[ovs-dev] [PATCH v2 ovn 2/3] Introduce icmp6.frag_mtu action
Lorenzo Bianconi
lorenzo.bianconi at redhat.com
Tue Jul 7 15:18:27 UTC 2020
Similar to what have been already done for IPv4, introduce
icmp6.frag_mtu action in order to set correct mtu in ICMPv6 "packet too
big" error message
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at redhat.com>
---
controller/pinctrl.c | 72 ++++++++++++++++++++++--------------
include/ovn/actions.h | 4 ++
include/ovn/logical-fields.h | 7 ++++
lib/actions.c | 13 ++++++-
lib/logical-fields.c | 5 +++
ovn-sb.xml | 7 ++--
tests/ovn.at | 8 ++++
utilities/ovn-trace.c | 7 +++-
8 files changed, 90 insertions(+), 33 deletions(-)
diff --git a/controller/pinctrl.c b/controller/pinctrl.c
index 61dad9752..f07fc92c8 100644
--- a/controller/pinctrl.c
+++ b/controller/pinctrl.c
@@ -228,12 +228,12 @@ static void pinctrl_handle_nd_ns(struct rconn *swconn,
struct dp_packet *pkt_in,
const struct match *md,
struct ofpbuf *userdata);
-static void pinctrl_handle_put_icmp4_frag_mtu(struct rconn *swconn,
- const struct flow *in_flow,
- struct dp_packet *pkt_in,
- struct ofputil_packet_in *pin,
- struct ofpbuf *userdata,
- struct ofpbuf *continuation);
+static void pinctrl_handle_put_icmp_frag_mtu(struct rconn *swconn,
+ const struct flow *in_flow,
+ struct dp_packet *pkt_in,
+ struct ofputil_packet_in *pin,
+ struct ofpbuf *userdata,
+ struct ofpbuf *continuation);
static void
pinctrl_handle_event(struct ofpbuf *userdata)
OVS_REQUIRES(pinctrl_mutex);
@@ -2783,8 +2783,9 @@ process_packet_in(struct rconn *swconn, const struct ofp_header *msg)
break;
case ACTION_OPCODE_PUT_ICMP4_FRAG_MTU:
- pinctrl_handle_put_icmp4_frag_mtu(swconn, &headers, &packet,
- &pin, &userdata, &continuation);
+ case ACTION_OPCODE_PUT_ICMP6_FRAG_MTU:
+ pinctrl_handle_put_icmp_frag_mtu(swconn, &headers, &packet, &pin,
+ &userdata, &continuation);
break;
case ACTION_OPCODE_EVENT:
@@ -5465,42 +5466,59 @@ exit:
/* Called with in the pinctrl_handler thread context. */
static void
-pinctrl_handle_put_icmp4_frag_mtu(struct rconn *swconn,
- const struct flow *in_flow,
- struct dp_packet *pkt_in,
- struct ofputil_packet_in *pin,
- struct ofpbuf *userdata,
- struct ofpbuf *continuation)
+pinctrl_handle_put_icmp_frag_mtu(struct rconn *swconn,
+ const struct flow *in_flow,
+ struct dp_packet *pkt_in,
+ struct ofputil_packet_in *pin,
+ struct ofpbuf *userdata,
+ struct ofpbuf *continuation)
{
enum ofp_version version = rconn_get_version(swconn);
enum ofputil_protocol proto = ofputil_protocol_from_ofp_version(version);
struct dp_packet *pkt_out = NULL;
/* This action only works for ICMPv4 packets. */
- if (!is_icmpv4(in_flow, NULL)) {
+ if (!is_icmpv4(in_flow, NULL) && !is_icmpv6(in_flow, NULL)) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
VLOG_WARN_RL(&rl, "put_icmp4_frag_mtu action on non-ICMPv4 packet");
goto exit;
}
- ovs_be16 *mtu = ofpbuf_try_pull(userdata, sizeof *mtu);
- if (!mtu) {
- goto exit;
- }
-
pkt_out = dp_packet_clone(pkt_in);
pkt_out->l2_5_ofs = pkt_in->l2_5_ofs;
pkt_out->l2_pad_size = pkt_in->l2_pad_size;
pkt_out->l3_ofs = pkt_in->l3_ofs;
