login-proxy.c revision 45312f52ff3a3d4c137447be4c7556500c2f8bf2
/* Copyright (c) 2004-2009 Dovecot authors, see the included COPYING file */
#include "common.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "llist.h"
#include "str-sanitize.h"
#include "client-common.h"
#include "login-proxy.h"
#define MAX_PROXY_INPUT_SIZE 4096
#define OUTBUF_THRESHOLD 1024
struct login_proxy {
struct login_proxy *prev, *next;
int client_fd, server_fd;
struct io *client_io, *server_io;
struct istream *server_input;
struct ostream *client_output, *server_output;
struct ip_addr ip;
char *host, *user;
unsigned int port;
proxy_callback_t *callback;
void *context;
unsigned int destroying:1;
};
static struct login_proxy *login_proxies = NULL;
static unsigned int login_proxy_count = 0;
static void server_input(struct login_proxy *proxy)
{
unsigned char buf[OUTBUF_THRESHOLD];
ssize_t ret;
if (o_stream_get_buffer_used_size(proxy->client_output) >
OUTBUF_THRESHOLD) {
/* client's output buffer is already quite full.
don't send more until we're below threshold. */
io_remove(&proxy->server_io);
return;
}
ret = net_receive(proxy->server_fd, buf, sizeof(buf));
if (ret < 0 || o_stream_send(proxy->client_output, buf, ret) != ret)
login_proxy_free(&proxy);
}
static void proxy_client_input(struct login_proxy *proxy)
{
unsigned char buf[OUTBUF_THRESHOLD];
ssize_t ret;
if (o_stream_get_buffer_used_size(proxy->server_output) >
OUTBUF_THRESHOLD) {
/* proxy's output buffer is already quite full.
don't send more until we're below threshold. */
io_remove(&proxy->client_io);
return;
}
ret = net_receive(proxy->client_fd, buf, sizeof(buf));
if (ret < 0 || o_stream_send(proxy->server_output, buf, ret) != ret)
login_proxy_free(&proxy);
}
static int server_output(struct login_proxy *proxy)
{
if (o_stream_flush(proxy->server_output) < 0) {
login_proxy_free(&proxy);
return 1;
}
if (proxy->client_io == NULL &&
o_stream_get_buffer_used_size(proxy->server_output) <
OUTBUF_THRESHOLD) {
/* there's again space in proxy's output buffer, so we can
read more from client. */
proxy->client_io = io_add(proxy->client_fd, IO_READ,
proxy_client_input, proxy);
}
return 1;
}
static int proxy_client_output(struct login_proxy *proxy)
{
if (o_stream_flush(proxy->client_output) < 0) {
login_proxy_free(&proxy);
return 1;
}
if (proxy->server_io == NULL &&
o_stream_get_buffer_used_size(proxy->client_output) <
OUTBUF_THRESHOLD) {
/* there's again space in client's output buffer, so we can
read more from proxy. */
proxy->server_io =
io_add(proxy->server_fd, IO_READ, server_input, proxy);
}
return 1;
}
static void proxy_prelogin_input(struct login_proxy *proxy)
{
proxy->callback(proxy->server_input, proxy->server_output,
proxy->context);
}
static void proxy_wait_connect(struct login_proxy *proxy)
{
int err;
err = net_geterror(proxy->server_fd);
if (err != 0) {
i_error("proxy: connect(%s, %u) failed: %s",
proxy->host, proxy->port, strerror(err));
login_proxy_free(&proxy);
return;
}
/* connect successful */
proxy->server_input =
i_stream_create_fd(proxy->server_fd, MAX_PROXY_INPUT_SIZE,
FALSE);
proxy->server_output =
o_stream_create_fd(proxy->server_fd, (size_t)-1, FALSE);
io_remove(&proxy->server_io);
proxy->server_io =
io_add(proxy->server_fd, IO_READ, proxy_prelogin_input, proxy);
}
#undef login_proxy_new
struct login_proxy *
login_proxy_new(struct client *client, const char *host, unsigned int port,
proxy_callback_t *callback, void *context)
{
struct login_proxy *proxy;
struct ip_addr ip;
int fd;
if (host == NULL) {
i_error("proxy(%s): host not given", client->virtual_user);
