upgrade to the new version of wprobe - includes reconfigurable layer 2 statistics, remote access, more configuration options and many bugfixes

SVN-Revision: 16719

1 files changed, 1203 insertions, 0 deletions

diff --git a/package/wprobe/src/user/wprobe-lib.c b/package/wprobe/src/user/wprobe-lib.c
new file mode 100644
index 0000000000..a3b0fb5e5e
--- /dev/null
+++ b/package/wprobe/src/user/wprobe-lib.c
@@ -0,0 +1,1203 @@
+/*
+ * wprobe.c: Wireless probe user space library
+ * Copyright (C) 2008-2009 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <math.h>
+#include <linux/wprobe.h>
+#include <netlink/netlink.h>
+#include <netlink/attr.h>
+#include <netlink/genl/genl.h>
+#ifndef NO_LOCAL_ACCESS 
+#include <netlink/genl/ctrl.h>
+#include <netlink/genl/family.h>
+#include <endian.h>
+#endif
+#include "wprobe.h"
+
+#define DEBUG 1
+#ifdef DEBUG
+#define DPRINTF(fmt, ...) fprintf(stderr, "%s(%d): " fmt, __func__, __LINE__, ##__VA_ARGS__)
+#else
+#define DPRINTF(fmt, ...) do {} while (0)
+#endif
+
+#if defined(BYTE_ORDER) && !defined(__BYTE_ORDER)
+#define __LITTLE_ENDIAN LITTLE_ENDIAN
+#define __BIG_ENDIAN BIG_ENDIAN
+#define __BYTE_ORDER BYTE_ORDER
+#endif
+
+#ifndef __BYTE_ORDER
+#error Unknown endian type
+#endif
+
+#define WPROBE_MAX_MSGLEN	65536
+
+static inline __u16 __swab16(__u16 x)
+{
+	return x<<8 | x>>8;
+}
+
+static inline __u32 __swab32(__u32 x)
+{
+	return x<<24 | x>>24 |
+		(x & (__u32)0x0000ff00UL)<<8 |
+		(x & (__u32)0x00ff0000UL)>>8;
+}
+
+static inline __u64 __swab64(__u64 x)
+{
+	return x<<56 | x>>56 |
+		(x & (__u64)0x000000000000ff00ULL)<<40 |
+		(x & (__u64)0x0000000000ff0000ULL)<<24 |
+		(x & (__u64)0x00000000ff000000ULL)<< 8 |
+		(x & (__u64)0x000000ff00000000ULL)>> 8 |
+		(x & (__u64)0x0000ff0000000000ULL)>>24 |
+		(x & (__u64)0x00ff000000000000ULL)>>40;
+}
+
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define SWAP16(var) var = __swab16(var)
+#define SWAP32(var) var = __swab32(var)
+#define SWAP64(var) var = __swab64(var)
+#else
+#define SWAP16(var) do {} while(0)
+#define SWAP32(var) do {} while(0)
+#define SWAP64(var) do {} while(0)
+#endif
+
+int wprobe_port = 17990;
+static struct nlattr *tb[WPROBE_ATTR_LAST+1];
+static struct nla_policy attribute_policy[WPROBE_ATTR_LAST+1] = {
+	[WPROBE_ATTR_ID] = { .type = NLA_U32 },
+	[WPROBE_ATTR_MAC] = { .type = NLA_UNSPEC, .minlen = 6, .maxlen = 6 },
+	[WPROBE_ATTR_NAME] = { .type = NLA_STRING },
+	[WPROBE_ATTR_FLAGS] = { .type = NLA_U32 },
+	[WPROBE_ATTR_TYPE] = { .type = NLA_U8 },
+	[WPROBE_ATTR_FLAGS] = { .type = NLA_U32 },
+	[WPROBE_VAL_S8] = { .type = NLA_U8 },
+	[WPROBE_VAL_S16] = { .type = NLA_U16 },
+	[WPROBE_VAL_S32] = { .type = NLA_U32 },
+	[WPROBE_VAL_S64] = { .type = NLA_U64 },
+	[WPROBE_VAL_U8] = { .type = NLA_U8 },
+	[WPROBE_VAL_U16] = { .type = NLA_U16 },
+	[WPROBE_VAL_U32] = { .type = NLA_U32 },
+	[WPROBE_VAL_U64] = { .type = NLA_U64 },
+	[WPROBE_VAL_SUM] = { .type = NLA_U64 },
+	[WPROBE_VAL_SUM_SQ] = { .type = NLA_U64 },
+	[WPROBE_VAL_SAMPLES] = { .type = NLA_U32 },
+	[WPROBE_VAL_SCALE_TIME] = { .type = NLA_U64 },
+	[WPROBE_ATTR_INTERVAL] = { .type = NLA_U64 },
