Re: cvm-vmailmgr lookup problem (internal temporary error)

Dale Woolridge <[email protected]> Thu, 15 Sep 2005 03:08:24 -0400
Newsgroups gmane.comp.sysutils.bgware
Message-ID <[email protected]> 
On 15-Sep-2005 00:02 Scott Gifford wrote:
| Josh Trutwin <[email protected]> writes:
| >
| > Please, I wouldn't mind looking at this.  
| 
| Here's a patch of what I'm currently using at one of my installations
| vs. stock CVM 0.32; no guarantees about anything.  It creates a new
| CVME_DONTKNOW error code.  If a module returns anything other than
| CVME_DONTKNOW, cvm-chain won't look any further.  It contains a random
| assortment of other, unrelated changes, too.  :)

    Attached is a version for cvm 0.76, with changes isolated to the
    specific features under discussion.  In case it's not obvious,
    cvm-vmailmgr must precede cvm-qmail with this patch.

    Notable differences:
      - renamed DONTKNOW to CHAIN_OK and made it a flag instead of a code
      - check for env var CVM_CHAIN_WEAK and enable the CHAIN_OK/DONTKNOW
        behaviour only when it's set (old behaviour otherwise)

    Special note: patch not tested, heck not even compiled.
--
-dale


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cvm-0.76-sg.dw.chainok.1-freebsd (text/plain, 2.2 KB) 
Index: vmlookup.c
===================================================================
--- vmlookup.c	(revision 406)
+++ vmlookup.c	(working copy)
@@ -73,14 +73,16 @@
   case -1: return CVME_IO;
   case 0:  return CVME_PERMFAIL;
   }
-  if (virtuser.len == 0)
-    return CVME_PERMFAIL;
+  if (virtuser.len == 0) return CVME_PERMFAIL | CVME_CHAIN_OK;
 
   memset(&cdb, 0, sizeof cdb);
   str_lower(&virtuser);
   /* Found a virtual user, authenticate it. */
   if (chdir(vmuser.homedir.s) == -1) return CVME_IO;
-  if ((fd = open(pwfile, O_RDONLY)) == -1) return CVME_IO;
+  if ((fd = open(pwfile, O_RDONLY)) == -1) {
+    if (errno == ENOENT) return CVME_IO | CVME_CHAIN_OK;
+    return CVME_IO;
+  }
   cdb_init(&cdb, fd);
   switch (cdb_get(&cdb, &virtuser, &vpwdata)) {
   case -1:
Index: errors.h
===================================================================
--- errors.h	(revision 406)
+++ errors.h	(working copy)
@@ -14,6 +14,11 @@
    is fatal and should cause module shutdown. */
 #define CVME_FATAL 0x100
 
+/* This is for chaining.  Modules can return errors, but ones
+   that are masked with this flag indicate it's okay to pass
+   along to next chain entry */
+#define	CVME_CHAIN_OK 0x200
+
 #define CVME_MASK  0x0ff
 
 extern const char* const cvm_errlist[];
Index: cvm-chain.c
===================================================================
--- cvm-chain.c	(revision 406)
+++ cvm-chain.c	(working copy)
@@ -12,6 +12,7 @@
 
 const char* chains[10];
 int chain_count;
+int chain_weak = 0;
 
 static void cvm_chain_init()
 {
@@ -33,6 +34,8 @@
   int i;
   char varname[] = "CVM_CHAIN#";
 
+  chain_weak = !!getenv("CVM_CHAIN_WEAK");
+
   chain_count = 0;
   for (i = 0; i <= 9; ++i) {
     varname[9] = i + '0';
@@ -48,6 +51,7 @@
 
 int cvm_module_lookup(void)
 {
+#define CHAIN_BROKEN(c)		(chain_weak?(((c) & CVME_CHAIN_OK) == 0):(((c) & CVME_FATAL) != 0))
   int i;
   int credcount;
   int code;
@@ -61,11 +65,10 @@
     }
   }
 
-  for (code = i = 0; i < chain_count && ((code & CVME_FATAL) == 0); i++) {
+  for (code = i = 0; i < chain_count; i++) {
     cvm_chain_init();
     code = cvm_client_authenticate(chains[i], credcount, creds);
-    if (code == 0)
-      return 0;
+    if (CHAIN_BROKEN(code)) break;
   }
   return code;
 }