s3: Fix the async echo responder for netbios keepalives
[obnox/samba-ctdb.git] / source3 / smbd / process.c
index caf92413372848b931a29667124d69facbbb7421..cf50417cff2428d4edd5e449dbb9aa67730d5f81 100644 (file)
@@ -26,22 +26,72 @@ extern bool global_machine_password_needs_changing;
 static void construct_reply_common(struct smb_request *req, const char *inbuf,
                                   char *outbuf);
 
+bool smbd_lock_socket(struct smbd_server_connection *sconn)
+{
+       bool ok;
+
+       if (smbd_server_conn->smb1.echo_handler.socket_lock_fd == -1) {
+               return true;
+       }
+
+       DEBUG(10,("pid[%d] wait for socket lock\n", (int)sys_getpid()));
+
+       ok = fcntl_lock(smbd_server_conn->smb1.echo_handler.socket_lock_fd,
+                       SMB_F_SETLKW, 0, 0, F_WRLCK);
+       if (!ok) {
+               return false;
+       }
+
+       DEBUG(10,("pid[%d] got for socket lock\n", (int)sys_getpid()));
+
+       return true;
+}
+
+bool smbd_unlock_socket(struct smbd_server_connection *sconn)
+{
+       bool ok;
+
+       if (smbd_server_conn->smb1.echo_handler.socket_lock_fd == -1) {
+               return true;
+       }
+
+       ok = fcntl_lock(smbd_server_conn->smb1.echo_handler.socket_lock_fd,
+                       SMB_F_SETLKW, 0, 0, F_UNLCK);
+       if (!ok) {
+               return false;
+       }
+
+       DEBUG(10,("pid[%d] unlocked socket\n", (int)sys_getpid()));
+
+       return true;
+}
+
 /* Accessor function for smb_read_error for smbd functions. */
 
 /****************************************************************************
  Send an smb to a fd.
 ****************************************************************************/
 
-bool srv_send_smb(int fd, char *buffer, bool do_encrypt,
-                 struct smb_perfcount_data *pcd)
+bool srv_send_smb(int fd, char *buffer,
+                 bool do_signing, uint32_t seqnum,
+                 bool do_encrypt,
+                 struct smb_perfcount_data *pcd)
 {
        size_t len = 0;
        size_t nwritten=0;
        ssize_t ret;
        char *buf_out = buffer;
+       bool ok;
 
-       /* Sign the outgoing packet if required. */
-       srv_calculate_sign_mac(buf_out);
+       ok = smbd_lock_socket(smbd_server_conn);
+       if (!ok) {
+               exit_server_cleanly("failed to lock socket");
+       }
+
+       if (do_signing) {
+               /* Sign the outgoing packet if required. */
+               srv_calculate_sign_mac(smbd_server_conn, buf_out, seqnum);
+       }
 
        if (do_encrypt) {
                NTSTATUS status = srv_encrypt_buffer(buffer, &buf_out);
@@ -58,8 +108,8 @@ bool srv_send_smb(int fd, char *buffer, bool do_encrypt,
        while (nwritten < len) {
                ret = write_data(fd,buf_out+nwritten,len - nwritten);
                if (ret <= 0) {
-                       DEBUG(0,("Error writing %d bytes to client. %d. (%s)\n",
-                               (int)len,(int)ret, strerror(errno) ));
+                       DEBUG(0,("pid[%d] Error writing %d bytes to client. %d. (%s)\n",
+                               (int)sys_getpid(), (int)len,(int)ret, strerror(errno) ));
                        srv_free_enc_buffer(buf_out);
                        goto out;
                }
@@ -70,6 +120,12 @@ bool srv_send_smb(int fd, char *buffer, bool do_encrypt,
        srv_free_enc_buffer(buf_out);
 out:
        SMB_PERFCOUNT_END(pcd);
+
+       ok = smbd_unlock_socket(smbd_server_conn);
+       if (!ok) {
+               exit_server_cleanly("failed to unlock socket");
+       }
+
        return true;
 }
 
