Merge "core: Tweak startup order."
[asterisk/asterisk.git] / main / tcptls.c
index f51a447..02a2af5 100644 (file)
  * \author Brett Bryant <brettbryant@gmail.com>
  */
 
-#include "asterisk.h"
+/*** MODULEINFO
+       <use type="external">openssl</use>
+       <support_level>core</support_level>
+ ***/
 
-ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+#include "asterisk.h"
 
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
 
-#include <sys/signal.h>
+#include <signal.h>
+#include <sys/stat.h>
 
 #include "asterisk/compat.h"
 #include "asterisk/tcptls.h"
+#include "asterisk/io.h"
 #include "asterisk/http.h"
 #include "asterisk/utils.h"
 #include "asterisk/strings.h"
 #include "asterisk/options.h"
 #include "asterisk/manager.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/pbx.h"
+#include "asterisk/app.h"
 
-/*! \brief
- * replacement read/write functions for SSL support.
- * We use wrappers rather than SSL_read/SSL_write directly so
- * we can put in some debugging.
- */
-
-#ifdef DO_SSL
-static HOOK_T ssl_read(void *cookie, char *buf, LEN_T len)
+static void session_instance_destructor(void *obj)
 {
-       int i = SSL_read(cookie, buf, len-1);
-#if 0
-       if (i >= 0)
-               buf[i] = '\0';
-       ast_verb(0, "ssl read size %d returns %d <%s>\n", (int)len, i, buf);
-#endif
-       return i;
-}
+       struct ast_tcptls_session_instance *i = obj;
 
-static HOOK_T ssl_write(void *cookie, const char *buf, LEN_T len)
-{
-#if 0
-       char *s = alloca(len+1);
-       strncpy(s, buf, len);
-       s[len] = '\0';
-       ast_verb(0, "ssl write size %d <%s>\n", (int)len, s);
-#endif
-       return SSL_write(cookie, buf, len);
+       if (i->stream) {
+               ast_iostream_close(i->stream);
+               i->stream = NULL;
+       }
+       ast_free(i->overflow_buf);
+       ao2_cleanup(i->private_data);
 }
 
-static int ssl_close(void *cookie)
+#ifdef DO_SSL
+static int check_tcptls_cert_name(ASN1_STRING *cert_str, const char *hostname, const char *desc)
 {
-       close(SSL_get_fd(cookie));
-       SSL_shutdown(cookie);
-       SSL_free(cookie);
-       return 0;
-}
-#endif /* DO_SSL */
+       unsigned char *str;
+       int ret;
 
-HOOK_T ast_tcptls_server_read(struct ast_tcptls_session_instance *ser, void *buf, size_t count)
-{
-       if (ser->fd == -1) {
-               ast_log(LOG_ERROR, "server_read called with an fd of -1\n");
-               errno = EIO;
+       ret = ASN1_STRING_to_UTF8(&str, cert_str);
+       if (ret < 0 || !str) {
                return -1;
        }
 
-#ifdef DO_SSL
-       if (ser->ssl)
-               return ssl_read(ser->ssl, buf, count);
-#endif
-       return read(ser->fd, buf, count);
+       if (strlen((char *) str) != ret) {
+               ast_log(LOG_WARNING, "Invalid certificate %s length (contains NULL bytes?)\n", desc);
+
+               ret = -1;
+       } else if (!strcasecmp(hostname, (char *) str)) {
+               ret = 0;
+       } else {
+               ret = -1;
+       }
+
+       ast_debug(3, "SSL %s compare s1='%s' s2='%s'\n", desc, hostname, str);
+       OPENSSL_free(str);
+
+       return ret;
 }
+#endif
 
-HOOK_T ast_tcptls_server_write(struct ast_tcptls_session_instance *ser, void *buf, size_t count)
+/*! \brief
+* creates a FILE * from the fd passed by the accept thread.
+* This operation is potentially expensive (certificate verification),
+* so we do it in the child thread context.
+*
+* \note must decrement ref count before returning NULL on error
+*/
+static void *handle_tcptls_connection(void *data)
 {
-       if (ser->fd == -1) {
-               ast_log(LOG_ERROR, "server_write called with an fd of -1\n");
-               errno = EIO;
-               return -1;
+       struct ast_tcptls_session_instance *tcptls_session = data;
+#ifdef DO_SSL
+       SSL *ssl;
+#endif
+
+       /* TCP/TLS connections are associated with external protocols, and
+        * should not be allowed to execute 'dangerous' functions. This may
+        * need to be pushed down into the individual protocol handlers, but
+        * this seems like a good general policy.
+        */
+       if (ast_thread_inhibit_escalations()) {
+               ast_log(LOG_ERROR, "Failed to inhibit privilege escalations; killing connection\n");
+               ast_tcptls_close_session_file(tcptls_session);
+               ao2_ref(tcptls_session, -1);
+               return NULL;
        }
 
+       if (tcptls_session->parent->tls_cfg) {
 #ifdef DO_SSL
-       if (ser->ssl)
-               return ssl_write(ser->ssl, buf, count);
-#endif
-       return write(ser->fd, buf, count);
-}
+               if (ast_iostream_start_tls(&tcptls_session->stream, tcptls_session->parent->tls_cfg->ssl_ctx, tcptls_session->client) < 0) {
+                       ast_tcptls_close_session_file(tcptls_session);
+                       ao2_ref(tcptls_session, -1);
+                       return NULL;
+               }
 
