1 files changed, 317 insertions, 0 deletions

diff --git a/src/postscreen/postscreen_state.c b/src/postscreen/postscreen_state.c
new file mode 100644
index 0000000..5f610e6
--- /dev/null
+++ b/src/postscreen/postscreen_state.c
@@ -0,0 +1,317 @@
+/*++
+/* NAME
+/*	postscreen_state 3
+/* SUMMARY
+/*	postscreen session state and queue length management
+/* SYNOPSIS
+/*	#include <postscreen.h>
+/*
+/*	PSC_STATE *psc_new_session_state(stream, client_addr, client_port,
+/*						server_addr, server_port)
+/*	VSTREAM *stream;
+/*	const char *client_addr;
+/*	const char *client_port;
+/*	const char *server_addr;
+/*	const char *server_port;
+/*
+/*	void	psc_free_session_state(state)
+/*	PSC_STATE *state;
+/*
+/*	char	*psc_print_state_flags(flags, context)
+/*	int	flags;
+/*	const char *context;
+/*
+/*	void	PSC_ADD_SERVER_STATE(state, server_fd)
+/*	PSC_STATE *state;
+/*	int	server_fd;
+/*
+/*	void	PSC_DEL_SERVER_STATE(state)
+/*	PSC_STATE *state;
+/*
+/*	void	PSC_DEL_CLIENT_STATE(state)
+/*	PSC_STATE *state;
+/*
+/*	void	PSC_DROP_SESSION_STATE(state, final_reply)
+/*	PSC_STATE *state;
+/*	const char *final_reply;
+/*
+/*	void	PSC_ENFORCE_SESSION_STATE(state, rcpt_reply)
+/*	PSC_STATE *state;
+/*	const char *rcpt_reply;
+/*
+/*	void	PSC_PASS_SESSION_STATE(state, testname, pass_flag)
+/*	PSC_STATE *state;
+/*	const char *testname;
+/*	int	pass_flag;
+/*
+/*	void	PSC_FAIL_SESSION_STATE(state, fail_flag)
+/*	PSC_STATE *state;
+/*	int	fail_flag;
+/*
+/*	void	PSC_UNFAIL_SESSION_STATE(state, fail_flag)
+/*	PSC_STATE *state;
+/*	int	fail_flag;
+/* DESCRIPTION
+/*	This module maintains per-client session state, and two
+/*	global file descriptor counters:
+/* .IP psc_check_queue_length
+/*	The total number of remote SMTP client sockets.
+/* .IP psc_post_queue_length
+/*	The total number of server file descriptors that are currently
+/*	in use for client file descriptor passing. This number
+/*	equals the number of client file descriptors in transit.
+/* .PP
+/*	psc_new_session_state() creates a new session state object
+/*	for the specified client stream, and increments the
+/*	psc_check_queue_length counter.  The flags and per-test time
+/*	stamps are initialized with PSC_INIT_TESTS(), or for concurrent
+/*	sessions, with PSC_INIT_TEST_FLAGS_ONLY().  The addr and
+/*	port arguments are null-terminated strings with the remote
+/*	SMTP client endpoint. The _reply members are set to
+/*	polite "try again" SMTP replies. The protocol member is set
+/*	to "SMTP".
+/*
+/*	The psc_stress variable is set to non-zero when
+/*	psc_check_queue_length passes over a high-water mark.
+/*
+/*	psc_free_session_state() destroys the specified session state
+/*	object, closes the applicable I/O channels, and decrements
+/*	the applicable file descriptor counters: psc_check_queue_length
+/*	and psc_post_queue_length.
+/*
+/*	The psc_stress variable is reset to zero when psc_check_queue_length
+/*	passes under a low-water mark.
+/*
+/*	psc_print_state_flags() converts per-session flags into
+/*	human-readable form. The context is for error reporting.
+/*	The result is overwritten upon each call.
+/*
+/*	PSC_ADD_SERVER_STATE() updates the specified session state
+/*	object with the specified server file descriptor, and
+/*	increments the global psc_post_queue_length file descriptor
+/*	counter.
+/*
+/*	PSC_DEL_SERVER_STATE() closes the specified session state
+/*	object's server file descriptor, and decrements the global
+/*	psc_post_queue_length file descriptor counter.