+	[WPROBE_ATTR_SAMPLES_MIN] = { .type = NLA_U32 },
+	[WPROBE_ATTR_SAMPLES_MAX] = { .type = NLA_U32 },
+	[WPROBE_ATTR_SAMPLES_SCALE_M] = { .type = NLA_U32 },
+	[WPROBE_ATTR_SAMPLES_SCALE_D] = { .type = NLA_U32 },
+	[WPROBE_ATTR_FILTER_GROUP] = { .type = NLA_NESTED },
+	[WPROBE_ATTR_RXCOUNT] = { .type = NLA_U64 },
+	[WPROBE_ATTR_TXCOUNT] = { .type = NLA_U64 },
+};
+
+typedef int (*wprobe_cb_t)(struct nl_msg *, void *);
+
+struct wprobe_iface_ops {
+	int (*send_msg)(struct wprobe_iface *dev, struct nl_msg *msg, wprobe_cb_t cb, void *arg);
+	void (*free)(struct wprobe_iface *dev);
+};
+
+struct wprobe_attr_cb {
+	struct list_head *list;
+	char *addr;
+};
+
+#define WPROBE_MAGIC_STR "WPROBE"
+struct wprobe_init_hdr {
+	struct {
+		char magic[sizeof(WPROBE_MAGIC_STR)];
+
+		/* protocol version */
+		uint8_t version;
+
+		/* extra header length (unused for now) */
+		uint16_t extra;
+	} pre __attribute__((packed));
+	union {
+		struct {
+			uint16_t genl_family;
+		} v0 __attribute__((packed));
+	};
+} __attribute__((packed));
+
+struct wprobe_msg_hdr {
+	__u16 status;
+	__u16 error;
+	__u32 len;
+};
+
+enum wprobe_resp_status {
+	WPROBE_MSG_DONE = 0,
+	WPROBE_MSG_DATA = 1,
+};
+
+static inline void
+wprobe_swap_msg_hdr(struct wprobe_msg_hdr *mhdr)
+{
+	SWAP16(mhdr->status);
+	SWAP16(mhdr->error);
+	SWAP32(mhdr->len);
+}
+
+static int
+save_attribute_handler(struct nl_msg *msg, void *arg)
+{
+	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+	const char *name = "N/A";
+	struct wprobe_attribute *attr;
+	int type = 0;
+	struct wprobe_attr_cb *cb = arg;
+
+	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
+			genlmsg_attrlen(gnlh, 0), attribute_policy);
+
+	if (tb[WPROBE_ATTR_NAME])
+		name = nla_data(tb[WPROBE_ATTR_NAME]);
+
+	attr = malloc(sizeof(struct wprobe_attribute) + strlen(name) + 1);
+	if (!attr)
+		return -1;
+
+	memset(attr, 0, sizeof(struct wprobe_attribute));
+
+	if (tb[WPROBE_ATTR_ID])
+		attr->id = nla_get_u32(tb[WPROBE_ATTR_ID]);
+
+	if (tb[WPROBE_ATTR_MAC] && cb->addr)
+		memcpy(cb->addr, nla_data(tb[WPROBE_ATTR_MAC]), 6);
+
+	if (tb[WPROBE_ATTR_FLAGS])
+		attr->flags = nla_get_u32(tb[WPROBE_ATTR_FLAGS]);
+
+	if (tb[WPROBE_ATTR_TYPE])
+		type = nla_get_u8(tb[WPROBE_ATTR_TYPE]);
+
+	if ((type < WPROBE_VAL_STRING) ||
+		(type > WPROBE_VAL_U64))
+		type = 0;
+
+	attr->type = type;
+	strcpy(attr->name, name);
+	INIT_LIST_HEAD(&attr->list);
+	list_add(&attr->list, cb->list);
+	return 0;
+}
+
+static struct nl_msg *
+wprobe_new_msg(struct wprobe_iface *dev, int cmd, bool dump)
+{
+	struct nl_msg *msg;
+	uint32_t flags = 0;
+
+	msg = nlmsg_alloc_size(65536);
+	if (!msg)
+		return NULL;
+
+	if (dump)
+		flags |= NLM_F_DUMP;
+
+	genlmsg_put(msg, 0, 0, dev->genl_family,
+			0, flags, cmd, 0);
+
+	NLA_PUT_STRING(msg, WPROBE_ATTR_INTERFACE, dev->ifname);
+nla_put_failure:
+	return msg;
+}
+
+
+static int
+dump_attributes(struct wprobe_iface *dev, bool link, struct list_head *list, char *addr)
+{
+	struct nl_msg *msg;
+	struct wprobe_attr_cb cb;
+
+	cb.list = list;
+	cb.addr = addr;
+	msg = wprobe_new_msg(dev, WPROBE_CMD_GET_LIST, true);
