[PATCH iproute2-next] geneve: fix ttl inherit behavior

[PATCH iproute2-next] geneve: fix ttl inherit behavior

[Hangbin Liu]

Currently when we add geneve with "ttl inherit", we set ttl to 0, which
is actually use whatever default value instead of inherit the inner
protocol's ttl value.

To respect compatibility with old behavior and make a difference between
ttl inherit and ttl == 0, we add an attribute IFLA_GENEVE_TTL_INHERIT in
kernel commit 52d0d404d39dd ("geneve: add ttl inherit support").

Now let's use "ttl inherit" to inherit the inner protocol's ttl, and use
"ttl auto" to means "use whatever default value", the same behavior with
ttl == 0.

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 include/uapi/linux/if_link.h |  1 +
 ip/iplink_geneve.c           | 20 +++++++++++++-------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index f4a9715..02d7bdf 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -552,6 +552,7 @@ enum {
 	IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
 	IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
 	IFLA_GENEVE_LABEL,
+	IFLA_GENEVE_TTL_INHERIT,
 	__IFLA_GENEVE_MAX
 };
 #define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
diff --git a/ip/iplink_geneve.c b/ip/iplink_geneve.c
index 26e70ff..c417842 100644
--- a/ip/iplink_geneve.c
+++ b/ip/iplink_geneve.c
@@ -34,7 +34,7 @@ static void print_explain(FILE *f)
 		"Where: VNI   := 0-16777215\n"
 		"       ADDR  := IP_ADDRESS\n"
 		"       TOS   := { NUMBER | inherit }\n"
-		"       TTL   := { 1..255 | inherit }\n"
+		"       TTL   := { 1..255 | auto | inherit }\n"
 		"       LABEL := 0-1048575\n"
 	);
 }
@@ -94,7 +94,9 @@ static int geneve_parse_opt(struct link_util *lu, int argc, char **argv,
 
 			NEXT_ARG();
 			check_duparg(&attrs, IFLA_GENEVE_TTL, "ttl", *argv);
-			if (strcmp(*argv, "inherit") != 0) {
+			if (strcmp(*argv, "inherit") == 0) {
+				addattr8(n, 1024, IFLA_GENEVE_TTL_INHERIT, 1);
+			} else if (strcmp(*argv, "auto") != 0) {
 				if (get_unsigned(&uval, *argv, 0))
 					invarg("invalid TTL", *argv);
 				if (uval > 255)
@@ -265,12 +267,16 @@ static void geneve_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		}
 	}
 
-	if (tb[IFLA_GENEVE_TTL])
-		ttl = rta_getattr_u8(tb[IFLA_GENEVE_TTL]);
-	if (is_json_context() || ttl)
-		print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
-	else
+	if (tb[IFLA_GENEVE_TTL_INHERIT] &&
+	    rta_getattr_u8(tb[IFLA_GENEVE_TTL_INHERIT])) {
 		print_string(PRINT_FP, NULL, "ttl %s ", "inherit");
+	} else if (tb[IFLA_GENEVE_TTL]) {
+		ttl = rta_getattr_u8(tb[IFLA_GENEVE_TTL]);
+		if (is_json_context() || ttl)
+			print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
+		else
+			print_string(PRINT_FP, NULL, "ttl %s ", "auto");
+	}
 
 	if (tb[IFLA_GENEVE_TOS])
 		tos = rta_getattr_u8(tb[IFLA_GENEVE_TOS]);
-- 
2.5.5

Re: [PATCH iproute2-next] geneve: fix ttl inherit behavior

[Phil Sutter]

On Thu, Sep 27, 2018 at 03:27:37PM +0800, Hangbin Liu wrote:
> Currently when we add geneve with "ttl inherit", we set ttl to 0, which
> is actually use whatever default value instead of inherit the inner
> protocol's ttl value.
> 
> To respect compatibility with old behavior and make a difference between
> ttl inherit and ttl == 0, we add an attribute IFLA_GENEVE_TTL_INHERIT in
> kernel commit 52d0d404d39dd ("geneve: add ttl inherit support").
> 
> Now let's use "ttl inherit" to inherit the inner protocol's ttl, and use
> "ttl auto" to means "use whatever default value", the same behavior with
> ttl == 0.
> 
> Reported-by: Jianlin Shi <jishi@redhat.com>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>

Acked-by: Phil Sutter <phil@nwl.cc>

Re: [PATCH iproute2-next] geneve: fix ttl inherit behavior

[Hangbin Liu]

On Thu, Sep 27, 2018 at 11:08:36AM +0200, Phil Sutter wrote:
> On Thu, Sep 27, 2018 at 03:27:37PM +0800, Hangbin Liu wrote:
> > Currently when we add geneve with "ttl inherit", we set ttl to 0, which
> > is actually use whatever default value instead of inherit the inner
> > protocol's ttl value.
> > 
> > To respect compatibility with old behavior and make a difference between
> > ttl inherit and ttl == 0, we add an attribute IFLA_GENEVE_TTL_INHERIT in
> > kernel commit 52d0d404d39dd ("geneve: add ttl inherit support").
> > 
> > Now let's use "ttl inherit" to inherit the inner protocol's ttl, and use
> > "ttl auto" to means "use whatever default value", the same behavior with
> > ttl == 0.
> > 
> > Reported-by: Jianlin Shi <jishi@redhat.com>
> > Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> 
> Acked-by: Phil Sutter <phil@nwl.cc>

Hi Stephen, David,

Please hold on this path and let me fix the inherit flag issue first.

