/*
* Attempt to read a Notify response message.
* This is possible in several places, so we break it out as a subroutine.
* Entry: 'A' message type and length have already been consumed.
* Exit: returns 0 if successfully consumed Notify message.
* returns EOF if not enough data.
*/
static int
getNotify(PGconn *conn)
{
int be_pid;
char *svname;
int nmlen;
int extralen;
PGnotify *newNotify;
if (pqGetInt(&be_pid, 4, conn))
return EOF;
if (pqGets(&conn->workBuffer, conn))
return EOF;
/* must save name while getting extra string */
svname = strdup(conn->workBuffer.data);
if (!svname)
return EOF;
if (pqGets(&conn->workBuffer, conn))
{
free(svname);
return EOF;
}
/*
* Store the strings right after the PQnotify structure so it can all be
* freed at once. We don't use NAMEDATALEN because we don't want to tie
* this interface to a specific server name length.
*/
nmlen = strlen(svname);
extralen = strlen(conn->workBuffer.data);
newNotify = (PGnotify *) malloc(sizeof(PGnotify) + nmlen + extralen + 2);
if (newNotify)
{
newNotify->relname = (char *) newNotify + sizeof(PGnotify);
strcpy(newNotify->relname, svname);
newNotify->extra = newNotify->relname + nmlen + 1;
strcpy(newNotify->extra, conn->workBuffer.data);
newNotify->be_pid = be_pid;
newNotify->next = NULL;
if (conn->notifyTail)
conn->notifyTail->next = newNotify;
else
conn->notifyHead = newNotify;
conn->notifyTail = newNotify;
}
free(svname);
return 0;
}
/*
* Attempt to read a ParameterStatus message.
* This is possible in several places, so we break it out as a subroutine.
* Entry: 'S' message type and length have already been consumed.
* Exit: returns 0 if successfully consumed message.
* returns EOF if not enough data.
*/
static int
getParameterStatus(PGconn *conn)
{
PQExpBufferData valueBuf;
/* Get the parameter name */
if (pqGets(&conn->workBuffer, conn))
return EOF;
/* Get the parameter value (could be large) */
initPQExpBuffer(&valueBuf);
if (pqGets(&valueBuf, conn))
{
termPQExpBuffer(&valueBuf);
return EOF;
}
/* And save it */
pqSaveParameterStatus(conn, conn->workBuffer.data, valueBuf.data);
termPQExpBuffer(&valueBuf);
return 0;
}
/*
* Attempt to read a Notify response message.
* This is possible in several places, so we break it out as a subroutine.
* Entry: 'A' message type and length have already been consumed.
* Exit: returns 0 if successfully consumed Notify message.
* returns EOF if not enough data.
*/
static int
getNotify(PGconn *conn)
{
int be_pid;
int nmlen;
PGnotify *newNotify;
if (pqGetInt(&be_pid, 4, conn))
return EOF;
if (pqGets(&conn->workBuffer, conn))
return EOF;
/*
* Store the relation name right after the PQnotify structure so it can
* all be freed at once. We don't use NAMEDATALEN because we don't want
* to tie this interface to a specific server name length.
*/
nmlen = strlen(conn->workBuffer.data);
newNotify = (PGnotify *) malloc(sizeof(PGnotify) + nmlen + 1);
if (newNotify)
{
newNotify->relname = (char *) newNotify + sizeof(PGnotify);
strcpy(newNotify->relname, conn->workBuffer.data);
/* fake up an empty-string extra field */
newNotify->extra = newNotify->relname + nmlen;
newNotify->be_pid = be_pid;
newNotify->next = NULL;
if (conn->notifyTail)
conn->notifyTail->next = newNotify;
else
conn->notifyHead = newNotify;
conn->notifyTail = newNotify;
}
return 0;
}
/*
* Attempt to read an Error or Notice response message.
* This is possible in several places, so we break it out as a subroutine.
* Entry: 'E' or 'N' message type has already been consumed.
* Exit: returns 0 if successfully consumed message.
* returns EOF if not enough data.
*/
static int
pqGetErrorNotice2(PGconn *conn, bool isError)
{
PGresult *res = NULL;
PQExpBufferData workBuf;
char *startp;
char *splitp;
/*
* Since the message might be pretty long, we create a temporary
* PQExpBuffer rather than using conn->workBuffer. workBuffer is intended
* for stuff that is expected to be short.
*/
initPQExpBuffer(&workBuf);
if (pqGets(&workBuf, conn))
goto failure;
/*
* Make a PGresult to hold the message. We temporarily lie about the
* result status, so that PQmakeEmptyPGresult doesn't uselessly copy
* conn->errorMessage.
*
* NB: This allocation can fail, if you run out of memory. The rest of the
* function handles that gracefully, and we still try to set the error
* message as the connection's error message.
*/
res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
if (res)
{
res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
res->errMsg = pqResultStrdup(res, workBuf.data);
}
/*
* Break the message into fields. We can't do very much here, but we can
* split the severity code off, and remove trailing newlines. Also, we use
* the heuristic that the primary message extends only to the first
* newline --- anything after that is detail message. (In some cases it'd
* be better classed as hint, but we can hardly be expected to guess that
* here.)
*/
while (workBuf.len > 0 && workBuf.data[workBuf.len - 1] == '\n')
workBuf.data[--workBuf.len] = '\0';
splitp = strstr(workBuf.data, ": ");
if (splitp)
{
/* what comes before the colon is severity */
*splitp = '\0';
pqSaveMessageField(res, PG_DIAG_SEVERITY, workBuf.data);
startp = splitp + 3;
}
else
{
/* can't find a colon? oh well... */
startp = workBuf.data;
}
splitp = strchr(startp, '\n');
if (splitp)
{
/* what comes before the newline is primary message */
*splitp++ = '\0';
pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, startp);
/* the rest is detail; strip any leading whitespace */
while (*splitp && isspace((unsigned char) *splitp))
splitp++;
pqSaveMessageField(res, PG_DIAG_MESSAGE_DETAIL, splitp);
}
else
{
/* single-line message, so all primary */
pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, startp);
}
/*
* Either save error as current async result, or just emit the notice.
* Also, if it's an error and we were in a transaction block, assume the
* server has now gone to error-in-transaction state.
*/
if (isError)
{
pqClearAsyncResult(conn);
conn->result = res;
resetPQExpBuffer(&conn->errorMessage);
if (res && !PQExpBufferDataBroken(workBuf) && res->errMsg)
appendPQExpBufferStr(&conn->errorMessage, res->errMsg);
else
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory"));
if (conn->xactStatus == PQTRANS_INTRANS)
conn->xactStatus = PQTRANS_INERROR;
}
else
{
if (res)
{
if (res->noticeHooks.noticeRec != NULL)
(*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res);
PQclear(res);
}
}
termPQExpBuffer(&workBuf);
return 0;
failure:
if (res)
PQclear(res);
termPQExpBuffer(&workBuf);
return EOF;
}
/*
* parseInput subroutine to read a 'T' (row descriptions) message.
* We build a PGresult structure containing the attribute data.
* Returns: 0 if completed message, EOF if error or not enough data
* received yet.
*
* Note that if we run out of data, we have to suspend and reprocess
* the message after more data is received. Otherwise, conn->inStart
* must get advanced past the processed data.
*/
static int
getRowDescriptions(PGconn *conn)
{
PGresult *result;
int nfields;
const char *errmsg;
int i;
result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
if (!result)
{
errmsg = NULL; /* means "out of memory", see below */
goto advance_and_error;
}
/* parseInput already read the 'T' label. */
/* the next two bytes are the number of fields */
if (pqGetInt(&(result->numAttributes), 2, conn))
goto EOFexit;
nfields = result->numAttributes;
/* allocate space for the attribute descriptors */
if (nfields > 0)
{
result->attDescs = (PGresAttDesc *)
pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
if (!result->attDescs)
{
errmsg = NULL; /* means "out of memory", see below */
goto advance_and_error;
}
MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
}
/* get type info */
for (i = 0; i < nfields; i++)
{
int typid;
int typlen;
int atttypmod;
if (pqGets(&conn->workBuffer, conn) ||
pqGetInt(&typid, 4, conn) ||
pqGetInt(&typlen, 2, conn) ||
pqGetInt(&atttypmod, 4, conn))
goto EOFexit;
/*
* Since pqGetInt treats 2-byte integers as unsigned, we need to
* coerce the result to signed form.
*/
typlen = (int) ((int16) typlen);
result->attDescs[i].name = pqResultStrdup(result,
conn->workBuffer.data);
if (!result->attDescs[i].name)
{
errmsg = NULL; /* means "out of memory", see below */
goto advance_and_error;
}
result->attDescs[i].tableid = 0;
result->attDescs[i].columnid = 0;
result->attDescs[i].format = 0;
result->attDescs[i].typid = typid;
result->attDescs[i].typlen = typlen;
result->attDescs[i].atttypmod = atttypmod;
}
/* Success! */
conn->result = result;
/* Advance inStart to show that the "T" message has been processed. */
conn->inStart = conn->inCursor;
/*
* We could perform additional setup for the new result set here, but for
* now there's nothing else to do.
*/
/* And we're done. */
return 0;
advance_and_error:
/*
* Discard the failed message. Unfortunately we don't know for sure where
* the end is, so just throw away everything in the input buffer. This is
* not very desirable but it's the best we can do in protocol v2.
*/
conn->inStart = conn->inEnd;
/*
* Replace partially constructed result with an error result. First
* discard the old result to try to win back some memory.
*/
pqClearAsyncResult(conn);
/*
* If preceding code didn't provide an error message, assume "out of
* memory" was meant. The advantage of having this special case is that
* freeing the old result first greatly improves the odds that gettext()
* will succeed in providing a translation.
*/
if (!errmsg)
errmsg = libpq_gettext("out of memory for query result");
printfPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
/*
* XXX: if PQmakeEmptyPGresult() fails, there's probably not much we can
* do to recover...
*/
conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
conn->asyncStatus = PGASYNC_READY;
EOFexit:
if (result && result != conn->result)
PQclear(result);
return EOF;
}
/*
* parseInput: if appropriate, parse input data from backend
* until input is exhausted or a stopping state is reached.
* Note that this function will NOT attempt to read more data from the backend.
*/
void
pqParseInput2(PGconn *conn)
{
char id;
/*
* Loop to parse successive complete messages available in the buffer.
*/
for (;;)
{
/*
* Quit if in COPY_OUT state: we expect raw data from the server until
* PQendcopy is called. Don't try to parse it according to the normal
* protocol. (This is bogus. The data lines ought to be part of the
* protocol and have identifying leading characters.)
*/
if (conn->asyncStatus == PGASYNC_COPY_OUT)
return;
/*
* OK to try to read a message type code.
*/
conn->inCursor = conn->inStart;
if (pqGetc(&id, conn))
return;
/*
* NOTIFY and NOTICE messages can happen in any state besides COPY
* OUT; always process them right away.
*
* Most other messages should only be processed while in BUSY state.
* (In particular, in READY state we hold off further parsing until
* the application collects the current PGresult.)
*
* However, if the state is IDLE then we got trouble; we need to deal
* with the unexpected message somehow.
*/
if (id == 'A')
{
if (getNotify(conn))
return;
}
else if (id == 'N')
{
if (pqGetErrorNotice2(conn, false))
return;
}
else if (conn->asyncStatus != PGASYNC_BUSY)
{
/* If not IDLE state, just wait ... */
if (conn->asyncStatus != PGASYNC_IDLE)
return;
/*
* Unexpected message in IDLE state; need to recover somehow.
* ERROR messages are displayed using the notice processor;
* anything else is just dropped on the floor after displaying a
* suitable warning notice. (An ERROR is very possibly the
* backend telling us why it is about to close the connection, so
* we don't want to just discard it...)
*/
if (id == 'E')
{
if (pqGetErrorNotice2(conn, false /* treat as notice */ ))
return;
}
else
{
pqInternalNotice(&conn->noticeHooks,
"message type 0x%02x arrived from server while idle",
id);
/* Discard the unexpected message; good idea?? */
conn->inStart = conn->inEnd;
break;
}
}
else
{
/*
* In BUSY state, we can process everything.
*/
switch (id)
{
case 'C': /* command complete */
if (pqGets(&conn->workBuffer, conn))
return;
if (conn->result == NULL)
{
conn->result = PQmakeEmptyPGresult(conn,
PGRES_COMMAND_OK);
if (!conn->result)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory"));
pqSaveErrorResult(conn);
}
}
if (conn->result)
{
strlcpy(conn->result->cmdStatus, conn->workBuffer.data,
CMDSTATUS_LEN);
}
checkXactStatus(conn, conn->workBuffer.data);
conn->asyncStatus = PGASYNC_READY;
break;
case 'E': /* error return */
if (pqGetErrorNotice2(conn, true))
return;
conn->asyncStatus = PGASYNC_READY;
break;
case 'Z': /* backend is ready for new query */
conn->asyncStatus = PGASYNC_IDLE;
break;
case 'I': /* empty query */
/* read and throw away the closing '\0' */
if (pqGetc(&id, conn))
return;
if (id != '\0')
pqInternalNotice(&conn->noticeHooks,
"unexpected character %c following empty query response (\"I\" message)",
id);
if (conn->result == NULL)
{
conn->result = PQmakeEmptyPGresult(conn,
PGRES_EMPTY_QUERY);
if (!conn->result)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory"));
pqSaveErrorResult(conn);
}
}
conn->asyncStatus = PGASYNC_READY;
break;
case 'K': /* secret key data from the backend */
/*
* This is expected only during backend startup, but it's
* just as easy to handle it as part of the main loop.
* Save the data and continue processing.
*/
if (pqGetInt(&(conn->be_pid), 4, conn))
return;
if (pqGetInt(&(conn->be_key), 4, conn))
return;
break;
case 'P': /* synchronous (normal) portal */
if (pqGets(&conn->workBuffer, conn))
return;
/* We pretty much ignore this message type... */
break;
case 'T': /* row descriptions (start of query results) */
if (conn->result == NULL)
{
/* First 'T' in a query sequence */
if (getRowDescriptions(conn))
return;
/* getRowDescriptions() moves inStart itself */
continue;
}
else
{
/*
* A new 'T' message is treated as the start of
* another PGresult. (It is not clear that this is
* really possible with the current backend.) We stop
* parsing until the application accepts the current
* result.
