openpcd/firmware/src/simtrace/iso7816_uart.c

642 lines
15 KiB
C

/* Driver for AT91SAM7 USART0 in ISO7816-3 mode for passive sniffing
* (C) 2010 by Harald Welte <hwelte@hmw-consulting.de>
*
* 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 <errno.h>
#include <string.h>
#include <sys/types.h>
#include <AT91SAM7.h>
#include <lib_AT91SAM7.h>
#include <openpcd.h>
#include <simtrace_usb.h>
#include <os/usb_handler.h>
#include <os/dbgu.h>
#include <os/pio_irq.h>
#include "../simtrace.h"
#include "../openpcd.h"
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
static const AT91PS_USART usart = AT91C_BASE_US0;
enum iso7816_3_state {
ISO7816_S_RESET, /* in Reset */
ISO7816_S_WAIT_ATR, /* waiting for ATR to start */
ISO7816_S_IN_ATR, /* while we are receiving the ATR */
ISO7816_S_WAIT_APDU, /* waiting for start of new APDU */
ISO7816_S_IN_APDU, /* inside a single APDU */
ISO7816_S_IN_PTS, /* while we are inside the PTS / PSS */
};
/* detailed sub-states of ISO7816_S_IN_ATR */
enum atr_state {
ATR_S_WAIT_TS,
ATR_S_WAIT_T0,
ATR_S_WAIT_TA,
ATR_S_WAIT_TB,
ATR_S_WAIT_TC,
ATR_S_WAIT_TD,
ATR_S_WAIT_HIST,
ATR_S_WAIT_TCK,
ATR_S_DONE,
};
/* detailed sub-states of ISO7816_S_IN_PTS */
enum pts_state {
PTS_S_WAIT_REQ_PTSS,
PTS_S_WAIT_REQ_PTS0,
PTS_S_WAIT_REQ_PTS1,
PTS_S_WAIT_REQ_PTS2,
PTS_S_WAIT_REQ_PTS3,
PTS_S_WAIT_REQ_PCK,
PTS_S_WAIT_RESP_PTSS = PTS_S_WAIT_REQ_PTSS | 0x10,
PTS_S_WAIT_RESP_PTS0 = PTS_S_WAIT_REQ_PTS0 | 0x10,
PTS_S_WAIT_RESP_PTS1 = PTS_S_WAIT_REQ_PTS1 | 0x10,
PTS_S_WAIT_RESP_PTS2 = PTS_S_WAIT_REQ_PTS2 | 0x10,
PTS_S_WAIT_RESP_PTS3 = PTS_S_WAIT_REQ_PTS3 | 0x10,
PTS_S_WAIT_RESP_PCK = PTS_S_WAIT_REQ_PCK | 0x10,
};
#define _PTSS 0
#define _PTS0 1
#define _PTS1 2
#define _PTS2 3
#define _PTS3 4
#define _PCK 5
struct iso7816_3_handle {
enum iso7816_3_state state;
u_int8_t fi;
u_int8_t di;
u_int8_t wi;
u_int32_t waiting_time;
enum atr_state atr_state;
u_int8_t atr_idx;
u_int8_t atr_hist_len;
u_int8_t atr_last_td;
u_int8_t atr[64];
enum pts_state pts_state;
u_int8_t pts_req[6];
u_int8_t pts_resp[6];
struct simtrace_hdr sh;
int rctx_must_be_sent;
struct req_ctx *rctx;
};
struct iso7816_3_handle isoh;
/* Table 6 from ISO 7816-3 */
static const u_int16_t fi_table[] = {
0, 372, 558, 744, 1116, 1488, 1860, 0,
0, 512, 768, 1024, 1536, 2048, 0, 0
};
/* Table 7 from ISO 7816-3 */
static const u_int8_t di_table[] = {
0, 1, 2, 4, 8, 16, 0, 0,
0, 0, 2, 4, 8, 16, 32, 64,
};
/* compute the F/D ratio based on Fi and Di values */
static int compute_fidi_ratio(u_int8_t fi, u_int8_t di)
{
u_int16_t f, d;
int ret;
if (fi >= ARRAY_SIZE(fi_table) ||
di >= ARRAY_SIZE(di_table))
return -EINVAL;
f = fi_table[fi];
if (f == 0)
return -EINVAL;
d = di_table[di];
if (d == 0)
return -EINVAL;
if (di < 8)
ret = f / d;
else
ret = f * d;
return ret;
}
static void refill_rctx(struct iso7816_3_handle *ih)
{
struct req_ctx *rctx;
rctx = req_ctx_find_get(0, RCTX_STATE_FREE,
RCTX_STATE_LIBRFID_BUSY);
if (!rctx) {
ih->rctx = NULL;
return;
}
ih->sh.cmd = SIMTRACE_MSGT_DATA;
/* reserve spece at start of rctx */
rctx->tot_len = sizeof(struct simtrace_hdr);
ih->rctx = rctx;
}
static void send_rctx(struct iso7816_3_handle *ih)
{
struct req_ctx *rctx = ih->rctx;
if (!rctx)
return;
/* copy the simtrace header */
memcpy(rctx->data, &ih->sh, sizeof(ih->sh));
req_ctx_set_state(rctx, RCTX_STATE_UDP_EP2_PENDING);
memset(&ih->sh, 0, sizeof(ih->sh));
ih->rctx = NULL;
}
/* Update the ATR sub-state */
static void set_atr_state(struct iso7816_3_handle *ih, enum atr_state new_atrs)
{
if (new_atrs == ATR_S_WAIT_TS) {
ih->atr_idx = 0;
ih->atr_hist_len = 0;
ih->atr_last_td = 0;
memset(ih->atr, 0, sizeof(ih->atr));
} else if (ih->atr_state == new_atrs)
return;
//DEBUGPCR("ATR state %u -> %u", ih->atr_state, new_atrs);
ih->atr_state = new_atrs;
}
#define ISO7816_3_INIT_WTIME 9600
#define ISO7816_3_DEFAULT_WI 10
static void update_fidi(struct iso7816_3_handle *ih)
{
int rc;
rc = compute_fidi_ratio(ih->fi, ih->di);
if (rc > 0 && rc < 0x400) {
DEBUGPCR("computed Fi(%u) Di(%u) ratio: %d", ih->fi, ih->di, rc);
/* make sure UART uses new F/D ratio */
usart->US_CR |= AT91C_US_RXDIS | AT91C_US_RSTRX;
usart->US_FIDI = rc & 0x3ff;
usart->US_CR |= AT91C_US_RXEN | AT91C_US_STTTO;
/* notify ETU timer about this */
tc_etu_set_etu(rc);
} else
DEBUGPCRF("computed FiDi ratio %d unsupported", rc);
}
/* Update the ISO 7816-3 APDU receiver state */
static void set_state(struct iso7816_3_handle *ih, enum iso7816_3_state new_state)
{
if (new_state == ISO7816_S_RESET) {
usart->US_CR |= AT91C_US_RXDIS | AT91C_US_RSTRX;
} else if (new_state == ISO7816_S_WAIT_ATR) {
/* Reset to initial Fi / Di ratio */
ih->fi = 1;
ih->di = 1;
update_fidi(ih);
/* initialize todefault WI, this will be overwritten if we
* receive TC2, and it will be programmed into hardware after
* ATR is finished */
ih->wi = ISO7816_3_DEFAULT_WI;
/* update waiting time to initial waiting time */
ih->waiting_time = ISO7816_3_INIT_WTIME;
tc_etu_set_wtime(ih->waiting_time);
/* Set ATR sub-state to initial state */
set_atr_state(ih, ATR_S_WAIT_TS);
/* Notice that we are just coming out of reset */
ih->sh.flags |= SIMTRACE_FLAG_ATR;
}
if (ih->state == new_state)
return;
//DEBUGPCR("7816 state %u -> %u", ih->state, new_state);
ih->state = new_state;
}
/* determine the next ATR state based on received interface byte */
static enum atr_state next_intb_state(struct iso7816_3_handle *ih, u_int8_t ch)
{
switch (ih->atr_state) {
case ATR_S_WAIT_TD:
case ATR_S_WAIT_T0:
ih->atr_last_td = ch;
goto from_td;
case ATR_S_WAIT_TC:
if ((ih->atr_last_td & 0x0f) == 0x02) {
/* TC2 contains WI */
ih->wi = ch;
}
goto from_tc;
case ATR_S_WAIT_TB:
goto from_tb;
case ATR_S_WAIT_TA:
goto from_ta;
default:
DEBUGPCR("something wrong, old_state != TA");
return ATR_S_WAIT_TCK;
}
from_td:
if (ih->atr_last_td & 0x10)
return ATR_S_WAIT_TA;