+/*
+/*	PSC_DEL_CLIENT_STATE() updates the specified session state
+/*	object, closes the client stream, and decrements the global
+/*	psc_check_queue_length file descriptor counter.
+/*
+/*	PSC_DROP_SESSION_STATE() updates the specified session state
+/*	object and closes the client stream after sending the
+/*	specified SMTP reply.
+/*
+/*	PSC_ENFORCE_SESSION_STATE() updates the specified session
+/*	state object. It arranges that the built-in SMTP engine
+/*	logs sender/recipient information and rejects all RCPT TO
+/*	commands with the specified SMTP reply.
+/*
+/*	PSC_PASS_SESSION_STATE() sets the specified "pass" flag.
+/*	The testname is used for debug logging.
+/*
+/*	PSC_FAIL_SESSION_STATE() sets the specified "fail" flag.
+/*
+/*	PSC_UNFAIL_SESSION_STATE() unsets the specified "fail" flag.
+/* 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>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <name_mask.h>
+#include <htable.h>
+
+/* Global library. */
+
+#include <mail_proto.h>
+
+/* Master server protocols. */
+
+#include <mail_server.h>
+
+/* Application-specific. */
+
+#include <postscreen.h>
+
+/* psc_new_session_state - fill in connection state for event processing */
+
+PSC_STATE *psc_new_session_state(VSTREAM *stream,
+				         const char *client_addr,
+				         const char *client_port,
+				         const char *server_addr,
+				         const char *server_port)
+{
+    PSC_STATE *state;
+
+    state = (PSC_STATE *) mymalloc(sizeof(*state));
+    if ((state->smtp_client_stream = stream) != 0)
+	psc_check_queue_length++;
+    state->smtp_server_fd = (-1);
+    state->smtp_client_addr = mystrdup(client_addr);
+    state->smtp_client_port = mystrdup(client_port);
+    state->smtp_server_addr = mystrdup(server_addr);
+    state->smtp_server_port = mystrdup(server_port);
+    state->send_buf = vstring_alloc(100);
+    state->test_name = "TEST NAME HERE";
+    state->dnsbl_reply = 0;
+    state->final_reply = "421 4.3.2 Service currently unavailable\r\n";
+    state->rcpt_reply = "450 4.3.2 Service currently unavailable\r\n";
+    state->command_count = 0;
+    state->protocol = MAIL_PROTO_SMTP;
+    state->helo_name = 0;
+    state->sender = 0;
+    state->cmd_buffer = 0;
+    state->read_state = 0;
+    state->ehlo_discard_mask = 0;		/* XXX Should be ~0 */
+    state->expand_buf = 0;
+    state->where = PSC_SMTPD_CMD_CONNECT;
+
+    /*
+     * Update the stress level.
+     */
+    if (psc_stress == 0
+	&& psc_check_queue_length >= psc_hiwat_check_queue_length) {
+	psc_stress = 1;
+	msg_info("entering STRESS mode with %d connections",
+		 psc_check_queue_length);
+    }
+
+    /*
+     * Update the per-client session count.
+     */
+    if ((state->client_info = (PSC_CLIENT_INFO *)
+	 htable_find(psc_client_concurrency, client_addr)) == 0) {
+	state->client_info = (PSC_CLIENT_INFO *)
+	    mymalloc(sizeof(state->client_info[0]));
+	(void) htable_enter(psc_client_concurrency, client_addr,
+			    (void *) state->client_info);
+	PSC_INIT_TESTS(state);
+	state->client_info->concurrency = 1;
+	state->client_info->pass_new_count = 0;
+    } else {
+	PSC_INIT_TEST_FLAGS_ONLY(state);
+	state->client_info->concurrency += 1;
+    }
+
+    return (state);
+}
+
+/* psc_free_session_state - destroy connection state including connections */
+
+void    psc_free_session_state(PSC_STATE *state)
+{
+    const char *myname = "psc_free_session_state";
+    HTABLE_INFO *ht;
+
+    /*
+     * Update the per-client session count.
