From 79f0ea73a2da29b358e2488abe949d2a494af100 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Mon, 5 Apr 2021 17:55:54 +0200 Subject: card_emu: Clarify and differentiate F/Fi/F_index/Fi_index The ISO7816 spec terms are well-defined, let's not abuse them. We used to consider "Fi" as the "index into the table of F values", while the spec actually considers Fi as the initial value for F. Let's make sure we use the terms quite clearly: * Fi and Di are the initial values for F and D * F*_index and D*_index are the indexes into the ISO7816-3 Tables Furthermore, let's track Fi separately from F, as e.g. the waiting time definition only considers Fi as indicated in the ATR, despite an actually different F value might have been negotiated via PTS meanwhile. Change-Id: Ieb2425e8380a81b79df7b2bd072902994e9c3ee7 Related: OS##1704 --- firmware/libcommon/include/simtrace_prot.h | 16 +++++--- firmware/libcommon/source/card_emu.c | 62 ++++++++++++++++++++---------- 2 files changed, 52 insertions(+), 26 deletions(-) diff --git a/firmware/libcommon/include/simtrace_prot.h b/firmware/libcommon/include/simtrace_prot.h index eca844a..e550616 100644 --- a/firmware/libcommon/include/simtrace_prot.h +++ b/firmware/libcommon/include/simtrace_prot.h @@ -230,11 +230,17 @@ struct cardemu_usb_msg_status { uint32_t flags; /* phone-applied target voltage in mV */ uint16_t voltage_mv; - /* Fi/Di related information */ - uint8_t fi; - uint8_t di; - uint8_t wi; - uint32_t waiting_time; + /* F/D related information. Not actual Fn/Dn values but indexes into tables! */ + union { + uint8_t F_index; /* + * (C) 2010-2021 by Harald Welte * (C) 2018 by sysmocom -s.f.m.c. GmbH, Author: Kevin Redon * * This program is free software; you can redistribute it and/or modify @@ -154,19 +154,35 @@ struct card_handle { bool in_reset; /*< if card is in reset (true = RST low/asserted, false = RST high/ released) */ bool clocked; /*< if clock is active ( true = active, false = inactive) */ - /* timing parameters, from PTS */ - uint8_t Fi; - uint8_t Di; + /* All below variables with _index suffix are indexes from 0..15 into Tables 7 + 8 + * of ISO7816-3. */ + + /*! Index to clock rate conversion integer Fi (ISO7816-3 Table 7). + * \note this represents the maximum value supported by the card, and can be indicated in TA1 */ + uint8_t Fi_index; + /*! Current value of index to clock rate conversion integer F (ISO 7816-3 Section 7.1). */ + uint8_t F_index; + + /*! Index to baud rate adjustment factor Di (ISO7816-3 Table 8). + * \note this represents the maximum value supported by the card, and can be indicated in TA1 */ + uint8_t Di_index; + /*! Current value of index to baud rate adjustment factor D (ISO 7816-3 Section 7.1). */ + uint8_t D_index; + + /*! Waiting Integer (ISO7816-3 Section 10.2). + * \note this value can be set in TA2 */ uint8_t wi; + /*! Waiting Time, in ETU (ISO7816-3 Section 8.1). + * \note this depends on Fi, Di, and WI if T=0 is used */ + uint32_t waiting_time; /* in etu */ + uint8_t tc_chan; /* TC channel number */ uint8_t uart_chan; /* UART channel */ uint8_t in_ep; /* USB IN EP */ uint8_t