pkt_out->l4_ofs = pkt_in->l4_ofs;
- struct ip_header *nh = dp_packet_l3(pkt_out);
- struct icmp_header *ih = dp_packet_l4(pkt_out);
- ovs_be16 old_frag_mtu = ih->icmp_fields.frag.mtu;
- ih->icmp_fields.frag.mtu = *mtu;
- ih->icmp_csum = recalc_csum16(ih->icmp_csum, old_frag_mtu, *mtu);
- nh->ip_csum = 0;
- nh->ip_csum = csum(nh, sizeof *nh);
+ if (is_icmpv4(in_flow, NULL)) {
+ ovs_be16 *mtu = ofpbuf_try_pull(userdata, sizeof *mtu);
+ if (!mtu) {
+ goto exit;
+ }
+
+ struct ip_header *nh = dp_packet_l3(pkt_out);
+ struct icmp_header *ih = dp_packet_l4(pkt_out);
+ ovs_be16 old_frag_mtu = ih->icmp_fields.frag.mtu;
+ ih->icmp_fields.frag.mtu = *mtu;
+ ih->icmp_csum = recalc_csum16(ih->icmp_csum, old_frag_mtu, *mtu);
+ nh->ip_csum = 0;
+ nh->ip_csum = csum(nh, sizeof *nh);
+ } else {
+ ovs_be32 *mtu = ofpbuf_try_pull(userdata, sizeof *mtu);
+ if (!mtu) {
+ goto exit;
+ }
+
+ struct icmp6_data_header *ih = dp_packet_l4(pkt_out);
+ put_16aligned_be32(ih->icmp6_data.be32, *mtu);
+
+ /* compute checksum and set correct mtu */
+ ih->icmp6_base.icmp6_cksum = 0;
+ uint32_t csum = packet_csum_pseudoheader6(dp_packet_l3(pkt_out));
+ uint32_t size = (uint8_t *)dp_packet_tail(pkt_out) - (uint8_t *)ih;
+ ih->icmp6_base.icmp6_cksum = csum_finish(
+ csum_continue(csum, ih, size));
+ }
pin->packet = dp_packet_data(pkt_out);
pin->packet_len = dp_packet_size(pkt_out);
diff --git a/include/ovn/actions.h b/include/ovn/actions.h
index 652873676..0f7f4cdb8 100644
--- a/include/ovn/actions.h
+++ b/include/ovn/actions.h
@@ -598,6 +598,10 @@ enum action_opcode {
* The actions, in OpenFlow 1.3 format, follow the action_header.
*/
ACTION_OPCODE_ICMP6_ERROR,
+
+ /* MTU value (to put in the icmp6 header field - frag_mtu) follow the
+ * action header. */
+ ACTION_OPCODE_PUT_ICMP6_FRAG_MTU,
};
/* Header. */
diff --git a/include/ovn/logical-fields.h b/include/ovn/logical-fields.h
index c7bd2dba9..61d17d14f 100644
--- a/include/ovn/logical-fields.h
+++ b/include/ovn/logical-fields.h
@@ -108,6 +108,13 @@ enum ovn_field_id {
* packet as per the RFC 1191.
*/
OVN_ICMP4_FRAG_MTU,
+ /*
+ * Name: "icmp6.frag_mtu" -
+ * Type: be32
+ * Description: Sets the first 32 bits of the ICMPv6 body to the MTU of
+ * next-hop link (RFC 4443)
+ */
+ OVN_ICMP6_FRAG_MTU,
OVN_FIELD_N_IDS
};
diff --git a/lib/actions.c b/lib/actions.c
index 6a3b1ba87..e14907e3d 100644
--- a/lib/actions.c
+++ b/lib/actions.c
@@ -3056,6 +3056,7 @@ format_OVNFIELD_LOAD(const struct ovnact_load *load , struct ds *s)
const struct ovn_field *f = ovn_field_from_name(load->dst.symbol->name);
switch (f->id) {
case OVN_ICMP4_FRAG_MTU:
+ case OVN_ICMP6_FRAG_MTU:
ds_put_format(s, "%s = %u;", f->name,
ntohs(load->imm.value.be16_int));
break;
@@ -3075,12 +3076,20 @@ encode_OVNFIELD_LOAD(const struct ovnact_load *load,
switch (f->id) {
case OVN_ICMP4_FRAG_MTU: {
size_t oc_offset = encode_start_controller_op(
- ACTION_OPCODE_PUT_ICMP4_FRAG_MTU, true, NX_CTLR_NO_METER,
- ofpacts);
+ ACTION_OPCODE_PUT_ICMP4_FRAG_MTU, true,
+ NX_CTLR_NO_METER, ofpacts);
ofpbuf_put(ofpacts, &load->imm.value.be16_int, sizeof(ovs_be16));
encode_finish_controller_op(oc_offset, ofpacts);