-static void session_instance_destructor(void *obj)
-{
-       struct ast_tcptls_session_instance *i = obj;
-       ast_mutex_destroy(&i->lock);
+               ssl = ast_iostream_get_ssl(tcptls_session->stream);
+               if ((tcptls_session->client && !ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
+                       || (!tcptls_session->client && ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
+                       X509 *peer;
+                       long res;
+                       peer = SSL_get_peer_certificate(ssl);
+                       if (!peer) {
+                               ast_log(LOG_ERROR, "No peer SSL certificate to verify\n");
+                               ast_tcptls_close_session_file(tcptls_session);
+                               ao2_ref(tcptls_session, -1);
+                               return NULL;
+                       }
+
+                       res = SSL_get_verify_result(ssl);
+                       if (res != X509_V_OK) {
+                               ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
+                               X509_free(peer);
+                               ast_tcptls_close_session_file(tcptls_session);
+                               ao2_ref(tcptls_session, -1);
+                               return NULL;
+                       }
+                       if (!ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
+                               ASN1_STRING *str;
+                               X509_NAME *name = X509_get_subject_name(peer);
+                               STACK_OF(GENERAL_NAME) *alt_names;
+                               int pos = -1;
+                               int found = 0;
+
+                               for (;;) {
+                                       /* Walk the certificate to check all available "Common Name" */
+                                       /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
+                                       pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
+                                       if (pos < 0) {
+                                               break;
+                                       }
+                                       str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
+                                       if (!check_tcptls_cert_name(str, tcptls_session->parent->hostname, "common name")) {
+                                               found = 1;
+                                               break;
+                                       }
+                               }
+
+                               if (!found) {
+                                       alt_names = X509_get_ext_d2i(peer, NID_subject_alt_name, NULL, NULL);
+                                       if (alt_names != NULL) {
+                                               int alt_names_count = sk_GENERAL_NAME_num(alt_names);
+
+                                               for (pos = 0; pos < alt_names_count; pos++) {
+                                                       const GENERAL_NAME *alt_name = sk_GENERAL_NAME_value(alt_names, pos);
+
+                                                       if (alt_name->type != GEN_DNS) {
+                                                               continue;
+                                                       }
+
+                                                       if (!check_tcptls_cert_name(alt_name->d.dNSName, tcptls_session->parent->hostname, "alt name")) {
+                                                               found = 1;
+                                                               break;
+                                                       }
+                                               }
+
+                                               sk_GENERAL_NAME_pop_free(alt_names, GENERAL_NAME_free);
+                                       }
+                               }
+
+                               if (!found) {
+                                       ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", tcptls_session->parent->hostname);
+                                       X509_free(peer);
+                                       ast_tcptls_close_session_file(tcptls_session);
+                                       ao2_ref(tcptls_session, -1);
+                                       return NULL;
+                               }
+                       }
+                       X509_free(peer);
+               }
+#else
+               ast_log(LOG_ERROR, "Attempted a TLS connection without OpenSSL support. This will not work!\n");
+               ast_tcptls_close_session_file(tcptls_session);
+               ao2_ref(tcptls_session, -1);
+               return NULL;
+#endif /* DO_SSL */
+       }
+
+       if (tcptls_session->parent->worker_fn) {
+               return tcptls_session->parent->worker_fn(tcptls_session);
+       } else {
+               return tcptls_session;
+       }
 }
 
 void *ast_tcptls_server_root(void *data)
 {
-       struct server_args *desc = data;
+       struct ast_tcptls_session_args *desc = data;
        int fd;
-       struct sockaddr_in sin;
-       socklen_t sinlen;
-       struct ast_tcptls_session_instance *ser;
+       struct ast_sockaddr addr;
+       struct ast_tcptls_session_instance *tcptls_session;
        pthread_t launched;
-       
+
        for (;;) {
-               int i, flags;
+               int i;
 
-               if (desc->periodic_fn)
+               if (desc->periodic_fn) {
                        desc->periodic_fn(desc);
+               }
                i = ast_wait_for_input(desc->accept_fd, desc->poll_timeout);
-               if (i <= 0)
+               if (i <= 0) {
+                       /* Prevent tight loop from hogging CPU */
+                       usleep(1);
                        continue;
-               sinlen = sizeof(sin);
-               fd = accept(desc->accept_fd, (struct sockaddr *)&sin, &sinlen);
+               }
+               fd = ast_accept(desc->accept_fd, &addr);
                if (fd < 0) {
-                       if ((errno != EAGAIN) && (errno != EINTR))
-                               ast_log(LOG_WARNING, "Accept failed: %s\n", strerror(errno));
+                       if (errno != EAGAIN
+                               && errno != EWOULDBLOCK
+                               && errno != EINTR
+                               && errno != ECONNABORTED) {
+                               ast_log(LOG_ERROR, "TCP/TLS accept failed: %s\n", strerror(errno));
+                               if (errno != EMFILE) {
+                                       break;
+                               }
+                       }
+                       /* Prevent tight loop from hogging CPU */
+                       usleep(1);
                        continue;
                }
-               ser = ao2_alloc(sizeof(*ser), session_instance_destructor);
-               if (!ser) {
-                       ast_log(LOG_WARNING, "No memory for new session: %s\n", strerror(errno));
+               tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
+               if (!tcptls_session) {
                        close(fd);
                        continue;
                }
 
-               ast_mutex_init(&ser->lock);
+               tcptls_session->overflow_buf = ast_str_create(128);
+               if (!tcptls_session->overflow_buf) {
+                       ao2_ref(tcptls_session, -1);
+                       close(fd);
+                       continue;
+               }
+               ast_fd_clear_flags(fd, O_NONBLOCK);
 
-               flags = fcntl(fd, F_GETFL);
-               fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
-               ser->fd = fd;
-               ser->parent = desc;
-               memcpy(&ser->requestor, &sin, sizeof(ser->requestor));
+               tcptls_session->stream = ast_iostream_from_fd(&fd);
+               if (!tcptls_session->stream) {
+                       ao2_ref(tcptls_session, -1);
+                       close(fd);
+                       continue;
+               }
 
-               ser->client = 0;
-                       
-               if (ast_pthread_create_detached_background(&launched, NULL, ast_make_file_from_fd, ser)) {
-                       ast_log(LOG_WARNING, "Unable to launch helper thread: %s\n", strerror(errno));
-                       close(ser->fd);
-                       ao2_ref(ser, -1);
+               tcptls_session->parent = desc;
+               ast_sockaddr_copy(&tcptls_session->remote_address, &addr);
+
+               tcptls_session->client = 0;
+
+               /* This thread is now the only place that controls the single ref to tcptls_session */
+               if (ast_pthread_create_detached_background(&launched, NULL, handle_tcptls_connection, tcptls_session)) {
+                       ast_log(LOG_ERROR, "TCP/TLS unable to launch helper thread: %s\n",
+                               strerror(errno));
+                       ao2_ref(tcptls_session, -1);
                }
        }
+
+       ast_log(LOG_ERROR, "TCP/TLS listener thread ended abnormally\n");
+
+       /* Close the listener socket so Asterisk doesn't appear dead. */
+       fd = desc->accept_fd;
+       desc->accept_fd = -1;
+       if (0 <= fd) {
+               close(fd);
+       }
        return NULL;
 }
 
+#ifdef DO_SSL
+static void __ssl_setup_certs(struct ast_tls_config *cfg, const size_t cert_file_len, const char *key_type_extension, const char *key_type)
+{
+       char *cert_file = ast_strdupa(cfg->certfile);
+
+       memcpy(cert_file + cert_file_len - 8, key_type_extension, 5);
+       if (access(cert_file, F_OK) == 0) {
+               if (SSL_CTX_use_certificate_chain_file(cfg->ssl_ctx, cert_file) == 0) {
+                       ast_log(LOG_WARNING, "TLS/SSL error loading public %s key (certificate) from <%s>.\n", key_type, cert_file);
+               } else if (SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, cert_file, SSL_FILETYPE_PEM) == 0) {
+                       ast_log(LOG_WARNING, "TLS/SSL error loading private %s key from <%s>.\n", key_type, cert_file);
+               } else if (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0) {
+                       ast_log(LOG_WARNING, "TLS/SSL error matching private %s key and certificate in <%s>.\n", key_type, cert_file);
+               }
+       }
+}
+#endif
+
 static int __ssl_setup(struct ast_tls_config *cfg, int client)
 {
 #ifndef DO_SSL
-       cfg->enabled = 0;
+       if (cfg->enabled) {
+               ast_log(LOG_NOTICE, "Configured without OpenSSL Development Headers");
+               cfg->enabled = 0;
+       }
        return 0;
 #else
-       if (!cfg->enabled)
+       int disable_ssl = 0;
+       long ssl_opts = 0;
+
+       if (!cfg->enabled) {
                return 0;
+       }
+
+       /* Get rid of an old SSL_CTX since we're about to
+        * allocate a new one
+        */
+       if (cfg->ssl_ctx) {
+               SSL_CTX_free(cfg->ssl_ctx);
+               cfg->ssl_ctx = NULL;
+       }
 
-       SSL_load_error_strings();
-       SSLeay_add_ssl_algorithms();
+       if (client) {
+#if !defined(OPENSSL_NO_SSL2) && (OPENSSL_VERSION_NUMBER < 0x10100000L)
+               if (ast_test_flag(&cfg->flags, AST_SSL_SSLV2_CLIENT)) {
+                       ast_log(LOG_WARNING, "Usage of SSLv2 is discouraged due to known vulnerabilities. Please use 'tlsv1' or leave the TLS method unspecified!\n");
+                       cfg->ssl_ctx = SSL_CTX_new(SSLv2_client_method());
+               } else
+#endif
+#ifndef OPENSSL_NO_SSL3_METHOD
+               if (ast_test_flag(&cfg->flags, AST_SSL_SSLV3_CLIENT)) {
+                       ast_log(LOG_WARNING, "Usage of SSLv3 is discouraged due to known vulnerabilities. Please use 'tlsv1' or leave the TLS method unspecified!\n");
+                       cfg->ssl_ctx = SSL_CTX_new(SSLv3_client_method());
+               } else
+#endif
+#if defined(OPENSSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER  >= 0x10100000L)
+               cfg->ssl_ctx = SSL_CTX_new(TLS_client_method());
+#else
+               if (ast_test_flag(&cfg->flags, AST_SSL_TLSV1_CLIENT)) {
+                       cfg->ssl_ctx = SSL_CTX_new(TLSv1_client_method());
+               } else {
+                       disable_ssl = 1;
+                       cfg->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
+               }
+#endif
+       } else {
+               disable_ssl = 1;
+               cfg->ssl_ctx = SSL_CTX_new(SSLv23_server_method());
+       }
 
