nss/nss_files/files-parse.c

   1 /* Common code for file-based database parsers in nss_files module.
   2    Copyright (C) 1996, 1997, 1998, 1999, 2000 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 not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <ctype.h>
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24
  25 /* These symbols are defined by the including source file:
  26
  27    ENTNAME -- database name of the structure and functions (hostent, pwent).
  28    STRUCTURE -- struct name, define only if not ENTNAME (passwd, group).
  29    DATABASE -- string of the database file's name ("hosts", "passwd").
  30
  31    ENTDATA -- if defined, `struct ENTDATA' is used by the parser to store
  32               things pointed to by the resultant `struct STRUCTURE'.
  33
  34    NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
  35
  36    EXTRA_ARGS -- defined iff extra parameters must be passed to the parser
  37    EXTRA_ARGS_DECL -- declaration for these extra parameters
  38    EXTRA_ARGS_VALUE -- values to be passed for these parameters
  39
  40    Also see files-XXX.c.  */
  41
  42 #ifndef EXTRA_ARGS
  43 # define EXTRA_ARGS
  44 # define EXTRA_ARGS_DECL
  45 # define EXTRA_ARGS_VALUE
  46 #endif
  47
  48 #define CONCAT(a,b) CONCAT1(a,b)
  49 #define CONCAT1(a,b) a##b
  50
  51 #ifndef STRUCTURE
  52 # define STRUCTURE ENTNAME
  53 #endif
  54
  55
  56 struct parser_data
  57   {
  58 #ifdef ENTDATA
  59     struct ENTDATA entdata;
  60 # define ENTDATA_DECL(data) struct ENTDATA *const entdata = &data->entdata;
  61 #else
  62 # define ENTDATA_DECL(data)
  63 #endif
  64     char linebuffer[0];
  65   };
  66
  67 #ifdef ENTDATA
  68 /* The function can't be exported, because the entdata structure
  69    is defined only in files-foo.c.  */
  70 # define parser_stclass static inline
  71 #else
  72 /* Export the line parser function so it can be used in nss_db.  */
  73 # define parser_stclass /* Global */
  74 # define parse_line CONCAT(_nss_files_parse_,ENTNAME)
  75 #endif
  76
  77
  78 #ifdef EXTERN_PARSER
  79
  80 /* The parser is defined in a different module.  */
  81 extern int parse_line (char *line, struct STRUCTURE *result,
  82                        struct parser_data *data, size_t datalen, int *errnop
  83                        EXTRA_ARGS_DECL);
  84
  85 # define LINE_PARSER(EOLSET, BODY) /* Do nothing */
  86
  87 #else
  88
  89 /* Define a line parsing function.  */
  90
  91 # define LINE_PARSER(EOLSET, BODY)                                            \
  92 parser_stclass int                                                            \
  93 parse_line (char *line, struct STRUCTURE *result,                             \
  94             struct parser_data *data, size_t datalen, int *errnop             \
  95             EXTRA_ARGS_DECL)                                                  \
  96 {                                                                             \
  97   ENTDATA_DECL (data)                                                         \
  98   char *p = strpbrk (line, EOLSET "\n");                                      \
  99   if (p != NULL)                                                              \
 100     *p = '\0';                                                                \
 101   BODY;                                                                       \
 102   TRAILING_LIST_PARSER;                                                       \
 103   return 1;                                                                   \
 104 }
 105
 106
 107 # define STRING_FIELD(variable, terminator_p, swallow)                        \
 108   {                                                                           \
 109     variable = line;                                                          \
 110     while (*line != '\0' && !terminator_p (*line))                            \
 111       ++line;                                                                 \
 112     if (*line != '\0')                                                        \
 113       {                                                                       \
 114         *line = '\0';                                                         \
 115         do                                                                    \
 116           ++line;                                                             \
 117         while (swallow && terminator_p (*line));                              \
 118       }                                                                       \
 119   }
 120
 121 # define INT_FIELD(variable, terminator_p, swallow, base, convert)            \
 122   {                                                                           \
 123     char *endp;                                                               \
 124     variable = convert (strtoul (line, &endp, base));                         \
 125     if (endp == line)                                                         \
 126       return 0;                                                               \
 127     else if (terminator_p (*endp))                                            \
 128       do                                                                      \
 129         ++endp;                                                               \
 130       while (swallow && terminator_p (*endp));                                \
 131     else if (*endp != '\0')                                                   \
 132       return 0;                                                               \
 133     line = endp;                                                              \
 134   }
 135
 136 # define INT_FIELD_MAYBE_NULL(variable, terminator_p, swallow, base, convert, default)        \
 137   {                                                                           \
