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return a REJECT reason
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@folkertvanheusden
folkertvanheusden committed Oct 13, 2024
1 parent ecd328e commit 3bcca70
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Showing 6 changed files with 93 additions and 55 deletions.
7 changes: 5 additions & 2 deletions iscsi-pdu.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1156,7 +1156,7 @@ std::vector<blob_t> iscsi_pdu_taskman_reply::get() const
return get_helper(taskman_reply, nullptr, 0);
}

std::optional<blob_t> generate_reject_pdu(const iscsi_pdu_bhs & about)
std::optional<blob_t> generate_reject_pdu(const iscsi_pdu_bhs & about, const std::optional<uint8_t> reason)
{
struct __reject__ {
uint8_t b1;
Expand Down Expand Up @@ -1202,7 +1202,10 @@ std::optional<blob_t> generate_reject_pdu(const iscsi_pdu_bhs & about)
set_bits(&reject->b1, 0, 6, iscsi_pdu_bhs::iscsi_bhs_opcode::o_reject); // 0x3f
set_bits(&reject->b2, 7, 1, true);

reject->reason = 0x09; // (invalid PDU field)
if (reason.has_value())
reject->reason = reason.value();
else
reject->reason = 0x09; // (invalid PDU field)

size_t s = sizeof *reject;
blob_t out { duplicate_new(reinterpret_cast<uint8_t *>(reject), s), s };
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2 changes: 1 addition & 1 deletion iscsi-pdu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -142,7 +142,7 @@ struct iscsi_response_set

std::optional<std::string> pdu_opcode_to_string(const iscsi_pdu_bhs::iscsi_bhs_opcode opcode);

std::optional<blob_t> generate_reject_pdu(const iscsi_pdu_bhs & about);
std::optional<blob_t> generate_reject_pdu(const iscsi_pdu_bhs & about, const std::optional<uint8_t> reason = { });

class iscsi_pdu_login_request : public iscsi_pdu_bhs // login request 0x03
{
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2 changes: 2 additions & 0 deletions iscsi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,8 @@

enum residual { iSR_OVERFLOW, iSR_UNDERFLOW, iSR_OK }; // iSR: iS(CSI) Residual

enum iscsi_fail_reason { IFR_OK, IFR_CONNECTION, IFR_INVALID_FIELD, IFR_DIGEST, IFR_IO_ERROR, IFR_MISC, IFR_INVALID_COMMAND };

typedef struct {
uint8_t *data;
size_t n;
Expand Down
2 changes: 1 addition & 1 deletion log.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -86,7 +86,7 @@ namespace logging {
#if defined(RP2040W)
log_level_t log_level_syslog = logging::ll_info;
#else
log_level_t log_level_syslog = logging::ll_error;
log_level_t log_level_syslog = logging::ll_debug;
#endif

void sendsyslog(const logging::log_level_t ll, const char *const component, const std::string context, const char *fmt, ...)
Expand Down
129 changes: 81 additions & 48 deletions server.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@ server::~server()
#endif
}

std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *const cc, session **const ses)
std::tuple<iscsi_pdu_bhs *, iscsi_fail_reason, uint64_t> server::receive_pdu(com_client *const cc, session **const ses)
{
if (*ses == nullptr) {
*ses = new session(cc, target_name, digest_chk);
Expand All @@ -60,7 +60,7 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
uint8_t pdu[48] { };
if (cc->recv(pdu, sizeof pdu) == false) {
DOLOG(logging::ll_info, "server::receive_pdu", cc->get_endpoint_name(), "PDU receive error");
return { nullptr, false, 0 };
return { nullptr, IFR_CONNECTION, 0 };
}

uint64_t tx_start = get_micros();
Expand All @@ -71,7 +71,7 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
iscsi_pdu_bhs bhs(*ses);
if (bhs.set(pdu, sizeof pdu) == false) {
DOLOG(logging::ll_debug, "server::receive_pdu", cc->get_endpoint_name(), "BHS validation error");
return { nullptr, false, tx_start };
return { nullptr, IFR_INVALID_FIELD, tx_start };
}

