@@ -36,6 +36,7 @@
#define P4TC_HDRFIELD_IS_VALIDITY_BIT 0x1
struct p4tc_percpu_scratchpad {
+ u32 prog_cookie;
u32 keysz;
u32 maskid;
u8 key[BITS_TO_BYTES(P4TC_MAX_KEYSZ)];
@@ -724,6 +724,24 @@ enum {
#define TCA_MATCHALL_MAX (__TCA_MATCHALL_MAX - 1)
+/* P4 classifier */
+
+enum {
+ TCA_P4_UNSPEC,
+ TCA_P4_CLASSID,
+ TCA_P4_ACT,
+ TCA_P4_PNAME,
+ TCA_P4_PROG_FD,
+ TCA_P4_PROG_NAME,
+ TCA_P4_PROG_TYPE,
+ TCA_P4_PROG_COOKIE,
+ TCA_P4_PROG_ID,
+ TCA_P4_PAD,
+ __TCA_P4_MAX,
+};
+
+#define TCA_P4_MAX (__TCA_P4_MAX - 1)
+
/* Extended Matches */
struct tcf_ematch_tree_hdr {
@@ -566,6 +566,18 @@ config NET_CLS_MATCHALL
To compile this code as a module, choose M here: the module will
be called cls_matchall.
+config NET_CLS_P4
+ tristate "P4 classifier"
+ select NET_CLS
+ select NET_P4_TC
+ help
+ If you say Y here, you will be able to bind a P4 pipeline
+ program. You will need to install P4 templates scripts successfully to
+ use this feature.
+
+ To compile this code as a module, choose M here: the module will
+ be called cls_p4.
+
config NET_EMATCH
bool "Extended Matches"
select NET_CLS
@@ -73,6 +73,7 @@ obj-$(CONFIG_NET_CLS_CGROUP) += cls_cgroup.o
obj-$(CONFIG_NET_CLS_BPF) += cls_bpf.o
obj-$(CONFIG_NET_CLS_FLOWER) += cls_flower.o
obj-$(CONFIG_NET_CLS_MATCHALL) += cls_matchall.o
+obj-$(CONFIG_NET_CLS_P4) += cls_p4.o
obj-$(CONFIG_NET_EMATCH) += ematch.o
obj-$(CONFIG_NET_EMATCH_CMP) += em_cmp.o
obj-$(CONFIG_NET_EMATCH_NBYTE) += em_nbyte.o
new file mode 100644
@@ -0,0 +1,510 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/cls_p4.c - P4 Classifier
+ * Copyright (c) 2022-2023, Mojatatu Networks
+ * Copyright (c) 2022-2023, Intel Corporation.
+ * Authors: Jamal Hadi Salim <jhs@mojatatu.com>
+ * Victor Nogueira <victor@mojatatu.com>
+ * Pedro Tammela <pctammela@mojatatu.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+
+#include <net/sch_generic.h>
+#include <net/pkt_cls.h>
+
+#include <net/p4tc.h>
+
+#include "p4tc/trace.h"
+
+#define CLS_P4_PROG_NAME_LEN 256
+
+struct p4tc_bpf_prog {
+ struct bpf_prog *p4_prog;
+ const char *p4_prog_name;
+};
+
+struct cls_p4_head {
+ struct tcf_exts exts;
+ struct tcf_result res;
+ struct rcu_work rwork;
+ struct p4tc_pipeline *pipeline;
+ struct p4tc_bpf_prog *prog;
+ u32 p4_prog_cookie;
+ u32 handle;
+};
+
+static int p4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+ struct tcf_result *res)
+{
+ struct cls_p4_head *head = rcu_dereference_bh(tp->root);
+ bool at_ingress = skb_at_tc_ingress(skb);
+ int rc = TC_ACT_PIPE;
+ struct p4tc_percpu_scratchpad *pad;
+ struct tcf_result p4res = {};
+ struct p4tc_pipeline *pipeline;
+
+ if (unlikely(!head)) {
+ pr_err("P4 classifier not found\n");
+ return -1;
+ }
+
+ pad = this_cpu_ptr(&p4tc_percpu_scratchpad);
+
+ if (head->prog) {
+ /* If eBPF program is loaded into TC */
+ if (head->prog->p4_prog->type == BPF_PROG_TYPE_SCHED_ACT) {
+ if (at_ingress) {
+ /* It is safe to push/pull even if skb_shared() */
+ __skb_push(skb, skb->mac_len);
+ bpf_compute_data_pointers(skb);
+ rc = bpf_prog_run(head->prog->p4_prog,
+ skb);
+ __skb_pull(skb, skb->mac_len);
+ } else {
+ bpf_compute_data_pointers(skb);
+ rc = bpf_prog_run(head->prog->p4_prog,
+ skb);
+ }
+ /* Potentially eBPF program was executed before at XDP and we
+ * need to check the cookie to see if that was the case.
+ */
+ } else {
+ if (head->p4_prog_cookie != pad->prog_cookie) {
+ net_notice_ratelimited("prog_cookie doesn't match");
+ return TC_ACT_SHOT;
+ }
+ }
+ }
+
+ if (rc != TC_ACT_PIPE)
+ goto zero_pad;
+
+ pipeline = head->pipeline;
+ trace_p4_classify(skb, pipeline);
+
+ rc = tcf_action_exec(skb, pipeline->preacts, pipeline->num_preacts,
+ &p4res);
+ if (rc != TC_ACT_PIPE)
+ goto zero_pad;
+
+ rc = tcf_action_exec(skb, pipeline->postacts, pipeline->num_postacts,
+ &p4res);
+ if (rc != TC_ACT_PIPE)
+ goto zero_pad;
+
+ *res = head->res;
+
+ rc = tcf_exts_exec(skb, &head->exts, res);
+
+zero_pad:
+ /* Pad will always be zero initialised after boot.
+ * Zero it at the end after all users are done with it.
+ */
+ memset(pad, 0, sizeof(*pad));
+
+ return rc;
+}
+
+static int p4_init(struct tcf_proto *tp)
+{
+ return 0;
+}
+
+static void p4_bpf_prog_destroy(struct p4tc_bpf_prog *prog)
+{
+ bpf_prog_put(prog->p4_prog);
+ kfree(prog->p4_prog_name);
+ kfree(prog);
+}
+
+static void __p4_destroy(struct cls_p4_head *head)
+{
+ tcf_exts_destroy(&head->exts);
+ tcf_exts_put_net(&head->exts);
+ if (head->prog)
+ p4_bpf_prog_destroy(head->prog);
+ __tcf_pipeline_put(head->pipeline);
+ kfree(head);
+}
+
+static void p4_destroy_work(struct work_struct *work)
+{
+ struct cls_p4_head *head =
+ container_of(to_rcu_work(work), struct cls_p4_head, rwork);
+
+ rtnl_lock();
+ __p4_destroy(head);
+ rtnl_unlock();
+}
+
+static void p4_destroy(struct tcf_proto *tp, bool rtnl_held,
+ struct netlink_ext_ack *extack)
+{
+ struct cls_p4_head *head = rtnl_dereference(tp->root);
+
+ if (!head)
+ return;
+
+ tcf_unbind_filter(tp, &head->res);
+
+ if (tcf_exts_get_net(&head->exts))
+ tcf_queue_work(&head->rwork, p4_destroy_work);
+ else
+ __p4_destroy(head);
+}
+
+static void *p4_get(struct tcf_proto *tp, u32 handle)
+{
+ struct cls_p4_head *head = rtnl_dereference(tp->root);
+
+ if (head && head->handle == handle)
+ return head;
+
+ return NULL;
+}
+
+static const struct nla_policy p4_policy[TCA_P4_MAX + 1] = {
+ [TCA_P4_UNSPEC] = { .type = NLA_UNSPEC },
+ [TCA_P4_CLASSID] = { .type = NLA_U32 },
+ [TCA_P4_ACT] = { .type = NLA_NESTED },
+ [TCA_P4_PNAME] = { .type = NLA_STRING, .len = PIPELINENAMSIZ },
+ [TCA_P4_PROG_FD] = { .type = NLA_U32},
+ [TCA_P4_PROG_NAME] = { .type = NLA_STRING, .len = CLS_P4_PROG_NAME_LEN },
+ [TCA_P4_PROG_TYPE] = { .type = NLA_U32},
+ [TCA_P4_PROG_COOKIE] = { .type = NLA_U32 }
+};
+
+static int cls_p4_prog_from_efd(struct nlattr **tb,
+ struct p4tc_bpf_prog *prog, u32 flags,
+ struct netlink_ext_ack *extack)
+{
+ struct bpf_prog *fp;
+ u32 prog_type;
+ bool skip_sw;
+ char *name;
+ u32 bpf_fd;
+
+ bpf_fd = nla_get_u32(tb[TCA_P4_PROG_FD]);
+ prog_type = nla_get_u32(tb[TCA_P4_PROG_TYPE]);
+ skip_sw = flags & TCA_CLS_FLAGS_SKIP_SW;
+
+ if (prog_type != BPF_PROG_TYPE_XDP &&
+ prog_type != BPF_PROG_TYPE_SCHED_ACT) {
+ NL_SET_ERR_MSG(extack,
+ "BPF prog type must be BPF_PROG_TYPE_SCHED_ACT or BPF_PROG_TYPE_XDP");
+ return -EINVAL;
+ }
+
+ fp = bpf_prog_get_type_dev(bpf_fd, prog_type, skip_sw);
+ if (IS_ERR(fp))
+ return PTR_ERR(fp);
+
+ name = nla_memdup(tb[TCA_P4_PROG_NAME], GFP_KERNEL);
+ if (!name) {
+ bpf_prog_put(fp);
+ return -ENOMEM;
+ }
+
+ prog->p4_prog_name = name;
+ prog->p4_prog = fp;
+
+ return 0;
+}
+
+static int p4_set_parms(struct net *net, struct tcf_proto *tp,
+ struct cls_p4_head *head, unsigned long base,
+ struct nlattr **tb, struct nlattr *est, u32 flags,
+ struct netlink_ext_ack *extack)
+{
+ bool load_bpf_prog = tb[TCA_P4_PROG_NAME] && tb[TCA_P4_PROG_FD] &&
+ tb[TCA_P4_PROG_TYPE];
+ struct p4tc_bpf_prog *prog = NULL;
+ int err;
+
+ err = tcf_exts_validate_ex(net, tp, tb, est, &head->exts, flags, 0,
+ extack);
+ if (err < 0)
+ return err;
+
+ if (load_bpf_prog) {
+ prog = kzalloc(GFP_KERNEL, sizeof(*prog));
+ if (!prog) {
+ err = -ENOMEM;
+ goto exts_destroy;
+ }
+
+ err = cls_p4_prog_from_efd(tb, prog, flags, extack);
+ if (err < 0) {
+ kfree(prog);
+ goto exts_destroy;
+ }
+ }
+
+ if (tb[TCA_P4_PROG_COOKIE]) {
+ struct p4tc_bpf_prog *prog_aux = prog ?: head->prog;
+ u32 *p4_prog_cookie;
+
+ if (!prog_aux) {
+ err = -EINVAL;
+ NL_SET_ERR_MSG(extack,
+ "Must have a BPF program to specify xdp prog_cookie");
+ goto prog_put;
+ }
+
+ if (prog_aux->p4_prog->type != BPF_PROG_TYPE_XDP) {
+ err = -EINVAL;
+ NL_SET_ERR_MSG(extack,
+ "Program must be attached to XDP to specify prog_cookie");
+ goto prog_put;
+ }
+
+ p4_prog_cookie = nla_data(tb[TCA_P4_PROG_COOKIE]);
+ head->p4_prog_cookie = *p4_prog_cookie;
+ } else {
+ struct p4tc_bpf_prog *prog_aux = prog ?: head->prog;
+
+ if (prog_aux && prog_aux->p4_prog->type == BPF_PROG_TYPE_XDP &&
+ !head->p4_prog_cookie) {
+ NL_SET_ERR_MSG(extack,
+ "MUST provide prog_cookie when loading into XDP");
+ err = -EINVAL;
+ goto prog_put;
+ }
+ }
+
+ if (tb[TCA_P4_CLASSID]) {
+ head->res.classid = nla_get_u32(tb[TCA_P4_CLASSID]);
+ tcf_bind_filter(tp, &head->res, base);
+ }
+
+ if (head->prog) {
+ pr_notice("cls_p4: Substituting old BPF program with id %u with new one with id %u\n",
+ head->prog->p4_prog->aux->id, prog->p4_prog->aux->id);
+ p4_bpf_prog_destroy(head->prog);
+ }
+ head->prog = prog;
+
+ return 0;
+
+prog_put:
+ if (prog)
+ p4_bpf_prog_destroy(prog);
+exts_destroy:
+ tcf_exts_destroy(&head->exts);
+ return err;
+}
+
+static int p4_change(struct net *net, struct sk_buff *in_skb,
+ struct tcf_proto *tp, unsigned long base, u32 handle,
+ struct nlattr **tca, void **arg, u32 flags,
+ struct netlink_ext_ack *extack)
+{
+ struct cls_p4_head *head = rtnl_dereference(tp->root);
+ struct p4tc_pipeline *pipeline = NULL;
+ char *pname = NULL;
+ struct nlattr *tb[TCA_P4_MAX + 1];
+ struct cls_p4_head *new;
+ int err;
+
+ if (!tca[TCA_OPTIONS]) {
+ NL_SET_ERR_MSG(extack, "Must provide pipeline options");
+ return -EINVAL;
+ }
+
+ if (head)
+ return -EEXIST;
+
+ err = nla_parse_nested(tb, TCA_P4_MAX, tca[TCA_OPTIONS], p4_policy,
+ extack);
+ if (err < 0)
+ return err;
+
+ if (tb[TCA_P4_PNAME])
+ pname = nla_data(tb[TCA_P4_PNAME]);
+
+ if (pname) {
+ pipeline = tcf_pipeline_get(net, pname, 0, extack);
+ if (IS_ERR(pipeline))
+ return PTR_ERR(pipeline);
+ } else {
+ NL_SET_ERR_MSG(extack, "MUST provide pipeline name");
+ return -EINVAL;
+ }
+
+ if (!pipeline_sealed(pipeline)) {
+ err = -EINVAL;
+ NL_SET_ERR_MSG(extack, "Pipeline must be sealed before use");
+ goto pipeline_put;
+ }
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (!new) {
+ err = -ENOMEM;
+ goto pipeline_put;
+ }
+
+ err = tcf_exts_init(&new->exts, net, TCA_P4_ACT, 0);
+ if (err)
+ goto err_exts_init;
+
+ if (!handle)
+ handle = 1;
+
+ new->handle = handle;
+
+ err = p4_set_parms(net, tp, new, base, tb, tca[TCA_RATE], flags,
+ extack);
+ if (err)
+ goto err_set_parms;
+
+ new->pipeline = pipeline;
+ *arg = head;
+ rcu_assign_pointer(tp->root, new);
+ return 0;
+
+err_set_parms:
+ tcf_exts_destroy(&new->exts);
+err_exts_init:
+ kfree(new);
+pipeline_put:
+ __tcf_pipeline_put(pipeline);
+ return err;
+}
+
+static int p4_delete(struct tcf_proto *tp, void *arg, bool *last,
+ bool rtnl_held, struct netlink_ext_ack *extack)
+{
+ *last = true;
+ return 0;
+}
+
+static void p4_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+ bool rtnl_held)
+{
+ struct cls_p4_head *head = rtnl_dereference(tp->root);
+
+ if (arg->count < arg->skip)
+ goto skip;
+
+ if (!head)
+ return;
+ if (arg->fn(tp, head, arg) < 0)
+ arg->stop = 1;
+skip:
+ arg->count++;
+}
+
+static int p4_prog_dump(struct sk_buff *skb, struct p4tc_bpf_prog *prog,
+ u32 prog_cookie)
+{
+ unsigned char *b = nlmsg_get_pos(skb);
+
+ if (nla_put_u32(skb, TCA_P4_PROG_ID, prog->p4_prog->aux->id))
+ goto nla_put_failure;
+
+ if (nla_put_string(skb, TCA_P4_PROG_NAME, prog->p4_prog_name))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_P4_PROG_TYPE, prog->p4_prog->type))
+ goto nla_put_failure;
+
+ if (prog_cookie &&
+ nla_put_u32(skb, TCA_P4_PROG_COOKIE, prog_cookie))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int p4_dump(struct net *net, struct tcf_proto *tp, void *fh,
+ struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
+{
+ struct cls_p4_head *head = fh;
+ struct nlattr *nest;
+
+ if (!head)
+ return skb->len;
+
+ t->tcm_handle = head->handle;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (!nest)
+ goto nla_put_failure;
+
+ if (nla_put_string(skb, TCA_P4_PNAME, head->pipeline->common.name))
+ goto nla_put_failure;
+
+ if (head->res.classid &&
+ nla_put_u32(skb, TCA_P4_CLASSID, head->res.classid))
+ goto nla_put_failure;
+
+ if (head->prog && p4_prog_dump(skb, head->prog, head->p4_prog_cookie))
+ goto nla_put_failure;
+
+ if (tcf_exts_dump(skb, &head->exts))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+
+ if (tcf_exts_dump_stats(skb, &head->exts) < 0)
+ goto nla_put_failure;
+
+ return skb->len;
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -1;
+}
+
+static void p4_bind_class(void *fh, u32 classid, unsigned long cl, void *q,
+ unsigned long base)
+{
+ struct cls_p4_head *head = fh;
+
+ if (head && head->res.classid == classid) {
+ if (cl)
+ __tcf_bind_filter(q, &head->res, base);
+ else
+ __tcf_unbind_filter(q, &head->res);
+ }
+}
+
+static struct tcf_proto_ops cls_p4_ops __read_mostly = {
+ .kind = "p4",
+ .classify = p4_classify,
+ .init = p4_init,
+ .destroy = p4_destroy,
+ .get = p4_get,
+ .change = p4_change,
+ .delete = p4_delete,
+ .walk = p4_walk,
+ .dump = p4_dump,
+ .bind_class = p4_bind_class,
+ .owner = THIS_MODULE,
+};
+
+static int __init cls_p4_init(void)
+{
+ return register_tcf_proto_ops(&cls_p4_ops);
+}
+
+static void __exit cls_p4_exit(void)
+{
+ unregister_tcf_proto_ops(&cls_p4_ops);
+}
+
+module_init(cls_p4_init);
+module_exit(cls_p4_exit);
+
+MODULE_AUTHOR("Mojatatu Networks");
+MODULE_DESCRIPTION("P4 Classifier");
+MODULE_LICENSE("GPL");
@@ -1,5 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
+CFLAGS_trace.o := -I$(src)
+
obj-y := p4tc_types.o p4tc_pipeline.o p4tc_tmpl_api.o p4tc_meta.o \
p4tc_parser_api.o p4tc_hdrfield.o p4tc_action.o p4tc_table.o \
- p4tc_tbl_api.o p4tc_register.o p4tc_cmds.o
+ p4tc_tbl_api.o p4tc_register.o p4tc_cmds.o trace.o
new file mode 100644
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022, Mojatatu Networks
+ * Copyright (c) 2022, Intel Corporation.
+ * Authors: Jamal Hadi Salim <jhs@mojatatu.com>
+ * Victor Nogueira <victor@mojatatu.com>
+ * Pedro Tammela <pctammela@mojatatu.com>
+ */
+
+#include <linux/bpf_verifier.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/filter.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/btf_ids.h>
+#include <linux/net_namespace.h>
+#include <net/p4tc.h>
+#include <linux/netdevice.h>
+#include <net/sock.h>
+#include <linux/filter.h>
+
+BTF_ID_LIST(btf_p4tc_ids)
+BTF_ID(struct, p4tc_parser_buffer_act_bpf)
+
+struct p4tc_parser_buffer_act_bpf *bpf_p4tc_get_parser_buffer(void)
+{
+ struct p4tc_percpu_scratchpad *pad;
+ struct p4tc_parser_buffer_act_bpf *parser_buffer;
+
+ pad = this_cpu_ptr(&p4tc_percpu_scratchpad);
+
+ parser_buffer = (struct p4tc_parser_buffer_act_bpf *)&pad->hdrs;
+
+ return parser_buffer;
+}
+
+int is_p4tc_kfunc(const struct bpf_reg_state *reg)
+{
+ const struct btf_type *p4tc_parser_type, *t;
+
+ p4tc_parser_type = btf_type_by_id(reg->btf, btf_p4tc_ids[0]);
+
+ t = btf_type_by_id(reg->btf, reg->btf_id);
+
+ return p4tc_parser_type == t;
+}
+
+void bpf_p4tc_set_cookie(u32 cookie)
+{
+ struct p4tc_percpu_scratchpad *pad;
+
+ pad = this_cpu_ptr(&p4tc_percpu_scratchpad);
+ pad->prog_cookie = cookie;
+}
+
+BTF_SET8_START(p4tc_tbl_kfunc_set)
+BTF_ID_FLAGS(func, bpf_p4tc_get_parser_buffer, 0);
+BTF_ID_FLAGS(func, bpf_p4tc_set_cookie, 0);
+BTF_SET8_END(p4tc_tbl_kfunc_set)
+
+static const struct btf_kfunc_id_set p4tc_table_kfunc_set = {
+ .owner = THIS_MODULE,
+ .set = &p4tc_tbl_kfunc_set,
+};
+
+int register_p4tc_tbl_bpf(void)
+{
+ int ret;
+
+ ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_ACT,
+ &p4tc_table_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP,
+ &p4tc_table_kfunc_set);
+
+ return ret;
+}
new file mode 100644
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+#include <net/p4tc.h>
+
+#ifndef __CHECKER__
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+EXPORT_TRACEPOINT_SYMBOL_GPL(p4_classify);
+#endif
new file mode 100644
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM p4tc
+
+#if !defined(__P4TC_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
+#define __P4TC_TRACE_H
+
+#include <linux/tracepoint.h>
+
+struct p4tc_pipeline;
+
+TRACE_EVENT(p4_classify,
+ TP_PROTO(struct sk_buff *skb, struct p4tc_pipeline *pipeline),
+
+ TP_ARGS(skb, pipeline),
+
+ TP_STRUCT__entry(__string(pname, pipeline->common.name)
+ __field(u32, p_id)
+ __field(u32, ifindex)
+ __field(u32, ingress)
+ ),
+
+ TP_fast_assign(__assign_str(pname, pipeline->common.name);
+ __entry->p_id = pipeline->common.p_id;
+ __entry->ifindex = skb->dev->ifindex;
+ __entry->ingress = skb_at_tc_ingress(skb);
+ ),
+
+ TP_printk("dev=%u dir=%s pipeline=%s p_id=%u",
+ __entry->ifindex,
+ __entry->ingress ? "ingress" : "egress",
+ __get_str(pname),
+ __entry->p_id
+ )
+);
+
+#endif
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+
+#include <trace/define_trace.h>
Introduce P4 tc classifier. A tc filter instantiated on this classifier is used to bind a P4 pipeline to one or more netdev ports. To use P4 classifier you must specify a pipeline name that will be associated to this filter. That pipeline must have already been create via a template. For example, if we were to add a filter to ingress of network interface of network interface device eth0 and associate it to P4 pipeline simple_l3 we'd issue the following command: tc filter add dev lo parent ffff: protocol any prio 6 p4 pname simple_l3 The filter itself has the