proxy-dict with tcp connection

[Aki Tuomi]

> On August 3, 2017 at 2:10 PM Ralf Becker <rb at egroupware.org> wrote:
> 
> 
> I try to create a patch to allow (proxy-)dict to use tcp connections
> instead of a unix domain socket.
> 
> I'm replacing connection_init_client_unix with connection_init_client_ip:
> 
> --- ./src/lib-dict/dict-client.c.orig
> +++ ./src/lib-dict/dict-client.c
> @@ -721,6 +721,10 @@ client_dict_init(struct dict *driver, const char *uri,
>      struct ioloop *old_ioloop = current_ioloop;
>      struct client_dict *dict;
>      const char *p, *dest_uri, *path;
> +    const char *const *args;
> +    unsigned int argc;
> +    struct ip_addr ip;
> +    in_port_t port=0;
>      unsigned int idle_msecs = DICT_CLIENT_DEFAULT_TIMEOUT_MSECS;
>      unsigned int warn_slow_msecs = DICT_CLIENT_DEFAULT_WARN_SLOW_MSECS;
> 
> @@ -772,7 +776,21 @@ client_dict_init(struct dict *driver, const char *uri,
>      dict->warn_slow_msecs = warn_slow_msecs;
>      i_array_init(&dict->cmds, 32);
> 
> -    if (uri[0] == ':') {
> +    args = t_strsplit(uri, ":");
> +    for(argc=0; args[argc] != NULL; argc++);
> +
> +    if (argc == 3) {    /* host:ip:somewhere --> argc == 3 */
> +        if (net_addr2ip(args[0], &ip) < 0) {
> +            *error_r = t_strdup_printf("Invalid IP: %s in URI: %s",
> args[0], uri);
> +            return -1;
> +        }
> +        if (net_str2port(args[1], &port) < 0) {
> +            *error_r = t_strdup_printf("Invalid port: %s in URI: %s",
> args[1], uri);
> +            return -1;
> +        }
> +        dest_uri = strrchr(uri, ':');
> +    } else if (uri[0] == ':') {
>          /* default path */
>          path = t_strconcat(set->base_dir,
>              "/"DEFAULT_DICT_SERVER_SOCKET_FNAME, NULL);
> @@ -784,7 +802,13 @@ client_dict_init(struct dict *driver, const char *uri,
>          path = t_strconcat(set->base_dir, "/",
>              t_strdup_until(uri, dest_uri), NULL);
>      }
> -    connection_init_client_unix(dict_connections, &dict->conn.conn, path);
> +    if (port > 0) {
> +        connection_init_client_ip(dict_connections, &dict->conn.conn,
> &ip, port);
> +    } else {
> +        connection_init_client_unix(dict_connections, &dict->conn.conn,
> path);
> +    }
>      dict->uri = i_strdup(dest_uri + 1);
> 
>      dict->ioloop = io_loop_create();
> 
> But unfortunately this crashes:
> 
> Jul 28 13:20:04 auth: Error: auth worker: Aborted PASSL request for
> info at outdoor-training.de: Worker process died unexpectedly
> Jul 28 13:20:04 auth-worker(705): Fatal: master: service(auth-worker):
> child 705 killed with signal 11 (core dumped)
> Jul 28 13:20:04 doveadm(10.44.88.1,info at outdoor-training.de): Error:
> user info at outdoor-training.de: Auth PASS lookup failed
> 
> It looks like the tcp connection gets opened non-blocking and the first
> write / dict lookup happens to early:
> 
> 4303041 13:44:25.120398220 0 auth (29884) < connect
> res=-115(EINPROGRESS) tuple=172.18.0.2:47552->10.44.99.180:2001
> 
> Looking at dict-memcached-ascii.c I probably need to do something like:
> 
>     i_array_init(&dict->input_states, 4);
>     i_array_init(&dict->replies, 4);
> 
>     dict->ioloop = io_loop_create();
>     io_loop_set_current(old_ioloop);
>     *dict_r = &dict->dict;
> 
> to wait until the socket is ready ...
> 
> Any idea / tips?
> 
> Ralf

It's probably cleaner to make a "proxy-tcp" driver so parsing all the funny things gets easier. Also it will require some restructing in the client_dict_connect code.

Aki