+	if (!msg)
+		return -ENOMEM;
+
+	if (link)
+		NLA_PUT(msg, WPROBE_ATTR_MAC, 6, "\x00\x00\x00\x00\x00\x00");
+
+	return dev->ops->send_msg(dev, msg, save_attribute_handler, &cb);
+
+nla_put_failure:
+	nlmsg_free(msg);
+	return -EINVAL;
+}
+
+static struct wprobe_iface *
+wprobe_alloc_dev(void)
+{
+	struct wprobe_iface *dev;
+
+	dev = malloc(sizeof(struct wprobe_iface));
+	if (!dev)
+		return NULL;
+
+	memset(dev, 0, sizeof(struct wprobe_iface));
+
+	dev->interval = -1;
+	dev->scale_min = -1;
+	dev->scale_max = -1;
+	dev->scale_m = -1;
+	dev->scale_d = -1;
+	dev->sockfd = -1;
+
+	INIT_LIST_HEAD(&dev->global_attr);
+	INIT_LIST_HEAD(&dev->link_attr);
+	INIT_LIST_HEAD(&dev->links);
+	return dev;
+}
+
+static int
+wprobe_init_dev(struct wprobe_iface *dev)
+{
+	dump_attributes(dev, false, &dev->global_attr, NULL);
+	dump_attributes(dev, true, &dev->link_attr, NULL);
+	return 0;
+}
+
+#ifndef NO_LOCAL_ACCESS 
+static int n_devs = 0;
+static struct nl_sock *handle = NULL;
+static struct nl_cache *cache = NULL;
+static struct genl_family *family = NULL;
+
+static int
+error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err, void *arg)
+{
+	int *ret = arg;
+	*ret = err->error;
+	return NL_STOP;
+}
+
+static int
+finish_handler(struct nl_msg *msg, void *arg)
+{
+	int *ret = arg;
+	*ret = 0;
+	return NL_SKIP;
+}
+
+static int
+ack_handler(struct nl_msg *msg, void *arg)
+{
+	int *ret = arg;
+	*ret = 0;
+	return NL_STOP;
+}
+
+static void
+wprobe_local_free(struct wprobe_iface *dev)
+{
+	/* should not happen */
+	if (n_devs == 0)
+		return;
+
+	if (--n_devs != 0)
+		return;
+
+	if (cache)
+		nl_cache_free(cache);
+	if (handle)
+		nl_socket_free(handle);
+	handle = NULL;
+	cache = NULL;
+}
+
+static int
+wprobe_local_init(void)
+{
+	int ret;
+
+	if (n_devs++ > 0)
+		return 0;
+
+	handle = nl_socket_alloc();
+	if (!handle) {
+		DPRINTF("Failed to create handle\n");
+		goto err;
+	}
+
+	if (genl_connect(handle)) {
+		DPRINTF("Failed to connect to generic netlink\n");
+		goto err;
+	}
+
+	ret = genl_ctrl_alloc_cache(handle, &cache);
+	if (ret < 0) {
+		DPRINTF("Failed to allocate netlink cache\n");
+		goto err;
+	}
+
+	family = genl_ctrl_search_by_name(cache, "wprobe");
+	if (!family) {
+		DPRINTF("wprobe API not present\n");
+		goto err;
+	}
+	return 0;
+
+err:
+	wprobe_local_free(NULL);
+	return -EINVAL;
+}
+
+
+static int
+wprobe_local_send_msg(struct wprobe_iface *dev, struct nl_msg *msg, wprobe_cb_t callback, void *arg)
+{
+	struct nl_cb *cb;
+	int err = 0;
+
+	cb = nl_cb_alloc(NL_CB_DEFAULT);
+	if (!cb)
+		goto out_no_cb;
+
+	if (callback)
+		nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, callback, arg);
+
+	err = nl_send_auto_complete(handle, msg);
+	if (err < 0)
+		goto out;
+
+	err = 1;
+
+	nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
+	nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
+	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
+
+	while (err > 0)
+		nl_recvmsgs(handle, cb);
+
+out:
+	nl_cb_put(cb);
+out_no_cb:
+	nlmsg_free(msg);
+	return err;
+}
+
+static const struct wprobe_iface_ops wprobe_local_ops = {
