src/lib-imap-client/imapc-client.c

/* Copyright (c) 2011-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "str.h"
#include "ioloop.h"
#include "safe-mkstemp.h"
#include "iostream-ssl.h"
#include "imapc-msgmap.h"
#include "imapc-connection.h"
#include "imapc-client-private.h"

#include <unistd.h>

const char *imapc_command_state_names[] = {
    "OK", "NO", "BAD", "(auth failed)", "(disconnected)"

};

const struct imapc_capability_name imapc_capability_names[] = {
    { "SASL-IR", IMAPC_CAPABILITY_SASL_IR },
    { "LITERAL+", IMAPC_CAPABILITY_LITERALPLUS },
    { "QRESYNC", IMAPC_CAPABILITY_QRESYNC },
    { "IDLE", IMAPC_CAPABILITY_IDLE },
    { "UIDPLUS", IMAPC_CAPABILITY_UIDPLUS },
    { "AUTH=PLAIN", IMAPC_CAPABILITY_AUTH_PLAIN },
    { "STARTTLS", IMAPC_CAPABILITY_STARTTLS },
    { "X-GM-EXT-1", IMAPC_CAPABILITY_X_GM_EXT_1 },
    { "CONDSTORE", IMAPC_CAPABILITY_CONDSTORE },
    { "NAMESPACE", IMAPC_CAPABILITY_NAMESPACE },
    { "UNSELECT", IMAPC_CAPABILITY_UNSELECT },
    { "ESEARCH", IMAPC_CAPABILITY_ESEARCH },
    { "WITHIN", IMAPC_CAPABILITY_WITHIN },
    { "QUOTA", IMAPC_CAPABILITY_QUOTA },
    { "ID", IMAPC_CAPABILITY_ID },

    { "IMAP4REV1", IMAPC_CAPABILITY_IMAP4REV1 },
    { NULL, 0 }
};

unsigned int imapc_client_cmd_tag_counter = 0;

static void
default_untagged_callback(const struct imapc_untagged_reply *reply ATTR_UNUSED,
              void *context ATTR_UNUSED)
{
}

struct imapc_client *
imapc_client_init(const struct imapc_client_settings *set)
{
    struct imapc_client *client;
    struct ssl_iostream_settings ssl_set;
    const char *error;
    pool_t pool;

    i_assert(set->connect_retry_count == 0 ||
         set->connect_retry_interval_msecs > 0);

    pool = pool_alloconly_create("imapc client", 1024);
    client = p_new(pool, struct imapc_client, 1);
    client->pool = pool;
    client->refcount = 1;

    client->set.debug = set->debug;
    client->set.host = p_strdup(pool, set->host);
    client->set.port = set->port;
    client->set.master_user = p_strdup_empty(pool, set->master_user);
    client->set.username = p_strdup(pool, set->username);
    client->set.password = p_strdup(pool, set->password);
    client->set.sasl_mechanisms = p_strdup(pool, set->sasl_mechanisms);
    client->set.session_id_prefix = p_strdup(pool, set->session_id_prefix);
    client->set.use_proxyauth = set->use_proxyauth;
    client->set.dns_client_socket_path =
        p_strdup(pool, set->dns_client_socket_path);
    client->set.temp_path_prefix =
        p_strdup(pool, set->temp_path_prefix);
    client->set.rawlog_dir = p_strdup(pool, set->rawlog_dir);
    client->set.max_idle_time = set->max_idle_time;
    client->set.connect_timeout_msecs = set->connect_timeout_msecs != 0 ?
        set->connect_timeout_msecs :
        IMAPC_DEFAULT_CONNECT_TIMEOUT_MSECS;
    client->set.connect_retry_count = set->connect_retry_count;
    client->set.connect_retry_interval_msecs = set->connect_retry_interval_msecs;
    client->set.cmd_timeout_msecs = set->cmd_timeout_msecs != 0 ?
        set->cmd_timeout_msecs : IMAPC_DEFAULT_COMMAND_TIMEOUT_MSECS;
    client->set.max_line_length = set->max_line_length != 0 ?
        set->max_line_length : IMAPC_DEFAULT_MAX_LINE_LENGTH;
    client->set.throttle_set = set->throttle_set;

