On Thu, Aug 10, 2023 at 09:49:46PM +0200, Stefano Brivio wrote:
> On Thu, 10 Aug 2023 12:33:06 +1000
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > We call tap_sock_reset() if tap_handler_passt() fails, or if we get an
> > error event on the socket.  Fold that logic into tap_handler() passt itself
> > which simplifies the caller.
> > 
> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> > ---
> >  tap.c | 63 ++++++++++++++++++++++++++++++-----------------------------
> >  1 file changed, 32 insertions(+), 31 deletions(-)
> > 
> > diff --git a/tap.c b/tap.c
> > index 866ca4d..501af33 100644
> > --- a/tap.c
> > +++ b/tap.c
> > @@ -891,19 +891,41 @@ append:
> >  	return in->count;
> >  }
> >  
> > +/**
> > + * tap_sock_reset() - Handle closing or failure of connect AF_UNIX socket
> > + * @c:		Execution context
> > + */
> > +static void tap_sock_reset(struct ctx *c)
> > +{
> > +	if (c->one_off) {
> > +		info("Client closed connection, exiting");
> > +		exit(EXIT_SUCCESS);
> > +	}
> > +
> > +	/* Close the connected socket, wait for a new connection */
> > +	epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_tap, NULL);
> > +	close(c->fd_tap);
> > +	c->fd_tap = -1;
> > +}
> > +
> >  /**
> >   * tap_handler_passt() - Packet handler for AF_UNIX file descriptor
> >   * @c:		Execution context
> > + * @events:	epoll events
> >   * @now:	Current timestamp
> > - *
> > - * Return: -ECONNRESET on receive error, 0 otherwise
> >   */
> > -static int tap_handler_passt(struct ctx *c, const struct timespec *now)
> > +static void tap_handler_passt(struct ctx *c, uint32_t events,
> > +			      const struct timespec *now)
> >  {
> >  	struct ethhdr *eh;
> >  	ssize_t n, rem;
> >  	char *p;
> >  
> > +	if (events & (EPOLLRDHUP | EPOLLHUP | EPOLLERR)) {
> > +		tap_sock_reset(c);
> > +		return;
> > +	}
> > +
> >  redo:
> >  	p = pkt_buf;
> >  	rem = 0;
> > @@ -914,12 +936,13 @@ redo:
> >  	n = recv(c->fd_tap, p, TAP_BUF_FILL, MSG_DONTWAIT);
> >  	if (n < 0) {
> >  		if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
> > -			return 0;
> > +			return;
> >  
> >  		epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_tap, NULL);
> >  		close(c->fd_tap);
> >  
> > -		return -ECONNRESET;
> > +		tap_sock_reset(c);
> 
> ...also reported by covscan: close() before this is redundant now.

Oops, yes.  I spotted that, but then forgot to fix it.  Fixed for a
new spin.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson