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view auto/os/linux @ 5356:acd51b0f6fd4
Disable symlinks: use O_PATH to open path components.
It was introduced in Linux 2.6.39, glibc 2.14 and allows to obtain
file descriptors without actually opening files. Thus made it possible
to traverse path with openat() syscalls without the need to have read
permissions for path components. It is effectively emulates O_SEARCH
which is missing on Linux.
O_PATH is used in combination with O_RDONLY. The last one is ignored
if O_PATH is used, but it allows nginx to not fail when it was built on
modern system (i.e. glibc 2.14+) and run with a kernel older than 2.6.39.
Then O_PATH is unknown to the kernel and ignored, while O_RDONLY is used.
Sadly, fstat() is not working with O_PATH descriptors till Linux 3.6.
As a workaround we fallback to fstatat() with the AT_EMPTY_PATH flag
that was introduced at the same time as O_PATH.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Mon, 02 Sep 2013 08:07:59 +0400 |
parents | f31162fefe01 |
children | 36b58ddb566d |
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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} # enable the rt signals on Linux between 2.2.19 and 2.6.17 if [ \( $version -ge 131603 -a $version -lt 132626 \) -o $EVENT_RTSIG = YES ] then echo " + rt signals found" have=NGX_HAVE_RTSIG . auto/have EVENT_MODULES="$EVENT_MODULES $RTSIG_MODULE" CORE_SRCS="$CORE_SRCS $RTSIG_SRCS" EVENT_FOUND=YES fi # 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; 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 $EPOLL_MODULE" EVENT_FOUND=YES fi # O_PATH and AT_EMPTY_PATH were introduced in 2.6.39, glibc 2.14 ngx_feature="O_PATH" ngx_feature_name="NGX_HAVE_O_PATH" ngx_feature_run=no ngx_feature_incs="#include <sys/types.h> #include <sys/stat.h> #include <fcntl.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="int fd; struct stat sb; fd = openat(AT_FDCWD, \".\", O_PATH|O_DIRECTORY|O_NOFOLLOW); if (fstatat(fd, \"\", &sb, AT_EMPTY_PATH) != 0) return 1" . auto/feature # sendfile() CC_AUX_FLAGS="$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 # sched_setaffinity() ngx_feature="sched_setaffinity()" ngx_feature_name="NGX_HAVE_SCHED_SETAFFINITY" ngx_feature_run=no ngx_feature_incs="#include <sched.h>" ngx_feature_path= ngx_feature_libs= ngx_feature_test="cpu_set_t mask; CPU_ZERO(&mask); sched_setaffinity(0, sizeof(cpu_set_t), &mask)" . 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 CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"