-       if (!(cfg->ssl_ctx = SSL_CTX_new( client ? SSLv23_client_method() : SSLv23_server_method() ))) {
+       if (!cfg->ssl_ctx) {
                ast_debug(1, "Sorry, SSL_CTX_new call returned null...\n");
                cfg->enabled = 0;
                return 0;
        }
+
+       /* Due to the POODLE vulnerability, completely disable
+        * SSLv2 and SSLv3 if we are not explicitly told to use
+        * them. SSLv23_*_method supports TLSv1+.
+        */
+       if (disable_ssl) {
+               ssl_opts |= SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
+       }
+
+       if (ast_test_flag(&cfg->flags, AST_SSL_SERVER_CIPHER_ORDER)) {
+               ssl_opts |= SSL_OP_CIPHER_SERVER_PREFERENCE;
+       }
+
+       if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV1)) {
+               ssl_opts |= SSL_OP_NO_TLSv1;
+       }
+#if defined(HAVE_SSL_OP_NO_TLSV1_1) && defined(HAVE_SSL_OP_NO_TLSV1_2)
+       if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV11)) {
+               ssl_opts |= SSL_OP_NO_TLSv1_1;
+       }
+       if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV12)) {
+               ssl_opts |= SSL_OP_NO_TLSv1_2;
+       }
+#else
+       ast_log(LOG_WARNING, "Your version of OpenSSL leaves you potentially vulnerable "
+                       "to the SSL BEAST attack. Please upgrade to OpenSSL 1.0.1 or later\n");
+#endif
+
+       SSL_CTX_set_options(cfg->ssl_ctx, ssl_opts);
+
+       SSL_CTX_set_verify(cfg->ssl_ctx,
+               ast_test_flag(&cfg->flags, AST_SSL_VERIFY_CLIENT) ? SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT : SSL_VERIFY_NONE,
+               NULL);
+
        if (!ast_strlen_zero(cfg->certfile)) {
-               if (SSL_CTX_use_certificate_file(cfg->ssl_ctx, cfg->certfile, SSL_FILETYPE_PEM) == 0 ||
-                   SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, cfg->certfile, SSL_FILETYPE_PEM) == 0 ||
-                   SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 ) {
+               char *tmpprivate = ast_strlen_zero(cfg->pvtfile) ? cfg->certfile : cfg->pvtfile;
+               if (SSL_CTX_use_certificate_chain_file(cfg->ssl_ctx, cfg->certfile) == 0) {
                        if (!client) {
                                /* Clients don't need a certificate, but if its setup we can use it */
-                               ast_verb(0, "SSL cert error <%s>", cfg->certfile);
-                               sleep(2);
+                               ast_log(LOG_ERROR, "TLS/SSL error loading cert file. <%s>\n", cfg->certfile);
                                cfg->enabled = 0;
+                               SSL_CTX_free(cfg->ssl_ctx);
+                               cfg->ssl_ctx = NULL;
                                return 0;
                        }
                }
+               if ((SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, tmpprivate, SSL_FILETYPE_PEM) == 0) || (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 )) {
+                       if (!client) {
+                               /* Clients don't need a private key, but if its setup we can use it */
+                               ast_log(LOG_ERROR, "TLS/SSL error loading private key file. <%s>\n", tmpprivate);
+                               cfg->enabled = 0;
+                               SSL_CTX_free(cfg->ssl_ctx);
+                               cfg->ssl_ctx = NULL;
+                               return 0;
+                       }
+               }
+               if (!client) {
+                       size_t certfile_len = strlen(cfg->certfile);
+
+                       /* expects a file name which contains _rsa. like asterisk_rsa.pem
+                        * ignores any 3-character file-extension like .pem, .cer, .crt
+                        */
+                       if (certfile_len >= 8 && !strncmp(cfg->certfile + certfile_len - 8, "_rsa.", 5)) {
+                               __ssl_setup_certs(cfg, certfile_len, "_ecc.", "ECC");
+                               __ssl_setup_certs(cfg, certfile_len, "_dsa.", "DSA");
+                       }
+               }
        }
        if (!ast_strlen_zero(cfg->cipher)) {
                if (SSL_CTX_set_cipher_list(cfg->ssl_ctx, cfg->cipher) == 0 ) {
                        if (!client) {
-                               ast_verb(0, "SSL cipher error <%s>", cfg->cipher);
-                               sleep(2);
+                               ast_log(LOG_ERROR, "TLS/SSL cipher error <%s>\n", cfg->cipher);
                                cfg->enabled = 0;
+                               SSL_CTX_free(cfg->ssl_ctx);
+                               cfg->ssl_ctx = NULL;
                                return 0;
                        }
                }
        }
        if (!ast_strlen_zero(cfg->cafile) || !ast_strlen_zero(cfg->capath)) {
-               if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0)
-                       ast_verb(0, "SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
+               if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0) {
+                       ast_log(LOG_ERROR, "TLS/SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
+               }
+       }
+
+#ifdef HAVE_OPENSSL_EC
+
+       if (!ast_strlen_zero(cfg->pvtfile)) {
+               BIO *bio = BIO_new_file(cfg->pvtfile, "r");
+               if (bio != NULL) {
+                       DH *dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
+                       if (dh != NULL) {
+                               if (SSL_CTX_set_tmp_dh(cfg->ssl_ctx, dh)) {
+                                       long options = SSL_OP_CIPHER_SERVER_PREFERENCE | SSL_OP_SINGLE_DH_USE | SSL_OP_SINGLE_ECDH_USE;
+                                       options = SSL_CTX_set_options(cfg->ssl_ctx, options);
+                                       ast_verb(2, "TLS/SSL DH initialized, PFS cipher-suites enabled\n");
+                               }
+                               DH_free(dh);
+                       }
+                       BIO_free(bio);
+               }
+       }
+       #ifndef SSL_CTRL_SET_ECDH_AUTO
+               #define SSL_CTRL_SET_ECDH_AUTO 94
+       #endif
+       /* SSL_CTX_set_ecdh_auto(cfg->ssl_ctx, on); requires OpenSSL 1.0.2 which wraps: */
+       if (SSL_CTX_ctrl(cfg->ssl_ctx, SSL_CTRL_SET_ECDH_AUTO, 1, NULL)) {
+               ast_verb(2, "TLS/SSL ECDH initialized (automatic), faster PFS ciphers enabled\n");
+       } else {
+               /* enables AES-128 ciphers, to get AES-256 use NID_secp384r1 */
+               EC_KEY *ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
+               if (ecdh != NULL) {
+                       if (SSL_CTX_set_tmp_ecdh(cfg->ssl_ctx, ecdh)) {
+                               ast_verb(2, "TLS/SSL ECDH initialized (secp256r1), faster PFS cipher-suites enabled\n");
+                       }
+                       EC_KEY_free(ecdh);
+               }
        }
 
