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author | James Morris <jmorris@namei.org> | 2009-01-07 09:58:22 +1100 |
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committer | James Morris <jmorris@namei.org> | 2009-01-07 09:58:22 +1100 |
commit | ac8cc0fa5395fe2278e305a4cbed48e90d88d878 (patch) | |
tree | 515f577bfddd054ee4373228be7c974dfb8133af /security/smack/smack_lsm.c | |
parent | 238c6d54830c624f34ac9cf123ac04aebfca5013 (diff) | |
parent | 3699c53c485bf0168e6500d0ed18bf931584dd7c (diff) | |
download | linux-ac8cc0fa5395fe2278e305a4cbed48e90d88d878.tar.gz linux-ac8cc0fa5395fe2278e305a4cbed48e90d88d878.tar.bz2 linux-ac8cc0fa5395fe2278e305a4cbed48e90d88d878.zip |
Merge branch 'next' into for-linus
Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r-- | security/smack/smack_lsm.c | 310 |
1 files changed, 255 insertions, 55 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 848212fd4845..0278bc083044 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1277,6 +1277,7 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) ssp->smk_in = csp; ssp->smk_out = csp; + ssp->smk_labeled = SMACK_CIPSO_SOCKET; ssp->smk_packet[0] = '\0'; sk->sk_security = ssp; @@ -1341,45 +1342,69 @@ static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) struct smack_cipso cipso; int rc; - switch (smack_net_nltype) { - case NETLBL_NLTYPE_CIPSOV4: - nlsp->domain = smack; - nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; + nlsp->domain = smack; + nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; - rc = smack_to_cipso(smack, &cipso); - if (rc == 0) { - nlsp->attr.mls.lvl = cipso.smk_level; - smack_set_catset(cipso.smk_catset, nlsp); - } else { - nlsp->attr.mls.lvl = smack_cipso_direct; - smack_set_catset(smack, nlsp); - } - break; - default: - break; + rc = smack_to_cipso(smack, &cipso); + if (rc == 0) { + nlsp->attr.mls.lvl = cipso.smk_level; + smack_set_catset(cipso.smk_catset, nlsp); + } else { + nlsp->attr.mls.lvl = smack_cipso_direct; + smack_set_catset(smack, nlsp); } } /** * smack_netlabel - Set the secattr on a socket * @sk: the socket + * @labeled: socket label scheme * * Convert the outbound smack value (smk_out) to a * secattr and attach it to the socket. * * Returns 0 on success or an error code */ -static int smack_netlabel(struct sock *sk) +static int smack_netlabel(struct sock *sk, int labeled) { struct socket_smack *ssp; struct netlbl_lsm_secattr secattr; - int rc; + int rc = 0; ssp = sk->sk_security; - netlbl_secattr_init(&secattr); - smack_to_secattr(ssp->smk_out, &secattr); - rc = netlbl_sock_setattr(sk, &secattr); - netlbl_secattr_destroy(&secattr); + /* + * Usually the netlabel code will handle changing the + * packet labeling based on the label. + * The case of a single label host is different, because + * a single label host should never get a labeled packet + * even though the label is usually associated with a packet + * label. + */ + local_bh_disable(); + bh_lock_sock_nested(sk); + + if (ssp->smk_out == smack_net_ambient || + labeled == SMACK_UNLABELED_SOCKET) + netlbl_sock_delattr(sk); + else { + netlbl_secattr_init(&secattr); + smack_to_secattr(ssp->smk_out, &secattr); + rc = netlbl_sock_setattr(sk, &secattr); + netlbl_secattr_destroy(&secattr); + } + + bh_unlock_sock(sk); + local_bh_enable(); + /* + * Remember the label scheme used so that it is not + * necessary to do the netlabel setting if it has not + * changed the next time through. + * + * The -EDESTADDRREQ case is an indication that there's + * a single level host involved. + */ + if (rc == 0) + ssp->smk_labeled = labeled; return rc; } @@ -1432,7 +1457,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name, ssp->smk_in = sp; else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { ssp->smk_out = sp; - rc = smack_netlabel(sock->sk); + rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); if (rc != 0) printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", __func__, -rc); @@ -1462,7 +1487,108 @@ static int smack_socket_post_create(struct socket *sock, int family, /* * Set the outbound netlbl. */ - return smack_netlabel(sock->sk); + return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); +} + + +/** + * smack_host_label - check host based restrictions + * @sip: the object end + * + * looks for host based access restrictions + * + * This version will only be appropriate for really small + * sets of single label hosts. Because