frankenphp/cgi.go
2023-07-18 14:58:22 +02:00

287 lines
8.4 KiB
Go

package frankenphp
import (
"crypto/tls"
"net"
"net/http"
"path/filepath"
"strings"
)
// populateEnv returns a set of CGI environment variables for the request.
//
// TODO: handle this case https://github.com/caddyserver/caddy/issues/3718
// Inspired by https://github.com/caddyserver/caddy/blob/master/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
func populateEnv(request *http.Request) error {
fc, ok := FromContext(request.Context())
if !ok {
panic("not a FrankenPHP request")
}
if fc.populated {
return nil
}
_, addrOk := fc.Env["REMOTE_ADDR"]
_, portOk := fc.Env["REMOTE_PORT"]
if !addrOk || !portOk {
// Separate remote IP and port; more lenient than net.SplitHostPort
var ip, port string
if idx := strings.LastIndex(request.RemoteAddr, ":"); idx > -1 {
ip = request.RemoteAddr[:idx]
port = request.RemoteAddr[idx+1:]
} else {
ip = request.RemoteAddr
}
// Remove [] from IPv6 addresses
ip = strings.Replace(ip, "[", "", 1)
ip = strings.Replace(ip, "]", "", 1)
if _, ok := fc.Env["REMOTE_ADDR"]; !ok {
fc.Env["REMOTE_ADDR"] = ip
}
if _, ok := fc.Env["REMOTE_HOST"]; !ok {
fc.Env["REMOTE_HOST"] = ip // For speed, remote host lookups disabled
}
if _, ok := fc.Env["REMOTE_PORT"]; !ok {
fc.Env["REMOTE_PORT"] = port
}
}
if _, ok := fc.Env["DOCUMENT_ROOT"]; !ok {
// make sure file root is absolute
root, err := filepath.Abs(fc.DocumentRoot)
if err != nil {
return err
}
if fc.ResolveRootSymlink {
if root, err = filepath.EvalSymlinks(root); err != nil {
return err
}
}
fc.Env["DOCUMENT_ROOT"] = root
}
fpath := request.URL.Path
scriptName := fpath
docURI := fpath
// split "actual path" from "path info" if configured
if splitPos := splitPos(fc, fpath); splitPos > -1 {
docURI = fpath[:splitPos]
fc.Env["PATH_INFO"] = fpath[splitPos:]
// Strip PATH_INFO from SCRIPT_NAME
scriptName = strings.TrimSuffix(scriptName, fc.Env["PATH_INFO"])
}
// SCRIPT_FILENAME is the absolute path of SCRIPT_NAME
scriptFilename := sanitizedPathJoin(fc.Env["DOCUMENT_ROOT"], scriptName)
// Ensure the SCRIPT_NAME has a leading slash for compliance with RFC3875
// Info: https://tools.ietf.org/html/rfc3875#section-4.1.13
if scriptName != "" && !strings.HasPrefix(scriptName, "/") {
scriptName = "/" + scriptName
}
if _, ok := fc.Env["PHP_SELF"]; !ok {
fc.Env["PHP_SELF"] = fpath
}
if _, ok := fc.Env["DOCUMENT_URI"]; !ok {
fc.Env["DOCUMENT_URI"] = docURI
}
if _, ok := fc.Env["SCRIPT_FILENAME"]; !ok {
fc.Env["SCRIPT_FILENAME"] = scriptFilename
}
if _, ok := fc.Env["SCRIPT_NAME"]; !ok {
fc.Env["SCRIPT_NAME"] = scriptName
}
if _, ok := fc.Env["REQUEST_SCHEME"]; !ok {
if request.TLS == nil {
fc.Env["REQUEST_SCHEME"] = "http"
} else {
fc.Env["REQUEST_SCHEME"] = "https"
}
}
if request.TLS != nil {
if _, ok := fc.Env["HTTPS"]; !ok {
fc.Env["HTTPS"] = "on"
}
// and pass the protocol details in a manner compatible with apache's mod_ssl
// (which is why these have a SSL_ prefix and not TLS_).
_, sslProtocolOk := fc.Env["SSL_PROTOCOL"]
v, versionOk := tlsProtocolStrings[request.TLS.Version]
if !sslProtocolOk && versionOk {
fc.Env["SSL_PROTOCOL"] = v
}
}
_, serverNameOk := fc.Env["SERVER_NAME"]
_, serverPortOk := fc.Env["SERVER_PORT"]
if !serverNameOk || !serverPortOk {
reqHost, reqPort, err := net.SplitHostPort(request.Host)
if err == nil {
if !serverNameOk {
fc.Env["SERVER_NAME"] = reqHost
}
// compliance with the CGI specification requires that
// SERVER_PORT should only exist if it's a valid numeric value.
// Info: https://www.ietf.org/rfc/rfc3875 Page 18
if !serverPortOk {
// compliance with the CGI specification requires that
// the SERVER_PORT variable MUST be set to the TCP/IP port number on which this request is received from the client
// even if the port is the default port for the scheme and could otherwise be omitted from a URI.
