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 could 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. I envision that this error would primarily be generated by a kernel upcall for the kernel to then pass back to the original userspace caller. The kernel itself might not actually pay any attention to it, except as a hint as to whether to retry. Signed-off-by: David Howells <[email protected]> Acked-by: Jeff Layton <[email protected]> Acked-by: Steven Whitehouse <[email protected]> Acked-by: Steve Dickson <[email protected]> Liked-by: Simo Sorce <[email protected]> --- arch/alpha/include/asm/errno.h | 2 ++ 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, 6 insertions(+), 0 deletions(-) diff --git a/arch/alpha/include/asm/errno.h b/arch/alpha/include/asm/errno.h index e5f29ca..dce5fc9 100644 --- a/arch/alpha/include/asm/errno.h +++ b/arch/alpha/include/asm/errno.h @@ -124,4 +124,6 @@ #define EHWPOISON 139 /* Memory page has hardware error */ +#define ENOAUTHSERVICE 140 /* Authentication service not available */ + #endif diff --git a/arch/mips/include/asm/errno.h b/arch/mips/include/asm/errno.h index 6dcd358..67c46bd 100644 --- a/arch/mips/include/asm/errno.h +++ b/arch/mips/include/asm/errno.h @@ -122,6 +122,7 @@ #define ERFKILL 167 /* Operation not possible due to RF-kill */ #define EHWPOISON 168 /* Memory page has hardware error */ +#define ENOAUTHSERVICE 169 /* 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 135ad60..3a6ffcd 100644 --- a/arch/parisc/include/asm/errno.h +++ b/arch/parisc/include/asm/errno.h @@ -123,5 +123,6 @@ #define ERFKILL 256 /* Operation not possible due to RF-kill */ #define EHWPOISON 257 /* Memory page has hardware error */ +#define ENOAUTHSERVICE 258 /* Authentication service not available */ #endif diff --git a/arch/sparc/include/asm/errno.h b/arch/sparc/include/asm/errno.h index c351aba..94a878f 100644 --- a/arch/sparc/include/asm/errno.h +++ b/arch/sparc/include/asm/errno.h @@ -113,5 +113,6 @@ #define ERFKILL 134 /* Operation not possible due to RF-kill */ #define EHWPOISON 135 /* Memory page has hardware error */ +#define ENOAUTHSERVICE 136 /* Authentication service not available */ #endif diff --git a/include/asm-generic/errno.h b/include/asm-generic/errno.h index a1331ce..5e2b296 100644 --- a/include/asm-generic/errno.h +++ b/include/asm-generic/errno.h @@ -109,5 +109,6 @@ #define ERFKILL 132 /* Operation not possible due to RF-kill */ #define EHWPOISON 133 /* Memory page has hardware error */ +#define ENOAUTHSERVICE 134 /* Authentication service not available */ #endif -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
