Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 345 insertions, 0 deletions

diff --git a/src/smtpd/smtpd_chat.c b/src/smtpd/smtpd_chat.c
new file mode 100644
index 0000000..c172ab3
--- /dev/null
+++ b/src/smtpd/smtpd_chat.c
@@ -0,0 +1,345 @@
+/*++
+/* NAME
+/*	smtpd_chat 3
+/* SUMMARY
+/*	SMTP server request/response support
+/* SYNOPSIS
+/*	#include <smtpd.h>
+/*	#include <smtpd_chat.h>
+/*
+/*	void	smtpd_chat_pre_jail_init(void)
+/*
+/*	int	smtpd_chat_query_limit(state, limit)
+/*	SMTPD_STATE *state;
+/*	int limit;
+/*
+/*	void	smtpd_chat_query(state)
+/*	SMTPD_STATE *state;
+/*
+/*	void	smtpd_chat_reply(state, format, ...)
+/*	SMTPD_STATE *state;
+/*	char	*format;
+/*
+/*	void	smtpd_chat_notify(state)
+/*	SMTPD_STATE *state;
+/*
+/*	void	smtpd_chat_reset(state)
+/*	SMTPD_STATE *state;
+/* DESCRIPTION
+/*	This module implements SMTP server support for request/reply
+/*	conversations, and maintains a limited SMTP transaction log.
+/*
+/*	smtpd_chat_pre_jail_init() performs one-time initialization.
+/*
+/*	smtpd_chat_query_limit() reads a line from the client that is
+/*	at most "limit" bytes long.  A copy is appended to the SMTP
+/*	transaction log.  The return value is non-zero for a complete
+/*	line or else zero if the length limit was exceeded.
+/*
+/*	smtpd_chat_query() receives a client request and appends a copy
+/*	to the SMTP transaction log.
+/*
+/*	smtpd_chat_reply() formats a server reply, sends it to the
+/*	client, and appends a copy to the SMTP transaction log.
+/*	When soft_bounce is enabled, all 5xx (reject) responses are
+/*	replaced by 4xx (try again). In case of a 421 reply the
+/*	SMTPD_FLAG_HANGUP flag is set for orderly disconnect.
+/*
+/*	smtpd_chat_notify() sends a copy of the SMTP transaction log
+/*	to the postmaster for review. The postmaster notice is sent only
+/*	when delivery is possible immediately. It is an error to call
+/*	smtpd_chat_notify() when no SMTP transaction log exists.
+/*
+/*	smtpd_chat_reset() resets the transaction log. This is
+/*	typically done at the beginning of an SMTP session, or
+/*	within a session to discard non-error information.
+/* DIAGNOSTICS
+/*	Panic: interface violations. Fatal errors: out of memory.
+/*	internal protocol errors.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <setjmp.h>
+#include <unistd.h>
+#include <time.h>
+#include <stdlib.h>			/* 44BSD stdarg.h uses abort() */
+#include <stdarg.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <argv.h>
+#include <vstring.h>
+#include <vstream.h>
+#include <stringops.h>
+#include <line_wrap.h>
+#include <mymalloc.h>
+
+/* Global library. */
+
+#include <smtp_stream.h>
+#include <record.h>
+#include <rec_type.h>
+#include <mail_proto.h>
+#include <mail_params.h>
+#include <mail_addr.h>
+#include <maps.h>
+#include <post_mail.h>
+#include <mail_error.h>
+#include <smtp_reply_footer.h>
+
+/* Application-specific. */
+
+#include "smtpd.h"
+#include "smtpd_expand.h"
+#include "smtpd_chat.h"
+
+ /*
+  * Reject footer.
+  */
+static MAPS *smtpd_rej_ftr_maps;
+
+#define STR	vstring_str
+#define LEN	VSTRING_LEN
+
+/* smtpd_chat_pre_jail_init - initialize */
+
+void    smtpd_chat_pre_jail_init(void)
+{
+    static int init_count = 0;
+
+    if (init_count++ != 0)
+	msg_panic("smtpd_chat_pre_jail_init: multiple calls");
+
+    /*
+     * SMTP server reject footer.
