[PATCH 2/2] Module for ip utility to support veth device

[PATCH 2/2] Module for ip utility to support veth device

[Vitaliy Gusev]

module link_veth

Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>

---

 link_veth.c |   76 +++++++++++++++++++-----------------------------------------
 veth.h      |    2 -
 2 files changed, 25 insertions(+), 53 deletions(-)

diff --git a/ip/link_veth.c b/ip/link_veth.c
index a4764f2..226b4ef 100644
--- a/ip/link_veth.c
+++ b/ip/link_veth.c
@@ -10,78 +10,52 @@
  *
  */
 
-#include <stdio.h>
 #include <string.h>
 
 #include "utils.h"
 #include "ip_common.h"
 #include "veth.h"
 
-#define ETH_ALEN	6
+#define	IFNAMSIZ	16
 
 static void usage(void)
 {
-	printf("Usage: ip link add ... type veth "
-			"[peer <peer-name>] [mac <mac>] [peer_mac <mac>]\n");
+	printf("Usage: ip link <options> type veth "
+		"[peer <options>]\nTo get <options> type "
+		"'ip link add help'\n");
 }
 
 static int veth_parse_opt(struct link_util *lu, int argc, char **argv,
 		struct nlmsghdr *hdr)
 {
-	__u8 mac[ETH_ALEN];
+	char *name, *type, *link, *dev;
+	int err, len;
+	struct rtattr * data;
 
-	for (; argc != 0; argv++, argc--) {
-		if (strcmp(*argv, "peer") == 0) {
-			argv++;
-			argc--;
-			if (argc == 0) {
-				usage();
-				return -1;
-			}
-
-			addattr_l(hdr, 1024, VETH_INFO_PEER,
-					*argv, strlen(*argv));
-
-			continue;
-		}
-
-		if (strcmp(*argv, "mac") == 0) {
-			argv++;
-			argc--;
-			if (argc == 0) {
-				usage();
-				return -1;
-			}
-
-			if (hexstring_a2n(*argv, mac, sizeof(mac)) == NULL)
-				return -1;
-
-			addattr_l(hdr, 1024, VETH_INFO_MAC,
-					mac, ETH_ALEN);
-			continue;
-		}
+	if (strcmp(argv[0], "peer") != 0) {
+		usage();
+		return -1;
+	}
 
-		if (strcmp(*argv, "peer_mac") == 0) {
-			argv++;
-			argc--;
-			if (argc == 0) {
-				usage();
-				return -1;
-			}
+	data = NLMSG_TAIL(hdr);
+	addattr_l(hdr, 1024, VETH_INFO_PEER, NULL, 0);
 
-			if (hexstring_a2n(*argv, mac, sizeof(mac)) == NULL)
-				return -1;
+	hdr->nlmsg_len += sizeof(struct ifinfomsg);
 
-			addattr_l(hdr, 1024, VETH_INFO_PEER_MAC,
-					mac, ETH_ALEN);
-			continue;
-		}
+	err = iplink_parse(argc - 1, argv + 1, (struct iplink_req *)hdr,
+			&name, &type, &link, &dev);
+	if (err < 0)
+		return err;
 
-		usage();
-		return -1;
+	if (name) {
+		len = strlen(name) + 1;
+		if (len > IFNAMSIZ)
+			invarg("\"name\" too long\n", *argv);
+		addattr_l(hdr, 1024, IFLA_IFNAME, name, len);
 	}
 
-	return 0;
+	data->rta_len = (void *)NLMSG_TAIL(hdr) - (void *)data;
+	return argc - 1 - err;
 }
 
 struct link_util veth_link_util = {
diff --git a/ip/veth.h b/ip/veth.h
index b84a530..aa2e6f9 100644
--- a/ip/veth.h
+++ b/ip/veth.h
@@ -3,9 +3,7 @@
 
 enum {
 	VETH_INFO_UNSPEC,
-	VETH_INFO_MAC,
 	VETH_INFO_PEER,
-	VETH_INFO_PEER_MAC,
 
 	__VETH_INFO_MAX
 #define VETH_INFO_MAX	(__VETH_INFO_MAX - 1)
-- 
Thank,
Vitaliy Gusev

Re: [PATCH 2/2] Module for ip utility to support veth device

[Stephen Hemminger]

On Tue, 18 Dec 2007 15:15:38 +0300
Vitaliy Gusev <vgusev@openvz.org> wrote:

> 
> module link_veth
> 
> Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>
> 
> ---
> 

Applied both patches, and moved veth.h from ip/veth.h to include/net/veth.h
so that the header file will be correctly updated if ABI changes.

-- 
Stephen Hemminger <stephen.hemminger@vyatta.com>

[PATCH] Virtual ethernet device (v.4)

[Pavel Emelyanov]

Veth stands for Virtual ETHernet. It is a simple tunnel driver
that works at the link layer and looks like a pair of ethernet
devices interconnected with each other.

Mainly it allows to communicate between network namespaces but
it can be used as is as well. E.g. one may join to bridged
networking segments together.

