From b1edeb102397546438ab4624489c6ccd7b410d97 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:31 -0400 Subject: netlabel: Replace protocol/NetLabel linking with refrerence counts NetLabel has always had a list of backpointers in the CIPSO DOI definition structure which pointed to the NetLabel LSM domain mapping structures which referenced the CIPSO DOI struct. The rationale for this was that when an administrator removed a CIPSO DOI from the system all of the associated NetLabel LSM domain mappings should be removed as well; a list of backpointers made this a simple operation. Unfortunately, while the backpointers did make the removal easier they were a bit of a mess from an implementation point of view which was making further development difficult. Since the removal of a CIPSO DOI is a realtively rare event it seems to make sense to remove this backpointer list as the optimization was hurting us more then it was helping. However, we still need to be able to track when a CIPSO DOI definition is being used so replace the backpointer list with a reference count. In order to preserve the current functionality of removing the associated LSM domain mappings when a CIPSO DOI is removed we walk the LSM domain mapping table, removing the relevant entries. Signed-off-by: Paul Moore Reviewed-by: James Morris --- net/ipv4/cipso_ipv4.c | 235 +++++++++++++++++++++----------------------------- 1 file changed, 98 insertions(+), 137 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 2c0e4572cc9..bf87eddfec3 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -47,17 +47,7 @@ #include #include -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 @@ -193,25 +183,6 @@ static void cipso_v4_bitmap_setbit(unsigned char *bitmap, bitmap[byte_spot] &= ~bitmask; } -/** - * 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 @@ -457,7 +428,7 @@ 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; } @@ -501,9 +472,8 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) } } - doi_def->valid = 1; + atomic_set(&doi_def->refcount, 1); INIT_RCU_HEAD(&doi_def->rcu); - INIT_LIST_HEAD(&doi_def->dom_list); spin_lock(&cipso_v4_doi_list_lock); if (cipso_v4_doi_search(doi_def->doi) != NULL) @@ -518,60 +488,130 @@ doi_add_failure: 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_STD: + 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) { struct cipso_v4_doi *doi_def; - struct cipso_v4_domhsh_entry *dom_iter; 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; + return -ENOENT; + } + if (!atomic_dec_and_test(&doi_def->refcount)) { + spin_unlock(&cipso_v4_doi_list_lock); + return -EBUSY; } + 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); + + return 0; } /** - * 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 +637,7 @@ 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 +653,6 @@ 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 */ -- cgit v1.2.3 From 948bf85c1bc9a84754786a9d5dd99b7ecc46451e Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:32 -0400 Subject: netlabel: Add functionality to set the security attributes of a packet This patch builds upon the new NetLabel address selector functionality by providing the NetLabel KAPI and CIPSO engine support needed to enable the new packet-based labeling. The only new addition to the NetLabel KAPI at this point is shown below: * int netlbl_skbuff_setattr(skb, family, secattr) ... and is designed to be called from a Netfilter hook after the packet's IP header has been populated such as in the FORWARD or LOCAL_OUT hooks. This patch also provides the necessary SELinux hooks to support this new functionality. Smack support is not currently included due to uncertainty regarding the permissions needed to expand the Smack network access controls. Signed-off-by: Paul Moore Reviewed-by: James Morris --- net/ipv4/cipso_ipv4.c | 222 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 183 insertions(+), 39 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index bf87eddfec3..e13d6dbb66a 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -13,7 +13,7 @@ */ /* - * (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 @@ -1665,48 +1665,27 @@ 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 @@ -1734,8 +1713,7 @@ int cipso_v4_sock_setattr(struct sock *sk, buf_len - CIPSO_V4_HDR_LEN); break; default: - ret_val = -EPERM; - goto socket_setattr_failure; + return -EPERM; } iter++; @@ -1743,9 +1721,58 @@ 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 *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 @@ -1853,6 +1880,123 @@ int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) secattr); } +/** + * 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; + + buf_len = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (buf_len < 0) + return buf_len; + 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; +} + /** * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option * @skb: the packet -- cgit v1.2.3 From 014ab19a69c325f52d7bae54ceeda73d6307ae0c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:33 -0400 Subject: selinux: Set socket NetLabel based on connection endpoint Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to solve that by applying NetLabel socket labels when sockets are connect()'d. This should alleviate the per-packet NetLabel labeling for all connected sockets (yes, it even works for connected DGRAM sockets). Signed-off-by: Paul Moore Reviewed-by: James Morris --- net/ipv4/cipso_ipv4.