caif: Disconnect without waiting for response

Changes:
o Function cfcnfg_disconn_adapt_layer is changed to do asynchronous
  disconnect, not waiting for any response from the modem. Due to this
  the function cfcnfg_linkdestroy_rsp does nothing anymore.
o Because disconnect may take down a connection before a connect response
  is received the function cfcnfg_linkup_rsp is checking if the client is
  still waiting for the response, if not a disconnect request is sent to
  the modem.
o cfctrl is no longer keeping track of pending disconnect requests.
o Added function cfctrl_cancel_req, which is used for deleting a pending
  connect request if disconnect is done before connect response is received.
o Removed unused function cfctrl_insert_req2
o Added better handling of connect reject from modem.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 107 insertions, 143 deletions

diff --git a/net/caif/cfcnfg.c b/net/caif/cfcnfg.c
index f94f3dfe85c1..471c62939fad 100644
--- a/net/caif/cfcnfg.c
+++ b/net/caif/cfcnfg.c
@@ -54,8 +54,7 @@ struct cfcnfg {
 static void cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id,
                              enum cfctrl_srv serv, u8 phyid,
                              struct cflayer *adapt_layer);
-static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id,
-                                  struct cflayer *client_layer);
+static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id);
 static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
                              struct cflayer *adapt_layer);
 static void cfctrl_resp_func(void);
@@ -175,73 +174,65 @@ int cfcnfg_get_named(struct cfcnfg *cnfg, char *name)
         return 0;
 }
 
-/*
- * NOTE: What happens on destroy failure:
- *       1a) No response - Too early
- *            This will not happen because enumerate has already
- *            completed.
- *       1b) No response - FATAL
- *            Not handled, but this should be a CAIF PROTOCOL ERROR
- *            Modem error, response is really expected -  this
- *            case is not really handled.
- *       2) O/E-bit indicate error
- *            Ignored - this link is destroyed anyway.
- *       3) Not able to match on request
- *            Not handled, but this should be a CAIF PROTOCOL ERROR
- *       4) Link-Error - (no response)
- *            Not handled, but this should be a CAIF PROTOCOL ERROR
- */
 int cfcnfg_disconn_adapt_layer(struct cfcnfg *cnfg, struct cflayer *adap_layer)
 {
         u8 channel_id = 0;
         int ret = 0;
+        struct cflayer *servl = NULL;
         struct cfcnfg_phyinfo *phyinfo = NULL;
         u8 phyid = 0;
-
         caif_assert(adap_layer != NULL);
         channel_id = adap_layer->id;
-        if (channel_id == 0) {
+        if (adap_layer->dn == NULL || channel_id == 0) {
                 pr_err("CAIF: %s():adap_layer->id is 0\n", __func__);
                 ret = -ENOTCONN;
                 goto end;
         }
-
-        if (adap_layer->dn == NULL) {
-                pr_err("CAIF: %s():adap_layer->dn is NULL\n", __func__);
-                ret = -ENODEV;
-                goto end;
-        }
-
-        if (adap_layer->dn != NULL)
-                phyid = cfsrvl_getphyid(adap_layer->dn);
-
-        phyinfo = cfcnfg_get_phyinfo(cnfg, phyid);
-        if (phyinfo == NULL) {
-                pr_warning("CAIF: %s(): No interface to send disconnect to\n",
-                           __func__);
-                ret = -ENODEV;
+        servl = cfmuxl_remove_uplayer(cnfg->mux, channel_id);
+        if (servl == NULL)
                 goto end;
-        }
-
-        if (phyinfo->id != phyid
-                || phyinfo->phy_layer->id != phyid
-                || phyinfo->frm_layer->id != phyid) {
-
-                pr_err("CAIF: %s(): Inconsistency in phy registration\n",
-                        __func__);
+        layer_set_up(servl, NULL);
+        ret = cfctrl_linkdown_req(cnfg->ctrl, channel_id, adap_layer);
+        if (servl == NULL) {
+                pr_err("CAIF: %s(): PROTOCOL ERROR "
+                       "- Error removing service_layer Channel_Id(%d)",
+                        __func__, channel_id);
                 ret = -EINVAL;
                 goto end;
         }
+        caif_assert(channel_id == servl->id);
+        if (adap_layer->dn != NULL) {
+                phyid = cfsrvl_getphyid(adap_layer->dn);
 
