Added the via option.

svn path=/trunk/; revision=1179

9 files changed, 107 insertions, 26 deletions

diff --git a/NEWS b/NEWS
index ffa50749..d05a25a3 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,7 @@
 ------------------------------------------------------------------------------
 fetchmail 4.0.3 ()
 * Replace vsprintf with vnsprintf to avoid buffer-overrun screws.
+* Added via option to make ssh configuration cleaner.
 
 There are 257 people on the fetchmail-friends list.
 
diff --git a/driver.c b/driver.c
index aba38f09..934ddacb 100644
--- a/driver.c
+++ b/driver.c
@@ -114,23 +114,32 @@ static int is_host_alias(const char *name, struct query *ctl)
 	ctl->server.lead_server ? ctl->server.lead_server : &ctl->server;
 
     /*
-     * The first two checks are optimizations that will catch a good
-     * many cases.  (1) check against the hostname the user
-     * specified.  Odds are good this will either be the mailserver's
-     * FQDN or a suffix of it with the mailserver's domain's default
-     * host name omitted.  Then check the rest of the `also known as'
+     * The first three checks are optimizations that will catch a good
+     * many cases.
+     *
+     * (1) check against the poll name the user specified.  Odds are
+     * good this will either be the mailserver's FQDN or a suffix of
+     * it with the mailserver's domain's default host name omitted.
+     *
+     * (2) Check the `via' or true host name if present, just in case
+     * the poll name is a label for one of a couple of different 
+     * configurations and the real server name is here.
+     *
+     * (3) Then check the rest of the `also known as'
      * cache accumulated by previous DNS checks.  This cache is primed
      * by the aka list option.
      *
-     * (2) check against the mailserver's FQDN, in case
+     * (4) Finally check against the mailserver's FQDN, in case
      * it's not the same as the declared hostname.
      *
-     * Either of these on a mail address is definitive.  Only if the
-     * name doesn't match either is it time to call the bind library.
+     * Any of these on a mail address is definitive.  Only if the
+     * name doesn't match any is it time to call the bind library.
      * If this happens odds are good we're looking at an MX name.
      */
     if (str_in_list(&lead_server->names, name))
 	return(TRUE);
+    else if (ctl->server.via && strcmp(name, ctl->server.via) == 0)
+	return(TRUE);
     else if (strcmp(name, ctl->server.canonical_name) == 0)
 	return(TRUE);
     else if (!ctl->server.dns)
@@ -391,11 +400,48 @@ int smtp_open(struct query *ctl)
 	/* if no socket to this host is already set up, try to open ESMTP */
 	if (ctl->smtp_socket == -1)
 	{
+#ifndef HAVE_RES_SEARCH
+	    char	*fakename;
+#endif /* HAVE_RES_SEARCH */
+
 	    if ((ctl->smtp_socket = SockOpen(idp->id,SMTP_PORT)) == -1)
 		continue;
-	    else if (SMTP_ok(ctl->smtp_socket) != SM_OK
+
+#ifndef HAVE_RES_SEARCH
+	    /*
+	     * How we compute the fake client name to pass to the
+	     * listener doesn't affect behavior on RFC1123- violating
+	     * listener that check for name match; we're going to lose
+	     * on those anyway because we can never give them a name
+	     * that matches the local machine fetchmail is running on.
+	     * What it will affect is the listener's logging.
+	     *
+	     * If we have the mailserver's canonical FQDN that is clearly
+	     * the right thing to log.  If we don't life is more complicated.
+	     * The problem is there are two clashing cases:
+	     *
+	     * (1) The poll name is a label.  In that case we want the
+	     * log to show the via or true mailserver name.
+	     *
+	     * (2) The poll name is the true one, the via name is localhost.
+	     * This is going to be typical for ssh-using configurations.
+	     *
+	     * We're going to assume the via name is true unless it's
+	     * localhost.
+	     */
+	    if (ctrl->server.via && strcmp(ctrl->server.via, "localhost"))
+		fakename = ctrl->server.via;
+	    else
+		fakename = ctrl->server->names.id;
+#endif /* HAVE_RES_SEARCH */
+
+	    if (SMTP_ok(ctl->smtp_socket) != SM_OK
 		     || SMTP_ehlo(ctl->smtp_socket, 
-				  ctl->server.names->id,
+#ifdef HAVE_RES_SEARCH
+				  ctl->server.canonical_name,
+#else
+				  fakename,
+#endif /* HAVE_RES_SEARCH */
 				  &ctl->server.esmtp_options) != SM_OK)
 	    {
 		/*
@@ -418,7 +464,13 @@ int smtp_open(struct query *ctl)
 	    if ((ctl->smtp_socket = SockOpen(idp->id,SMTP_PORT)) == -1)
 		continue;
 	    else if (SMTP_ok(ctl->smtp_socket) != SM_OK
-		     || SMTP_helo(ctl->smtp_socket, ctl->server.names->id) != SM_OK)
+		     || SMTP_helo(ctl->smtp_socket, 
+#ifdef HAVE_RES_SEARCH
+				  ctl->server.canonical_name
+#else
+				  fakename
+#endif /* HAVE_RES_SEARCH */
+				  ) != SM_OK)
 	    {
 		close(ctl->smtp_socket);
 		ctl->smtp_socket = -1;
@@ -1242,7 +1294,7 @@ const struct method *proto;	/* protocol method table */
     }
     else
     {
-	char buf [POPBUFSIZE+1], *sp;
+	char buf [POPBUFSIZE+1], *sp, *realhost;
 	int *msgsizes, len, num, count, new, deletions = 0;
 	int port, fetches;
 	struct idlist *idp;
@@ -1258,7 +1310,8 @@ const struct method *proto;	/* protocol method table */
 
