[2/3] app/testpmd: add actions to modify TCP header fields
Checks
Commit Message
Add actions:
- INC_TCP_SEQ - Increase sequence number in the outermost TCP header.
- DEC_TCP_SEQ - Decrease sequence number in the outermost TCP header.
- INC_TCP_ACK - Increase acknowledgment number in the outermost TCP
header.
- DEC_TCP_ACK - Decrease acknowledgment number in the outermost TCP
header.
Original work by Xiaoyu Min.
Signed-off-by: Dekel Peled <dekelp@mellanox.com>
---
app/test-pmd/cmdline_flow.c | 100 ++++++++++++++++++++++++++++
doc/guides/testpmd_app_ug/testpmd_funcs.rst | 16 +++++
2 files changed, 116 insertions(+)
Comments
On Thu, Mar 21, 2019 at 04:18:36PM +0200, Dekel Peled wrote:
> Add actions:
> - INC_TCP_SEQ - Increase sequence number in the outermost TCP header.
> - DEC_TCP_SEQ - Decrease sequence number in the outermost TCP header.
> - INC_TCP_ACK - Increase acknowledgment number in the outermost TCP
> header.
> - DEC_TCP_ACK - Decrease acknowledgment number in the outermost TCP
> header.
>
> Original work by Xiaoyu Min.
>
> Signed-off-by: Dekel Peled <dekelp@mellanox.com>
I suggest to merge this patch into the previous one. No reason for testpmd
to be updated separately.
Some comments below.
> ---
> app/test-pmd/cmdline_flow.c | 100 ++++++++++++++++++++++++++++
> doc/guides/testpmd_app_ug/testpmd_funcs.rst | 16 +++++
> 2 files changed, 116 insertions(+)
>
> diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
> index 36659a6..5cd4ceb 100644
> --- a/app/test-pmd/cmdline_flow.c
> +++ b/app/test-pmd/cmdline_flow.c
> @@ -271,6 +271,14 @@ enum index {
> ACTION_SET_MAC_SRC_MAC_SRC,
> ACTION_SET_MAC_DST,
> ACTION_SET_MAC_DST_MAC_DST,
> + ACTION_INC_TCP_SEQ,
> + ACTION_INC_TCP_SEQ_VALUE,
> + ACTION_DEC_TCP_SEQ,
> + ACTION_DEC_TCP_SEQ_VALUE,
> + ACTION_INC_TCP_ACK,
> + ACTION_INC_TCP_ACK_VALUE,
> + ACTION_DEC_TCP_ACK,
> + ACTION_DEC_TCP_ACK_VALUE,
> };
>
> /** Maximum size for pattern in struct rte_flow_item_raw. */
> @@ -884,6 +892,10 @@ struct parse_action_priv {
> ACTION_SET_TTL,
> ACTION_SET_MAC_SRC,
> ACTION_SET_MAC_DST,
> + ACTION_INC_TCP_SEQ,
> + ACTION_DEC_TCP_SEQ,
> + ACTION_INC_TCP_ACK,
> + ACTION_DEC_TCP_ACK,
> ZERO,
> };
>
> @@ -1046,6 +1058,30 @@ struct parse_action_priv {
> ZERO,
> };
>
> +static const enum index action_inc_tcp_seq[] = {
> + ACTION_INC_TCP_SEQ_VALUE,
> + ACTION_NEXT,
> + ZERO,
> +};
> +
> +static const enum index action_dec_tcp_seq[] = {
> + ACTION_DEC_TCP_SEQ_VALUE,
> + ACTION_NEXT,
> + ZERO,
> +};
> +
> +static const enum index action_inc_tcp_ack[] = {
> + ACTION_INC_TCP_ACK_VALUE,
> + ACTION_NEXT,
> + ZERO,
> +};
> +
> +static const enum index action_dec_tcp_ack[] = {
> + ACTION_DEC_TCP_ACK_VALUE,
> + ACTION_NEXT,
> + ZERO,
> +};
> +
> static int parse_init(struct context *, const struct token *,
> const char *, unsigned int,
> void *, unsigned int);
> @@ -2843,6 +2879,70 @@ static int comp_vc_action_rss_queue(struct context *, const struct token *,
> (struct rte_flow_action_set_mac, mac_addr)),
> .call = parse_vc_conf,
> },
> + [ACTION_INC_TCP_SEQ] = {
> + .name = "inc_tcp_seq",
> + .help = "increase TCP sequence number",
> + .priv = PRIV_ACTION(INC_TCP_SEQ,
> + sizeof(struct rte_flow_action_modify_tcp_seq)),
> + .next = NEXT(action_inc_tcp_seq),
> + .call = parse_vc,
> + },
> + [ACTION_INC_TCP_SEQ_VALUE] = {
> + .name = "value",
> + .help = "the value to increase TCP sequence number by",
> + .next = NEXT(action_inc_tcp_seq, NEXT_ENTRY(UNSIGNED)),
> + .args = ARGS(ARGS_ENTRY_HTON
> + (struct rte_flow_action_modify_tcp_seq, value)),
You may need to remove HTON here depending on the chosen endian for the
API, see my comments on previous patch.
> + .call = parse_vc_conf,
> + },
> + [ACTION_DEC_TCP_SEQ] = {
> + .name = "dec_tcp_seq",
> + .help = "decrease TCP sequence number",
> + .priv = PRIV_ACTION(DEC_TCP_SEQ,
> + sizeof(struct rte_flow_action_modify_tcp_seq)),
> + .next = NEXT(action_dec_tcp_seq),
> + .call = parse_vc,
> + },
> + [ACTION_DEC_TCP_SEQ_VALUE] = {
> + .name = "value",
> + .help = "the value to decrease TCP sequence number by",
> + .next = NEXT(action_dec_tcp_seq, NEXT_ENTRY(UNSIGNED)),
> + .args = ARGS(ARGS_ENTRY_HTON
> + (struct rte_flow_action_modify_tcp_seq, value)),
Same here.
> + .call = parse_vc_conf,
> + },
> + [ACTION_INC_TCP_ACK] = {
> + .name = "inc_tcp_ack",
> + .help = "increase TCP acknowledgment number",
> + .priv = PRIV_ACTION(INC_TCP_ACK,
> + sizeof(struct rte_flow_action_modify_tcp_ack)),
> + .next = NEXT(action_inc_tcp_ack),
> + .call = parse_vc,
> + },
> + [ACTION_INC_TCP_ACK_VALUE] = {
> + .name = "value",
> + .help = "the value to increase TCP acknowledgment number by",
> + .next = NEXT(action_inc_tcp_ack, NEXT_ENTRY(UNSIGNED)),
> + .args = ARGS(ARGS_ENTRY_HTON
> + (struct rte_flow_action_modify_tcp_ack, value)),
Ditto.
> + .call = parse_vc_conf,
> + },
> + [ACTION_DEC_TCP_ACK] = {
> + .name = "dec_tcp_ack",
> + .help = "decrease TCP acknowledgment number",
> + .priv = PRIV_ACTION(DEC_TCP_ACK,
> + sizeof(struct rte_flow_action_modify_tcp_ack)),
> + .next = NEXT(action_dec_tcp_ack),
> + .call = parse_vc,
> + },
> + [ACTION_DEC_TCP_ACK_VALUE] = {
> + .name = "value",
> + .help = "the value to decrease TCP acknowledgment number by",
> + .next = NEXT(action_dec_tcp_ack, NEXT_ENTRY(UNSIGNED)),
> + .args = ARGS(ARGS_ENTRY_HTON
> + (struct rte_flow_action_modify_tcp_ack, value)),
Ditto.
> + .call = parse_vc_conf,
> + },
> };
>
> /** Remove and return last entry from argument stack. */
> diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> index 1a12da4..c6f8b2c 100644
> --- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> +++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> @@ -3961,6 +3961,22 @@ This section lists supported actions and their attributes, if any.
