2000-08-02 H.J. Lu <hjl@lucon.org>

[nfs-utils.git] / utils / mountd / auth.c

diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c
index 9f63120b8b58b5677bcfd99060ed6081a9377222..49567c93158b384a592ebed479a689c733dea593 100644 (file)
--- a/utils/mountd/auth.c
+++ b/utils/mountd/auth.c
@@ -16,6 +16,7 @@
 #include "nfslib.h"
 #include "exportfs.h"
 #include "mountd.h"
+#include "xmalloc.h"
 
 enum auth_error
 {
@@ -25,6 +26,7 @@ enum auth_error
   not_exported,
   illegal_port,
   faked_hostent,
+  no_forward_dns,
   success
 };
 
@@ -76,35 +78,58 @@ auth_authenticate_internal(char *what, struct sockaddr_in *caller,
        }
        auth_fixpath(path);
 
-       if (!(*hpp = gethostbyaddr((const char *)&addr, sizeof(addr), AF_INET)))
-               *hpp = get_hostent((const char *)&addr, sizeof(addr),
-                                  AF_INET);
-       else {
+       /* First try it w/o doing a hostname lookup... */
+       *hpp = get_hostent((const char *)&addr, sizeof(addr), AF_INET);
+       exp = export_find(*hpp, path);
+
+       if (!exp) {
+           /* Ok, that didn't fly.  Try it with a reverse lookup. */
+           free (*hpp);
+           *hpp = gethostbyaddr((const char *)&addr, sizeof(addr),
+                                AF_INET);
+           if (!(*hpp)) {
+               *error = no_entry;
+               return NULL;
+           } else {
                /* must make sure the hostent is authorative. */
-               char *name = strdup((*hpp)->h_name);
                char **sp;
-               *hpp = gethostbyname(name);
-               /* now make sure the "addr" is in the list */
-               for (sp = (*hpp)->h_addr_list ; *sp ; sp++) {
-                       if (memcmp(*sp, &addr, (*hpp)->h_length)==0)
-                               break;
+               struct hostent *forward = NULL;
+               char *tmpname;
+
+               tmpname = xstrdup((*hpp)->h_name);
+               if (tmpname) {
+                       forward = gethostbyname(tmpname);
+                       free(tmpname);
                }
+               if (forward) {
+                       /* now make sure the "addr" is in the list */
+                       for (sp = forward->h_addr_list ; *sp ; sp++) {
+                               if (memcmp(*sp, &addr, forward->h_length)==0)
+                                       break;
+                       }
                
-               if (!*sp) {
-                       free(name);
-                       /* it was a FAKE */
-                       *error = faked_hostent;
-                       *hpp = NULL;
+                       if (!*sp) {
+                               /* it was a FAKE */
+                               *error = faked_hostent;
+                               *hpp = hostent_dup (*hpp);
+                               return NULL;
+                       }
+                       *hpp = hostent_dup (forward);
+               }
+               else {
+                       /* never heard of it. misconfigured DNS? */
+                       *error = no_forward_dns;
+                       *hpp = hostent_dup (*hpp);
                        return NULL;
                }
-               *hpp = hostent_dup (*hpp);
-               free(name);
-       }
+           }
 
-       if (!(exp = export_find(*hpp, path))) {
+           if (!(exp = export_find(*hpp, path))) {
                *error = no_entry;
                return NULL;
+           }
        }
+
        if (!exp->m_mayexport) {
                *error = not_exported;
                return NULL;
@@ -181,8 +206,13 @@ auth_authenticate(char *what, struct sockaddr_in *caller, char *path)
                break;
 
        case faked_hostent:
-               xlog(L_WARNING, "refused %s request from %s for %s (%s): faked hostent",
-                    what, inet_ntoa(addr), path, epath);
+               xlog(L_WARNING, "refused %s request from %s (%s) for %s (%s): DNS forward lookup does't match with reverse",
+                    what, inet_ntoa(addr), hp->h_name, path, epath);
+               break;
+
+       case no_forward_dns:
+               xlog(L_WARNING, "refused %s request from %s (%s) for %s (%s): no DNS forward lookup",
+                    what, inet_ntoa(addr), hp->h_name, path, epath);
                break;
 
        case success: