<p>Kévin Redon has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/9882">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">sniffer: add waiting time WT update<br><br>the waiting time (WT) is used to detect timeouts (e.g. for<br>unresponsive card or just to signal an error/NAK). it is essential<br>to detect to timeout to end current data transfer (e.g. change state).<br>by default (after a reset) to timeout is 9600 ETU, but this can change<br>at two places:<br>- after the ATR using the value of TC2 (if present)<br>- after a PPS (only F is used, and not D)<br><br>because the timeout value can be larger than the 16-bit of the USART<br>TO register, an external variable needs to be used for the count down.<br><br>Change-Id: I9735660ffce161cec8d4e63fa60a66fc8ef57525<br>---<br>M firmware/libcommon/source/sniffer.c<br>1 file changed, 66 insertions(+), 6 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/simtrace2 refs/changes/82/9882/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/firmware/libcommon/source/sniffer.c b/firmware/libcommon/source/sniffer.c</span><br><span>index 70d3734..e6fe68f 100644</span><br><span>--- a/firmware/libcommon/source/sniffer.c</span><br><span>+++ b/firmware/libcommon/source/sniffer.c</span><br><span>@@ -178,6 +178,11 @@</span><br><span> /*! Current index in TPDU packet */</span><br><span> uint16_t tpdu_packet_i = 0;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/*! Waiting Time (WT)</span><br><span style="color: hsl(120, 100%, 40%);">+ * @note defined in ISO/IEC 7816-3:2006(E) section 8.1 and 10.2</span><br><span style="color: hsl(120, 100%, 40%);">+ */</span><br><span style="color: hsl(120, 100%, 40%);">+uint32_t wt = 9600;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*------------------------------------------------------------------------------</span><br><span> * Internal functions</span><br><span> *------------------------------------------------------------------------------*/</span><br><span>@@ -188,6 +193,27 @@</span><br><span> */</span><br><span> 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, };</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/*! Update Waiting Time (WT)</span><br><span style="color: hsl(120, 100%, 40%);">+ * @param[in] wi Waiting Integer (0 if unchanged)</span><br><span style="color: hsl(120, 100%, 40%);">+ * @param[in] d Baud Rate divider (0 if unchanged)</span><br><span style="color: hsl(120, 100%, 40%);">+ * @note set wt to be used by the receiver timeout</span><br><span style="color: hsl(120, 100%, 40%);">+ * @note defined in ISO/IEC 7816-3:2006(E) section 8.1 and 10.2</span><br><span style="color: hsl(120, 100%, 40%);">+ */</span><br><span style="color: hsl(120, 100%, 40%);">+static void update_wt(uint8_t wi, uint8_t d)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ static uint8_t wt_wi = 10; /* Waiting time Integer (WI), used to calculate the Waiting Time (WT) */</span><br><span style="color: hsl(120, 100%, 40%);">+ static uint8_t wt_d = 1; /* baud rate adjustment integer (the actual value, not the table index) */</span><br><span style="color: hsl(120, 100%, 40%);">+ </span><br><span style="color: hsl(120, 100%, 40%);">+ if (0!=wi) {</span><br><span style="color: hsl(120, 100%, 40%);">+ wt_wi = wi;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ if (0!=d) {</span><br><span style="color: hsl(120, 100%, 40%);">+ wt_d = d;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ wt = wt_wi*960UL*wt_d;</span><br><span style="color: hsl(120, 100%, 40%);">+ TRACE_INFO("WT updated to %u\n\r", wt);</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! Update the ISO 7816-3 state</span><br><span> * @param[in] iso_state_new new ISO 7816-3 state to update to</span><br><span> */</span><br><span>@@ -203,6 +229,7 @@</span><br><span> switch (iso_state_new) {</span><br><span> case ISO7816_S_RESET:</span><br><span> update_fidi(sniff_usart.base, 0x11); /* reset baud rate to default Di/Fi