Fix bug #8197 - winbind does not properly detect when a DC connection is dead.

[kai/samba.git] / lib / async_req / async_sock.c

diff --git a/lib/async_req/async_sock.c b/lib/async_req/async_sock.c
index 86053d94e87952b40bed3059ae8725e5aee317da..dfb1a1cdbd7ef4690351227fe99e3c23fba6202e 100644 (file)
--- a/lib/async_req/async_sock.c
+++ b/lib/async_req/async_sock.c
@@ -386,6 +386,7 @@ struct writev_state {
        int count;
        size_t total_size;
        uint16_t flags;
+       bool err_on_readability;
 };
 
 static void writev_trigger(struct tevent_req *req, void *private_data);
@@ -413,10 +414,8 @@ struct tevent_req *writev_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
        if (state->iov == NULL) {
                goto fail;
        }
-       state->flags = TEVENT_FD_WRITE;
-       if (err_on_readability) {
-               state->flags |= TEVENT_FD_READ;
-       }
+       state->flags = TEVENT_FD_WRITE|TEVENT_FD_READ;
+       state->err_on_readability = err_on_readability;
 
        if (queue == NULL) {
                struct tevent_fd *fde;
@@ -462,8 +461,35 @@ static void writev_handler(struct tevent_context *ev, struct tevent_fd *fde,
        to_write = 0;
 
        if ((state->flags & TEVENT_FD_READ) && (flags & TEVENT_FD_READ)) {
-               tevent_req_error(req, EPIPE);
-               return;
+               int ret, value;
+
+               if (state->err_on_readability) {
+                       /* Readable and the caller wants an error on read. */
+                       tevent_req_error(req, EPIPE);
+                       return;
+               }
+
+               /* Might be an error. Check if there are bytes to read */
+               ret = ioctl(state->fd, FIONREAD, &value);
+               /* FIXME - should we also check
+                  for ret == 0 and value == 0 here ? */
+               if (ret == -1) {
+                       /* There's an error. */
+                       tevent_req_error(req, EPIPE);
+                       return;
+               }
+               /* A request for TEVENT_FD_READ will succeed from now and
+                  forevermore until the bytes are read so if there was
+                  an error we'll wait until we do read, then get it in
+                  the read callback function. Until then, remove TEVENT_FD_READ
+                  from the flags we're waiting for. */
+               state->flags &= ~TEVENT_FD_READ;
+               TEVENT_FD_NOT_READABLE(fde);
+
+               /* If not writable, we're done. */
+               if (!(flags & TEVENT_FD_WRITE)) {
+                       return;
+               }
        }
 
        for (i=0; i<state->count; i++) {