include/nss_files.h

   1 /* Internal routines for nss_files.
   2    Copyright (C) 2020-2022 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _NSS_FILES_H
  20 #define _NSS_FILES_H
  21
  22 #include <nss.h>
  23 #include <stdio.h>
  24 #if IS_IN (libc)
  25 #include <libc-lock.h>
  26 #endif
  27
  28 /* Open PATH for reading, as a data source for nss_files.  */
  29 FILE *__nss_files_fopen (const char *path);
  30 libc_hidden_proto (__nss_files_fopen)
  31
  32 /* Read a line from FP, storing it BUF.  Strip leading blanks and skip
  33    comments.  Sets errno and returns error code on failure.  Special
  34    failure: ERANGE means the buffer is too small.  The function writes
  35    the original offset to *POFFSET (which can be negative in the case
  36    of non-seekable input).  */
  37 int __nss_readline (FILE *fp, char *buf, size_t len, off64_t *poffset);
  38 libc_hidden_proto (__nss_readline)
  39
  40 /* Seek FP to OFFSET.  Sets errno and returns error code on failure.
  41    On success, sets errno to ERANGE and returns ERANGE (to indicate
  42    re-reading of the same input line to the caller).  If OFFSET is
  43    negative, fail with ESPIPE without seeking.  Intended to be used
  44    after parsing data read by __nss_readline failed with ERANGE.  */
  45 int __nss_readline_seek (FILE *fp, off64_t offset) attribute_hidden;
  46
  47 /* Handles the result of a parse_line call (as defined by
  48    nss/nss_files/files-parse.c).  Adjusts the file offset of FP as
  49    necessary.  Returns 0 on success, and updates errno on failure (and
  50    returns that error code).  */
  51 int __nss_parse_line_result (FILE *fp, off64_t offset, int parse_line_result);
  52 libc_hidden_proto (__nss_parse_line_result)
  53
  54 /* Per-file data.  Used by the *ent functions that need to preserve
  55    state across calls.  */
  56 struct nss_files_per_file_data
  57 {
  58   FILE *stream;
  59 #if IS_IN (libc)
  60   /* The size of locks changes between libc and nss_files, so this
  61      member must be last and is only available in libc.  */
  62   __libc_lock_define (, lock);
  63 #endif
  64 };
  65
  66 /* File index for __nss_files_data_get.  */
  67 enum nss_files_file
  68   {
  69     nss_file_aliasent,
  70     nss_file_etherent,
  71     nss_file_grent,
  72     nss_file_hostent,
  73     nss_file_netent,
  74     nss_file_protoent,
  75     nss_file_pwent,
  76     nss_file_rpcent,
  77     nss_file_servent,
  78     nss_file_sgent,
  79     nss_file_spent,
  80
  81     nss_file_count
  82   };
  83
  84 /* Obtains a pointer to the per-file data for FILE, which is written
  85    to *PDATA, and tries to open the file at PATH for it.  On success,
  86    returns NSS_STATUS_SUCCESS, and the caller must later call
  87    __nss_files_data_put.  On failure, NSS_STATUS_TRYAGAIN is returned,
  88    and *ERRNOP and *HERRNOP are updated if these pointers are not
  89    null.  */
  90 enum nss_status __nss_files_data_open (struct nss_files_per_file_data **pdata,
  91                                        enum nss_files_file file,
  92                                        const char *path,
  93                                        int *errnop, int *herrnop);
  94 libc_hidden_proto (__nss_files_data_open)
  95
  96 /* Unlock the per-file data, previously obtained by
  97    __nss_files_data_open.  */
  98 void __nss_files_data_put (struct nss_files_per_file_data *data);
  99 libc_hidden_proto (__nss_files_data_put)
 100
 101 /* Performs the set*ent operation for FILE.  PATH is the file to
 102    open.  */
 103 enum nss_status __nss_files_data_setent (enum nss_files_file file,
 104                                            const char *path);
 105 libc_hidden_proto (__nss_files_data_setent)
 106
 107 /* Performs the end*ent operation for FILE.  */
 108 enum nss_status __nss_files_data_endent (enum nss_files_file file);
 109 libc_hidden_proto (__nss_files_data_endent)
 110
 111 struct parser_data;
 112
 113 /* Instances of the parse_line function from
 114    nss/nss_files/files-parse.c.  */
 115 typedef int nss_files_parse_line (char *line, void *result,
 116                                   struct parser_data *data,
 117                                   size_t datalen, int *errnop);
 118 extern nss_files_parse_line _nss_files_parse_etherent;
 119 extern nss_files_parse_line _nss_files_parse_grent;
 120 extern nss_files_parse_line _nss_files_parse_netent;
 121 extern nss_files_parse_line _nss_files_parse_protoent;
 122 extern nss_files_parse_line _nss_files_parse_pwent;
 123 extern nss_files_parse_line _nss_files_parse_rpcent;
 124 extern nss_files_parse_line _nss_files_parse_servent;
 125 extern nss_files_parse_line _nss_files_parse_sgent;
 126 extern nss_files_parse_line _nss_files_parse_spent;
 127
 128 libc_hidden_proto (_nss_files_parse_etherent)
 129 libc_hidden_proto (_nss_files_parse_grent)
 130 libc_hidden_proto (_nss_files_parse_netent)
 131 libc_hidden_proto (_nss_files_parse_protoent)
 132 libc_hidden_proto (_nss_files_parse_pwent)
 133 libc_hidden_proto (_nss_files_parse_rpcent)
 134 libc_hidden_proto (_nss_files_parse_servent)
 135 libc_hidden_proto (_nss_files_parse_sgent)
 136 libc_hidden_proto (_nss_files_parse_spent)
 137
 138 NSS_DECLARE_MODULE_FUNCTIONS (files)
 139 #undef DEFINE_NSS_FUNCTION
 140 #define DEFINE_NSS_FUNCTION(x) libc_hidden_proto (_nss_files_##x)
 141 #include <nss/function.def>
 142 #undef DEFINE_NSS_FUNCTION
 143
 144 void _nss_files_init (void (*cb) (size_t, struct traced_file *));
 145 libc_hidden_proto (_nss_files_init)
 146
 147 /* Generic implementation of fget*ent_r.  Reads lines from FP until
 148    EOF or a successful parse into *RESULT using PARSER.  Returns 0 on
 149    success, ENOENT on EOF, ERANGE on too-small buffer.  */
 150 int __nss_fgetent_r (FILE *fp, void *result,
 151                      char *buffer, size_t buffer_length,
 152                      nss_files_parse_line parser) attribute_hidden;
 153
 154 #endif /* _NSS_FILES_H */