>
> - ``mac_addr {MAC-48}``: new destination MAC address
>
> +- ``inc_tcp_seq``: Increase sequence number in the outermost TCP header
> +
> + - ``value {unsigned}``: Value to increase TCP sequence number by
> +
> +- ``dec_tcp_seq``: Decrease sequence number in the outermost TCP header
> +
> + - ``value {unsigned}``: Value to decrease TCP sequence number by
> +
> +- ``inc_tcp_ack``: Increase acknowledgment number in the outermost TCP header
> +
> + - ``value {unsigned}``: Value to increase TCP acknowledgment number by
> +
> +- ``dec_tcp_ack``: Decrease acknowledgment number in the outermost TCP header
> +
> + - ``value {unsigned}``: Value to decrease TCP acknowledgment number by
Please add missing "." to each line.
> +
> Destroying flow rules
> ~~~~~~~~~~~~~~~~~~~~~
>
> --
> 1.8.3.1
>
Thanks, PSB.
> -----Original Message-----
> From: Adrien Mazarguil <adrien.mazarguil@6wind.com>
> Sent: Friday, March 29, 2019 4:59 PM
> To: Dekel Peled <dekelp@mellanox.com>
> Cc: wenzhuo.lu@intel.com; jingjing.wu@intel.com;
> bernard.iremonger@intel.com; Yongseok Koh <yskoh@mellanox.com>;
> Shahaf Shuler <shahafs@mellanox.com>; dev@dpdk.org; Ori Kam
> <orika@mellanox.com>
> Subject: Re: [PATCH 2/3] app/testpmd: add actions to modify TCP header
> fields
>
> On Thu, Mar 21, 2019 at 04:18:36PM +0200, Dekel Peled wrote:
> > Add actions:
> > - INC_TCP_SEQ - Increase sequence number in the outermost TCP header.
> > - DEC_TCP_SEQ - Decrease sequence number in the outermost TCP
> header.
> > - INC_TCP_ACK - Increase acknowledgment number in the outermost TCP
> > header.
> > - DEC_TCP_ACK - Decrease acknowledgment number in the outermost TCP
> > header.
> >
> > Original work by Xiaoyu Min.
> >
> > Signed-off-by: Dekel Peled <dekelp@mellanox.com>
>
> I suggest to merge this patch into the previous one. No reason for testpmd
> to be updated separately.
>
I prefer it in separate patch since it is part of different SW module.
> Some comments below.
>
> > ---
> > app/test-pmd/cmdline_flow.c | 100
> ++++++++++++++++++++++++++++
> > doc/guides/testpmd_app_ug/testpmd_funcs.rst | 16 +++++
> > 2 files changed, 116 insertions(+)
> >
> > diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
> > index 36659a6..5cd4ceb 100644
> > --- a/app/test-pmd/cmdline_flow.c
> > +++ b/app/test-pmd/cmdline_flow.c
> > @@ -271,6 +271,14 @@ enum index {
> > ACTION_SET_MAC_SRC_MAC_SRC,
> > ACTION_SET_MAC_DST,
> > ACTION_SET_MAC_DST_MAC_DST,
> > + ACTION_INC_TCP_SEQ,
> > + ACTION_INC_TCP_SEQ_VALUE,
> > + ACTION_DEC_TCP_SEQ,
> > + ACTION_DEC_TCP_SEQ_VALUE,
> > + ACTION_INC_TCP_ACK,
> > + ACTION_INC_TCP_ACK_VALUE,
> > + ACTION_DEC_TCP_ACK,
> > + ACTION_DEC_TCP_ACK_VALUE,
> > };
> >
> > /** Maximum size for pattern in struct rte_flow_item_raw. */ @@
> > -884,6 +892,10 @@ struct parse_action_priv {
> > ACTION_SET_TTL,
> > ACTION_SET_MAC_SRC,
> > ACTION_SET_MAC_DST,
> > + ACTION_INC_TCP_SEQ,
> > + ACTION_DEC_TCP_SEQ,
> > + ACTION_INC_TCP_ACK,
> > + ACTION_DEC_TCP_ACK,
> > ZERO,
> > };
> >
> > @@ -1046,6 +1058,30 @@ struct parse_action_priv {
> > ZERO,
> > };
> >
> > +static const enum index action_inc_tcp_seq[] = {
> > + ACTION_INC_TCP_SEQ_VALUE,
> > + ACTION_NEXT,
> > + ZERO,
> > +};
> > +
