examples/ipsec-secgw/sp6.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2016 Intel Corporation
 */

/*
 * Security Policies
 */
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/ip6.h>

#include <rte_acl.h>
#include <rte_ip.h>

#include "ipsec.h"
#include "parser.h"

#define MAX_ACL_RULE_NUM    1024

#define IPV6_FROM_SP(acr, fidx_low, fidx_high) \
        (((uint64_t)(acr).field[(fidx_high)].value.u32 << 32) | \
        (acr).field[(fidx_low)].value.u32)

#define IPV6_DST_FROM_SP(addr, acr) do {\
        (addr).ip.ip6.ip6[0] = rte_cpu_to_be_64(IPV6_FROM_SP((acr), \
                        IP6_DST1, IP6_DST0));\
        (addr).ip.ip6.ip6[1] = rte_cpu_to_be_64(IPV6_FROM_SP((acr), \
                        IP6_DST3, IP6_DST2));\
        } while (0)

#define IPV6_SRC_FROM_SP(addr, acr) do {\
        (addr).ip.ip6.ip6[0] = rte_cpu_to_be_64(IPV6_FROM_SP((acr), \
                            IP6_SRC1, IP6_SRC0));\
        (addr).ip.ip6.ip6[1] = rte_cpu_to_be_64(IPV6_FROM_SP((acr), \
                            IP6_SRC3, IP6_SRC2));\
        } while (0)

#define IPV6_DST_MASK_FROM_SP(mask, acr) \
        ((mask) = (acr).field[IP6_DST0].mask_range.u32 + \
            (acr).field[IP6_DST1].mask_range.u32 + \
            (acr).field[IP6_DST2].mask_range.u32 + \
            (acr).field[IP6_DST3].mask_range.u32)

#define IPV6_SRC_MASK_FROM_SP(mask, acr) \
        ((mask) = (acr).field[IP6_SRC0].mask_range.u32 + \
            (acr).field[IP6_SRC1].mask_range.u32 + \
            (acr).field[IP6_SRC2].mask_range.u32 + \
            (acr).field[IP6_SRC3].mask_range.u32)

enum {
    IP6_PROTO,
    IP6_SRC0,
    IP6_SRC1,
    IP6_SRC2,
    IP6_SRC3,
    IP6_DST0,
    IP6_DST1,
    IP6_DST2,
    IP6_DST3,
    IP6_SRCP,
    IP6_DSTP,
    IP6_NUM
};

#define IP6_ADDR_SIZE 16

static struct rte_acl_field_def ip6_defs[IP6_NUM] = {
    {
    .type = RTE_ACL_FIELD_TYPE_BITMASK,
    .size = sizeof(uint8_t),
    .field_index = IP6_PROTO,
    .input_index = IP6_PROTO,
    .offset = 0,
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_SRC0,
    .input_index = IP6_SRC0,
    .offset = 2
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_SRC1,
    .input_index = IP6_SRC1,
    .offset = 6
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_SRC2,
    .input_index = IP6_SRC2,
    .offset = 10
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_SRC3,
    .input_index = IP6_SRC3,
    .offset = 14
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_DST0,
    .input_index = IP6_DST0,
    .offset = 18
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_DST1,
    .input_index = IP6_DST1,
    .offset = 22
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_DST2,
    .input_index = IP6_DST2,
    .offset = 26
    },
    {
    .type = RTE_ACL_FIELD_TYPE_MASK,
    .size = 4,
    .field_index = IP6_DST3,
    .input_index = IP6_DST3,
    .offset = 30
    },
    {
    .type = RTE_ACL_FIELD_TYPE_RANGE,
    .size = sizeof(uint16_t),
    .field_index = IP6_SRCP,
    .input_index = IP6_SRCP,
    .offset = 34
    },
    {
    .type = RTE_ACL_FIELD_TYPE_RANGE,
    .size = sizeof(uint16_t),
    .field_index = IP6_DSTP,
    .input_index = IP6_SRCP,
    .offset = 36
    }
};

RTE_ACL_RULE_DEF(acl6_rules, RTE_DIM(ip6_defs));

static struct acl6_rules acl6_rules_out[MAX_ACL_RULE_NUM];
static uint32_t nb_acl6_rules_out;

static struct acl6_rules acl6_rules_in[MAX_ACL_RULE_NUM];
static uint32_t nb_acl6_rules_in;

void
parse_sp6_tokens(char **tokens, uint32_t n_tokens,
    struct parse_status *status)
{
    struct acl6_rules *rule_ipv6 = NULL;

    uint32_t *ri = NULL; /* rule index */
    uint32_t ti = 0; /* token index */
    uint32_t tv;

    uint32_t esp_p = 0;
    uint32_t protect_p = 0;
    uint32_t bypass_p = 0;
    uint32_t discard_p = 0;
    uint32_t pri_p = 0;
    uint32_t src_p = 0;
    uint32_t dst_p = 0;
    uint32_t proto_p = 0;
    uint32_t sport_p = 0;
    uint32_t dport_p = 0;

    if (strcmp(tokens[1], "in") == 0) {
        ri = &nb_acl6_rules_in;

        APP_CHECK(*ri <= MAX_ACL_RULE_NUM - 1, status, "too "
            "many sp rules, abort insertion\n");
        if (status->status < 0)
            return;

        rule_ipv6 = &acl6_rules_in[*ri];

    } else if (strcmp(tokens[1], "out") == 0) {
        ri = &nb_acl6_rules_out;

        APP_CHECK(*ri <= MAX_ACL_RULE_NUM - 1, status, "too "
            "many sp rules, abort insertion\n");
        if (status->status < 0)
            return;

        rule_ipv6 = &acl6_rules_out[*ri];

    } else {
        APP_CHECK(0, status, "unrecognized input \"%s\", expect"
            " \"in\" or \"out\"\n", tokens[ti]);
        return;
    }

    rule_ipv6->data.category_mask = 1;


    for (ti = 2; ti < n_tokens; ti++) {
        if (strcmp(tokens[ti], "esp") == 0) {
            /* currently do nothing */
            APP_CHECK_PRESENCE(esp_p, tokens[ti], status);
            if (status->status < 0)
                return;
            esp_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "protect") == 0) {
            APP_CHECK_PRESENCE(protect_p, tokens[ti], status);
            if (status->status < 0)
                return;
            APP_CHECK(bypass_p == 0, status, "conflict item "
                "between \"%s\" and \"%s\"", tokens[ti],
                "bypass");
            if (status->status < 0)
                return;
            APP_CHECK(discard_p == 0, status, "conflict item "
                "between \"%s\" and \"%s\"", tokens[ti],
                "discard");
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;
            APP_CHECK_TOKEN_IS_NUM(tokens, ti, status);
            if (status->status < 0)
                return;

            tv = atoi(tokens[ti]);
            APP_CHECK(tv != DISCARD && tv != BYPASS, status,
                "invalid SPI: %s", tokens[ti]);
            if (status->status < 0)
                return;
            rule_ipv6->data.userdata = tv;

            protect_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "bypass") == 0) {
            APP_CHECK_PRESENCE(bypass_p, tokens[ti], status);
            if (status->status < 0)
                return;
            APP_CHECK(protect_p == 0, status, "conflict item "
                "between \"%s\" and \"%s\"", tokens[ti],
                "protect");
            if (status->status < 0)
                return;
            APP_CHECK(discard_p == 0, status, "conflict item "
                "between \"%s\" and \"%s\"", tokens[ti],
                "discard");
            if (status->status < 0)
                return;

            rule_ipv6->data.userdata = BYPASS;

            bypass_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "discard") == 0) {
            APP_CHECK_PRESENCE(discard_p, tokens[ti], status);
            if (status->status < 0)
                return;
            APP_CHECK(protect_p == 0, status, "conflict item "
                "between \"%s\" and \"%s\"", tokens[ti],
                "protect");
            if (status->status < 0)
                return;
            APP_CHECK(bypass_p == 0, status, "conflict item "
                "between \"%s\" and \"%s\"", tokens[ti],
                "discard");
            if (status->status < 0)
                return;

