rpc.tatd: refactor check to see if call is from loopback address

Refactor common logic to check if SM_FOO request is from loopback
address.

We'll have to do something about this for IPv6.  On IPv6-capable
systems, there will be only one AF_INET6 listener.  The loopback caller
will get either an IPv6 loopback address, or a mapped IPv4 loopback --
either way this will be an AF_INET6 address.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/statd/monitor.c b/utils/statd/monitor.c
index eadc43441fbd1e6a0ebeba00b6f5e6ca77754432..5d4aa49644492c776d0d96310a58d0674fae4c12 100644 (file)
--- a/utils/statd/monitor.c
+++ b/utils/statd/monitor.c
@@ -29,6 +29,36 @@ notify_list *                rtnl = NULL;    /* Run-time notify list. */
 
 #define LINELEN (4*(8+1)+SM_PRIV_SIZE*2+1)
 
+#ifdef RESTRICTED_STATD
+/*
+ * Reject requests from non-loopback addresses in order
+ * to prevent attack described in CERT CA-99.05.
+ */
+static int
+caller_is_localhost(struct svc_req *rqstp)
+{
+       struct in_addr  caller;
+
+       caller = svc_getcaller(rqstp->rq_xprt)->sin_addr;
+       if (caller.s_addr != htonl(INADDR_LOOPBACK)) {
+               note(N_WARNING,
+                       "Call to statd from non-local host %s",
+                       inet_ntoa(caller));
+               return 0;
+       }
+       return 1;
+}
+#else  /* RESTRICTED_STATD */
+/*
+ * No restrictions for remote callers.
+ */
+static int
+caller_is_localhost(struct svc_req *rqstp)
+{
+       return 1;
+}
+#endif /* RESTRICTED_STATD */
+
 /*
  * Services SM_MON requests.
  */
@@ -45,31 +75,19 @@ sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp)
        notify_list     *clnt;
        struct in_addr  my_addr;
        char            *dnsname;
-#ifdef RESTRICTED_STATD
-       struct in_addr  caller;
-#endif
        struct hostent  *hostinfo = NULL;
 
        /* Assume that we'll fail. */
        result.res_stat = STAT_FAIL;
        result.state = -1;      /* State is undefined for STAT_FAIL. */
 
-       /* Restrict access to statd.
-        * In the light of CERT CA-99.05, we tighten access to
-        * statd.                       --okir
-        */
 #ifdef RESTRICTED_STATD
-       /* 1.   Reject anyone not calling from 127.0.0.1.
+       /* 1.   Reject any remote callers.
         *      Ignore the my_name specified by the caller, and
         *      use "127.0.0.1" instead.
         */
-       caller = svc_getcaller(rqstp->rq_xprt)->sin_addr;
-       if (caller.s_addr != htonl(INADDR_LOOPBACK)) {
-               note(N_WARNING,
-                       "Call to statd from non-local host %s",
-                       inet_ntoa(caller));
+       if (!caller_is_localhost(rqstp))
                goto failure;
-       }
        my_addr.s_addr = htonl(INADDR_LOOPBACK);
 
        /* 2.   Reject any registrations for non-lockd services.
@@ -329,25 +347,12 @@ sm_unmon_1_svc(struct mon_id *argp, struct svc_req *rqstp)
                        *my_name  = argp->my_id.my_name;
        struct my_id    *id = &argp->my_id;
        char            *cp;
-#ifdef RESTRICTED_STATD
-       struct in_addr  caller;
-#endif
 
        result.state = MY_STATE;
 
-#ifdef RESTRICTED_STATD
-       /* 1.   Reject anyone not calling from 127.0.0.1.
-        *      Ignore the my_name specified by the caller, and
-        *      use "127.0.0.1" instead.
-        */
-       caller = svc_getcaller(rqstp->rq_xprt)->sin_addr;
-       if (caller.s_addr != htonl(INADDR_LOOPBACK)) {
-               note(N_WARNING,
-                       "Call to statd from non-local host %s",
-                       inet_ntoa(caller));
+       if (!caller_is_localhost(rqstp))
                goto failure;
-       }
-#endif
+
        /* my_name must not have white space */
        for (cp=my_name ; *cp ; cp++)
                if (*cp == ' ' || *cp == '\t' || *cp == '\r' || *cp == '\n')
@@ -388,9 +393,7 @@ sm_unmon_1_svc(struct mon_id *argp, struct svc_req *rqstp)
                        clnt = NL_NEXT(clnt);
        }
 
-#ifdef RESTRICTED_STATD
  failure:
-#endif
        note(N_WARNING, "Received erroneous SM_UNMON request from %s for %s",
                my_name, mon_name);
        return (&result);
@@ -404,21 +407,9 @@ sm_unmon_all_1_svc(struct my_id *argp, struct svc_req *rqstp)
        static sm_stat  result;
        notify_list     *clnt;
        char            *my_name = argp->my_name;
-#ifdef RESTRICTED_STATD
-       struct in_addr  caller;
 
-       /* 1.   Reject anyone not calling from 127.0.0.1.
-        *      Ignore the my_name specified by the caller, and
-        *      use "127.0.0.1" instead.
-        */
-       caller = svc_getcaller(rqstp->rq_xprt)->sin_addr;
-       if (caller.s_addr != htonl(INADDR_LOOPBACK)) {
-               note(N_WARNING,
-                       "Call to statd from non-local host %s",
-                       inet_ntoa(caller));
+       if (!caller_is_localhost(rqstp))
                goto failure;
-       }
-#endif
 
        result.state = MY_STATE;
 
@@ -457,8 +448,7 @@ sm_unmon_all_1_svc(struct my_id *argp, struct svc_req *rqstp)
                dprintf(N_DEBUG, "SM_UNMON_ALL request from %s with no "
                        "SM_MON requests from it.", my_name);
        }
-#ifdef RESTRICTED_STATD
+
  failure:
-#endif
        return (&result);
 }