> > +static const enum index action_dec_tcp_seq[] = {
> > + ACTION_DEC_TCP_SEQ_VALUE,
> > + ACTION_NEXT,
> > + ZERO,
> > +};
> > +
> > +static const enum index action_inc_tcp_ack[] = {
> > + ACTION_INC_TCP_ACK_VALUE,
> > + ACTION_NEXT,
> > + ZERO,
> > +};
> > +
> > +static const enum index action_dec_tcp_ack[] = {
> > + ACTION_DEC_TCP_ACK_VALUE,
> > + ACTION_NEXT,
> > + ZERO,
> > +};
> > +
> > static int parse_init(struct context *, const struct token *,
> > const char *, unsigned int,
> > void *, unsigned int);
> > @@ -2843,6 +2879,70 @@ static int comp_vc_action_rss_queue(struct
> context *, const struct token *,
> > (struct rte_flow_action_set_mac, mac_addr)),
> > .call = parse_vc_conf,
> > },
> > + [ACTION_INC_TCP_SEQ] = {
> > + .name = "inc_tcp_seq",
> > + .help = "increase TCP sequence number",
> > + .priv = PRIV_ACTION(INC_TCP_SEQ,
> > + sizeof(struct rte_flow_action_modify_tcp_seq)),
> > + .next = NEXT(action_inc_tcp_seq),
> > + .call = parse_vc,
> > + },
> > + [ACTION_INC_TCP_SEQ_VALUE] = {
> > + .name = "value",
> > + .help = "the value to increase TCP sequence number by",
> > + .next = NEXT(action_inc_tcp_seq, NEXT_ENTRY(UNSIGNED)),
> > + .args = ARGS(ARGS_ENTRY_HTON
> > + (struct rte_flow_action_modify_tcp_seq, value)),
>
> You may need to remove HTON here depending on the chosen endian for
> the API, see my comments on previous patch.
>
> > + .call = parse_vc_conf,
> > + },
> > + [ACTION_DEC_TCP_SEQ] = {
> > + .name = "dec_tcp_seq",
> > + .help = "decrease TCP sequence number",
> > + .priv = PRIV_ACTION(DEC_TCP_SEQ,
> > + sizeof(struct rte_flow_action_modify_tcp_seq)),
> > + .next = NEXT(action_dec_tcp_seq),
> > + .call = parse_vc,
> > + },
> > + [ACTION_DEC_TCP_SEQ_VALUE] = {
> > + .name = "value",
> > + .help = "the value to decrease TCP sequence number by",
> > + .next = NEXT(action_dec_tcp_seq,
> NEXT_ENTRY(UNSIGNED)),
> > + .args = ARGS(ARGS_ENTRY_HTON
> > + (struct rte_flow_action_modify_tcp_seq, value)),
>
> Same here.
>
> > + .call = parse_vc_conf,
> > + },
> > + [ACTION_INC_TCP_ACK] = {
> > + .name = "inc_tcp_ack",
> > + .help = "increase TCP acknowledgment number",
> > + .priv = PRIV_ACTION(INC_TCP_ACK,
> > + sizeof(struct rte_flow_action_modify_tcp_ack)),
> > + .next = NEXT(action_inc_tcp_ack),
> > + .call = parse_vc,
> > + },
> > + [ACTION_INC_TCP_ACK_VALUE] = {
> > + .name = "value",
> > + .help = "the value to increase TCP acknowledgment number
> by",
> > + .next = NEXT(action_inc_tcp_ack, NEXT_ENTRY(UNSIGNED)),
> > + .args = ARGS(ARGS_ENTRY_HTON
> > + (struct rte_flow_action_modify_tcp_ack, value)),
>
> Ditto.
>
> > + .call = parse_vc_conf,
> > + },
> > + [ACTION_DEC_TCP_ACK] = {
> > + .name = "dec_tcp_ack",
> > + .help = "decrease TCP acknowledgment number",
> > + .priv = PRIV_ACTION(DEC_TCP_ACK,
> > + sizeof(struct rte_flow_action_modify_tcp_ack)),
> > + .next = NEXT(action_dec_tcp_ack),
> > + .call = parse_vc,
> > + },
> > + [ACTION_DEC_TCP_ACK_VALUE] = {
> > + .name = "value",
> > + .help = "the value to decrease TCP acknowledgment number
> by",
> > + .next = NEXT(action_dec_tcp_ack,
> NEXT_ENTRY(UNSIGNED)),
> > + .args = ARGS(ARGS_ENTRY_HTON
> > + (struct rte_flow_action_modify_tcp_ack, value)),
>
> Ditto.