+	.send_msg = wprobe_local_send_msg,
+	.free = wprobe_local_free,
+};
+
+struct wprobe_iface *
+wprobe_get_dev(const char *ifname)
+{
+	struct wprobe_iface *dev;
+
+	if (wprobe_local_init() != 0)
+		return NULL;
+
+	dev = wprobe_alloc_dev();
+	if (!dev)
+		goto error_alloc;
+
+	dev->ifname = strdup(ifname);
+	dev->ops = &wprobe_local_ops;
+	dev->genl_family = genl_family_get_id(family);
+
+	if (wprobe_init_dev(dev) < 0)
+		goto error;
+
+	return dev;
+
+error:
+	free(dev);
+error_alloc:
+	wprobe_local_free(NULL);
+	return NULL;
+}
+
+#endif
+
+static void swap_nlmsghdr(struct nlmsghdr *nlh)
+{
+	SWAP32(nlh->nlmsg_len);
+	SWAP16(nlh->nlmsg_type);
+	SWAP16(nlh->nlmsg_flags);
+	SWAP32(nlh->nlmsg_seq);
+	SWAP32(nlh->nlmsg_pid);
+}
+
+static void swap_genlmsghdr(struct genlmsghdr *gnlh)
+{
+#if 0 /* probably unnecessary */
+	SWAP16(gnlh->reserved);
+#endif
+}
+
+static void
+wprobe_swap_nested(void *data, int len, bool outgoing)
+{
+	void *end = data + len;
+
+	while (data < end) {
+		struct nlattr *nla = data;
+		unsigned int type, len;
+
+		if (!outgoing) {
+			SWAP16(nla->nla_len);
+			SWAP16(nla->nla_type);
+
+			/* required for further sanity checks */
+			if (data + nla->nla_len > end)
+				nla->nla_len = end - data;
+		}
+
+		len = NLA_ALIGN(nla->nla_len);
+		type = nla->nla_type & NLA_TYPE_MASK;
+
+		if (type <= WPROBE_ATTR_LAST) {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+			switch(attribute_policy[type].type) {
+			case NLA_U16:
+				SWAP16(*(__u16 *)nla_data(nla));
+				break;
+			case NLA_U32:
+				SWAP32(*(__u32 *)nla_data(nla));
+				break;
+			case NLA_U64:
+				SWAP64(*(__u64 *)nla_data(nla));
+				break;
+			case NLA_NESTED:
+				wprobe_swap_nested(nla_data(nla), nla_len(nla), outgoing);
+				break;
+			}
+#endif
+		}
+		data += len;
+
+		if (outgoing) {
+			SWAP16(nla->nla_len);
+			SWAP16(nla->nla_type);
+		}
+		if (!nla->nla_len)
+			break;
+	}
+}
+
+static struct nl_msg *
+wprobe_msg_from_network(int socket, int len)
+{
+	struct genlmsghdr *gnlh;
+	struct nlmsghdr *nlh;
+	struct nl_msg *msg;
+	void *data;
+
+	msg = nlmsg_alloc_size(len + 32);
+	if (!msg)
+		return NULL;
+
+	nlh = nlmsg_hdr(msg);
+	if (read(socket, nlh, len) != len)
+		goto free;
+
+	swap_nlmsghdr(nlh);
+	if (nlh->nlmsg_len > len)
+		goto free;
+
+	gnlh = nlmsg_data(nlh);
+	swap_genlmsghdr(gnlh);
+
+	data = genlmsg_data(gnlh);
+	wprobe_swap_nested(data, genlmsg_len(gnlh), false);
+
+	return msg;
+free:
+	nlmsg_free(msg);
+	return NULL;
+}
+
+static int
+wprobe_msg_to_network(int socket, struct nl_msg *msg)
+{
+	struct nlmsghdr *nlh = nlmsg_hdr(msg);
+	struct wprobe_msg_hdr mhdr;
+	struct genlmsghdr *gnlh;
+	void *buf, *data;
+	int buflen, datalen;
+	int ret;
+
+	buflen = nlh->nlmsg_len;
+	buf = malloc(buflen);
+	if (!buf)
+		return -ENOMEM;
+
+	memset(&mhdr, 0, sizeof(mhdr));
+	mhdr.status = WPROBE_MSG_DATA;
+	mhdr.len = buflen;
+	wprobe_swap_msg_hdr(&mhdr);
+	write(socket, &mhdr, sizeof(mhdr));
+
+	memcpy(buf, nlh, buflen);
+	nlh = buf;
+	gnlh = nlmsg_data(nlh);
+	data = genlmsg_data(gnlh);
+	datalen = genlmsg_len(gnlh);
+
