mISDN: L2 timeouts need to be queued as L2 event

To be full preemptiv safe, we cannot handle a L2 timeout in the timer
context itself, we should do all actions via the D-channel thread.

Signed-off-by: Karsten Keil <kkeil@linux-pingi.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 69 insertions, 9 deletions

diff --git a/drivers/isdn/mISDN/layer2.c b/drivers/isdn/mISDN/layer2.c
index 39d7375fa551..b6fbaec1d612 100644
--- a/drivers/isdn/mISDN/layer2.c
+++ b/drivers/isdn/mISDN/layer2.c
@@ -58,6 +58,8 @@ enum {
         EV_L1_DEACTIVATE,
         EV_L2_T200,
         EV_L2_T203,
+        EV_L2_T200I,
+        EV_L2_T203I,
         EV_L2_SET_OWN_BUSY,
         EV_L2_CLEAR_OWN_BUSY,
         EV_L2_FRAME_ERROR,
@@ -86,6 +88,8 @@ static char *strL2Event[] =
         "EV_L1_DEACTIVATE",
         "EV_L2_T200",
         "EV_L2_T203",
+        "EV_L2_T200I",
+        "EV_L2_T203I",
         "EV_L2_SET_OWN_BUSY",
         "EV_L2_CLEAR_OWN_BUSY",
         "EV_L2_FRAME_ERROR",
@@ -276,6 +280,31 @@ ph_data_confirm(struct layer2 *l2, struct mISDNhead *hh, struct sk_buff *skb) {
         return ret;
 }
 
