Quelle  error.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Error string handling
 *
 * Plan 9 uses error strings, Unix uses error numbers.  These functions
 * try to help manage that and provide for dynamically adding error
 * mappings.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/errno.h>
#include <linux/hashtable.h>
#include <net/9p/9p.h>

/**
 * struct errormap - map string errors from Plan 9 to Linux numeric ids
 * @name: string sent over 9P
 * @val: numeric id most closely representing @name
 * @namelen: length of string
 * @list: hash-table list for string lookup
 */
struct errormap {
 char *name;
 int val;

 int namelen;
 struct hlist_node list;
};

#define ERRHASH_BITS 5
static DEFINE_HASHTABLE(hash_errmap, ERRHASH_BITS);

/* FixMe - reduce to a reasonable size */
static struct errormap errmap[] = {
 {"Operation not permitted", EPERM},
 {"wstat prohibited", EPERM},
 {"No such file or directory", ENOENT},
 {"directory entry not found", ENOENT},
 {"file not found", ENOENT},
 {"Interrupted system call", EINTR},
 {"Input/output error", EIO},
 {"No such device or address", ENXIO},
 {"Argument list too long", E2BIG},
 {"Bad file descriptor", EBADF},
 {"Resource temporarily unavailable", EAGAIN},
 {"Cannot allocate memory", ENOMEM},
 {"Permission denied", EACCES},
 {"Bad address", EFAULT},
 {"Block device required", ENOTBLK},
 {"Device or resource busy", EBUSY},
 {"File exists", EEXIST},
 {"Invalid cross-device link", EXDEV},
 {"No such device", ENODEV},
 {"Not a directory", ENOTDIR},
 {"Is a directory", EISDIR},
 {"Invalid argument", EINVAL},
 {"Too many open files in system", ENFILE},
 {"Too many open files", EMFILE},
 {"Text file busy", ETXTBSY},
 {"File too large", EFBIG},
 {"No space left on device", ENOSPC},
 {"Illegal seek", ESPIPE},
 {"Read-only file system", EROFS},
 {"Too many links", EMLINK},
 {"Broken pipe", EPIPE},
 {"Numerical argument out of domain", EDOM},
 {"Numerical result out of range", ERANGE},
 {"Resource deadlock avoided", EDEADLK},
 {"File name too long", ENAMETOOLONG},
 {"No locks available", ENOLCK},
 {"Function not implemented", ENOSYS},
 {"Directory not empty", ENOTEMPTY},
 {"Too many levels of symbolic links", ELOOP},
 {"No message of desired type", ENOMSG},
 {"Identifier removed", EIDRM},
 {"No data available", ENODATA},
 {"Machine is not on the network", ENONET},
 {"Package not installed", ENOPKG},
 {"Object is remote", EREMOTE},
 {"Link has been severed", ENOLINK},
 {"Communication error on send", ECOMM},
 {"Protocol error", EPROTO},
 {"Bad message", EBADMSG},
 {"File descriptor in bad state", EBADFD},
 {"Streams pipe error", ESTRPIPE},
 {"Too many users", EUSERS},
 {"Socket operation on non-socket", ENOTSOCK},
 {"Message too long", EMSGSIZE},
 {"Protocol not available", ENOPROTOOPT},
 {"Protocol not supported", EPROTONOSUPPORT},
 {"Socket type not supported", ESOCKTNOSUPPORT},
 {"Operation not supported", EOPNOTSUPP},
 {"Protocol family not supported", EPFNOSUPPORT},
 {"Network is down", ENETDOWN},
 {"Network is unreachable", ENETUNREACH},
 {"Network dropped connection on reset", ENETRESET},
 {"Software caused connection abort", ECONNABORTED},
 {"Connection reset by peer", ECONNRESET},
 {"No buffer space available", ENOBUFS},
 {"Transport endpoint is already connected", EISCONN},
 {"Transport endpoint is not connected", ENOTCONN},
 {"Cannot send after transport endpoint shutdown", ESHUTDOWN},
 {"Connection timed out", ETIMEDOUT},
 {"Connection refused", ECONNREFUSED},
 {"Host is down", EHOSTDOWN},
 {"No route to host", EHOSTUNREACH},
 {"Operation already in progress", EALREADY},
 {"Operation now in progress", EINPROGRESS},
 {"Is a named type file", EISNAM},
 {"Remote I/O error", EREMOTEIO},
 {"Disk quota exceeded", EDQUOT},
/* errors from fossil, vacfs, and u9fs */
 {"fid unknown or out of range", EBADF},
 {"permission denied", EACCES},
 {"file does not exist", ENOENT},
 {"authentication failed", ECONNREFUSED},
 {"bad offset in directory read", ESPIPE},
 {"bad use of fid", EBADF},
 {"wstat can't convert between files and directories", EPERM},
 {"directory is not empty", ENOTEMPTY},
 {"file exists", EEXIST},
 {"file already exists", EEXIST},
 {"file or directory already exists", EEXIST},
 {"fid already in use", EBADF},
 {"file in use", ETXTBSY},
 {"i/o error", EIO},
 {"file already open for I/O", ETXTBSY},
 {"illegal mode", EINVAL},
 {"illegal name", ENAMETOOLONG},
 {"not a directory", ENOTDIR},
 {"not a member of proposed group", EPERM},
 {"not owner", EACCES},
 {"only owner can change group in wstat", EACCES},
 {"read only file system", EROFS},
 {"no access to special file", EPERM},
 {"i/o count too large", EIO},
 {"unknown group", EINVAL},
 {"unknown user", EINVAL},
 {"bogus wstat buffer", EPROTO},
 {"exclusive use file already open", EAGAIN},
 {"corrupted directory entry", EIO},
 {"corrupted file entry", EIO},
 {"corrupted block label", EIO},
 {"corrupted meta data", EIO},
 {"illegal offset", EINVAL},
 {"illegal path element", ENOENT},
 {"root of file system is corrupted", EIO},
 {"corrupted super block", EIO},
 {"protocol botch", EPROTO},
 {"file system is full", ENOSPC},
 {"file is in use", EAGAIN},
 {"directory entry is not allocated", ENOENT},
 {"file is read only", EROFS},
 {"file has been removed", EIDRM},
 {"only support truncation to zero length", EPERM},
 {"cannot remove root", EPERM},
 {"file too big", EFBIG},
 {"venti i/o error", EIO},
 /* these are not errors */
 {"u9fs rhostsauth: no authentication required", 0},
 {"u9fs authnone: no authentication required", 0},
 {NULL, -1}
};