            rule_ipv6->data.userdata = DISCARD;

            discard_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "pri") == 0) {
            APP_CHECK_PRESENCE(pri_p, tokens[ti], status);
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;
            APP_CHECK_TOKEN_IS_NUM(tokens, ti, status);
            if (status->status < 0)
                return;

            rule_ipv6->data.priority = atoi(tokens[ti]);

            pri_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "src") == 0) {
            struct in6_addr ip;
            uint32_t depth;

            APP_CHECK_PRESENCE(src_p, tokens[ti], status);
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;

            APP_CHECK(parse_ipv6_addr(tokens[ti], &ip,
                &depth) == 0, status, "unrecognized "
                "input \"%s\", expect valid ipv6 "
                "addr", tokens[ti]);
            if (status->status < 0)
                return;

            rule_ipv6->field[1].value.u32 =
                (uint32_t)ip.s6_addr[0] << 24 |
                (uint32_t)ip.s6_addr[1] << 16 |
                (uint32_t)ip.s6_addr[2] << 8 |
                (uint32_t)ip.s6_addr[3];
            rule_ipv6->field[1].mask_range.u32 =
                (depth > 32) ? 32 : depth;
            depth = (depth > 32) ? (depth - 32) : 0;
            rule_ipv6->field[2].value.u32 =
                (uint32_t)ip.s6_addr[4] << 24 |
                (uint32_t)ip.s6_addr[5] << 16 |
                (uint32_t)ip.s6_addr[6] << 8 |
                (uint32_t)ip.s6_addr[7];
            rule_ipv6->field[2].mask_range.u32 =
                (depth > 32) ? 32 : depth;
            depth = (depth > 32) ? (depth - 32) : 0;
            rule_ipv6->field[3].value.u32 =
                (uint32_t)ip.s6_addr[8] << 24 |
                (uint32_t)ip.s6_addr[9] << 16 |
                (uint32_t)ip.s6_addr[10] << 8 |
                (uint32_t)ip.s6_addr[11];
            rule_ipv6->field[3].mask_range.u32 =
                (depth > 32) ? 32 : depth;
            depth = (depth > 32) ? (depth - 32) : 0;
            rule_ipv6->field[4].value.u32 =
                (uint32_t)ip.s6_addr[12] << 24 |
                (uint32_t)ip.s6_addr[13] << 16 |
                (uint32_t)ip.s6_addr[14] << 8 |
                (uint32_t)ip.s6_addr[15];
            rule_ipv6->field[4].mask_range.u32 =
                (depth > 32) ? 32 : depth;

            src_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "dst") == 0) {
            struct in6_addr ip;
            uint32_t depth;

            APP_CHECK_PRESENCE(dst_p, tokens[ti], status);
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;

            APP_CHECK(parse_ipv6_addr(tokens[ti], &ip,
                &depth) == 0, status, "unrecognized "
                "input \"%s\", expect valid ipv6 "
                "addr", tokens[ti]);
            if (status->status < 0)
                return;

