[dovecot-cvs] dovecot/src/imap-login .cvsignore,NONE,1.1 Makefile.am,NONE,1.1 client-authenticate.c,NONE,1.1 client-authenticate.h,NONE,1.1 client.c,NONE,1.1 client.h,NONE,1.1 common.h,NONE,1.1

[cras at procontrol.fi]

Update of /home/cvs/dovecot/src/imap-login
In directory danu:/tmp/cvs-serv28480/src/imap-login

Added Files:
	.cvsignore Makefile.am client-authenticate.c 
	client-authenticate.h client.c client.h common.h 
Log Message:
Moved common login process code to login-common, created pop3-login.



--- NEW FILE: .cvsignore ---
*.la
*.lo
*.o
.deps
.libs
Makefile
Makefile.in
so_locations
imap-login

--- NEW FILE: Makefile.am ---
pkglibexecdir = $(libexecdir)/dovecot

pkglibexec_PROGRAMS = imap-login

INCLUDES = \
	-I$(top_srcdir)/src/lib \
	-I$(top_srcdir)/src/lib-imap \
	-I$(top_srcdir)/src/login-common

imap_login_LDADD = \
	../login-common/liblogin-common.a \
	../lib-imap/imap-parser.o \
	../lib/liblib.a \
	$(SSL_LIBS)

imap_login_SOURCES = \
	client.c \
	client-authenticate.c

noinst_HEADERS = \
	common.h \
	client.h

--- NEW FILE: client-authenticate.c ---
/* Copyright (C) 2002 Timo Sirainen */

#include "common.h"
#include "base64.h"
#include "buffer.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "safe-memset.h"
#include "str.h"
#include "imap-parser.h"
#include "auth-connection.h"
#include "../auth/auth-mech-desc.h"
#include "client.h"
#include "client-authenticate.h"
#include "master.h"

static enum auth_mech auth_mechs = 0;
static char *auth_mechs_capability = NULL;

const char *client_authenticate_get_capabilities(void)
{
	string_t *str;
	int i;

	if (auth_mechs == available_auth_mechs)
		return auth_mechs_capability;

	auth_mechs = available_auth_mechs;
	i_free(auth_mechs_capability);

	str = t_str_new(128);

	for (i = 0; i < AUTH_MECH_COUNT; i++) {
		if ((auth_mechs & auth_mech_desc[i].mech) &&
		    auth_mech_desc[i].name != NULL) {
			str_append_c(str, ' ');
			str_append(str, "AUTH=");
			str_append(str, auth_mech_desc[i].name);
		}
	}

	auth_mechs_capability = i_strdup_empty(str_c(str));
	return auth_mechs_capability;
}

static struct auth_mech_desc *auth_mech_find(const char *name)
{
	int i;

	for (i = 0; i < AUTH_MECH_COUNT; i++) {
		if (auth_mech_desc[i].name != NULL &&
		    strcasecmp(auth_mech_desc[i].name, name) == 0)
			return &auth_mech_desc[i];
	}

	return NULL;
}

static void client_auth_abort(struct imap_client *client, const char *msg)
{
	if (client->auth_request != NULL) {
		auth_abort_request(client->auth_request);
		client->auth_request = NULL;
	}

	client_send_tagline(client, msg != NULL ? msg :
			    "NO Authentication failed.");
	o_stream_flush(client->output);

	/* get back to normal client input */
	if (client->io != NULL)
		io_remove(client->io);
	client->io = client->common.fd == -1 ? NULL :
		io_add(client->common.fd, IO_READ, client_input, client);

	client_unref(client);
}

static void master_callback(struct client *_client, int success)
{
	struct imap_client *client = (struct imap_client *) _client;
	const char *reason = NULL;

	if (success)
		reason = t_strconcat("Login: ", client->virtual_user, NULL);
	else {
		reason = t_strconcat("Internal login failure: ",
				     client->virtual_user, NULL);
		client_send_line(client, "* BYE Internal login failure.");
	}

	client_destroy(client, reason);
	client_unref(client);
}

static void client_send_auth_data(struct imap_client *client,
				  const unsigned char *data, size_t size)
{
	buffer_t *buf;

	t_push();

	buf = buffer_create_dynamic(data_stack_pool, size*2, (size_t)-1);
	buffer_append(buf, "+ ", 2);
	base64_encode(data, size, buf);
	buffer_append(buf, "\r\n", 2);

