diff options
Diffstat (limited to 'net/nfc')
| -rw-r--r-- | net/nfc/Kconfig | 1 | ||||
| -rw-r--r-- | net/nfc/digital.h | 58 | ||||
| -rw-r--r-- | net/nfc/digital_core.c | 145 | ||||
| -rw-r--r-- | net/nfc/digital_technology.c | 288 |
4 files changed, 488 insertions, 4 deletions
diff --git a/net/nfc/Kconfig b/net/nfc/Kconfig index 13e1237e1ea..4f4d2481325 100644 --- a/net/nfc/Kconfig +++ b/net/nfc/Kconfig @@ -16,6 +16,7 @@ menuconfig NFC config NFC_DIGITAL depends on NFC + select CRC_CCITT tristate "NFC Digital Protocol stack support" default n help diff --git a/net/nfc/digital.h b/net/nfc/digital.h index 0a2767098da..fb5324b792d 100644 --- a/net/nfc/digital.h +++ b/net/nfc/digital.h @@ -19,6 +19,8 @@ #include <net/nfc/nfc.h> #include <net/nfc/digital.h> +#include <linux/crc-ccitt.h> + #define PR_DBG(fmt, ...) pr_debug("%s: " fmt "\n", __func__, ##__VA_ARGS__) #define PR_ERR(fmt, ...) pr_err("%s: " fmt "\n", __func__, ##__VA_ARGS__) #define PROTOCOL_ERR(req) pr_err("%s:%d: NFC Digital Protocol error: %s\n", \ @@ -32,6 +34,16 @@ #define DIGITAL_MAX_HEADER_LEN 7 #define DIGITAL_CRC_LEN 2 +#define DIGITAL_DRV_CAPS_IN_CRC(ddev) \ + ((ddev)->driver_capabilities & NFC_DIGITAL_DRV_CAPS_IN_CRC) +#define DIGITAL_DRV_CAPS_TG_CRC(ddev) \ + ((ddev)->driver_capabilities & NFC_DIGITAL_DRV_CAPS_TG_CRC) + +struct digital_data_exch { + data_exchange_cb_t cb; + void *cb_context; +}; + struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev, unsigned int len); @@ -53,4 +65,50 @@ void digital_poll_next_tech(struct nfc_digital_dev *ddev); int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech); +int digital_target_found(struct nfc_digital_dev *ddev, + struct nfc_target *target, u8 protocol); + +int digital_in_recv_mifare_res(struct sk_buff *resp); + +typedef u16 (*crc_func_t)(u16, const u8 *, size_t); + +#define CRC_A_INIT 0x6363 +#define CRC_B_INIT 0xFFFF + +void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init, + u8 bitwise_inv, u8 msb_first); + +static inline void digital_skb_add_crc_a(struct sk_buff *skb) +{ + digital_skb_add_crc(skb, crc_ccitt, CRC_A_INIT, 0, 0); +} + +static inline void digital_skb_add_crc_b(struct sk_buff *skb) +{ + digital_skb_add_crc(skb, crc_ccitt, CRC_B_INIT, 1, 0); +} + +static inline void digital_skb_add_crc_none(struct sk_buff *skb) +{ + return; +} + +int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func, + u16 crc_init, u8 bitwise_inv, u8 msb_first); + +static inline int digital_skb_check_crc_a(struct sk_buff *skb) +{ + return digital_skb_check_crc(skb, crc_ccitt, CRC_A_INIT, 0, 0); +} + +static inline int digital_skb_check_crc_b(struct sk_buff *skb) +{ + return digital_skb_check_crc(skb, crc_ccitt, CRC_B_INIT, 1, 0); +} + +static inline int digital_skb_check_crc_none(struct sk_buff *skb) +{ + return 0; +} + #endif /* __DIGITAL_H */ diff --git a/net/nfc/digital_core.c b/net/nfc/digital_core.c index 13abd293ca3..4b3ceb45834 100644 --- a/net/nfc/digital_core.c +++ b/net/nfc/digital_core.c @@ -47,6 +47,51 @@ struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev, return skb; } +void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init, + u8 bitwise_inv, u8 msb_first) +{ + u16 crc; + + crc = crc_func(init, skb->data, skb->len); + + if (bitwise_inv) + crc = ~crc; + + if (msb_first) + crc = __fswab16(crc); + + *skb_put(skb, 1) = crc & 