*/
conn->asyncStatus = PGASYNC_READY;
return;
}
break;
case 'D': /* ASCII data tuple */
if (conn->result != NULL)
{
/* Read another tuple of a normal query response */
if (getAnotherTuple(conn, FALSE))
return;
/* getAnotherTuple() moves inStart itself */
continue;
}
else
{
pqInternalNotice(&conn->noticeHooks,
"server sent data (\"D\" message) without prior row description (\"T\" message)");
/* Discard the unexpected message; good idea?? */
conn->inStart = conn->inEnd;
return;
}
break;
case 'B': /* Binary data tuple */
if (conn->result != NULL)
{
/* Read another tuple of a normal query response */
if (getAnotherTuple(conn, TRUE))
return;
/* getAnotherTuple() moves inStart itself */
continue;
}
else
{
pqInternalNotice(&conn->noticeHooks,
"server sent binary data (\"B\" message) without prior row description (\"T\" message)");
/* Discard the unexpected message; good idea?? */
conn->inStart = conn->inEnd;
return;
}
break;
case 'G': /* Start Copy In */
conn->asyncStatus = PGASYNC_COPY_IN;
break;
case 'H': /* Start Copy Out */
conn->asyncStatus = PGASYNC_COPY_OUT;
break;
/*
* Don't need to process CopyBothResponse here because it
* never arrives from the server during protocol 2.0.
*/
default:
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext(
"unexpected response from server; first received character was \"%c\"\n"),
id);
/* build an error result holding the error message */
pqSaveErrorResult(conn);
/* Discard the unexpected message; good idea?? */
conn->inStart = conn->inEnd;
conn->asyncStatus = PGASYNC_READY;
return;
} /* switch on protocol character */
}
/* Successfully consumed this message */
conn->inStart = conn->inCursor;
}
}
/*
* Attempt to read an Error or Notice response message.
* This is possible in several places, so we break it out as a subroutine.
* Entry: 'E' or 'N' message type and length have already been consumed.
* Exit: returns 0 if successfully consumed message.
* returns EOF if not enough data.
*/
int
pqGetErrorNotice3(PGconn *conn, bool isError)
{
PGresult *res = NULL;
PQExpBufferData workBuf;
char id;
const char *val;
const char *querytext = NULL;
int querypos = 0;
/*
* Since the fields might be pretty long, we create a temporary
* PQExpBuffer rather than using conn->workBuffer. workBuffer is intended
* for stuff that is expected to be short. We shouldn't use
* conn->errorMessage either, since this might be only a notice.
*/
initPQExpBuffer(&workBuf);
/*
* Make a PGresult to hold the accumulated fields. We temporarily lie
* about the result status, so that PQmakeEmptyPGresult doesn't uselessly
* copy conn->errorMessage.
*/
res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
if (!res)
goto fail;
res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
/*
* Read the fields and save into res.
*/
for (;;)
{
if (pqGetc(&id, conn))
goto fail;
if (id == '\0')
break; /* terminator found */
if (pqGets(&workBuf, conn))
goto fail;
pqSaveMessageField(res, id, workBuf.data);
}
/*
* Now build the "overall" error message for PQresultErrorMessage.
*/
resetPQExpBuffer(&workBuf);
val = PQresultErrorField(res, PG_DIAG_SEVERITY);
if (val)
appendPQExpBuffer(&workBuf, "%s: ", val);
if (conn->verbosity == PQERRORS_VERBOSE)
{
val = PQresultErrorField(res, PG_DIAG_SQLSTATE);
if (val)
appendPQExpBuffer(&workBuf, "%s: ", val);
}
val = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
if (val)
appendPQExpBufferStr(&workBuf, val);
val = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
if (val)
{
if (conn->verbosity != PQERRORS_TERSE && conn->last_query != NULL)
{
/* emit position as a syntax cursor display */
querytext = conn->last_query;
querypos = atoi(val);
}
else
{
/* emit position as text addition to primary message */
/* translator: %s represents a digit string */
appendPQExpBuffer(&workBuf, libpq_gettext(" at character %s"),
val);
}
}
else
{
val = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
if (val)
{
querytext = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
if (conn->verbosity != PQERRORS_TERSE && querytext != NULL)
{
/* emit position as a syntax cursor display */
querypos = atoi(val);
}
else
{
/* emit position as text addition to primary message */
/* translator: %s represents a digit string */
appendPQExpBuffer(&workBuf, libpq_gettext(" at character %s"),
val);
}
}
}
appendPQExpBufferChar(&workBuf, '\n');
if (conn->verbosity != PQERRORS_TERSE)
{
if (querytext && querypos > 0)
reportErrorPosition(&workBuf, querytext, querypos,
conn->client_encoding);
val = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
if (val)
appendPQExpBuffer(&workBuf, libpq_gettext("DETAIL: %s\n"), val);
val = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
if (val)
appendPQExpBuffer(&workBuf, libpq_gettext("HINT: %s\n"), val);
val = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
if (val)
appendPQExpBuffer(&workBuf, libpq_gettext("QUERY: %s\n"), val);
val = PQresultErrorField(res, PG_DIAG_CONTEXT);
if (val)
appendPQExpBuffer(&workBuf, libpq_gettext("CONTEXT: %s\n"), val);
}
if (conn->verbosity == PQERRORS_VERBOSE)
{
const char *valf;
const char *vall;
valf = PQresultErrorField(res, PG_DIAG_SOURCE_FILE);
vall = PQresultErrorField(res, PG_DIAG_SOURCE_LINE);
val = PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION);
if (val || valf || vall)
{
appendPQExpBufferStr(&workBuf, libpq_gettext("LOCATION: "));
if (val)
appendPQExpBuffer(&workBuf, libpq_gettext("%s, "), val);
if (valf && vall) /* unlikely we'd have just one */
appendPQExpBuffer(&workBuf, libpq_gettext("%s:%s"),
valf, vall);
appendPQExpBufferChar(&workBuf, '\n');
}
}
/*
* Either save error as current async result, or just emit the notice.
*/
if (isError)
{
res->errMsg = pqResultStrdup(res, workBuf.data);
if (!res->errMsg)
goto fail;
pqClearAsyncResult(conn);
conn->result = res;
resetPQExpBuffer(&conn->errorMessage);
appendPQExpBufferStr(&conn->errorMessage, workBuf.data);
}
else
{
/* We can cheat a little here and not copy the message. */
res->errMsg = workBuf.data;
if (res->noticeHooks.noticeRec != NULL)
(*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res);
PQclear(res);
}
termPQExpBuffer(&workBuf);
return 0;
fail:
PQclear(res);
termPQExpBuffer(&workBuf);
return EOF;
}
/*
* parseInput: if appropriate, parse input data from backend
* until input is exhausted or a stopping state is reached.
* Note that this function will NOT attempt to read more data from the backend.
*/
void
pqParseInput3(PGconn *conn)
{
char id;
int msgLength;
int avail;
/*
* Loop to parse successive complete messages available in the buffer.
*/
for (;;)
{
/*
* Try to read a message. First get the type code and length. Return
* if not enough data.
*/
conn->inCursor = conn->inStart;
if (pqGetc(&id, conn))
return;
if (pqGetInt(&msgLength, 4, conn))
return;
/*
* Try to validate message type/length here. A length less than 4 is
* definitely broken. Large lengths should only be believed for a few
* message types.
*/
if (msgLength < 4)
{
handleSyncLoss(conn, id, msgLength);
return;
}
if (msgLength > 30000 && !VALID_LONG_MESSAGE_TYPE(id))
{
handleSyncLoss(conn, id, msgLength);
return;
}
/*
* Can't process if message body isn't all here yet.
*/
msgLength -= 4;
avail = conn->inEnd - conn->inCursor;
if (avail < msgLength)
{
/*
* Before returning, enlarge the input buffer if needed to hold
* the whole message. This is better than leaving it to
* pqReadData because we can avoid multiple cycles of realloc()
* when the message is large; also, we can implement a reasonable
* recovery strategy if we are unable to make the buffer big
* enough.
*/
if (pqCheckInBufferSpace(conn->inCursor + msgLength, conn))
{
/*
* XXX add some better recovery code... plan is to skip over
* the message using its length, then report an error. For the
* moment, just treat this like loss of sync (which indeed it
* might be!)
*/
handleSyncLoss(conn, id, msgLength);
}
return;
}
/*
* NOTIFY and NOTICE messages can happen in any state; always process
* them right away.
*
* Most other messages should only be processed while in BUSY state.
* (In particular, in READY state we hold off further parsing until
* the application collects the current PGresult.)
*
* However, if the state is IDLE then we got trouble; we need to deal
* with the unexpected message somehow.
*
* ParameterStatus ('S') messages are a special case: in IDLE state we
* must process 'em (this case could happen if a new value was adopted
* from config file due to SIGHUP), but otherwise we hold off until
* BUSY state.
*/
if (id == 'A')
{
if (getNotify(conn))
return;
}
else if (id == 'N')
{
if (pqGetErrorNotice3(conn, false))
return;
}
else if (conn->asyncStatus != PGASYNC_BUSY)
{
/* If not IDLE state, just wait ... */
if (conn->asyncStatus != PGASYNC_IDLE)
return;
/*
* Unexpected message in IDLE state; need to recover somehow.
* ERROR messages are displayed using the notice processor;
* ParameterStatus is handled normally; anything else is just
* dropped on the floor after displaying a suitable warning
* notice. (An ERROR is very possibly the backend telling us why
* it is about to close the connection, so we don't want to just
* discard it...)
*/
if (id == 'E')
{
if (pqGetErrorNotice3(conn, false /* treat as notice */ ))
return;
}
else if (id == 'S')
{
if (getParameterStatus(conn))
return;
}
else
{
pqInternalNotice(&conn->noticeHooks,
"message type 0x%02x arrived from server while idle",
id);
/* Discard the unexpected message */
conn->inCursor += msgLength;
}
}
else
{
/*
* In BUSY state, we can process everything.
*/
switch (id)
{
case 'C': /* command complete */
if (pqGets(&conn->workBuffer, conn))
return;
if (conn->result == NULL)
{
conn->result = PQmakeEmptyPGresult(conn,
PGRES_COMMAND_OK);
if (!conn->result)
return;
}
strncpy(conn->result->cmdStatus, conn->workBuffer.data,
CMDSTATUS_LEN);
conn->asyncStatus = PGASYNC_READY;
break;
case 'E': /* error return */
if (pqGetErrorNotice3(conn, true))
return;
conn->asyncStatus = PGASYNC_READY;
break;
case 'Z': /* backend is ready for new query */
if (getReadyForQuery(conn))
return;
conn->asyncStatus = PGASYNC_IDLE;
break;
case 'I': /* empty query */
if (conn->result == NULL)
{
conn->result = PQmakeEmptyPGresult(conn,
PGRES_EMPTY_QUERY);
if (!conn->result)
return;
}
conn->asyncStatus = PGASYNC_READY;
break;
case '1': /* Parse Complete */
/* If we're doing PQprepare, we're done; else ignore */
if (conn->queryclass == PGQUERY_PREPARE)
{
if (conn->result == NULL)
{
conn->result = PQmakeEmptyPGresult(conn,
PGRES_COMMAND_OK);
if (!conn->result)
return;
}
conn->asyncStatus = PGASYNC_READY;
}
break;
case '2': /* Bind Complete */
case '3': /* Close Complete */
/* Nothing to do for these message types */
break;
case 'S': /* parameter status */
if (getParameterStatus(conn))
return;
break;
case 'K': /* secret key data from the backend */
/*
* This is expected only during backend startup, but it's
* just as easy to handle it as part of the main loop.
* Save the data and continue processing.
*/
if (pqGetInt(&(conn->be_pid), 4, conn))
return;
if (pqGetInt(&(conn->be_key), 4, conn))
return;
break;
case 'T': /* Row Description */
if (conn->result == NULL ||
conn->queryclass == PGQUERY_DESCRIBE)
{
/* First 'T' in a query sequence */
if (getRowDescriptions(conn))
return;
/*
* If we're doing a Describe, we're ready to pass the
* result back to the client.
*/
if (conn->queryclass == PGQUERY_DESCRIBE)
conn->asyncStatus = PGASYNC_READY;
}
else
{
/*
* A new 'T' message is treated as the start of
* another PGresult. (It is not clear that this is
* really possible with the current backend.) We stop
* parsing until the application accepts the current
* result.
*/
conn->asyncStatus = PGASYNC_READY;
return;
}
break;
case 'n': /* No Data */
/*
* NoData indicates that we will not be seeing a
* RowDescription message because the statement or portal
* inquired about doesn't return rows. Set up a COMMAND_OK
* result, instead of TUPLES_OK.
*/
if (conn->result == NULL)
conn->result = PQmakeEmptyPGresult(conn,
PGRES_COMMAND_OK);
/*
* If we're doing a Describe, we're ready to pass the
* result back to the client.
*/
if (conn->queryclass == PGQUERY_DESCRIBE)
conn->asyncStatus = PGASYNC_READY;
break;
case 't': /* Parameter Description */
if (getParamDescriptions(conn))
return;
break;
case 'D': /* Data Row */
if (conn->result != NULL &&
conn->result->resultStatus == PGRES_TUPLES_OK)
{
/* Read another tuple of a normal query response */
if (getAnotherTuple(conn, msgLength))
return;
}
else if (conn->result != NULL &&
conn->result->resultStatus == PGRES_FATAL_ERROR)
{
/*
* We've already choked for some reason. Just discard
* tuples till we get to the end of the query.
*/
conn->inCursor += msgLength;
}
else
{
/* Set up to report error at end of query */
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("server sent data (\"D\" message) without prior row description (\"T\" message)\n"));
pqSaveErrorResult(conn);
/* Discard the unexpected message */
conn->inCursor += msgLength;
}
break;
case 'G': /* Start Copy In */
if (getCopyStart(conn, PGRES_COPY_IN))
return;
conn->asyncStatus = PGASYNC_COPY_IN;
break;
case 'H': /* Start Copy Out */
if (getCopyStart(conn, PGRES_COPY_OUT))
return;
conn->asyncStatus = PGASYNC_COPY_OUT;
conn->copy_already_done = 0;
break;
case 'd': /* Copy Data */
/*
* If we see Copy Data, just silently drop it. This would
* only occur if application exits COPY OUT mode too
* early.
