Adding upstream version 3.7.10.upstream/3.7.10

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

1 files changed, 319 insertions, 0 deletions

diff --git a/src/dnsblog/dnsblog.c b/src/dnsblog/dnsblog.c
new file mode 100644
index 0000000..bc87c4b
--- /dev/null
+++ b/src/dnsblog/dnsblog.c
@@ -0,0 +1,319 @@
+/*++
+/* NAME
+/*	dnsblog 8
+/* SUMMARY
+/*	Postfix DNS allow/denylist logger
+/* SYNOPSIS
+/*	\fBdnsblog\fR [generic Postfix daemon options]
+/* DESCRIPTION
+/*	The \fBdnsblog\fR(8) server implements an ad-hoc DNS
+/*	allow/denylist lookup service. This may eventually be
+/*	replaced by an UDP client that is built directly into the
+/*	\fBpostscreen\fR(8) server.
+/* PROTOCOL
+/* .ad
+/* .fi
+/*	With each connection, the \fBdnsblog\fR(8) server receives
+/*	a DNS allow/denylist domain name, an IP address, and an ID.
+/*	If the IP address is listed under the DNS allow/denylist, the
+/*	\fBdnsblog\fR(8) server logs the match and replies with the
+/*	query arguments plus an address list with the resulting IP
+/*	addresses, separated by whitespace, and the reply TTL.
+/*	Otherwise it replies with the query arguments plus an empty
+/*	address list and the reply TTL; the reply TTL is -1 if there
+/*	is no reply, or a negative reply that contains no SOA record.
+/*	Finally, the \fBdnsblog\fR(8) server closes the connection.
+/* DIAGNOSTICS
+/*	Problems and transactions are logged to \fBsyslogd\fR(8)
+/*	or \fBpostlogd\fR(8).
+/* CONFIGURATION PARAMETERS
+/* .ad
+/* .fi
+/*	Changes to \fBmain.cf\fR are picked up automatically, as
+/*	\fBdnsblog\fR(8) processes run for only a limited amount
+/*	of time. Use the command "\fBpostfix reload\fR" to speed
+/*	up a change.
+/*
+/*	The text below provides only a parameter summary. See
+/*	\fBpostconf\fR(5) for more details including examples.
+/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
+/*	The default location of the Postfix main.cf and master.cf
+/*	configuration files.
+/* .IP "\fBdaemon_timeout (18000s)\fR"
+/*	How much time a Postfix daemon process may take to handle a
+/*	request before it is terminated by a built-in watchdog timer.
+/* .IP "\fBpostscreen_dnsbl_sites (empty)\fR"
+/*	Optional list of DNS allow/denylist domains, filters and weight
+/*	factors.
+/* .IP "\fBipc_timeout (3600s)\fR"
+/*	The time limit for sending or receiving information over an internal
+/*	communication channel.
+/* .IP "\fBprocess_id (read-only)\fR"
+/*	The process ID of a Postfix command or daemon process.
+/* .IP "\fBprocess_name (read-only)\fR"
+/*	The process name of a Postfix command or daemon process.
+/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR"
+/*	The location of the Postfix top-level queue directory.
+/* .IP "\fBsyslog_facility (mail)\fR"
+/*	The syslog facility of Postfix logging.
+/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
+/*	A prefix that is prepended to the process name in syslog
+/*	records, so that, for example, "smtpd" becomes "prefix/smtpd".
+/* .PP
+/*	Available in Postfix 3.3 and later:
+/* .IP "\fBservice_name (read-only)\fR"
+/*	The master.cf service name of a Postfix daemon process.
+/* SEE ALSO
+/*	smtpd(8), Postfix SMTP server
+/*	postconf(5), configuration parameters
+/*	postlogd(8), Postfix logging
+/*	syslogd(8), system logging
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* HISTORY
+/* .ad
+/* .fi
+/*	This service was introduced with Postfix version 2.8.
+/* 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 <limits.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <vstream.h>
+#include <vstring.h>
+#include <argv.h>
+#include <myaddrinfo.h>
+#include <valid_hostname.h>
+#include <sock_addr.h>
+
+/* Global library. */
+
+#include <mail_conf.h>
+#include <mail_version.h>
+#include <mail_proto.h>
+#include <mail_params.h>
+
+/* DNS library. */
+
+#include <dns.h>
+
+/* Server skeleton. */
+
+#include <mail_server.h>
+
+/* Application-specific. */
+
+ /*
+  * Tunable parameters.
