upgrade to the new version of wprobe - includes reconfigurable layer 2 statistics...
[openwrt/svn-archive/archive.git] / package / wprobe / src / user / wprobe-lib.c
diff --git a/package/wprobe/src/user/wprobe-lib.c b/package/wprobe/src/user/wprobe-lib.c
new file mode 100644 (file)
index 0000000..a3b0fb5
--- /dev/null
@@ -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;
+}
+
+