@@ -275,7 +331,8 @@ static NTSTATUS receive_smb_raw_talloc(TALLOC_CTX *mem_ctx, int fd,
        if (CVAL(lenbuf,0) == 0 && min_recv_size &&
            (smb_len_large(lenbuf) > /* Could be a UNIX large writeX. */
                (min_recv_size + STANDARD_WRITE_AND_X_HEADER_SIZE)) &&
-           !srv_is_signing_active()) {
+           !srv_is_signing_active(smbd_server_conn) &&
+           smbd_server_conn->smb1.echo_handler.trusted_fde == NULL) {
 
                return receive_smb_raw_talloc_partial_read(
                        mem_ctx, lenbuf, fd, buffer, timeout, p_unread, plen);
@@ -311,7 +368,9 @@ static NTSTATUS receive_smb_raw_talloc(TALLOC_CTX *mem_ctx, int fd,
 static NTSTATUS receive_smb_talloc(TALLOC_CTX *mem_ctx,        int fd,
                                   char **buffer, unsigned int timeout,
                                   size_t *p_unread, bool *p_encrypted,
-                                  size_t *p_len)
+                                  size_t *p_len,
+                                  uint32_t *seqnum,
+                                  bool trusted_channel)
 {
        size_t len = 0;
        NTSTATUS status;
@@ -336,7 +395,7 @@ static NTSTATUS receive_smb_talloc(TALLOC_CTX *mem_ctx,     int fd,
        }
 
        /* Check the incoming SMB signature. */
-       if (!srv_check_sign_mac(*buffer, true)) {
+       if (!srv_check_sign_mac(smbd_server_conn, *buffer, seqnum, trusted_channel)) {
                DEBUG(0, ("receive_smb: SMB Signature verification failed on "
                          "incoming packet!\n"));
                return NT_STATUS_INVALID_NETWORK_RESPONSE;
@@ -366,6 +425,7 @@ void init_smb_request(struct smb_request *req,
        req->flags2 = SVAL(inbuf, smb_flg2);
        req->smbpid = SVAL(inbuf, smb_pid);
        req->mid    = SVAL(inbuf, smb_mid);
+       req->seqnum = 0;
        req->vuid   = SVAL(inbuf, smb_uid);
        req->tid    = SVAL(inbuf, smb_tid);
        req->wct    = CVAL(inbuf, smb_wct);
@@ -402,7 +462,8 @@ void init_smb_request(struct smb_request *req,
 
 static void process_smb(struct smbd_server_connection *conn,
                        uint8_t *inbuf, size_t nread, size_t unread_bytes,
-                       bool encrypted, struct smb_perfcount_data *deferred_pcd);
+                       uint32_t seqnum, bool encrypted,
+                       struct smb_perfcount_data *deferred_pcd);
 
 static void smbd_deferred_open_timer(struct event_context *ev,
                                     struct timed_event *te,
@@ -412,6 +473,7 @@ static void smbd_deferred_open_timer(struct event_context *ev,
        struct pending_message_list *msg = talloc_get_type(private_data,
                                           struct pending_message_list);
        TALLOC_CTX *mem_ctx = talloc_tos();
+       uint16_t mid = SVAL(msg->buf.data,smb_mid);
        uint8_t *inbuf;
 
        inbuf = (uint8_t *)talloc_memdup(mem_ctx, msg->buf.data,
@@ -424,11 +486,21 @@ static void smbd_deferred_open_timer(struct event_context *ev,
        /* We leave this message on the queue so the open code can
           know this is a retry. */
        DEBUG(5,("smbd_deferred_open_timer: trigger mid %u.\n",
-               (unsigned int)SVAL(msg->buf.data,smb_mid)));
+               (unsigned int)mid));
+
+       /* Mark the message as processed so this is not
+        * re-processed in error. */
+       msg->processed = true;
 
        process_smb(smbd_server_conn, inbuf,
                    msg->buf.length, 0,
-                   msg->encrypted, &msg->pcd);
+                   msg->seqnum, msg->encrypted, &msg->pcd);
+
+       /* If it's still there and was processed, remove it. */
+       msg = get_open_deferred_message(mid);
+       if (msg && msg->processed) {
+               remove_deferred_open_smb_message(mid);
+       }
 }
 
