// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause

/*
 * Topology:
 * ---------
 *   NS0 namespace         |   NS1 namespace        | NS2 namespace
 *                         |                        |
 *   +---------------+     |   +---------------+    |
 *   |    ipsec0     |---------|    ipsec0     |    |
 *   | 192.168.1.100 |     |   | 192.168.1.200 |    |
 *   | if_id: bpf    |     |   +---------------+    |
 *   +---------------+     |                        |
 *           |             |                        |   +---------------+
 *           |             |                        |   |    ipsec0     |
 *           \------------------------------------------| 192.168.1.200 |
 *                         |                        |   +---------------+
 *                         |                        |
 *                         |                        | (overlay network)
 *      ------------------------------------------------------
 *                         |                        | (underlay network)
 *   +--------------+      |   +--------------+     |
 *   |    veth01    |----------|    veth10    |     |
 *   | 172.16.1.100 |      |   | 172.16.1.200 |     |
 *   ---------------+      |   +--------------+     |
 *                         |                        |
 *   +--------------+      |                        |   +--------------+
 *   |    veth02    |-----------------------------------|    veth20    |
 *   | 172.16.2.100 |      |                        |   | 172.16.2.200 |
 *   +--------------+      |                        |   +--------------+
 *
 *
 * Test Packet flow
 * -----------
 *  The tests perform 'ping 192.168.1.200' from the NS0 namespace:
 *  1) request is routed to NS0 ipsec0
 *  2) NS0 ipsec0 tc egress BPF program is triggered and sets the if_id based
 *     on the requested value. This makes the ipsec0 device in external mode
 *     select the destination tunnel
 *  3) ping reaches the other namespace (NS1 or NS2 based on which if_id was
 *     used) and response is sent
 *  4) response is received on NS0 ipsec0, tc ingress program is triggered and
 *     records the response if_id
 *  5) requested if_id is compared with received if_id
 */

#include <net/if.h>
#include <linux/rtnetlink.h>
#include <linux/if_link.h>

#include "test_progs.h"
#include "network_helpers.h"
#include "xfrm_info.skel.h"

#define NS0 "xfrm_test_ns0"
#define NS1 "xfrm_test_ns1"
#define NS2 "xfrm_test_ns2"

#define IF_ID_0_TO_1 1
#define IF_ID_0_TO_2 2
#define IF_ID_1 3
#define IF_ID_2 4

#define IP4_ADDR_VETH01 "172.16.1.100"
#define IP4_ADDR_VETH10 "172.16.1.200"
#define IP4_ADDR_VETH02 "172.16.2.100"
#define IP4_ADDR_VETH20 "172.16.2.200"

#define ESP_DUMMY_PARAMS \
    "proto esp aead 'rfc4106(gcm(aes))' " \
    "0xe4d8f4b4da1df18a3510b3781496daa82488b713 128 mode tunnel "

static int attach_tc_prog(struct bpf_tc_hook *hook, int igr_fd, int egr_fd)
{
        LIBBPF_OPTS(bpf_tc_opts, opts1, .handle = 1, .priority = 1,
                    .prog_fd = igr_fd);
        LIBBPF_OPTS(bpf_tc_opts, opts2, .handle = 1, .priority = 1,
                    .prog_fd = egr_fd);
        int ret;

        ret = bpf_tc_hook_create(hook);
        if (!ASSERT_OK(ret, "create tc hook"))
                return ret;

        if (igr_fd >= 0) {
                hook->attach_point = BPF_TC_INGRESS;
                ret = bpf_tc_attach(hook, &opts1);
                if (!ASSERT_OK(ret, "bpf_tc_attach")) {
                        bpf_tc_hook_destroy(hook);
                        return ret;
                }
        }

        if (egr_fd >= 0) {
                hook->attach_point = BPF_TC_EGRESS;
                ret = bpf_tc_attach(hook, &opts2);
                if (!ASSERT_OK(ret, "bpf_tc_attach")) {
                        bpf_tc_hook_destroy(hook);
                        return ret;
                }
        }

        return 0;
}

static void cleanup(void)
{
        SYS_NOFAIL("test -f /var/run/netns/" NS0 " && ip netns delete " NS0);
        SYS_NOFAIL("test -f /var/run/netns/" NS1 " && ip netns delete " NS1);
        SYS_NOFAIL("test -f /var/run/netns/" NS2 " && ip netns delete " NS2);
}

static int config_underlay(void)
{
        SYS(fail, "ip netns add " NS0);
        SYS(fail, "ip netns add " NS1);
        SYS(fail, "ip netns add " NS2);

        /* NS0 <-> NS1 [veth01 <-> veth10] */
        SYS(fail, "ip link add veth01 netns " NS0 " type veth peer name veth10 netns " NS1);
        SYS(fail, "ip -net " NS0 " addr add " IP4_ADDR_VETH01 "/24 dev veth01");
        SYS(fail, "ip -net " NS0 " link set dev veth01 up");
        SYS(fail, "ip -net " NS1 " addr add " IP4_ADDR_VETH10 "/24 dev veth10");
        SYS(fail, "ip -net " NS1 " link set dev veth10 up");

        /* NS0 <-> NS2 [veth02 <-> veth20] */
        SYS(fail, "ip link add veth02 netns " NS0 " type veth peer name veth20 netns " NS2);
        SYS(fail, "ip -net " NS0 " addr add " IP4_ADDR_VETH02 "/24 dev veth02");
        SYS(fail, "ip -net " NS0 " link set dev veth02 up");
        SYS(fail, "ip -net " NS2 " addr add " IP4_ADDR_VETH20 "/24 dev veth20");
        SYS(fail, "ip -net " NS2 " link set dev veth20 up");

        return 0;
fail:
        return -1;
}

static int setup_xfrm_tunnel_ns(const char *ns, const char *ipv4_local,
                                const char *ipv4_remote, int if_id)
{
        /* State: local -> remote */
        SYS(fail, "ip -net %s xfrm state add src %s dst %s spi 1 "
            ESP_DUMMY_PARAMS "if_id %d", ns, ipv4_local, ipv4_remote, if_id);

        /* State: local <- remote */
        SYS(fail, "ip -net %s xfrm state add src %s dst %s spi 1 "
            ESP_DUMMY_PARAMS "if_id %d", ns, ipv4_remote, ipv4_local, if_id);

        /* Policy: local -> remote */
        SYS(fail, "ip -net %s xfrm policy add dir out src 0.0.0.0/0 dst 0.0.0.0/0 "
            "if_id %d tmpl src %s dst %s proto esp mode tunnel if_id %d", ns,
            if_id, ipv4_local, ipv4_remote, if_id);

        /* Policy: local <- remote */
        SYS(fail, "ip -net %s xfrm policy add dir in src 0.0.0.0/0 dst 0.0.0.0/0 "
            "if_id %d tmpl src %s dst %s proto esp mode tunnel if_id %d", ns,
            if_id, ipv4_remote, ipv4_local, if_id);

        return 0;
fail:
        return -1;
}

static int setup_xfrm_tunnel(const char *ns_a, const char *ns_b,
                             const char *ipv4_a, const char *ipv4_b,
                             int if_id_a, int if_id_b)
{
        return setup_xfrm_tunnel_ns(ns_a, ipv4_a, ipv4_b, if_id_a) ||
                setup_xfrm_tunnel_ns(ns_b, ipv4_b, ipv4_a, if_id_b);
}

static struct rtattr *rtattr_add(struct nlmsghdr *nh, unsigned short type,
                                 unsigned short len)
{
        struct rtattr *rta =
                (struct rtattr *)((uint8_t *)nh + RTA_ALIGN(nh->nlmsg_len));
        rta->rta_type = type;
        rta->rta_len = RTA_LENGTH(len);
        nh->nlmsg_len = RTA_ALIGN(nh->nlmsg_len) + RTA_ALIGN(rta->rta_len);
        return rta;
}

static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short type,
                                     const char *s)
{
        struct rtattr *rta = rtattr_add(nh, type, strlen(s));

        memcpy(RTA_DATA(rta), s, strlen(s));
        return rta;
}

static struct rtattr *rtattr_begin(struct nlmsghdr *nh, unsigned short type)
{
        return rtattr_add(nh, type, 0);
}

static void rtattr_end(struct nlmsghdr *nh, struct rtattr *attr)
{
        uint8_t *end = (uint8_t *)nh + nh->nlmsg_len;

        attr->rta_len = end - (uint8_t *)attr;
}

static int setup_xfrmi_external_dev(const char *ns)
{
        struct {
                struct nlmsghdr nh;
                struct ifinfomsg info;
                unsigned char data[128];
        } req;
        struct rtattr *link_info, *info_data;
        struct nstoken *nstoken;
        int ret = -1, sock = -1;
        struct nlmsghdr *nh;

        memset(&req, 0, sizeof(req));
        nh = &req.nh;
        nh->nlmsg_len = NLMSG_LENGTH(sizeof(req.info));
        nh->nlmsg_type = RTM_NEWLINK;
        nh->nlmsg_flags |= NLM_F_CREATE | NLM_F_REQUEST;

        rtattr_add_str(nh, IFLA_IFNAME, "ipsec0");
        link_info = rtattr_begin(nh, IFLA_LINKINFO);
        rtattr_add_str(nh, IFLA_INFO_KIND, "xfrm");
        info_data = rtattr_begin(nh, IFLA_INFO_DATA);
        rtattr_add(nh, IFLA_XFRM_COLLECT_METADATA, 0);
        rtattr_end(nh, info_data);
        rtattr_end(nh, link_info);

