diff options
Diffstat (limited to 'lib/odp-util.h')
| -rw-r--r-- | lib/odp-util.h | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/lib/odp-util.h b/lib/odp-util.h index 415db60b..a6adad5a 100644 --- a/lib/odp-util.h +++ b/lib/odp-util.h @@ -65,8 +65,16 @@ void format_odp_actions(struct ds *, const struct nlattr *odp_actions, int odp_actions_from_string(const char *, const struct shash *port_names, struct ofpbuf *odp_actions); -/* Upper bound on the length of a nlattr-formatted flow key. The longest - * nlattr-formatted flow key would be: +/* The maximum number of bytes that odp_flow_key_from_flow() appends to a + * buffer. This is the upper bound on the length of a nlattr-formatted flow + * key that ovs-vswitchd fully understands. + * + * OVS doesn't insist that ovs-vswitchd and the datapath have exactly the same + * idea of a flow, so therefore this value isn't necessarily an upper bound on + * the length of a flow key that the datapath can pass to ovs-vswitchd. + * + * The longest nlattr-formatted flow key appended by odp_flow_key_from_flow() + * would be: * * struct pad nl hdr total * ------ --- ------ ----- @@ -74,15 +82,20 @@ int odp_actions_from_string(const char *, const struct shash *port_names, * OVS_KEY_ATTR_TUN_ID 8 -- 4 12 * OVS_KEY_ATTR_IN_PORT 4 -- 4 8 * OVS_KEY_ATTR_ETHERNET 12 -- 4 16 + * OVS_KEY_ATTR_ETHERTYPE 2 2 4 8 (outer VLAN ethertype) * OVS_KEY_ATTR_8021Q 4 -- 4 8 - * OVS_KEY_ATTR_ETHERTYPE 2 2 4 8 + * OVS_KEY_ATTR_ENCAP 0 -- 4 4 (VLAN encapsulation) + * OVS_KEY_ATTR_ETHERTYPE 2 2 4 8 (inner VLAN ethertype) * OVS_KEY_ATTR_IPV6 40 -- 4 44 * OVS_KEY_ATTR_ICMPV6 2 2 4 8 * OVS_KEY_ATTR_ND 28 -- 4 32 * ------------------------------------------------- - * total 144 + * total 156 + * + * We include some slack space in case the calculation isn't quite right or we + * add another field and forget to adjust this value. */ -#define ODPUTIL_FLOW_KEY_BYTES 144 +#define ODPUTIL_FLOW_KEY_BYTES 200 /* A buffer with sufficient size and alignment to hold an nlattr-formatted flow * key. An array of "struct nlattr" might not, in theory, be sufficiently |