src/topology/friends.c

   1 /*
   2      This file is part of GNUnet.
   3      Copyright (C) 2013 Christian Grothoff
   4
   5      GNUnet is free software: you can redistribute it and/or modify it
   6      under the terms of the GNU Affero General Public License as published
   7      by the Free Software Foundation, either version 3 of the License,
   8      or (at your option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      Affero General Public License for more details.
  14
  15      You should have received a copy of the GNU Affero General Public License
  16      along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18      SPDX-License-Identifier: AGPL3.0-or-later
  19  */
  20
  21 /**
  22  * @file topology/friends.c
  23  * @brief library to read and write the FRIENDS file
  24  * @author Christian Grothoff
  25  */
  26 #include "platform.h"
  27 #include "gnunet_friends_lib.h"
  28
  29
  30 /**
  31  * Parse the FRIENDS file.
  32  *
  33  * @param cfg our configuration
  34  * @param cb function to call on each friend found
  35  * @param cb_cls closure for @a cb
  36  * @return #GNUNET_OK on success, #GNUNET_SYSERR on parsing errors
  37  */
  38 int
  39 GNUNET_FRIENDS_parse(const struct GNUNET_CONFIGURATION_Handle *cfg,
  40                      GNUNET_FRIENDS_Callback cb,
  41                      void *cb_cls)
  42 {
  43   char *fn;
  44   char *data;
  45   size_t pos;
  46   size_t start;
  47   struct GNUNET_PeerIdentity pid;
  48   uint64_t fsize;
  49   ssize_t ssize;
  50
  51   if (GNUNET_OK !=
  52       GNUNET_CONFIGURATION_get_value_filename(cfg,
  53                                               "TOPOLOGY",
  54                                               "FRIENDS",
  55                                               &fn))
  56     {
  57       GNUNET_log_config_missing(GNUNET_ERROR_TYPE_ERROR,
  58                                 "topology",
  59                                 "FRIENDS");
  60       return GNUNET_SYSERR;
  61     }
  62   if (GNUNET_SYSERR ==
  63       GNUNET_DISK_directory_create_for_file(fn))
  64     {
  65       GNUNET_log_strerror_file(GNUNET_ERROR_TYPE_WARNING,
  66                                "mkdir",
  67                                fn);
  68       GNUNET_free(fn);
  69       return GNUNET_SYSERR;
  70     }
  71   if ((GNUNET_OK !=
  72        GNUNET_DISK_file_test(fn)) &&
  73       (GNUNET_OK !=
  74        GNUNET_DISK_fn_write(fn,
  75                             NULL,
  76                             0,
  77                             GNUNET_DISK_PERM_USER_READ |
  78                             GNUNET_DISK_PERM_USER_WRITE |
  79                             GNUNET_DISK_OPEN_CREATE)))
  80     GNUNET_log_strerror_file(GNUNET_ERROR_TYPE_WARNING,
  81                              "write",
  82                              fn);
  83   if ((GNUNET_OK !=
  84        GNUNET_DISK_file_size(fn,
  85                              &fsize,
  86                              GNUNET_NO,
  87                              GNUNET_YES)) ||
  88       (0 == fsize))
  89     {
  90       GNUNET_free(fn);
  91       return GNUNET_OK;
  92     }
  93   data = GNUNET_malloc_large(fsize);
  94   if (NULL == data)
  95     {
  96       GNUNET_log_strerror(GNUNET_ERROR_TYPE_ERROR, "malloc");
  97       GNUNET_free(fn);
  98       return GNUNET_SYSERR;
  99     }
 100   ssize = GNUNET_DISK_fn_read(fn,
 101                               data,
 102                               fsize);
 103   if ((ssize < 0) ||
 104       (fsize != (uint64_t)ssize))
 105     {
 106       GNUNET_log_strerror_file(GNUNET_ERROR_TYPE_ERROR,
 107                                "read",
 108                                "fn");
 109       GNUNET_free(fn);
 110       GNUNET_free(data);
 111       return GNUNET_SYSERR;
 112     }
 113   start = 0;
 114   pos = 0;
 115   while (pos < fsize)
 116     {
 117       while ((pos < fsize) &&
 118              (!isspace((unsigned char)data[pos])))
 119         pos++;
 120       if (GNUNET_OK !=
 121           GNUNET_CRYPTO_eddsa_public_key_from_string(&data[start],
 122                                                      pos - start,
 123                                                      &pid.public_key))
 124         {
 125           GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
 126                      _("Syntax error in FRIENDS file at offset %llu, skipping bytes `%.*s'.\n"),
 127                      (unsigned long long)pos,
 128                      (int)(pos - start),
 129                      &data[start]);
 130           pos++;
 131           start = pos;
 132           continue;
 133         }
 134       pos++;
 135       start = pos;
 136       cb(cb_cls, &pid);
 137     }
 138   GNUNET_free(data);
 139   GNUNET_free(fn);
 140   return GNUNET_OK;
 141 }
 142
 143
 144 /**
 145  * Handle for writing a friends file.
