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linux/net/caif/cfcnfg.c
Eric W. Biederman 8a8ee9aff6 net caif: Register properly as a pernet subsystem. 
caif is a subsystem and as such it needs to register with
register_pernet_subsys instead of register_pernet_device.

Among other problems using register_pernet_device was resulting in
net_generic being called before the caif_net structure was allocated.
Which has been causing net_generic to fail with either BUG_ON's or by
return NULL pointers.

A more ugly problem that could be caused is packets in flight why the
subsystem is shutting down.

To remove confusion also remove the cruft cause by inappropriately
trying to fix this bug.

With the aid of the previous patch I have tested this patch and
confirmed that using register_pernet_subsys makes the failure go away as
it should.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-27 21:06:03 -05:00

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/*
* Copyright (C) ST-Ericsson AB 2010
* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/module.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfcnfg.h>
#include <net/caif/cfctrl.h>
#include <net/caif/cfmuxl.h>
#include <net/caif/cffrml.h>
#include <net/caif/cfserl.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/caif_dev.h>
#define container_obj(layr) container_of(layr, struct cfcnfg, layer)
/* Information about CAIF physical interfaces held by Config Module in order
* to manage physical interfaces
*/
struct cfcnfg_phyinfo {
struct list_head node;
bool up;
/* Pointer to the layer below the MUX (framing layer) */
struct cflayer *frm_layer;
/* Pointer to the lowest actual physical layer */
struct cflayer *phy_layer;
/* Unique identifier of the physical interface */
unsigned int id;
/* Preference of the physical in interface */
enum cfcnfg_phy_preference pref;
/* Information about the physical device */
struct dev_info dev_info;
/* Interface index */
int ifindex;
/* Protocol head room added for CAIF link layer */
int head_room;
/* Use Start of frame checksum */
bool use_fcs;
};
struct cfcnfg {
struct cflayer layer;
struct cflayer *ctrl;
struct cflayer *mux;
struct list_head phys;
struct mutex lock;
};
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);
static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
struct cflayer *adapt_layer);
static void cfctrl_resp_func(void);
static void cfctrl_enum_resp(void);
struct cfcnfg *cfcnfg_create(void)
{
struct cfcnfg *this;
struct cfctrl_rsp *resp;
might_sleep();
/* Initiate this layer */
this = kzalloc(sizeof(struct cfcnfg), GFP_ATOMIC);
if (!this)
return NULL;
this->mux = cfmuxl_create();
if (!this->mux)
goto out_of_mem;
this->ctrl = cfctrl_create();
if (!this->ctrl)
goto out_of_mem;
/* Initiate response functions */
resp = cfctrl_get_respfuncs(this->ctrl);
resp->enum_rsp = cfctrl_enum_resp;
resp->linkerror_ind = cfctrl_resp_func;
resp->linkdestroy_rsp = cfcnfg_linkdestroy_rsp;
resp->sleep_rsp = cfctrl_resp_func;
resp->wake_rsp = cfctrl_resp_func;
resp->restart_rsp = cfctrl_resp_func;
resp->radioset_rsp = cfctrl_resp_func;
resp->linksetup_rsp = cfcnfg_linkup_rsp;
resp->reject_rsp = cfcnfg_reject_rsp;
INIT_LIST_HEAD(&this->phys);
cfmuxl_set_uplayer(this->mux, this->ctrl, 0);
layer_set_dn(this->ctrl, this->mux);
layer_set_up(this->ctrl, this);
mutex_init(&this->lock);
return this;
out_of_mem:
synchronize_rcu();
kfree(this->mux);
kfree(this->ctrl);
kfree(this);
return NULL;
}
void cfcnfg_remove(struct cfcnfg *cfg)
{
might_sleep();
if (cfg) {
synchronize_rcu();
kfree(cfg->mux);
cfctrl_remove(cfg->ctrl);
kfree(cfg);
}
}
static void cfctrl_resp_func(void)
