diff options
Diffstat (limited to 'security/smack')
| -rw-r--r-- | security/smack/smack.h | 1 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 260 |
2 files changed, 143 insertions, 118 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h index 64164f8fde70..5e5a3bcb599a 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -42,7 +42,6 @@ struct superblock_smack { struct socket_smack { char *smk_out; /* outbound label */ char *smk_in; /* inbound label */ - int smk_labeled; /* label scheme */ char smk_packet[SMK_LABELLEN]; /* TCP peer label */ }; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 23ad420a49aa..8ed502c2ad45 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -7,6 +7,8 @@ * Casey Schaufler <casey@schaufler-ca.com> * * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul.moore@hp.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, @@ -20,6 +22,7 @@ #include <linux/ext2_fs.h> #include <linux/kd.h> #include <asm/ioctls.h> +#include <linux/ip.h> #include <linux/tcp.h> #include <linux/udp.h> #include <linux/mutex.h> @@ -1275,7 +1278,6 @@ 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; @@ -1295,6 +1297,39 @@ static void smack_sk_free_security(struct sock *sk) } /** +* 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. The caller is responsible for ensuring that the RCU read lock is +* taken before calling this function. +* +* 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; + struct in_addr *siap = &sip->sin_addr; + + if (siap->s_addr == 0) + return NULL; + + list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) + /* + * we break after finding the first match because + * the list is sorted from longest to shortest mask + * so we have found the most specific match + */ + if ((&snp->smk_host.sin_addr)->s_addr == + (siap->s_addr & (&snp->smk_mask)->s_addr)) + return snp->smk_label; + + return NULL; +} + +/** * smack_set_catset - convert a capset to netlabel mls categories * @catset: the Smack categories * @sap: where to put the netlabel categories @@ -1365,11 +1400,10 @@ static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) */ static int smack_netlabel(struct sock *sk, int labeled) { - struct socket_smack *ssp; + struct socket_smack *ssp = sk->sk_security; struct netlbl_lsm_secattr secattr; int rc = 0; - ssp = sk->sk_security; /* * Usually the netlabel code will handle changing the * packet labeling based on the label. @@ -1393,21 +1427,45 @@ static int smack_netlabel(struct sock *sk, int labeled) 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; } /** + * smack_netlbel_send - Set the secattr on a socket and perform access checks + * @sk: the socket + * @sap: the destination address + * + * Set the correct secattr for the given socket based on the destination + * address and perform any outbound access checks needed. + * + * Returns 0 on success or an error code. + * + */ +static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) +{ + int rc; + int sk_lbl; + char *hostsp; + struct socket_smack *ssp = sk->sk_security; + + rcu_read_lock(); + hostsp = smack_host_label(sap); + if (hostsp != NULL) { + sk_lbl = SMACK_UNLABELED_SOCKET; + rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE); + } else { + sk_lbl = SMACK_CIPSO_SOCKET; + rc = 0; + } + rcu_read_unlock(); + if (rc != 0) + return rc; + + return smack_netlabel(sk, sk_lbl); +} + +/** * smack_inode_setsecurity - set smack xattrs * @inode: the object * @name: attribute name @@ -1488,43 +1546,6 @@ static int smack_socket_post_create(struct socket *sock, int family, 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. - * - * 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; - struct in_addr *siap = &sip->sin_addr; - - if (siap->s_addr == 0) - return NULL; - - rcu_read_lock(); - list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) { - /* - * we break after finding the first match because - * the list is sorted from longest to shortest mask - * so we have found the most specific match - */ - if ((&snp->smk_host.sin_addr)->s_addr == - (siap->s_addr & (&snp->smk_mask)->s_addr)) { - rcu_read_unlock(); - return snp->smk_label; - } - } - rcu_read_unlock(); - return NULL; -} - /** * smack_socket_connect - connect access check * @sock: the socket @@ -1538,30 +1559,12 @@ static char *smack_host_label(struct sockaddr_in *sip) 