+     */
+    if (*var_smtpd_rej_ftr_maps)
+	smtpd_rej_ftr_maps = maps_create(VAR_SMTPD_REJ_FTR_MAPS,
+					 var_smtpd_rej_ftr_maps,
+					 DICT_FLAG_LOCK);
+}
+
+/* smtp_chat_reset - reset SMTP transaction log */
+
+void    smtpd_chat_reset(SMTPD_STATE *state)
+{
+    if (state->history) {
+	argv_free(state->history);
+	state->history = 0;
+    }
+}
+
+/* smtp_chat_append - append record to SMTP transaction log */
+
+static void smtp_chat_append(SMTPD_STATE *state, char *direction,
+			             const char *text)
+{
+    char   *line;
+
+    if (state->notify_mask == 0)
+	return;
+
+    if (state->history == 0)
+	state->history = argv_alloc(10);
+    line = concatenate(direction, text, (char *) 0);
+    argv_add(state->history, line, (char *) 0);
+    myfree(line);
+}
+
+/* smtpd_chat_query - receive and record an SMTP request */
+
+int     smtpd_chat_query_limit(SMTPD_STATE *state, int limit)
+{
+    int     last_char;
+
+    /*
+     * We can't parse or store input that exceeds var_line_limit, so we skip
+     * over it to avoid loss of synchronization.
+     */
+    last_char = smtp_get(state->buffer, state->client, limit,
+			 SMTP_GET_FLAG_SKIP);
+    smtp_chat_append(state, "In:  ", STR(state->buffer));
+    if (last_char != '\n')
+	msg_warn("%s: request longer than %d: %.30s...",
+		 state->namaddr, limit,
+		 printable(STR(state->buffer), '?'));
+
+    if (msg_verbose)
+	msg_info("< %s: %s", state->namaddr, STR(state->buffer));
+    return (last_char == '\n');
+}
+
+/* smtpd_chat_reply - format, send and record an SMTP response */
+
+void    smtpd_chat_reply(SMTPD_STATE *state, const char *format,...)
+{
+    va_list ap;
+
+    va_start(ap, format);
+    vsmtpd_chat_reply(state, format, ap);
+    va_end(ap);
+}
+
+/* vsmtpd_chat_reply - format, send and record an SMTP response */
+
+void    vsmtpd_chat_reply(SMTPD_STATE *state, const char *format, va_list ap)
+{
+    int     delay = 0;
+    char   *cp;
+    char   *next;
+    char   *end;
+    const char *footer;
+
+    /*
+     * Slow down clients that make errors. Sleep-on-anything slows down
+     * clients that make an excessive number of errors within a session.
+     */
+    if (state->error_count >= var_smtpd_soft_erlim)
+	sleep(delay = var_smtpd_err_sleep);
+
+    vstring_vsprintf(state->buffer, format, ap);
+
+    if ((*(cp = STR(state->buffer)) == '4' || *cp == '5')
+	&& ((smtpd_rej_ftr_maps != 0
+	     && (footer = maps_find(smtpd_rej_ftr_maps, cp, 0)) != 0)
+	    || *(footer = var_smtpd_rej_footer) != 0))
+	smtp_reply_footer(state->buffer, 0, footer, STR(smtpd_expand_filter),
+			  smtpd_expand_lookup, (void *) state);
+
+    /* All 5xx replies must have a 5.xx.xx detail code. */
+    for (cp = STR(state->buffer), end = cp + strlen(STR(state->buffer));;) {
+	if (var_soft_bounce) {
+	    if (cp[0] == '5') {
+		cp[0] = '4';
+		if (cp[4] == '5')
+		    cp[4] = '4';
+	    }
+	}
+	/* This is why we use strlen() above instead of VSTRING_LEN(). */
+	if ((next = strstr(cp, "\r\n")) != 0) {
+	    *next = 0;
+	    if (next[2] != 0)
+		cp[3] = '-';			/* contact footer kludge */
+	    else
+		next = end;			/* strip trailing \r\n */
+	} else {
+	    next = end;
+	}
+	smtp_chat_append(state, "Out: ", cp);
+
+	if (msg_verbose)
+	    msg_info("> %s: %s", state->namaddr, cp);
+
+	smtp_fputs(cp, next - cp, state->client);
+	if (next < end)
+	    cp = next + 2;
+	else
+	    break;
+    }
+
+    /*
+     * Flush unsent output if no I/O happened for a while. This avoids
+     * timeouts with pipelined SMTP sessions that have lots of server-side
+     * delays (tarpit delays or DNS lookups for UCE restrictions).