from_ta:
if (ih->atr_last_td & 0x20)
return ATR_S_WAIT_TB;
from_tb:
if (ih->atr_last_td & 0x40)
return ATR_S_WAIT_TC;
from_tc:
if (ih->atr_last_td & 0x80)
return ATR_S_WAIT_TD;
return ATR_S_WAIT_HIST;
}
/* process an incomng ATR byte */
static enum iso7816_3_state
process_byte_atr(struct iso7816_3_handle *ih, u_int8_t byte)
{
/* add byte to ATR buffer */
ih->atr[ih->atr_idx] = byte;
ih->atr_idx++;
switch (ih->atr_state) {
case ATR_S_WAIT_TS:
/* FIXME: if we don't have the RST line we might get this */
if (byte == 0) {
ih->atr_idx--;
break;
}
/* FIXME: check inverted logic */
set_atr_state(ih, ATR_S_WAIT_T0);
break;
case ATR_S_WAIT_T0:
/* obtain the number of historical bytes */
ih->atr_hist_len = byte & 0xf;
/* Mask out the hist-byte-length to indiicate T=0 */
set_atr_state(ih, next_intb_state(ih, byte & 0xf0));
break;
case ATR_S_WAIT_TA:
case ATR_S_WAIT_TB:
case ATR_S_WAIT_TC:
case ATR_S_WAIT_TD:
set_atr_state(ih, next_intb_state(ih, byte));
break;
case ATR_S_WAIT_HIST:
ih->atr_hist_len--;
/* after all historical bytes are recieved, go to TCK */
if (ih->atr_hist_len == 0)
set_atr_state(ih, ATR_S_WAIT_TCK);
break;
case ATR_S_WAIT_TCK:
/* FIXME: process and verify the TCK */
set_atr_state(ih, ATR_S_DONE);
/* send off the USB context */
ih->rctx_must_be_sent = 1;
/* update the waiting time */
ih->waiting_time = 960 * di_table[ih->di] * ih->wi;
tc_etu_set_wtime(ih->waiting_time);
return ISO7816_S_WAIT_APDU;
}
return ISO7816_S_IN_ATR;
}
/* Update the ATR sub-state */
static void set_pts_state(struct iso7816_3_handle *ih, enum pts_state new_ptss)
{
//DEBUGPCR("PTS state %u -> %u", ih->pts_state, new_ptss);
ih->pts_state = new_ptss;
}
/* Determine the next PTS state */
static enum pts_state next_pts_state(struct iso7816_3_handle *ih)
{
u_int8_t is_resp = ih->pts_state & 0x10;
u_int8_t sstate = ih->pts_state & 0x0f;
u_int8_t *pts_ptr;
if (!is_resp)
pts_ptr = ih->pts_req;
else
pts_ptr = ih->pts_resp;
switch (sstate) {
case PTS_S_WAIT_REQ_PTSS:
goto from_ptss;
case PTS_S_WAIT_REQ_PTS0:
goto from_pts0;
case PTS_S_WAIT_REQ_PTS1:
goto from_pts1;
case PTS_S_WAIT_REQ_PTS2:
goto from_pts2;
case PTS_S_WAIT_REQ_PTS3:
goto from_pts3;
}
if (ih->pts_state == PTS_S_WAIT_REQ_PCK)
return PTS_S_WAIT_RESP_PTSS;
from_ptss:
return PTS_S_WAIT_REQ_PTS0 | is_resp;
from_pts0:
if (pts_ptr[_PTS0] & (1 << 4))
return PTS_S_WAIT_REQ_PTS1 | is_resp;
from_pts1:
if (pts_ptr[_PTS0] & (1 << 5))
return PTS_S_WAIT_REQ_PTS2 | is_resp;
from_pts2:
if (pts_ptr[_PTS0] & (1 << 6))
return PTS_S_WAIT_REQ_PTS3 | is_resp;
from_pts3:
return PTS_S_WAIT_REQ_PCK | is_resp;
}
static enum iso7816_3_state
process_byte_pts(struct iso7816_3_handle *ih, u_int8_t byte)
{
switch (ih->pts_state) {
case PTS_S_WAIT_REQ_PTSS:
ih->pts_req[_PTSS] = byte;
break;
case PTS_S_WAIT_REQ_PTS0:
ih->pts_req[_PTS0] = byte;
break;
case PTS_S_WAIT_REQ_PTS1:
ih->pts_req[_PTS1] = byte;
break;
case PTS_S_WAIT_REQ_PTS2:
ih->pts_req[_PTS2] = byte;
break;
case PTS_S_WAIT_REQ_PTS3:
ih->pts_req[_PTS3] = byte;
break;
case PTS_S_WAIT_REQ_PCK:
/* FIXME: check PCK */
ih->pts_req[_PCK] = byte;
break;
case PTS_S_WAIT_RESP_PTSS:
ih->pts_resp[_PTSS] = byte;
break;
case PTS_S_WAIT_RESP_PTS0:
ih->pts_resp[_PTS0] = byte;
break;
case PTS_S_WAIT_RESP_PTS1:
/* This must be TA1 */
ih->fi = byte >> 4;
ih->di = byte & 0xf;
DEBUGPCR("found Fi=%u Di=%u", ih->fi, ih->di);
ih->pts_resp[_PTS1] = byte;
break;
case PTS_S_WAIT_RESP_PTS2:
ih->pts_resp[_PTS2] = byte;
break;
case PTS_S_WAIT_RESP_PTS3:
ih->pts_resp[_PTS3] = byte;
break;
case PTS_S_WAIT_RESP_PCK:
ih->pts_resp[_PCK] = byte;
/* FIXME: check PCK */
set_pts_state(ih, PTS_S_WAIT_REQ_PTSS);
/* update baud rate generator with Fi/Di */
update_fidi(ih);
/* Wait for the next APDU */
return ISO7816_S_WAIT_APDU;
}
/* calculate the next state and set it */
set_pts_state(ih, next_pts_state(ih));
return ISO7816_S_IN_PTS;
}
static void process_byte(struct iso7816_3_handle *ih, u_int8_t byte)
{
int new_state = -1;
struct req_ctx *rctx;
if (!ih->rctx)
refill_rctx(ih);
switch (ih->state) {
case ISO7816_S_RESET:
break;
case ISO7816_S_WAIT_ATR:
case ISO7816_S_IN_ATR:
new_state = process_byte_atr(ih, byte);
break;
case ISO7816_S_WAIT_APDU:
if (byte == 0xff) {
new_state = process_byte_pts(ih, byte);
goto out_silent;
}
case ISO7816_S_IN_APDU:
new_state = ISO7816_S_IN_APDU;
break;
case ISO7816_S_IN_PTS:
new_state = process_byte_pts(ih, byte);
goto out_silent;
}
/* The USB buffer could be gone in case the timer expired or code above
* this line explicitly sent it off */
if (!ih->rctx)
refill_rctx(ih);
rctx = ih->rctx;
if (!rctx) {
DEBUGPCR("==> Lost byte, missing rctx");
return;
}
/* store the byte in the USB request context */
rctx->data[rctx->tot_len] = byte;
rctx->tot_len++;
if (rctx->tot_len >= rctx->size || ih->rctx_must_be_sent) {
ih->rctx_must_be_sent = 0;
send_rctx(ih);
}
out_silent:
if (new_state != -1)
set_state(ih, new_state);
}
/* timeout of work waiting time during receive */
void iso7816_wtime_expired(void)
{
/* Always flush the URB at Rx timeout as this indicates end of APDU */
if (isoh.rctx) {
isoh.sh.flags |= SIMTRACE_FLAG_WTIME_EXP;
send_rctx(&isoh);
}
if (isoh.state == ISO7816_S_IN_PTS) {
/* Timout during PTS: Card does not support PTS */
}
set_state(&isoh, ISO7816_S_WAIT_APDU);
}
static __ramfunc void usart_irq(void)
{
u_int32_t csr = usart->US_CSR;
u_int8_t octet;
//DEBUGP("USART IRQ, CSR=0x%08x\n", csr);
if (csr & AT91C_US_RXRDY) {
/* at least one character received */
octet = usart->US_RHR & 0xff;
//DEBUGP("%02x ", octet);
process_byte(&isoh, octet);
}
if (csr & AT91C_US_TXRDY) {
/* nothing to transmit anymore */
}
if (csr & (AT91C_US_PARE|AT91C_US_FRAME|AT91C_US_OVRE)) {
/* FIXME: some error has occurrerd */
}
}
/* handler for the RST input pin state change */
static void reset_pin_irq(u_int32_t pio)
{
if (!AT91F_PIO_IsInputSet(AT91C_BASE_PIOA, pio)) {
