get_by_index(net, iface->ifindex); netlbl_af4list_audit_addr(audit_buf, 1, (dev != NULL ? dev->name : NULL), addr->s_addr, mask->s_addr); if (dev != NULL) dev_put(dev); if (entry != NULL && security_secid_to_secctx(entry->secid, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); security_release_secctx(secctx, secctx_len); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); audit_log_end(audit_buf); } if (entry == NULL) return -ENOENT; kfree_rcu(entry, rcu); return 0; } #if IS_ENABLED(CONFIG_IPV6) /** * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry * @net: network namespace * @iface: interface entry * @addr: IP address * @mask: IP address mask * @audit_info: NetLabel audit information * * Description: * Remove an IP address entry from the unlabeled connection hash table. * Returns zero on success, negative values on failure. * */ static int netlbl_unlhsh_remove_addr6(struct net *net, struct netlbl_unlhsh_iface *iface, const struct in6_addr *addr, const struct in6_addr *mask, struct netlbl_audit *audit_info) { struct netlbl_af6list *list_entry; struct netlbl_unlhsh_addr6 *entry; struct audit_buffer *audit_buf; struct net_device *dev; char *secctx; u32 secctx_len; spin_lock(&netlbl_unlhsh_lock); list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list); spin_unlock(&netlbl_unlhsh_lock); if (list_entry != NULL) entry = netlbl_unlhsh_addr6_entry(list_entry); else entry = NULL; audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL, audit_info); if (audit_buf != NULL) { dev = dev_get_by_index(net, iface->ifindex); netlbl_af6list_audit_addr(audit_buf, 1, (dev != NULL ? dev->name : NULL), addr, mask); if (dev != NULL) dev_put(dev); if (entry != NULL && security_secid_to_secctx(entry->secid, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); security_release_secctx(secctx, secctx_len); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); audit_log_end(audit_buf); } if (entry == NULL) return -ENOENT; kfree_rcu(entry, rcu); return 0; } #endif /* IPv6 */ /** * netlbl_unlhsh_condremove_iface - Remove an interface entry * @iface: the interface entry * * Description: * Remove an interface entry from the unlabeled connection hash table if it is * empty. An interface entry is considered to be empty if there are no * address entries assigned to it. * */ static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface) { struct netlbl_af4list *iter4; #if IS_ENABLED(CONFIG_IPV6) struct netlbl_af6list *iter6; #endif /* IPv6 */ spin_lock(&netlbl_unlhsh_lock); netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list) goto unlhsh_condremove_failure; #if IS_ENABLED(CONFIG_IPV6) netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list) goto unlhsh_condremove_failure; #endif /* IPv6 */ iface->valid = 0; if (iface->ifindex > 0) list_del_rcu(&iface->list); else RCU_INIT_POINTER(netlbl_unlhsh_def, NULL); spin_unlock(&netlbl_unlhsh_lock); call_rcu(&iface->rcu, netlbl_unlhsh_free_iface); return; unlhsh_condremove_failure: spin_unlock(&netlbl_unlhsh_lock); } /** * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table * @net: network namespace * @dev_name: interface name * @addr: IP address in network byte order * @mask: address mask in network byte order * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6) * @audit_info: NetLabel audit information * * Description: * Removes and existing entry from the unlabeled connection hash table. * Returns zero on success, negative values on failure. * */ int netlbl_unlhsh_remove(struct net *net, const char *dev_name, const void *addr, const void *mask, u32 addr_len, struct netlbl_audit *audit_info) { int ret_val; struct net_device *dev; struct netlbl_unlhsh_iface *iface; if (addr_len != sizeof(struct in_addr) && addr_len != sizeof(struct in6_addr)) return -EINVAL; rcu_read_lock(); if (dev_name != NULL) { dev = dev_get_by_name_rcu(net, dev_name); if (dev == NULL) { ret_val = -ENODEV; goto unlhsh_remove_return; } iface = netlbl_unlhsh_search_iface(dev->ifindex); } else iface = rcu_dereference(netlbl_unlhsh_def); if (iface == NULL) { ret_val = -ENOENT; goto unlhsh_remove_return; } switch (addr_len) { case sizeof(struct in_addr): ret_val = netlbl_unlhsh_remove_addr4(net, iface, addr, mask, audit_info); break; #if IS_ENABLED(CONFIG_IPV6) case sizeof(struct in6_addr): ret_val = netlbl_unlhsh_remove_addr6(net, iface, addr, mask, audit_info); break; #endif /* IPv6 */ default: ret_val = -EINVAL; } if (ret_val == 0) { netlbl_unlhsh_condremove_iface(iface); atomic_dec(&netlabel_mgmt_protocount); } unlhsh_remove_return: rcu_read_unlock(); return ret_val; } /* * General Helper Functions */ /** * netlbl_unlhsh_netdev_handler - Network device notification handler * @this: notifier block * @event: the event * @ptr: the netdevice notifier info (cast to void) * * Description: * Handle network device events, although at present all we care about is a * network device going away. In the case of a device going away we clear any * related entries from the unlabeled connection hash table. * */ static int netlbl_unlhsh_netdev_handler(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct netlbl_unlhsh_iface *iface = NULL; if (!net_eq(dev_net(dev), &init_net)) return NOTIFY_DONE; /* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */ if (event == NETDEV_DOWN) { spin_lock(&netlbl_unlhsh_lock); iface = netlbl_unlhsh_search_iface(dev->ifindex); if (iface != NULL && iface->valid) { iface->valid = 0; list_del_rcu(&iface->list); } else iface = NULL; spin_unlock(&netlbl_unlhsh_lock); } if (iface != NULL) call_rcu(&iface->rcu, netlbl_unlhsh_free_iface); return NOTIFY_DONE; } /** * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag * @value: desired value * @audit_info: NetLabel audit information * * Description: * Set the value of the unlabeled accept flag to @value. * */ static void netlbl_unlabel_acceptflg_set(u8 value, struct netlbl_audit *audit_info) { struct audit_buffer *audit_buf; u8 old_val; old_val = netlabel_unlabel_acceptflg; netlabel_unlabel_acceptflg = value; audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW, audit_info); if (audit_buf != NULL) { audit_log_format(audit_buf, " unlbl_accept=%u old=%u", value, old_val); audit_log_end(audit_buf); } } /** * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information * @info: the Generic NETLINK info block * @addr: the IP address * @mask: the IP address mask * @len: the address length * * Description: * Examine the Generic NETLINK message and extract the IP address information. * Returns zero on success, negative values on failure. * */ static int netlbl_unlabel_addrinfo_get(struct genl_info *info, void **addr, void **mask, u32 *len) { u32 addr_len; if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR]) { addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]); if (addr_len != sizeof(struct in_addr) && addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK])) return -EINVAL; *len = addr_len; *addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]); *mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4MASK]); return 0; } else if (info->attrs[NLBL_UNLABEL_A_IPV6ADDR]) { addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]); if (addr_len != sizeof(struct in6_addr) && addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV6MASK])) return -EINVAL; *len = addr_len; *addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]); *mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6MASK]); return 0; } return -EINVAL; } /* * NetLabel Command Handlers */ /** * netlbl_unlabel_accept - Handle an ACCEPT message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated ACCEPT message and set the accept flag accordingly. * Returns zero on success, negative values on failure. * */ static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info) { u8 value; struct netlbl_audit audit_info; if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) { value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]); if (value == 1 || value == 0) { netlbl_netlink_auditinfo(skb, &audit_info); netlbl_unlabel_acceptflg_set(value, &audit_info); return 0; } } return -EINVAL; } /** * netlbl_unlabel_list - Handle a LIST message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated LIST message and respond with the current status. * Returns zero on success, negative values on failure. * */ static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info) { int ret_val = -EINVAL; struct sk_buff *ans_skb; void *data; ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (ans_skb == NULL) goto list_failure; data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family, 0, NLBL_UNLABEL_C_LIST); if (data == NULL) { ret_val = -ENOMEM; goto list_failure; } ret_val = nla_put_u8(ans_skb, NLBL_UNLABEL_A_ACPTFLG, netlabel_unlabel_acceptflg); if (ret_val != 0) goto list_failure; genlmsg_end(ans_skb, data); return genlmsg_reply(ans_skb, info); list_failure: kfree_skb(ans_skb); return ret_val; } /** * netlbl_unlabel_staticadd - Handle a STATICADD message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICADD message and add a new unlabeled * connection entry to the hash table. Returns zero on success, negative * values on failure. * */ static int netlbl_unlabel_staticadd(struct sk_buff *skb, struct genl_info *info) { int ret_val; char *dev_name; void *addr; void *mask; u32 addr_len; u32 secid; struct netlbl_audit audit_info; /* Don't allow users to add both IPv4 and IPv6 addresses for a * single entry. However, allow users to create two entries, one each * for IPv4 and IPv4, with the same LSM security context which should * achieve the same result. */ if (!info->attrs[NLBL_UNLABEL_A_SECCTX] || !info->attrs[NLBL_UNLABEL_A_IFACE] || !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^ (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV6MASK]))) return -EINVAL; netlbl_netlink_auditinfo(skb, &audit_info); ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len); if (ret_val != 0) return ret_val; dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]); ret_val = security_secctx_to_secid( nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]), nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]), &secid); if (ret_val != 0) return ret_val; return netlbl_unlhsh_add(&init_net, dev_name, addr, mask, addr_len, secid, &audit_info); } /** * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICADDDEF message and add a new default * unlabeled connection entry. Returns zero on success, negative values on * failure. * */ static int netlbl_unlabel_staticadddef(struct sk_buff *skb, struct genl_info *info) { int ret_val; void *addr; void *mask; u32 addr_len; u32 secid; struct netlbl_audit audit_info; /* Don't allow users to add both IPv4 and IPv6 addresses for a * single entry. However, allow users to create two entries, one each * for IPv4 and IPv6, with the same LSM security context which should * achieve the same result. */ if (!info->attrs[NLBL_UNLABEL_A_SECCTX] || !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^ (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV6MASK]))) return -EINVAL; netlbl_netlink_auditinfo(skb, &audit_info); ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len); if (ret_val != 0) return ret_val; ret_val = security_secctx_to_secid( nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]), nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]), &secid); if (ret_val != 0) return ret_val; return netlbl_unlhsh_add(&init_net, NULL, addr, mask, addr_len, secid, &audit_info); } /** * netlbl_unlabel_staticremove - Handle a STATICREMOVE message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICREMOVE message and remove the specified * unlabeled connection entry. Returns zero on success, negative values on * failure. * */ static int netlbl_unlabel_staticremove(struct sk_buff *skb, struct genl_info *info) { int ret_val; char *dev_name; void *addr; void *mask; u32 addr_len; struct netlbl_audit audit_info; /* See the note in netlbl_unlabel_staticadd() about not allowing both * IPv4 and IPv6 in the same entry. */ if (!info->attrs[NLBL_UNLABEL_A_IFACE] || !