[openldap] MozNSS - implement full non-blocking semantics

jvcelak jvcelak at fedoraproject.org
Mon Nov 22 17:50:24 UTC 2010


commit bff7316e6d172fac813eb9070d68ddace9619050
Author: Jan Vcelak <jvcelak at redhat.com>
Date:   Thu Nov 18 12:00:08 2010 +0100

    MozNSS - implement full non-blocking semantics
    
    fix: ldapsearch -Z hangs server if starttls fails (#652822)
    
    Resolves: #652822

 openldap-nss-non-blocking.patch |  361 +++++++++++++++++++++++++++++++++++++++
 openldap.spec                   |    9 +-
 2 files changed, 369 insertions(+), 1 deletions(-)
---
diff --git a/openldap-nss-non-blocking.patch b/openldap-nss-non-blocking.patch
new file mode 100644
index 0000000..38508f3
--- /dev/null
+++ b/openldap-nss-non-blocking.patch
@@ -0,0 +1,361 @@
+Mozilla NSS - implement full non-blocking semantics
+
+Resolves: #652822
+Upstream ITS: #6714
+Author: Rich Megginson (rmeggins at redhat.com)
+
+diff -u -uNPrp openldap-2.4.23/libraries/libldap/tls_m.c openldap-2.4.23.new/libraries/libldap/tls_m.c
+--- openldap-2.4.23/libraries/libldap/tls_m.c	2010-11-22 15:50:48.752386500 +0100
++++ openldap-2.4.23.new/libraries/libldap/tls_m.c	2010-11-22 15:53:44.936512466 +0100
+@@ -2105,49 +2105,74 @@ struct tls_data {
+ 	   we will just see if the IO op returns EAGAIN or EWOULDBLOCK,
+ 	   and just set this flag */
+ 	PRBool              nonblock;
++	/*
++	 * NSS tries hard to be backwards compatible with SSLv2 clients, or
++	 * clients that send an SSLv2 client hello.  This message is not
++	 * tagged in any way, so NSS has no way to know if the incoming
++	 * message is a valid SSLv2 client hello or just some bogus data
++	 * (or cleartext LDAP).  We store the first byte read from the
++	 * client here.  The most common case will be a client sending
++	 * LDAP data instead of SSL encrypted LDAP data.  This can happen,
++	 * for example, if using ldapsearch -Z - if the starttls fails,
++	 * the client will fallback to plain cleartext LDAP.  So if we
++	 * see that the firstbyte is a valid LDAP tag, we can be
++	 * pretty sure this is happening.
++	 */
++	ber_tag_t           firsttag;
++	/*
++	 * NSS doesn't return SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE, etc.
++	 * when it is blocked, so we have to set a flag in the wrapped send
++	 * and recv calls that tells us what operation NSS was last blocked
++	 * on
++	 */
++#define TLSM_READ  1
++#define TLSM_WRITE 2
++	int io_flag;
+ };
+ 
+-static int
+-tlsm_is_io_ready( PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags )
++static struct tls_data *
++tlsm_get_pvt_tls_data( PRFileDesc *fd )
+ {
+ 	struct tls_data		*p;
+-	PRFileDesc *pollfd = NULL;
+ 	PRFileDesc *myfd;
+-	PRPollDesc polldesc;
+-	int rc;
++
++	if ( !fd ) {
++		return NULL;
++	}
+ 
+ 	myfd = PR_GetIdentitiesLayer( fd, tlsm_layer_id );
+ 
+ 	if ( !myfd ) {
+-		return 0;
++		return NULL;
+ 	}
+ 
+ 	p = (struct tls_data *)myfd->secret;
+ 
++	return p;
++}
++
++static int
++tlsm_is_non_ssl_message( PRFileDesc *fd, ber_tag_t *thebyte )
++{
++	struct tls_data		*p;
++
++	if ( thebyte ) {
++		*thebyte = LBER_DEFAULT;
++	}
++
++	p = tlsm_get_pvt_tls_data( fd );
+ 	if ( p == NULL || p->sbiod == NULL ) {
+ 		return 0;
+ 	}
+ 
+-	/* wrap the sockbuf fd with a NSPR FD created especially
+-	   for use with polling, and only with polling */
+-	pollfd = PR_CreateSocketPollFd( p->sbiod->sbiod_sb->sb_fd );
+-	polldesc.fd = pollfd;
+-	polldesc.in_flags = in_flags;
+-	polldesc.out_flags = 0;
+-
+-	/* do the poll - no waiting, no blocking */
+-	rc = PR_Poll( &polldesc, 1, PR_INTERVAL_NO_WAIT );
+-
+-	/* unwrap the socket */
+-	PR_DestroySocketPollFd( pollfd );
+-
+-	/* rc will be either 1 if IO is ready, 0 if IO is not
+-	   ready, or -1 if there was some error (and the caller
+-	   should use PR_GetError() to figure out what */
+-	if (out_flags) {
+-		*out_flags = polldesc.out_flags;
++	if ( p->firsttag == LBER_SEQUENCE ) {
++		if ( *thebyte ) {
++			*thebyte = p->firsttag;
++		}
++		return 1;
+ 	}
+-	return rc;
++
++	return 0;
+ }
+ 
+ static tls_session *
+@@ -2157,6 +2182,7 @@ tlsm_session_new ( tls_ctx * ctx, int is
+ 	tlsm_session *session;
+ 	PRFileDesc *fd;
+ 	PRStatus status;
++	int rc;
+ 
+ 	c->tc_is_server = is_server;
+ 	status = PR_CallOnceWithArg( &c->tc_callonce, tlsm_deferred_ctx_init, c );
+@@ -2184,121 +2210,80 @@ tlsm_session_new ( tls_ctx * ctx, int is
+ 		SSL_ConfigServerSessionIDCache( 0, 0, 0, NULL );
+ 	}
+ 
++	rc = SSL_ResetHandshake( session, is_server );
++	if ( rc ) {
++		PRErrorCode err = PR_GetError();
++		Debug( LDAP_DEBUG_TRACE, 
++			   "TLS: error: new session - reset handshake failure %d - error %d:%s\n",
++			   rc, err,
++			   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
++		PR_DELETE( fd );
++		PR_Close( session );
++		session = NULL;
++	}
++
+ 	return (tls_session *)session;
+ } 
+ 
+ static int
+-tlsm_session_accept( tls_session *session )
++tlsm_session_accept_or_connect( tls_session *session, int is_accept )
+ {
+ 	tlsm_session *s = (tlsm_session *)session;
+-	int rc;
+-	PRErrorCode err;
+-	int waitcounter = 0;
+-
+-	rc = SSL_ResetHandshake( s, PR_TRUE /* server */ );
+-	if (rc) {
+-		err = PR_GetError();
+-		Debug( LDAP_DEBUG_TRACE, 
+-			   "TLS: error: accept - reset handshake failure %d - error %d:%s\n",
+-			   rc, err,
+-			   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
+-	}
++	int rc = SSL_ForceHandshake( s );
++	const char *op = is_accept ? "accept" : "connect";
+ 
+-	do {
+-		PRInt32 filesReady;
+-		PRInt16 in_flags;
+-		PRInt16 out_flags;
+-
+-		errno = 0;
+-		rc = SSL_ForceHandshake( s );
+-		if (rc == SECSuccess) {
+-			rc = 0;
+-			break; /* done */
+-		}
+-		err = PR_GetError();
+-		if ( errno == EAGAIN || errno == EWOULDBLOCK ) {
+-			waitcounter++;
+-			in_flags = PR_POLL_READ | PR_POLL_EXCEPT;
+-			out_flags = 0;
+-			errno = 0;
+-			filesReady = tlsm_is_io_ready( s, in_flags, &out_flags );
+-			if ( filesReady < 0 ) {
+-				err = PR_GetError();
+-				Debug( LDAP_DEBUG_ANY, 
+-					   "TLS: error: accept - error waiting for socket to be ready: %d - error %d:%s\n",
+-					   errno, err,
+-					   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
+-				rc = -1;
+-				break; /* hard error */
+-			} else if ( out_flags & PR_POLL_NVAL ) {
+-				PR_SetError(PR_BAD_DESCRIPTOR_ERROR, 0);
+-				Debug( LDAP_DEBUG_ANY, 
+-					   "TLS: error: accept failure - invalid socket\n",
+-					   NULL, NULL, NULL );
+-				rc = -1;
+-				break;
+-			} else if ( out_flags & PR_POLL_EXCEPT ) {
+-				err = PR_GetError();
++	if ( rc ) {
++		PRErrorCode err = PR_GetError();
++		rc = -1;
++		if ( err == PR_WOULD_BLOCK_ERROR ) {
++			ber_tag_t thetag = LBER_DEFAULT;
++			/* see if we are blocked because of a bogus packet */
++			if ( tlsm_is_non_ssl_message( s, &thetag ) ) { /* see if we received a non-SSL message */
+ 				Debug( LDAP_DEBUG_ANY, 
+-					   "TLS: error: accept - error waiting for socket to be ready: %d - error %d:%s\n",
+-					   errno, err,
+-					   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
+-				rc = -1;
+-				break; /* hard error */
++					   "TLS: error: %s - error - received non-SSL message [0x%x]\n",
++					   op, (unsigned int)thetag, 0 );
++				/* reset error to something more descriptive */
++				PR_SetError( SSL_ERROR_RX_MALFORMED_HELLO_REQUEST, EPROTO );
+ 			}
+-		} else { /* hard error */
+-			err = PR_GetError();
++		} else {
+ 			Debug( LDAP_DEBUG_ANY, 
+-				   "TLS: error: accept - force handshake failure: %d - error %d:%s\n",
+-				   errno, err,
+-				   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
+-			rc = -1;
+-			break; /* hard error */
++				   "TLS: error: %s - force handshake failure: errno %d - moznss error %d\n",
++				   op, errno, err );
+ 		}
+-	} while (rc == SECFailure);
+-
+-	Debug( LDAP_DEBUG_TRACE, 
