mISDN: Fix TEI and SAPI handling

Added SAPI value to use SAPIs different than 0.

Now fixed TEIs work in NT mode. This allows PTP endpoint to be connected
to PTMP ports together with other PTMP endpoints.

New enhanced version, thanks to Sam Ravnborg <sam@ravnborg.org> for the
hints.
Signed-off-by: Andreas Eversberg <andreas@eversberg.eu>
Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/mISDN/layer2.c

@@ -2068,7 +2068,8 @@ l2_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
 }
 
 struct layer2 *
-create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, u_long arg)
+create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, int tei,
+		int sapi)
 {
 	struct layer2		*l2;
 	struct channel_req	rq;
@@ -2089,7 +2090,7 @@ create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, u_long arg)
 		test_and_set_bit(FLG_LAPD, &l2->flag);
 		test_and_set_bit(FLG_LAPD_NET, &l2->flag);
 		test_and_set_bit(FLG_MOD128, &l2->flag);
-		l2->sapi = 0;
+		l2->sapi = sapi;
 		l2->maxlen = MAX_DFRAME_LEN;
 		if (test_bit(OPTION_L2_PMX, &options))
 			l2->window = 7;
@@ -2099,7 +2100,7 @@ create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, u_long arg)
 			test_and_set_bit(FLG_PTP, &l2->flag);
 		if (test_bit(OPTION_L2_FIXEDTEI, &options))
 			test_and_set_bit(FLG_FIXED_TEI, &l2->flag);
-		l2->tei = (u_int)arg;
+		l2->tei = tei;
 		l2->T200 = 1000;
 		l2->N200 = 3;
 		l2->T203 = 10000;
@@ -2114,7 +2115,7 @@ create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, u_long arg)
 		test_and_set_bit(FLG_LAPD, &l2->flag);
 		test_and_set_bit(FLG_MOD128, &l2->flag);
 		test_and_set_bit(FLG_ORIG, &l2->flag);
-		l2->sapi = 0;
+		l2->sapi = sapi;
 		l2->maxlen = MAX_DFRAME_LEN;
 		if (test_bit(OPTION_L2_PMX, &options))
 			l2->window = 7;
@@ -2124,7 +2125,7 @@ create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, u_long arg)
 			test_and_set_bit(FLG_PTP, &l2->flag);
 		if (test_bit(OPTION_L2_FIXEDTEI, &options))
 			test_and_set_bit(FLG_FIXED_TEI, &l2->flag);
-		l2->tei = (u_int)arg;
+		l2->tei = tei;
 		l2->T200 = 1000;
 		l2->N200 = 3;
 		l2->T203 = 10000;
@@ -2180,7 +2181,7 @@ x75create(struct channel_req *crq)
 
 	if (crq->protocol != ISDN_P_B_X75SLP)
 		return -EPROTONOSUPPORT;
-	l2 = create_l2(crq->ch, crq->protocol, 0, 0);
+	l2 = create_l2(crq->ch, crq->protocol, 0, 0, 0);
 	if (!l2)
 		return -ENOMEM;
 	crq->ch = &l2->ch;

drivers/isdn/mISDN/layer2.h

@@ -90,7 +90,7 @@ enum {
 #define L2_STATE_COUNT (ST_L2_8+1)
 
 extern struct layer2	*create_l2(struct mISDNchannel *, u_int,
-				u_long, u_long);
+				u_long, int, int);
 extern int		tei_l2(struct layer2 *, u_int, u_long arg);
 
 

drivers/isdn/mISDN/tei.c

@@ -426,7 +426,7 @@ findtei(struct manager *mgr, int tei)
 }
 
 static void
-put_tei_msg(struct manager *mgr, u_char m_id, unsigned int ri, u_char tei)
+put_tei_msg(struct manager *mgr, u_char m_id, unsigned int ri, int tei)
 {
 	struct sk_buff *skb;
 	u_char bp[8];
@@ -440,9 +440,8 @@ put_tei_msg(struct manager *mgr, u_char m_id, unsigned int ri, u_char tei)
 	bp[4] = ri >> 8;
 	bp[5] = ri & 0xff;
 	bp[6] = m_id;
-	bp[7] = (tei << 1) | 1;
-	skb = _alloc_mISDN_skb(PH_DATA_REQ, new_id(mgr),
-	    8, bp, GFP_ATOMIC);
+	bp[7] = ((tei << 1) & 0xff) | 1;
+	skb = _alloc_mISDN_skb(PH_DATA_REQ, new_id(mgr), 8, bp, GFP_ATOMIC);
 	if (!skb) {
 		printk(KERN_WARNING "%s: no skb for tei msg\n", __func__);
 		return;
@@ -777,7 +776,7 @@ tei_ph_data_ind(struct teimgr *tm, u_int mt, u_char *dp, int len)
 }
 
