With --bare, it will produce a bare hexified payload with no spaces or
offset indicators inserted, which is useful in tests to produce frames
to pass to e.g. `ovs-ofctl receive`.
With --bad-csum, it will produce a frame that has an invalid IP checksum
(applicable to IPv4 only because IPv6 doesn't have checksums.)
The command is now more useful in tests, where we may need to produce
hex frame payloads to compare observed frames against.
As an example of the tool use, a single test case is converted to it.
The test uses both normal --bare and --bad-csum behaviors of the
command, confirming they work as advertised.
Signed-off-by: Ihar Hrachyshka
---
v1: - initial version.
v2: - convert from appctl to ovstest.
- add --bad-csum support.
- drop separate test case and man for the tool.
v3: - fix build warnings on restricted ovs_be16 ++.
v4: - migrate to compose-packet.
v5: - rename --hexified into --bare.
- some other minor nits in test code, comments, commit msg etc.
---
lib/flow.c | 17 +++--
lib/flow.h | 2 +-
lib/netdev-dummy.c | 4 +--
ofproto/ofproto-dpif-trace.c | 2 +-
ofproto/ofproto-dpif.c | 4 +--
tests/dpif-netdev.at | 45 --
utilities/ovs-ofctl.c| 47 ++--
7 files changed, 81 insertions(+), 40 deletions(-)
diff --git a/lib/flow.c b/lib/flow.c
index fe226cf0f..b8f99f66b 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -3306,6 +3306,8 @@ packet_expand(struct dp_packet *p, const struct flow
*flow, size_t size)
* (This is useful only for testing, obviously, and the packet isn't really
* valid. Lots of fields are just zeroed.)
*
+ * If 'bad_csum' is true, the final IP checksum is invalid.
+ *
* For packets whose protocols can encapsulate arbitrary L7 payloads, 'l7' and
* 'l7_len' determine that payload:
*
@@ -3318,7 +3320,7 @@ packet_expand(struct dp_packet *p, const struct flow
*flow, size_t size)
* from 'l7'. */
void
flow_compose(struct dp_packet *p, const struct flow *flow,
- const void *l7, size_t l7_len)
+ const void *l7, size_t l7_len, bool bad_csum)
{
/* Add code to this function (or its callees) for emitting new fields or
* protocols. (This isn't essential, so it can be skipped for initial
@@ -3370,7 +3372,18 @@ flow_compose(struct dp_packet *p, const struct flow
*flow,
/* Checksum has already been zeroed by put_zeros call. */
ip->ip_csum = csum(ip, sizeof *ip);
-dp_packet_ol_set_ip_csum_good(p);
+if (bad_csum) {
+/*
+ * Internet checksum is a sum complement to zero, so any other
+ * value will result in an invalid checksum. Here, we flip one
+ * bit.
+ */
+ip->ip_csum ^= (OVS_FORCE ovs_be16) 0x1;
+dp_packet_ip_checksum_bad(p);
+} else {
+dp_packet_ol_set_ip_csum_good(p);
+}
+
pseudo_hdr_csum = packet_csum_pseudoheader(ip);
flow_compose_l4_csum(p, flow, pseudo_hdr_csum);
} else if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
diff --git a/lib/flow.h b/lib/flow.h
index a9d026e1c..75a9be3c1 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -127,7 +127,7 @@ void flow_set_mpls_bos(struct flow *, int idx, uint8_t
stack);
void flow_set_mpls_lse(struct flow *, int idx, ovs_be32 lse);
void flow_compose(struct dp_packet *, const struct flow *,
- const void *l7, size_t l7_len);
+ const void *l7, size_t l7_len, bool bad_csum);
void packet_expand(struct dp_packet *, const struct flow *, size_t size);
bool parse_ipv6_ext_hdrs(const void **datap, size_t *sizep, uint8_t *nw_proto,
diff --git a/lib/netdev-dummy.c b/lib/netdev-dummy.c
index fe82317d7..8c6e6d448 100644
--- a/lib/netdev-dummy.c
+++ b/lib/netdev-dummy.c
@@ -1769,7 +1769,7 @@ eth_from_flow_str(const char *s, size_t packet_size,
packet = dp_packet_new(0);
if (packet_size) {
-flow_compose(packet, flow, NULL, 0);
+flow_compose(packet, flow, NULL, 0, false);
if (dp_packet_size(packet) < packet_size) {
packet_expand(packet, flow, packet_size);
} else if (dp_packet_size(packet) > packet_size){
@@ -1777,7 +1777,7 @@ eth_from_flow_str(const char *s, size_t packet_size,
packet = NULL;
}
} else {
-flow_compose(packet, flow, NULL, 64);
+flow_compose(packet, flow, NULL, 64, false);
}
ofpbuf_uninit(_key);
diff --git a/ofproto/ofproto-dpif-trace.c b/ofproto/ofproto-dpif-trace.c
index 527e2f17e..b86e7fe07 100644
--- a/ofproto/ofproto-dpif-trace.c
+++ b/ofproto/ofproto-dpif-trace.c
@@ -440,7 +440,7 @@ parse_flow_and_packet(int argc, const char *argv[],
if (generate_packet) {
/* Generate a packet, as requested. */
packet = dp_packet_new(0);
-flow_compose(packet, flow, l7, l7_len);
+flow_compose(packet,
