diplodocus.org Git - nmh/blob - uip/mhcachesbr.c

   1
   2 /*
   3  * mhcachesbr.c -- routines to manipulate the MIME content cache
   4  *
   5  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11 #include <fcntl.h>
  12 #include <h/md5.h>
  13 #include <h/mts.h>
  14 #include <h/tws.h>
  15 #include <h/mime.h>
  16 #include <h/mhparse.h>
  17 #include <h/mhcachesbr.h>
  18 #include <h/utils.h>
  19
  20 #ifdef HAVE_SYS_TIME_H
  21 # include <sys/time.h>
  22 #endif
  23 #include <time.h>
  24
  25 extern int debugsw;
  26
  27 /* cache policies */
  28 int rcachesw = CACHE_ASK;
  29 int wcachesw = CACHE_ASK;
  30
  31 /*
  32  * Location of public and private cache.  These must
  33  * be set before these routines are called.
  34  */
  35 char *cache_public;
  36 char *cache_private;
  37
  38
  39 /* mhmisc.c */
  40 int part_ok (CT);
  41 int type_ok (CT, int);
  42 void content_error (char *, CT, char *, ...);
  43 void flush_errors (void);
  44
  45 /*
  46  * prototypes
  47  */
  48 void cache_all_messages (CT *);
  49 int find_cache (CT, int, int *, char *, char *, int);
  50
  51 /*
  52  * static prototypes
  53  */
  54 static void cache_content (CT);
  55 static int find_cache_aux (int, char *, char *, char *, int);
  56 static int find_cache_aux2 (char *, char *, char *, int);
  57
  58
  59 /*
  60  * Top level entry point to cache content
  61  * from a group of messages
  62  */
  63
  64 void
  65 cache_all_messages (CT *cts)
  66 {
  67     CT ct, *ctp;
  68
  69     for (ctp = cts; *ctp; ctp++) {
  70         ct = *ctp;
  71         if (type_ok (ct, 1)) {
  72             cache_content (ct);
  73             if (ct->c_fp) {
  74                 fclose (ct->c_fp);
  75                 ct->c_fp = NULL;
  76             }
  77             if (ct->c_ceclosefnx)
  78                 (*ct->c_ceclosefnx) (ct);
  79         }
  80     }
  81     flush_errors ();
  82 }
  83
  84
  85 /*
  86  * Entry point to cache content from external sources.
  87  */
  88
  89 static void
  90 cache_content (CT ct)
  91 {
  92     int cachetype;
  93     char *file, cachefile[BUFSIZ];
  94     CE ce = &ct->c_cefile;
  95
  96     if (!ct->c_id) {
  97         advise (NULL, "no %s: field in %s", ID_FIELD, ct->c_file);
  98         return;
  99     }
 100
 101     if (!ce) {
 102         advise (NULL, "unable to decode %s", ct->c_file);
 103         return;
 104     }
 105
 106     if (find_cache (NULL, wcachesw != CACHE_NEVER ? wcachesw : CACHE_ASK,
 107                     &cachetype, ct->c_id, cachefile, sizeof(cachefile))
 108             == NOTOK) {
 109         advise (NULL, "unable to cache %s's contents", ct->c_file);
 110         return;
 111     }
 112     if (wcachesw != CACHE_NEVER && wcachesw != CACHE_ASK) {
 113         fflush (stdout);
 114         fprintf (stderr, "caching message %s as file %s\n", ct->c_file,
 115                  cachefile);
 116     }
 117
 118     if (ce->ce_file) {
 119         int mask = umask (cachetype ? ~m_gmprot () : 0222);
 120         FILE *fp;
 121
 122         if (debugsw)
 123             fprintf (stderr, "caching by copying %s...\n", ce->ce_file);
 124
 125         file = NULL;
 126         if ((*ct->c_ceopenfnx) (ct, &file) == NOTOK)
 127             goto reset_umask;
 128
 129         if ((fp = fopen (cachefile, "w"))) {
 130             int cc;
 131             char buffer[BUFSIZ];
 132             FILE *gp = ce->ce_fp;
 133
 134             fseek (gp, 0L, SEEK_SET);
 135
 136             while ((cc = fread (buffer, sizeof(*buffer), sizeof(buffer), gp))
 137                        > 0)
 138                 if ((int) fwrite (buffer, sizeof(*buffer), cc, fp) < cc) {
 139                     advise ("cache_content", "fwrite");
 140                 }
 141             fflush (fp);
 142
 143             if (ferror (gp)) {
 144                 admonish (ce->ce_file, "error reading");
 145                 (void) m_unlink (cachefile);
 146             } else {
 147                 if (ferror (fp)) {
 148                     admonish (cachefile, "error writing");
 149                     (void) m_unlink (cachefile);
 150                 }
 151             }
 152             fclose (fp);
 153         } else
