diff --git a/flock/container.c b/flock/container.c
index 476ef8ff..02d5ef99 100644
--- a/flock/container.c
+++ b/flock/container.c
@@ -21,7 +21,7 @@
 static struct hypervisor_container_forker {
   sock *s;
   pool *p;
-  struct cbor_stream stream;
+  CBOR_STREAM_EMBED(stream, 4);
   struct birdloop *loop;
   HASH(struct container_runtime) hash;
   struct container_runtime *cur_crt;
@@ -29,7 +29,7 @@ static struct hypervisor_container_forker {
 } hcf;
 
 struct container_fork_request {
-  struct cbor_channel cch;
+  CBOR_CHANNEL_EMBED(cch, 4);
   struct cbor_channel *ctl_ch;
   struct container_runtime *crt;
   int reply_state;
@@ -40,7 +40,7 @@ struct container_runtime {
   uint hash;
   pid_t pid;
   sock *s;
-  struct cbor_stream stream;
+  CBOR_STREAM_EMBED(stream, 4);
   char hostname[];
 };
 
@@ -646,6 +646,20 @@ container_start(struct flock_machine_container_config *ccf)
 
 /* The Parent */
 
+static struct container_runtime *
+container_find_by_name(const char *name)
+{
+  uint h = mem_hash(name, strlen(name));
+  return HASH_FIND(hcf.hash, CRT, name, h);
+}
+
+struct cbor_channel *
+container_get_channel(const char *name)
+{
+  struct container_runtime *crt = container_find_by_name(name);
+  return crt ? cbor_channel_new(&crt->stream) : NULL;
+}
+
 static void
 container_cleanup(struct container_runtime *crt)
 {
@@ -655,7 +669,7 @@ container_cleanup(struct container_runtime *crt)
 }
 
 struct container_ctl_msg {
-  struct cbor_channel cch;
+  CBOR_CHANNEL_EMBED(cch, 4);
   struct cbor_channel *ctl_ch;
   int msg_state;
   int down_signal;
@@ -812,7 +826,7 @@ container_fork_request_reply(struct cbor_channel *cch, enum cbor_parse_result re
       cbor_put_string(cw, "OK");
     }
 
-  cbor_done_channel(&cfr->cch);
+  cbor_channel_done(&cfr->cch);
 
   return CPR_BLOCK_END;
 #undef FAIL
@@ -826,7 +840,7 @@ hypervisor_container_start(struct cbor_channel *cch, struct flock_machine_contai
 #define FAIL(id, msg) do { \
   CBOR_REPLY(cch, cw) CBOR_PUT_MAP(cw) { \
     cbor_put_int(cw, id); cbor_put_string(cw, msg);\
-  } cbor_done_channel(cch); \
+  } cbor_channel_done(cch); \
   birdloop_leave(hcf.loop); \
   return; } while (0)
 
@@ -860,7 +874,7 @@ hypervisor_container_start(struct cbor_channel *cch, struct flock_machine_contai
   cfr->cch.parse = container_fork_request_reply;
 
   crt->stream.parse = container_ctl_parse;
-  cbor_stream_init(&crt->stream, 2);
+  CBOR_STREAM_INIT(crt, stream, cch, hcf.p, struct container_ctl_msg);
 
   CBOR_REPLY(&cfr->cch, cw)
     CBOR_PUT_MAP(cw)
@@ -941,7 +955,7 @@ container_stopped(struct cbor_channel *cch, enum cbor_parse_result res)
       cbor_put_string(cw, "OK");
     }
 
-  cbor_done_channel(&ccc->cch);
+  cbor_channel_done(&ccc->cch);
   return CPR_BLOCK_END;
 #undef FAIL
 }
@@ -964,7 +978,7 @@ hypervisor_container_shutdown(struct cbor_channel *cch, struct flock_machine_con
 	cbor_put_string(cw, "BAD: Not found");
       }
 
