wprobe: move measurement task to the kernel, add some configurability (work in progress)

SVN-Revision: 16402

3 files changed, 232 insertions, 84 deletions

diff --git a/package/wprobe/src/user/wprobe-info.c b/package/wprobe/src/user/wprobe-info.c
index b891871..8361c02 100644
--- a/package/wprobe/src/user/wprobe-info.c
+++ b/package/wprobe/src/user/wprobe-info.c
@@ -64,15 +64,15 @@ wprobe_dump_value(struct wprobe_attribute *attr)
 
 
 static void
-wprobe_dump_data(const char *ifname, struct list_head *gl, struct list_head *ll, struct list_head *ls)
+wprobe_dump_data(struct wprobe_iface *dev)
 {
 	struct wprobe_attribute *attr;
 	struct wprobe_link *link;
 	bool first = true;
 
 	fprintf(stderr, "\n");
-	wprobe_request_data(ifname, gl, NULL, 2);
-	list_for_each_entry(attr, gl, list) {
+	wprobe_request_data(dev, NULL);
+	list_for_each_entry(attr, &dev->global_attr, list) {
 		fprintf(stderr, (first ?
 			"Global:            %s=%s\n" :
 			"                   %s=%s\n"),
@@ -82,10 +82,10 @@ wprobe_dump_data(const char *ifname, struct list_head *gl, struct list_head *ll,
 		first = false;
 	}
 
-	list_for_each_entry(link, ls, list) {
+	list_for_each_entry(link, &dev->links, list) {
 		first = true;
-		wprobe_request_data(ifname, ll, link->addr, 2);
-		list_for_each_entry(attr, ll, list) {
+		wprobe_request_data(dev, link->addr);
+		list_for_each_entry(attr, &dev->link_attr, list) {
 			if (first) {
 				fprintf(stderr,
 					"%02x:%02x:%02x:%02x:%02x:%02x: %s=%s\n",
@@ -119,57 +119,92 @@ static const char *attr_typestr[] = {
 
 static int usage(const char *prog)
 {
-	fprintf(stderr, "Usage: %s <interface>\n", prog);
-	return 1;
+	fprintf(stderr,
+		"Usage: %s <interface> [options]\n"
+		"\n"
+		"Options:\n"
+		"  -c:            Only apply configuration\n"
+		"  -h:            This help text\n"
+		"  -i <interval>: Set measurement interval\n"
+		"  -m:            Run measurement loop\n"
+		"\n"
+		, prog);
+	exit(1);
 }
 
-int main(int argc, char **argv)
+static void show_attributes(struct wprobe_iface *dev)
 {
 	struct wprobe_attribute *attr;
-	const char *ifname;
-	LIST_HEAD(global_attr);
-	LIST_HEAD(link_attr);
-	LIST_HEAD(links);
-	int i = 0;
+	list_for_each_entry(attr, &dev->global_attr, list) {
+		fprintf(stderr, "Global attribute: '%s' (%s)\n",
+			attr->name, attr_typestr[attr->type]);
+	}
+	list_for_each_entry(attr, &dev->link_attr, list) {
+		fprintf(stderr, "Link attribute: '%s' (%s)\n",
+			attr->name, attr_typestr[attr->type]);
+	}
+}
 
-	if (argc < 2)
-		return usage(argv[0]);
+static void loop_measurement(struct wprobe_iface *dev)
+{
+	while (1) {
+		sleep(1);
+		wprobe_update_links(dev);
+		wprobe_dump_data(dev);
+	}
+}
 
-	ifname = argv[1];
+int main(int argc, char **argv)
+{
+	struct wprobe_iface *dev;
+	const char *ifname;
+	const char *prog = argv[0];
+	enum {
+		CMD_NONE,
+		CMD_CONFIG,
+		CMD_MEASURE,
+	} cmd = CMD_NONE;
+	int ch;
 
-	if (wprobe_init() != 0)
-		return -1;
+	if ((argc < 2) || (argv[1][0] == '-'))
+		return usage(prog);
 
-	wprobe_dump_attributes(ifname, false, &global_attr, NULL);
-	wprobe_dump_attributes(ifname, true, &link_attr, NULL);
+	ifname = argv[1];
+	dev = wprobe_get_dev(ifname);
+	argv++;
+	argc--;
 
-	if (list_empty(&global_attr) &&
-		list_empty(&link_attr)) {
+	if (!dev || (list_empty(&dev->global_attr) &&
+		list_empty(&dev->link_attr))) {
 		fprintf(stderr, "Interface '%s' not found\n", ifname);
 		return -1;
 	}
 
-	list_for_each_entry(attr, &global_attr, list) {
-		fprintf(stderr, "Global attribute: '%s' (%s)\n",
-			attr->name, attr_typestr[attr->type]);
-	}
-	list_for_each_entry(attr, &link_attr, list) {
-		fprintf(stderr, "Link attribute: '%s' (%s)\n",
-			attr->name, attr_typestr[attr->type]);
+	while ((ch = getopt(argc, argv, "chi:m")) != -1) {
+		switch(ch) {
+		case 'c':
+			cmd = CMD_CONFIG;
+			break;
+		case 'm':
+			cmd = CMD_MEASURE;
+			break;
+		case 'i':
+			dev->interval = strtoul(optarg, NULL, 10);
+			break;
+		case 'h':
+		default:
+			usage(prog);
+			break;
+		}
 	}
 
-	while (1) {
-		usleep(100 * 1000);
-		wprobe_measure(ifname);
-
-		if (i-- > 0)
-			continue;
+	wprobe_apply_config(dev);
+	if (cmd != CMD_CONFIG)
+		show_attributes(dev);
+	if (cmd == CMD_MEASURE)
+		loop_measurement(dev);
 
-		i = 10;
-		wprobe_update_links(ifname, &links);
-		wprobe_dump_data(ifname, &global_attr, &link_attr, &links);
-	}
-	wprobe_free();
+	wprobe_free_dev(dev);
 
 	return 0;
 }
diff --git a/package/wprobe/src/user/wprobe.c b/package/wprobe/src/user/wprobe.c
index 1f8df6c..e48f768 100644
--- a/package/wprobe/src/user/wprobe.c
+++ b/package/wprobe/src/user/wprobe.c
@@ -35,6 +35,7 @@
 #define DPRINTF(fmt, ...) do {} while (0)
 #endif
 
+static int n_devs = 0;
 static struct nl_sock *handle = NULL;
 static struct nl_cache *cache = NULL;
 static struct genl_family *family = NULL;
@@ -83,9 +84,16 @@ ack_handler(struct nl_msg *msg, void *arg)
 }
 
 
-void
+static void
 wprobe_free(void)
 {
+	/* should not happen */
+	if (n_devs == 0)
+		return;
+
+	if (--n_devs != 0)
+		return;
+
 	if (cache)
 		nl_cache_free(cache);
 	if (handle)
@@ -94,11 +102,14 @@ wprobe_free(void)
 	cache = NULL;
 }
 
-int
+static int
 wprobe_init(void)
 {
 	int ret;
 
+	if (n_devs++ > 0)
+		return 0;
+
 	handle = nl_socket_alloc();
 	if (!handle) {
 		DPRINTF("Failed to create handle\n");
@@ -233,8 +244,8 @@ save_attribute_handler(struct nl_msg *msg, void *arg)
 }
 
 
-int
-wprobe_dump_attributes(const char *ifname, bool link, struct list_head *list, char *addr)
+static int
+dump_attributes(const char *ifname, bool link, struct list_head *list, char *addr)
 {
 	struct nl_msg *msg;
 	struct wprobe_attr_cb cb;
@@ -255,6 +266,64 @@ nla_put_failure:
 	return -EINVAL;
 }
 
+struct wprobe_iface *
+wprobe_get_dev(const char *ifname)
+{
+	struct wprobe_iface *dev;
+
+	if (wprobe_init() != 0)
+		return NULL;
+
+	dev = malloc(sizeof(struct wprobe_iface));
+	if (!dev)
+		return NULL;
+
+	memset(dev, 0, sizeof(struct wprobe_iface));
+	dev->ifname = strdup(ifname);
+	if (!dev->ifname)
+		goto error;
+
+	dev->interval = -1;
+	dev->scale_min = -1;
+	dev->scale_max = -1;
+	dev->scale_m = -1;
+	dev->scale_d = -1;
+
+	INIT_LIST_HEAD(&dev->global_attr);
+	INIT_LIST_HEAD(&dev->link_attr);
+	INIT_LIST_HEAD(&dev->links);
+
+	dump_attributes(ifname, false, &dev->global_attr, NULL);
+	dump_attributes(ifname, true, &dev->link_attr, NULL);
+
+	return dev;
+
+error:
+	free(dev);
+	return NULL;
+}
+
+static void
+free_attr_list(struct list_head *list)
+{
+	struct wprobe_attribute *attr, *tmp;
+
+	list_for_each_entry_safe(attr, tmp, list, list) {
+		list_del(&attr->list);
+		free(attr);
+	}
+}
+
+void
+wprobe_free_dev(struct wprobe_iface *dev)
+{
+	wprobe_free();
+	free_attr_list(&dev->global_attr);
+	free_attr_list(&dev->link_attr);
+	free((void *)dev->ifname);
+	free(dev);
+}
+
 static struct wprobe_link *
 get_link(struct list_head *list, const char *addr)
 {
@@ -313,7 +382,7 @@ save_link_handler(struct nl_msg *msg, void *arg)
 
 
 int
-wprobe_update_links(const char *ifname, struct list_head *list)
+wprobe_update_links(struct wprobe_iface *dev)
 {
 	struct wprobe_link *l, *tmp;
 	struct nl_msg *msg;
@@ -321,10 +390,10 @@ wprobe_update_links(const char *ifname, struct list_head *list)
 	int err;
 
 	INIT_LIST_HEAD(&cb.old_list);
-	list_splice_init(list, &cb.old_list);
-	cb.list = list;
+	list_splice_init(&dev->links, &cb.old_list);
+	cb.list = &dev->links;
 
-	msg = wprobe_new_msg(ifname, WPROBE_CMD_GET_LINKS, true);
+	msg = wprobe_new_msg(dev->ifname, WPROBE_CMD_GET_LINKS, true);
 	if (!msg)
 		return -ENOMEM;
 
@@ -340,16 +409,37 @@ wprobe_update_links(const char *ifname, struct list_head *list)
 	return 0;
 }
 
-void
-wprobe_measure(const char *ifname)
+int
+wprobe_apply_config(struct wprobe_iface *dev)
 {
 	struct nl_msg *msg;
 
-	msg = wprobe_new_msg(ifname, WPROBE_CMD_MEASURE, false);
+	msg = wprobe_new_msg(dev->ifname, WPROBE_CMD_CONFIG, false);
 	if (!msg)
-		return;
+		return -ENOMEM;
+
+	if (dev->interval >= 0)
+		NLA_PUT_MSECS(msg, WPROBE_ATTR_INTERVAL, dev->interval);
+
+	wprobe_send_msg(msg, NULL, NULL);
+	return 0;
+
+nla_put_failure:
+	nlmsg_free(msg);
+	return -ENOMEM;
+}
+
+int
+wprobe_measure(struct wprobe_iface *dev)
+{
+	struct nl_msg *msg;
+
+	msg = wprobe_new_msg(dev->ifname, WPROBE_CMD_MEASURE, false);
+	if (!msg)
+		return -ENOMEM;
 
 	wprobe_send_msg(msg, NULL, NULL);
+	return 0;
 }
 
 struct wprobe_request_cb {
@@ -431,6 +521,10 @@ found:
 		if (attr->val.n > 0) {
 			float avg = ((float) attr->val.s) / attr->val.n;
 			float stdev = sqrt((((float) attr->val.ss) / attr->val.n) - (avg * avg));
+			if (isnan(stdev))
+				stdev = 0.0f;
+			if (isnan(avg))
+				avg = 0.0f;
 			attr->val.avg = avg;
 			attr->val.stdev = stdev;
 		}
@@ -443,25 +537,24 @@ out:
 
 
 int
-wprobe_request_data(const char *ifname, struct list_head *attrs, const unsigned char *addr, int scale)
+wprobe_request_data(struct wprobe_iface *dev, const unsigned char *addr)
 {
 	struct wprobe_request_cb cb;
+	struct list_head *attrs;
 	struct nl_msg *msg;
 	int err;
 
-	msg = wprobe_new_msg(ifname, WPROBE_CMD_GET_INFO, true);
+	msg = wprobe_new_msg(dev->ifname, WPROBE_CMD_GET_INFO, true);
 	if (!msg)
 		return -ENOMEM;
 