 154             content_error (cachefile, ct, "unable to fopen for writing");
 155 reset_umask:
 156         umask (mask);
 157     } else {
 158         if (debugsw)
 159             fprintf (stderr, "in place caching...\n");
 160
 161         file = cachefile;
 162         if ((*ct->c_ceopenfnx) (ct, &file) != NOTOK)
 163             chmod (cachefile, cachetype ? m_gmprot () : 0444);
 164     }
 165 }
 166
 167
 168 int
 169 find_cache (CT ct, int policy, int *writing, char *id,
 170         char *buffer, int buflen)
 171 {
 172     int status = NOTOK;
 173
 174     if (id == NULL)
 175         return NOTOK;
 176     id = trimcpy (id);
 177
 178     if (debugsw)
 179         fprintf (stderr, "find_cache %s(%d) %s %s\n", caches[policy].sw,
 180                  policy, writing ? "writing" : "reading", id);
 181
 182     switch (policy) {
 183         case CACHE_NEVER:
 184         default:
 185             break;
 186
 187         case CACHE_ASK:
 188         case CACHE_PUBLIC:
 189             if (cache_private
 190                     && !writing
 191                     && find_cache_aux (writing ? 2 : 0, cache_private, id,
 192                                        buffer, buflen) == OK) {
 193                 if (access (buffer, R_OK) != NOTOK) {
 194 got_private:
 195                     if (writing)
 196                         *writing = 1;
 197 got_it:
 198                     status = OK;
 199                     break;
 200                 }
 201             }
 202             if (cache_public
 203                     && find_cache_aux (writing ? 1 : 0, cache_public, id,
 204                                        buffer, buflen) == OK) {
 205                 if (writing || access (buffer, R_OK) != NOTOK) {
 206                     if (writing)
 207                         *writing = 0;
 208                     goto got_it;
 209                 }
 210             }
 211             break;
 212
 213         case CACHE_PRIVATE:
 214             if (cache_private
 215                     && find_cache_aux (writing ? 2 : 0, cache_private, id,
 216                                        buffer, buflen) == OK) {
 217                 if (writing || access (buffer, R_OK) != NOTOK)
 218                     goto got_private;
 219             }
 220             break;
 221
 222     }
 223
 224     if (status == OK && policy == CACHE_ASK) {
 225         int len, buflen;
 226         char *bp, query[BUFSIZ];
 227
 228         /* Get buffer ready to go */
 229         bp = query;
 230         buflen = sizeof(query);
 231
 232         /* Now, construct query */
 233         if (writing) {
 234             snprintf (bp, buflen, "Make cached, publicly-accessible copy");
 235         } else {
 236             struct stat st;
 237
 238             snprintf (bp, buflen, "Use cached copy");
 239             len = strlen (bp);
 240             bp += len;
 241             buflen -= len;
 242
 243             if (ct->c_partno) {
 244                 snprintf (bp, buflen, " of content %s", ct->c_partno);
 245                 len = strlen (bp);
 246                 bp += len;
 247                 buflen -= len;
 248             }
 249
 250             stat (buffer, &st);
 251             snprintf (bp, buflen, " (size %lu octets)",
 252                             (unsigned long) st.st_size);
 253         }
 254         len = strlen (bp);
 255         bp += len;
 256         buflen -= len;
 257
 258         snprintf (bp, buflen, "\n    in file %s? ", buffer);
 259
 260         /* Now, check answer */
 261         if (!read_yes_or_no_if_tty (query))
 262             status = NOTOK;
 263     }
 264
 265     if (status == OK && writing) {
 266         if (*writing && strchr(buffer, '/'))
 267             make_intermediates (buffer);
 268         (void) m_unlink (buffer);
 269     }
 270
 271     free (id);
 272     return status;
 273 }
 274
 275
 276 static int
 277 find_cache_aux (int writing, char *directory, char *id,
 278         char *buffer, int buflen)
 279 {
 280     int mask, usemap;
 281     char mapfile[BUFSIZ], mapname[BUFSIZ];
 282     FILE *fp;
 283     int failed_to_lock = 0;
 284     static int partno, pid;
 285     static time_t clock = 0;