 /****************************************************************************
@@ -459,7 +531,9 @@ static bool push_queued_message(struct smb_request *req,
        }
 
        msg->request_time = request_time;
+       msg->seqnum = req->seqnum;
        msg->encrypted = req->encrypted;
+       msg->processed = false;
        SMB_PERFCOUNT_DEFER_OP(&req->pcd, &msg->pcd);
 
        if (private_data) {
@@ -501,7 +575,7 @@ void remove_deferred_open_smb_message(uint16 mid)
 
        for (pml = deferred_open_queue; pml; pml = pml->next) {
                if (mid == SVAL(pml->buf.data,smb_mid)) {
-                       DEBUG(10,("remove_sharing_violation_open_smb_message: "
+                       DEBUG(10,("remove_deferred_open_smb_message: "
                                  "deleting mid %u len %u\n",
                                  (unsigned int)mid,
                                  (unsigned int)pml->buf.length ));
@@ -531,6 +605,15 @@ void schedule_deferred_open_smb_message(uint16 mid)
                if (mid == msg_mid) {
                        struct timed_event *te;
 
+                       if (pml->processed) {
+                               /* A processed message should not be
+                                * rescheduled. */
+                               DEBUG(0,("schedule_deferred_open_smb_message: LOGIC ERROR "
+                                       "message mid %u was already processed\n",
+                                       msg_mid ));
+                               continue;
+                       }
+
                        DEBUG(10,("schedule_deferred_open_smb_message: scheduling mid %u\n",
                                mid ));
 
@@ -557,7 +640,7 @@ void schedule_deferred_open_smb_message(uint16 mid)
 }
 
 /****************************************************************************
- Return true if this mid is on the deferred queue.
+ Return true if this mid is on the deferred queue and was not yet processed.
 ****************************************************************************/
 
 bool open_was_deferred(uint16 mid)
@@ -565,7 +648,7 @@ bool open_was_deferred(uint16 mid)
        struct pending_message_list *pml;
 
        for (pml = deferred_open_queue; pml; pml = pml->next) {
-               if (SVAL(pml->buf.data,smb_mid) == mid) {
+               if (SVAL(pml->buf.data,smb_mid) == mid && !pml->processed) {
                        return True;
                }
        }
@@ -796,6 +879,17 @@ static NTSTATUS smbd_server_connection_loop_once(struct smbd_server_connection *
                errno = sav;
        }
 
+        if ((conn->smb1.echo_handler.trusted_fd != -1)
+           && FD_ISSET(smbd_server_fd(), &r_fds)
+           && FD_ISSET(conn->smb1.echo_handler.trusted_fd, &r_fds)) {
+               /*
+                * Prefer to read pending requests from the echo handler. To
+                * quote Jeremy (da70f8ab1): This is a hack of monstrous
+                * proportions...
+                */
+               FD_CLR(smbd_server_fd(), &r_fds);
+        }
+
        if (run_events(smbd_event_context(), selrtn, &r_fds, &w_fds)) {
                return NT_STATUS_RETRY;
        }
@@ -1300,7 +1394,6 @@ static connection_struct *switch_message(uint8 type, struct smb_request *req, in
 
                if (!change_to_user(conn,session_tag)) {
                        reply_nterror(req, NT_STATUS_DOS(ERRSRV, ERRbaduid));
-                       remove_deferred_open_smb_message(req->mid);
                        return conn;
                }
 
@@ -1363,7 +1456,7 @@ static connection_struct *switch_message(uint8 type, struct smb_request *req, in
 ****************************************************************************/
 
 static void construct_reply(char *inbuf, int size, size_t unread_bytes,
-                           bool encrypted,
+                           uint32_t seqnum, bool encrypted,
                            struct smb_perfcount_data *deferred_pcd)
 {
        connection_struct *conn;
@@ -1375,6 +1468,7 @@ static void construct_reply(char *inbuf, int size, size_t unread_bytes,
 
        init_smb_request(req, (uint8 *)inbuf, unread_bytes, encrypted);
        req->inbuf  = (uint8_t *)talloc_move(req, &inbuf);
+       req->seqnum = seqnum;
 
        /* we popped this message off the queue - keep original perf data */
        if (deferred_pcd)
@@ -1411,6 +1505,7 @@ static void construct_reply(char *inbuf, int size, size_t unread_bytes,
 
        if (!srv_send_smb(smbd_server_fd(),
                        (char *)req->outbuf,
+                       true, req->seqnum+1,
                        IS_CONN_ENCRYPTED(conn)||req->encrypted,
                        &req->pcd)) {
                exit_server_cleanly("construct_reply: srv_send_smb failed.");
@@ -1426,7 +1521,8 @@ static void construct_reply(char *inbuf, int size, size_t unread_bytes,
 ****************************************************************************/
 static void process_smb(struct smbd_server_connection *conn,
                        uint8_t *inbuf, size_t nread, size_t unread_bytes,
-                       bool encrypted, struct smb_perfcount_data *deferred_pcd)
+                       uint32_t seqnum, bool encrypted,
+                       struct smb_perfcount_data *deferred_pcd)
 {
        int msg_type = CVAL(inbuf,0);
 
