Kévin Redon has uploaded this change for review. (
https://gerrit.osmocom.org/9882
Change subject: sniffer: add waiting time WT update
......................................................................
sniffer: add waiting time WT update
the waiting time (WT) is used to detect timeouts (e.g. for
unresponsive card or just to signal an error/NAK). it is essential
to detect to timeout to end current data transfer (e.g. change state).
by default (after a reset) to timeout is 9600 ETU, but this can change
at two places:
- after the ATR using the value of TC2 (if present)
- after a PPS (only F is used, and not D)
because the timeout value can be larger than the 16-bit of the USART
TO register, an external variable needs to be used for the count down.
Change-Id: I9735660ffce161cec8d4e63fa60a66fc8ef57525
---
M firmware/libcommon/source/sniffer.c
1 file changed, 66 insertions(+), 6 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/simtrace2 refs/changes/82/9882/1
diff --git a/firmware/libcommon/source/sniffer.c
b/firmware/libcommon/source/sniffer.c
index 70d3734..e6fe68f 100644
--- a/firmware/libcommon/source/sniffer.c
+++ b/firmware/libcommon/source/sniffer.c
@@ -178,6 +178,11 @@
/*! Current index in TPDU packet */
uint16_t tpdu_packet_i = 0;
+/*! Waiting Time (WT)
+ * @note defined in ISO/IEC 7816-3:2006(E) section 8.1 and 10.2
+ */
+uint32_t wt = 9600;
+
/*------------------------------------------------------------------------------
* Internal functions
*------------------------------------------------------------------------------*/
@@ -188,6 +193,27 @@
*/
static const uint8_t convention_convert_lut[256] = { 0xff, 0x7f, 0xbf, 0x3f,
0xdf, 0x5f, 0x9f, 0x1f, 0xef, 0x6f, 0xaf, 0x2f, 0xcf, 0x4f, 0x8f, 0x0f, 0xf7,
0x77, 0xb7, 0x37, 0xd7, 0x57, 0x97, 0x17, 0xe7, 0x67, 0xa7, 0x27, 0xc7, 0x47,
0x87, 0x07, 0xfb, 0x7b, 0xbb, 0x3b, 0xdb, 0x5b, 0x9b, 0x1b, 0xeb, 0x6b, 0xab,
0x2b, 0xcb, 0x4b, 0x8b, 0x0b, 0xf3, 0x73, 0xb3, 0x33, 0xd3, 0x53, 0x93, 0x13,
0xe3, 0x63, 0xa3, 0x23, 0xc3, 0x43, 0x83, 0x03, 0xfd, 0x7d, 0xbd, 0x3d, 0xdd,
0x5d, 0x9d, 0x1d, 0xed, 0x6d, 0xad, 0x2d, 0xcd, 0x4d, 0x8d, 0x0d, 0xf5, 0x75,
0xb5, 0x35, 0xd5, 0x55, 0x95, 0x15, 0xe5, 0x65, 0xa5, 0x25, 0xc5, 0x45, 0x85,
0x05, 0xf9, 0x79, 0xb9, 0x39, 0xd9, 0x59, 0x99, 0x19, 0xe9, 0x69, 0xa9, 0x29,
0xc9, 0x49, 0x89, 0x09, 0xf1, 0x71, 0xb1, 0x31, 0xd1, 0x51, 0x91, 0x11, 0xe1,
0x61, 0xa1, 0x21, 0xc1, 0x41, 0x81, 0x01, 0xfe, 0x7e, 0xbe, 0x3e, 0xde, 0x5e,
0x9e, 0x1e, 0xee, 0x6e, 0xae, 0x2e, 0xce, 0x4e, 0x8e, 0x0e, 0xf6, 0x76, 0xb6,
0x36, 0xd6, 0x56, 0x96, 0x16, 0xe6, 0x66, 0xa6, 0x26, 0xc6, 0x46, 0x86, 0x06,
0xfa, 0x7a, 0xba, 0x3a, 0xda, 0x5a, 0x9a, 0x1a, 0xea, 0x6a, 0xaa, 0x2a, 0xca,
0x4a, 0x8a, 0x0a, 0xf2, 0x72, 0xb2, 0x32, 0xd2, 0x52, 0x92, 0x12, 0xe2, 0x62,
0xa2, 0x22, 0xc2, 0x42, 0x82, 0x02, 0xfc, 0x7c, 0xbc, 0x3c, 0xdc, 0x5c, 0x9c,
0x1c, 0xec, 0x6c, 0xac, 0x2c, 0xcc, 0x4c, 0x8c, 0x0c, 0xf4, 0x74, 0xb4, 0x34,