-    cbor_done_channel(cch);
+    cbor_channel_done(cch);
     birdloop_leave(hcf.loop);
     return;
   }
@@ -1182,7 +1196,7 @@ hypervisor_container_fork(void)
 
     hcf.s->type = SK_UNIX_MSG;
     hcf.stream.parse = container_fork_request_reply;
-    cbor_stream_init(&hcf.stream, 3);
+    CBOR_STREAM_INIT(&hcf, stream, cch, hcf.p, struct container_fork_request);
     cbor_stream_attach(&hcf.stream, hcf.s);
 
     birdloop_leave(hcf.loop);
diff --git a/flock/ctl.c b/flock/ctl.c
index c5b4c801..66f323e4 100644
--- a/flock/ctl.c
+++ b/flock/ctl.c
@@ -27,11 +27,11 @@ struct hcs_parser_stream {
   u64 bytes_consumed;
   u64 major_state;
 
-  struct cbor_stream stream;
+  CBOR_STREAM_EMBED(stream, 4);
 };
 
 struct hcs_parser_channel {
-  struct cbor_channel cch;
+  CBOR_CHANNEL_EMBED(cch, 4);
   struct hcs_parser_stream *htx;
 
   enum {
@@ -58,18 +58,18 @@ hcs_request_poweroff(struct hcs_parser_channel *hpc)
       cbor_put_string(cw, "OK");
     }
 
-  cbor_done_channel(&hpc->cch);
+  cbor_channel_done(&hpc->cch);
 }
 
 struct hcs_parser_stream *
 hcs_parser_init(sock *s)
 {
-  struct cbor_parser_context *ctx = cbor_parser_new(s->pool, 4);
   struct hcs_parser_stream *htx = mb_allocz(s->pool, sizeof *htx);
 
-  htx->ctx = ctx;
-  htx->sock = s;
-  cbor_stream_init(&htx->stream, 3);
+  CBOR_STREAM_INIT(htx, stream, cch, s->pool, struct hcs_parser_channel);
+  cbor_stream_attach(&htx->stream, s);
+  htx->stream.parse = hcs_parse;
+  htx->stream.cancel = hcs_parser_cleanup;
 
   return htx;
 }
diff --git a/flock/flock-cli b/flock/flock-cli
index 67e2153b..dc137dd1 100755
--- a/flock/flock-cli
+++ b/flock/flock-cli
@@ -35,6 +35,9 @@ class HypervisorStaleError(HandlerError):
     def __init__(self, *args, **kwargs):
         return super().__init__("Hypervisor stale", *args, **kwargs)
 
+class GarbledReplyError(HandlerError):
+    pass
+
 def connect(where: pathlib.Path):
     if not where.exists():
         raise HypervisorNonexistentError()
@@ -49,15 +52,20 @@ def connect(where: pathlib.Path):
 def ctl_path(name: str):
     return DEFAULT_RUN_PATH / f"{name}.ctl"
 
-def msg(name: str, data: dict):
+def msg(name: str, cmd: int, data):
     try:
         ctl = connect(ctl_path(name))
     except HypervisorNonexistentError as e:
         e.add_note(f"Failed to send message {data} to {name}")
         raise e
 
-    ctl.sendall(cbor2.dumps(data))
-    return cbor2.loads(ctl.recv(1024))
+    ctl.sendall(cbor2.dumps([ 0, cmd, data]))
+    data = cbor2.loads(ctl.recv(1024))
+    if len(data) != 2:
+        raise GarbledReplyError(f"Expected 2 array items, got {len(data)}")
+    if data[0] != 0:
+        raise GarbledReplyError(f"Expected zero ID, got {data[0]}")
+    return data[1]
 
 @handler
 def start(name: str):
@@ -72,7 +80,7 @@ def start(name: str):
 
 @handler
 def stop(name: str):
-    for k,v in msg(name, { 0: None }).items():
+    for k,v in msg(name, 1, None).items():
         assert(k == -1)
         assert(v == "OK")
 