            rule_ipv6->field[5].value.u32 =
                (uint32_t)ip.s6_addr[0] << 24 |
                (uint32_t)ip.s6_addr[1] << 16 |
                (uint32_t)ip.s6_addr[2] << 8 |
                (uint32_t)ip.s6_addr[3];
            rule_ipv6->field[5].mask_range.u32 =
                (depth > 32) ? 32 : depth;
            depth = (depth > 32) ? (depth - 32) : 0;
            rule_ipv6->field[6].value.u32 =
                (uint32_t)ip.s6_addr[4] << 24 |
                (uint32_t)ip.s6_addr[5] << 16 |
                (uint32_t)ip.s6_addr[6] << 8 |
                (uint32_t)ip.s6_addr[7];
            rule_ipv6->field[6].mask_range.u32 =
                (depth > 32) ? 32 : depth;
            depth = (depth > 32) ? (depth - 32) : 0;
            rule_ipv6->field[7].value.u32 =
                (uint32_t)ip.s6_addr[8] << 24 |
                (uint32_t)ip.s6_addr[9] << 16 |
                (uint32_t)ip.s6_addr[10] << 8 |
                (uint32_t)ip.s6_addr[11];
            rule_ipv6->field[7].mask_range.u32 =
                (depth > 32) ? 32 : depth;
            depth = (depth > 32) ? (depth - 32) : 0;
            rule_ipv6->field[8].value.u32 =
                (uint32_t)ip.s6_addr[12] << 24 |
                (uint32_t)ip.s6_addr[13] << 16 |
                (uint32_t)ip.s6_addr[14] << 8 |
                (uint32_t)ip.s6_addr[15];
            rule_ipv6->field[8].mask_range.u32 =
                (depth > 32) ? 32 : depth;

            dst_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "proto") == 0) {
            uint16_t low, high;

            APP_CHECK_PRESENCE(proto_p, tokens[ti], status);
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;

            APP_CHECK(parse_range(tokens[ti], &low, &high)
                == 0, status, "unrecognized input \"%s\""
                ", expect \"from:to\"", tokens[ti]);
            if (status->status < 0)
                return;
            APP_CHECK(low <= 0xff, status, "proto low "
                "over-limit");
            if (status->status < 0)
                return;
            APP_CHECK(high <= 0xff, status, "proto high "
                "over-limit");
            if (status->status < 0)
                return;

            rule_ipv6->field[0].value.u8 = (uint8_t)low;
            rule_ipv6->field[0].mask_range.u8 = (uint8_t)high;

            proto_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "sport") == 0) {
            uint16_t port_low, port_high;

            APP_CHECK_PRESENCE(sport_p, tokens[ti], status);
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;

            APP_CHECK(parse_range(tokens[ti], &port_low,
                &port_high) == 0, status, "unrecognized "
                "input \"%s\", expect \"port_from:"
                "port_to\"", tokens[ti]);
            if (status->status < 0)
                return;

            rule_ipv6->field[9].value.u16 = port_low;
            rule_ipv6->field[9].mask_range.u16 = port_high;

            sport_p = 1;
            continue;
        }

        if (strcmp(tokens[ti], "dport") == 0) {
            uint16_t port_low, port_high;

            APP_CHECK_PRESENCE(dport_p, tokens[ti], status);
            if (status->status < 0)
                return;
            INCREMENT_TOKEN_INDEX(ti, n_tokens, status);
            if (status->status < 0)
                return;

            APP_CHECK(parse_range(tokens[ti], &port_low,
                &port_high) == 0, status, "unrecognized "
                "input \"%s\", expect \"port_from:"
                "port_to\"", tokens[ti]);
            if (status->status < 0)
                return;

            rule_ipv6->field[10].value.u16 = port_low;
            rule_ipv6->field[10].mask_range.u16 = port_high;

            dport_p = 1;
            continue;
        }

        /* unrecognizeable input */
        APP_CHECK(0, status, "unrecognized input \"%s\"",
            tokens[ti]);
        return;
    }

    /* check if argument(s) are missing */
    APP_CHECK(esp_p == 1, status, "missing argument \"esp\"");
    if (status->status < 0)
        return;

    APP_CHECK(protect_p | bypass_p | discard_p, status, "missing "
        "argument \"protect\", \"bypass\", or \"discard\"");
    if (status->status < 0)
        return;

