From d745a3f117783fb4aa4bcdf62a0a18e589520574 Mon Sep 17 00:00:00 2001 From: Aurelien DARRAGON Date: Fri, 6 Jan 2023 15:06:49 +0100 Subject: [PATCH] MINOR: http_ext/7239: warn the user when fetch is not available http option forwarded (rfc7239) supports sample expressions when configuring 'host', 'for' and 'by' parameters. However, since we are in a http-backend-only context, right after http header is processed, we have a limited resolution scope for the sample expression provided by the user. To prevent any confusion, a warning is emitted when parsing the option if the user relies on a sample expression (more precisely a fetch) which would yield unexpected results at runtime when processing the option. --- src/http_ext.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/src/http_ext.c b/src/http_ext.c index 4a9a0b0..f2e3781 100644 --- a/src/http_ext.c +++ b/src/http_ext.c @@ -1143,6 +1143,19 @@ int proxy_http_compile_7239(struct proxy *curproxy) ha_free(&err); cfgerr++; } + else if (!(cur_expr->fetch->val & SMP_VAL_BE_HRQ_HDR)) { + /* fetch not available in this context: sample expr is resolved + * within backend right after headers are processed. + * (in http_process_request()) + * -> we simply warn the user about the misuse + */ + ha_warning("%s '%s' [%s:%d]: in 'option forwarded' sample expression '%s' : " + "some args extract information from '%s', " + "none of which is available here.\n", + proxy_type_str(curproxy), curproxy->id, + curproxy->http.fwd.c_file, curproxy->http.fwd.c_line, + *expr_str, sample_ckp_names(cur_expr->fetch->use)); + } /* post parsing individual expr cleanup */ ha_free(expr_str); -- 1.7.10.4