lmtp: proxy - Add per-connection counter to session_id

This way connections to two different backends don't try to use the same
session_id. Add 'P' letter before the counter to clarify that it's the
proxy connection counter.

diff --git a/src/lmtp/lmtp-proxy.c b/src/lmtp/lmtp-proxy.c
index d8a6d7beb75dea0d15f2594ba347793f31bca173..bf03c756ab1f3dbbd5e20036a1d86c8da98a24de 100644 (file)
--- a/src/lmtp/lmtp-proxy.c
+++ b/src/lmtp/lmtp-proxy.c
@@ -87,6 +87,7 @@ struct lmtp_proxy {
        struct istream *data_input;
 
        unsigned int max_timeout_msecs;
+       unsigned int proxy_session_seq;
 
        bool finished:1;
 };
@@ -126,6 +127,8 @@ lmtp_proxy_init(struct client *client,
                                              &lmtp_set.proxy_data);
        lmtp_set.proxy_data.source_ip = client->remote_ip;
        lmtp_set.proxy_data.source_port = client->remote_port;
+       /* This initial session_id is used only locally by lib-smtp. Each LMTP
+          proxy connection gets a more specific updated session_id. */
        lmtp_set.proxy_data.session = trans->id;
        if (lmtp_set.proxy_data.ttl_plus_1 == 0)
                lmtp_set.proxy_data.ttl_plus_1 = LMTP_PROXY_DEFAULT_TTL + 1;
@@ -279,6 +282,11 @@ lmtp_proxy_get_connection(struct lmtp_proxy *proxy,
                        conn->set.host, conn->set.port,
                        ssl_mode, &lmtp_set);
        }
+       struct smtp_proxy_data proxy_data = {
+               .session = t_strdup_printf("%s:P%u", proxy->trans->id,
+                                          ++proxy->proxy_session_seq),
+       };
+       smtp_client_connection_update_proxy_data(conn->lmtp_conn, &proxy_data);
        smtp_client_connection_accept_extra_capability(conn->lmtp_conn,
                                                       &cap_rcpt_forward);
        smtp_client_connection_connect(conn->lmtp_conn, NULL, NULL);