Feature: bad-header {reject|pass}

10 files changed, 74 insertions, 5 deletions

diff --git a/NEWS b/NEWS
index 44cba404..7ae09a7d 100644
--- a/NEWS
+++ b/NEWS
@@ -49,6 +49,12 @@ removed from a 6.4.0 or newer release.)
 
 fetchmail 6.3.15 (not yet released):
 
+# FEATURE
+* Fetchmail now supports a bad-header command line or rcfile option that takes
+  exactly one argument, pass or reject (default).  If set to pass, fetchmail
+  will pass messages with bad headers on.  This has been rejected for a long
+  time, and the right behaviour was disputed for too long.
+
 # CHANGES
 * The repository has been converted and moved from the Subversion (SVN) format
   kindly hosted by Graham Wilson over the past years to Git format hosted on
diff --git a/conf.c b/conf.c
index 60eb3ebb..5b5d8779 100644
--- a/conf.c
+++ b/conf.c
@@ -312,6 +312,13 @@ void dump_config(struct runctl *runp, struct query *querylist)
 	    if (ctl->server.esmtp_password)
 	        stringdump("esmtppassword",ctl->server.esmtp_password);
 	    booldump("tracepolls", ctl->server.tracepolls);
+	    indent(0);
+	    switch(ctl->server.badheader) {
+		/* this is a hack - we map this to a boolean option for
+		 * fetchmailconf purposes */
+		case BHREJECT: puts("'badheader': FALSE,"); break;
+		case BHPASS:   puts("'badheader': TRUE,"); break;
+	    }
 
 	    indent(0);
 	    fputs("'users': ", stdout);
diff --git a/fetchmail.c b/fetchmail.c
index cb1bc900..5d02a289 100644
--- a/fetchmail.c
+++ b/fetchmail.c
@@ -944,6 +944,7 @@ static void optmerge(struct query *h2, struct query *h1, int force)
     FLAG_MERGE(server.plugin);
     FLAG_MERGE(server.plugout);
     FLAG_MERGE(server.tracepolls);
+    FLAG_MERGE(server.badheader);
 
     FLAG_MERGE(wildcard);
     FLAG_MERGE(remotename);
@@ -1012,6 +1013,7 @@ static int load_params(int argc, char **argv, int optind)
     def_opts.server.protocol = P_AUTO;
     def_opts.server.timeout = CLIENT_TIMEOUT;
     def_opts.server.esmtp_name = user;
+    def_opts.server.badheader = BHREJECT;
     def_opts.warnings = WARNING_INTERVAL;
     def_opts.remotename = user;
     def_opts.listener = SMTP_MODE;
@@ -1949,6 +1951,16 @@ static void dump_params (struct runctl *runp,
         else if (outlevel >= O_VERBOSE)
             printf(GT_("  No poll trace information will be added to the Received header.\n.\n"));
 
+	switch (ctl->server.badheader) {
+	    case BHREJECT:
+		if (outlevel >= O_VERBOSE)
+		    printf(GT_("  Messages with bad headers will be rejected.\n"));
+		break;
+	    case BHPASS:
+		printf(GT_("  Messages with bad headers will be passed on.\n"));
+		break;
+	}
+
 	if (ctl->properties)
 	    printf(GT_("  Pass-through properties \"%s\".\n"),
 		   visbuf(ctl->properties));
diff --git a/fetchmail.h b/fetchmail.h
index d0991386..88f7dd33 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -245,6 +245,8 @@ struct method		/* describe methods for protocol state machine */
     flag retry;			/* can getrange poll for new messages? */
 };
 
+enum badheader { BHREJECT = 0, BHPASS };
+
 struct hostdata		/* shared among all user connections to given server */
 {
     /* rc file data */
@@ -270,6 +272,7 @@ struct hostdata		/* shared among all user connections to given server */
     flag tracepolls;			/* if TRUE, add poll trace info to Received */
     char *principal;			/* Kerberos principal for mail service */
     char *esmtp_name, *esmtp_password;	/* ESMTP AUTH information */
+    enum badheader badheader;		/* bad-header {pass|reject} */
 
 #if defined(linux) || defined(__FreeBSD__)
 #define CAN_MONITOR
diff --git a/fetchmail.man b/fetchmail.man
index d2b51197..f63f381f 100644
--- a/fetchmail.man
+++ b/fetchmail.man
@@ -699,6 +699,15 @@ to be written to standard output.  Note that fetchmail's
 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
 MAILBOXES below apply.
+.TP
+.B \-\-bad\-header {reject|pass}
+(Keyword: bad\-header; since v6.3.15)
+.br
+Specify how fetchmail is supposed to treat messages with bad headers,
+i. e. headers with bad syntax. Traditionally, fetchmail has rejected such
+messages, but some distributors modified fetchmail to pass them. You can now
+configure fetchmail's behaviour per server.
+
 .SS Resource Limit Control Options
 .TP
 .B \-l <maxbytes> | \-\-limit <maxbytes>
@@ -1749,6 +1758,9 @@ T}
 esmtppassword	\&	\&	T{
 Set password for RFC2554 authentication to the ESMTP server.
 T}
+bad-header	\&	\&	T{
+How to treat messages with a bad header. Can be reject (default) or pass.
+T}
 .TE
 
 Here are the legal user descriptions and options:
diff --git a/fetchmailconf.py b/fetchmailconf.py
index 90a2dea5..4aae48f8 100755
--- a/fetchmailconf.py
+++ b/fetchmailconf.py
@@ -5,7 +5,7 @@
 # Matthias Andree <matthias.andree@gmx.de>
 # Requires Python with Tkinter, and the following OS-dependent services:
 #	posix, posixpath, socket
-version = "1.56 $Revision$"
+version = "1.57"
 
 from Tkinter import *
 from Dialog import *
@@ -103,6 +103,7 @@ class Server:
 	self.esmtpname = None		# ESMTP 2554 name
 	self.esmtppassword = None	# ESMTP 2554 password
 	self.tracepolls = FALSE		# Add trace-poll info to headers
+	self.badheader = FALSE		# Pass messages with bad headers on?
 	self.users = []			# List of user entries for site
 	Server.typemap = (
 	    ('pollname',  'String'),
@@ -127,7 +128,8 @@ class Server:
 	    ('esmtpname', 'String'),
 	    ('esmtppassword', 'String'),
 	    ('principal', 'String'),
-	    ('tracepolls','Boolean'))
+	    ('tracepolls','Boolean'),
+	    ('badheader', 'Boolean'))
 
     def dump(self, folded):
 	res = ""
@@ -197,6 +199,8 @@ class Server:
 	if self.interface or self.monitor or self.principal or self.plugin or self.plugout:
 	    if folded:
 		res = res + "\n"
+	if self.badheader:
+		res = res + "bad-header pass "
 
 	if res[-1] == " ": res = res[0:-1]
 
@@ -1129,6 +1133,8 @@ class ServerEdit(Frame, MyWidget):
 	    ctlwin = Frame(leftwin, relief=RAISED, bd=5)
 	    Label(ctlwin, text="Run Controls").pack(side=TOP)
 	    Checkbutton(ctlwin, text='Poll ' + host + ' normally?', variable=self.active).pack(side=TOP)
+	    Checkbutton(ctlwin, text='Pass messages with bad headers?',
+		    variable=self.badheader).pack(side=TOP)
 	    LabeledEntry(ctlwin, 'True name of ' + host + ':',
 		      self.via, leftwidth).pack(side=TOP, fill=X)
 	    LabeledEntry(ctlwin, 'Cycles to skip between polls:',
diff --git a/options.c b/options.c
index e85682d5..066a8ab0 100644
--- a/options.c
+++ b/options.c
@@ -53,7 +53,8 @@ enum {
     LA_LIMITFLUSH,
     LA_IDLE,
     LA_NOSOFTBOUNCE,
-    LA_SOFTBOUNCE
+    LA_SOFTBOUNCE,
+    LA_BADHEADER
 };
 
 /* options still left: CgGhHjJoORTWxXYz */
@@ -93,6 +94,7 @@ static const struct option longoptions[] = {
   {"timeout",	required_argument, (int *) 0, 't' },
   {"envelope",	required_argument, (int *) 0, 'E' },
   {"qvirtual",	required_argument, (int *) 0, 'Q' },
+  {"bad-header",required_argument, (int *) 0, LA_BADHEADER},
 
