statd - use dnsname to ensure correct matching of NOTIFY requests.

When lockd asks to monitor a host, we find the FQDN from the DNS
and remember that, both internally and in the /var/lib/nfs/sm/*
file.
When we receive an SM_NOTIFY request, we compare both the
mon_name and the source IP address against that DNS name to find
a match.

If a DNS name is not available, we fall back to the name provided by
lockd, which at least is known to map to an IP address via
gethostbyname.

Signed-off-by: Neil Brown <neilb@suse.de>

diff --git a/utils/statd/callback.c b/utils/statd/callback.c
index bb8bf523be139199e06b17e765c2825b8ddb409e..b19bb901d8ee2305d38b7c30e0a00ac5fdb8ebbb 100644 (file)
--- a/utils/statd/callback.c
+++ b/utils/statd/callback.c
@@ -27,6 +27,8 @@ sm_notify_1_svc(struct stat_chge *argp, struct svc_req *rqstp)
 {
        notify_list    *lp, *call;
        static char    *result = NULL;
+       char *ip_addr = xstrdup(inet_ntoa(svc_getcaller(rqstp->rq_xprt)
+                                         ->sin_addr));
 
        dprintf(N_DEBUG, "Received SM_NOTIFY from %s, state: %d",
                                argp->mon_name, argp->state);
@@ -45,14 +47,15 @@ sm_notify_1_svc(struct stat_chge *argp, struct svc_req *rqstp)
         * it. Lockd will want to continue monitoring the remote host
         * until it issues an SM_UNMON call.
         */
-       while ((lp = nlist_gethost(lp, argp->mon_name, 0)) != NULL) {
-               if (NL_STATE(lp) != argp->state) {
+       for (lp = rtnl ; lp ; lp = lp->next)
+               if (NL_STATE(lp) != argp->state &&
+                   (matchhostname(argp->mon_name, lp->dns_name) ||
+                    matchhostname(ip_addr, lp->dns_name))) {
                        NL_STATE(lp) = argp->state;
                        call = nlist_clone(lp);
                        nlist_insert(&notify, call);
                }
-               lp = NL_NEXT(lp);
-       }
+
 
        return ((void *) &result);
 }

diff --git a/utils/statd/monitor.c b/utils/statd/monitor.c
index b0b19da0c0d18202e8e424604a86f1fdda7d6ff9..b95b0ad51692e7b6708a2a94d289ad7484ccbbd1 100644 (file)
--- a/utils/statd/monitor.c
+++ b/utils/statd/monitor.c
@@ -43,11 +43,11 @@ sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp)
        int             fd;
        notify_list     *clnt;
        struct in_addr  my_addr;
+       char            *dnsname;
 #ifdef RESTRICTED_STATD
        struct in_addr  caller;
-#else
-       struct hostent  *hostinfo = NULL;
 #endif
+       struct hostent  *hostinfo = NULL;
 
        /* Assume that we'll fail. */
        result.res_stat = STAT_FAIL;
@@ -104,6 +104,12 @@ sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp)
                goto failure;
        }
 #endif
+#else
+       if (!(hostinfo = gethostbyname(my_name))) {
+               note(N_WARNING, "gethostbyname error for %s", my_name);
+               goto failure;
+       } else
+               my_addr = *(struct in_addr *) hostinfo->h_addr;
 #endif
        /*
         * Check hostnames.  If I can't look them up, I won't monitor.  This
@@ -116,21 +122,27 @@ sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp)
                     "or starting '.': %s", mon_name);
                note(N_CRIT, "POSSIBLE SPOOF/ATTACK ATTEMPT!");
                goto failure;
-       } else if (gethostbyname(mon_name) == NULL) {
+       } else if ((hostinfo = gethostbyname(mon_name)) == NULL) {
                note(N_WARNING, "gethostbyname error for %s", mon_name);
                goto failure;
        }
-#ifndef RESTRICTED_STATD
-       if (!(hostinfo = gethostbyname(my_name))) {
-               note(N_WARNING, "gethostbyname error for %s", my_name);
-               goto failure;
-       } else
-               my_addr = *(struct in_addr *) hostinfo->h_addr;
-#endif
 
        /*
         * Hostnames checked OK.
-        * Now check to see if this is a duplicate, and warn if so.
+        * Now choose a hostname to use for matching.  We cannot
+        * really trust much in the incoming NOTIFY, so to make
+        * sure that multi-homed hosts work nicely, we get an
+        * FQDN now, and use that for matching
+        */
+       hostinfo = gethostbyaddr(hostinfo->h_addr,
+                                hostinfo->h_length,
+                                hostinfo->h_addrtype);
+       if (hostinfo)
+               dnsname = xstrdup(hostinfo->h_name);
+       else
+               dnsname = xstrdup(my_name);
+
+       /* Now check to see if this is a duplicate, and warn if so.
         * I will also return STAT_FAIL. (I *think* this is how I should
         * handle it.)
         *
@@ -175,13 +187,14 @@ sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp)
        NL_MY_VERS(clnt) = id->my_vers;
        NL_MY_PROC(clnt) = id->my_proc;
        memcpy(NL_PRIV(clnt), argp->priv, SM_PRIV_SIZE);
+       clnt->dns_name = dnsname;
 
        /*
         * Now, Create file on stable storage for host.
         */
 
-       path=xmalloc(strlen(SM_DIR)+strlen(mon_name)+2);
-       sprintf(path, "%s/%s", SM_DIR, mon_name);
+       path=xmalloc(strlen(SM_DIR)+strlen(dnsname)+2);
+       sprintf(path, "%s/%s", SM_DIR, dnsname);
        if ((fd = open(path, O_WRONLY|O_SYNC|O_CREAT|O_APPEND,
                       S_IRUSR|S_IWUSR)) < 0) {
                /* Didn't fly.  We won't monitor. */
@@ -268,6 +281,7 @@ void load_state(void)
                        NL_MY_PROG(clnt) = prog;
                        NL_MY_VERS(clnt) = vers;
                        NL_MY_PROC(clnt) = proc;
+                       clnt->dns_name = xstrdup(de->d_name);
                        memcpy(NL_PRIV(clnt), priv, SM_PRIV_SIZE);
                        nlist_insert(&rtnl, clnt);
                }

diff --git a/utils/statd/notlist.h b/utils/statd/notlist.h
index 12962af5ec00c18c16bbfd032efdc6192b578b8e..664c9d881bc84021b123ed75f3ed8463f08627ea 100644 (file)
--- a/utils/statd/notlist.h
+++ b/utils/statd/notlist.h
@@ -16,6 +16,8 @@ struct notify_list {
   unsigned short       port;   /* port number for callback */
   short int            times;  /* Counter used for various things. */
   int                  state;  /* For storing notified state for callbacks. */
+  char                 *dns_name; /* used for matching incoming
+                                   * NOTIFY requests */
   struct notify_list   *next;  /* Linked list forward pointer. */
   struct notify_list   *prev;  /* Linked list backward pointer. */
   u_int32_t            xid;    /* XID of MS_NOTIFY RPC call */