[ovs-dev] [PATCH v2] ofproto-dpif: Enable NXAST_SAMPLE only if the datapath supports it.
Ben Pfaff
blp at nicira.com
Mon Dec 30 23:35:59 UTC 2013
Thanks, applied to master.
On Mon, Dec 30, 2013 at 03:12:20PM -0800, Romain Lenglet wrote:
> This looks good to me. Thanks!
> --
> Romain Lenglet
>
> ----- Original Message -----
> > From: "Ben Pfaff" <blp at nicira.com>
> > To: dev at openvswitch.org
> > Cc: "Ben Pfaff" <blp at nicira.com>, "Romain Lenglet" <rlenglet at vmware.com>
> > Sent: Monday, December 30, 2013 2:50:59 PM
> > Subject: [PATCH v2] ofproto-dpif: Enable NXAST_SAMPLE only if the datapath supports it.
> >
> > This prevents using an older datapath from breaking forwarding.
> >
> > CC: Romain Lenglet <rlenglet at vmware.com>
> > Signed-off-by: Ben Pfaff <blp at nicira.com>
> > ---
> > v1->v2: Check for variable-length data support in the correct place
> > (see Romain's comments in
> > https://urldefense.proofpoint.com/v1/url?u=http://patchwork.openvswitch.org/patch/1627/&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=zXHlW45sT8%2FAsm%2BMbdJ6DyHSNzIfOMAfy9flPhaH%2FAg%3D%0A&m=AocvK29H8OSuhXPkW%2BHNDFt6Oq4fBfLiLK5ohOjZJ7M%3D%0A&s=31fde9854655304ed23c9d96c031b0fab4d37355f90cd099f69ddc105a0a1d29).
> >
> > ofproto/ofproto-dpif-xlate.c | 18 ++++++++-
> > ofproto/ofproto-dpif-xlate.h | 2 +-
> > ofproto/ofproto-dpif.c | 92
> > +++++++++++++++++++++++++++++++++++++++++-
> > 3 files changed, 109 insertions(+), 3 deletions(-)
> >
> > diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
> > index 848c778..558598c 100644
> > --- a/ofproto/ofproto-dpif-xlate.c
> > +++ b/ofproto/ofproto-dpif-xlate.c
> > @@ -87,6 +87,11 @@ struct xbridge {
> > enum ofp_config_flags frag; /* Fragmentation handling. */
> > bool has_in_band; /* Bridge has in band control? */
> > bool forward_bpdu; /* Bridge forwards STP BPDUs? */
> > +
> > + /* True if the datapath supports variable-length
> > + * OVS_USERSPACE_ATTR_USERDATA in OVS_ACTION_ATTR_USERSPACE actions.
> > + * False if the datapath supports only 8-byte (or shorter) userdata. */
> > + bool variable_length_userdata;
> > };
> >
> > struct xbundle {
> > @@ -249,7 +254,8 @@ xlate_ofproto_set(struct ofproto_dpif *ofproto, const
> > char *name,
> > const struct dpif_sflow *sflow,
> > const struct dpif_ipfix *ipfix,
> > const struct netflow *netflow, enum ofp_config_flags frag,
> > - bool forward_bpdu, bool has_in_band)
> > + bool forward_bpdu, bool has_in_band,
> > + bool variable_length_userdata)
> > {
> > struct xbridge *xbridge = xbridge_lookup(ofproto);
> >
> > @@ -301,6 +307,7 @@ xlate_ofproto_set(struct ofproto_dpif *ofproto, const
> > char *name,
> > xbridge->frag = frag;
> > xbridge->miss_rule = miss_rule;
> > xbridge->no_packet_in_rule = no_packet_in_rule;
> > + xbridge->variable_length_userdata = variable_length_userdata;
> > }
> >
> > void
> > @@ -2521,6 +2528,15 @@ xlate_sample_action(struct xlate_ctx *ctx,
> > * the same percentage. */
> > uint32_t probability = (os->probability << 16) | os->probability;
> >
> > + if (!ctx->xbridge->variable_length_userdata) {
> > + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
> > +
> > + VLOG_ERR_RL(&rl, "ignoring NXAST_SAMPLE action because datapath "
