cmd: Split unix sockets for admin endpoint addresses (#5696)

* cmd: fix cli when admin endpoint uses new unix socket permission format

Fixes a bug where the following Caddyfile

```Caddyfile
{
	admin unix/admin.sock|0660
}
```

and `caddy reload --config Caddyfile`
would throw the following error instead of reloading it:

```
INFO    using provided configuration    {"config_file": "Caddyfile", "config_adapter": ""}
Error: sending configuration to instance: performing request: Post "http://127.0.0.1/load": dial unix admin.sock|0660: connect: no such file or directory
[ERROR] exit status 1
```

---

This bug also affected `caddy start` and `caddy stop`.

* Move splitter function to internal

---------

Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>

1 files changed, 3 insertions, 36 deletions

diff --git a/listeners.go b/listeners.go
index fe5ad0c..9e761be 100644
--- a/listeners.go
+++ b/listeners.go
@@ -31,6 +31,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/caddyserver/caddy/v2/internal"
 	"github.com/quic-go/quic-go"
 	"github.com/quic-go/quic-go/http3"
 	"go.uber.org/zap"
@@ -157,7 +158,7 @@ func (na NetworkAddress) listen(ctx context.Context, portOffset uint, config net
 	// is independent of permissions bits
 	if na.IsUnixNetwork() {
 		var err error
-		address, unixFileMode, err = splitUnixSocketPermissionsBits(na.Host)
+		address, unixFileMode, err = internal.SplitUnixSocketPermissionsBits(na.Host)
 		if err != nil {
 			return nil, err
 		}
@@ -319,40 +320,6 @@ func IsUnixNetwork(netw string) bool {
 	return strings.HasPrefix(netw, "unix")
 }
 
-// Takes a unix socket address in the unusual "path|bits" format
-// (e.g. /run/caddy.sock|0222) and tries to split it into
-// socket path (host) and permissions bits (port). Colons (":")
-// can't be used as separator, as socket paths on Windows may
-// include a drive letter (e.g. `unix/c:\absolute\path.sock`).
-// Permission bits will default to 0200 if none are specified.
-// Throws an error, if the first carrying bit does not
-// include write perms (e.g. `0422` or `022`).
-// Symbolic permission representation (e.g. `u=w,g=w,o=w`)
-// is not supported and will throw an error for now!
-func splitUnixSocketPermissionsBits(addr string) (path string, fileMode fs.FileMode, err error) {
-	addrSplit := strings.SplitN(addr, "|", 2)
-
-	if len(addrSplit) == 2 {
-		// parse octal permission bit string as uint32
-		fileModeUInt64, err := strconv.ParseUint(addrSplit[1], 8, 32)
-		if err != nil {
-			return "", 0, fmt.Errorf("could not parse octal permission bits in %s: %v", addr, err)
-		}
-		fileMode = fs.FileMode(fileModeUInt64)
-
-		// FileMode.String() returns a string like `-rwxr-xr--` for `u=rwx,g=rx,o=r` (`0754`)
-		if string(fileMode.String()[2]) != "w" {
-			return "", 0, fmt.Errorf("owner of the socket requires '-w-' (write, octal: '2') permissions at least; got '%s' in %s", fileMode.String()[1:4], addr)
-		}
-
-		return addrSplit[0], fileMode, nil
-	}
-
-	// default to 0200 (symbolic: `u=w,g=,o=`)
-	// if no permission bits are specified
-	return addr, 0200, nil
-}
-
 // ParseNetworkAddress parses addr into its individual
 // components. The input string is expected to be of
 // the form "network/host:port-range" where any part is
@@ -377,7 +344,7 @@ func ParseNetworkAddressWithDefaults(addr, defaultNetwork string, defaultPort ui
 		network = defaultNetwork
 	}
 	if IsUnixNetwork(network) {
-		_, _, err := splitUnixSocketPermissionsBits(host)
+		_, _, err := internal.SplitUnixSocketPermissionsBits(host)
 		return NetworkAddress{
 			Network: network,
 			Host:    host,