1 files changed, 53 insertions, 0 deletions
diff --git a/src/lib/string/compat_string.c b/src/lib/string/compat_string.c
index 6df1bc4a1d..3f8a4d515d 100644
--- a/src/lib/string/compat_string.c
+++ b/src/lib/string/compat_string.c
@@ -4,6 +4,7 @@
 /* See LICENSE for licensing information */
 
 #include "lib/string/compat_string.h"
+#include "lib/err/torerr.h"
 
 /* Inline the strl functions if the platform doesn't have them. */
 #ifndef HAVE_STRLCPY
@@ -12,3 +13,55 @@
 #ifndef HAVE_STRLCAT
 #include "strlcat.c"
 #endif
+
+#include <stdlib.h>
+
+/** Helper for tor_strtok_r_impl: Advances cp past all characters in
+ * <b>sep</b>, and returns its new value. */
+static char *
+strtok_helper(char *cp, const char *sep)
+{
+  if (sep[1]) {
+    while (*cp && strchr(sep, *cp))
+      ++cp;
+  } else {
+    while (*cp && *cp == *sep)
+      ++cp;
+  }
+  return cp;
+}
+
+/** Implementation of strtok_r for platforms whose coders haven't figured out
+ * how to write one.  Hey, retrograde libc developers!  You can use this code
+ * here for free! */
+char *
+tor_strtok_r_impl(char *str, const char *sep, char **lasts)
+{
+  char *cp, *start;
+  raw_assert(*sep);
+  if (str) {
+    str = strtok_helper(str, sep);
+    if (!*str)
+      return NULL;
+    start = cp = *lasts = str;
+  } else if (!*lasts || !**lasts) {
+    return NULL;
+  } else {
+    start = cp = *lasts;
+  }
+
+  if (sep[1]) {
+    while (*cp && !strchr(sep, *cp))
+      ++cp;
+  } else {
+    cp = strchr(cp, *sep);
+  }
+
+  if (!cp || !*cp) {
+    *lasts = NULL;
+  } else {
+    *cp++ = '\0';
+    *lasts = strtok_helper(cp, sep);
+  }
+  return start;
+}