svn rev #21749: trunk/src/lib/krb5/os/

[raeburn@MIT.EDU]

http://src.mit.edu/fisheye/changelog/krb5/?cs=21749
Commit By: raeburn
Log Message:
ticket: 6339

Add new routine krb5int_net_writev using scatter-gather source.
Use it from krb5_net_write to ensure testing and reduce duplication.
Use it from krb5_write_message to avoid Nagle+DelayedAck problem.


Changed Files:
U   trunk/src/lib/krb5/os/deps
U   trunk/src/lib/krb5/os/net_write.c
U   trunk/src/lib/krb5/os/os-proto.h
U   trunk/src/lib/krb5/os/write_msg.c
Modified: trunk/src/lib/krb5/os/deps
===================================================================
--- trunk/src/lib/krb5/os/deps	2009-01-14 23:36:04 UTC (rev 21748)
+++ trunk/src/lib/krb5/os/deps	2009-01-15 00:59:27 UTC (rev 21749)
@@ -277,7 +277,7 @@
   $(SRCTOP)/include/k5-plugin.h $(SRCTOP)/include/k5-thread.h \
   $(SRCTOP)/include/krb5.h $(SRCTOP)/include/krb5/locate_plugin.h \
   $(SRCTOP)/include/krb5/preauth_plugin.h $(SRCTOP)/include/port-sockets.h \
-  $(SRCTOP)/include/socket-utils.h net_write.c
+  $(SRCTOP)/include/socket-utils.h net_write.c os-proto.h
 osconfig.so osconfig.po $(OUTPRE)osconfig.$(OBJEXT): \
   $(BUILDTOP)/include/autoconf.h $(BUILDTOP)/include/krb5/krb5.h \
   $(BUILDTOP)/include/osconf.h $(BUILDTOP)/include/profile.h \
@@ -429,7 +429,7 @@
   $(SRCTOP)/include/k5-plugin.h $(SRCTOP)/include/k5-thread.h \
   $(SRCTOP)/include/krb5.h $(SRCTOP)/include/krb5/locate_plugin.h \
   $(SRCTOP)/include/krb5/preauth_plugin.h $(SRCTOP)/include/port-sockets.h \
-  $(SRCTOP)/include/socket-utils.h write_msg.c
+  $(SRCTOP)/include/socket-utils.h os-proto.h write_msg.c
 t_an_to_ln.so t_an_to_ln.po $(OUTPRE)t_an_to_ln.$(OBJEXT): \
   $(BUILDTOP)/include/krb5/krb5.h $(COM_ERR_DEPS) $(SRCTOP)/include/krb5.h \
   t_an_to_ln.c

Modified: trunk/src/lib/krb5/os/net_write.c
===================================================================
--- trunk/src/lib/krb5/os/net_write.c	2009-01-14 23:36:04 UTC (rev 21748)
+++ trunk/src/lib/krb5/os/net_write.c	2009-01-15 00:59:27 UTC (rev 21749)
@@ -1,7 +1,7 @@
 /*
  * lib/krb5/os/net_write.c
  *
- * Copyright 1987, 1988, 1990 by the Massachusetts Institute of Technology.
+ * Copyright 1987, 1988, 1990, 2009 by the Massachusetts Institute of Technology.
  * All Rights Reserved.
  *
  * Export of this software from the United States of America may
@@ -26,6 +26,7 @@
  */
 
 #include "k5-int.h"
+#include "os-proto.h"
 