	o_stream_send(client->output, buffer_get_data(buf, NULL),
		      buffer_get_used_size(buf));
	o_stream_flush(client->output);

	t_pop();
}

static const char *auth_login_get_str(struct auth_login_reply *reply,
				      const unsigned char *data, size_t idx)
{
	size_t stop;

	if (idx >= reply->data_size || idx >= reply->reply_idx)
		return NULL;

	stop = reply->reply_idx < reply->data_size ?
		reply->reply_idx-1 : reply->data_size;

	return t_strndup(data, stop);
}

static int auth_callback(struct auth_request *request,
			 struct auth_login_reply *reply,
			 const unsigned char *data, void *context)
{
	struct imap_client *client = context;
	const char *user, *realm;

	if (reply == NULL) {
		/* failed */
		client->auth_request = NULL;
		client_auth_abort(client, "NO Authentication process died.");
		return FALSE;
	}

	switch (reply->result) {
	case AUTH_LOGIN_RESULT_CONTINUE:
		client->auth_request = request;
		return TRUE;

	case AUTH_LOGIN_RESULT_SUCCESS:
		client->auth_request = NULL;

		user = auth_login_get_str(reply, data, reply->username_idx);
		realm = auth_login_get_str(reply, data, reply->realm_idx);

		i_free(client->virtual_user);
		client->virtual_user = realm == NULL ?
			i_strdup(user) : i_strconcat(user, "@", realm, NULL);

		/* we should be able to log in. if we fail, just
		   disconnect the client. */
		client_send_tagline(client, "OK Logged in.");

		master_request_imap(&client->common, master_callback,
				    request->conn->pid, request->id);

		/* disable IO until we're back from master */
		if (client->io != NULL) {
			io_remove(client->io);
			client->io = NULL;
		}
		return FALSE;

	case AUTH_LOGIN_RESULT_FAILURE:
		/* see if we have error message */
		client->auth_request = NULL;

		if (reply->data_size > 0 && data[reply->data_size-1] == '\0') {
			client_auth_abort(client, t_strconcat(
				"NO Authentication failed: ",
				(const char *) data, NULL));
		} else {
			/* default error message */
			client_auth_abort(client, NULL);
		}
		return FALSE;
	}

	i_unreached();
}

static void login_callback(struct auth_request *request,
			   struct auth_login_reply *reply,
			   const unsigned char *data, struct client *_client)
{
	struct imap_client *client = (struct imap_client *) _client;
	const void *ptr;
	size_t size;

	if (auth_callback(request, reply, data, client)) {
		ptr = buffer_get_data(client->plain_login, &size);
		auth_continue_request(request, ptr, size);

		buffer_set_used_size(client->plain_login, 0);
	}
}

int cmd_login(struct imap_client *client, struct imap_arg *args)
{
	const char *user, *pass, *error;

	/* two arguments: username and password */
	if (args[0].type != IMAP_ARG_ATOM && args[0].type != IMAP_ARG_STRING)
		return FALSE;
	if (args[1].type != IMAP_ARG_ATOM && args[1].type != IMAP_ARG_STRING)
		return FALSE;
	if (args[2].type != IMAP_ARG_EOL)
		return FALSE;

	user = IMAP_ARG_STR(&args[0]);
	pass = IMAP_ARG_STR(&args[1]);

	if (!client->tls && disable_plaintext_auth) {
		client_send_tagline(client,
				    "NO Plaintext authentication disabled.");
		return TRUE;
	}

	/* authorization ID \0 authentication ID \0 pass */
	buffer_set_used_size(client->plain_login, 0);
	buffer_append_c(client->plain_login, '\0');
	buffer_append(client->plain_login, user, strlen(user));
	buffer_append_c(client->plain_login, '\0');
	buffer_append(client->plain_login, pass, strlen(pass));

	client_ref(client);
	if (auth_init_request(AUTH_MECH_PLAIN, login_callback,
			      &client->common, &error)) {
		/* don't read any input from client until login is finished */
		if (client->io != NULL) {
			io_remove(client->io);
			client->io = NULL;
		}
		return TRUE;
	} else {
		client_send_tagline(client, t_strconcat(
			"NO Login failed: ", error, NULL));
		client_unref(client);
		return TRUE;
	}
}

static void authenticate_callback(struct auth_request *request,
				  struct auth_login_reply *reply,
				  const unsigned char *data,
				  struct client *_client)
{
	struct imap_client *client = (struct imap_client *) _client;