0xd4, 0x54, 0x94, 0x14, 0xe4, 0x64, 0xa4, 0x24, 0xc4, 0x44, 0x84, 0x04, 0xf8,
0x78, 0xb8, 0x38, 0xd8, 0x58, 0x98, 0x18, 0xe8, 0x68, 0xa8, 0x28, 0xc8, 0x48,
0x88, 0x08, 0xf0, 0x70, 0xb0, 0x30, 0xd0, 0x50, 0x90, 0x10, 0xe0, 0x60, 0xa0,
0x20, 0xc0, 0x40, 0x80, 0x00, };
+/*! Update Waiting Time (WT)
+ * @param[in] wi Waiting Integer (0 if unchanged)
+ * @param[in] d Baud Rate divider (0 if unchanged)
+ * @note set wt to be used by the receiver timeout
+ * @note defined in ISO/IEC 7816-3:2006(E) section 8.1 and 10.2
+ */
+static void update_wt(uint8_t wi, uint8_t d)
+{
+ static uint8_t wt_wi = 10; /* Waiting time Integer (WI), used to
calculate the Waiting Time (WT) */
+ static uint8_t wt_d = 1; /* baud rate adjustment integer (the actual
value, not the table index) */
+
+ if (0!=wi) {
+ wt_wi = wi;
+ }
+ if (0!=d) {
+ wt_d = d;
+ }
+ wt = wt_wi*960UL*wt_d;
+ TRACE_INFO("WT updated to %u\n\r", wt);
+}
+
/*! Update the ISO 7816-3 state
* @param[in] iso_state_new new ISO 7816-3 state to update to
*/
@@ -203,6 +229,7 @@
switch (iso_state_new) {
case ISO7816_S_RESET:
update_fidi(sniff_usart.base, 0x11); /* reset baud rate to
default Di/Fi values */
+ update_wt(10, 1); /* reset WT time-out */
change_flags |= SNIFF_CHANGE_FLAG_RESET_HOLD; /* set flag and
let main loop send it */
break;
case ISO7816_S_WAIT_ATR:
@@ -287,6 +314,7 @@
{
static uint8_t atr_hist_len = 0; /* store the number of expected
historical bytes */
static uint8_t y = 0; /* last mask of the upcoming TA, TB, TC, TD
interface bytes */
+ static uint8_t i = 0; /* interface byte subgroup number */
/* sanity check */
if (ISO7816_S_IN_ATR!=iso_state) {
@@ -316,6 +344,7 @@
atr_i--; /* revert last byte */
TRACE_WARNING("Invalid TS received\n\r");
}
+ i = 0; /* first interface byte sub-group is coming (T0 is kind
of TD0) */
break;
case ATR_S_WAIT_T0: /* see ISO/IEC 7816-3:2006 section 8.2.2 */
case ATR_S_WAIT_TD: /* see ISO/IEC 7816-3:2006 section 8.2.3 */
@@ -325,6 +354,7 @@
t_protocol_support |= (1<<(byte&0x0f)); /* remember
supported protocol to know if TCK will be present */
}
y = (byte&0xf0); /* remember upcoming interface bytes */
+ i++; /* next interface byte sub-group is coming */
if (y&0x10) {
atr_state = ATR_S_WAIT_TA; /* wait for interface byte
TA */
break;
@@ -340,6 +370,14 @@
break;
}
case ATR_S_WAIT_TC: /* see ISO/IEC 7816-3:2006 section 8.2.3 */
+ /* retrieve WI encoded in TC2*/
+ if (ATR_S_WAIT_TC==atr_state && 2==i) {
+ if (0==byte) {
+ update_wt(10, 0);
+ } else {
+ update_wt(byte, 0);
+ }
+ }
if (y&0x80) {
atr_state = ATR_S_WAIT_TD; /* wait for interface byte
TD */
break;
@@ -548,6 +586,7 @@
}
TRACE_INFO("PPS negotiation successful: Fn=%u
Dn=%u\n\r", fi_table[fn], di_table[dn]);
update_fidi(sniff_usart.base, pps_cur[2]);
+ update_wt(0, di_table[dn]);
usb_send_fidi(pps_cur[2]); /* send Fi/Di change
notification to host software over USB */
} else { /* checksum is invalid */
TRACE_INFO("PPS negotiation failed\n\r");