{
}
static struct cfcnfg_phyinfo *cfcnfg_get_phyinfo_rcu(struct cfcnfg *cnfg,
u8 phyid)
{
struct cfcnfg_phyinfo *phy;
list_for_each_entry_rcu(phy, &cnfg->phys, node)
if (phy->id == phyid)
return phy;
return NULL;
}
static void cfctrl_enum_resp(void)
{
}
static struct dev_info *cfcnfg_get_phyid(struct cfcnfg *cnfg,
enum cfcnfg_phy_preference phy_pref)
{
/* Try to match with specified preference */
struct cfcnfg_phyinfo *phy;
list_for_each_entry_rcu(phy, &cnfg->phys, node) {
if (phy->up && phy->pref == phy_pref &&
phy->frm_layer != NULL)
return &phy->dev_info;
}
/* Otherwise just return something */
list_for_each_entry_rcu(phy, &cnfg->phys, node)
if (phy->up)
return &phy->dev_info;
return NULL;
}
static int cfcnfg_get_id_from_ifi(struct cfcnfg *cnfg, int ifi)
{
struct cfcnfg_phyinfo *phy;
list_for_each_entry_rcu(phy, &cnfg->phys, node)
if (phy->ifindex == ifi && phy->up)
return phy->id;
return -ENODEV;
}
int caif_disconnect_client(struct net *net, struct cflayer *adap_layer)
{
u8 channel_id;
struct cfcnfg *cfg = get_cfcnfg(net);
caif_assert(adap_layer != NULL);
cfctrl_cancel_req(cfg->ctrl, adap_layer);
channel_id = adap_layer->id;
if (channel_id != 0) {
struct cflayer *servl;
servl = cfmuxl_remove_uplayer(cfg->mux, channel_id);
cfctrl_linkdown_req(cfg->ctrl, channel_id, adap_layer);
if (servl != NULL)
layer_set_up(servl, NULL);
} else
pr_debug("nothing to disconnect\n");
/* Do RCU sync before initiating cleanup */
synchronize_rcu();
if (adap_layer->ctrlcmd != NULL)
adap_layer->ctrlcmd(adap_layer, CAIF_CTRLCMD_DEINIT_RSP, 0);
return 0;
}
EXPORT_SYMBOL(caif_disconnect_client);
static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id)
{
}
static const int protohead[CFCTRL_SRV_MASK] = {
[CFCTRL_SRV_VEI] = 4,
[CFCTRL_SRV_DATAGRAM] = 7,
[CFCTRL_SRV_UTIL] = 4,
[CFCTRL_SRV_RFM] = 3,
[CFCTRL_SRV_DBG] = 3,
};
static int caif_connect_req_to_link_param(struct cfcnfg *cnfg,
struct caif_connect_request *s,
struct cfctrl_link_param *l)
{
struct dev_info *dev_info;
enum cfcnfg_phy_preference pref;
int res;
memset(l, 0, sizeof(*l));
/* In caif protocol low value is high priority */
l->priority = CAIF_PRIO_MAX - s->priority + 1;
if (s->ifindex != 0) {
res = cfcnfg_get_id_from_ifi(cnfg, s->ifindex);
if (res < 0)
return res;
l->phyid = res;
} else {
switch (s->link_selector) {
case CAIF_LINK_HIGH_BANDW:
pref = CFPHYPREF_HIGH_BW;
break;
case CAIF_LINK_LOW_LATENCY:
pref = CFPHYPREF_LOW_LAT;
break;
default:
return -EINVAL;
}
dev_info = cfcnfg_get_phyid(cnfg, pref);
if (dev_info == NULL)
return -ENODEV;
l->phyid = dev_info->id;
}
switch (s->protocol) {
case CAIFPROTO_AT:
l->linktype = CFCTRL_SRV_VEI;
l->endpoint = (s->sockaddr.u.at.type >> 2) & 0x3;
l->chtype = s->sockaddr.u.at.type & 0x3;
break;
case CAIFPROTO_DATAGRAM:
l->linktype = CFCTRL_SRV_DATAGRAM;
l->chtype = 0x00;
l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
break;
case CAIFPROTO_DATAGRAM_LOOP:
l->linktype = CFCTRL_SRV_DATAGRAM;
l->chtype = 0x03;
l->endpoint = 0x00;
l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
break;
case CAIFPROTO_RFM:
l->linktype = CFCTRL_SRV_RFM;
l->u.datagram.connid = s->sockaddr.u.rfm.connection_id;
strncpy(l->u.rfm.volume, s->sockaddr.u.rfm.volume,
sizeof(l->u.rfm.volume)-1);
l->u.rfm.volume[sizeof(l->u.rfm.volume)-1] = 0;
break;
case CAIFPROTO_UTIL:
l->linktype = CFCTRL_SRV_UTIL;
l->endpoint = 0x00;
l->chtype = 0x00;
strncpy(l->u.utility.name, s->sockaddr.u.util.service,
sizeof(l->u.utility.name)-1);
l->u.utility.name[sizeof(l->u.utility.name)-1] = 0;
caif_assert(sizeof(l->u.utility.name) > 10);
l->u.utility.paramlen = s->param.size;
