Merge pull request #9 from privacybydesign/sigpipe-transport

Sigpipe transport

internal/disable_sigpipe/disable_sigpipe.go

+// +build ios
+
+package disable_sigpipe
+
+import (
+	"net"
+	"reflect"
+	"syscall"
+)
+
+// Taken from github.com/keybase/go-framed-msgpack-rpc/rpc/sigpipe_bsd.go
+func DisableSigPipe(c net.Conn) error {
+	// Disable SIGPIPE on this connection since we currently need to do this manually for iOS
+	// to prevent the signal from crashing iOS apps.
+	// See: https://github.com/golang/go/issues/17393
+	netFD := reflect.ValueOf(c).Elem().FieldByName("fd").Elem()
+	sysfd := netFD.FieldByName("sysfd")
+	var fd int
+	if sysfd.IsValid() {
+		fd = int(sysfd.Int())
+	} else { // After go +3792db5
+		fd = int(netFD.FieldByName("pfd").FieldByName("Sysfd").Int())
+	}
+	return syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_NOSIGPIPE, 1)
+}
\ No newline at end of file

internal/disable_sigpipe/noop.go

+// +build !ios
+
+package disable_sigpipe
+
+import "net"
+
+func DisableSigPipe(c net.Conn) error {
+	return nil
+}
\ No newline at end of file

transport.go

@@ -6,11 +6,13 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"path/filepath"
 	"strings"
 	"time"
 
+	"github.com/privacybydesign/irmago/internal/disable_sigpipe"
 	"github.com/privacybydesign/irmago/internal/fs"
 )
 
@@ -29,11 +31,27 @@ func NewHTTPTransport(serverURL string) *HTTPTransport {
 	if serverURL != "" && !strings.HasSuffix(url, "/") { // TODO fix this
 		url += "/"
 	}
+
+	// Create a transport that dials with a SIGPIPE handler (which is only active on iOS)
+	var innerTransport http.Transport
+
+	innerTransport.Dial = func(network, addr string) (c net.Conn, err error) {
+		c, err = net.Dial(network, addr)
+		if err != nil {
+			return c, err
+		}
+		if err = disable_sigpipe.DisableSigPipe(c); err != nil {
+			return c, err
+		}
+		return c, nil
+	}
+
 	return &HTTPTransport{
 		Server:  url,
 		headers: map[string]string{},
 		client: &http.Client{
-			Timeout: time.Second * 15,
+			Timeout:   time.Second * 15,
+			Transport: &innerTransport,
 		},
 	}
 }