Eric recently sent a similar driver called etun with the sysfs
interface. This implementation uses another interface - the 
RTM_NRELINK message introduced by Patric.

The newlink callback is organized that way to make it easy to 
create the peer device in the separate namespace when we have 
them in kernel.

Many thanks to Patrick for reviewing the patches and his advises
on how to make driver cleaner.

Changes from v.3:
 * Reserved place for struct ifinfomsg in IFLA_INFO_DATA part
   of the packet. This is not used yet, but may be in the
   future.

Changes from v.2.1:
 * Made the generic routine for link creation to be used
   by veth driver, any other tunnel driver that needs to
   create several devices at once and rtnl_newlink() code.

Changes from v.2:
 * Rebase over latest netdev tree. No actual changes;
 * Small code rework.

Changes from v.1:
 * Per-cpu statistics;
 * Standard convention for nla policy names;
 * Module alias added;
 * Xmit function fixes noticed by Patric;
 * Code cleanup.

The patch for an ip utility is also provided.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Patrick McHardy <kaber@trash.net>

[PATCH] Module for ip utility to support veth device (v.3)

[Pavel Emelyanov]

The usage is
# ip link add [name] type veth [device parameters] peer [name <name> <other device params>]

This consists of two parts:
1/2 makes some copy-paste changes in ip/iplink.c for generic CLI
attributes parsing,
2/2 the module itself.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Patrick McHardy <kaber@trash.net>

[PATCH 2/2] Module for ip utility to support veth device

[Pavel Emelyanov]

The link_veth.so itself.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Patrick McHardy <kaber@trash.net>

---

 Makefile    |    6 ++++-
 link_veth.c |   63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 veth.h      |   12 +++++++++++
 3 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/ip/Makefile b/ip/Makefile
index 9a5bfe3..b46bce3 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -8,8 +8,9 @@ RTMONOBJ=rtmon.o
 ALLOBJ=$(IPOBJ) $(RTMONOBJ)
 SCRIPTS=ifcfg rtpr routel routef
 TARGETS=ip rtmon
+LIBS=link_veth.so
 
-all: $(TARGETS) $(SCRIPTS)
+all: $(TARGETS) $(SCRIPTS) $(LIBS)
 
 ip: $(IPOBJ) $(LIBNETLINK) $(LIBUTIL)
 
@@ -24,3 +25,6 @@ clean:
 
 LDLIBS	+= -ldl
 LDFLAGS	+= -Wl,-export-dynamic
+
+%.so: %.c
+	$(CC) $(CFLAGS) -shared $< -o $@
diff --git a/ip/link_veth.c b/ip/link_veth.c
new file mode 100644
index 0000000..ded2cdd
--- /dev/null
+++ b/ip/link_veth.c
@@ -0,0 +1,63 @@
+/*
+ * link_veth.c	veth driver module
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Authors:	Pavel Emelianov <xemul@openvz.org>
+ *
+ */
+
+#include <string.h>
+
+#include "utils.h"
+#include "ip_common.h"
+#include "veth.h"
+
+#define	IFNAMSIZ	16
+
+static void usage(void)
+{
+	printf("Usage: ip link add ... type veth "
+			"[peer <peer-name>] [mac <mac>] [peer_mac <mac>]\n");
+}
+
+static int veth_parse_opt(struct link_util *lu, int argc, char **argv,
+		struct nlmsghdr *hdr)
+{
+	char *name, *type, *link, *dev;
+	int err, len;
+	struct rtattr * data;
+
+	if (strcmp(argv[0], "peer") != 0) {
+		usage();
+		return -1;
+	}
+
+	data = NLMSG_TAIL(hdr);
+	addattr_l(hdr, 1024, VETH_INFO_PEER, NULL, 0);
+
+	hdr->nlmsg_len += sizeof(struct ifinfomsg);
+
+	err = iplink_parse(argc - 1, argv + 1, (struct iplink_req *)hdr,
+			&name, &type, &link, &dev);
+	if (err < 0)
+		return err;
+
+	if (name) {
+		len = strlen(name) + 1;
+		if (len > IFNAMSIZ)
+			invarg("\"name\" too long\n", *argv);
+		addattr_l(hdr, 1024, IFLA_IFNAME, name, len);
+	}
+
+	data->rta_len = (void *)NLMSG_TAIL(hdr) - (void *)data;
+	return argc - 1 - err;
+}
+
+struct link_util veth_link_util = {
+	.id = "veth",
+	.parse_opt = veth_parse_opt,
+};
diff --git a/ip/veth.h b/ip/veth.h
new file mode 100644
index 0000000..aa2e6f9
--- /dev/null
+++ b/ip/veth.h
@@ -0,0 +1,12 @@
+#ifndef __NET_VETH_H__
+#define __NET_VETH_H__
+
+enum {
+	VETH_INFO_UNSPEC,
+	VETH_INFO_PEER,
+
+	__VETH_INFO_MAX
+#define VETH_INFO_MAX	(__VETH_INFO_MAX - 1)
+};
+
+#endif

[PATCH 0/2] Virtual ethernet device (v3)

[Pavel Emelianov]

Veth stands for Virtual ETHernet. It is a simple tunnel driver
that works at the link layer and looks like a pair of ethernet
devices interconnected with each other.