+  */
+int     var_dnsblog_delay;
+
+ /*
+  * Static so we don't allocate and free on every request.
+  */
+static VSTRING *rbl_domain;
+static VSTRING *addr;
+static VSTRING *query;
+static VSTRING *why;
+static VSTRING *result;
+
+ /*
+  * Silly little macros.
+  */
+#define STR(x)			vstring_str(x)
+#define LEN(x)			VSTRING_LEN(x)
+
+/* static void dnsblog_query - query DNSBL for client address */
+
+static VSTRING *dnsblog_query(VSTRING *result, int *result_ttl,
+			              const char *dnsbl_domain,
+			              const char *addr)
+{
+    const char *myname = "dnsblog_query";
+    ARGV   *octets;
+    int     i;
+    struct addrinfo *res;
+    unsigned char *ipv6_addr;
+    int     dns_status;
+    DNS_RR *addr_list;
+    DNS_RR *rr;
+    MAI_HOSTADDR_STR hostaddr;
+
+    if (msg_verbose)
+	msg_info("%s: addr %s dnsbl_domain %s",
+		 myname, addr, dnsbl_domain);
+
+    VSTRING_RESET(query);
+
+    /*
+     * Reverse the client IPV6 address, represented as 32 hexadecimal
+     * nibbles. We use the binary address to avoid tricky code. Asking for an
+     * AAAA record makes no sense here. Just like with IPv4 we use the lookup
+     * result as a bit mask, not as an IP address.
+     */
+#ifdef HAS_IPV6
+    if (valid_ipv6_hostaddr(addr, DONT_GRIPE)) {
+	if (hostaddr_to_sockaddr(addr, (char *) 0, 0, &res) != 0
+	    || res->ai_family != PF_INET6)
+	    msg_fatal("%s: unable to convert address %s", myname, addr);
+	ipv6_addr = (unsigned char *) &SOCK_ADDR_IN6_ADDR(res->ai_addr);
+	for (i = sizeof(SOCK_ADDR_IN6_ADDR(res->ai_addr)) - 1; i >= 0; i--)
+	    vstring_sprintf_append(query, "%x.%x.",
+				   ipv6_addr[i] & 0xf, ipv6_addr[i] >> 4);
+	freeaddrinfo(res);
+    } else
+#endif
+
+	/*
+	 * Reverse the client IPV4 address, represented as four decimal octet
+	 * values. We use the textual address for convenience.
+	 */
+    {
+	octets = argv_split(addr, ".");
+	for (i = octets->argc - 1; i >= 0; i--) {
+	    vstring_strcat(query, octets->argv[i]);
+	    vstring_strcat(query, ".");
+	}
+	argv_free(octets);
+    }
+
+    /*
+     * Tack on the RBL domain name and query the DNS for an A record.
+     */
+    vstring_strcat(query, dnsbl_domain);
+    dns_status = dns_lookup_x(STR(query), T_A, 0, &addr_list, (VSTRING *) 0,
+			      why, (int *) 0, DNS_REQ_FLAG_NCACHE_TTL);
+
+    /*
+     * We return the lowest TTL in the response from the A record(s) if
+     * found, or from the SOA record(s) if available. If the reply specifies
+     * no TTL, or if the query fails, we return a TTL of -1.
