memcmp(sa->clientid, sb->clientid, sizeof(sa->clientid));
}
+/* Do-nothing "plug" implementation, used by x11_setup_display() when it
+ * creates a trial connection (and then immediately closes it).
+ * XXX: bit out of place here, could in principle live in a platform-
+ * independent network.c or something */
+static void dummy_plug_log(Plug p, int type, SockAddr addr, int port,
+ const char *error_msg, int error_code) { }
+static int dummy_plug_closing
+ (Plug p, const char *error_msg, int error_code, int calling_back)
+{ return 1; }
+static int dummy_plug_receive(Plug p, int urgent, char *data, int len)
+{ return 1; }
+static void dummy_plug_sent(Plug p, int bufsize) { }
+static int dummy_plug_accepting(Plug p, OSSocket sock) { return 1; }
+static const struct plug_function_table dummy_plug = {
+ dummy_plug_log, dummy_plug_closing, dummy_plug_receive,
+ dummy_plug_sent, dummy_plug_accepting
+};
+
struct X11Display *x11_setup_display(char *display, int authtype,
const Config *cfg)
{
disp->hostname = NULL;
disp->displaynum = -1;
disp->screennum = 0;
+ disp->addr = NULL;
} else {
char *colon, *dot, *slash;
char *protocol, *hostname;
disp->hostname = dupstr("localhost");
disp->unixsocketpath = NULL;
+ disp->addr = NULL;
sfree(localcopy);
}
/*
* Look up the display hostname, if we need to.
*/
- if (disp->unixdomain) {
- disp->addr = platform_get_x11_unix_address(disp->unixsocketpath,
- disp->displaynum);
- if (disp->unixsocketpath)
- disp->realhost = dupstr(disp->unixsocketpath);
- else
- disp->realhost = dupprintf("unix:%d", disp->displaynum);
- disp->port = 0;
- } else {
+ if (!disp->unixdomain) {
const char *err;
disp->port = 6000 + disp->displaynum;
}
/*
+ * Try upgrading an IP-style localhost display to a Unix-socket
+ * display (as the standard X connection libraries do).
+ */
+ if (!disp->unixdomain && sk_address_is_local(disp->addr)) {
+ SockAddr ux = platform_get_x11_unix_address(NULL, disp->displaynum);
+ const char *err = sk_addr_error(ux);
+ if (!err) {
+ /* Create trial connection to see if there is a useful Unix-domain
+ * socket */
+ const struct plug_function_table *dummy = &dummy_plug;
+ Socket s = sk_new(sk_addr_dup(ux), 0, 0, 0, 0, 0, (Plug)&dummy);
+ err = sk_socket_error(s);
+ sk_close(s);
+ }
+ if (err) {
+ sk_addr_free(ux);
+ } else {
+ sk_addr_free(disp->addr);
+ disp->unixdomain = TRUE;
+ disp->addr = ux;
+ /* Fill in the rest in a moment */
+ }
+ }
+
+ if (disp->unixdomain) {
+ if (!disp->addr)
+ disp->addr = platform_get_x11_unix_address(disp->unixsocketpath,
+ disp->displaynum);
+ if (disp->unixsocketpath)
+ disp->realhost = dupstr(disp->unixsocketpath);
+ else
+ disp->realhost = dupprintf("unix:%d", disp->displaynum);
+ disp->port = 0;
+ }
+
+ /*
* Invent the remote authorisation details.
*/
if (authtype == X11_MIT) {
char *buf, *ptr, *str[4];
int len[4];
int family, protocol;
+ int ideal_match = FALSE;
+ char *ourhostname = get_hostname();
+
+ /*
+ * Normally we should look for precisely the details specified in
+ * `disp'. However, there's an oddity when the display is local:
+ * displays like "localhost:0" usually have their details stored
+ * in a Unix-domain-socket record (even if there isn't actually a
+ * real Unix-domain socket available, as with OpenSSH's proxy X11
+ * server).
+ *
+ * This is apparently a fudge to get round the meaninglessness of
+ * "localhost" in a shared-home-directory context -- xauth entries
+ * for Unix-domain sockets already disambiguate this by storing
+ * the *local* hostname in the conveniently-blank hostname field,
+ * but IP "localhost" records couldn't do this. So, typically, an
+ * IP "localhost" entry in the auth database isn't present and if
+ * it were it would be ignored.
+ *
+ * However, we don't entirely trust that (say) Windows X servers
+ * won't rely on a straight "localhost" entry, bad idea though
+ * that is; so if we can't find a Unix-domain-socket entry we'll
+ * fall back to an IP-based entry if we can find one.
+ */
+ int localhost = !disp->unixdomain && sk_address_is_local(disp->addr);
authfp = fopen(authfilename, "rb");
if (!authfp)
/* Records in .Xauthority contain four strings of up to 64K each */
buf = snewn(65537 * 4, char);
- while (1) {
- int c, i, j;
+ while (!ideal_match) {
+ int c, i, j, match = FALSE;
#define GET do { c = fgetc(authfp); if (c == EOF) goto done; c = (unsigned char)c; } while (0)
/* Expect a big-endian 2-byte number giving address family */
continue; /* don't recognise this protocol, look for another */
switch (family) {
- case 0:
+ case 0: /* IPv4 */
if (!disp->unixdomain &&
sk_addrtype(disp->addr) == ADDRTYPE_IPV4) {
char buf[4];
sk_addrcopy(disp->addr, buf);
- if (len[0] == 4 && !memcmp(str[0], buf, 4))
- goto found;
+ if (len[0] == 4 && !memcmp(str[0], buf, 4)) {
+ match = TRUE;
+ /* If this is a "localhost" entry, note it down
+ * but carry on looking for a Unix-domain entry. */
+ ideal_match = !localhost;
+ }
}
break;
- case 6:
+ case 6: /* IPv6 */
if (!disp->unixdomain &&
sk_addrtype(disp->addr) == ADDRTYPE_IPV6) {
char buf[16];
sk_addrcopy(disp->addr, buf);
- if (len[0] == 16 && !memcmp(str[0], buf, 16))
- goto found;
+ if (len[0] == 16 && !memcmp(str[0], buf, 16)) {
+ match = TRUE;
+ ideal_match = !localhost;
+ }
}
break;
- case 256:
- if (disp->unixdomain && !strcmp(disp->hostname, str[0]))
- goto found;
+ case 256: /* Unix-domain / localhost */
+ if ((disp->unixdomain || localhost)
+ && ourhostname && !strcmp(ourhostname, str[0]))
+ /* A matching Unix-domain socket is always the best
+ * match. */
+ match = ideal_match = TRUE;
break;
}
- }
- found:
- disp->localauthproto = protocol;
- disp->localauthdata = snewn(len[3], unsigned char);
- memcpy(disp->localauthdata, str[3], len[3]);
- disp->localauthdatalen = len[3];
+ if (match) {
+ /* Current best guess -- may be overridden if !ideal_match */
+ disp->localauthproto = protocol;
+ sfree(disp->localauthdata); /* free previous guess, if any */
+ disp->localauthdata = snewn(len[3], unsigned char);
+ memcpy(disp->localauthdata, str[3], len[3]);
+ disp->localauthdatalen = len[3];
+ }
+ }
done:
fclose(authfp);
memset(buf, 0, 65537 * 4);
sfree(buf);
+ sfree(ourhostname);
}
static void x11_log(Plug p, int type, SockAddr addr, int port,
~mdw / sgt / putty / blobdiff