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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    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 # define nss_files_parse_hidden_def(name)
  72 #else
  73 /* Export the line parser function so it can be used in nss_db.  */
  74 # define parser_stclass /* Global */
  75 # define parse_line CONCAT(_nss_files_parse_,ENTNAME)
  76 # define nss_files_parse_hidden_def(name) libc_hidden_def (name)
  77 #endif
  78
  79
  80 #ifdef EXTERN_PARSER
  81
  82 /* The parser is defined in a different module.  */
  83 extern int parse_line (char *line, struct STRUCTURE *result,
  84                        struct parser_data *data, size_t datalen, int *errnop
  85                        EXTRA_ARGS_DECL);
  86
  87 # define LINE_PARSER(EOLSET, BODY) /* Do nothing */
  88
  89 #else
  90
  91 /* Define a line parsing function.  */
  92
  93 # define LINE_PARSER(EOLSET, BODY)                                            \
  94 parser_stclass int                                                            \
  95 parse_line (char *line, struct STRUCTURE *result,                             \
  96             struct parser_data *data, size_t datalen, int *errnop             \
  97             EXTRA_ARGS_DECL)                                                  \
  98 {                                                                             \
  99   ENTDATA_DECL (data)                                                         \
 100   char *p = strpbrk (line, EOLSET "\n");                                      \
 101   if (p != NULL)                                                              \
 102     *p = '\0';                                                                \
 103   BODY;                                                                       \
 104   TRAILING_LIST_PARSER;                                                       \
 105   return 1;                                                                   \
 106 }                                                                             \
 107 nss_files_parse_hidden_def (parse_line)
 108
 109
 110 # define STRING_FIELD(variable, terminator_p, swallow)                        \
 111   {                                                                           \
 112     variable = line;                                                          \
 113     while (*line != '\0' && !terminator_p (*line))                            \
 114       ++line;                                                                 \
 115     if (*line != '\0')                                                        \
 116       {                                                                       \
 117         *line = '\0';                                                         \
 118         do                                                                    \
 119           ++line;                                                             \
 120         while (swallow && terminator_p (*line));                              \
 121       }                                                                       \
 122   }
 123
 124 # define INT_FIELD(variable, terminator_p, swallow, base, convert)            \
 125   {                                                                           \
 126     char *endp;                                                               \
 127     variable = convert (strtoul (line, &endp, base));                         \
 128     if (endp == line)                                                         \
 129       return 0;                                                               \
 130     else if (terminator_p (*endp))                                            \
 131       do                                                                      \
 132         ++endp;                                                               \
 133       while (swallow && terminator_p (*endp));                                \
 134     else if (*endp != '\0')                                                   \
 135       return 0;                                                               \
 136     line = endp;                                                              \
 137   }
 138
 139 # define INT_FIELD_MAYBE_NULL(variable, terminator_p, swallow, base, convert, default)        \
 140   {                                                                           \
 141     char *endp;                                                               \
 142     if (*line == '\0')                                                        \
 143       /* We expect some more input, so don't allow the string to end here. */ \
 144       return 0;                                                               \
 145     variable = convert (strtoul (line, &endp, base));                         \
 146     if (endp == line)                                                         \
 147       variable = default;                                                     \
 148     if (terminator_p (*endp))                                                 \
 149       do                                                                      \
 150         ++endp;                                                               \
 151       while (swallow && terminator_p (*endp));                                \
 152     else if (*endp != '\0')                                                   \
 153       return 0;                                                               \
 154     line = endp;                                                              \
 155   }
 156
 157 # define ISCOLON(c) ((c) == ':')
 158
 159
 160 # ifndef TRAILING_LIST_MEMBER
 161 #  define TRAILING_LIST_PARSER /* Nothing to do.  */
 162 # else
 163
 164 #  define TRAILING_LIST_PARSER                                                \
 165 {                                                                             \
 166   char **list = parse_list (line, data, datalen, errnop);                     \
 167   if (list)                                                                   \
 168     result->TRAILING_LIST_MEMBER = list;                                      \
 169   else                                                                        \
 170     return -1;          /* -1 indicates we ran out of space.  */              \
 171 }
 172
 173 static inline char **
 174 parse_list (char *line, struct parser_data *data, size_t datalen, int *errnop)
 175 {
 176   char *eol, **list, **p;
 177
 178   if (line >= data->linebuffer && line < (char *) data + datalen)
 179     /* Find the end of the line buffer, we will use the space in DATA after
 180        it for storing the vector of pointers.  */
 181     eol = strchr (line, '\0') + 1;
 182   else
 183     /* LINE does not point within DATA->linebuffer, so that space is
 184        not being used for scratch space right now.  We can use all of
 185        it for the pointer vector storage.  */
 186     eol = data->linebuffer;
 187   /* Adjust the pointer so it is aligned for storing pointers.  */
 188   eol += __alignof__ (char *) - 1;
 189   eol -= (eol - (char *) 0) % __alignof__ (char *);
 190   /* We will start the storage here for the vector of pointers.  */
 191   list = (char **) eol;
 192
 193   p = list;
 194   while (1)
 195     {
 196       char *elt;
 197
 198       if ((size_t) ((char *) &p[1] - (char *) data) > datalen)
 199         {
 200           /* We cannot fit another pointer in the buffer.  */
 201           *errnop = ERANGE;
 202           return NULL;
 203         }
 204       if (*line == '\0')
 205         break;
 206
 207       /* Skip leading white space.  This might not be portable but useful.  */
 208       while (isspace (*line))
 209         ++line;
 210
 211       elt = line;
 212       while (1)
 213         {
 214           if (*line == '\0' || TRAILING_LIST_SEPARATOR_P (*line))
 215             {
 216               /* End of the next entry.  */
 217               if (line > elt)
 218                 /* We really found some data.  */
 219                 *p++ = elt;
 220
 221               /* Terminate string if necessary.  */
 222               if (*line != '\0')
 223                 *line++ = '\0';
 224               break;
 225             }
 226           ++line;
 227         }
 228     }
 229   *p = NULL;
 230
 231   return list;
 232 }
 233
 234 # endif /* TRAILING_LIST_MEMBER */
 235 #endif  /* EXTERN_PARSER */
 236
 237
 238 #define LOOKUP_NAME(nameelt, aliaselt)                                        \
 239 {                                                                             \
 240   char **ap;                                                                  \
 241   if (! strcmp (name, result->nameelt))                                       \
 242     break;                                                                    \
 243   for (ap = result->aliaselt; *ap; ++ap)                                      \
 244     if (! strcmp (name, *ap))                                                 \
 245       break;                                                                  \
 246   if (*ap)                                                                    \
 247     break;                                                                    \
 248 }
 249
 250 #define LOOKUP_NAME_CASE(nameelt, aliaselt)                                   \
 251 {                                                                             \
 252   char **ap;                                                                  \
 253   if (! __strcasecmp (name, result->nameelt))                                 \
 254     break;                                                                    \
 255   for (ap = result->aliaselt; *ap; ++ap)                                      \
 256     if (! __strcasecmp (name, *ap))                                           \
 257       break;                                                                  \
 258   if (*ap)                                                                    \
 259     break;                                                                    \
 260 }
 261
 262
 263 /* This is defined by db-*.c to include "../nss_db/db-XXX.c" instead.  */
 264 #ifndef GENERIC
 265 # define GENERIC "files-XXX.c"
 266 #endif