0xFF; + *skb_put(skb, 1) = (crc >> 8) & 0xFF; +} + +int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func, + u16 crc_init, u8 bitwise_inv, u8 msb_first) +{ + int rc; + u16 crc; + + if (skb->len <= 2) + return -EIO; + + crc = crc_func(crc_init, skb->data, skb->len - 2); + + if (bitwise_inv) + crc = ~crc; + + if (msb_first) + crc = __swab16(crc); + + rc = (skb->data[skb->len - 2] - (crc & 0xFF)) + + (skb->data[skb->len - 1] - ((crc >> 8) & 0xFF)); + + if (rc) + return -EIO; + + skb_trim(skb, skb->len - 2); + + return 0; +} + static inline void digital_switch_rf(struct nfc_digital_dev *ddev, bool on) { ddev->ops->switch_rf(ddev, on); @@ -183,6 +228,62 @@ int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param) return rc; } +int digital_target_found(struct nfc_digital_dev *ddev, + struct nfc_target *target, u8 protocol) +{ + int rc; + u8 framing; + u8 rf_tech; + int (*check_crc)(struct sk_buff *skb); + void (*add_crc)(struct sk_buff *skb); + + rf_tech = ddev->poll_techs[ddev->poll_tech_index].rf_tech; + + switch (protocol) { + case NFC_PROTO_JEWEL: + framing = NFC_DIGITAL_FRAMING_NFCA_T1T; + check_crc = digital_skb_check_crc_b; + add_crc = digital_skb_add_crc_b; + break; + + case NFC_PROTO_MIFARE: + framing = NFC_DIGITAL_FRAMING_NFCA_T2T; + check_crc = digital_skb_check_crc_a; + add_crc = digital_skb_add_crc_a; + break; + + default: + PR_ERR("Invalid protocol %d", protocol); + return -EINVAL; + } + + PR_DBG("rf_tech=%d, protocol=%d", rf_tech, protocol); + + ddev->curr_rf_tech = rf_tech; + ddev->curr_protocol = protocol; + + if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) { + ddev->skb_add_crc = digital_skb_add_crc_none; + ddev->skb_check_crc = digital_skb_check_crc_none; + } else { + ddev->skb_add_crc = add_crc; + ddev->skb_check_crc = check_crc; + } + + rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, framing); + if (rc) + return rc; + + target->supported_protocols = (1 << protocol); + rc = nfc_targets_found(ddev->nfc_dev, target, 1); + if (rc) + return rc; + + ddev->poll_tech_count = 0; + + return 0; +} + void digital_poll_next_tech(struct nfc_digital_dev *ddev) { digital_switch_rf(ddev, 0); @@ -363,11 +464,53 @@ static int digital_tg_send(struct nfc_dev *dev, struct sk_buff *skb) return -EOPNOTSUPP; } +static void digital_in_send_complete(struct nfc_digital_dev *ddev, void *arg, + struct sk_buff *resp) +{ + struct digital_data_exch *data_exch = arg; + int rc; + + if (IS_ERR(resp)) { + rc = PTR_ERR(resp); + goto done; + } + + if (ddev->curr_protocol == NFC_PROTO_MIFARE) + rc = digital_in_recv_mifare_res(resp); + else + rc = ddev->skb_check_crc(resp); + + if (rc) { + kfree_skb(resp); + resp = NULL; + } + +done: + data_exch->cb(data_exch->cb_context, resp, rc); + + kfree(data_exch); +} + static int digital_in_send(struct nfc_dev *nfc_dev, struct nfc_target *target, struct sk_buff *skb, data_exchange_cb_t cb, void *cb_context) { - return -EOPNOTSUPP; + struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev); + struct digital_data_exch *data_exch; + + data_exch = kzalloc(sizeof(struct digital_data_exch), GFP_KERNEL); + if (!data_exch) { + PR_ERR("Failed to allocate data_exch struct"); + return -ENOMEM; + } + + data_exch->cb = cb; + data_exch->cb_context = cb_context; + + ddev->skb_add_crc(skb); + + return digital_in_send_cmd(ddev, skb, 