+	wprobe_swap_nested(data, datalen, true);
+	swap_genlmsghdr(gnlh);
+	swap_nlmsghdr(nlh);
+	ret = write(socket, buf, buflen);
+	free(buf);
+
+	return ret;
+}
+
+static int
+wprobe_remote_send_msg(struct wprobe_iface *dev, struct nl_msg *msg, wprobe_cb_t callback, void *arg)
+{
+	struct wprobe_msg_hdr mhdr;
+	int msgs = 0;
+
+	wprobe_msg_to_network(dev->sockfd, msg);
+	nlmsg_free(msg);
+	do {
+		if (read(dev->sockfd, &mhdr, sizeof(mhdr)) != sizeof(mhdr)) {
+			DPRINTF("Failed to read response header\n");
+			return -1;
+		}
+		wprobe_swap_msg_hdr(&mhdr);
+
+		switch(mhdr.status) {
+		case WPROBE_MSG_DATA:
+			if (mhdr.len > WPROBE_MAX_MSGLEN) {
+				fprintf(stderr, "Invalid length in received response message.\n");
+				exit(1);
+			}
+
+			msg = wprobe_msg_from_network(dev->sockfd, mhdr.len);
+			if (!msg)
+				return -EINVAL;
+
+			msgs++;
+			callback(msg, arg);
+			nlmsg_free(msg);
+			break;
+		}
+	} while (mhdr.status != WPROBE_MSG_DONE);
+
+	if (mhdr.error)
+		return -mhdr.error;
+	else
+		return msgs;
+}
+
+
+static void
+wprobe_socket_dev_free(struct wprobe_iface *dev)
+{
+	if (dev->sockfd >= 0)
+		close(dev->sockfd);
+}
+
+static const struct wprobe_iface_ops wprobe_remote_ops = {
+	.send_msg = wprobe_remote_send_msg,
+	.free = wprobe_socket_dev_free,
+};
+
+
+#ifndef NO_LOCAL_ACCESS 
+int
+wprobe_server_init(int socket)
+{
+	struct wprobe_init_hdr hdr;
+	int ret;
+
+	ret = wprobe_local_init();
+	if (ret != 0)
+		return ret;
+
+	memset(&hdr, 0, sizeof(hdr));
+	memcpy(hdr.pre.magic, WPROBE_MAGIC_STR, sizeof(WPROBE_MAGIC_STR));
+	hdr.pre.version = 0;
+	hdr.v0.genl_family = genl_family_get_id(family);
+	SWAP16(hdr.v0.genl_family);
+	write(socket, (unsigned char *)&hdr, sizeof(hdr));
+
+	return 0;
+}
+
+static int
+wprobe_server_cb(struct nl_msg *msg, void *arg)
+{
+	int *socket = arg;
+	int ret;
+
+	ret = wprobe_msg_to_network(*socket, msg);
+	if (ret > 0)
+		ret = 0;
+
+	return ret;
+}
+
+
+int
+wprobe_server_handle(int socket)
+{
+	struct wprobe_msg_hdr mhdr;
+	struct nl_msg *msg;
+	int ret;
+
+	ret = read(socket, &mhdr, sizeof(mhdr));
+	if (ret != sizeof(mhdr)) {
+		if (ret <= 0)
+			return -1;
+
+		DPRINTF("Failed to read request header\n");
+		return -EINVAL;
+	}
+	wprobe_swap_msg_hdr(&mhdr);
+
+	switch(mhdr.status) {
+	case WPROBE_MSG_DATA:
+		if (mhdr.len > WPROBE_MAX_MSGLEN) {
+			DPRINTF("Invalid length in received response message.\n");
+			return -EINVAL;
+		}
+		msg = wprobe_msg_from_network(socket, mhdr.len);
+		break;
+	default:
+		DPRINTF("Invalid request header type\n");
+		return -ENOENT;
+	}
+
+	if (!msg) {
+		DPRINTF("Failed to get message\n");
+		return -EINVAL;
+	}
+
+	ret = wprobe_local_send_msg(NULL, msg, wprobe_server_cb, &socket);
+
+	memset(&mhdr, 0, sizeof(mhdr));
+	mhdr.status = WPROBE_MSG_DONE;
+	if (ret < 0)
+		mhdr.error = (uint16_t) -ret;
+
+	ret = write(socket, (unsigned char *)&mhdr, sizeof(mhdr));
+	if (ret > 0)
+		ret = 0;
+
+	return ret;
+}
+
+void
+wprobe_server_done(void)
+{
+	wprobe_local_free(NULL);
+}
+#endif
+
+struct wprobe_iface *
+wprobe_get_from_socket(int socket, const char *name)
+{
+	struct wprobe_iface *dev;