>
> > + .call = parse_vc_conf,
> > + },
> > };
> >
> > /** Remove and return last entry from argument stack. */ diff --git
> > a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > index 1a12da4..c6f8b2c 100644
> > --- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > +++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > @@ -3961,6 +3961,22 @@ This section lists supported actions and their
> attributes, if any.
> >
> > - ``mac_addr {MAC-48}``: new destination MAC address
> >
> > +- ``inc_tcp_seq``: Increase sequence number in the outermost TCP
> > +header
> > +
> > + - ``value {unsigned}``: Value to increase TCP sequence number by
> > +
> > +- ``dec_tcp_seq``: Decrease sequence number in the outermost TCP
> > +header
> > +
> > + - ``value {unsigned}``: Value to decrease TCP sequence number by
> > +
> > +- ``inc_tcp_ack``: Increase acknowledgment number in the outermost
> > +TCP header
> > +
> > + - ``value {unsigned}``: Value to increase TCP acknowledgment number
> > + by
> > +
> > +- ``dec_tcp_ack``: Decrease acknowledgment number in the outermost
> > +TCP header
> > +
> > + - ``value {unsigned}``: Value to decrease TCP acknowledgment number
> > + by
>
> Please add missing "." to each line.
Will add.
>
> > +
> > Destroying flow rules
> > ~~~~~~~~~~~~~~~~~~~~~
> >
> > --
> > 1.8.3.1
> >
>
> --
> Adrien Mazarguil
> 6WIND
@@ -271,6 +271,14 @@ enum index {
ACTION_SET_MAC_SRC_MAC_SRC,
ACTION_SET_MAC_DST,
ACTION_SET_MAC_DST_MAC_DST,
+ ACTION_INC_TCP_SEQ,
+ ACTION_INC_TCP_SEQ_VALUE,
+ ACTION_DEC_TCP_SEQ,
+ ACTION_DEC_TCP_SEQ_VALUE,
+ ACTION_INC_TCP_ACK,
+ ACTION_INC_TCP_ACK_VALUE,
+ ACTION_DEC_TCP_ACK,
+ ACTION_DEC_TCP_ACK_VALUE,
};
/** Maximum size for pattern in struct rte_flow_item_raw. */
@@ -884,6 +892,10 @@ struct parse_action_priv {
ACTION_SET_TTL,
ACTION_SET_MAC_SRC,
ACTION_SET_MAC_DST,
+ ACTION_INC_TCP_SEQ,
+ ACTION_DEC_TCP_SEQ,
+ ACTION_INC_TCP_ACK,
+ ACTION_DEC_TCP_ACK,
ZERO,
};
@@ -1046,6 +1058,30 @@ struct parse_action_priv {
ZERO,
};
+static const enum index action_inc_tcp_seq[] = {
+ ACTION_INC_TCP_SEQ_VALUE,
+ ACTION_NEXT,
+ ZERO,
+};
+
+static const enum index action_dec_tcp_seq[] = {
+ ACTION_DEC_TCP_SEQ_VALUE,
+ ACTION_NEXT,
+ ZERO,
+};
+
+static const enum index action_inc_tcp_ack[] = {
+ ACTION_INC_TCP_ACK_VALUE,
+ ACTION_NEXT,
+ ZERO,
+};
+
+static const enum index action_dec_tcp_ack[] = {
+ ACTION_DEC_TCP_ACK_VALUE,
+ ACTION_NEXT,
+ ZERO,
+};
+
static int parse_init(struct context *, const struct token *,
const char *, unsigned int,
void *, unsigned int);
@@ -2843,6 +2879,70 @@ static int comp_vc_action_rss_queue(struct context *, const struct token *,
(struct rte_flow_action_set_mac, mac_addr)),
.call = parse_vc_conf,
},
+ [ACTION_INC_TCP_SEQ] = {
+ .name = "inc_tcp_seq",
+ .help = "increase TCP sequence number",
+ .priv = PRIV_ACTION(INC_TCP_SEQ,
