From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52443) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3mJQ-0003pC-OP for qemu-devel@nongnu.org; Thu, 27 Apr 2017 12:30:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d3mJN-0001f5-IY for qemu-devel@nongnu.org; Thu, 27 Apr 2017 12:30:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43202) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d3mJN-0001ed-9Q for qemu-devel@nongnu.org; Thu, 27 Apr 2017 12:30:33 -0400 Date: Thu, 27 Apr 2017 17:30:25 +0100 From: "Daniel P. Berrange" Message-ID: <20170427163025.GD30599@redhat.com> Reply-To: "Daniel P. Berrange" References: <2bc05de0edd61cdcdd3d2b894378a874d1e12327.1493191677.git.maozy.fnst@cn.fujitsu.com> <87shktu8cu.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87shktu8cu.fsf@dusky.pond.sub.org> Subject: Re: [Qemu-devel] [PATCH v2 3/4] net/socket: Convert error report message to Error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Mao Zhongyi , jasowang@redhat.com, qemu-devel@nongnu.org On Thu, Apr 27, 2017 at 06:24:17PM +0200, Markus Armbruster wrote: > No review, just an observation. > > Mao Zhongyi writes: > > > Currently, net_socket_mcast_create(), net_socket_fd_init_dgram() and > > net_socket_fd_init() use the function such as fprintf(), perror() to > > report an error message. > > > > Now, convert these functions to Error. > > > > CC: jasowang@redhat.com, armbru@redhat.com > > Signed-off-by: Mao Zhongyi > > --- > > net/socket.c | 66 +++++++++++++++++++++++++++++++++++++----------------------- > > 1 file changed, 41 insertions(+), 25 deletions(-) > > > > diff --git a/net/socket.c b/net/socket.c > > index b0decbe..559e09a 100644 > > --- a/net/socket.c > > +++ b/net/socket.c > [...] > > @@ -433,25 +437,27 @@ static NetSocketState *net_socket_fd_init_stream(NetClientState *peer, > > > > static NetSocketState *net_socket_fd_init(NetClientState *peer, > > const char *model, const char *name, > > - int fd, int is_connected) > > + int fd, int is_connected, > > + Error **errp) > > { > > int so_type = -1, optlen=sizeof(so_type); > > > > if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type, > > (socklen_t *)&optlen)< 0) { > > - fprintf(stderr, "qemu: error: getsockopt(SO_TYPE) for fd=%d failed\n", > > + error_setg(errp, "qemu: error: getsockopt(SO_TYPE) for fd=%d failed", > > fd); > > closesocket(fd); > > return NULL; > > } > > switch(so_type) { > > case SOCK_DGRAM: > > - return net_socket_fd_init_dgram(peer, model, name, fd, is_connected); > > + return net_socket_fd_init_dgram(peer, model, name, fd, is_connected, errp); > > case SOCK_STREAM: > > return net_socket_fd_init_stream(peer, model, name, fd, is_connected); > > default: > > /* who knows ... this could be a eg. a pty, do warn and continue as stream */ > > - fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd); > > + error_setg(errp, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM" > > + " or SOCK_STREAM", so_type, fd); > > Not this patches problem: this case is odd, and the comment is bogus. > If @fd really was a pty, getsockopt() would fail with ENOTSOCK, wouldn't > it? If @fd is a socket, but neither SOCK_DGRAM nor SOCK_STREAM (say > SOCK_RAW), why is it safe to continue as if it was SOCK_STREAM? Jason? IMHO it is a problem with this patch. Previously we merely printed a warning & carried on, which is conceptually ok in general, though dubious here for the reason you say. Now we are filling an Error **errp object, and carrying on - this is conceptually broken anywhere. If an Error ** is filled, we must return. If we want to carry on, we shouldn't fill Error **. > > > return net_socket_fd_init_stream(peer, model, name, fd, is_connected); IMHO, we just kill this and put return NULL here. If there is a genuine reason to support something like SOCK_RAW, it should be explicitly handled, because this default: case will certainly break SOCK_SEQPACKET and SOCK_RDM which can't be treated as streams. > > } > > return NULL; > > Not reachable. Ugly, but not your patch's concern. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|