diff options
Diffstat (limited to 'net/ipv4/cipso_ipv4.c')
| -rw-r--r-- | net/ipv4/cipso_ipv4.c | 912 |
1 files changed, 669 insertions, 243 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 2c0e4572cc9..69e77c8ff28 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -3,17 +3,22 @@ * * This is an implementation of the CIPSO 2.2 protocol as specified in * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in - * FIPS-188, copies of both documents can be found in the Documentation - * directory. While CIPSO never became a full IETF RFC standard many vendors + * FIPS-188. While CIPSO never became a full IETF RFC standard many vendors * have chosen to adopt the protocol and over the years it has become a * de-facto standard for labeled networking. * + * The CIPSO draft specification can be found in the kernel's Documentation + * directory as well as the following URL: + * http://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt + * The FIPS-188 specification can be found at the following URL: + * http://www.itl.nist.gov/fipspubs/fip188.htm + * * Author: Paul Moore <paul.moore@hp.com> * */ /* - * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + * (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 @@ -26,8 +31,7 @@ * 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, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * along with this program; if not, see <http://www.gnu.org/licenses/>. * */ @@ -38,26 +42,18 @@ #include <linux/spinlock.h> #include <linux/string.h> #include <linux/jhash.h> +#include <linux/audit.h> +#include <linux/slab.h> #include <net/ip.h> #include <net/icmp.h> #include <net/tcp.h> #include <net/netlabel.h> #include <net/cipso_ipv4.h> -#include <asm/atomic.h> +#include <linux/atomic.h> #include <asm/bug.h> #include <asm/unaligned.h> -struct cipso_v4_domhsh_entry { - char *domain; - u32 valid; - struct list_head list; - struct rcu_head rcu; -}; - /* List of available DOI definitions */ -/* XXX - Updates should be minimal so having a single lock for the - * cipso_v4_doi_list and the cipso_v4_doi_list->dom_list should be - * okay. */ /* XXX - This currently assumes a minimal number of different DOIs in use, * if in practice there are a lot of different DOIs this list should * probably be turned into a hash table or something similar so we @@ -115,10 +111,23 @@ int cipso_v4_rbm_strictvalid = 1; /* The maximum number of category ranges permitted in the ranged category tag * (tag #5). You may note that the IETF draft states that the maximum number * of category ranges is 7, but if the low end of the last category range is - * zero then it is possibile to fit 8 category ranges because the zero should + * zero then it is possible to fit 8 category ranges because the zero should * be omitted. */ #define CIPSO_V4_TAG_RNG_CAT_MAX 8 +/* Base length of the local tag (non-standard tag). + * Tag definition (may change between kernel versions) + * + * 0 8 16 24 32 + * +----------+----------+----------+----------+ + * | 10000000 | 00000110 | 32-bit secid value | + * +----------+----------+----------+----------+ + * | in (host byte order)| + * +----------+----------+ + * + */ +#define CIPSO_V4_TAG_LOC_BLEN 6 + /* * Helper Functions */ @@ -194,25 +203,6 @@ static void cipso_v4_bitmap_setbit(unsigned char *bitmap, } /** - * cipso_v4_doi_domhsh_free - Frees a domain list entry - * @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 a domain list entry can be released - * safely. - * - */ -static void cipso_v4_doi_domhsh_free(struct rcu_head *entry) -{ - struct cipso_v4_domhsh_entry *ptr; - - ptr = container_of(entry, struct cipso_v4_domhsh_entry, rcu); - kfree(ptr->domain); - kfree(ptr); -} - -/** * cipso_v4_cache_entry_free - Frees a cache entry * @entry: the entry to free * @@ -299,8 +289,6 @@ void cipso_v4_cache_invalidate(void) cipso_v4_cache[iter].size = 0; spin_unlock_bh(&cipso_v4_cache[iter].lock); } - - return; } /** @@ -449,7 +437,7 @@ cache_add_failure: * * Description: * Search the DOI definition list for a DOI definition with a DOI value that - * matches @doi. The caller is responsibile for calling rcu_read_[un]lock(). + * 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 cipso_v4_doi *cipso_v4_doi_search(u32 doi) @@ -457,7 +445,7 @@ static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi) struct cipso_v4_doi *iter; list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) - if (iter->doi == doi && iter->valid) + if (iter->doi == doi && atomic_read(&iter->refcount)) return iter; return NULL; } @@ -465,6 +453,7 @@ static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi) /** * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine * @doi_def: the DOI structure + * @audit_info: NetLabel audit information * * Description: * The caller defines a new DOI for use by the CIPSO engine and calls this @@ -474,104 +463,218 @@ static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi) * zero on success and non-zero on failure. * */ -int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) +int cipso_v4_doi_add(struct cipso_v4_doi *doi_def, + struct netlbl_audit *audit_info) { + int ret_val = -EINVAL; u32 iter; + u32 doi; + u32 doi_type; + struct audit_buffer *audit_buf; - if (doi_def == NULL || doi_def->doi == CIPSO_V4_DOI_UNKNOWN) - return -EINVAL; + doi = doi_def->doi; + doi_type = doi_def->type; + + if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN) + goto doi_add_return; for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) { switch (doi_def->tags[iter]) { case CIPSO_V4_TAG_RBITMAP: break; case CIPSO_V4_TAG_RANGE: + case CIPSO_V4_TAG_ENUM: if (doi_def->type != CIPSO_V4_MAP_PASS) - return -EINVAL; + goto doi_add_return; + break; + case CIPSO_V4_TAG_LOCAL: + if (doi_def->type != CIPSO_V4_MAP_LOCAL) + goto doi_add_return; break; case CIPSO_V4_TAG_INVALID: if (iter == 0) - return -EINVAL; - break; - case CIPSO_V4_TAG_ENUM: - if (doi_def->type != CIPSO_V4_MAP_PASS) - return -EINVAL; + goto doi_add_return; break; default: - return -EINVAL; + goto doi_add_return; } } - doi_def->valid = 1; - INIT_RCU_HEAD(&doi_def->rcu); - INIT_LIST_HEAD(&doi_def->dom_list); + atomic_set(&doi_def->refcount, 1); spin_lock(&cipso_v4_doi_list_lock); - if (cipso_v4_doi_search(doi_def->doi) != NULL) - goto doi_add_failure; + if (cipso_v4_doi_search(doi_def->doi) != NULL) { + spin_unlock(&cipso_v4_doi_list_lock); + ret_val = -EEXIST; + goto doi_add_return; + } list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list); spin_unlock(&cipso_v4_doi_list_lock); + ret_val = 0; + +doi_add_return: + audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info); + if (audit_buf != NULL) { + const char *type_str; + switch (doi_type) { + case CIPSO_V4_MAP_TRANS: + type_str = "trans"; + break; + case CIPSO_V4_MAP_PASS: + type_str = "pass"; + break; + case CIPSO_V4_MAP_LOCAL: + type_str = "local"; + break; + default: + type_str = "(unknown)"; + } + audit_log_format(audit_buf, + " cipso_doi=%u cipso_type=%s res=%u", + doi, type_str, ret_val == 0 ? 1 : 0); + audit_log_end(audit_buf); + } - return 0; + return ret_val; +} -doi_add_failure: - spin_unlock(&cipso_v4_doi_list_lock); - return -EEXIST; +/** + * cipso_v4_doi_free - Frees a DOI definition + * @entry: the entry's RCU field + * + * Description: + * This function frees all of the memory associated with a DOI definition. + * + */ +void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) +{ + if (doi_def == NULL) + return; + + switch (doi_def->type) { + case CIPSO_V4_MAP_TRANS: + kfree(doi_def->map.std->lvl.cipso); + kfree(doi_def->map.std->lvl.local); + kfree(doi_def->map.std->cat.cipso); + kfree(doi_def->map.std->cat.local); + break; + } + kfree(doi_def); +} + +/** + * cipso_v4_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 cipso_v4_doi_free_rcu(struct rcu_head *entry) +{ + struct cipso_v4_doi *doi_def; + + doi_def = container_of(entry, struct cipso_v4_doi, rcu); + cipso_v4_doi_free(doi_def); } /** * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine * @doi: the DOI value * @audit_secid: the LSM secid to use in the audit message - * @callback: the DOI cleanup/free callback * * Description: - * Removes a DOI definition from the CIPSO engine, @callback is called to - * free any memory. 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. + * Removes a DOI definition from the CIPSO 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. * */ -int cipso_v4_doi_remove(u32 doi, - struct netlbl_audit *audit_info, - void (*callback) (struct rcu_head * head)) +int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info) { + int ret_val; struct cipso_v4_doi *doi_def; - struct cipso_v4_domhsh_entry *dom_iter; + struct audit_buffer *audit_buf; spin_lock(&cipso_v4_doi_list_lock); doi_def = cipso_v4_doi_search(doi); - if (doi_def != NULL) { - doi_def->valid = 0; - list_del_rcu(&doi_def->list); + if (doi_def == NULL) { spin_unlock(&cipso_v4_doi_list_lock); - rcu_read_lock(); - list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list) - if (dom_iter->valid) - netlbl_cfg_map_del(dom_iter->domain, - audit_info); - rcu_read_unlock(); - cipso_v4_cache_invalidate(); - call_rcu(&doi_def->rcu, callback); - return 0; + ret_val = -ENOENT; + goto doi_remove_return; + } + if (!atomic_dec_and_test(&doi_def->refcount)) { + spin_unlock(&cipso_v4_doi_list_lock); + ret_val = -EBUSY; + goto doi_remove_return; } + list_del_rcu(&doi_def->list); spin_unlock(&cipso_v4_doi_list_lock); - return -ENOENT; + cipso_v4_cache_invalidate(); + call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); + ret_val = 0; + +doi_remove_return: + audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info); + if (audit_buf != NULL) { + audit_log_format(audit_buf, + " cipso_doi=%u res=%u", + doi, ret_val == 0 ? 