    if (client->set.throttle_set.init_msecs == 0)
        client->set.throttle_set.init_msecs = IMAPC_THROTTLE_DEFAULT_INIT_MSECS;
    if (client->set.throttle_set.max_msecs == 0)
        client->set.throttle_set.max_msecs = IMAPC_THROTTLE_DEFAULT_MAX_MSECS;
    if (client->set.throttle_set.shrink_min_msecs == 0)
        client->set.throttle_set.shrink_min_msecs = IMAPC_THROTTLE_DEFAULT_SHRINK_MIN_MSECS;

    if (set->ssl_mode != IMAPC_CLIENT_SSL_MODE_NONE) {
        client->set.ssl_mode = set->ssl_mode;
        client->set.ssl_ca_dir = p_strdup(pool, set->ssl_ca_dir);
        client->set.ssl_ca_file = p_strdup(pool, set->ssl_ca_file);
        client->set.ssl_verify = set->ssl_verify;

        i_zero(&ssl_set);
        ssl_set.ca_dir = set->ssl_ca_dir;
        ssl_set.ca_file = set->ssl_ca_file;
        ssl_set.allow_invalid_cert = !set->ssl_verify;
        ssl_set.crypto_device = set->ssl_crypto_device;

        if (ssl_iostream_client_context_cache_get(&ssl_set,
                              &client->ssl_ctx,
                              &error) < 0) {
            i_error("imapc(%s:%u): Couldn't initialize SSL context: %s",
                set->host, set->port, error);
        }
    }
    client->untagged_callback = default_untagged_callback;

    p_array_init(&client->conns, pool, 8);
    return client;
}

void imapc_client_ref(struct imapc_client *client)
{
    i_assert(client->refcount > 0);

    client->refcount++;
}

void imapc_client_unref(struct imapc_client **_client)
{
    struct imapc_client *client = *_client;

    *_client = NULL;

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

    if (client->ssl_ctx != NULL)
        ssl_iostream_context_unref(&client->ssl_ctx);
    pool_unref(&client->pool);
}

void imapc_client_disconnect(struct imapc_client *client)
{
    struct imapc_client_connection *const *conns, *conn;
    unsigned int i, count;

    conns = array_get(&client->conns, &count);
    for (i = count; i > 0; i--) {
        conn = conns[i-1];
        array_delete(&client->conns, i-1, 1);

        i_assert(imapc_connection_get_mailbox(conn->conn) == NULL);
        imapc_connection_deinit(&conn->conn);
        i_free(conn);
    }
}

void imapc_client_deinit(struct imapc_client **_client)
{
    struct imapc_client *client = *_client;

    imapc_client_disconnect(client);
    imapc_client_unref(_client);
}

void imapc_client_register_untagged(struct imapc_client *client,
                    imapc_untagged_callback_t *callback,
                    void *context)
{
    client->untagged_callback = callback;
    client->untagged_context = context;
}

static void imapc_client_run_pre(struct imapc_client *client)
{
    struct imapc_client_connection *const *connp;
    struct ioloop *prev_ioloop = current_ioloop;

    i_assert(client->ioloop == NULL);

    client->ioloop = io_loop_create();
    io_loop_set_running(client->ioloop);

    array_foreach(&client->conns, connp) {
        imapc_connection_ioloop_changed((*connp)->conn);
        if (imapc_connection_get_state((*connp)->conn) == IMAPC_CONNECTION_STATE_DISCONNECTED)
            imapc_connection_connect((*connp)->conn);
    }

    if (io_loop_is_running(client->ioloop))
        io_loop_run(client->ioloop);
    io_loop_set_current(prev_ioloop);
}

