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Fix broadcasting of messages with headers with NULL or all-whitespace values #873

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Merged
kozlovic merged 2 commits into from
Jun 4, 2025
Merged

Fix broadcasting of messages with headers with NULL or all-whitespace values #873

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a039043
Fix broadcasting of messages with headers with NULL or all-whitespace…
habbbe Jun 2, 2025
03c6965
PR feedback: Improve tests
habbbe Jun 2, 2025
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46 changes: 35 additions & 11 deletions src/msg.c
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Original file line number Diff line number Diff line change
Expand Up @@ -53,7 +53,7 @@ natsMsgHeader_encodedLen(natsMsg *msg)
for (c = v; c != NULL; c = c->next)
{
hl += (int) strlen(key) + 2; // 2 for ": "
hl += (int) strlen(c->value) + _CRLF_LEN_;
hl += (int) (c->value == NULL ? 0 : strlen(c->value)) + _CRLF_LEN_;
}
}
natsStrHashIter_Done(&iter);
Expand Down Expand Up @@ -98,7 +98,7 @@ natsMsgHeader_encode(natsBuffer *buf, natsMsg *msg)
s = natsBuf_Append(buf, ": ", 2);
if (s == NATS_OK)
{
int vl = (int) strlen(c->value);
int vl = (c->value == NULL ? 0 : (int) strlen(c->value));
int pos = natsBuf_Len(buf);

s = natsBuf_Append(buf, (const char*) c->value, vl);
Expand Down Expand Up @@ -209,6 +209,8 @@ _processKeyValue(int line, natsMsg *msg, char *endPtr, char **pPtr, char **lastK
bool ml = false;
char *start;
char *endval;
bool isNullVal = false;
bool tmpCarRet = false;

start = ptr;
if (*ptr == '\r')
Expand Down Expand Up @@ -243,7 +245,19 @@ _processKeyValue(int line, natsMsg *msg, char *endPtr, char **pPtr, char **lastK
}

while ((ptr != endPtr) && (isspace((unsigned char) *ptr)))
{
if (tmpCarRet && (*ptr == '\n'))
{
// Value was NULL, or only whitespaces. Set pointer to before
// \r\n for further processing.
isNullVal = true;
ptr--;
break;
}

tmpCarRet = *ptr == '\r';
ptr++;
}

if (ptr == endPtr)
return nats_setError(NATS_PROTOCOL_ERROR, "no value found for key %s", key);
Expand All @@ -254,16 +268,26 @@ _processKeyValue(int line, natsMsg *msg, char *endPtr, char **pPtr, char **lastK
if (ptr == endPtr)
return nats_setError(NATS_PROTOCOL_ERROR, "no CRLF found for value of key %s", key);

// Trim right spaces and set to \0 to terminate the value string.
endval = ptr;
// Backtrack to \r and any space characters. Make sure we don't go
// past the beginning of the value pointer.
endval--;
if (*endval == '\r')
endval--;
while ((endval != val) && (isspace((unsigned char) *endval)))
if (isNullVal)
{
// For NULL or all-whitespace values, set the end value to the \r
// at the end.
endval = val;
}
else
{
// Trim right spaces and set to \0 to terminate the value string.
endval = ptr;
// Backtrack to \r and any space characters. Make sure we don't go
// past the beginning of the value pointer.
endval--;
endval++;
if (*endval == '\r')
endval--;
while ((endval != val) && (isspace((unsigned char)*endval)))
endval--;
endval++;
}

*(endval) = '\0';

if (ml)
Expand Down
69 changes: 57 additions & 12 deletions test/test.c
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Original file line number Diff line number Diff line change
Expand Up @@ -5129,6 +5129,12 @@ void test_HeadersLift(void)
snprintf(buf, sizeof(buf), "%sk: a\r\n bc\r\n def\r\n\r\n", HDR_LINE);
_testHeader("Multiline values: ", buf, NATS_OK, "", "k", "a bc def");

snprintf(buf, sizeof(buf), "%sk:\r\n\r\n", HDR_LINE);
_testHeader("No value: ", buf, NATS_OK, "no value found for key", "k", "");

snprintf(buf, sizeof(buf), "%sk: \r\n\r\n", HDR_LINE);
_testHeader("No value (extra spaces): ", buf, NATS_OK, "no value found for key", "k", "");

snprintf(buf, sizeof(buf), "%s", "NATS\r\nk:v\r\n\r\n");
_testHeader("NATS header missing: ", buf, NATS_PROTOCOL_ERROR, "header prefix missing", NULL, NULL);

