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Message-ID: <53a410d3-92a6-37b4-f59a-e5081fe1604e@mellanox.com>
Date: Tue, 10 Mar 2020 09:52:24 +0200
From: Paul Blakey <paulb@...lanox.com>
To: Edward Cree <ecree@...arflare.com>,
Saeed Mahameed <saeedm@...lanox.com>,
Oz Shlomo <ozsh@...lanox.com>,
Jakub Kicinski <jakub.kicinski@...ronome.com>,
Vlad Buslov <vladbu@...lanox.com>,
David Miller <davem@...emloft.net>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
Jiri Pirko <jiri@...lanox.com>, Roi Dayan <roid@...lanox.com>
Subject: Re: [PATCH net-next ct-offload v2 02/13] net/sched: act_ct:
Instantiate flow table entry actions
On 3/9/2020 7:36 PM, Edward Cree wrote:
> On 08/03/2020 14:10, Paul Blakey wrote:
>> NF flow table API associate 5-tuple rule with an action list by calling
>> the flow table type action() CB to fill the rule's actions.
>>
>> In action CB of act_ct, populate the ct offload entry actions with a new
>> ct_metadata action. Initialize the ct_metadata with the ct mark, label and
>> zone information. If ct nat was performed, then also append the relevant
>> packet mangle actions (e.g. ipv4/ipv6/tcp/udp header rewrites).
>>
>> Drivers that offload the ft entries may match on the 5-tuple and perform
>> the action list.
>>
>> Signed-off-by: Paul Blakey <paulb@...lanox.com>
>> Reviewed-by: Jiri Pirko <jiri@...lanox.com>
>> ---
>> Changelog:
>> v1->v2:
>> Remove zone from metadata
>> Add add mangle helper func (removes the unneccasry () and correct the mask there)
>> Remove "abuse" of ? operator and use switch case
>> Check protocol and ports in relevant function and return err
>> On error restore action entries (on the topic, validaiting num of action isn't available)
>> Add comment expalining nat
>> Remove Inlinie from tcf_ct_flow_table_flow_action_get_next
>> Refactor tcf_ct_flow_table_add_action_nat_ipv6 with helper
>> On nats, allow both src and dst mangles
>>
>> include/net/flow_offload.h | 5 +
>> include/net/netfilter/nf_flow_table.h | 23 ++++
>> net/netfilter/nf_flow_table_offload.c | 23 ----
>> net/sched/act_ct.c | 208 ++++++++++++++++++++++++++++++++++
>> 4 files changed, 236 insertions(+), 23 deletions(-)
>>
>> <snip>
>> diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
>> index 23eba61..d57e7969 100644
>> --- a/net/sched/act_ct.c
>> +++ b/net/sched/act_ct.c
>> @@ -55,7 +55,215 @@ struct tcf_ct_flow_table {
>> .automatic_shrinking = true,
>> };
>>
>> +static struct flow_action_entry *
>> +tcf_ct_flow_table_flow_action_get_next(struct flow_action *flow_action)
>> +{
>> + int i = flow_action->num_entries++;
>> +
>> + return &flow_action->entries[i];
>> +}
>> +
>> +static void tcf_ct_add_mangle_action(struct flow_action *action,
>> + enum flow_action_mangle_base htype,
>> + u32 offset,
>> + u32 mask,
>> + u32 val)
>> +{
>> + struct flow_action_entry *entry;
>> +
>> + entry = tcf_ct_flow_table_flow_action_get_next(action);
>> + entry->id = FLOW_ACTION_MANGLE;
>> + entry->mangle.htype = htype;
>> + entry->mangle.mask = ~mask;
>> + entry->mangle.offset = offset;
>> + entry->mangle.val = val;
>> +}
>> +
>> +static void
>> +tcf_ct_flow_table_add_action_nat_ipv4(const struct nf_conntrack_tuple *tuple,
>> + struct nf_conntrack_tuple target,
>> + struct flow_action *action)
>> +{
>> + if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
>> + offsetof(struct iphdr, saddr),
>> + 0xFFFFFF,
> Why is this mask only 24 bits?
>
>> + be32_to_cpu(target.src.u3.ip));
>> + if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
>> + offsetof(struct iphdr, daddr),
>> + 0xFFFFFF,
>> + be32_to_cpu(target.dst.u3.ip));
>> +}
>> +
>> +static void
>> +tcf_ct_add_ipv6_addr_mangle_action(struct flow_action *action,
>> + union nf_inet_addr *addr,
>> + u32 offset)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i++)
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP6,
>> + i * sizeof(u32) + offset,
>> + 0xFFFFFF, be32_to_cpu(addr->ip6[i]));
> Again, looks like this is meant to be 0xffffffff.
will fix.
>
>> +}
>> +
>> +static void
>> +tcf_ct_flow_table_add_action_nat_ipv6(const struct nf_conntrack_tuple *tuple,
>> + struct nf_conntrack_tuple target,
>> + struct flow_action *action)
>> +{
>> + if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
>> + tcf_ct_add_ipv6_addr_mangle_action(action, &target.src.u3,
>> + offsetof(struct ipv6hdr,
>> + saddr));
>> + if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
>> + tcf_ct_add_ipv6_addr_mangle_action(action, &target.dst.u3,
>> + offsetof(struct ipv6hdr,
>> + daddr));
>> +}
>> +
>> +static void
>> +tcf_ct_flow_table_add_action_nat_tcp(const struct nf_conntrack_tuple *tuple,
>> + struct nf_conntrack_tuple target,
>> + struct flow_action *action)
>> +{
>> + __be16 target_src = target.src.u.tcp.port;
>> + __be16 target_dst = target.dst.u.tcp.port;
>> +
>> + if (target_src != tuple->src.u.tcp.port)
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
>> + offsetof(struct tcphdr, source),
>> + 0xFFFF, htons(target_src));
> htons() on a __be16 is wrong — did you run this through sparse?
> (htons takes a u16 and returns a __be16: "host to network short".)
> Either ntohs() or, canonically, be16_to_cpu().
yes will do.
>> + if (target_dst != tuple->dst.u.tcp.port)
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
>> + offsetof(struct tcphdr, dest),
>> + 0xFFFF, htons(target_dst));
>> +}
>> +
>> +static void
>> +tcf_ct_flow_table_add_action_nat_udp(const struct nf_conntrack_tuple *tuple,
>> + struct nf_conntrack_tuple target,
>> + struct flow_action *action)
>> +{
>> + __be16 target_src = target.src.u.udp.port;
>> + __be16 target_dst = target.dst.u.udp.port;
>> +
>> + if (target_src != tuple->src.u.udp.port)
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
>> + offsetof(struct udphdr, source),
>> + 0xFFFF, htons(target_src));
>> + if (target_dst != tuple->dst.u.udp.port)
>> + tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
>> + offsetof(struct udphdr, dest),
>> + 0xFFFF, htons(target_dst));
>> +}
>> +
>> +static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct,
>> + enum ip_conntrack_dir dir,
>> + struct flow_action *action)
>> +{
>> + struct nf_conn_labels *ct_labels;
>> + struct flow_action_entry *entry;
>> + u32 *act_ct_labels;
>> +
>> + entry = tcf_ct_flow_table_flow_action_get_next(action);
>> + entry->id = FLOW_ACTION_CT_METADATA;
>> +#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
>> + entry->ct_metadata.mark = ct->mark;
>> +#endif
>> +
>> + act_ct_labels = entry->ct_metadata.labels;
>> + ct_labels = nf_ct_labels_find(ct);
>> + if (ct_labels)
>> + memcpy(act_ct_labels, ct_labels->bits, NF_CT_LABELS_MAX_SIZE);
>> + else
>> + memset(act_ct_labels, 0, NF_CT_LABELS_MAX_SIZE);
>> +}
>> +
>> +static int tcf_ct_flow_table_add_action_nat(struct net *net,
>> + struct nf_conn *ct,
>> + enum ip_conntrack_dir dir,
>> + struct flow_action *action)
>> +{
>> + const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
>> + struct nf_conntrack_tuple target;
>> +
>> + nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple);
>> +
>> + /* The following helper functions check if the inverted reverse tuple
>> + * is different then the current dir tuple - meaning nat for ports
>> + * and/or ip is needed, and add the relevant mangle actions.
>> + */
> Probably better to put this comment above the helpers, ratherthan the
> calls to them, so that people reading the source linearly see the comment
> before the memcmp()s.
yes thanks.
> -ed
>> +
>> + switch (tuple->src.l3num) {
>> + case NFPROTO_IPV4:
>> + tcf_ct_flow_table_add_action_nat_ipv4(tuple, target,
>> + action);
>> + break;
>> + case NFPROTO_IPV6:
>> + tcf_ct_flow_table_add_action_nat_ipv6(tuple, target,
>> + action);
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + switch (nf_ct_protonum(ct)) {
>> + case IPPROTO_TCP:
>> + tcf_ct_flow_table_add_action_nat_tcp(tuple, target, action);
>> + break;
>> + case IPPROTO_UDP:
>> + tcf_ct_flow_table_add_action_nat_udp(tuple, target, action);
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int tcf_ct_flow_table_fill_actions(struct net *net,
>> + const struct flow_offload *flow,
>> + enum flow_offload_tuple_dir tdir,
>> + struct nf_flow_rule *flow_rule)
>> +{
>> + struct flow_action *action = &flow_rule->rule->action;
>> + int num_entries = action->num_entries;
>> + struct nf_conn *ct = flow->ct;
>> + enum ip_conntrack_dir dir;
>> + int i, err;
>> +
>> + switch (tdir) {
>> + case FLOW_OFFLOAD_DIR_ORIGINAL:
>> + dir = IP_CT_DIR_ORIGINAL;
>> + break;
>> + case FLOW_OFFLOAD_DIR_REPLY:
>> + dir = IP_CT_DIR_REPLY;
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + err = tcf_ct_flow_table_add_action_nat(net, ct, dir, action);
>> + if (err)
>> + goto err_nat;
>> +
>> + tcf_ct_flow_table_add_action_meta(ct, dir, action);
>> + return 0;
>> +
>> +err_nat:
>> + /* Clear filled actions */
>> + for (i = num_entries; i < action->num_entries; i++)
>> + memset(&action->entries[i], 0, sizeof(action->entries[i]));
>> + action->num_entries = num_entries;
>> +
>> + return err;
>> +}
>> +
>> static struct nf_flowtable_type flowtable_ct = {
>> + .action = tcf_ct_flow_table_fill_actions,
>> .owner = THIS_MODULE,
>> };
>>
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