static void imapc_client_run_post(struct imapc_client *client)
{
    struct imapc_client_connection *const *connp;
    struct ioloop *ioloop = client->ioloop;

    client->ioloop = NULL;
    array_foreach(&client->conns, connp)
        imapc_connection_ioloop_changed((*connp)->conn);

    io_loop_set_current(ioloop);
    io_loop_destroy(&ioloop);
}

void imapc_client_run(struct imapc_client *client)
{
    imapc_client_run_pre(client);
    imapc_client_run_post(client);
}

void imapc_client_stop(struct imapc_client *client)
{
    if (client->ioloop != NULL)
        io_loop_stop(client->ioloop);
}

void imapc_client_try_stop(struct imapc_client *client)
{
    struct imapc_client_connection *const *connp;
    array_foreach(&client->conns, connp)
        if (imapc_connection_get_state((*connp)->conn) != IMAPC_CONNECTION_STATE_DISCONNECTED)
            return;
    imapc_client_stop(client);
}

bool imapc_client_is_running(struct imapc_client *client)
{
    return client->ioloop != NULL;
}

static void imapc_client_login_callback(const struct imapc_command_reply *reply,
                    void *context)
{
    struct imapc_client_connection *conn = context;
    struct imapc_client *client = conn->client;
    struct imapc_client_mailbox *box = conn->box;

    if (box != NULL && box->reconnecting) {
        box->reconnecting = FALSE;

        if (reply->state == IMAPC_COMMAND_STATE_OK) {
            /* reopen the mailbox */
            box->reopen_callback(box->reopen_context);
        } else {
            imapc_connection_abort_commands(box->conn, NULL, FALSE);
        }
    }

    /* call the login callback only once */
    if (client->login_callback != NULL) {
        imapc_command_callback_t *callback = client->login_callback;
        void *context = client->login_context;

        client->login_callback = NULL;
        client->login_context = NULL;
        callback(reply, context);
    }
}

static struct imapc_client_connection *
imapc_client_add_connection(struct imapc_client *client)
{
    struct imapc_client_connection *conn;

    conn = i_new(struct imapc_client_connection, 1);
    conn->client = client;
    conn->conn = imapc_connection_init(client, imapc_client_login_callback,
                       conn);
    array_append(&client->conns, &conn, 1);
    return conn;
}

static struct imapc_connection *
imapc_client_find_connection(struct imapc_client *client)
{
    struct imapc_client_connection *const *connp;

    /* FIXME: stupid algorithm */
    if (array_count(&client->conns) == 0)
        return imapc_client_add_connection(client)->conn;
    connp = array_idx(&client->conns, 0);
    return (*connp)->conn;
}

struct imapc_command *
imapc_client_cmd(struct imapc_client *client,
         imapc_command_callback_t *callback, void *context)
{
    struct imapc_connection *conn;

    conn = imapc_client_find_connection(client);
    return imapc_connection_cmd(conn, callback, context);
}

static struct imapc_client_connection *
imapc_client_get_unboxed_connection(struct imapc_client *client)
{
    struct imapc_client_connection *const *conns;
    unsigned int i, count;

    conns = array_get(&client->conns, &count);
    for (i = 0; i < count; i++) {
        if (conns[i]->box == NULL)
            return conns[i];
    }
    return imapc_client_add_connection(client);
}


void imapc_client_login(struct imapc_client *client)
{
    struct imapc_client_connection *conn;

    i_assert(client->login_callback != NULL);
    i_assert(array_count(&client->conns) == 0);

    conn = imapc_client_add_connection(client);
    imapc_connection_connect(conn->conn);
}

struct imapc_logout_ctx {
    struct imapc_client *client;
    unsigned int logout_count;
};

static void
imapc_client_logout_callback(const struct imapc_command_reply *reply ATTR_UNUSED,
                 void *context)
{
    struct imapc_logout_ctx *ctx = context;

    i_assert(ctx->logout_count > 0);

    if (--ctx->logout_count == 0)
        imapc_client_stop(ctx->client);
}

void imapc_client_logout(struct imapc_client *client)
{
    struct imapc_logout_ctx ctx = { .client = client };
    struct imapc_client_connection *const *connp;
    struct imapc_command *cmd;

    client->logging_out = TRUE;