@@ -86,28 +94,28 @@ def cleanup(name: str):
 
 @handler
 def telnet(name: str):
-    for k,v in msg(name, { 1: None}).items():
+    for k,v in msg(name, 2, None).items():
         assert(k == -2)
         os.execlp("telnet", "telnet", "localhost", str(v))
 
 @handler
 def container_start(hypervisor: str, name: str):
-    for k,v in msg(hypervisor, { 3: {
+    for k,v in msg(hypervisor, 3, {
         0: name,
         1: 1,
         2: b"/",
         3: bytes(DEFAULT_RUN_PATH / hypervisor / name),
-        }}).items():
+        }).items():
         print(k,v)
 
 @handler
 def container_stop(hypervisor: str, name: str):
-    for k,v in msg(hypervisor, { 4: { 0: name, }}).items():
+    for k,v in msg(hypervisor, 4, { 0: name, }).items():
         print(k,v)
 
 @handler
 def container_telnet(hypervisor: str, name: str):
-    for k,v in msg(hypervisor, { 1: name}).items():
+    for k,v in msg(hypervisor, 2, name).items():
         assert(k == -2)
         os.execlp("telnet", "telnet", "localhost", str(v))
 
diff --git a/flock/flock.h b/flock/flock.h
index 1182fc85..eabef9be 100644
--- a/flock/flock.h
+++ b/flock/flock.h
@@ -52,7 +52,8 @@ union flock_machine_config {
 
 void hypervisor_container_start(struct cbor_channel *, struct flock_machine_container_config *);
 void hypervisor_container_shutdown(struct cbor_channel *, struct flock_machine_container_config *);
-int container_ctl_fd(const char *name);
+
+struct cbor_channel *container_get_channel(const char *name);
 
 void hexp_cleanup_after_fork(void);
 
diff --git a/flock/hypervisor.c b/flock/hypervisor.c
index 1310d974..95cd5a4d 100644
--- a/flock/hypervisor.c
+++ b/flock/hypervisor.c
@@ -20,53 +20,12 @@ static pool *hcs_pool;
 
 OBSREF(struct shutdown_placeholder) hcs_shutdown_placeholder;
 
-static int
-hcs_rx(sock *s, uint size)
-{
-  s64 sz = hcs_parse(s->data, s->rbuf, size);
-  if (sz < 0)
-  {
-    log(L_INFO "CLI parser error at position %ld: %s", -sz-1, hcs_error(s->data));
-    sk_close(s);
-    return 0; /* Must return 0 when closed */
-  }
-
-  if (!hcs_complete(s->data))
-  {
-    ASSERT_DIE(sz == size);
-    return 1;
-  }
-
-  log(L_INFO "Parsed command.");
-
-  /* TODO do something more */
-  if (sz < size)
-    memmove(s->rbuf, s->rbuf + sz, size - sz);
-  if (!s->rx_hook)
-    return (sz == size);
-
-  hcs_parser_cleanup(s->data);
-  s->data = hcs_parser_init(s);
-
-  return (sz < size) ? hcs_rx(s, size - sz) : 1;
-}
-
-static void
-hcs_err(sock *s, int err)
-{
-  log(L_INFO "CLI dropped: %s", strerror(err));
-  hcs_parser_cleanup(s->data);
-  sk_close(s);
-}
-
 static int
 hcs_connect(sock *s, uint size UNUSED)
 {
   log(L_INFO "CLI connected: %p", s);
 
-  s->rx_hook = hcs_rx;
-  s->err_hook = hcs_err;
-  s->data = hcs_parser_init(s);
+  hcs_parser_init(s);
   return 1;
 }
 
@@ -127,8 +86,7 @@ static struct hypervisor_exposed {
   pool *p;
   sock *s;
   struct birdloop *loop;
-  const char *port_name;
-  sock *port_sreq;
+  struct hcs_parser_channel *hpc;
 } he;
 
 /**
@@ -281,13 +239,19 @@ hypervisor_exposed_child_rx(sock *sk, uint size)
 
     sk->txfd = sfd;
 
-    linpool *lp = lp_new(sk->pool);
-    struct cbor_writer *cw = cbor_init(sk->tbuf, sk->tbsize, lp);
-    cbor_open_block_with_length(cw, 1);
-    cbor_add_int(cw, -2);
-    cbor_add_int(cw, r);
+    struct {
+      struct cbor_writer cw;
+      struct cbor_writer_stack_item si[2];
+    } cw;
 
-    e = sk_send(sk, cw->pt);
+    cbor_writer_init(&cw.cw, 2, sk->tbuf, sk->tbsize);
+    CBOR_PUT_MAP(&cw.cw)
+    {
+      cbor_put_int(&cw.cw, -2);
+      cbor_put_int(&cw.cw, r);
+    }
+
+    e = sk_send(sk, cw.cw.data.pos - cw.cw.data.start);
     if (e < 0)
       log(L_ERR "Failed to send socket: %m");
 
@@ -388,9 +352,7 @@ hexp_cleanup_after_fork(void)
 static void
 hexp_sock_err(sock *s, int err UNUSED)
 {
-  ASSERT_DIE(s == he.port_sreq);
-  he.port_name = NULL;
-  he.port_sreq = NULL;
+  he.hpc = NULL;
 }
 
 void
@@ -406,17 +368,31 @@ hexp_get_telnet(struct hcs_parser_channel *hpc)
   int e = write(he.s->fd, buf, sizeof buf);
   if (e != sizeof buf)
     bug("write error handling not implemented, got %d (%m)", e);
-
-  s->err_paused = hexp_sock_err;
-  sk_pause_rx(s->loop, s);
 }
 
-static void hexp_received_telnet(struct hexp_received_telnet *hrt)
+struct hcs_parser_channel {
+  struct cbor_channel cch;
+  struct hcs_parser_stream *htx;
+
+  enum {
+    HCS_CMD_SHUTDOWN = 1,
+    HCS_CMD_TELNET,
+    HCS_CMD_MACHINE_START,
+    HCS_CMD_MACHINE_STOP,
+    HCS_CMD__MAX,
+  } cmd;
+
+  union flock_machine_config cfg;
+};
+
+static void hexp_received_telnet(void *_hrt)
 {
-  if (hrt->name[0])
+  struct hexp_received_telnet *hrt = _hrt;
+
+  if (he.hpc->cfg.cf.name[0])
   {
     /* Transferring the received listening socket to the container */
-    struct cbor_channel *ccc = container_get_channel(hrt->name);
+    struct cbor_channel *ccc = container_get_channel(he.hpc->cfg.cf.name);
 
     CBOR_REPLY(ccc, cw)
       CBOR_PUT_MAP(cw) {
@@ -440,21 +416,16 @@ static void hexp_received_telnet(struct hexp_received_telnet *hrt)
       bug("Telnet listener: sk_open failed");
   }
 
-  if (s)
+  if (he.hpc)
   {
-    linpool *lp = lp_new(hcs_pool);
-    struct cbor_writer *cw = cbor_init(s->tbuf, s->tbsize, lp);
-    cbor_open_block_with_length(cw, 1);
-    cbor_add_int(cw, -2);
-    cbor_add_int(cw, hrt->port);
+    CBOR_REPLY(&he.hpc->cch, cw)
+      CBOR_PUT_MAP(cw)
+      {
+	cbor_put_int(cw, -2);
+	cbor_put_int(cw, hrt->port);
+      }
 
-    sk_send(s, cw->pt);
-    sk_resume_rx(hcs_loop, s);
-
-    hcs_parser_cleanup(s->data);
-    s->data = hcs_parser_init(s);
-
-    rfree(lp);
+    cbor_channel_done(&he.hpc->cch);
   }
 
   birdloop_enter(he.loop);