mmdebstrap/tests/dev-ptmx
Johannes Schauer Marin Rodrigues 009089ee8a
Mount a new instance of /dev/pts in the chroot
Before, we bind-mounted /dev/ptmx and /dev/pts from the host into the
chroot. This will make posix_openpt() fail with 'No such file or
directory'.  The ability to create pseudo terminals is important for apt
(which will throw a warning otherwise) or running script(1) or source
package testsuites like for src:util-linux. This functionality is
restored by mounting a new devpts instance to /dev/pts and making
/dev/ptmx a symlink to /dev/pts/ptmx. Mounting with ptmxmode=666 is
required such that also non-root users in unshare mode are able to
create pseudo terminals. See also:

https://www.kernel.org/doc/Documentation/filesystems/devpts.txt
https://salsa.debian.org/debian/schroot/-/merge_requests/2
https://bugs.debian.org/856877
https://bugs.debian.org/817236
2022-06-14 08:26:48 +02:00

145 lines
3.7 KiB
Bash

#!/bin/sh
set -eu
export LC_ALL=C.UTF-8
if [ {{ MODE }} != unshare ] && [ {{ MODE }} != root ]; then
echo "test requires root or unshare mode" >&2
exit 1
fi
if [ ! -e /mmdebstrap-testenv ]; then
echo "this test modifies the system and should only be run inside a container" >&2
exit 1
fi
if [ "$(id -u)" -eq 0 ] && ! id -u user > /dev/null 2>&1; then
adduser --gecos user --disabled-password user
fi
prefix=
[ "$(id -u)" -eq 0 ] && [ "{{ MODE }}" != "root" ] && prefix="runuser -u user --"
# this mimics what apt does in apt-pkg/deb/dpkgpm.cc/pkgDPkgPM::StartPtyMagic()
cat > /tmp/test.c << 'END'
#define _GNU_SOURCE
#include <stdlib.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <signal.h>
int main() {
int ret;
int fd = posix_openpt(O_RDWR | O_NOCTTY);
if (fd < 0) {
perror("posix_openpt");
return 1;
}
char buf[64]; // 64 is used by apt
ret = ptsname_r(fd, buf, sizeof(buf));
if (ret != 0) {
perror("ptsname_r");
return 1;
}
ret = grantpt(fd);
if (ret == -1) {
perror("grantpt");
return 1;
}
struct termios origtt;
ret = tcgetattr(STDIN_FILENO, &origtt);
if (ret != 0) {
perror("tcgetattr1");
return 1;
}
struct termios tt;
ret = tcgetattr(STDOUT_FILENO, &tt);
if (ret != 0) {
perror("tcgetattr2");
return 1;
}
struct winsize win;
ret = ioctl(STDOUT_FILENO, TIOCGWINSZ, &win);
if (ret < 0) {
perror("ioctl stdout TIOCGWINSZ");
return 1;
}
ret = ioctl(fd, TIOCSWINSZ, &win);
if (ret < 0) {
perror("ioctl fd TIOCGWINSZ");
return 1;
}
ret = tcsetattr(fd, TCSANOW, &tt);
if (ret != 0) {
perror("tcsetattr1");
return 1;
}
cfmakeraw(&tt);
tt.c_lflag &= ~ECHO;
tt.c_lflag |= ISIG;
sigset_t sigmask;
sigset_t sigmask_old;
ret = sigemptyset(&sigmask);
if (ret != 0) {
perror("sigemptyset");
return 1;
}
ret = sigaddset(&sigmask, SIGTTOU);
if (ret != 0) {
perror("sigaddset");
return 1;
}
ret = sigprocmask(SIG_BLOCK,&sigmask, &sigmask_old);
if (ret != 0) {
perror("sigprocmask1");
return 1;
}
ret = tcsetattr(STDIN_FILENO, TCSAFLUSH, &tt);
if (ret != 0) {
perror("tcsetattr2");
return 1;
}
ret = sigprocmask(SIG_BLOCK,&sigmask_old, NULL);
if (ret != 0) {
perror("sigprocmask2");
return 1;
}
ret = tcsetattr(STDIN_FILENO, TCSAFLUSH, &origtt);
if (ret != 0) {
perror("tcsetattr3");
return 1;
}
return 0;
}
END
# use script to create a fake tty
# run all tests as root and as a normal user (the latter requires ptmxmode=666)
script -qfc "$prefix {{ CMD }} --mode={{ MODE }} --variant=apt \
--include=gcc,libc6-dev,python3 \
--customize-hook='chroot \"\$1\" adduser --gecos user --disabled-password user' \
--customize-hook='chroot \"\$1\" python3 -c \"import pty; print(pty.openpty())\"' \
--customize-hook='chroot \"\$1\" runuser -u user -- python3 -c \"import pty; print(pty.openpty())\"' \
--customize-hook='chroot \"\$1\" script -c \"echo foobar\"' \
--customize-hook='chroot \"\$1\" runuser -u user -- env --chdir=/home/user script -c \"echo foobar\"' \
--customize-hook='chroot \"\$1\" apt-get install --yes doc-debian 2>&1 | tee /tmp/log' \
--customize-hook=\"copy-in /tmp/test.c /tmp\" \
--customize-hook='chroot \"\$1\" gcc /tmp/test.c -o /tmp/test' \
--customize-hook='chroot \"\$1\" /tmp/test' \
--customize-hook='chroot \"\$1\" runuser -u user -- /tmp/test' \
--customize-hook='rm \"\$1\"/tmp/test \"\$1\"/tmp/test.c' \
{{ DIST }} /dev/null {{ MIRROR }}" /dev/null
fail=0
grep '^E:' /tmp/log && fail=1
grep 'Can not write log' /tmp/log && fail=1
grep 'posix_openpt' /tmp/log && fail=1
grep 'No such file or directory' /tmp/log && fail=1
if [ $fail -eq 1 ]; then
echo "apt failed to write log:" >&2
cat /tmp/log >&2
exit 1
fi
rm /tmp/test.c /tmp/log