/**
 * p9_error_init - preload mappings into hash list
 *
 */

int p9_error_init(void)
{
 struct errormap *c;
 u32 hash;

 /* load initial error map into hash table */
 for (c = errmap; c->name; c++) {
  c->namelen = strlen(c->name);
  hash = jhash(c->name, c->namelen, 0);
  INIT_HLIST_NODE(&c->list);
  hash_add(hash_errmap, &c->list, hash);
 }

 return 1;
}
EXPORT_SYMBOL(p9_error_init);

/**
 * p9_errstr2errno - convert error string to error number
 * @errstr: error string
 * @len: length of error string
 *
 */

int p9_errstr2errno(char *errstr, int len)
{
 int errno;
 struct errormap *c;
 u32 hash;

 errno = 0;
 c = NULL;
 hash = jhash(errstr, len, 0);
 hash_for_each_possible(hash_errmap, c, list, hash) {
  if (c->namelen == len && !memcmp(c->name, errstr, len)) {
   errno = c->val;
   break;
  }
 }

 if (errno == 0) {
  /* TODO: if error isn't found, add it dynamically */
  errstr[len] = 0;
  pr_err("%s: server reported unknown error %s\n",
         __func__, errstr);
  errno = ESERVERFAULT;
 }

 return -errno;
}
EXPORT_SYMBOL(p9_errstr2errno);