source: mainline/uspace/lib/inet/src/addr.c

/*
 * Copyright (c) 2024 Jiri Svoboda
 * Copyright (c) 2013 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libinet
 * @{
 */
/** @file Internet address parsing and formatting.
 */

#include <assert.h>
#include <errno.h>
#include <inet/addr.h>
#include <inet/eth_addr.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <bitops.h>
#include <inttypes.h>
#include <str.h>

#define INET_PREFIXSTRSIZE  5

#define INET6_ADDRSTRLEN (8 * 4 + 7 + 1)

#if !(defined(__BE__) ^ defined(__LE__))
#error The architecture must be either big-endian or little-endian.
#endif

const addr32_t addr32_broadcast_all_hosts = 0xffffffff;

static eth_addr_t inet_eth_addr_solicited_node =
    ETH_ADDR_INITIALIZER(0x33, 0x33, 0xff, 0, 0, 0);

static const inet_addr_t inet_addr_any_addr = {
        .version = ip_v4,
        .addr = 0
};

static const inet_addr_t inet_addr_any_addr6 = {
        .version = ip_v6,
        .addr6 = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};

void addr128(const addr128_t src, addr128_t dst)
{
        memcpy(dst, src, 16);
}

/** Compare addr128.
 *
 * @return Non-zero if equal, zero if not equal.
 */
int addr128_compare(const addr128_t a, const addr128_t b)
{
        return memcmp(a, b, 16) == 0;
}

/** Compute solicited node MAC multicast address from target IPv6 address
 *
 * @param ip  Target IPv6 address
 * @param mac Solicited MAC address to be assigned
 *
 */
void eth_addr_solicited_node(const addr128_t ip, eth_addr_t *mac)
{
        uint8_t b[6];
        mac->a = inet_eth_addr_solicited_node.a;

        eth_addr_encode(&inet_eth_addr_solicited_node, b);
        memcpy(&b[3], ip + 13, 3);
        eth_addr_decode(b, mac);
}

void host2addr128_t_be(const addr128_t host, addr128_t be)
{
        memcpy(be, host, 16);
}

void addr128_t_be2host(const addr128_t be, addr128_t host)
{
        memcpy(host, be, 16);
}

void inet_addr(inet_addr_t *addr, uint8_t a, uint8_t b, uint8_t c, uint8_t d)
{
        addr->version = ip_v4;
        addr->addr = ((addr32_t) a << 24) | ((addr32_t) b << 16) |
            ((addr32_t) c << 8) | ((addr32_t) d);
}

void inet_naddr(inet_naddr_t *naddr, uint8_t a, uint8_t b, uint8_t c, uint8_t d,
    uint8_t prefix)
{
        naddr->version = ip_v4;
        naddr->addr = ((addr32_t) a << 24) | ((addr32_t) b << 16) |
            ((addr32_t) c << 8) | ((addr32_t) d);
        naddr->prefix = prefix;
}

void inet_addr6(inet_addr_t *addr, uint16_t a, uint16_t b, uint16_t c,
    uint16_t d, uint16_t e, uint16_t f, uint16_t g, uint16_t h)
{
        addr->version = ip_v6;
        addr->addr6[0] = (a >> 8) & 0xff;
        addr->addr6[1] = a & 0xff;
        addr->addr6[2] = (b >> 8) & 0xff;
        addr->addr6[3] = b & 0xff;
        addr->addr6[4] = (c >> 8) & 0xff;
        addr->addr6[5] = c & 0xff;
        addr->addr6[6] = (d >> 8) & 0xff;
        addr->addr6[7] = d & 0xff;
        addr->addr6[8] = (e >> 8) & 0xff;
        addr->addr6[9] = e & 0xff;
        addr->addr6[10] = (f >> 8) & 0xff;
        addr->addr6[11] = f & 0xff;
        addr->addr6[12] = (g >> 8) & 0xff;
        addr->addr6[13] = g & 0xff;
        addr->addr6[14] = (h >> 8) & 0xff;
        addr->addr6[15] = h & 0xff;
}

