add a channel hopper for wireless interfaces. the channel hopper will

jump to the next available channel after a configurable delay for the
specified list of wireless "hostap" interfaces, see the new "set
hostap hopper" commands in hostapd.conf(5).

with help by jsg@

5 files changed, 154 insertions, 5 deletions

diff --git a/usr.sbin/hostapd/apme.c b/usr.sbin/hostapd/apme.c
index 7fa1513644a..34d63ff7d4f 100644
--- a/usr.sbin/hostapd/apme.c
+++ b/usr.sbin/hostapd/apme.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: apme.c,v 1.13 2006/06/01 22:09:09 reyk Exp $	*/
+/*	$OpenBSD: apme.c,v 1.14 2006/12/31 03:25:58 reyk Exp $	*/
 
 /*
  * Copyright (c) 2004, 2005 Reyk Floeter <reyk@openbsd.org>
@@ -46,6 +46,7 @@
 #include "iapp.h"
 
 void	 hostapd_apme_frame(struct hostapd_apme *, u_int8_t *, u_int);
+void	 hostapd_apme_hopper(int, short, void *);
 
 int
 hostapd_apme_add(struct hostapd_config *cfg, const char *name)
@@ -60,6 +61,7 @@ hostapd_apme_add(struct hostapd_config *cfg, const char *name)
 
 	strlcpy(apme->a_iface, name, sizeof(apme->a_iface));
 	apme->a_cfg = cfg;
+	apme->a_chanavail = NULL;
 
 	TAILQ_INSERT_TAIL(&cfg->c_apmes, apme, a_entries);
 
@@ -115,11 +117,85 @@ hostapd_apme_lookup(struct hostapd_config *cfg, const char *name)
 	return (NULL);
 }
 
+struct hostapd_apme *
+hostapd_apme_addhopper(struct hostapd_config *cfg, const char *name)
+{
+	struct hostapd_apme *apme;
+
+	if ((apme = hostapd_apme_lookup(cfg, name)) == NULL)
+		return (NULL);
+	if (apme->a_chanavail != NULL)
+		return (NULL);
+	apme->a_curchan = IEEE80211_CHAN_MAX;
+	apme->a_maxchan = roundup(IEEE80211_CHAN_MAX, NBBY);
+	if ((apme->a_chanavail = (u_int8_t *)
+	    calloc(apme->a_maxchan, sizeof(u_int8_t))) == NULL)
+		return (NULL);
+	memset(apme->a_chanavail, 0xff,
+	    apme->a_maxchan * sizeof(u_int8_t));
+	strlcpy(apme->a_chanreq.i_name, apme->a_iface, IFNAMSIZ);
+
+	return (apme);
+}
+
+void
+hostapd_apme_sethopper(struct hostapd_apme *apme, int now)
+{
+	struct hostapd_config *cfg = (struct hostapd_config *)apme->a_cfg;
+	struct timeval tv;
+
+	bzero(&tv, sizeof(tv));
+	if (!now)
+		bcopy(&cfg->c_apme_hopdelay, &tv, sizeof(tv));
+
+	if (!evtimer_initialized(&apme->a_chanev))
+		evtimer_set(&apme->a_chanev, hostapd_apme_hopper, apme);
+	evtimer_add(&apme->a_chanev, &tv);
+}
+
+void
+hostapd_apme_hopper(int fd, short sig, void *arg)
+{
+	struct hostapd_apme *apme = (struct hostapd_apme *)arg;
+	struct hostapd_config *cfg = (struct hostapd_config *)apme->a_cfg;
+	int ret;
+
+	if (apme->a_curchan >= IEEE80211_CHAN_MAX)
+		apme->a_curchan = 0;
+
+	do {
+		if (apme->a_curchan >= IEEE80211_CHAN_MAX)
+			return;
+		apme->a_curchan %= IEEE80211_CHAN_MAX;
+		apme->a_curchan++;
+	} while (isclr(apme->a_chanavail, apme->a_curchan));
+
+	apme->a_chanreq.i_channel = apme->a_curchan;
+	if ((ret = ioctl(cfg->c_apme_ctl, SIOCS80211CHANNEL,
+	    &apme->a_chanreq)) != 0) {
+		hostapd_apme_sethopper(apme, 1);
+		return;
+	}
+
+	hostapd_log(HOSTAPD_LOG_DEBUG,
+	    "[priv]: %s setting to channel %d",
+	    apme->a_iface, apme->a_curchan);
+
+	hostapd_apme_sethopper(apme, 0);
+}
+
 void
 hostapd_apme_term(struct hostapd_apme *apme)
 {
 	struct hostapd_config *cfg = (struct hostapd_config *)apme->a_cfg;
 