*/
conn->inCursor += msgLength;
break;
case 'c': /* Copy Done */
/*
* If we see Copy Done, just silently drop it. This is
* the normal case during PQendcopy. We will keep
* swallowing data, expecting to see command-complete for
* the COPY command.
*/
break;
default:
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext(
"unexpected response from server; first received character was \"%c\"\n"),
id);
/* build an error result holding the error message */
pqSaveErrorResult(conn);
/* not sure if we will see more, so go to ready state */
conn->asyncStatus = PGASYNC_READY;
/* Discard the unexpected message */
conn->inCursor += msgLength;
break;
} /* switch on protocol character */
}
/* Successfully consumed this message */
if (conn->inCursor == conn->inStart + 5 + msgLength)
{
/* Normal case: parsing agrees with specified length */
conn->inStart = conn->inCursor;
}
else
{
/* Trouble --- report it */
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("message contents do not agree with length in message type \"%c\"\n"),
id);
/* build an error result holding the error message */
pqSaveErrorResult(conn);
conn->asyncStatus = PGASYNC_READY;
/* trust the specified message length as what to skip */
conn->inStart += 5 + msgLength;
}
}
}
/*
* parseInput subroutine to read a 'T' (row descriptions) message.
* We'll build a new PGresult structure (unless called for a Describe
* command for a prepared statement) containing the attribute data.
* Returns: 0 if completed message, EOF if not enough data yet.
*
* Note that if we run out of data, we have to release the partially
* constructed PGresult, and rebuild it again next time. Fortunately,
* that shouldn't happen often, since 'T' messages usually fit in a packet.
*/
static int
getRowDescriptions(PGconn *conn)
{
PGresult *result;
int nfields;
int i;
/*
* When doing Describe for a prepared statement, there'll already be a
* PGresult created by getParamDescriptions, and we should fill data into
* that. Otherwise, create a new, empty PGresult.
*/
if (conn->queryclass == PGQUERY_DESCRIBE)
{
if (conn->result)
result = conn->result;
else
result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK);
}
else
result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
if (!result)
goto failure;
/* parseInput already read the 'T' label and message length. */
/* the next two bytes are the number of fields */
if (pqGetInt(&(result->numAttributes), 2, conn))
goto failure;
nfields = result->numAttributes;
/* allocate space for the attribute descriptors */
if (nfields > 0)
{
result->attDescs = (PGresAttDesc *)
pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
if (!result->attDescs)
goto failure;
MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
}
/* result->binary is true only if ALL columns are binary */
result->binary = (nfields > 0) ? 1 : 0;
/* get type info */
for (i = 0; i < nfields; i++)
{
int tableid;
int columnid;
int typid;
int typlen;
int atttypmod;
int format;
if (pqGets(&conn->workBuffer, conn) ||
pqGetInt(&tableid, 4, conn) ||
pqGetInt(&columnid, 2, conn) ||
pqGetInt(&typid, 4, conn) ||
pqGetInt(&typlen, 2, conn) ||
pqGetInt(&atttypmod, 4, conn) ||
pqGetInt(&format, 2, conn))
{
goto failure;
}
/*
* Since pqGetInt treats 2-byte integers as unsigned, we need to
* coerce these results to signed form.
*/
columnid = (int) ((int16) columnid);
typlen = (int) ((int16) typlen);
format = (int) ((int16) format);
result->attDescs[i].name = pqResultStrdup(result,
conn->workBuffer.data);
if (!result->attDescs[i].name)
goto failure;
result->attDescs[i].tableid = tableid;
result->attDescs[i].columnid = columnid;
result->attDescs[i].format = format;
result->attDescs[i].typid = typid;
result->attDescs[i].typlen = typlen;
result->attDescs[i].atttypmod = atttypmod;
if (format != 1)
result->binary = 0;
}
/* Success! */
conn->result = result;
return 0;
failure:
/*
* Discard incomplete result, unless it's from getParamDescriptions.
*
* Note that if we hit a bufferload boundary while handling the
* describe-statement case, we'll forget any PGresult space we just
* allocated, and then reallocate it on next try. This will bloat the
* PGresult a little bit but the space will be freed at PQclear, so it
* doesn't seem worth trying to be smarter.
*/
if (result != conn->result)
PQclear(result);
return EOF;
}
/*
* parseInput subroutine to read a 'T' (row descriptions) message.
* We build a PGresult structure containing the attribute data.
* Returns: 0 if completed message, EOF if not enough data yet.