+	struct wprobe_init_hdr hdr;
+
+	dev = wprobe_alloc_dev();
+	if (!dev)
+		goto out;
+
+	dev->ops = &wprobe_remote_ops;
+	dev->sockfd = socket;
+	dev->ifname = strdup(name);
+
+	/* read version and header length */
+	if (read(socket, &hdr.pre, sizeof(hdr.pre)) != sizeof(hdr.pre)) {
+		DPRINTF("Could not read header\n");
+		goto error;
+	}
+
+	/* magic not found */
+	if (memcmp(hdr.pre.magic, WPROBE_MAGIC_STR, sizeof(hdr.pre.magic)) != 0) {
+		DPRINTF("Magic does not match\n");
+		goto error;
+	}
+
+	/* unsupported version */
+	if (hdr.pre.version != 0) {
+		DPRINTF("Protocol version does not match\n");
+		goto error;
+	}
+
+	if (read(socket, &hdr.v0, sizeof(hdr.v0)) != sizeof(hdr.v0)) {
+		DPRINTF("Could not read header data\n");
+		goto error;
+	}
+
+	SWAP16(hdr.pre.extra);
+	SWAP16(hdr.v0.genl_family);
+	dev->genl_family = hdr.v0.genl_family;
+
+	if (wprobe_init_dev(dev) < 0) {
+		DPRINTF("Could not initialize device\n");
+		goto error;
+	}
+
+out:
+	return dev;
+
+error:
+	wprobe_free_dev(dev);
+	return NULL;
+}
+
+struct wprobe_iface *
+wprobe_get_auto(const char *arg, char **err)
+{
+	static struct sockaddr_in sa;
+	static char errbuf[512];
+
+	struct wprobe_iface *dev = NULL;
+	struct hostent *h;
+	char *devstr = strdup(arg);
+	char *sep = NULL;
+	int sock = -1;
+	int len;
+
+	if (err)
+		*err = NULL;
+
+	sep = strchr(devstr, ':');
+	if (!sep) {
+#ifndef NO_LOCAL_ACCESS 
+		free(devstr);
+		return wprobe_get_dev(arg);
+#else
+		*err = "Invalid argument";
+		goto out;
+#endif
+	}
+
+	*sep = 0;
+	sep++;
+
+	sock = socket(AF_INET, SOCK_STREAM, 0);
+	if (sock < 0)
+		goto syserr;
+
+	h = gethostbyname(devstr);
+	if (!h) {
+		sprintf(errbuf, "Host not found");
+		goto out_err;
+	}
+
+	memcpy(&sa.sin_addr, h->h_addr, h->h_length);
+	sa.sin_family = AF_INET;
+	sa.sin_port = htons(wprobe_port);
+	if (connect(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0)
+		goto syserr;
+
+	dev = wprobe_get_from_socket(sock, sep);
+	if (!dev) {
+		sprintf(errbuf, "wprobe connection initialization failed");
+		goto out_err;
+	}
+	goto out;
+
+syserr:
+	if (err) {
+		strcpy(errbuf, "Connection failed: ");
+		len = strlen(errbuf);
+		strerror_r(errno, errbuf + len, sizeof(errbuf) - len - 1);
+	}
+out_err:
+	if (err)
+		*err = errbuf;
+	if (sock >= 0)
+		close(sock);
+out:
+	if (devstr)
+		free(devstr);
+	return dev;
+}
+
+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)
+{
+	if (dev->ops->free)
+		dev->ops->free(dev);
+	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)
+{
+	struct wprobe_link *l;
+
+	list_for_each_entry(l, list, list) {
+		if (!memcmp(l->addr, addr, 6)) {
+			list_del_init(&l->list);
+			goto out;
+		}
+	}
+
+	/* no previous link found, allocate a new one */
+	l = malloc(sizeof(struct wprobe_link));
+	if (!l)
+		goto out;
+
+	memset(l, 0, sizeof(struct wprobe_link));
+	memcpy(l->addr, addr, sizeof(l->addr));
+	INIT_LIST_HEAD(&l->list);
+
+out:
+	return l;
+}
+
+struct wprobe_save_cb {
+	struct list_head *list;
+	struct list_head old_list;
+};
+
+static int
+save_link_handler(struct nl_msg *msg, void *arg)
+{
