From 4c8abb84e399f964d6b70f24c6324f261fd4565a Mon Sep 17 00:00:00 2001 From: Ruslan Ermilov Date: Thu, 23 Apr 2020 15:10:24 +0300 Subject: [PATCH] gRPC: RST_STREAM(NO_ERROR) handling (ticket #1792). As per https://tools.ietf.org/html/rfc7540#section-8.1, : A server can send a complete response prior to the client : sending an entire request if the response does not depend on : any portion of the request that has not been sent and : received. When this is true, a server MAY request that the : client abort transmission of a request without error by : sending a RST_STREAM with an error code of NO_ERROR after : sending a complete response (i.e., a frame with the : END_STREAM flag). Clients MUST NOT discard responses as a : result of receiving such a RST_STREAM, though clients can : always discard responses at their discretion for other : reasons. Previously, RST_STREAM(NO_ERROR) received from upstream after a frame with the END_STREAM flag was incorrectly treated as an error. Now, a single RST_STREAM(NO_ERROR) is properly handled. This fixes problems observed with modern grpc-c [1], as well as with the Go gRPC module. [1] https://github.com/grpc/grpc/pull/1661 --- src/http/modules/ngx_http_grpc_module.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/src/http/modules/ngx_http_grpc_module.c b/src/http/modules/ngx_http_grpc_module.c index d4af66dbf..9e62d8e2a 100644 --- a/src/http/modules/ngx_http_grpc_module.c +++ b/src/http/modules/ngx_http_grpc_module.c @@ -120,6 +120,7 @@ typedef struct { unsigned end_stream:1; unsigned done:1; unsigned status:1; + unsigned rst:1; ngx_http_request_t *request; @@ -1205,6 +1206,7 @@ ngx_http_grpc_reinit_request(ngx_http_request_t *r) ctx->end_stream = 0; ctx->done = 0; ctx->status = 0; + ctx->rst = 0; ctx->connection = NULL; return NGX_OK; @@ -2088,7 +2090,9 @@ ngx_http_grpc_filter(void *data, ssize_t bytes) return NGX_ERROR; } - if (ctx->stream_id && ctx->done) { + if (ctx->stream_id && ctx->done + && ctx->type != NGX_HTTP_V2_RST_STREAM_FRAME) + { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "upstream sent frame for closed stream %ui", ctx->stream_id); @@ -2131,11 +2135,21 @@ ngx_http_grpc_filter(void *data, ssize_t bytes) return NGX_ERROR; } - ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, - "upstream rejected request with error %ui", - ctx->error); + if (ctx->error || !ctx->done) { + ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, + "upstream rejected request with error %ui", + ctx->error); + return NGX_ERROR; + } - return NGX_ERROR; + if (ctx->rst) { + ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, + "upstream sent frame for closed stream %ui", + ctx->stream_id); + return NGX_ERROR; + } + + ctx->rst = 1; } if (ctx->type == NGX_HTTP_V2_GOAWAY_FRAME) {