[PATCH 1/2] Define ENOAUTHSERVICE to indicate "Authentication service unavailable"

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 <redacted>
---

 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

Now that the kernel has filesystems (and possibly other services) that want to
look up internet addresses corresponding to arbitrary hostnames retrieved from
the server, it would seem useful to provide a couple of error codes to indicate
problems with the look up, rather than overloading some other error code.

Define ENONAMESERVICE to indicate "Network name service unavailable".  This can
be used to indicate, for example, that an attempt was made by dns_query() to
make a query, but the name server (e.g. a DNS server) it is supposed to contact
didn't answer or that it couldn't determine the location of a suitable server.

Define ENAMEUNKNOWN to indicate "Network name unknown".  This can be used to
indicate, for example, that an attempt was made by dns_query() to make a query,
but the name server (e.g. a DNS server) replied indicating that it had no
matching records.

The DNS query upcall program can report these to keyctl_reject() so that cached
failed queries will respond with these errors until they expire.

Signed-off-by: David Howells <redacted>
---

 arch/alpha/include/asm/errno.h  |    2 ++
 arch/mips/include/asm/errno.h   |    2 ++
 arch/parisc/include/asm/errno.h |    2 ++
 arch/sparc/include/asm/errno.h  |    2 ++
 include/asm-generic/errno.h     |    2 ++
 5 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/alpha/include/asm/errno.h b/arch/alpha/include/asm/errno.h
index 519663c..ee8a3f0 100644
--- a/arch/alpha/include/asm/errno.h
+++ b/arch/alpha/include/asm/errno.h

@@ -122,5 +122,7 @@
 
 #define	ERFKILL		138	/* Operation not possible due to RF-kill */
 #define	ENOAUTHSERVICE	139	/* Authentication service not available */
+#define	ENONAMESERVICE	140	/* Network name service unavailable */
+#define	ENAMEUNKNOWN	141	/* Network name unknown */
 
 #endif

diff --git a/arch/mips/include/asm/errno.h b/arch/mips/include/asm/errno.h
index 5fa7fed..faed965 100644
--- a/arch/mips/include/asm/errno.h
+++ b/arch/mips/include/asm/errno.h

@@ -121,6 +121,8 @@
 
 #define	ERFKILL		167	/* Operation not possible due to RF-kill */
 #define	ENOAUTHSERVICE	168	/* Authentication service not available */
+#define	ENONAMESERVICE	169	/* Network name service unavailable */
+#define	ENAMEUNKNOWN	170	/* Network name unknown */
 
 #define EDQUOT		1133	/* Quota exceeded */
 

diff --git a/arch/parisc/include/asm/errno.h b/arch/parisc/include/asm/errno.h
index 6a19346..63ee0bc 100644
--- a/arch/parisc/include/asm/errno.h
+++ b/arch/parisc/include/asm/errno.h

@@ -122,5 +122,7 @@
 
 #define	ERFKILL		256	/* Operation not possible due to RF-kill */
 #define	ENOAUTHSERVICE	257	/* Authentication service not available */
+#define	ENONAMESERVICE	258	/* Network name service unavailable */
+#define	ENAMEUNKNOWN	259	/* Network name unknown */
 
 #endif

diff --git a/arch/sparc/include/asm/errno.h b/arch/sparc/include/asm/errno.h
index ab3a26a..f40d5ae 100644
--- a/arch/sparc/include/asm/errno.h
+++ b/arch/sparc/include/asm/errno.h

@@ -112,5 +112,7 @@
 
 #define	ERFKILL		134	/* Operation not possible due to RF-kill */
 #define	ENOAUTHSERVICE	135	/* Authentication service not available */
+#define	ENONAMESERVICE	136	/* Network name service unavailable */
+#define	ENAMEUNKNOWN	137	/* Network name unknown */
 
 #endif

diff --git a/include/asm-generic/errno.h b/include/asm-generic/errno.h
index bcf1908..25878f1 100644
--- a/include/asm-generic/errno.h
+++ b/include/asm-generic/errno.h

@@ -108,5 +108,7 @@
 
 #define ERFKILL		132	/* Operation not possible due to RF-kill */
 #define	ENOAUTHSERVICE	133	/* Authentication service not available */
+#define	ENONAMESERVICE	134	/* Network name service unavailable */
+#define	ENAMEUNKNOWN	135	/* Network name unknown */
 
 #endif

Define ENONAMESERVICE to indicate "Network name service unavailable".  This can
be used to indicate, for example, that an attempt was made by dns_query() to
make a query, but the name server (e.g. a DNS server) it is supposed to contact
didn't answer or that it couldn't determine the location of a suitable server.

Are these in glibc and are there glibc patches submitted and accepted for
this ?

(I only ask because I know its previously taken years for glibc to catch
up with stuff)