// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <linux/pkt_sched.h>
#include <linux/tc_act/tc_vlan.h>
#include <linux/tc_act/tc_gact.h>
#include <linux/if_ether.h>
#include <net/if.h>

#include <ynl.h>

#include "tc-user.h"

#define TC_HANDLE (0xFFFF << 16)

const char *vlan_act_name(struct tc_vlan *p)
{
        switch (p->v_action) {
        case TCA_VLAN_ACT_POP:
                return "pop";
        case TCA_VLAN_ACT_PUSH:
                return "push";
        case TCA_VLAN_ACT_MODIFY:
                return "modify";
        default:
                break;
        }

        return "not supported";
}

const char *gact_act_name(struct tc_gact *p)
{
        switch (p->action) {
        case TC_ACT_SHOT:
                return "drop";
        case TC_ACT_OK:
                return "ok";
        case TC_ACT_PIPE:
                return "pipe";
        default:
                break;
        }

        return "not supported";
}

static void print_vlan(struct tc_act_vlan_attrs *vlan)
{
        printf("%s ", vlan_act_name(vlan->parms));
        if (vlan->_present.push_vlan_id)
                printf("id %u ", vlan->push_vlan_id);
        if (vlan->_present.push_vlan_protocol)
                printf("protocol %#x ", ntohs(vlan->push_vlan_protocol));
        if (vlan->_present.push_vlan_priority)
                printf("priority %u ", vlan->push_vlan_priority);
}

static void print_gact(struct tc_act_gact_attrs *gact)
{
        struct tc_gact *p = gact->parms;

        printf("%s ", gact_act_name(p));
}

static void flower_print(struct tc_flower_attrs *flower, const char *kind)
{
        struct tc_act_attrs *a;
        unsigned int i;

        printf("%s:\n", kind);

        if (flower->_present.key_vlan_id)
                printf("  vlan_id: %u\n", flower->key_vlan_id);
        if (flower->_present.key_vlan_prio)
                printf("  vlan_prio: %u\n", flower->key_vlan_prio);
        if (flower->_present.key_num_of_vlans)
                printf("  num_of_vlans: %u\n", flower->key_num_of_vlans);

        for (i = 0; i < flower->_count.act; i++) {
                a = &flower->act[i];
                printf("action order: %i %s ", i + 1, a->kind);
                if (a->options._present.vlan)
                        print_vlan(&a->options.vlan);
                else if (a->options._present.gact)
                        print_gact(&a->options.gact);
                printf("\n");
        }
        printf("\n");
}

static void tc_filter_print(struct tc_gettfilter_rsp *f)
{
        struct tc_options_msg *opt = &f->options;

        if (opt->_present.flower)
                flower_print(&opt->flower, f->kind);
        else if (f->_len.kind)
                printf("%s pref %u proto: %#x\n", f->kind,
                       (f->_hdr.tcm_info >> 16),
                        ntohs(TC_H_MIN(f->_hdr.tcm_info)));
}

static int tc_filter_add(struct ynl_sock *ys, int ifi)
{
        struct tc_newtfilter_req *req;
        struct tc_act_attrs *acts;
        struct tc_vlan p = {
                .action = TC_ACT_PIPE,
                .v_action = TCA_VLAN_ACT_PUSH
        };
        __u16 flags = NLM_F_REQUEST | NLM_F_EXCL | NLM_F_CREATE;
        int ret;

        req = tc_newtfilter_req_alloc();
        if (!req) {
                fprintf(stderr, "tc_newtfilter_req_alloc failed\n");
                return -1;
        }
        memset(req, 0, sizeof(*req));

        acts = tc_act_attrs_alloc(3);
        if (!acts) {
                fprintf(stderr, "tc_act_attrs_alloc\n");
                tc_newtfilter_req_free(req);
                return -1;
        }
        memset(acts, 0, sizeof(*acts) * 3);

        req->_hdr.tcm_ifindex = ifi;
        req->_hdr.tcm_parent = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
        req->_hdr.tcm_info = TC_H_MAKE(1 << 16, htons(ETH_P_8021Q));
        req->chain = 0;

        tc_newtfilter_req_set_nlflags(req, flags);
        tc_newtfilter_req_set_kind(req, "flower");
        tc_newtfilter_req_set_options_flower_key_vlan_id(req, 100);
        tc_newtfilter_req_set_options_flower_key_vlan_prio(req, 5);
        tc_newtfilter_req_set_options_flower_key_num_of_vlans(req, 3);

        __tc_newtfilter_req_set_options_flower_act(req, acts, 3);

        /* Skip action at index 0 because in TC, the action array
         * index starts at 1, with each index defining the action's
         * order. In contrast, in YNL indexed arrays start at index 0.
         */
        tc_act_attrs_set_kind(&acts[1], "vlan");
        tc_act_attrs_set_options_vlan_parms(&acts[1], &p, sizeof(p));
        tc_act_attrs_set_options_vlan_push_vlan_id(&acts[1], 200);
        tc_act_attrs_set_kind(&acts[2], "vlan");
        tc_act_attrs_set_options_vlan_parms(&acts[2], &p, sizeof(p));
        tc_act_attrs_set_options_vlan_push_vlan_id(&acts[2], 300);