if (l->u.utility.paramlen > sizeof(l->u.utility.params))
l->u.utility.paramlen = sizeof(l->u.utility.params);
memcpy(l->u.utility.params, s->param.data,
l->u.utility.paramlen);
break;
case CAIFPROTO_DEBUG:
l->linktype = CFCTRL_SRV_DBG;
l->endpoint = s->sockaddr.u.dbg.service;
l->chtype = s->sockaddr.u.dbg.type;
break;
default:
return -EINVAL;
}
return 0;
}
int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
struct cflayer *adap_layer, int *ifindex,
int *proto_head,
int *proto_tail)
{
struct cflayer *frml;
struct cfcnfg_phyinfo *phy;
int err;
struct cfctrl_link_param param;
struct cfcnfg *cfg = get_cfcnfg(net);
rcu_read_lock();
err = caif_connect_req_to_link_param(cfg, conn_req, &param);
if (err)
goto unlock;
phy = cfcnfg_get_phyinfo_rcu(cfg, param.phyid);
if (!phy) {
err = -ENODEV;
goto unlock;
}
err = -EINVAL;
if (adap_layer == NULL) {
pr_err("adap_layer is zero\n");
goto unlock;
}
if (adap_layer->receive == NULL) {
pr_err("adap_layer->receive is NULL\n");
goto unlock;
}
if (adap_layer->ctrlcmd == NULL) {
pr_err("adap_layer->ctrlcmd == NULL\n");
goto unlock;
}
err = -ENODEV;
frml = phy->frm_layer;
if (frml == NULL) {
pr_err("Specified PHY type does not exist!\n");
goto unlock;
}
caif_assert(param.phyid == phy->id);
caif_assert(phy->frm_layer->id ==
param.phyid);
caif_assert(phy->phy_layer->id ==
param.phyid);
*ifindex = phy->ifindex;
*proto_tail = 2;
*proto_head = protohead[param.linktype] + phy->head_room;
rcu_read_unlock();
/* FIXME: ENUMERATE INITIALLY WHEN ACTIVATING PHYSICAL INTERFACE */
cfctrl_enum_req(cfg->ctrl, param.phyid);
return cfctrl_linkup_request(cfg->ctrl, &param, adap_layer);
unlock:
rcu_read_unlock();
return err;
}
EXPORT_SYMBOL(caif_connect_client);
static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
struct cflayer *adapt_layer)
{
if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
adapt_layer->ctrlcmd(adapt_layer,
CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
}
static void
cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
u8 phyid, struct cflayer *adapt_layer)
{
struct cfcnfg *cnfg = container_obj(layer);
struct cflayer *servicel = NULL;
struct cfcnfg_phyinfo *phyinfo;
struct net_device *netdev;
if (channel_id == 0) {
pr_warn("received channel_id zero\n");
if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
adapt_layer->ctrlcmd(adapt_layer,
CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
return;
}
rcu_read_lock();
if (adapt_layer == NULL) {
pr_debug("link setup response but no client exist,"
"send linkdown back\n");
cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
goto unlock;
}
caif_assert(cnfg != NULL);
caif_assert(phyid != 0);
phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
if (phyinfo == NULL) {
pr_err("ERROR: Link Layer Device dissapeared"
"while connecting\n");
goto unlock;
}
caif_assert(phyinfo != NULL);
caif_assert(phyinfo->id == phyid);
caif_assert(phyinfo->phy_layer != NULL);
caif_assert(phyinfo->phy_layer->id == phyid);
adapt_layer->id = channel_id;
switch (serv) {
case CFCTRL_SRV_VEI:
servicel = cfvei_create(channel_id, &phyinfo->dev_info);
break;
case CFCTRL_SRV_DATAGRAM:
servicel = cfdgml_create(channel_id,
&phyinfo->dev_info);
break;
case CFCTRL_SRV_RFM:
netdev = phyinfo->dev_info.dev;
servicel = cfrfml_create(channel_id, &phyinfo->dev_info,
netdev->mtu);
break;
case CFCTRL_SRV_UTIL:
servicel = cfutill_create(channel_id, &phyinfo->dev_info);
break;
case CFCTRL_SRV_VIDEO:
servicel = cfvidl_create(channel_id, &phyinfo->dev_info);
break;
case CFCTRL_SRV_DBG:
servicel = cfdbgl_create(channel_id, &phyinfo->dev_info);
break;
default:
pr_err("Protocol error. Link setup response "
"- unknown channel type\n");