+-		   "TLS: accept completed after %d waits\n", waitcounter, NULL, NULL );
++	}
+ 
+ 	return rc;
+ }
++static int
++tlsm_session_accept( tls_session *session )
++{
++	return tlsm_session_accept_or_connect( session, 1 );
++}
+ 
+ static int
+ tlsm_session_connect( LDAP *ld, tls_session *session )
+ {
+-	tlsm_session *s = (tlsm_session *)session;
+-	int rc;
+-	PRErrorCode err;
+-
+-	rc = SSL_ResetHandshake( s, PR_FALSE /* server */ );
+-	if (rc) {
+-		err = PR_GetError();
+-		Debug( LDAP_DEBUG_TRACE, 
+-			   "TLS: error: connect - reset handshake failure %d - error %d:%s\n",
+-			   rc, err,
+-			   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
+-	}
+-
+-	rc = SSL_ForceHandshake( s );
+-	if (rc) {
+-		err = PR_GetError();
+-		Debug( LDAP_DEBUG_TRACE, 
+-			   "TLS: error: connect - force handshake failure %d - error %d:%s\n",
+-			   rc, err,
+-			   err ? PR_ErrorToString( err, PR_LANGUAGE_I_DEFAULT ) : "unknown" );
+-	}
+-
+-	return rc;
++	return tlsm_session_accept_or_connect( session, 0 );
+ }
+ 
+ static int
+ tlsm_session_upflags( Sockbuf *sb, tls_session *session, int rc )
+ {
+-	/* Should never happen */
+-	rc = PR_GetError();
++	int prerror = PR_GetError();
++
++	if ( ( prerror == PR_PENDING_INTERRUPT_ERROR ) || ( prerror == PR_WOULD_BLOCK_ERROR ) ) {
++		tlsm_session *s = (tlsm_session *)session;
++		struct tls_data *p = tlsm_get_pvt_tls_data( s );
++
++		if ( p && ( p->io_flag == TLSM_READ ) ) {
++			sb->sb_trans_needs_read = 1;
++			return 1;
++		} else if ( p && ( p->io_flag == TLSM_WRITE ) ) {
++			sb->sb_trans_needs_write = 1;
++			return 1;
++		}
++	}
+ 
+-	if ( rc != PR_PENDING_INTERRUPT_ERROR && rc != PR_WOULD_BLOCK_ERROR )
+-		return 0;
+ 	return 0;
+ }
+ 
+@@ -2587,7 +2572,7 @@ tlsm_PR_Recv(PRFileDesc *fd, void *buf, 
+ 
+ 	if ( buf == NULL || len <= 0 ) return 0;
+ 
+-	p = (struct tls_data *)fd->secret;
++	p = tlsm_get_pvt_tls_data( fd );
+ 
+ 	if ( p == NULL || p->sbiod == NULL ) {
+ 		return 0;
+@@ -2603,7 +2588,10 @@ tlsm_PR_Recv(PRFileDesc *fd, void *buf, 
+ 			       "TLS: error: tlsm_PR_Recv returned %d - error %d:%s\n",
+ 			       rc, errno, STRERROR(errno) );
+ 		}
++	} else if ( ( rc > 0 ) && ( len > 0 ) && ( p->firsttag == LBER_DEFAULT ) ) {
++		p->firsttag = (ber_tag_t)*((char *)buf);
+ 	}
++	p->io_flag = TLSM_READ;
+ 
+ 	return rc;
+ }
+@@ -2617,7 +2605,7 @@ tlsm_PR_Send(PRFileDesc *fd, const void 
+ 
+ 	if ( buf == NULL || len <= 0 ) return 0;
+ 
+-	p = (struct tls_data *)fd->secret;
++	p = tlsm_get_pvt_tls_data( fd );
+ 
+ 	if ( p == NULL || p->sbiod == NULL ) {
+ 		return 0;
+@@ -2634,6 +2622,7 @@ tlsm_PR_Send(PRFileDesc *fd, const void 
+ 			       rc, errno, STRERROR(errno) );
+ 		}
+ 	}
++	p->io_flag = TLSM_WRITE;
+ 
+ 	return rc;
+ }
+@@ -2656,7 +2645,7 @@ tlsm_PR_GetPeerName(PRFileDesc *fd, PRNe
+ 	struct tls_data		*p;
+ 	ber_socklen_t len;
+ 
+-	p = (struct tls_data *)fd->secret;
++ 	p = tlsm_get_pvt_tls_data( fd );
+ 
+ 	if ( p == NULL || p->sbiod == NULL ) {
+ 		return PR_FAILURE;
+@@ -2669,7 +2658,7 @@ static PRStatus PR_CALLBACK
+ tlsm_PR_GetSocketOption(PRFileDesc *fd, PRSocketOptionData *data)
+ {
+ 	struct tls_data		*p;
+-	p = (struct tls_data *)fd->secret;
++ 	p = tlsm_get_pvt_tls_data( fd );
+ 
+ 	if ( !data ) {
+ 		return PR_FAILURE;
+@@ -2804,6 +2793,7 @@ tlsm_sb_setup( Sockbuf_IO_Desc *sbiod, v
+ 	fd->secret = (PRFilePrivate *)p;
+ 	p->session = session;
+ 	p->sbiod = sbiod;
++	p->firsttag = LBER_DEFAULT;
+ 	sbiod->sbiod_pvt = p;
+ 	return 0;
+ }
+@@ -2851,7 +2841,7 @@ tlsm_sb_ctrl( Sockbuf_IO_Desc *sbiod, in
+ 		return 1;
+ 		
+ 	} else if ( opt == LBER_SB_OPT_DATA_READY ) {
+-		if ( tlsm_is_io_ready( p->session, PR_POLL_READ, NULL ) > 0 ) {
++		if ( p && ( SSL_DataPending( p->session ) > 0 ) ) {
+ 			return 1;
+ 		}
+ 		
diff --git a/openldap.spec b/openldap.spec
index c0ec47b..387c269 100644
--- a/openldap.spec
+++ b/openldap.spec
@@ -7,7 +7,7 @@
 