        tc_newtfilter_req_set_options_flower_flags(req, 0);
        tc_newtfilter_req_set_options_flower_key_eth_type(req, htons(0x8100));

        ret = tc_newtfilter(ys, req);
        if (ret)
                fprintf(stderr, "tc_newtfilter: %s\n", ys->err.msg);

        tc_newtfilter_req_free(req);

        return ret;
}

static int tc_filter_show(struct ynl_sock *ys, int ifi)
{
        struct tc_gettfilter_req_dump *req;
        struct tc_gettfilter_list *rsp;

        req = tc_gettfilter_req_dump_alloc();
        if (!req) {
                fprintf(stderr, "tc_gettfilter_req_dump_alloc failed\n");
                return -1;
        }
        memset(req, 0, sizeof(*req));

        req->_hdr.tcm_ifindex = ifi;
        req->_hdr.tcm_parent = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
        req->_present.chain = 1;
        req->chain = 0;

        rsp = tc_gettfilter_dump(ys, req);
        tc_gettfilter_req_dump_free(req);
        if (!rsp) {
                fprintf(stderr, "YNL: %s\n", ys->err.msg);
                return -1;
        }

        if (ynl_dump_empty(rsp))
                fprintf(stderr, "Error: no filters reported\n");
        else
                ynl_dump_foreach(rsp, flt) tc_filter_print(flt);

        tc_gettfilter_list_free(rsp);

        return 0;
}

static int tc_filter_del(struct ynl_sock *ys, int ifi)
{
        struct tc_deltfilter_req *req;
        __u16 flags = NLM_F_REQUEST;
        int ret;

        req = tc_deltfilter_req_alloc();
        if (!req) {
                fprintf(stderr, "tc_deltfilter_req_alloc failed\n");
                return -1;
        }
        memset(req, 0, sizeof(*req));

        req->_hdr.tcm_ifindex = ifi;
        req->_hdr.tcm_parent = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
        req->_hdr.tcm_info = TC_H_MAKE(1 << 16, htons(ETH_P_8021Q));
        tc_deltfilter_req_set_nlflags(req, flags);

        ret = tc_deltfilter(ys, req);
        if (ret)
                fprintf(stderr, "tc_deltfilter failed: %s\n", ys->err.msg);

        tc_deltfilter_req_free(req);

        return ret;
}

static int tc_clsact_add(struct ynl_sock *ys, int ifi)
{
        struct tc_newqdisc_req *req;
        __u16 flags = NLM_F_REQUEST | NLM_F_EXCL | NLM_F_CREATE;
        int ret;

        req = tc_newqdisc_req_alloc();
        if (!req) {
                fprintf(stderr, "tc_newqdisc_req_alloc failed\n");
                return -1;
        }
        memset(req, 0, sizeof(*req));

        req->_hdr.tcm_ifindex = ifi;
        req->_hdr.tcm_parent = TC_H_CLSACT;
        req->_hdr.tcm_handle = TC_HANDLE;
        tc_newqdisc_req_set_nlflags(req, flags);
        tc_newqdisc_req_set_kind(req, "clsact");

        ret = tc_newqdisc(ys, req);
        if (ret)
                fprintf(stderr, "tc_newqdisc failed: %s\n", ys->err.msg);

        tc_newqdisc_req_free(req);

        return ret;
}

static int tc_clsact_del(struct ynl_sock *ys, int ifi)
{
        struct tc_delqdisc_req *req;
        __u16 flags = NLM_F_REQUEST;
        int ret;

        req = tc_delqdisc_req_alloc();
        if (!req) {
                fprintf(stderr, "tc_delqdisc_req_alloc failed\n");
                return -1;
        }
        memset(req, 0, sizeof(*req));

        req->_hdr.tcm_ifindex = ifi;
        req->_hdr.tcm_parent = TC_H_CLSACT;
        req->_hdr.tcm_handle = TC_HANDLE;
        tc_delqdisc_req_set_nlflags(req, flags);

        ret = tc_delqdisc(ys, req);
        if (ret)
                fprintf(stderr, "tc_delqdisc failed: %s\n", ys->err.msg);

        tc_delqdisc_req_free(req);

        return ret;
}

static int tc_filter_config(struct ynl_sock *ys, int ifi)
{
        int ret = 0;

        if (tc_filter_add(ys, ifi))
                return -1;

        ret = tc_filter_show(ys, ifi);

        if (tc_filter_del(ys, ifi))
                return -1;

        return ret;
}

int main(int argc, char **argv)
{
        struct ynl_error yerr;
        struct ynl_sock *ys;
        int ifi, ret = 0;

        if (argc < 2) {
                fprintf(stderr, "Usage: %s <interface_name>\n", argv[0]);
                return 1;
        }
        ifi = if_nametoindex(argv[1]);
        if (!ifi) {
                perror("if_nametoindex");
                return 1;
        }

        ys = ynl_sock_create(&ynl_tc_family, &yerr);
        if (!ys) {
                fprintf(stderr, "YNL: %s\n", yerr.msg);
                return 1;
        }

        if (tc_clsact_add(ys, ifi)) {
                ret = 2;
                goto err_destroy;
        }

        if (tc_filter_config(ys, ifi))
                ret = 3;

        if (tc_clsact_del(ys, ifi))
                ret = 4;

err_destroy:
        ynl_sock_destroy(ys);
        return ret;
}