    *ri = *ri + 1;
}

static inline void
print_one_ip6_rule(const struct acl6_rules *rule, int32_t extra)
{
    uint8_t a, b, c, d;

    uint32_t_to_char(rule->field[IP6_SRC0].value.u32,
        &a, &b, &c, &d);
    printf("%.2x%.2x:%.2x%.2x", a, b, c, d);
    uint32_t_to_char(rule->field[IP6_SRC1].value.u32,
        &a, &b, &c, &d);
    printf(":%.2x%.2x:%.2x%.2x", a, b, c, d);
    uint32_t_to_char(rule->field[IP6_SRC2].value.u32,
        &a, &b, &c, &d);
    printf(":%.2x%.2x:%.2x%.2x", a, b, c, d);
    uint32_t_to_char(rule->field[IP6_SRC3].value.u32,
        &a, &b, &c, &d);
    printf(":%.2x%.2x:%.2x%.2x/%u ", a, b, c, d,
            rule->field[IP6_SRC0].mask_range.u32
            + rule->field[IP6_SRC1].mask_range.u32
            + rule->field[IP6_SRC2].mask_range.u32
            + rule->field[IP6_SRC3].mask_range.u32);

    uint32_t_to_char(rule->field[IP6_DST0].value.u32,
        &a, &b, &c, &d);
    printf("%.2x%.2x:%.2x%.2x", a, b, c, d);
    uint32_t_to_char(rule->field[IP6_DST1].value.u32,
        &a, &b, &c, &d);
    printf(":%.2x%.2x:%.2x%.2x", a, b, c, d);
    uint32_t_to_char(rule->field[IP6_DST2].value.u32,
        &a, &b, &c, &d);
    printf(":%.2x%.2x:%.2x%.2x", a, b, c, d);
    uint32_t_to_char(rule->field[IP6_DST3].value.u32,
        &a, &b, &c, &d);
    printf(":%.2x%.2x:%.2x%.2x/%u ", a, b, c, d,
            rule->field[IP6_DST0].mask_range.u32
            + rule->field[IP6_DST1].mask_range.u32
            + rule->field[IP6_DST2].mask_range.u32
            + rule->field[IP6_DST3].mask_range.u32);

    printf("%hu : %hu %hu : %hu 0x%hhx/0x%hhx ",
        rule->field[IP6_SRCP].value.u16,
        rule->field[IP6_SRCP].mask_range.u16,
        rule->field[IP6_DSTP].value.u16,
        rule->field[IP6_DSTP].mask_range.u16,
        rule->field[IP6_PROTO].value.u8,
        rule->field[IP6_PROTO].mask_range.u8);
    if (extra)
        printf("0x%x-0x%x-0x%x ",
            rule->data.category_mask,
            rule->data.priority,
            rule->data.userdata);
}

static inline void
dump_ip6_rules(const struct acl6_rules *rule, int32_t num, int32_t extra)
{
    int32_t i;

    for (i = 0; i < num; i++, rule++) {
        printf("\t%d:", i + 1);
        print_one_ip6_rule(rule, extra);
        printf("\n");
    }
}

static struct rte_acl_ctx *
acl6_init(const char *name, int32_t socketid, const struct acl6_rules *rules,
        uint32_t rules_nb)
{
    char s[PATH_MAX];
    struct rte_acl_param acl_param;
    struct rte_acl_config acl_build_param;
    struct rte_acl_ctx *ctx;

    printf("Creating SP context with %u max rules\n", MAX_ACL_RULE_NUM);

    memset(&acl_param, 0, sizeof(acl_param));

    /* Create ACL contexts */
    snprintf(s, sizeof(s), "%s_%d", name, socketid);

    printf("IPv4 %s entries [%u]:\n", s, rules_nb);
    dump_ip6_rules(rules, rules_nb, 1);

    acl_param.name = s;
    acl_param.socket_id = socketid;
    acl_param.rule_size = RTE_ACL_RULE_SZ(RTE_DIM(ip6_defs));
    acl_param.max_rule_num = MAX_ACL_RULE_NUM;

    ctx = rte_acl_create(&acl_param);
    if (ctx == NULL)
        rte_exit(EXIT_FAILURE, "Failed to create ACL context\n");

    if (rte_acl_add_rules(ctx, (const struct rte_acl_rule *)rules,
                rules_nb) < 0)
        rte_exit(EXIT_FAILURE, "add rules failed\n");

