Via Syntax
© R.A.Sol
A via string identifies a transport endpoint.
Grammar
Full form:
scheme+host[:port]Bare form (auto-negotiate transport):
host[:port]Hostless form (used in HELLO Transport headers where
host is already known):
scheme[:port]Unix domain socket:
unix+<absolute-path>Schemes
| Scheme | Default port | Transport |
|---|---|---|
tcp |
4777 |
TCP plaintext |
quib |
4776 |
QUIB encrypted (033) |
ws |
4778 |
WebSocket |
udp |
4777 |
UDP datagram (stateless) |
auto |
4777 |
Auto-negotiate (equivalent to bare form) |
Host
Host is a hostname, IPv4 address, or bracketed IPv6 address.
IPv6 bracket form: [::1] or
[::1]:port.
Port
Port is optional. When omitted, the scheme default applies. Bare
form defaults to 4777.
Hostless Resolution
Hostless forms appear in HELLO Transport headers.
The client fills in the host from its existing connection.
Examples:
tcp— TCP on default port, same hostudp:4777— UDP on port 4777, same hostquib:4776— QUIB on port 4776, same host
Display Form
The canonical display form is:
scheme+host:portwhen a scheme is sethost:portfor auto-negotiateunix+<path>for Unix sockets
Examples
| Input | Scheme | Host | Port |
|---|---|---|---|
tcp+10.0.0.1 |
tcp | 10.0.0.1 | 4777 |
tcp+10.0.0.1:9000 |
tcp | 10.0.0.1 | 9000 |
quib+1.1.1.1:4776 |
quib | 1.1.1.1 | 4776 |
udp+10.0.0.1 |
udp | 10.0.0.1 | 4777 |
ws+example.com |
ws | example.com | 4778 |
auto+example.com |
auto | example.com | 4777 |
example.com |
auto | example.com | 4777 |
example.com:9000 |
auto | example.com | 9000 |
tcp:4777 |
tcp | (from context) | 4777 |
udp |
udp | (from context) | 4777 |
unix+/tmp/hppr.sock |
— | — | — |