nss/nss_files/files-parse.c

   1 /* Common code for file-based database parsers in nss_files module.
   2    Copyright (C) 1996-2000, 2003, 2004 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
  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 # ifdef IS_IN_libc
  77 /* We are defining one of the functions that actually lives in libc
  78    because it is used to implement fget*ent and suchlike.  */
  79 #  define nss_files_parse_hidden_def(name) libc_hidden_def (name)
  80 # else
  81 #  define nss_files_parse_hidden_def(name) libnss_files_hidden_def (name)
  82 # endif
  83 #endif
  84
  85
  86 #ifdef EXTERN_PARSER
  87
  88 /* The parser is defined in a different module.  */
  89 extern int parse_line (char *line, struct STRUCTURE *result,
  90                        struct parser_data *data, size_t datalen, int *errnop
  91                        EXTRA_ARGS_DECL);
  92
  93 # define LINE_PARSER(EOLSET, BODY) /* Do nothing */
  94
  95 #else
  96
  97 /* Define a line parsing function.  */
  98
  99 # define LINE_PARSER(EOLSET, BODY)                                            \
 100 parser_stclass int                                                            \
 101 parse_line (char *line, struct STRUCTURE *result,                             \
 102             struct parser_data *data, size_t datalen, int *errnop             \
 103             EXTRA_ARGS_DECL)                                                  \
 104 {                                                                             \
 105   ENTDATA_DECL (data)                                                         \
 106   char *p = strpbrk (line, EOLSET "\n");                                      \
 107   if (p != NULL)                                                              \
 108     *p = '\0';                                                                \
 109   BODY;                                                                       \
 110   TRAILING_LIST_PARSER;                                                       \
 111   return 1;                                                                   \
 112 }                                                                             \
 113 nss_files_parse_hidden_def (parse_line)
 114
 115
 116 # define STRING_FIELD(variable, terminator_p, swallow)                        \
 117   {                                                                           \
 118     variable = line;                                                          \
 119     while (*line != '\0' && !terminator_p (*line))                            \
 120       ++line;                                                                 \
 121     if (*line != '\0')                                                        \
 122       {                                                                       \
 123         *line = '\0';                                                         \
 124         do                                                                    \
 125           ++line;                                                             \
 126         while (swallow && terminator_p (*line));                              \
 127       }                                                                       \
 128   }
 129
 130 # define INT_FIELD(variable, terminator_p, swallow, base, convert)            \
 131   {                                                                           \
 132     char *endp;                                                               \
 133     variable = convert (strtoul (line, &endp, base));                         \
 134     if (endp == line)                                                         \
 135       return 0;                                                               \
 136     else if (terminator_p (*endp))                                            \
 137       do                                                                      \
 138         ++endp;                                                               \
 139       while (swallow && terminator_p (*endp));                                \
 140     else if (*endp != '\0')                                                   \
 141       return 0;                                                               \
 142     line = endp;                                                              \
 143   }
 144
 145 # define INT_FIELD_MAYBE_NULL(variable, terminator_p, swallow, base, convert, default)        \
 146   {                                                                           \
 147     char *endp;                                                               \
 148     if (*line == '\0')                                                        \
 149       /* We expect some more input, so don't allow the string to end here. */ \
 150       return 0;                                                               \
 151     variable = convert (strtoul (line, &endp, base));                         \
 152     if (endp == line)                                                         \
 153       variable = default;                                                     \
 154     if (terminator_p (*endp))                                                 \
 155       do                                                                      \
 156         ++endp;                                                               \
 157       while (swallow && terminator_p (*endp));                                \
 158     else if (*endp != '\0')                                                   \
 159       return 0;                                                               \
 160     line = endp;                                                              \
 161   }
 162
 163 # define ISCOLON(c) ((c) == ':')
 164
 165
 166 # ifndef TRAILING_LIST_MEMBER
 167 #  define TRAILING_LIST_PARSER /* Nothing to do.  */
 168 # else
 169
 170 #  define TRAILING_LIST_PARSER                                                \
 171 {                                                                             \
 172   char **list = parse_list (line, data, datalen, errnop);                     \
 173   if (list)                                                                   \
 174     result->TRAILING_LIST_MEMBER = list;                                      \
 175   else                                                                        \
 176     return -1;          /* -1 indicates we ran out of space.  */              \
 177 }
 178
 179 static inline char **
 180 __attribute ((always_inline))
 181 parse_list (char *line, struct parser_data *data, size_t datalen, int *errnop)
 182 {
 183   char *eol, **list, **p;
 184
 185   if (line >= data->linebuffer && line < (char *) data + datalen)
 186     /* Find the end of the line buffer, we will use the space in DATA after
 187        it for storing the vector of pointers.  */
 188     eol = strchr (line, '\0') + 1;
 189   else
 190     /* LINE does not point within DATA->linebuffer, so that space is
 191        not being used for scratch space right now.  We can use all of
 192        it for the pointer vector storage.  */
 193     eol = data->linebuffer;
 194   /* Adjust the pointer so it is aligned for storing pointers.  */
 195   eol += __alignof__ (char *) - 1;
 196   eol -= (eol - (char *) 0) % __alignof__ (char *);
 197   /* We will start the storage here for the vector of pointers.  */
 198   list = (char **) eol;
 199
 200   p = list;
 201   while (1)
 202     {
 203       char *elt;
 204
 205       if ((size_t) ((char *) &p[1] - (char *) data) > datalen)
 206         {
 207           /* We cannot fit another pointer in the buffer.  */
 208           *errnop = ERANGE;
 209           return NULL;
 210         }
 211       if (*line == '\0')
 212         break;
 213
 214       /* Skip leading white space.  This might not be portable but useful.  */
 215       while (isspace (*line))
 216         ++line;
 217
 218       elt = line;
 219       while (1)
 220         {
 221           if (*line == '\0' || TRAILING_LIST_SEPARATOR_P (*line))
 222             {
 223               /* End of the next entry.  */
 224               if (line > elt)
 225                 /* We really found some data.  */
 226                 *p++ = elt;
 227
 228               /* Terminate string if necessary.  */
 229               if (*line != '\0')
 230                 *line++ = '\0';
 231               break;
 232             }
 233           ++line;
 234         }
 235     }
 236   *p = NULL;
 237
 238   return list;
 239 }
 240
 241 # endif /* TRAILING_LIST_MEMBER */
 242 #endif  /* EXTERN_PARSER */
 243
 244
 245 #define LOOKUP_NAME(nameelt, aliaselt)                                        \
 246 {                                                                             \
 247   char **ap;                                                                  \
 248   if (! strcmp (name, result->nameelt))                                       \
 249     break;                                                                    \
 250   for (ap = result->aliaselt; *ap; ++ap)                                      \
 251     if (! strcmp (name, *ap))                                                 \
 252       break;                                                                  \
 253   if (*ap)                                                                    \
 254     break;                                                                    \
 255 }
 256
 257 #define LOOKUP_NAME_CASE(nameelt, aliaselt)                                   \
 258 {                                                                             \
 259   char **ap;                                                                  \
 260   if (! __strcasecmp (name, result->nameelt))                                 \
 261     break;                                                                    \
 262   for (ap = result->aliaselt; *ap; ++ap)                                      \
 263     if (! __strcasecmp (name, *ap))                                           \
 264       break;                                                                  \
 265   if (*ap)                                                                    \
 266     break;                                                                    \
 267 }
 268
 269
 270 /* This is defined by db-*.c to include "../nss_db/db-XXX.c" instead.  */
 271 #ifndef GENERIC
 272 # define GENERIC "files-XXX.c"
 273 #endif