Samba 3.0: climessage.c patch

[Jelmer Vernooij]

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Thanks, I'll take a look at this.

jelmer

On Thursday 24 April 2003 23:16, David Lee wrote:
> Enclosed is a patch to fix a blocking problem in the family of routines:
>    cli_message_start()
>    cli_message_text()
>    cli_message_end()
>
> As written each of these is:
>
> cli_message_X() {
>    inline_build_message_X;
>    cli_send_smb(cli);
>    cli_receive_smb(cli);
> }
>
> This has the potential to block, especially between "send" and "receive".
>
> If the caller is something simple and synchronous, such as the "smbclient"
> program, there is not really a problem.  But if one builds a more
> sophisticated caller, which requires asynchronous, polling I/O, then this
> blocking could be unpleasant.  (A potential example is "write"/"wall"
> functionality discussed in recent years, which might even be part of a
> future "smbd".)
>
> The idea of the patch is to put the intricate, non-blocking
> "inline_build_message_X" code as separate subroutines, so each routine now
> becomes a pair:
>
> cli_message_X_build() {
>    inline_build_message_X;
> }
>
> cli_message_X() {
>    cli_message_X_build();
>    cli_send_smb(cli);
>    cli_receive_smb(cli);
> }
>
>
> The change is entirely self-contained and makes (or should make!) no
> difference whatsoever to existing applications and linking (such as the
> "smbclient" program which continues to use the unchanged "cli_message_X()"
> interface.
>
> The gain is allowing the writing of newer applications which can call the
> common-code "cli_message_X_build()" routines, and then do their own,
> async, calling of "cli_send_smb()" and "cli_receive_smb()".
>
> The patch below is against 3.0alpha23:
>
> ================================ snip ===============================
> --- climessage.c.orig	Mon Mar 31 03:28:29 2003
> +++ climessage.c	Wed Apr 23 18:00:39 2003
> @@ -26,12 +26,11 @@
> 
> /**************************************************************************
>** start a message sequence
> 
> ***************************************************************************
>*/ -BOOL cli_message_start(struct cli_state *cli, char *host, char
> *username, -			      int *grp)
> +int cli_message_start_build(struct cli_state *cli, char *host, char
> *username) {
>  	char *p;
>
> -	/* send a SMBsendstrt command */
> +	/* construct a SMBsendstrt command */
>  	memset(cli->outbuf,'\0',smb_size);
>  	set_message(cli->outbuf,0,0,True);
>  	SCVAL(cli->outbuf,smb_com,SMBsendstrt);
> @@ -45,6 +44,14 @@
>  	p += clistr_push(cli, p, host, -1, STR_TERMINATE);
>
>  	cli_setup_bcc(cli, p);
> +
> +	return(PTR_DIFF(p, cli->outbuf));
> +}
> +
> +BOOL cli_message_start(struct cli_state *cli, char *host, char *username,
> +			      int *grp)
> +{
> +	cli_message_start_build(cli, host, username);
>
>  	cli_send_smb(cli);
>
> @@ -63,7 +70,7 @@
> 
> /**************************************************************************
>** send a message
> 
> ***************************************************************************
>*/ -BOOL cli_message_text(struct cli_state *cli, char *msg, int len, int
> grp) +int cli_message_text_build(struct cli_state *cli, char *msg, int len,
> int grp) {
>  	char *msgdos;
>  	int lendos;
> @@ -93,6 +100,14 @@
>  	}
>
>  	cli_setup_bcc(cli, p);
> +
> +	return(PTR_DIFF(p, cli->outbuf));
> +}
> +
> +BOOL cli_message_text(struct cli_state *cli, char *msg, int len, int grp)
> +{
> +	cli_message_text_build(cli, msg, len, grp);
> +
>  	cli_send_smb(cli);
>
>  	if (!cli_receive_smb(cli)) {
> @@ -107,8 +122,10 @@
> 
> /**************************************************************************
>** end a message
> 
> ***************************************************************************
>*/ -BOOL cli_message_end(struct cli_state *cli, int grp)
> +int cli_message_end_build(struct cli_state *cli, int grp)
>  {
> +	char *p;
> +
>  	memset(cli->outbuf,'\0',smb_size);
>  	set_message(cli->outbuf,1,0,True);
>  	SCVAL(cli->outbuf,smb_com,SMBsendend);
> @@ -117,7 +134,16 @@
>  	SSVAL(cli->outbuf,smb_vwv0,grp);
>
>  	cli_setup_packet(cli);
> -
> +
> +	p = smb_buf(cli->outbuf);
> +
> +	return(PTR_DIFF(p, cli->outbuf));
> +}
> +
> +BOOL cli_message_end(struct cli_state *cli, int grp)
> +{
> +	cli_message_end_build(cli, grp);
> +
>  	cli_send_smb(cli);
>
>  	if (!cli_receive_smb(cli)) {
> ================================ snip ===============================

- -- 
Jelmer Vernooij <jelmer at nl.linux.org> - http://nl.linux.org/~jelmer/
 21:30:14 up 1 day,  2:26, 10 users,  load average: 0.08, 0.11, 0.13
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