> > + "lacks support (needs Linux 3.10+ or kernel module from "
> > + "OVS 1.11+)");
> > + return;
> > + }
> > +
> > ctx->xout->slow |= commit_odp_actions(&ctx->xin->flow, &ctx->base_flow,
> > &ctx->xout->odp_actions,
> > &ctx->xout->wc,
> > diff --git a/ofproto/ofproto-dpif-xlate.h b/ofproto/ofproto-dpif-xlate.h
> > index 68076ca..982f1a4 100644
> > --- a/ofproto/ofproto-dpif-xlate.h
> > +++ b/ofproto/ofproto-dpif-xlate.h
> > @@ -129,7 +129,7 @@ void xlate_ofproto_set(struct ofproto_dpif *, const char
> > *name,
> > const struct mbridge *, const struct dpif_sflow *,
> > const struct dpif_ipfix *, const struct netflow *,
> > enum ofp_config_flags, bool forward_bpdu,
> > - bool has_in_band)
> > + bool has_in_band, bool variable_length_userdata)
> > OVS_REQ_WRLOCK(xlate_rwlock);
> > void xlate_remove_ofproto(struct ofproto_dpif *)
> > OVS_REQ_WRLOCK(xlate_rwlock);
> >
> > diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
> > index 52759b5..e48cc00 100644
> > --- a/ofproto/ofproto-dpif.c
> > +++ b/ofproto/ofproto-dpif.c
> > @@ -42,6 +42,7 @@
> > #include "netdev-vport.h"
> > #include "netdev.h"
> > #include "netlink.h"
> > +#include "netlink-socket.h"
> > #include "nx-match.h"
> > #include "odp-util.h"
> > #include "odp-execute.h"
> > @@ -251,6 +252,11 @@ struct dpif_backer {
> > enum revalidate_reason need_revalidate; /* Revalidate all flows. */
> >
> > bool recv_set_enable; /* Enables or disables receiving packets. */
> > +
> > + /* True if the datapath supports variable-length
> > + * OVS_USERSPACE_ATTR_USERDATA in OVS_ACTION_ATTR_USERSPACE actions.
> > + * False if the datapath supports only 8-byte (or shorter) userdata. */
> > + bool variable_length_userdata;
> > };
> >
> > /* All existing ofproto_backer instances, indexed by ofproto->up.type. */
> > @@ -552,7 +558,8 @@ type_run(const char *type)
> > ofproto->sflow, ofproto->ipfix,
> > ofproto->netflow, ofproto->up.frag_handling,
> > ofproto->up.forward_bpdu,
> > - connmgr_has_in_band(ofproto->up.connmgr));
> > + connmgr_has_in_band(ofproto->up.connmgr),
> > + ofproto->backer->variable_length_userdata);
> >
> > HMAP_FOR_EACH (bundle, hmap_node, &ofproto->bundles) {
> > xlate_bundle_set(ofproto, bundle, bundle->name,
> > @@ -774,6 +781,8 @@ struct odp_garbage {
> > odp_port_t odp_port;
> > };
> >
> > +static bool check_variable_length_userdata(struct dpif_backer *backer);
> > +
> > static int
> > open_dpif_backer(const char *type, struct dpif_backer **backerp)
> > {
> > @@ -872,6 +881,7 @@ open_dpif_backer(const char *type, struct dpif_backer
> > **backerp)
> > close_dpif_backer(backer);
> > return error;
> > }
> > + backer->variable_length_userdata =
> > check_variable_length_userdata(backer);
> >
> > if (backer->recv_set_enable) {
> > udpif_set_threads(backer->udpif, n_handlers, n_revalidators);
> > @@ -880,6 +890,86 @@ open_dpif_backer(const char *type, struct dpif_backer
> > **backerp)
> > return error;
> > }
> >
> > +/* Tests whether 'backer''s datapath supports variable-length
> > + * OVS_USERSPACE_ATTR_USERDATA in OVS_ACTION_ATTR_USERSPACE actions. We
> > need
> > + * to disable some features on older datapaths that don't support this
> > + * feature.
> > + *
> > + * Returns false if 'backer' definitely does not support variable-length
> > + * userdata, true if it seems to support them or if at least the error we
> > get
> > + * is ambiguous. */
> > +static bool
> > +check_variable_length_userdata(struct dpif_backer *backer)
> > +{
> > + struct eth_header *eth;
> > + struct ofpbuf actions;
> > + struct ofpbuf key;
> > + struct ofpbuf packet;
> > + size_t start;
> > + int error;
> > +
> > + /* Compose a userspace action that will cause an ERANGE error on older
> > + * datapaths that don't support variable-length userdata.
> > + *
> > + * We really test for using userdata longer than 8 bytes, but older
> > + * datapaths accepted these, silently truncating the userdata to 8
> > bytes.
> > + * The same older datapaths rejected userdata shorter than 8 bytes, so
> > we
> > + * test for that instead as a proxy for longer userdata support. */
> > + ofpbuf_init(&actions, 64);
> > + start = nl_msg_start_nested(&actions, OVS_ACTION_ATTR_USERSPACE);
> > + nl_msg_put_u32(&actions, OVS_USERSPACE_ATTR_PID,
> > + dpif_port_get_pid(backer->dpif, ODPP_NONE));
> > + nl_msg_put_unspec_zero(&actions, OVS_USERSPACE_ATTR_USERDATA, 4);
> > + nl_msg_end_nested(&actions, start);
> > +
> > + /* Compose an ODP flow key. The key is arbitrary but it must match the
> > + * packet that we compose later. */
> > + ofpbuf_init(&key, 64);
> > + nl_msg_put_u32(&key, OVS_KEY_ATTR_IN_PORT, 0);
> > + nl_msg_put_unspec_zero(&key, OVS_KEY_ATTR_ETHERNET,
> > + sizeof(struct ovs_key_ethernet));
> > + nl_msg_put_be16(&key, OVS_KEY_ATTR_ETHERTYPE, htons(0x1234));
> > +
> > + /* Compose a packet that matches the key. */
> > + ofpbuf_init(&packet, ETH_HEADER_LEN);
> > + eth = ofpbuf_put_zeros(&packet, ETH_HEADER_LEN);
> > + eth->eth_type = htons(0x1234);
> > +
> > + /* Execute the actions. On older datapaths this fails with -ERANGE, on
> > + * newer datapaths it succeeds. */
> > + error = dpif_execute(backer->dpif, key.data, key.size,
> > + actions.data, actions.size, &packet, false);
> > +
> > + ofpbuf_uninit(&packet);
> > + ofpbuf_uninit(&key);
> > + ofpbuf_uninit(&actions);
> > +
> > + switch (error) {
> > + case 0:
> > + /* Variable-length userdata is supported.
> > + *
> > + * Purge received packets to avoid processing the nonsense packet we
> > + * sent to userspace, then report success. */
> > + dpif_recv_purge(backer->dpif);
> > + return true;
> > +
> > + case ERANGE:
> > + /* Variable-length userdata is not supported. */
> > + VLOG_WARN("%s: datapath does not support variable-length userdata "
> > + "feature (needs Linux 3.10+ or kernel module from OVS "
> > + "1..11+). The NXAST_SAMPLE action will be ignored.",
> > + dpif_name(backer->dpif));
> > + return false;
> > +
> > + default:
> > + /* Something odd happened. We're not sure whether variable-length
> > + * userdata is supported. Default to "yes". */
> > + VLOG_WARN("%s: variable-length userdata feature probe failed (%s)",
> > + dpif_name(backer->dpif), ovs_strerror(error));
> > + return true;
> > + }
> > +}
> > +
> > static int
> > construct(struct ofproto *ofproto_)
> > {
> > --
> > 1.7.10.4
> >
> >
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