lee@rochester.UUCP (Lee Moore) (08/07/85)
I hope this questions isn't too lame but what is the easiest
way to make sendmail re-write aliases for hosts to be the official
names? Can this be done without actually touching the C code?
thanks!
--
TCP/IP: lee@rochester.arpa
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XNS: Lee Moore:CS:Univ Rochester
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Physical: 43 01' 40'' N, 77 37' 49'' Whedrick@topaz.RUTGERS.EDU (Chuck Hedrick) (08/08/85)
In article <10904@rochester.UUCP>, lee@rochester.UUCP (Lee Moore) writes: > I hope this questions isn't too lame but what is the easiest > way to make sendmail re-write aliases for hosts to be the official > names? Can this be done without actually touching the C code? We have not figured out any way to do this without modifying the C code. For those who don't understand the request, this is part of the Arpanet domain conversion. Our full domain names are thing like TOPAZ.RUTGERS.EDU. Local users do not want to type these. So we will provide aliases such as TOPAZ. However according to the RFC's, if a message leaves Rutgers, any host names mentioned in headers should have the full domain qualification. The simplest way to enforce this is to turn the aliases into the official host name automatically. The following code does two things: (1) it prevents sendmail from appending .ARPA to all host names. (2) it adds an operator to be used in SENDMAIL.CF that maps a host name into its official form. This operator works only on the RHS side of a production. $%2 works just like $2. I.e. it causes the second thing matched by the LHS to be replaced. However the thing being replaced it first checked against /etc/hosts and if it is a nickname is turned into the primary host name. If the thing is not a nickname it is copied with change. There is a warning about the implementation: The item on the RHS is put in a fixed place in memory. This means that there can be only one such mapped host name active at any given time. A second one would be put in the same place as the first. This does not seem to be a problem the way we use it, since sendmail analyses one address at a time. However you should be careful if you play with things like foo%bar@baz. If you tried to dealias both bar and baz, you would get in trouble. *** daemon.c.ORIG Fri Feb 10 06:59:21 1984 --- daemon.c Sat Aug 3 07:49:46 1985 *************** *** 183,189 /* determine host name */ hp = gethostbyaddr(&otherend.sin_addr, sizeof otherend.sin_addr, AF_INET); if (hp != NULL) ! (void) sprintf(buf, "%s.ARPA", hp->h_name); else /* this should produce a dotted quad */ (void) sprintf(buf, "%lx", otherend.sin_addr.s_addr); --- 185,191 ----- /* determine host name */ hp = gethostbyaddr(&otherend.sin_addr, sizeof otherend.sin_addr, AF_INET); if (hp != NULL) ! (void) sprintf(buf, "%s", hp->h_name); else /* this should produce a dotted quad */ (void) sprintf(buf, "%lx", otherend.sin_addr.s_addr); *** main.c.ORIG Fri Feb 10 11:17:52 1984 --- main.c Sat Aug 3 05:08:28 1985 *************** *** 702,707 /* and finally the conditional operations */ '?', CONDIF, '|', CONDELSE, '.', CONDFI, '\0' }; --- 702,710 ----- /* and finally the conditional operations */ '?', CONDIF, '|', CONDELSE, '.', CONDFI, + /* now the normalization operator */ + '%', NORMREPL, + '\0' }; *** parseaddr.c.ORIG Fri Feb 10 06:59:12 1984 --- parseaddr.c Sat Aug 3 06:08:42 1985 *************** *** 446,451 # define MAXMATCH 9 /* max params per rewrite */ rewrite(pvp, ruleset) char **pvp; --- 446,452 ----- # define MAXMATCH 9 /* max params per rewrite */ + char hostbuf[512]; rewrite(pvp, ruleset) *************** *** 447,452 # define MAXMATCH 9 /* max params per rewrite */ rewrite(pvp, ruleset) char **pvp; int ruleset; --- 448,454 ----- char hostbuf[512]; + rewrite(pvp, ruleset) char **pvp; int ruleset; *************** *** 626,631 /* substitute */ for (avp = npvp; *rvp != NULL; rvp++) { register struct match *m; register char **pp; --- 628,634 ----- /* substitute */ for (avp = npvp; *rvp != NULL; rvp++) { + #include <netdb.h> register struct match *m; register char **pp; char **oldavp,**tavp; *************** *** 628,633 { register struct match *m; register char **pp; rp = *rvp; if (*rp != MATCHREPL) --- 631,638 ----- #include <netdb.h> register struct match *m; register char **pp; + char **oldavp,**tavp; + struct hostent *hostpt; rp = *rvp; if ((*rp != MATCHREPL) && (*rp != NORMREPL)) *************** *** 630,636 register char **pp; rp = *rvp; ! if (*rp != MATCHREPL) { if (avp >= &npvp[MAXATOM]) { --- 635,641 ----- struct hostent *hostpt; rp = *rvp; ! if ((*rp != MATCHREPL) && (*rp != NORMREPL)) { if (avp >= &npvp[MAXATOM]) { *************** *** 642,647 } /* substitute from LHS */ m = &mlist[rp[1] - '1']; # ifdef DEBUG if (tTd(21, 15)) --- 647,653 ----- } /* substitute from LHS */ + m = &mlist[rp[1] - '1']; # ifdef DEBUG if (tTd(21, 15)) *************** *** 658,663 } # endif DEBUG pp = m->first; while (pp <= m->last) { if (avp >= &npvp[MAXATOM]) --- 664,670 ----- } # endif DEBUG pp = m->first; + oldavp = avp; while (pp <= m->last) { if (avp >= &npvp[MAXATOM]) *************** *** 666,671 return; } *avp++ = *pp++; } } *avp++ = NULL; --- 673,688 ----- return; } *avp++ = *pp++; + } + if (*rp == NORMREPL) { + hostbuf[0] = '\0'; + for (tavp = oldavp; tavp < avp; tavp++) + strcat(hostbuf,*tavp); + hostpt = gethostbyname(hostbuf); + if (hostpt) { + *oldavp = hostpt -> h_name; + avp = oldavp + 1; + } } } *avp++ = NULL; *** sendmail.h.ORIG Fri Feb 10 06:59:10 1984 --- sendmail.h Sat Aug 3 05:06:53 1985 *************** *** 290,295 # define CONDIF '\031' /* conditional if-then */ # define CONDELSE '\032' /* conditional else */ # define CONDFI '\033' /* conditional fi */ /* ** Symbol table definitions */ --- 290,299 ----- # define CONDIF '\031' /* conditional if-then */ # define CONDELSE '\032' /* conditional else */ # define CONDFI '\033' /* conditional fi */ + + /* normalize Internet address operator */ + # define NORMREPL '\034' /* normalized host replacement */ + /* ** Symbol table definitions */