 	/* open a socket to the mail server */
 	port = ctl->server.port ? ctl->server.port : protocol->port;
-	if ((sock = SockOpen(ctl->server.names->id, port)) == -1)
+	realhost = ctl->server.via ? ctl->server.via : ctl->server.names->id;
+	if ((sock = SockOpen(realhost, port)) == -1)
 	{
 #ifndef EHOSTUNREACH
 #define EHOSTUNREACH (-1)
diff --git a/fetchmail-FAQ.html b/fetchmail-FAQ.html
index bbf1d34c..d2788233 100644
--- a/fetchmail-FAQ.html
+++ b/fetchmail-FAQ.html
@@ -480,14 +480,14 @@ but only supports one user at a time.<P>
 First, a lightly edited version of a recipe from Masafumi NAKANE:<p>
 
 1. You must have ssh (the ssh client) on the local host and sshd (ssh
-server) on the remote mail server.  And, you have to configure ssh so
+server) on the remote mail server.  And you have to configure ssh so
 you can login to the sshd server host without a password.  (Refer to ssh
 man page for several authentication methods.)<p>
 
 2. Add something like following to your .fetchmailrc file: <p>
 
 <pre>
-poll localhost port 1234 with pop3:
+poll mailhost port 1234 via localhost with pop3:
         preconnect "ssh -f -L 1234:mailhost:110 mailhost sleep 20 </dev/null >/dev/null";
 </pre>
 
@@ -1200,7 +1200,7 @@ biff n
 
 to solve the problem system-wide.<P>
 
-$Id: fetchmail-FAQ.html,v 1.47 1997/07/24 08:22:49 esr Exp $<p>
+$Id: fetchmail-FAQ.html,v 1.48 1997/07/24 20:56:41 esr Exp $<p>
 
 <HR>
 <ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com">&lt;esr@snark.thyrsus.com&gt;</A></ADDRESS>
diff --git a/fetchmail.c b/fetchmail.c
index 7810ec9b..dfd0c300 100644
--- a/fetchmail.c
+++ b/fetchmail.c
@@ -135,8 +135,12 @@ int main (int argc, char **argv)
 	    printf("\n");
 	else
 	    printf(" and %s\n", rcfile);
+	if (poll_interval)
+	    printf("Poll interval is %d seconds\n", poll_interval);
 	if (outlevel == O_VERBOSE)
 	    printf("Lockfile at %s\n", tmpbuf);
+	if (logfile)
+	    printf("Logfile is %s\n", logfile);
 	for (ctl = querylist; ctl; ctl = ctl->next) {
 	    if (ctl->active && !(implicitmode && ctl->server.skip))
 		dump_params(ctl);
@@ -779,10 +783,9 @@ void dump_params (struct query *ctl)
     printf("Options for retrieving from %s@%s:\n",
 	   ctl->remotename, visbuf(ctl->server.names->id));
 
-    if (logfile)
-	printf("  Logfile is %s\n", logfile);
-    if (poll_interval)
-	printf("  Poll interval is %d seconds\n", poll_interval);
+    if (ctl->server.via)
+	printf("  Mail will be retrieved via %s\n", ctl->server.via);
+
     if (ctl->server.interval)
 	printf("  Poll of this server will occur every %d intervals.\n",
 	       ctl->server.interval);
diff --git a/fetchmail.h b/fetchmail.h
index a9775c70..24ef5ee0 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -78,6 +78,7 @@ typedef	char	flag;
 struct hostdata		/* shared among all user connections to given server */
 {
     /* rc file data */
+    char *via;				/* "true" server name if non-NULL */
     struct idlist *names;		/* server name first, then akas */
     struct idlist *localdomains;	/* list of pass-through domains */
     int protocol;			/* protocol type */
diff --git a/fetchmail.man b/fetchmail.man
index e2b4ce62..792093fb 100644
--- a/fetchmail.man
+++ b/fetchmail.man
@@ -657,6 +657,7 @@ safely, or easily disable entries for hosts that are temporarily down.)
 .PP
 Legal server options are:
 