1 : 0); + audit_log_end(audit_buf); + } + + return ret_val; } /** - * cipso_v4_doi_getdef - Returns a pointer to a valid DOI definition + * cipso_v4_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 - * rcu_read_lock() is held while accessing the returned definition. + * rcu_read_lock() is held while accessing the returned definition and the DOI + * definition reference count is decremented when the caller is done. * */ struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi) { - return cipso_v4_doi_search(doi); + struct cipso_v4_doi *doi_def; + + rcu_read_lock(); + doi_def = cipso_v4_doi_search(doi); + if (doi_def == NULL) + goto doi_getdef_return; + if (!atomic_inc_not_zero(&doi_def->refcount)) + doi_def = NULL; + +doi_getdef_return: + rcu_read_unlock(); + return doi_def; +} + +/** + * cipso_v4_doi_putdef - Releases a reference for the given DOI definition + * @doi_def: the DOI definition + * + * Description: + * Releases a DOI definition reference obtained from cipso_v4_doi_getdef(). + * + */ +void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def) +{ + if (doi_def == NULL) + return; + + if (!atomic_dec_and_test(&doi_def->refcount)) + return; + spin_lock(&cipso_v4_doi_list_lock); + list_del_rcu(&doi_def->list); + spin_unlock(&cipso_v4_doi_list_lock); + + cipso_v4_cache_invalidate(); + call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); } /** @@ -597,7 +700,7 @@ int cipso_v4_doi_walk(u32 *skip_cnt, rcu_read_lock(); list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list) - if (iter_doi->valid) { + if (atomic_read(&iter_doi->refcount) > 0) { if (doi_cnt++ < *skip_cnt) continue; ret_val = callback(iter_doi, cb_arg); @@ -613,85 +716,6 @@ doi_walk_return: return ret_val; } -/** - * cipso_v4_doi_domhsh_add - Adds a domain entry to a DOI definition - * @doi_def: the DOI definition - * @domain: the domain to add - * - * Description: - * Adds the @domain to the DOI specified by @doi_def, this function - * should only be called by external functions (i.e. NetLabel). This function - * does allocate memory. Returns zero on success, negative values on failure. - * - */ -int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def, const char *domain) -{ - struct cipso_v4_domhsh_entry *iter; - struct cipso_v4_domhsh_entry *new_dom; - - new_dom = kzalloc(sizeof(*new_dom), GFP_KERNEL); - if (new_dom == NULL) - return -ENOMEM; - if (domain) { - new_dom->domain = kstrdup(domain, GFP_KERNEL); - if (new_dom->domain == NULL) { - kfree(new_dom); - return -ENOMEM; - } - } - new_dom->valid = 1; - INIT_RCU_HEAD(&new_dom->rcu); - - spin_lock(&cipso_v4_doi_list_lock); - list_for_each_entry(iter, &doi_def->dom_list, list) - if (iter->valid && - ((domain != NULL && iter->domain != NULL && - strcmp(iter->domain, domain) == 0) || - (domain == NULL && iter->domain == NULL))) { - spin_unlock(&cipso_v4_doi_list_lock); - kfree(new_dom->domain); - kfree(new_dom); - return -EEXIST; - } - list_add_tail_rcu(&new_dom->list, &doi_def->dom_list); - spin_unlock(&cipso_v4_doi_list_lock); - - return 0; -} - -/** - * cipso_v4_doi_domhsh_remove - Removes a domain entry from a DOI definition - * @doi_def: the DOI definition - * @domain: the domain to remove - * - * Description: - * Removes the @domain from the DOI specified by @doi_def, this function - * should only be called by external functions (i.e. NetLabel). Returns zero - * on success and negative values on error. - * - */ -int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def, - const char *domain) -{ - struct cipso_v4_domhsh_entry *iter; - - spin_lock(&cipso_v4_doi_list_lock); - list_for_each_entry(iter, &doi_def->dom_list, list) - if (iter->valid && - ((domain != NULL && iter->domain != NULL && - strcmp(iter->domain, domain) == 0) || - (domain == NULL && iter->domain == NULL))) { - iter->valid = 0; - list_del_rcu(&iter->list); - spin_unlock(&cipso_v4_doi_list_lock); - call_rcu(&iter->rcu, cipso_v4_doi_domhsh_free); - return 0; - } - spin_unlock(&cipso_v4_doi_list_lock); - - return -ENOENT; -} - /* * Label Mapping Functions */ @@ -712,7 +736,7 @@ static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level) switch (doi_def->type) { case CIPSO_V4_MAP_PASS: return 0; - case CIPSO_V4_MAP_STD: + case CIPSO_V4_MAP_TRANS: if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL) return 0; break; @@ -741,7 +765,7 @@ static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def, case CIPSO_V4_MAP_PASS: *net_lvl = host_lvl; return 0; - case CIPSO_V4_MAP_STD: + case CIPSO_V4_MAP_TRANS: if (host_lvl < doi_def->map.std->lvl.local_size && doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) { *net_lvl = doi_def->map.std->lvl.local[host_lvl]; @@ -775,7 +799,7 @@ static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def, case CIPSO_V4_MAP_PASS: *host_lvl = net_lvl; return 0; - case CIPSO_V4_MAP_STD: + case CIPSO_V4_MAP_TRANS: map_tbl = doi_def->map.std; if (net_lvl < map_tbl->lvl.cipso_size && map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) { @@ -812,7 +836,7 @@ static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def, switch (doi_def->type) { case CIPSO_V4_MAP_PASS: return 0; - case CIPSO_V4_MAP_STD: + case CIPSO_V4_MAP_TRANS: cipso_cat_size = doi_def->map.std->cat.cipso_size; cipso_array = doi_def->map.std->cat.cipso; for (;;) { @@ -860,7 +884,7 @@ static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def, u32 host_cat_size = 0; u32 *host_cat_array = NULL; - if (doi_def->type == CIPSO_V4_MAP_STD) { + if (doi_def->type == CIPSO_V4_MAP_TRANS) { host_cat_size = doi_def->map.std->cat.local_size; host_cat_array = doi_def->map.std->cat.local; } @@ -875,7 +899,7 @@ static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def, case CIPSO_V4_MAP_PASS: net_spot = host_spot; break; - case CIPSO_V4_MAP_STD: + case CIPSO_V4_MAP_TRANS: if (host_spot >= host_cat_size) return -EPERM; net_spot = host_cat_array[host_spot]; @@ -921,7 +945,7 @@ static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, u32 net_cat_size = 0; u32 *net_cat_array = NULL; - if (doi_def->type == CIPSO_V4_MAP_STD) { + if (doi_def->type == CIPSO_V4_MAP_TRANS) { net_cat_size = doi_def->map.std->cat.cipso_size; net_cat_array = doi_def->map.std->cat.cipso; } @@ -941,7 +965,7 @@ static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, case CIPSO_V4_MAP_PASS: host_spot = net_spot; break; - case CIPSO_V4_MAP_STD: + case CIPSO_V4_MAP_TRANS: if (net_spot >= net_cat_size) return -EPERM; host_spot = net_cat_array[net_spot]; @@ -1268,7 +1292,7 @@ static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, return ret_val; /* This will send packets using the "optimized" format when - * possibile as specified in section 3.4.2.6 of the + * possible as specified in section 3.4.2.6 of the * CIPSO draft. */ if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10) tag_len = 14; @@ -1277,7 +1301,7 @@ static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, } else tag_len = 4; - buffer[0] = 0x01; + buffer[0] = CIPSO_V4_TAG_RBITMAP; buffer[1] = tag_len; buffer[3] = level; @@ -1311,8 +1335,7 @@ static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, secattr->flags |= NETLBL_SECATTR_MLS_LVL; if (tag_len > 4) { - secattr->attr.mls.cat = - netlbl_secattr_catmap_alloc(GFP_ATOMIC); + secattr->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); if (secattr->attr.mls.cat == NULL) return -ENOMEM; @@ -1373,7 +1396,7 @@ static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def, } else tag_len = 4; - buffer[0] = 0x02; + buffer[0] = CIPSO_V4_TAG_ENUM; buffer[1] = tag_len; buffer[3] = level; @@ -1407,8 +1430,7 @@ static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def, secattr->flags |= NETLBL_SECATTR_MLS_LVL; if (tag_len > 4) { - secattr->attr.mls.cat = - netlbl_secattr_catmap_alloc(GFP_ATOMIC); + secattr->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); if (secattr->attr.mls.cat == NULL) return -ENOMEM; @@ -1469,7 +1491,7 @@ static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def, } else tag_len = 4; - buffer[0] = 0x05; + buffer[0] = CIPSO_V4_TAG_RANGE; buffer[1] = tag_len; buffer[3] = level; @@ -1502,8 +1524,7 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, secattr->flags |= NETLBL_SECATTR_MLS_LVL; if (tag_len > 4) { - secattr->attr.mls.cat = - netlbl_secattr_catmap_alloc(GFP_ATOMIC); + secattr->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); if (secattr->attr.mls.cat == NULL) return -ENOMEM; @@ -1523,6 +1544,54 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, } /** + * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard) + * @doi_def: the DOI definition + * @secattr: the security attributes + * @buffer: the option buffer + * @buffer_len: length of buffer in bytes + * + * Description: + * Generate a CIPSO option using the local tag. Returns the size of the tag + * on success, negative values on failure. + * + */ +static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *buffer, + u32 buffer_len) +{ + if (!(secattr->flags & NETLBL_SECATTR_SECID)) + return -EPERM; + + buffer[0] = CIPSO_V4_TAG_LOCAL; + buffer[1] = CIPSO_V4_TAG_LOC_BLEN; + *(u32 *)&buffer[2] = secattr->attr.secid; + + return CIPSO_V4_TAG_LOC_BLEN; +} + +/** + * cipso_v4_parsetag_loc - Parse a CIPSO local tag + * @doi_def: the DOI definition + * @tag: the CIPSO tag + * @secattr: the security attributes + * + * Description: + * Parse a CIPSO local tag and return the security attributes in @secattr. + * Return zero on success, negatives values on failure. + * + */ +static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def, + const unsigned char *tag, + struct netlbl_lsm_secattr *secattr) +{ + secattr->attr.secid = *(u32 *)&tag[2]; + secattr->flags |= NETLBL_SECATTR_SECID; + + return 0; +} + +/** * cipso_v4_validate - Validate a CIPSO option * @option: the start of the option, on error it is set to point to the error * @@ -1541,7 +1610,7 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, * that is unrecognized." * */ -int cipso_v4_validate(unsigned char **option) +int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) { unsigned char *opt = *option; unsigned char *tag; @@ -1566,7 +1635,7 @@ int cipso_v4_validate(unsigned char **option) goto validate_return_locked; } - opt_iter = 6; + opt_iter = CIPSO_V4_HDR_LEN; tag = opt + opt_iter; while (opt_iter < opt_len) { for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];) @@ -1584,7 +1653,7 @@ int cipso_v4_validate(unsigned char **option) switch (tag[0]) { case CIPSO_V4_TAG_RBITMAP: - if (tag_len < 4) { + if (tag_len < CIPSO_V4_TAG_RBM_BLEN) { err_offset = opt_iter + 1; goto validate_return_locked; } @@ -1602,7 +1671,7 @@ int cipso_v4_validate(unsigned char **option) err_offset = opt_iter + 3; goto validate_return_locked; } - if (tag_len > 4 && + if (tag_len > CIPSO_V4_TAG_RBM_BLEN && cipso_v4_map_cat_rbm_valid(doi_def, &tag[4], tag_len - 4) < 0) { @@ -1612,7 +1681,7 @@ int cipso_v4_validate(unsigned char **option) } break; case CIPSO_V4_TAG_ENUM: - if (tag_len < 4) { + if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) { err_offset = opt_iter + 1; goto validate_return_locked; } @@ -1622,7 +1691,7 @@ int cipso_v4_validate(unsigned char **option) err_offset = opt_iter + 3; goto validate_return_locked; } - if (tag_len > 4 && + if (tag_len > CIPSO_V4_TAG_ENUM_BLEN && cipso_v4_map_cat_enum_valid(doi_def, &tag[4], tag_len - 4) < 0) { @@ -1631,7 +1700,7 @@ int cipso_v4_validate(unsigned char **option) } break; case CIPSO_V4_TAG_RANGE: - if (tag_len < 4) { + if (tag_len < CIPSO_V4_TAG_RNG_BLEN) { err_offset = opt_iter + 1; goto validate_return_locked; } @@ -1641,7 +1710,7 @@ int cipso_v4_validate(unsigned char **option) err_offset = opt_iter + 3; goto validate_return_locked; } - if (tag_len > 4 && + if (tag_len > CIPSO_V4_TAG_RNG_BLEN && cipso_v4_map_cat_rng_valid(doi_def, &tag[4], tag_len - 4) < 0) { @@ -1649,6 +1718,21 @@ int cipso_v4_validate(unsigned char **option) goto validate_return_locked; } break; + case CIPSO_V4_TAG_LOCAL: + /* This is a non-standard tag that we only allow for + * local connections, so if the incoming interface is + * not the loopback device drop the packet. Further, + * there is no legitimate reason for setting this from + * userspace so reject it if skb is NULL. */ + if (skb == NULL || !(skb->dev->flags & IFF_LOOPBACK)) { + err_offset = opt_iter; + goto validate_return_locked; + } + if (tag_len != CIPSO_V4_TAG_LOC_BLEN) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + break; default: err_offset = opt_iter; goto validate_return_locked; @@ -1666,7 +1750,7 @@ validate_return: } /** - * cipso_v4_error - Send the correct reponse for a bad packet + * cipso_v4_error - Send the correct response for a bad packet * @skb: the packet * @error: the error code * @gateway: CIPSO gateway flag @@ -1704,48 +1788,27 @@ void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway) } /** - * cipso_v4_sock_setattr - Add a CIPSO option to a socket - * @sk: the socket + * cipso_v4_genopt - Generate a CIPSO option + * @buf: the option buffer + * @buf_len: the size of opt_buf * @doi_def: the CIPSO DOI to use - * @secattr: the specific security attributes of the socket + * @secattr: the security attributes * * Description: - * Set the CIPSO option on the given socket using the DOI definition and - * security attributes passed to the function. This function requires - * exclusive access to @sk, which means it either needs to be in the - * process of being created or locked. Returns zero on success and negative - * values on failure. + * Generate a CIPSO option using the DOI definition and security attributes + * passed to the function. Returns the length of the option on success and + * negative values on failure. * */ -int cipso_v4_sock_setattr(struct sock *sk, - const struct cipso_v4_doi *doi_def, - const struct netlbl_lsm_secattr *secattr) +static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) { - int ret_val = -EPERM; + int ret_val; u32 iter; - unsigned char *buf; - u32 buf_len = 0; - u32 opt_len; - struct ip_options *opt = NULL; - struct inet_sock *sk_inet; - struct inet_connection_sock *sk_conn; - /* In the case of sock_create_lite(), the sock->sk field is not - * defined yet but it is not a problem as the only users of these - * "lite" PF_INET sockets are functions which do an accept() call - * afterwards so we will label the socket as part of the accept(). */ - if (sk == NULL) - return 0; - - /* We allocate the maximum CIPSO option size here so we are probably - * being a little wasteful, but it makes our life _much_ easier later - * on and after all we are only talking about 40 bytes. */ - buf_len = CIPSO_V4_OPT_LEN_MAX; - buf = kmalloc(buf_len, GFP_ATOMIC); - if (buf == NULL) { - ret_val = -ENOMEM; - goto socket_setattr_failure; - } + if (buf_len <= CIPSO_V4_HDR_LEN) + return -ENOSPC; /* XXX - This code assumes only one tag per CIPSO option which isn't * really a good assumption to make but since we only support the MAC @@ -1772,9 +1835,14 @@ int cipso_v4_sock_setattr(struct sock *sk, &buf[CIPSO_V4_HDR_LEN], buf_len - CIPSO_V4_HDR_LEN); break; + case CIPSO_V4_TAG_LOCAL: + ret_val = cipso_v4_gentag_loc(doi_def, + secattr, + &buf[CIPSO_V4_HDR_LEN], + buf_len - CIPSO_V4_HDR_LEN); + break; default: - ret_val = -EPERM; - goto socket_setattr_failure; + return -EPERM; } iter++; @@ -1782,9 +1850,58 @@ int cipso_v4_sock_setattr(struct sock *sk, iter < CIPSO_V4_TAG_MAXCNT && doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); if (ret_val < 0) - goto socket_setattr_failure; + return ret_val; cipso_v4_gentag_hdr(doi_def, buf, ret_val); - buf_len = CIPSO_V4_HDR_LEN + ret_val; + return CIPSO_V4_HDR_LEN + ret_val; +} + +/** + * cipso_v4_sock_setattr - Add a CIPSO option to a socket + * @sk: the socket + * @doi_def: the CIPSO DOI to use + * @secattr: the specific security attributes of the socket + * + * Description: + * Set the CIPSO option on the given socket using the DOI definition and + * security attributes passed to the function. This function requires + * exclusive access to @sk, which means it either needs to be in the + * process of being created or locked. Returns zero on success and negative + * values on failure. + * + */ +int cipso_v4_sock_setattr(struct sock *sk, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -EPERM; + unsigned char *buf = NULL; + u32 buf_len; + u32 opt_len; + struct ip_options_rcu *old, *opt = NULL; + struct inet_sock *sk_inet; + struct inet_connection_sock *sk_conn; + + /* In the case of sock_create_lite(), the sock->sk field is not + * defined yet but it is not a problem as the only users of these + * "lite" PF_INET sockets are functions which do an accept() call + * afterwards so we will label the socket as part of the accept(). */ + if (sk == NULL) + return 0; + + /* We allocate the maximum CIPSO option size here so we are probably + * being a little wasteful, but it makes our life _much_ easier later + * on and after all we are only talking about 40 bytes. */ + buf_len = CIPSO_V4_OPT_LEN_MAX; + buf = kmalloc(buf_len, GFP_ATOMIC); + if (buf == NULL) { + ret_val = -ENOMEM; + goto socket_setattr_failure; + } + + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + goto socket_setattr_failure; + buf_len = ret_val; /* We can't use ip_options_get() directly because it makes a call to * ip_options_get_alloc() which allocates memory with GFP_KERNEL and @@ -1796,22 +1913,25 @@ int cipso_v4_sock_setattr(struct sock *sk, ret_val = -ENOMEM; goto socket_setattr_failure; } - memcpy(opt->__data, buf, buf_len); - opt->optlen = opt_len; - opt->cipso = sizeof(struct iphdr); + memcpy(opt->opt.__data, buf, buf_len); + opt->opt.optlen = opt_len; + opt->opt.cipso = sizeof(struct iphdr); kfree(buf); buf = NULL; sk_inet = inet_sk(sk); + + old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk)); if (sk_inet->is_icsk) { sk_conn = inet_csk(sk); - if (sk_inet->opt) - sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen; - sk_conn->icsk_ext_hdr_len += opt->optlen; + if (old) + sk_conn->icsk_ext_hdr_len -= old->opt.optlen; + sk_conn->icsk_ext_hdr_len += opt->opt.optlen; sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); } - opt = xchg(&sk_inet->opt, opt); - kfree(opt); + rcu_assign_pointer(sk_inet->inet_opt, opt); + if (old) + kfree_rcu(old, rcu); return 0; @@ -1822,6 +1942,187 @@ socket_setattr_failure: } /** + * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket + * @req: the connection request socket + * @doi_def: the CIPSO DOI to use + * @secattr: the specific security attributes of the socket + * + * Description: + * Set the CIPSO option on the given socket using the DOI definition and + * security attributes passed to the function. Returns zero on success and + * negative values on failure. + * + */ +int cipso_v4_req_setattr(struct request_sock *req, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -EPERM; + unsigned char *buf = NULL; + u32 buf_len; + u32 opt_len; + struct ip_options_rcu *opt = NULL; + struct inet_request_sock *req_inet; + + /* We allocate the maximum CIPSO option size here so we are probably + * being a little wasteful, but it makes our life _much_ easier later + * on and after all we are only talking about 40 bytes. */ + buf_len = CIPSO_V4_OPT_LEN_MAX; + buf = kmalloc(buf_len, GFP_ATOMIC); + if (buf == NULL) { + ret_val = -ENOMEM; + goto req_setattr_failure; + } + + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + goto req_setattr_failure; + buf_len = ret_val; + + /* We can't use ip_options_get() directly because it makes a call to + * ip_options_get_alloc() which allocates memory with GFP_KERNEL and + * we won't always have CAP_NET_RAW even though we _always_ want to + * set the IPOPT_CIPSO option. */ + opt_len = (buf_len + 3) & ~3; + opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); + if (opt == NULL) { + ret_val = -ENOMEM; + goto req_setattr_failure; + } + memcpy(opt->opt.__data, buf, buf_len); + opt->opt.optlen = opt_len; + opt->opt.cipso = sizeof(struct iphdr); + kfree(buf); + buf = NULL; + + req_inet = inet_rsk(req); + opt = xchg(&req_inet->opt, opt); + if (opt) + kfree_rcu(opt, rcu); + + return 0; + +req_setattr_failure: + kfree(buf); + kfree(opt); + return ret_val; +} + +/** + * cipso_v4_delopt - Delete the CIPSO option from a set of IP options + * @opt_ptr: IP option pointer + * + * Description: + * Deletes the CIPSO IP option from a set of IP options and makes the necessary + * adjustments to the IP option structure. Returns zero on success, negative + * values on failure. + * + */ +static int cipso_v4_delopt(struct ip_options_rcu **opt_ptr) +{ + int hdr_delta = 0; + struct ip_options_rcu *opt = *opt_ptr; + + if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) { + u8 cipso_len; + u8 cipso_off; + unsigned char *cipso_ptr; + int iter; + int optlen_new; + + cipso_off = opt->opt.cipso - sizeof(struct iphdr); + cipso_ptr = &opt->opt.__data[cipso_off]; + cipso_len = cipso_ptr[1]; + + if (opt->opt.srr > opt->opt.cipso) + opt->opt.srr -= cipso_len; + if (opt->opt.rr > opt->opt.cipso) + opt->opt.rr -= cipso_len; + if (opt->opt.ts > opt->opt.cipso) + opt->opt.ts -= cipso_len; + if (opt->opt.router_alert > opt->opt.cipso) + opt->opt.router_alert -= cipso_len; + opt->opt.cipso = 0; + + memmove(cipso_ptr, cipso_ptr + cipso_len, + opt->opt.optlen - cipso_off - cipso_len); + + /* determining the new total option length is tricky because of + * the padding necessary, the only thing i can think to do at + * this point is walk the options one-by-one, skipping the + * padding at the end to determine the actual option size and + * from there we can determine the new total option length */ + iter = 0; + optlen_new = 0; + while (iter < opt->opt.optlen) + if (opt->opt.__data[iter] != IPOPT_NOP) { + iter += opt->opt.__data[iter + 1]; + optlen_new = iter; + } else + iter++; + hdr_delta = opt->opt.optlen; + opt->opt.optlen = (optlen_new + 3) & ~3; + hdr_delta -= opt->opt.optlen; + } else { + /* only the cipso option was present on the socket so we can + * remove the entire option struct */ + *opt_ptr = NULL; + hdr_delta = opt->opt.optlen; + kfree_rcu(opt, rcu); + } + + return hdr_delta; +} + +/** + * cipso_v4_sock_delattr - Delete the CIPSO option from a socket + * @sk: the socket + * + * Description: + * Removes the CIPSO option from a socket, if present. + * + */ +void cipso_v4_sock_delattr(struct sock *sk) +{ + int hdr_delta; + struct ip_options_rcu *opt; + struct inet_sock *sk_inet; + + sk_inet = inet_sk(sk); + opt = rcu_dereference_protected(sk_inet->inet_opt, 1); + if (opt == NULL || opt->opt.cipso == 0) + return; + + hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt); + if (sk_inet->is_icsk && hdr_delta > 0) { + struct inet_connection_sock *sk_conn = inet_csk(sk); + sk_conn->icsk_ext_hdr_len -= hdr_delta; + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + } +} + +/** + * cipso_v4_req_delattr - Delete the CIPSO option from a request socket + * @reg: the request socket + * + * Description: + * Removes the CIPSO option from a request socket, if present. + * + */ +void cipso_v4_req_delattr(struct request_sock *req) +{ + struct ip_options_rcu *opt; + struct inet_request_sock *req_inet; + + req_inet = inet_rsk(req); + opt = req_inet->opt; + if (opt == NULL || opt->opt.cipso == 0) + return; + + cipso_v4_delopt(&req_inet->opt); +} + +/** * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions * @cipso: the CIPSO v4 option * @secattr: the security attributes @@ -1859,6 +2160,9 @@ static int cipso_v4_getattr(const unsigned char *cipso, case CIPSO_V4_TAG_RANGE: ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr); break; + case CIPSO_V4_TAG_LOCAL: + ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr); + break; } if (ret_val == 0) secattr->type = NETLBL_NLTYPE_CIPSOV4; @@ -1882,14 +2186,136 @@ getattr_return: */ int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) { - struct ip_options *opt; + struct ip_options_rcu *opt; + int res = -ENOMSG; - opt = inet_sk(sk)->opt; - if (opt == NULL || opt->cipso == 0) - return -ENOMSG; + rcu_read_lock(); + opt = rcu_dereference(inet_sk(sk)->inet_opt); + if (opt && opt->opt.cipso) + res = cipso_v4_getattr(opt->opt.__data + + opt->opt.cipso - + sizeof(struct iphdr), + secattr); + rcu_read_unlock(); + return res; +} + +/** + * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet + * @skb: the packet + * @secattr: the security attributes + * + * Description: + * Set the CIPSO option on the given packet based on the security attributes. + * Returns a pointer to the IP header on success and NULL on failure. + * + */ +int cipso_v4_skbuff_setattr(struct sk_buff *skb, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + struct iphdr *iph; + struct ip_options *opt = &IPCB(skb)->opt; + unsigned char buf[CIPSO_V4_OPT_LEN_MAX]; + u32 buf_len = CIPSO_V4_OPT_LEN_MAX; + u32 opt_len; + int len_delta; - return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr), - secattr); + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + return ret_val; + buf_len = ret_val; + opt_len = (buf_len + 3) & ~3; + + /* we overwrite any existing options to ensure that we have enough + * room for the CIPSO option, the reason is that we _need_ to guarantee + * that the security label is applied to the packet - we do the same + * thing when using the socket options and it hasn't caused a problem, + * if we need to we can always revisit this choice later */ + + len_delta = opt_len - opt->optlen; + /* if we don't ensure enough headroom we could panic on the skb_push() + * call below so make sure we have enough, we are also "mangling" the + * packet so we should probably do a copy-on-write call anyway */ + ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); + if (ret_val < 0) + return ret_val; + + if (len_delta > 0) { + /* we assume that the header + opt->optlen have already been + * "pushed" in ip_options_build() or similar */ + iph = ip_hdr(skb); + skb_push(skb, len_delta); + memmove((char *)iph - len_delta, iph, iph->ihl << 2); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + } else if (len_delta < 0) { + iph = ip_hdr(skb); + memset(iph + 1, IPOPT_NOP, opt->optlen); + } else + iph = ip_hdr(skb); + + if (opt->optlen > 0) + memset(opt, 0, sizeof(*opt)); + opt->optlen = opt_len; + opt->cipso = sizeof(struct iphdr); + opt->is_changed = 1; + + /* we have to do the following because we are being called from a + * netfilter hook which means the packet already has had the header + * fields populated and the checksum calculated - yes this means we + * are doing more work than needed but we do it to keep the core + * stack clean and tidy */ + memcpy(iph + 1, buf, buf_len); + if (opt_len > buf_len) + memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len); + if (len_delta != 0) { + iph->ihl = 5 + (opt_len >> 2); + iph->tot_len = htons(skb->len); + } + ip_send_check(iph); + + return 0; +} + +/** + * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet + * @skb: the packet + * + * Description: + * Removes any and all CIPSO options from the given packet. Returns zero on + * success, negative values on failure. + * + */ +int cipso_v4_skbuff_delattr(struct sk_buff *skb) +{ + int ret_val; + struct iphdr *iph; + struct ip_options *opt = &IPCB(skb)->opt; + unsigned char *cipso_ptr; + + if (opt->cipso == 0) + return 0; + + /* since we are changing the packet we should make a copy */ + ret_val = skb_cow(skb, skb_headroom(skb)); + if (ret_val < 0) + return ret_val; + + /* the easiest thing to do is just replace the cipso option with noop + * options since we don't change the size of the packet, although we + * still need to recalculate the checksum */ + + iph = ip_hdr(skb); + cipso_ptr = (unsigned char *)iph + opt->cipso; + memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]); + opt->cipso = 0; + opt->is_changed = 1; + + ip_send_check(iph); + + return 0; } /** |