selinux: Add IB Port SMP access vector

Add a type for Infiniband ports and an access vector for subnet
management packets. Implement the ib_port_smp hook to check that the
caller has permission to send and receive SMPs on the end port specified
by the device name and port. Add interface to query the SID for a IB
port, which walks the IB_PORT ocontexts to find an entry for the
given name and port.

Signed-off-by: Daniel Jurgens <[e-mail]>
Reviewed-by: James Morris <[e-mail]>
Acked-by: Doug Ledford <[e-mail]>
Signed-off-by: Paul Moore <[e-mail]>

include/linux/lsm_audit.h

···
 #include <linux/path.h>
 #include <linux/key.h>
 #include <linux/skbuff.h>
+#include <rdma/ib_verbs.h>
 
 struct lsm_network_audit {
 	int netif;
···
 	u16	pkey;
 };
 
+struct lsm_ibendport_audit {
+	char	dev_name[IB_DEVICE_NAME_MAX];
+	u8	port;
+};
+
 /* Auxiliary data to use in generating the audit record. */
 struct common_audit_data {
 	char type;
···
 #define LSM_AUDIT_DATA_IOCTL_OP	11
 #define LSM_AUDIT_DATA_FILE	12
 #define LSM_AUDIT_DATA_IBPKEY	13
+#define LSM_AUDIT_DATA_IBENDPORT 14
 	union 	{
 		struct path path;
 		struct dentry *dentry;
···
 		struct lsm_ioctlop_audit *op;
 		struct file *file;
 		struct lsm_ibpkey_audit *ibpkey;
+		struct lsm_ibendport_audit *ibendport;
 	} u;
 	/* this union contains LSM specific data */
 	union {

security/lsm_audit.c

···
 				 a->u.ibpkey->pkey, &sbn_pfx);
 		break;
 	}
+	case LSM_AUDIT_DATA_IBENDPORT:
+		audit_log_format(ab, " device=%s port_num=%u",
+				 a->u.ibendport->dev_name,
+				 a->u.ibendport->port);
+		break;
 	} /* switch (a->type) */
 }
 

security/selinux/hooks.c

···
 			    INFINIBAND_PKEY__ACCESS, &ad);
 }
 
+static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
+					    u8 port_num)
+{
+	struct common_audit_data ad;
+	int err;
+	u32 sid = 0;
+	struct ib_security_struct *sec = ib_sec;
+	struct lsm_ibendport_audit ibendport;
+
+	err = security_ib_endport_sid(dev_name, port_num, &sid);
+
+	if (err)
+		return err;
+
+	ad.type = LSM_AUDIT_DATA_IBENDPORT;
+	strncpy(ibendport.dev_name, dev_name, sizeof(ibendport.dev_name));
+	ibendport.port = port_num;
+	ad.u.ibendport = &ibendport;
+	return avc_has_perm(sec->sid, sid,
+			    SECCLASS_INFINIBAND_ENDPORT,
+			    INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
+}
+
 static int selinux_ib_alloc_security(void **ib_sec)
 {
 	struct ib_security_struct *sec;
···
 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
 #ifdef CONFIG_SECURITY_INFINIBAND
 	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
+	LSM_HOOK_INIT(ib_endport_manage_subnet,
+		      selinux_ib_endport_manage_subnet),
 	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
 	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
 #endif

security/selinux/include/classmap.h

···
 	  { COMMON_SOCK_PERMS, NULL } },
 	{ "infiniband_pkey",
 	  { "access", NULL } },
+	{ "infiniband_endport",
+	  { "manage_subnet", NULL } },
 	{ NULL }
   };
 

security/selinux/include/security.h

···
 
 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid);
 
+int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid);
+
 int security_netif_sid(char *name, u32 *if_sid);
 
 int security_node_sid(u16 domain, void *addr, u32 addrlen,

security/selinux/ss/services.c

···
 }
 
 /**
+ * security_ib_endport_sid - Obtain the SID for a subnet management interface.
+ * @dev_name: device name
+ * @port: port number
+ * @out_sid: security identifier
+ */
+int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
+{
+	struct ocontext *c;
+	int rc = 0;
+
+	read_lock(&policy_rwlock);
+
+	c = policydb.ocontexts[OCON_IBENDPORT];
+	while (c) {
+		if (c->u.ibendport.port == port_num &&
+		    !strncmp(c->u.ibendport.dev_name,
+			     dev_name,
+			     IB_DEVICE_NAME_MAX))
+			break;
+
+		c = c->next;
+	}
+
+	if (c) {
+		if (!c->sid[0]) {
+			rc = sidtab_context_to_sid(&sidtab,
+						   &c->context[0],
+						   &c->sid[0]);
+			if (rc)
+				goto out;
+		}
+		*out_sid = c->sid[0];
+	} else
+		*out_sid = SECINITSID_UNLABELED;
+
+out:
+	read_unlock(&policy_rwlock);
+	return rc;
+}
+
+/**
  * security_netif_sid - Obtain the SID for a network interface.
  * @name: interface name
  * @if_sid: interface SID