Re: [PATCH] iw: Resolve namespace clash between station plink and vlan commands

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2010-11-16 at 20:41 -0800, Javier Cardona wrote:

> > Actually, I won't have time today, but it looks like they can be shared
> > in some way? Maybe by sharing the same callback function or something? I
> > mean -- it should be possible to do two things on set... not sure now,
> > I'll take a look later. Maybe you can work with an older iw version
> > until then?
> 
> We tried that at first but could not get the usage message right in
> case of missing parameters.  If you can suggest a solution to this,
> we'll be happy to implement it.

Try this please?

johannes

diff --git a/info.c b/info.c
index d842c26..0783701 100644
--- a/info.c
+++ b/info.c
@@ -223,7 +223,7 @@ static int handle_info(struct nl80211_state *state,
 	return 0;
 }
 __COMMAND(NULL, info, "info", NULL, NL80211_CMD_GET_WIPHY, 0, 0, CIB_PHY, handle_info,
-	 "Show capabilities for the specified wireless device.");
+	 "Show capabilities for the specified wireless device.", NULL);
 TOPLEVEL(list, NULL, NL80211_CMD_GET_WIPHY, NLM_F_DUMP, CIB_NONE, handle_info,
 	 "List all wireless devices and their capabilities.");
 TOPLEVEL(phy, NULL, NL80211_CMD_GET_WIPHY, NLM_F_DUMP, CIB_NONE, handle_info, NULL);
diff --git a/iw.c b/iw.c
index 562f17b..2593481 100644
--- a/iw.c
+++ b/iw.c
@@ -358,6 +358,12 @@ static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
 			return 1;
 	}
 
+	if (cmd->selector) {
+		cmd = cmd->selector(argc, argv);
+		if (!cmd)
+			return 1;
+	}
+
 	if (cmdout)
 		*cmdout = cmd;
 
diff --git a/iw.h b/iw.h
index 5eb9083..b0bc489 100644
--- a/iw.h
+++ b/iw.h
@@ -51,12 +51,13 @@ struct cmd {
 		       struct nl_cb *cb,
 		       struct nl_msg *msg,
 		       int argc, char **argv);
+	const struct cmd *(*selector)(int argc, char **argv);
 	const struct cmd *parent;
 };
 
 #define ARRAY_SIZE(ar) (sizeof(ar)/sizeof(ar[0]))
 
-#define __COMMAND(_section, _symname, _name, _args, _nlcmd, _flags, _hidden, _idby, _handler, _help)\
+#define __COMMAND(_section, _symname, _name, _args, _nlcmd, _flags, _hidden, _idby, _handler, _help, _sel)\
 	static struct cmd						\
 	__cmd ## _ ## _symname ## _ ## _handler ## _ ## _nlcmd ## _ ## _idby ## _ ## _hidden\
 	__attribute__((used)) __attribute__((section("__cmd")))	= {	\
@@ -69,11 +70,17 @@ struct cmd {
 		.handler = (_handler),					\
 		.help = (_help),					\
 		.parent = _section,					\
-	 }
+		.selector = (_sel),					\
+	}
+#define __ACMD(_section, _symname, _name, _args, _nlcmd, _flags, _hidden, _idby, _handler, _help, _sel, _alias)\
+	__COMMAND(_section, _symname, _name, _args, _nlcmd, _flags, _hidden, _idby, _handler, _help, _sel);\
+	static const struct cmd *_alias = &__cmd ## _ ## _symname ## _ ## _handler ## _ ## _nlcmd ## _ ## _idby ## _ ## _hidden
 #define COMMAND(section, name, args, cmd, flags, idby, handler, help)	\
-	__COMMAND(&(__section ## _ ## section), name, #name, args, cmd, flags, 0, idby, handler, help)
+	__COMMAND(&(__section ## _ ## section), name, #name, args, cmd, flags, 0, idby, handler, help, NULL)
+#define COMMAND_ALIAS(section, name, args, cmd, flags, idby, handler, help, selector, alias)\
+	__ACMD(&(__section ## _ ## section), name, #name, args, cmd, flags, 0, idby, handler, help, selector, alias)
 #define HIDDEN(section, name, args, cmd, flags, idby, handler)		\
-	__COMMAND(&(__section ## _ ## section), name, #name, args, cmd, flags, 1, idby, handler, NULL)
+	__COMMAND(&(__section ## _ ## section), name, #name, args, cmd, flags, 1, idby, handler, NULL, NULL)
 
 #define TOPLEVEL(_name, _args, _nlcmd, _flags, _idby, _handler, _help)	\
 	struct cmd							\
diff --git a/station.c b/station.c
index 7639553..bfcc5d1 100644
--- a/station.c
+++ b/station.c
@@ -204,6 +204,21 @@ COMMAND(station, del, "<MAC address>",
 	NL80211_CMD_DEL_STATION, 0, CIB_NETDEV, handle_station_get,
 	"Remove the given station entry (use with caution!)");
 
+static const struct cmd *station_set_plink;
+static const struct cmd *station_set_vlan;
+
+static const struct cmd *select_station_cmd(int argc, char **argv)
+{
+	if (argc < 2)
+		return NULL;
+	if (strcmp(argv[1], "plink_action") == 0)
+		return station_set_plink;
+	if (strcmp(argv[1], "vlan") == 0)
+		return station_set_vlan;
+	return NULL;
+}
+
+
 static int handle_station_set_plink(struct nl80211_state *state,
 			      struct nl_cb *cb,
 			      struct nl_msg *msg,
@@ -248,9 +263,10 @@ static int handle_station_set_plink(struct nl80211_state *state,
  nla_put_failure:
 	return -ENOBUFS;
 }
-COMMAND(station, set, "<MAC address> plink_action <open|block>",
+COMMAND_ALIAS(station, set, "<MAC address> plink_action <open|block>",
 	NL80211_CMD_SET_STATION, 0, CIB_NETDEV, handle_station_set_plink,
-	"Set mesh peer link action for this station (peer).");
+	"Set mesh peer link action for this station (peer).",
+	select_station_cmd, station_set_plink);
 
 static int handle_station_set_vlan(struct nl80211_state *state,
 			      struct nl_cb *cb,
@@ -294,9 +310,10 @@ static int handle_station_set_vlan(struct nl80211_state *state,
  nla_put_failure:
 	return -ENOBUFS;
 }
-COMMAND(station, set, "<MAC address> vlan <ifindex>",
+COMMAND_ALIAS(station, set, "<MAC address> vlan <ifindex>",
 	NL80211_CMD_SET_STATION, 0, CIB_NETDEV, handle_station_set_vlan,
-	"Set an AP VLAN for this station.");
+	"Set an AP VLAN for this station.",
+	select_station_cmd, station_set_vlan);
 
 
 static int handle_station_dump(struct nl80211_state *state,