   {"user",	required_argument, (int *) 0, 'u' },
   {"username",	required_argument, (int *) 0, 'u' },
@@ -310,6 +312,17 @@ int parsecmdline (int argc /** argument count */,
 	case LA_SOFTBOUNCE:
 	    run.softbounce = TRUE;
 	    break;
+	case LA_BADHEADER:
+	    if (strcasecmp(optarg,"pass") == 0) {
+		ctl->server.badheader = BHPASS;
+	    } else if (strcasecmp(optarg,"reject") == 0) {
+		ctl->server.badheader = BHREJECT;
+	    } else {
+		fprintf(stderr,GT_("Invalid bad-header policy `%s' specified.\n"), optarg);
+		errflag++;
+	    }
+	    break;
+
 	case 'p':
 	    /* XXX -- should probably use a table lookup here */
 	    if (strcasecmp(optarg,"auto") == 0)
@@ -635,6 +648,8 @@ int parsecmdline (int argc /** argument count */,
 #endif
 	P(GT_("      --plugin      specify external command to open connection\n"));
 	P(GT_("      --plugout     specify external command to open smtp connection\n"));
+	P(GT_("      --bad-header {reject|pass}\n"
+	      "                    specify policy for handling messages with bad headers\n"));
 
 	P(GT_("  -p, --protocol    specify retrieval protocol (see man page)\n"));
 	P(GT_("  -U, --uidl        force the use of UIDLs (pop3 only)\n"));
diff --git a/rcfile_l.l b/rcfile_l.l
index 67317a6b..679a5b4e 100644
--- a/rcfile_l.l
+++ b/rcfile_l.l
@@ -113,7 +113,9 @@ qvirtual	{ return QVIRTUAL; }
 principal	{ return PRINCIPAL; }
 esmtpname	{ return ESMTPNAME; }
 esmtppassword	{ return ESMTPPASSWORD; }
-
+bad-header	{ return BADHEADER; }
+pass		{ return PASS; }
+reject		{ return REJECT_; }
 
 user(name)?	{SETSTATE(NAME); return USERNAME; }
 <INITIAL,NAME>pass(word)?	{SETSTATE(NAME); return PASSWORD; }
diff --git a/rcfile_y.y b/rcfile_y.y
index e57973b6..b5765d77 100644
--- a/rcfile_y.y
+++ b/rcfile_y.y
@@ -70,6 +70,7 @@ extern char * yytext;
 %token BATCHLIMIT FETCHLIMIT FETCHSIZELIMIT FASTUIDL EXPUNGE PROPERTIES
 %token SET LOGFILE DAEMON SYSLOG IDFILE PIDFILE INVISIBLE POSTMASTER BOUNCEMAIL
 %token SPAMBOUNCE SOFTBOUNCE SHOWDOTS
+%token BADHEADER PASS REJECT_
 %token <proto> PROTO AUTHTYPE
 %token <sval>  STRING
 %token <number> NUMBER
@@ -231,6 +232,8 @@ serv_option	: AKA alias_list
 		| NO ENVELOPE		{current.server.envelope = STRING_DISABLED;}
 		| TRACEPOLLS		{current.server.tracepolls = FLAG_TRUE;}
 		| NO TRACEPOLLS		{current.server.tracepolls = FLAG_FALSE;}
+		| BADHEADER PASS	{current.server.badheader = BHPASS;}
+		| BADHEADER REJECT_	{current.server.badheader = BHREJECT;}
 		;
 
 userspecs	: user1opts		{record_current(); user_reset();}
diff --git a/transact.c b/transact.c
index c6ea7e35..9d151607 100644
--- a/transact.c
+++ b/transact.c
@@ -583,7 +583,10 @@ eoh:
 	     * message/rfc822 attachment and forward to postmaster (Rob
 	     * MacGregor)
 	     */
-	    if (!refuse_mail && !isspace((unsigned char)line[0]) && !strchr(line, ':'))
+	    if (!refuse_mail
+		&& !ctl->server.badheader == BHPASS
+		&& !isspace((unsigned char)line[0])
+		&& !strchr(line, ':'))
 	    {
 		if (linelen != strlen (line))
 		    has_nuls = TRUE;