// SPDX-FileCopyrightText: Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
// SPDX-License-Identifier: GPL-3.0-or-later

mod common;

use {
    crate::common::{Eai, Restriction, Restrictions},
    anyhow::Result,
    elf::ElfStream,
    libc::{freeaddrinfo, gai_strerror, getaddrinfo},
    once_cell::sync::Lazy,
    rusty_fork::rusty_fork_test,
    std::net::{IpAddr, Ipv4Addr, Ipv6Addr},
    std::os::unix::fs::FileExt,
    std::path::PathBuf,
};

static DNS0_PARENTALCONTROL_ADDRS: Lazy<Restrictions> = Lazy::new(|| {
    vec![
        Restriction {
            ip: IpAddr::V4(Ipv4Addr::new(193, 110, 81, 1)),
            hostname: "kids.dns0.eu".into(),
        },
        Restriction {
            ip: IpAddr::V4(Ipv4Addr::new(185, 253, 5, 1)),
            hostname: "kids.dns0.eu".into(),
        },
        Restriction {
            ip: IpAddr::V6(Ipv6Addr::new(0x2a0f, 0xfc80, 0, 0, 0, 0, 0, 0x1)),
            hostname: "kids.dns0.eu".into(),
        },
        Restriction {
            ip: IpAddr::V6(Ipv6Addr::new(0x2a0f, 0xfc81, 0, 0, 0, 0, 0, 0x1)),
            hostname: "kids.dns0.eu".into(),
        },
    ]
});

static CLOUDFLARE_PARENTALCONTROL_ADDRS: Lazy<Restrictions> = Lazy::new(|| {
    vec![
        Restriction {
            ip: IpAddr::V4(Ipv4Addr::new(1, 1, 1, 3)),
            hostname: "family.cloudflare-dns.com".into(),
        },
        Restriction {
            ip: IpAddr::V4(Ipv4Addr::new(1, 0, 0, 3)),
            hostname: "family.cloudflare-dns.com".into(),
        },
        Restriction {
            ip: IpAddr::V6(Ipv6Addr::new(0x2606, 0x4700, 0x4700, 0, 0, 0, 0, 0x1113)),
            hostname: "family.cloudflare-dns.com".into(),
        },
        Restriction {
            ip: IpAddr::V6(Ipv6Addr::new(0x2606, 0x4700, 0x4700, 0, 0, 0, 0, 0x1003)),
            hostname: "family.cloudflare-dns.com".into(),
        },
    ]
});

static NO_RESTRICTIONS: Lazy<Restrictions> = Lazy::new(|| vec![]);

#[test]
fn sanity_check() -> Result<()> {
    let current_exe = PathBuf::from(std::env::current_exe().unwrap());
    let myself = std::fs::File::open(&current_exe)?;
    let mut elf_stream: ElfStream<elf::endian::AnyEndian, _> =
        elf::ElfStream::open_stream(&myself)?;
    let dynamic_section = elf_stream.dynamic()?.expect("No dynamic table");
    let rpath_off = dynamic_section
        .iter()
        .find(|x| x.d_tag == elf::abi::DT_RPATH)
        .map(|x| x.d_val())
        .expect("No DT_RPATH found in test executable ELF dyn section");
    let strtable = dynamic_section
        .into_iter()
        .find(|x| x.d_tag == elf::abi::DT_STRTAB)
        .map(|x| x.d_ptr())
        .expect("No DT_STRTAB found in test executable ELF dyn section");

    let mut buf = [0u8; 1024];
    let _ = myself.read_at(buf.as_mut_slice(), strtable + rpath_off)?;
    let end = buf
        .iter()
        .position(|c| *c == 0u8)
        .expect(&format!("RPATH is bigger than {} bytes", buf.len()));
    let rpath = std::str::from_utf8(&buf[..end])?;
    assert_eq!(rpath, "$ORIGIN");

    common::setup()?;
    let lib = current_exe.parent().unwrap().join("libnss_malcontent.so.2");
    assert!(lib.exists());

    Ok(())
}

rusty_fork_test! {
    #[test]
    fn application_dns_is_nodata() {
        common::setup().unwrap();

        let _dbus = common::DBusMockServerGuard::new(vec![CLOUDFLARE_PARENTALCONTROL_ADDRS.clone()]).unwrap();

        let hostname = std::ffi::CString::new("use-application-dns.net").unwrap();
        unsafe {
            let mut addr = std::ptr::null_mut();
            let getaddrinfo_status = getaddrinfo(
                hostname.as_ptr(),
                std::ptr::null(),
                std::ptr::null(),
                &mut addr,
            );

            let error = std::ffi::CStr::from_ptr(gai_strerror(getaddrinfo_status));
            assert_eq!(
                getaddrinfo_status,
                Eai::NoData.0,
                "Should have gotten no data (NODATA), instead got {}",
                error.to_str().unwrap()
            );
            freeaddrinfo(addr);
        };
    }

