Re: [Qemu-devel] [PATCH v5 2/4] net/socket: Convert error message to Error

[Mao Zhongyi]

Hi, Markus

On 06/27/2017 03:43 PM, Markus Armbruster wrote:
> Suggest "net/socket: Convert several helper functions to Error".

OK, I see.

> Mao Zhongyi <address@hidden> 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: address@hidden
> > Cc: address@hidden
> > Signed-off-by: Mao Zhongyi <address@hidden>
> > ---
> >  net/socket.c | 76 ++++++++++++++++++++++++++++++++++++++----------------------
> >  1 file changed, 48 insertions(+), 28 deletions(-)
> >
> > diff --git a/net/socket.c b/net/socket.c
> > index 53765bd..e136f87 100644
> > --- a/net/socket.c
> > +++ b/net/socket.c
> > @@ -209,7 +209,9 @@ static void net_socket_send_dgram(void *opaque)
> >      }
> >  }
> >
> > -static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct 
> > in_addr *localaddr)
> > +static int net_socket_mcast_create(struct sockaddr_in *mcastaddr,
> > +                                   struct in_addr *localaddr,
> > +                                   Error **errp)
> >  {
> >      struct ip_mreq imr;
> >      int fd;
> > @@ -221,8 +223,8 @@ static int net_socket_mcast_create(struct sockaddr_in 
> > *mcastaddr, struct in_addr
> >  #endif
> >
> >      if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
> > -        fprintf(stderr, "qemu: error: specified mcastaddr \"%s\" (0x%08x) "
> > -                "does not contain a multicast address\n",
> > +        error_setg(errp, "qemu: error: specified mcastaddr %s (0x%08x) "
> > +                "does not contain a multicast address",
>
> Please drop the "qemu: error: " prefix.  More of the same below.

OK, I will


> >                  inet_ntoa(mcastaddr->sin_addr),
> >                  (int)ntohl(mcastaddr->sin_addr.s_addr));
> >          return -1;
> > @@ -230,7 +232,8 @@ static int net_socket_mcast_create(struct sockaddr_in 
> > *mcastaddr, struct in_addr
> >      }
> >      fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
> >      if (fd < 0) {
> > -        perror("socket(PF_INET, SOCK_DGRAM)");
> > +        error_setg_errno(errp, errno, ")"
> > +                         " failed");
>
> I'm not a native speaker, but "Create FOO failed" doesn't feel right to
> me.  Where's the subject?  "Create" is a verb.  "Creation of FOO failed"
> has a subject, but doesn't feel right.  What about "can't create
> datagram socket"?

Thanks for your sharing.
My English is really poor, I will continue to improve.


> Same for many of the other new error messages.
>
> >          return -1;
> >      }
> >
> > @@ -242,13 +245,15 @@ static int net_socket_mcast_create(struct sockaddr_in 
> > *mcastaddr, struct in_addr
> >      val = 1;
> >      ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
> >      if (ret < 0) {
> > -        perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
> > +        error_setg_errno(errp, errno, "Set the socket fd=%d attribute"
> > +                         " SO_REUSEADDR failed", fd);
>
> Why would the user want to know the value of @fd here?
>
> Same for many of the other new error messages.

It really doesn't make sense. I will drop it.

> >          goto fail;
> >      }
> >
> >      ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
> >      if (ret < 0) {
> > -        perror("bind");
> > +        error_setg_errno(errp, errno, "Bind ip=%s to fd=%d failed",
> > +                         inet_ntoa(mcastaddr->sin_addr), fd);
> >          goto fail;
> >      }
> >
> > @@ -263,7 +268,8 @@ static int net_socket_mcast_create(struct sockaddr_in 
> > *mcastaddr, struct in_addr
> >      ret = qemu_setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
> >                            &imr, sizeof(struct ip_mreq));
> >      if (ret < 0) {
> > -        perror("setsockopt(IP_ADD_MEMBERSHIP)");
> > +        error_setg_errno(errp, errno, "Add socket fd=%d to multicast group %s"
> > +                         " failed", fd, inet_ntoa(imr.imr_multiaddr));
> >          goto fail;
> >      }
> >
> > @@ -272,7 +278,8 @@ static int net_socket_mcast_create(struct sockaddr_in 
> > *mcastaddr, struct in_addr
> >      ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
> >                            &loop, sizeof(loop));
> >      if (ret < 0) {
> > -        perror("setsockopt(SOL_IP, IP_MULTICAST_LOOP)");
> > +        error_setg_errno(errp, errno, "Force multicast message to loopback"
> > +                         " failed");
> >          goto fail;
> >      }
> >
> > @@ -281,7 +288,8 @@ static int net_socket_mcast_create(struct sockaddr_in 
> > *mcastaddr, struct in_addr
> >          ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
> >                                localaddr, sizeof(*localaddr));
> >          if (ret < 0) {
> > -            perror("setsockopt(IP_MULTICAST_IF)");
> > +            error_setg_errno(errp, errno, "Set the default network send "
> > +                             "interfaec failed");
>
> s/interfaec/interface/

OK, I see.