@@ -1448,7 +1544,7 @@ static void process_smb(struct smbd_server_connection *conn,
 
        show_msg((char *)inbuf);
 
-       construct_reply((char *)inbuf,nread,unread_bytes,encrypted,deferred_pcd);
+       construct_reply((char *)inbuf,nread,unread_bytes,seqnum,encrypted,deferred_pcd);
        trans_num++;
 
 done:
@@ -1650,6 +1746,7 @@ void chain_reply(struct smb_request *req)
                           talloc_get_size(req->chain_outbuf) - 4);
 
                if (!srv_send_smb(smbd_server_fd(), (char *)req->chain_outbuf,
+                                 true, req->seqnum+1,
                                  IS_CONN_ENCRYPTED(req->conn)
                                  ||req->encrypted,
                                  &req->pcd)) {
@@ -1774,6 +1871,7 @@ void chain_reply(struct smb_request *req)
        show_msg((char *)(req->chain_outbuf));
 
        if (!srv_send_smb(smbd_server_fd(), (char *)req->chain_outbuf,
+                         true, req->seqnum+1,
                          IS_CONN_ENCRYPTED(req->conn)||req->encrypted,
                          &req->pcd)) {
                exit_server_cleanly("construct_reply: srv_send_smb failed.");
@@ -1831,12 +1929,29 @@ void check_reload(time_t t)
        }
 }
 
+static bool fd_is_readable(int fd)
+{
+       fd_set fds;
+       struct timeval timeout = {0, };
+       int ret;
+
+       FD_ZERO(&fds);
+       FD_SET(fd, &fds);
+
+       ret = sys_select(fd+1, &fds, NULL, NULL, &timeout);
+       if (ret == -1) {
+               return false;
+       }
+       return FD_ISSET(fd, &fds);
+}
+
 static void smbd_server_connection_write_handler(struct smbd_server_connection *conn)
 {
        /* TODO: make write nonblocking */
 }
 
-static void smbd_server_connection_read_handler(struct smbd_server_connection *conn)
+static void smbd_server_connection_read_handler(
+       struct smbd_server_connection *conn, int fd)
 {
        uint8_t *inbuf = NULL;
        size_t inbuf_len = 0;
@@ -1844,15 +1959,50 @@ static void smbd_server_connection_read_handler(struct smbd_server_connection *c
        bool encrypted = false;
        TALLOC_CTX *mem_ctx = talloc_tos();
        NTSTATUS status;
+       uint32_t seqnum;
 
-       /* TODO: make this completely nonblocking */
+       bool ok;
+
+       bool from_client = (smbd_server_fd() == fd)?true:false;
+
+       if (from_client) {
+               ok = smbd_lock_socket(conn);
+               if (!ok) {
+                       exit_server_cleanly("failed to lock socket");
+               }
+
+               if (!fd_is_readable(smbd_server_fd())) {
+                       DEBUG(10,("the echo listener was faster\n"));
+                       ok = smbd_unlock_socket(conn);
+                       if (!ok) {
+                               exit_server_cleanly("failed to unlock");
+                       }
+                       return;
+               }
+
+               /* TODO: make this completely nonblocking */
+               status = receive_smb_talloc(mem_ctx, fd,
+                                           (char **)(void *)&inbuf,
+                                           0, /* timeout */
+                                           &unread_bytes,
+                                           &encrypted,
+                                           &inbuf_len, &seqnum,
+                                           false /* trusted channel */);
+               ok = smbd_unlock_socket(conn);
+               if (!ok) {
+                       exit_server_cleanly("failed to unlock");
+               }
+       } else {
+               /* TODO: make this completely nonblocking */
+               status = receive_smb_talloc(mem_ctx, fd,
+                                           (char **)(void *)&inbuf,
+                                           0, /* timeout */
+                                           &unread_bytes,
+                                           &encrypted,
+                                           &inbuf_len, &seqnum,
+                                           true /* trusted channel */);
+       }
 
