src/auth/auth-worker-client.c

	auth-worker-client.c revision e9371f899a3d4207a0ffd3923ea5ec7250cf5e75
/* Copyright (c) 2005-2011 Dovecot authors, see the included COPYING file */

#include "auth-common.h"
#include "base64.h"
#include "ioloop.h"
#include "network.h"
#include "istream.h"
#include "ostream.h"
#include "hex-binary.h"
#include "str.h"
#include "master-service.h"
#include "auth-request.h"
#include "auth-worker-client.h"

#include <stdlib.h>

#define OUTBUF_THROTTLE_SIZE (1024*10)

struct auth_worker_client {
    int refcount;

        struct auth *auth;
    int fd;
    struct io *io;
    struct istream *input;
    struct ostream *output;

    unsigned int version_received:1;
    unsigned int dbhash_received:1;
};

struct auth_worker_list_context {
    struct auth_worker_client *client;
    struct auth_request *auth_request;
    struct userdb_iterate_context *iter;
    bool sending, sent, done;
};

struct auth_worker_client *auth_worker_client;

static void auth_worker_input(struct auth_worker_client *client);
static int auth_worker_output(struct auth_worker_client *client);

static void
auth_worker_client_check_throttle(struct auth_worker_client *client)
{
    if (o_stream_get_buffer_used_size(client->output) >=
        OUTBUF_THROTTLE_SIZE) {
        /* stop reading new requests until client has read the pending
           replies. */
        if (client->io != NULL)
            io_remove(&client->io);
    }
}

static struct auth_request *
worker_auth_request_new(struct auth_worker_client *client, unsigned int id,
            const char *const *args)
{
    struct auth_request *auth_request;
    const char *key, *value;

    auth_request = auth_request_new_dummy();

    client->refcount++;
    auth_request->context = client;
    auth_request->id = id;

    for (; *args != NULL; args++) {
        value = strchr(*args, '=');
        if (value != NULL) {
            key = t_strdup_until(*args, value++);
            (void)auth_request_import(auth_request, key, value);
        }
    }

    auth_request_init(auth_request);
    return auth_request;
}

static void auth_worker_send_reply(struct auth_worker_client *client,
                   string_t *str)
{
    if (shutdown_request)
        o_stream_send_str(client->output, "SHUTDOWN\n");
    o_stream_send(client->output, str_data(str), str_len(str));
}

static void verify_plain_callback(enum passdb_result result,
                  struct auth_request *request)
{
    struct auth_worker_client *client = request->context;
    struct auth_stream_reply *reply;
    string_t *str;

    if (request->passdb_failure && result == PASSDB_RESULT_OK)
        result = PASSDB_RESULT_PASSWORD_MISMATCH;

    reply = auth_stream_reply_init(pool_datastack_create());
    auth_stream_reply_add(reply, NULL, dec2str(request->id));

    if (result == PASSDB_RESULT_OK)
        auth_stream_reply_add(reply, "OK", NULL);
    else {
        auth_stream_reply_add(reply, "FAIL", NULL);
        auth_stream_reply_add(reply, NULL,
                      t_strdup_printf("%d", result));
    }
    if (result != PASSDB_RESULT_INTERNAL_FAILURE) {
        auth_stream_reply_add(reply, NULL, request->user);
        auth_stream_reply_add(reply, NULL,
                      request->passdb_password == NULL ? "" :
                      request->passdb_password);
        if (request->extra_fields != NULL) {
            const char *fields =
                auth_stream_reply_export(request->extra_fields);
            auth_stream_reply_import(reply, fields);
        }
        if (request->extra_cache_fields != NULL) {
            const char *fields =
                auth_stream_reply_export(request->extra_cache_fields);
            auth_stream_reply_import(reply, fields);
        }
    }
    str = auth_stream_reply_get_str(reply);
    str_append_c(str, '\n');
    auth_worker_send_reply(client, str);

    auth_request_unref(&request);
    auth_worker_client_check_throttle(client);
    auth_worker_client_unref(&client);
}

static bool
auth_worker_handle_passv(struct auth_worker_client *client,
             unsigned int id, const char *const *args)
{
    /* verify plaintext password */
    struct auth_request *auth_request;
        struct auth_passdb *passdb;
    const char *password;
    unsigned int passdb_id;

    /* <passdb id> <password> [<args>] */
    if (str_to_uint(args[0], &passdb_id) < 0 || args[1] == NULL) {
        i_error("BUG: Auth worker server sent us invalid PASSV");
        return FALSE;
    }
    password = args[1];

    auth_request = worker_auth_request_new(client, id, args + 2);
    auth_request->mech_password =
        p_strdup(auth_request->pool, password);

    if (auth_request->user == NULL || auth_request->service == NULL) {
        i_error("BUG: PASSV had missing parameters");
        auth_request_unref(&auth_request);
        return FALSE;
    }

    passdb = auth_request->passdb;
    while (passdb != NULL && passdb->passdb->id != passdb_id)
        passdb = passdb->next;

    if (passdb == NULL) {
        /* could be a masterdb */
        passdb = auth_request_get_auth(auth_request)->masterdbs;
        while (passdb != NULL && passdb->passdb->id != passdb_id)
            passdb = passdb->next;

        if (passdb == NULL) {
            i_error("BUG: PASSV had invalid passdb ID");
            auth_request_unref(&auth_request);
            return FALSE;
        }
    }

    auth_request->passdb = passdb;
    passdb->passdb->iface.
        verify_plain(auth_request, password, verify_plain_callback);
    return TRUE;
}

static void
lookup_credentials_callback(enum passdb_result result,
                const unsigned char *credentials, size_t size,
                struct auth_request *request)
{
    struct auth_worker_client *client = request->context;
    struct auth_stream_reply *reply;
    string_t *str;

    if (request->passdb_failure && result == PASSDB_RESULT_OK)
        result = PASSDB_RESULT_PASSWORD_MISMATCH;

    reply = auth_stream_reply_init(pool_datastack_create());
    auth_stream_reply_add(reply, NULL, dec2str(request->id));

    if (result != PASSDB_RESULT_OK) {
        auth_stream_reply_add(reply, "FAIL", NULL);
        auth_stream_reply_add(reply, NULL,
                      t_strdup_printf("%d", result));
    } else {
        auth_stream_reply_add(reply, "OK", NULL);
        auth_stream_reply_add(reply, NULL, request->user);

        str = t_str_new(64);
        str_printfa(str, "{%s.b64}", request->credentials_scheme);
        base64_encode(credentials, size, str);
        auth_stream_reply_add(reply, NULL, str_c(str));

        if (request->extra_fields != NULL) {
            const char *fields =
                auth_stream_reply_export(request->extra_fields);
            auth_stream_reply_import(reply, fields);
        }
        if (request->extra_cache_fields != NULL) {
            const char *fields =
                auth_stream_reply_export(request->extra_cache_fields);
            auth_stream_reply_import(reply, fields);
        }
    }
    str = auth_stream_reply_get_str(reply);
    str_append_c(str, '\n');
    auth_worker_send_reply(client, str);

    auth_request_unref(&request);
    auth_worker_client_check_throttle(client);
    auth_worker_client_unref(&client);
}

static bool
auth_worker_handle_passl(struct auth_worker_client *client,
             unsigned int id, const char *const *args)
{
    /* lookup credentials */
    struct auth_request *auth_request;
    const char *scheme;
    unsigned int passdb_id;

    /* <passdb id> <scheme> [<args>] */
    if (str_to_uint(args[0], &passdb_id) < 0 || args[1] == NULL) {
        i_error("BUG: Auth worker server sent us invalid PASSL");
        return FALSE;
    }
    scheme = args[1];

    auth_request = worker_auth_request_new(client, id, args + 2);
    auth_request->credentials_scheme = p_strdup(auth_request->pool, scheme);

    if (auth_request->user == NULL || auth_request->service == NULL) {
        i_error("BUG: PASSL had missing parameters");
        auth_request_unref(&auth_request);
        return FALSE;
    }

    while (auth_request->passdb->passdb->id != passdb_id) {
        auth_request->passdb = auth_request->passdb->next;
        if (auth_request->passdb == NULL) {
            i_error("BUG: PASSL had invalid passdb ID");
            auth_request_unref(&auth_request);
            return FALSE;
        }
    }

    if (auth_request->passdb->passdb->iface.lookup_credentials == NULL) {
        i_error("BUG: PASSL lookup not supported by given passdb");
        auth_request_unref(&auth_request);
        return FALSE;
    }

    auth_request->prefer_plain_credentials = TRUE;
    auth_request->passdb->passdb->iface.
        lookup_credentials(auth_request, lookup_credentials_callback);
    return TRUE;
}

static void
set_credentials_callback(bool success, struct auth_request *request)
{
    struct auth_worker_client *client = request->context;

    string_t *str;

    str = t_str_new(64);
    str_printfa(str, "%u\t%s\n", request->id, success ? "OK" : "FAIL");
    auth_worker_send_reply(client, str);

    auth_request_unref(&request);
    auth_worker_client_check_throttle(client);
    auth_worker_client_unref(&client);
}

static bool
auth_worker_handle_setcred(struct auth_worker_client *client,
               unsigned int id, const char *const *args)
{
    struct auth_request *auth_request;
    unsigned int passdb_id;
    const char *creds;

    /* <passdb id> <credentials> [<args>] */
    if (str_to_uint(args[0], &passdb_id) < 0 || args[1] == NULL) {
        i_error("BUG: Auth worker server sent us invalid SETCRED");
        return FALSE;
    }
    creds = args[1];

    auth_request = worker_auth_request_new(client, id, args + 2);
    if (auth_request->user == NULL || auth_request->service == NULL) {
        i_error("BUG: SETCRED had missing parameters");
        auth_request_unref(&auth_request);
        return FALSE;
    }

    while (auth_request->passdb->passdb->id != passdb_id) {
        auth_request->passdb = auth_request->passdb->next;
        if (auth_request->passdb == NULL) {
            i_error("BUG: SETCRED had invalid passdb ID");
            auth_request_unref(&auth_request);
            return FALSE;
        }
    }

    auth_request->passdb->passdb->iface.
        set_credentials(auth_request, creds, set_credentials_callback);
    return TRUE;
}

static void
lookup_user_callback(enum userdb_result result,
             struct auth_request *auth_request)
{
    struct auth_worker_client *client = auth_request->context;
    struct auth_stream_reply *reply = auth_request->userdb_reply;
    string_t *str;

    str = t_str_new(128);
    str_printfa(str, "%u\t", auth_request->id);
    switch (result) {
    case USERDB_RESULT_INTERNAL_FAILURE:
        str_append(str, "FAIL\t");
        break;
    case USERDB_RESULT_USER_UNKNOWN:
        str_append(str, "NOTFOUND\t");
        break;
    case USERDB_RESULT_OK:
        str_append(str, "OK\t");
        str_append(str, auth_stream_reply_export(reply));
        if (auth_request->userdb_lookup_failed)
            str_append(str, "\ttempfail");
        break;
    }
    str_append_c(str, '\n');

    auth_worker_send_reply(client, str);

    auth_request_unref(&auth_request);
    auth_worker_client_check_throttle(client);
    auth_worker_client_unref(&client);
}

static struct auth_userdb *
auth_userdb_find_by_id(struct auth_userdb *userdbs, unsigned int id)
{
    struct auth_userdb *db;

    for (db = userdbs; db != NULL; db = db->next) {
        if (db->userdb->id == id)
            return db;
    }
    return NULL;
}

static bool
auth_worker_handle_user(struct auth_worker_client *client,
            unsigned int id, const char *const *args)
{
    /* lookup user */
    struct auth_request *auth_request;
    unsigned int userdb_id;

    /* <userdb id> [<args>] */
    if (str_to_uint(args[0], &userdb_id) < 0) {
        i_error("BUG: Auth worker server sent us invalid USER");
        return FALSE;
    }

    auth_request = worker_auth_request_new(client, id, args + 1);
    if (auth_request->user == NULL || auth_request->service == NULL) {
        i_error("BUG: USER had missing parameters");
        auth_request_unref(&auth_request);
        return FALSE;
    }

    auth_request->userdb =
        auth_userdb_find_by_id(auth_request->userdb, userdb_id);
    if (auth_request->userdb == NULL) {
        i_error("BUG: USER had invalid userdb ID");
        auth_request_unref(&auth_request);
        return FALSE;
    }

    auth_request->userdb->userdb->iface->
        lookup(auth_request, lookup_user_callback);
    return TRUE;
}

static void list_iter_deinit(struct auth_worker_list_context *ctx)
{
    struct auth_worker_client *client = ctx->client;
    string_t *str;

    i_assert(client->io == NULL);

    str = t_str_new(32);
    if (ctx->auth_request->userdb->userdb->iface->
                iterate_deinit(ctx->iter) < 0)
        str_printfa(str, "%u\tFAIL\n", ctx->auth_request->id);
    else
        str_printfa(str, "%u\tOK\n", ctx->auth_request->id);
    auth_worker_send_reply(client, str);

    client->io = io_add(client->fd, IO_READ, auth_worker_input, client);
    o_stream_set_flush_callback(client->output, auth_worker_output, client);
    auth_request_unref(&ctx->auth_request);
    auth_worker_client_unref(&client);
    i_free(ctx);
}

static void list_iter_callback(const char *user, void *context)
{
    struct auth_worker_list_context *ctx = context;
    string_t *str;

    if (user == NULL) {
        if (ctx->sending)
            ctx->done = TRUE;
        else
            list_iter_deinit(ctx);
        return;
    }

    T_BEGIN {
        str = t_str_new(128);
        str_printfa(str, "%u\t*\t%s\n", ctx->auth_request->id, user);
        o_stream_send(ctx->client->output, str_data(str), str_len(str));
    } T_END;

    if (ctx->sending) {
        /* avoid recursively looping to this same function */
        ctx->sent = TRUE;
        return;
    }

    do {
        ctx->sending = TRUE;
        ctx->sent = FALSE;
        ctx->auth_request->userdb->userdb->iface->
            iterate_next(ctx->iter);
    } while (ctx->sent &&
         o_stream_get_buffer_used_size(ctx->client->output) == 0);
    ctx->sending = FALSE;
    if (ctx->done)
        list_iter_deinit(ctx);
}

static int auth_worker_list_output(struct auth_worker_list_context *ctx)
{
    int ret;

    if ((ret = o_stream_flush(ctx->client->output)) < 0) {
        list_iter_deinit(ctx);
        return 1;
    }
    if (ret > 0) {
        ctx->auth_request->userdb->userdb->iface->
            iterate_next(ctx->iter);
    }
    return 1;
}

static bool
auth_worker_handle_list(struct auth_worker_client *client,
            unsigned int id, const char *const *args)
{
    struct auth_worker_list_context *ctx;
    struct auth_userdb *userdb;
    unsigned int userdb_id;

    if (str_to_uint(args[0], &userdb_id) < 0) {
        i_error("BUG: Auth worker server sent us invalid LIST");
        return FALSE;
    }

    userdb = auth_userdb_find_by_id(client->auth->userdbs, userdb_id);
    if (userdb == NULL) {
        i_error("BUG: LIST had invalid userdb ID");
        return FALSE;
    }

    ctx = i_new(struct auth_worker_list_context, 1);
    ctx->client = client;
    ctx->auth_request = worker_auth_request_new(client, id, args + 1);
    ctx->auth_request->userdb = userdb;
    if (ctx->auth_request->user == NULL ||
        ctx->auth_request->service == NULL) {
        i_error("BUG: LIST had missing parameters");
        auth_request_unref(&ctx->auth_request);
        i_free(ctx);
        return FALSE;
    }

    io_remove(&ctx->client->io);
    o_stream_set_flush_callback(ctx->client->output,
                    auth_worker_list_output, ctx);
    ctx->iter = ctx->auth_request->userdb->userdb->iface->
        iterate_init(ctx->auth_request, list_iter_callback, ctx);
    ctx->auth_request->userdb->userdb->iface->iterate_next(ctx->iter);
    return TRUE;
}

static bool
auth_worker_handle_line(struct auth_worker_client *client, const char *line)
{
    const char *const *args;
    unsigned int id;
    bool ret = FALSE;

    args = t_strsplit(line, "\t");
    if (args[0] == NULL || args[1] == NULL || args[2] == NULL ||
        str_to_uint(args[0], &id) < 0) {
        i_error("BUG: Invalid input: %s", line);
        return FALSE;
    }

    if (strcmp(args[1], "PASSV") == 0)
        ret = auth_worker_handle_passv(client, id, args + 2);
    else if (strcmp(args[1], "PASSL") == 0)
        ret = auth_worker_handle_passl(client, id, args + 2);
    else if (strcmp(args[1], "SETCRED") == 0)
        ret = auth_worker_handle_setcred(client, id, args + 2);
    else if (strcmp(args[1], "USER") == 0)
        ret = auth_worker_handle_user(client, id, args + 2);
    else if (strcmp(args[1], "LIST") == 0)
        ret = auth_worker_handle_list(client, id, args + 2);
    else {
        i_error("BUG: Auth-worker received unknown command: %s",
            args[1]);
    }
        return ret;
}

static bool auth_worker_verify_db_hash(const char *line)
{
    string_t *str;
    unsigned char passdb_md5[MD5_RESULTLEN];
    unsigned char userdb_md5[MD5_RESULTLEN];

    passdbs_generate_md5(passdb_md5);
    userdbs_generate_md5(userdb_md5);

    str = t_str_new(128);
    str_append(str, "DBHASH\t");
    binary_to_hex_append(str, passdb_md5, sizeof(passdb_md5));
    str_append_c(str, '\t');
    binary_to_hex_append(str, userdb_md5, sizeof(userdb_md5));

    return strcmp(line, str_c(str)) == 0;
}

static void auth_worker_input(struct auth_worker_client *client)
{
    char *line;
    bool ret;

    switch (i_stream_read(client->input)) {
    case 0:
        return;
    case -1:
        /* disconnected */
        auth_worker_client_destroy(&client);
        return;
    case -2:
        /* buffer full */
        i_error("BUG: Auth worker server sent us more than %d bytes",
            (int)AUTH_WORKER_MAX_LINE_LENGTH);
        auth_worker_client_destroy(&client);
        return;
    }

    if (!client->version_received) {
        line = i_stream_next_line(client->input);
        if (line == NULL)
            return;

        if (!version_string_verify(line, "auth-worker",
                     AUTH_WORKER_PROTOCOL_MAJOR_VERSION)) {
            i_error("Auth worker not compatible with this server "
                "(mixed old and new binaries?)");
            auth_worker_client_destroy(&client);
            return;
        }
        client->version_received = TRUE;
    }
    if (!client->dbhash_received) {
        line = i_stream_next_line(client->input);
        if (line == NULL)
            return;

        if (!auth_worker_verify_db_hash(line)) {
            i_error("Auth worker sees different passdbs/userdbs "
                "than auth server. Maybe config just changed "
                "and this goes away automatically?");
            auth_worker_client_destroy(&client);
            return;
        }
        client->dbhash_received = TRUE;
    }

        client->refcount++;
    while ((line = i_stream_next_line(client->input)) != NULL) {
        T_BEGIN {
            ret = auth_worker_handle_line(client, line);
        } T_END;

        if (!ret) {
            struct auth_worker_client *client2 = client;
            auth_worker_client_destroy(&client2);
            break;
        }
    }
    auth_worker_client_unref(&client);
}

static int auth_worker_output(struct auth_worker_client *client)
{
    if (o_stream_flush(client->output) < 0) {
        auth_worker_client_destroy(&client);
        return 1;
    }

    if (o_stream_get_buffer_used_size(client->output) <=
        OUTBUF_THROTTLE_SIZE/3 && client->io == NULL) {
        /* allow input again */
        client->io = io_add(client->fd, IO_READ,
                    auth_worker_input, client);
    }
    return 1;
}

struct auth_worker_client *
auth_worker_client_create(struct auth *auth, int fd)
{
        struct auth_worker_client *client;

    client = i_new(struct auth_worker_client, 1);
    client->refcount = 1;

    client->auth = auth;
    client->fd = fd;
    client->input = i_stream_create_fd(fd, AUTH_WORKER_MAX_LINE_LENGTH,
                       FALSE);
    client->output = o_stream_create_fd(fd, (size_t)-1, FALSE);
    o_stream_set_flush_callback(client->output, auth_worker_output, client);
    client->io = io_add(fd, IO_READ, auth_worker_input, client);

    auth_worker_client = client;
    return client;
}

void auth_worker_client_destroy(struct auth_worker_client **_client)
{
    struct auth_worker_client *client = *_client;

    *_client = NULL;
    if (client->fd == -1)
        return;

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

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

    net_disconnect(client->fd);
    client->fd = -1;
    auth_worker_client_unref(&client);

    auth_worker_client = NULL;
    master_service_client_connection_destroyed(master_service);
}

void auth_worker_client_unref(struct auth_worker_client **_client)
{
    struct auth_worker_client *client = *_client;

    *_client = NULL;

    if (--client->refcount > 0)
        return;

    i_stream_unref(&client->input);
    o_stream_unref(&client->output);
    i_free(client);
}