[PATCH 5/5] isdn/gigaset: correct CAPI connection state storage

From: Tilman Schmidt
Date: Mon Jun 21 2010 - 20:05:09 EST


CAPI applications can handle several connections in parallel,
so one connection state per application isn't sufficient.
Store the connection state in the channel structure instead.

Impact: bugfix
Signed-off-by: Tilman Schmidt <tilman@xxxxxxx>
---
drivers/isdn/gigaset/capi.c | 225 ++++++++++++++++++++++++++++++---------
drivers/isdn/gigaset/common.c | 4 +
drivers/isdn/gigaset/gigaset.h | 4 +-
3 files changed, 180 insertions(+), 53 deletions(-)

diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c
index 7d9549e..c38750c 100644
--- a/drivers/isdn/gigaset/capi.c
+++ b/drivers/isdn/gigaset/capi.c
@@ -70,7 +70,7 @@
#define MAX_NUMBER_DIGITS 20
#define MAX_FMT_IE_LEN 20

-/* values for gigaset_capi_appl.connected */
+/* values for bcs->apconnstate */
#define APCONN_NONE 0 /* inactive/listening */
#define APCONN_SETUP 1 /* connecting */
#define APCONN_ACTIVE 2 /* B channel up */
@@ -84,7 +84,6 @@ struct gigaset_capi_appl {
u16 nextMessageNumber;
u32 listenInfoMask;
u32 listenCIPmask;
- int connected;
};

/* CAPI specific controller data structure */
@@ -384,7 +383,7 @@ void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *dskb)
}

/* don't send further B3 messages if disconnected */
- if (ap->connected < APCONN_ACTIVE) {
+ if (bcs->apconnstate < APCONN_ACTIVE) {
gig_dbg(DEBUG_LLDATA, "disconnected, discarding ack");
return;
}
@@ -428,7 +427,7 @@ void gigaset_skb_rcvd(struct bc_state *bcs, struct sk_buff *skb)
}

/* don't send further B3 messages if disconnected */
- if (ap->connected < APCONN_ACTIVE) {
+ if (bcs->apconnstate < APCONN_ACTIVE) {
gig_dbg(DEBUG_LLDATA, "disconnected, discarding data");
dev_kfree_skb_any(skb);
return;
@@ -500,6 +499,7 @@ int gigaset_isdn_icall(struct at_state_t *at_state)
u32 actCIPmask;
struct sk_buff *skb;
unsigned int msgsize;
+ unsigned long flags;
int i;

/*
@@ -624,7 +624,14 @@ int gigaset_isdn_icall(struct at_state_t *at_state)
format_ie(iif->hcmsg.CalledPartyNumber));

/* scan application list for matching listeners */
- bcs->ap = NULL;
+ spin_lock_irqsave(&bcs->aplock, flags);
+ if (bcs->ap != NULL || bcs->apconnstate != APCONN_NONE) {
+ dev_warn(cs->dev, "%s: channel not properly cleared (%p/%d)\n",
+ __func__, bcs->ap, bcs->apconnstate);
+ bcs->ap = NULL;
+ bcs->apconnstate = APCONN_NONE;
+ }
+ spin_unlock_irqrestore(&bcs->aplock, flags);
actCIPmask = 1 | (1 << iif->hcmsg.CIPValue);
list_for_each_entry(ap, &iif->appls, ctrlist)
if (actCIPmask & ap->listenCIPmask) {
@@ -642,10 +649,12 @@ int gigaset_isdn_icall(struct at_state_t *at_state)
dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);

/* add to listeners on this B channel, update state */
+ spin_lock_irqsave(&bcs->aplock, flags);
ap->bcnext = bcs->ap;
bcs->ap = ap;
bcs->chstate |= CHS_NOTIFY_LL;
- ap->connected = APCONN_SETUP;
+ bcs->apconnstate = APCONN_SETUP;
+ spin_unlock_irqrestore(&bcs->aplock, flags);