	if (auth_callback(request, reply, data, client))
		client_send_auth_data(client, data, reply->data_size);
}

static void client_auth_input(void *context)
{
	struct imap_client *client = context;
	buffer_t *buf;
	char *line;
	size_t linelen, bufsize;

	if (!client_read(client))
		return;

	if (client->skip_line) {
		if (i_stream_next_line(client->input) == NULL)
			return;

		client->skip_line = FALSE;
	}

	/* @UNSAFE */
	line = i_stream_next_line(client->input);
	if (line == NULL)
		return;

	if (strcmp(line, "*") == 0) {
		client_auth_abort(client, "NO Authentication aborted");
		return;
	}

	linelen = strlen(line);
	buf = buffer_create_static_hard(data_stack_pool, linelen);

	if (base64_decode((const unsigned char *) line, linelen,
			  NULL, buf) <= 0) {
		/* failed */
		client_auth_abort(client, "NO Invalid base64 data");
	} else if (client->auth_request == NULL) {
		client_auth_abort(client, "NO Don't send unrequested data");
	} else {
		auth_continue_request(client->auth_request,
				      buffer_get_data(buf, NULL),
				      buffer_get_used_size(buf));
	}

	/* clear sensitive data */
	safe_memset(line, 0, linelen);

	bufsize = buffer_get_used_size(buf);
	safe_memset(buffer_free_without_data(buf), 0, bufsize);
}

int cmd_authenticate(struct imap_client *client, struct imap_arg *args)
{
	struct auth_mech_desc *mech;
	const char *mech_name, *error;

	/* we want only one argument: authentication mechanism name */
	if (args[0].type != IMAP_ARG_ATOM && args[0].type != IMAP_ARG_STRING)
		return FALSE;
	if (args[1].type != IMAP_ARG_EOL)
		return FALSE;

	mech_name = IMAP_ARG_STR(&args[0]);
	if (*mech_name == '\0')
		return FALSE;

	mech = auth_mech_find(mech_name);
	if (mech == NULL) {
		client_send_tagline(client,
				    "NO Unsupported authentication mechanism.");
		return TRUE;
	}

	if (!client->tls && mech->plaintext && disable_plaintext_auth) {
		client_send_tagline(client,
				    "NO Plaintext authentication disabled.");
		return TRUE;
	}

	client_ref(client);
	if (auth_init_request(mech->mech, authenticate_callback,
			      &client->common, &error)) {
		/* following input data will go to authentication */
		if (client->io != NULL)
			io_remove(client->io);
		client->io = io_add(client->common.fd, IO_READ,
				    client_auth_input, client);
	} else {
		client_send_tagline(client, t_strconcat(
			"NO Authentication failed: ", error, NULL));
		client_unref(client);
	}

	return TRUE;
}

--- NEW FILE: client-authenticate.h ---
#ifndef __CLIENT_AUTHENTICATE_H
#define __CLIENT_AUTHENTICATE_H

const char *client_authenticate_get_capabilities(void);

int cmd_login(struct imap_client *client, struct imap_arg *args);
int cmd_authenticate(struct imap_client *client, struct imap_arg *args);

#endif

--- NEW FILE: client.c ---
/* Copyright (C) 2002 Timo Sirainen */

#include "common.h"
#include "buffer.h"
#include "hash.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "process-title.h"
#include "safe-memset.h"
#include "strescape.h"
#include "imap-parser.h"
#include "client.h"
#include "client-authenticate.h"
#include "ssl-proxy.h"

/* max. size of one parameter in line */
#define MAX_INBUF_SIZE 512

/* max. number of IMAP argument elements to accept. The maximum memory usage
   for command from user is around MAX_INBUF_SIZE * MAX_IMAP_ARG_ELEMENTS */
#define MAX_IMAP_ARG_ELEMENTS 4

/* Disconnect client after idling this many seconds */
#define CLIENT_LOGIN_IDLE_TIMEOUT 60

/* Disconnect client when it sends too many bad commands */
#define CLIENT_MAX_BAD_COMMANDS 10

