Mercurial > hg > nginx
view auto/os/linux @ 9300:5be23505292b
SSI: fixed incorrect or duplicate stub output.
Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set
if there are data in the first buffer sent in the subrequest. As a
result, following the change mentioned this flag cannot be used to
prevent duplicate ngx_http_ssi_stub_output() calls, since it is not
set if there was already some output, but the first buffer was empty.
Still, when there are multiple subrequests, even an empty subrequest
response might be delayed by the postpone filter, leading to a second
call of ngx_http_ssi_stub_output() during finalization from
ngx_http_writer() the subreqest buffers are released by the postpone
filter. Since r->request_output is not set after the first call, this
resulted in duplicate stub output.
Additionally, checking only the first buffer might be wrong in some
unusual cases. For example, the first buffer might be empty if
$r->flush() is called before printing any data in the embedded Perl
module.
Depending on the postpone_output value and corresponding sizes, this
issue can result in either duplicate or unexpected stub output, or
"zero size buf in writer" alerts.
Following 8124:f5515e727656 (1.23.4), it became slightly easier to
reproduce the issue, as empty static files and empty cache items now
result in a response with an empty buffer. Before the change, an empty
proxied response can be used to reproduce the issue.
Fix is check all buffers and set r->request_output if any non-empty
buffers are sent. This ensures that all unusual cases of non-empty
responses are covered, and also that r->request_output will be set
after the first stub output, preventing duplicate output.
Reported by Jan Gassen.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 04 Jul 2024 17:41:28 +0300 |
parents | 0af598651e33 |
children |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. have=NGX_LINUX . auto/have_headers CORE_INCS="$UNIX_INCS" CORE_DEPS="$UNIX_DEPS $LINUX_DEPS" CORE_SRCS="$UNIX_SRCS $LINUX_SRCS" ngx_spacer=' ' cc_aux_flags="$CC_AUX_FLAGS" CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64" # Linux kernel version version=$((`uname -r \ | sed -n -e 's/^\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/ \ \1*256*256+\2*256+\3/p' \ -e 's/^\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/\1*256*256+\2*256/p'`)) version=${version:-0} # posix_fadvise64() had been implemented in 2.5.60 if [ $version -lt 132412 ]; then have=NGX_HAVE_POSIX_FADVISE . auto/nohave fi # epoll, EPOLLET version ngx_feature="epoll" ngx_feature_name="NGX_HAVE_EPOLL" ngx_feature_run=yes ngx_feature_incs="#include <sys/epoll.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int efd = 0; struct epoll_event ee; ee.events = EPOLLIN|EPOLLOUT|EPOLLET; ee.data.ptr = NULL; (void) ee; efd = epoll_create(100); if (efd == -1) return 1;" . auto/feature if [ $ngx_found = yes ]; then have=NGX_HAVE_CLEAR_EVENT . auto/have CORE_SRCS="$CORE_SRCS $EPOLL_SRCS" EVENT_MODULES="$EVENT_MODULES $EPOLL_MODULE" EVENT_FOUND=YES # EPOLLRDHUP appeared in Linux 2.6.17, glibc 2.8 ngx_feature="EPOLLRDHUP" ngx_feature_name="NGX_HAVE_EPOLLRDHUP" ngx_feature_run=no ngx_feature_incs="#include <sys/epoll.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int efd = 0, fd = 0; struct epoll_event ee; ee.events = EPOLLIN|EPOLLRDHUP|EPOLLET; ee.data.ptr = NULL; epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)" . auto/feature # EPOLLEXCLUSIVE appeared in Linux 4.5, glibc 2.24 ngx_feature="EPOLLEXCLUSIVE" ngx_feature_name="NGX_HAVE_EPOLLEXCLUSIVE" ngx_feature_run=no ngx_feature_incs="#include <sys/epoll.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int efd = 0, fd = 0; struct epoll_event ee; ee.events = EPOLLIN|EPOLLEXCLUSIVE; ee.data.ptr = NULL; epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)" . auto/feature # eventfd() ngx_feature="eventfd()" ngx_feature_name="NGX_HAVE_EVENTFD" ngx_feature_run=no ngx_feature_incs="#include <sys/eventfd.