/* emit message */
capi_ctr_handle_message(&iif->ctr, ap->id, skb);
@@ -670,7 +679,7 @@ static void send_disconnect_ind(struct bc_state *bcs,
struct gigaset_capi_ctr *iif = cs->iif;
struct sk_buff *skb;

- if (ap->connected == APCONN_NONE)
+ if (bcs->apconnstate == APCONN_NONE)
return;

capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_DISCONNECT, CAPI_IND,
@@ -684,7 +693,6 @@ static void send_disconnect_ind(struct bc_state *bcs,
}
capi_cmsg2message(&iif->hcmsg, __skb_put(skb, CAPI_DISCONNECT_IND_LEN));
dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
- ap->connected = APCONN_NONE;
capi_ctr_handle_message(&iif->ctr, ap->id, skb);
}

@@ -701,9 +709,9 @@ static void send_disconnect_b3_ind(struct bc_state *bcs,
struct sk_buff *skb;

/* nothing to do if no logical connection active */
- if (ap->connected < APCONN_ACTIVE)
+ if (bcs->apconnstate < APCONN_ACTIVE)
return;
- ap->connected = APCONN_SETUP;
+ bcs->apconnstate = APCONN_SETUP;

capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_DISCONNECT_B3, CAPI_IND,
ap->nextMessageNumber++,
@@ -730,14 +738,25 @@ void gigaset_isdn_connD(struct bc_state *bcs)
{
struct cardstate *cs = bcs->cs;
struct gigaset_capi_ctr *iif = cs->iif;
- struct gigaset_capi_appl *ap = bcs->ap;
+ struct gigaset_capi_appl *ap;
struct sk_buff *skb;
unsigned int msgsize;
+ unsigned long flags;

+ spin_lock_irqsave(&bcs->aplock, flags);
+ ap = bcs->ap;
if (!ap) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
dev_err(cs->dev, "%s: no application\n", __func__);
return;
}
+ if (bcs->apconnstate == APCONN_NONE) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+ dev_warn(cs->dev, "%s: application %u not connected\n",
+ __func__, ap->id);
+ return;
+ }
+ spin_unlock_irqrestore(&bcs->aplock, flags);
while (ap->bcnext) {
/* this should never happen */
dev_warn(cs->dev, "%s: dropping extra application %u\n",
@@ -746,11 +765,6 @@ void gigaset_isdn_connD(struct bc_state *bcs)
CapiCallGivenToOtherApplication);
ap->bcnext = ap->bcnext->bcnext;
}
- if (ap->connected == APCONN_NONE) {
- dev_warn(cs->dev, "%s: application %u not connected\n",
- __func__, ap->id);
- return;
- }

/* prepare CONNECT_ACTIVE_IND message
* Note: LLC not supported by device
@@ -788,17 +802,24 @@ void gigaset_isdn_connD(struct bc_state *bcs)
void gigaset_isdn_hupD(struct bc_state *bcs)
{
struct gigaset_capi_appl *ap;
+ unsigned long flags;

/*
* ToDo: pass on reason code reported by device
* (requires ev-layer state machine extension to collect
* ZCAU device reply)
*/
- for (ap = bcs->ap; ap != NULL; ap = ap->bcnext) {
+ spin_lock_irqsave(&bcs->aplock, flags);
+ while (bcs->ap != NULL) {
+ ap = bcs->ap;
+ bcs->ap = ap->bcnext;
+ spin_unlock_irqrestore(&bcs->aplock, flags);
send_disconnect_b3_ind(bcs, ap);
send_disconnect_ind(bcs, ap, 0);
+ spin_lock_irqsave(&bcs->aplock, flags);
}
- bcs->ap = NULL;
+ bcs->apconnstate = APCONN_NONE;
+ spin_unlock_irqrestore(&bcs->aplock, flags);
}