Mainly it allows to communicate between network namespaces but
it can be used as is as well.

Eric recently sent a similar driver called etun with the sysfs
interface. This implementation uses another interface - the 
RTM_NRELINK message introduced by Patric.

The newlink callback is organized that way to make it easy to 
create the peer device in the separate namespace when we have 
them in kernel.

Changes from v.2.1:
 * Made the generic routine for link creation to be used
   by veth driver, any other tunnel driver that needs to
   create several devices at once and rtnl_newlink() code.

Changes from v.2:
 * Rebase over latest netdev tree. No actual changes;
 * Small code rework.

Changes from v.1:
 * percpu statistics;
 * standard convention for nla policy names;
 * module alias added;
 * xmit function fixes noticed by Patric;
 * code cleanup.

The patch for an ip utility is also provided.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: Patrick McHardy <kaber@trash.net>

[PATCH 0/2] Module for ip utility to support veth device (v.3)

[Pavel Emelianov]

The usage is
# ip link add [name] type veth [peer <name>] [mac <mac>] [peer_mac <mac>]

This consists of two parts:
1/2 makes some copy-paste changes in ip/iplink.c for generic CLI
attributes parsing,
2/2 the module itself.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>

[PATCH 2/2] Module for ip utility to support veth device

[Pavel Emelianov]

The link_veth.so itself.

The usage is
ip link add <name> type veth [peer ...]

where ... are the same options as in regular ip link add usage.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>

---

 Makefile    |    6 +++++-
 link_veth.c |   60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 veth.h      |   12 ++++++++++++
 3 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/ip/Makefile b/ip/Makefile
index 9a5bfe3..b46bce3 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -8,8 +8,9 @@ RTMONOBJ=rtmon.o
 ALLOBJ=$(IPOBJ) $(RTMONOBJ)
 SCRIPTS=ifcfg rtpr routel routef
 TARGETS=ip rtmon
+LIBS=link_veth.so
 
-all: $(TARGETS) $(SCRIPTS)
+all: $(TARGETS) $(SCRIPTS) $(LIBS)
 
 ip: $(IPOBJ) $(LIBNETLINK) $(LIBUTIL)
 
@@ -24,3 +25,6 @@ clean:
 
 LDLIBS	+= -ldl
 LDFLAGS	+= -Wl,-export-dynamic
+
+%.so: %.c
+	$(CC) $(CFLAGS) -shared $< -o $@
diff --git a/ip/link_veth.c b/ip/link_veth.c
new file mode 100644
index 0000000..0ceab86
--- /dev/null
+++ b/ip/link_veth.c
@@ -0,0 +1,60 @@
+/*
+ * link_veth.c	veth driver module
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Authors:	Pavel Emelianov <xemul@openvz.org>
+ *
+ */
+
+#include <string.h>
+
+#include "utils.h"
+#include "ip_common.h"
+#include "veth.h"
+
+#define	IFNAMSIZ	16
+
+static void usage(void)
+{
+	printf("Usage: ip link add ... type veth "
+			"[peer <peer-name>] [mac <mac>] [peer_mac <mac>]\n");
+}
+
+static int veth_parse_opt(struct link_util *lu, int argc, char **argv,
+		struct nlmsghdr *hdr)
+{
+	char *name, *type, *link, *dev;
+	int err, len;
+	struct rtattr * data = NLMSG_TAIL(hdr);
+
+	if (strcmp(argv[0], "peer") != 0) {
+		usage();
+		return -1;
+	}
+
+	addattr_l(hdr, 1024, VETH_INFO_PEER, NULL, 0);
+
+	err = iplink_parse(argc - 1, argv + 1, (struct iplink_req *)hdr,
+			&name, &type, &link, &dev);
+	if (err < 0)
+		return err;
+
+	if (name) {
+		len = strlen(name) + 1;
+		if (len > IFNAMSIZ)
+			invarg("\"name\" too long\n", *argv);
+		addattr_l(hdr, 1024, IFLA_IFNAME, name, len);
+	}
+
+	data->rta_len = (void *)NLMSG_TAIL(hdr) - (void *)data;
+	return argc - 1 - err;
+}
+
+struct link_util veth_link_util = {
+	.id = "veth",
+	.parse_opt = veth_parse_opt,
+};
diff --git a/ip/veth.h b/ip/veth.h
new file mode 100644
index 0000000..aa2e6f9
--- /dev/null
+++ b/ip/veth.h
@@ -0,0 +1,12 @@
+#ifndef __NET_VETH_H__
+#define __NET_VETH_H__
+
+enum {
+	VETH_INFO_UNSPEC,
+	VETH_INFO_PEER,
+
+	__VETH_INFO_MAX
+#define VETH_INFO_MAX	(__VETH_INFO_MAX - 1)
+};
+
+#endif