// https://tools.ietf.org/html/rfc3875#section-4.1.15
if reqPort != "" {
fc.Env["SERVER_PORT"] = reqPort
} else if fc.Env["REQUEST_SCHEME"] == "http" {
fc.Env["SERVER_PORT"] = "80"
} else if fc.Env["REQUEST_SCHEME"] == "https" {
fc.Env["SERVER_PORT"] = "443"
}
}
} else if !serverNameOk {
// whatever, just assume there was no port
fc.Env["SERVER_NAME"] = request.Host
}
}
// Variables defined in CGI 1.1 spec
// Some variables are unused but cleared explicitly to prevent
// the parent environment from interfering.
// We never override an entry previously set
if _, ok := fc.Env["REMOTE_IDENT"]; !ok {
fc.Env["REMOTE_IDENT"] = "" // Not used
}
if _, ok := fc.Env["AUTH_TYPE"]; !ok {
fc.Env["AUTH_TYPE"] = "" // Not used
}
if _, ok := fc.Env["CONTENT_LENGTH"]; !ok {
fc.Env["CONTENT_LENGTH"] = request.Header.Get("Content-Length")
}
if _, ok := fc.Env["CONTENT_TYPE"]; !ok {
fc.Env["CONTENT_TYPE"] = request.Header.Get("Content-Type")
}
if _, ok := fc.Env["GATEWAY_INTERFACE"]; !ok {
fc.Env["GATEWAY_INTERFACE"] = "CGI/1.1"
}
if _, ok := fc.Env["QUERY_STRING"]; !ok {
fc.Env["QUERY_STRING"] = request.URL.RawQuery
}
if _, ok := fc.Env["QUERY_STRING"]; !ok {
fc.Env["QUERY_STRING"] = request.URL.RawQuery
}
if _, ok := fc.Env["REQUEST_METHOD"]; !ok {
fc.Env["REQUEST_METHOD"] = request.Method
}
if _, ok := fc.Env["SERVER_PROTOCOL"]; !ok {
fc.Env["SERVER_PROTOCOL"] = request.Proto
}
if _, ok := fc.Env["SERVER_SOFTWARE"]; !ok {
fc.Env["SERVER_SOFTWARE"] = "FrankenPHP"
}
if _, ok := fc.Env["HTTP_HOST"]; !ok {
fc.Env["HTTP_HOST"] = request.Host // added here, since not always part of headers
}
if _, ok := fc.Env["REQUEST_URI"]; !ok {
fc.Env["REQUEST_URI"] = request.URL.RequestURI()
}
// compliance with the CGI specification requires that
// PATH_TRANSLATED should only exist if PATH_INFO is defined.
// Info: https://www.ietf.org/rfc/rfc3875 Page 14
if fc.Env["PATH_INFO"] != "" {
fc.Env["PATH_TRANSLATED"] = sanitizedPathJoin(fc.Env["DOCUMENT_ROOT"], fc.Env["PATH_INFO"]) // Info: http://www.oreilly.com/openbook/cgi/ch02_04.html
}
// Add all HTTP headers to env variables
for field, val := range request.Header {
k := "HTTP_" + headerNameReplacer.Replace(strings.ToUpper(field))
if _, ok := fc.Env[k]; !ok {
fc.Env[k] = strings.Join(val, ", ")
}
}
if _, ok := fc.Env["REMOTE_USER"]; !ok {
var (
authUser string
ok bool
)
authUser, fc.authPassword, ok = request.BasicAuth()
if ok {
fc.Env["REMOTE_USER"] = authUser
}
}
fc.populated = true
return nil
}
// splitPos returns the index where path should
// be split based on SplitPath.
//
// Adapted from https://github.com/caddyserver/caddy/blob/master/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
// Copyright 2015 Matthew Holt and The Caddy Authors
func splitPos(fc *FrankenPHPContext, path string) int {
if len(fc.SplitPath) == 0 {
return 0
}
lowerPath := strings.ToLower(path)
for _, split := range fc.SplitPath {
if idx := strings.Index(lowerPath, strings.ToLower(split)); idx > -1 {
return idx + len(split)
}
}
return -1
}
// Map of supported protocols to Apache ssl_mod format
// Note that these are slightly different from SupportedProtocols in caddytls/config.go
var tlsProtocolStrings = map[uint16]string{
tls.VersionTLS10: "TLSv1",
tls.VersionTLS11: "TLSv1.1",
tls.VersionTLS12: "TLSv1.2",
tls.VersionTLS13: "TLSv1.3",
}
var headerNameReplacer = strings.NewReplacer(" ", "_", "-", "_")
// SanitizedPathJoin performs filepath.Join(root, reqPath) that
// is safe against directory traversal attacks. It uses logic
// similar to that in the Go standard library, specifically
// in the implementation of http.Dir. The root is assumed to
// be a trusted path, but reqPath is not; and the output will
// never be outside of root. The resulting path can be used
// with the local file system.
//
// Adapted from https://github.com/caddyserver/caddy/blob/master/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
// Copyright 2015 Matthew Holt and The Caddy Authors
func sanitizedPathJoin(root, reqPath string) string {
if root == "" {
root = "."
}
path := filepath.Join(root, filepath.Clean("/"+reqPath))
// filepath.Join also cleans the path, and cleaning strips
// the trailing slash, so we need to re-add it afterwards.
// if the length is 1, then it's a path to the root,
// and that should return ".", so we don't append the separator.
if strings.HasSuffix(reqPath, "/") && len(reqPath) > 1 {
path += separator
}
return path
}
const separator = string(filepath.Separator)