src/hci/strerror.c

   1 #include <errno.h>
   2 #include <string.h>
   3 #include <stdio.h>
   4 #include <gpxe/errortab.h>
   5
   6 /** @file
   7  *
   8  * Error descriptions.
   9  *
  10  * The error numbers used by Etherboot are a superset of those defined
  11  * by the PXE specification version 2.1.  See errno.h for a listing of
  12  * the error values.
  13  *
  14  * To save space in ROM images, error string tables are optional.  Use
  15  * the ERRORMSG_XXX options in config.h to select which error string
  16  * tables you want to include.  If an error string table is omitted,
  17  * strerror() will simply return the text "Error 0x<errno>".
  18  *
  19  */
  20
  21 static struct errortab errortab_start[0]
  22         __table_start ( struct errortab, errortab );
  23 static struct errortab errortab_end[0]
  24         __table_end ( struct errortab, errortab );
  25
  26 /**
  27  * Find error description
  28  *
  29  * @v errno             Error number
  30  * @v mask              Mask of bits that we care about
  31  * @ret errortab        Error description, or NULL
  32  */
  33 static struct errortab * find_error ( int errno, int mask ) {
  34         struct errortab *errortab;
  35
  36         for ( errortab = errortab_start ; errortab < errortab_end ;
  37               errortab++ ) {
  38                 if ( ( ( errortab->errno ^ errno ) & mask ) == 0 )
  39                         return errortab;
  40         }
  41
  42         return NULL;
  43 }
  44
  45 /**
  46  * Find closest error description
  47  *
  48  * @v errno             Error number
  49  * @ret errortab        Error description, or NULL
  50  *
  51  *
  52  */
  53 static struct errortab * find_closest_error ( int errno ) {
  54         struct errortab *errortab;
  55
  56         /* First, look for an exact match */
  57         if ( ( errortab = find_error ( errno, 0x7fffffff ) ) != NULL )
  58                 return errortab;
  59
  60         /* Second, try masking off the gPXE-specific bit and seeing if
  61          * we have an entry for the generic POSIX error message.
  62          */
  63         if ( ( errortab = find_error ( errno, 0x0000ffff ) ) != NULL )
  64                 return errortab;
  65
  66         /* Lastly, try masking off the POSIX bits and seeing if we
  67          * have a match just based on the PXENV component.  This
  68          * allows us to report errors from underlying PXE stacks.
  69          */
  70         if ( ( errortab = find_error ( ( errno & 0x000000ff ),
  71                                        0xffff00ff ) ) != NULL )
  72                 return errortab;
  73
  74         return NULL;
  75 }
  76
  77 /**
  78  * Retrieve string representation of error number.
  79  *
  80  * @v errno/rc          Error number or return status code
  81  * @ret strerror        Pointer to error text
  82  *
  83  * If the error is not found in the linked-in error tables, generates
  84  * a generic "Error 0x<errno>" message.
  85  *
  86  * The pointer returned by strerror() is valid only until the next
  87  * call to strerror().
  88  *
  89  */
  90 const char * strerror ( int errno ) {
  91         static char errbuf[64];
  92         struct errortab *errortab;
  93
  94         /* Allow for strerror(rc) as well as strerror(errno) */
  95         if ( errno < 0 )
  96                 errno = -errno;
  97
  98         /* Find the error description, if one exists */
  99         errortab = find_closest_error ( errno );
 100
 101         /* Construct the error message */
 102         if ( errortab ) {
 103                 snprintf ( errbuf, sizeof ( errbuf ), "%s (%#08x)",
 104                            errortab->text, errno );
 105         } else {
 106                 snprintf ( errbuf, sizeof ( errbuf ), "Error %#08x", errno );
 107         }
 108
 109         return errbuf;
 110 }
 111
 112 /** The most common errors */
 113 struct errortab common_errors[] __errortab = {
 114         { 0, "No error" },
 115         { ENOMEM, "Out of memory" },
 116         { EINVAL, "Invalid argument" },
 117         { ENOSPC, "No space left on device" },
 118         { EIO, "Input/output error" },
 119         { EACCES, "Permission denied" },
 120         { ENOENT, "File not found" },
 121         { ENETUNREACH, "Network unreachable" },
 122         { ETIMEDOUT, "Connection timed out" },
 123         { EPIPE, "Broken pipe" },
 124 };