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^ (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV6MASK]))) return -EINVAL; netlbl_netlink_auditinfo(skb, &audit_info); ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len); if (ret_val != 0) return ret_val; dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]); return netlbl_unlhsh_remove(&init_net, dev_name, addr, mask, addr_len, &audit_info); } /** * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICREMOVEDEF message and remove the default * unlabeled connection entry. Returns zero on success, negative values on * failure. * */ static int netlbl_unlabel_staticremovedef(struct sk_buff *skb, struct genl_info *info) { int ret_val; void *addr; void *mask; u32 addr_len; struct netlbl_audit audit_info; /* See the note in netlbl_unlabel_staticadd() about not allowing both * IPv4 and IPv6 in the same entry. */ if (!((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^ (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] || !info->attrs[NLBL_UNLABEL_A_IPV6MASK]))) return -EINVAL; netlbl_netlink_auditinfo(skb, &audit_info); ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len); if (ret_val != 0) return ret_val; return netlbl_unlhsh_remove(&init_net, NULL, addr, mask, addr_len, &audit_info); } /** * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF] * @cmd: command/message * @iface: the interface entry * @addr4: the IPv4 address entry * @addr6: the IPv6 address entry * @arg: the netlbl_unlhsh_walk_arg structure * * Description: * This function is designed to be used to generate a response for a * STATICLIST or STATICLISTDEF message. When called either @addr4 or @addr6 * can be specified, not both, the other unspecified entry should be set to * NULL by the caller. Returns the size of the message on success, negative * values on failure. * */ static int netlbl_unlabel_staticlist_gen(u32 cmd, const struct netlbl_unlhsh_iface *iface, const struct netlbl_unlhsh_addr4 *addr4, const struct netlbl_unlhsh_addr6 *addr6, void *arg) { int ret_val = -ENOMEM; struct netlbl_unlhsh_walk_arg *cb_arg = arg; struct net_device *dev; void *data; u32 secid; char *secctx; u32 secctx_len; data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid, cb_arg->seq, &netlbl_unlabel_gnl_family, NLM_F_MULTI, cmd); if (data == NULL) goto list_cb_failure; if (iface->ifindex > 0) { dev = dev_get_by_index(&init_net, iface->ifindex); if (!dev) { ret_val = -ENODEV; goto list_cb_failure; } ret_val = nla_put_string(cb_arg->skb, NLBL_UNLABEL_A_IFACE, dev->name); dev_put(dev); if (ret_val != 0) goto list_cb_failure; } if (addr4) { struct in_addr addr_struct; addr_struct.s_addr = addr4->list.addr; ret_val = nla_put_in_addr(cb_arg->skb, NLBL_UNLABEL_A_IPV4ADDR, addr_struct.s_addr); if (ret_val != 0) goto list_cb_failure; addr_struct.s_addr = addr4->list.mask; ret_val = nla_put_in_addr(cb_arg->skb, NLBL_UNLABEL_A_IPV4MASK, addr_struct.s_addr); if (ret_val != 0) goto list_cb_failure; secid = addr4->secid; } else { ret_val = nla_put_in6_addr(cb_arg->skb, NLBL_UNLABEL_A_IPV6ADDR, &addr6->list.addr); if (ret_val != 0) goto list_cb_failure; ret_val = nla_put_in6_addr(cb_arg->skb, NLBL_UNLABEL_A_IPV6MASK, &addr6->list.mask); if (ret_val != 0) goto list_cb_failure; secid = addr6->secid; } ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len); if (ret_val != 0) goto list_cb_failure; ret_val = nla_put(cb_arg->skb, NLBL_UNLABEL_A_SECCTX, secctx_len, secctx); security_release_secctx(secctx, secctx_len); if (ret_val != 0) goto list_cb_failure; cb_arg->seq++; genlmsg_end(cb_arg->skb, data); return 0; list_cb_failure: genlmsg_cancel(cb_arg->skb, data); return ret_val; } /** * netlbl_unlabel_staticlist - Handle a STATICLIST message * @skb: the NETLINK buffer * @cb: the NETLINK callback * * Description: * Process a user generated STATICLIST message and dump the unlabeled * connection hash table in a form suitable for use in a kernel generated * STATICLIST message. Returns the length of @skb. * */ static int netlbl_unlabel_staticlist(struct sk_buff *skb, struct netlink_callback *cb) { struct netlbl_unlhsh_walk_arg cb_arg; u32 skip_bkt = cb->args[0]; u32 skip_chain = cb->args[1]; u32 iter_bkt; u32 iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0; struct netlbl_unlhsh_iface *iface; struct list_head *iter_list; struct netlbl_af4list *addr4; #if