[PATCH iproute2-next] erspan: Add type I version 0 support.

[PATCH iproute2-next] erspan: Add type I version 0 support.

[William Tu]

The Type I ERSPAN frame format is based on the barebones
IP + GRE(4-byte) encapsulation on top of the raw mirrored frame.
Both type I and II use 0x88BE as protocol type. Unlike type II
and III, no sequence number or key is required.

To creat a type I erspan tunnel device:
$ ip link add dev erspan11 type erspan \
	local 172.16.1.100 remote 172.16.1.200 \
	erspan_ver 0

CC: Dmitriy Andreyevskiy <dandreye@cisco.com>
Signed-off-by: William Tu <u9012063@gmail.com>
---
I didn't notice there is Type I when I did first erspan type II code
because it is not in the ietf draft 00 and 01. It's until recently I got
request for adding type I. Spec is below at draft 02:
https://tools.ietf.org/html/draft-foschiano-erspan-02#section-4.1

To verify with Wireshark, make sure you have:
commit ef76d65fc61d01c2ce5184140f4b1bba0019078b
Author: Guy Harris <guy@alum.mit.edu>
Date:   Mon Sep 30 16:35:35 2019 -0700

	Fix checks for "do we have an ERSPAN header?"
---
 ip/link_gre.c         | 4 ++--
 ip/link_gre6.c        | 6 +++---
 man/man8/ip-link.8.in | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/ip/link_gre.c b/ip/link_gre.c
index d616a970e9a2..0461e5d06ef3 100644
--- a/ip/link_gre.c
+++ b/ip/link_gre.c
@@ -354,8 +354,8 @@ get_failed:
 			NEXT_ARG();
 			if (get_u8(&erspan_ver, *argv, 0))
 				invarg("invalid erspan version\n", *argv);
-			if (erspan_ver != 1 && erspan_ver != 2)
-				invarg("erspan version must be 1 or 2\n", *argv);
+			if (erspan_ver > 2)
+				invarg("erspan version must be 0/1/2\n", *argv);
 		} else if (is_erspan && strcmp(*argv, "erspan_dir") == 0) {
 			NEXT_ARG();
 			if (matches(*argv, "ingress") == 0)
diff --git a/ip/link_gre6.c b/ip/link_gre6.c
index 94a4ee700431..9d270f4b4455 100644
--- a/ip/link_gre6.c
+++ b/ip/link_gre6.c
@@ -389,8 +389,8 @@ get_failed:
 			NEXT_ARG();
 			if (get_u8(&erspan_ver, *argv, 0))
 				invarg("invalid erspan version\n", *argv);
-			if (erspan_ver != 1 && erspan_ver != 2)
-				invarg("erspan version must be 1 or 2\n", *argv);
+			if (erspan_ver > 2)
+				invarg("erspan version must be 0/1/2\n", *argv);
 		} else if (strcmp(*argv, "erspan_dir") == 0) {
 			NEXT_ARG();
 			if (matches(*argv, "ingress") == 0)
@@ -430,7 +430,7 @@ get_failed:
 	addattr_l(n, 1024, IFLA_GRE_FLOWINFO, &flowinfo, 4);
 	addattr32(n, 1024, IFLA_GRE_FLAGS, flags);
 	addattr32(n, 1024, IFLA_GRE_FWMARK, fwmark);
-	if (erspan_ver) {
+	if (erspan_ver <= 2) {
 		addattr8(n, 1024, IFLA_GRE_ERSPAN_VER, erspan_ver);
 		if (erspan_ver == 1 && erspan_idx != 0) {
 			addattr32(n, 1024, IFLA_GRE_ERSPAN_INDEX, erspan_idx);
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 939e2ad49f4e..e8a25451f7cd 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -1163,8 +1163,8 @@ It must be an address on another interface on this host.
 .BR erspan_ver " \fIversion "
 - specifies the ERSPAN version number.
 .IR version
-indicates the ERSPAN version to be created: 1 for version 1 (type II)
-or 2 for version 2 (type III).
+indicates the ERSPAN version to be created: 0 for version 0 type I,
+1 for version 1 (type II) or 2 for version 2 (type III).
 
 .sp
 .BR erspan " \fIIDX "
-- 
2.7.4

Re: [PATCH iproute2-next] erspan: Add type I version 0 support.

[David Ahern]

On 4/26/20 9:04 AM, William Tu wrote:
> The Type I ERSPAN frame format is based on the barebones
> IP + GRE(4-byte) encapsulation on top of the raw mirrored frame.
> Both type I and II use 0x88BE as protocol type. Unlike type II
> and III, no sequence number or key is required.

should this be considered a bug fix or -next is what you prefer?

Re: [PATCH iproute2-next] erspan: Add type I version 0 support.

[William Tu]

On Wed, Apr 29, 2020 at 2:52 PM David Ahern <dsahern@gmail.com> wrote:
>
> On 4/26/20 9:04 AM, William Tu wrote:
> > The Type I ERSPAN frame format is based on the barebones
> > IP + GRE(4-byte) encapsulation on top of the raw mirrored frame.
> > Both type I and II use 0x88BE as protocol type. Unlike type II
> > and III, no sequence number or key is required.
>
> should this be considered a bug fix or -next is what you prefer?
>
Hi David,
Since it's supporting a new type, I'd consider -next.
But either way is ok to me, I don't have have any preference.
Thanks!
William

Re: [PATCH iproute2-next] erspan: Add type I version 0 support.

[David Ahern]

On 4/29/20 6:45 PM, William Tu wrote:
> On Wed, Apr 29, 2020 at 2:52 PM David Ahern <dsahern@gmail.com> wrote:
>>
>> On 4/26/20 9:04 AM, William Tu wrote:
>>> The Type I ERSPAN frame format is based on the barebones
>>> IP + GRE(4-byte) encapsulation on top of the raw mirrored frame.
>>> Both type I and II use 0x88BE as protocol type. Unlike type II
>>> and III, no sequence number or key is required.
>>
>> should this be considered a bug fix or -next is what you prefer?
>>
> Hi David,
> Since it's supporting a new type, I'd consider -next.
> But either way is ok to me, I don't have have any preference.
> Thanks!
> William
> 

applied to iproute2-next.