-       status = receive_smb_talloc(mem_ctx, smbd_server_fd(),
-                                   (char **)(void *)&inbuf,
-                                   0, /* timeout */
-                                   &unread_bytes,
-                                   &encrypted,
-                                   &inbuf_len);
        if (NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
                goto process;
        }
@@ -1864,7 +2014,8 @@ static void smbd_server_connection_read_handler(struct smbd_server_connection *c
        }
 
 process:
-       process_smb(conn, inbuf, inbuf_len, unread_bytes, encrypted, NULL);
+       process_smb(conn, inbuf, inbuf_len, unread_bytes,
+                   seqnum, encrypted, NULL);
 }
 
 static void smbd_server_connection_handler(struct event_context *ev,
@@ -1878,10 +2029,25 @@ static void smbd_server_connection_handler(struct event_context *ev,
        if (flags & EVENT_FD_WRITE) {
                smbd_server_connection_write_handler(conn);
        } else if (flags & EVENT_FD_READ) {
-               smbd_server_connection_read_handler(conn);
+               smbd_server_connection_read_handler(conn, smbd_server_fd());
        }
 }
 
+static void smbd_server_echo_handler(struct event_context *ev,
+                                    struct fd_event *fde,
+                                    uint16_t flags,
+                                    void *private_data)
+{
+       struct smbd_server_connection *conn = talloc_get_type(private_data,
+                                             struct smbd_server_connection);
+
+       if (flags & EVENT_FD_WRITE) {
+               smbd_server_connection_write_handler(conn);
+       } else if (flags & EVENT_FD_READ) {
+               smbd_server_connection_read_handler(
+                       conn, conn->smb1.echo_handler.trusted_fd);
+       }
+}
 
 /****************************************************************************
 received when we should release a specific IP
@@ -1942,7 +2108,22 @@ static int client_get_tcp_info(struct sockaddr_storage *server,
  */
 static bool keepalive_fn(const struct timeval *now, void *private_data)
 {
-       if (!send_keepalive(smbd_server_fd())) {
+       bool ok;
+       bool ret;
+
+       ok = smbd_lock_socket(smbd_server_conn);
+       if (!ok) {
+               exit_server_cleanly("failed to lock socket");
+       }
+
+       ret = send_keepalive(smbd_server_fd());
+
+       ok = smbd_unlock_socket(smbd_server_conn);
+       if (!ok) {
+               exit_server_cleanly("failed to unlock socket");
+       }
+
+       if (!ret) {
                DEBUG( 2, ( "Keepalive failed - exiting.\n" ) );
                return False;
        }
@@ -1990,6 +2171,392 @@ static bool housekeeping_fn(const struct timeval *now, void *private_data)
        return true;
 }
 
+static int create_unlink_tmp(const char *dir)
+{
+       char *fname;
+       int fd;
+
+       fname = talloc_asprintf(talloc_tos(), "%s/listenerlock_XXXXXX", dir);
+       if (fname == NULL) {
+               errno = ENOMEM;
+               return -1;
+       }
+       fd = mkstemp(fname);
+       if (fd == -1) {
+               TALLOC_FREE(fname);
+               return -1;
+       }
+       if (unlink(fname) == -1) {
+               int sys_errno = errno;
+               close(fd);
+               TALLOC_FREE(fname);
+               errno = sys_errno;
+               return -1;
+       }
+       TALLOC_FREE(fname);
+       return fd;
+}
+
+struct smbd_echo_state {
+       struct tevent_context *ev;
+       struct iovec *pending;
+       struct smbd_server_connection *sconn;
+       int parent_pipe;
+
+       struct tevent_fd *parent_fde;
+
+       struct tevent_fd *read_fde;
+       struct tevent_req *write_req;
+};
+
+static void smbd_echo_writer_done(struct tevent_req *req);
+
+static void smbd_echo_activate_writer(struct smbd_echo_state *state)
+{
+       int num_pending;
+
+       if (state->write_req != NULL) {
+               return;
+       }
+
+       num_pending = talloc_array_length(state->pending);
+       if (num_pending == 0) {
+               return;
+       }
+
+       state->write_req = writev_send(state, state->ev, NULL,
+                                      state->parent_pipe,
+                                      state->pending, num_pending);
+       if (state->write_req == NULL) {
+               DEBUG(1, ("writev_send failed\n"));
+               exit(1);
+       }
+
+       talloc_steal(state->write_req, state->pending);
+       state->pending = NULL;
+
+       tevent_req_set_callback(state->write_req, smbd_echo_writer_done,
+                               state);
+}
+
+static void smbd_echo_writer_done(struct tevent_req *req)
+{
+       struct smbd_echo_state *state = tevent_req_callback_data(
+               req, struct smbd_echo_state);
+       ssize_t written;
+       int err;
+
+       written = writev_recv(req, &err);
+       TALLOC_FREE(req);
+       state->write_req = NULL;
+       if (written == -1) {
+               DEBUG(1, ("writev to parent failed: %s\n", strerror(err)));
+               exit(1);
+       }
+       DEBUG(10,("echo_handler[%d]: forwarded pdu to main\n", (int)sys_getpid()));
+       smbd_echo_activate_writer(state);
+}
+
+static bool smbd_echo_reply(int fd,
+                           uint8_t *inbuf, size_t inbuf_len,
+                           uint32_t seqnum)
+{
+       struct smb_request req;
+       uint16_t num_replies;
+       size_t out_len;
+       char *outbuf;
+       bool ok;
+
+       if ((inbuf_len == 4) && (CVAL(inbuf, 0) == SMBkeepalive)) {
+               DEBUG(10, ("Got netbios keepalive\n"));
+               /*
+                * Just swallow it
+                */
+               return true;
+       }
+
+       if (inbuf_len < smb_size) {
+               DEBUG(10, ("Got short packet: %d bytes\n", (int)inbuf_len));
+               return false;
+       }
+       if (!valid_smb_header(inbuf)) {
+               DEBUG(10, ("Got invalid SMB header\n"));
+               return false;
+       }
+
+       init_smb_request(&req, inbuf, 0, false);
+       req.inbuf = inbuf;
+       req.seqnum = seqnum;
+
+       DEBUG(10, ("smbecho handler got cmd %d (%s)\n", (int)req.cmd,
+                  smb_messages[req.cmd].name
+                  ? smb_messages[req.cmd].name : "unknown"));
+
+       if (req.cmd != SMBecho) {
+               return false;
+       }
+       if (req.wct < 1) {
+               return false;
+       }
+
+       num_replies = SVAL(req.vwv+0, 0);
+       if (num_replies != 1) {
+               /* Not a Windows "Hey, you're still there?" request */
+               return false;
+       }
+
+       if (!create_outbuf(talloc_tos(), &req, (char *)req.inbuf, &outbuf,
+                          1, req.buflen)) {
+               DEBUG(10, ("create_outbuf failed\n"));
+               return false;
+       }
+       req.outbuf = (uint8_t *)outbuf;
+
+       SSVAL(req.outbuf, smb_vwv0, num_replies);
+
+       if (req.buflen > 0) {
+               memcpy(smb_buf(req.outbuf), req.buf, req.buflen);
+       }
+
+       out_len = smb_len(req.outbuf) + 4;
+
+       ok = srv_send_smb(smbd_server_fd(),
+                         (char *)outbuf,
+                         true, seqnum+1,
+                         false, &req.pcd);
+       TALLOC_FREE(outbuf);
+       if (!ok) {
+               exit(1);
+       }
+
+       return true;
+}
+
+static void smbd_echo_exit(struct tevent_context *ev,
+                          struct tevent_fd *fde, uint16_t flags,
+                          void *private_data)
+{
+       DEBUG(2, ("smbd_echo_exit: lost connection to parent\n"));
+       exit(0);
+}
+
+static void smbd_echo_reader(struct tevent_context *ev,
+                            struct tevent_fd *fde, uint16_t flags,
+                            void *private_data)
+{
+       struct smbd_echo_state *state = talloc_get_type_abort(
+               private_data, struct smbd_echo_state);
+       struct smbd_server_connection *sconn = state->sconn;
+       size_t unread, num_pending;
+       NTSTATUS status;
+       struct iovec *tmp;
+       uint32_t seqnum = 0;
+       bool reply;
+       bool ok;
+       bool encrypted = false;
+
+       smb_msleep(1000);
+
+       ok = smbd_lock_socket(sconn);
+       if (!ok) {
+               DEBUG(0, ("%s: failed to lock socket\n",
+                       __location__));
+               exit(1);
+       }
+
+       if (!fd_is_readable(smbd_server_fd())) {
+               DEBUG(10,("echo_handler[%d] the parent smbd was faster\n",
+                         (int)sys_getpid()));
+               ok = smbd_unlock_socket(sconn);
+               if (!ok) {
+                       DEBUG(1, ("%s: failed to unlock socket in\n",
+                               __location__));
+                       exit(1);
+               }
+               return;
+       }
+
+       num_pending = talloc_array_length(state->pending);
+       tmp = talloc_realloc(state, state->pending, struct iovec,
+                            num_pending+1);
+       if (tmp == NULL) {
+               DEBUG(1, ("talloc_realloc failed\n"));
+               exit(1);
+       }
+       state->pending = tmp;
+
+       DEBUG(10,("echo_handler[%d]: reading pdu\n", (int)sys_getpid()));
+
+       status = receive_smb_talloc(state->pending, smbd_server_fd(),
+                                   (char **)(void *)&state->pending[num_pending].iov_base,
+                                   0 /* timeout */,
+                                   &unread,
+                                   &encrypted,
+                                   &state->pending[num_pending].iov_len,
+                                   &seqnum,
+                                   false /* trusted_channel*/);
+       if (!NT_STATUS_IS_OK(status)) {
+               DEBUG(1, ("echo_handler[%d]: receive_smb_raw_talloc failed: %s\n",
+                         (int)sys_getpid(), nt_errstr(status)));
+               exit(1);
+       }
+
+       ok = smbd_unlock_socket(sconn);
+       if (!ok) {
+               DEBUG(1, ("%s: failed to unlock socket in\n",
+                       __location__));
+               exit(1);
+       }
+
+       reply = smbd_echo_reply(smbd_server_fd(),
+                               (uint8_t *)state->pending[num_pending].iov_base,
+                               state->pending[num_pending].iov_len,
+                               seqnum);
+       if (reply) {
+               DEBUG(10,("echo_handler[%d]: replied to client\n", (int)sys_getpid()));
+               /* no check, shrinking by some bytes does not fail */
+               state->pending = talloc_realloc(state, state->pending,
+                                               struct iovec,
+                                               num_pending);
+               return;
+       }
+
+       if (state->pending[num_pending].iov_len >= smb_size) {
+               /*
+                * place the seqnum in the packet so that the main process
+                * can reply with signing
+                */
+               SIVAL((uint8_t *)state->pending[num_pending].iov_base,
+                     smb_ss_field, seqnum);
+               SIVAL((uint8_t *)state->pending[num_pending].iov_base,
+                     smb_ss_field+4, NT_STATUS_V(NT_STATUS_OK));
+       }
+
+       DEBUG(10,("echo_handler[%d]: forward to main\n", (int)sys_getpid()));
+       smbd_echo_activate_writer(state);
+}
+
+static void smbd_echo_loop(struct smbd_server_connection *sconn,
+                          int parent_pipe)
+{
+       struct smbd_echo_state *state;
+
+       state = talloc_zero(sconn, struct smbd_echo_state);
+       if (state == NULL) {
+               DEBUG(1, ("talloc failed\n"));
+               return;
+       }
+       state->sconn = sconn;
+       state->parent_pipe = parent_pipe;
+       state->ev = s3_tevent_context_init(state);
+       if (state->ev == NULL) {
+               DEBUG(1, ("tevent_context_init failed\n"));
+               TALLOC_FREE(state);
+               return;
+       }
+       state->parent_fde = tevent_add_fd(state->ev, state, parent_pipe,
+                                       TEVENT_FD_READ, smbd_echo_exit,
+                                       state);
+       if (state->parent_fde == NULL) {
+               DEBUG(1, ("tevent_add_fd failed\n"));
+               TALLOC_FREE(state);
+               return;
+       }
+       state->read_fde = tevent_add_fd(state->ev, state, smbd_server_fd(),
+                                       TEVENT_FD_READ, smbd_echo_reader,
+                                       state);
+       if (state->read_fde == NULL) {
+               DEBUG(1, ("tevent_add_fd failed\n"));
+               TALLOC_FREE(state);
+               return;
+       }
+
+       while (true) {
+               if (tevent_loop_once(state->ev) == -1) {
+                       DEBUG(1, ("tevent_loop_once failed: %s\n",
+                                 strerror(errno)));
+                       break;
+               }
+       }
+       TALLOC_FREE(state);
+}
+
+/*
+ * Handle SMBecho requests in a forked child process
+ */
+static bool fork_echo_handler(struct smbd_server_connection *sconn)
+{
+       int listener_pipe[2];
+       int res;
+       pid_t child;
+
+       res = pipe(listener_pipe);
+       if (res == -1) {
+               DEBUG(1, ("pipe() failed: %s\n", strerror(errno)));
+               return false;
+       }
+       sconn->smb1.echo_handler.socket_lock_fd = create_unlink_tmp(lp_lockdir());
+       if (sconn->smb1.echo_handler.socket_lock_fd == -1) {
+               DEBUG(1, ("Could not create lock fd: %s\n", strerror(errno)));
+               goto fail;
+       }
+
+       child = sys_fork();
+       if (child == 0) {
+               NTSTATUS status;
+
+               close(listener_pipe[0]);
+               set_blocking(listener_pipe[1], false);
+
+               status = reinit_after_fork(smbd_messaging_context(),
+                                          smbd_event_context(), false);
+               if (!NT_STATUS_IS_OK(status)) {
+                       DEBUG(1, ("reinit_after_fork failed: %s\n",
+                                 nt_errstr(status)));
+                       exit(1);
+               }
+               smbd_echo_loop(sconn, listener_pipe[1]);
+               exit(0);
+       }
+       close(listener_pipe[1]);
+       listener_pipe[1] = -1;
+       sconn->smb1.echo_handler.trusted_fd = listener_pipe[0];
+
+       DEBUG(10,("fork_echo_handler: main[%d] echo_child[%d]\n", (int)sys_getpid(), child));
+
+       /*
+        * Without smb signing this is the same as the normal smbd
+        * listener. This needs to change once signing comes in.
+        */
+       sconn->smb1.echo_handler.trusted_fde = event_add_fd(smbd_event_context(),
+                                       sconn,
+                                       sconn->smb1.echo_handler.trusted_fd,
+                                       EVENT_FD_READ,
+                                       smbd_server_echo_handler,
+                                       sconn);
+       if (sconn->smb1.echo_handler.trusted_fde == NULL) {
+               DEBUG(1, ("event_add_fd failed\n"));
+               goto fail;
+       }
+
+       return true;
+
+fail:
+       if (listener_pipe[0] != -1) {
+               close(listener_pipe[0]);
+       }
+       if (listener_pipe[1] != -1) {
+               close(listener_pipe[1]);
+       }
+       sconn->smb1.echo_handler.trusted_fd = -1;
+       if (sconn->smb1.echo_handler.socket_lock_fd != -1) {
+               close(sconn->smb1.echo_handler.socket_lock_fd);
+       }
+       sconn->smb1.echo_handler.trusted_fd = -1;
+       sconn->smb1.echo_handler.socket_lock_fd = -1;
+       return false;
+}
+
 /****************************************************************************
  Process commands from the client
 ****************************************************************************/
@@ -2004,6 +2571,9 @@ void smbd_process(void)
                exit_server("failed to create smbd_server_connection");
        }
 
+       smbd_server_conn->smb1.echo_handler.socket_lock_fd = -1;
+       smbd_server_conn->smb1.echo_handler.trusted_fd = -1;
+
        /* Ensure child is set to blocking mode */
        set_blocking(smbd_server_fd(),True);
 
@@ -2036,7 +2606,8 @@ void smbd_process(void)
                unsigned char buf[5] = {0x83, 0, 0, 1, 0x81};
                DEBUG( 1, ("Connection denied from %s\n",
                           client_addr(get_client_fd(),addr,sizeof(addr)) ) );
-               (void)srv_send_smb(smbd_server_fd(),(char *)buf,false, NULL);
+               (void)srv_send_smb(smbd_server_fd(),(char *)buf, false,
+                                  0, false, NULL);
                exit_server_cleanly("connection denied");
        }
 
@@ -2062,6 +2633,14 @@ void smbd_process(void)
                DEBUG(0,("Changed root to %s\n", lp_rootdir()));
        }
 
+       if (!srv_init_signing(smbd_server_conn)) {
+               exit_server("Failed to init smb_signing");
+       }
+
+       if (lp_async_smb_echo_handler() && !fork_echo_handler(smbd_server_conn)) {
+               exit_server("Failed to fork echo handler");
+       }
+
        /* Setup oplocks */
        if (!init_oplocks(smbd_messaging_context()))
                exit_server("Failed to init oplocks");