From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 30 Dec 2009 03:45:53 +0000 (+0000)
Subject: Set errno to zero before invoking SSL_read or SSL_write.  It appears that
X-Git-Tag: REL8_4_3~78
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=eb63765a389b020a86fd04cf9333027d37b8f572;p=postgresql

Set errno to zero before invoking SSL_read or SSL_write.  It appears that
at least in some Windows versions, these functions are capable of returning
a failure indication without setting errno.  That puts us into an infinite
loop if the previous value happened to be EINTR.  Per report from Brendan
Hill.

Back-patch to 8.2.  We could take it further back, but since this is only
known to be an issue on Windows and we don't support Windows before 8.2,
it does not seem worth the trouble.
---

diff --git a/src/backend/libpq/be-secure.c b/src/backend/libpq/be-secure.c
index 9456b254b4..1b59c19b33 100644
--- a/src/backend/libpq/be-secure.c
+++ b/src/backend/libpq/be-secure.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.92.2.1 2009/12/09 06:37:29 mha Exp $
+ *	  $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.92.2.2 2009/12/30 03:45:53 tgl Exp $
  *
  *	  Since the server static private key ($DataDir/server.key)
  *	  will normally be stored unencrypted so that the database
@@ -245,6 +245,7 @@ secure_read(Port *port, void *ptr, size_t len)
 		int			err;
 
 rloop:
+		errno = 0;
 		n = SSL_read(port->ssl, ptr, len);
 		err = SSL_get_error(port->ssl, n);
 		switch (err)
@@ -339,6 +340,7 @@ secure_write(Port *port, void *ptr, size_t len)
 		}
 
 wloop:
+		errno = 0;
 		n = SSL_write(port->ssl, ptr, len);
 		err = SSL_get_error(port->ssl, n);
 		switch (err)
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index 4a12bd1b1d..03318424ab 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.127.2.1 2009/12/09 06:37:29 mha Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.127.2.2 2009/12/30 03:45:53 tgl Exp $
  *
  * NOTES
  *
@@ -288,6 +288,7 @@ pqsecure_read(PGconn *conn, void *ptr, size_t len)
 		DISABLE_SIGPIPE(return -1);
 
 rloop:
+		SOCK_ERRNO_SET(0);
 		n = SSL_read(conn->ssl, ptr, len);
 		err = SSL_get_error(conn->ssl, n);
 		switch (err)
@@ -372,6 +373,7 @@ pqsecure_write(PGconn *conn, const void *ptr, size_t len)
 	{
 		int			err;
 
+		SOCK_ERRNO_SET(0);
 		n = SSL_write(conn->ssl, ptr, len);
 		err = SSL_get_error(conn->ssl, n);
 		switch (err)