+	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+	struct wprobe_link *link;
+	struct wprobe_save_cb *cb = arg;
+	const char *addr;
+
+	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
+			genlmsg_attrlen(gnlh, 0), attribute_policy);
+
+	if (!tb[WPROBE_ATTR_MAC] || (nla_len(tb[WPROBE_ATTR_MAC]) != 6))
+		return -1;
+
+	addr = nla_data(tb[WPROBE_ATTR_MAC]);
+	link = get_link(&cb->old_list, addr);
+	if (!link)
+		return -1;
+
+	if (tb[WPROBE_ATTR_FLAGS])
+		link->flags = nla_get_u32(tb[WPROBE_ATTR_FLAGS]);
+
+	list_add_tail(&link->list, cb->list);
+	return 0;
+}
+
+
+int
+wprobe_update_links(struct wprobe_iface *dev)
+{
+	struct wprobe_link *l, *tmp;
+	struct nl_msg *msg;
+	struct wprobe_save_cb cb;
+	int err;
+
+	INIT_LIST_HEAD(&cb.old_list);
+	list_splice_init(&dev->links, &cb.old_list);
+	cb.list = &dev->links;
+
+	msg = wprobe_new_msg(dev, WPROBE_CMD_GET_LINKS, true);
+	if (!msg)
+		return -ENOMEM;
+
+	err = dev->ops->send_msg(dev, msg, save_link_handler, &cb);
+	if (err < 0)
+		return err;
+
+	list_for_each_entry_safe(l, tmp, &cb.old_list, list) {
+		list_del(&l->list);
+		free(l);
+	}
+
+	return 0;
+}
+
+
+struct wprobe_filter_data
+{
+	wprobe_filter_cb cb;
+	void *arg;
+	struct wprobe_filter_item *buf;
+	int buflen;
+};
+
+static int
+dump_filter_handler(struct nl_msg *msg, void *arg)
+{
+	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+	struct wprobe_filter_data *data = arg;
+	struct nlattr *p;
+	const char *name;
+	int count = 0;
+	int len;
+
+	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
+			genlmsg_attrlen(gnlh, 0), attribute_policy);
+
+	if (!tb[WPROBE_ATTR_NAME] || !tb[WPROBE_ATTR_FILTER_GROUP])
+		return -1;
+
+	name = nla_data(tb[WPROBE_ATTR_NAME]);
+	nla_for_each_nested(p, tb[WPROBE_ATTR_FILTER_GROUP], len) {
+		count++;
+	}
+
+	if (data->buflen < count) {
+		if (data->buf)
+			free(data->buf);
+		data->buflen = count;
+		data->buf = malloc(sizeof(struct wprobe_filter_item) * count);
+		memset(data->buf, 0, sizeof(struct wprobe_filter_item) * count);
+	}
+
+	count = 0;
+	nla_for_each_nested(p, tb[WPROBE_ATTR_FILTER_GROUP], len) {
+		struct wprobe_filter_item *fi;
+
+		nla_parse(tb, WPROBE_ATTR_LAST, nla_data(p),
+				nla_len(p), attribute_policy);
+
+		if (!tb[WPROBE_ATTR_NAME] || !tb[WPROBE_ATTR_RXCOUNT]
+				|| !tb[WPROBE_ATTR_TXCOUNT])
+			continue;
+
+		fi = &data->buf[count++];
+		strncpy(fi->name, nla_data(tb[WPROBE_ATTR_NAME]), sizeof(fi->name) - 1);
+		fi->name[sizeof(fi->name) - 1] = 0;
+		fi->rx = nla_get_u64(tb[WPROBE_ATTR_RXCOUNT]);
+		fi->tx = nla_get_u64(tb[WPROBE_ATTR_TXCOUNT]);
+	}
+	data->cb(data->arg, name, data->buf, count);
+
+	return 0;
+}
+
+int
+wprobe_dump_filters(struct wprobe_iface *dev, wprobe_filter_cb cb, void *arg)
+{
+	struct wprobe_filter_data data;
+	struct nl_msg *msg;
+	int err;
+
+	data.buf = 0;
+	data.buflen = 0;
+	data.cb = cb;
+	data.arg = arg;
+
+	msg = wprobe_new_msg(dev, WPROBE_CMD_GET_FILTER, true);
+	if (!msg)
+		return -ENOMEM;
+
+	err = dev->ops->send_msg(dev, msg, dump_filter_handler, &data);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+int
+wprobe_apply_config(struct wprobe_iface *dev)