of the masking + * it cannot shortcut out on the first match. There are + * numerious ways to address the problem, but none of them + * have been applied here. + * + * Returns the label of the far end or NULL if it's not special. + */ +static char *smack_host_label(struct sockaddr_in *sip) +{ + struct smk_netlbladdr *snp; + char *bestlabel = NULL; + struct in_addr *siap = &sip->sin_addr; + struct in_addr *liap; + struct in_addr *miap; + struct in_addr bestmask; + + if (siap->s_addr == 0) + return NULL; + + bestmask.s_addr = 0; + + for (snp = smack_netlbladdrs; snp != NULL; snp = snp->smk_next) { + liap = &snp->smk_host.sin_addr; + miap = &snp->smk_mask; + /* + * If the addresses match after applying the list entry mask + * the entry matches the address. If it doesn't move along to + * the next entry. + */ + if ((liap->s_addr & miap->s_addr) != + (siap->s_addr & miap->s_addr)) + continue; + /* + * If the list entry mask identifies a single address + * it can't get any more specific. + */ + if (miap->s_addr == 0xffffffff) + return snp->smk_label; + /* + * If the list entry mask is less specific than the best + * already found this entry is uninteresting. + */ + if ((miap->s_addr | bestmask.s_addr) == bestmask.s_addr) + continue; + /* + * This is better than any entry found so far. + */ + bestmask.s_addr = miap->s_addr; + bestlabel = snp->smk_label; + } + + return bestlabel; +} + +/** + * smack_socket_connect - connect access check + * @sock: the socket + * @sap: the other end + * @addrlen: size of sap + * + * Verifies that a connection may be possible + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, + int addrlen) +{ + struct socket_smack *ssp = sock->sk->sk_security; + char *hostsp; + int rc; + + if (sock->sk == NULL || sock->sk->sk_family != PF_INET) + return 0; + + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + + hostsp = smack_host_label((struct sockaddr_in *)sap); + if (hostsp == NULL) { + if (ssp->smk_labeled != SMACK_CIPSO_SOCKET) + return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); + return 0; + } + + rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE); + if (rc != 0) + return rc; + + if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET) + return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET); + return 0; } /** @@ -2101,8 +2227,14 @@ static int smack_setprocattr(struct task_struct *p, char *name, if (newsmack == NULL) return -EINVAL; + /* + * No process is ever allowed the web ("@") label. + */ + if (newsmack == smack_known_web.smk_known) + return -EPERM; + new = prepare_creds(); - if (!new) + if (new == NULL) return -ENOMEM; new->security = newsmack; commit_creds(new); @@ -2144,6 +2276,49 @@ static int smack_unix_may_send(struct socket *sock, struct socket *other) } /** + * smack_socket_sendmsg - Smack check based on destination host + * @sock: the socket + * @msghdr: the message + * @size: the size of the message + * + * Return 0 if the current subject can write to the destination + * host. This is only a question if the destination is a single + * label host. + */ +static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, + int size) +{ + struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; + struct socket_smack *ssp = sock->sk->sk_security; + char *hostsp; + int rc; + + /* + * Perfectly reasonable for this to be NULL + */ + if (sip == NULL || sip->sin_family != PF_INET) + return 0; + + hostsp = smack_host_label(sip); + if (hostsp == NULL) { + if (ssp->smk_labeled != SMACK_CIPSO_SOCKET) + return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); + return 0; + } + + rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE); + if (rc != 0) + return rc; + + if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET) + return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET); + + return 0; + +} + + +/** * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat * pair to smack * @sap: netlabel secattr @@ -2154,44 +2329,66 @@ static int smack_unix_may_send(struct socket *sock, struct socket *other) static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) { char smack[SMK_LABELLEN]; + char *sp; int pcat; - if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) { + if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { /* + * Looks like a CIPSO packet. * If there are flags but no level netlabel isn't * behaving the way we expect it to. * + * Get the categories, if