/**
@@ -812,24 +833,21 @@ void gigaset_isdn_connB(struct bc_state *bcs)
{
struct cardstate *cs = bcs->cs;
struct gigaset_capi_ctr *iif = cs->iif;
- struct gigaset_capi_appl *ap = bcs->ap;
+ struct gigaset_capi_appl *ap;
struct sk_buff *skb;
+ unsigned long flags;
unsigned int msgsize;
u8 command;

+ spin_lock_irqsave(&bcs->aplock, flags);
+ ap = bcs->ap;
if (!ap) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
dev_err(cs->dev, "%s: no application\n", __func__);
return;
}
- while (ap->bcnext) {
- /* this should never happen */
- dev_warn(cs->dev, "%s: dropping extra application %u\n",
- __func__, ap->bcnext->id);
- send_disconnect_ind(bcs, ap->bcnext,
- CapiCallGivenToOtherApplication);
- ap->bcnext = ap->bcnext->bcnext;
- }
- if (!ap->connected) {
+ if (!bcs->apconnstate) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
dev_warn(cs->dev, "%s: application %u not connected\n",
__func__, ap->id);
return;
@@ -841,13 +859,26 @@ void gigaset_isdn_connB(struct bc_state *bcs)
* CONNECT_B3_ACTIVE_IND in reply to CONNECT_B3_RESP
* Parameters in both cases always: NCCI = 1, NCPI empty
*/
- if (ap->connected >= APCONN_ACTIVE) {
+ if (bcs->apconnstate >= APCONN_ACTIVE) {
command = CAPI_CONNECT_B3_ACTIVE;
msgsize = CAPI_CONNECT_B3_ACTIVE_IND_BASELEN;
} else {
command = CAPI_CONNECT_B3;
msgsize = CAPI_CONNECT_B3_IND_BASELEN;
}
+ bcs->apconnstate = APCONN_ACTIVE;
+
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+
+ while (ap->bcnext) {
+ /* this should never happen */
+ dev_warn(cs->dev, "%s: dropping extra application %u\n",
+ __func__, ap->bcnext->id);
+ send_disconnect_ind(bcs, ap->bcnext,
+ CapiCallGivenToOtherApplication);
+ ap->bcnext = ap->bcnext->bcnext;
+ }
+
capi_cmsg_header(&iif->hcmsg, ap->id, command, CAPI_IND,
ap->nextMessageNumber++,
iif->ctr.cnr | ((bcs->channel + 1) << 8) | (1 << 16));
@@ -858,7 +889,6 @@ void gigaset_isdn_connB(struct bc_state *bcs)
}
capi_cmsg2message(&iif->hcmsg, __skb_put(skb, msgsize));
dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
- ap->connected = APCONN_ACTIVE;
capi_ctr_handle_message(&iif->ctr, ap->id, skb);
}

@@ -964,6 +994,61 @@ static void gigaset_register_appl(struct capi_ctr *ctr, u16 appl,
ap->rp = *rp;

list_add(&ap->ctrlist, &iif->appls);
+ dev_info(cs->dev, "application %u registered\n", ap->id);
+}
+
+/*
+ * remove CAPI application from channel
+ * helper function to keep indentation levels down and stay in 80 columns
+ */
+
+static inline void remove_appl_from_channel(struct bc_state *bcs,
+ struct gigaset_capi_appl *ap)
+{
+ struct cardstate *cs = bcs->cs;
+ struct gigaset_capi_appl *bcap;
+ unsigned long flags;
+ int prevconnstate;
+
+ spin_lock_irqsave(&bcs->aplock, flags);
+ bcap = bcs->ap;
+ if (bcap == NULL) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+ return;
+ }
+
+ /* check first application on channel */
+ if (bcap == ap) {
+ bcs->ap = ap->bcnext;
+ if (bcs->ap != NULL) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+ return;
+ }
+
+ /* none left, clear channel state */
+ prevconnstate = bcs->apconnstate;
+ bcs->apconnstate = APCONN_NONE;
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+
+ if (prevconnstate == APCONN_ACTIVE) {
+ dev_notice(cs->dev, "%s: hanging up channel %u\n",
+ __func__, bcs->channel);
+ gigaset_add_event(cs, &bcs->at_state,
+ EV_HUP, NULL, 0, NULL);
+ gigaset_schedule_event(cs);
+ }
+ return;
+ }
+
+ /* check remaining list */
+ do {
+ if (bcap->bcnext == ap) {
+ bcap->bcnext = bcap->bcnext->bcnext;
+ return;
+ }
+ bcap = bcap->bcnext;
+ } while (bcap != NULL);
+ spin_unlock_irqrestore(&bcs->aplock, flags);
}