 138     char *endp;                                                               \
 139     if (*line == '\0')                                                        \
 140       /* We expect some more input, so don't allow the string to end here. */ \
 141       return 0;                                                               \
 142     variable = convert (strtoul (line, &endp, base));                         \
 143     if (endp == line)                                                         \
 144       variable = default;                                                     \
 145     if (terminator_p (*endp))                                                 \
 146       do                                                                      \
 147         ++endp;                                                               \
 148       while (swallow && terminator_p (*endp));                                \
 149     else if (*endp != '\0')                                                   \
 150       return 0;                                                               \
 151     line = endp;                                                              \
 152   }
 153
 154 # define ISCOLON(c) ((c) == ':')
 155
 156
 157 # ifndef TRAILING_LIST_MEMBER
 158 #  define TRAILING_LIST_PARSER /* Nothing to do.  */
 159 # else
 160
 161 #  define TRAILING_LIST_PARSER                                                \
 162 {                                                                             \
 163   char **list = parse_list (line, data, datalen, errnop);                     \
 164   if (list)                                                                   \
 165     result->TRAILING_LIST_MEMBER = list;                                      \
 166   else                                                                        \
 167     return -1;          /* -1 indicates we ran out of space.  */              \
 168 }
 169
 170 static inline char **
 171 parse_list (char *line, struct parser_data *data, size_t datalen, int *errnop)
 172 {
 173   char *eol, **list, **p;
 174
 175   if (line >= data->linebuffer && line < (char *) data + datalen)
 176     /* Find the end of the line buffer, we will use the space in DATA after
 177        it for storing the vector of pointers.  */
 178     eol = strchr (line, '\0') + 1;
 179   else
 180     /* LINE does not point within DATA->linebuffer, so that space is
 181        not being used for scratch space right now.  We can use all of
 182        it for the pointer vector storage.  */
 183     eol = data->linebuffer;
 184   /* Adjust the pointer so it is aligned for storing pointers.  */
 185   eol += __alignof__ (char *) - 1;
 186   eol -= (eol - (char *) 0) % __alignof__ (char *);
 187   /* We will start the storage here for the vector of pointers.  */
 188   list = (char **) eol;
 189
 190   p = list;
 191   while (1)
 192     {
 193       char *elt;
 194
 195       if ((size_t) ((char *) &p[1] - (char *) data) > datalen)
 196         {
 197           /* We cannot fit another pointer in the buffer.  */
 198           *errnop = ERANGE;
 199           return NULL;
 200         }
 201       if (*line == '\0')
 202         break;
 203
 204       /* Skip leading white space.  This might not be portable but useful.  */
 205       while (isspace (*line))
 206         ++line;
 207
 208       elt = line;
 209       while (1)
 210         {
 211           if (*line == '\0' || TRAILING_LIST_SEPARATOR_P (*line))
 212             {
 213               /* End of the next entry.  */
 214               if (line > elt)
 215                 /* We really found some data.  */
 216                 *p++ = elt;
 217
 218               /* Terminate string if necessary.  */
 219               if (*line != '\0')
 220                 *line++ = '\0';
 221               break;
 222             }
 223           ++line;
 224         }
 225     }
 226   *p = NULL;
 227
 228   return list;
 229 }
 230
 231 # endif /* TRAILING_LIST_MEMBER */
 232 #endif  /* EXTERN_PARSER */
 233
 234
 235 #define LOOKUP_NAME(nameelt, aliaselt)                                        \
 236 {                                                                             \
 237   char **ap;                                                                  \
 238   if (! strcmp (name, result->nameelt))                                       \
 239     break;                                                                    \
 240   for (ap = result->aliaselt; *ap; ++ap)                                      \
 241     if (! strcmp (name, *ap))                                                 \
 242       break;                                                                  \
 243   if (*ap)                                                                    \
 244     break;                                                                    \
 245 }
 246
 247 #define LOOKUP_NAME_CASE(nameelt, aliaselt)                                   \
 248 {                                                                             \
 249   char **ap;                                                                  \
 250   if (! __strcasecmp (name, result->nameelt))                                 \
 251     break;                                                                    \
 252   for (ap = result->aliaselt; *ap; ++ap)                                      \
 253     if (! __strcasecmp (name, *ap))                                           \
 254       break;                                                                  \
 255   if (*ap)                                                                    \
 256     break;                                                                    \
 257 }
 258
 259
 260 /* This is defined by db-*.c to include "../nss_db/db-XXX.c" instead.  */
 261 #ifndef GENERIC
 262 # define GENERIC "files-XXX.c"
 263 #endif