added the --safe-links option to disallow symlinks outside the

[rsync/rsync.git] / util.c

diff --git a/util.c b/util.c
index 34c8f8b..bfa35f1 100644 (file)
--- a/util.c
+++ b/util.c
@@ -686,7 +686,7 @@ int u_strcmp(const char *cs1, const char *cs2)
        return (int)*s1 - (int)*s2;
 }
 
-static int last_pct = -1;
+static OFF_T last_ofs;
 
 void end_progress(void)
 {
@@ -695,7 +695,7 @@ void end_progress(void)
        if (do_progress && !am_server) {
                rprintf(FINFO,"\n");
        }
-       last_pct = -1;
+       last_ofs = 0;
 }
 
 void show_progress(OFF_T ofs, OFF_T size)
@@ -703,10 +703,57 @@ void show_progress(OFF_T ofs, OFF_T size)
        extern int do_progress, am_server;
 
        if (do_progress && !am_server) {
-               int pct = (int)((100.0*ofs)/size + 0.5);
-               if (pct != last_pct) {
+               if (ofs > last_ofs + 1000) {
+                       int pct = (int)((100.0*ofs)/size);
                        rprintf(FINFO,"%.0f (%d%%)\r", (double)ofs, pct);
-                       last_pct = pct;
+                       last_ofs = ofs;
                }
        }
 }
+
+/* determine if a symlink points outside the current directory tree */
+int unsafe_symlink(char *dest, char *src)
+{
+       char *tok;
+       int depth = 0;
+
+       /* all absolute and null symlinks are unsafe */
+       if (!dest || !(*dest) || (*dest == '/')) return 1;
+
+       src = strdup(src);
+       if (!src) out_of_memory("unsafe_symlink");
+
+       /* find out what our safety margin is */
+       for (tok=strtok(src,"/"); tok; tok=strtok(NULL,"/")) {
+               if (strcmp(tok,"..") == 0) {
+                       depth=0;
+               } else if (strcmp(tok,".") == 0) {
+                       /* nothing */
+               } else {
+                       depth++;
+               }
+       }
+       free(src);
+
+       /* drop by one to account for the filename portion */
+       depth--;
+
+       dest = strdup(dest);
+       if (!dest) out_of_memory("unsafe_symlink");
+
+       for (tok=strtok(dest,"/"); tok; tok=strtok(NULL,"/")) {
+               if (strcmp(tok,"..") == 0) {
+                       depth--;
+               } else if (strcmp(tok,".") == 0) {
+                       /* nothing */
+               } else {
+                       depth++;
+               }
+               /* if at any point we go outside the current directory then
+                  stop - it is unsafe */
+               if (depth < 0) break;
+       }
+
+       free(dest);
+       return (depth < 0);
+}