sniffing: move conversion convertion and flag processing from ISR to main loop to keep ISR fast and focus on data capture

Change-Id: Ieefa8a5f81dbcc12c1ad3059660dbffa0c1a4961
This commit is contained in:
Kevin Redon 2018-07-03 16:10:04 +02:00
parent bdb0795e61
commit 36be182ea2
2 changed files with 98 additions and 73 deletions

View File

@ -19,8 +19,7 @@
*/
/* This code implement the Sniffer mode to sniff the communication between a SIM card (or any ISO 7816 smart card) and a phone (or any ISO 7816 card reader).
* For historical reasons (i.e. SIMtrace hardware) the USART peripheral connected to the SIM card is used.
* TODO handle RST, PTS, and send data over USB
* TODO put common ISO7816-3 code is separate library (and combine clean with iso7816_4)
* TODO put common ISO7816-3 code is separate library (and combine clean with iso7816_4)
*/
#include "board.h"
#include "simtrace.h"
@ -188,35 +187,6 @@ uint8_t tpdu_packet_i = 0;
*/
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, };
/*! Send card change flags over USB
* @param[in] flags change flags corresponding to SIMTRACE_MSGT_SNIFF_CHANGE
*/
static void usb_send_change(uint32_t flags)
{
/* Check flags */
if(0==flags) { /* no changes */
return;
}
/* Send message over USB */
struct msgb *usb_msg = usb_buf_alloc(SIMTRACE_USB_EP_CARD_DATAIN);
if (!usb_msg) {
return;
}
struct simtrace_msg_hdr *usb_msg_header;
usb_msg->l1h = msgb_put(usb_msg, sizeof(*usb_msg_header));
usb_msg_header = (struct simtrace_msg_hdr *) usb_msg->l1h;
memset(usb_msg_header, 0, sizeof(*usb_msg_header));
usb_msg_header->msg_class = SIMTRACE_MSGC_SNIFF;
usb_msg_header->msg_type = SIMTRACE_MSGT_SNIFF_CHANGE;
usb_msg->l2h = usb_msg->l1h + sizeof(*usb_msg_header);
struct sniff_change *usb_sniff_change;
usb_sniff_change = (struct sniff_change *) msgb_put(usb_msg, sizeof(*usb_sniff_change));
usb_sniff_change->flags = flags;
usb_msg_header->msg_len = msgb_length(usb_msg);
usb_buf_submit(usb_msg);
}
/*! Update the ISO 7816-3 state
* @param[in] iso_state_new new ISO 7816-3 state to update to
*/
@ -232,11 +202,11 @@ static void change_state(enum iso7816_3_sniff_state iso_state_new)
switch (iso_state_new) {
case ISO7816_S_RESET:
update_fidi(sniff_usart.base, 0x11); /* reset baud rate to default Di/Fi values */
usb_send_change(SNIFF_CHANGE_FLAG_RESET_HOLD); /* send reset change to host software over USB */
change_flags |= SNIFF_CHANGE_FLAG_RESET_HOLD; /* set flag and let main loop send it */
break;
case ISO7816_S_WAIT_ATR:
rbuf_reset(&sniff_buffer); /* reset buffer for new communication */
usb_send_change(SNIFF_CHANGE_FLAG_RESET_RELEASE); /* send reset change to host software over USB */
change_flags |= SNIFF_CHANGE_FLAG_RESET_RELEASE; /* set flag and let main loop send it */
break;
case ISO7816_S_IN_ATR:
atr_i = 0;
@ -714,42 +684,34 @@ static void process_byte_tpdu(uint8_t byte)
void Sniffer_usart_isr(void)
{
/* Read channel status register */
uint32_t csr = sniff_usart.base->US_CSR & sniff_usart.base->US_IMR;
uint32_t csr = sniff_usart.base->US_CSR;
/* Verify if there was an error */
if (csr & US_CSR_OVRE) {
TRACE_WARNING("USART overrun error\n\r");
sniff_usart.base->US_CR |= US_CR_RSTSTA;
}
if (csr & US_CSR_FRAME) {
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;
/* Convert convention if required */
if (convention_convert) {
byte = convention_convert_lut[byte];
}
/* Store sniffed data into buffer (also clear interrupt */
rbuf_write(&sniff_buffer, byte);
if (rbuf_is_full(&sniff_buffer)) {