#if defined(ESP32) || defined(RP2040W)
Expand All @@ -84,13 +84,13 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
DOLOG(logging::ll_debug, "server::receive_pdu", cc->get_endpoint_name(), "opcode: %02xh / %s", bhs.get_opcode(), descr.has_value() ? descr.value().c_str() : "?");
#endif

iscsi_pdu_bhs *pdu_obj = nullptr;
bool pdu_error = false;
auto opcode = bhs.get_opcode();
iscsi_pdu_bhs *pdu_obj = nullptr;
iscsi_fail_reason pdu_error = IFR_OK;
bool has_digest = true;
auto opcode = bhs.get_opcode();
#if !defined(ARDUINO) && !defined(NDEBUG)
cmd_use_count[opcode]++;
#endif
bool has_digest = true;

switch(opcode) {
case iscsi_pdu_bhs::iscsi_bhs_opcode::o_login_req:
Expand Down Expand Up @@ -121,7 +121,7 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
default:
DOLOG(logging::ll_error, "server::receive_pdu", cc->get_endpoint_name(), "opcode %02xh not implemented", bhs.get_opcode());
pdu_obj = new iscsi_pdu_bhs(*ses);
pdu_error = true;
pdu_error = IFR_INVALID_COMMAND;
break;
}

Expand Down Expand Up @@ -182,7 +182,7 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
// verify digest
if (remote_header_digest != incoming_crc32c.first && digest_chk) {
ok = false;
pdu_error = true;
pdu_error = IFR_DIGEST;
DOLOG(logging::ll_info, "server::receive_pdu", cc->get_endpoint_name(), "header digest mismatch: received=%08x, calculated=%08x", remote_header_digest, incoming_crc32c.first);
}

Expand All @@ -194,7 +194,7 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
if (data_length > MAX_DATA_SEGMENT_SIZE) {
DOLOG(logging::ll_debug, "server::receive_pdu", cc->get_endpoint_name(), "initiator is pushing too many data (%zu bytes, max is %u)", data_length, MAX_DATA_SEGMENT_SIZE);
ok = false;
pdu_error = true;
pdu_error = IFR_INVALID_FIELD;
}
else if (data_length) {
size_t padded_data_length = (data_length + 3) & ~3;
Expand Down Expand Up @@ -228,7 +228,7 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
// verify digest
if (remote_data_digest != incoming_crc32c.first && digest_chk) {
ok = false;
pdu_error = true;
pdu_error = IFR_DIGEST;
DOLOG(logging::ll_info, "server::receive_pdu", cc->get_endpoint_name(), "data digest mismatch: received=%08x, calculated=%08x", remote_data_digest, incoming_crc32c.first);
}

Expand All @@ -247,9 +247,9 @@ std::tuple<iscsi_pdu_bhs *, bool, uint64_t> server::receive_pdu(com_client *cons
return { pdu_obj, pdu_error, tx_start };
}

bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_bhs *const pdu)
iscsi_fail_reason server::push_response(com_client *const cc, session *const ses, iscsi_pdu_bhs *const pdu)
{
bool ok = true;
iscsi_fail_reason ifr = IFR_OK;

std::optional<iscsi_response_set> response_set;

Expand All @@ -270,20 +270,20 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b

if (session == nullptr) {
DOLOG(logging::ll_debug, "server::push_response", cc->get_endpoint_name(), "DATA-OUT PDU references unknown TTT (%08x)", transfer_tag);
return false;
return IFR_INVALID_FIELD;
}
else if (data.has_value() && data.value().second > 0) {
auto block_size = s->get_block_size();
DOLOG(logging::ll_debug, "server::push_response", cc->get_endpoint_name(), "writing %zu bytes to offset LBA %zu + offset %u => %zu (in bytes)", data.value().second, session->buffer_lba, offset, session->buffer_lba * block_size + offset);

if (offset % block_size) {
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "offset is not multiple of block size");
return false;
return IFR_INVALID_FIELD;
}