    #[test]
    fn getaddrinfo_resolution() {
        common::setup().unwrap();

        const HOSTNAME: &str = "gnome.org";

        let _dbus = common::DBusMockServerGuard::new(vec![CLOUDFLARE_PARENTALCONTROL_ADDRS.clone()]).unwrap();

        unsafe {
            let mut addr = std::ptr::null_mut();
            let hostname = std::ffi::CString::new(HOSTNAME).unwrap();
            let getaddrinfo_status = getaddrinfo(
                hostname.as_ptr(),
                std::ptr::null(),
                std::ptr::null(),
                &mut addr,
            );

            let error = std::ffi::CStr::from_ptr(gai_strerror(getaddrinfo_status));
            assert_eq!(
                getaddrinfo_status,
                Eai::Success.0,
                "Should have gotten an hostname, instead got {}",
                error.to_str().unwrap()
            );
            freeaddrinfo(addr);
        };
    }

    #[test]
    fn wikipedia_is_unrestricted() {
        common::setup().unwrap();

        const HOSTNAME: &str = "wikipedia.org";

        let _dbus = common::DBusMockServerGuard::new(vec![CLOUDFLARE_PARENTALCONTROL_ADDRS.clone()]).unwrap();

        for family in [libc::AF_INET, libc::AF_INET6] {
            let system_addr = common::resolve_with_system(family, HOSTNAME).unwrap();
            let our_addrs = common::resolve_with_module(family, HOSTNAME).unwrap();
            assert!(our_addrs.contains(&system_addr));
        }
    }

    #[test]
    fn dns0_adultsites_are_restricted() {
        common::setup().unwrap();

        const HOSTNAME: &str = "pornhub.com";

        let _dbus = common::DBusMockServerGuard::new(vec![DNS0_PARENTALCONTROL_ADDRS.clone()]).unwrap();

        let our_addrs_ipv4 = common::resolve_with_module(libc::AF_INET, HOSTNAME).unwrap();
        let our_addrs_ipv6 = common::resolve_with_module(libc::AF_INET, HOSTNAME).unwrap();
        assert!(
            our_addrs_ipv4.is_empty(),
            "Resolver answered with {:?}, should be empty",
            our_addrs_ipv4
        );
        assert!(
            our_addrs_ipv6.is_empty(),
            "Resolver answered with {:?}, should be empty",
            our_addrs_ipv6
        );
    }

    #[test]
    fn cloudflare_adultsite_is_restricted_ipv4() {
        common::setup().unwrap();

        const HOSTNAME: &str = "nudity.testcategory.com";

        let _dbus = common::DBusMockServerGuard::new(vec![CLOUDFLARE_PARENTALCONTROL_ADDRS.clone()]).unwrap();

        let system_addr = common::resolve_with_system(libc::AF_INET, HOSTNAME).unwrap();
        let our_addrs = common::resolve_with_module(libc::AF_INET, HOSTNAME).unwrap();
        assert!(
            !our_addrs.contains(&system_addr),
            "Resolver answered with {:?}, should not contain {}",
            our_addrs,
            system_addr
        );
        assert_eq!(our_addrs, [IpAddr::V4(Ipv4Addr::UNSPECIFIED)]);
    }

    #[test]
    fn cloudflare_adultsite_is_restricted_ipv6() {
        common::setup().unwrap();

        const HOSTNAME: &str = "nudity.testcategory.com";

        let _dbus = common::DBusMockServerGuard::new(vec![CLOUDFLARE_PARENTALCONTROL_ADDRS.clone()]).unwrap();

        let system_addr = common::resolve_with_system(libc::AF_INET6, HOSTNAME).unwrap();
        let our_addrs = common::resolve_with_module(libc::AF_INET6, HOSTNAME).unwrap();
        assert!(
            !our_addrs.contains(&system_addr),
            "Resolver answered with {:?}, should not contain {}",
            our_addrs,
            system_addr
        );
        assert_eq!(our_addrs, [IpAddr::V6(Ipv6Addr::UNSPECIFIED)]);
    }

    #[test]
    fn privileged_user_bypasses_restrictions() {
        common::setup().unwrap();

        const HOSTNAME: &str = "malware.testcategory.com";

        let _dbus = common::DBusMockServerGuard::new(vec![NO_RESTRICTIONS.clone()]).unwrap();

        for family in [libc::AF_INET, libc::AF_INET6] {
            let system_addr = common::resolve_with_system(family, HOSTNAME).unwrap();
            let our_addrs = common::resolve_with_module(family, HOSTNAME).unwrap();
            assert!(our_addrs.contains(&system_addr));
        }
    }

}