Re: [Qemu-devel] [PATCH 4/6] qemu-char: set socket filename to disconnected when not connected

[Paolo Bonzini <pbonzini@redhat.com>]

Il 22/09/2014 01:04, minyard@acm.org ha scritto:
> From: Corey Minyard <cminyard@mvista.com>
> 
> This way we can tell if the socket is connected or not.  It also splits
> the string conversions out into separate functions to make this more
> convenient.
> 
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
>  qemu-char.c | 102 ++++++++++++++++++++++++++++++++++++++++--------------------
>  1 file changed, 69 insertions(+), 33 deletions(-)
> 
> diff --git a/qemu-char.c b/qemu-char.c
> index e59321d..8418e33 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -117,6 +117,60 @@ static void qapi_copy_SocketAddress(SocketAddress **p_dest,
>      qobject_decref(obj);
>  }
>  
> +static int SocketAddress_to_str(char *dest, int max_len,
> +                                const char *prefix, SocketAddress *addr,
> +                                bool is_listen, bool is_telnet)
> +{
> +    switch (addr->kind) {
> +    case SOCKET_ADDRESS_KIND_INET:
> +        return snprintf(dest, max_len, "%s%s:%s:%s%s", prefix,
> +                        is_telnet ? "telnet" : "tcp", addr->inet->host,
> +                        addr->inet->port, is_listen ? ",server" : "");
> +        break;
> +    case SOCKET_ADDRESS_KIND_UNIX:
> +        return snprintf(dest, max_len, "%sunix:%s%s", prefix,
> +                        addr->q_unix->path, is_listen ? ",server" : "");
> +        break;
> +    case SOCKET_ADDRESS_KIND_FD:
> +        return snprintf(dest, max_len, "%sfd:%s%s", prefix, addr->fd->str,
> +                        is_listen ? ",server" : "");
> +        break;
> +    default:
> +        abort();
> +    }
> +}
> +
> +static int sockaddr_to_str(char *dest, int max_len,
> +                           struct sockaddr_storage *ss, socklen_t ss_len,
> +                           bool is_listen, bool is_telnet)
> +{
> +    char host[NI_MAXHOST], serv[NI_MAXSERV];
> +    const char *left = "", *right = "";
> +
> +    switch (ss->ss_family) {
> +#ifndef _WIN32
> +    case AF_UNIX:
> +        return snprintf(dest, max_len, "unix:%s%s",
> +                        ((struct sockaddr_un *)(ss))->sun_path,
> +                        is_listen ? ",server" : "");
> +#endif
> +    case AF_INET6:
> +        left  = "[";
> +        right = "]";
> +        /* fall through */
> +    case AF_INET:
> +        getnameinfo((struct sockaddr *) ss, ss_len, host, sizeof(host),
> +                    serv, sizeof(serv), NI_NUMERICHOST | NI_NUMERICSERV);
> +        return snprintf(dest, max_len, "%s:%s%s%s:%s%s",
> +                        is_telnet ? "telnet" : "tcp",
> +                        left, host, right, serv,
> +                        is_listen ? ",server" : "");
> +
> +    default:
> +        return snprintf(dest, max_len, "unknown");
> +    }
> +}
> +
>  /***********************************************************/
>  /* character device */
>  
> @@ -2719,6 +2773,8 @@ static void tcp_chr_disconnect(CharDriverState *chr)
>      s->chan = NULL;
>      closesocket(s->fd);
>      s->fd = -1;
> +    SocketAddress_to_str(chr->filename, CHR_MAX_FILENAME_SIZE,
> +                         "disconnected:", s->addr, s->is_listen, s->is_telnet);
>      qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
>  }
>  
> @@ -2790,6 +2846,17 @@ static void tcp_chr_connect(void *opaque)
>  {
>      CharDriverState *chr = opaque;
>      TCPCharDriver *s = chr->opaque;
> +    struct sockaddr_storage ss;
> +    socklen_t ss_len = sizeof(ss);
> +
> +    memset(&ss, 0, ss_len);
> +    if (getsockname(s->fd, (struct sockaddr *) &ss, &ss_len) != 0) {
> +        snprintf(chr->filename, CHR_MAX_FILENAME_SIZE,
> +                 "Error in getsockname: %s\n", strerror(errno));
> +    } else {
> +        sockaddr_to_str(chr->filename, CHR_MAX_FILENAME_SIZE, &ss, ss_len,
> +                        s->is_listen, s->is_telnet);
> +    }

Why move this from qemu_chr_finish_socket_connection to tcp_chr_connect?
 Perhaps move this part of the patch earlier, either just before or just
after patch 2?

Except for this question, the patch looks good.  Thanks,

Paolo

>      s->connected = 1;
>      if (s->chan) {
> @@ -2924,39 +2991,6 @@ static bool qemu_chr_finish_socket_connection(CharDriverState *chr, int fd,
>                                                Error **errp)
>  {
>      TCPCharDriver *s = chr->opaque;
> -    char host[NI_MAXHOST], serv[NI_MAXSERV];
> -    const char *left = "", *right = "";
> -    struct sockaddr_storage ss;
> -    socklen_t ss_len = sizeof(ss);
> -
> -    memset(&ss, 0, ss_len);
> -    if (getsockname(fd, (struct sockaddr *) &ss, &ss_len) != 0) {
> -        closesocket(fd);
> -        error_setg_errno(errp, errno, "getsockname");
> -        return false;
> -    }
> -
> -    switch (ss.ss_family) {
> -#ifndef _WIN32
> -    case AF_UNIX:
> -        snprintf(chr->filename, CHR_MAX_FILENAME_SIZE, "unix:%s%s",
> -                 ((struct sockaddr_un *)(&ss))->sun_path,
> -                 s->is_listen ? ",server" : "");
> -        break;
> -#endif
> -    case AF_INET6:
> -        left  = "[";
> -        right = "]";
> -        /* fall through */
> -    case AF_INET:
> -        getnameinfo((struct sockaddr *) &ss, ss_len, host, sizeof(host),
> -                    serv, sizeof(serv), NI_NUMERICHOST | NI_NUMERICSERV);
> -        snprintf(chr->filename, CHR_MAX_FILENAME_SIZE, "%s:%s%s%s:%s%s",
> -                 s->is_telnet ? "telnet" : "tcp",
> -                 left, host, right, serv,
> -                 s->is_listen ? ",server" : "");
> -        break;
> -    }
>  
>      if (s->is_listen) {
>          s->listen_fd = fd;
> @@ -4016,6 +4050,8 @@ static CharDriverState *qmp_chardev_open_socket(ChardevSocket *sock,
>      chr->explicit_be_open = true;
>  
>      chr->filename = g_malloc(CHR_MAX_FILENAME_SIZE);
> +    SocketAddress_to_str(chr->filename, CHR_MAX_FILENAME_SIZE, "disconnected:",
> +                         addr, is_listen, is_telnet);
>  
>      if (is_listen) {
>          if (is_telnet) {
>