Add support for extended header BSM tokens. Currently we use the

regular header tokens.  The extended header tokens contain an IP
or IPv6 address which makes it possible to identify which host an
audit record came from when audit records are centralized.

If the host information has not been specified, the system will
default to the old style headers.  Otherwise, audit records that
are created as a result of system calls will contain host information.

This implemented has been designed to be consistent with the Solaris
implementation.  Host information is set/retrieved using the A_GETKAUDIT
and A_SETKAUDIT auditon(2) commands.  These commands require that a
pointer to a auditinfo_addr_t object is passed.  Currently only IP and
IPv6 address families are supported.

The users pace bits associated with this change will follow in an
openbsm import.

Reviewed by:	rwatson, (sson, wsalamon (older version))
MFC after:	1 month

sys/bsm/audit_internal.h

@@ -72,7 +72,9 @@ typedef	struct au_record	au_record_t;
  * token structures may contain pointers of whose contents we do not know the
  * size (e.g text tokens).
  */
+#define	AUDIT_HEADER_EX_SIZE(a)	((a)->ai_termid.at_type+18+sizeof(u_int32_t))
 #define	AUDIT_HEADER_SIZE	18
+#define	MAX_AUDIT_HEADER_SIZE	(5*sizeof(u_int32_t)+18)
 #define	AUDIT_TRAILER_SIZE	7
 
 /*

sys/bsm/audit_record.h

@@ -244,10 +244,13 @@ token_t	*au_to_file(char *file, struct timeval tm);
 
 token_t	*au_to_header32_tm(int rec_size, au_event_t e_type, au_emod_t e_mod,
 	    struct timeval tm);
+token_t	*au_to_header32_ex_tm(int rec_size, au_event_t e_type, au_emod_t e_mod,
+	    struct timeval tm, struct auditinfo_addr *aia);
 token_t	*au_to_header64_tm(int rec_size, au_event_t e_type, au_emod_t e_mod,
 	    struct timeval tm);
 #if !defined(KERNEL) && !defined(_KERNEL)
 token_t	*au_to_header(int rec_size, au_event_t e_type, au_emod_t e_mod);
+token_t	*au_to_header_ex(int rec_size, au_event_t e_type, au_emod_t e_mod);
 token_t	*au_to_header32(int rec_size, au_event_t e_type, au_emod_t e_mod);
 token_t	*au_to_header64(int rec_size, au_event_t e_type, au_emod_t e_mod);
 #endif

sys/security/audit/audit.c

@@ -157,6 +157,45 @@ struct cv		audit_watermark_cv;
  */
 static struct cv	audit_fail_cv;
 
+/*
+ * Kernel audit information.  This will store the current audit address
+ * or host information that the kernel will use when it's generating
+ * audit records.  This data is modified by the A_GET{SET}KAUDIT auditon(2)
+ * command.
+ */
+static struct auditinfo_addr	audit_kinfo;
+static struct rwlock		audit_kinfo_lock;
+
+#define	KINFO_LOCK_INIT()	rw_init(&audit_kinfo_lock, "kernel audit info lock")
+#define	KINFO_RLOCK()		rw_rlock(&audit_kinfo_lock)
+#define	KINFO_WLOCK()		rw_wlock(&audit_kinfo_lock)
+#define	KINFO_RUNLOCK()		rw_runlock(&audit_kinfo_lock)
+#define	KINFO_WUNLOCK()		rw_wunlock(&audit_kinfo_lock)
+
+void
+audit_set_kinfo(struct auditinfo_addr *ak)
+{
+
+	KASSERT(ak->ai_termid.at_type == AU_IPv4 ||
+	    ak->ai_termid.at_type == AU_IPv6,
+	    ("audit_set_kinfo: invalid address type"));
+	KINFO_WLOCK();
+	audit_kinfo = *ak;
+	KINFO_WUNLOCK();
+}
+
+void
+audit_get_kinfo(struct auditinfo_addr *ak)
+{
+
+	KASSERT(audit_kinfo.ai_termid.at_type == AU_IPv4 ||
+	    audit_kinfo.ai_termid.at_type == AU_IPv6,
+	    ("audit_set_kinfo: invalid address type"));
+	KINFO_RLOCK();
+	*ak = audit_kinfo;
+	KINFO_RUNLOCK();
+}
+
 /*
  * Construct an audit record for the passed thread.
  */
@@ -241,7 +280,11 @@ audit_init(void)
 	audit_qctrl.aq_bufsz = AQ_BUFSZ;
 	audit_qctrl.aq_minfree = AU_FS_MINFREE;
 
+	audit_kinfo.ai_termid.at_type = AU_IPv4;
+	audit_kinfo.ai_termid.at_addr[0] = INADDR_ANY;
+
 	mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF);
+	KINFO_LOCK_INIT();
 	cv_init(&audit_worker_cv, "audit_worker_cv");
 	cv_init(&audit_watermark_cv, "audit_watermark_cv");
 	cv_init(&audit_fail_cv, "audit_fail_cv");

sys/security/audit/audit.h

@@ -180,6 +180,8 @@ void	 audit_cred_proc1(struct ucred *cred);
 void	 audit_proc_coredump(struct thread *td, char *path, int errcode);
 void	 audit_thread_alloc(struct thread *td);
 void	 audit_thread_free(struct thread *td);
+void	 audit_set_kinfo(struct auditinfo_addr *);
+void	 audit_get_kinfo(struct auditinfo_addr *);
 