Thanks,
Mao

> >              goto fail;
> >          }
> >      }
> > @@ -320,7 +328,8 @@ static NetClientInfo net_dgram_socket_info = {
> >  static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
> >                                                  const char *model,
> >                                                  const char *name,
> > -                                                int fd, int is_connected)
> > +                                                int fd, int is_connected,
> > +                                                Error **errp)
> >  {
> >      struct sockaddr_in saddr;
> >      int newfd;
> > @@ -337,14 +346,13 @@ static NetSocketState 
> > *net_socket_fd_init_dgram(NetClientState *peer,
> >          if (getsockname(fd, (struct sockaddr *) &saddr, &saddr_len) == 0) {
> >              /* must be bound */
> >              if (saddr.sin_addr.s_addr == 0) {
> > -                fprintf(stderr, "qemu: error: init_dgram: fd=%d unbound, "
> > -                        "cannot setup multicast dst addr\n", fd);
> > +                error_setg(errp, "qemu: error: init_dgram: fd=%d unbound, "
> > +                        "cannot setup multicast dst addr", fd);
> >                  goto err;
> >              }
> >              /* clone dgram socket */
> > -            newfd = net_socket_mcast_create(&saddr, NULL);
> > +            newfd = net_socket_mcast_create(&saddr, NULL, errp);
> >              if (newfd < 0) {
> > -                /* error already reported by net_socket_mcast_create() */
> >                  goto err;
> >              }
> >              /* clone newfd to fd, close newfd */
> > @@ -352,8 +360,8 @@ static NetSocketState 
> > *net_socket_fd_init_dgram(NetClientState *peer,
> >              close(newfd);
> >
> >          } else {
> > -            fprintf(stderr,
> > -                    "qemu: error: init_dgram: fd=%d failed getsockname(): 
> > %s\n",
> > +            error_setg(errp,
> > +                    "qemu: error: init_dgram: fd=%d failed getsockname(): %s",
> >                      fd, strerror(errno));
> >              goto err;
> >          }
> > @@ -432,24 +440,26 @@ 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:
> > -        error_report("qemu: error: socket type=%d for fd=%d is not"
> > +        error_setg(errp, "qemu: error: socket type=%d for fd=%d is not"
> >                  " SOCK_DGRAM or SOCK_STREAM", so_type, fd);
> >          closesocket(fd);
> >      }
> > @@ -536,6 +546,7 @@ static int net_socket_connect_init(NetClientState *peer,
> >      NetSocketState *s;
> >      int fd, connected, ret;
> >      struct sockaddr_in saddr;
> > +    Error *err = NULL;
> >
> >      if (parse_host_port(&saddr, host_str) < 0)
> >          return -1;
> > @@ -567,9 +578,11 @@ static int net_socket_connect_init(NetClientState *peer,
> >              break;
> >          }
> >      }
> > -    s = net_socket_fd_init(peer, model, name, fd, connected);
> > -    if (!s)
> > +    s = net_socket_fd_init(peer, model, name, fd, connected, &err);
> > +    if (!s) {
> > +        error_report_err(err);
> >          return -1;
> > +    }
> >      snprintf(s->nc.info_str, sizeof(s->nc.info_str),
> >               "socket: connect to %s:%d",
> >               inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
> > @@ -586,6 +599,7 @@ static int net_socket_mcast_init(NetClientState *peer,
> >      int fd;
> >      struct sockaddr_in saddr;
> >      struct in_addr localaddr, *param_localaddr;
> > +    Error *err = NULL;
> >
> >      if (parse_host_port(&saddr, host_str) < 0)
> >          return -1;
> > @@ -598,13 +612,17 @@ static int net_socket_mcast_init(NetClientState *peer,
> >          param_localaddr = NULL;
> >      }
> >
> > -    fd = net_socket_mcast_create(&saddr, param_localaddr);
> > -    if (fd < 0)
> > +    fd = net_socket_mcast_create(&saddr, param_localaddr, &err);
> > +    if (fd < 0) {
> > +        error_report_err(err);
> >          return -1;
> > +    }
> >
> > -    s = net_socket_fd_init(peer, model, name, fd, 0);
> > -    if (!s)
> > +    s = net_socket_fd_init(peer, model, name, fd, 0, &err);
> > +    if (!s) {
> > +        error_report_err(err);
> >          return -1;
> > +    }
> >
> >      s->dgram_dst = saddr;
> >
> > @@ -624,6 +642,7 @@ static int net_socket_udp_init(NetClientState *peer,
> >      NetSocketState *s;
> >      int fd, ret;
> >      struct sockaddr_in laddr, raddr;
> > +    Error *err = NULL;
> >
> >      if (parse_host_port(&laddr, lhost) < 0) {
> >          return -1;
> > @@ -652,8 +671,9 @@ static int net_socket_udp_init(NetClientState *peer,
> >      }
> >      qemu_set_nonblock(fd);
> >
> > -    s = net_socket_fd_init(peer, model, name, fd, 0);
> > +    s = net_socket_fd_init(peer, model, name, fd, 0, &err);
> >      if (!s) {
> > +        error_report_err(err);
> >          return -1;
> >      }
> >
> > @@ -696,7 +716,7 @@ int net_init_socket(const Netdev *netdev, const char *name,
> >              return -1;
> >          }
> >          qemu_set_nonblock(fd);
> > -        if (!net_socket_fd_init(peer, "socket", name, fd, 1)) {
> > +        if (!net_socket_fd_init(peer, "socket", name, fd, 1, errp)) {
> >              return -1;
> >          }
> >          return 0;
>
> Looks good to me otherwise.