diff options
Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 348 |
1 files changed, 308 insertions, 40 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index d52c780bdb78..609e89de3c24 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -27,10 +27,13 @@ #include <linux/ip.h> #include <linux/tcp.h> #include <linux/udp.h> +#include <linux/dccp.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/pipe_fs_i.h> #include <net/cipso_ipv4.h> +#include <net/ip.h> +#include <net/ipv6.h> #include <linux/audit.h> #include <linux/magic.h> #include <linux/dcache.h> @@ -45,6 +48,12 @@ #define TRANS_TRUE "TRUE" #define TRANS_TRUE_SIZE 4 +#define SMK_CONNECTING 0 +#define SMK_RECEIVING 1 +#define SMK_SENDING 2 + +LIST_HEAD(smk_ipv6_port_list); + /** * smk_fetch - Fetch the smack label from a file. * @ip: a pointer to the inode @@ -1878,6 +1887,155 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) } /** + * smk_ipv6_port_label - Smack port access table management + * @sock: socket + * @address: address + * + * Create or update the port list entry + */ +static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) +{ + struct sock *sk = sock->sk; + struct sockaddr_in6 *addr6; + struct socket_smack *ssp = sock->sk->sk_security; + struct smk_port_label *spp; + unsigned short port = 0; + + if (address == NULL) { + /* + * This operation is changing the Smack information + * on the bound socket. Take the changes to the port + * as well. + */ + list_for_each_entry(spp, &smk_ipv6_port_list, list) { + if (sk != spp->smk_sock) + continue; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + return; + } + /* + * A NULL address is only used for updating existing + * bound entries. If there isn't one, it's OK. + */ + return; + } + + addr6 = (struct sockaddr_in6 *)address; + port = ntohs(addr6->sin6_port); + /* + * This is a special case that is safely ignored. + */ + if (port == 0) + return; + + /* + * Look for an existing port list entry. + * This is an indication that a port is getting reused. + */ + list_for_each_entry(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port) + continue; + spp->smk_port = port; + spp->smk_sock = sk; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + return; + } + + /* + * A new port entry is required. + */ + spp = kzalloc(sizeof(*spp), GFP_KERNEL); + if (spp == NULL) + return; + + spp->smk_port = port; + spp->smk_sock = sk; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + + list_add(&spp->list, &smk_ipv6_port_list); + return; +} + +/** + * smk_ipv6_port_check - check Smack port access + * @sock: socket + * @address: address + * + * Create or update the port list entry + */ +static int smk_ipv6_port_check(struct sock *sk, struct sockaddr *address, + int act) +{ + __be16 *bep; + __be32 *be32p; + struct sockaddr_in6 *addr6; + struct smk_port_label *spp; + struct socket_smack *ssp = sk->sk_security; + unsigned short port = 0; + char *subject; + char *object; + struct smk_audit_info ad; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + + if (act == SMK_RECEIVING) { + subject = smack_net_ambient; + object = ssp->smk_in; + } else { + subject = ssp->smk_out; + object = smack_net_ambient; + } + + /* + * Get the IP address and port from the address. + */ + addr6 = (struct sockaddr_in6 *)address; + port = ntohs(addr6->sin6_port); + bep = (__be16 *)(&addr6->sin6_addr); + be32p = (__be32 *)(&addr6->sin6_addr); + + /* + * It's remote, so port lookup does no good. + */ + if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1) + goto auditout; + + /* + * It's local so the send check has to have passed. + */ + if (act == SMK_RECEIVING) { + subject = smack_known_web.smk_known; + goto auditout; + } + + list_for_each_entry(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port) + continue; + object = spp->smk_in; + if (act == SMK_CONNECTING) + ssp->smk_packet = spp->smk_out; + break; + } + +auditout: + +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = sk->sk_family; + ad.a.u.net->dport = port; + if (act == SMK_RECEIVING) + ad.a.u.net->v6info.saddr = addr6->sin6_addr; + else + ad.a.u.net->v6info.daddr = addr6->sin6_addr; +#endif + return smk_access(subject, object, MAY_WRITE, &ad); +} + +/** * smack_inode_setsecurity - set smack xattrs * @inode: the object * @name: attribute name @@ -1926,7 +2084,7 @@ 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; - if (sock->sk->sk_family != PF_UNIX) { + if (sock->sk->sk_family == PF_INET) { rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); if (rc != 0) printk(KERN_WARNING @@ -1936,6 +2094,9 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name, } else return -EOPNOTSUPP; + if (sock->sk->sk_family == PF_INET6) + smk_ipv6_port_label(sock, NULL); + return 0; } @@ -1963,6 +2124,25 @@ static int smack_socket_post_create(struct socket *sock, int family, } /** + * smack_socket_bind - record port binding information. + * @sock: the socket + * @address: the port address + * @addrlen: size of the address + * + * Records the label bound to a port. + * + * Returns 0 + */ +static int smack_socket_bind(struct socket *sock, struct sockaddr *address, + int addrlen) +{ + if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) + smk_ipv6_port_label(sock, address); + + return 0; +} + +/** * smack_socket_connect - connect access check * @sock: the socket * @sap: the other end @@ -1975,12 +2155,24 @@ static int smack_socket_post_create(struct socket *sock, int family, static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, int addrlen) { - if (sock->sk == NULL || sock->sk->sk_family != PF_INET) + int rc = 0; + + if (sock->sk == NULL) return 0; - if (addrlen < sizeof(struct sockaddr_in)) - return -EINVAL; - return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); + switch (sock->sk->sk_family) { + case PF_INET: + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); + break; + case PF_INET6: + if (addrlen < sizeof(struct sockaddr_in6)) + return -EINVAL; + rc = smk_ipv6_port_check(sock->sk, sap, SMK_CONNECTING); + break; + } + return rc; } /** @@ -2792,22 +2984,32 @@ static int smack_unix_may_send(struct socket *sock, struct socket *other) * @msg: 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. + * Return 0 if the current subject can write to the destination host. + * For IPv4 this is only a question if the destination is a single label host. + * For IPv6 this is a check against the label of the port. */ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size) { struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; + struct sockaddr *sap = (struct sockaddr *) msg->msg_name; + int rc = 0; /* * Perfectly reasonable for this to be NULL */ - if (sip == NULL || sip->sin_family != AF_INET) + if (sip == NULL) return 0; - return smack_netlabel_send(sock->sk, sip); + switch (sip->sin_family) { + case AF_INET: + rc = smack_netlabel_send(sock->sk, sip); + break; + case AF_INET6: + rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); + break; + } + return rc; } /** @@ -2878,6 +3080,54 @@ static char *smack_from_secattr(struct netlbl_lsm_secattr *sap, return smack_net_ambient; } +static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr *sap) +{ + struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; + u8 nexthdr; + int offset; + int proto = -EINVAL; + struct ipv6hdr _ipv6h; + struct ipv6hdr *ip6; + __be16 frag_off; + struct tcphdr _tcph, *th; + struct udphdr _udph, *uh; + struct dccp_hdr _dccph, *dh; + + sip->sin6_port = 0; + + offset = skb_network_offset(skb); + ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); + if (ip6 == NULL) + return -EINVAL; + sip->sin6_addr = ip6->saddr; + + nexthdr = ip6->nexthdr; + offset += sizeof(_ipv6h); + offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); + if (offset < 0) + return -EINVAL; + + proto = nexthdr; + switch (proto) { + case IPPROTO_TCP: + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th != NULL) + sip->sin6_port = th->source; + break; + case IPPROTO_UDP: + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh != NULL) + sip->sin6_port = uh->source; + break; + case IPPROTO_DCCP: + dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); + if (dh != NULL) + sip->sin6_port = dh->dccph_sport; + break; + } + return proto; +} + /** * smack_socket_sock_rcv_skb - Smack packet delivery access check * @sk: socket @@ -2889,43 +3139,52 @@ 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; + struct sockaddr sadd; char *csp; - int rc; + int rc = 0; struct smk_audit_info ad; #ifdef CONFIG_AUDIT struct lsm_network_audit net; #endif - if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) - return 0; - - /* - * Translate what netlabel gave us. - */ - netlbl_secattr_init(&secattr); + switch (sk->sk_family) { + case PF_INET: + /* + * Translate what netlabel gave us. + */ + netlbl_secattr_init(&secattr); - rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); - if (rc == 0) - csp = smack_from_secattr(&secattr, ssp); - else - csp = smack_net_ambient; + rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); + if (rc == 0) + csp = smack_from_secattr(&secattr, ssp); + else + csp = smack_net_ambient; - netlbl_secattr_destroy(&secattr); + netlbl_secattr_destroy(&secattr); #ifdef CONFIG_AUDIT - smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); - ad.a.u.net->family = sk->sk_family; - ad.a.u.net->netif = skb->skb_iif; - ipv4_skb_to_auditdata(skb, &ad.a, NULL); + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = sk->sk_family; + ad.a.u.net->netif = skb->skb_iif; + ipv4_skb_to_auditdata(skb, &ad.a, NULL); #endif - /* - * 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(csp, ssp->smk_in, MAY_WRITE, &ad); - if (rc != 0) - netlbl_skbuff_err(skb, rc, 0); + /* + * 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(csp, ssp->smk_in, MAY_WRITE, &ad); + if (rc != 0) + netlbl_skbuff_err(skb, rc, 0); + break; + case PF_INET6: + rc = smk_skb_to_addr_ipv6(skb, &sadd); + if (rc == IPPROTO_UDP || rc == IPPROTO_TCP) + rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); + else + rc = 0; + break; + } return rc; } @@ -3063,9 +3322,17 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct lsm_network_audit net; #endif - /* handle mapped IPv4 packets arriving via IPv6 sockets */ - if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) - family = PF_INET; + if (family == PF_INET6) { + /* + * Handle mapped IPv4 packets arriving + * via IPv6 sockets. Don't set up netlabel + * processing on IPv6. + */ + if (skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + else + return 0; + } netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); @@ -3498,6 +3765,7 @@ struct security_operations smack_ops = { .unix_may_send = smack_unix_may_send, .socket_post_create = smack_socket_post_create, + .socket_bind = smack_socket_bind, .socket_connect = smack_socket_connect, .socket_sendmsg = smack_socket_sendmsg, .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, |