Thanks
Hangbin

[PATCHv2 iproute2-next] ip/geneve: fix ttl inherit behavior

[Hangbin Liu]

Currently when we add geneve with "ttl inherit", we only set ttl to 0, which
is actually use whatever default value instead of inherit the inner protocol's
ttl value.

To make a difference with ttl inherit and ttl == 0, we add an attribute
IFLA_GENEVE_TTL_INHERIT in kernel commit 52d0d404d39dd ("geneve: add ttl
inherit support"). Now let's use "ttl inherit" to inherit the inner
protocol's ttl, and use "ttl auto" to means "use whatever default value",
the same behavior with ttl == 0.

v2:
1) remove IFLA_GENEVE_TTL_INHERIT defination in if_link.h as it's already
   updated.
2) Still use addattr8() so we can enable/disable ttl inherit, as Michal
   suggested.

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 ip/iplink_geneve.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/ip/iplink_geneve.c b/ip/iplink_geneve.c
index 26e70ff..c417842 100644
--- a/ip/iplink_geneve.c
+++ b/ip/iplink_geneve.c
@@ -34,7 +34,7 @@ static void print_explain(FILE *f)
 		"Where: VNI   := 0-16777215\n"
 		"       ADDR  := IP_ADDRESS\n"
 		"       TOS   := { NUMBER | inherit }\n"
-		"       TTL   := { 1..255 | inherit }\n"
+		"       TTL   := { 1..255 | auto | inherit }\n"
 		"       LABEL := 0-1048575\n"
 	);
 }
@@ -94,7 +94,9 @@ static int geneve_parse_opt(struct link_util *lu, int argc, char **argv,
 
 			NEXT_ARG();
 			check_duparg(&attrs, IFLA_GENEVE_TTL, "ttl", *argv);
-			if (strcmp(*argv, "inherit") != 0) {
+			if (strcmp(*argv, "inherit") == 0) {
+				addattr8(n, 1024, IFLA_GENEVE_TTL_INHERIT, 1);
+			} else if (strcmp(*argv, "auto") != 0) {
 				if (get_unsigned(&uval, *argv, 0))
 					invarg("invalid TTL", *argv);
 				if (uval > 255)
@@ -265,12 +267,16 @@ static void geneve_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		}
 	}
 
-	if (tb[IFLA_GENEVE_TTL])
-		ttl = rta_getattr_u8(tb[IFLA_GENEVE_TTL]);
-	if (is_json_context() || ttl)
-		print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
-	else
+	if (tb[IFLA_GENEVE_TTL_INHERIT] &&
+	    rta_getattr_u8(tb[IFLA_GENEVE_TTL_INHERIT])) {
 		print_string(PRINT_FP, NULL, "ttl %s ", "inherit");
+	} else if (tb[IFLA_GENEVE_TTL]) {
+		ttl = rta_getattr_u8(tb[IFLA_GENEVE_TTL]);
+		if (is_json_context() || ttl)
+			print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
+		else
+			print_string(PRINT_FP, NULL, "ttl %s ", "auto");
+	}
 
 	if (tb[IFLA_GENEVE_TOS])
 		tos = rta_getattr_u8(tb[IFLA_GENEVE_TOS]);
-- 
2.5.5

Re: [PATCHv2 iproute2-next] ip/geneve: fix ttl inherit behavior

[David Ahern]

On 10/18/18 1:01 AM, Hangbin Liu wrote:
> Currently when we add geneve with "ttl inherit", we only set ttl to 0, which
> is actually use whatever default value instead of inherit the inner protocol's
> ttl value.
> 
> To make a difference with ttl inherit and ttl == 0, we add an attribute
> IFLA_GENEVE_TTL_INHERIT in kernel commit 52d0d404d39dd ("geneve: add ttl
> inherit support"). Now let's use "ttl inherit" to inherit the inner
> protocol's ttl, and use "ttl auto" to means "use whatever default value",
> the same behavior with ttl == 0.
> 
> v2:
> 1) remove IFLA_GENEVE_TTL_INHERIT defination in if_link.h as it's already
>    updated.
> 2) Still use addattr8() so we can enable/disable ttl inherit, as Michal
>    suggested.
> 
> Reported-by: Jianlin Shi <jishi@redhat.com>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  ip/iplink_geneve.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
> 

please update the man page as well.