/*
@@ -975,19 +1060,19 @@ static void gigaset_release_appl(struct capi_ctr *ctr, u16 appl)
= container_of(ctr, struct gigaset_capi_ctr, ctr);
struct cardstate *cs = iif->ctr.driverdata;
struct gigaset_capi_appl *ap, *tmp;
+ unsigned ch;

list_for_each_entry_safe(ap, tmp, &iif->appls, ctrlist)
if (ap->id == appl) {
- if (ap->connected != APCONN_NONE) {
- dev_err(cs->dev,
- "%s: application %u still connected\n",
- __func__, ap->id);
- /* ToDo: clear active connection */
- }
+ /* remove from any channels */
+ for (ch = 0; ch < cs->channels; ch++)
+ remove_appl_from_channel(&cs->bcs[ch], ap);
+
+ /* remove from registration list */
list_del(&ap->ctrlist);
kfree(ap);
+ dev_info(cs->dev, "application %u released\n", appl);
}
-
}

/*
@@ -1166,6 +1251,7 @@ static void do_connect_req(struct gigaset_capi_ctr *iif,
char **commands;
char *s;
u8 *pp;
+ unsigned long flags;
int i, l, lbc, lhlc;
u16 info;

@@ -1181,8 +1267,15 @@ static void do_connect_req(struct gigaset_capi_ctr *iif,
send_conf(iif, ap, skb, CapiNoPlciAvailable);
return;
}
+ spin_lock_irqsave(&bcs->aplock, flags);
+ if (bcs->ap != NULL || bcs->apconnstate != APCONN_NONE)
+ dev_warn(cs->dev, "%s: channel not properly cleared (%p/%d)\n",
+ __func__, bcs->ap, bcs->apconnstate);
ap->bcnext = NULL;
bcs->ap = ap;
+ bcs->apconnstate = APCONN_SETUP;
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+
bcs->rx_bufsize = ap->rp.datablklen;
dev_kfree_skb(bcs->rx_skb);
gigaset_new_rx_skb(bcs);
@@ -1419,7 +1512,6 @@ static void do_connect_req(struct gigaset_capi_ctr *iif,
goto error;
}
gigaset_schedule_event(cs);
- ap->connected = APCONN_SETUP;
send_conf(iif, ap, skb, CapiSuccess);
return;

@@ -1447,6 +1539,7 @@ static void do_connect_resp(struct gigaset_capi_ctr *iif,
_cmsg *cmsg = &iif->acmsg;
struct bc_state *bcs;
struct gigaset_capi_appl *oap;
+ unsigned long flags;
int channel;

