1 files changed, 95 insertions, 0 deletions
diff --git a/src/feature/control/control_fmt.c b/src/feature/control/control_fmt.c
index c87a224ac5..290ea61450 100644
--- a/src/feature/control/control_fmt.c
+++ b/src/feature/control/control_fmt.c
@@ -297,3 +297,98 @@ read_escaped_data(const char *data, size_t len, char **out)
   *outp = '\0';
   return outp - *out;
 }
+
+/** Send a "DONE" message down the control connection <b>conn</b>. */
+void
+send_control_done(control_connection_t *conn)
+{
+  connection_write_str_to_buf("250 OK\r\n", conn);
+}
+
+/** If the first <b>in_len_max</b> characters in <b>start</b> contain a
+ * double-quoted string with escaped characters, return the length of that
+ * string (as encoded, including quotes).  Otherwise return -1. */
+static inline int
+get_escaped_string_length(const char *start, size_t in_len_max,
+                          int *chars_out)
+{
+  const char *cp, *end;
+  int chars = 0;
+
+  if (*start != '\"')
+    return -1;
+
+  cp = start+1;
+  end = start+in_len_max;
+
+  /* Calculate length. */
+  while (1) {
+    if (cp >= end) {
+      return -1; /* Too long. */
+    } else if (*cp == '\\') {
+      if (++cp == end)
+        return -1; /* Can't escape EOS. */
+      ++cp;
+      ++chars;
+    } else if (*cp == '\"') {
+      break;
+    } else {
+      ++cp;
+      ++chars;
+    }
+  }
+  if (chars_out)
+    *chars_out = chars;
+  return (int)(cp - start+1);
+}
+
+/** As decode_escaped_string, but does not decode the string: copies the
+ * entire thing, including quotation marks. */
+const char *
+extract_escaped_string(const char *start, size_t in_len_max,
+                       char **out, size_t *out_len)
+{
+  int length = get_escaped_string_length(start, in_len_max, NULL);
+  if (length<0)
+    return NULL;
+  *out_len = length;
+  *out = tor_strndup(start, *out_len);
+  return start+length;
+}
+
+/** Given a pointer to a string starting at <b>start</b> containing
+ * <b>in_len_max</b> characters, decode a string beginning with one double
+ * quote, containing any number of non-quote characters or characters escaped
+ * with a backslash, and ending with a final double quote.  Place the resulting
+ * string (unquoted, unescaped) into a newly allocated string in *<b>out</b>;
+ * store its length in <b>out_len</b>.  On success, return a pointer to the
+ * character immediately following the escaped string.  On failure, return
+ * NULL. */
+const char *
+decode_escaped_string(const char *start, size_t in_len_max,
+                   char **out, size_t *out_len)
+{
+  const char *cp, *end;
+  char *outp;
+  int len, n_chars = 0;
+
+  len = get_escaped_string_length(start, in_len_max, &n_chars);
+  if (len<0)
+    return NULL;
+
+  end = start+len-1; /* Index of last quote. */
+  tor_assert(*end == '\"');
+  outp = *out = tor_malloc(len+1);
+  *out_len = n_chars;
+
+  cp = start+1;
+  while (cp < end) {
+    if (*cp == '\\')
+      ++cp;
+    *outp++ = *cp++;
+  }
+  *outp = '\0';
+  tor_assert((outp - *out) == (int)*out_len);
+
+  return end+1;
+}