+	/* Remove the channel hopper, if active */
+	if (apme->a_chanavail != NULL) {
+		event_del(&apme->a_chanev);
+		free(apme->a_chanavail);
+		apme->a_chanavail = NULL;
+	}
+
 	/* Kick a specified Host AP interface */
 	event_del(&apme->a_ev);
 	close(apme->a_raw);
diff --git a/usr.sbin/hostapd/hostapd.conf.5 b/usr.sbin/hostapd/hostapd.conf.5
index ba16596b637..5b9606289f5 100644
--- a/usr.sbin/hostapd/hostapd.conf.5
+++ b/usr.sbin/hostapd/hostapd.conf.5
@@ -1,4 +1,4 @@
-.\" $OpenBSD: hostapd.conf.5,v 1.34 2006/08/31 18:44:48 jmc Exp $
+.\" $OpenBSD: hostapd.conf.5,v 1.35 2006/12/31 03:25:58 reyk Exp $
 .\"
 .\" Copyright (c) 2004, 2005, 2006 Reyk Floeter <reyk@openbsd.org>
 .\"
@@ -140,6 +140,18 @@ signal levels.
 .It Ic pcap
 Capture plain IEEE 802.11 frames.
 .El
+.It Xo
+.Ic set hostap hopper interface
+.Ar interface \*(Ba\ \&
+.Pf { Ar interface0 , interface1 , ... No }
+.Xc
+Enable a channel hopper on the selected wireless interface.
+Multiple hostap interfaces may be specified as a comma-separated list,
+surrounded by curly braces.
+.It Ic set hostap hopper delay Ar number
+Set the delay in milliseconds for the channel hopper before hopping to
+the next available channel.
+The default value is 800 milliseconds.
 .It Ic set iapp interface Ar interface
 Specify the mandatory Inter-Access-Point (IAPP) interface.
 It is important that the IAPP interface is on a trusted
diff --git a/usr.sbin/hostapd/hostapd.h b/usr.sbin/hostapd/hostapd.h
index 3048c3a9d18..3bf4a9e1761 100644
--- a/usr.sbin/hostapd/hostapd.h
+++ b/usr.sbin/hostapd/hostapd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hostapd.h,v 1.19 2006/09/28 17:43:42 reyk Exp $	*/
+/*	$OpenBSD: hostapd.h,v 1.20 2006/12/31 03:25:58 reyk Exp $	*/
 
 /*
  * Copyright (c) 2004, 2005 Reyk Floeter <reyk@openbsd.org>
@@ -279,9 +279,21 @@ struct hostapd_apme {
 	void				*a_cfg;
 	struct sockaddr_in		a_addr;
 
+	struct event			a_chanev;
+	u_int8_t			*a_chanavail;
+	u_int8_t			a_curchan;
+	u_int				a_maxchan;
+	struct ieee80211chanreq		a_chanreq;
+
 	TAILQ_ENTRY(hostapd_apme)	a_entries;
 };
 
+#ifndef IEEE80211_CHAN_MAX
+#define IEEE80211_CHAN_MAX	255
+#endif
+
+#define HOSTAPD_HOPPER_MDELAY	800
+
 struct hostapd_iapp {
 	u_int16_t			i_cnt;
 	int				i_raw;
@@ -313,6 +325,7 @@ struct hostapd_iapp {
 struct hostapd_config {
 	int				c_apme_ctl;
 	u_int				c_apme_dlt;
+	struct timeval			c_apme_hopdelay;
 
 	struct hostapd_iapp		c_iapp;
 
@@ -413,6 +426,9 @@ int	 hostapd_apme_delnode(struct hostapd_apme *,
 	    struct hostapd_node *node);
 int	 hostapd_apme_offset(struct hostapd_apme *, u_int8_t *,
 	    const u_int);
+struct hostapd_apme *hostapd_apme_addhopper(struct hostapd_config *,
+	    const char *);
+void	 hostapd_apme_sethopper(struct hostapd_apme *, int);
 
 void	 hostapd_iapp_init(struct hostapd_config *);
 void	 hostapd_iapp_term(struct hostapd_config *);
diff --git a/usr.sbin/hostapd/parse.y b/usr.sbin/hostapd/parse.y
index d6b66d5768b..dd14209fa2d 100644
--- a/usr.sbin/hostapd/parse.y
+++ b/usr.sbin/hostapd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.26 2006/10/13 15:36:57 reyk Exp $	*/
+/*	$OpenBSD: parse.y,v 1.27 2006/12/31 03:25:58 reyk Exp $	*/
 
 /*
  * Copyright (c) 2004, 2005, 2006 Reyk Floeter <reyk@openbsd.org>
@@ -105,10 +105,12 @@ typedef struct {
 		long			val;
 		u_int16_t		reason;
 		enum hostapd_op		op;
+		struct timeval		timeout;
 	} v;
 	int lineno;
 } YYSTYPE;
 