@@ -706,6 +745,9 @@
/*! Interrupt Service Routine called on USART activity */
void Sniffer_usart_isr(void)
{
+ /* Remaining Waiting Time (WI) counter (>16 bits) */
+ static volatile uint32_t wt_remaining = 9600;
+
/* Read channel status register */
uint32_t csr = sniff_usart.base->US_CSR;
/* Verify if there was an error */
@@ -717,10 +759,13 @@
TRACE_WARNING("USART framing error\n\r");
sniff_usart.base->US_CR |= US_CR_RSTSTA;
}
+
/* Verify if character has been received */
if (csr & US_CSR_RXRDY) {
/* Read communication data byte between phone and SIM */
uint8_t byte = sniff_usart.base->US_RHR;
+ /* Reset WT timer */
+ wt_remaining = wt;
/* Store sniffed data into buffer (also clear interrupt */
if (rbuf_is_full(&sniff_buffer)) {
TRACE_ERROR("USART buffer full\n\r");
@@ -728,13 +773,28 @@
rbuf_write(&sniff_buffer, byte);
}
}
-
+
/* Verify it WT timeout occurred, to detect unresponsive card */
if (csr & US_CSR_TIMEOUT) {
- /* Stop timeout until next character is received */
+ if (wt_remaining<=(sniff_usart.base->US_RTOR&0xffff)) {
+ /* Just set the flag and let the main loop handle it */
+ change_flags |= SNIFF_CHANGE_FLAG_TIMEOUT_WT;
+ /* Reset timeout value */
+ wt_remaining = wt;
+ } else {
+ wt_remaining -= (sniff_usart.base->US_RTOR&0xffff); /*
be sure to subtract the actual timeout since the new might not have been set
and reloaded yet */
+ }
+ if (wt_remaining>0xffff) {
+ sniff_usart.base->US_RTOR = 0xffff;
+ } else {
+ sniff_usart.base->US_RTOR = wt_remaining;
+ }
+ /* Stop timeout until next character is received (and clears
the timeout flag) */
sniff_usart.base->US_CR |= US_CR_STTTO;
- /* Just set the flag and let the main loop handle it */
- change_flags |= SNIFF_CHANGE_FLAG_TIMEOUT_WT;
+ if (!(change_flags & SNIFF_CHANGE_FLAG_TIMEOUT_WT)) {
+ /* Immediately restart the counter it the WT timeout
did not occur (needs the timeout flag to be cleared) */
+ sniff_usart.base->US_CR |= US_CR_RETTO;
+ }
}
}
@@ -825,8 +885,8 @@
ISO7816_Init(&sniff_usart, CLK_SLAVE);
/* Only receive data when sniffing */
USART_SetReceiverEnabled(sniff_usart.base, 1);
- /* Enable Receiver time-out WT to detect unresponsive cards */
- sniff_usart.base->US_RTOR = 9600-12; /* -12 because the timer starts at
the end of the 12 ETU frame */
+ /* Enable Receiver time-out to detect waiting time (WT) time-out (e.g.
unresponsive cards) */
+ sniff_usart.base->US_RTOR = wt;
/* Enable interrupt to indicate when data has been received or timeout
occurred */
USART_EnableIt(sniff_usart.base, US_IER_RXRDY | US_IER_TIMEOUT);
/* Set USB priority lower than USART to not miss sniffing data (both at
0 per default) */
--
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Gerrit-Project: simtrace2
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I9735660ffce161cec8d4e63fa60a66fc8ef57525
Gerrit-Change-Number: 9882
Gerrit-PatchSet: 1
Gerrit-Owner: Kévin Redon <kre...@sysmocom.de>