following steps: ================================1 PARSING================================ The parser is implemented in ebpf residing either at the TC or XDP level. The parser produces meta-information which prescribes the different headers defined in the P4 program reside. Note: the different headers and their IDs are already described in the templating definition and the generated ebpf code. The ebpf parser invokes a kfunc(bpf_p4tc_get_parser_buffer) to pass on the metainfo to P4TC. To load the eBPF parser program into TC, we issue the following command: tc filter add dev $P0 ingress protocol any prio 1 p4 pname redirect_srcip \ prog tc obj $PROGNAME.o section parser/tc-ingress To load the eBPF parser program into XDP, we first need to load it into XDP using, for example, the ip command: ip link set $P0 xdp obj $PROGNAME.o section parser/xdp verbose Then we pin it: bpftool prog pin id $ID pin /tmp/ After that we create the P4 filter and refernce the XDP program: $TC filter add dev $P0 ingress protocol ip prio 1 p4 pname redirect_srcip \ prog xdp pinned /tmp/xdp_parser prog_cookie 22 Note that we also specify a the "prog_cookie", which is used to verify whether the eBPF program has executed or not before we reach the P4 classifier. To eBPF program sets this cookie by using the kfunc bpf_p4tc_set_cookie. ===============================2 PREACTIONS=============================== After parsing, the classifier will execute the pipeline preactions. Most of the time, the pipeline preactions will consist of a dynamic action table apply command, which will start the match action chain common to P4 programs. The preactions will return a standard action code (TC_ACT_OK, TC_ACT_SHOT and etc). If the preaction returns TC_ACT_PIPE, we'll continue to the next step of the filter execution, otherwise it will stop executing the filter and return the op code. ===============================3 POSTACTIONS=============================== After the pipeline preactions have executed and returned TC_ACT_PIPE, the filter will execute the pipeline postactions. Like the preactions, the postactions will return a standard action code. If the postaction returns TC_ACT_PIPE, we'll continue to the next step of the filter execution, otherwise it will stop executing the filter and return the op code. ==================4 ADDITIONALLY OPTIONAL FILTER ACTIONS================== After the pipeline preactions have executed and returned TC_ACT_PIPE, the filter will execute the filter actions, if any were associated with it. Filter actions are the ones defined outside the P4 program, example: tc filter add dev lo parent ffff: protocol ip prio 6 p4 \ pname simple_l3 action ok The action "ok" is classical Linux gact action. The filter will return the op code returned by this action. Co-developed-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Victor Nogueira <victor@mojatatu.com> Co-developed-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> --- include/net/p4tc.h | 1 + include/uapi/linux/pkt_cls.h | 18 ++ net/sched/Kconfig | 12 + net/sched/Makefile | 1 + net/sched/cls_p4.c | 510 +++++++++++++++++++++++++++++++++++ net/sched/p4tc/Makefile | 4 +- net/sched/p4tc/p4tc_bpf.c | 77 ++++++ net/sched/p4tc/trace.c | 10 + net/sched/p4tc/trace.h | 44 +++ 9 files changed, 676 insertions(+), 1 deletion(-) create mode 100644 net/sched/cls_p4.c create mode 100644 net/sched/p4tc/p4tc_bpf.c create mode 100644 net/sched/p4tc/trace.c create mode 100644 net/sched/p4tc/trace.h