/* When max. number of simultaneous connections is reached, few of the
   oldest connections are disconnected. Since we have to go through the whole
   client hash, it's faster if we disconnect multiple clients. */
#define CLIENT_DESTROY_OLDEST_COUNT 16

static struct hash_table *clients;
static struct timeout *to_idle;

static void client_set_title(struct imap_client *client)
{
	const char *host;

	if (!verbose_proctitle || !process_per_connection)
		return;

	host = net_ip2host(&client->common.ip);
	if (host == NULL)
		host = "??";

	process_title_set(t_strdup_printf(client->tls ? "[%s TLS]" : "[%s]",
					  host));
}

static int cmd_capability(struct imap_client *client)
{
	const char *capability;

	capability = t_strconcat("* CAPABILITY " CAPABILITY_STRING,
				 ssl_initialized ? " STARTTLS" : "",
				 disable_plaintext_auth && !client->tls ?
				 " LOGINDISABLED" : "",
				 client_authenticate_get_capabilities(),
				 NULL);
	client_send_line(client, capability);
	client_send_tagline(client, "OK Capability completed.");
	return TRUE;
}

static int cmd_starttls(struct imap_client *client)
{
	int fd_ssl;

	if (client->tls) {
		client_send_tagline(client, "BAD TLS is already active.");
		return TRUE;
	}

	if (!ssl_initialized) {
		client_send_tagline(client, "BAD TLS support isn't enabled.");
		return TRUE;
	}

	client_send_tagline(client, "OK Begin TLS negotiation now.");
	o_stream_flush(client->output);

	/* must be removed before ssl_proxy_new(), since it may
	   io_add() the same fd. */
	if (client->io != NULL) {
		io_remove(client->io);
		client->io = NULL;
	}

	fd_ssl = ssl_proxy_new(client->common.fd);
	if (fd_ssl != -1) {
		client->tls = TRUE;
                client_set_title(client);

		client->common.fd = fd_ssl;

		i_stream_unref(client->input);
		o_stream_unref(client->output);

		client->input = i_stream_create_file(fd_ssl, default_pool,
						     8192, FALSE);
		client->output = o_stream_create_file(fd_ssl, default_pool,
						      1024, IO_PRIORITY_DEFAULT,
						      FALSE);
	} else {
		client_send_line(client, " * BYE TLS handehake failed.");
		client_destroy(client, "TLS handshake failed");
	}

	client->io = io_add(client->common.fd, IO_READ, client_input, client);
	return TRUE;
}

static int cmd_noop(struct imap_client *client)
{
	client_send_tagline(client, "OK NOOP completed.");
	return TRUE;
}

static int cmd_logout(struct imap_client *client)
{
	client_send_line(client, "* BYE Logging out");
	client_send_tagline(client, "OK Logout completed.");
	client_destroy(client, "Aborted login");
	return TRUE;
}

static int client_command_execute(struct imap_client *client, const char *cmd,
				  struct imap_arg *args)
{
	cmd = str_ucase(t_strdup_noconst(cmd));
	if (strcmp(cmd, "LOGIN") == 0)
		return cmd_login(client, args);
	if (strcmp(cmd, "AUTHENTICATE") == 0)
		return cmd_authenticate(client, args);
	if (strcmp(cmd, "CAPABILITY") == 0)
		return cmd_capability(client);
	if (strcmp(cmd, "STARTTLS") == 0)
		return cmd_starttls(client);
	if (strcmp(cmd, "NOOP") == 0)
		return cmd_noop(client);
	if (strcmp(cmd, "LOGOUT") == 0)
		return cmd_logout(client);

	return FALSE;
}

/* Skip incoming data until newline is found,
   returns TRUE if newline was found. */
static int client_skip_line(struct imap_client *client)
{
	const unsigned char *data;
	size_t i, data_size;

	data = i_stream_get_data(client->input, &data_size);

	for (i = 0; i < data_size; i++) {
		if (data[i] == '\n') {
			i_stream_skip(client->input, i+1);
			return TRUE;
		}
	}

	return FALSE;
}

static void client_handle_input(struct imap_client *client)
{
	struct imap_arg *args;

	if (client->cmd_finished) {
		/* clear the previous command from memory. don't do this
		   immediately after handling command since we need the
		   cmd_tag to stay some time after authentication commands. */
		client->cmd_tag = NULL;
		client->cmd_name = NULL;
		imap_parser_reset(client->parser);

