Add a check to prevent sending the double body response to the agent

Author: joelwurtz

src/ngx_http_redirectionio_module.c

@@ -174,6 +174,7 @@ static ngx_int_t ngx_http_redirectionio_create_ctx_handler(ngx_http_request_t *r
         ctx->is_redirected = 0;
         ctx->headers_sent = 0;
         ctx->body_buffer = NULL;
+        ctx->body_sent = 0;
         ctx->read_binary_handler = NULL;
         ctx->first_buffer = 1;
         ctx->last_chain_sent = NULL;

src/ngx_http_redirectionio_module.h

@@ -61,6 +61,7 @@ typedef struct {
 
     ngx_chain_t                                     *body_buffer;
     ngx_chain_t                                     *last_chain_sent;
+    ngx_uint_t                                      body_sent;
 } ngx_http_redirectionio_ctx_t;
 
 void ngx_http_redirectionio_read_dummy_handler(ngx_event_t *rev, cJSON *json);

src/ngx_http_redirectionio_module_filter.c

@@ -57,6 +57,8 @@ ngx_int_t ngx_http_redirectionio_match_on_response_status_header_filter(ngx_http
     // Avoid loop if we redirect on the same status as we match
     ctx->is_redirected = 1;
 
+    // @TODO This will made a double body response (one from nginx / one from upstream)
+    // @TODO Find a way to cancel the current body response
     return ngx_http_special_response_handler(r, ctx->status);
 }
 
@@ -142,6 +144,10 @@ ngx_int_t ngx_http_redirectionio_body_filter(ngx_http_request_t *r, ngx_chain_t
         return ngx_http_next_body_filter(r, in);
     }
 
+    if (ctx->body_sent) {
+        return NGX_OK;
+    }
+
     // Check if we are waiting for filtering headers or connection
     if (ctx->wait_for_header_filtering || ctx->wait_for_connection) {
         // Set request is buffered to avoid its destruction by nginx
@@ -219,6 +225,7 @@ static void ngx_http_redirectionio_write_filter_body_handler(ngx_event_t *wev, n
     ngx_http_request_t              *r;
     ngx_http_redirectionio_conf_t   *conf;
     ngx_chain_t                     *cl;
+    ngx_uint_t                      last;
 
     c = wev->data;
     r = c->data;
@@ -240,7 +247,11 @@ static void ngx_http_redirectionio_write_filter_body_handler(ngx_event_t *wev, n
     ctx->last_chain_sent = in;
     ctx->read_binary_handler = ngx_http_redirectionio_read_filter_body_handler;
 
-    ngx_http_redirectionio_protocol_send_filter_body(c, in, &conf->project_key, &ctx->matched_rule_id, is_first);
+    last = ngx_http_redirectionio_protocol_send_filter_body(c, in, &conf->project_key, &ctx->matched_rule_id, is_first);
+
+    if (last == 1) {
+        ctx->body_sent = 1;
+    }
 }
 
 static void ngx_http_redirectionio_read_filter_headers_handler(ngx_event_t *rev, cJSON *json) {

src/ngx_http_redirectionio_protocol.c

@@ -1,4 +1,5 @@
 #include <ngx_http_redirectionio_protocol.h>
+#include <ngx_http_redirectionio_module.h>
 
 const char COMMAND_MATCH_NAME[] = "MATCH_WITH_RESPONSE";
 const char COMMAND_MATCH_QUERY[] = "{ \"project_id\": \"%V\", \"request_uri\": \"%V\", \"host\": \"%V\" }";
@@ -173,7 +174,7 @@ void ngx_http_redirectionio_protocol_send_filter_header(ngx_connection_t *c, ngx
     free((void *)dst);
 }
 
-void ngx_http_redirectionio_protocol_send_filter_body(ngx_connection_t *c, ngx_chain_t *in, ngx_str_t *project_key, ngx_str_t *rule_id, ngx_uint_t is_first) {
+ngx_uint_t ngx_http_redirectionio_protocol_send_filter_body(ngx_connection_t *c, ngx_chain_t *in, ngx_str_t *project_key, ngx_str_t *rule_id, ngx_uint_t is_first) {
     ngx_chain_t     *chain;
     uint64_t        bsize;
 
@@ -211,9 +212,12 @@ void ngx_http_redirectionio_protocol_send_filter_body(ngx_connection_t *c, ngx_c
     // If last write empty buffer
     if (chain->buf != NULL && chain->buf->last_buf) {
         bsize = htonll((uint64_t)-1);
-
         ngx_send(c, (u_char *)&bsize, sizeof(uint64_t));
+
+        return 1;
     }
+
+    return 0;
 }
 
 static void ngx_str_copy(ngx_str_t *src, ngx_str_t *dest) {

src/ngx_http_redirectionio_protocol.h

@@ -22,6 +22,6 @@ void ngx_http_redirectionio_protocol_send_log(ngx_connection_t *c, ngx_http_redi
 ngx_http_redirectionio_log_t* ngx_http_redirectionio_protocol_create_log(ngx_http_request_t *r, ngx_str_t *project_key, ngx_str_t *rule_id);
 void ngx_http_redirectionio_protocol_free_log(ngx_http_redirectionio_log_t *log);
 void ngx_http_redirectionio_protocol_send_filter_header(ngx_connection_t *c, ngx_http_request_t *r, ngx_str_t *project_key, ngx_str_t *rule_id);
-void ngx_http_redirectionio_protocol_send_filter_body(ngx_connection_t *c, ngx_chain_t *in, ngx_str_t *project_key, ngx_str_t *rule_id, ngx_uint_t is_first);
+ngx_uint_t ngx_http_redirectionio_protocol_send_filter_body(ngx_connection_t *c, ngx_chain_t *in, ngx_str_t *project_key, ngx_str_t *rule_id, ngx_uint_t is_first);
 
 #endif