return NULL;
}
if (net_addr2ip(host, &ip) < 0) {
i_error("proxy(%s): %s is not a valid IP",
client->virtual_user, host);
return NULL;
}
fd = net_connect_ip(&ip, port, NULL);
if (fd < 0) {
i_error("proxy(%s): connect(%s, %u) failed: %m",
client->virtual_user, host, port);
return NULL;
}
proxy = i_new(struct login_proxy, 1);
proxy->host = i_strdup(host);
proxy->user = i_strdup(client->virtual_user);
proxy->port = port;
proxy->server_fd = fd;
proxy->server_io = io_add(fd, IO_WRITE, proxy_wait_connect, proxy);
proxy->callback = callback;
proxy->context = context;
proxy->ip = client->ip;
proxy->client_fd = -1;
return proxy;
}
void login_proxy_free(struct login_proxy **_proxy)
{
struct login_proxy *proxy = *_proxy;
const char *ipstr;
*_proxy = NULL;
if (proxy->destroying)
return;
proxy->destroying = TRUE;
if (proxy->client_fd != -1) {
/* detached proxy */
main_unref();
DLLIST_REMOVE(&login_proxies, proxy);
login_proxy_count--;
ipstr = net_ip2addr(&proxy->ip);
i_info("proxy(%s): disconnecting %s",
str_sanitize(proxy->user, 80),
ipstr != NULL ? ipstr : "");
if (proxy->client_io != NULL)
io_remove(&proxy->client_io);
if (proxy->client_output != NULL)
o_stream_destroy(&proxy->client_output);
net_disconnect(proxy->client_fd);
} else {
i_assert(proxy->client_io == NULL);
i_assert(proxy->client_output == NULL);
proxy->callback(NULL, NULL, proxy->context);
}
if (proxy->server_io != NULL)
io_remove(&proxy->server_io);
if (proxy->server_input != NULL)
i_stream_destroy(&proxy->server_input);
if (proxy->server_output != NULL)
o_stream_destroy(&proxy->server_output);
net_disconnect(proxy->server_fd);
i_free(proxy->host);
i_free(proxy->user);
i_free(proxy);
main_listen_start();
}
bool login_proxy_is_ourself(const struct client *client, const char *host,
unsigned int port, const char *destuser)
{
struct ip_addr ip;
if (port != client->local_port)
return FALSE;
if (net_addr2ip(host, &ip) < 0)
return FALSE;
if (!net_ip_compare(&ip, &client->local_ip))
return FALSE;
return strcmp(client->virtual_user, destuser) == 0;
}
const char *login_proxy_get_host(const struct login_proxy *proxy)
{
return proxy->host;
}
unsigned int login_proxy_get_port(const struct login_proxy *proxy)
{
return proxy->port;
}
unsigned int login_proxy_get_count(void)
{
return login_proxy_count;
}
void login_proxy_detach(struct login_proxy *proxy, struct istream *client_input,
struct ostream *client_output)
{
const unsigned char *data;
size_t size;
i_assert(proxy->client_fd == -1);
i_assert(proxy->server_output != NULL);
proxy->client_fd = i_stream_get_fd(client_input);
proxy->client_output = client_output;
o_stream_set_max_buffer_size(client_output, (size_t)-1);
o_stream_set_flush_callback(client_output, proxy_client_output, proxy);
/* send all pending client input to proxy and get rid of the stream */
data = i_stream_get_data(client_input, &size);
if (size != 0)
(void)o_stream_send(proxy->server_output, data, size);
i_stream_unref(&client_input);
/* from now on, just do dummy proxying */
io_remove(&proxy->server_io);
proxy->server_io =
io_add(proxy->server_fd, IO_READ, server_input, proxy);
proxy->client_io =
io_add(proxy->client_fd, IO_READ, proxy_client_input, proxy);
o_stream_set_flush_callback(proxy->server_output, server_output, proxy);
i_stream_destroy(&proxy->server_input);
proxy->callback = NULL;
proxy->context = NULL;
login_proxy_count++;
DLLIST_PREPEND(&login_proxies, proxy);
main_ref();
}
void login_proxy_deinit(void)
{
struct login_proxy *proxy;
while (login_proxies != NULL) {
proxy = login_proxies;
login_proxy_free(&proxy);
}
}