2.9BSD/usr/src/ucb/delivermail/alias.c
# include <stdio.h>
# include <ctype.h>
# include <pwd.h>
# include "dlvrmail.h"
static char SccsId[] = "@(#)alias.c 2.2 12/6/80";
/*
** ALIAS -- Compute aliases.
**
** Scans the file ALIASFILE for a set of aliases.
** If found, it arranges to deliver to them by inserting the
** new names onto the SendQ queue. Uses libdbm database if -DDBM.
**
** Parameters:
** none
**
** Returns:
** none
**
** Side Effects:
** Aliases found on SendQ are removed and put onto
** AliasQ; replacements are added to SendQ. This is
** done until no such replacement occurs.
**
** Defined Constants:
** MAXRCRSN -- the maximum recursion depth.
**
** Called By:
** main
**
** Files:
** ALIASFILE -- the mail aliases. The format is
** a series of lines of the form:
** alias:name1,name2,name3,...
** where 'alias' expands to all of
** 'name[i]'. Continuations begin with
** space or tab.
** ALIASFILE.pag, ALIASFILE.dir: libdbm version
** of alias file. Keys are aliases, datums
** (data?) are name1,name2, ...
**
** Notes:
** If NoAlias (the "-n" flag) is set, no aliasing is
** done.
**
** Deficiencies:
** It should complain about names that are aliased to
** nothing.
** It is unsophisticated about line overflows.
*/
# define MAXRCRSN 10
#ifdef DBM
typedef struct {char *dptr; int dsize;} datum;
datum lhs, rhs;
extern datum fetch();
#endif DBM
alias()
{
register addrq *q;
addrq *q2;
FILE *af;
char line[MAXLINE+1];
register char *p;
extern int errno;
bool didalias;
bool gotmatch;
auto addrq al;
extern bool sameaddr();
extern addrq *parse();
if (NoAlias)
return;
# ifdef DEBUG
if (Debug)
printf("--- alias ---\n");
# endif
/* open alias file if not already open */
#ifndef DBM
# ifdef DEBUG
if (Debug && (af = fopen("mailaliases", "r")) != NULL)
printf(" [using local alias file]\n");
else
# endif
if ((af = fopen(ALIASFILE, "r")) == NULL)
{
# ifdef DEBUG
if (Debug)
printf("Can't open %s\n", ALIASFILE);
# endif
errno = 0;
return;
}
#else DBM
dbminit(ALIASFILE);
#endif DBM
#ifndef DBM
/*
** Scan alias file.
** If we find any user that any line matches any user, we
** will send to the line rather than to the user.
**
** We pass through the file several times. Didalias tells
** us if we took some alias on this pass through the file;
** when it goes false at the top of the loop we don't have
** to scan any more. Gotmatch tells the same thing, but
** on a line-by-line basis; it is used for processing
** continuation lines.
*/
do
{
didalias = FALSE;
gotmatch = FALSE;
rewind(af);
while (fgets(line, sizeof line, af) != NULL)
{
/* comments begin with `#' */
if (line[0] == '#')
continue;
/* check for continuation lines */
if (isspace(line[0]))
{
if (gotmatch)
{
sendto(line, 1);
}
continue;
}
gotmatch = FALSE;
/*
** Check to see if this pseudonym exists in SendQ.
** Turn the alias into canonical form.
** Then scan SendQ until you do (or do not)
** find that address.
*/
/* Get a canonical form for the alias. */
for (p = line; *p != '\0' && *p != ':' && *p != '\n'; p++)
continue;
if (*p == '\0' || *p == '\n')
{
syntaxerr:
syserr("Bad alias line `%s'", line);
continue;
}
*p++ = '\0';
if (parse(line, &al, -1) == NULL)
{
*--p = ':';
goto syntaxerr;
}
/* if already in AliasQ don't realias */
for (q = &AliasQ; (q = nxtinq(q)) != NULL; )
{
if (sameaddr(&al, q, TRUE))
break;
}
if (q != NULL)
continue;
/* Scan SendQ for that canonical form. */
for (q = &SendQ; (q = nxtinq(q)) != NULL; )
{
if (sameaddr(&al, q, TRUE))
break;
}
if (q != NULL)
{
/*
** Match on Alias.
** Deliver to the target list.
** Remove the alias from the send queue
** and put it on the Alias queue.
*/
# ifdef DEBUG
if (Debug)
printf("%s (%s, %s) aliased to %s (%s,%s,%s)\n",
q->q_paddr, q->q_host, q->q_user,
p, al.q_paddr, al.q_host, al.q_user);
# endif
tkoffq(q, &SendQ);
didalias++;
gotmatch++;
sendto(p, 1);
putonq(q, &AliasQ);
}
}
} while (didalias);
fclose(af);
#else DBM
/*
** Scan SendQ
** We only have to do this once, since anything we alias
** to is being put at the end of the queue we are
** scanning.
** If the alias on SendQ is also (already) on AliasQ, we
** have an alias such as:
** eric:eric,i:eric
** In this case we have already done this alias once, and
** we don't want to do it again (for obvious reasons!).
*/
for (q2 = nxtinq(&SendQ); q2 != NULL; )
{
/* if already in AliasQ, don't realias */
for (q = &AliasQ; (q = nxtinq(q)) != NULL; )
{
if (sameaddr(q, q2, TRUE))
break;
}
if (q != NULL)
{
q2 = nxtinq(q2);
continue;
}
/* save ptr to next address */
q = q2;
q2 = nxtinq(q);
/* only alias local users */
if (q->q_mailer != &Mailer[0])
continue;
/* create a key for fetch */
lhs.dptr = q->q_user;
lhs.dsize = strlen(q->q_user) + 1;
rhs = fetch(lhs);
/* find this alias? */
p = rhs.dptr;
if (p == NULL)
continue;
/*
** Match on Alias.
** Deliver to the target list.
** Remove the alias from the send queue
** and put it on the Alias queue.
*/
# ifdef DEBUG
if (Debug)
printf("%s (%s, %s) aliased to %s\n",
q->q_paddr, q->q_host, q->q_user, p);
# endif
tkoffq(q, &SendQ);
sendto(p, 1);
putonq(q, &AliasQ);
/* if our last entry had an alias, process them */
if (q2 == NULL)
q2 = nxtinq(&SendQ);
}
#endif DBM
}
/*
** FORWARD -- Try to forward mail
**
** This is similar but not identical to aliasing.
**
** Currently it is undefined, until the protocol for userinfo
** databases is finalized.
**
** Parameters:
** user -- the name of the user who's mail we
** would like to forward to.
**
** Returns:
** TRUE -- we have forwarded it somewhere.
** FALSE -- not forwarded; go ahead & deliver.
**
** Side Effects:
** New names are added to SendQ.
**
** Called By:
** recipient
*/
bool
forward(user)
addrq *user;
{
return (FALSE);
}