 146  */
 147 struct GNUNET_FRIENDS_Writer {
 148   /**
 149    * Handle to the file.
 150    */
 151   struct GNUNET_DISK_FileHandle *fh;
 152 };
 153
 154
 155 /**
 156  * Start writing a fresh FRIENDS file.  Will make a backup of the
 157  * old one.
 158  *
 159  * @param cfg configuration to use.
 160  * @return NULL on error
 161  */
 162 struct GNUNET_FRIENDS_Writer *
 163 GNUNET_FRIENDS_write_start(const struct GNUNET_CONFIGURATION_Handle *cfg)
 164 {
 165   struct GNUNET_FRIENDS_Writer *w;
 166   char *fn;
 167
 168   if (GNUNET_OK !=
 169       GNUNET_CONFIGURATION_get_value_filename(cfg, "TOPOLOGY", "FRIENDS", &fn))
 170     {
 171       GNUNET_log_config_missing(GNUNET_ERROR_TYPE_ERROR,
 172                                 "topology", "FRIENDS");
 173       return NULL;
 174     }
 175   if (GNUNET_OK !=
 176       GNUNET_DISK_directory_create_for_file(fn))
 177     {
 178       GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
 179                  _("Directory for file `%s' does not seem to be writable.\n"),
 180                  fn);
 181       GNUNET_free(fn);
 182       return NULL;
 183     }
 184   if (GNUNET_OK == GNUNET_DISK_file_test(fn))
 185     GNUNET_DISK_file_backup(fn);
 186   w = GNUNET_new(struct GNUNET_FRIENDS_Writer);
 187   w->fh = GNUNET_DISK_file_open(fn,
 188                                 GNUNET_DISK_OPEN_CREATE |
 189                                 GNUNET_DISK_OPEN_WRITE |
 190                                 GNUNET_DISK_OPEN_FAILIFEXISTS,
 191                                 GNUNET_DISK_PERM_USER_READ);
 192   GNUNET_free(fn);
 193   if (NULL == w->fh)
 194     {
 195       GNUNET_free(w);
 196       return NULL;
 197     }
 198   return w;
 199 }
 200
 201
 202 /**
 203  * Finish writing out the friends file.
 204  *
 205  * @param w write handle
 206  * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 207  */
 208 int
 209 GNUNET_FRIENDS_write_stop(struct GNUNET_FRIENDS_Writer *w)
 210 {
 211   int ret;
 212
 213   ret = GNUNET_DISK_file_close(w->fh);
 214   GNUNET_free(w);
 215   return ret;
 216 }
 217
 218
 219 /**
 220  * Add a friend to the friends file.
 221  *
 222  * @param w write handle
 223  * @param friend_id friend to add
 224  * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 225  */
 226 int
 227 GNUNET_FRIENDS_write(struct GNUNET_FRIENDS_Writer *w,
 228                      const struct GNUNET_PeerIdentity *friend_id)
 229 {
 230   char *buf;
 231   char *ret;
 232   size_t slen;
 233
 234   ret = GNUNET_CRYPTO_eddsa_public_key_to_string(&friend_id->public_key);
 235   GNUNET_asprintf(&buf,
 236                   "%s\n",
 237                   ret);
 238   GNUNET_free(ret);
 239   slen = strlen(buf);
 240   if (slen !=
 241       GNUNET_DISK_file_write(w->fh,
 242                              buf,
 243                              slen))
 244     {
 245       GNUNET_free(buf);
 246       return GNUNET_SYSERR;
 247     }
 248   GNUNET_free(buf);
 249   return GNUNET_OK;
 250 }
 251
 252
 253 /* end of friends.c */