Re: QMAILREMOTE patch

On 21 May 2017 at 17:57, Amitai Schleier <
[email protected]> wrote:

> A friend wants to DKIM-sign outgoing mail, probably using Kyle Wheeler's
> DKIM wrapper around qmail-remote (http://www.memoryhole.net/qmail/#dkim).
> But he doesn't want to confuse his package manager by moving aside the real
> qmail-remote binary and putting something else in its place.
>
> Inspired by the QMAILQUEUE patch, we patched qmail-rspawn to look for
> QMAILREMOTE in its environment. The 0th arg to execvp() is either the value
> of the env var (if set), or "qmail-remote" as usual. We tested with various
> arguments to qmail-start.
>
> Nice and quite useful. Have done exactly the same. I use the same variable
QMAILREMOTE. Additionally, I have modified qmail-lspawn.c to use QMAILLOCAL
and call a binary other than qmail-local. Use it for doing DKIM
verification.

I use the variables QMAILLOCAL and QMAILREMOTE to run some filters before
the actual delivery attempt.


>
> Does this patch look reasonable?
>
>
Yes, it does. Rather than moving the original binary, it helps preserve the
binary checksum. rpm -V does not complain. If the path defined by
QMAILREMOTE does not exist, the qmail-send logs will contain the standard
error message "Unable to run qmail-remote"


> --- Makefile.orig       2007-11-30 20:22:54.000000000 +0000
> +++ Makefile
> @@ -1462,19 +1462,19 @@ tcpto.h readwrite.h timeoutconn.h timeou
>
>  qmail-rspawn: \
>  load qmail-rspawn.o spawn.o tcpto_clean.o now.o coe.o sig.a open.a \
> -seek.a lock.a wait.a fd.a stralloc.a alloc.a substdio.a error.a str.a \
> +seek.a lock.a wait.a fd.a stralloc.a alloc.a substdio.a error.a env.a
> str.a \
>  auto_qmail.o auto_uids.o auto_spawn.o
>         ./load qmail-rspawn spawn.o tcpto_clean.o now.o coe.o \
>         sig.a open.a seek.a lock.a wait.a fd.a stralloc.a alloc.a \
> -       substdio.a error.a str.a auto_qmail.o auto_uids.o \
> -       auto_spawn.o
> +       substdio.a error.a env.a str.a auto_qmail.o auto_uids.o \
> +       auto_spawn.o
>
>  qmail-rspawn.0: \
>  qmail-rspawn.8
>         nroff -man qmail-rspawn.8 > qmail-rspawn.0
>
>  qmail-rspawn.o: \
> -compile qmail-rspawn.c fd.h wait.h substdio.h exit.h fork.h error.h \
> +compile qmail-rspawn.c fd.h wait.h substdio.h exit.h fork.h error.h env.h
> \
>  tcpto.h
>         ./compile qmail-rspawn.c
>
> --- qmail-rspawn.c.orig 1998-06-15 10:53:16.000000000 +0000
> +++ qmail-rspawn.c
> @@ -5,6 +5,17 @@
>  #include "fork.h"
>  #include "error.h"
>  #include "tcpto.h"
> +#include "env.h"
> +
> +static char *qrargs[1] = { 0 };
> +
> +static void setup_qrargs()
> +{
> + if (!qrargs[0])
> +  qrargs[0] = env_get("QMAILREMOTE");
> + if(!qrargs[0])
> +  qrargs[0] = "qmail-remote";
> +}
>
>  void initialize(argc,argv)
>  int argc;
> @@ -84,7 +95,9 @@ char *s; char *r; int at;
>   int f;
>   char *(args[5]);
>
> - args[0] = "qmail-remote";
> + setup_qrargs();
> +
> + args[0] = qrargs[0];
>   args[1] = r + at + 1;
>   args[2] = s;
>   args[3] = r;
>



-- 
Regards Manvendra - http://www.indimail.org
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