/* decode message */
@@ -1466,12 +1559,21 @@ static void do_connect_resp(struct gigaset_capi_ctr *iif,
switch (cmsg->Reject) {
case 0: /* Accept */
/* drop all competing applications, keep only this one */
- for (oap = bcs->ap; oap != NULL; oap = oap->bcnext)
- if (oap != ap)
+ spin_lock_irqsave(&bcs->aplock, flags);
+ while (bcs->ap != NULL) {
+ oap = bcs->ap;
+ bcs->ap = oap->bcnext;
+ if (oap != ap) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
send_disconnect_ind(bcs, oap,
CapiCallGivenToOtherApplication);
+ spin_lock_irqsave(&bcs->aplock, flags);
+ }
+ }
ap->bcnext = NULL;
bcs->ap = ap;
+ spin_unlock_irqrestore(&bcs->aplock, flags);
+
bcs->rx_bufsize = ap->rp.datablklen;
dev_kfree_skb(bcs->rx_skb);
gigaset_new_rx_skb(bcs);
@@ -1542,31 +1644,45 @@ static void do_connect_resp(struct gigaset_capi_ctr *iif,
send_disconnect_ind(bcs, ap, 0);

/* remove it from the list of listening apps */
+ spin_lock_irqsave(&bcs->aplock, flags);
if (bcs->ap == ap) {
bcs->ap = ap->bcnext;
- if (bcs->ap == NULL)
+ if (bcs->ap == NULL) {
/* last one: stop ev-layer hupD notifications */
+ bcs->apconnstate = APCONN_NONE;
bcs->chstate &= ~CHS_NOTIFY_LL;
+ }
+ spin_unlock_irqrestore(&bcs->aplock, flags);
return;
}
for (oap = bcs->ap; oap != NULL; oap = oap->bcnext) {
if (oap->bcnext == ap) {
oap->bcnext = oap->bcnext->bcnext;
+ spin_unlock_irqrestore(&bcs->aplock, flags);
return;
}
}
+ spin_unlock_irqrestore(&bcs->aplock, flags);
dev_err(cs->dev, "%s: application %u not found\n",
__func__, ap->id);
return;

default: /* Reject */
/* drop all competing applications, keep only this one */
- for (oap = bcs->ap; oap != NULL; oap = oap->bcnext)
- if (oap != ap)
+ spin_lock_irqsave(&bcs->aplock, flags);
+ while (bcs->ap != NULL) {
+ oap = bcs->ap;
+ bcs->ap = oap->bcnext;
+ if (oap != ap) {
+ spin_unlock_irqrestore(&bcs->aplock, flags);
send_disconnect_ind(bcs, oap,
CapiCallGivenToOtherApplication);
+ spin_lock_irqsave(&bcs->aplock, flags);
+ }
+ }
ap->bcnext = NULL;
bcs->ap = ap;
+ spin_unlock_irqrestore(&bcs->aplock, flags);

/* reject call - will trigger DISCONNECT_IND for this app */
dev_info(cs->dev, "%s: Reject=%x\n",
@@ -1589,6 +1705,7 @@ static void do_connect_b3_req(struct gigaset_capi_ctr *iif,
{
struct cardstate *cs = iif->ctr.driverdata;
_cmsg *cmsg = &iif->acmsg;
+ struct bc_state *bcs;
int channel;

/* decode message */
@@ -1603,9 +1720,10 @@ static void do_connect_b3_req(struct gigaset_capi_ctr *iif,
send_conf(iif, ap, skb, CapiIllContrPlciNcci);
return;
}
+ bcs = &cs->bcs[channel-1];

/* mark logical connection active */
- ap->connected = APCONN_ACTIVE;
+ bcs->apconnstate = APCONN_ACTIVE;

/* build NCCI: always 1 (one B3 connection only) */
cmsg->adr.adrNCCI |= 1 << 16;
@@ -1651,7 +1769,7 @@ static void do_connect_b3_resp(struct gigaset_capi_ctr *iif,

if (cmsg->Reject) {
/* Reject: clear B3 connect received flag */
- ap->connected = APCONN_SETUP;
+ bcs->apconnstate = APCONN_SETUP;

/* trigger hangup, causing eventual DISCONNECT_IND */
if (!gigaset_add_event(cs, &bcs->at_state,
@@ -1723,11 +1841,11 @@ static void do_disconnect_req(struct gigaset_capi_ctr *iif,
}