-        ret = cfctrl_linkdown_req(cnfg->ctrl, channel_id, adap_layer);
-
-end:
+                phyinfo = cfcnfg_get_phyinfo(cnfg, phyid);
+                if (phyinfo == NULL) {
+                        pr_warning("CAIF: %s(): "
+                                "No interface to send disconnect to\n",
+                                __func__);
+                        ret = -ENODEV;
+                        goto end;
+                }
+                if (phyinfo->id != phyid ||
+                        phyinfo->phy_layer->id != phyid ||
+                        phyinfo->frm_layer->id != phyid) {
+                        pr_err("CAIF: %s(): "
+                                "Inconsistency in phy registration\n",
+                                __func__);
+                        ret = -EINVAL;
+                        goto end;
+                }
+        }
         if (phyinfo != NULL && --phyinfo->phy_ref_count == 0 &&
                 phyinfo->phy_layer != NULL &&
                 phyinfo->phy_layer->modemcmd != NULL) {
                 phyinfo->phy_layer->modemcmd(phyinfo->phy_layer,
                                              _CAIF_MODEMCMD_PHYIF_USELESS);
         }
+end:
+        cfsrvl_put(servl);
+        cfctrl_cancel_req(cnfg->ctrl, adap_layer);
+        if (adap_layer->ctrlcmd != NULL)
+                adap_layer->ctrlcmd(adap_layer, CAIF_CTRLCMD_DEINIT_RSP, 0);
         return ret;
 
 }
@@ -254,69 +245,11 @@ void cfcnfg_release_adap_layer(struct cflayer *adap_layer)
 }
 EXPORT_SYMBOL(cfcnfg_release_adap_layer);
 
-static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id,
-                                  struct cflayer *client_layer)
+static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id)
 {
-        struct cfcnfg *cnfg = container_obj(layer);
-        struct cflayer *servl;
-
-        /*
-         * 1) Remove service from the MUX layer. The MUX must
-         *    guarante that no more payload sent "upwards" (receive)
-         */
-        servl = cfmuxl_remove_uplayer(cnfg->mux, channel_id);
-
-        if (servl == NULL) {
-                pr_err("CAIF: %s(): PROTOCOL ERROR "
-                       "- Error removing service_layer Channel_Id(%d)",
-                        __func__, channel_id);
-                return;
-        }
-        caif_assert(channel_id == servl->id);
-
-        if (servl != client_layer && servl->up != client_layer) {
-                pr_err("CAIF: %s(): Error removing service_layer "
-                       "Channel_Id(%d) %p %p",
-                        __func__, channel_id, (void *) servl,
-                        (void *) client_layer);
-                return;
-        }
-
-        /*
-         * 2) DEINIT_RSP must guarantee that no more packets are transmitted
-         *    from client (adap_layer) when it returns.
-         */
-
-        if (servl->ctrlcmd == NULL) {
-                pr_err("CAIF: %s(): Error servl->ctrlcmd == NULL", __func__);
-                return;
-        }
-
-        servl->ctrlcmd(servl, CAIF_CTRLCMD_DEINIT_RSP, 0);
-
-        /* 3) It is now safe to destroy the service layer. */
-        cfservl_destroy(servl);
 }
 
-/*
- * NOTE: What happens on linksetup failure:
- *       1a) No response - Too early
- *            This will not happen because enumerate is secured
- *            before using interface.
- *       1b) No response - FATAL
- *            Not handled, but this should be a CAIF PROTOCOL ERROR
- *            Modem error, response is really expected -  this case is
- *            not really handled.
- *       2) O/E-bit indicate error
- *            Handled in cnfg_reject_rsp
- *       3) Not able to match on request
- *            Not handled, but this should be a CAIF PROTOCOL ERROR
- *       4) Link-Error - (no response)
- *            Not handled, but this should be a CAIF PROTOCOL ERROR
- */
-
-int
-cfcnfg_add_adaptation_layer(struct cfcnfg *cnfg,
+int cfcnfg_add_adaptation_layer(struct cfcnfg *cnfg,
                                 struct cfctrl_link_param *param,
                                 struct cflayer *adap_layer)
 {
@@ -346,8 +279,7 @@ cfcnfg_add_adaptation_layer(struct cfcnfg *cnfg,
                      param->phyid);
         /* FIXME: ENUMERATE INITIALLY WHEN ACTIVATING PHYSICAL INTERFACE */
         cfctrl_enum_req(cnfg->ctrl, param->phyid);
-        cfctrl_linkup_request(cnfg->ctrl, param, adap_layer);
-        return 0;
+        return cfctrl_linkup_request(cnfg->ctrl, param, adap_layer);
 }
 EXPORT_SYMBOL(cfcnfg_add_adaptation_layer);
 
@@ -367,8 +299,10 @@ cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
         struct cflayer *servicel = NULL;
         struct cfcnfg_phyinfo *phyinfo;
         if (adapt_layer == NULL) {
-                pr_err("CAIF: %s(): PROTOCOL ERROR "
-                        "- LinkUp Request/Response did not match\n", __func__);
+                pr_debug("CAIF: %s(): link setup response "
+                                "but no client exist, send linkdown back\n",
+                                __func__);
+                cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
                 return;
         }
 
@@ -424,6 +358,7 @@ cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
         cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
         layer_set_up(servicel, adapt_layer);
         layer_set_dn(adapt_layer, servicel);
+        cfsrvl_get(servicel);
         servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
 }
 
diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c
index 11f80140f3cb..a521d32cfe56 100644
--- a/net/caif/cfctrl.c
+++ b/net/caif/cfctrl.c
@@ -32,6 +32,7 @@ static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
 
 struct cflayer *cfctrl_create(void)
 {
+        struct dev_info dev_info;
         struct cfctrl *this =
                 kmalloc(sizeof(struct cfctrl), GFP_ATOMIC);
         if (!this) {
@@ -39,12 +40,13 @@ struct cflayer *cfctrl_create(void)
                 return NULL;
         }
         caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
+        memset(&dev_info, 0, sizeof(dev_info));
+        dev_info.id = 0xff;
         memset(this, 0, sizeof(*this));
+        cfsrvl_init(&this->serv, 0, &dev_info);
         spin_lock_init(&this->info_list_lock);
         atomic_set(&this->req_seq_no, 1);
         atomic_set(&this->rsp_seq_no, 1);
-        this->serv.dev_info.id = 0xff;
-        this->serv.layer.id = 0;
         this->serv.layer.receive = cfctrl_recv;
         sprintf(this->serv.layer.name, "ctrl");
         this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
@@ -127,20 +129,6 @@ void cfctrl_insert_req(struct cfctrl *ctrl,
         spin_unlock(&ctrl->info_list_lock);
 }
 
-static void cfctrl_insert_req2(struct cfctrl *ctrl, enum cfctrl_cmd cmd,
-                               u8 linkid, struct cflayer *user_layer)
-{
-        struct cfctrl_request_info *req = kmalloc(sizeof(*req), GFP_KERNEL);
-        if (!req) {
-                pr_warning("CAIF: %s(): Out of memory\n", __func__);
-                return;
-        }
-        req->client_layer = user_layer;
-        req->cmd = cmd;
-        req->channel_id = linkid;
-        cfctrl_insert_req(ctrl, req);
-}
-
 /* Compare and remove request */
 struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
                                               struct cfctrl_request_info *req)
@@ -234,7 +222,7 @@ void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
         }
 }
 
-void cfctrl_linkup_request(struct cflayer *layer,
+int cfctrl_linkup_request(struct cflayer *layer,
                            struct cfctrl_link_param *param,
                            struct cflayer *user_layer)
 {
@@ -248,7 +236,7 @@ void cfctrl_linkup_request(struct cflayer *layer,
         struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
         if (!pkt) {
                 pr_warning("CAIF: %s(): Out of memory\n", __func__);
-                return;
+                return -ENOMEM;
         }
         cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
         cfpkt_addbdy(pkt, (param->chtype << 4) + param->linktype);
@@ -294,11 +282,12 @@ void cfctrl_linkup_request(struct cflayer *layer,
         default:
                 pr_warning("CAIF: %s():Request setup of bad link type = %d\n",
                            __func__, param->linktype);
+                return -EINVAL;
         }
         req = kmalloc(sizeof(*req), GFP_KERNEL);
         if (!req) {
                 pr_warning("CAIF: %s(): Out of memory\n", __func__);
-                return;
+                return -ENOMEM;
         }
         memset(req, 0, sizeof(*req));
         req->client_layer = user_layer;
@@ -306,6 +295,11 @@ void cfctrl_linkup_request(struct cflayer *layer,
         req->param = *param;
         cfctrl_insert_req(cfctrl, req);
         init_info(cfpkt_info(pkt), cfctrl);
+        /*
+         * NOTE:Always send linkup and linkdown request on the same
+         *      device as the payload. Otherwise old queued up payload
+         *      might arrive with the newly allocated channel ID.
+         */
         cfpkt_info(pkt)->dev_info->id = param->phyid;
         ret =
             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
@@ -313,7 +307,9 @@ void cfctrl_linkup_request(struct cflayer *layer,
                 pr_err("CAIF: %s(): Could not transmit linksetup request\n",
                         __func__);
                 cfpkt_destroy(pkt);
+                return -ENODEV;
         }
+        return 0;
 }
 
 int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
@@ -326,7 +322,6 @@ int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
                 pr_warning("CAIF: %s(): Out of memory\n", __func__);
                 return -ENOMEM;
         }
-        cfctrl_insert_req2(cfctrl, CFCTRL_CMD_LINK_DESTROY, channelid, client);
         cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
         cfpkt_addbdy(pkt, channelid);
         init_info(cfpkt_info(pkt), cfctrl);
@@ -392,6 +387,38 @@ void cfctrl_getstartreason_req(struct cflayer *layer)
 }
 