+ sizeof(struct rte_flow_action_modify_tcp_seq)),
+ .next = NEXT(action_inc_tcp_seq),
+ .call = parse_vc,
+ },
+ [ACTION_INC_TCP_SEQ_VALUE] = {
+ .name = "value",
+ .help = "the value to increase TCP sequence number by",
+ .next = NEXT(action_inc_tcp_seq, NEXT_ENTRY(UNSIGNED)),
+ .args = ARGS(ARGS_ENTRY_HTON
+ (struct rte_flow_action_modify_tcp_seq, value)),
+ .call = parse_vc_conf,
+ },
+ [ACTION_DEC_TCP_SEQ] = {
+ .name = "dec_tcp_seq",
+ .help = "decrease TCP sequence number",
+ .priv = PRIV_ACTION(DEC_TCP_SEQ,
+ sizeof(struct rte_flow_action_modify_tcp_seq)),
+ .next = NEXT(action_dec_tcp_seq),
+ .call = parse_vc,
+ },
+ [ACTION_DEC_TCP_SEQ_VALUE] = {
+ .name = "value",
+ .help = "the value to decrease TCP sequence number by",
+ .next = NEXT(action_dec_tcp_seq, NEXT_ENTRY(UNSIGNED)),
+ .args = ARGS(ARGS_ENTRY_HTON
+ (struct rte_flow_action_modify_tcp_seq, value)),
+ .call = parse_vc_conf,
+ },
+ [ACTION_INC_TCP_ACK] = {
+ .name = "inc_tcp_ack",
+ .help = "increase TCP acknowledgment number",
+ .priv = PRIV_ACTION(INC_TCP_ACK,
+ sizeof(struct rte_flow_action_modify_tcp_ack)),
+ .next = NEXT(action_inc_tcp_ack),
+ .call = parse_vc,
+ },
+ [ACTION_INC_TCP_ACK_VALUE] = {
+ .name = "value",
+ .help = "the value to increase TCP acknowledgment number by",
+ .next = NEXT(action_inc_tcp_ack, NEXT_ENTRY(UNSIGNED)),
+ .args = ARGS(ARGS_ENTRY_HTON
+ (struct rte_flow_action_modify_tcp_ack, value)),
+ .call = parse_vc_conf,
+ },
+ [ACTION_DEC_TCP_ACK] = {
+ .name = "dec_tcp_ack",
+ .help = "decrease TCP acknowledgment number",
+ .priv = PRIV_ACTION(DEC_TCP_ACK,
+ sizeof(struct rte_flow_action_modify_tcp_ack)),
+ .next = NEXT(action_dec_tcp_ack),
+ .call = parse_vc,
+ },
+ [ACTION_DEC_TCP_ACK_VALUE] = {
+ .name = "value",
+ .help = "the value to decrease TCP acknowledgment number by",
+ .next = NEXT(action_dec_tcp_ack, NEXT_ENTRY(UNSIGNED)),
+ .args = ARGS(ARGS_ENTRY_HTON
+ (struct rte_flow_action_modify_tcp_ack, value)),
+ .call = parse_vc_conf,
+ },
};
/** Remove and return last entry from argument stack. */
@@ -3961,6 +3961,22 @@ This section lists supported actions and their attributes, if any.
- ``mac_addr {MAC-48}``: new destination MAC address
+- ``inc_tcp_seq``: Increase sequence number in the outermost TCP header
+
+ - ``value {unsigned}``: Value to increase TCP sequence number by
+
+- ``dec_tcp_seq``: Decrease sequence number in the outermost TCP header
+
+ - ``value {unsigned}``: Value to decrease TCP sequence number by
+
+- ``inc_tcp_ack``: Increase acknowledgment number in the outermost TCP header
+
+ - ``value {unsigned}``: Value to increase TCP acknowledgment number by
+
+- ``dec_tcp_ack``: Decrease acknowledgment number in the outermost TCP header
+
+ - ``value {unsigned}``: Value to decrease TCP acknowledgment number by
+
Destroying flow rules
~~~~~~~~~~~~~~~~~~~~~