convert net_client_init() to OptsVisitor

The net_client_init() prototype is kept intact.

Based on "is_netdev", the QemuOpts-rooted QemuOpt-list is parsed as a
Netdev or a NetLegacy. The original meat of net_client_init() is moved to
and simplified in net_client_init1():

Fields not common between -net and -netdev are clearly separated. Getting
the name for the init functions is cleaner: Netdev::id is mandatory, and
all init functions handle a NULL NetLegacy::name. NetLegacy::vlan
explicitly depends on -net (see below).

Verifying the "type=" option for -netdev can be turned into a switch.

Format validation with qemu_opts_validate() can be removed because the
visitor covers it. Relatedly, the "net_client_types" array is reduced to
an array of init functions that can be directly indexed by opts->kind.
(Help text is available in the schema JSON.)

The outermost negation in the condition around qemu_find_vlan() was
flattened, because it expresses the dependent code's requirements more
clearly.

VLAN lookup is avoided if there's no init function to pass the VLAN to.

Whenever the value of type=... is needed, we substitute
NetClientOptionsKind_lookup[kind].

The individual init functions are not converted yet, thus the original
QemuOpts instance is passed transparently.

v1->v2:
- NetLegacy::name is optional. Tracked it through all init functions: they
  all handle a NULL name. Updated commit message accordingly.

v2->v3:
- NetLegacy::id is allowed and takes precedence over NetLegacy::name.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

11 files changed, 31 insertions, 13 deletions

diff --git a/net/dump.c b/net/dump.c
index 2124b9a081..27e95280e3 100644
--- a/net/dump.c
+++ b/net/dump.c
@@ -144,7 +144,8 @@ static int net_dump_init(VLANState *vlan, const char *device,
     return 0;
 }
 
-int net_init_dump(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_dump(QemuOpts *opts, const NetClientOptions *new_opts,
+                  const char *name, VLANState *vlan)
 {
     int len;
     const char *file;
diff --git a/net/dump.h b/net/dump.h
index 2b5d9ba644..85ac00be2c 100644
--- a/net/dump.h
+++ b/net/dump.h
@@ -26,7 +26,9 @@
 
 #include "net.h"
 #include "qemu-common.h"
+#include "qapi-types.h"
 
-int net_init_dump(QemuOpts *opts, const char *name, VLANState *vlan);
+int net_init_dump(QemuOpts *opts, const NetClientOptions *new_opts,
+                  const char *name, VLANState *vlan);
 
 #endif /* QEMU_NET_DUMP_H */
diff --git a/net/slirp.c b/net/slirp.c
index 1f63d50ed7..1243d43926 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -708,7 +708,8 @@ static int net_init_slirp_configs(const char *name, const char *value, void *opa
     return 0;
 }
 
-int net_init_slirp(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_slirp(QemuOpts *opts, const NetClientOptions *new_opts,
+                   const char *name, VLANState *vlan)
 {
     struct slirp_config_str *config;
     const char *vhost;
diff --git a/net/slirp.h b/net/slirp.h
index 53fe95dc12..ef13a65e9c 100644
--- a/net/slirp.h
+++ b/net/slirp.h
@@ -27,10 +27,12 @@
 #include "qemu-common.h"
 #include "qdict.h"
 #include "qemu-option.h"
+#include "qapi-types.h"
 
 #ifdef CONFIG_SLIRP
 
-int net_init_slirp(QemuOpts *opts, const char *name, VLANState *vlan);
+int net_init_slirp(QemuOpts *opts, const NetClientOptions *new_opts,
+                   const char *name, VLANState *vlan);
 
 void net_slirp_hostfwd_add(Monitor *mon, const QDict *qdict);
 void net_slirp_hostfwd_remove(Monitor *mon, const QDict *qdict);
diff --git a/net/socket.c b/net/socket.c
index 30536efbaf..563447d02e 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -586,7 +586,8 @@ static int net_socket_udp_init(VLANState *vlan,
     return 0;
 }
 
