Commit 4d12b8b1 authored by Lauro Ramos Venancio's avatar Lauro Ramos Venancio Committed by John W. Linville
Browse files

NFC: add nfc generic netlink interface



The NFC generic netlink interface exports the NFC control operations
to the user space.
Signed-off-by: default avatarLauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: default avatarAloisio Almeida Jr <aloisio.almeida@openbossa.org>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
Reviewed-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 3e256b8f
/*
* Copyright (C) 2011 Instituto Nokia de Tecnologia
*
* Authors:
* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef __LINUX_NFC_H
#define __LINUX_NFC_H
#define NFC_GENL_NAME "nfc"
#define NFC_GENL_VERSION 1
#define NFC_GENL_MCAST_EVENT_NAME "events"
/**
* enum nfc_commands - supported nfc commands
*
* @NFC_CMD_UNSPEC: unspecified command
*
* @NFC_CMD_GET_DEVICE: request information about a device (requires
* %NFC_ATTR_DEVICE_INDEX) or dump request to get a list of all nfc devices
* @NFC_CMD_START_POLL: start polling for targets using the given protocols
* (requires %NFC_ATTR_DEVICE_INDEX and %NFC_ATTR_PROTOCOLS)
* @NFC_CMD_STOP_POLL: stop polling for targets (requires
* %NFC_ATTR_DEVICE_INDEX)
* @NFC_CMD_GET_TARGET: dump all targets found by the previous poll (requires
* %NFC_ATTR_DEVICE_INDEX)
* @NFC_EVENT_TARGETS_FOUND: event emitted when a new target is found
* (it sends %NFC_ATTR_DEVICE_INDEX)
* @NFC_EVENT_DEVICE_ADDED: event emitted when a new device is registred
* (it sends %NFC_ATTR_DEVICE_NAME, %NFC_ATTR_DEVICE_INDEX and
* %NFC_ATTR_PROTOCOLS)
* @NFC_EVENT_DEVICE_REMOVED: event emitted when a device is removed
* (it sends %NFC_ATTR_DEVICE_INDEX)
*/
enum nfc_commands {
NFC_CMD_UNSPEC,
NFC_CMD_GET_DEVICE,
NFC_CMD_START_POLL,
NFC_CMD_STOP_POLL,
NFC_CMD_GET_TARGET,
NFC_EVENT_TARGETS_FOUND,
NFC_EVENT_DEVICE_ADDED,
NFC_EVENT_DEVICE_REMOVED,
/* private: internal use only */
__NFC_CMD_AFTER_LAST
};
#define NFC_CMD_MAX (__NFC_CMD_AFTER_LAST - 1)
/**
* enum nfc_attrs - supported nfc attributes
*
* @NFC_ATTR_UNSPEC: unspecified attribute
*
* @NFC_ATTR_DEVICE_INDEX: index of nfc device
* @NFC_ATTR_DEVICE_NAME: device name, max 8 chars
* @NFC_ATTR_PROTOCOLS: nfc protocols - bitwise or-ed combination from
* NFC_PROTO_*_MASK constants
* @NFC_ATTR_TARGET_INDEX: index of the nfc target
* @NFC_ATTR_TARGET_SENS_RES: NFC-A targets extra information such as NFCID
* @NFC_ATTR_TARGET_SEL_RES: NFC-A targets extra information (useful if the
* target is not NFC-Forum compliant)
*/
enum nfc_attrs {
NFC_ATTR_UNSPEC,
NFC_ATTR_DEVICE_INDEX,
NFC_ATTR_DEVICE_NAME,
NFC_ATTR_PROTOCOLS,
NFC_ATTR_TARGET_INDEX,
NFC_ATTR_TARGET_SENS_RES,
NFC_ATTR_TARGET_SEL_RES,
/* private: internal use only */
__NFC_ATTR_AFTER_LAST
};
#define NFC_ATTR_MAX (__NFC_ATTR_AFTER_LAST - 1)
#define NFC_DEVICE_NAME_MAXSIZE 8
/* NFC protocols */
#define NFC_PROTO_JEWEL 1
#define NFC_PROTO_MIFARE 2
#define NFC_PROTO_FELICA 3
#define NFC_PROTO_ISO14443 4
#define NFC_PROTO_NFC_DEP 5
#define NFC_PROTO_MAX 6
/* NFC protocols masks used in bitsets */
#define NFC_PROTO_JEWEL_MASK (1 << NFC_PROTO_JEWEL)
#define NFC_PROTO_MIFARE_MASK (1 << NFC_PROTO_MIFARE)
#define NFC_PROTO_FELICA_MASK (1 << NFC_PROTO_FELICA)
#define NFC_PROTO_ISO14443_MASK (1 << NFC_PROTO_ISO14443)
#define NFC_PROTO_NFC_DEP_MASK (1 << NFC_PROTO_NFC_DEP)
#endif /*__LINUX_NFC_H */
......@@ -58,10 +58,28 @@ struct nfc_ops {
void *cb_context);
};
struct nfc_target {
u32 idx;
u32 supported_protocols;
u16 sens_res;
u8 sel_res;
};
struct nfc_genl_data {
u32 poll_req_pid;
struct mutex genl_data_mutex;
};
struct nfc_dev {
unsigned idx;
unsigned target_idx;
struct nfc_target *targets;
int n_targets;
int targets_generation;
spinlock_t targets_lock;
struct device dev;
bool polling;
struct nfc_genl_data genl_data;
u32 supported_protocols;
struct nfc_ops *ops;
......@@ -132,4 +150,7 @@ static inline const char *nfc_device_name(struct nfc_dev *dev)
struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp);
int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
int ntargets);
#endif /* __NET_NFC_H */
......@@ -4,4 +4,4 @@
obj-$(CONFIG_NFC) += nfc.o
nfc-objs := core.o
nfc-objs := core.o netlink.o
......@@ -233,12 +233,60 @@ struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp)
}
EXPORT_SYMBOL(nfc_alloc_skb);
/**
* nfc_targets_found - inform that targets were found
*
* @dev: The nfc device that found the targets
* @targets: array of nfc targets found
* @ntargets: targets array size
*
* The device driver must call this function when one or many nfc targets
* are found. After calling this function, the device driver must stop
* polling for targets.