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="(void) eventfd(0, 0)" . auto/feature if [ $ngx_found = yes ]; then have=NGX_HAVE_SYS_EVENTFD_H . auto/have fi if [ $ngx_found = no ]; then ngx_feature="eventfd() (SYS_eventfd)" ngx_feature_incs="#include <sys/syscall.h>" ngx_feature_test="(void) SYS_eventfd" . auto/feature fi fi # O_PATH and AT_EMPTY_PATH were introduced in 2.6.39, glibc 2.14 ngx_feature="O_PATH" ngx_feature_name="NGX_HAVE_O_PATH" ngx_feature_run=no ngx_feature_incs="#include <sys/types.h> #include <sys/stat.h> #include <fcntl.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int fd; struct stat sb; fd = openat(AT_FDCWD, \".\", O_PATH|O_DIRECTORY|O_NOFOLLOW); if (fstatat(fd, \"\", &sb, AT_EMPTY_PATH) != 0) return 1" . auto/feature # sendfile() CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE" ngx_feature="sendfile()" ngx_feature_name="NGX_HAVE_SENDFILE" ngx_feature_run=yes ngx_feature_incs="#include <sys/sendfile.h> #include <errno.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int s = 0, fd = 1; ssize_t n; off_t off = 0; n = sendfile(s, fd, &off, 1); if (n == -1 && errno == ENOSYS) return 1" . auto/feature if [ $ngx_found = yes ]; then CORE_SRCS="$CORE_SRCS $LINUX_SENDFILE_SRCS" fi # sendfile64() CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64" ngx_feature="sendfile64()" ngx_feature_name="NGX_HAVE_SENDFILE64" ngx_feature_run=yes ngx_feature_incs="#include <sys/sendfile.h> #include <errno.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int s = 0, fd = 1; ssize_t n; off_t off = 0; n = sendfile(s, fd, &off, 1); if (n == -1 && errno == ENOSYS) return 1" . auto/feature ngx_include="sys/prctl.h"; . auto/include # prctl(PR_SET_DUMPABLE) ngx_feature="prctl(PR_SET_DUMPABLE)" ngx_feature_name="NGX_HAVE_PR_SET_DUMPABLE" ngx_feature_run=yes ngx_feature_incs="#include <sys/prctl.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1) return 1" . auto/feature # prctl(PR_SET_KEEPCAPS) ngx_feature="prctl(PR_SET_KEEPCAPS)" ngx_feature_name="NGX_HAVE_PR_SET_KEEPCAPS" ngx_feature_run=yes ngx_feature_incs="#include <sys/prctl.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) return 1" . auto/feature # capabilities ngx_feature="capabilities" ngx_feature_name="NGX_HAVE_CAPABILITIES" ngx_feature_run=no ngx_feature_incs="#include <linux/capability.h> #include <sys/syscall.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="struct __user_cap_data_struct data; struct __user_cap_header_struct header; header.version = _LINUX_CAPABILITY_VERSION_1; data.effective = CAP_TO_MASK(CAP_NET_RAW); data.permitted = 0; (void) header; (void) data; (void) SYS_capset" . auto/feature # crypt_r() ngx_feature="crypt_r()" ngx_feature_name="NGX_HAVE_GNU_CRYPT_R" ngx_feature_run=no ngx_feature_incs="#include <crypt.h>" ngx_feature_path= ngx_feature_libs=-lcrypt ngx_feature_test="struct crypt_data cd; crypt_r(\"key\", \"salt\", &cd);" . auto/feature ngx_include="sys/vfs.h"; . auto/include # BPF sockhash ngx_feature="BPF sockhash" ngx_feature_name="NGX_HAVE_BPF" ngx_feature_run=no ngx_feature_incs="#include <linux/bpf.h> #include <sys/syscall.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="union bpf_attr attr = { 0 }; attr.map_flags = 0; attr.map_type = BPF_MAP_TYPE_SOCKHASH; syscall(__NR_bpf, 0, &attr, 0);" . auto/feature if [ $ngx_found = yes ]; then CORE_SRCS="$CORE_SRCS src/core/ngx_bpf.c" CORE_DEPS="$CORE_DEPS src/core/ngx_bpf.h" if [ $QUIC_BPF != NONE ]; then QUIC_BPF=YES fi fi ngx_feature="SO_COOKIE" ngx_feature_name="NGX_HAVE_SO_COOKIE" ngx_feature_run=no ngx_feature_incs="#include <sys/socket.h> $NGX_INCLUDE_INTTYPES_H" ngx_feature_path= ngx_feature_libs= ngx_feature_test="socklen_t optlen = sizeof(uint64_t); uint64_t cookie; getsockopt(0, SOL_SOCKET, SO_COOKIE, &cookie, &optlen)" . auto/feature if [ $ngx_found = yes ]; then SO_COOKIE_FOUND=YES fi # UDP segmentation offloading ngx_feature="UDP_SEGMENT" ngx_feature_name="NGX_HAVE_UDP_SEGMENT" ngx_feature_run=no ngx_feature_incs="#include <sys/socket.h> #include <netinet/udp.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="socklen_t optlen = sizeof(int); int val; getsockopt(0, SOL_UDP, UDP_SEGMENT, &val, &optlen)" . auto/feature CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"