2 * netsniff-ng - the packet sniffing beast
3 * Copyright 2012 Daniel Borkmann.
4 * Subject to the GPL, version 2.
5 * Parts derived from iw, subject to ISC license.
6 * Copyright 2007, 2008 Johannes Berg
7 * Copyright 2007 Andy Lutomirski
8 * Copyright 2007 Mike Kershaw
9 * Copyright 2008-2009 Luis R. Rodriguez
18 #include <linux/nl80211.h>
19 #include <libnl3/netlink/genl/genl.h>
20 #include <libnl3/netlink/genl/family.h>
21 #include <libnl3/netlink/genl/ctrl.h>
22 #include <libnl3/netlink/msg.h>
23 #include <libnl3/netlink/attr.h>
32 struct nl80211_state
{
33 struct nl_sock
*nl_sock
;
34 struct nl_cache
*nl_cache
;
35 struct genl_family
*nl80211
;
38 static void get_mac80211_phydev(const char *device
, char *phydev_path
,
45 ret
= asprintf(&pathstr
, "/sys/class/net/%s/phy80211", device
);
47 panic("Can't generate path name string for /sys/class/net device");
49 num
= readlink(pathstr
, phydev_path
, phydev_len
);
51 if (errno
== ENOENT
|| errno
== EINVAL
)
52 panic("It's probably not a mac80211 device!\n");
53 panic("Can't readlink %s: %s!\n", pathstr
, strerror(errno
));
57 phydev_path
[min(num
, phydev_len
- 1)] = 0;
60 static inline struct nl_msg
*nl80211_nlmsg_xalloc(void)
62 struct nl_msg
*ret
= nlmsg_alloc();
64 panic("Cannot allocate nlmsg memory!\n");
68 static inline struct nl_sock
*nl80211_nl_socket_xalloc(void)
70 struct nl_sock
*ret
= nl_socket_alloc();
72 panic("Cannot allocate nl socket memory!\n");
76 static void nl80211_init(struct nl80211_state
*state
, const char *device
)
80 state
->nl_sock
= nl80211_nl_socket_xalloc();
82 ret
= genl_connect(state
->nl_sock
);
84 panic("Cannot connect generic netlink!\n");
86 ret
= genl_ctrl_alloc_cache(state
->nl_sock
, &state
->nl_cache
);
88 panic("Failed to allocate generic netlink cache: %s!",
91 state
->nl80211
= genl_ctrl_search_by_name(state
->nl_cache
, "nl80211");
93 panic("nl80211 not found in netlink cache!\n");
96 static void nl80211_cleanup(struct nl80211_state
*state
)
98 genl_family_put(state
->nl80211
);
100 nl_cache_free(state
->nl_cache
);
101 nl_socket_free(state
->nl_sock
);
104 static int nl80211_wait_handler(struct nl_msg
*msg
, void *arg
)
113 static int nl80211_error_handler(struct sockaddr_nl
*nla
,
114 struct nlmsgerr
*err
,
117 panic("nl80211 returned with error %d\n", err
->error
);
120 static int nl80211_add_mon_if(struct nl80211_state
*state
, const char *device
,
121 const char *mondevice
)
125 struct nl_cb
*cb
= NULL
;
128 ifindex
= device_ifindex(device
);
130 msg
= nl80211_nlmsg_xalloc();
132 genlmsg_put(msg
, 0, 0, genl_family_get_id(state
->nl80211
), 0,
133 0, NL80211_CMD_NEW_INTERFACE
, 0);
135 NLA_PUT_U32(msg
, NL80211_ATTR_IFINDEX
, ifindex
);
136 NLA_PUT_STRING(msg
, NL80211_ATTR_IFNAME
, mondevice
);
137 NLA_PUT_U32(msg
, NL80211_ATTR_IFTYPE
, NL80211_IFTYPE_MONITOR
);
139 ret
= nl_send_auto_complete(state
->nl_sock
, msg
);
141 if (ret
== -ENFILE
) {
146 panic("Cannot send_auto_complete!\n");
149 cb
= nl_cb_alloc(NL_CB_CUSTOM
);
151 panic("Cannot alloc nl_cb!\n");
153 nl_cb_set(cb
, NL_CB_ACK
, NL_CB_CUSTOM
, nl80211_wait_handler
, &finished
);
154 nl_cb_err(cb
, NL_CB_CUSTOM
, nl80211_error_handler
, NULL
);
156 nl_recvmsgs(state
->nl_sock
, cb
);
159 ret
= nl_wait_for_ack(state
->nl_sock
);
161 if (ret
== -ENFILE
) {
166 panic("Waiting for netlink ack failed!\n");
175 panic("nla put failure!\n");
176 return -EIO
; /* dummy */
179 static int nl80211_del_mon_if(struct nl80211_state
*state
, const char *device
,
180 const char *mondevice
)
185 ifindex
= device_ifindex(mondevice
);
187 msg
= nl80211_nlmsg_xalloc();
189 genlmsg_put(msg
, 0, 0, genl_family_get_id(state
->nl80211
), 0,
190 0, NL80211_CMD_DEL_INTERFACE
, 0);
192 NLA_PUT_U32(msg
, NL80211_ATTR_IFINDEX
, ifindex
);
194 ret
= nl_send_auto_complete(state
->nl_sock
, msg
);
196 panic("Cannot send_auto_complete!\n");
198 ret
= nl_wait_for_ack(state
->nl_sock
);
200 panic("Waiting for netlink ack failed!\n");
206 panic("nla put failure!\n");
207 return -EIO
; /* dummy */
210 void enter_rfmon_mac80211(const char *device
, char **mondev
)
215 char phydev_path
[256];
216 struct nl80211_state nlstate
;
218 /* XXX: is this already a monN device? */
219 get_mac80211_phydev(device
, phydev_path
, sizeof(phydev_path
));
220 nl80211_init(&nlstate
, device
);
222 for (n
= 0; n
< UINT_MAX
; n
++) {
225 slprintf(mondevice
, sizeof(mondevice
), "mon%u", n
);
226 ret
= nl80211_add_mon_if(&nlstate
, device
, mondevice
);
228 *mondev
= xstrdup(mondevice
);
230 flags
= device_get_flags(*mondev
);
231 flags
|= IFF_UP
| IFF_RUNNING
;
232 device_set_flags(*mondev
, flags
);
234 nl80211_cleanup(&nlstate
);
239 panic("No free monN interfaces!\n");
242 void leave_rfmon_mac80211(const char *device
, const char *mondev
)
245 struct nl80211_state nlstate
;
247 flags
= device_get_flags(mondev
);
248 flags
&= ~(IFF_UP
| IFF_RUNNING
);
249 device_set_flags(mondev
, flags
);
251 nl80211_init(&nlstate
, device
);
252 nl80211_del_mon_if(&nlstate
, device
, mondev
);
253 nl80211_cleanup(&nlstate
);