        nstoken = open_netns(ns);
        if (!ASSERT_OK_PTR(nstoken, "setns"))
                goto done;

        sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
        if (!ASSERT_GE(sock, 0, "netlink socket"))
                goto done;
        ret = send(sock, nh, nh->nlmsg_len, 0);
        if (!ASSERT_EQ(ret, nh->nlmsg_len, "netlink send length"))
                goto done;

        ret = 0;
done:
        if (sock != -1)
                close(sock);
        if (nstoken)
                close_netns(nstoken);
        return ret;
}

static int config_overlay(void)
{
        if (setup_xfrm_tunnel(NS0, NS1, IP4_ADDR_VETH01, IP4_ADDR_VETH10,
                              IF_ID_0_TO_1, IF_ID_1))
                goto fail;
        if (setup_xfrm_tunnel(NS0, NS2, IP4_ADDR_VETH02, IP4_ADDR_VETH20,
                              IF_ID_0_TO_2, IF_ID_2))
                goto fail;

        /* Older iproute2 doesn't support this option */
        if (!ASSERT_OK(setup_xfrmi_external_dev(NS0), "xfrmi"))
                goto fail;

        SYS(fail, "ip -net " NS0 " addr add 192.168.1.100/24 dev ipsec0");
        SYS(fail, "ip -net " NS0 " link set dev ipsec0 up");

        SYS(fail, "ip -net " NS1 " link add ipsec0 type xfrm if_id %d", IF_ID_1);
        SYS(fail, "ip -net " NS1 " addr add 192.168.1.200/24 dev ipsec0");
        SYS(fail, "ip -net " NS1 " link set dev ipsec0 up");

        SYS(fail, "ip -net " NS2 " link add ipsec0 type xfrm if_id %d", IF_ID_2);
        SYS(fail, "ip -net " NS2 " addr add 192.168.1.200/24 dev ipsec0");
        SYS(fail, "ip -net " NS2 " link set dev ipsec0 up");

        return 0;
fail:
        return -1;
}

static int test_xfrm_ping(struct xfrm_info *skel, u32 if_id)
{
        skel->bss->req_if_id = if_id;

        SYS(fail, "ping -i 0.01 -c 3 -w 10 -q 192.168.1.200 > /dev/null");

        if (!ASSERT_EQ(skel->bss->resp_if_id, if_id, "if_id"))
                goto fail;

        return 0;
fail:
        return -1;
}

static void _test_xfrm_info(void)
{
        LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
        int get_xfrm_info_prog_fd, set_xfrm_info_prog_fd;
        struct nstoken *nstoken = NULL;
        struct xfrm_info *skel;
        int ifindex;

        /* load and attach bpf progs to ipsec dev tc hook point */
        skel = xfrm_info__open_and_load();
        if (!ASSERT_OK_PTR(skel, "xfrm_info__open_and_load"))
                goto done;
        nstoken = open_netns(NS0);
        if (!ASSERT_OK_PTR(nstoken, "setns " NS0))
                goto done;
        ifindex = if_nametoindex("ipsec0");
        if (!ASSERT_NEQ(ifindex, 0, "ipsec0 ifindex"))
                goto done;
        tc_hook.ifindex = ifindex;
        set_xfrm_info_prog_fd = bpf_program__fd(skel->progs.set_xfrm_info);
        get_xfrm_info_prog_fd = bpf_program__fd(skel->progs.get_xfrm_info);
        if (!ASSERT_GE(set_xfrm_info_prog_fd, 0, "bpf_program__fd"))
                goto done;
        if (!ASSERT_GE(get_xfrm_info_prog_fd, 0, "bpf_program__fd"))
                goto done;
        if (attach_tc_prog(&tc_hook, get_xfrm_info_prog_fd,
                           set_xfrm_info_prog_fd))
                goto done;

        /* perform test */
        if (!ASSERT_EQ(test_xfrm_ping(skel, IF_ID_0_TO_1), 0, "ping " NS1))
                goto done;
        if (!ASSERT_EQ(test_xfrm_ping(skel, IF_ID_0_TO_2), 0, "ping " NS2))
                goto done;

done:
        if (nstoken)
                close_netns(nstoken);
        xfrm_info__destroy(skel);
}

void test_xfrm_info(void)
{
        cleanup();

        if (!ASSERT_OK(config_underlay(), "config_underlay"))
                goto done;
        if (!ASSERT_OK(config_overlay(), "config_overlay"))
                goto done;

        if (test__start_subtest("xfrm_info"))
                _test_xfrm_info();

done:
        cleanup();
}