 /*
  * krb5_net_write() writes "len" bytes from "buf" to the file
@@ -37,25 +38,45 @@
  */
 
 int
-krb5_net_write(krb5_context context, int fd, register const char *buf, int len)
+krb5_net_write(krb5_context context, int fd, const char *buf, int len)
 {
-    int cc;
-    register int wrlen = len;
-    do {
-	cc = SOCKET_WRITE((SOCKET)fd, buf, wrlen);
+    sg_buf sg;
+    SG_SET(&sg, buf, len);
+    return krb5int_net_writev(context, fd, &sg, 1);
+}
+
+int
+krb5int_net_writev(krb5_context context, int fd, sg_buf *sgp, int nsg)
+{
+    int cc, len = 0;
+    SOCKET_WRITEV_TEMP tmp;
+
+    while (nsg > 0) {
+	/* Skip any empty data blocks.  */
+	if (SG_LEN(sgp) == 0) {
+	    sgp++, nsg--;
+	    continue;
+	}
+	cc = SOCKET_WRITEV((SOCKET)fd, sgp, nsg, tmp);
 	if (cc < 0) {
 	    if (SOCKET_ERRNO == SOCKET_EINTR)
 		continue;
 
-		/* XXX this interface sucks! */
-        errno = SOCKET_ERRNO;           
-
-	    return(cc);
+	    /* XXX this interface sucks! */
+	    errno = SOCKET_ERRNO;           
+	    return -1;
 	}
-	else {
-	    buf += cc;
-	    wrlen -= cc;
+	len += cc;
+	while (cc > 0) {
+	    if ((unsigned)cc < SG_LEN(sgp)) {
+		SG_ADVANCE(sgp, (unsigned)cc);
+		cc = 0;
+	    } else {
+		cc -= SG_LEN(sgp);
+		sgp++, nsg--;
+		assert(nsg > 0 || cc == 0);
+	    }
 	}
-    } while (wrlen > 0);
-    return(len);
+    }
+    return len;
 }

Modified: trunk/src/lib/krb5/os/os-proto.h
===================================================================
--- trunk/src/lib/krb5/os/os-proto.h	2009-01-14 23:36:04 UTC (rev 21748)
+++ trunk/src/lib/krb5/os/os-proto.h	2009-01-15 00:59:27 UTC (rev 21749)
@@ -1,7 +1,7 @@
 /*
  * lib/krb5/os/os-proto.h
  *
- * Copyright 1990,1991 by the Massachusetts Institute of Technology.
+ * Copyright 1990,1991,2009 by the Massachusetts Institute of Technology.
  * All Rights Reserved.
  *
  * Export of this software from the United States of America may
@@ -62,6 +62,9 @@
 int _krb5_use_dns_kdc (krb5_context);
 int _krb5_conf_boolean (const char *);
 
+/* The io vector is *not* const here, unlike writev()!  */
+int krb5int_net_writev (krb5_context, int, sg_buf *, int);
+
 #include "k5-thread.h"
 extern k5_mutex_t krb5int_us_time_mutex;
 

Modified: trunk/src/lib/krb5/os/write_msg.c
===================================================================
--- trunk/src/lib/krb5/os/write_msg.c	2009-01-14 23:36:04 UTC (rev 21748)
+++ trunk/src/lib/krb5/os/write_msg.c	2009-01-15 00:59:27 UTC (rev 21749)
@@ -1,7 +1,7 @@
 /*
  * lib/krb5/os/write_msg.c
  *
- * Copyright 1991 by the Massachusetts Institute of Technology.
+ * Copyright 1991, 2009 by the Massachusetts Institute of Technology.
  * All Rights Reserved.
  *
  * Export of this software from the United States of America may
@@ -29,19 +29,20 @@
 
 #include "k5-int.h"
 #include <errno.h>
+#include "os-proto.h"
 
 krb5_error_code
 krb5_write_message(krb5_context context, krb5_pointer fdp, krb5_data *outbuf)
 {
 	krb5_int32	len;
 	int		fd = *( (int *) fdp);
+	sg_buf		sg[2];
 
 	len = htonl(outbuf->length);
-	if (krb5_net_write(context, fd, (char *)&len, 4) < 0) {
-		return(errno);
+	SG_SET(&sg[0], &len, 4);
+	SG_SET(&sg[1], outbuf->data, outbuf->length);
+	if (krb5int_net_writev(context, fd, sg, 2) < 0) {
+	    return errno;
 	}
-	if (outbuf->length && (krb5_net_write(context, fd, outbuf->data, outbuf->length) < 0)) {
-		return(errno);
-	}
 	return(0);
 }