-       ast_verb(0, "SSL certificate ok\n");
+#endif /* #ifdef HAVE_OPENSSL_EC */
+
+       ast_verb(2, "TLS/SSL certificate ok\n");        /* We should log which one that is ok. This message doesn't really make sense in production use */
        return 1;
 #endif
 }
@@ -222,118 +500,233 @@ int ast_ssl_setup(struct ast_tls_config *cfg)
        return __ssl_setup(cfg, 0);
 }
 
-/*! \brief A generic client routine for a TCP client
- *  and starts a thread for handling accept()
- */
-struct ast_tcptls_session_instance *ast_tcptls_client_start(struct server_args *desc)
+void ast_ssl_teardown(struct ast_tls_config *cfg)
+{
+#ifdef DO_SSL
+       if (cfg && cfg->ssl_ctx) {
+               SSL_CTX_free(cfg->ssl_ctx);
+               cfg->ssl_ctx = NULL;
+       }
+#endif
+}
+
+struct ast_tcptls_session_instance *ast_tcptls_client_start(struct ast_tcptls_session_instance *tcptls_session)
+{
+       struct ast_tcptls_session_args *desc;
+
+       if (!(desc = tcptls_session->parent)) {
+               goto client_start_error;
+       }
+
+       if (ast_connect(desc->accept_fd, &desc->remote_address)) {
+               ast_log(LOG_ERROR, "Unable to connect %s to %s: %s\n",
+                       desc->name,
+                       ast_sockaddr_stringify(&desc->remote_address),
+                       strerror(errno));
+               goto client_start_error;
+       }
+
+       ast_fd_clear_flags(desc->accept_fd, O_NONBLOCK);
+
+       if (desc->tls_cfg) {
+               desc->tls_cfg->enabled = 1;
+               __ssl_setup(desc->tls_cfg, 1);
+       }
+
+       return handle_tcptls_connection(tcptls_session);
+
+client_start_error:
+       if (desc) {
+               close(desc->accept_fd);
+               desc->accept_fd = -1;
+       }
+       ao2_ref(tcptls_session, -1);
+       return NULL;
+
+}
+
+struct ast_tcptls_session_instance *ast_tcptls_client_create(struct ast_tcptls_session_args *desc)
 {
-       int flags;
-       struct ast_tcptls_session_instance *ser = NULL;
+       int fd, x = 1;
+       struct ast_tcptls_session_instance *tcptls_session = NULL;
 
        /* Do nothing if nothing has changed */
-       if(!memcmp(&desc->oldsin, &desc->sin, sizeof(desc->oldsin))) {
+       if (!ast_sockaddr_cmp(&desc->old_address, &desc->remote_address)) {
                ast_debug(1, "Nothing changed in %s\n", desc->name);
                return NULL;
        }
 
-       desc->oldsin = desc->sin;
+       /* If we return early, there is no connection */
+       ast_sockaddr_setnull(&desc->old_address);
 
-       if (desc->accept_fd != -1)
+       if (desc->accept_fd != -1) {
                close(desc->accept_fd);
+       }
 
-       desc->accept_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+       fd = desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->remote_address) ?
+                                     AF_INET6 : AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (desc->accept_fd < 0) {
-               ast_log(LOG_WARNING, "Unable to allocate socket for %s: %s\n",
+               ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n",
                        desc->name, strerror(errno));
                return NULL;
        }
 
-       if (connect(desc->accept_fd, (const struct sockaddr *)&desc->sin, sizeof(desc->sin))) {
-               ast_log(LOG_ERROR, "Unable to connect %s to %s:%d: %s\n",
-                       desc->name,
-                       ast_inet_ntoa(desc->sin.sin_addr), ntohs(desc->sin.sin_port),
-                       strerror(errno));
-               goto error;
+       /* if a local address was specified, bind to it so the connection will
+          originate from the desired address */
+       if (!ast_sockaddr_isnull(&desc->local_address) &&
+           !ast_sockaddr_is_any(&desc->local_address)) {
+               setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
+               if (ast_bind(desc->accept_fd, &desc->local_address)) {
+                       ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
+                               desc->name,
+                               ast_sockaddr_stringify(&desc->local_address),
+                               strerror(errno));
+                       goto error;
+               }
        }
 
-       if (!(ser = ao2_alloc(sizeof(*ser), session_instance_destructor)))
+       tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
+       if (!tcptls_session) {
                goto error;
-
-       ast_mutex_init(&ser->lock);
-
-       flags = fcntl(desc->accept_fd, F_GETFL);
-       fcntl(desc->accept_fd, F_SETFL, flags & ~O_NONBLOCK);
-
-       ser->fd = desc->accept_fd;
-       ser->parent = desc;
-       ser->parent->worker_fn = NULL;
-       memcpy(&ser->requestor, &desc->sin, sizeof(ser->requestor));
-
-       ser->client = 1;
-
-       if (desc->tls_cfg) {
-               desc->tls_cfg->enabled = 1;
-               __ssl_setup(desc->tls_cfg, 1);
        }
 