-	if (scale < 0)
-		NLA_PUT_U32(msg, WPROBE_ATTR_FLAGS, WPROBE_F_RESET);
-	else if (scale > 0)
-		NLA_PUT_U32(msg, WPROBE_ATTR_SCALE, scale);
-
-	if (addr)
+	if (addr) {
+		attrs = &dev->link_attr;
 		NLA_PUT(msg, WPROBE_ATTR_MAC, 6, addr);
+	} else {
+		attrs = &dev->global_attr;
+	}
 
-nla_put_failure:
 	INIT_LIST_HEAD(&cb.old_list);
 	list_splice_init(attrs, &cb.old_list);
 	cb.list = attrs;
@@ -469,6 +562,10 @@ nla_put_failure:
 	err = wprobe_send_msg(msg, save_attrdata_handler, &cb);
 	list_splice(&cb.old_list, attrs->prev);
 	return err;
+
+nla_put_failure:
+	nlmsg_free(msg);
+	return -ENOMEM;
 }
 
 
diff --git a/package/wprobe/src/user/wprobe.h b/package/wprobe/src/user/wprobe.h
index e0c33fa..c0b4902 100644
--- a/package/wprobe/src/user/wprobe.h
+++ b/package/wprobe/src/user/wprobe.h
@@ -87,15 +87,21 @@ struct wprobe_link {
 	unsigned char addr[6];
 };
 
-/**
- * wprobe_init: initialize internal data structures and connect to the wprobe netlink api
- */
-extern int wprobe_init(void);
+struct wprobe_iface {
+	const char *ifname;
+	char addr[6];
 
-/**
- * wprobe_free: free all internally allocated data structures
- */
-extern void wprobe_free(void);
+	struct list_head global_attr;
+	struct list_head link_attr;
+	struct list_head links;
+
+	/* config */
+	int interval;
+	int scale_min;
+	int scale_max;
+	int scale_m;
+	int scale_d;
+};
 
 /**
  * wprobe_update_links: get a list of all link partners
@@ -105,7 +111,7 @@ extern void wprobe_free(void);
  * when wprobe_update_links is called multiple times, the linked list 
  * is updated with new link partners, old entries are automatically expired
  */
-extern int wprobe_update_links(const char *ifname, struct list_head *list);
+extern int wprobe_update_links(struct wprobe_iface *dev);
 
 /**
  * wprobe_measure: start a measurement request for all global attributes
@@ -115,29 +121,39 @@ extern int wprobe_update_links(const char *ifname, struct list_head *list);
  * it may be desirable to control the sampling interval from user space
  * you can use this function to do that.
  */
-extern void wprobe_measure(const char *ifname);
+extern int wprobe_measure(struct wprobe_iface *dev);
 
 /**
- * wprobe_dump_attributes: create a linked list of available attributes
+ * wprobe_get_dev: get device information
  * @ifname: name of the wprobe interface
- * @link: false: get the list of global attributes; true: get the list of per-link attributes
- * @list: linked list to store the attributes in
- * @addr: buffer to store the interface's mac address in (optional)
  *
- * attributes must be freed by the caller
+ * queries the wprobe interface for all attributes
+ * must be freed with wprobe_free_dev
+ */
+extern struct wprobe_iface *wprobe_get_dev(const char *ifname);
+
+/**
+ * wprobe_get_dev: free all device information
+ * @dev: wprobe device structure
+ */
+extern void wprobe_free_dev(struct wprobe_iface *dev);
+
+/**
+ * wprobe_apply_config: apply configuration data
+ * @dev: wprobe device structure
+ *
+ * uploads all configuration values from @dev that are not set to -1
  */
-extern int wprobe_dump_attributes(const char *ifname, bool link, struct list_head *list, char *addr);
+extern int wprobe_apply_config(struct wprobe_iface *dev);
 
 /**
  * wprobe_request_data: request new sampling values for the given list of attributes
- * @ifname: name of the wprobe interface
- * @attrs: attribute list
+ * @dev: wprobe device structure
  * @addr: (optional) mac address of the link partner
- * @scale: scale down values by a factor (scale < 0: reset statistics entirely)
  *
- * if addr is unset, attrs must point to the list of global attributes,
- * if addr is set, attrs must point to the list of per-link attributes
+ * if addr is unset, global values are stored in the global attributes list
+ * if addr is set, per-link values for the given address are stored in the link attributes list
  */
-extern int wprobe_request_data(const char *ifname, struct list_head *attrs, const unsigned char *addr, int scale);
+extern int wprobe_request_data(struct wprobe_iface *dev, const unsigned char *addr);
 
 #endif