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fix: allocate default extmap ids without colliding with remote mappings #34

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fix: allocate default extmap ids without colliding with remote mappings #34

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141 changes: 131 additions & 10 deletions src/peer_connection.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4438,17 +4438,20 @@ impl PeerConnectionInner {
self.merge_remote_rtx_into_answer(section);
}

// Browsers reject descriptions with duplicate extension ids.
let mut used_extmap_ids = self.get_remote_extmap_ids(&section.mid);

// Add extmap for Video
if kind == MediaKind::Video {
let (mut rid_id, mut repaired_rid_id) = self.get_remote_video_extmap_ids(&section.mid);

if sdp_type == SdpType::Offer && self.config.transport_mode != TransportMode::Rtp {
// If not found in remote (new transceiver), use defaults
if rid_id.is_none() {
rid_id = Some("1".to_string());
rid_id = Some(Self::claim_free_extmap_id(&mut used_extmap_ids, 1));
}
if repaired_rid_id.is_none() {
repaired_rid_id = Some("2".to_string());
repaired_rid_id = Some(Self::claim_free_extmap_id(&mut used_extmap_ids, 2));
}
}

Expand All @@ -4462,7 +4465,7 @@ impl PeerConnectionInner {
&& abs_send_time_id.is_none()
&& self.config.transport_mode != TransportMode::Rtp
{
abs_send_time_id = Some("3".to_string()); // Default ID for abs-send-time
abs_send_time_id = Some(Self::claim_free_extmap_id(&mut used_extmap_ids, 3));
}
if let Some(id) = abs_send_time_id {
section.attributes.push(crate::sdp::Attribute::new(
Expand All @@ -4480,7 +4483,7 @@ impl PeerConnectionInner {
&& sdes_mid_id.is_none()
&& self.config.transport_mode != TransportMode::Rtp
{
sdes_mid_id = Some("4".to_string());
sdes_mid_id = Some(Self::claim_free_extmap_id(&mut used_extmap_ids, 4));
}
if let Some(id) = sdes_mid_id {
section.attributes.push(crate::sdp::Attribute::new(
Expand Down Expand Up @@ -4709,6 +4712,40 @@ impl PeerConnectionInner {
None
}

/// All extension ids the remote has mapped on the given m-line.
fn get_remote_extmap_ids(&self, mid: &str) -> std::collections::HashSet<u8> {
let mut ids = std::collections::HashSet::new();
let remote = self.remote_description.lock();
if let Some(desc) = &*remote
&& let Some(remote_section) = desc.media_sections.iter().find(|s| s.mid == mid)
{
for attr in &remote_section.attributes {
if attr.key == "extmap"
&& let Some(val) = &attr.value
&& let Some(id_str) = val.split_whitespace().next()
&& let Ok(id) = id_str.parse::<u8>()
{
ids.insert(id);
}
}
}
ids
}

/// Pick `preferred` if free, otherwise the lowest free one-byte
/// extension id (RFC 8285: 1-14), and mark it as used.
fn claim_free_extmap_id(used: &mut std::collections::HashSet<u8>, preferred: u8) -> String {
let id = if used.contains(&preferred) {
(1..=14u8)
.find(|candidate| !used.contains(candidate))
.unwrap_or(preferred)
} else {
preferred
};
used.insert(id);
id.to_string()
}

fn close_with_reason(&self, reason: DisconnectReason) {
if *self.peer_state.borrow() == PeerConnectionState::Closed {
return;
Expand Down Expand Up @@ -6633,6 +6670,13 @@ impl PeerConnection {

#[cfg(test)]
mod tests {

fn test_addr() -> std::net::SocketAddr {
std::net::SocketAddr::new(
std::net::IpAddr::V4(std::net::Ipv4Addr::new(127, 0, 0, 1)),
5000,
)
}
use super::*;
use crate::transports::ice::IceTransportState;
use crate::{Direction, MediaKind, RtcConfiguration};
Expand Down Expand Up @@ -7806,18 +7850,28 @@ a=sendrecv\r\n";
let packet1 = RtpPacket::new(header.clone(), vec![1, 2, 3]);

// First packet initializes
assert!(handler.on_packet_received(&packet1).await.is_none());
assert!(
handler
.on_packet_received(&packet1, test_addr(), test_addr())
.await
.is_none()
);

// Consecutive packet
header.sequence_number = 101;
let packet2 = RtpPacket::new(header.clone(), vec![4, 5, 6]);
assert!(handler.on_packet_received(&packet2).await.is_none());
assert!(
handler
.on_packet_received(&packet2, test_addr(), test_addr())
.await
.is_none()
);

// Gap detected (102 missing)
header.sequence_number = 103;
let packet3 = RtpPacket::new(header.clone(), vec![7, 8, 9]);
let res = handler
.on_packet_received(&packet3)
.on_packet_received(&packet3, test_addr(), test_addr())
.await
.expect("Should generate NACK");
if let RtcpPacket::GenericNack(nack) = res {
Expand All @@ -7831,7 +7885,7 @@ a=sendrecv\r\n";
header.sequence_number = 106;
let packet4 = RtpPacket::new(header.clone(), vec![10]);
let res = handler
.on_packet_received(&packet4)
.on_packet_received(&packet4, test_addr(), test_addr())
.await
.expect("Should generate NACK");
if let RtcpPacket::GenericNack(nack) = res {
Expand All @@ -7852,7 +7906,9 @@ a=sendrecv\r\n";
let mut header = RtpHeader::new(96, 100, 0, 1234);
let packet1 = RtpPacket::new(header.clone(), vec![1, 2, 3]);

handler.on_packet_sent(&packet1).await;
handler
.on_packet_sent(&packet1, test_addr(), test_addr())
.await;

// Mock transport (we just need it to not crash, though it won't actually send)
let (_, socket_rx) = tokio::sync::watch::channel(None);
Expand All @@ -7875,7 +7931,11 @@ a=sendrecv\r\n";
for i in 101..115 {
header.sequence_number = i;
handler
.on_packet_sent(&RtpPacket::new(header.clone(), vec![0]))
.on_packet_sent(
&RtpPacket::new(header.clone(), vec![0]),
test_addr(),
test_addr(),
)
.await;
}

Expand Down Expand Up @@ -11157,4 +11217,65 @@ a=mid:0
"Should create a new transceiver when no offer transceiver exists"
);
}

#[tokio::test]
async fn renegotiation_offer_has_unique_extmap_ids() {
use crate::{SdpType, SessionDescription};
let pc = PeerConnection::new(RtcConfiguration::default());

// Firefox-style audio offer: sdes:mid on id 3, no abs-send-time.
let sdp_str = "v=0\r\n\
o=- 123456 0 IN IP4 127.0.0.1\r\n\
s=-\r\n\
t=0 0\r\n\
a=group:BUNDLE 0\r\n\
a=fingerprint:sha-256 AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99:AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99\r\n\
a=setup:actpass\r\n\
c=IN IP4 127.0.0.1\r\n\
m=audio 9 UDP/TLS/RTP/SAVPF 109\r\n\
a=mid:0\r\n\
a=rtpmap:109 opus/48000/2\r\n\
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\n\
a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid\r\n\
a=ice-ufrag:abcd\r\n\
a=ice-pwd:abcdefghijklmnopqrstuvwx\r\n\
a=sendrecv\r\n";
let offer = SessionDescription::parse(SdpType::Offer, sdp_str).unwrap();
pc.set_remote_description(offer).await.unwrap();
let answer = pc.create_answer().await.unwrap();
pc.set_local_description(answer).unwrap();

let reoffer = pc.create_offer().await.unwrap();
for section in &reoffer.media_sections {
let mut seen = std::collections::HashSet::new();
for attr in &section.attributes {
if attr.key == "extmap" {
let id: u8 = attr
.value
.as_ref()
.and_then(|v| v.split_whitespace().next())
.and_then(|v| v.parse().ok())
.expect("extmap id");
assert!(
seen.insert(id),
"duplicate extmap id {id} in m-section {}",
section.mid
);
}
}
}

let audio = &reoffer.media_sections[0];
let extmap_value = |uri: &str| -> String {
audio
.attributes
.iter()
.filter(|a| a.key == "extmap")
.filter_map(|a| a.value.clone())
.find(|v| v.contains(uri))
.unwrap_or_else(|| panic!("missing extmap for {uri}"))
};
assert!(extmap_value(crate::sdp::SDES_MID_URI).starts_with("3 "));
assert!(!extmap_value(crate::sdp::ABS_SEND_TIME_URI).starts_with("3 "));
}
}
19 changes: 16 additions & 3 deletions src/stats_collector.rs
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -208,6 +208,13 @@ impl StatsProvider for StatsCollector {

#[cfg(test)]
mod tests {

fn test_addr() -> std::net::SocketAddr {
std::net::SocketAddr::new(
std::net::IpAddr::V4(std::net::Ipv4Addr::new(127, 0, 0, 1)),
5000,
)
}
use super::*;
use crate::rtp::{ReportBlock, SenderReport};

Expand Down Expand Up @@ -263,15 +270,21 @@ mod tests {
let packet = RtpPacket::new(header.clone(), payload.clone());

// Test outbound interception
collector.on_packet_sent(&packet).await;
collector
.on_packet_sent(&packet, test_addr(), test_addr())
.await;

// Send another one
collector.on_packet_sent(&packet).await;
collector
.on_packet_sent(&packet, test_addr(), test_addr())
.await;

// Test inbound interception
header.ssrc = 67890;
let packet_in = RtpPacket::new(header, payload);
collector.on_packet_received(&packet_in).await;
collector
.on_packet_received(&packet_in, test_addr(), test_addr())
.await;

let stats = collector.collect().await.unwrap();

Expand Down