IS_ENABLED(CONFIG_IPV6) struct netlbl_af6list *addr6; #endif cb_arg.nl_cb = cb; cb_arg.skb = skb; cb_arg.seq = cb->nlh->nlmsg_seq; rcu_read_lock(); for (iter_bkt = skip_bkt; iter_bkt < rcu_dereference(netlbl_unlhsh)->size; iter_bkt++, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0) { iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt]; list_for_each_entry_rcu(iface, iter_list, list) { if (!iface->valid || iter_chain++ < skip_chain) continue; netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) { if (iter_addr4++ < cb->args[2]) continue; if (netlbl_unlabel_staticlist_gen( NLBL_UNLABEL_C_STATICLIST, iface, netlbl_unlhsh_addr4_entry(addr4), NULL, &cb_arg) < 0) { iter_addr4--; iter_chain--; goto unlabel_staticlist_return; } } #if IS_ENABLED(CONFIG_IPV6) netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) { if (iter_addr6++ < cb->args[3]) continue; if (netlbl_unlabel_staticlist_gen( NLBL_UNLABEL_C_STATICLIST, iface, NULL, netlbl_unlhsh_addr6_entry(addr6), &cb_arg) < 0) { iter_addr6--; iter_chain--; goto unlabel_staticlist_return; } } #endif /* IPv6 */ } } unlabel_staticlist_return: rcu_read_unlock(); cb->args[0] = iter_bkt; cb->args[1] = iter_chain; cb->args[2] = iter_addr4; cb->args[3] = iter_addr6; return skb->len; } /** * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message * @skb: the NETLINK buffer * @cb: the NETLINK callback * * Description: * Process a user generated STATICLISTDEF message and dump the default * unlabeled connection entry in a form suitable for use in a kernel generated * STATICLISTDEF message. Returns the length of @skb. * */ static int netlbl_unlabel_staticlistdef(struct sk_buff *skb, struct netlink_callback *cb) { struct netlbl_unlhsh_walk_arg cb_arg; struct netlbl_unlhsh_iface *iface; u32 iter_addr4 = 0, iter_addr6 = 0; struct netlbl_af4list *addr4; #if IS_ENABLED(CONFIG_IPV6) struct netlbl_af6list *addr6; #endif cb_arg.nl_cb = cb; cb_arg.skb = skb; cb_arg.seq = cb->nlh->nlmsg_seq; rcu_read_lock(); iface = rcu_dereference(netlbl_unlhsh_def); if (iface == NULL || !iface->valid) goto unlabel_staticlistdef_return; netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) { if (iter_addr4++ < cb->args[0]) continue; if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF, iface, netlbl_unlhsh_addr4_entry(addr4), NULL, &cb_arg) < 0) { iter_addr4--; goto unlabel_staticlistdef_return; } } #if IS_ENABLED(CONFIG_IPV6) netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) { if (iter_addr6++ < cb->args[1]) continue; if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF, iface, NULL, netlbl_unlhsh_addr6_entry(addr6), &cb_arg) < 0) { iter_addr6--; goto unlabel_staticlistdef_return; } } #endif /* IPv6 */ unlabel_staticlistdef_return: rcu_read_unlock(); cb->args[0] = iter_addr4; cb->args[1] = iter_addr6; return skb->len; } /* * NetLabel Generic NETLINK Command Definitions */ static const struct genl_ops netlbl_unlabel_genl_ops[] = { { .cmd = NLBL_UNLABEL_C_STATICADD, .flags = GENL_ADMIN_PERM, .policy = netlbl_unlabel_genl_policy, .doit = netlbl_unlabel_staticadd, .dumpit = NULL, }, { .cmd = NLBL_UNLABEL_C_STATICREMOVE, .flags = GENL_ADMIN_PERM, .policy = netlbl_unlabel_genl_policy, .doit = netlbl_unlabel_staticremove, .dumpit = NULL, }, { .cmd = NLBL_UNLABEL_C_STATICLIST, .flags = 0, .policy = netlbl_unlabel_genl_policy, .doit = NULL, .dumpit = netlbl_unlabel_staticlist, }, { .cmd = NLBL_UNLABEL_C_STATICADDDEF, .flags = GENL_ADMIN_PERM, .policy = netlbl_unlabel_genl_policy, .doit = netlbl_unlabel_staticadddef, .dumpit = NULL, }, { .cmd = NLBL_UNLABEL_C_STATICREMOVEDEF, .flags = GENL_ADMIN_PERM, .policy = netlbl_unlabel_genl_policy, .doit = netlbl_unlabel_staticremovedef, .dumpit = NULL, }, { .cmd = NLBL_UNLABEL_C_STATICLISTDEF, .flags = 0, .policy = netlbl_unlabel_genl_policy, .doit = NULL, .dumpit = netlbl_unlabel_staticlistdef, }, { .cmd = NLBL_UNLABEL_C_ACCEPT, .flags = GENL_ADMIN_PERM, .policy = netlbl_unlabel_genl_policy, .doit = netlbl_unlabel_accept, .dumpit = NULL, }, { .cmd = NLBL_UNLABEL_C_LIST, .flags = 0, .policy = netlbl_unlabel_genl_policy, .doit = netlbl_unlabel_list, .dumpit = NULL, }, }; /* * NetLabel Generic NETLINK Protocol Functions */ /** * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component * * Description: * Register the unlabeled packet NetLabel component with the Generic NETLINK * mechanism. Returns zero on success, negative values on failure. * */ int __init netlbl_unlabel_genl_init(void) { return genl_register_family_with_ops(&netlbl_unlabel_gnl_family, netlbl_unlabel_genl_ops); } /* * NetLabel KAPI Hooks */ static struct notifier_block netlbl_unlhsh_netdev_notifier = { .notifier_call = netlbl_unlhsh_netdev_handler, }; /** * netlbl_unlabel_init - Initialize the unlabeled connection hash table * @size: the number of bits to use for the hash buckets * * Description: * Initializes the unlabeled connection hash table and registers a network * device notification handler. This function should only be called by the * NetLabel subsystem itself during initialization. Returns zero on success, * non-zero values on error. * */ int __init netlbl_unlabel_init(u32 size) { u32 iter; struct netlbl_unlhsh_tbl *hsh_tbl; if (size == 0) return -EINVAL; hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL); if (hsh_tbl == NULL) return -ENOMEM; hsh_tbl->size = 1 << size; hsh_tbl->tbl = kcalloc(hsh_tbl->size, sizeof(struct list_head), GFP_KERNEL); if (hsh_tbl->tbl == NULL) { kfree(hsh_tbl); return -ENOMEM; } for (iter = 0; iter < hsh_tbl->size; iter++) INIT_LIST_HEAD(&hsh_tbl->tbl[iter]); spin_lock(&netlbl_unlhsh_lock); rcu_assign_pointer(netlbl_unlhsh, hsh_tbl); spin_unlock(&netlbl_unlhsh_lock); register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier); return 0; } /** * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet * @skb: the packet * @family: protocol family * @secattr: the security attributes * * Description: * Determine the security attributes, if any, for an unlabled packet and return * them in @secattr. Returns zero on success and negative values on failure. * */ int netlbl_unlabel_getattr(const struct sk_buff *skb, u16 family, struct netlbl_lsm_secattr *secattr) { struct netlbl_unlhsh_iface *iface; rcu_read_lock(); iface = netlbl_unlhsh_search_iface(skb->skb_iif); if (iface == NULL) iface = rcu_dereference(netlbl_unlhsh_def); if (iface == NULL || !iface->valid) goto unlabel_getattr_nolabel; switch (family) { case PF_INET: { struct iphdr *hdr4; struct netlbl_af4list *addr4; hdr4 = ip_hdr(skb); addr4 = netlbl_af4list_search(hdr4->saddr, &iface->addr4_list); if (addr4 == NULL) goto unlabel_getattr_nolabel; secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid; break; } #if IS_ENABLED(CONFIG_IPV6) case PF_INET6: { struct ipv6hdr *hdr6; struct netlbl_af6list *addr6; hdr6 = ipv6_hdr(skb); addr6 = netlbl_af6list_search(&hdr6->saddr, &iface->addr6_list); if (addr6 == NULL) goto unlabel_getattr_nolabel; secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid; break; } #endif /* IPv6 */ default: goto unlabel_getattr_nolabel; } rcu_read_unlock(); secattr->flags |= NETLBL_SECATTR_SECID; secattr->type = NETLBL_NLTYPE_UNLABELED; return 0; unlabel_getattr_nolabel: rcu_read_unlock(); if (netlabel_unlabel_acceptflg == 0) return -ENOMSG; secattr->type = NETLBL_NLTYPE_UNLABELED; return 0; } /** * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets * * Description: * Set the default NetLabel configuration to allow incoming unlabeled packets * and to send unlabeled network traffic by default. * */ int __init netlbl_unlabel_defconf(void) { int ret_val; struct netlbl_dom_map *entry; struct netlbl_audit audit_info; /* Only the kernel is allowed to call this function and the only time * it is called is at bootup before the audit subsystem is reporting * messages so don't worry to much about these values. */ security_task_getsecid(current, &audit_info.secid); audit_info.loginuid = GLOBAL_ROOT_UID; audit_info.sessionid = 0; entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (entry == NULL) return -ENOMEM; entry->def.type = NETLBL_NLTYPE_UNLABELED; ret_val = netlbl_domhsh_add_default(entry, &audit_info); if (ret_val != 0) return ret_val; netlbl_unlabel_acceptflg_set(1, &audit_info); return 0; }