// SPDX-License-Identifier: GPL-2.0-only /* * NFC Digital Protocol stack * Copyright (c) 2013, Intel Corporation. */ #define pr_fmt(fmt) "digital: %s: " fmt, __func__ #include "digital.h" #define DIGITAL_NFC_DEP_N_RETRY_NACK 2 #define DIGITAL_NFC_DEP_N_RETRY_ATN 2 #define DIGITAL_NFC_DEP_FRAME_DIR_OUT 0xD4 #define DIGITAL_NFC_DEP_FRAME_DIR_IN 0xD5 #define DIGITAL_NFC_DEP_NFCA_SOD_SB 0xF0 #define DIGITAL_CMD_ATR_REQ 0x00 #define DIGITAL_CMD_ATR_RES 0x01 #define DIGITAL_CMD_PSL_REQ 0x04 #define DIGITAL_CMD_PSL_RES 0x05 #define DIGITAL_CMD_DEP_REQ 0x06 #define DIGITAL_CMD_DEP_RES 0x07 #define DIGITAL_ATR_REQ_MIN_SIZE 16 #define DIGITAL_ATR_REQ_MAX_SIZE 64 #define DIGITAL_ATR_RES_TO_WT(s) ((s) & 0xF) #define DIGITAL_DID_MAX 14 #define DIGITAL_PAYLOAD_SIZE_MAX 254 #define DIGITAL_PAYLOAD_BITS_TO_PP(s) (((s) & 0x3) << 4) #define DIGITAL_PAYLOAD_PP_TO_BITS(s) (((s) >> 4) & 0x3) #define DIGITAL_PAYLOAD_BITS_TO_FSL(s) ((s) & 0x3) #define DIGITAL_PAYLOAD_FSL_TO_BITS(s) ((s) & 0x3) #define DIGITAL_GB_BIT 0x02 #define DIGITAL_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0) #define DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT 0x10 #define DIGITAL_NFC_DEP_PFB_MI_BIT 0x10 #define DIGITAL_NFC_DEP_PFB_NACK_BIT 0x10 #define DIGITAL_NFC_DEP_PFB_DID_BIT 0x04 #define DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb) \ ((pfb) & DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT) #define DIGITAL_NFC_DEP_MI_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_MI_BIT) #define DIGITAL_NFC_DEP_NACK_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_NACK_BIT) #define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08) #define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_DID_BIT) #define DIGITAL_NFC_DEP_PFB_PNI(pfb) ((pfb) & 0x03) #define DIGITAL_NFC_DEP_RTOX_VALUE(data) ((data) & 0x3F) #define DIGITAL_NFC_DEP_RTOX_MAX 59 #define DIGITAL_NFC_DEP_PFB_I_PDU 0x00 #define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU 0x40 #define DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU 0x80 struct digital_atr_req { u8 dir; u8 cmd; u8 nfcid3[10]; u8 did; u8 bs; u8 br; u8 pp; u8 gb[]; } __packed; struct digital_atr_res { u8 dir; u8 cmd; u8 nfcid3[10]; u8 did; u8 bs; u8 br; u8 to; u8 pp; u8 gb[]; } __packed; struct digital_psl_req { u8 dir; u8 cmd; u8 did; u8 brs; u8 fsl; } __packed; struct digital_psl_res { u8 dir; u8 cmd; u8 did; } __packed; struct digital_dep_req_res { u8 dir; u8 cmd; u8 pfb; } __packed; static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp); static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp); static const u8 digital_payload_bits_map[4] = { [0] = 64, [1] = 128, [2] = 192, [3] = 254 }; /* Response Waiting Time for ATR_RES PDU in ms * * RWT(ATR_RES) = RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator) * * with: * RWT(nfcdep,activation) = 4096 * 2^12 / f(c) s * dRWT(nfcdep) = 16 / f(c) s * dT(nfcdep,initiator) = 100 ms * f(c) = 13560000 Hz */ #define DIGITAL_ATR_RES_RWT 1337 /* Response Waiting Time for other DEP PDUs in ms * * max_rwt = rwt + dRWT(nfcdep) + dT(nfcdep,initiator) * * with: * rwt = (256 * 16 / f(c)) * 2^wt s * dRWT(nfcdep) = 16 / f(c) s * dT(nfcdep,initiator) = 100 ms * f(c) = 13560000 Hz * 0 <= wt <= 14 (given by the target by the TO field of ATR_RES response) */ #define DIGITAL_NFC_DEP_IN_MAX_WT 14 #define DIGITAL_NFC_DEP_TG_MAX_WT 14 static const u16 digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT + 1] = { 100, 101, 101, 102, 105, 110, 119, 139, 177, 255, 409, 719, 1337, 2575, 5049, }; static u8 digital_payload_bits_to_size(u8 payload_bits) { if (payload_bits >= ARRAY_SIZE(digital_payload_bits_map)) return 0; return digital_payload_bits_map[payload_bits]; } static u8 digital_payload_size_to_bits(u8 payload_size) { int i; for (i = 0; i < ARRAY_SIZE(digital_payload_bits_map); i++) if (digital_payload_bits_map[i] == payload_size) return i; return 0xff; } static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev, struct sk_buff *skb) { skb_push(skb, sizeof(u8)); skb->data[0] = skb->len; if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A) *(u8 *)skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB; } static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev, struct sk_buff *skb) { u8 size; if (skb->len < 2) return -EIO; if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A) skb_pull(skb, sizeof(u8)); size = skb->data[0]; if (size != skb->len) return -EIO; skb_pull(skb, sizeof(u8)); return 0; } static struct sk_buff * digital_send_dep_data_prep(struct nfc_digital_dev *ddev, struct sk_buff *skb, struct digital_dep_req_res *dep_req_res, struct digital_data_exch *data_exch) { struct sk_buff *new_skb; if (skb->len > ddev->remote_payload_max) { dep_req_res->pfb |= DIGITAL_NFC_DEP_PFB_MI_BIT; new_skb = digital_skb_alloc(ddev, ddev->remote_payload_max); if (!new_skb) { kfree_skb(ddev->chaining_skb); ddev->chaining_skb = NULL; return ERR_PTR(-ENOMEM); } skb_put_data(new_skb, skb->data, ddev->remote_payload_max); skb_pull(skb, ddev->remote_payload_max); ddev->chaining_skb = skb; ddev->data_exch = data_exch; } else { ddev->chaining_skb = NULL; new_skb = skb; } return new_skb; } static struct sk_buff * digital_recv_dep_data_gather(struct nfc_digital_dev *ddev, u8 pfb, struct sk_buff *resp, int (*send_ack)(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch), struct digital_data_exch *data_exch) { struct sk_buff *new_skb; int rc; if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb) && (!ddev->chaining_skb)) { ddev->chaining_skb = nfc_alloc_recv_skb(8 * ddev->local_payload_max, GFP_KERNEL); if (!ddev->chaining_skb) { rc = -ENOMEM; goto error; } } if (ddev->chaining_skb) { if (resp->len > skb_tailroom(ddev->chaining_skb)) { new_skb = skb_copy_expand(ddev->chaining_skb, skb_headroom( ddev->chaining_skb), 8 * ddev->local_payload_max, GFP_KERNEL); if (!new_skb) { rc = -ENOMEM; goto error; } kfree_skb(ddev->chaining_skb); ddev->chaining_skb = new_skb; } skb_put_data(ddev->chaining_skb, resp->data, resp->len); kfree_skb(resp); resp = NULL; if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb)) { rc = send_ack(ddev, data_exch); if (rc) goto error; return NULL; } resp = ddev->chaining_skb; ddev->chaining_skb = NULL; } return resp; error: kfree_skb(resp); kfree_skb(ddev->chaining_skb); ddev->chaining_skb = NULL; return ERR_PTR(rc); } static void digital_in_recv_psl_res(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { struct nfc_target *target = arg; struct digital_psl_res *psl_res; int rc; if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto exit; } rc = ddev->skb_check_crc(resp); if (rc) { PROTOCOL_ERR("14.4.1.6"); goto exit; } rc = digital_skb_pull_dep_sod(ddev, resp); if (rc) { PROTOCOL_ERR("14.4.1.2"); goto exit; } psl_res = (struct digital_psl_res *)resp->data; if ((resp->len != sizeof(*psl_res)) || (psl_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN) || (psl_res->cmd != DIGITAL_CMD_PSL_RES)) { rc = -EIO; goto exit; } rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, NFC_DIGITAL_RF_TECH_424F); if (rc) goto exit; rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, NFC_DIGITAL_FRAMING_NFCF_NFC_DEP); if (rc) goto exit; if (!DIGITAL_DRV_CAPS_IN_CRC(ddev) && (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)) { ddev->skb_add_crc = digital_skb_add_crc_f; ddev->skb_check_crc = digital_skb_check_crc_f; } ddev->curr_rf_tech = NFC_DIGITAL_RF_TECH_424F; nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE, NFC_RF_INITIATOR); ddev->curr_nfc_dep_pni = 0; exit: dev_kfree_skb(resp); if (rc) ddev->curr_protocol = 0; } static int digital_in_send_psl_req(struct nfc_digital_dev *ddev, struct nfc_target *target) { struct sk_buff *skb; struct digital_psl_req *psl_req; int rc; u8 payload_size, payload_bits; skb = digital_skb_alloc(ddev, sizeof(*psl_req)); if (!skb) return -ENOMEM; skb_put(skb, sizeof(*psl_req)); psl_req = (struct digital_psl_req *)skb->data; psl_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; psl_req->cmd = DIGITAL_CMD_PSL_REQ; psl_req->did = 0; psl_req->brs = (0x2 << 3) | 0x2; /* 424F both directions */ payload_size = min(ddev->local_payload_max, ddev->remote_payload_max); payload_bits = digital_payload_size_to_bits(payload_size); psl_req->fsl = DIGITAL_PAYLOAD_BITS_TO_FSL(payload_bits); ddev->local_payload_max = payload_size; ddev->remote_payload_max = payload_size; digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt, digital_in_recv_psl_res, target); if (rc) kfree_skb(skb); return rc; } static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { struct nfc_target *target = arg; struct digital_atr_res *atr_res; u8 gb_len, payload_bits; u8 wt; int rc; if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto exit; } rc = ddev->skb_check_crc(resp); if (rc) { PROTOCOL_ERR("14.4.1.6"); goto exit; } rc = digital_skb_pull_dep_sod(ddev, resp); if (rc) { PROTOCOL_ERR("14.4.1.2"); goto exit; } if (resp->len < sizeof(struct digital_atr_res)) { rc = -EIO; goto exit; } gb_len = resp->len - sizeof(struct digital_atr_res); atr_res = (struct digital_atr_res *)resp->data; wt = DIGITAL_ATR_RES_TO_WT(atr_res->to); if (wt > DIGITAL_NFC_DEP_IN_MAX_WT) wt = DIGITAL_NFC_DEP_IN_MAX_WT; ddev->dep_rwt = digital_rwt_map[wt]; payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_res->pp); ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits); if (!ddev->remote_payload_max) { rc = -EINVAL; goto exit; } rc = nfc_set_remote_general_bytes(ddev->nfc_dev, atr_res->gb, gb_len); if (rc) goto exit; if ((ddev->protocols & NFC_PROTO_FELICA_MASK) && (ddev->curr_rf_tech != NFC_DIGITAL_RF_TECH_424F)) { rc = digital_in_send_psl_req(ddev, target); if (!rc) goto exit; } rc = nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE, NFC_RF_INITIATOR); ddev->curr_nfc_dep_pni = 0; exit: dev_kfree_skb(resp); if (rc) ddev->curr_protocol = 0; } int digital_in_send_atr_req(struct nfc_digital_dev *ddev, struct nfc_target *target, __u8 comm_mode, __u8 *gb, size_t gb_len) { struct sk_buff *skb; struct digital_atr_req *atr_req; uint size; int rc; u8 payload_bits; size = DIGITAL_ATR_REQ_MIN_SIZE + gb_len; if (size > DIGITAL_ATR_REQ_MAX_SIZE) { PROTOCOL_ERR("14.6.1.1"); return -EINVAL; } skb = digital_skb_alloc(ddev, size); if (!skb) return -ENOMEM; skb_put(skb, sizeof(struct digital_atr_req)); atr_req = (struct digital_atr_req *)skb->data; memset(atr_req, 0, sizeof(struct digital_atr_req)); atr_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; atr_req->cmd = DIGITAL_CMD_ATR_REQ; if (target->nfcid2_len) memcpy(atr_req->nfcid3, target->nfcid2, NFC_NFCID2_MAXSIZE); else get_random_bytes(atr_req->nfcid3, NFC_NFCID3_MAXSIZE); atr_req->did = 0; atr_req->bs = 0; atr_req->br = 0; ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX; payload_bits = digital_payload_size_to_bits(ddev->local_payload_max); atr_req->pp = DIGITAL_PAYLOAD_BITS_TO_PP(payload_bits); if (gb_len) { atr_req->pp |= DIGITAL_GB_BIT; skb_put_data(skb, gb, gb_len); } digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); rc = digital_in_send_cmd(ddev, skb, DIGITAL_ATR_RES_RWT, digital_in_recv_atr_res, target); if (rc) kfree_skb(skb); return rc; } static int digital_in_send_ack(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch) { struct digital_dep_req_res *dep_req; struct sk_buff *skb; int rc; skb = digital_skb_alloc(ddev, 1); if (!skb) return -ENOMEM; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_req = (struct digital_dep_req_res *)skb->data; dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; dep_req->cmd = DIGITAL_CMD_DEP_REQ; dep_req->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU | ddev->curr_nfc_dep_pni; digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); ddev->saved_skb = pskb_copy(skb, GFP_KERNEL); rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt, digital_in_recv_dep_res, data_exch); if (rc) { kfree_skb(skb); kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; } return rc; } static int digital_in_send_nack(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch) { struct digital_dep_req_res *dep_req; struct sk_buff *skb; int rc; skb = digital_skb_alloc(ddev, 1); if (!skb) return -ENOMEM; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_req = (struct digital_dep_req_res *)skb->data; dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; dep_req->cmd = DIGITAL_CMD_DEP_REQ; dep_req->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU | DIGITAL_NFC_DEP_PFB_NACK_BIT | ddev->curr_nfc_dep_pni; digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt, digital_in_recv_dep_res, data_exch); if (rc) kfree_skb(skb); return rc; } static int digital_in_send_atn(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch) { struct digital_dep_req_res *dep_req; struct sk_buff *skb; int rc; skb = digital_skb_alloc(ddev, 1); if (!skb) return -ENOMEM; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_req = (struct digital_dep_req_res *)skb->data; dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; dep_req->cmd = DIGITAL_CMD_DEP_REQ; dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU; digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt, digital_in_recv_dep_res, data_exch); if (rc) kfree_skb(skb); return rc; } static int digital_in_send_rtox(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch, u8 rtox) { struct digital_dep_req_res *dep_req; struct sk_buff *skb; int rc; u16 rwt_int; rwt_int = ddev->dep_rwt * rtox; if (rwt_int > digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT]) rwt_int = digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT]; skb = digital_skb_alloc(ddev, 1); if (!skb) return -ENOMEM; skb_put_u8(skb, rtox); skb_push(skb, sizeof(struct digital_dep_req_res)); dep_req = (struct digital_dep_req_res *)skb->data; dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; dep_req->cmd = DIGITAL_CMD_DEP_REQ; dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU | DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT; digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); rc = digital_in_send_cmd(ddev, skb, rwt_int, digital_in_recv_dep_res, data_exch); if (rc) kfree_skb(skb); return rc; } static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch) { int rc; if (!ddev->saved_skb) return -EINVAL; skb_get(ddev->saved_skb); rc = digital_in_send_cmd(ddev, ddev->saved_skb, ddev->dep_rwt, digital_in_recv_dep_res, data_exch); if (rc) kfree_skb(ddev->saved_skb); return rc; } static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { struct digital_data_exch *data_exch = arg; struct digital_dep_req_res *dep_res; u8 pfb; uint size; int rc; u8 rtox; if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; if ((rc == -EIO || (rc == -ETIMEDOUT && ddev->nack_count)) && (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) { ddev->atn_count = 0; rc = digital_in_send_nack(ddev, data_exch); if (rc) goto error; return; } else if ((rc == -ETIMEDOUT) && (ddev->atn_count++ < DIGITAL_NFC_DEP_N_RETRY_ATN)) { ddev->nack_count = 0; rc = digital_in_send_atn(ddev, data_exch); if (rc) goto error; return; } goto exit; } rc = digital_skb_pull_dep_sod(ddev, resp); if (rc) { PROTOCOL_ERR("14.4.1.2"); goto exit; } rc = ddev->skb_check_crc(resp); if (rc) { if ((resp->len >= 4) && (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) { ddev->atn_count = 0; rc = digital_in_send_nack(ddev, data_exch); if (rc) goto error; kfree_skb(resp); return; } PROTOCOL_ERR("14.4.1.6"); goto error; } ddev->atn_count = 0; ddev->nack_count = 0; if (resp->len > ddev->local_payload_max) { rc = -EMSGSIZE; goto exit; } size = sizeof(struct digital_dep_req_res); dep_res = (struct digital_dep_req_res *)resp->data; if (resp->len < size || dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN || dep_res->cmd != DIGITAL_CMD_DEP_RES) { rc = -EIO; goto error; } pfb = dep_res->pfb; if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) { PROTOCOL_ERR("14.8.2.1"); rc = -EIO; goto error; } if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) { rc = -EIO; goto exit; } if (size > resp->len) { rc = -EIO; goto error; } skb_pull(resp, size); switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) { case DIGITAL_NFC_DEP_PFB_I_PDU: if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) { PROTOCOL_ERR("14.12.3.3"); rc = -EIO; goto error; } ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1); kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; resp = digital_recv_dep_data_gather(ddev, pfb, resp, digital_in_send_ack, data_exch); if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto error; } /* If resp is NULL then we're still chaining so return and * wait for the next part of the PDU. Else, the PDU is * complete so pass it up. */ if (!resp) return; rc = 0; break; case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU: if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { PROTOCOL_ERR("14.12.4.5"); rc = -EIO; goto exit; } if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) { PROTOCOL_ERR("14.12.3.3"); rc = -EIO; goto exit; } ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1); if (!ddev->chaining_skb) { PROTOCOL_ERR("14.12.4.3"); rc = -EIO; goto exit; } /* The initiator has received a valid ACK. Free the last sent * PDU and keep on sending chained skb. */ kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; rc = digital_in_send_dep_req(ddev, NULL, ddev->chaining_skb, ddev->data_exch); if (rc) goto error; goto free_resp; case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU: if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { /* ATN */ rc = digital_in_send_saved_skb(ddev, data_exch); if (rc) goto error; goto free_resp; } if (ddev->atn_count || ddev->nack_count) { PROTOCOL_ERR("14.12.4.4"); rc = -EIO; goto error; } rtox = DIGITAL_NFC_DEP_RTOX_VALUE(resp->data[0]); if (!rtox || rtox > DIGITAL_NFC_DEP_RTOX_MAX) { PROTOCOL_ERR("14.8.4.1"); rc = -EIO; goto error; } rc = digital_in_send_rtox(ddev, data_exch, rtox); if (rc) goto error; goto free_resp; } exit: data_exch->cb(data_exch->cb_context, resp, rc); error: kfree(data_exch); kfree_skb(ddev->chaining_skb); ddev->chaining_skb = NULL; kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; if (rc) kfree_skb(resp); return; free_resp: dev_kfree_skb(resp); } int digital_in_send_dep_req(struct nfc_digital_dev *ddev, struct nfc_target *target, struct sk_buff *skb, struct digital_data_exch *data_exch) { struct digital_dep_req_res *dep_req; struct sk_buff *chaining_skb, *tmp_skb; int rc; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_req = (struct digital_dep_req_res *)skb->data; dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; dep_req->cmd = DIGITAL_CMD_DEP_REQ; dep_req->pfb = ddev->curr_nfc_dep_pni; ddev->atn_count = 0; ddev->nack_count = 0; chaining_skb = ddev->chaining_skb; tmp_skb = digital_send_dep_data_prep(ddev, skb, dep_req, data_exch); if (IS_ERR(tmp_skb)) return PTR_ERR(tmp_skb); digital_skb_push_dep_sod(ddev, tmp_skb); ddev->skb_add_crc(tmp_skb); ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL); rc = digital_in_send_cmd(ddev, tmp_skb, ddev->dep_rwt, digital_in_recv_dep_res, data_exch); if (rc) { if (tmp_skb != skb) kfree_skb(tmp_skb); kfree_skb(chaining_skb); ddev->chaining_skb = NULL; kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; } return rc; } static void digital_tg_set_rf_tech(struct nfc_digital_dev *ddev, u8 rf_tech) { ddev->curr_rf_tech = rf_tech; ddev->skb_add_crc = digital_skb_add_crc_none; ddev->skb_check_crc = digital_skb_check_crc_none; if (DIGITAL_DRV_CAPS_TG_CRC(ddev)) return; switch (ddev->curr_rf_tech) { case NFC_DIGITAL_RF_TECH_106A: ddev->skb_add_crc = digital_skb_add_crc_a; ddev->skb_check_crc = digital_skb_check_crc_a; break; case NFC_DIGITAL_RF_TECH_212F: case NFC_DIGITAL_RF_TECH_424F: ddev->skb_add_crc = digital_skb_add_crc_f; ddev->skb_check_crc = digital_skb_check_crc_f; break; default: break; } } static int digital_tg_send_ack(struct nfc_digital_dev *ddev, struct digital_data_exch *data_exch) { struct digital_dep_req_res *dep_res; struct sk_buff *skb; int rc; skb = digital_skb_alloc(ddev, 1); if (!skb) return -ENOMEM; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_res = (struct digital_dep_req_res *)skb->data; dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN; dep_res->cmd = DIGITAL_CMD_DEP_RES; dep_res->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU | ddev->curr_nfc_dep_pni; if (ddev->did) { dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT; skb_put_data(skb, &ddev->did, sizeof(ddev->did)); } ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1); digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); ddev->saved_skb = pskb_copy(skb, GFP_KERNEL); rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req, data_exch); if (rc) { kfree_skb(skb); kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; } return rc; } static int digital_tg_send_atn(struct nfc_digital_dev *ddev) { struct digital_dep_req_res *dep_res; struct sk_buff *skb; int rc; skb = digital_skb_alloc(ddev, 1); if (!skb) return -ENOMEM; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_res = (struct digital_dep_req_res *)skb->data; dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN; dep_res->cmd = DIGITAL_CMD_DEP_RES; dep_res->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU; if (ddev->did) { dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT; skb_put_data(skb, &ddev->did, sizeof(ddev->did)); } digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req, NULL); if (rc) kfree_skb(skb); return rc; } static int digital_tg_send_saved_skb(struct nfc_digital_dev *ddev) { int rc; if (!ddev->saved_skb) return -EINVAL; skb_get(ddev->saved_skb); rc = digital_tg_send_cmd(ddev, ddev->saved_skb, 1500, digital_tg_recv_dep_req, NULL); if (rc) kfree_skb(ddev->saved_skb); return rc; } static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { int rc; struct digital_dep_req_res *dep_req; u8 pfb; size_t size; if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto exit; } rc = ddev->skb_check_crc(resp); if (rc) { PROTOCOL_ERR("14.4.1.6"); goto exit; } rc = digital_skb_pull_dep_sod(ddev, resp); if (rc) { PROTOCOL_ERR("14.4.1.2"); goto exit; } if (resp->len > ddev->local_payload_max) { rc = -EMSGSIZE; goto exit; } size = sizeof(struct digital_dep_req_res); dep_req = (struct digital_dep_req_res *)resp->data; if (resp->len < size || dep_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT || dep_req->cmd != DIGITAL_CMD_DEP_REQ) { rc = -EIO; goto exit; } pfb = dep_req->pfb; if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) { if (ddev->did && (ddev->did == resp->data[3])) { size++; } else { rc = -EIO; goto exit; } } else if (ddev->did) { rc = -EIO; goto exit; } if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) { rc = -EIO; goto exit; } if (size > resp->len) { rc = -EIO; goto exit; } skb_pull(resp, size); switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) { case DIGITAL_NFC_DEP_PFB_I_PDU: pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n"); if (ddev->atn_count) { /* The target has received (and replied to) at least one * ATN DEP_REQ. */ ddev->atn_count = 0; /* pni of resp PDU equal to the target current pni - 1 * means resp is the previous DEP_REQ PDU received from * the initiator so the target replies with saved_skb * which is the previous DEP_RES saved in * digital_tg_send_dep_res(). */ if (DIGITAL_NFC_DEP_PFB_PNI(pfb) == DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni - 1)) { rc = digital_tg_send_saved_skb(ddev); if (rc) goto exit; goto free_resp; } /* atn_count > 0 and PDU pni != curr_nfc_dep_pni - 1 * means the target probably did not received the last * DEP_REQ PDU sent by the initiator. The target * fallbacks to normal processing then. */ } if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) { PROTOCOL_ERR("14.12.3.4"); rc = -EIO; goto exit; } kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; resp = digital_recv_dep_data_gather(ddev, pfb, resp, digital_tg_send_ack, NULL); if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto exit; } /* If resp is NULL then we're still chaining so return and * wait for the next part of the PDU. Else, the PDU is * complete so pass it up. */ if (!resp) return; rc = 0; break; case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU: if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */ if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) != ddev->curr_nfc_dep_pni) { rc = -EIO; goto exit; } ddev->atn_count = 0; rc = digital_tg_send_saved_skb(ddev); if (rc) goto