    /* Perform builds */
    memset(&acl_build_param, 0, sizeof(acl_build_param));

    acl_build_param.num_categories = DEFAULT_MAX_CATEGORIES;
    acl_build_param.num_fields = RTE_DIM(ip6_defs);
    memcpy(&acl_build_param.defs, ip6_defs, sizeof(ip6_defs));

    if (rte_acl_build(ctx, &acl_build_param) != 0)
        rte_exit(EXIT_FAILURE, "Failed to build ACL trie\n");

    rte_acl_dump(ctx);

    return ctx;
}

/*
 * check that for each rule it's SPI has a correspondent entry in SAD
 */
static int
check_spi_value(int inbound)
{
    uint32_t i, num, spi;
    const struct acl6_rules *acr;

    if (inbound != 0) {
        acr = acl6_rules_in;
        num = nb_acl6_rules_in;
    } else {
        acr = acl6_rules_out;
        num = nb_acl6_rules_out;
    }

    for (i = 0; i != num; i++) {
        spi = acr[i].data.userdata;
        if (spi != DISCARD && spi != BYPASS &&
                sa_spi_present(spi, inbound) < 0) {
            RTE_LOG(ERR, IPSEC, "SPI %u is not present in SAD\n",
                spi);
            return -ENOENT;
        }
    }

    return 0;
}

void
sp6_init(struct socket_ctx *ctx, int32_t socket_id)
{
    const char *name;

    if (ctx == NULL)
        rte_exit(EXIT_FAILURE, "NULL context.\n");

    if (ctx->sp_ip6_in != NULL)
        rte_exit(EXIT_FAILURE, "Inbound IPv6 SP DB for socket %u "
                "already initialized\n", socket_id);

    if (ctx->sp_ip6_out != NULL)
        rte_exit(EXIT_FAILURE, "Outbound IPv6 SP DB for socket %u "
                "already initialized\n", socket_id);

    if (check_spi_value(1) < 0)
        rte_exit(EXIT_FAILURE,
            "Inbound IPv6 SP DB has unmatched in SAD SPIs\n");

    if (check_spi_value(0) < 0)
        rte_exit(EXIT_FAILURE,
            "Outbound IPv6 SP DB has unmatched in SAD SPIs\n");

    if (nb_acl6_rules_in > 0) {
        name = "sp_ip6_in";
        ctx->sp_ip6_in = (struct sp_ctx *)acl6_init(name,
            socket_id, acl6_rules_in, nb_acl6_rules_in);
    } else
        RTE_LOG(WARNING, IPSEC, "No IPv6 SP Inbound rule "
            "specified\n");

    if (nb_acl6_rules_out > 0) {
        name = "sp_ip6_out";
        ctx->sp_ip6_out = (struct sp_ctx *)acl6_init(name,
            socket_id, acl6_rules_out, nb_acl6_rules_out);
    } else
        RTE_LOG(WARNING, IPSEC, "No IPv6 SP Outbound rule "
            "specified\n");
}

/*
 * Search though SP rules for given SPI.
 */
int
sp6_spi_present(uint32_t spi, int inbound, struct ip_addr ip_addr[2],
            uint32_t mask[2])
{
    uint32_t i, num;
    const struct acl6_rules *acr;

    if (inbound != 0) {
        acr = acl6_rules_in;
        num = nb_acl6_rules_in;
    } else {
        acr = acl6_rules_out;
        num = nb_acl6_rules_out;
    }

    for (i = 0; i != num; i++) {
        if (acr[i].data.userdata == spi) {
            if (NULL != ip_addr && NULL != mask) {
                IPV6_SRC_FROM_SP(ip_addr[0], acr[i]);
                IPV6_DST_FROM_SP(ip_addr[1], acr[i]);
                IPV6_SRC_MASK_FROM_SP(mask[0], acr[i]);
                IPV6_DST_MASK_FROM_SP(mask[1], acr[i]);
            }
            return i;
        }
    }

    return -ENOENT;
}