if (data.value().second % block_size) {
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "data size is not multiple of block size");
return false;
return IFR_INVALID_FIELD;
}

scsi::scsi_rw_result rc = scsi::scsi_rw_result::rw_ok;
Expand All @@ -310,15 +310,15 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b

if (rc != scsi::rw_ok) {
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "DATA-OUT problem writing to backend: %d", rc);
return false;
return IFR_IO_ERROR;
}

session->bytes_done += data.value().second;
session->bytes_left -= data.value().second;
}
else if (!F) {
DOLOG(logging::ll_warning, "server::push_response", cc->get_endpoint_name(), "DATA-OUT PDU has no data?");
return false;
return IFR_INVALID_FIELD;
}

// create response
Expand All @@ -328,7 +328,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
iscsi_pdu_scsi_cmd response(ses);
if (response.set(session->PDU_initiator.data, session->PDU_initiator.n) == false) {
DOLOG(logging::ll_error, "server::push_response", cc->get_endpoint_name(), "response.set failed");
return false;
return IFR_MISC;
}
response_set = response.get_response(s, session->bytes_left);

Expand All @@ -347,7 +347,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
if (response->set(temp, transfer_tag, session->bytes_done, session->bytes_left) == false) {
DOLOG(logging::ll_error, "server::push_response", cc->get_endpoint_name(), "response->set failed");
delete response;
return false;
return IFR_MISC;
}

response_set.value().responses.push_back(response);
Expand All @@ -360,22 +360,25 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b

if (response_set.has_value() == false) {
DOLOG(logging::ll_debug, "server::push_response", cc->get_endpoint_name(), "no response from PDU");
return true;
return IFR_OK;
}

for(auto & pdu_out: response_set.value().responses) {
for(auto & blobs: pdu_out->get()) {
if (blobs.data == nullptr) {
ok = false;
ifr = IFR_INVALID_FIELD;
DOLOG(logging::ll_error, "server::push_response", cc->get_endpoint_name(), "PDU did not emit data bundle");
}

assert((blobs.n & 3) == 0);

if (ok) {
ok = cc->send(blobs.data, blobs.n);
if (!ok)
if (ifr == IFR_OK) {
bool ok = cc->send(blobs.data, blobs.n);
if (!ok) {
ifr = IFR_CONNECTION;
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "sending PDU to peer failed (%s)", strerror(errno));
}

ses->add_bytes_tx(blobs.n);
is->iscsiSsnTxDataOctets += blobs.n;
}
Expand Down Expand Up @@ -417,7 +420,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
residual_state = { iSR_OVERFLOW, scsi_has - iscsi_wants };

if (temp->set(reply_to, { }, residual_state, { }) == false) {
ok = false;
ifr = IFR_MISC;
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "iscsi_pdu_scsi_response::set returned error");
}

Expand All @@ -427,7 +430,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
delete [] out.data;
if (rc_tx == false) {
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "problem sending %zu bytes", out.n);
ok = false;
ifr = IFR_CONNECTION;
}
else {
ses->add_bytes_tx(out.n);
Expand Down Expand Up @@ -468,7 +471,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
if (rc != scsi::rw_ok) {
delete [] out.data;
DOLOG(logging::ll_error, "server::push_response", cc->get_endpoint_name(), "reading %u bytes failed: %d", current_n, rc);
ok = false;
ifr = IFR_CONNECTION;
break;
}

Expand All @@ -482,7 +485,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
delete [] out.data;
if (rc_tx == false) {
DOLOG(logging::ll_info, "server::push_response", cc->get_endpoint_name(), "problem sending %u bytes of block %" PRIu64 " to initiator", current_lba, current_n);
ok = false;
ifr = IFR_CONNECTION;
break;
}

