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MAC commands passed as messages to port 0 must be processed by LMIC, … #22

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MAC commands passed as messages to port 0 must be processed by LMIC, … #22

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260 changes: 147 additions & 113 deletions src/lmic/lmic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -626,7 +626,7 @@ void LMIC_disableChannel (u1_t channel) {
LMIC.channelMap &= ~(1<<channel);
}

static u4_t convFreq (xref2u1_t ptr) {
static u4_t convFreq (xref2cu1_t ptr) {
u4_t freq = (os_rlsbf4(ptr-1) >> 8) * 100;
if( freq < EU868_FREQ_MIN || freq > EU868_FREQ_MAX )
freq = 0;
Expand Down Expand Up @@ -1126,113 +1126,12 @@ static int decodeBeacon (void) {
}
#endif // !DISABLE_BEACONS


static bit_t decodeFrame (void) {
xref2u1_t d = LMIC.frame;
u1_t hdr = d[0];
u1_t ftype = hdr & HDR_FTYPE;
int dlen = LMIC.dataLen;
if( dlen < OFF_DAT_OPTS+4 ||
(hdr & HDR_MAJOR) != HDR_MAJOR_V1 ||
(ftype != HDR_FTYPE_DADN && ftype != HDR_FTYPE_DCDN) ) {
// Basic sanity checks failed
EV(specCond, WARN, (e_.reason = EV::specCond_t::UNEXPECTED_FRAME,
e_.eui = MAIN::CDEV->getEui(),
e_.info = dlen < 4 ? 0 : os_rlsbf4(&d[dlen-4]),
e_.info2 = hdr + (dlen<<8)));
norx:
#if LMIC_DEBUG_LEVEL > 0
const char *window = (LMIC.txrxFlags & TXRX_DNW1) ? "RX1" : ((LMIC.txrxFlags & TXRX_DNW2) ? "RX2" : "Other");
printf("%lu: Invalid downlink, window=%s\n", os_getTime(), window);
#endif
LMIC.dataLen = 0;
return 0;
}
// Validate exact frame length
// Note: device address was already read+evaluated in order to arrive here.
int fct = d[OFF_DAT_FCT];
u4_t addr = os_rlsbf4(&d[OFF_DAT_ADDR]);
u4_t seqno = os_rlsbf2(&d[OFF_DAT_SEQNO]);
int olen = fct & FCT_OPTLEN;
int ackup = (fct & FCT_ACK) != 0 ? 1 : 0; // ACK last up frame
int poff = OFF_DAT_OPTS+olen;
int pend = dlen-4; // MIC

if( addr != LMIC.devaddr ) {
EV(specCond, WARN, (e_.reason = EV::specCond_t::ALIEN_ADDRESS,
e_.eui = MAIN::CDEV->getEui(),
e_.info = addr,
e_.info2 = LMIC.devaddr));
goto norx;
}
if( poff > pend ) {
EV(specCond, ERR, (e_.reason = EV::specCond_t::CORRUPTED_FRAME,
e_.eui = MAIN::CDEV->getEui(),
e_.info = 0x1000000 + (poff-pend) + (fct<<8) + (dlen<<16)));
goto norx;
}

int port = -1;
int replayConf = 0;

if( pend > poff )
port = d[poff++];

seqno = LMIC.seqnoDn + (u2_t)(seqno - LMIC.seqnoDn);

if( !aes_verifyMic(LMIC.nwkKey, LMIC.devaddr, seqno, /*dn*/1, d, pend) ) {
EV(spe3Cond, ERR, (e_.reason = EV::spe3Cond_t::CORRUPTED_MIC,
e_.eui1 = MAIN::CDEV->getEui(),
e_.info1 = Base::lsbf4(&d[pend]),
e_.info2 = seqno,
e_.info3 = LMIC.devaddr));
goto norx;
}
if( seqno < LMIC.seqnoDn ) {
if( (s4_t)seqno > (s4_t)LMIC.seqnoDn ) {
EV(specCond, INFO, (e_.reason = EV::specCond_t::DNSEQNO_ROLL_OVER,
e_.eui = MAIN::CDEV->getEui(),
e_.info = LMIC.seqnoDn,
e_.info2 = seqno));
goto norx;
}
if( seqno != LMIC.seqnoDn-1 || !LMIC.dnConf || ftype != HDR_FTYPE_DCDN ) {
EV(specCond, INFO, (e_.reason = EV::specCond_t::DNSEQNO_OBSOLETE,
e_.eui = MAIN::CDEV->getEui(),
e_.info = LMIC.seqnoDn,
e_.info2 = seqno));
goto norx;
}
// Replay of previous sequence number allowed only if
// previous frame and repeated both requested confirmation
replayConf = 1;
}
else {
if( seqno > LMIC.seqnoDn ) {
EV(specCond, INFO, (e_.reason = EV::specCond_t::DNSEQNO_SKIP,
e_.eui = MAIN::CDEV->getEui(),
e_.info = LMIC.seqnoDn,
e_.info2 = seqno));
}
LMIC.seqnoDn = seqno+1; // next number to be expected
DO_DEVDB(LMIC.seqnoDn,seqnoDn);
// DN frame requested confirmation - provide ACK once with next UP frame
LMIC.dnConf = (ftype == HDR_FTYPE_DCDN ? FCT_ACK : 0);
}

