Questions and Answers

Amy Rich

Q The sendmail documentation seems very incomplete in explaining the difference between an MSP and an MSA. Can you tell me what these are (besides just expanding the abbreviations)?

A A bit of history will probably best help explain what an MSA (mail submission agent) actually is. SMTP was originally designed as a way to route and deliver complete mail messages between machines. Mail transfer agents (MTAs) were meant to handle SMTP transactions and not meant to modify the message beyond adding a few headers. Because many mail user agents (MUAs) like Outlook, Netscape, and others try to inject mail directly to the MTA, it now has to examine the message and possibly perform header and body modifications. The "program" that modifies the message is now known as the MSA. In sendmail, the MTA and the MSA are part of the same binary (sendmail). The MTA runs on port 25 while the MSA generally runs on port 587. For more detailed information about the MSA protocol, see RFC 2476:

http://www.faqs.org/rfcs/rfc2476.html

Q I'm trying to use the shell command join. It has an option (-t), which accepts a character as field delimiter. I'd like the data to be tab delimited, but my shell interprets the tab key as file completion. I tried the following ways to specify a tab on the command line:

join -t '\t' file1 file2
join -t 'echo '\t'' file1 file2

A It sounds like your version of join (you don't mention your OS) does not use \t to represent a tab character. I suggest you output the tab character by using the terminal's lnext key followed by the tab key. To find out what your lnext key is mapped to, use stty -a (generally it's control-v, as shown in the output below):

stty -a
speed 38400 baud; 56 rows; 80 columns;
lflags: icanon isig iexten echo echoe echok echoke -echonl echoctl
   -echoprt -altwerase -noflsh -tostop -flusho pendin -nokerninfo
   -extproc
iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -ignbrk
   brkint -inpck -ignpar -parmrk
oflags: opost onlcr -ocrnl -oxtabs -onocr -onlret
cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow
   -dtrflow -mdmbuf
cchars: discard = ^O; dsusp = <undef>; eof = ^D; eol = <undef>;
   eol2 = <undef>; erase = ^H; erase2 = ^H; intr = ^C; kill = ^U;
   lnext = ^V; min = 1; quit = ^\; reprint = ^R; start = ^Q;
   status = ^T; stop = ^S; susp = ^Z; time = 0; werase = ^W;

join -t'^V<tab>' file1 file2

TAB=$(echo x|tr x '\9')
join -t"${TAB}" file1 file2

A You need to specify "forward only" in the options section of your named.conf file, and then specify your forwarders:

options {
  forward only;
  forwarders { ip1; ip2; ip3; };
}

RewriteEngine On
RewriteBase /
RewriteRule ^(.*)$ info.php?s=$1

http://www.my.domain/info.php?s=info.php

A Your syntax is indeed incorrect. You need to specify the full path (relative to your docroot) to info.php in your RewriteRule. Making sure that /full/path/to matches whatever is right for your system, change your rule to:

RewriteRule ^(.*)$ /full/path/to/info.php?s=$1

RewriteRule ^(.*)$ /info.php?s=$1

RewriteLog "/tmp/rewrite.log"
RewriteLogLevel 9

<client IP> - - [05/May/2003:17:17:38 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (2) 
  init rewrite engine with requested uri /foo
<client IP> - - [05/May/2003:17:17:38 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (3) 
  applying pattern '^(.*)$' to uri '/foo'
<client IP> - - [05/May/2003:17:17:38 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (2) 
  rewrite /foo -> /info.php?s=/foo
<client IP> - - [05/May/2003:17:17:38 -0400]
  [www.my.domain/sid#8162160][rid#815c038/initial] (3) 
  split uri=/info.php?s=/foo -> uri=/info.php, args=s=/foo
<client IP> - - [05/May/2003:17:17:38 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (2) 
  local path result: /info.php

<client IP> - - [05/May/2003:17:17:50 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (2) 
  init rewrite engine with requested uri /bar
<client IP> - - [05/May/2003:17:17:50 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (3) 
  applying pattern '^(.*)$' to uri '/bar'
<client IP> - - [05/May/2003:17:17:50 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (2) 
  rewrite /bar -> /info.php?s=/bar
<client IP> - - [05/May/2003:17:17:50 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (3) 
  split uri=/info.php?s=/bar -> uri=/info.php, args=s=/bar
<client IP> - - [05/May/2003:17:17:50 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (2) 
  local path result: /info.php
<client IP> - - [05/May/2003:17:17:50 -0400] 
  [www.my.domain/sid#8162160][rid#815c038/initial] (1) 
  go-ahead with /info.php [OK]

A Since you're writing this from scratch, I highly recommend using bounce+<something>@my.domain instead, since sendmail and local delivery agents like cyrus and procmail have built-in support for user+detail handling. Using sendmail with procmail or cyrus as the local delivery agent then makes your task trivial. Take a look at the sendmail features file for more information:

http://www.sendmail.org/m4/features.html

  LOGNAME=$USER
  MAIL="/var/mail/$USER"