 /*
  * Define a macro to wrap the audit_arg_* calls by checking the global

sys/security/audit/audit_bsm.c

@@ -113,13 +113,34 @@ kau_close(struct au_record *rec, struct timespec *ctime, short event)
 	size_t tot_rec_size;
 	token_t *cur, *hdr, *trail;
 	struct timeval tm;
+	size_t hdrsize;
+	struct auditinfo_addr ak;
+	struct in6_addr *ap;
 
-	tot_rec_size = rec->len + AUDIT_HEADER_SIZE + AUDIT_TRAILER_SIZE;
+	audit_get_kinfo(&ak);
+	hdrsize = 0;
+	switch (ak.ai_termid.at_type) {
+	case AU_IPv4:
+		hdrsize = (ak.ai_termid.at_addr[0] == INADDR_ANY) ?
+		    AUDIT_HEADER_SIZE : AUDIT_HEADER_EX_SIZE(&ak);
+		break;
+	case AU_IPv6:
+		ap = (struct in6_addr *)&ak.ai_termid.at_addr[0];
+		hdrsize = (IN6_IS_ADDR_UNSPECIFIED(ap)) ? AUDIT_HEADER_SIZE :
+		    AUDIT_HEADER_EX_SIZE(&ak);
+		break;
+	default:
+		panic("kau_close: invalid address family");
+	}
+	tot_rec_size = rec->len + hdrsize + AUDIT_TRAILER_SIZE;
 	rec->data = malloc(tot_rec_size, M_AUDITBSM, M_WAITOK | M_ZERO);
 
 	tm.tv_usec = ctime->tv_nsec / 1000;
 	tm.tv_sec = ctime->tv_sec;
-	hdr = au_to_header32_tm(tot_rec_size, event, 0, tm);
+	if (hdrsize != AUDIT_HEADER_SIZE)
+		hdr = au_to_header32_ex_tm(tot_rec_size, event, 0, tm, &ak);
+	else
+		hdr = au_to_header32_tm(tot_rec_size, event, 0, tm);
 	TAILQ_INSERT_HEAD(&rec->token_q, hdr, tokens);
 
 	trail = au_to_trailer(tot_rec_size);

sys/security/audit/audit_bsm_token.c

@@ -1289,6 +1289,51 @@ au_to_exec_env(char **envp)
 }
 #endif
 
+/*
+ * token ID                1 byte
+ * record byte count       4 bytes
+ * version #               1 byte
+ * event type              2 bytes
+ * event modifier          2 bytes
+ * address type/length     4 bytes
+ * machine address         4 bytes/16 bytes (IPv4/IPv6 address)
+ * seconds of time         4 bytes/8 bytes  (32/64-bits)
+ * milliseconds of time    4 bytes/8 bytes  (32/64-bits) 
+ */
+token_t *
+au_to_header32_ex_tm(int rec_size, au_event_t e_type, au_emod_t e_mod,
+    struct timeval tm, struct auditinfo_addr *aia)
+{
+	token_t *t;  
+	u_char *dptr = NULL;
+	u_int32_t timems;
+	struct au_tid_addr *tid;
+
+	tid = &aia->ai_termid;
+	KASSERT(tid->at_type == AU_IPv4 || tid->at_type == AU_IPv6,
+	    ("au_to_header32_ex_tm: invalid address family"));
+
+	GET_TOKEN_AREA(t, dptr, sizeof(u_char) + sizeof(u_int32_t) +
+	    sizeof(u_char) + 2 * sizeof(u_int16_t) + 3 * sizeof(u_int32_t) +
+	    tid->at_type);
+
+	ADD_U_CHAR(dptr, AUT_HEADER32_EX);
+	ADD_U_INT32(dptr, rec_size);
+	ADD_U_CHAR(dptr, AUDIT_HEADER_VERSION_OPENBSM);
+	ADD_U_INT16(dptr, e_type);
+	ADD_U_INT16(dptr, e_mod);
+	ADD_U_INT32(dptr, tid->at_type);
+	if (tid->at_type == AU_IPv6)
+		ADD_MEM(dptr, &tid->at_addr[0], 4 * sizeof(u_int32_t));
+	else
+		ADD_MEM(dptr, &tid->at_addr[0], sizeof(u_int32_t));
+	timems = tm.tv_usec / 1000;
+	/* Add the timestamp */
+	ADD_U_INT32(dptr, tm.tv_sec);
+	ADD_U_INT32(dptr, timems);      /* We need time in ms. */
+	return (t);
+}
+
 /*
  * token ID                1 byte
  * record byte count       4 bytes

sys/security/audit/audit_private.h

@@ -132,6 +132,7 @@ union auditon_udata {
 	au_qctrl_t		au_qctrl;
 	au_stat_t		au_stat;
 	au_fstat_t		au_fstat;
+	auditinfo_addr_t	au_kau_info;
 };
 
 struct posix_ipc_perm {

sys/security/audit/audit_syscalls.c

@@ -395,11 +395,14 @@ auditon(struct thread *td, struct auditon_args *uap)
 		break;
 
 	case A_GETKAUDIT:
-		return (ENOSYS);
+		audit_get_kinfo(&udata.au_kau_info);
 		break;
 
 	case A_SETKAUDIT:
-		return (ENOSYS);
+		if (udata.au_kau_info.ai_termid.at_type != AU_IPv4 &&
+		    udata.au_kau_info.ai_termid.at_type != AU_IPv6)
+			return (EINVAL);
+		audit_set_kinfo(&udata.au_kau_info);
 		break;
 
 	case A_SENDTRIGGER: