Show some target change statistics in /stats t.

- the number of messages blocked by target change on
  this server since it was started
- the number of IPs currently subject to a a lower
  target limit on this server (these expire over time)

include/s_stats.h

@@ -71,6 +71,7 @@ struct ServerStatistics
 	unsigned int is_rej;	/* rejected from cache */
 	unsigned int is_ssuc;	/* successful sasl authentications */
 	unsigned int is_sbad;	/* failed sasl authentications */
+	unsigned int is_tgch;	/* messages blocked due to target change */
 };
 
 extern struct ServerStatistics *ServerStats;

modules/core/m_message.c

@@ -44,6 +44,7 @@
 #include "event.h"
 #include "patricia.h"
 #include "s_newconf.h"
+#include "s_stats.h"
 
 static int m_message(int, const char *, struct Client *, struct Client *, int, const char **);
 static int m_privmsg(struct Client *, struct Client *, int, const char **);
@@ -609,6 +610,7 @@ add_target(struct Client *source_p, struct Client *target_p)
 		/* cant clear any, full target list */
 		else if(USED_TARGETS(source_p) == 10)
 		{
+			ServerStats->is_tgch++;
 			add_tgchange(source_p->sockhost);
 			return 0;
 		}

src/s_stats.c

@@ -139,6 +139,9 @@ tstats(struct Client *source_p)
 			   sp->is_wrdi, sp->is_empt);
 	sendto_one_numeric(source_p, RPL_STATSDEBUG,
 			   "T :numerics seen %u", sp->is_num);
+	sendto_one_numeric(source_p, RPL_STATSDEBUG,
+			   "T :tgchange blocked msgs %u restricted addrs %u",
+			   sp->is_tgch, dlink_list_length(&tgchange_list));
 	sendto_one_numeric(source_p, RPL_STATSDEBUG,
 			   "T :auth successes %u fails %u",
 			   sp->is_asuc, sp->is_abad);