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);
 }