ngx_mail_init_connection(ngx_connection_t *c)
{
    size_t                     len;
    ngx_uint_t                 i;
    ngx_event_t               *rev;
    ngx_mail_port_t           *port;
    struct sockaddr           *sa;
    struct sockaddr_in        *sin;
    ngx_mail_log_ctx_t        *ctx;
    ngx_mail_in_addr_t        *addr;
    ngx_mail_session_t        *s;
    ngx_mail_addr_conf_t      *addr_conf;
    ngx_mail_core_srv_conf_t  *cscf;
    u_char                     text[NGX_SOCKADDR_STRLEN];
#if (NGX_HAVE_INET6)
    struct sockaddr_in6       *sin6;
    ngx_mail_in6_addr_t       *addr6;
#endif


    /* find the server configuration for the address:port */

    port = c->listening->servers;

    if (port->naddrs > 1) {

        /*
         * There are several addresses on this port and one of them
         * is the "*:port" wildcard so getsockname() is needed to determine
         * the server address.
         *
         * AcceptEx() already gave this address.
         */

        if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) {
            ngx_mail_close_connection(c);
            return;
        }

        sa = c->local_sockaddr;

        switch (sa->sa_family) {

#if (NGX_HAVE_INET6)
        case AF_INET6:
            sin6 = (struct sockaddr_in6 *) sa;

            addr6 = port->addrs;

            /* the last address is "*" */

            for (i = 0; i < port->naddrs - 1; i++) {
                if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) {
                    break;
                }
            }

            addr_conf = &addr6[i].conf;

            break;
#endif

        default: /* AF_INET */
            sin = (struct sockaddr_in *) sa;

            addr = port->addrs;

            /* the last address is "*" */

            for (i = 0; i < port->naddrs - 1; i++) {
                if (addr[i].addr == sin->sin_addr.s_addr) {
                    break;
                }
            }

            addr_conf = &addr[i].conf;

            break;
        }

    } else {
        switch (c->local_sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
        case AF_INET6:
            addr6 = port->addrs;
            addr_conf = &addr6[0].conf;
            break;
#endif

        default: /* AF_INET */
            addr = port->addrs;
            addr_conf = &addr[0].conf;
            break;
        }
    }

    s = ngx_pcalloc(c->pool, sizeof(ngx_mail_session_t));
    if (s == NULL) {
        ngx_mail_close_connection(c);
        return;
    }

    s->signature = NGX_MAIL_MODULE;

    s->main_conf = addr_conf->ctx->main_conf;
    s->srv_conf = addr_conf->ctx->srv_conf;

#if (NGX_MAIL_SSL)
    s->ssl = addr_conf->ssl;
#endif

    s->addr_text = &addr_conf->addr_text;

    c->data = s;
    s->connection = c;

    cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

    ngx_set_connection_log(c, cscf->error_log);

    len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1);

    ngx_log_error(NGX_LOG_INFO, c->log, 0, "*%uA client %*s connected to %V",
                  c->number, len, text, s->addr_text);

    ctx = ngx_palloc(c->pool, sizeof(ngx_mail_log_ctx_t));
    if (ctx == NULL) {
        ngx_mail_close_connection(c);
        return;
    }

    ctx->client = &c->addr_text;
    ctx->session = s;

    c->log->connection = c->number;
    c->log->handler = ngx_mail_log_error;
    c->log->data = ctx;
    c->log->action = "sending client greeting line";

    c->log_error = NGX_ERROR_INFO;

    rev = c->read;
    rev->handler = ngx_mail_init_session_handler;

    if (addr_conf->proxy_protocol) {
        c->log->action = "reading PROXY protocol";

        rev->handler = ngx_mail_proxy_protocol_handler;

        if (!rev->ready) {
            ngx_add_timer(rev, cscf->timeout);

            if (ngx_handle_read_event(rev, 0) != NGX_OK) {
                ngx_mail_close_connection(c);
            }

            return;
        }
    }

    if (ngx_use_accept_mutex) {
        ngx_post_event(rev, &ngx_posted_events);
        return;
    }

    rev->handler(rev);
}