500, digital_in_send_complete, + data_exch); } static struct nfc_ops digital_nfc_ops = { diff --git a/net/nfc/digital_technology.c b/net/nfc/digital_technology.c index 084b0fba5f4..0cad38001c5 100644 --- a/net/nfc/digital_technology.c +++ b/net/nfc/digital_technology.c @@ -26,13 +26,269 @@ #define DIGITAL_SDD_RES_CT 0x88 #define DIGITAL_SDD_RES_LEN 5 +#define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04)) +#define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60)) + +#define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x000C) == 0x000C) +#define DIGITAL_SENS_RES_IS_VALID(sens_res) \ + ((!((sens_res) & 0x1F00) && (((sens_res) & 0x000C) == 0x000C)) || \ + (((sens_res) & 0x1F00) && ((sens_res) & 0x000C) != 0x000C)) + +#define DIGITAL_MIFARE_READ_RES_LEN 16 +#define DIGITAL_MIFARE_ACK_RES 0x0A + +struct digital_sdd_res { + u8 nfcid1[4]; + u8 bcc; +} __packed; + +struct digital_sel_req { + u8 sel_cmd; + u8 b2; + u8 nfcid1[4]; + u8 bcc; +} __packed; + +static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev, + struct nfc_target *target); + +static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg, + struct sk_buff *resp) +{ + struct nfc_target *target = arg; + int rc; + u8 sel_res; + u8 nfc_proto; + + if (IS_ERR(resp)) { + rc = PTR_ERR(resp); + resp = NULL; + goto exit; + } + + if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) { + rc = digital_skb_check_crc_a(resp); + if (rc) { + PROTOCOL_ERR("4.4.1.3"); + goto exit; + } + } + + if (!resp->len) { + rc = -EIO; + goto exit; + } + + sel_res = resp->data[0]; + + if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) { + rc = digital_in_send_sdd_req(ddev, target); + if (rc) + goto exit; + + goto exit_free_skb; + } + + if (DIGITAL_SEL_RES_IS_T2T(sel_res)) { + nfc_proto = NFC_PROTO_MIFARE; + } else { + rc = -EOPNOTSUPP; + goto exit; + } + + target->sel_res = sel_res; + + rc = digital_target_found(ddev, target, nfc_proto); + +exit: + kfree(target); + +exit_free_skb: + dev_kfree_skb(resp); + + if (rc) + digital_poll_next_tech(ddev); +} + +static int digital_in_send_sel_req(struct nfc_digital_dev *ddev, + struct nfc_target *target, + struct digital_sdd_res *sdd_res) +{ + struct sk_buff *skb; + struct digital_sel_req *sel_req; + u8 sel_cmd; + int rc; + + skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req)); + if (!skb) + return -ENOMEM; + + skb_put(skb, sizeof(struct digital_sel_req)); + sel_req = (struct digital_sel_req *)skb->data; + + if (target->nfcid1_len <= 4) + sel_cmd = DIGITAL_CMD_SEL_REQ_CL1; + else if (target->nfcid1_len < 10) + sel_cmd = DIGITAL_CMD_SEL_REQ_CL2; + else + sel_cmd = DIGITAL_CMD_SEL_REQ_CL3; + + sel_req->sel_cmd = sel_cmd; + sel_req->b2 = 0x70; + memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4); + sel_req->bcc = sdd_res->bcc; + + if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) { + rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, + NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A); + if (rc) + goto exit; + } else { + digital_skb_add_crc_a(skb); + } + + rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res, + target); +exit: + if (rc) + kfree_skb(skb); + + return rc; +} + +static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg, + struct sk_buff *resp) +{ + struct nfc_target *target = arg; + struct digital_sdd_res *sdd_res; + int rc; + u8 offset, size; + u8 