more robust http(ish) handling

svn:r123

1 files changed, 24 insertions, 2 deletions

diff --git a/src/or/buffers.c b/src/or/buffers.c
index 30b476e200..5b4053c90d 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -129,9 +129,9 @@ int write_to_buf(char *string, int string_len,
 }
 
 int fetch_from_buf(char *string, int string_len,
-                 char **buf, int *buflen, int *buf_datalen) {
+                   char **buf, int *buflen, int *buf_datalen) {
 
-  /* if there is string_len bytes in buf, write them onto string,
+  /* if there are string_len bytes in buf, write them onto string,
    * then memmove buf back (that is, remove them from buf) */
 
   assert(string && buf && *buf && buflen && buf_datalen);
@@ -147,3 +147,25 @@ int fetch_from_buf(char *string, int string_len,
   return *buf_datalen;
 }
 
+int find_on_inbuf(char *string, int string_len,
+                  char *buf, int buf_datalen) {
+  /* find first instance of needle 'string' on haystack 'buf'. return how
+   * many bytes from the beginning of buf to the end of string.
+   * If it's not there, return -1.
+   */
+
+  char *location;
+  char *last_possible = buf + buf_datalen - string_len;
+
+  assert(string && string_len > 0 && buf);
+
+  if(buf_datalen < string_len)
+    return -1;
+
+  for(location = buf; location <= last_possible; location++)
+    if((*location == *string) && !memcmp(location+1, string+1, string_len-1))
+      return location-buf+string_len;
+
+  return -1;
+}
+