linux/include/net/nfc/nfc.h
Gustavo A. R. Silva da60fbe7ef NFC: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27 12:06:20 -08:00

353 lines
9.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2011 Instituto Nokia de Tecnologia
* Copyright (C) 2014 Marvell International Ltd.
*
* Authors:
* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
*/
#ifndef __NET_NFC_H
#define __NET_NFC_H
#include <linux/nfc.h>
#include <linux/device.h>
#include <linux/skbuff.h>
#define nfc_dbg(dev, fmt, ...) dev_dbg((dev), "NFC: " fmt, ##__VA_ARGS__)
#define nfc_info(dev, fmt, ...) dev_info((dev), "NFC: " fmt, ##__VA_ARGS__)
#define nfc_err(dev, fmt, ...) dev_err((dev), "NFC: " fmt, ##__VA_ARGS__)
struct nfc_phy_ops {
int (*write)(void *dev_id, struct sk_buff *skb);
int (*enable)(void *dev_id);
void (*disable)(void *dev_id);
};
struct nfc_dev;
/**
* data_exchange_cb_t - Definition of nfc_data_exchange callback
*
* @context: nfc_data_exchange cb_context parameter
* @skb: response data
* @err: If an error has occurred during data exchange, it is the
* error number. Zero means no error.
*
* When a rx or tx package is lost or corrupted or the target gets out
* of the operating field, err is -EIO.
*/
typedef void (*data_exchange_cb_t)(void *context, struct sk_buff *skb,
int err);
typedef void (*se_io_cb_t)(void *context, u8 *apdu, size_t apdu_len, int err);
struct nfc_target;
struct nfc_ops {
int (*dev_up)(struct nfc_dev *dev);
int (*dev_down)(struct nfc_dev *dev);
int (*start_poll)(struct nfc_dev *dev,
u32 im_protocols, u32 tm_protocols);
void (*stop_poll)(struct nfc_dev *dev);
int (*dep_link_up)(struct nfc_dev *dev, struct nfc_target *target,
u8 comm_mode, u8 *gb, size_t gb_len);
int (*dep_link_down)(struct nfc_dev *dev);
int (*activate_target)(struct nfc_dev *dev, struct nfc_target *target,
u32 protocol);
void (*deactivate_target)(struct nfc_dev *dev,
struct nfc_target *target, u8 mode);
int (*im_transceive)(struct nfc_dev *dev, struct nfc_target *target,
struct sk_buff *skb, data_exchange_cb_t cb,
void *cb_context);
int (*tm_send)(struct nfc_dev *dev, struct sk_buff *skb);
int (*check_presence)(struct nfc_dev *dev, struct nfc_target *target);
int (*fw_download)(struct nfc_dev *dev, const char *firmware_name);
/* Secure Element API */
int (*discover_se)(struct nfc_dev *dev);
int (*enable_se)(struct nfc_dev *dev, u32 se_idx);
int (*disable_se)(struct nfc_dev *dev, u32 se_idx);
int (*se_io) (struct nfc_dev *dev, u32 se_idx,
u8 *apdu, size_t apdu_length,
se_io_cb_t cb, void *cb_context);
};
#define NFC_TARGET_IDX_ANY -1
#define NFC_MAX_GT_LEN 48
#define NFC_ATR_RES_GT_OFFSET 15
#define NFC_ATR_REQ_GT_OFFSET 14
/**
* struct nfc_target - NFC target descriptiom
*
* @sens_res: 2 bytes describing the target SENS_RES response, if the target
* is a type A one. The %sens_res most significant byte must be byte 2
* as described by the NFC Forum digital specification (i.e. the platform
* configuration one) while %sens_res least significant byte is byte 1.
*/
struct nfc_target {
u32 idx;
u32 supported_protocols;
u16 sens_res;
u8 sel_res;
u8 nfcid1_len;
u8 nfcid1[NFC_NFCID1_MAXSIZE];
u8 nfcid2_len;
u8 nfcid2[NFC_NFCID2_MAXSIZE];
u8 sensb_res_len;
u8 sensb_res[NFC_SENSB_RES_MAXSIZE];
u8 sensf_res_len;
u8 sensf_res[NFC_SENSF_RES_MAXSIZE];
u8 hci_reader_gate;
u8 logical_idx;
u8 is_iso15693;
u8 iso15693_dsfid;
u8 iso15693_uid[NFC_ISO15693_UID_MAXSIZE];
};
/**
* nfc_se - A structure for NFC accessible secure elements.
*
* @idx: The secure element index. User space will enable or
* disable a secure element by its index.
* @type: The secure element type. It can be SE_UICC or
* SE_EMBEDDED.
* @state: The secure element state, either enabled or disabled.
*
*/
struct nfc_se {
struct list_head list;
u32 idx;
u16 type;
u16 state;
};
/**
* nfc_evt_transaction - A struct for NFC secure element event transaction.