+struct hostapd_apme *apme;
 struct hostapd_table *table;
 struct hostapd_entry *entry;
 struct hostapd_frame frame, *frame_ptr;
@@ -149,6 +151,7 @@ struct hostapd_ieee80211_frame *frame_ieee80211;
 %token	REASON UNSPECIFIED EXPIRE LEAVE ASSOC TOOMANY NOT AUTHED ASSOCED
 %token	RESERVED RSN REQUIRED INCONSISTENT IE INVALID MIC FAILURE OPEN
 %token	ADDRESS PORT ON NOTIFY TTL INCLUDE ROUTE ROAMING RSSI TXRATE FREQ
+%token	HOPPER DELAY
 %token	<v.string>	STRING
 %token	<v.val>		VALUE
 %type	<v.val>		number
@@ -163,6 +166,7 @@ struct hostapd_ieee80211_frame *frame_ieee80211;
 %type	<v.val>		txrate
 %type	<v.val>		freq
 %type	<v.val>		not
+%type	<v.timeout>	timeout
 
 %%
 
@@ -201,6 +205,12 @@ option		: SET HOSTAP INTERFACE hostapifaces
 			if (!TAILQ_EMPTY(&hostapd_cfg.c_apmes))
 				hostapd_cfg.c_flags |= HOSTAPD_CFG_F_APME;
 		}
+		| SET HOSTAP HOPPER INTERFACE hopperifaces
+		| SET HOSTAP HOPPER DELAY timeout
+		{
+			bcopy(&$5, &hostapd_cfg.c_apme_hopdelay,
+			    sizeof(struct timeval));
+		}
 		| SET HOSTAP MODE hostapmode
 		| SET IAPP INTERFACE STRING passive
 		{
@@ -298,6 +308,26 @@ hostapiface	: STRING
 		}
 		;
 
+hopperifaces	: '{' optnl hopperifacelist optnl '}'
+		| hopperiface
+		;
+
+hopperifacelist	: hopperiface
+		| hopperifacelist comma hopperiface
+		;
+
+hopperiface	: STRING
+		{
+			if ((apme = hostapd_apme_addhopper(&hostapd_cfg,
+			    $1)) == NULL) {
+				yyerror("failed to add hopper %s", $1);
+				free($1);
+				YYERROR;
+			}
+			free($1);
+		}
+		;
+
 hostapmatch	: /* empty */
 		| ON not STRING
 		{
@@ -1151,6 +1181,13 @@ freq		: STRING
 			free($1);
 		}
 		;
+
+timeout		: number
+		{
+			$$.tv_sec = $1 / 1000;
+			$$.tv_usec = ($1 % 1000) * 1000;
+		}
+		;
 %%
 
 /*
@@ -1187,6 +1224,7 @@ lookup(char *token)
 		{ "const",		CONST },
 		{ "data",		DATA },
 		{ "deauth",		DEAUTH },
+		{ "delay",		DELAY },
 		{ "delete",		DELETE },
 		{ "dir",		DIR },
 		{ "disassoc",		DISASSOC },
@@ -1197,6 +1235,7 @@ lookup(char *token)
 		{ "freq",		FREQ },
 		{ "from",		FROM },
 		{ "handle",		HANDLE },
+		{ "hopper",		HOPPER },
 		{ "hostap",		HOSTAP },
 		{ "iapp",		IAPP },
 		{ "ie",			IE },
@@ -1589,6 +1628,8 @@ hostapd_parse_file(struct hostapd_config *cfg)
 	cfg->c_iapp.i_multicast.sin_addr.s_addr = INADDR_ANY;
 	cfg->c_iapp.i_flags = HOSTAPD_IAPP_F_DEFAULT;
 	cfg->c_iapp.i_ttl = IP_DEFAULT_MULTICAST_TTL;
+	cfg->c_apme_hopdelay.tv_sec = HOSTAPD_HOPPER_MDELAY / 1000;
+	cfg->c_apme_hopdelay.tv_usec = (HOSTAPD_HOPPER_MDELAY % 1000) * 1000;
 
 	errors = 0;
 
diff --git a/usr.sbin/hostapd/privsep.c b/usr.sbin/hostapd/privsep.c
index 0cd46f9a056..a25129995b7 100644
--- a/usr.sbin/hostapd/privsep.c
+++ b/usr.sbin/hostapd/privsep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: privsep.c,v 1.20 2006/06/01 22:09:09 reyk Exp $	*/
+/*	$OpenBSD: privsep.c,v 1.21 2006/12/31 03:25:58 reyk Exp $	*/
 
 /*
  * Copyright (c) 2004, 2005 Reyk Floeter <reyk@openbsd.org>
@@ -81,6 +81,7 @@ void
 hostapd_priv_init(struct hostapd_config *cfg)
 {
 	struct hostapd_iapp *iapp = &cfg->c_iapp;
+	struct hostapd_apme *apme;
 	int i, socks[2];
 	struct passwd *pw;
 	struct servent *se;
@@ -152,6 +153,9 @@ hostapd_priv_init(struct hostapd_config *cfg)
 	if (cfg->c_flags & HOSTAPD_CFG_F_APME) {
 		if ((cfg->c_apme_ctl = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
 			hostapd_fatal("unable to open ioctl socket\n");
+		TAILQ_FOREACH(apme, &cfg->c_apmes, a_entries)
+			if (apme->a_chanavail != NULL)
+				hostapd_apme_sethopper(apme, 0);
 	}
 
 	hostapd_roaming_init(cfg);