*/
int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
int n_targets)
{
int i;
nfc_dbg("dev_name=%s n_targets=%d", dev_name(&dev->dev), n_targets);
dev->polling = false;
for (i = 0; i < n_targets; i++)
targets[i].idx = dev->target_idx++;
spin_lock_bh(&dev->targets_lock);
dev->targets_generation++;
kfree(dev->targets);
dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
GFP_ATOMIC);
if (!dev->targets) {
dev->n_targets = 0;
spin_unlock_bh(&dev->targets_lock);
return -ENOMEM;
}
dev->n_targets = n_targets;
spin_unlock_bh(&dev->targets_lock);
nfc_genl_targets_found(dev);
return 0;
}
EXPORT_SYMBOL(nfc_targets_found);
static void nfc_release(struct device *d)
{
struct nfc_dev *dev = to_nfc_dev(d);
nfc_dbg("dev_name=%s", dev_name(&dev->dev));
nfc_genl_data_exit(&dev->genl_data);
kfree(dev->targets);
kfree(dev);
}
......@@ -298,6 +346,12 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
dev->ops = ops;
dev->supported_protocols = supported_protocols;
spin_lock_init(&dev->targets_lock);
nfc_genl_data_init(&dev->genl_data);
/* first generation must not be 0 */
dev->targets_generation = 1;
return dev;
}
EXPORT_SYMBOL(nfc_allocate_device);
......@@ -318,7 +372,16 @@ int nfc_register_device(struct nfc_dev *dev)
rc = device_add(&dev->dev);
mutex_unlock(&nfc_devlist_mutex);
return rc;
if (rc < 0)
return rc;
rc = nfc_genl_device_added(dev);
if (rc)
nfc_dbg("The userspace won't be notified that the device %s was"
" added", dev_name(&dev->dev));
return 0;
}
EXPORT_SYMBOL(nfc_register_device);
......@@ -329,6 +392,8 @@ EXPORT_SYMBOL(nfc_register_device);
*/
void nfc_unregister_device(struct nfc_dev *dev)
{
int rc;
nfc_dbg("dev_name=%s", dev_name(&dev->dev));
mutex_lock(&nfc_devlist_mutex);
......@@ -341,18 +406,42 @@ void nfc_unregister_device(struct nfc_dev *dev)
device_unlock(&dev->dev);
mutex_unlock(&nfc_devlist_mutex);
rc = nfc_genl_device_removed(dev);
if (rc)
nfc_dbg("The userspace won't be notified that the device %s"
" was removed", dev_name(&dev->dev));
}
EXPORT_SYMBOL(nfc_unregister_device);
static int __init nfc_init(void)
{
int rc;
nfc_info("NFC Core ver %s", VERSION);
return class_register(&nfc_class);
rc = class_register(&nfc_class);
if (rc)
return rc;
rc = nfc_genl_init();
if (rc)
goto err_genl;
/* the first generation must not be 0 */
nfc_devlist_generation = 1;
return 0;
err_genl:
class_unregister(&nfc_class);
return rc;
}
static void __exit nfc_exit(void)
{
nfc_genl_exit();
class_unregister(&nfc_class);
}
......
