tsocket/bsd: more correctly check if the cached tevent_fd is still valid

I some cases the pointer value of tevent_context is the same again,
if we do something like:

	ev1 = tevent_context_init();
	...
	fde = tevent_add_fd(ev1, fd, TEVENT_FD_READ...);
	...
	talloc_free(ev1);
	...
	ev2 = tevent_context_init();

	if (ev1 == ev2) {
		/* this can happen! */
	}

	if (tevent_fd_get_flags(fde) == 0) {
		/* this is always true */
	}

But the "talloc_free(ev1)" will set fde->event_ctx to NULL
and tevent_fd_get_flags() will always return 0.

metze

diff --git a/lib/tsocket/tsocket_bsd.c b/lib/tsocket/tsocket_bsd.c
index a4cbda8b8378d8b28434c98e13a265a9b8a75df8..4f4b166e7da070b70ba7a6ecc6de87360e0c1984 100644 (file)
--- a/lib/tsocket/tsocket_bsd.c
+++ b/lib/tsocket/tsocket_bsd.c
@@ -612,7 +612,9 @@ static int tdgram_bsd_set_readable_handler(struct tdgram_bsd *bsds,
                TALLOC_FREE(bsds->fde);
        }
 
-       if (bsds->fde == NULL) {
+       if (tevent_fd_get_flags(bsds->fde) == 0) {
+               TALLOC_FREE(bsds->fde);
+
                bsds->fde = tevent_add_fd(ev, bsds,
                                          bsds->fd, TEVENT_FD_READ,
                                          tdgram_bsd_fde_handler,
@@ -664,7 +666,9 @@ static int tdgram_bsd_set_writeable_handler(struct tdgram_bsd *bsds,
                TALLOC_FREE(bsds->fde);
        }
 
-       if (bsds->fde == NULL) {
+       if (tevent_fd_get_flags(bsds->fde) == 0) {
+               TALLOC_FREE(bsds->fde);
+
                bsds->fde = tevent_add_fd(ev, bsds,
                                          bsds->fd, TEVENT_FD_WRITE,
                                          tdgram_bsd_fde_handler,
@@ -1325,7 +1329,9 @@ static int tstream_bsd_set_readable_handler(struct tstream_bsd *bsds,
                TALLOC_FREE(bsds->fde);
        }
 
-       if (bsds->fde == NULL) {
+       if (tevent_fd_get_flags(bsds->fde) == 0) {
+               TALLOC_FREE(bsds->fde);
+
                bsds->fde = tevent_add_fd(ev, bsds,
                                          bsds->fd, TEVENT_FD_READ,
                                          tstream_bsd_fde_handler,
@@ -1377,7 +1383,9 @@ static int tstream_bsd_set_writeable_handler(struct tstream_bsd *bsds,
                TALLOC_FREE(bsds->fde);
        }
 
-       if (bsds->fde == NULL) {
+       if (tevent_fd_get_flags(bsds->fde) == 0) {
+               TALLOC_FREE(bsds->fde);
+
                bsds->fde = tevent_add_fd(ev, bsds,
                                          bsds->fd, TEVENT_FD_WRITE,
                                          tstream_bsd_fde_handler,