irq_ep; /* USB IN EP */ - uint32_t waiting_time; /* in etu */ - /* ATR state machine */ struct { uint8_t idx; @@ -361,16 +377,16 @@ static void emu_update_fidi(struct card_handle *ch) { int rc; - rc = compute_fidi_ratio(ch->Fi, ch->Di); + rc = compute_fidi_ratio(ch->F_index, ch->D_index); if (rc > 0 && rc < 0x400) { - TRACE_INFO("%u: computed Fi(%u) Di(%u) ratio: %d\r\n", - ch->num, ch->Fi, ch->Di, rc); + TRACE_INFO("%u: computed F(%u)/D(%u) ratio: %d\r\n", ch->num, + ch->F_index, ch->D_index, rc); /* make sure UART uses new F/D ratio */ card_emu_uart_update_fidi(ch->uart_chan, rc); /* notify ETU timer about this */ tc_etu_set_etu(ch->tc_chan, rc); } else - TRACE_INFO("%u: computed FiDi ration %d unsupported\r\n", + TRACE_INFO("%u: computed F/D ratio %d unsupported\r\n", ch->num, rc); } @@ -395,8 +411,10 @@ static void card_set_state(struct card_handle *ch, break; case ISO_S_WAIT_ATR: /* Reset to initial Fi / Di ratio */ - ch->Fi = 1; - ch->Di = 1; + ch->Fi_index = ch->F_index = 1; + ch->Di_index = ch->D_index = 1; + ch->wi = ISO7816_3_DEFAULT_WI; + ch->waiting_time = ISO7816_3_INIT_WTIME; emu_update_fidi(ch); /* the ATR should only be sent 400 to 40k clock cycles after the RESET. * we use the tc_etu mechanism to wait this time. @@ -490,7 +508,7 @@ static int tx_byte_atr(struct card_handle *ch) } } /* update waiting time (see ISO 7816-3 10.2) */ - ch->waiting_time = ch->wi * 960 * ch->Fi; + ch->waiting_time = ch->wi * 960 * fi_table[ch->F_index]; tc_etu_set_wtime(ch->tc_chan, ch->waiting_time); /* go to next state */ card_set_state(ch, ISO_S_WAIT_TPDU); @@ -626,9 +644,11 @@ static int tx_byte_pts(struct card_handle *ch) case PTS_S_WAIT_RESP_PTS1: byte = ch->pts.resp[_PTS1]; /* This must be TA1 */ - ch->Fi = byte >> 4; - ch->Di = byte & 0xf; - TRACE_DEBUG("%u: found Fi=%u Di=%u\r\n", ch->num, ch->Fi, ch->Di); + ch->F_index = byte >> 4; + ch->D_index = byte & 0xf; + TRACE_DEBUG("%u: found F=%u D=%u\r\n", ch->num, + fi_table[ch->F_index], di_table[ch->D_index]); + /* FIXME: if F or D are 0, become unresponsive to signal error condition */ break; case PTS_S_WAIT_RESP_PTS2: byte = ch->pts.resp[_PTS2]; @@ -653,7 +673,7 @@ static int tx_byte_pts(struct card_handle *ch) switch (ch->pts.state) { case PTS_S_WAIT_RESP_PCK: card_emu_uart_wait_tx_idle(ch->uart_chan); - /* update baud rate generator with Fi/Di */ + /* update baud rate generator with F/D */ emu_update_fidi(ch); /* Wait for the next TPDU */ card_set_state(ch, ISO_S_WAIT_TPDU); @@ -1024,8 +1044,8 @@ void card_emu_report_status(struct card_handle *ch, bool report_on_irq) if (ch->in_reset) sts->flags |= CEMU_STATUS_F_RESET_ACTIVE; /* FIXME: voltage + card insert */ - sts->fi = ch->Fi; - sts->di = ch->Di; + sts->F_index = ch->F_index; + sts->D_index = ch->D_index; sts->wi = ch->wi; sts->waiting_time = ch->waiting_time; @@ -1231,8 +1251,8 @@ struct card_handle *card_emu_init(uint8_t slot_num, uint8_t tc_chan, uint8_t uar ch->in_reset = in_reset; ch->clocked = clocked; - ch->Fi = 0; - ch->Di = 1; + ch->Fi_index = ch->F_index = 1; + ch->Di_index = ch->D_index = 1; ch->wi = ISO7816_3_DEFAULT_WI; ch->tc_chan = tc_chan; -- cgit v1.2.3