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; + return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); } /** @@ -2262,9 +2265,6 @@ 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 @@ -2272,22 +2272,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 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; - + return smack_netlabel_send(sock->sk, sip); } @@ -2492,31 +2477,24 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, } /** - * smack_sock_graft - graft access state between two sockets - * @sk: fresh sock - * @parent: donor socket + * smack_sock_graft - Initialize a newly created socket with an existing sock + * @sk: child sock + * @parent: parent socket * - * Sets the netlabel socket state on sk from parent + * Set the smk_{in,out} state of an existing sock based on the process that + * is creating the new socket. */ static void smack_sock_graft(struct sock *sk, struct socket *parent) { struct socket_smack *ssp; - int rc; - - if (sk == NULL) - return; - if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + if (sk == NULL || + (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) return; ssp = sk->sk_security; ssp->smk_in = ssp->smk_out = current_security(); - ssp->smk_packet[0] = '\0'; - - rc = smack_netlabel(sk, SMACK_CIPSO_SOCKET); - if (rc != 0) - printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", - __func__, -rc); + /* cssp->smk_packet is already set in smack_inet_csk_clone() */ } /** @@ -2531,35 +2509,82 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent) static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - struct netlbl_lsm_secattr skb_secattr; + u16 family = sk->sk_family; struct socket_smack *ssp = sk->sk_security; + struct netlbl_lsm_secattr secattr; + struct sockaddr_in addr; + struct iphdr *hdr; char smack[SMK_LABELLEN]; int rc; - if (skb == NULL) - return -EACCES; + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; - netlbl_secattr_init(&skb_secattr); - rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr); + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) - smack_from_secattr(&skb_secattr, smack); + smack_from_secattr(&secattr, smack); else strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); - netlbl_secattr_destroy(&skb_secattr); + netlbl_secattr_destroy(&secattr); + /* - * Receiving a packet requires that the other end - * be able to write here. Read access is not required. - * - * If the request is successful save the peer's label - * so that SO_PEERCRED can report it. + * Receiving a packet requires that the other end be able to write + * here. Read access is not required. */ rc = smk_access(smack, ssp->smk_in, MAY_WRITE); - if (rc == 0) - strncpy(ssp->smk_packet, smack, SMK_MAXLEN); + if (rc != 0) + return rc; + + /* + * Save the peer's label in the request_sock so we can later setup + * smk_packet in the child socket so that SO_PEERCRED can report it. + */ + req->peer_secid = smack_to_secid(smack); + + /* + * We need to decide if we want to label the incoming connection here + * if we do we only need to label the request_sock and the stack will + * propogate the wire-label to the sock when it is created. + */ + hdr = ip_hdr(skb); + addr.sin_addr.s_addr = hdr->saddr; + rcu_read_lock(); + if (smack_host_label(&addr) == NULL) { + rcu_read_unlock(); + netlbl_secattr_init(&secattr); + smack_to_secattr(smack, &secattr); + rc = netlbl_req_setattr(req, &secattr); + netlbl_secattr_destroy(&secattr); + } else { + rcu_read_unlock(); + netlbl_req_delattr(req); + } return rc; } +/** + * smack_inet_csk_clone - Copy the connection information to the new socket + * @sk: the new socket + * @req: the connection's request_sock + * + * Transfer the connection's peer label to the newly created socket. + */ +static void smack_inet_csk_clone(struct sock *sk, + const struct request_sock *req) +{ + struct socket_smack *ssp = sk->sk_security; + char *smack; + + if (req->peer_secid != 0) { + smack = smack_from_secid(req->peer_secid); + strncpy(ssp->smk_packet, smack, SMK_MAXLEN); + } else + ssp->smk_packet[0] = '\0'; +} + /* * Key management security hooks * @@ -2911,6 +2936,7 @@ struct security_operations smack_ops = { .sk_free_security = smack_sk_free_security, .sock_graft = smack_sock_graft, .inet_conn_request = smack_inet_conn_request, + .inet_csk_clone = smack_inet_csk_clone, /* key management security hooks */ #ifdef CONFIG_KEYS |