MAJOR: http: reset msg->sov after headers are forwarded

In order to avoid abusively relying on buf->o to guess how many bytes to
rewind during a redispatch, we now clear msg->sov. Thus the meaning of this
field is exactly "how many bytes of headers are left to be forwarded". It
is still possible to rewind because msg->eoh + msg->eol equal that value
before scheduling the forwarding, so we can always subtract them.

diff --git a/include/proto/proto_http.h b/include/proto/proto_http.h
index 53f0eca04cec96fc88f7d113ada43a375011b0eb..2c8b062a99c9c6d8ab9c6fad75fe1a6c5d726d01 100644 (file)
--- a/include/proto/proto_http.h
+++ b/include/proto/proto_http.h
@@ -134,10 +134,13 @@ enum http_meth_t find_http_meth(const char *str, const int len);
 /* Return the amount of bytes that need to be rewound before buf->p to access
  * the current message's headers. The purpose is to be able to easily fetch
  * the message's beginning before headers are forwarded, as well as after.
+ * The principle is that msg->eoh and msg->eol are immutable while msg->sov
+ * equals the sum of the two before forwarding and is zero after forwarding,
+ * so the difference cancels the rewinding.
  */
 static inline int http_hdr_rewind(const struct http_msg *msg)
 {
-       return msg->chn->buf->o;
+       return msg->eoh + msg->eol - msg->sov;
 }
 
 /* Return the amount of bytes that need to be rewound before buf->p to access
@@ -179,7 +182,7 @@ static inline int http_body_bytes(const struct http_msg *msg)
 {
        int len;
 
-       len = buffer_len(msg->chn->buf) - msg->sov - msg->sol;
+       len = msg->chn->buf->i - msg->sov - msg->sol;
        if (len > msg->body_len)
                len = msg->body_len;
        return len;

diff --git a/src/proto_http.c b/src/proto_http.c
index 0c30d0e0186780d55f4953768a22468cd86fd77c..328f28b51bc8216f2c0a3ff0424c08ea1648b8df 100644 (file)
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -5064,6 +5064,7 @@ int http_request_forward_body(struct session *s, struct channel *req, int an_bit
                        msg->chunk_len += msg->next;
                        msg->chunk_len -= channel_forward(req, msg->chunk_len);
                        msg->next       = 0;
+                       msg->sov        = 0;
                }
 
                if (msg->msg_state == HTTP_MSG_DATA) {
@@ -6188,6 +6189,7 @@ int http_response_forward_body(struct session *s, struct channel *res, int an_bi
                 */
                channel_forward(res, msg->sov);
                msg->next = 0;
+               msg->sov  = 0;
 
                if (msg->flags & HTTP_MSGF_TE_CHNK)
                        msg->msg_state = HTTP_MSG_CHUNK_SIZE;
@@ -6213,6 +6215,7 @@ int http_response_forward_body(struct session *s, struct channel *res, int an_bi
                                msg->chunk_len += msg->next;
                                msg->chunk_len -= channel_forward(res, msg->chunk_len);
                                msg->next       = 0;
+                               msg->sov        = 0;
                        }
                }
 
@@ -6302,6 +6305,7 @@ int http_response_forward_body(struct session *s, struct channel *res, int an_bi
                                /* forwarding trailers */
                                channel_forward(res, msg->next);
                                msg->next = 0;
+                               msg->sov  = 0;
                        }
                        /* we're in HTTP_MSG_DONE now, but we might still have
                         * some data pending, so let's loop over once.
@@ -6373,6 +6377,7 @@ int http_response_forward_body(struct session *s, struct channel *res, int an_bi
                        msg->chunk_len += msg->next;
                        msg->chunk_len -= channel_forward(res, msg->chunk_len);
                        msg->next       = 0;
+                       msg->sov        = 0;
                }
        }