diff options
Diffstat (limited to 'security/selinux/ss/services.c')
| -rw-r--r-- | security/selinux/ss/services.c | 629 |
1 files changed, 626 insertions, 3 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 85e429884393..0c219a1b3243 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -13,6 +13,11 @@ * * Added conditional policy language extensions * + * Updated: Hewlett-Packard <paul.moore@hp.com> + * + * Added support for NetLabel + * + * Copyright (C) 2006 Hewlett-Packard Development Company, L.P. * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. * Copyright (C) 2003 - 2004 Tresys Technology, LLC * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> @@ -29,6 +34,8 @@ #include <linux/sched.h> #include <linux/audit.h> #include <linux/mutex.h> +#include <net/sock.h> +#include <net/netlabel.h> #include "flask.h" #include "avc.h" @@ -40,6 +47,8 @@ #include "services.h" #include "conditional.h" #include "mls.h" +#include "objsec.h" +#include "selinux_netlabel.h" extern void selnl_notify_policyload(u32 seqno); unsigned int policydb_loaded_version; @@ -1241,6 +1250,7 @@ int security_load_policy(void *data, size_t len) selinux_complete_init(); avc_ss_reset(seqno); selnl_notify_policyload(seqno); + selinux_netlbl_cache_invalidate(); return 0; } @@ -1295,6 +1305,7 @@ int security_load_policy(void *data, size_t len) avc_ss_reset(seqno); selnl_notify_policyload(seqno); + selinux_netlbl_cache_invalidate(); return 0; @@ -1817,6 +1828,75 @@ out: return rc; } +/* + * security_sid_mls_copy() - computes a new sid based on the given + * sid and the mls portion of mls_sid. + */ +int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) +{ + struct context *context1; + struct context *context2; + struct context newcon; + char *s; + u32 len; + int rc = 0; + + if (!ss_initialized || !selinux_mls_enabled) { + *new_sid = sid; + goto out; + } + + context_init(&newcon); + + POLICY_RDLOCK; + context1 = sidtab_search(&sidtab, sid); + if (!context1) { + printk(KERN_ERR "security_sid_mls_copy: unrecognized SID " + "%d\n", sid); + rc = -EINVAL; + goto out_unlock; + } + + context2 = sidtab_search(&sidtab, mls_sid); + if (!context2) { + printk(KERN_ERR "security_sid_mls_copy: unrecognized SID " + "%d\n", mls_sid); + rc = -EINVAL; + goto out_unlock; + } + + newcon.user = context1->user; + newcon.role = context1->role; + newcon.type = context1->type; + rc = mls_copy_context(&newcon, context2); + if (rc) + goto out_unlock; + + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(&policydb, &newcon)) { + rc = convert_context_handle_invalid_context(&newcon); + if (rc) + goto bad; + } + + rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); + goto out_unlock; + +bad: + if (!context_struct_to_string(&newcon, &s, &len)) { + audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, + "security_sid_mls_copy: invalid context %s", s); + kfree(s); + } + +out_unlock: + POLICY_RDUNLOCK; + context_destroy(&newcon); +out: + return rc; +} + struct selinux_audit_rule { u32 au_seqno; struct context au_ctxt; @@ -1923,7 +2003,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, return rc; } -int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op, +int selinux_audit_rule_match(u32 sid, u32 field, u32 op, struct selinux_audit_rule *rule, struct audit_context *actx) { @@ -1946,11 +2026,11 @@ int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op, goto out; } - ctxt = sidtab_search(&sidtab, ctxid); + ctxt = sidtab_search(&sidtab, sid); if (!ctxt) { audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, "selinux_audit_rule_match: unrecognized SID %d\n", - ctxid); + sid); match = -ENOENT; goto out; } @@ -2064,3 +2144,546 @@ void selinux_audit_set_callback(int (*callback)(void)) { aurule_callback = callback; } + +#ifdef CONFIG_NETLABEL +/* + * This is the structure we store inside the NetLabel cache block. + */ +#define NETLBL_CACHE(x) ((struct netlbl_cache *)(x)) +#define NETLBL_CACHE_T_NONE 0 +#define NETLBL_CACHE_T_SID 1 +#define NETLBL_CACHE_T_MLS 2 +struct netlbl_cache { + u32 type; + union { + u32 sid; + struct mls_range mls_label; + } data; +}; + +/** + * selinux_netlbl_cache_free - Free the NetLabel cached data + * @data: the data to free + * + * Description: + * This function is intended to be used as the free() callback inside the + * netlbl_lsm_cache structure. + * + */ +static void selinux_netlbl_cache_free(const void *data) +{ + struct netlbl_cache *cache = NETLBL_CACHE(data); + switch (cache->type) { + case NETLBL_CACHE_T_MLS: + ebitmap_destroy(&cache->data.mls_label.level[0].cat); + break; + } + kfree(data); +} + +/** + * selinux_netlbl_cache_add - Add an entry to the NetLabel cache + * @skb: the packet + * @ctx: the SELinux context + * + * Description: + * Attempt to cache the context in @ctx, which was derived from the packet in + * @skb, in the NetLabel subsystem cache. + * + */ +static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx) +{ + struct netlbl_cache *cache = NULL; + struct netlbl_lsm_secattr secattr; + + netlbl_secattr_init(&secattr); + + cache = kzalloc(sizeof(*cache), GFP_ATOMIC); + if (cache == NULL) + goto netlbl_cache_add_failure; + secattr.cache.free = selinux_netlbl_cache_free; + secattr.cache.data = (void *)cache; + + cache->type = NETLBL_CACHE_T_MLS; + if (ebitmap_cpy(&cache->data.mls_label.level[0].cat, + &ctx->range.level[0].cat) != 0) + goto netlbl_cache_add_failure; + cache->data.mls_label.level[1].cat.highbit = + cache->data.mls_label.level[0].cat.highbit; + cache->data.mls_label.level[1].cat.node = + cache->data.mls_label.level[0].cat.node; + cache->data.mls_label.level[0].sens = ctx->range.level[0].sens; + cache->data.mls_label.level[1].sens = ctx->range.level[0].sens; + + if (netlbl_cache_add(skb, &secattr) != 0) + goto netlbl_cache_add_failure; + + return; + +netlbl_cache_add_failure: + netlbl_secattr_destroy(&secattr, 1); +} + +/** + * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache + * + * Description: + * Invalidate the NetLabel security attribute mapping cache. + * + */ +void selinux_netlbl_cache_invalidate(void) +{ + netlbl_cache_invalidate(); +} + +/** + * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID + * @skb: the network packet + * @secattr: the NetLabel packet security attributes + * @base_sid: the SELinux SID to use as a context for MLS only attributes + * @sid: the SELinux SID + * + * Description: + * Convert the given NetLabel packet security attributes in @secattr into a + * SELinux SID. If the @secattr field does not contain a full SELinux + * SID/context then use the context in @base_sid as the foundation. If @skb + * is not NULL attempt to cache as much data as possibile. Returns zero on + * success, negative values on failure. + * + */ +static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb, + struct netlbl_lsm_secattr *secattr, + u32 base_sid, + u32 *sid) +{ + int rc = -EIDRM; + struct context *ctx; + struct context ctx_new; + struct netlbl_cache *cache; + + POLICY_RDLOCK; + + if (secattr->cache.data) { + cache = NETLBL_CACHE(secattr->cache.data); + switch (cache->type) { + case NETLBL_CACHE_T_SID: + *sid = cache->data.sid; + rc = 0; + break; + case NETLBL_CACHE_T_MLS: + ctx = sidtab_search(&sidtab, base_sid); + if (ctx == NULL) + goto netlbl_secattr_to_sid_return; + + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + ctx_new.range.level[0].sens = + cache->data.mls_label.level[0].sens; + ctx_new.range.level[0].cat.highbit = + cache->data.mls_label.level[0].cat.highbit; + ctx_new.range.level[0].cat.node = + cache->data.mls_label.level[0].cat.node; + ctx_new.range.level[1].sens = + cache->data.mls_label.level[1].sens; + ctx_new.range.level[1].cat.highbit = + cache->data.mls_label.level[1].cat.highbit; + ctx_new.range.level[1].cat.node = + cache->data.mls_label.level[1].cat.node; + + rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); + break; + default: + goto netlbl_secattr_to_sid_return; + } + } else if (secattr->mls_lvl_vld) { + ctx = sidtab_search(&sidtab, base_sid); + if (ctx == NULL) + goto netlbl_secattr_to_sid_return; + + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + mls_import_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl); + if (secattr->mls_cat) { + if (mls_import_cat(&ctx_new, + secattr->mls_cat, + secattr->mls_cat_len, + NULL, + 0) != 0) + goto netlbl_secattr_to_sid_return; + ctx_new.range.level[1].cat.highbit = + ctx_new.range.level[0].cat.highbit; + ctx_new.range.level[1].cat.node = + ctx_new.range.level[0].cat.node; + } else { + ebitmap_init(&ctx_new.range.level[0].cat); + ebitmap_init(&ctx_new.range.level[1].cat); + } + if (mls_context_isvalid(&policydb, &ctx_new) != 1) + goto netlbl_secattr_to_sid_return_cleanup; + + rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); + if (rc != 0) + goto netlbl_secattr_to_sid_return_cleanup; + + if (skb != NULL) + selinux_netlbl_cache_add(skb, &ctx_new); + ebitmap_destroy(&ctx_new.range.level[0].cat); + } else { + *sid = SECINITSID_UNLABELED; + rc = 0; + } + +netlbl_secattr_to_sid_return: + POLICY_RDUNLOCK; + return rc; +netlbl_secattr_to_sid_return_cleanup: + ebitmap_destroy(&ctx_new.range.level[0].cat); + goto netlbl_secattr_to_sid_return; +} + +/** + * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel + * @skb: the packet + * @base_sid: the SELinux SID to use as a context for MLS only attributes + * @sid: the SID + * + * Description: + * Call the NetLabel mechanism to get the security attributes of the given + * packet and use those attributes to determine the correct context/SID to + * assign to the packet. Returns zero on success, negative values on failure. + * + */ +static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, + u32 base_sid, + u32 *sid) +{ + int rc; + struct netlbl_lsm_secattr secattr; + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, &secattr); + if (rc == 0) + rc = selinux_netlbl_secattr_to_sid(skb, + &secattr, + base_sid, + sid); + netlbl_secattr_destroy(&secattr, 0); + + return rc; +} + +/** + * selinux_netlbl_socket_setsid - Label a socket using the NetLabel mechanism + * @sock: the socket to label + * @sid: the SID to use + * + * Description: + * Attempt to label a socket using the NetLabel mechanism using the given + * SID. Returns zero values on success, negative values on failure. + * + */ +static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid) +{ + int rc = -ENOENT; + struct sk_security_struct *sksec = sock->sk->sk_security; + struct netlbl_lsm_secattr secattr; + struct context *ctx; + + if (!ss_initialized) + return 0; + + POLICY_RDLOCK; + + ctx = sidtab_search(&sidtab, sid); + if (ctx == NULL) + goto netlbl_socket_setsid_return; + + netlbl_secattr_init(&secattr); + secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1], + GFP_ATOMIC); + mls_export_lvl(ctx, &secattr.mls_lvl, NULL); + secattr.mls_lvl_vld = 1; + mls_export_cat(ctx, + &secattr.mls_cat, + &secattr.mls_cat_len, + NULL, + NULL); + + rc = netlbl_socket_setattr(sock, &secattr); + if (rc == 0) + sksec->nlbl_state = NLBL_LABELED; + + netlbl_secattr_destroy(&secattr, 0); + +netlbl_socket_setsid_return: + POLICY_RDUNLOCK; + return rc; +} + +/** + * selinux_netlbl_sk_security_init - Setup the NetLabel fields + * @ssec: the sk_security_struct + * @family: the socket family + * + * Description: + * Called when a new sk_security_struct is allocated to initialize the NetLabel + * fields. + * + */ +void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec, + int family) +{ + if (family == PF_INET) + ssec->nlbl_state = NLBL_REQUIRE; + else + ssec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_sk_clone_security - Copy the NetLabel fields + * @ssec: the original sk_security_struct + * @newssec: the cloned sk_security_struct + * + * Description: + * Clone the NetLabel specific sk_security_struct fields from @ssec to + * @newssec. + * + */ +void selinux_netlbl_sk_clone_security(struct sk_security_struct *ssec, + struct sk_security_struct *newssec) +{ + newssec->sclass = ssec->sclass; + if (ssec->nlbl_state != NLBL_UNSET) + newssec->nlbl_state = NLBL_REQUIRE; + else + newssec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_socket_post_create - Label a socket using NetLabel + * @sock: the socket to label + * @sock_family: the socket family + * @sid: the SID to use + * + * Description: + * Attempt to label a socket using the NetLabel mechanism using the given + * SID. Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_post_create(struct socket *sock, + int sock_family, + u32 sid) +{ + struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; + struct sk_security_struct *sksec = sock->sk->sk_security; + + sksec->sclass = isec->sclass; + + if (sock_family != PF_INET) + return 0; + + sksec->nlbl_state = NLBL_REQUIRE; + return selinux_netlbl_socket_setsid(sock, sid); +} + +/** + * selinux_netlbl_sock_graft - Netlabel the new socket + * @sk: the new connection + * @sock: the new socket + * + * Description: + * The connection represented by @sk is being grafted onto @sock so set the + * socket's NetLabel to match the SID of @sk. + * + */ +void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) +{ + struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr secattr; + u32 nlbl_peer_sid; + + sksec->sclass = isec->sclass; + + if (sk->sk_family != PF_INET) + return; + + netlbl_secattr_init(&secattr); + if (netlbl_sock_getattr(sk, &secattr) == 0 && + selinux_netlbl_secattr_to_sid(NULL, + &secattr, + sksec->sid, + &nlbl_peer_sid) == 0) + sksec->peer_sid = nlbl_peer_sid; + netlbl_secattr_destroy(&secattr, 0); + + sksec->nlbl_state = NLBL_REQUIRE; + + /* Try to set the NetLabel on the socket to save time later, if we fail + * here we will pick up the pieces in later calls to + * selinux_netlbl_inode_permission(). */ + selinux_netlbl_socket_setsid(sock, sksec->sid); +} + +/** + * selinux_netlbl_inet_conn_request - Handle a new connection request + * @skb: the packet + * @sock_sid: the SID of the parent socket + * + * Description: + * If present, use the security attributes of the packet in @skb and the + * parent sock's SID to arrive at a SID for the new child sock. Returns the + * SID of the connection or SECSID_NULL on failure. + * + */ +u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid) +{ + int rc; + u32 peer_sid; + + rc = selinux_netlbl_skbuff_getsid(skb, sock_sid, &peer_sid); + if (rc != 0) + return SECSID_NULL; + + if (peer_sid == SECINITSID_UNLABELED) + return SECSID_NULL; + + return peer_sid; +} + +/** + * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled + * @inode: the file descriptor's inode + * @mask: the permission mask + * + * Description: + * Looks at a file's inode and if it is marked as a socket protected by + * NetLabel then verify that the socket has been labeled, if not try to label + * the socket now with the inode's SID. Returns zero on success, negative + * values on failure. + * + */ +int selinux_netlbl_inode_permission(struct inode *inode, int mask) +{ + int rc; + struct inode_security_struct *isec; + struct sk_security_struct *sksec; + struct socket *sock; + + if (!S_ISSOCK(inode->i_mode)) + return 0; + + sock = SOCKET_I(inode); + isec = inode->i_security; + sksec = sock->sk->sk_security; + mutex_lock(&isec->lock); + if (unlikely(sksec->nlbl_state == NLBL_REQUIRE && + (mask & (MAY_WRITE | MAY_APPEND)))) { + lock_sock(sock->sk); + rc = selinux_netlbl_socket_setsid(sock, sksec->sid); + release_sock(sock->sk); + } else + rc = 0; + mutex_unlock(&isec->lock); + + return rc; +} + +/** + * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel + * @sksec: the sock's sk_security_struct + * @skb: the packet + * @ad: the audit data + * + * Description: + * Fetch the NetLabel security attributes from @skb and perform an access check + * against the receiving socket. Returns zero on success, negative values on + * error. + * + */ +int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, + struct avc_audit_data *ad) +{ + int rc; + u32 netlbl_sid; + u32 recv_perm; + + rc = selinux_netlbl_skbuff_getsid(skb, SECINITSID_NETMSG, &netlbl_sid); + if (rc != 0) + return rc; + + if (netlbl_sid == SECINITSID_UNLABELED) + return 0; + + switch (sksec->sclass) { + case SECCLASS_UDP_SOCKET: + recv_perm = UDP_SOCKET__RECVFROM; + break; + case SECCLASS_TCP_SOCKET: + recv_perm = TCP_SOCKET__RECVFROM; + break; + default: + recv_perm = RAWIP_SOCKET__RECVFROM; + } + + rc = avc_has_perm(sksec->sid, + netlbl_sid, + sksec->sclass, + recv_perm, + ad); + if (rc == 0) + return 0; + + netlbl_skbuff_err(skb, rc); + return rc; +} + +/** + * selinux_netlbl_socket_getpeersec_stream - Return the connected peer's SID + * @sock: the socket + * + * Description: + * Examine @sock to find the connected peer's SID. Returns the SID on success + * or SECSID_NULL on error. + * + */ +u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock) +{ + struct sk_security_struct *sksec = sock->sk->sk_security; + + if (sksec->peer_sid == SECINITSID_UNLABELED) + return SECSID_NULL; + + return sksec->peer_sid; +} + +/** + * selinux_netlbl_socket_getpeersec_dgram - Return the SID of a NetLabel packet + * @skb: the packet + * + * Description: + * Examine @skb to find the SID assigned to it by NetLabel. Returns the SID on + * success, SECSID_NULL on error. + * + */ +u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb) +{ + int peer_sid; + struct sock *sk = skb->sk; + struct inode_security_struct *isec; + + if (sk == NULL || sk->sk_socket == NULL) + return SECSID_NULL; + + isec = SOCK_INODE(sk->sk_socket)->i_security; + if (selinux_netlbl_skbuff_getsid(skb, isec->sid, &peer_sid) != 0) + return SECSID_NULL; + if (peer_sid == SECINITSID_UNLABELED) + return SECSID_NULL; + + return peer_sid; +} +#endif /* CONFIG_NETLABEL */ |