MEDIUM: http: refrain from sending "Connection: close" when Upgrade is present
Some servers are not totally HTTP-compliant when it comes to parsing the
Connection header. This is particularly true with WebSocket where it happens
from time to time that a server doesn't support having a "close" token along
with the "Upgrade" token in the Connection header. This broken behaviour has
also been noticed on some clients though the problem is less frequent on the
response path.
Sometimes the workaround consists in enabling "option http-pretend-keepalive"
to leave the request Connection header untouched, but this is not always the
most convenient solution. This patch introduces a new solution : haproxy now
also looks for the "Upgrade" token in the Connection header and if it finds
it, then it refrains from adding any other token to the Connection header
(though "keep-alive" and "close" may still be removed if found). The same is
done for the response headers.
This way, WebSocket much with less changes even when facing non-compliant
clients or servers. At least it fixes the DISCONNECT issue that was seen
on the websocket.org test.
Note that haproxy does not change its internal mode, it just refrains from
adding new tokens to the connection header.
diff --git a/src/proto_http.c b/src/proto_http.c
index 8e96ae6..c1fd6a7 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -1631,6 +1631,7 @@
* be removed, we remove them now. The <to_del> flags are used for that :
* - bit 0 means remove "close" headers (in HTTP/1.0 requests/responses)
* - bit 1 means remove "keep-alive" headers (in HTTP/1.1 reqs/resp to 1.1).
+ * Presence of the "Upgrade" token is also checked and reported.
* The TX_HDR_CONN_* flags are adjusted in txn->flags depending on what was
* found, and TX_CON_*_SET is adjusted depending on what is left so only
* harmless combinations may be removed. Do not call that after changes have
@@ -1667,6 +1668,9 @@
else
txn->flags |= TX_CON_CLO_SET;
}
+ else if (ctx.vlen >= 7 && word_match(ctx.line + ctx.val, ctx.vlen, "upgrade", 7)) {
+ txn->flags |= TX_HDR_CONN_UPG;
+ }
}
txn->flags |= TX_HDR_CONN_PRS;
@@ -2545,7 +2549,7 @@
msg->flags |= HTTP_MSGF_VER_11;
/* "connection" has not been parsed yet */
- txn->flags &= ~(TX_HDR_CONN_PRS | TX_HDR_CONN_CLO | TX_HDR_CONN_KAL);
+ txn->flags &= ~(TX_HDR_CONN_PRS | TX_HDR_CONN_CLO | TX_HDR_CONN_KAL | TX_HDR_CONN_UPG);
/* if the frontend has "option http-use-proxy-header", we'll check if
* we have what looks like a proxied connection instead of a connection,
@@ -3661,9 +3665,14 @@
}
}
- /* 11: add "Connection: close" or "Connection: keep-alive" if needed and not yet set. */
- if (((txn->flags & TX_CON_WANT_MSK) != TX_CON_WANT_TUN) ||
- ((s->fe->options|s->be->options) & PR_O_HTTP_CLOSE)) {
+ /* 11: add "Connection: close" or "Connection: keep-alive" if needed and not yet set.
+ * If an "Upgrade" token is found, the header is left untouched in order not to have
+ * to deal with some servers bugs : some of them fail an Upgrade if anything but
+ * "Upgrade" is present in the Connection header.
+ */
+ if (!(txn->flags & TX_HDR_CONN_UPG) &&
+ (((txn->flags & TX_CON_WANT_MSK) != TX_CON_WANT_TUN) ||
+ ((s->fe->options|s->be->options) & PR_O_HTTP_CLOSE))) {
unsigned int want_flags = 0;
if (msg->flags & HTTP_MSGF_VER_11) {
@@ -4970,7 +4979,7 @@
msg->flags |= HTTP_MSGF_VER_11;
/* "connection" has not been parsed yet */
- txn->flags &= ~(TX_HDR_CONN_PRS|TX_HDR_CONN_CLO|TX_HDR_CONN_KAL|TX_CON_CLO_SET|TX_CON_KAL_SET);
+ txn->flags &= ~(TX_HDR_CONN_PRS|TX_HDR_CONN_CLO|TX_HDR_CONN_KAL|TX_HDR_CONN_UPG|TX_CON_CLO_SET|TX_CON_KAL_SET);
/* transfer length unknown*/
msg->flags &= ~HTTP_MSGF_XFER_LEN;
@@ -5447,9 +5456,13 @@
/*
* 8: adjust "Connection: close" or "Connection: keep-alive" if needed.
+ * If an "Upgrade" token is found, the header is left untouched in order
+ * not to have to deal with some client bugs : some of them fail an upgrade
+ * if anything but "Upgrade" is present in the Connection header.
*/
- if (((txn->flags & TX_CON_WANT_MSK) != TX_CON_WANT_TUN) ||
- ((t->fe->options|t->be->options) & PR_O_HTTP_CLOSE)) {
+ if (!(txn->flags & TX_HDR_CONN_UPG) &&
+ (((txn->flags & TX_CON_WANT_MSK) != TX_CON_WANT_TUN) ||
+ ((t->fe->options|t->be->options) & PR_O_HTTP_CLOSE))) {
unsigned int want_flags = 0;
if ((txn->flags & TX_CON_WANT_MSK) == TX_CON_WANT_KAL ||