 Name: openldap
 Version: 2.4.23
-Release: 3%{?dist}
+Release: 4%{?dist}
 Summary: LDAP support libraries
 Group: System Environment/Daemons
 License: OpenLDAP
@@ -36,6 +36,8 @@ Patch103: openldap-reject-non-file-keyfiles.patch
 Patch104: openldap-use-cacert-dir-and-file.patch
 Patch105: openldap-cacertdir-hash-only.patch
 Patch106: openldap-improve-trace-messages.patch
+# patches sent upstream
+Patch107: openldap-nss-non-blocking.patch
 
 # patches for the evolution library (see README.evolution)
 Patch200: openldap-evolution-ntlm.patch
@@ -144,6 +146,7 @@ pushd openldap-%{version}
 %patch104 -p1 -b .use-cacert-dir-and-file-dir
 %patch105 -p1 -b .cacertdir-hash-only
 %patch106 -p1 -b .improve-trace-messages
+%patch107 -p1 -b .nss-non-blocking
 
 cp %{_datadir}/libtool/config/config.{sub,guess} build/
 
@@ -651,6 +654,10 @@ exit 0
 %attr(0644,root,root)      %{evolution_connector_libdir}/*.a
 
 %changelog
+* Mon Nov 22 2010 Jan Vcelak <jvcelak at redhat.com> 2.4.23-4
+- Mozilla NSS - implement full non-blocking semantics
+  ldapsearch -Z hangs server if starttls fails (#652822)
+
 * Thu Nov 18 2010 Jan Vcelak <jvcelak at redhat.com> 2.4.23-3
 - add support for multiple prefixed Mozilla NSS database files in TLS_CACERTDIR
 - reject non-file keyfiles in TLS_CACERTDIR (#652315)


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