    /* send LOGOUT to all connections */
    array_foreach(&client->conns, connp) {
        if (imapc_connection_get_state((*connp)->conn) == IMAPC_CONNECTION_STATE_DISCONNECTED)
            continue;
        imapc_connection_set_no_reconnect((*connp)->conn);
        ctx.logout_count++;
        cmd = imapc_connection_cmd((*connp)->conn,
            imapc_client_logout_callback, &ctx);
        imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_PRELOGIN |
                    IMAPC_COMMAND_FLAG_LOGOUT);
        imapc_command_send(cmd, "LOGOUT");
    }

    /* wait for LOGOUT to finish */
    while (ctx.logout_count > 0)
        imapc_client_run(client);

    /* we should have disconnected all clients already, but if there were
       any timeouts there may be some clients left. */
    imapc_client_disconnect(client);
}

struct imapc_client_mailbox *
imapc_client_mailbox_open(struct imapc_client *client,
              void *untagged_box_context)
{
    struct imapc_client_mailbox *box;
    struct imapc_client_connection *conn;

    box = i_new(struct imapc_client_mailbox, 1);
    box->client = client;
    box->untagged_box_context = untagged_box_context;
    conn = imapc_client_get_unboxed_connection(client);
    conn->box = box;
    box->conn = conn->conn;
    box->msgmap = imapc_msgmap_init();
    /* if we get disconnected before the SELECT is finished, allow
       one reconnect retry. */
    box->reconnect_ok = TRUE;
    return box;
}

void imapc_client_mailbox_set_reopen_cb(struct imapc_client_mailbox *box,
                    void (*callback)(void *context),
                    void *context)
{
    box->reopen_callback = callback;
    box->reopen_context = context;
}

bool imapc_client_mailbox_can_reconnect(struct imapc_client_mailbox *box)
{
    /* the reconnect_ok flag attempts to avoid infinite reconnection loops
       to a server that keeps disconnecting us (e.g. some of the commands
       we send keeps crashing it always) */
    return box->reopen_callback != NULL && box->reconnect_ok;
}

void imapc_client_mailbox_reconnect(struct imapc_client_mailbox *box,
                    const char *errmsg)
{
    i_assert(!box->reconnecting);

    imapc_connection_try_reconnect(box->conn, errmsg, 0, FALSE);
}

void imapc_client_mailbox_close(struct imapc_client_mailbox **_box)
{
    struct imapc_client_mailbox *box = *_box;
    struct imapc_client_connection *const *connp;

    box->closing = TRUE;

    /* cancel any pending commands */
    imapc_connection_unselect(box);

    if (box->reconnecting) {
        /* need to abort the reconnection so it won't try to access
           the box */
        imapc_connection_disconnect(box->conn);
    }

    /* set this only after unselect, which may cancel some commands that
       reference this box */
    *_box = NULL;

    array_foreach(&box->client->conns, connp) {
        if ((*connp)->box == box) {
            (*connp)->box = NULL;
            break;
        }
    }

    imapc_msgmap_deinit(&box->msgmap);
    timeout_remove(&box->to_send_idle);
    i_free(box);
}

struct imapc_command *
imapc_client_mailbox_cmd(struct imapc_client_mailbox *box,
             imapc_command_callback_t *callback, void *context)
{
    struct imapc_command *cmd;

    i_assert(!box->closing);

    cmd = imapc_connection_cmd(box->conn, callback, context);
    imapc_command_set_mailbox(cmd, box);
    return cmd;
}

struct imapc_msgmap *
imapc_client_mailbox_get_msgmap(struct imapc_client_mailbox *box)
{
    return box->msgmap;
}

static void imapc_client_mailbox_idle_send(struct imapc_client_mailbox *box)
{
    timeout_remove(&box->to_send_idle);
    if (imapc_client_mailbox_is_opened(box))
        imapc_connection_idle(box->conn);
}

void imapc_client_mailbox_idle(struct imapc_client_mailbox *box)
{
    /* send the IDLE with a delay to avoid unnecessary IDLEs that are
       immediately aborted */
    if (box->to_send_idle == NULL && imapc_client_mailbox_is_opened(box)) {
        box->to_send_idle =
            timeout_add_short(IMAPC_CLIENT_IDLE_SEND_DELAY_MSECS,
                      imapc_client_mailbox_idle_send, box);
    }
    /* we're done with all work at this point. */
    box->reconnect_ok = TRUE;
}

bool imapc_client_mailbox_is_opened(struct imapc_client_mailbox *box)
{
    struct imapc_client_mailbox *selected_box;

    if (box->closing ||
        imapc_connection_get_state(box->conn) != IMAPC_CONNECTION_STATE_DONE)
        return FALSE;

    selected_box = imapc_connection_get_mailbox(box->conn);
    if (selected_box != box) {
        if (selected_box != NULL)
            i_error("imapc: Selected mailbox changed unexpectedly");
        return FALSE;
    }
    return TRUE;
}

static bool
imapc_client_get_any_capabilities(struct imapc_client *client,
                  enum imapc_capability *capabilities_r)
{
    struct imapc_client_connection *const *connp;
    struct imapc_connection *conn = NULL;

    array_foreach(&client->conns, connp) {
        conn = (*connp)->conn;
        if (imapc_connection_get_state(conn) == IMAPC_CONNECTION_STATE_DONE) {
            *capabilities_r = imapc_connection_get_capabilities(conn);
            return TRUE;
        }
    }
    return FALSE;
}

int imapc_client_get_capabilities(struct imapc_client *client,
                  enum imapc_capability *capabilities_r)
{
    /* try to find a connection that is already logged in */
    if (imapc_client_get_any_capabilities(client, capabilities_r))
        return 0;

    /* if there are no connections yet, create one */
    if (array_count(&client->conns) == 0)
        (void)imapc_client_add_connection(client);

    /* wait for any of the connections to login */
    client->stop_on_state_finish = TRUE;
    imapc_client_run(client);
    client->stop_on_state_finish = FALSE;
    if (imapc_client_get_any_capabilities(client, capabilities_r))
        return 0;

    /* failed */
    return -1;
}

int imapc_client_create_temp_fd(struct imapc_client *client,
                const char **path_r)
{
    string_t *path;
    int fd;

    if (client->set.temp_path_prefix == NULL) {
        i_error("imapc: temp_path_prefix not set, "
            "can't create temp file");
        return -1;
    }

    path = t_str_new(128);
    str_append(path, client->set.temp_path_prefix);
    fd = safe_mkstemp(path, 0600, (uid_t)-1, (gid_t)-1);
    if (fd == -1) {
        i_error("safe_mkstemp(%s) failed: %m", str_c(path));
        return -1;
    }

    /* we just want the fd, unlink it */
    if (i_unlink(str_c(path)) < 0) {
        /* shouldn't happen.. */
        i_close_fd(&fd);
        return -1;
    }
    *path_r = str_c(path);
    return fd;
}

void imapc_client_register_state_change_callback(struct imapc_client *client,
                         imapc_state_change_callback_t *cb,
                         void *context)
{
    i_assert(client->state_change_callback == NULL);
    i_assert(client->state_change_context == NULL);

    client->state_change_callback = cb;
    client->state_change_context = context;
}

void
imapc_client_set_login_callback(struct imapc_client *client,
                imapc_command_callback_t *callback, void *context)
{
    client->login_callback = callback;
    client->login_context  = context;
}