nss/nss_files/files-parse.c

   1 /* Common code for file-based database parsers in nss_files module.
   2 Copyright (C) 1996 Free Software Foundation, Inc.
   3 This file is part of the GNU C Library.
   4
   5 The GNU C Library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 License, or (at your option) any later version.
   9
  10 The GNU C Library is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #include <ctype.h>
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24
  25
  26 #define CONCAT(a,b) CONCAT1(a,b)
  27 #define CONCAT1(a,b) a##b
  28
  29 #ifndef STRUCTURE
  30 #define STRUCTURE ENTNAME
  31 #endif
  32
  33
  34 struct parser_data
  35   {
  36     struct CONCAT(ENTNAME,_data) entdata;
  37     char linebuffer[0];
  38   };
  39
  40 #define LINE_PARSER(BODY)                                                     \
  41 static inline int                                                             \
  42 parse_line (char *line, struct STRUCTURE *result,                             \
  43             struct parser_data *data, int datalen)                            \
  44 {                                                                             \
  45   struct CONCAT(ENTNAME,_data) *const entdata __attribute__ ((unused))        \
  46     = &data->entdata;                                                         \
  47   BODY;                                                                       \
  48   TRAILING_LIST_PARSER;                                                       \
  49   return 1;                                                                   \
  50 }
  51
  52
  53 /* Comments can come mid-line; trim the line at the first # seen.  */
  54 #define MIDLINE_COMMENTS                                                      \
  55   {                                                                           \
  56     char *p = strchr (line, '#');                                             \
  57     if (p)                                                                    \
  58       *p = '\0';                                                              \
  59   }
  60
  61 #define STRING_FIELD(variable, terminator_p, swallow)                         \
  62   {                                                                           \
  63     variable = line;                                                          \
  64     while (!terminator_p (*line))                                             \
  65       if (*++line == '\0')                                                    \
  66         return 0;                                                             \
  67     *line = '\0';                                                             \
  68     do                                                                        \
  69       ++line;                                                                 \
  70     while (swallow && terminator_p (*line));                                  \
  71   }
  72
  73 #define INT_FIELD(variable, terminator_p, swallow, base, convert)             \
  74   {                                                                           \
  75     char *endp;                                                               \
  76     variable = convert (strtol (line, &endp, base));                          \
  77     if (endp == line)                                                         \
  78       return 0;                                                               \
  79     else if (terminator_p (*endp))                                            \
  80       do                                                                      \
  81         ++endp;                                                               \
  82       while (swallow && terminator_p (*endp));                                \
  83     else if (*endp != '\0')                                                   \
  84       return 0;                                                               \
  85     line = endp;                                                              \
  86   }
  87
  88 #define ISCOLON(c) ((c) == ':')
  89
  90
  91 #ifndef TRAILING_LIST_MEMBER
  92 #define TRAILING_LIST_PARSER /* Nothing to do.  */
  93 #else
  94
  95 #define TRAILING_LIST_PARSER                                                  \
  96 {                                                                             \
  97   char **list = parse_list (line, data, datalen);                             \
  98   if (list)                                                                   \
  99     result->TRAILING_LIST_MEMBER = list;                                      \
 100   else                                                                        \
 101     return 0;                                                                 \
 102 }
 103
 104 static inline char **
 105 parse_list (char *line, struct parser_data *data, int datalen)
 106 {
 107   char *eol, **list, **p;
 108
 109   /* Find the end of the line buffer.  */
 110   eol = strchr (line, '\0');
 111   /* Adjust the pointer so it is aligned for storing pointers.  */
 112   eol += (eol - (char *) 0) % __alignof__ (char *);
 113   /* We will start the storage here for the vector of pointers.  */
 114   list = (char **) eol;
 115
 116   p = list;
 117   while (1)
 118     {
 119       char *elt;
 120
 121       if ((char *) &p[1] - (char *) data > datalen)
 122         {
 123           /* We cannot fit another pointer in the buffer.  */
 124           errno = ERANGE;
 125           return NULL;
 126         }
 127       if (*line == '\0')
 128         break;
 129
 130       elt = line;
 131       while (1)
 132         {
 133           if (TRAILING_LIST_SEPARATOR_P (*line))
 134             {
 135               *p++ = elt;
 136               *line = '\0';
 137               do
 138                 ++line;
 139               while (TRAILING_LIST_SEPARATOR_P (*line));
 140             }
 141           else if (*line == '\0' || *line == '\n')
 142             {
 143               /* End of the line.  */
 144               if (line > elt)
 145                 /* Last element.  */
 146                 *p++ = elt;
 147               *line = '\0';
 148               break;
 149             }
 150           else
 151             ++line;
 152         }
 153     }
 154   *p = NULL;
 155
 156   return list;
 157 }
 158
 159 #define LOOKUP_NAME(nameelt, aliaselt)                                        \
 160 {                                                                             \
 161   char **ap;                                                                  \
 162   if (! strcmp (name, result->nameelt))                                       \
 163     break;                                                                    \
 164   for (ap = result->aliaselt; *ap; ++ap)                                      \
 165     if (! strcmp (name, *ap))                                                 \
 166       break;                                                                  \
 167   if (*ap)                                                                    \
 168     break;                                                                    \
 169 }
 170
 171 #endif