*
* Note that if we run out of data, we have to release the partially
* constructed PGresult, and rebuild it again next time. Fortunately,
* that shouldn't happen often, since 'T' messages usually fit in a packet.
*/
static int
getRowDescriptions(PGconn *conn)
{
PGresult *result = NULL;
int nfields;
int i;
result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
if (!result)
goto failure;
/* parseInput already read the 'T' label. */
/* the next two bytes are the number of fields */
if (pqGetInt(&(result->numAttributes), 2, conn))
goto failure;
nfields = result->numAttributes;
/* allocate space for the attribute descriptors */
if (nfields > 0)
{
result->attDescs = (PGresAttDesc *)
pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
if (!result->attDescs)
goto failure;
MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
}
/* get type info */
for (i = 0; i < nfields; i++)
{
int typid;
int typlen;
int atttypmod;
if (pqGets(&conn->workBuffer, conn) ||
pqGetInt(&typid, 4, conn) ||
pqGetInt(&typlen, 2, conn) ||
pqGetInt(&atttypmod, 4, conn))
goto failure;
/*
* Since pqGetInt treats 2-byte integers as unsigned, we need to
* coerce the result to signed form.
*/
typlen = (int) ((int16) typlen);
result->attDescs[i].name = pqResultStrdup(result,
conn->workBuffer.data);
if (!result->attDescs[i].name)
goto failure;
result->attDescs[i].tableid = 0;
result->attDescs[i].columnid = 0;
result->attDescs[i].format = 0;
result->attDescs[i].typid = typid;
result->attDescs[i].typlen = typlen;
result->attDescs[i].atttypmod = atttypmod;
}
/* Success! */
conn->result = result;
return 0;
failure:
if (result)
PQclear(result);
return EOF;
}
/*
* Initialize SASL authentication exchange.
*/
static int
pg_SASL_init(PGconn *conn, int payloadlen)
{
char *initialresponse = NULL;
int initialresponselen;
bool done;
bool success;
const char *selected_mechanism;
PQExpBufferData mechanism_buf;
initPQExpBuffer(&mechanism_buf);
if (conn->sasl_state)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("duplicate SASL authentication request\n"));
goto error;
}
/*
* Parse the list of SASL authentication mechanisms in the
* AuthenticationSASL message, and select the best mechanism that we
* support. (Only SCRAM-SHA-256 is supported at the moment.)
*/
selected_mechanism = NULL;
for (;;)
{
if (pqGets(&mechanism_buf, conn))
{
printfPQExpBuffer(&conn->errorMessage,
"fe_sendauth: invalid authentication request from server: invalid list of authentication mechanisms\n");
goto error;
}
if (PQExpBufferDataBroken(mechanism_buf))
goto oom_error;
/* An empty string indicates end of list */
if (mechanism_buf.data[0] == '\0')
break;
/*
* If we have already selected a mechanism, just skip through the rest
* of the list.
*/
if (selected_mechanism)
continue;
/*
* Do we support this mechanism?
*/
if (strcmp(mechanism_buf.data, SCRAM_SHA_256_NAME) == 0)
{
char *password;
conn->password_needed = true;
password = conn->connhost[conn->whichhost].password;
if (password == NULL)
password = conn->pgpass;
if (password == NULL || password[0] == '\0')
{
printfPQExpBuffer(&conn->errorMessage,
PQnoPasswordSupplied);
goto error;
}
conn->sasl_state = pg_fe_scram_init(conn->pguser, password);
if (!conn->sasl_state)
goto oom_error;
selected_mechanism = SCRAM_SHA_256_NAME;
}
}
if (!selected_mechanism)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("none of the server's SASL authentication mechanisms are supported\n"));
goto error;
}
/* Get the mechanism-specific Initial Client Response, if any */
pg_fe_scram_exchange(conn->sasl_state,
NULL, -1,
&initialresponse, &initialresponselen,
&done, &success, &conn->errorMessage);
if (done && !success)
goto error;
/*
* Build a SASLInitialResponse message, and send it.
*/
if (pqPutMsgStart('p', true, conn))
goto error;
if (pqPuts(selected_mechanism, conn))
goto error;
if (initialresponse)
{
if (pqPutInt(initialresponselen, 4, conn))
goto error;
if (pqPutnchar(initialresponse, initialresponselen, conn))
goto error;
}
if (pqPutMsgEnd(conn))
goto error;
if (pqFlush(conn))
goto error;
termPQExpBuffer(&mechanism_buf);
if (initialresponse)
free(initialresponse);
return STATUS_OK;
error:
termPQExpBuffer(&mechanism_buf);
if (initialresponse)
free(initialresponse);
return STATUS_ERROR;
oom_error:
termPQExpBuffer(&mechanism_buf);
if (initialresponse)
free(initialresponse);
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory\n"));
return STATUS_ERROR;
}