goto unlock;
}
if (!servicel)
goto unlock;
layer_set_dn(servicel, cnfg->mux);
cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
layer_set_up(servicel, adapt_layer);
layer_set_dn(adapt_layer, servicel);
rcu_read_unlock();
servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
return;
unlock:
rcu_read_unlock();
}
void
cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
struct net_device *dev, struct cflayer *phy_layer,
enum cfcnfg_phy_preference pref,
struct cflayer *link_support,
bool fcs, int head_room)
{
struct cflayer *frml;
struct cfcnfg_phyinfo *phyinfo = NULL;
int i;
u8 phyid;
mutex_lock(&cnfg->lock);
/* CAIF protocol allow maximum 6 link-layers */
for (i = 0; i < 7; i++) {
phyid = (dev->ifindex + i) & 0x7;
if (phyid == 0)
continue;
if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
goto got_phyid;
}
pr_warn("Too many CAIF Link Layers (max 6)\n");
goto out;
got_phyid:
phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
if (!phyinfo)
goto out_err;
phy_layer->id = phyid;
phyinfo->pref = pref;
phyinfo->id = phyid;
phyinfo->dev_info.id = phyid;
phyinfo->dev_info.dev = dev;
phyinfo->phy_layer = phy_layer;
phyinfo->ifindex = dev->ifindex;
phyinfo->head_room = head_room;
phyinfo->use_fcs = fcs;
frml = cffrml_create(phyid, fcs);
if (!frml)
goto out_err;
phyinfo->frm_layer = frml;
layer_set_up(frml, cnfg->mux);
if (link_support != NULL) {
link_support->id = phyid;
layer_set_dn(frml, link_support);
layer_set_up(link_support, frml);
layer_set_dn(link_support, phy_layer);
layer_set_up(phy_layer, link_support);
} else {
layer_set_dn(frml, phy_layer);
layer_set_up(phy_layer, frml);
}
list_add_rcu(&phyinfo->node, &cnfg->phys);
out:
mutex_unlock(&cnfg->lock);
return;
out_err:
kfree(phyinfo);
mutex_unlock(&cnfg->lock);
}
EXPORT_SYMBOL(cfcnfg_add_phy_layer);
int cfcnfg_set_phy_state(struct cfcnfg *cnfg, struct cflayer *phy_layer,
bool up)
{
struct cfcnfg_phyinfo *phyinfo;
rcu_read_lock();
phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phy_layer->id);
if (phyinfo == NULL) {
rcu_read_unlock();
return -ENODEV;
}
if (phyinfo->up == up) {
rcu_read_unlock();
return 0;
}
phyinfo->up = up;
if (up) {
cffrml_hold(phyinfo->frm_layer);
cfmuxl_set_dnlayer(cnfg->mux, phyinfo->frm_layer,
phy_layer->id);
} else {
cfmuxl_remove_dnlayer(cnfg->mux, phy_layer->id);
cffrml_put(phyinfo->frm_layer);
}
rcu_read_unlock();
return 0;
}
EXPORT_SYMBOL(cfcnfg_set_phy_state);
int cfcnfg_del_phy_layer(struct cfcnfg *cnfg, struct cflayer *phy_layer)
{
struct cflayer *frml, *frml_dn;
u16 phyid;
struct cfcnfg_phyinfo *phyinfo;
might_sleep();
mutex_lock(&cnfg->lock);
phyid = phy_layer->id;
phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
if (phyinfo == NULL) {
mutex_unlock(&cnfg->lock);
return 0;
}
caif_assert(phyid == phyinfo->id);
caif_assert(phy_layer == phyinfo->phy_layer);
caif_assert(phy_layer->id == phyid);
caif_assert(phyinfo->frm_layer->id == phyid);
list_del_rcu(&phyinfo->node);
synchronize_rcu();
/* Fail if reference count is not zero */
if (cffrml_refcnt_read(phyinfo->frm_layer) != 0) {
pr_info("Wait for device inuse\n");
list_add_rcu(&phyinfo->node, &cnfg->phys);
mutex_unlock(&cnfg->lock);
return -EAGAIN;
}
frml = phyinfo->frm_layer;
frml_dn = frml->dn;
cffrml_set_uplayer(frml, NULL);
cffrml_set_dnlayer(frml, NULL);
if (phy_layer != frml_dn) {
layer_set_up(frml_dn, NULL);
layer_set_dn(frml_dn, NULL);
}
layer_set_up(phy_layer, NULL);
if (phyinfo->phy_layer != frml_dn)
kfree(frml_dn);
cffrml_free(frml);
kfree(phyinfo);
mutex_unlock(&cnfg->lock);
return 0;
}
EXPORT_SYMBOL(cfcnfg_del_phy_layer);
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