if( LMIC.dnConf || (fct & FCT_MORE) )
LMIC.opmode |= OP_POLL;

// We heard from network
LMIC.adrChanged = LMIC.rejoinCnt = 0;
if( LMIC.adrAckReq != LINK_CHECK_OFF )
LMIC.adrAckReq = LINK_CHECK_INIT;

// Process OPTS
int m = LMIC.rssi - RSSI_OFF - getSensitivity(LMIC.rps);
LMIC.margin = m < 0 ? 0 : m > 254 ? 254 : m;

xref2u1_t opts = &d[OFF_DAT_OPTS];
// scan mac commands starting at opts[] for olen, return count of bytes consumed.
static int
scan_mac_cmds(
const uint8_t *opts,
int olen
) {
int oidx = 0;
while( oidx < olen ) {
switch( opts[oidx] ) {
Expand Down Expand Up @@ -1363,14 +1262,133 @@ static bit_t decodeFrame (void) {
#endif // !DISABLE_MCMD_BCNI_ANS && !DISABLE_BEACONS
oidx += 4;
continue;
}
}
} /* end case */
} /* end switch */
/* unrecognized mac commands fall out of switch to here */
EV(specCond, ERR, (e_.reason = EV::specCond_t::BAD_MAC_CMD,
e_.eui = MAIN::CDEV->getEui(),
e_.info = Base::lsbf4(&d[pend]),
e_.info2 = Base::msbf4(&opts[oidx])));
/* stop processing options */
break;
} /* end while */
return oidx;
}

static bit_t decodeFrame (void) {
xref2u1_t d = LMIC.frame;
u1_t hdr = d[0];
u1_t ftype = hdr & HDR_FTYPE;
int dlen = LMIC.dataLen;
#if LMIC_DEBUG_LEVEL > 0
const char *window = (LMIC.txrxFlags & TXRX_DNW1) ? "RX1" : ((LMIC.txrxFlags & TXRX_DNW2) ? "RX2" : "Other");
#endif

if( dlen < OFF_DAT_OPTS+4 ||
(hdr & HDR_MAJOR) != HDR_MAJOR_V1 ||
(ftype != HDR_FTYPE_DADN && ftype != HDR_FTYPE_DCDN) ) {
// Basic sanity checks failed
EV(specCond, WARN, (e_.reason = EV::specCond_t::UNEXPECTED_FRAME,
e_.eui = MAIN::CDEV->getEui(),
e_.info = dlen < 4 ? 0 : os_rlsbf4(&d[dlen-4]),
e_.info2 = hdr + (dlen<<8)));
norx:
#if LMIC_DEBUG_LEVEL > 0
printf("%lu: Invalid downlink, window=%s\n", os_getTime(), window);
#endif
LMIC.dataLen = 0;
return 0;
}
// Validate exact frame length
// Note: device address was already read+evaluated in order to arrive here.
int fct = d[OFF_DAT_FCT];
u4_t addr = os_rlsbf4(&d[OFF_DAT_ADDR]);
u4_t seqno = os_rlsbf2(&d[OFF_DAT_SEQNO]);
int olen = fct & FCT_OPTLEN;
int ackup = (fct & FCT_ACK) != 0 ? 1 : 0; // ACK last up frame
int poff = OFF_DAT_OPTS+olen;
int pend = dlen-4; // MIC

if( addr != LMIC.devaddr ) {
EV(specCond, WARN, (e_.reason = EV::specCond_t::ALIEN_ADDRESS,
e_.eui = MAIN::CDEV->getEui(),
e_.info = addr,
e_.info2 = LMIC.devaddr));
goto norx;
}
if( poff > pend ) {
EV(specCond, ERR, (e_.reason = EV::specCond_t::CORRUPTED_FRAME,
e_.eui = MAIN::CDEV->getEui(),
e_.info = 0x1000000 + (poff-pend) + (fct<<8) + (dlen<<16)));
goto norx;
}

int port = -1;
int replayConf = 0;

if( pend > poff )
port = d[poff++];

seqno = LMIC.seqnoDn + (u2_t)(seqno - LMIC.seqnoDn);