-int net_init_socket(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_socket(QemuOpts *opts, const NetClientOptions *new_opts,
+                    const char *name, VLANState *vlan)
 {
     if (qemu_opt_get(opts, "fd")) {
         int fd;
diff --git a/net/socket.h b/net/socket.h
index e1fe959412..e44d26ea9e 100644
--- a/net/socket.h
+++ b/net/socket.h
@@ -26,7 +26,9 @@
 
 #include "net.h"
 #include "qemu-common.h"
+#include "qapi-types.h"
 
-int net_init_socket(QemuOpts *opts, const char *name, VLANState *vlan);
+int net_init_socket(QemuOpts *opts, const NetClientOptions *new_opts,
+                    const char *name, VLANState *vlan);
 
 #endif /* QEMU_NET_SOCKET_H */
diff --git a/net/tap-win32.c b/net/tap-win32.c
index f7b6129131..b738f45bd6 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -699,7 +699,8 @@ static int tap_win32_init(VLANState *vlan, const char *model,
     return 0;
 }
 
-int net_init_tap(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_tap(QemuOpts *opts, const NetClientOptions *new_opts,
+                 const char *name, VLANState *vlan)
 {
     const char *ifname;
 
diff --git a/net/tap.c b/net/tap.c
index 9131ef5564..0fc856c0b4 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -513,7 +513,8 @@ static int net_bridge_run_helper(const char *helper, const char *bridge)
     return -1;
 }
 
-int net_init_bridge(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_bridge(QemuOpts *opts, const NetClientOptions *new_opts,
+                    const char *name, VLANState *vlan)
 {
     TAPState *s;
     int fd, vnet_hdr;
@@ -583,7 +584,8 @@ static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
     return fd;
 }
 
-int net_init_tap(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_tap(QemuOpts *opts, const NetClientOptions *new_opts,
+                 const char *name, VLANState *vlan)
 {
     TAPState *s;
     int fd, vnet_hdr = 0;
diff --git a/net/tap.h b/net/tap.h
index b2a9450aab..44e31cefa9 100644
--- a/net/tap.h
+++ b/net/tap.h
@@ -28,11 +28,13 @@
 
 #include "qemu-common.h"
 #include "qemu-option.h"
+#include "qapi-types.h"
 
 #define DEFAULT_NETWORK_SCRIPT "/etc/qemu-ifup"
 #define DEFAULT_NETWORK_DOWN_SCRIPT "/etc/qemu-ifdown"
 
-int net_init_tap(QemuOpts *opts, const char *name, VLANState *vlan);
+int net_init_tap(QemuOpts *opts, const NetClientOptions *new_opts,
+                 const char *name, VLANState *vlan);
 
 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required);
 
@@ -57,6 +59,7 @@ int tap_get_fd(VLANClientState *vc);
 struct vhost_net;
 struct vhost_net *tap_get_vhost_net(VLANClientState *vc);
 
-int net_init_bridge(QemuOpts *opts, const char *name, VLANState *vlan);
+int net_init_bridge(QemuOpts *opts, const NetClientOptions *new_opts,
+                    const char *name, VLANState *vlan);
 
 #endif /* QEMU_NET_TAP_H */
diff --git a/net/vde.c b/net/vde.c
index 0e8bf23222..8e60f68800 100644
--- a/net/vde.c
+++ b/net/vde.c
@@ -110,7 +110,8 @@ static int net_vde_init(VLANState *vlan, const char *model,
     return 0;
 }
 
-int net_init_vde(QemuOpts *opts, const char *name, VLANState *vlan)
+int net_init_vde(QemuOpts *opts, const NetClientOptions *new_opts,
+                 const char *name, VLANState *vlan)
 {
     const char *sock;
     const char *group;
diff --git a/net/vde.h b/net/vde.h
index 732e5756f6..5fc17f980e 100644
--- a/net/vde.h
+++ b/net/vde.h
@@ -26,10 +26,12 @@
 
 #include "qemu-common.h"
 #include "qemu-option.h"
+#include "qapi-types.h"
 
 #ifdef CONFIG_VDE
 
-int net_init_vde(QemuOpts *opts, const char *name, VLANState *vlan);
+int net_init_vde(QemuOpts *opts, const NetClientOptions *new_opts,
+                 const char *name, VLANState *vlan);
 
 #endif /* CONFIG_VDE */