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) (limited to 'net/ipv4') diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index e13d6dbb66a..23768b9d6b6 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1809,6 +1809,80 @@ socket_setattr_failure: return ret_val; } +/** + * 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) +{ + u8 hdr_delta; + struct ip_options *opt; + struct inet_sock *sk_inet; + + sk_inet = inet_sk(sk); + opt = sk_inet->opt; + if (opt == NULL || opt->cipso == 0) + return; + + if (opt->srr || opt->rr || opt->ts || opt->router_alert) { + u8 cipso_len; + u8 cipso_off; + unsigned char *cipso_ptr; + int iter; + int optlen_new; + + cipso_off = opt->cipso - sizeof(struct iphdr); + cipso_ptr = &opt->__data[cipso_off]; + cipso_len = cipso_ptr[1]; + + if (opt->srr > opt->cipso) + opt->srr -= cipso_len; + if (opt->rr > opt->cipso) + opt->rr -= cipso_len; + if (opt->ts > opt->cipso) + opt->ts -= cipso_len; + if (opt->router_alert > opt->cipso) + opt->router_alert -= cipso_len; + opt->cipso = 0; + + memmove(cipso_ptr, cipso_ptr + cipso_len, + 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->optlen) + if (opt->__data[iter] != IPOPT_NOP) { + iter += opt->__data[iter + 1]; + optlen_new = iter; + } else + iter++; + hdr_delta = opt->optlen; + opt->optlen = (optlen_new + 3) & ~3; + hdr_delta -= opt->optlen; + } else { + /* only the cipso option was present on the socket so we can + * remove the entire option struct */ + sk_inet->opt = NULL; + hdr_delta = opt->optlen; + kfree(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_getattr - Helper function for the cipso_v4_*_getattr functions * @cipso: the CIPSO v4 option -- cgit v1.2.3 From 15c45f7b2e81655f6eb500ec949c8bd70a04325a Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:34 -0400 Subject: cipso: Add support for native local labeling and fixup mapping names This patch accomplishes three minor tasks: add a new tag type for local labeling, rename the CIPSO_V4_MAP_STD define to CIPSO_V4_MAP_TRANS and replace some of the CIPSO "magic numbers" with constants from the header file. The first change allows CIPSO to support full LSM labels/contexts, not just MLS attributes. The second change brings the mapping names inline with what userspace is using, compatibility is preserved since we don't actually change the value. The last change is to aid readability and help prevent mistakes. Signed-off-by: Paul Moore --- net/ipv4/cipso_ipv4.c | 127 ++++++++++++++++++++++++++++++++++++++++++-------- net/ipv4/ip_options.c | 2 +- 2 files changed, 108 insertions(+), 21 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 23768b9d6b6..490e035c6d9 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -109,6 +109,19 @@ int cipso_v4_rbm_strictvalid = 1; * 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 */ @@ -467,6 +480,10 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) if (doi_def->type != CIPSO_V4_MAP_PASS) return -EINVAL; break; + case CIPSO_V4_TAG_LOCAL: + if (doi_def->type != CIPSO_V4_MAP_LOCAL) + return -EINVAL; + break; default: return -EINVAL; } @@ -502,7 +519,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) return; switch (doi_def->type) { - case CIPSO_V4_MAP_STD: + 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); @@ -673,7 +690,7 @@ 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; @@ -702,7 +719,7 @@ 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]; @@ -736,7 +753,7 @@ 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) { @@ -773,7 +790,7 @@ 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 (;;) { @@ -821,7 +838,7 @@ 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; } @@ -836,7 +853,7 @@ 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]; @@ -882,7 +899,7 @@ 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; } @@ -902,7 +919,7 @@ 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]; @@ -1238,7 +1255,7 @@ 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; @@ -1334,7 +1351,7 @@ 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; @@ -1430,7 +1447,7 @@ 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; @@ -1483,6 +1500,54 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, return 0; } +/** + * 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 @@ -1502,7 +1567,7 @@ 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; @@ -1527,7 +1592,7 @@ 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];) @@ -1545,7 +1610,7 @@ 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; } @@ -1563,7 +1628,7 @@ 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) { @@ -1573,7 +1638,7 @@ 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; } @@ -1583,7 +1648,7 @@ 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) { @@ -1592,7 +1657,7 @@ 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; } @@ -1602,7 +1667,7 @@ 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) { @@ -1610,6 +1675,19 @@ 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. */ + if (!(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; @@ -1712,6 +1790,12 @@ static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, &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: return -EPERM; } @@ -1921,6 +2005,9 @@ 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; diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index be3f18a7a40..2c88da6e786 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -438,7 +438,7 @@ int ip_options_compile(struct net *net, goto error; } opt->cipso = optptr - iph; - if (cipso_v4_validate(&optptr)) { + if (cipso_v4_validate(skb, &optptr)) { pp_ptr = optptr; goto error; } -- cgit v1.2.3