From: Claudio Jeker <cjeker@diehard.n-r-g.com>
Subject: Re: file: use better imsg API
To: tech@openbsd.org
Date: Wed, 21 Aug 2024 21:12:20 +0200

On Wed, Aug 21, 2024 at 07:17:27PM +0200, Florian Obser wrote:
> Hang on, there is an imsg_get_data?! Why do I only learn about this now?
> I see a flurry of commits in my future...

You should read imsg_init.3 and ibuf_add.3 I added a lot of good stuff
over the last year. bgpd(8) is using most of this already.
 
> Anyway, this reads OK florian

> On 2024-08-21 17:44 +02, Claudio Jeker <cjeker@diehard.n-r-g.com> wrote:
> > Tired of old crufty imsg fiddling. Lets use the real deal.
> >
> > -- 
> > :wq Claudio
> >
> > Index: file.c
> > ===================================================================
> > RCS file: /cvs/src/usr.bin/file/file.c,v
> > diff -u -p -r1.70 file.c
> > --- file.c	16 Jan 2024 13:07:29 -0000	1.70
> > +++ file.c	21 Aug 2024 15:41:10 -0000
> > @@ -125,7 +125,7 @@ main(int argc, char **argv)
> >  	struct imsgbuf		 ibuf;
> >  	struct imsg		 imsg;
> >  	struct input_msg	 msg;
> > -	struct input_ack	*ack;
> > +	struct input_ack	 ack;
> >  	pid_t			 pid, parent;
> >  
> >  	tzset();
> > @@ -223,10 +223,9 @@ main(int argc, char **argv)
> >  
> >  		if (read_message(&ibuf, &imsg, pid) == 0)
> >  			break;
> > -		if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof *ack)
> > -			errx(1, "message too small");
> > -		ack = imsg.data;
> > -		if (ack->idx != idx)
> > +		if (imsg_get_data(&imsg, &ack, sizeof ack) == -1)
> > +			err(1, "bad message");
> > +		if (ack.idx != idx)
> >  			errx(1, "index not expected");
> >  		imsg_free(&imsg);
> >  	}
> > @@ -365,7 +364,7 @@ child(int fd, pid_t parent, int argc, ch
> >  	struct magic		*m;
> >  	struct imsgbuf		 ibuf;
> >  	struct imsg		 imsg;
> > -	struct input_msg	*msg;
> > +	struct input_msg	 msg;
> >  	struct input_ack	 ack;
> >  	struct input_file	 inf;
> >  	int			 i, idx;
> > @@ -405,17 +404,16 @@ child(int fd, pid_t parent, int argc, ch
> >  	for (;;) {
> >  		if (read_message(&ibuf, &imsg, parent) == 0)
> >  			break;
> > -		if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof *msg)
> > -			errx(1, "message too small");
> > -		msg = imsg.data;
> > +		if (imsg_get_data(&imsg, &msg, sizeof msg) == -1)
> > +			err(1, "bad message");
> >  
> > -		idx = msg->idx;
> > +		idx = msg.idx;
> >  		if (idx < 0 || idx >= argc)
> >  			errx(1, "index out of range");
> >  
> >  		memset(&inf, 0, sizeof inf);
> >  		inf.m = m;
> > -		inf.msg = msg;
> > +		inf.msg = &msg;
> >  
> >  		inf.path = argv[idx];
> >  		inf.fd = imsg_get_fd(&imsg);
> >
> 
> -- 
> In my defence, I have been left unsupervised.
> 

-- 
:wq Claudio