+{
+	struct nl_msg *msg;
+
+	msg = wprobe_new_msg(dev, WPROBE_CMD_CONFIG, false);
+	if (!msg)
+		return -ENOMEM;
+
+	if (dev->interval >= 0)
+		NLA_PUT_MSECS(msg, WPROBE_ATTR_INTERVAL, dev->interval);
+
+	if (dev->filter_len < 0) {
+		NLA_PUT(msg, WPROBE_ATTR_FILTER, 0, NULL);
+		dev->filter_len = 0;
+	} else if (dev->filter && dev->filter_len > 0) {
+		NLA_PUT(msg, WPROBE_ATTR_FILTER, dev->filter_len, dev->filter);
+	}
+	dev->filter = NULL;
+
+	dev->ops->send_msg(dev, 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, WPROBE_CMD_MEASURE, false);
+	if (!msg)
+		return -ENOMEM;
+
+	dev->ops->send_msg(dev, msg, NULL, NULL);
+	return 0;
+}
+
+struct wprobe_request_cb {
+	struct list_head *list;
+	struct list_head old_list;
+	char *addr;
+};
+
+static int
+save_attrdata_handler(struct nl_msg *msg, void *arg)
+{
+	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+	struct wprobe_request_cb *cb = arg;
+	struct wprobe_attribute *attr;
+	int type, id;
+
+	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
+			genlmsg_attrlen(gnlh, 0), attribute_policy);
+
+	if (!tb[WPROBE_ATTR_ID])
+		return -1;
+
+	if (!tb[WPROBE_ATTR_TYPE])
+		return -1;
+
+	id = nla_get_u32(tb[WPROBE_ATTR_ID]);
+	list_for_each_entry(attr, &cb->old_list, list) {
+		if (attr->id == id)
+			goto found;
+	}
+	/* not found */
+	return -1;
+
+found:
+	list_del_init(&attr->list);
+
+	type = nla_get_u8(tb[WPROBE_ATTR_TYPE]);
+	if (type != attr->type) {
+		DPRINTF("WARNING: type mismatch for %s attribute '%s' (%d != %d)\n",
+			(cb->addr ? "link" : "global"),
+			attr->name,
+			type, attr->type);
+		goto out;
+	}
+
+	if ((type < WPROBE_VAL_STRING) ||
+		(type > WPROBE_VAL_U64))
+		goto out;
+
+	memset(&attr->val, 0, sizeof(attr->val));
+
+#define HANDLE_INT_TYPE(_idx, _type) \
+	case WPROBE_VAL_S##_type: \
+	case WPROBE_VAL_U##_type: \
+		attr->val.U##_type = nla_get_u##_type(tb[_idx]); \
+		break
+
+	switch(type) {
+		HANDLE_INT_TYPE(type, 8);
+		HANDLE_INT_TYPE(type, 16);
+		HANDLE_INT_TYPE(type, 32);
+		HANDLE_INT_TYPE(type, 64);
+		case WPROBE_VAL_STRING:
+			/* unimplemented */
+			break;
+	}
+#undef HANDLE_TYPE
+
+	if (attr->flags & WPROBE_F_KEEPSTAT) {
+		if (tb[WPROBE_VAL_SUM])
+			attr->val.s = nla_get_u64(tb[WPROBE_VAL_SUM]);
+
+		if (tb[WPROBE_VAL_SUM_SQ])
+			attr->val.ss = nla_get_u64(tb[WPROBE_VAL_SUM_SQ]);
+
+		if (tb[WPROBE_VAL_SAMPLES])
+			attr->val.n = nla_get_u32(tb[WPROBE_VAL_SAMPLES]);
+
+		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;
+		}
+	}
+
+out:
+	list_add_tail(&attr->list, cb->list);
+	return 0;
+}
+
+
+int
+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(dev, WPROBE_CMD_GET_INFO, true);
+	if (!msg)
+		return -ENOMEM;
+
+	if (addr) {
+		attrs = &dev->link_attr;
+		NLA_PUT(msg, WPROBE_ATTR_MAC, 6, addr);
+	} else {
+		attrs = &dev->global_attr;
+	}
+
+	INIT_LIST_HEAD(&cb.old_list);
+	list_splice_init(attrs, &cb.old_list);
+	cb.list = attrs;
+
+	err = dev->ops->send_msg(dev, msg, save_attrdata_handler, &cb);
+	list_splice(&cb.old_list, attrs->prev);
+	return err;
+
+nla_put_failure:
+	nlmsg_free(msg);
+	return -ENOMEM;
+}
+
+