[PATCHv3 iproute2-next] ip/geneve: fix ttl inherit behavior

[Hangbin Liu]

Currently when we add geneve with "ttl inherit", we only set ttl to 0, which
is actually use whatever default value instead of inherit the inner protocol's
ttl value.

To make a difference with ttl inherit and ttl == 0, we add an attribute
IFLA_GENEVE_TTL_INHERIT in kernel commit 52d0d404d39dd ("geneve: add ttl
inherit support"). Now let's use "ttl inherit" to inherit the inner
protocol's ttl, and use "ttl auto" to means "use whatever default value",
the same behavior with ttl == 0.

v2:
1) remove IFLA_GENEVE_TTL_INHERIT defination in if_link.h as it's already
   updated.
2) Still use addattr8() so we can enable/disable ttl inherit, as Michal
   suggested.

v3: Update man page

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 ip/iplink_geneve.c    | 20 +++++++++++++-------
 man/man8/ip-link.8.in |  4 +++-
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/ip/iplink_geneve.c b/ip/iplink_geneve.c
index 26e70ff..c417842 100644
--- a/ip/iplink_geneve.c
+++ b/ip/iplink_geneve.c
@@ -34,7 +34,7 @@ static void print_explain(FILE *f)
 		"Where: VNI   := 0-16777215\n"
 		"       ADDR  := IP_ADDRESS\n"
 		"       TOS   := { NUMBER | inherit }\n"
-		"       TTL   := { 1..255 | inherit }\n"
+		"       TTL   := { 1..255 | auto | inherit }\n"
 		"       LABEL := 0-1048575\n"
 	);
 }
@@ -94,7 +94,9 @@ static int geneve_parse_opt(struct link_util *lu, int argc, char **argv,
 
 			NEXT_ARG();
 			check_duparg(&attrs, IFLA_GENEVE_TTL, "ttl", *argv);
-			if (strcmp(*argv, "inherit") != 0) {
+			if (strcmp(*argv, "inherit") == 0) {
+				addattr8(n, 1024, IFLA_GENEVE_TTL_INHERIT, 1);
+			} else if (strcmp(*argv, "auto") != 0) {
 				if (get_unsigned(&uval, *argv, 0))
 					invarg("invalid TTL", *argv);
 				if (uval > 255)
@@ -265,12 +267,16 @@ static void geneve_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		}
 	}
 
-	if (tb[IFLA_GENEVE_TTL])
-		ttl = rta_getattr_u8(tb[IFLA_GENEVE_TTL]);
-	if (is_json_context() || ttl)
-		print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
-	else
+	if (tb[IFLA_GENEVE_TTL_INHERIT] &&
+	    rta_getattr_u8(tb[IFLA_GENEVE_TTL_INHERIT])) {
 		print_string(PRINT_FP, NULL, "ttl %s ", "inherit");
+	} else if (tb[IFLA_GENEVE_TTL]) {
+		ttl = rta_getattr_u8(tb[IFLA_GENEVE_TTL]);
+		if (is_json_context() || ttl)
+			print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
+		else
+			print_string(PRINT_FP, NULL, "ttl %s ", "auto");
+	}
 
 	if (tb[IFLA_GENEVE_TOS])
 		tos = rta_getattr_u8(tb[IFLA_GENEVE_TOS]);
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index ecbbd4f..4489162 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -1190,7 +1190,9 @@ the following additional arguments are supported:
 
 .sp
 .BI ttl " TTL"
-- specifies the TTL value to use in outgoing packets.
+- specifies the TTL value to use in outgoing packets. "0" or "auto" means
+use whatever default value, "inherit" means inherit the inner protocol's
+ttl. Default option is "0".
 
 .sp
 .BI tos " TOS"
-- 
2.5.5

Re: [PATCHv3 iproute2-next] ip/geneve: fix ttl inherit behavior

[David Ahern]

On 10/22/18 1:46 AM, Hangbin Liu wrote:
> Currently when we add geneve with "ttl inherit", we only set ttl to 0, which
> is actually use whatever default value instead of inherit the inner protocol's
> ttl value.
> 
> To make a difference with ttl inherit and ttl == 0, we add an attribute
> IFLA_GENEVE_TTL_INHERIT in kernel commit 52d0d404d39dd ("geneve: add ttl
> inherit support"). Now let's use "ttl inherit" to inherit the inner
> protocol's ttl, and use "ttl auto" to means "use whatever default value",
> the same behavior with ttl == 0.
> 
> v2:
> 1) remove IFLA_GENEVE_TTL_INHERIT defination in if_link.h as it's already
>    updated.
> 2) Still use addattr8() so we can enable/disable ttl inherit, as Michal
>    suggested.
> 
> v3: Update man page
> 
> Reported-by: Jianlin Shi <jishi@redhat.com>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  ip/iplink_geneve.c    | 20 +++++++++++++-------
>  man/man8/ip-link.8.in |  4 +++-
>  2 files changed, 16 insertions(+), 8 deletions(-)
> 


applied to iproute2-next. Thanks