if( !aes_verifyMic(LMIC.nwkKey, LMIC.devaddr, seqno, /*dn*/1, d, pend) ) {
EV(spe3Cond, ERR, (e_.reason = EV::spe3Cond_t::CORRUPTED_MIC,
e_.eui1 = MAIN::CDEV->getEui(),
e_.info1 = Base::lsbf4(&d[pend]),
e_.info2 = seqno,
e_.info3 = LMIC.devaddr));
goto norx;
}
if( seqno < LMIC.seqnoDn ) {
if( (s4_t)seqno > (s4_t)LMIC.seqnoDn ) {
EV(specCond, INFO, (e_.reason = EV::specCond_t::DNSEQNO_ROLL_OVER,
e_.eui = MAIN::CDEV->getEui(),
e_.info = LMIC.seqnoDn,
e_.info2 = seqno));
goto norx;
}
if( seqno != LMIC.seqnoDn-1 || !LMIC.dnConf || ftype != HDR_FTYPE_DCDN ) {
EV(specCond, INFO, (e_.reason = EV::specCond_t::DNSEQNO_OBSOLETE,
e_.eui = MAIN::CDEV->getEui(),
e_.info = LMIC.seqnoDn,
e_.info2 = seqno));
goto norx;
}
// Replay of previous sequence number allowed only if
// previous frame and repeated both requested confirmation
replayConf = 1;
}
else {
if( seqno > LMIC.seqnoDn ) {
EV(specCond, INFO, (e_.reason = EV::specCond_t::DNSEQNO_SKIP,
e_.eui = MAIN::CDEV->getEui(),
e_.info = LMIC.seqnoDn,
e_.info2 = seqno));
}
LMIC.seqnoDn = seqno+1; // next number to be expected
DO_DEVDB(LMIC.seqnoDn,seqnoDn);
// DN frame requested confirmation - provide ACK once with next UP frame
LMIC.dnConf = (ftype == HDR_FTYPE_DCDN ? FCT_ACK : 0);
}

if( LMIC.dnConf || (fct & FCT_MORE) )
LMIC.opmode |= OP_POLL;

// We heard from network
LMIC.adrChanged = LMIC.rejoinCnt = 0;
if( LMIC.adrAckReq != LINK_CHECK_OFF )
LMIC.adrAckReq = LINK_CHECK_INIT;

// Process OPTS
int m = LMIC.rssi - RSSI_OFF - getSensitivity(LMIC.rps);
LMIC.margin = m < 0 ? 0 : m > 254 ? 254 : m;

#if LMIC_DEBUG_LEVEL > 0
printf("%lu: process options (olen=%#x)\n", os_getTime(), olen);
#endif

xref2u1_t opts = &d[OFF_DAT_OPTS];
int oidx = scan_mac_cmds(opts, olen);
if( oidx != olen ) {
EV(specCond, ERR, (e_.reason = EV::specCond_t::CORRUPTED_FRAME,
e_.eui = MAIN::CDEV->getEui(),
Expand All @@ -1380,9 +1398,25 @@ static bit_t decodeFrame (void) {
if( !replayConf ) {
// Handle payload only if not a replay
// Decrypt payload - if any
if( port >= 0 && pend-poff > 0 )
if( port >= 0 && pend-poff > 0 ) {
aes_cipher(port <= 0 ? LMIC.nwkKey : LMIC.artKey, LMIC.devaddr, seqno, /*dn*/1, d+poff, pend-poff);

if (port == 0) {
// this is a mac command. scan the options.
#if LMIC_DEBUG_LEVEL > 0
printf("%lu: process mac commands for port 0 (olen=%#x)\n", os_getTime(), pend-poff);
#endif
int optendindex = scan_mac_cmds(d+poff, pend-poff);
if (optendindex != pend-poff) {
#if LMIC_DEBUG_LEVEL > 0
printf(
"%lu: error processing mac commands for port 0 "
"(len=%#x, optendindex=%#x)\n",
os_getTime(), pend-poff, optendindex
);
#endif
}
}
} // end decrypt payload
EV(dfinfo, DEBUG, (e_.deveui = MAIN::CDEV->getEui(),
e_.devaddr = LMIC.devaddr,
e_.seqno = seqno,
Expand Down Expand Up @@ -1416,7 +1450,7 @@ static bit_t decodeFrame (void) {
if( LMIC.txCnt != 0 ) // we requested an ACK
LMIC.txrxFlags |= ackup ? TXRX_ACK : TXRX_NACK;

if( port < 0 ) {
if( port <= 0 ) {
LMIC.txrxFlags |= TXRX_NOPORT;
LMIC.dataBeg = poff;
LMIC.dataLen = 0;
Expand Down