-       ao2_ref(ser, +1);
-       if (!ast_make_file_from_fd(ser))
+       tcptls_session->overflow_buf = ast_str_create(128);
+       if (!tcptls_session->overflow_buf) {
+               goto error;
+       }
+       tcptls_session->client = 1;
+       tcptls_session->stream = ast_iostream_from_fd(&fd);
+       if (!tcptls_session->stream) {
                goto error;
+       }
 
-       return ser;
+       tcptls_session->parent = desc;
+       tcptls_session->parent->worker_fn = NULL;
+       ast_sockaddr_copy(&tcptls_session->remote_address,
+                         &desc->remote_address);
+
+       /* Set current info */
+       ast_sockaddr_copy(&desc->old_address, &desc->remote_address);
+       return tcptls_session;
 
 error:
        close(desc->accept_fd);
        desc->accept_fd = -1;
-       if (ser)
-               ao2_ref(ser, -1);
+       ao2_cleanup(tcptls_session);
        return NULL;
 }
 
-/*! \brief
- * This is a generic (re)start routine for a TCP server,
- * which does the socket/bind/listen and starts a thread for handling
- * accept().
- */
-void ast_tcptls_server_start(struct server_args *desc)
+void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 {
-       int flags;
        int x = 1;
-       
+       int tls_changed = 0;
+       int sd_socket;
+
+       if (desc->tls_cfg) {
+               char hash[41];
+               char *str = NULL;
+               struct stat st;
+
+               /* Store the hashes of the TLS certificate etc. */
+               if (stat(desc->tls_cfg->certfile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->certfile))) {
+                       memset(hash, 0, 41);
+               } else {
+                       ast_sha1_hash(hash, str);
+               }
+               ast_free(str);
+               str = NULL;
+               memcpy(desc->tls_cfg->certhash, hash, 41);
+               if (stat(desc->tls_cfg->pvtfile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->pvtfile))) {
+                       memset(hash, 0, 41);
+               } else {
+                       ast_sha1_hash(hash, str);
+               }
+               ast_free(str);
+               str = NULL;
+               memcpy(desc->tls_cfg->pvthash, hash, 41);
+               if (stat(desc->tls_cfg->cafile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->cafile))) {
+                       memset(hash, 0, 41);
+               } else {
+                       ast_sha1_hash(hash, str);
+               }
+               ast_free(str);
+               str = NULL;
+               memcpy(desc->tls_cfg->cahash, hash, 41);
+
+               /* Check whether TLS configuration has changed */
+               if (!desc->old_tls_cfg) { /* No previous configuration */
+                       tls_changed = 1;
+                       desc->old_tls_cfg = ast_calloc(1, sizeof(*desc->old_tls_cfg));
+               } else if (memcmp(desc->tls_cfg->certhash, desc->old_tls_cfg->certhash, 41)) {
+                       tls_changed = 1;
+               } else if (memcmp(desc->tls_cfg->pvthash, desc->old_tls_cfg->pvthash, 41)) {
+                       tls_changed = 1;
+               } else if (strcmp(desc->tls_cfg->cipher, desc->old_tls_cfg->cipher)) {
+                       tls_changed = 1;
+               } else if (memcmp(desc->tls_cfg->cahash, desc->old_tls_cfg->cahash, 41)) {
+                       tls_changed = 1;
+               } else if (strcmp(desc->tls_cfg->capath, desc->old_tls_cfg->capath)) {
+                       tls_changed = 1;
+               } else if (memcmp(&desc->tls_cfg->flags, &desc->old_tls_cfg->flags, sizeof(desc->tls_cfg->flags))) {
+                       tls_changed = 1;
+               }
+
+               if (tls_changed) {
+                       ast_debug(1, "Changed parameters for %s found\n", desc->name);
+               }
+       }
+
        /* Do nothing if nothing has changed */
-       if (!memcmp(&desc->oldsin, &desc->sin, sizeof(desc->oldsin))) {
+       if (!tls_changed && !ast_sockaddr_cmp(&desc->old_address, &desc->local_address)) {
                ast_debug(1, "Nothing changed in %s\n", desc->name);
                return;
        }
-       
-       desc->oldsin = desc->sin;
-       
+
+       /* If we return early, there is no one listening */
+       ast_sockaddr_setnull(&desc->old_address);
+
        /* Shutdown a running server if there is one */
        if (desc->master != AST_PTHREADT_NULL) {
                pthread_cancel(desc->master);
                pthread_kill(desc->master, SIGURG);
                pthread_join(desc->master, NULL);
        }
-       
-       if (desc->accept_fd != -1)
+
+       sd_socket = ast_sd_get_fd(SOCK_STREAM, &desc->local_address);
+
+       if (sd_socket != -1) {
+               if (desc->accept_fd != sd_socket) {
+                       if (desc->accept_fd != -1) {
+                               close(desc->accept_fd);
+                       }
+                       desc->accept_fd = sd_socket;
+               }
+
+               goto systemd_socket_activation;
+       }
+
+       if (desc->accept_fd != -1) {
                close(desc->accept_fd);
+       }
 
        /* If there's no new server, stop here */
-       if (desc->sin.sin_family == 0)
+       if (ast_sockaddr_isnull(&desc->local_address)) {
+               ast_debug(2, "Server disabled:  %s\n", desc->name);
                return;
+       }
 