break;
}
+ case OVN_ICMP6_FRAG_MTU: {
+ size_t oc_offset = encode_start_controller_op(
+ ACTION_OPCODE_PUT_ICMP6_FRAG_MTU, true,
+ NX_CTLR_NO_METER, ofpacts);
+ ofpbuf_put(ofpacts, &load->imm.value.be32_int, sizeof(ovs_be32));
+ encode_finish_controller_op(oc_offset, ofpacts);
+ break;
+ }
case OVN_FIELD_N_IDS:
default:
OVS_NOT_REACHED();
diff --git a/lib/logical-fields.c b/lib/logical-fields.c
index 8ad56aa53..8639523ea 100644
--- a/lib/logical-fields.c
+++ b/lib/logical-fields.c
@@ -29,6 +29,10 @@ const struct ovn_field ovn_fields[OVN_FIELD_N_IDS] = {
OVN_ICMP4_FRAG_MTU,
"icmp4.frag_mtu",
2, 16,
+ }, {
+ OVN_ICMP6_FRAG_MTU,
+ "icmp6.frag_mtu",
+ 4, 32,
},
};
@@ -257,6 +261,7 @@ ovn_init_symtab(struct shash *symtab)
expr_symtab_add_field(symtab, "pkt.mark", MFF_PKT_MARK, NULL, false);
expr_symtab_add_ovn_field(symtab, "icmp4.frag_mtu", OVN_ICMP4_FRAG_MTU);
+ expr_symtab_add_ovn_field(symtab, "icmp6.frag_mtu", OVN_ICMP6_FRAG_MTU);
}
const char *
diff --git a/ovn-sb.xml b/ovn-sb.xml
index bc69b58c0..a626dbba8 100644
--- a/ovn-sb.xml
+++ b/ovn-sb.xml
@@ -1170,10 +1170,11 @@
<ul>
<li>
<code>icmp4.frag_mtu</code>
+ <code>icmp6.frag_mtu</code>
<p>
- This field sets the low-order 16 bits of the ICMP4 header field
- that is labelled "unused" in the ICMP specification as defined
- in the RFC 1191 with the value specified in
+ This field sets the low-order 16 bits of the ICMP{4,6} header
+ field that is labelled "unused" in the ICMP specification as
+ defined in the RFC 1191 with the value specified in
<var>constant</var>.
</p>
diff --git a/tests/ovn.at b/tests/ovn.at
index 30ee27ae9..4c19f82da 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -1510,6 +1510,14 @@ icmp6_error { };
encodes as controller(userdata=00.00.00.14.00.00.00.00)
has prereqs ip6
+# icmp6_error with icmp6.frag_mtu
+icmp6_error { eth.dst = ff:ff:ff:ff:ff:ff; icmp6.frag_mtu = 1500; output; }; output;
+ encodes as controller(userdata=00.00.00.14.00.00.00.00.00.19.00.10.80.00.06.06.ff.ff.ff.ff.ff.ff.00.00.ff.ff.00.28.00.00.23.20.00.25.00.00.00.00.00.00.00.03.00.10.00.00.00.15.00.00.00.00.00.00.05.dc.00.04.00.04.00.00.00.00.ff.ff.00.10.00.00.23.20.00.0e.ff.f8.40.00.00.00),resubmit(,64)
+ has prereqs ip6
+
+icmp6.frag_mtu = 1500;
+ encodes as controller(userdata=00.00.00.15.00.00.00.00.00.00.05.dc,pause)
+
# tcp_reset
tcp_reset { eth.dst = ff:ff:ff:ff:ff:ff; output; }; output;
encodes as controller(userdata=00.00.00.0b.00.00.00.00.00.19.00.10.80.00.06.06.ff.ff.ff.ff.ff.ff.00.00.ff.ff.00.10.00.00.23.20.00.0e.ff.f8.40.00.00.00),resubmit(,64)
diff --git a/utilities/ovn-trace.c b/utilities/ovn-trace.c
index d1ab051ce..de7508851 100644
--- a/utilities/ovn-trace.c
+++ b/utilities/ovn-trace.c
@@ -2081,7 +2081,12 @@ execute_ovnfield_load(const struct ovnact_load *load,
ntohs(load->imm.value.be16_int));
break;
}
-
+ case OVN_ICMP6_FRAG_MTU: {
+ ovntrace_node_append(super, OVNTRACE_NODE_MODIFY,
+ "icmp6.frag_mtu = %u",
+ ntohs(load->imm.value.be16_int));
+ break;
+ }
case OVN_FIELD_N_IDS:
default:
OVS_NOT_REACHED();
--
2.26.2
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