src/director/login-connection.c

	login-connection.c revision f0d8efc20cfcb38c132d333704bb08de2e9c62f1
/* Copyright (c) 2010-2015 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "ioloop.h"
#include "net.h"
#include "ostream.h"
#include "llist.h"
#include "master-service.h"
#include "director.h"
#include "director-request.h"
#include "auth-connection.h"
#include "login-connection.h"

#include <unistd.h>

struct login_connection {
    struct login_connection *prev, *next;

    int refcount;

    int fd;
    struct io *io;
    struct ostream *output;
    struct auth_connection *auth;
    struct director *dir;

    unsigned int destroyed:1;
    unsigned int userdb:1;
};

struct login_host_request {
    struct login_connection *conn;
    char *line, *username;

    struct ip_addr local_ip;
    unsigned int local_port;
    unsigned int dest_port;
    bool director_proxy_maybe;
};

static struct login_connection *login_connections;

static void login_connection_unref(struct login_connection **_conn);

static void login_connection_input(struct login_connection *conn)
{
    unsigned char buf[4096];
    ssize_t ret;

    ret = read(conn->fd, buf, sizeof(buf));
    if (ret <= 0) {
        if (ret < 0) {
            if (errno == EAGAIN)
                return;
            if (errno != ECONNRESET)
                i_error("read(login connection) failed: %m");
        }
        login_connection_deinit(&conn);
        return;
    }
    auth_connection_send(conn->auth, buf, ret);
}

static void
login_connection_send_line(struct login_connection *conn, const char *line)
{
    struct const_iovec iov[2];

    if (conn->destroyed)
        return;

    iov[0].iov_base = line;
    iov[0].iov_len = strlen(line);
    iov[1].iov_base = "\n";
    iov[1].iov_len = 1;
    o_stream_nsendv(conn->output, iov, N_ELEMENTS(iov));
}

static bool login_host_request_is_self(struct login_host_request *request,
                       const struct ip_addr *dest_ip)
{
    if (!net_ip_compare(dest_ip, &request->local_ip))
        return FALSE;
    if (request->dest_port != 0 && request->local_port != 0 &&
        request->dest_port != request->local_port)
        return FALSE;
    return TRUE;
}

static void
login_host_callback(const struct ip_addr *ip, const char *errormsg,
            void *context)
{
    struct login_host_request *request = context;
    struct director *dir = request->conn->dir;
    const char *line, *line_params;
    unsigned int secs;

    if (ip == NULL) {
        if (strncmp(request->line, "OK\t", 3) == 0)
            line_params = request->line + 3;
        else if (strncmp(request->line, "PASS\t", 5) == 0)
            line_params = request->line + 5;
        else
            i_panic("BUG: Unexpected line: %s", request->line);

        i_error("director: User %s host lookup failed: %s",
            request->username, errormsg);
        line = t_strconcat("FAIL\t", t_strcut(line_params, '\t'),
                   "\ttemp", NULL);
    } else if (request->director_proxy_maybe &&
           login_host_request_is_self(request, ip)) {
        line = request->line;
    } else {
        secs = dir->set->director_user_expire / 2;
        line = t_strdup_printf("%s\thost=%s\tproxy_refresh=%u",
                       request->line, net_ip2addr(ip), secs);
    }
    login_connection_send_line(request->conn, line);

    login_connection_unref(&request->conn);
    i_free(request->username);
    i_free(request->line);
    i_free(request);
}

static void auth_input_line(const char *line, void *context)
{
    struct login_connection *conn = context;
    struct login_host_request *request, temp_request;
    const char *const *args, *line_params, *username = NULL, *tag = "";
    bool proxy = FALSE, host = FALSE;

    if (line == NULL) {
        /* auth connection died -> kill also this login connection */
        login_connection_deinit(&conn);
        return;
    }
    if (!conn->userdb && strncmp(line, "OK\t", 3) == 0)
        line_params = line + 3;
    else if (conn->userdb && strncmp(line, "PASS\t", 5) == 0)
        line_params = line + 5;
    else {
        login_connection_send_line(conn, line);
        return;
    }

    /* OK <id> [<parameters>] */
    args = t_strsplit_tab(line_params);
    if (*args != NULL) {
        /* we should always get here, but in case we don't just
           forward as-is and let login process handle the error. */
        args++;
    }

    memset(&temp_request, 0, sizeof(temp_request));
    for (; *args != NULL; args++) {
        if (strncmp(*args, "proxy", 5) == 0 &&
            ((*args)[5] == '=' || (*args)[5] == '\0'))
            proxy = TRUE;
        else if (strncmp(*args, "host=", 5) == 0)
            host = TRUE;
        else if (strncmp(*args, "lip=", 4) == 0) {
            if (net_addr2ip((*args) + 4, &temp_request.local_ip) < 0)
                i_error("auth sent invalid lip field: %s", (*args) + 6);
        } else if (strncmp(*args, "lport=", 6) == 0) {
            if (str_to_uint((*args) + 6, &temp_request.local_port) < 0)
                i_error("auth sent invalid lport field: %s", (*args) + 6);
        } else if (strncmp(*args, "port=", 5) == 0) {
            if (str_to_uint((*args) + 5, &temp_request.dest_port) < 0)
                i_error("auth sent invalid port field: %s", (*args) + 6);
        } else if (strncmp(*args, "destuser=", 9) == 0)
            username = *args + 9;
        else if (strncmp(*args, "director_tag=", 13) == 0)
            tag = *args + 13;
        else if (strncmp(*args, "director_proxy_maybe", 20) == 0 &&
             ((*args)[20] == '=' || (*args)[20] == '\0'))
            temp_request.director_proxy_maybe = TRUE;
        else if (strncmp(*args, "user=", 5) == 0) {
            if (username == NULL)
                username = *args + 5;
        }
    }
    if ((!proxy && !temp_request.director_proxy_maybe) ||
        host || username == NULL) {
        login_connection_send_line(conn, line);
        return;
    }
    if (*conn->dir->set->master_user_separator != '\0') {
        /* with master user logins we still want to use only the
           login username */
        username = t_strcut(username,
                    *conn->dir->set->master_user_separator);
    }

    /* we need to add the host. the lookup might be asynchronous */
    request = i_new(struct login_host_request, 1);
    *request = temp_request;
    request->conn = conn;
    request->line = i_strdup(line);
    request->username = i_strdup(username);

    conn->refcount++;
    director_request(conn->dir, username, tag, login_host_callback, request);
}

struct login_connection *
login_connection_init(struct director *dir, int fd,
              struct auth_connection *auth, bool userdb)
{
    struct login_connection *conn;

    conn = i_new(struct login_connection, 1);
    conn->refcount = 1;
    conn->fd = fd;
    conn->auth = auth;
    conn->dir = dir;
    conn->output = o_stream_create_fd(conn->fd, (size_t)-1, FALSE);
    o_stream_set_no_error_handling(conn->output, TRUE);
    conn->io = io_add(conn->fd, IO_READ, login_connection_input, conn);
    conn->userdb = userdb;

    auth_connection_set_callback(conn->auth, auth_input_line, conn);
    DLLIST_PREPEND(&login_connections, conn);
    return conn;
}

void login_connection_deinit(struct login_connection **_conn)
{
    struct login_connection *conn = *_conn;

    *_conn = NULL;

    if (conn->destroyed)
        return;
    conn->destroyed = TRUE;

    DLLIST_REMOVE(&login_connections, conn);
    io_remove(&conn->io);
    o_stream_destroy(&conn->output);
    if (close(conn->fd) < 0)
        i_error("close(login connection) failed: %m");
    conn->fd = -1;

    auth_connection_deinit(&conn->auth);
    login_connection_unref(&conn);

    master_service_client_connection_destroyed(master_service);
}

static void login_connection_unref(struct login_connection **_conn)
{
    struct login_connection *conn = *_conn;

    *_conn = NULL;

    i_assert(conn->refcount > 0);
    if (--conn->refcount == 0)
        i_free(conn);
}

void login_connections_deinit(void)
{
    while (login_connections != NULL) {
        struct login_connection *conn = login_connections;

        login_connection_deinit(&conn);
    }
}