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. I envision that these errors 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 them, except as hints as to whether to retry. I have combined the NXDOMAIN and NODATA resolver errors into ENAMEUNKNOWN. I'm not sure whether it's worth separating them out. I don't see the kernel really needing to know the difference - if any optimised handling of NODATA is to be done (say falling back from one DNS record type to another), I would expect that to be done in the upcall rather than in the kernel. However, it may be worth it from the point of view of reporting to the user. 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]> --- 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 dce5fc9..a4fc77e 100644 --- a/arch/alpha/include/asm/errno.h +++ b/arch/alpha/include/asm/errno.h @@ -125,5 +125,7 @@ #define EHWPOISON 139 /* Memory page has hardware error */ #define ENOAUTHSERVICE 140 /* Authentication service not available */ +#define ENONAMESERVICE 141 /* Network name service unavailable */ +#define ENAMEUNKNOWN 142 /* Network name unknown */ #endif diff --git a/arch/mips/include/asm/errno.h b/arch/mips/include/asm/errno.h index 67c46bd..ac95669 100644 --- a/arch/mips/include/asm/errno.h +++ b/arch/mips/include/asm/errno.h @@ -123,6 +123,8 @@ #define EHWPOISON 168 /* Memory page has hardware error */ #define ENOAUTHSERVICE 169 /* Authentication service not available */ +#define ENONAMESERVICE 170 /* Network name service unavailable */ +#define ENAMEUNKNOWN 171 /* 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 3a6ffcd..753cc5c 100644 --- a/arch/parisc/include/asm/errno.h +++ b/arch/parisc/include/asm/errno.h @@ -124,5 +124,7 @@ #define EHWPOISON 257 /* Memory page has hardware error */ #define ENOAUTHSERVICE 258 /* Authentication service not available */ +#define ENONAMESERVICE 259 /* Network name service unavailable */ +#define ENAMEUNKNOWN 260 /* Network name unknown */ #endif diff --git a/arch/sparc/include/asm/errno.h b/arch/sparc/include/asm/errno.h index 94a878f..01c9769 100644 --- a/arch/sparc/include/asm/errno.h +++ b/arch/sparc/include/asm/errno.h @@ -114,5 +114,7 @@ #define EHWPOISON 135 /* Memory page has hardware error */ #define ENOAUTHSERVICE 136 /* Authentication service not available */ +#define ENONAMESERVICE 137 /* Network name service unavailable */ +#define ENAMEUNKNOWN 138 /* Network name unknown */ #endif diff --git a/include/asm-generic/errno.h b/include/asm-generic/errno.h index 5e2b296..5d012c1 100644 --- a/include/asm-generic/errno.h +++ b/include/asm-generic/errno.h @@ -110,5 +110,7 @@ #define EHWPOISON 133 /* Memory page has hardware error */ #define ENOAUTHSERVICE 134 /* Authentication service not available */ +#define ENONAMESERVICE 135 /* Network name service unavailable */ +#define ENAMEUNKNOWN 136 /* Network name unknown */ #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