+    via
     protocol (or proto)
     port
     authenticate (or auth)
@@ -704,9 +705,26 @@ The 'folder' and 'smtphost' options can take a space- or
 comma-separated list of names following them.
 .PP
 All options correspond to the obvious command-line arguments, except
-the following: `interval', `aka', `is', `to', `dns'/`no dns', `password',
-\&`preconnect', `localdomains', `stripcr'/`no stripcr' ,
-\&`forcecr'/`no forcecr', `pass8bits'/`no pass8bits' and `no received'.
+the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
+\&`password', \&`preconnect', `localdomains', `stripcr'/`no stripcr' ,
+\&`forcecr'/`no forcecr', `pass8bits'/`no pass8bits' and `no
+received'.
+.PP
+The `via' option is for use with ssh, or if you want to have more
+than one configuration pointing at the same site.  If it is present,
+the string argument will be taken as the actual DNS name of the 
+mailserver host to query.  So, for example, you can say:
+
+.nf
+poll mailhost.net via localhost port 1234 with pop3:
+        preconnect "ssh -f -L 1234:mailhost.net:110 mailhost.net sleep 20 </dev/null >/dev/null";
+.fi
+
+This will override the argument of poll, which can simply be a
+distinct label for the configuration.  The poll name will still be the
+one you would give on the command line to explicitly query this host.
+It will also still be used as a possible match in multidrop mode, in
+case it is (as in this case) the real host name.
 .PP
 The `interval' option (which takes a numeric argument) allows you to poll a
 server less frequently than the basic poll interval.  If you say
diff --git a/rcfile_l.l b/rcfile_l.l
index f708f157..fdb6e03d 100644
--- a/rcfile_l.l
+++ b/rcfile_l.l
@@ -30,6 +30,7 @@ defaults 	{ return DEFAULTS; }
 server 		{ return POLL; }
 poll		{ return POLL; }
 skip		{ return SKIP; }
+via		{ return VIA; }
 aka		{ return AKA; }
 local(domains)	{ return LOCALDOMAINS; }
 proto(col)? 	{ return PROTOCOL; }
diff --git a/rcfile_y.y b/rcfile_y.y
index ea163e10..d9705945 100644
--- a/rcfile_y.y
+++ b/rcfile_y.y
@@ -54,7 +54,7 @@ extern char * yytext;
   char *sval;
 }
 
-%token DEFAULTS POLL SKIP AKA LOCALDOMAINS PROTOCOL
+%token DEFAULTS POLL SKIP VIA AKA LOCALDOMAINS PROTOCOL
 %token AUTHENTICATE TIMEOUT KPOP KERBEROS4
 %token ENVELOPE USERNAME PASSWORD FOLDER SMTPHOST MDA PRECONNECT LIMIT
 %token IS HERE THERE TO MAP WILDCARD
@@ -126,6 +126,7 @@ domain_list	: STRING		{save_str(&current.server.localdomains,-1,$1);}
 		;
 
 serv_option	: AKA alias_list
+		| VIA STRING		{current.server.via = xstrdup($2);}
 		| LOCALDOMAINS domain_list
 		| PROTOCOL PROTO	{current.server.protocol = $2;}
 		| PROTOCOL KPOP		{
@@ -398,6 +399,7 @@ static void record_current(void)
 /* register current parameters and append to the host list */
 {
 #define FLAG_FORCE(fld) if (cmd_opts.fld) current.fld = cmd_opts.fld
+    FLAG_FORCE(server.via);
     FLAG_FORCE(server.protocol);
     FLAG_FORCE(server.port);
     FLAG_FORCE(server.interval);
@@ -449,6 +451,7 @@ void optmerge(struct query *h2, struct query *h1)
     append_str_list(&h2->smtphunt, &h1->smtphunt);
 
 #define FLAG_MERGE(fld) if (!h2->fld) h2->fld = h1->fld
+    FLAG_MERGE(server.via);
     FLAG_MERGE(server.protocol);
     FLAG_MERGE(server.port);
     FLAG_MERGE(server.interval);
diff --git a/sample.rcfile b/sample.rcfile
index 9f0fa62b..fd648fc6 100644
--- a/sample.rcfile
+++ b/sample.rcfile
@@ -19,8 +19,9 @@
 # arguments in this file, the command-line arguments take precedence.
 #
 # Legal keywords are
-#   poll                      -- must be followed by a mailserver name
-#   skip                      -- must be followed by a mailserver name
+#   poll                      -- must be followed by a mailserver name or label
+#   skip                      -- must be followed by a mailserver name or label
+#   via                       -- must be followed by true name of host to poll
 #   interval                  -- must be followed by an interval skip count
 #   protocol (or proto)       -- must be followed by a protocol ID
 #   uidl