From 4d12b8b129f170d0fc3188de1e51a2a1b0f87730 Mon Sep 17 00:00:00 2001 From: Lauro Ramos Venancio Date: Fri, 1 Jul 2011 19:31:34 -0300 Subject: NFC: add nfc generic netlink interface The NFC generic netlink interface exports the NFC control operations to the user space. Signed-off-by: Lauro Ramos Venancio Signed-off-by: Aloisio Almeida Jr Signed-off-by: Samuel Ortiz Reviewed-by: Johannes Berg Signed-off-by: John W. Linville --- net/nfc/Makefile | 2 +- net/nfc/core.c | 93 +++++++++- net/nfc/netlink.c | 537 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ net/nfc/nfc.h | 11 ++ 4 files changed, 640 insertions(+), 3 deletions(-) create mode 100644 net/nfc/netlink.c (limited to 'net/nfc') diff --git a/net/nfc/Makefile b/net/nfc/Makefile index 28bee5958687..fa6fc16246d6 100644 --- a/net/nfc/Makefile +++ b/net/nfc/Makefile @@ -4,4 +4,4 @@ obj-$(CONFIG_NFC) += nfc.o -nfc-objs := core.o +nfc-objs := core.o netlink.o diff --git a/net/nfc/core.c b/net/nfc/core.c index 19f8035a1ba9..c70f607455c5 100644 --- a/net/nfc/core.c +++ b/net/nfc/core.c @@ -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); } diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c new file mode 100644 index 000000000000..ccdff7953f7d --- /dev/null +++ b/net/nfc/netlink.c @@ -0,0 +1,537 @@ +/* + * Copyright (C) 2011 Instituto Nokia de Tecnologia + * + * Authors: + * Lauro Ramos Venancio + * Aloisio Almeida Jr + * + * 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 +#include +#include + +#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; + + nfc_dbg("entry"); + + if (!info->attrs[NFC_ATTR_DEVICE_INDEX]) + return -EINVAL; + + idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]); + + dev = nfc_get_device(idx); + if (!dev) + return -ENODEV; + + msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + if (!msg) { + rc = -ENOMEM; + goto out_putdev; + } + + rc = nfc_genl_send_device(msg, dev, info->snd_pid, info->snd_seq, + NULL, 0); + if (rc < 0) + goto out_free; + + nfc_put_device(dev); + + return genlmsg_reply(msg, info); + +out_free: + nlmsg_free(msg); +out_putdev: + nfc_put_device(dev); + return rc; +} + +static int nfc_genl_start_poll(struct sk_buff *skb, struct genl_info *info) +{ + struct nfc_dev *dev; + int rc; + u32 idx; + u32 protocols; + + nfc_dbg("entry"); + + if (!info->attrs[NFC_ATTR_DEVICE_INDEX] || + !info->attrs[NFC_ATTR_PROTOCOLS]) + return -EINVAL; + + idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]); + protocols = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]); + + dev = nfc_get_device(idx); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->genl_data.genl_data_mutex); + + rc = nfc_start_poll(dev, protocols); + if (!rc) + dev->genl_data.poll_req_pid = info->snd_pid; + + mutex_unlock(&dev->genl_data.genl_data_mutex); + + nfc_put_device(dev); + return rc; +} + +static int nfc_genl_stop_poll(struct sk_buff *skb, struct genl_info *info) +{ + struct nfc_dev *dev; + int rc; + u32 idx; + + nfc_dbg("entry"); + + if (!info->attrs[NFC_ATTR_DEVICE_INDEX]) + return -EINVAL; + + idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]); + + dev = nfc_get_device(idx); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->genl_data.genl_data_mutex); + + if (dev->genl_data.poll_req_pid != info->snd_pid) { + rc = -EBUSY; + goto out; + } + + rc = nfc_stop_poll(dev); + dev->genl_data.poll_req_pid = 0; + +out: + mutex_unlock(&dev->genl_data.genl_data_mutex); + nfc_put_device(dev); + return rc; +} + +static struct genl_ops nfc_genl_ops[] = { + { + .cmd = NFC_CMD_GET_DEVICE, + .doit = nfc_genl_get_device, + .dumpit = nfc_genl_dump_devices, + .done = nfc_genl_dump_devices_done, + .policy = nfc_genl_policy, + }, + { + .cmd = NFC_CMD_START_POLL, + .doit = nfc_genl_start_poll, + .policy = nfc_genl_policy, + }, + { + .cmd = NFC_CMD_STOP_POLL, + .doit = nfc_genl_stop_poll, + .policy = nfc_genl_policy, + }, + { + .cmd = NFC_CMD_GET_TARGET, + .dumpit = nfc_genl_dump_targets, + .done = nfc_genl_dump_targets_done, + .policy = nfc_genl_policy, + }, +}; + +static int nfc_genl_rcv_nl_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct netlink_notify *n = ptr; + struct class_dev_iter iter; + struct nfc_dev *dev; + + if (event != NETLINK_URELEASE || n->protocol != NETLINK_GENERIC) + goto out; + + nfc_dbg("NETLINK_URELEASE event from id %d", n->pid); + + nfc_device_iter_init(&iter); + dev = nfc_device_iter_next(&iter); + + while (dev) { + mutex_lock(&dev->genl_data.genl_data_mutex); + if (dev->genl_data.poll_req_pid == n->pid) { + nfc_stop_poll(dev); + dev->genl_data.poll_req_pid = 0; + } + mutex_unlock(&dev->genl_data.genl_data_mutex); + dev = nfc_device_iter_next(&iter); + } + + nfc_device_iter_exit(&iter); + +out: + return NOTIFY_DONE; +} + +void nfc_genl_data_init(struct nfc_genl_data *genl_data) +{ + genl_data->poll_req_pid = 0; + mutex_init(&genl_data->genl_data_mutex); +} + +void nfc_genl_data_exit(struct nfc_genl_data *genl_data) +{ + mutex_destroy(&genl_data->genl_data_mutex); +} + +static struct notifier_block nl_notifier = { + .notifier_call = nfc_genl_rcv_nl_event, +}; + +/** + * nfc_genl_init() - Initialize netlink interface + * + * This initialization function registers the nfc netlink family. + */ +int __init nfc_genl_init(void) +{ + int rc; + + rc = genl_register_family_with_ops(&nfc_genl_family, nfc_genl_ops, + ARRAY_SIZE(nfc_genl_ops)); + if (rc) + return rc; + + rc = genl_register_mc_group(&nfc_genl_family, &nfc_genl_event_mcgrp); + + netlink_register_notifier(&nl_notifier); + + return rc; +} + +/** + * nfc_genl_exit() - Deinitialize netlink interface + * + * This exit function unregisters the nfc netlink family. + */ +void nfc_genl_exit(void) +{ + netlink_unregister_notifier(&nl_notifier); + genl_unregister_family(&nfc_genl_family); +} diff --git a/net/nfc/nfc.h b/net/nfc/nfc.h index 55f83f86fe2c..2b31e808e6fb 100644 --- a/net/nfc/nfc.h +++ b/net/nfc/nfc.h @@ -36,6 +36,17 @@ int nfc_printk(const char *level, const char *fmt, ...); extern int nfc_devlist_generation; extern struct mutex nfc_devlist_mutex; +int __init nfc_genl_init(void); +void nfc_genl_exit(void); + +void nfc_genl_data_init(struct nfc_genl_data *genl_data); +void nfc_genl_data_exit(struct nfc_genl_data *genl_data); + +int nfc_genl_targets_found(struct nfc_dev *dev); + +int nfc_genl_device_added(struct nfc_dev *dev); +int nfc_genl_device_removed(struct nfc_dev *dev); + struct nfc_dev *nfc_get_device(unsigned idx); static inline void nfc_put_device(struct nfc_dev *dev) -- cgit v1.2.3-59-g8ed1b