 static struct layer2 *
-create_new_tei(struct manager *mgr, int tei)
+create_new_tei(struct manager *mgr, int tei, int sapi)
 {
 	u_long		opt = 0;
 	u_long		flags;
@@ -786,12 +785,12 @@ create_new_tei(struct manager *mgr, int tei)
 
 	if (!mgr->up)
 		return NULL;
-	if (tei < 64)
+	if ((tei >= 0) && (tei < 64))
 		test_and_set_bit(OPTION_L2_FIXEDTEI, &opt);
 	if (mgr->ch.st->dev->Dprotocols
 	  & ((1 << ISDN_P_TE_E1) | (1 << ISDN_P_NT_E1)))
 		test_and_set_bit(OPTION_L2_PMX, &opt);
-	l2 = create_l2(mgr->up, ISDN_P_LAPD_NT, (u_int)opt, (u_long)tei);
+	l2 = create_l2(mgr->up, ISDN_P_LAPD_NT, opt, tei, sapi);
 	if (!l2) {
 		printk(KERN_WARNING "%s:no memory for layer2\n", __func__);
 		return NULL;
@@ -839,12 +838,17 @@ new_tei_req(struct manager *mgr, u_char *dp)
 	ri += dp[1];
 	if (!mgr->up)
 		goto denied;
+	if (!(dp[3] & 1)) /* Extension bit != 1 */
+		goto denied;
+	if (dp[3] != 0xff)
+		tei = dp[3] >> 1; /* 3GPP TS 08.56 6.1.11.2 */
+	else
 		tei = get_free_tei(mgr);
 	if (tei < 0) {
 		printk(KERN_WARNING "%s:No free tei\n", __func__);
 		goto denied;
 	}
-	l2 = create_new_tei(mgr, tei);
+	l2 = create_new_tei(mgr, tei, CTRL_SAPI);
 	if (!l2)
 		goto denied;
 	else
@@ -976,8 +980,6 @@ create_teimgr(struct manager *mgr, struct channel_req *crq)
 			__func__, dev_name(&mgr->ch.st->dev->dev),
 			crq->protocol, crq->adr.dev, crq->adr.channel,
 			crq->adr.sapi, crq->adr.tei);
-	if (crq->adr.sapi != 0) /* not supported yet */
-		return -EINVAL;
 	if (crq->adr.tei > GROUP_TEI)
 		return -EINVAL;
 	if (crq->adr.tei < 64)
@@ -1024,8 +1026,8 @@ create_teimgr(struct manager *mgr, struct channel_req *crq)
 		}
 		return 0;
 	}
-	l2 = create_l2(crq->ch, crq->protocol, (u_int)opt,
-		(u_long)crq->adr.tei);
+	l2 = create_l2(crq->ch, crq->protocol, opt,
+		crq->adr.tei, crq->adr.sapi);
 	if (!l2)
 		return -ENOMEM;
 	l2->tm = kzalloc(sizeof(struct teimgr), GFP_KERNEL);
@@ -1166,7 +1168,7 @@ static int
 check_data(struct manager *mgr, struct sk_buff *skb)
 {
 	struct mISDNhead	*hh =  mISDN_HEAD_P(skb);
-	int			ret, tei;
+	int			ret, tei, sapi;
 	struct layer2		*l2;
 
 	if (*debug & DEBUG_L2_CTRL)
@@ -1178,18 +1180,18 @@ check_data(struct manager *mgr, struct sk_buff *skb)
 		return -ENOTCONN;
 	if (skb->len != 3)
 		return -ENOTCONN;
-	if (skb->data[0] != 0)
-		/* only SAPI 0 command */
-		return -ENOTCONN;
+	if (skb->data[0] & 3) /* EA0 and CR must be  0 */
+		return -EINVAL;
+	sapi = skb->data[0] >> 2;
 	if (!(skb->data[1] & 1)) /* invalid EA1 */
 		return -EINVAL;
-	tei = skb->data[1] >> 0;
+	tei = skb->data[1] >> 1;
 	if (tei > 63) /* not a fixed tei */
 		return -ENOTCONN;
 	if ((skb->data[2] & ~0x10) != SABME)
 		return -ENOTCONN;
 	/* We got a SABME for a fixed TEI */
-	l2 = create_new_tei(mgr, tei);
+	l2 = create_new_tei(mgr, tei, sapi);
 	if (!l2)
 		return -ENOMEM;
 	ret = l2->ch.send(&l2->ch, skb);