 
+void cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
+{
+        struct cfctrl_request_info *p, *req;
+        struct cfctrl *ctrl = container_obj(layr);
+        spin_lock(&ctrl->info_list_lock);
+
+        if (ctrl->first_req == NULL) {
+                spin_unlock(&ctrl->info_list_lock);
+                return;
+        }
+
+        if (ctrl->first_req->client_layer == adap_layer) {
+
+                req = ctrl->first_req;
+                ctrl->first_req = ctrl->first_req->next;
+                kfree(req);
+        }
+
+        p = ctrl->first_req;
+        while (p != NULL && p->next != NULL) {
+                if (p->next->client_layer == adap_layer) {
+
+                        req = p->next;
+                        p->next = p->next->next;
+                        kfree(p->next);
+                }
+                p = p->next;
+        }
+
+        spin_unlock(&ctrl->info_list_lock);
+}
+
 static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
 {
         u8 cmdrsp;
@@ -409,11 +436,8 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
         cmd = cmdrsp & CFCTRL_CMD_MASK;
         if (cmd != CFCTRL_CMD_LINK_ERR
             && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)) {
-                if (handle_loop(cfctrl, cmd, pkt) == CAIF_FAILURE) {
-                        pr_info("CAIF: %s() CAIF Protocol error:"
-                                "Response bit not set\n", __func__);
-                        goto error;
-                }
+                if (handle_loop(cfctrl, cmd, pkt) == CAIF_FAILURE)
+                        cmdrsp |= CFCTRL_ERR_BIT;
         }
 
         switch (cmd) {
@@ -451,12 +475,16 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
                         switch (serv) {
                         case CFCTRL_SRV_VEI:
                         case CFCTRL_SRV_DBG:
+                                if (CFCTRL_ERR_BIT & cmdrsp)
+                                        break;
                                 /* Link ID */
                                 cfpkt_extr_head(pkt, &linkid, 1);
                                 break;
                         case CFCTRL_SRV_VIDEO:
                                 cfpkt_extr_head(pkt, &tmp, 1);
                                 linkparam.u.video.connid = tmp;
+                                if (CFCTRL_ERR_BIT & cmdrsp)
+                                        break;
                                 /* Link ID */
                                 cfpkt_extr_head(pkt, &linkid, 1);
                                 break;
@@ -465,6 +493,8 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
                                 cfpkt_extr_head(pkt, &tmp32, 4);
                                 linkparam.u.datagram.connid =
                                     le32_to_cpu(tmp32);
+                                if (CFCTRL_ERR_BIT & cmdrsp)
+                                        break;
                                 /* Link ID */
                                 cfpkt_extr_head(pkt, &linkid, 1);
                                 break;
@@ -483,6 +513,8 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
                                         *cp++ = tmp;
                                 *cp = '\0';
 
+                                if (CFCTRL_ERR_BIT & cmdrsp)
+                                        break;
                                 /* Link ID */
                                 cfpkt_extr_head(pkt, &linkid, 1);
 
@@ -519,6 +551,8 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
                                         cfpkt_extr_head(pkt, &tmp, 1);
                                         *cp++ = tmp;
                                 }
+                                if (CFCTRL_ERR_BIT & cmdrsp)
+                                        break;
                                 /* Link ID */
                                 cfpkt_extr_head(pkt, &linkid, 1);
                                 /* Length */
@@ -560,13 +594,7 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
                 break;
         case CFCTRL_CMD_LINK_DESTROY:
                 cfpkt_extr_head(pkt, &linkid, 1);
-                rsp.cmd = cmd;
-                rsp.channel_id = linkid;
-                req = cfctrl_remove_req(cfctrl, &rsp);
-                cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid,
-                                            req ? req->client_layer : NULL);
-                if (req != NULL)
-                        kfree(req);
+                cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
                 break;
         case CFCTRL_CMD_LINK_ERR:
                 pr_err("CAIF: %s(): Frame Error Indication received\n",
@@ -608,7 +636,7 @@ static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
         case CAIF_CTRLCMD_FLOW_OFF_IND:
                 spin_lock(&this->info_list_lock);
                 if (this->first_req != NULL) {
-                        pr_warning("CAIF: %s(): Received flow off in "
+                        pr_debug("CAIF: %s(): Received flow off in "
                                    "control layer", __func__);
                 }
                 spin_unlock(&this->info_list_lock);
@@ -633,6 +661,7 @@ static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
                         if (!ctrl->loop_linkused[linkid])
                                 goto found;
                 spin_unlock(&ctrl->loop_linkid_lock);
+                pr_err("CAIF: %s(): Out of link-ids\n", __func__);
                 return -EINVAL;
 found:
                 if (!ctrl->loop_linkused[linkid])