void inet_naddr6(inet_naddr_t *naddr, uint16_t a, uint16_t b, uint16_t c,
    uint16_t d, uint16_t e, uint16_t f, uint16_t g, uint16_t h, uint8_t prefix)
{
        naddr->version = ip_v6;
        naddr->addr6[0] = (a >> 8) & 0xff;
        naddr->addr6[1] = a & 0xff;
        naddr->addr6[2] = (b >> 8) & 0xff;
        naddr->addr6[3] = b & 0xff;
        naddr->addr6[4] = (c >> 8) & 0xff;
        naddr->addr6[5] = c & 0xff;
        naddr->addr6[6] = (d >> 8) & 0xff;
        naddr->addr6[7] = d & 0xff;
        naddr->addr6[8] = (e >> 8) & 0xff;
        naddr->addr6[9] = e & 0xff;
        naddr->addr6[10] = (f >> 8) & 0xff;
        naddr->addr6[11] = f & 0xff;
        naddr->addr6[12] = (g >> 8) & 0xff;
        naddr->addr6[13] = g & 0xff;
        naddr->addr6[14] = (h >> 8) & 0xff;
        naddr->addr6[15] = h & 0xff;
        naddr->prefix = prefix;
}

void inet_naddr_addr(const inet_naddr_t *naddr, inet_addr_t *addr)
{
        addr->version = naddr->version;
        memcpy(addr->addr6, naddr->addr6, 16);
}

void inet_addr_naddr(const inet_addr_t *addr, uint8_t prefix,
    inet_naddr_t *naddr)
{
        naddr->version = addr->version;
        memcpy(naddr->addr6, addr->addr6, 16);
        naddr->prefix = prefix;
}

void inet_addr_any(inet_addr_t *addr)
{
        addr->version = ip_any;
        memset(addr->addr6, 0, 16);
}

void inet_naddr_any(inet_naddr_t *naddr)
{
        naddr->version = ip_any;
        memset(naddr->addr6, 0, 16);
        naddr->prefix = 0;
}

int inet_addr_compare(const inet_addr_t *a, const inet_addr_t *b)
{
        if (a->version != b->version)
                return 0;

        switch (a->version) {
        case ip_v4:
                return (a->addr == b->addr);
        case ip_v6:
                return addr128_compare(a->addr6, b->addr6);
        default:
                return 0;
        }
}

int inet_addr_is_any(const inet_addr_t *addr)
{
        return ((addr->version == ip_any) ||
            (inet_addr_compare(addr, &inet_addr_any_addr)) ||
            (inet_addr_compare(addr, &inet_addr_any_addr6)));
}

int inet_naddr_compare(const inet_naddr_t *naddr, const inet_addr_t *addr)
{
        if (naddr->version != addr->version)
                return 0;

        switch (naddr->version) {
        case ip_v4:
                return (naddr->addr == addr->addr);
        case ip_v6:
                return addr128_compare(naddr->addr6, addr->addr6);
        default:
                return 0;
        }
}

int inet_naddr_compare_mask(const inet_naddr_t *naddr, const inet_addr_t *addr)
{
        if (naddr->version != addr->version)
                return 0;

        switch (naddr->version) {
        case ip_v4:
                if (naddr->prefix > 32)
                        return 0;

                addr32_t mask =
                    BIT_RANGE(addr32_t, 31, 31 - (naddr->prefix - 1));
                return ((naddr->addr & mask) == (addr->addr & mask));
        case ip_v6:
                if (naddr->prefix > 128)
                        return 0;

                size_t pos = 0;
                for (size_t i = 0; i < 16; i++) {
                        /* Further bits do not matter */
                        if (naddr->prefix < pos)
                                break;