TRACE_ERROR("USART buffer full\n\r");
} else {
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 */
sniff_usart.base->US_CR |= US_CR_STTTO;
/* Use timeout to detect end of ATR/PPS/TPDU */
switch (iso_state) {
case ISO7816_S_RESET:
case ISO7816_S_WAIT_ATR:
break;
case ISO7816_S_IN_ATR:
change_state(ISO7816_S_WAIT_ATR);
break;
case ISO7816_S_WAIT_TPDU:
break;
case ISO7816_S_WAIT_PPS_RSP:
case ISO7816_S_IN_TPDU:
case ISO7816_S_IN_PPS_REQ:
case ISO7816_S_IN_PPS_RSP:
change_state(ISO7816_S_WAIT_TPDU);
break;
default:
break;
}
usb_send_change(SNIFF_CHANGE_FLAG_TIMEOUT_WT); /* send timeout to host software over USB */
/* Just set the flag and let the main loop handle it */
change_flags |= SNIFF_CHANGE_FLAG_TIMEOUT_WT;
}
}
@ -853,6 +815,40 @@ void Sniffer_init(void)
}
}
/*! Send card change flags over USB
* @param[in] flags change flags corresponding to SIMTRACE_MSGT_SNIFF_CHANGE
* @note Also print the TPDU over the debug console
*/
static void usb_send_change(uint32_t flags)
{
/* Check flags */
if(0==flags) { /* no changes */
return;
}
if (flags&SNIFF_CHANGE_FLAG_TIMEOUT_WT) {
printf("waiting time (WT) timeout\n\r");
}
/* Send message over USB */
struct msgb *usb_msg = usb_buf_alloc(SIMTRACE_USB_EP_CARD_DATAIN);
if (!usb_msg) {
return;
}
struct simtrace_msg_hdr *usb_msg_header;
usb_msg->l1h = msgb_put(usb_msg, sizeof(*usb_msg_header));
usb_msg_header = (struct simtrace_msg_hdr *) usb_msg->l1h;
memset(usb_msg_header, 0, sizeof(*usb_msg_header));
usb_msg_header->msg_class = SIMTRACE_MSGC_SNIFF;
usb_msg_header->msg_type = SIMTRACE_MSGT_SNIFF_CHANGE;
usb_msg->l2h = usb_msg->l1h + sizeof(*usb_msg_header);
struct sniff_change *usb_sniff_change;
usb_sniff_change = (struct sniff_change *) msgb_put(usb_msg, sizeof(*usb_sniff_change));
usb_sniff_change->flags = flags;
usb_msg_header->msg_len = msgb_length(usb_msg);
usb_buf_submit(usb_msg);
}
/* Main (idle/busy) loop of this USB configuration */
void Sniffer_run(void)
{
@ -871,7 +867,11 @@ void Sniffer_run(void)
/* Handle sniffed data */
if (!rbuf_is_empty(&sniff_buffer)) { /* use if instead of while to let the main loop restart the watchdog */
uint8_t byte = rbuf_read(&sniff_buffer);
TRACE_DEBUG_WP("< 0x%02x\n\r", byte);
/* Convert convention if required */
if (convention_convert) {
byte = convention_convert_lut[byte];
}
//TRACE_ERROR_WP(">%02x", byte);
switch (iso_state) { /* Handle byte depending on state */
case ISO7816_S_RESET: /* During reset we shouldn't receive any data */
break;
@ -908,6 +908,31 @@ void Sniffer_run(void)
/* Handle flags */
if (change_flags) { /* WARNING this is not synced with the data buffer handling */
if (change_flags&SNIFF_CHANGE_FLAG_TIMEOUT_WT) {
/* Use timeout to detect interrupted data transmission */
switch (iso_state) {
case ISO7816_S_IN_ATR:
usb_send_atr(false); /* send incomplete ATR to host software using USB */
change_state(ISO7816_S_WAIT_ATR);
break;
case ISO7816_S_IN_TPDU:
usb_send_tpdu(false); /* send incomplete PPS to host software using USB */
change_state(ISO7816_S_WAIT_TPDU);
break;
case ISO7816_S_IN_PPS_REQ:
case ISO7816_S_IN_PPS_RSP:
usb_send_pps(false); /* send incomplete TPDU to host software using USB */
change_state(ISO7816_S_WAIT_TPDU);
break;
default:
change_flags &= ~SNIFF_CHANGE_FLAG_TIMEOUT_WT; /* We don't care about the timeout is all other cases */
break;
}
}
if (change_flags) {
usb_send_change(change_flags); /* send timeout to host software over USB */
change_flags = 0; /* Reset flags */
}
}
}
#endif /* HAVE_SNIFFER */

