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

   1 /* mhcachesbr.c -- routines to manipulate the MIME content cache
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include <h/mh.h>
   9 #include <fcntl.h>
  10 #include <h/md5.h>
  11 #include <h/mts.h>
  12 #include <h/tws.h>
  13 #include <h/mime.h>
  14 #include <h/mhparse.h>
  15 #include <h/mhcachesbr.h>
  16 #include <h/utils.h>
  17 #include "../sbr/lock_file.h"
  18 #include "../sbr/m_mktemp.h"
  19
  20 #ifdef HAVE_SYS_TIME_H
  21 # include <sys/time.h>
  22 #endif
  23 #include <time.h>
  24
  25 #define X(sw, minchars, id) { sw, minchars, id },
  26 DEFINE_SWITCH_ARRAY(CACHE, caches);
  27 #undef X
  28 struct swit *cache_policy = caches;
  29
  30 extern int debugsw;
  31
  32 /* cache policies */
  33 int rcachesw = CACHE_ASK;
  34 int wcachesw = CACHE_ASK;
  35
  36 /*
  37  * Location of public and private cache.  These must
  38  * be set before these routines are called.
  39  */
  40 char *cache_public;
  41 char *cache_private;
  42
  43
  44 /* mhmisc.c */
  45 int part_ok (CT);
  46 int type_ok (CT, int);
  47 void content_error (char *, CT, char *, ...);
  48 void flush_errors (void);
  49
  50 /*
  51  * static prototypes
  52  */
  53 static void cache_content (CT);
  54 static int find_cache_aux (int, char *, char *, char *, int);
  55 static int find_cache_aux2 (char *, char *, char *, int);
  56
  57
  58 /*
  59  * Top level entry point to cache content
  60  * from a group of messages
  61  */
  62
  63 void
  64 cache_all_messages (CT *cts)
  65 {
  66     CT ct, *ctp;
  67
  68     for (ctp = cts; *ctp; ctp++) {
  69         ct = *ctp;
  70         if (type_ok (ct, 1)) {
  71             cache_content (ct);
  72             if (ct->c_fp) {
  73                 fclose (ct->c_fp);
  74                 ct->c_fp = NULL;
  75             }
  76             if (ct->c_ceclosefnx)
  77                 (*ct->c_ceclosefnx) (ct);
  78         }
  79     }
  80     flush_errors ();
  81 }
  82
  83
  84 /*
  85  * Entry point to cache content from external sources.
  86  */
  87
  88 static void
  89 cache_content (CT ct)
  90 {
  91     int cachetype;
  92     char *file, cachefile[BUFSIZ];
  93     CE ce = &ct->c_cefile;
  94
  95     if (!ct->c_id) {
  96         inform("no %s: field in %s", ID_FIELD, ct->c_file);
  97         return;
  98     }
  99
 100     if (!ce) {
 101         inform("unable to decode %s", ct->c_file);
 102         return;
 103     }
 104
 105     if (find_cache (NULL, wcachesw != CACHE_NEVER ? wcachesw : CACHE_ASK,
 106                     &cachetype, ct->c_id, cachefile, sizeof(cachefile))
 107             == NOTOK) {
 108         inform("unable to cache %s's contents", ct->c_file);
 109         return;
 110     }
 111     if (wcachesw != CACHE_NEVER && wcachesw != CACHE_ASK) {
 112         fflush (stdout);
 113         fprintf (stderr, "caching message %s as file %s\n", ct->c_file,
 114                  cachefile);
 115     }
 116
 117     if (ce->ce_file) {
 118         int mask = umask (cachetype ? ~m_gmprot () : 0222);
 119         FILE *fp;
 120
 121         if (debugsw)
 122             fprintf (stderr, "caching by copying %s...\n", ce->ce_file);
 123
 124         file = NULL;
 125         if ((*ct->c_ceopenfnx) (ct, &file) == NOTOK)
 126             goto reset_umask;
 127
 128         if ((fp = fopen (cachefile, "w"))) {
 129             int cc;
 130             char buffer[BUFSIZ];
 131             FILE *gp = ce->ce_fp;
 132
 133             fseek (gp, 0L, SEEK_SET);
 134
 135             while ((cc = fread (buffer, sizeof(*buffer), sizeof(buffer), gp))
 136                        > 0)
 137                 if ((int) fwrite (buffer, sizeof(*buffer), cc, fp) < cc) {
 138                     advise ("cache_content", "fwrite");
 139                 }
 140             fflush (fp);