+static void
+l2_timeout(struct FsmInst *fi, int event, void *arg)
+{
+        struct layer2 *l2 = fi->userdata;
+        struct sk_buff *skb;
+        struct mISDNhead *hh;
+
+        skb = mI_alloc_skb(0, GFP_ATOMIC);
+        if (!skb) {
+                printk(KERN_WARNING "L2(%d,%d) nr:%x timer %s lost - no skb\n",
+                       l2->sapi, l2->tei, l2->ch.nr, event == EV_L2_T200 ?
+                       "T200" : "T203");
+                return;
+        }
+        hh = mISDN_HEAD_P(skb);
+        hh->prim = event == EV_L2_T200 ? DL_TIMER200_IND : DL_TIMER203_IND;
+        hh->id = l2->ch.nr;
+        if (*debug & DEBUG_TIMER)
+                printk(KERN_DEBUG "L2(%d,%d) nr:%x timer %s expired\n",
+                       l2->sapi, l2->tei, l2->ch.nr, event == EV_L2_T200 ?
+                       "T200" : "T203");
+        if (l2->ch.st)
+                l2->ch.st->own.recv(&l2->ch.st->own, skb);
+}
+
 static int
 l2mgr(struct layer2 *l2, u_int prim, void *arg) {
         long c = (long)arg;
@@ -1814,11 +1843,16 @@ static struct FsmNode L2FnList[] =
         {ST_L2_8, EV_L2_SUPER, l2_st8_got_super},
         {ST_L2_7, EV_L2_I, l2_got_iframe},
         {ST_L2_8, EV_L2_I, l2_got_iframe},
-        {ST_L2_5, EV_L2_T200, l2_st5_tout_200},
-        {ST_L2_6, EV_L2_T200, l2_st6_tout_200},
-        {ST_L2_7, EV_L2_T200, l2_st7_tout_200},
-        {ST_L2_8, EV_L2_T200, l2_st8_tout_200},
-        {ST_L2_7, EV_L2_T203, l2_st7_tout_203},
+        {ST_L2_5, EV_L2_T200, l2_timeout},
+        {ST_L2_6, EV_L2_T200, l2_timeout},
+        {ST_L2_7, EV_L2_T200, l2_timeout},
+        {ST_L2_8, EV_L2_T200, l2_timeout},
+        {ST_L2_7, EV_L2_T203, l2_timeout},
+        {ST_L2_5, EV_L2_T200I, l2_st5_tout_200},
+        {ST_L2_6, EV_L2_T200I, l2_st6_tout_200},
+        {ST_L2_7, EV_L2_T200I, l2_st7_tout_200},
+        {ST_L2_8, EV_L2_T200I, l2_st8_tout_200},
+        {ST_L2_7, EV_L2_T203I, l2_st7_tout_203},
         {ST_L2_7, EV_L2_ACK_PULL, l2_pull_iqueue},
         {ST_L2_7, EV_L2_SET_OWN_BUSY, l2_set_own_busy},
         {ST_L2_8, EV_L2_SET_OWN_BUSY, l2_set_own_busy},
@@ -1932,6 +1966,14 @@ l2_send(struct mISDNchannel *ch, struct sk_buff *skb)
         if (*debug & DEBUG_L2_RECV)
                 printk(KERN_DEBUG "%s: prim(%x) id(%x) sapi(%d) tei(%d)\n",
                        __func__, hh->prim, hh->id, l2->sapi, l2->tei);
+        if (hh->prim == DL_INTERN_MSG) {
+                struct mISDNhead *chh = hh + 1; /* saved copy */
+
+                *hh = *chh;
+                if (*debug & DEBUG_L2_RECV)
+                        printk(KERN_DEBUG "%s: prim(%x) id(%x) internal msg\n",
+                               __func__, hh->prim, hh->id);
+        }
         switch (hh->prim) {
         case PH_DATA_IND:
                 ret = ph_data_indication(l2, hh, skb);
@@ -1987,6 +2029,12 @@ l2_send(struct mISDNchannel *ch, struct sk_buff *skb)
                 ret = mISDN_FsmEvent(&l2->l2m, EV_L2_DL_RELEASE_REQ,
                                      skb);
                 break;
+        case DL_TIMER200_IND:
+                mISDN_FsmEvent(&l2->l2m, EV_L2_T200I, NULL);
+                break;
+        case DL_TIMER203_IND:
+                mISDN_FsmEvent(&l2->l2m, EV_L2_T203I, NULL);
+                break;
         default:
                 if (*debug & DEBUG_L2)
                         l2m_debug(&l2->l2m, "l2 unknown pr %04x",
diff --git a/drivers/isdn/mISDN/tei.c b/drivers/isdn/mISDN/tei.c
index 109276a0d1a0..be88728f1106 100644
--- a/drivers/isdn/mISDN/tei.c
+++ b/drivers/isdn/mISDN/tei.c
@@ -1294,7 +1294,7 @@ static int
 mgr_bcast(struct mISDNchannel *ch, struct sk_buff *skb)
 {
         struct manager          *mgr = container_of(ch, struct manager, bcast);
-        struct mISDNhead        *hh = mISDN_HEAD_P(skb);
+        struct mISDNhead        *hhc, *hh = mISDN_HEAD_P(skb);
         struct sk_buff          *cskb = NULL;
         struct layer2           *l2;
         u_long                  flags;
@@ -1309,10 +1309,17 @@ mgr_bcast(struct mISDNchannel *ch, struct sk_buff *skb)
                                 skb = NULL;
                         } else {
                                 if (!cskb)
-                                        cskb = skb_copy(skb, GFP_KERNEL);
+                                        cskb = skb_copy(skb, GFP_ATOMIC);
                         }
                         if (cskb) {
-                                ret = l2->ch.send(&l2->ch, cskb);
+                                hhc = mISDN_HEAD_P(cskb);
+                                /* save original header behind normal header */
+                                hhc++;
+                                *hhc = *hh;
+                                hhc--;
+                                hhc->prim = DL_INTERN_MSG;
+                                hhc->id = l2->ch.nr;
+                                ret = ch->st->own.recv(&ch->st->own, cskb);
                                 if (ret) {
                                         if (*debug & DEBUG_SEND_ERR)
                                                 printk(KERN_DEBUG
diff --git a/include/linux/mISDNif.h b/include/linux/mISDNif.h
index b5e7f2202484..b80f7648562a 100644
--- a/include/linux/mISDNif.h
+++ b/include/linux/mISDNif.h
@@ -37,7 +37,7 @@
  */
 #define MISDN_MAJOR_VERSION     1
 #define MISDN_MINOR_VERSION     1
-#define MISDN_RELEASE           21
+#define MISDN_RELEASE           26
 
 /* primitives for information exchange
  * generell format
@@ -115,6 +115,11 @@
 #define MDL_ERROR_IND           0x1F04
 #define MDL_ERROR_RSP           0x5F04
 
+/* intern layer 2 */
+#define DL_TIMER200_IND         0x7004
+#define DL_TIMER203_IND         0x7304
+#define DL_INTERN_MSG           0x7804
+
 /* DL_INFORMATION_IND types */
 #define DL_INFO_L2_CONNECT      0x0001
 #define DL_INFO_L2_REMOVED      0x0002