		/* remove \r\n */
		if (client->skip_line) {
			if (!client_skip_line(client))
				return;
                        client->skip_line = FALSE;
		}

		client->cmd_finished = FALSE;
	}

	if (client->cmd_tag == NULL) {
                client->cmd_tag = imap_parser_read_word(client->parser);
		if (client->cmd_tag == NULL)
			return; /* need more data */
	}

	if (client->cmd_name == NULL) {
                client->cmd_name = imap_parser_read_word(client->parser);
		if (client->cmd_name == NULL)
			return; /* need more data */
	}

	switch (imap_parser_read_args(client->parser, 0, 0, &args)) {
	case -1:
		/* error */
		client_destroy(client, NULL);
		return;
	case -2:
		/* not enough data */
		return;
	}
	client->skip_line = TRUE;

	if (*client->cmd_tag == '\0' ||
	    !client_command_execute(client, client->cmd_name, args)) {
		if (++client->bad_counter >= CLIENT_MAX_BAD_COMMANDS) {
			client_send_line(client,
				"* BYE Too many invalid IMAP commands.");
			client_destroy(client, "Disconnected: "
				       "Too many invalid commands");
			return;
		} 
		client_send_tagline(client,
			"BAD Error in IMAP command received by server.");
	}

	client->cmd_finished = TRUE;
}

int client_read(struct imap_client *client)
{
	switch (i_stream_read(client->input)) {
	case -2:
		/* buffer full */
		client_send_line(client, "* BYE Input buffer full, aborting");
		client_destroy(client, "Disconnected: Input buffer full");
		return FALSE;
	case -1:
		/* disconnected */
		client_destroy(client, "Disconnected");
		return FALSE;
	default:
		/* something was read */
		return TRUE;
	}
}

void client_input(void *context)
{
	struct imap_client *client = context;

	client->last_input = ioloop_time;

	if (!client_read(client))
		return;

	client_ref(client);

	o_stream_cork(client->output);
	client_handle_input(client);

	if (client_unref(client))
		o_stream_flush(client->output);
}

static void client_hash_destroy_oldest(void *key, void *value __attr_unused__,
				       void *context)
{
	struct imap_client *client = key;
	struct imap_client *const *destroy_clients;
	buffer_t *destroy_buf = context;
	size_t i, count;

	destroy_clients = buffer_get_data(destroy_buf, &count);
	count /= sizeof(struct imap_client *);

	for (i = 0; i < count; i++) {
		if (destroy_clients[i]->created > client->created) {
			buffer_insert(destroy_buf,
				      i * sizeof(struct imap_client *),
				      &client, sizeof(struct imap_client *));
			break;
		}
	}
}

static void client_destroy_oldest(void)
{
	struct imap_client *const *destroy_clients;
	buffer_t *destroy_buf;
	size_t i, count;

	/* find the oldest clients and put them to destroy-buffer */
	destroy_buf = buffer_create_static_hard(data_stack_pool,
						sizeof(struct imap_client *) *
						CLIENT_DESTROY_OLDEST_COUNT);
	hash_foreach(clients, client_hash_destroy_oldest, destroy_buf);

	/* then kill them */
	destroy_clients = buffer_get_data(destroy_buf, &count);
	count /= sizeof(struct imap_client *);

	for (i = 0; i < count; i++) {
		client_destroy(destroy_clients[i],
			       "Disconnected: Connection queue full");
	}
}

struct client *client_create(int fd, struct ip_addr *ip, int ssl)
{
	struct imap_client *client;

	if (max_logging_users > CLIENT_DESTROY_OLDEST_COUNT &&
	    hash_size(clients) >= max_logging_users) {
		/* reached max. users count, kill few of the
		   oldest connections */
		client_destroy_oldest();
	}

	/* always use nonblocking I/O */
	net_set_nonblock(fd, TRUE);

	client = i_new(struct imap_client, 1);
	client->created = ioloop_time;
	client->refcount = 1;
	client->tls = ssl;

	client->common.ip = *ip;
	client->common.fd = fd;
	client->io = io_add(fd, IO_READ, client_input, client);
	client->input = i_stream_create_file(fd, default_pool,
					     MAX_INBUF_SIZE, FALSE);
	client->output = o_stream_create_file(fd, default_pool, 1024,
					      IO_PRIORITY_DEFAULT, FALSE);
	client->parser = imap_parser_create(client->input, client->output,
					    MAX_INBUF_SIZE,
					    MAX_IMAP_ARG_ELEMENTS);
	client->plain_login = buffer_create_dynamic(system_pool, 128, 8192);