DEBUGPCR("nRST");
set_state(&isoh, ISO7816_S_RESET);
} else {
DEBUGPCR("RST");
set_state(&isoh, ISO7816_S_WAIT_ATR);
}
}
void iso_uart_dump(void)
{
u_int32_t csr = usart->US_CSR;
DEBUGPCR("USART CSR=0x%08x", csr);
}
void iso_uart_rst(unsigned int state)
{
DEBUGPCR("USART set nRST set state=%u", state);
switch (state) {
case 0:
AT91F_PIO_ClearOutput(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
AT91F_PIO_CfgOutput(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
break;
case 1:
AT91F_PIO_SetOutput(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
AT91F_PIO_CfgOutput(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
break;
default:
AT91F_PIO_CfgInput(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
break;
}
}
void iso_uart_rx_mode(void)
{
DEBUGPCR("USART Entering Rx Mode");
/* Enable receive interrupts */
usart->US_IER = AT91C_US_RXRDY | AT91C_US_OVRE | AT91C_US_FRAME |
AT91C_US_PARE | AT91C_US_NACK | AT91C_US_ITERATION;
/* call interrupt handler once to set initial state RESET / ATR */
reset_pin_irq(SIMTRACE_PIO_nRST);
}
void iso_uart_clk_master(unsigned int master)
{
DEBUGPCR("USART Clock Master %u", master);
if (master) {
usart->US_MR = AT91C_US_USMODE_ISO7816_0 | AT91C_US_CLKS_CLOCK |
AT91C_US_CHRL_8_BITS | AT91C_US_NBSTOP_1_BIT |
AT91C_US_CKLO | AT91C_US_INACK;
usart->US_BRGR = (0x0000 << 16) | 16;
} else {
usart->US_MR = AT91C_US_USMODE_ISO7816_0 | AT91C_US_CLKS_EXT |
AT91C_US_CHRL_8_BITS | AT91C_US_NBSTOP_1_BIT |
AT91C_US_CKLO | AT91C_US_INACK;
usart->US_BRGR = (0x0000 << 16) | 0x0001;
}
}
void iso_uart_init(void)
{
DEBUGPCR("USART Initializing");
refill_rctx(&isoh);
/* make sure we get clock from the power management controller */
AT91F_US0_CfgPMC();
/* configure all 3 signals as input */
AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA, SIMTRACE_PIO_IO, SIMTRACE_PIO_CLK);
AT91F_PIO_CfgInput(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
AT91F_AIC_ConfigureIt(AT91C_BASE_AIC, AT91C_ID_US0,
OPENPCD_IRQ_PRIO_USART,
AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, &usart_irq);
AT91F_AIC_EnableIt(AT91C_BASE_AIC, AT91C_ID_US0);
usart->US_CR = AT91C_US_RXDIS | AT91C_US_TXDIS |
(AT91C_US_RSTRX | AT91C_US_RSTTX);
/* FIXME: wait for some time */
usart->US_CR = AT91C_US_RXDIS | AT91C_US_TXDIS;
/* ISO7816 T=0 mode with external clock input */
usart->US_MR = AT91C_US_USMODE_ISO7816_0 | AT91C_US_CLKS_EXT |
AT91C_US_CHRL_8_BITS | AT91C_US_NBSTOP_1_BIT |
AT91C_US_CKLO | AT91C_US_INACK;
/* Disable all interrupts */
usart->US_IDR = 0xff;
/* Clock Divider = 1, i.e. no division of SCLK */
usart->US_BRGR = (0x0000 << 16) | 0x0001;
/* Disable Receiver Time-out */
usart->US_RTOR = 0;
/* Disable Transmitter Timeguard */
usart->US_TTGR = 0;
pio_irq_register(SIMTRACE_PIO_nRST, &reset_pin_irq);
AT91F_PIO_CfgInputFilter(AT91C_BASE_PIOA, SIMTRACE_PIO_nRST);
pio_irq_enable(SIMTRACE_PIO_nRST);
}