-       desc->accept_fd = socket(AF_INET, SOCK_STREAM, 0);
+       desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->local_address) ?
+                                AF_INET6 : AF_INET, SOCK_STREAM, 0);
        if (desc->accept_fd < 0) {
-               ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n",
-                       desc->name, strerror(errno));
+               ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n", desc->name, strerror(errno));
                return;
        }
-       
+
        setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
-       if (bind(desc->accept_fd, (struct sockaddr *)&desc->sin, sizeof(desc->sin))) {
-               ast_log(LOG_ERROR, "Unable to bind %s to %s:%d: %s\n",
+       if (ast_bind(desc->accept_fd, &desc->local_address)) {
+               ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
                        desc->name,
-                       ast_inet_ntoa(desc->sin.sin_addr), ntohs(desc->sin.sin_port),
+                       ast_sockaddr_stringify(&desc->local_address),
                        strerror(errno));
                goto error;
        }
@@ -341,15 +734,36 @@ void ast_tcptls_server_start(struct server_args *desc)
                ast_log(LOG_ERROR, "Unable to listen for %s!\n", desc->name);
                goto error;
        }
-       flags = fcntl(desc->accept_fd, F_GETFL);
-       fcntl(desc->accept_fd, F_SETFL, flags | O_NONBLOCK);
+
+systemd_socket_activation:
+       ast_fd_set_flags(desc->accept_fd, O_NONBLOCK);
        if (ast_pthread_create_background(&desc->master, NULL, desc->accept_fn, desc)) {
-               ast_log(LOG_ERROR, "Unable to launch thread for %s on %s:%d: %s\n",
+               ast_log(LOG_ERROR, "Unable to launch thread for %s on %s: %s\n",
                        desc->name,
-                       ast_inet_ntoa(desc->sin.sin_addr), ntohs(desc->sin.sin_port),
+                       ast_sockaddr_stringify(&desc->local_address),
                        strerror(errno));
                goto error;
        }
+
+       /* Set current info */
+       ast_sockaddr_copy(&desc->old_address, &desc->local_address);
+       if (desc->old_tls_cfg) {
+               ast_free(desc->old_tls_cfg->certfile);
+               ast_free(desc->old_tls_cfg->pvtfile);
+               ast_free(desc->old_tls_cfg->cipher);
+               ast_free(desc->old_tls_cfg->cafile);
+               ast_free(desc->old_tls_cfg->capath);
+               desc->old_tls_cfg->certfile = ast_strdup(desc->tls_cfg->certfile);
+               desc->old_tls_cfg->pvtfile = ast_strdup(desc->tls_cfg->pvtfile);
+               desc->old_tls_cfg->cipher = ast_strdup(desc->tls_cfg->cipher);
+               desc->old_tls_cfg->cafile = ast_strdup(desc->tls_cfg->cafile);
+               desc->old_tls_cfg->capath = ast_strdup(desc->tls_cfg->capath);
+               memcpy(desc->old_tls_cfg->certhash, desc->tls_cfg->certhash, 41);
+               memcpy(desc->old_tls_cfg->pvthash, desc->tls_cfg->pvthash, 41);
+               memcpy(desc->old_tls_cfg->cahash, desc->tls_cfg->cahash, 41);
+               memcpy(&desc->old_tls_cfg->flags, &desc->tls_cfg->flags, sizeof(desc->old_tls_cfg->flags));
+       }
+
        return;
 
 error:
@@ -357,117 +771,93 @@ error:
        desc->accept_fd = -1;
 }
 
-/*! \brief Shutdown a running server if there is one */
-void ast_tcptls_server_stop(struct server_args *desc)
+void ast_tcptls_close_session_file(struct ast_tcptls_session_instance *tcptls_session)
+{
+       if (tcptls_session->stream) {
+               ast_iostream_close(tcptls_session->stream);
+               tcptls_session->stream = NULL;
+       } else {
+               ast_debug(1, "ast_tcptls_close_session_file invoked on session instance without file or file descriptor\n");
+       }
+}
+
+void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc)
 {
        if (desc->master != AST_PTHREADT_NULL) {
                pthread_cancel(desc->master);
                pthread_kill(desc->master, SIGURG);
                pthread_join(desc->master, NULL);
+               desc->master = AST_PTHREADT_NULL;
        }
-       if (desc->accept_fd != -1)
+       if (desc->accept_fd != -1) {
                close(desc->accept_fd);
+       }
        desc->accept_fd = -1;
+
+       if (desc->old_tls_cfg) {
+               ast_free(desc->old_tls_cfg->certfile);
+               ast_free(desc->old_tls_cfg->pvtfile);
+               ast_free(desc->old_tls_cfg->cipher);
+               ast_free(desc->old_tls_cfg->cafile);
+               ast_free(desc->old_tls_cfg->capath);
+               ast_free(desc->old_tls_cfg);
+               desc->old_tls_cfg = NULL;
+       }
+
+       ast_debug(2, "Stopped server :: %s\n", desc->name);
 }
 