values */</span><br><span style="color: hsl(120, 100%, 40%);">+ update_wt(10, 1); /* reset WT time-out */</span><br><span> change_flags |= SNIFF_CHANGE_FLAG_RESET_HOLD; /* set flag and let main loop send it */</span><br><span> break;</span><br><span> case ISO7816_S_WAIT_ATR:</span><br><span>@@ -287,6 +314,7 @@</span><br><span> {</span><br><span> static uint8_t atr_hist_len = 0; /* store the number of expected historical bytes */</span><br><span> static uint8_t y = 0; /* last mask of the upcoming TA, TB, TC, TD interface bytes */</span><br><span style="color: hsl(120, 100%, 40%);">+ static uint8_t i = 0; /* interface byte subgroup number */</span><br><span> </span><br><span> /* sanity check */</span><br><span> if (ISO7816_S_IN_ATR!=iso_state) {</span><br><span>@@ -316,6 +344,7 @@</span><br><span> atr_i--; /* revert last byte */</span><br><span> TRACE_WARNING("Invalid TS received\n\r");</span><br><span> }</span><br><span style="color: hsl(120, 100%, 40%);">+ i = 0; /* first interface byte sub-group is coming (T0 is kind of TD0) */</span><br><span> break;</span><br><span> case ATR_S_WAIT_T0: /* see ISO/IEC 7816-3:2006 section 8.2.2 */</span><br><span> case ATR_S_WAIT_TD: /* see ISO/IEC 7816-3:2006 section 8.2.3 */</span><br><span>@@ -325,6 +354,7 @@</span><br><span> t_protocol_support |= (1<<(byte&0x0f)); /* remember supported protocol to know if TCK will be present */</span><br><span> }</span><br><span> y = (byte&0xf0); /* remember upcoming interface bytes */</span><br><span style="color: hsl(120, 100%, 40%);">+ i++; /* next interface byte sub-group is coming */</span><br><span> if (y&0x10) {</span><br><span> atr_state = ATR_S_WAIT_TA; /* wait for interface byte TA */</span><br><span> break;</span><br><span>@@ -340,6 +370,14 @@</span><br><span> break;</span><br><span> }</span><br><span> case ATR_S_WAIT_TC: /* see ISO/IEC 7816-3:2006 section 8.2.3 */</span><br><span style="color: hsl(120, 100%, 40%);">+ /* retrieve WI encoded in TC2*/</span><br><span style="color: hsl(120, 100%, 40%);">+ if (ATR_S_WAIT_TC==atr_state && 2==i) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (0==byte) {</span><br><span style="color: hsl(120, 100%, 40%);">+ update_wt(10, 0);</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ update_wt(byte, 0);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> if (y&0x80) {</span><br><span> atr_state = ATR_S_WAIT_TD; /* wait for interface byte TD */</span><br><span> break;</span><br><span>@@ -548,6 +586,7 @@</span><br><span> }</span><br><span> TRACE_INFO("PPS negotiation successful: Fn=%u Dn=%u\n\r", fi_table[fn], di_table[dn]);</span><br><span> update_fidi(sniff_usart.base, pps_cur[2]);</span><br><span style="color: hsl(120, 100%, 40%);">+ update_wt(0, di_table[dn]);</span><br><span> usb_send_fidi(pps_cur[2]); /* send Fi/Di change notification to host software over USB */</span><br><span> } else { /* checksum is invalid */</span><br><span> TRACE_INFO("PPS negotiation failed\n\r");</span><br><span>@@ -706,6 +745,9 @@</span><br><span> /*! Interrupt Service Routine called on USART activity */</span><br><span> void Sniffer_usart_isr(void)</span><br><span> {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Remaining Waiting Time (WI) counter (>16 bits) */</span><br><span style="color: hsl(120, 100%, 40%);">+ static volatile uint32_t wt_remaining = 9600;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Read channel status register */</span><br><span> uint32_t csr = sniff_usart.base->US_CSR;</span><br><span> /* Verify if there was an error */</span><br><span>@@ -717,10 +759,13 @@</span><br><span> TRACE_WARNING("USART framing error\n\r");</span><br><span> sniff_usart.base->US_CR |= US_CR_RSTSTA;</span><br><span> }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Verify if character has been received */</span><br><span> if (csr & US_CSR_RXRDY) {</span><br><span> /* Read communication data byte between phone and SIM */</span><br><span> uint8_t byte = sniff_usart.base->US_RHR;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Reset WT timer */</span><br><span style="color: hsl(120, 100%, 40%);">+ wt_remaining = wt;</span><br><span> /* Store sniffed data into buffer (also clear interrupt */</span><br><span> if (rbuf_is_full(&sniff_buffer)) {</span><br><span> TRACE_ERROR("USART buffer full\n\r");</span><br><span>@@ -728,13 +773,28 @@</span><br><span> rbuf_write(&sniff_buffer, byte);</span><br><span> }</span><br><span> }</span><br><span style="color: hsl(0, 100%, 40%);">- </span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Verify it WT timeout occurred, to detect unresponsive card */</span><br><span> if (csr & US_CSR_TIMEOUT) {</span><br><span style="color: hsl(0, 100%, 40%);">- /* Stop timeout until next character is received */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (wt_remaining<=(sniff_usart.base->US_RTOR&0xffff)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Just set the flag and let the main loop handle it */</span><br><span style="color: hsl(120, 100%, 40%);">+ change_flags |= SNIFF_CHANGE_FLAG_TIMEOUT_WT;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Reset timeout value */</span><br><span style="color: hsl(120, 100%, 40%);">+ wt_remaining = wt;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ 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 */</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ if (wt_remaining>0xffff) {</span><br><span style="color: hsl(120, 100%, 40%);">+ sniff_usart.base->US_RTOR = 0xffff;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ sniff_usart.base->US_RTOR = wt_remaining;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Stop timeout until next character is received (and clears the timeout flag) */</span><br><span> sniff_usart.base->US_CR |= US_CR_STTTO;</span><br><span style="color: hsl(0, 100%, 40%);">- /* Just set the flag and let the main loop handle it */</span><br><span style="color: hsl(0, 100%, 40%);">- change_flags |= SNIFF_CHANGE_FLAG_TIMEOUT_WT;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!(change_flags & SNIFF_CHANGE_FLAG_TIMEOUT_WT)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Immediately restart the counter it the WT timeout did not occur (needs the timeout flag to be cleared) */</span><br><span style="color: hsl(120, 100%, 40%);">+ sniff_usart.base->US_CR |= US_CR_RETTO;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> }</span><br><span> }</span><br><span> </span><br><span>@@ -825,8 +885,8 @@</span><br><span> ISO7816_Init(&sniff_usart, CLK_SLAVE);</span><br><span> /* Only receive data when sniffing */</span><br><span> USART_SetReceiverEnabled(sniff_usart.base, 1);</span><br><span style="color: hsl(0, 100%, 40%);">- /* Enable Receiver time-out WT to detect unresponsive cards */</span><br><span style="color: hsl(0, 100%, 40%);">- sniff_usart.base->US_RTOR = 9600-12; /* -12 because the timer starts at the end of the 12 ETU frame */</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Enable Receiver time-out to detect waiting time (WT) time-out (e.g. unresponsive cards) */</span><br><span style="color: hsl(120, 100%, 40%);">+ sniff_usart.base->US_RTOR = wt;</span><br><span> /* Enable interrupt to indicate when data has been received or timeout occurred */</span><br><span> USART_EnableIt(sniff_usart.base, US_IER_RXRDY | US_IER_TIMEOUT);</span><br><span> /* Set USB priority lower than USART to not miss sniffing data (both at 0 per default) */</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/9882">change 9882</a>. 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<div style="display:none"> Gerrit-Project: simtrace2 </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>
<div style="display:none"> Gerrit-Change-Id: I9735660ffce161cec8d4e63fa60a66fc8ef57525 </div>
<div style="display:none"> Gerrit-Change-Number: 9882 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Kévin Redon <kredon@sysmocom.de> </div>