nginx/auto/os/linux
Valentin Bartenev 7b37384140 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.
2013-09-02 08:07:59 +04:00

186 lines
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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 $EPOLL_MODULE"
EVENT_FOUND=YES
# EPOLLRDHUP appeared in Linux 2.6.17, glibc 2.8
ngx_feature="EPOLLRDHUP"
ngx_feature_name="NGX_HAVE_EPOLLRDHUP"
ngx_feature_run=no
ngx_feature_incs="#include <sys/epoll.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int efd = 0, fd = 0;
struct epoll_event ee;
ee.events = EPOLLIN|EPOLLRDHUP|EPOLLET;
ee.data.ptr = NULL;
epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)"
. auto/feature
fi
# O_PATH and AT_EMPTY_PATH were introduced in 2.6.39, glibc 2.14
ngx_feature="O_PATH"
ngx_feature_name="NGX_HAVE_O_PATH"
ngx_feature_run=no
ngx_feature_incs="#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int fd; struct stat sb;
fd = openat(AT_FDCWD, \".\", O_PATH|O_DIRECTORY|O_NOFOLLOW);
if (fstatat(fd, \"\", &sb, AT_EMPTY_PATH) != 0) return 1"
. auto/feature
# sendfile()
CC_AUX_FLAGS="$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"