+     */
+    VSTRING_RESET(result);
+    *result_ttl = -1;
+    if (dns_status == DNS_OK) {
+	for (rr = addr_list; rr != 0; rr = rr->next) {
+	    if (dns_rr_to_pa(rr, &hostaddr) == 0) {
+		msg_warn("%s: skipping reply record type %s for query %s: %m",
+			 myname, dns_strtype(rr->type), STR(query));
+	    } else {
+		msg_info("addr %s listed by domain %s as %s",
+			 addr, dnsbl_domain, hostaddr.buf);
+		if (LEN(result) > 0)
+		    vstring_strcat(result, " ");
+		vstring_strcat(result, hostaddr.buf);
+		/* Grab the positive reply TTL. */
+		if (*result_ttl < 0 || *result_ttl > rr->ttl)
+		    *result_ttl = rr->ttl;
+	    }
+	}
+	dns_rr_free(addr_list);
+    } else if (dns_status == DNS_NOTFOUND) {
+	if (msg_verbose)
+	    msg_info("%s: addr %s not listed by domain %s",
+		     myname, addr, dnsbl_domain);
+	/* Grab the negative reply TTL. */
+	for (rr = addr_list; rr != 0; rr = rr->next) {
+	    if (rr->type == T_SOA && (*result_ttl < 0 || *result_ttl > rr->ttl))
+		*result_ttl = rr->ttl;
+	}
+	dns_rr_free(addr_list);
+    } else {
+	msg_warn("%s: lookup error for DNS query %s: %s",
+		 myname, STR(query), STR(why));
+    }
+    VSTRING_TERMINATE(result);
+    return (result);
+}
+
+/* dnsblog_service - perform service for client */
+
+static void dnsblog_service(VSTREAM *client_stream, char *unused_service,
+			            char **argv)
+{
+    int     request_id;
+    int     result_ttl;
+
+    /*
+     * Sanity check. This service takes no command-line arguments.
+     */
+    if (argv[0])
+	msg_fatal("unexpected command-line argument: %s", argv[0]);
+
+    /*
+     * This routine runs whenever a client connects to the socket dedicated
+     * to the dnsblog service. All connection-management stuff is handled by
+     * the common code in single_server.c.
+     */
+    if (attr_scan(client_stream,
+		  ATTR_FLAG_MORE | ATTR_FLAG_STRICT,
+		  RECV_ATTR_STR(MAIL_ATTR_RBL_DOMAIN, rbl_domain),
+		  RECV_ATTR_STR(MAIL_ATTR_ACT_CLIENT_ADDR, addr),
+		  RECV_ATTR_INT(MAIL_ATTR_LABEL, &request_id),
+		  ATTR_TYPE_END) == 3) {
+	(void) dnsblog_query(result, &result_ttl, STR(rbl_domain), STR(addr));
+	if (var_dnsblog_delay > 0)
+	    sleep(var_dnsblog_delay);
+	attr_print(client_stream, ATTR_FLAG_NONE,
+		   SEND_ATTR_STR(MAIL_ATTR_RBL_DOMAIN, STR(rbl_domain)),
+		   SEND_ATTR_STR(MAIL_ATTR_ACT_CLIENT_ADDR, STR(addr)),
+		   SEND_ATTR_INT(MAIL_ATTR_LABEL, request_id),
+		   SEND_ATTR_STR(MAIL_ATTR_RBL_ADDR, STR(result)),
+		   SEND_ATTR_INT(MAIL_ATTR_TTL, result_ttl),
+		   ATTR_TYPE_END);
+	vstream_fflush(client_stream);
+    }
+}
+
+/* post_jail_init - post-jail initialization */
+
+static void post_jail_init(char *unused_name, char **unused_argv)
+{
+    rbl_domain = vstring_alloc(100);
+    addr = vstring_alloc(100);
+    query = vstring_alloc(100);
+    why = vstring_alloc(100);
+    result = vstring_alloc(100);
+    var_use_limit = 0;
+}
+
+MAIL_VERSION_STAMP_DECLARE;
+
+/* main - pass control to the multi-threaded skeleton */
+
+int     main(int argc, char **argv)
+{
+    static const CONFIG_TIME_TABLE time_table[] = {
+	VAR_DNSBLOG_DELAY, DEF_DNSBLOG_DELAY, &var_dnsblog_delay, 0, 0,
+	0,
+    };
+
+    /*
+     * Fingerprint executables and core dumps.
+     */
+    MAIL_VERSION_STAMP_ALLOCATE;
+
+    single_server_main(argc, argv, dnsblog_service,
+		       CA_MAIL_SERVER_TIME_TABLE(time_table),
+		       CA_MAIL_SERVER_POST_INIT(post_jail_init),
+		       CA_MAIL_SERVER_UNLIMITED,
+		       CA_MAIL_SERVER_RETIRE_ME,
+		       0);
+}