                        if (naddr->prefix - pos > 8) {
                                /* Comparison without masking */
                                if (naddr->addr6[i] != addr->addr6[i])
                                        return 0;
                        } else {
                                /* Comparison with masking */
                                uint8_t mask =
                                    BIT_RANGE(uint8_t, 8, 8 - (naddr->prefix - pos - 1));
                                if ((naddr->addr6[i] & mask) != (addr->addr6[i] & mask))
                                        return 0;
                        }

                        pos += 8;
                }

                return 1;
        default:
                return 0;
        }
}

static errno_t inet_addr_parse_v4(const char *str, inet_addr_t *raddr,
    int *prefix, char **endptr)
{
        uint32_t a = 0;
        uint8_t b;
        char *cur = (char *)str;
        size_t i = 0;

        while (i < 4) {
                errno_t rc = str_uint8_t(cur, (const char **)&cur, 10, false, &b);
                if (rc != EOK)
                        return rc;

                a = (a << 8) + b;

                i++;

                if (*cur != '.')
                        break;

                if (i < 4)
                        cur++;
        }

        if (prefix != NULL) {
                if (*cur != '/')
                        return EINVAL;
                cur++;

                *prefix = strtoul(cur, &cur, 10);
                if (*prefix > 32)
                        return EINVAL;
        }

        if (i != 4)
                return EINVAL;

        if (endptr == NULL && *cur != '\0')
                return EINVAL;

        raddr->version = ip_v4;
        raddr->addr = a;

        if (endptr != NULL)
                *endptr = cur;

        return EOK;
}

static errno_t inet_addr_parse_v6(const char *str, inet_addr_t *raddr, int *prefix,
    char **endptr)
{
        uint8_t data[16];
        int explicit_groups;

        memset(data, 0, 16);

        const char *cur = str;
        size_t i = 0;
        size_t wildcard_pos = (size_t) -1;
        size_t wildcard_size = 0;

        /* Handle initial wildcard */
        if ((str[0] == ':') && (str[1] == ':')) {
                cur = str + 2;
                wildcard_pos = 0;
                wildcard_size = 16;
        }

        while (i < 16) {
                uint16_t bioctet;
                const char *gend;
                errno_t rc = str_uint16_t(cur, &gend, 16, false, &bioctet);
                if (rc != EOK)
                        break;

                data[i] = (bioctet >> 8) & 0xff;
                data[i + 1] = bioctet & 0xff;

                if (wildcard_pos != (size_t) -1) {
                        if (wildcard_size < 2)
                                return EINVAL;

                        wildcard_size -= 2;
                }

                i += 2;

                if (*gend != ':') {
                        cur = gend;
                        break;
                }

                if (i < 16) {
                        /* Handle wildcard */
                        if (gend[1] == ':') {
                                if (wildcard_pos != (size_t) -1)
                                        return EINVAL;

                                wildcard_pos = i;
                                wildcard_size = 16 - i;
                                cur = gend + 2;
                                continue;
                        }
                }

                cur = gend + 1;
        }

        /* Number of explicitly specified groups */
        explicit_groups = i;

        if (prefix != NULL) {
                if (*cur != '/')
                        return EINVAL;
                cur++;

                *prefix = strtoul(cur, (char **)&cur, 10);
                if (*prefix > 128)
                        return EINVAL;
        }

        if (endptr == NULL && *cur != '\0')
                return EINVAL;

        /* Create wildcard positions */
        if ((wildcard_pos != (size_t) -1) && (wildcard_size > 0)) {
                size_t wildcard_shift = 16 - wildcard_size;

                for (i = wildcard_pos + wildcard_shift; i > wildcard_pos; i--) {
                        size_t j = i - 1;
                        data[j + wildcard_size] = data[j];
                        data[j] = 0;
                }
        } else {
                /* Verify that all groups have been specified */
                if (explicit_groups != 16)
                        return EINVAL;
        }

        raddr->version = ip_v6;
        memcpy(raddr->addr6, data, 16);
        if (endptr != NULL)
                *endptr = (char *)cur;
        return EOK;
}