-/*! \brief
-* creates a FILE * from the fd passed by the accept thread.
-* This operation is potentially expensive (certificate verification),
-* so we do it in the child thread context.
-*/
-void *ast_make_file_from_fd(void *data)
+int ast_tls_read_conf(struct ast_tls_config *tls_cfg, struct ast_tcptls_session_args *tls_desc, const char *varname, const char *value)
 {
-       struct ast_tcptls_session_instance *ser = data;
-#ifdef DO_SSL
-       int (*ssl_setup)(SSL *) = (ser->client) ? SSL_connect : SSL_accept;
-       int ret;
-       char err[256];
-#endif
-
-       /*
-       * open a FILE * as appropriate.
-       */
-       if (!ser->parent->tls_cfg)
-               ser->f = fdopen(ser->fd, "w+");
-#ifdef DO_SSL
-       else if ( (ser->ssl = SSL_new(ser->parent->tls_cfg->ssl_ctx)) ) {
-               SSL_set_fd(ser->ssl, ser->fd);
-               if ((ret = ssl_setup(ser->ssl)) <= 0) {
-                       ast_verb(2, "Problem setting up ssl connection: %s\n", ERR_error_string(ERR_get_error(), err));
-               } else {
-#if defined(HAVE_FUNOPEN)      /* the BSD interface */
-                       ser->f = funopen(ser->ssl, ssl_read, ssl_write, NULL, ssl_close);
-
-#elif defined(HAVE_FOPENCOOKIE)        /* the glibc/linux interface */
-                       static const cookie_io_functions_t cookie_funcs = {
-                               ssl_read, ssl_write, NULL, ssl_close
-                       };
-                       ser->f = fopencookie(ser->ssl, "w+", cookie_funcs);
-#else
-                       /* could add other methods here */
-                       ast_debug(2, "no ser->f methods attempted!");
-#endif
-                       if ((ser->client && !ast_test_flag(&ser->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
-                               || (!ser->client && ast_test_flag(&ser->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
-                               X509 *peer;
-                               long res;
-                               peer = SSL_get_peer_certificate(ser->ssl);
-                               if (!peer)
-                                       ast_log(LOG_WARNING, "No peer SSL certificate\n");
-                               res = SSL_get_verify_result(ser->ssl);
-                               if (res != X509_V_OK)
-                                       ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
-                               if (!ast_test_flag(&ser->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
-                                       ASN1_STRING *str;
-                                       unsigned char *str2;
-                                       X509_NAME *name = X509_get_subject_name(peer);
-                                       int pos = -1;
-                                       int found = 0;
-                               
-                                       for (;;) {
-                                               /* Walk the certificate to check all available "Common Name" */
-                                               /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
-                                               pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
-                                               if (pos < 0)
-                                                       break;
-                                               str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
-                                               ASN1_STRING_to_UTF8(&str2, str);
-                                               if (str2) {
-                                                       if (!strcasecmp(ser->parent->hostname, (char *) str2))
-                                                               found = 1;
-                                                       ast_debug(3, "SSL Common Name compare s1='%s' s2='%s'\n", ser->parent->hostname, str2);
-                                                       OPENSSL_free(str2);
-                                               }
-                                               if (found)
-                                                       break;
-                                       }
-                                       if (!found) {
-                                               ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", ser->parent->hostname);
-                                               if (peer)
-                                                       X509_free(peer);
-                                               fclose(ser->f);
-                                               return NULL;
-                                       }
-                               }
-                               if (peer)
-                                       X509_free(peer);
-                       }
+       if (!strcasecmp(varname, "tlsenable") || !strcasecmp(varname, "sslenable")) {
+               tls_cfg->enabled = ast_true(value) ? 1 : 0;
+       } else if (!strcasecmp(varname, "tlscertfile") || !strcasecmp(varname, "sslcert") || !strcasecmp(varname, "tlscert")) {
+               ast_free(tls_cfg->certfile);
+               tls_cfg->certfile = ast_strdup(value);
+       } else if (!strcasecmp(varname, "tlsprivatekey") || !strcasecmp(varname, "sslprivatekey")) {
+               ast_free(tls_cfg->pvtfile);
+               tls_cfg->pvtfile = ast_strdup(value);
+       } else if (!strcasecmp(varname, "tlscipher") || !strcasecmp(varname, "sslcipher")) {
+               ast_free(tls_cfg->cipher);
+               tls_cfg->cipher = ast_strdup(value);
+       } else if (!strcasecmp(varname, "tlscafile")) {
+               ast_free(tls_cfg->cafile);
+               tls_cfg->cafile = ast_strdup(value);
+       } else if (!strcasecmp(varname, "tlscapath") || !strcasecmp(varname, "tlscadir")) {
+               ast_free(tls_cfg->capath);
+               tls_cfg->capath = ast_strdup(value);
+       } else if (!strcasecmp(varname, "tlsverifyclient")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_VERIFY_CLIENT);
+       } else if (!strcasecmp(varname, "tlsdontverifyserver")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DONT_VERIFY_SERVER);
+       } else if (!strcasecmp(varname, "tlsbindaddr") || !strcasecmp(varname, "sslbindaddr")) {
+               if (ast_parse_arg(value, PARSE_ADDR, &tls_desc->local_address))
+                       ast_log(LOG_ERROR, "Invalid %s '%s'\n", varname, value);
+       } else if (!strcasecmp(varname, "tlsclientmethod") || !strcasecmp(varname, "sslclientmethod")) {
+               if (!strcasecmp(value, "tlsv1")) {
+                       ast_set_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
+                       ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
+                       ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
+               } else if (!strcasecmp(value, "sslv3")) {
+                       ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
+                       ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
+                       ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
+               } else if (!strcasecmp(value, "sslv2")) {
+                       ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
+                       ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
+                       ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
                }
-               if (!ser->f)    /* no success opening descriptor stacking */
-                       SSL_free(ser->ssl);
-   }
-#endif /* DO_SSL */
-
-       if (!ser->f) {
-               close(ser->fd);
-               ast_log(LOG_WARNING, "FILE * open failed!\n");
-               ao2_ref(ser, -1);
-               return NULL;
+       } else if (!strcasecmp(varname, "tlsservercipherorder")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_SERVER_CIPHER_ORDER);
+       } else if (!strcasecmp(varname, "tlsdisablev1")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV1);
+       } else if (!strcasecmp(varname, "tlsdisablev11")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV11);
+       } else if (!strcasecmp(varname, "tlsdisablev12")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV12);
+       } else {
+               return -1;
        }
 
-       if (ser && ser->parent->worker_fn)
-               return ser->parent->worker_fn(ser);
-       else
-               return ser;
+       return 0;
 }
-