+     */
+    if ((ht = htable_locate(psc_client_concurrency,
+			    state->smtp_client_addr)) == 0)
+	msg_panic("%s: unknown client address: %s",
+		  myname, state->smtp_client_addr);
+    if (--(state->client_info->concurrency) == 0)
+	htable_delete(psc_client_concurrency, state->smtp_client_addr, myfree);
+
+    if (state->smtp_client_stream != 0) {
+	PSC_DEL_CLIENT_STATE(state);
+    }
+    if (state->smtp_server_fd >= 0) {
+	PSC_DEL_SERVER_STATE(state);
+    }
+    if (state->send_buf != 0)
+	state->send_buf = vstring_free(state->send_buf);
+    myfree(state->smtp_client_addr);
+    myfree(state->smtp_client_port);
+    myfree(state->smtp_server_addr);
+    myfree(state->smtp_server_port);
+    if (state->dnsbl_reply)
+	vstring_free(state->dnsbl_reply);
+    if (state->helo_name)
+	myfree(state->helo_name);
+    if (state->sender)
+	myfree(state->sender);
+    if (state->cmd_buffer)
+	vstring_free(state->cmd_buffer);
+    if (state->expand_buf)
+	vstring_free(state->expand_buf);
+    myfree((void *) state);
+
+    if (psc_check_queue_length < 0 || psc_post_queue_length < 0)
+	msg_panic("bad queue length: check_queue=%d, post_queue=%d",
+		  psc_check_queue_length, psc_post_queue_length);
+
+    /*
+     * Update the stress level.
+     */
+    if (psc_stress != 0
+	&& psc_check_queue_length <= psc_lowat_check_queue_length) {
+	psc_stress = 0;
+	msg_info("leaving STRESS mode with %d connections",
+		 psc_check_queue_length);
+    }
+}
+
+/* psc_print_state_flags - format state flags */
+
+const char *psc_print_state_flags(int flags, const char *context)
+{
+    static const NAME_MASK flags_mask[] = {
+	"NOFORWARD", PSC_STATE_FLAG_NOFORWARD,
+	"USING_TLS", PSC_STATE_FLAG_USING_TLS,
+	"NEW", PSC_STATE_FLAG_NEW,
+	"BLIST_FAIL", PSC_STATE_FLAG_BLIST_FAIL,
+	"HANGUP", PSC_STATE_FLAG_HANGUP,
+	/* unused */
+	"WLIST_FAIL", PSC_STATE_FLAG_WLIST_FAIL,
+
+	"PREGR_FAIL", PSC_STATE_FLAG_PREGR_FAIL,
+	"PREGR_PASS", PSC_STATE_FLAG_PREGR_PASS,
+	"PREGR_TODO", PSC_STATE_FLAG_PREGR_TODO,
+	"PREGR_DONE", PSC_STATE_FLAG_PREGR_DONE,
+
+	"DNSBL_FAIL", PSC_STATE_FLAG_DNSBL_FAIL,
+	"DNSBL_PASS", PSC_STATE_FLAG_DNSBL_PASS,
+	"DNSBL_TODO", PSC_STATE_FLAG_DNSBL_TODO,
+	"DNSBL_DONE", PSC_STATE_FLAG_DNSBL_DONE,
+
+	"PIPEL_FAIL", PSC_STATE_FLAG_PIPEL_FAIL,
+	"PIPEL_PASS", PSC_STATE_FLAG_PIPEL_PASS,
+	"PIPEL_TODO", PSC_STATE_FLAG_PIPEL_TODO,
+	"PIPEL_SKIP", PSC_STATE_FLAG_PIPEL_SKIP,
+
+	"NSMTP_FAIL", PSC_STATE_FLAG_NSMTP_FAIL,
+	"NSMTP_PASS", PSC_STATE_FLAG_NSMTP_PASS,
+	"NSMTP_TODO", PSC_STATE_FLAG_NSMTP_TODO,
+	"NSMTP_SKIP", PSC_STATE_FLAG_NSMTP_SKIP,
+
+	"BARLF_FAIL", PSC_STATE_FLAG_BARLF_FAIL,
+	"BARLF_PASS", PSC_STATE_FLAG_BARLF_PASS,
+	"BARLF_TODO", PSC_STATE_FLAG_BARLF_TODO,
+	"BARLF_SKIP", PSC_STATE_FLAG_BARLF_SKIP,
+	0,
+    };
+
+    return (str_name_mask_opt((VSTRING *) 0, context, flags_mask, flags,
+			      NAME_MASK_PIPE | NAME_MASK_NUMBER));
+}