/*
* Restart a previous scan. If the previous scan completed
* then we start again using the existing channel list.
*/
int
ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
const struct ieee80211_scanner *scan;
scan = ieee80211_scanner_get(vap->iv_opmode);
if (scan == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no scanner support for %s mode\n",
__func__, vap->iv_opmode);
/* XXX stat */
return 0;
}
IEEE80211_LOCK(ic);
if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
u_int duration;
/*
* Go off-channel for a fixed interval that is large
* enough to catch most ap's but short enough that
* we can return on-channel before our listen interval
* expires.
*/
duration = IEEE80211_SCAN_OFFCHANNEL;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan, ticks %u duration %lu\n", __func__,
ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
ticks, duration);
scan_update_locked(vap, scan);
if (ss->ss_ops != NULL) {
ss->ss_vap = vap;
/*
* A background scan does not select a new sta; it
* just refreshes the scan cache. Also, indicate
* the scan logic should follow the beacon schedule:
* we go off-channel and scan for a while, then
* return to the bss channel to receive a beacon,
* then go off-channel again. All during this time
* we notify the ap we're in power save mode. When
* the scan is complete we leave power save mode.
* If any beacon indicates there are frames pending
* for us then we drop out of power save mode
* (and background scan) automatically by way of the
* usual sta power save logic.
*/
ss->ss_flags |= IEEE80211_SCAN_NOPICK
| IEEE80211_SCAN_BGSCAN
| flags
;
/* if previous scan completed, restart */
if (ss->ss_next >= ss->ss_last) {
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
vap->iv_stats.is_scan_active++;
else
vap->iv_stats.is_scan_passive++;
/*
* NB: beware of the scan cache being flushed;
* if the channel list is empty use the
* scan_start method to populate it.
*/
ss->ss_next = 0;
if (ss->ss_last != 0)
ss->ss_ops->scan_restart(ss, vap);
else {
ss->ss_ops->scan_start(ss, vap);
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap))
scan_dump(ss);
#endif /* IEEE80211_DEBUG */
}
}
/* NB: flush frames rx'd before 1st channel change */
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
SCAN_PRIVATE(ss)->ss_duration = duration;
ss->ss_maxdwell = duration;
ic->ic_flags |= IEEE80211_F_SCAN;
ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
} else {
/* XXX msg+stat */
}
} else {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan already in progress\n", __func__,
ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
}
IEEE80211_UNLOCK(ic);
/* NB: racey, does it matter? */
return (ic->ic_flags & IEEE80211_F_SCAN);
}
/*
* tries to (re)open log file, nomove flag is used with -x switch
* returns 0: success, 1: retry (log moved), -1: error
*/
int
try_reset_dump(int nomove)
{
struct pcap_file_header hdr;
struct stat st;
int fd;
FILE *fp;
if (hpcap == NULL)
return (-1);
if (dpcap) {
flush_buffer(dpcap);
fclose(dpcap);
dpcap = NULL;
}
/*
* Basically reimplement pcap_dump_open() because it truncates
* files and duplicates headers and such.
*/
fd = priv_open_log();
if (fd < 0)
return (-1);
fp = fdopen(fd, "a+");
if (fp == NULL) {
logmsg(LOG_ERR, "Error: %s: %s", filename, strerror(errno));
close(fd);
return (-1);
}
if (fstat(fileno(fp), &st) == -1) {
logmsg(LOG_ERR, "Error: %s: %s", filename, strerror(errno));
fclose(fp);
return (-1);
}
/* set FILE unbuffered, we do our own buffering */
if (setvbuf(fp, NULL, _IONBF, 0)) {
logmsg(LOG_ERR, "Failed to set output buffers");
fclose(fp);
return (-1);
}
#define TCPDUMP_MAGIC 0xa1b2c3d4
if (st.st_size == 0) {
if (snaplen != cur_snaplen) {
logmsg(LOG_NOTICE, "Using snaplen %d", snaplen);
if (set_snaplen(snaplen))
logmsg(LOG_WARNING,
"Failed, using old settings");
}
hdr.magic = TCPDUMP_MAGIC;
hdr.version_major = PCAP_VERSION_MAJOR;
hdr.version_minor = PCAP_VERSION_MINOR;
hdr.thiszone = hpcap->tzoff;
hdr.snaplen = hpcap->snapshot;
hdr.sigfigs = 0;
hdr.linktype = hpcap->linktype;
if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
fclose(fp);
return (-1);
}
} else if (scan_dump(fp, st.st_size)) {
fclose(fp);
if (nomove || priv_move_log()) {
logmsg(LOG_ERR,
"Invalid/incompatible log file, move it away");
return (-1);
}
return (1);
}
dpcap = fp;
set_suspended(0);
flush_buffer(fp);
return (0);
}
/*
* Start a scan unless one is already going.
*/
static int
start_scan_locked(const struct ieee80211_scanner *scan,
struct ieee80211vap *vap, int flags, u_int duration,
u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[])
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: scan inhibited by pending channel change\n", __func__);
} else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
, __func__
, flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
, duration, mindwell, maxdwell
, ieee80211_phymode_name[vap->iv_des_mode]
, flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
, flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
, flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
, flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
, flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
, flags & IEEE80211_SCAN_ONCE ? ", once" : ""
);
scan_update_locked(vap, scan);
if (ss->ss_ops != NULL) {
if ((flags & IEEE80211_SCAN_NOSSID) == 0)
copy_ssid(vap, ss, nssid, ssids);
/* NB: top 4 bits for internal use */
ss->ss_flags = flags & 0xfff;
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
vap->iv_stats.is_scan_active++;
else
vap->iv_stats.is_scan_passive++;
if (flags & IEEE80211_SCAN_FLUSH)
ss->ss_ops->scan_flush(ss);
/* NB: flush frames rx'd before 1st channel change */
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
SCAN_PRIVATE(ss)->ss_duration = duration;
ss->ss_next = 0;
ss->ss_mindwell = mindwell;
ss->ss_maxdwell = maxdwell;
/* NB: scan_start must be before the scan runtask */
ss->ss_ops->scan_start(ss, vap);
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap))
scan_dump(ss);
#endif /* IEEE80211_DEBUG */
ic->ic_flags |= IEEE80211_F_SCAN;
ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
}
} else {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan already in progress\n", __func__,
ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
}
return (ic->ic_flags & IEEE80211_F_SCAN);
}
