[tor-commits] [tor/master] Use evbuffer_copyout() in inspect_evbuffer().

[nickm at torproject.org]

commit d2cd67c83fff5097d214c8c86169054a5558b902
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Aug 17 13:07:43 2011 -0400

    Use evbuffer_copyout() in inspect_evbuffer().
---
 changes/require-le-2.0.13 |    5 +++++
 src/or/buffers.c          |   26 ++++++++------------------
 2 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/changes/require-le-2.0.13 b/changes/require-le-2.0.13
index 0b9b2f9..56e7b31 100644
--- a/changes/require-le-2.0.13
+++ b/changes/require-le-2.0.13
@@ -5,3 +5,8 @@
       Tor work badly with bufferevents. Requiring 2.0.13-stable also
       means that Tor with bufferevents can take advantage of Libevent
       APIs introduced after 2.0.8-rc.
+
+  o Minor bugfixes:
+    - Use evbuffer_copyout() in inspect_evbuffer(). This fixes a memory
+      leak, and lets Libevent worry about how to best copy data out
+      of a buffer.
diff --git a/src/or/buffers.c b/src/or/buffers.c
index 488289c..c9c8e43 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -1054,13 +1054,13 @@ fetch_var_cell_from_buf(buf_t *buf, var_cell_t **out, int linkproto)
 #ifdef USE_BUFFEREVENTS
 /** Try to read <b>n</b> bytes from <b>buf</b> at <b>pos</b> (which may be
  * NULL for the start of the buffer), copying the data only if necessary.  Set
- * *<b>data</b> to a pointer to the desired bytes.  Set <b>free_out</b> to 1
+ * *<b>data_out</b> to a pointer to the desired bytes.  Set <b>free_out</b> to 1
  * if we needed to malloc *<b>data</b> because the original bytes were
  * noncontiguous; 0 otherwise.  Return the number of bytes actually available
- * at <b>data</b>.
+ * at *<b>data_out</b>.
  */
 static ssize_t
-inspect_evbuffer(struct evbuffer *buf, char **data, size_t n, int *free_out,
+inspect_evbuffer(struct evbuffer *buf, char **data_out, size_t n, int *free_out,
                  struct evbuffer_ptr *pos)
 {
   int n_vecs, i;
@@ -1075,25 +1075,15 @@ inspect_evbuffer(struct evbuffer *buf, char **data, size_t n, int *free_out,
     struct evbuffer_iovec v;
     i = evbuffer_peek(buf, n, pos, &v, 1);
     tor_assert(i == 1);
-    *data = v.iov_base;
+    *data_out = v.iov_base;
     *free_out = 0;
     return v.iov_len;
   } else {
-    struct evbuffer_iovec *vecs =
-      tor_malloc(sizeof(struct evbuffer_iovec)*n_vecs);
-    size_t copied = 0;
-    i = evbuffer_peek(buf, n, NULL, vecs, n_vecs);
-    tor_assert(i == n_vecs);
-    *data = tor_malloc(n);
-    for (i=0; i < n_vecs; ++i) {
-      size_t copy = n - copied;
-      if (copy > vecs[i].iov_len)
-        copy = vecs[i].iov_len;
-      tor_assert(copied+copy <= n);
-      memcpy(data+copied, vecs[i].iov_base, copy);
-      copied += copy;
-    }
+    ev_ssize_t copied;
+    *data_out = tor_malloc(n);
     *free_out = 1;
+    copied = evbuffer_copyout(buf, *data_out, n);
+    tor_assert(copied >= 0 && (size_t)copied == n);
     return copied;
   }
 }