any * Without guidance regarding the smack value * for the packet fall back on the network * ambient value. */ - strncpy(sip, smack_net_ambient, SMK_MAXLEN); + memset(smack, '\0', SMK_LABELLEN); + if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) + for (pcat = -1;;) { + pcat = netlbl_secattr_catmap_walk( + sap->attr.mls.cat, pcat + 1); + if (pcat < 0) + break; + smack_catset_bit(pcat, smack); + } + /* + * If it is CIPSO using smack direct mapping + * we are already done. WeeHee. + */ + if (sap->attr.mls.lvl == smack_cipso_direct) { + memcpy(sip, smack, SMK_MAXLEN); + return; + } + /* + * Look it up in the supplied table if it is not + * a direct mapping. + */ + smack_from_cipso(sap->attr.mls.lvl, smack, sip); return; } - /* - * Get the categories, if any - */ - memset(smack, '\0', SMK_LABELLEN); - if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) - for (pcat = -1;;) { - pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat, - pcat + 1); - if (pcat < 0) - break; - smack_catset_bit(pcat, smack); - } - /* - * If it is CIPSO using smack direct mapping - * we are already done. WeeHee. - */ - if (sap->attr.mls.lvl == smack_cipso_direct) { - memcpy(sip, smack, SMK_MAXLEN); + if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { + /* + * Looks like a fallback, which gives us a secid. + */ + sp = smack_from_secid(sap->attr.secid); + /* + * This has got to be a bug because it is + * impossible to specify a fallback without + * specifying the label, which will ensure + * it has a secid, and the only way to get a + * secid is from a fallback. + */ + BUG_ON(sp == NULL); + strncpy(sip, sp, SMK_MAXLEN); return; } /* - * Look it up in the supplied table if it is not a direct mapping. + * Without guidance regarding the smack value + * for the packet fall back on the network + * ambient value. */ - smack_from_cipso(sap->attr.mls.lvl, smack, sip); + strncpy(sip, smack_net_ambient, SMK_MAXLEN); return; } @@ -2207,6 +2404,7 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) struct netlbl_lsm_secattr secattr; struct socket_smack *ssp = sk->sk_security; char smack[SMK_LABELLEN]; + char *csp; int rc; if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) @@ -2215,21 +2413,24 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) /* * Translate what netlabel gave us. */ - memset(smack, '\0', SMK_LABELLEN); netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); - if (rc == 0) + if (rc == 0) { smack_from_secattr(&secattr, smack); - else - strncpy(smack, smack_net_ambient, SMK_MAXLEN); + csp = smack; + } else + csp = smack_net_ambient; + netlbl_secattr_destroy(&secattr); + /* * Receiving a packet requires that the other end * be able to write here. Read access is not required. * This is the simplist possible security model * for networking. */ - rc = smk_access(smack, ssp->smk_in, MAY_WRITE); + rc = smk_access(csp, ssp->smk_in, MAY_WRITE); if (rc != 0) netlbl_skbuff_err(skb, rc, 0); return rc; @@ -2298,7 +2499,6 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, /* * Translate what netlabel gave us. */ - memset(smack, '\0', SMK_LABELLEN); netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) @@ -2341,7 +2541,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent) ssp->smk_in = ssp->smk_out = current_security(); ssp->smk_packet[0] = '\0'; - rc = smack_netlabel(sk); + rc = smack_netlabel(sk, SMACK_CIPSO_SOCKET); if (rc != 0) printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", __func__, -rc); @@ -2367,7 +2567,6 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, if (skb == NULL) return -EACCES; - memset(smack, '\0', SMK_LABELLEN); netlbl_secattr_init(&skb_secattr); rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr); if (rc == 0) @@ -2732,6 +2931,8 @@ struct security_operations smack_ops = { .unix_may_send = smack_unix_may_send, .socket_post_create = smack_socket_post_create, + .socket_connect = smack_socket_connect, + .socket_sendmsg = smack_socket_sendmsg, .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, .socket_getpeersec_stream = smack_socket_getpeersec_stream, .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, @@ -2783,7 +2984,6 @@ static __init int smack_init(void) /* * Initialize locks */ - spin_lock_init(&smack_known_unset.smk_cipsolock); spin_lock_init(&smack_known_huh.smk_cipsolock); spin_lock_init(&smack_known_hat.smk_cipsolock); spin_lock_init(&smack_known_star.smk_cipsolock); |