$NetBSD: patch-CacheCheckSize,v 1.2 1999/05/09 21:12:32 tron Exp $

*** /dev/null	Tue Feb  6 11:05:04 1996
--- README-CACHE_CHECK_SIZE	Tue Feb  6 13:27:32 1996
***************
*** 0 ****
--- 1,11 ----
+ Patch to avoid serving truncated files from the cache.
+ 
+ Apply the patch, modify WWW/All/<model>/Makefile.include (for your model
+ system) and add '-DCACHE_CHECK_SIZE' to CFLAGS.
+ 
+ With the patch, the server checks the size of a file in the cache before
+ returning it to the user; if the size is incorrect, the server will
+ refresh the file in the cache.
+ 
+ -- 
+ -- 19960205, Gertjan van Oosten, gertjan@West.NL, West Consulting bv
*** WWW/Daemon/Implementation/HTCache.c.orig	Fri Aug 12 12:36:11 1994
--- Daemon/Implementation/HTCache.c	Mon Feb  5 14:02:11 1996
***************
*** 382,387 ****
--- 382,437 ----
  }
  
  
+ #ifdef CACHE_CHECK_SIZE
+ /*
+ **	Check whether cache file has correct size
+ **
+ ** On exit:
+ **	return YES
+ **		if size is good
+ **	return NO
+ **		if size is too small or too large
+ **
+ */
+ PRIVATE BOOL cache_check_size ARGS2(char *, cfn,
+                                     struct stat *, stat_info)
+ {
+     char buf[BUF_SIZE+2];
+     FILE *cf;
+     long cl = 0, pos, size, actual;
+ 
+     if (!cfn)
+ 	return NO;
+ 
+     cf = fopen(cfn, "r");
+     if (!cf)
+ 	return NO;
+ 
+     while (fgets(buf, sizeof(buf), cf)) {
+ 	if (!buf[0]
+ 	    || (buf[0] == '\n' && !buf[1])
+ 	    || (buf[0] == '\r' && buf[1] == '\n' && !buf[2]))
+ 	    break;
+ 
+         if (!strncasecomp(buf, "content-length:", 15))
+ 	    sscanf(buf+15, "%ld", &cl);
+     }
+     pos = ftell(cf);
+     fclose(cf);
+ 
+     size = stat_info->st_size;
+ 
+     actual = size - pos;
+     if (TRACE) {
+ 	fprintf(stderr,"Cache....... checking \"%s\": content-length %ld =?= %ld\n",
+ 		cfn,cl,actual);
+     }
+ 
+     return (cl == actual ? YES : NO);
+ }
+ #endif /* CACHE_CHECK_SIZE */
+ 
+ 
  PRIVATE BOOL do_caching ARGS1(char *, url)
  {
      HTList * cur = cc.no_caching;
***************
*** 460,465 ****
--- 510,518 ----
  				      time_t *,	expires)
  {
      struct stat stat_info;
+ #ifdef CACHE_CHECK_SIZE
+     BOOL size_ok;
+ #endif
  
      if (!url || !cfn || !cf || !if_ms) return CACHE_NO;
      *cfn = NULL;
***************
*** 497,503 ****
--- 550,563 ----
  	    }
  
  	    success = HTCacheInfo_for(*cfn, &ld, &lc, &ex, &mu, &lm);
+ #ifdef CACHE_CHECK_SIZE
+ 	    /* Check whether file in cache has correct size */
+ 	    size_ok = cache_check_size(*cfn, &stat_info);
+ #endif
  	    if (!success				  /* no entry */
+ #ifdef CACHE_CHECK_SIZE
+ 		|| !size_ok				  /* wrong size */
+ #endif
  		|| ex - cc.cache_time_margin <= cur_time  /* expired */
  		|| cur_time - lc >= refresh_interval	  /* time to refresh */
  		|| in.no_cache_pragma) {		  /* override cache */
***************
*** 507,512 ****
--- 567,576 ----
  		if (TRACE) {
  		    if (!success)
  			fprintf(stderr, "NoEntry..... %s -- expiring\n",*cfn);
+ #ifdef CACHE_CHECK_SIZE
+ 		    else if (!size_ok)
+ 			fprintf(stderr, "Truncated...... %s -- refresh\n",*cfn);
+ #endif
  		    else if (in.no_cache_pragma)
  			fprintf(stderr, "Forced...... refresh of %s\n",*cfn);
  		    else if (ex - cc.cache_time_margin <= cur_time)
***************
*** 527,533 ****
--- 591,601 ----
  		if (cc.cache_no_connect) {
  		    CTRACE(stderr, "Standalone.. caching mode but expired\n");
  		    cache_hit = YES;
+ #ifdef CACHE_CHECK_SIZE
+ 		    return size_ok ? CACHE_IF_MODIFIED : CACHE_CREATE;
+ #else
  		    return CACHE_IF_MODIFIED;
+ #endif
  		}
  
  		if (!(*cf = do_lock(*cfn))) {
***************
*** 550,556 ****
--- 618,628 ----
  		CTRACE(stderr,"IfModSince.. time: %s", ctime(if_ms));
  
  		free(backup);
+ #ifdef CACHE_CHECK_SIZE
+ 		return size_ok ? CACHE_IF_MODIFIED : CACHE_CREATE;
+ #else
  		return CACHE_IF_MODIFIED;
+ #endif
  	    }
  	    else {
  		CTRACE(stderr, "Cache....... not expired %s\n", *cfn);