i, bcc; + + if (IS_ERR(resp)) { + rc = PTR_ERR(resp); + resp = NULL; + goto exit; + } + + if (resp->len < DIGITAL_SDD_RES_LEN) { + PROTOCOL_ERR("4.7.2.8"); + rc = -EINVAL; + goto exit; + } + + sdd_res = (struct digital_sdd_res *)resp->data; + + for (i = 0, bcc = 0; i < 4; i++) + bcc ^= sdd_res->nfcid1[i]; + + if (bcc != sdd_res->bcc) { + PROTOCOL_ERR("4.7.2.6"); + rc = -EINVAL; + goto exit; + } + + if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) { + offset = 1; + size = 3; + } else { + offset = 0; + size = 4; + } + + memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset, + size); + target->nfcid1_len += size; + + rc = digital_in_send_sel_req(ddev, target, sdd_res); + +exit: + dev_kfree_skb(resp); + + if (rc) { + kfree(target); + digital_poll_next_tech(ddev); + } +} + +static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev, + struct nfc_target *target) +{ + int rc; + struct sk_buff *skb; + u8 sel_cmd; + + rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, + NFC_DIGITAL_FRAMING_NFCA_STANDARD); + if (rc) + return rc; + + skb = digital_skb_alloc(ddev, 2); + if (!skb) { + PR_ERR("alloc_skb failed"); + return -ENOMEM; + } + + if (target->nfcid1_len == 0) + sel_cmd = DIGITAL_CMD_SEL_REQ_CL1; + else if (target->nfcid1_len == 3) + sel_cmd = DIGITAL_CMD_SEL_REQ_CL2; + else + sel_cmd = DIGITAL_CMD_SEL_REQ_CL3; + + *skb_put(skb, sizeof(u8)) = sel_cmd; + *skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR; + + return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res, + target); +} + static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { - if (!IS_ERR(resp)) - dev_kfree_skb(resp); + struct nfc_target *target = NULL; + u16 sens_res; + int rc; + + if (IS_ERR(resp)) { + rc = PTR_ERR(resp); + resp = NULL; + goto exit; + } + + if (resp->len < sizeof(u16)) { + rc = -EIO; + goto exit; + } + + target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL); + if (!target) { + rc = -ENOMEM; + goto exit; + } + + memcpy(&target->sens_res, resp->data, sizeof(u16)); - digital_poll_next_tech(ddev); + sens_res = be16_to_cpu(target->sens_res); + + if (!DIGITAL_SENS_RES_IS_VALID(sens_res)) { + PROTOCOL_ERR("4.6.3.3"); + rc = -EINVAL; + goto exit; + } + + if (DIGITAL_SENS_RES_IS_T1T(sens_res)) + rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL); + else + rc = digital_in_send_sdd_req(ddev, target); + +exit: + dev_kfree_skb(resp); + + if (rc) { + kfree(target); + digital_poll_next_tech(ddev); + } } int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech) @@ -62,3 +318,29 @@ int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech) return rc; } + +int digital_in_recv_mifare_res(struct sk_buff *resp) +{ + /* Successful READ command response is 16 data bytes + 2 CRC bytes long. + * Since the driver can't differentiate a ACK/NACK response from a valid + * READ response, the CRC calculation must be handled at digital level + * even if the driver supports it for this technology. + */ + if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) { + if (digital_skb_check_crc_a(resp)) { + PROTOCOL_ERR("9.4.1.2"); + return -EIO; + } + + return 0; + } + + /* ACK response (i.e. successful WRITE). */ + if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) { + resp->data[0] = 0; + return 0; + } + + /* NACK and any other responses are treated as error. */ + return -EIO; +} |