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
line wrap: on
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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"