/* skip if DISCONNECT_IND already sent */
- if (!ap->connected)
+ if (!bcs->apconnstate)
return;

/* check for active logical connection */
- if (ap->connected >= APCONN_ACTIVE) {
+ if (bcs->apconnstate >= APCONN_ACTIVE) {
/*
* emit DISCONNECT_B3_IND with cause 0x3301
* use separate cmsg structure, as the content of iif->acmsg
@@ -1776,6 +1894,7 @@ static void do_disconnect_b3_req(struct gigaset_capi_ctr *iif,
{
struct cardstate *cs = iif->ctr.driverdata;
_cmsg *cmsg = &iif->acmsg;
+ struct bc_state *bcs;
int channel;

/* decode message */
@@ -1791,17 +1910,17 @@ static void do_disconnect_b3_req(struct gigaset_capi_ctr *iif,
send_conf(iif, ap, skb, CapiIllContrPlciNcci);
return;
}
+ bcs = &cs->bcs[channel-1];

/* reject if logical connection not active */
- if (ap->connected < APCONN_ACTIVE) {
+ if (bcs->apconnstate < APCONN_ACTIVE) {
send_conf(iif, ap, skb,
CapiMessageNotSupportedInCurrentState);
return;
}

/* trigger hangup, causing eventual DISCONNECT_B3_IND */
- if (!gigaset_add_event(cs, &cs->bcs[channel-1].at_state,
- EV_HUP, NULL, 0, NULL)) {
+ if (!gigaset_add_event(cs, &bcs->at_state, EV_HUP, NULL, 0, NULL)) {
send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
return;
}
@@ -1822,6 +1941,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
struct sk_buff *skb)
{
struct cardstate *cs = iif->ctr.driverdata;
+ struct bc_state *bcs;
int channel = CAPIMSG_PLCI_PART(skb->data);
u16 ncci = CAPIMSG_NCCI_PART(skb->data);
u16 msglen = CAPIMSG_LEN(skb->data);
@@ -1844,6 +1964,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
send_conf(iif, ap, skb, CapiIllContrPlciNcci);
return;
}
+ bcs = &cs->bcs[channel-1];
if (msglen != CAPI_DATA_B3_REQ_LEN && msglen != CAPI_DATA_B3_REQ_LEN64)
dev_notice(cs->dev, "%s: unexpected length %d\n",
"DATA_B3_REQ", msglen);
@@ -1863,7 +1984,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
}

/* reject if logical connection not active */
- if (ap->connected < APCONN_ACTIVE) {
+ if (bcs->apconnstate < APCONN_ACTIVE) {
send_conf(iif, ap, skb, CapiMessageNotSupportedInCurrentState);
return;
}
@@ -1874,7 +1995,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
skb_pull(skb, msglen);

/* pass to device-specific module */
- if (cs->ops->send_skb(&cs->bcs[channel-1], skb) < 0) {
+ if (cs->ops->send_skb(bcs, skb) < 0) {
send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
return;
}
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 9778fab..5d4befb 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -649,6 +649,10 @@ static struct bc_state *gigaset_initbcs(struct bc_state *bcs,
for (i = 0; i < AT_NUM; ++i)
bcs->commands[i] = NULL;

+ spin_lock_init(&bcs->aplock);
+ bcs->ap = NULL;
+ bcs->apconnstate = 0;
+
gig_dbg(DEBUG_INIT, " setting up bcs[%d]->hw", channel);
if (cs->ops->initbcshw(bcs))
return bcs;
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index c4e6c26..8738b08 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -403,7 +403,9 @@ struct bc_state {
struct bas_bc_state *bas; /* usb hardware driver (base) */
} hw;

- void *ap; /* LL application structure */
+ void *ap; /* associated LL application */
+ int apconnstate; /* LL application connection state */
+ spinlock_t aplock;
};

struct cardstate {
--
1.6.5.3.298.g39add

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