/*
* Copyright (C) 2011 Instituto Nokia de Tecnologia
*
* Authors:
* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <net/genetlink.h>
#include <linux/nfc.h>
#include <linux/slab.h>
#include "nfc.h"
static struct genl_multicast_group nfc_genl_event_mcgrp = {
.name = NFC_GENL_MCAST_EVENT_NAME,
};
struct genl_family nfc_genl_family = {
.id = GENL_ID_GENERATE,
.hdrsize = 0,
.name = NFC_GENL_NAME,
.version = NFC_GENL_VERSION,
.maxattr = NFC_ATTR_MAX,
};
static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
[NFC_ATTR_DEVICE_INDEX] = { .type = NLA_U32 },
[NFC_ATTR_DEVICE_NAME] = { .type = NLA_STRING,
.len = NFC_DEVICE_NAME_MAXSIZE },
[NFC_ATTR_PROTOCOLS] = { .type = NLA_U32 },
};
static int nfc_genl_send_target(struct sk_buff *msg, struct nfc_target *target,
struct netlink_callback *cb, int flags)
{
void *hdr;
nfc_dbg("entry");
hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
&nfc_genl_family, flags, NFC_CMD_GET_TARGET);
if (!hdr)
return -EMSGSIZE;
genl_dump_check_consistent(cb, hdr, &nfc_genl_family);
NLA_PUT_U32(msg, NFC_ATTR_TARGET_INDEX, target->idx);
NLA_PUT_U32(msg, NFC_ATTR_PROTOCOLS,
target->supported_protocols);
NLA_PUT_U16(msg, NFC_ATTR_TARGET_SENS_RES, target->sens_res);
NLA_PUT_U8(msg, NFC_ATTR_TARGET_SEL_RES, target->sel_res);
return genlmsg_end(msg, hdr);
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static struct nfc_dev *__get_device_from_cb(struct netlink_callback *cb)
{
struct nfc_dev *dev;
int rc;
u32 idx;
rc = nlmsg_parse(cb->nlh, GENL_HDRLEN + nfc_genl_family.hdrsize,
nfc_genl_family.attrbuf,
nfc_genl_family.maxattr,
nfc_genl_policy);
if (rc < 0)
return ERR_PTR(rc);
if (!nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX])
return ERR_PTR(-EINVAL);
idx = nla_get_u32(nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return ERR_PTR(-ENODEV);
return dev;
}
static int nfc_genl_dump_targets(struct sk_buff *skb,
struct netlink_callback *cb)
{
int i = cb->args[0];
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
int rc;
nfc_dbg("entry");
if (!dev) {
dev = __get_device_from_cb(cb);
if (IS_ERR(dev))
return PTR_ERR(dev);
cb->args[1] = (long) dev;
}
spin_lock_bh(&dev->targets_lock);
cb->seq = dev->targets_generation;
while (i < dev->n_targets) {
rc = nfc_genl_send_target(skb, &dev->targets[i], cb,
NLM_F_MULTI);
if (rc < 0)
break;
i++;
}
spin_unlock_bh(&dev->targets_lock);
cb->args[0] = i;
return skb->len;
}
static int nfc_genl_dump_targets_done(struct netlink_callback *cb)
{
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
nfc_dbg("entry");
if (dev)
nfc_put_device(dev);
return 0;
}
int nfc_genl_targets_found(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
nfc_dbg("entry");
dev->genl_data.poll_req_pid = 0;
msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_TARGETS_FOUND);
if (!hdr)
goto free_msg;
NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
genlmsg_end(msg, hdr);
return genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);
nla_put_failure:
genlmsg_cancel(msg, hdr);
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_device_added(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
nfc_dbg("entry");
msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_DEVICE_ADDED);
if (!hdr)
goto free_msg;
NLA_PUT_STRING(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev));
NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
NLA_PUT_U32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols);
genlmsg_end(msg, hdr);
genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_device_removed(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
nfc_dbg("entry");
msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_DEVICE_REMOVED);
if (!hdr)
goto free_msg;
NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
genlmsg_end(msg, hdr);
genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
static int nfc_genl_send_device(struct sk_buff *msg, struct nfc_dev *dev,
u32 pid, u32 seq,
struct netlink_callback *cb,
int flags)
{
void *hdr;
nfc_dbg("entry");
hdr = genlmsg_put(msg, pid, seq, &nfc_genl_family, flags,
NFC_CMD_GET_DEVICE);
if (!hdr)
return -EMSGSIZE;
if (cb)
genl_dump_check_consistent(cb, hdr, &nfc_genl_family);
NLA_PUT_STRING(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev));
NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
NLA_PUT_U32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols);
return genlmsg_end(msg, hdr);
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static int nfc_genl_dump_devices(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
bool first_call = false;
nfc_dbg("entry");
if (!iter) {
first_call = true;
iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
if (!iter)
return -ENOMEM;
cb->args[0] = (long) iter;
}
mutex_lock(&nfc_devlist_mutex);
cb->seq = nfc_devlist_generation;
if (first_call) {
nfc_device_iter_init(iter);
dev = nfc_device_iter_next(iter);
}
while (dev) {
int rc;
rc = nfc_genl_send_device(skb, dev, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
cb, NLM_F_MULTI);
if (rc < 0)
break;
dev = nfc_device_iter_next(iter);
}
mutex_unlock(&nfc_devlist_mutex);
cb->args[1] = (long) dev;
return skb->len;
}
static int nfc_genl_dump_devices_done(struct netlink_callback *cb)
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
nfc_dbg("entry");
nfc_device_iter_exit(iter);
kfree(iter);
return 0;
}
static int nfc_genl_get_device(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
struct nfc_dev *dev;
u32 idx;
int rc = -ENOBUFS;