[PULL,07/12] slirp: use libslirp migration code

diff --git a/include/migration/qemu-file-types.h b/include/migration/qemu-file-types.h
index bd6d7dd7f9..bbe04d4484 100644
--- a/include/migration/qemu-file-types.h
+++ b/include/migration/qemu-file-types.h
@@ -25,6 +25,8 @@ 
 #ifndef QEMU_FILE_H
 #define QEMU_FILE_H
 
+int qemu_file_get_error(QEMUFile *f);
+
 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size);
 void qemu_put_byte(QEMUFile *f, int v);
 
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index 2ccfcfb2a8..13baf896bd 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -149,7 +149,6 @@  void qemu_update_position(QEMUFile *f, size_t size);
 void qemu_file_reset_rate_limit(QEMUFile *f);
 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 int64_t qemu_file_get_rate_limit(QEMUFile *f);
-int qemu_file_get_error(QEMUFile *f);
 void qemu_file_set_error(QEMUFile *f, int ret);
 int qemu_file_shutdown(QEMUFile *f);
 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
diff --git a/net/slirp.c b/net/slirp.c
index a8fd9e6364..059b2d9b08 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -44,6 +44,8 @@ 
 #include "qapi/error.h"
 #include "qapi/qmp/qdict.h"
 #include "util.h"
+#include "migration/register.h"
+#include "migration/qemu-file-types.h"
 
 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
 {
@@ -146,6 +148,7 @@  static void net_slirp_cleanup(NetClientState *nc)
 
     g_slist_free_full(s->fwd, slirp_free_fwd);
     main_loop_poll_remove_notifier(&s->poll_notifier);
+    unregister_savevm(NULL, "slirp", s->slirp);
     slirp_cleanup(s->slirp);
     if (s->exit_notifier.notify) {
         qemu_remove_exit_notifier(&s->exit_notifier);
@@ -303,6 +306,46 @@  static void net_slirp_poll_notify(Notifier *notifier, void *data)
     }
 }
 
+static ssize_t
+net_slirp_stream_read(void *buf, size_t size, void *opaque)
+{
+    QEMUFile *f = opaque;
+
+    return qemu_get_buffer(f, buf, size);
+}
+
+static ssize_t
+net_slirp_stream_write(const void *buf, size_t size, void *opaque)
+{
+    QEMUFile *f = opaque;
+
+    qemu_put_buffer(f, buf, size);
+    if (qemu_file_get_error(f)) {
+        return -1;
+    }
+
+    return size;
+}
+
+static int net_slirp_state_load(QEMUFile *f, void *opaque, int version_id)
+{
+    Slirp *slirp = opaque;
+
+    return slirp_state_load(slirp, version_id, net_slirp_stream_read, f);
+}
+
+static void net_slirp_state_save(QEMUFile *f, void *opaque)
+{
+    Slirp *slirp = opaque;
+
+    slirp_state_save(slirp, net_slirp_stream_write, f);
+}
+
+static SaveVMHandlers savevm_slirp_state = {
+    .save_state = net_slirp_state_save,
+    .load_state = net_slirp_state_load,
+};
+
 static int net_slirp_init(NetClientState *peer, const char *model,
                           const char *name, int restricted,
                           bool ipv4, const char *vnetwork, const char *vhost,
@@ -523,6 +566,18 @@  static int net_slirp_init(NetClientState *peer, const char *model,
                           &slirp_cb, s);
     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 
+    /*
+     * Make sure the current bitstream version of slirp is 4, to avoid
+     * QEMU migration incompatibilities, if upstream slirp bumped the
+     * version.
+     *
+     * FIXME: use bitfields of features? teach libslirp to save with
+     * specific version?
+     */
+    g_assert(slirp_state_version() == 4);
+    register_savevm_live(NULL, "slirp", 0, slirp_state_version(),
+                         &savevm_slirp_state, s->slirp);
+
     s->poll_notifier.notify = net_slirp_poll_notify;
     main_loop_poll_add_notifier(&s->poll_notifier);
 
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index 18c50bd7ba..7ce1e4d0d4 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -101,6 +101,14 @@  void slirp_socket_recv(Slirp *slirp, struct in_addr guest_addr,
                        int guest_port, const uint8_t *buf, int size);
 size_t slirp_socket_can_recv(Slirp *slirp, struct in_addr guest_addr,
                              int guest_port);
+
+void slirp_state_save(Slirp *s, SlirpWriteCb write_cb, void *opaque);
+
+int slirp_state_load(Slirp *s, int version_id,
+                     SlirpReadCb read_cb, void *opaque);
+
+int slirp_state_version(void);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/slirp/slirp.c b/slirp/slirp.c
index cbdf9f778d..18af670a0a 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -23,9 +23,6 @@ 
  */
 #include "slirp.h"
 
-#ifdef WITH_QEMU
-#include "state.h"
-#endif
 
 #ifndef _WIN32
 #include <net/if.h>
@@ -326,9 +323,6 @@  Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
         translate_dnssearch(slirp, vdnssearch);
     }
 
-#ifdef WITH_QEMU
-    slirp_state_register(slirp);
-#endif
     return slirp;
 }
 
@@ -342,9 +336,6 @@  void slirp_cleanup(Slirp *slirp)
         g_free(e);
     }
 
-#ifdef WITH_QEMU
-    slirp_state_unregister(slirp);
-#endif
     ip_cleanup(slirp);
     ip6_cleanup(slirp);
     m_cleanup(slirp);
diff --git a/slirp/state.c b/slirp/state.c
index 0e5a706e87..f5dd80cdc8 100644
--- a/slirp/state.c
+++ b/slirp/state.c
@@ -21,13 +21,10 @@ 
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-#include "qemu/osdep.h"
-
 #include "slirp.h"
+#include "vmstate.h"
 #include "state.h"
-#include "migration/vmstate.h"
-#include "migration/qemu-file-types.h"
-#include "migration/register.h"
+#include "stream.h"
 
 static int slirp_tcp_post_load(void *opaque, int version)
 {
@@ -180,7 +177,7 @@  static int slirp_socket_pre_load(void *opaque)
 #else
 /* Win uses u_long rather than uint32_t - but it's still 32bits long */
 #define VMSTATE_SIN4_ADDR(f, s, t) VMSTATE_SINGLE_TEST(f, s, t, 0, \
-                                       vmstate_info_uint32, u_long)
+                                       slirp_vmstate_info_uint32, u_long)
 #endif
 
 /* The OS provided ss_family field isn't that portable; it's size
@@ -322,10 +319,13 @@  static const VMStateDescription vmstate_slirp = {
     }
 };
 
-static void slirp_state_save(QEMUFile *f, void *opaque)
+void slirp_state_save(Slirp *slirp, SlirpWriteCb write_cb, void *opaque)
 {
-    Slirp *slirp = opaque;
     struct gfwd_list *ex_ptr;
+    SlirpOStream f = {
+        .write_cb = write_cb,
+        .opaque = opaque,
+    };
 
     for (ex_ptr = slirp->guestfwd_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
         if (ex_ptr->write_cb) {
@@ -336,25 +336,29 @@  static void slirp_state_save(QEMUFile *f, void *opaque)
                 continue;
             }
 
-            qemu_put_byte(f, 42);
-            vmstate_save_state(f, &vmstate_slirp_socket, so, NULL);
+            slirp_ostream_write_u8(&f, 42);
+            slirp_vmstate_save_state(&f, &vmstate_slirp_socket, so);
         }
-    qemu_put_byte(f, 0);
+    slirp_ostream_write_u8(&f, 0);
 
-    vmstate_save_state(f, &vmstate_slirp, slirp, NULL);
+    slirp_vmstate_save_state(&f, &vmstate_slirp, slirp);
 }
 
 
-static int slirp_state_load(QEMUFile *f, void *opaque, int version_id)
+int slirp_state_load(Slirp *slirp, int version_id,
+                     SlirpReadCb read_cb, void *opaque)
 {
-    Slirp *slirp = opaque;
     struct gfwd_list *ex_ptr;
+    SlirpIStream f = {
+        .read_cb = read_cb,
+        .opaque = opaque,
+    };
 
-    while (qemu_get_byte(f)) {
+    while (slirp_istream_read_u8(&f)) {
         int ret;
         struct socket *so = socreate(slirp);
 
-        ret = vmstate_load_state(f, &vmstate_slirp_socket, so, version_id);
+        ret = slirp_vmstate_load_state(&f, &vmstate_slirp_socket, so, version_id);
         if (ret < 0) {
             return ret;
         }
@@ -375,20 +379,10 @@  static int slirp_state_load(QEMUFile *f, void *opaque, int version_id)
         }
     }
 
-    return vmstate_load_state(f, &vmstate_slirp, slirp, version_id);
-}
-
-void slirp_state_register(Slirp *slirp)
-{
-    static SaveVMHandlers savevm_slirp_state = {
-        .save_state = slirp_state_save,
-        .load_state = slirp_state_load,
-    };
-
-    register_savevm_live(NULL, "slirp", 0, 4, &savevm_slirp_state, slirp);
+    return slirp_vmstate_load_state(&f, &vmstate_slirp, slirp, version_id);
 }
 
-void slirp_state_unregister(Slirp *slirp)
+int slirp_state_version(void)
 {
-    unregister_savevm(NULL, "slirp", slirp);
+    return 4;
 }
diff --git a/slirp/state.h b/slirp/state.h
index 154866898f..e69de29bb2 100644
--- a/slirp/state.h
+++ b/slirp/state.h
@@ -1,9 +0,0 @@ 
-#ifndef SLIRP_STATE_H_
-#define SLIRP_STATE_H_
-
-#include "libslirp.h"
-
-void slirp_state_register(Slirp *slirp);
-void slirp_state_unregister(Slirp *slirp);
-
-#endif /* SLIRP_STATE_H_ */