	client->last_input = ioloop_time;
	hash_insert(clients, client, client);

	main_ref();

	client_send_line(client, "* OK " PACKAGE " ready.");
	client_set_title(client);
	return &client->common;
}

void client_destroy(struct imap_client *client, const char *reason)
{
	if (reason != NULL)
		client_syslog(client, reason);

	hash_remove(clients, client);

	imap_parser_destroy(client->parser);
	i_stream_close(client->input);
	o_stream_close(client->output);

	if (client->io != NULL) {
		io_remove(client->io);
		client->io = NULL;
	}

	net_disconnect(client->common.fd);
	client->common.fd = -1;

	i_free(client->virtual_user);
	client_unref(client);
}

void client_ref(struct imap_client *client)
{
	client->refcount++;
}

int client_unref(struct imap_client *client)
{
	if (--client->refcount > 0)
		return TRUE;

	i_stream_unref(client->input);
	o_stream_unref(client->output);

	buffer_free(client->plain_login);
	i_free(client);

	main_unref();
	return FALSE;
}

void client_send_line(struct imap_client *client, const char *line)
{
	o_stream_send_str(client->output, line);
	o_stream_send(client->output, "\r\n", 2);
}

void client_send_tagline(struct imap_client *client, const char *line)
{
	client_send_line(client, t_strconcat(client->cmd_tag, " ", line, NULL));
}

void client_syslog(struct imap_client *client, const char *text)
{
	const char *host;

	host = net_ip2host(&client->common.ip);
	if (host == NULL)
		host = "??";

	i_info("%s [%s]", text, host);
}

static void client_hash_check_idle(void *key, void *value __attr_unused__,
				   void *context __attr_unused__)
{
	struct imap_client *client = key;

	if (ioloop_time - client->last_input >= CLIENT_LOGIN_IDLE_TIMEOUT) {
		client_send_line(client, "* BYE Disconnected for inactivity.");
		client_destroy(client, "Disconnected: Inactivity");
	}
}

static void idle_timeout(void *context __attr_unused__)
{
	hash_foreach(clients, client_hash_check_idle, NULL);
}

unsigned int clients_get_count(void)
{
	return hash_size(clients);
}

static void client_hash_destroy(void *key, void *value __attr_unused__,
				void *context __attr_unused__)
{
	client_destroy(key, NULL);
}

void clients_destroy_all(void)
{
	hash_foreach(clients, client_hash_destroy, NULL);
}

void clients_init(void)
{
	clients = hash_create(default_pool, default_pool, 128, NULL, NULL);
	to_idle = timeout_add(1000, idle_timeout, NULL);
}

void clients_deinit(void)
{
	clients_destroy_all();
	hash_destroy(clients);

	timeout_remove(to_idle);
}

--- NEW FILE: client.h ---
#ifndef __CLIENT_H
#define __CLIENT_H

#include "network.h"
#include "master.h"
#include "client-common.h"

struct imap_client {
	struct client common;

	time_t created;
	int refcount;

	struct io *io;
	struct istream *input;
	struct ostream *output;
	struct imap_parser *parser;

	time_t last_input;
	unsigned int bad_counter;

	const char *cmd_tag, *cmd_name;

	buffer_t *plain_login;
	struct auth_request *auth_request;
	char *virtual_user;

	unsigned int tls:1;
	unsigned int cmd_finished:1;
	unsigned int skip_line:1;
};

struct client *client_create(int fd, struct ip_addr *ip, int ssl);
void client_destroy(struct imap_client *client, const char *reason);

void client_ref(struct imap_client *client);
int client_unref(struct imap_client *client);

void client_send_line(struct imap_client *client, const char *line);
void client_send_tagline(struct imap_client *client, const char *line);
void client_syslog(struct imap_client *client, const char *text);

int client_read(struct imap_client *client);
void client_input(void *context);

unsigned int clients_get_count(void);
void clients_destroy_all(void);

void clients_init(void);
void clients_deinit(void);

#endif

--- NEW FILE: common.h ---
#ifndef __COMMON_H
#define __COMMON_H

#include "lib.h"
#include "../auth/auth-login-interface.h"

extern int disable_plaintext_auth, process_per_connection, verbose_proctitle;
extern unsigned int max_logging_users;
extern unsigned int login_process_uid;

void main_ref(void);
void main_unref(void);

void main_close_listen(void);

#endif