tipc: Add support for "-s" configuration option

Provide initial support for displaying overall TIPC status/statistics
information at runtime.  Currently, only version info for the TIPC
kernel module is displayed.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/config.c b/net/tipc/config.c
index 7370241..961d1b0 100644
--- a/net/tipc/config.c
+++ b/net/tipc/config.c
@@ -246,13 +246,48 @@
 	default:
 		rv = tipc_cfg_cmd(msg, data, sz, (u32 *)&msg_sect[1].iov_len, orig);
 	}
-	exit:
+exit:
 	rmsg.result_len = htonl(msg_sect[1].iov_len);
 	rmsg.retval = htonl(rv);
 	tipc_cfg_respond(msg_sect, 2u, orig);
 }
 #endif
 
+#define MAX_STATS_INFO 2000
+
+static struct sk_buff *tipc_show_stats(void)
+{
+	struct sk_buff *buf;
+	struct tlv_desc *rep_tlv;
+	struct print_buf pb;
+	int str_len;
+	u32 value;
+
+	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
+		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
+
+	value = ntohl(*(u32 *)TLV_DATA(req_tlv_area));
+	if (value != 0)
+		return tipc_cfg_reply_error_string("unsupported argument");
+
+	buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_STATS_INFO));
+	if (buf == NULL)
+		return NULL;
+
+	rep_tlv = (struct tlv_desc *)buf->data;
+	tipc_printbuf_init(&pb, (char *)TLV_DATA(rep_tlv), MAX_STATS_INFO);
+
+	tipc_printf(&pb, "TIPC version " TIPC_MOD_VER "\n");
+
+	/* Use additional tipc_printf()'s to return more info ... */
+
+	str_len = tipc_printbuf_validate(&pb);
+	skb_put(buf, TLV_SPACE(str_len));
+	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
+
+	return buf;
+}
+
 static struct sk_buff *cfg_enable_bearer(void)
 {
 	struct tipc_bearer_config *args;
@@ -536,6 +571,9 @@
 	case TIPC_CMD_DUMP_LOG:
 		rep_tlv_buf = tipc_log_dump();
 		break;
+	case TIPC_CMD_SHOW_STATS:
+		rep_tlv_buf = tipc_show_stats();
+		break;
 	case TIPC_CMD_SET_LINK_TOL:
 	case TIPC_CMD_SET_LINK_PRI:
 	case TIPC_CMD_SET_LINK_WINDOW: