FUNKY_SCO
};
+enum {
+ /*
+ * Network address types. Used for specifying choice of IPv4/v6
+ * in config; also used in proxy.c to indicate whether a given
+ * host name has already been resolved or will be resolved at
+ * the proxy end.
+ */
+ ADDRTYPE_UNSPEC, ADDRTYPE_IPV4, ADDRTYPE_IPV6, ADDRTYPE_NAME
+};
+
struct backend_tag {
const char *(*init) (void *frontend_handle, void **backend_handle,
Config *cfg,
* buffer is clearing.
*/
void (*unthrottle) (void *handle, int);
+ int (*cfg_info) (void *handle);
int default_port;
};
char host[512];
int port;
int protocol;
+ int addressfamily;
int close_on_exit;
int warn_on_close;
int ping_interval; /* in seconds */
/* SSH bug compatibility modes */
int sshbug_ignore1, sshbug_plainpw1, sshbug_rsa1,
sshbug_hmac2, sshbug_derivekey2, sshbug_rsapad2,
- sshbug_pksessid2;
+ sshbug_pksessid2, sshbug_rekey2;
/* Options for pterm. Should split out into platform-dependent part. */
int stamp_utmp;
int login_shell;
void get_window_pos(void *frontend, int *x, int *y);
void get_window_pixels(void *frontend, int *x, int *y);
char *get_window_title(void *frontend, int icon);
+/* Hint from backend to frontend about time-consuming operations.
+ * Initial state is assumed to be BUSY_NOT. */
+enum {
+ BUSY_NOT, /* Not busy, all user interaction OK */
+ BUSY_WAITING, /* Waiting for something; local event loops still running
+ so some local interaction (e.g. menus) OK, but network
+ stuff is suspended */
+ BUSY_CPU /* Locally busy (e.g. crypto); user interaction suspended */
+};
+void set_busy_status(void *frontend, int status);
void cleanup_exit(int);
*/
struct controlbox;
void setup_config_box(struct controlbox *b, struct sesslist *sesslist,
- int midsession, int protocol);
+ int midsession, int protocol, int protcfginfo);
/*
* Exports from minibidi.c.
* notifies the front end that a new timer has been added to the
* list which is sooner than any existing ones. It provides the
* time when that timer needs to go off.
+ *
+ * *** FRONT END IMPLEMENTORS NOTE:
+ *
+ * There's an important subtlety in the front-end implementation of
+ * the timer interface. When a front end is given a `next' value,
+ * either returned from run_timers() or via timer_change_notify(),
+ * it should ensure that it really passes _that value_ as the `now'
+ * parameter to its next run_timers call. It should _not_ simply
+ * call GETTICKCOUNT() to get the `now' parameter when invoking
+ * run_timers().
+ *
+ * The reason for this is that an OS's system clock might not agree
+ * exactly with the timing mechanisms it supplies to wait for a
+ * given interval. I'll illustrate this by the simple example of
+ * Unix Plink, which uses timeouts to select() in a way which for
+ * these purposes can simply be considered to be a wait() function.
+ * Suppose, for the sake of argument, that this wait() function
+ * tends to return early by 1%. Then a possible sequence of actions
+ * is:
+ *
+ * - run_timers() tells the front end that the next timer firing
+ * is 10000ms from now.
+ * - Front end calls wait(10000ms), but according to
+ * GETTICKCOUNT() it has only waited for 9900ms.
+ * - Front end calls run_timers() again, passing time T-100ms as
+ * `now'.
+ * - run_timers() does nothing, and says the next timer firing is
+ * still 100ms from now.
+ * - Front end calls wait(100ms), which only waits for 99ms.
+ * - Front end calls run_timers() yet again, passing time T-1ms.
+ * - run_timers() says there's still 1ms to wait.
+ * - Front end calls wait(1ms).
+ *
+ * If you're _lucky_ at this point, wait(1ms) will actually wait
+ * for 1ms and you'll only have woken the program up three times.
+ * If you're unlucky, wait(1ms) might do nothing at all due to
+ * being below some minimum threshold, and you might find your
+ * program spends the whole of the last millisecond tight-looping
+ * between wait() and run_timers().
+ *
+ * Instead, what you should do is to _save_ the precise `next'
+ * value provided by run_timers() or via timer_change_notify(), and
+ * use that precise value as the input to the next run_timers()
+ * call. So:
+ *
+ * - run_timers() tells the front end that the next timer firing
+ * is at time T, 10000ms from now.
+ * - Front end calls wait(10000ms).
+ * - Front end then immediately calls run_timers() and passes it
+ * time T, without stopping to check GETTICKCOUNT() at all.
+ *
+ * This guarantees that the program wakes up only as many times as
+ * there are actual timer actions to be taken, and that the timing
+ * mechanism will never send it into a tight loop.
+ *
+ * (It does also mean that the timer action in the above example
+ * will occur 100ms early, but this is not generally critical. And
+ * the hypothetical 1% error in wait() will be partially corrected
+ * for anyway when, _after_ run_timers() returns, you call
+ * GETTICKCOUNT() and compare the result with the returned `next'
+ * value to find out how long you have to make your next wait().)
*/
typedef void (*timer_fn_t)(void *ctx, long now);
long schedule_timer(int ticks, timer_fn_t fn, void *ctx);