diff options
Diffstat (limited to 'src/backend/tcop/postgres.c')
| -rw-r--r-- | src/backend/tcop/postgres.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index 1216a2b397b..2d6d145ecc0 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -343,6 +343,7 @@ static int SocketBackend(StringInfo inBuf) { int qtype; + int maxmsglen; /* * Get message type code from the frontend. @@ -375,7 +376,9 @@ SocketBackend(StringInfo inBuf) /* * Validate message type code before trying to read body; if we have lost * sync, better to say "command unknown" than to run out of memory because - * we used garbage as a length word. + * we used garbage as a length word. We can also select a type-dependent + * limit on what a sane length word could be. (The limit could be chosen + * more granularly, but it's not clear it's worth fussing over.) * * This also gives us a place to set the doing_extended_query_message flag * as soon as possible. @@ -383,28 +386,37 @@ SocketBackend(StringInfo inBuf) switch (qtype) { case 'Q': /* simple query */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; doing_extended_query_message = false; break; case 'F': /* fastpath function call */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; doing_extended_query_message = false; break; case 'X': /* terminate */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; doing_extended_query_message = false; ignore_till_sync = false; break; case 'B': /* bind */ + case 'P': /* parse */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; + doing_extended_query_message = true; + break; + case 'C': /* close */ case 'D': /* describe */ case 'E': /* execute */ case 'H': /* flush */ - case 'P': /* parse */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; doing_extended_query_message = true; break; case 'S': /* sync */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; /* stop any active skip-till-Sync */ ignore_till_sync = false; /* mark not-extended, so that a new error doesn't begin skip */ @@ -412,8 +424,13 @@ SocketBackend(StringInfo inBuf) break; case 'd': /* copy data */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; + doing_extended_query_message = false; + break; + case 'c': /* copy done */ case 'f': /* copy fail */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; doing_extended_query_message = false; break; @@ -427,6 +444,7 @@ SocketBackend(StringInfo inBuf) ereport(FATAL, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("invalid frontend message type %d", qtype))); + maxmsglen = 0; /* keep compiler quiet */ break; } @@ -435,7 +453,7 @@ SocketBackend(StringInfo inBuf) * after the type code; we can read the message contents independently of * the type. */ - if (pq_getmessage(inBuf, 0)) + if (pq_getmessage(inBuf, maxmsglen)) return EOF; /* suitable message already logged */ RESUME_CANCEL_INTERRUPTS(); |