exit; goto free_resp; } /* ACK */ if (ddev->atn_count) { /* The target has previously recevied one or more ATN * PDUs. */ ddev->atn_count = 0; /* If the ACK PNI is equal to the target PNI - 1 means * that the initiator did not receive the previous PDU * sent by the target so re-send it. */ if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) == ddev->curr_nfc_dep_pni) { rc = digital_tg_send_saved_skb(ddev); if (rc) goto exit; goto free_resp; } /* Otherwise, the target did not receive the previous * ACK PDU from the initiator. Fallback to normal * processing of chained PDU then. */ } /* Keep on sending chained PDU */ if (!ddev->chaining_skb || DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) { rc = -EIO; goto exit; } kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb); if (rc) goto exit; goto free_resp; case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU: if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { rc = -EINVAL; goto exit; } rc = digital_tg_send_atn(ddev); if (rc) goto exit; ddev->atn_count++; goto free_resp; } rc = nfc_tm_data_received(ddev->nfc_dev, resp); if (rc) resp = NULL; exit: kfree_skb(ddev->chaining_skb); ddev->chaining_skb = NULL; ddev->atn_count = 0; kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; if (rc) kfree_skb(resp); return; free_resp: dev_kfree_skb(resp); } int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb) { struct digital_dep_req_res *dep_res; struct sk_buff *chaining_skb, *tmp_skb; int rc; skb_push(skb, sizeof(struct digital_dep_req_res)); dep_res = (struct digital_dep_req_res *)skb->data; dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN; dep_res->cmd = DIGITAL_CMD_DEP_RES; dep_res->pfb = ddev->curr_nfc_dep_pni; if (ddev->did) { dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT; skb_put_data(skb, &ddev->did, sizeof(ddev->did)); } ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1); chaining_skb = ddev->chaining_skb; tmp_skb = digital_send_dep_data_prep(ddev, skb, dep_res, NULL); if (IS_ERR(tmp_skb)) return PTR_ERR(tmp_skb); digital_skb_push_dep_sod(ddev, tmp_skb); ddev->skb_add_crc(tmp_skb); ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL); rc = digital_tg_send_cmd(ddev, tmp_skb, 1500, digital_tg_recv_dep_req, NULL); if (rc) { if (tmp_skb != skb) kfree_skb(tmp_skb); kfree_skb(chaining_skb); ddev->chaining_skb = NULL; kfree_skb(ddev->saved_skb); ddev->saved_skb = NULL; } return rc; } static void digital_tg_send_psl_res_complete(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { u8 rf_tech = (unsigned long)arg; if (IS_ERR(resp)) return; digital_tg_set_rf_tech(ddev, rf_tech); digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech); digital_tg_listen(ddev, 1500, digital_tg_recv_dep_req, NULL); dev_kfree_skb(resp); } static int digital_tg_send_psl_res(struct nfc_digital_dev *ddev, u8 did, u8 rf_tech) { struct digital_psl_res *psl_res; struct sk_buff *skb; int rc; skb = digital_skb_alloc(ddev, sizeof(struct digital_psl_res)); if (!skb) return -ENOMEM; skb_put(skb, sizeof(struct digital_psl_res)); psl_res = (struct digital_psl_res *)skb->data; psl_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN; psl_res->cmd = DIGITAL_CMD_PSL_RES; psl_res->did = did; digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); ddev->curr_nfc_dep_pni = 0; rc = digital_tg_send_cmd(ddev, skb, 0, digital_tg_send_psl_res_complete, (void *)(unsigned long)rf_tech); if (rc) kfree_skb(skb); return rc; } static void digital_tg_recv_psl_req(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { int rc; struct digital_psl_req *psl_req; u8 rf_tech; u8 dsi, payload_size, payload_bits; if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto exit; } rc = ddev->skb_check_crc(resp); if (rc) { PROTOCOL_ERR("14.4.1.6"); goto exit; } rc = digital_skb_pull_dep_sod(ddev, resp); if (rc) { PROTOCOL_ERR("14.4.1.2"); goto exit; } psl_req = (struct digital_psl_req *)resp->data; if (resp->len != sizeof(struct digital_psl_req) || psl_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT || psl_req->cmd != DIGITAL_CMD_PSL_REQ) { rc = -EIO; goto