Re: [PATCH v1 19/59] block/ssh.c: remove unneeded labels

["Richard W.M. Jones" <rjones@redhat.com>]

On Mon, Jan 06, 2020 at 03:23:45PM -0300, Daniel Henrique Barboza wrote:
> The 'out' labels for check_host_key_knownhosts() and authenticate()
> functions can be removed and, instead, call 'return' with the
> appropriate return value. The 'ret' integer from both functions
> could also be removed.
> 
> CC: Richard W.M. Jones <rjones@redhat.com>
> CC: qemu-block@nongnu.org
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>  block/ssh.c | 61 +++++++++++++++++------------------------------------
>  1 file changed, 19 insertions(+), 42 deletions(-)
> 
> diff --git a/block/ssh.c b/block/ssh.c
> index b4375cf7d2..e0c56d002a 100644
> --- a/block/ssh.c
> +++ b/block/ssh.c
> @@ -276,7 +276,6 @@ static void ssh_parse_filename(const char *filename, QDict *options,
>  
>  static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp)
>  {
> -    int ret;
>  #ifdef HAVE_LIBSSH_0_8
>      enum ssh_known_hosts_e state;
>      int r;
> @@ -295,7 +294,6 @@ static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp)
>          trace_ssh_check_host_key_knownhosts();
>          break;
>      case SSH_KNOWN_HOSTS_CHANGED:
> -        ret = -EINVAL;
>          r = ssh_get_server_publickey(s->session, &pubkey);
>          if (r == 0) {
>              r = ssh_get_publickey_hash(pubkey, SSH_PUBLICKEY_HASH_SHA256,
> @@ -320,28 +318,23 @@ static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp)
>                         "host key does not match the one in known_hosts; this "
>                         "may be a possible attack");
>          }
> -        goto out;
> +        return -EINVAL;
>      case SSH_KNOWN_HOSTS_OTHER:
> -        ret = -EINVAL;
>          error_setg(errp,
>                     "host key for this server not found, another type exists");
> -        goto out;
> +        return -EINVAL;
>      case SSH_KNOWN_HOSTS_UNKNOWN:
> -        ret = -EINVAL;
>          error_setg(errp, "no host key was found in known_hosts");
> -        goto out;
> +        return -EINVAL;
>      case SSH_KNOWN_HOSTS_NOT_FOUND:
> -        ret = -ENOENT;
>          error_setg(errp, "known_hosts file not found");
> -        goto out;
> +        return -ENOENT;
>      case SSH_KNOWN_HOSTS_ERROR:
> -        ret = -EINVAL;
>          error_setg(errp, "error while checking the host");
> -        goto out;
> +        return -EINVAL;
>      default:
> -        ret = -EINVAL;
>          error_setg(errp, "error while checking for known server (%d)", state);
> -        goto out;
> +        return -EINVAL;
>      }
>  #else /* !HAVE_LIBSSH_0_8 */
>      int state;
> @@ -355,40 +348,31 @@ static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp)
>          trace_ssh_check_host_key_knownhosts();
>          break;
>      case SSH_SERVER_KNOWN_CHANGED:
> -        ret = -EINVAL;
>          error_setg(errp,
>                     "host key does not match the one in known_hosts; this "
>                     "may be a possible attack");
> -        goto out;
> +        return -EINVAL;
>      case SSH_SERVER_FOUND_OTHER:
> -        ret = -EINVAL;
>          error_setg(errp,
>                     "host key for this server not found, another type exists");
> -        goto out;
> +        return -EINVAL;
>      case SSH_SERVER_FILE_NOT_FOUND:
> -        ret = -ENOENT;
>          error_setg(errp, "known_hosts file not found");
> -        goto out;
> +        return -ENOENT;
>      case SSH_SERVER_NOT_KNOWN:
> -        ret = -EINVAL;
>          error_setg(errp, "no host key was found in known_hosts");
> -        goto out;
> +        return -EINVAL;
>      case SSH_SERVER_ERROR:
> -        ret = -EINVAL;
>          error_setg(errp, "server error");
> -        goto out;
> +        return -EINVAL;
>      default:
> -        ret = -EINVAL;
>          error_setg(errp, "error while checking for known server (%d)", state);
> -        goto out;
> +        return -EINVAL;
>      }
>  #endif /* !HAVE_LIBSSH_0_8 */
>  
>      /* known_hosts checking successful. */
> -    ret = 0;
> -
> - out:
> -    return ret;
> +    return 0;
>  }
>  
>  static unsigned hex2decimal(char ch)
> @@ -501,20 +485,18 @@ static int check_host_key(BDRVSSHState *s, SshHostKeyCheck *hkc, Error **errp)
>  
>  static int authenticate(BDRVSSHState *s, Error **errp)
>  {
> -    int r, ret;
> +    int r;
>      int method;
>  
>      /* Try to authenticate with the "none" method. */
>      r = ssh_userauth_none(s->session, NULL);
>      if (r == SSH_AUTH_ERROR) {
> -        ret = -EPERM;
>          session_error_setg(errp, s, "failed to authenticate using none "
>                                      "authentication");
> -        goto out;
> +        return -EPERM;
>      } else if (r == SSH_AUTH_SUCCESS) {
>          /* Authenticated! */
> -        ret = 0;
> -        goto out;
> +        return 0;
>      }
>  
>      method = ssh_userauth_list(s->session, NULL);
> @@ -527,23 +509,18 @@ static int authenticate(BDRVSSHState *s, Error **errp)
>      if (method & SSH_AUTH_METHOD_PUBLICKEY) {
>          r = ssh_userauth_publickey_auto(s->session, NULL, NULL);
>          if (r == SSH_AUTH_ERROR) {
> -            ret = -EINVAL;
>              session_error_setg(errp, s, "failed to authenticate using "
>                                          "publickey authentication");
> -            goto out;
> +            return -EINVAL;
>          } else if (r == SSH_AUTH_SUCCESS) {
>              /* Authenticated! */
> -            ret = 0;
> -            goto out;
> +            return 0;
>          }
>      }
>  
> -    ret = -EPERM;
>      error_setg(errp, "failed to authenticate using publickey authentication "
>                 "and the identities held by your ssh-agent");
> -
> - out:
> -    return ret;
> +    return -EPERM;
>  }
>  
>  static QemuOptsList ssh_runtime_opts = {

I agree that the code is functionality the same after this change.
Don't know whether or not one style or the other is preferred by qemu,
but in any case:

Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

Rich.

-- 
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