 141
 142             if (ferror (gp)) {
 143                 admonish (ce->ce_file, "error reading");
 144                 (void) m_unlink (cachefile);
 145             } else {
 146                 if (ferror (fp)) {
 147                     admonish (cachefile, "error writing");
 148                     (void) m_unlink (cachefile);
 149                 }
 150             }
 151             fclose (fp);
 152         } else
 153             content_error (cachefile, ct, "unable to fopen for writing");
 154 reset_umask:
 155         umask (mask);
 156     } else {
 157         if (debugsw)
 158             fprintf (stderr, "in place caching...\n");
 159
 160         file = cachefile;
 161         if ((*ct->c_ceopenfnx) (ct, &file) != NOTOK)
 162             chmod (cachefile, cachetype ? m_gmprot () : 0444);
 163     }
 164 }
 165
 166
 167 int
 168 find_cache (CT ct, int policy, int *writing, char *id,
 169         char *buffer, int buflen)
 170 {
 171     int status = NOTOK;
 172
 173     if (id == NULL)
 174         return NOTOK;
 175     id = trimcpy (id);
 176
 177     if (debugsw)
 178         fprintf (stderr, "find_cache %s(%d) %s %s\n", caches[policy].sw,
 179                  policy, writing ? "writing" : "reading", id);
 180
 181     switch (policy) {
 182         case CACHE_NEVER:
 183         default:
 184             break;
 185
 186         case CACHE_ASK:
 187         case CACHE_PUBLIC:
 188             if (cache_private
 189                     && !writing
 190                     && find_cache_aux (writing ? 2 : 0, cache_private, id,
 191                                        buffer, buflen) == OK) {
 192                 if (access (buffer, R_OK) != NOTOK) {
 193 got_private:
 194                     if (writing)
 195                         *writing = 1;
 196 got_it:
 197                     status = OK;
 198                     break;
 199                 }
 200             }
 201             if (cache_public
 202                     && find_cache_aux (writing ? 1 : 0, cache_public, id,
 203                                        buffer, buflen) == OK) {
 204                 if (writing || access (buffer, R_OK) != NOTOK) {
 205                     if (writing)
 206                         *writing = 0;
 207                     goto got_it;
 208                 }
 209             }
 210             break;
 211
 212         case CACHE_PRIVATE:
 213             if (cache_private
 214                     && find_cache_aux (writing ? 2 : 0, cache_private, id,
 215                                        buffer, buflen) == OK) {
 216                 if (writing || access (buffer, R_OK) != NOTOK)
 217                     goto got_private;
 218             }
 219             break;
 220
 221     }
 222
 223     if (status == OK && policy == CACHE_ASK) {
 224         int len, buflen;
 225         char *bp, query[BUFSIZ];
 226
 227         /* Get buffer ready to go */
 228         bp = query;
 229         buflen = sizeof(query);
 230
 231         /* Now, construct query */
 232         if (writing) {
 233             snprintf (bp, buflen, "Make cached, publicly-accessible copy");
 234         } else {
 235             struct stat st;
 236
 237             snprintf (bp, buflen, "Use cached copy");
 238             len = strlen (bp);
 239             bp += len;
 240             buflen -= len;
 241
 242             if (ct->c_partno) {
 243                 snprintf (bp, buflen, " of content %s", ct->c_partno);
 244                 len = strlen (bp);
 245                 bp += len;
 246                 buflen -= len;
 247             }
 248
 249             stat (buffer, &st);
 250             snprintf (bp, buflen, " (size %lu octets)",
 251                             (unsigned long) st.st_size);
 252         }
 253         len = strlen (bp);
 254         bp += len;
