From 724e30c9f886efd852f714d47c56336ffa6916ec Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 27 Aug 2011 14:16:14 -0400 Subject: Ensure we discard unread/unsent data when abandoning a connection attempt. There are assorted situations wherein PQconnectPoll() will abandon a connection attempt and try again with different parameters (eg, SSL versus not SSL). However, the code forgot to discard any pending data in libpq's I/O buffers when doing this. In at least one case (server returns E message during SSL negotiation), there is unread input data which bollixes the next connection attempt. I have not checked to see whether this is possible in the other cases where we close the socket and retry, but it seems like a matter of good defensive programming to add explicit buffer-flushing code to all of them. This is one of several issues exposed by Daniel Farina's report of misbehavior after a server-side fork failure. This has been wrong since forever, so back-patch to all supported branches. --- src/interfaces/libpq/fe-connect.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'src') diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c index 3523582145..bf6aaae761 100644 --- a/src/interfaces/libpq/fe-connect.c +++ b/src/interfaces/libpq/fe-connect.c @@ -2068,6 +2068,9 @@ keep_going: /* We will come back to here until there is closesocket(conn->sock); conn->sock = -1; conn->status = CONNECTION_NEEDED; + /* Discard any unread/unsent data */ + conn->inStart = conn->inCursor = conn->inEnd = 0; + conn->outCount = 0; goto keep_going; } else @@ -2105,6 +2108,9 @@ keep_going: /* We will come back to here until there is closesocket(conn->sock); conn->sock = -1; conn->status = CONNECTION_NEEDED; + /* Discard any unread/unsent data */ + conn->inStart = conn->inCursor = conn->inEnd = 0; + conn->outCount = 0; goto keep_going; } } @@ -2218,6 +2224,9 @@ keep_going: /* We will come back to here until there is closesocket(conn->sock); conn->sock = -1; conn->status = CONNECTION_NEEDED; + /* Discard any unread/unsent data */ + conn->inStart = conn->inCursor = conn->inEnd = 0; + conn->outCount = 0; goto keep_going; } @@ -2285,6 +2294,9 @@ keep_going: /* We will come back to here until there is closesocket(conn->sock); conn->sock = -1; conn->status = CONNECTION_NEEDED; + /* Discard any unread/unsent data */ + conn->inStart = conn->inCursor = conn->inEnd = 0; + conn->outCount = 0; goto keep_going; } @@ -2304,6 +2316,9 @@ keep_going: /* We will come back to here until there is closesocket(conn->sock); conn->sock = -1; conn->status = CONNECTION_NEEDED; + /* Discard any unread/unsent data */ + conn->inStart = conn->inCursor = conn->inEnd = 0; + conn->outCount = 0; goto keep_going; } #endif @@ -2467,6 +2482,9 @@ keep_going: /* We will come back to here until there is closesocket(conn->sock); conn->sock = -1; conn->status = CONNECTION_NEEDED; + /* Discard any unread/unsent data */ + conn->inStart = conn->inCursor = conn->inEnd = 0; + conn->outCount = 0; goto keep_going; } } -- cgit v1.2.1