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4 commits

Author SHA1 Message Date
Aritra Basu
e78b1b3ecc
HTTP/3: add proxy CONNECT and MASQUE CONNECT-UDP support (ngtcp2 QUIC)
This patch adds two major proxy capabilities to curl (ngtcp2 QUIC):
- HTTP/3 Proxy CONNECT: Tunnel HTTP/1.1 or HTTP/2 traffic through an
  HTTPS proxy that speaks HTTP/3 (QUIC) using the standard CONNECT
  method over an HTTP/3 connection.
- MASQUE CONNECT-UDP: Tunnel HTTP/3 (QUIC) traffic through an HTTP
  proxy (speaking HTTP/1.1, HTTP/2, or HTTP/3) using the extended
  CONNECT method with the CONNECT-UDP protocol (RFC9297 & RFC9298).

Public API additions:
- `CURLPROXY_HTTPS3`: new proxy type constant for HTTP/3 proxy
- `--proxy-http3`: new CLI flag to negotiate HTTP/3 with HTTPS proxy

The implementation adds two new filters:
- `H3-PROXY` - enables negotiating HTTP/3 (QUIC) to the proxy and
  running CONNECT/CONNECT-UDP through that proxy transport.
- `CAPSULE` - dedicated filter inserted between QUIC transport and
  HTTP-PROXY to handle datagram capsule encapsulation/decapsulation.

Here is how the curl filter chaining looks in different scenarios:
- HTTP/3 Proxy CONNECT (tunneling TCP protocols over QUIC proxy):
  conn -> HTTP/1.1 or HTTP/2  -> SSL -> HTTP-PROXY ->
                                 H3-PROXY -> HAPPY-EYEBALLS -> UDP
- MASQUE CONNECT-UDP (tunneling QUIC over any proxy):
  conn -> HTTP/3 -> CAPSULE -> HTTP-PROXY -> H3-PROXY ->
                               HAPPY-EYEBALLS -> UDP
  conn -> HTTP/3 -> CAPSULE -> HTTP-PROXY -> H1-PROXY or H2-PROXY ->
                               SSL -> HAPPY-EYEBALLS -> TCP

- Both features currently require the ngtcp2 QUIC backend.
- Both features are experimental (disabled by default). Enable with
  `--enable-proxy-http3`(autotools) or `-DUSE_PROXY_HTTP3=ON`(CMake).

Tests:
- tests/unit/unit3400.c: Unit tests for capsule protocol encode/decode
- tests/http/test_60_h3_proxy.py: Comprehensive pytest integration suite
- tests/http/testenv/h2o.py: Managing h2o instances with HTTP/1.1, HTTP/2,
  and HTTP/3 (QUIC) listeners, proxy.connect and proxy.connect-udp enabled.

References:
  RFC 9297 - HTTP Datagrams and the Capsule Protocol
  RFC 9298 - Proxying UDP in HTTP
  RFC 9000 §16 — Variable-Length Integer Encoding

Signed-off-by: Aritra Basu <aritrbas+gh@cisco.com>

Closes #21153
2026-05-27 08:49:53 +02:00
Viktor Szakats
614b94eecc
tidy-up: miscellaneous
- avoid "will" in builds scripts, scripts folder, curl_easy_ssls_export.md,
  and few other files.
- badwords: add "initialise", "nul terminated", "thread safety" and
  variations.
- prefer "null-terminat", where missing (two places).
- fix "null-terminat*" missing dash.
- hostip: merge two `#if` blocks.
- tool_doswin: fix comment
  Spotted by GitHub Code Quality
  Follow-up to 9a2663322c #17572
- fix stray spaces and newlines.

Closes #21638
2026-05-16 01:56:17 +02:00
Stefan Eissing
455bebc2c7
peer: fix compare of hostname for uds
Unix domain socket paths need to be compared case-senstive, in contrast
to DNS hostnames.

Follow-up to bc40e09f63

Pointed out by Codex Security

Closes #21511
2026-05-06 10:14:17 +02:00
Stefan Eissing
bc40e09f63
lib: introduce Curl_peer
`struct Curl_peer` keeps information about a communication endpoint
together. It will replace `conn->host` and `conn->conn_to_host` and
proxyinfo host. It will also become part of `struct ssl_peer`.

It has a reference counter, so an instance can be shared between
connections and filters.

Elminiates `conn->host` and `conn->connect_to_host`, used in the
proxyinfo structures. Passed to DNS resolution and socks filters, etc.

Pass peer to http proxy and socks tunnel filters. Use peer in dns filter
and resolving. Make `Curl_peer` a member in the `struct ssl_peer`.

Add `docs/internals/PEERS.md` for documentation.

Closes #21472
2026-05-05 16:22:11 +02:00