exit; } dsi = (psl_req->brs >> 3) & 0x07; switch (dsi) { case 0: rf_tech = NFC_DIGITAL_RF_TECH_106A; break; case 1: rf_tech = NFC_DIGITAL_RF_TECH_212F; break; case 2: rf_tech = NFC_DIGITAL_RF_TECH_424F; break; default: pr_err("Unsupported dsi value %d\n", dsi); goto exit; } payload_bits = DIGITAL_PAYLOAD_FSL_TO_BITS(psl_req->fsl); payload_size = digital_payload_bits_to_size(payload_bits); if (!payload_size || (payload_size > min(ddev->local_payload_max, ddev->remote_payload_max))) { rc = -EINVAL; goto exit; } ddev->local_payload_max = payload_size; ddev->remote_payload_max = payload_size; rc = digital_tg_send_psl_res(ddev, psl_req->did, rf_tech); exit: kfree_skb(resp); } static void digital_tg_send_atr_res_complete(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { int offset; if (IS_ERR(resp)) { digital_poll_next_tech(ddev); return; } offset = 2; if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB) offset++; ddev->atn_count = 0; if (resp->data[offset] == DIGITAL_CMD_PSL_REQ) digital_tg_recv_psl_req(ddev, arg, resp); else digital_tg_recv_dep_req(ddev, arg, resp); } static int digital_tg_send_atr_res(struct nfc_digital_dev *ddev, struct digital_atr_req *atr_req) { struct digital_atr_res *atr_res; struct sk_buff *skb; u8 *gb, payload_bits; size_t gb_len; int rc; gb = nfc_get_local_general_bytes(ddev->nfc_dev, &gb_len); if (!gb) gb_len = 0; skb = digital_skb_alloc(ddev, sizeof(struct digital_atr_res) + gb_len); if (!skb) return -ENOMEM; skb_put(skb, sizeof(struct digital_atr_res)); atr_res = (struct digital_atr_res *)skb->data; memset(atr_res, 0, sizeof(struct digital_atr_res)); atr_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN; atr_res->cmd = DIGITAL_CMD_ATR_RES; memcpy(atr_res->nfcid3, atr_req->nfcid3, sizeof(atr_req->nfcid3)); atr_res->to = DIGITAL_NFC_DEP_TG_MAX_WT; ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX; payload_bits = digital_payload_size_to_bits(ddev->local_payload_max); atr_res->pp = DIGITAL_PAYLOAD_BITS_TO_PP(payload_bits); if (gb_len) { skb_put(skb, gb_len); atr_res->pp |= DIGITAL_GB_BIT; memcpy(atr_res->gb, gb, gb_len); } digital_skb_push_dep_sod(ddev, skb); ddev->skb_add_crc(skb); ddev->curr_nfc_dep_pni = 0; rc = digital_tg_send_cmd(ddev, skb, 999, digital_tg_send_atr_res_complete, NULL); if (rc) kfree_skb(skb); return rc; } void digital_tg_recv_atr_req(struct nfc_digital_dev *ddev, void *arg, struct sk_buff *resp) { int rc; struct digital_atr_req *atr_req; size_t gb_len, min_size; u8 poll_tech_count, payload_bits; if (IS_ERR(resp)) { rc = PTR_ERR(resp); resp = NULL; goto exit; } if (!resp->len) { rc = -EIO; goto exit; } if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB) { min_size = DIGITAL_ATR_REQ_MIN_SIZE + 2; digital_tg_set_rf_tech(ddev, NFC_DIGITAL_RF_TECH_106A); } else { min_size = DIGITAL_ATR_REQ_MIN_SIZE + 1; digital_tg_set_rf_tech(ddev, NFC_DIGITAL_RF_TECH_212F); } if (resp->len < min_size) { rc = -EIO; goto exit; } ddev->curr_protocol = NFC_PROTO_NFC_DEP_MASK; rc = ddev->skb_check_crc(resp); if (rc) { PROTOCOL_ERR("14.4.1.6"); goto exit; } rc = digital_skb_pull_dep_sod(ddev, resp); if (rc) { PROTOCOL_ERR("14.4.1.2"); goto exit; } atr_req = (struct digital_atr_req *)resp->data; if (atr_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT || atr_req->cmd != DIGITAL_CMD_ATR_REQ || atr_req->did > DIGITAL_DID_MAX) { rc = -EINVAL; goto exit; } payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_req->pp); ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits); if (!ddev->remote_payload_max) { rc = -EINVAL; goto exit; } ddev->did = atr_req->did; rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED); if (rc) goto exit; rc = digital_tg_send_atr_res(ddev, atr_req); if (rc) goto exit; gb_len = resp->len - sizeof(struct digital_atr_req); poll_tech_count = ddev->poll_tech_count; ddev->poll_tech_count = 0; rc = nfc_tm_activated(ddev->nfc_dev, NFC_PROTO_NFC_DEP_MASK, NFC_COMM_PASSIVE, atr_req->gb, gb_len); if (rc) { ddev->poll_tech_count = poll_tech_count; goto exit; } rc = 0; exit: if (rc) digital_poll_next_tech(ddev); dev_kfree_skb(resp); }