View File

@ -92,7 +92,7 @@ static int gsmtap_send_sim(const uint8_t *apdu, unsigned int len)
return 0;
}
static int process_change(uint8_t *buf, int len)
static int process_change(const uint8_t *buf, int len)
{
/* check if there is enough data for the structure */
if (len<sizeof(struct sniff_change)) {
@ -100,9 +100,7 @@ static int process_change(uint8_t *buf, int len)
}
struct sniff_change *change = (struct sniff_change *)buf;
if (SNIFF_CHANGE_FLAG_TIMEOUT_WT!=change->flags) {
printf("Card state change: ");
}
printf("Card state change: ");
if (change->flags&SNIFF_CHANGE_FLAG_CARD_INSERT) {
printf("card inserted ");
}
@ -116,11 +114,9 @@ static int process_change(uint8_t *buf, int len)
printf("reset release ");
}
if (change->flags&SNIFF_CHANGE_FLAG_TIMEOUT_WT) {
// do nothing since this also triggers on inactivity
}
if (SNIFF_CHANGE_FLAG_TIMEOUT_WT!=change->flags) {
printf("\n");
printf("data transfer timeout ");
}
printf("\n");
return 0;
}
@ -131,7 +127,7 @@ static const uint16_t fi_table[] = { 372, 372, 558, 744, 1116, 1488, 1860, 0, 0,
/* Table 8 from ISO 7816-3:2006 */
static const uint8_t di_table[] = { 0, 1, 2, 4, 8, 16, 32, 64, 12, 20, 2, 4, 8, 16, 32, 64, };
static int process_fidi(uint8_t *buf, int len)
static int process_fidi(const uint8_t *buf, int len)
{
/* check if there is enough data for the structure */
if (len<sizeof(struct sniff_fidi)) {
@ -143,7 +139,7 @@ static int process_fidi(uint8_t *buf, int len)
return 0;
}
static int process_atr(uint8_t *buf, int len)
static int process_atr(const uint8_t *buf, int len)
{
/* check if there is enough data for the structure */
if (len<sizeof(struct sniff_data)) {
@ -164,7 +160,7 @@ static int process_atr(uint8_t *buf, int len)
return 0;
}
static int process_pps(uint8_t *buf, int len)
static int process_pps(const uint8_t *buf, int len)
{
/* check if there is enough data for the structure */
if (len<sizeof(struct sniff_data)) {
@ -185,7 +181,7 @@ static int process_pps(uint8_t *buf, int len)
return 0;
}
static int process_tpdu(uint8_t *buf, int len)
static int process_tpdu(const uint8_t *buf, int len)
{
/* check if there is enough data for the structure */
if (len<sizeof(struct sniff_data)) {
@ -198,16 +194,20 @@ static int process_tpdu(uint8_t *buf, int len)
return -2;
}
/* print TPDU */
printf("TPDU%s: ", tpdu->complete ? "" : " (incomplete)");
for (uint16_t i=0; i<tpdu->length; i++) {
printf("%02x ", tpdu->data[i]);
}
printf("\n");
/* send TPDU (now considered as APDU) to GSMTAP */
gsmtap_send_sim(tpdu->data, tpdu->length);
return 0;
}
/*! \brief Process an incoming message from the SIMtrace2 */
static int process_usb_msg(uint8_t *buf, int len)
static int process_usb_msg(const uint8_t *buf, int len)
{
/* check if enough data for the header is present */
if (len<sizeof(struct simtrace_msg_hdr)) {