cache_safe_filename() needs more buffers

The single static buffer makes it impossible to use the result of two
different calls to this function simultaneously. Fix it by using 4
buffers.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/cache.c b/cache.c
index 7cdea9b..372e38d 100644
--- a/cache.c
+++ b/cache.c
@@ -1,114 +1,119 @@
 /* cache.c: cache management
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 const int NOLOCK = -1;
 
 char *cache_safe_filename(const char *unsafe)
 {
-	static char buf[PATH_MAX];
-	char *s = buf;
+	static char buf[4][PATH_MAX];
+	static int bufidx;
+	char *s;
 	char c;
 
+	bufidx++;
+	bufidx &= 3;
+	s = buf[bufidx];
+
 	while(unsafe && (c = *unsafe++) != 0) {
-		if (c == '/' || c == ' ' || c == '&' || c == '|' || 
+		if (c == '/' || c == ' ' || c == '&' || c == '|' ||
 		    c == '>' || c == '<' || c == '.')
 			c = '_';
 		*s++ = c;
 	}
 	*s = '\0';
-	return buf;
+	return buf[bufidx];
 }
 
 int cache_exist(struct cacheitem *item)
 {
 	if (stat(item->name, &item->st)) {
 		item->st.st_mtime = 0;
 		return 0;
 	}
 	return 1;
 }
 
 int cache_create_dirs()
 {
 	char *path;
 
 	path = fmt("%s", cgit_cache_root);
 	if (mkdir(path, S_IRWXU) && errno!=EEXIST)
 		return 0;
 
 	if (!cgit_repo)
 		return 0;
 
 	path = fmt("%s/%s", cgit_cache_root,
 		   cache_safe_filename(cgit_repo->url));
 
 	if (mkdir(path, S_IRWXU) && errno!=EEXIST)
 		return 0;
 
 	if (cgit_query_page) {
 		path = fmt("%s/%s/%s", cgit_cache_root,
 			   cache_safe_filename(cgit_repo->url),
 			   cgit_query_page);
 		if (mkdir(path, S_IRWXU) && errno!=EEXIST)
 			return 0;
 	}
 	return 1;
 }
 
 int cache_refill_overdue(const char *lockfile)
 {
 	struct stat st;
 
 	if (stat(lockfile, &st))
 		return 0;
 	else
 		return (time(NULL) - st.st_mtime > cgit_cache_max_create_time);
 }
 
 int cache_lock(struct cacheitem *item)
 {
 	int i = 0;
 	char *lockfile = xstrdup(fmt("%s.lock", item->name));
 
  top:
 	if (++i > cgit_max_lock_attempts)
 		die("cache_lock: unable to lock %s: %s",
 		    item->name, strerror(errno));
 
        	item->fd = open(lockfile, O_WRONLY|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR);
 
 	if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs())
 		goto top;
 
 	if (item->fd == NOLOCK && errno == EEXIST &&
 	    cache_refill_overdue(lockfile) && !unlink(lockfile))
 			goto top;
 
 	free(lockfile);
 	return (item->fd > 0);
 }
 
 int cache_unlock(struct cacheitem *item)
 {
 	close(item->fd);
 	return (rename(fmt("%s.lock", item->name), item->name) == 0);
 }
 
 int cache_cancel_lock(struct cacheitem *item)
 {
 	return (unlink(fmt("%s.lock", item->name)) == 0);
 }
 
 int cache_expired(struct cacheitem *item)
 {
 	if (item->ttl < 0)
 		return 0;
 	return item->st.st_mtime + item->ttl * 60 < time(NULL);
 }