rqbit/crates/upnp-serve/src/ssdp.rs

506 lines
16 KiB
Rust

use std::{
collections::HashSet,
net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6},
time::Duration,
};
use anyhow::{bail, Context};
use bstr::BStr;
use librqbit_upnp::ipv6_is_link_local;
use network_interface::NetworkInterfaceConfig;
use parking_lot::Mutex;
use tokio_util::sync::CancellationToken;
use tracing::{debug, trace, warn};
use crate::constants::{UPNP_DEVICE_MEDIASERVER, UPNP_DEVICE_ROOT};
const SSDP_PORT: u16 = 1900;
const SSDM_MCAST_IPV4: Ipv4Addr = Ipv4Addr::new(239, 255, 255, 250);
const SSDP_MCAST_IPV6_LINK_LOCAL: Ipv6Addr = Ipv6Addr::new(0xff02, 0, 0, 0, 0, 0, 0, 0xc);
const SSDP_MCAST_IPV6_SITE_LOCAL: Ipv6Addr = Ipv6Addr::new(0xff05, 0, 0, 0, 0, 0, 0, 0xc);
const NTS_ALIVE: &str = "ssdp:alive";
const NTS_BYEBYE: &str = "ssdp:byebye";
#[derive(Debug)]
pub enum SsdpMessage<'a, 'h> {
MSearch(SsdpMSearchRequest<'a>),
#[allow(dead_code)]
OtherRequest(httparse::Request<'h, 'a>),
#[allow(dead_code)]
Response(httparse::Response<'h, 'a>),
}
#[derive(Debug)]
pub struct SsdpMSearchRequest<'a> {
#[allow(dead_code)]
pub host: &'a BStr,
pub man: &'a BStr,
pub st: &'a BStr,
}
impl<'a> SsdpMSearchRequest<'a> {
fn matches_media_server(&self) -> bool {
if self.man != "\"ssdp:discover\"" {
return false;
}
if self.st == UPNP_DEVICE_ROOT || self.st == UPNP_DEVICE_MEDIASERVER {
return true;
}
false
}
}
pub fn try_parse_ssdp<'a, 'h>(
buf: &'a [u8],
headers: &'h mut [httparse::Header<'a>],
) -> anyhow::Result<SsdpMessage<'a, 'h>> {
if buf.starts_with(b"HTTP/") {
let mut resp = httparse::Response::new(headers);
resp.parse(buf).context("error parsing response")?;
return Ok(SsdpMessage::Response(resp));
}
let mut req = httparse::Request::new(headers);
req.parse(buf).context("error parsing request")?;
match req.method {
Some("M-SEARCH") => {
let mut host = None;
let mut man = None;
let mut st = None;
for header in req.headers.iter() {
match header.name {
"HOST" | "Host" | "host" => host = Some(header.value),
"MAN" | "Man" | "man" => man = Some(header.value),
"ST" | "St" | "st" => st = Some(header.value),
other => trace!(header=?BStr::new(other), "ignoring SSDP header"),
}
}
match (host, man, st) {
(Some(host), Some(man), Some(st)) => {
return Ok(SsdpMessage::MSearch(SsdpMSearchRequest {
host: BStr::new(host),
man: BStr::new(man),
st: BStr::new(st),
}))
}
_ => bail!("not all of host, man and st are set"),
}
}
_ => return Ok(SsdpMessage::OtherRequest(req)),
}
}
pub struct SsdpRunnerOptions {
pub usn: String,
pub description_http_location: url::Url,
pub server_string: String,
pub notify_interval: Duration,
pub shutdown: CancellationToken,
}
struct UdpSocket {
sock2: socket2::Socket,
tokio: tokio::net::UdpSocket,
}
pub struct SsdpRunner {
opts: SsdpRunnerOptions,
socket_v4: Option<UdpSocket>,
socket_v6: Option<UdpSocket>,
}
fn socket_presetup(bind_addr: SocketAddr) -> anyhow::Result<UdpSocket> {
let domain = if bind_addr.is_ipv4() {
socket2::Domain::IPV4
} else {
socket2::Domain::IPV6
};
let sock = socket2::Socket::new(domain, socket2::Type::DGRAM, None)
.context(bind_addr)
.context("error creating socket")?;
#[cfg(not(target_os = "windows"))]
sock.set_reuse_port(true)
.context("error setting SO_REUSEPORT")?;
sock.set_reuse_address(true)
.context("error setting SO_REUSEADDR")?;
trace!(addr=?bind_addr, "binding UDP");
sock.bind(&bind_addr.into())
.context(bind_addr)
.context("error binding")?;
sock.set_nonblocking(true)?;
let sock_clone = sock.try_clone().context("can't clone socket")?;
let tokio_socket = tokio::net::UdpSocket::from_std(sock_clone.into())
.context("error converting socket2 socket to tokio")?;
Ok(UdpSocket {
sock2: sock,
tokio: tokio_socket,
})
}
async fn bind_v4_socket() -> anyhow::Result<UdpSocket> {
let bind_addr = SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, SSDP_PORT);
let socket = socket_presetup(bind_addr.into())?;
let default_multiast_membership_ip = std::iter::once(Ipv4Addr::UNSPECIFIED);
let all_multicast_membership_ips = network_interface::NetworkInterface::show()
.into_iter()
.flatten()
.flat_map(|nic| nic.addr.into_iter())
.filter_map(|addr| {
let ip = addr.ip();
match ip {
std::net::IpAddr::V4(addr) if addr.is_private() && !addr.is_loopback() => {
Some(addr)
}
_ => None,
}
});
for ifaddr in default_multiast_membership_ip.chain(all_multicast_membership_ips) {
trace!(multiaddr=?SSDM_MCAST_IPV4, interface=?ifaddr, "joining multicast v4 group");
if let Err(e) = socket.tokio.join_multicast_v4(SSDM_MCAST_IPV4, ifaddr) {
debug!(multiaddr=?SSDM_MCAST_IPV4, interface=?ifaddr, "error joining multicast v4 group: {e:#}");
}
}
Ok(socket)
}
async fn bind_v6_socket() -> anyhow::Result<UdpSocket> {
let bind_addr = SocketAddrV6::new(Ipv6Addr::UNSPECIFIED, SSDP_PORT, 0, 0);
let socket = socket_presetup(bind_addr.into())?;
for nic in network_interface::NetworkInterface::show()
.into_iter()
.flatten()
{
let mut has_link_local = false;
let mut has_site_local = false;
for addr in nic.addr.iter() {
let addr = match addr.ip() {
IpAddr::V4(_) => continue,
IpAddr::V6(v6) => v6,
};
if addr.is_loopback() {
continue;
}
if ipv6_is_link_local(addr) {
has_link_local = true;
} else {
has_site_local = true;
}
}
for (present, multiaddr) in [
(has_site_local, SSDP_MCAST_IPV6_SITE_LOCAL),
(has_link_local, SSDP_MCAST_IPV6_LINK_LOCAL),
] {
if !present {
continue;
}
trace!(multiaddr=?multiaddr, interface=?nic.index, "joining multicast v6 group");
if let Err(e) = socket.tokio.join_multicast_v6(&multiaddr, nic.index) {
debug!(multiaddr=?multiaddr, interface=?nic.index, "error joining multicast v6 group: {e:#}");
}
}
}
Ok(socket)
}
struct MulticastOpts {
interface_addr: IpAddr,
#[allow(dead_code)]
interface_id: u32,
mcast_addr: SocketAddr,
}
impl MulticastOpts {
fn addr_no_scope(&self) -> SocketAddr {
let mut addr = self.mcast_addr;
if let SocketAddr::V6(v6) = &mut addr {
v6.set_scope_id(0);
}
addr
}
}
impl SsdpRunner {
pub async fn new(opts: SsdpRunnerOptions) -> anyhow::Result<Self> {
let socket_v4 = bind_v4_socket()
.await
.map_err(|e| warn!("error creating IPv4 SSDP socket: {e:#}"))
.ok();
let socket_v6 = bind_v6_socket()
.await
.map_err(|e| warn!("error creating IPv6 SSDP socket: {e:#}"))
.ok();
Ok(Self {
opts,
socket_v4,
socket_v6,
})
}
fn generate_notify_message(
&self,
device_kind: &str,
nts: &str,
opts: &MulticastOpts,
) -> String {
let usn: &str = &self.opts.usn;
let server: &str = &self.opts.server_string;
let host = opts.addr_no_scope();
let mut location = self.opts.description_http_location.clone();
let _ = location.set_ip_host(opts.interface_addr);
format!(
"NOTIFY * HTTP/1.1\r
Host: {host}\r
Cache-Control: max-age=75\r
Location: {location}\r
NT: {device_kind}\r
NTS: {nts}\r
Server: {server}\r
USN: {usn}::{device_kind}\r
\r
"
)
}
fn generate_ssdp_discover_response(
&self,
st: &str,
addr: SocketAddr,
) -> anyhow::Result<String> {
let local_ip = ::librqbit_upnp::get_local_ip_relative_to(addr)?;
let location = {
let mut loc = self.opts.description_http_location.clone();
let _ = loc.set_ip_host(local_ip);
loc
};
let usn = &self.opts.usn;
let server = &self.opts.server_string;
Ok(format!(
"HTTP/1.1 200 OK\r
Cache-Control: max-age=75\r
Ext: \r
Location: {location}\r
Server: {server}\r
St: {st}\r
Usn: {usn}::{st}\r
Content-Length: 0\r\n\r\n"
))
}
async fn try_send_mcast_everywhere(
&self,
get_payload: &impl Fn(&MulticastOpts) -> bstr::BString,
) {
use network_interface::NetworkInterfaceConfig;
let interfaces = network_interface::NetworkInterface::show();
let interfaces = match interfaces {
Ok(interfaces) => interfaces,
Err(e) => {
warn!(error=?e, "error determining network interfaces");
return;
}
};
let sent = Mutex::new(HashSet::new());
let sent = &sent;
let futs = interfaces
.into_iter()
.flat_map(|ni|
ni.addr.into_iter().map(move |a| (ni.index, a))
)
.filter_map(|(ifidx, addr)| match addr.ip() {
std::net::IpAddr::V4(a) if !a.is_loopback() && a.is_private() => {
Some(MulticastOpts {
interface_addr: addr.ip(),
interface_id: ifidx,
mcast_addr: SocketAddr::V4(SocketAddrV4::new(SSDM_MCAST_IPV4, SSDP_PORT)),
})
}
std::net::IpAddr::V6(a) if !a.is_loopback() => Some(MulticastOpts {
interface_addr: addr.ip(),
interface_id: ifidx,
mcast_addr: {
if ipv6_is_link_local(a) {
SocketAddr::V6(SocketAddrV6::new(SSDP_MCAST_IPV6_LINK_LOCAL, SSDP_PORT, 0, ifidx))
} else {
SocketAddr::V6(SocketAddrV6::new(SSDP_MCAST_IPV6_SITE_LOCAL, SSDP_PORT, 0, 0))
}
},
}),
_ => {
trace!(oif_id=ifidx, addr=%addr.ip(), "ignoring address");
None
},
})
.map(|opts| async move {
let payload = get_payload(&opts);
if !sent
.lock()
.insert((payload.clone(), opts.interface_id, opts.mcast_addr))
{
trace!(oif_id=opts.interface_id, addr=%opts.mcast_addr, "not sending duplicate payload");
return;
}
let sock = match (
opts.interface_addr,
self.socket_v4.as_ref(),
self.socket_v6.as_ref(),
) {
// Call setsockopt(IP_MULTICAST_IF), so that the message
// gets sent out of the interface we want (otherwise it'll get sent through
// default one).
(IpAddr::V4(ip), Some(sock_v4), _) => {
if let Err(e) = sock_v4.sock2.set_multicast_if_v4(&ip) {
debug!(addr=%ip, "error calling set_multicast_if_v4: {e:#}");
}
sock_v4
}
(IpAddr::V6(_), _, Some(sock_v6)) => {
if let Err(e) = sock_v6.sock2.set_multicast_if_v6(opts.interface_id) {
debug!(oif_id=opts.interface_id, "error calling set_multicast_if_v6: {e:#}");
}
sock_v6
},
_ => {
trace!(addr=%opts.interface_addr, "ignoring address, no socket to send to");
return;
},
};
match sock.tokio.send_to(payload.as_slice(), opts.mcast_addr).await {
Ok(sz) => trace!(addr=%opts.mcast_addr, oif_id=opts.interface_id, oif_addr=%opts.interface_addr, size=sz, payload=?payload, "sent"),
Err(e) => {
debug!(addr=%opts.mcast_addr, oif_id=opts.interface_id, oif_addr=%opts.interface_addr, payload=?payload, "error sending: {e:#}")
}
};
});
futures::future::join_all(futs).await;
}
async fn try_send_notifies(&self, nts: &str) {
self.try_send_mcast_everywhere(&|opts| {
self.generate_notify_message(UPNP_DEVICE_MEDIASERVER, nts, opts)
.into()
})
.await
}
async fn task_send_alive_notifies_periodically(&self) {
let mut interval = tokio::time::interval(self.opts.notify_interval);
loop {
interval.tick().await;
self.try_send_notifies(NTS_ALIVE).await;
}
}
async fn process_incoming_message(
&self,
msg: &[u8],
sock: &UdpSocket,
addr: SocketAddr,
) -> anyhow::Result<()> {
let mut headers = [httparse::EMPTY_HEADER; 16];
trace!(content = ?BStr::new(msg), ?addr, "received message");
let parsed = try_parse_ssdp(msg, &mut headers);
let msg = match parsed {
Ok(SsdpMessage::MSearch(msg)) => msg,
Ok(m) => {
trace!("ignoring {m:?}");
return Ok(());
}
Err(e) => {
debug!(error=?e, "error parsing SSDP message");
return Ok(());
}
};
if !msg.matches_media_server() {
trace!("not a media server request, ignoring");
return Ok(());
}
if let Ok(st) = std::str::from_utf8(msg.st) {
let response = self.generate_ssdp_discover_response(st, addr)?;
trace!(content = response, ?addr, "sending SSDP discover response");
sock.tokio
.send_to(response.as_bytes(), addr)
.await
.context("error sending")?;
}
Ok(())
}
async fn task_respond_on_msearches(&self, sock: Option<&UdpSocket>) {
let mut buf = vec![0u8; 16184];
let sock = match sock {
Some(sock) => sock,
None => return,
};
loop {
let (sz, addr) = match sock.tokio.recv_from(&mut buf).await {
Ok((sz, addr)) => (sz, addr),
Err(e) => {
warn!(error=?e, "error receving");
return;
}
};
let msg = &buf[..sz];
if let Err(e) = self.process_incoming_message(msg, sock, addr).await {
warn!(error=?e, ?addr, "error processing incoming SSDP message")
}
}
}
async fn try_send_example_msearch(&self) {
self.try_send_mcast_everywhere(&|opts| {
let dest = opts.addr_no_scope();
format!(
"M-SEARCH * HTTP/1.1\r
HOST: {dest}\r
ST: urn:schemas-upnp-org:device:MediaServer:1\r
MAN: \"ssdp:discover\"\r
MX: 2\r\n\r\n"
)
.into()
})
.await
}
pub async fn run_forever(&self) -> anyhow::Result<()> {
// This isn't necessary, but would show that it works.
let t0 = self.try_send_example_msearch();
let t1 = self.task_respond_on_msearches(self.socket_v4.as_ref());
let t2 = self.task_respond_on_msearches(self.socket_v6.as_ref());
let t3 = self.task_send_alive_notifies_periodically();
let wait = async move {
tokio::join!(t0, t1, t2, t3);
Ok(())
};
tokio::select! {
r = wait => r,
_ = self.opts.shutdown.cancelled() => {
self.try_send_notifies(NTS_BYEBYE).await;
Ok(())
}
}
}
}