/** Parse node address.
 *
 * Will fail if @a text contains extra characters at the and and @a endptr
 * is @c NULL.
 *
 * @param text Network address in common notation.
 * @param addr Place to store node address.
 * @param endptr Place to store pointer to next character oc @c NULL
 *
 * @return EOK on success, EINVAL if input is not in valid format.
 *
 */
errno_t inet_addr_parse(const char *text, inet_addr_t *addr, char **endptr)
{
        errno_t rc;

        rc = inet_addr_parse_v4(text, addr, NULL, endptr);
        if (rc == EOK)
                return EOK;

        rc = inet_addr_parse_v6(text, addr, NULL, endptr);
        if (rc == EOK)
                return EOK;

        return EINVAL;
}

/** Parse network address.
 *
 * Will fail if @a text contains extra characters at the and and @a endptr
 * is @c NULL.
 *
 * @param text  Network address in common notation.
 * @param naddr Place to store network address.
 * @param endptr Place to store pointer to next character oc @c NULL
 *
 * @return EOK on success, EINVAL if input is not in valid format.
 *
 */
errno_t inet_naddr_parse(const char *text, inet_naddr_t *naddr, char **endptr)
{
        errno_t rc;
        inet_addr_t addr;
        int prefix;

        rc = inet_addr_parse_v4(text, &addr, &prefix, endptr);
        if (rc == EOK) {
                inet_addr_naddr(&addr, prefix, naddr);
                return EOK;
        }

        rc = inet_addr_parse_v6(text, &addr, &prefix, endptr);
        if (rc == EOK) {
                inet_addr_naddr(&addr, prefix, naddr);
                return EOK;
        }

        return EINVAL;
}

static errno_t inet_addr_format_v4(addr32_t addr, char **bufp)
{
        int rc;

        rc = asprintf(bufp, "%u.%u.%u.%u", (addr >> 24) & 0xff,
            (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff);
        if (rc < 0)
                return ENOMEM;

        return EOK;
}

static errno_t inet_addr_format_v6(const addr128_t addr, char **bufp)
{
        *bufp = (char *) malloc(INET6_ADDRSTRLEN);
        if (*bufp == NULL)
                return ENOMEM;

        /* Find the longest zero subsequence */

        uint16_t zeroes[8];
        uint16_t bioctets[8];

        for (size_t i = 8; i > 0; i--) {
                size_t j = i - 1;

                bioctets[j] = (addr[j << 1] << 8) | addr[(j << 1) + 1];

                if (bioctets[j] == 0) {
                        zeroes[j] = 1;
                        if (j < 7)
                                zeroes[j] += zeroes[j + 1];
                } else
                        zeroes[j] = 0;
        }

        size_t wildcard_pos = (size_t) -1;
        size_t wildcard_size = 0;

        for (size_t i = 0; i < 8; i++) {
                if (zeroes[i] > wildcard_size) {
                        wildcard_pos = i;
                        wildcard_size = zeroes[i];
                }
        }

        char *cur = *bufp;
        size_t rest = INET6_ADDRSTRLEN;
        bool tail_zero = false;
        int ret;

        for (size_t i = 0; i < 8; i++) {
                if ((i == wildcard_pos) && (wildcard_size > 1)) {
                        ret = snprintf(cur, rest, ":");
                        i += wildcard_size - 1;
                        tail_zero = true;
                } else if (i == 0) {
                        ret = snprintf(cur, rest, "%" PRIx16, bioctets[i]);
                        tail_zero = false;
                } else {
                        ret = snprintf(cur, rest, ":%" PRIx16, bioctets[i]);
                        tail_zero = false;
                }

                if (ret < 0)
                        return EINVAL;

                cur += ret;
                rest -= ret;
        }

        if (tail_zero)
                (void) snprintf(cur, rest, ":");

