Change in simtrace2[master]: sniffing: move conversion convertion and flag processing from ISR to ...

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Harald Welte gerrit-no-reply at lists.osmocom.org
Wed Jul 4 20:44:18 UTC 2018


Harald Welte has submitted this change and it was merged. ( https://gerrit.osmocom.org/9878 )

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

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

Change-Id: Ieefa8a5f81dbcc12c1ad3059660dbffa0c1a4961
---
M firmware/libcommon/source/sniffer.c
M host/simtrace2-sniff.c
2 files changed, 88 insertions(+), 64 deletions(-)

Approvals:
  Jenkins Builder: Verified
  Harald Welte: Looks good to me, approved



diff --git a/firmware/libcommon/source/sniffer.c b/firmware/libcommon/source/sniffer.c
index fe550ea..c2b8725 100644
--- a/firmware/libcommon/source/sniffer.c
+++ b/firmware/libcommon/source/sniffer.c
@@ -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"
@@ -221,26 +220,6 @@
 	usb_buf_submit(usb_msg);
 }
 
-/*! 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_msg_alloc_hdr(SIMTRACE_USB_EP_CARD_DATAIN, SIMTRACE_MSGC_SNIFF, SIMTRACE_MSGT_SNIFF_CHANGE);
-	if (!usb_msg) {
-		return;
-	}
-	struct sniff_change *usb_sniff_change = (struct sniff_change *) msgb_put(usb_msg, sizeof(*usb_sniff_change));
-	usb_sniff_change->flags = flags;
-	usb_msg_upd_len_and_submit(usb_msg);
-}
-
 /*! Update the ISO 7816-3 state
  *  @param[in] iso_state_new new ISO 7816-3 state to update to
  */
@@ -256,11 +235,11 @@
 	switch (iso_state_new) {
 	case ISO7816_S_RESET:
 		update_fidi(&sniff_usart, 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;
@@ -705,42 +684,34 @@
 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;
 	}
 }
 
@@ -844,6 +815,30 @@
 	}
 }
 
+/*! 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;
+	}
+
+	if (flags&SNIFF_CHANGE_FLAG_TIMEOUT_WT) {
+		printf("waiting time (WT) timeout\n\r");
+	}
+
+	/* Send message over USB */
+	struct msgb *usb_msg = usb_msg_alloc_hdr(SIMTRACE_USB_EP_CARD_DATAIN, SIMTRACE_MSGC_SNIFF, SIMTRACE_MSGT_SNIFF_CHANGE);
+	if (!usb_msg) {
+		return;
+	}
+	struct sniff_change *usb_sniff_change = (struct sniff_change *) msgb_put(usb_msg, sizeof(*usb_sniff_change));
+	usb_sniff_change->flags = flags;
+	usb_msg_upd_len_and_submit(usb_msg);
+}
+
 /* Main (idle/busy) loop of this USB configuration */
 void Sniffer_run(void)
 {
@@ -862,7 +857,11 @@
 	/* 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;
@@ -899,6 +898,31 @@
 
 	/* 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 */
diff --git a/host/simtrace2-sniff.c b/host/simtrace2-sniff.c
index dc4708f..67bfb79 100644
--- a/host/simtrace2-sniff.c
+++ b/host/simtrace2-sniff.c
@@ -92,7 +92,7 @@
 	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 @@
 	}
 	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 @@
 		printf("reset release ");
 	}
 	if (change->flags&SNIFF_CHANGE_FLAG_TIMEOUT_WT) {
-		// do nothing since this also triggers on inactivity
+		printf("data transfer timeout ");
 	}
-	if (SNIFF_CHANGE_FLAG_TIMEOUT_WT!=change->flags) {
-		printf("\n");
-	}
+	printf("\n");
 
 	return 0;
 }
@@ -131,7 +127,7 @@
 /* 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 @@
 	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)) {
@@ -165,7 +161,7 @@
 	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)) {
@@ -187,7 +183,7 @@
 	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)) {
@@ -200,17 +196,21 @@
 		return -2;
 	}
 
+	/* print TPDU */
 	printf("TPDU%s: ", tpdu->complete ? "" : " (incomplete)");
 	uint16_t i;
 	for (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)) {

-- 
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Gerrit-Project: simtrace2
Gerrit-Branch: master
Gerrit-MessageType: merged
Gerrit-Change-Id: Ieefa8a5f81dbcc12c1ad3059660dbffa0c1a4961
Gerrit-Change-Number: 9878
Gerrit-PatchSet: 13
Gerrit-Owner: Kévin Redon <kredon at sysmocom.de>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: Kévin Redon <kredon at sysmocom.de>
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