[MEDIUM] http: make the analyser not rely on msg being initialized anymore

The HTTP parser needed the msg structure to hold pre-initialized pointers.
This causes a trouble with keep-alive because if some data is still in the
buffer, the pointers can be anywhere after the data and later become invalid
when the buffer gets realigned.

It was not needed to rely on that since we have two valid information
in the buffer itself :

  - buf->lr : last visited place
  - buf->w + buf->send_max : beginning of next message

So by doing the maths only on those values, we can avoid doing tricks
on msg->som.

diff --git a/src/proto_http.c b/src/proto_http.c
index 791d52e..4d5d8e8 100644 (file)
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -1381,7 +1381,9 @@ const char *http_parse_reqline(struct http_msg *msg, const char *msg_buf,
  * when data are missing and recalled at the exact same location with no
  * information loss. The header index is re-initialized when switching from
  * MSG_R[PQ]BEFORE to MSG_RPVER|MSG_RQMETH. It modifies msg->sol among other
- * fields.
+ * fields. Note that msg->som and msg->sol will be initialized after completing
+ * the first state, so that none of the msg pointers has to be initialized
+ * prior to the first call.
  */
 void http_msg_analyzer(struct buffer *buf, struct http_msg *msg, struct hdr_idx *idx)
 {
@@ -1404,11 +1406,20 @@ void http_msg_analyzer(struct buffer *buf, struct http_msg *msg, struct hdr_idx
        http_msg_rpbefore:
        case HTTP_MSG_RPBEFORE:
                if (likely(HTTP_IS_TOKEN(*ptr))) {
-                       if (likely(ptr != buf->data + msg->som)) {
+                       /* we have a start of message, but we have to check
+                        * first if we need to remove some CRLF. We can only
+                        * do this when send_max=0.
+                        */
+                       char *beg = buf->w + buf->send_max;
+                       if (beg >= buf->data + buf->size)
+                               beg -= buf->size;
+                       if (unlikely(ptr != beg)) {
+                               if (buf->send_max)
+                                       goto http_msg_ood;
                                /* Remove empty leading lines, as recommended by RFC2616. */
-                               buffer_ignore(buf, ptr - buf->data - msg->som);
-                               msg->som = ptr - buf->data;
+                               buffer_ignore(buf, ptr - beg);
                        }
+                       msg->som = ptr - buf->data;
                        msg->sol = ptr;
                        hdr_idx_init(idx);
                        state = HTTP_MSG_RPVER;
@@ -1464,11 +1475,20 @@ void http_msg_analyzer(struct buffer *buf, struct http_msg *msg, struct hdr_idx
        http_msg_rqbefore:
        case HTTP_MSG_RQBEFORE:
                if (likely(HTTP_IS_TOKEN(*ptr))) {
-                       if (likely(ptr != buf->data + msg->som)) {
+                       /* we have a start of message, but we have to check
+                        * first if we need to remove some CRLF. We can only
+                        * do this when send_max=0.
+                        */
+                       char *beg = buf->w + buf->send_max;
+                       if (beg >= buf->data + buf->size)
+                               beg -= buf->size;
+                       if (likely(ptr != beg)) {
+                               if (buf->send_max)
+                                       goto http_msg_ood;
                                /* Remove empty leading lines, as recommended by RFC2616. */
-                               buffer_ignore(buf, ptr - buf->data - msg->som);
-                               msg->som = ptr - buf->data;
+                               buffer_ignore(buf, ptr - beg);
                        }
+                       msg->som = ptr - buf->data;
                        msg->sol = ptr;
                        /* we will need this when keep-alive will be supported
                           hdr_idx_init(idx);