Expand All @@ -495,7 +498,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b

DOLOG(logging::ll_debug, "server::push_response", "-", "---");

return ok;
return ifr;
}

void server::handler()
Expand Down Expand Up @@ -534,12 +537,13 @@ void server::handler()
#else
DOLOG(logging::ll_info, "server::handler", "-", "new session with %s", endpoint.c_str());
#endif
auto prev_output = get_millis();
uint32_t pdu_count = 0;
unsigned long busy = 0;
const long interval = 5000;
session *ses = nullptr;
bool ok = true;
auto prev_output = get_millis();
uint32_t pdu_count = 0;
unsigned long busy = 0;
const long interval = 5000;
session *ses = nullptr;
bool ok = true;
int fail_counter = 0;

do {
auto incoming = receive_pdu(cc, &ses);
Expand All @@ -552,12 +556,30 @@ void server::handler()

is->iscsiSsnCmdPDUs++;

if (std::get<1>(incoming)) { // something wrong with the received PDU?
DOLOG(logging::ll_debug, "server::handler", endpoint, "invalid PDU received");
iscsi_fail_reason ifr = std::get<1>(incoming);
if (ifr == IFR_OK) {
ifr = push_response(cc, ses, pdu);
if (ifr != IFR_OK)
is->iscsiInstSsnFailures++;
}

if (ifr != IFR_OK && ifr != IFR_CONNECTION) { // something wrong with the received PDU?
DOLOG(logging::ll_debug, "server::handler", endpoint, "invalid PDU");

is->iscsiInstSsnFormatErrors++;

std::optional<blob_t> reject = generate_reject_pdu(*pdu);
std::optional<uint8_t> reason;

if (ifr == IFR_INVALID_FIELD || ifr == IFR_IO_ERROR || ifr == IFR_MISC)
reason = 0x09;
else if (ifr == IFR_DIGEST)
reason = 0x02;
else if (ifr == IFR_INVALID_COMMAND)
reason = 0x05;
else
DOLOG(logging::ll_error, "server::handler", endpoint, "internal error, IFR %d not known", ifr);

std::optional<blob_t> reject = generate_reject_pdu(*pdu, reason);
if (reject.has_value() == false) {
DOLOG(logging::ll_error, "server::handler", endpoint, "cannot generate reject PDU");
continue;
Expand All @@ -567,22 +589,33 @@ void server::handler()
delete [] reject.value().data;
if (rc == false) {
DOLOG(logging::ll_error, "server::handler", endpoint, "cannot transmit reject PDU");
break;
ok = false;
}
else {
is->iscsiSsnTxDataOctets += reject.value().n;
DOLOG(logging::ll_debug, "server::handler", endpoint, "transmitted reject PDU");
}
is->iscsiSsnTxDataOctets += reject.value().n;

DOLOG(logging::ll_debug, "server::handler", endpoint, "transmitted reject PDU");
}
else {
ok = push_response(cc, ses, pdu);
if (!ok)
is->iscsiInstSsnFailures++;
}

delete pdu;

pdu_count++;

if (ifr == IFR_OK)
fail_counter = 0;
else {
fail_counter++;
if (fail_counter >= 16) {
ok = false;
DOLOG(logging::ll_info, "server::handler", endpoint, "disconnecting because of too many consecutive errors");
}
}

if (ifr == IFR_CONNECTION) {
DOLOG(logging::ll_debug, "server::handler", endpoint, "disconnected");
ok = false;
}

auto tx_start = std::get<2>(incoming);
auto tx_end = get_micros();
busy += tx_end - tx_start;
Expand Down
6 changes: 3 additions & 3 deletions server.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,9 +29,9 @@ class server
std::atomic_uint64_t cmd_use_count[64] { };
#endif

std::tuple<iscsi_pdu_bhs *, bool, uint64_t>
receive_pdu (com_client *const cc, session **const s);
bool push_response(com_client *const cc, session *const s, iscsi_pdu_bhs *const pdu);
std::tuple<iscsi_pdu_bhs *, iscsi_fail_reason, uint64_t>
receive_pdu (com_client *const cc, session **const s);
iscsi_fail_reason push_response(com_client *const cc, session *const s, iscsi_pdu_bhs *const pdu);

public:
server(scsi *const s, com *const c, iscsi_stats_t *is, const std::string & target_name, const bool digest_chk);
Expand Down

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