From 4d37351eab0ea02ca065f4415aa6ac556a8c7820 Mon Sep 17 00:00:00 2001 From: Benjamin Barenblat Date: Mon, 7 Nov 2016 17:31:19 -0500 Subject: FastCGI: Track request IDs during processing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When processing a FastCGI request, save its request ID in thread-local storage and respond with the same request ID (rather than hard-coding 1). This fixes FastCGI on picky web servers (nginx). For more background, see https://github.com/urweb/urweb/issues/57 and ยง3.3 of the FastCGI specification. Tested with nginx 1.10.2 and lighttpd 1.4.39. Closes https://github.com/urweb/urweb/issues/57. --- configure.ac | 1 + m4/ax_tls.m4 | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ src/c/fastcgi.c | 45 ++++++++++++++++++++++++++++++++++- 3 files changed, 119 insertions(+), 1 deletion(-) create mode 100644 m4/ax_tls.m4 diff --git a/configure.ac b/configure.ac index 8ee3e795..0dda6d3b 100644 --- a/configure.ac +++ b/configure.ac @@ -12,6 +12,7 @@ AC_PROG_LIBTOOL() AC_CONFIG_HEADERS([include/urweb/config.h]) AX_PTHREAD([echo >/dev/null], [echo "Your C compiler does not support POSIX threads."; exit 1]) +AX_TLS([echo >/dev/null], [echo "Your C compiler does not support thread-local storage."; exit 1]) AX_CHECK_OPENSSL([echo >/dev/null], [echo "You must install OpenSSL development files."; exit 1]) diff --git a/m4/ax_tls.m4 b/m4/ax_tls.m4 new file mode 100644 index 00000000..809b761a --- /dev/null +++ b/m4/ax_tls.m4 @@ -0,0 +1,74 @@ +# =========================================================================== +# http://www.gnu.org/software/autoconf-archive/ax_tls.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_TLS([action-if-found], [action-if-not-found]) +# +# DESCRIPTION +# +# Provides a test for the compiler support of thread local storage (TLS) +# extensions. Defines TLS if it is found. Currently knows about GCC/ICC +# and MSVC. I think SunPro uses the same as GCC, and Borland apparently +# supports either. +# +# LICENSE +# +# Copyright (c) 2008 Alan Woodland +# Copyright (c) 2010 Diego Elio Petteno` +# +# This program is free software: you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation, either version 3 of the License, or (at your +# option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General +# Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program. If not, see . +# +# As a special exception, the respective Autoconf Macro's copyright owner +# gives unlimited permission to copy, distribute and modify the configure +# scripts that are the output of Autoconf when processing the Macro. You +# need not follow the terms of the GNU General Public License when using +# or distributing such scripts, even though portions of the text of the +# Macro appear in them. The GNU General Public License (GPL) does govern +# all other use of the material that constitutes the Autoconf Macro. +# +# This special exception to the GPL applies to versions of the Autoconf +# Macro released by the Autoconf Archive. When you make and distribute a +# modified version of the Autoconf Macro, you may extend this special +# exception to the GPL to apply to your modified version as well. + +#serial 11 + +AC_DEFUN([AX_TLS], [ + AC_MSG_CHECKING([for thread local storage (TLS) class]) + AC_CACHE_VAL([ac_cv_tls], + [for ax_tls_keyword in __thread '__declspec(thread)' none; do + AS_CASE([$ax_tls_keyword], + [none], [ac_cv_tls=none ; break], + [AC_TRY_COMPILE( + [#include + static void + foo(void) { + static ] $ax_tls_keyword [ int bar; + exit(1); + }], + [], + [ac_cv_tls=$ax_tls_keyword ; break], + ac_cv_tls=none + )]) + done + ]) + AC_MSG_RESULT([$ac_cv_tls]) + + AS_IF([test "$ac_cv_tls" != "none"], + [AC_DEFINE_UNQUOTED([TLS],[$ac_cv_tls],[If the compiler supports a TLS storage class define it to that here]) + m4_ifnblank([$1],[$1])], + [m4_ifnblank([$2],[$2])]) +]) diff --git a/src/c/fastcgi.c b/src/c/fastcgi.c index cda3e1f6..c37debf7 100644 --- a/src/c/fastcgi.c +++ b/src/c/fastcgi.c @@ -1,5 +1,7 @@ #include "config.h" +#include +#include #include #include #include @@ -20,6 +22,8 @@ #include "fastcgi.h" +#define THREAD_LOCAL __thread + extern uw_app uw_application; typedef struct { @@ -44,6 +48,21 @@ typedef struct { int available, used, sock; } FCGI_Input; +// The FastCGI request ID corresponding to the request being handled by the +// current worker thread. (Each worker thread can only handle one request at a +// time.) +static THREAD_LOCAL int current_request_id; + +// Reads the FastCGI request ID from a FastCGI record. The result is guaranteed +// to be in the range [0, 2^16); this function returns an int to avoid C type +// promotion insanity. +static int fastcgi_request_id(const FCGI_Record* const r) { + const int requestid = r->requestIdB1 << 8 | r->requestIdB0; + assert(requestid >= 0); + assert(requestid <= UINT16_MAX); + return requestid; +} + static FCGI_Output *fastcgi_output() { FCGI_Output *o = malloc(sizeof(FCGI_Output)); @@ -70,7 +89,9 @@ static int fastcgi_send(FCGI_Output *o, unsigned char type, unsigned short contentLength) { o->r.type = type; - o->r.requestIdB1 = o->r.requestIdB0 = 0; + assert(current_request_id <= UINT16_MAX); + o->r.requestIdB1 = current_request_id >> 8; + o->r.requestIdB0 = current_request_id & 0x000000ff; o->r.contentLengthB1 = contentLength >> 8; o->r.contentLengthB0 = contentLength & 255; return uw_really_send(o->sock, &o->r, sizeof(o->r) - 65535 + contentLength); @@ -356,6 +377,10 @@ static void *worker(void *data) { goto done; } + // Save the FastCGI request ID this worker is handling so that fastcgi_send + // can include it in its response. + current_request_id = fastcgi_request_id(r); + if (r->type != FCGI_BEGIN_REQUEST) { write_stderr(out, "First message is not BEGIN_REQUEST\n"); goto done; @@ -373,6 +398,15 @@ static void *worker(void *data) { goto done; } + if (fastcgi_request_id(r) != current_request_id) { + write_stderr(out, + "Ignoring environment variables for request %d (current" + " request has id %d)\n", + fastcgi_request_id(r), + current_request_id); + continue; + } + if (r->type != FCGI_PARAMS) { write_stderr(out, "Expected FCGI_PARAMS but got %d\n", r->type); goto done; @@ -428,6 +462,15 @@ static void *worker(void *data) { goto done; } + if (fastcgi_request_id(r) != current_request_id) { + write_stderr(out, + "Ignoring STDIN for request %d (current request has id" + " %d)\n", + fastcgi_request_id(r), + current_request_id); + continue; + } + if (r->type != FCGI_STDIN) { write_stderr(out, "Expected FCGI_STDIN but got %d\n", r->type); goto done; -- cgit v1.2.3