As the kernel has or will have filesystems (and possibly other services) that
want to obtain authentication tokens and/or encryption data on demand (via
GSSAPI for example), it would seem useful to provide an additional error code
to indicate a problem with the lookup, rather than overloading some other error
code.

We already have EKEYREJECTED, EKEYREVOKED and EKEYEXPIRED to indicate problems
with a token that we already have, but what if the authentication server just
isn't available?

Define ENOAUTHSERVICE to indicate "Authentication service unavailable".  This
can be used to indicate, for example, that an attempt was made by request_key()
to retrieve a key, but the authentication server (e.g. a KDC) it is supposed to
contact didn't answer or that it couldn't determine the location of a suitable
server.

One way this can be used is that the user of a network filesystem can get a TGT
from the KDC and stash it in their session keyring, then the filesystem can
attempt to automatically get a ticket for accessing the filesystem - but if the
server is uncontactable then the ticket can be negatively instantiated with
KEYCTL_REJECT, giving the error to be handed to future requests as
ENOAUTHSERVICE and a small timeout so that the key will expire from the cache
and allow a retry after a short while to prevent thrashing.

Signed-off-by: David Howells <[email protected]>
---

 arch/alpha/include/asm/errno.h  |    1 +
 arch/mips/include/asm/errno.h   |    1 +
 arch/parisc/include/asm/errno.h |    1 +
 arch/sparc/include/asm/errno.h  |    1 +
 include/asm-generic/errno.h     |    1 +
 5 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/alpha/include/asm/errno.h b/arch/alpha/include/asm/errno.h
index 98099bd..519663c 100644
--- a/arch/alpha/include/asm/errno.h
+++ b/arch/alpha/include/asm/errno.h
@@ -121,5 +121,6 @@
 #define        ENOTRECOVERABLE 137     /* State not recoverable */
 
 #define        ERFKILL         138     /* Operation not possible due to 
RF-kill */
+#define        ENOAUTHSERVICE  139     /* Authentication service not available 
*/
 
 #endif
diff --git a/arch/mips/include/asm/errno.h b/arch/mips/include/asm/errno.h
index a0efc73..5fa7fed 100644
--- a/arch/mips/include/asm/errno.h
+++ b/arch/mips/include/asm/errno.h
@@ -120,6 +120,7 @@
 #define        ENOTRECOVERABLE 166     /* State not recoverable */
 
 #define        ERFKILL         167     /* Operation not possible due to 
RF-kill */
+#define        ENOAUTHSERVICE  168     /* Authentication service not available 
*/
 
 #define EDQUOT         1133    /* Quota exceeded */
 
diff --git a/arch/parisc/include/asm/errno.h b/arch/parisc/include/asm/errno.h
index 9992abd..6a19346 100644
--- a/arch/parisc/include/asm/errno.h
+++ b/arch/parisc/include/asm/errno.h
@@ -121,5 +121,6 @@
 #define ENOTRECOVERABLE        255     /* State not recoverable */
 
 #define        ERFKILL         256     /* Operation not possible due to 
RF-kill */
+#define        ENOAUTHSERVICE  257     /* Authentication service not available 
*/
 
 #endif
diff --git a/arch/sparc/include/asm/errno.h b/arch/sparc/include/asm/errno.h
index 4e2bc49..ab3a26a 100644
--- a/arch/sparc/include/asm/errno.h
+++ b/arch/sparc/include/asm/errno.h
@@ -111,5 +111,6 @@
 #define        ENOTRECOVERABLE 133     /* State not recoverable */
 
 #define        ERFKILL         134     /* Operation not possible due to 
RF-kill */
+#define        ENOAUTHSERVICE  135     /* Authentication service not available 
*/
 
 #endif
diff --git a/include/asm-generic/errno.h b/include/asm-generic/errno.h
index 28cc03b..bcf1908 100644
--- a/include/asm-generic/errno.h
+++ b/include/asm-generic/errno.h
@@ -107,5 +107,6 @@
 #define        ENOTRECOVERABLE 131     /* State not recoverable */
 
 #define ERFKILL                132     /* Operation not possible due to 
RF-kill */
+#define        ENOAUTHSERVICE  133     /* Authentication service not available 
*/
 
 #endif

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