        return EOK;
}

/** Format node address.
 *
 * @param addr Node address.
 * @param bufp Place to store pointer to formatted string.
 *
 * @return EOK on success.
 * @return ENOMEM if out of memory.
 * @return ENOTSUP on unsupported address family.
 *
 */
errno_t inet_addr_format(const inet_addr_t *addr, char **bufp)
{
        errno_t rc;
        int ret;

        rc = ENOTSUP;

        switch (addr->version) {
        case ip_any:
                ret = asprintf(bufp, "none");
                if (ret < 0)
                        return ENOMEM;
                rc = EOK;
                break;
        case ip_v4:
                rc = inet_addr_format_v4(addr->addr, bufp);
                break;
        case ip_v6:
                rc = inet_addr_format_v6(addr->addr6, bufp);
                break;
        }

        return rc;
}

/** Format network address.
 *
 * @param naddr Network address.
 * @param bufp  Place to store pointer to formatted string.
 *
 * @return EOK on success.
 * @return ENOMEM if out of memory.
 * @return ENOTSUP on unsupported address family.
 *
 */
errno_t inet_naddr_format(const inet_naddr_t *naddr, char **bufp)
{
        errno_t rc;
        int ret;
        char *astr;

        rc = ENOTSUP;

        switch (naddr->version) {
        case ip_any:
                ret = asprintf(bufp, "none");
                if (ret < 0)
                        return ENOMEM;
                rc = EOK;
                break;
        case ip_v4:
                rc = inet_addr_format_v4(naddr->addr, &astr);
                if (rc != EOK)
                        return ENOMEM;

                ret = asprintf(bufp, "%s/%" PRIu8, astr, naddr->prefix);
                if (ret < 0) {
                        free(astr);
                        return ENOMEM;
                }

                rc = EOK;
                break;
        case ip_v6:
                rc = inet_addr_format_v6(naddr->addr6, &astr);
                if (rc != EOK)
                        return ENOMEM;

                ret = asprintf(bufp, "%s/%" PRIu8, astr, naddr->prefix);
                if (ret < 0) {
                        free(astr);
                        return ENOMEM;
                }

                rc = EOK;
                break;
        }

        return rc;
}

ip_ver_t inet_addr_get(const inet_addr_t *addr, addr32_t *v4, addr128_t *v6)
{
        switch (addr->version) {
        case ip_v4:
                if (v4 != NULL)
                        *v4 = addr->addr;
                break;
        case ip_v6:
                if (v6 != NULL)
                        memcpy(*v6, addr->addr6, 16);
                break;
        default:
                assert(false);
                break;
        }

        return addr->version;
}

ip_ver_t inet_naddr_get(const inet_naddr_t *naddr, addr32_t *v4, addr128_t *v6,
    uint8_t *prefix)
{
        switch (naddr->version) {
        case ip_v4:
                if (v4 != NULL)
                        *v4 = naddr->addr;
                if (prefix != NULL)
                        *prefix = naddr->prefix;
                break;
        case ip_v6:
                if (v6 != NULL)
                        memcpy(*v6, naddr->addr6, 16);
                if (prefix != NULL)
                        *prefix = naddr->prefix;
                break;
        default:
                assert(false);
                break;
        }

        return naddr->version;
}

void inet_addr_set(addr32_t v4, inet_addr_t *addr)
{
        addr->version = ip_v4;
        addr->addr = v4;
}

void inet_naddr_set(addr32_t v4, uint8_t prefix, inet_naddr_t *naddr)
{
        naddr->version = ip_v4;
        naddr->addr = v4;
        naddr->prefix = prefix;
}

void inet_addr_set6(addr128_t v6, inet_addr_t *addr)
{
        addr->version = ip_v6;
        memcpy(addr->addr6, v6, 16);
}

void inet_naddr_set6(addr128_t v6, uint8_t prefix, inet_naddr_t *naddr)
{
        naddr->version = ip_v6;
        memcpy(naddr->addr6, v6, 16);
        naddr->prefix = prefix;
}

/** @}
 */