Sybren A. Stüvel
ab8ecc24cc
Add license specifiers to Go files that were missing them: ``` // SPDX-License-Identifier: GPL-3.0-or-later ``` No functional changes.
114 lines
2.9 KiB
Go
114 lines
2.9 KiB
Go
// Package own_url provides a way for a process to find a URL on which it can be reached.
|
|
package own_url
|
|
|
|
// SPDX-License-Identifier: GPL-3.0-or-later
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"net/url"
|
|
|
|
"github.com/rs/zerolog/log"
|
|
)
|
|
|
|
func AvailableURLs(schema, listen string) ([]url.URL, error) {
|
|
if listen == "" {
|
|
panic("empty 'listen' parameter")
|
|
}
|
|
|
|
hostURL := specificHostURL(schema, listen)
|
|
if hostURL != nil {
|
|
return []url.URL{*hostURL}, nil
|
|
}
|
|
log.Debug().Str("listen", listen).Msg("not listening on any specific host")
|
|
|
|
addrs, err := networkInterfaces()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
log.Debug().Msg("iterating network interfaces to find possible URLs for Flamenco Manager.")
|
|
return urlsForNetworkInterfaces(schema, listen, addrs)
|
|
}
|
|
|
|
// ToStringers converts an array of URLs to an array of `fmt.Stringer`.
|
|
func ToStringers(urls []url.URL) []fmt.Stringer {
|
|
stringers := make([]fmt.Stringer, len(urls))
|
|
for idx := range urls {
|
|
stringers[idx] = &urls[idx]
|
|
}
|
|
return stringers
|
|
}
|
|
|
|
// specificHostURL returns the hosts's URL if the "listen" string is specific enough, otherwise nil.
|
|
// Examples: "192.168.0.1:8080" is specific enough, "0.0.0.0:8080" and ":8080" are not.
|
|
func specificHostURL(scheme, listen string) *url.URL {
|
|
var (
|
|
host string
|
|
err error
|
|
)
|
|
|
|
// Figure out which port we're supposted to listen on.
|
|
if host, _, err = net.SplitHostPort(listen); err != nil {
|
|
// This is annoying. SplitHostPort() doesn't return specific errors, so we
|
|
// have to test on the error message to see what's the problem.
|
|
// A missing port is fine, but other errors are not.
|
|
addrErr := err.(*net.AddrError)
|
|
if addrErr.Err != "missing port in address" {
|
|
log.Warn().Str("address", listen).Err(err).Msg("unable to split host and port in address")
|
|
return nil
|
|
}
|
|
|
|
// 'listen' doesn't have a port number, so it's just the host.
|
|
host = listen
|
|
}
|
|
if host == "" {
|
|
// An empty host is never specific enough.
|
|
return nil
|
|
}
|
|
|
|
ip := net.ParseIP(host)
|
|
if ip != nil && ip.IsUnspecified() {
|
|
// The host is "::0" or "0.0.0.0"; not specific.
|
|
return nil
|
|
}
|
|
|
|
// We can just construct a URL here, since we know it's a specific host anyway.
|
|
return &url.URL{
|
|
Scheme: scheme,
|
|
Host: listen,
|
|
Path: "/",
|
|
}
|
|
}
|
|
|
|
func urlsForNetworkInterfaces(scheme, listen string, addrs []net.IP) ([]url.URL, error) {
|
|
// Find the port number in the 'listen' string.
|
|
var (
|
|
port string
|
|
err error
|
|
)
|
|
// Get the port number as integer.
|
|
if _, port, err = net.SplitHostPort(listen); err != nil {
|
|
return nil, fmt.Errorf("unable to split host and port in address %q", listen)
|
|
}
|
|
|
|
links := make([]url.URL, 0)
|
|
for _, addr := range addrs {
|
|
var strAddr string
|
|
if ipv4 := addr.To4(); ipv4 != nil {
|
|
strAddr = ipv4.String()
|
|
} else {
|
|
strAddr = fmt.Sprintf("[%s]", addr)
|
|
}
|
|
|
|
urlForAddr := url.URL{
|
|
Scheme: scheme,
|
|
Host: fmt.Sprintf("%s:%s", strAddr, port),
|
|
Path: "/",
|
|
}
|
|
links = append(links, urlForAddr)
|
|
}
|
|
|
|
return links, nil
|
|
}
|