 286
 287     usemap = 1;
 288
 289     if (debugsw)
 290         fprintf (stderr, "find_cache_aux %s usemap=%d\n", directory, usemap);
 291
 292     snprintf (mapfile, sizeof(mapfile), "%s/cache.map", directory);
 293     if (find_cache_aux2 (mapfile, id, mapname, sizeof(mapname)) == OK)
 294         goto done_map;
 295
 296     if (!writing) {
 297         if (usemap)
 298             return NOTOK;
 299
 300 use_raw:
 301         snprintf (buffer, buflen, "%s/%s", directory, id);
 302         return OK;
 303     }
 304
 305     if (!usemap && access (mapfile, W_OK) == NOTOK)
 306         goto use_raw;
 307
 308     if (clock != 0) {
 309         time_t now;
 310
 311         time (&now);
 312         if (now > clock)
 313             clock = 0;
 314     } else {
 315         pid = getpid ();
 316     }
 317
 318     if (clock == 0) {
 319         time (&clock);
 320         partno = 0;
 321     } else {
 322         if (partno > 0xff) {
 323             clock++;
 324             partno = 0;
 325         }
 326     }
 327
 328     snprintf (mapname, sizeof(mapname), "%08x%04x%02x",
 329                 (unsigned int) (clock & 0xffffffff),
 330                 (unsigned int) (pid & 0xffff),
 331                 (unsigned int) (partno++ & 0xff));
 332
 333     if (debugsw)
 334         fprintf (stderr, "creating mapping %s->%s\n", mapname, id);
 335
 336     make_intermediates (mapfile);
 337     mask = umask (writing == 2 ? 0077 : 0);
 338     if (!(fp = lkfopendata (mapfile, "a", &failed_to_lock)) && errno == ENOENT) {
 339         int fd;
 340
 341         if ((fd = creat (mapfile, 0666)) != NOTOK) {
 342             close (fd);
 343             fp = lkfopendata (mapfile, "a", &failed_to_lock);
 344             if (failed_to_lock) {
 345                 adios (mapfile, "failed to lock");
 346             }
 347         }
 348     }
 349     umask (mask);
 350     if (!fp)
 351         return NOTOK;
 352     fprintf (fp, "%s: %s\n", mapname, id);
 353     lkfclosedata (fp, mapfile);
 354
 355 done_map:
 356     if (*mapname == '/')
 357         strncpy (buffer, mapname, buflen);
 358     else
 359         snprintf (buffer, buflen, "%s/%s", directory, mapname);
 360     if (debugsw)
 361         fprintf (stderr, "use %s\n", buffer);
 362
 363     return OK;
 364 }
 365
 366
 367 static int
 368 find_cache_aux2 (char *mapfile, char *id, char *mapname, int namelen)
 369 {
 370     int state;
 371     char buf[BUFSIZ], name[NAMESZ];
 372     FILE *fp;
 373     m_getfld_state_t gstate = 0;
 374     int failed_to_lock = 0;
 375
 376     if (!(fp = lkfopendata (mapfile, "r", &failed_to_lock)))
 377         return NOTOK;
 378
 379     for (;;) {
 380         int result;
 381         char *cp, *dp;
 382         int bufsz = sizeof buf;
 383
 384         switch (state = m_getfld (&gstate, name, buf, &bufsz, fp)) {
 385             case FLD:
 386             case FLDPLUS:
 387                 strncpy (mapname, name, namelen);
 388                 if (state != FLDPLUS)
 389                     cp = buf;
 390                 else {
 391                     cp = mh_xstrdup(buf);
 392                     while (state == FLDPLUS) {
 393                         bufsz = sizeof buf;
 394                         state = m_getfld (&gstate, name, buf, &bufsz, fp);
 395                         cp = add (buf, cp);
 396                     }
 397                 }
 398                 dp = trimcpy (cp);
 399                 if (cp != buf)
 400                     free (cp);
 401                 if (debugsw)
 402                     fprintf (stderr, "compare %s to %s <- %s\n", id, dp,
 403                              mapname);
 404                 result = strcmp (id, dp);
 405                 free (dp);
 406                 if (result == 0) {
 407                     lkfclosedata (fp, mapfile);
 408                     return OK;
 409                 }
 410                 continue;
 411
 412             case BODY:
 413             case FILEEOF:
 414             default:
 415                 break;
 416         }
 417         break;
 418     }
 419     m_getfld_state_destroy (&gstate);
 420
 421     lkfclosedata (fp, mapfile);
 422     return NOTOK;
 423 }