AdGuardHome/home/helpers.go

242 lines
6.3 KiB
Go

package home
import (
"context"
"fmt"
"net"
"net/http"
"net/url"
"os"
"os/exec"
"path"
"path/filepath"
"runtime"
"strconv"
"strings"
"time"
"github.com/AdguardTeam/golibs/log"
"github.com/joomcode/errorx"
)
// ----------------------------------
// helper functions for HTTP handlers
// ----------------------------------
func ensure(method string, handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
log.Debug("%s %v", r.Method, r.URL)
if r.Method != method {
http.Error(w, "This request must be "+method, http.StatusMethodNotAllowed)
return
}
if method == "POST" || method == "PUT" || method == "DELETE" {
Context.controlLock.Lock()
defer Context.controlLock.Unlock()
}
handler(w, r)
}
}
func ensurePOST(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
return ensure("POST", handler)
}
func ensureGET(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
return ensure("GET", handler)
}
// Bridge between http.Handler object and Go function
type httpHandler struct {
handler func(http.ResponseWriter, *http.Request)
}
func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
h.handler(w, r)
}
func ensureHandler(method string, handler func(http.ResponseWriter, *http.Request)) http.Handler {
h := httpHandler{}
h.handler = ensure(method, handler)
return &h
}
// -------------------
// first run / install
// -------------------
func detectFirstRun() bool {
configfile := Context.configFilename
if !filepath.IsAbs(configfile) {
configfile = filepath.Join(Context.workDir, Context.configFilename)
}
_, err := os.Stat(configfile)
if !os.IsNotExist(err) {
// do nothing, file exists
return false
}
return true
}
// preInstall lets the handler run only if firstRun is true, no redirects
func preInstall(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
if !Context.firstRun {
// if it's not first run, don't let users access it (for example /install.html when configuration is done)
http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)
return
}
handler(w, r)
}
}
// preInstallStruct wraps preInstall into a struct that can be returned as an interface where necessary
type preInstallHandlerStruct struct {
handler http.Handler
}
func (p *preInstallHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) {
preInstall(p.handler.ServeHTTP)(w, r)
}
// preInstallHandler returns http.Handler interface for preInstall wrapper
func preInstallHandler(handler http.Handler) http.Handler {
return &preInstallHandlerStruct{handler}
}
// postInstall lets the handler run only if firstRun is false, and redirects to /install.html otherwise
// it also enforces HTTPS if it is enabled and configured
func postInstall(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
if Context.firstRun &&
!strings.HasPrefix(r.URL.Path, "/install.") &&
r.URL.Path != "/favicon.png" {
http.Redirect(w, r, "/install.html", http.StatusSeeOther) // should not be cacheable
return
}
// enforce https?
if config.TLS.ForceHTTPS && r.TLS == nil && config.TLS.Enabled && config.TLS.PortHTTPS != 0 && Context.httpsServer.server != nil {
// yes, and we want host from host:port
host, _, err := net.SplitHostPort(r.Host)
if err != nil {
// no port in host
host = r.Host
}
// construct new URL to redirect to
newURL := url.URL{
Scheme: "https",
Host: net.JoinHostPort(host, strconv.Itoa(config.TLS.PortHTTPS)),
Path: r.URL.Path,
RawQuery: r.URL.RawQuery,
}
http.Redirect(w, r, newURL.String(), http.StatusTemporaryRedirect)
return
}
w.Header().Set("Access-Control-Allow-Origin", "*")
handler(w, r)
}
}
type postInstallHandlerStruct struct {
handler http.Handler
}
func (p *postInstallHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) {
postInstall(p.handler.ServeHTTP)(w, r)
}
func postInstallHandler(handler http.Handler) http.Handler {
return &postInstallHandlerStruct{handler}
}
// Connect to a remote server resolving hostname using our own DNS server
func customDialContext(ctx context.Context, network, addr string) (net.Conn, error) {
log.Tracef("network:%v addr:%v", network, addr)
host, port, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
dialer := &net.Dialer{
Timeout: time.Minute * 5,
}
if net.ParseIP(host) != nil || config.DNS.Port == 0 {
con, err := dialer.DialContext(ctx, network, addr)
return con, err
}
addrs, e := Context.dnsServer.Resolve(host)
log.Debug("dnsServer.Resolve: %s: %v", host, addrs)
if e != nil {
return nil, e
}
if len(addrs) == 0 {
return nil, fmt.Errorf("couldn't lookup host: %s", host)
}
var dialErrs []error
for _, a := range addrs {
addr = net.JoinHostPort(a.String(), port)
con, err := dialer.DialContext(ctx, network, addr)
if err != nil {
dialErrs = append(dialErrs, err)
continue
}
return con, err
}
return nil, errorx.DecorateMany(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...)
}
// ---------------------
// general helpers
// ---------------------
// fileExists returns TRUE if file exists
func fileExists(fn string) bool {
_, err := os.Stat(fn)
if err != nil {
return false
}
return true
}
// runCommand runs shell command
func runCommand(command string, arguments ...string) (int, string, error) {
cmd := exec.Command(command, arguments...)
out, err := cmd.Output()
if err != nil {
return 1, "", fmt.Errorf("exec.Command(%s) failed: %s", command, err)
}
return cmd.ProcessState.ExitCode(), string(out), nil
}
// ---------------------
// debug logging helpers
// ---------------------
func _Func() string {
pc := make([]uintptr, 10) // at least 1 entry needed
runtime.Callers(2, pc)
f := runtime.FuncForPC(pc[0])
return path.Base(f.Name())
}
// SplitNext - split string by a byte and return the first chunk
// Whitespace is trimmed
func SplitNext(str *string, splitBy byte) string {
i := strings.IndexByte(*str, splitBy)
s := ""
if i != -1 {
s = (*str)[0:i]
*str = (*str)[i+1:]
} else {
s = *str
*str = ""
}
return strings.TrimSpace(s)
}