Expand All @@ -5144,12 +5150,6 @@ void test_HeadersLift(void)
snprintf(buf, sizeof(buf), "%sk\r\n\r\n", HDR_LINE);
_testHeader("Column missing: ", buf, NATS_PROTOCOL_ERROR, "column delimiter not found", NULL, NULL);

snprintf(buf, sizeof(buf), "%sk:\r\n\r\n", HDR_LINE);
_testHeader("No value: ", buf, NATS_PROTOCOL_ERROR, "no value found for key", NULL, NULL);

snprintf(buf, sizeof(buf), "%sk: \r\n\r\n", HDR_LINE);
_testHeader("No value (extra spaces): ", buf, NATS_PROTOCOL_ERROR, "no value found for key", NULL, NULL);

// Check status description in header line prefix...

snprintf(buf, sizeof(buf), "%s 503\r\n\r\n", HDR_LINE_PRE);
Expand Down Expand Up @@ -20072,12 +20072,14 @@ void test_HeadersNotSupported(void)
void test_HeadersBasic(void)
{
natsStatus s;
natsConnection *nc = NULL;
natsPid pid = NATS_INVALID_PID;
natsMsg *msg = NULL;
natsMsg *rmsg = NULL;
natsSubscription *sub = NULL;
const char *val = NULL;
natsConnection *nc = NULL;
natsPid pid = NATS_INVALID_PID;
natsMsg *msg = NULL;
natsMsg *rmsg = NULL;
natsSubscription *sub = NULL;
const char *val = NULL;
int count = 0;
const char **values = NULL;

if (!serverVersionAtLeast(2, 2, 0))
{
Expand Down Expand Up @@ -20109,6 +20111,24 @@ void test_HeadersBasic(void)
IFOK(s, natsMsgHeader_Set(msg, "Headers", "Hello Headers!"))
testCond(s == NATS_OK);

test("Add NULL header: ");
IFOK(s, natsMsgHeader_Add(msg, "NULL header", NULL))
testCond(s == NATS_OK);

test("Add empty header: ");
IFOK(s, natsMsgHeader_Add(msg, "Empty header", ""))
testCond(s == NATS_OK);

test("Add whitespace header: ");
IFOK(s, natsMsgHeader_Add(msg, "Whitespace header", " "))
testCond(s == NATS_OK);

test("Add NULL, empty, and whitespace values under same header: ");
IFOK(s, natsMsgHeader_Add(msg, "Special-Headers", NULL))
IFOK(s, natsMsgHeader_Add(msg, "Special-Headers", ""))
IFOK(s, natsMsgHeader_Add(msg, "Special-Headers", " "))
testCond(s == NATS_OK);

test("Publish with headers ok: ");
s = natsConnection_PublishMsg(nc, msg);
testCond(s == NATS_OK);
Expand All @@ -20134,6 +20154,31 @@ void test_HeadersBasic(void)
&& (natsMsg_GetDataLength(rmsg) == 4)
&& (strncmp(natsMsg_GetData(msg), "body", 4) == 0));

test("Check NULL header: ");
s = natsMsgHeader_Get(rmsg, "NULL header", &val);
testCond((s == NATS_OK)
&& (val != NULL) && *val == '\0');

test("Check empty header: ");
s = natsMsgHeader_Get(rmsg, "Empty header", &val);
testCond((s == NATS_OK)
&& (val != NULL) && *val == '\0');

test("Check whitespace header: ");
s = natsMsgHeader_Get(rmsg, "Whitespace header", &val);
testCond((s == NATS_OK)
&& (val != NULL) && *val == '\0');

test("Check getting values from special header: ");
s = natsMsgHeader_Values(rmsg, "Special-Headers", &values, &count);
testCond((s == NATS_OK) && (count == 3)
&& (values != NULL)
&& (*values[0] == '\0')
&& (*values[1] == '\0')
&& (*values[2] == '\0'));
free(values);
values = NULL;

natsMsg_Destroy(rmsg);
rmsg = NULL;
test("Value with CRLFs replaced with spaces: ");
Expand Down