*
* @aid: The application identifier triggering the event
*
* @aid_len: The application identifier length [5:16]
*
* @params: The application parameters transmitted during the transaction
*
* @params_len: The applications parameters length [0:255]
*
*/
#define NFC_MIN_AID_LENGTH 5
#define NFC_MAX_AID_LENGTH 16
#define NFC_MAX_PARAMS_LENGTH 255
#define NFC_EVT_TRANSACTION_AID_TAG 0x81
#define NFC_EVT_TRANSACTION_PARAMS_TAG 0x82
struct nfc_evt_transaction {
u32 aid_len;
u8 aid[NFC_MAX_AID_LENGTH];
u8 params_len;
u8 params[];
} __packed;
struct nfc_genl_data {
u32 poll_req_portid;
struct mutex genl_data_mutex;
};
struct nfc_vendor_cmd {
__u32 vendor_id;
__u32 subcmd;
int (*doit)(struct nfc_dev *dev, void *data, size_t data_len);
};
struct nfc_dev {
int idx;
u32 target_next_idx;
struct nfc_target *targets;
int n_targets;
int targets_generation;
struct device dev;
bool dev_up;
bool fw_download_in_progress;
u8 rf_mode;
bool polling;
struct nfc_target *active_target;
bool dep_link_up;
struct nfc_genl_data genl_data;
u32 supported_protocols;
struct list_head secure_elements;
int tx_headroom;
int tx_tailroom;
struct timer_list check_pres_timer;
struct work_struct check_pres_work;
bool shutting_down;
struct rfkill *rfkill;
struct nfc_vendor_cmd *vendor_cmds;
int n_vendor_cmds;
struct nfc_ops *ops;
struct genl_info *cur_cmd_info;
};
#define to_nfc_dev(_dev) container_of(_dev, struct nfc_dev, dev)
extern struct class nfc_class;
struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
u32 supported_protocols,
int tx_headroom,
int tx_tailroom);
/**
* nfc_free_device - free nfc device
*
* @dev: The nfc device to free
*/
static inline void nfc_free_device(struct nfc_dev *dev)
{
put_device(&dev->dev);
}
int nfc_register_device(struct nfc_dev *dev);
void nfc_unregister_device(struct nfc_dev *dev);
/**
* nfc_set_parent_dev - set the parent device
*
* @nfc_dev: The nfc device whose parent is being set
* @dev: The parent device
*/
static inline void nfc_set_parent_dev(struct nfc_dev *nfc_dev,
struct device *dev)
{
nfc_dev->dev.parent = dev;
}
/**
* nfc_set_drvdata - set driver specifc data
*
* @dev: The nfc device
* @data: Pointer to driver specifc data
*/
static inline void nfc_set_drvdata(struct nfc_dev *dev, void *data)
{
dev_set_drvdata(&dev->dev, data);
}
/**
* nfc_get_drvdata - get driver specifc data
*
* @dev: The nfc device
*/
static inline void *nfc_get_drvdata(struct nfc_dev *dev)
{
return dev_get_drvdata(&dev->dev);
}
/**
* nfc_device_name - get the nfc device name
*
* @dev: The nfc device whose name to return
*/
static inline const char *nfc_device_name(struct nfc_dev *dev)
{
return dev_name(&dev->dev);
}
struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
unsigned int flags, unsigned int size,
unsigned int *err);
struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp);
int nfc_set_remote_general_bytes(struct nfc_dev *dev,
u8 *gt, u8 gt_len);
u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len);
int nfc_fw_download_done(struct nfc_dev *dev, const char *firmware_name,
u32 result);
int nfc_targets_found(struct nfc_dev *dev,
struct nfc_target *targets, int ntargets);
int nfc_target_lost(struct nfc_dev *dev, u32 target_idx);
int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode);
int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
u8 *gb, size_t gb_len);
int nfc_tm_deactivated(struct nfc_dev *dev);
int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb);
void nfc_driver_failure(struct nfc_dev *dev, int err);
int nfc_se_transaction(struct nfc_dev *dev, u8 se_idx,
struct nfc_evt_transaction *evt_transaction);
int nfc_se_connectivity(struct nfc_dev *dev, u8 se_idx);
int nfc_add_se(struct nfc_dev *dev, u32 se_idx, u16 type);
int nfc_remove_se(struct nfc_dev *dev, u32 se_idx);
struct nfc_se *nfc_find_se(struct nfc_dev *dev, u32 se_idx);
void nfc_send_to_raw_sock(struct nfc_dev *dev, struct sk_buff *skb,
u8 payload_type, u8 direction);
static inline int nfc_set_vendor_cmds(struct nfc_dev *dev,
struct nfc_vendor_cmd *cmds,
int n_cmds)
{
if (dev->vendor_cmds || dev->n_vendor_cmds)
return -EINVAL;
dev->vendor_cmds = cmds;
dev->n_vendor_cmds = n_cmds;
return 0;
}
struct sk_buff *__nfc_alloc_vendor_cmd_reply_skb(struct nfc_dev *dev,
enum nfc_attrs attr,
u32 oui, u32 subcmd,
int approxlen);
int nfc_vendor_cmd_reply(struct sk_buff *skb);
/**
* nfc_vendor_cmd_alloc_reply_skb - allocate vendor command reply
* @dev: nfc device
* @oui: vendor oui
* @approxlen: an upper bound of the length of the data that will
* be put into the skb
*
* This function allocates and pre-fills an skb for a reply to
* a vendor command. Since it is intended for a reply, calling
* it outside of a vendor command's doit() operation is invalid.
*
* The returned skb is pre-filled with some identifying data in
* a way that any data that is put into the skb (with skb_put(),
* nla_put() or similar) will end up being within the
* %NFC_ATTR_VENDOR_DATA attribute, so all that needs to be done
* with the skb is adding data for the corresponding userspace tool
* which can then read that data out of the vendor data attribute.
* You must not modify the skb in any other way.
*
* When done, call nfc_vendor_cmd_reply() with the skb and return
* its error code as the result of the doit() operation.
*
* Return: An allocated and pre-filled skb. %NULL if any errors happen.
*/
static inline struct sk_buff *
nfc_vendor_cmd_alloc_reply_skb(struct nfc_dev *dev,
u32 oui, u32 subcmd, int approxlen)
{
return __nfc_alloc_vendor_cmd_reply_skb(dev,
NFC_ATTR_VENDOR_DATA,
oui,
subcmd, approxlen);
}
#endif /* __NET_NFC_H */