 255         buflen -= len;
 256
 257         snprintf (bp, buflen, "\n    in file %s? ", buffer);
 258
 259         /* Now, check answer */
 260         if (!read_yes_or_no_if_tty (query))
 261             status = NOTOK;
 262     }
 263
 264     if (status == OK && writing) {
 265         if (*writing && strchr(buffer, '/'))
 266             make_intermediates (buffer);
 267         (void) m_unlink (buffer);
 268     }
 269
 270     free (id);
 271     return status;
 272 }
 273
 274
 275 static int
 276 find_cache_aux (int writing, char *directory, char *id,
 277         char *buffer, int buflen)
 278 {
 279     int mask, usemap;
 280     char mapfile[BUFSIZ], mapname[BUFSIZ];
 281     FILE *fp;
 282     int failed_to_lock = 0;
 283     static int partno, pid;
 284     static time_t clock = 0;
 285
 286     usemap = 1;
 287
 288     if (debugsw)
 289         fprintf (stderr, "find_cache_aux %s usemap=%d\n", directory, usemap);
 290
 291     snprintf (mapfile, sizeof(mapfile), "%s/cache.map", directory);
 292     if (find_cache_aux2 (mapfile, id, mapname, sizeof(mapname)) == OK)
 293         goto done_map;
 294
 295     if (!writing) {
 296         if (usemap)
 297             return NOTOK;
 298
 299 use_raw:
 300         snprintf (buffer, buflen, "%s/%s", directory, id);
 301         return OK;
 302     }
 303
 304     if (!usemap && access (mapfile, W_OK) == NOTOK)
 305         goto use_raw;
 306
 307     if (clock != 0) {
 308         time_t now;
 309
 310         time (&now);
 311         if (now > clock)
 312             clock = 0;
 313     } else {
 314         pid = getpid ();
 315     }
 316
 317     if (clock == 0) {
 318         time (&clock);
 319         partno = 0;
 320     } else {
 321         if (partno > 0xff) {
 322             clock++;
 323             partno = 0;
 324         }
 325     }
 326
 327     snprintf (mapname, sizeof(mapname), "%08x%04x%02x",
 328                 (unsigned int) (clock & 0xffffffff),
 329                 (unsigned int) (pid & 0xffff),
 330                 (unsigned int) (partno++ & 0xff));
 331
 332     if (debugsw)
 333         fprintf (stderr, "creating mapping %s->%s\n", mapname, id);
 334
 335     make_intermediates (mapfile);
 336     mask = umask (writing == 2 ? 0077 : 0);
 337     if (!(fp = lkfopendata (mapfile, "a", &failed_to_lock)) && errno == ENOENT) {
 338         int fd;
 339
 340         if ((fd = creat (mapfile, 0666)) != NOTOK) {
 341             close (fd);
 342             fp = lkfopendata (mapfile, "a", &failed_to_lock);
 343             if (failed_to_lock) {
 344                 adios (mapfile, "failed to lock");
 345             }
 346         }
 347     }
 348     umask (mask);
 349     if (!fp)
 350         return NOTOK;
 351     fprintf (fp, "%s: %s\n", mapname, id);
 352     lkfclosedata (fp, mapfile);
 353
 354 done_map:
 355     if (*mapname == '/')
 356         strncpy (buffer, mapname, buflen);
 357     else
 358         snprintf (buffer, buflen, "%s/%s", directory, mapname);
 359     if (debugsw)
 360         fprintf (stderr, "use %s\n", buffer);
 361
 362     return OK;
 363 }
 364
 365
 366 static int
 367 find_cache_aux2 (char *mapfile, char *id, char *mapname, int namelen)
 368 {
 369     int state;
 370     char buf[NMH_BUFSIZ], name[NAMESZ];
 371     FILE *fp;
 372     m_getfld_state_t gstate;
 373     int failed_to_lock = 0;
 374
 375     if (!(fp = lkfopendata (mapfile, "r", &failed_to_lock)))
 376         return NOTOK;
 377
 378     gstate = m_getfld_state_init(fp);
 379     for (;;) {
 380         int result;
 381         char *cp, *dp;
 382         int bufsz = sizeof buf;
 383
 384         switch (state = m_getfld2(&gstate, name, buf, &bufsz)) {
 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_getfld2(&gstate, name, buf, &bufsz);
 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 }