  EDITOR=/usr/local/bin/vim
  VISUAL=/usr/local/bin/vim
  HISTFILESIZE=1000
  HISTSIZE=1000
  PAGER=/usr/bin/less
  MANPATH=/usr/man:/usr/X11R6/man:/usr/local/man:/usr/share/man
  PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/games:/usr/local/sbin:/usr/ \
  local/bin:/usr/X11R6/bin:/usr/local/bin

  export USER SHELL LOGNAME MAIL EDITOR VISUAL HISTFILESIZE HISTSIZE
  export PAGER MANPATH PATH

  export HOSTNAME='/bin/hostname'
  export ARCH='/usr/bin/uname -p'
  export OSREV='/usr/bin/uname -r'

  export PS1="[\u@\h \w]\\$ "

  umask 022
  set -o history
  set -o notify
  set -o vi
  set -o noclobber

  if [ "${BASH_VERSION%.*}" \> "2.04" ]; then
    complete -A shopt shopt
    complete -A directory  mkdir rmdir
    complete -A directory -o default cd
    complete -f -o default -X '!*.gz'  gunzip
    complete -f -o default -X '!*.bz2' bunzip2
    complete -f -o default -X '!*.pl'  perl perl5
    complete -f -o default -X '!*.ps'  gs ghostview ps2pdf ps2ascii
    complete -f -o default -X '!*.dvi' dvips dvipdf xdvi dviselect dvitype
    complete -f -o default -X '!*.pdf' acroread pdf2ps
    complete -f -o default -X '!*.+(pdf|ps)' gv
    complete -f -o default -X '!*.texi*' makeinfo texi2dvi texi2html texi2pdf
    complete -f -o default -X '!*.tex' tex latex slitex
    complete -f -o default -X '!*.lyx' lyx
    complete -f -o default -X '!*.+(jpg|gif|xpm|png|bmp)' xv gimp
    complete -f -o default -X '!*.mp3' mpg123
    complete -f -o default -X '!*.ogg' ogg123
  fi

Q I'm running BIND 8.2.3-REL on Solaris 2.5, and I'm seeing a lot of these error messages in /var/adm/messages:

Jun 18 11:27:29 myhost named[1302]: denied update from [IP].4126 for "my.domain"

logging {
  category statistics { null; };
  category maintenance { null; };
  category update { null; };
  category lame-servers { null; };
};

options {
  datasize default;
  stacksize default;
  coresize default;
  files unlimited;
  transfer-format one-answer;
  directory "/etc/named";
  pid-file "/var/run/named.pid";
  interface-interval 0;
  listen-on {
    127.0.0.1;
    192.168.1.1;
  };
  allow-recursion { 192.168.1.1/24; };
};

zone "0.0.127.IN-ADDR.ARPA" {
  type master;
  file "local";
};

zone "1.168.192.IN-ADDR.ARPA" {
  type master;
  file "192.168.1";
  allow-transfer {
    192.168.1.2;
  };
};

zone "my.domain" {
  type master;
  file "my.domain";
  allow-transfer {
    192.168.1.2;
  };
};

channel securitylog {
  file "/var/log/named.security";
  severity info;
};

category security { securitylog; };

category security { null; };

May  19 00:19:09 linux-box mimedefang[PID]: MIMEDefang: connect[ID]: unknown family 54
May  19 00:19:09 solaris-box sendmail[PID]: [mail.error] <ID>: 
  milter_read(mimedefang): cmd read returned 0, expecting 5

define('confCC', 'gcc')
define('confLDOPTS_SO', '-G')
define('confBEFORE', 'sysexits.h')
define('confMAPDEF', '-DNDBM -DMAP_REGEX')
define('confENVDEF', '-DSOLARIS=20900 -DNETINET6')
define('confSM_OS_HEADER', 'sm_os_sunos')
define('confLIBS', '-lsocket -lnsl')
define('confMTCCOPTS', '-D_REENTRANT')
define('confMTLDOPTS', '-lpthread')
define('confMBINDIR', '/usr/lib')
define('confEBINDIR', '/usr/lib')
define('confSBINGRP', 'sys')
define('confINSTALL', '${BUILDBIN}/install.sh')
define('confDEPEND_TYPE', 'CC-M')
PUSHDIVERT(3)
sysexits.h:
 if [ -r /usr/include/sysexits.h ]; \
 then \
   ln -s /usr/include/sysexits.h; \
 fi
POPDIVERT

INPUT_MAIL_FILTER('mimedefang', 'S=inet:port@linux-box.my.domain, <options>')
DAEMON_OPTIONS('Name=MTA-v6, Family=inet6')       

DAEMON_OPTIONS('Name=MTA-v4, Family=inet')

If I comment out the INPUT_MAIL_FILTER but leave the DAEMON_OPTIONS('Name=MTA-v6, Family=inet6') line in, then mail gets delivered over IPv6, but it's not running MIMEDefang. Obviously, I don't have the right sequence of declarations in here, or I've managed to mess up the compile somehow. Any help would be appreciated.

A Your version of MIMEDefang does not support IPv6. IPv6 support was added to mimedefang.c's mfconnect in version 2.31. If you grab a new source distribution, read the accompanying docs and recompile, you should be able to use the IPv6 addresses as well as the IPv4 ones. You can get the latest source from:

http://www.roaringpenguin.com/mimedefang/

Amy Rich, president of the Boston-based Oceanwave Consulting, Inc. (http://www.oceanwave.com), has been a UNIX systems administrator for more than 10 years. She received a BSCS at Worcester Polytechnic Institute, and can be reached at: qna@oceanwave.com.