+     */
+    if (delay || time((time_t *) 0) - vstream_ftime(state->client) > 10)
+	vstream_fflush(state->client);
+
+    /*
+     * Abort immediately if the connection is broken.
+     */
+    if (vstream_ftimeout(state->client))
+	vstream_longjmp(state->client, SMTP_ERR_TIME);
+    if (vstream_ferror(state->client))
+	vstream_longjmp(state->client, SMTP_ERR_EOF);
+
+    /*
+     * Orderly disconnect in case of 421 or 521 reply.
+     */
+    if (strncmp(STR(state->buffer), "421", 3) == 0
+	|| strncmp(STR(state->buffer), "521", 3) == 0)
+	state->flags |= SMTPD_FLAG_HANGUP;
+}
+
+/* print_line - line_wrap callback */
+
+static void print_line(const char *str, int len, int indent, void *context)
+{
+    VSTREAM *notice = (VSTREAM *) context;
+
+    post_mail_fprintf(notice, " %*s%.*s", indent, "", len, str);
+}
+
+/* smtpd_chat_notify - notify postmaster */
+
+void    smtpd_chat_notify(SMTPD_STATE *state)
+{
+    const char *myname = "smtpd_chat_notify";
+    VSTREAM *notice;
+    char  **cpp;
+
+    /*
+     * Sanity checks.
+     */
+    if (state->history == 0)
+	msg_panic("%s: no conversation history", myname);
+    if (msg_verbose)
+	msg_info("%s: notify postmaster", myname);
+
+    /*
+     * Construct a message for the postmaster, explaining what this is all
+     * about. This is junk mail: don't send it when the mail posting service
+     * is unavailable, and use the double bounce sender address to prevent
+     * mail bounce wars. Always prepend one space to message content that we
+     * generate from untrusted data.
+     */
+#define NULL_TRACE_FLAGS	0
+#define NO_QUEUE_ID		((VSTRING *) 0)
+#define LENGTH	78
+#define INDENT	4
+
+    notice = post_mail_fopen_nowait(mail_addr_double_bounce(),
+				    (state->error_mask & MAIL_ERROR_BOUNCE) ?
+				    var_bounce_rcpt : var_error_rcpt,
+				    MAIL_SRC_MASK_NOTIFY, NULL_TRACE_FLAGS,
+				    SMTPUTF8_FLAG_NONE, NO_QUEUE_ID);
+    if (notice == 0) {
+	msg_warn("postmaster notify: %m");
+	return;
+    }
+    post_mail_fprintf(notice, "From: %s (Mail Delivery System)",
+		      mail_addr_mail_daemon());
+    post_mail_fprintf(notice, "To: %s (Postmaster)", var_error_rcpt);
+    post_mail_fprintf(notice, "Subject: %s SMTP server: errors from %s",
+		      var_mail_name, state->namaddr);
+    post_mail_fputs(notice, "");
+    post_mail_fputs(notice, "Transcript of session follows.");
+    post_mail_fputs(notice, "");
+    argv_terminate(state->history);
+    for (cpp = state->history->argv; *cpp; cpp++)
+	line_wrap(printable(*cpp, '?'), LENGTH, INDENT, print_line,
+		  (void *) notice);
+    post_mail_fputs(notice, "");
+    if (state->reason)
+	post_mail_fprintf(notice, "Session aborted, reason: %s", state->reason);
+    post_mail_fputs(notice, "");
+    post_mail_fprintf(notice, "For other details, see the local mail logfile");
+    (void) post_mail_fclose(notice);
+}