inet_ntop.h File Reference

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Functions
static const char *	inet_ntop4 (const unsigned char *src, char *dst, size_t size)
static const char *	inet_ntop6 (const unsigned char *src, char *dst, size_t size)
static const char *	os_inet_ntop (int af, const void *src, char *dst, size_t size)

Function Documentation

inet_ntop4()

static const char * inet_ntop4 ( const unsigned char *  src, char *  dst, size_t  size  )

static

const char * inet_ntop4(src, dst, size) format an IPv4 address return: ‘dst’ (as a const) notes: (1) uses no statics (2) takes a unsigned char* not an in_addr as input author: Paul Vixie, 1996.

Definition at line 66 of file inet_ntop.h.

{
    static const char fmt[] = "%u.%u.%u.%u";
    char tmp[sizeof("255.255.255.255")];
    size_t len;
 
    len = Q_snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
    if (len >= size) {
        /* errno = ENOSPC; */
        return (NULL);
    }
    strcpy(dst, tmp);
 
    return (dst);
}

Referenced by inet_ntop6(), and os_inet_ntop().

inet_ntop6()

static const char * inet_ntop6 ( const unsigned char *  src, char *  dst, size_t  size  )

static

const char * inet_ntop6(src, dst, size) convert IPv6 binary address into presentation (printable) format author: Paul Vixie, 1996.

Note that int32_t and int16_t need only be "at least" large enough to contain a value of the specified size. On some systems, like Crays, there is no such thing as an integer variable with 16 bits. Keep this in mind if you think this function should have been coded to use pointer overlays. All the world's not a VAX.

Definition at line 89 of file inet_ntop.h.

{
    char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp;
    struct {
        int base, len;
    } best, cur;
    unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
    int i;
 
    /*
     * Preprocess:
     *  Copy the input (bytewise) array into a wordwise array.
     *  Find the longest run of 0x00's in src[] for :: shorthanding.
     */
    memset(words, '\0', sizeof(words));
    for (i = 0; i < NS_IN6ADDRSZ; i++)
        words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
    best.base = -1;
    best.len = 0;
    cur.base = -1;
    cur.len = 0;
    for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
        if (words[i] == 0) {
            if (cur.base == -1)
                cur.base = i, cur.len = 1;
            else
                cur.len++;
        } else {
            if (cur.base != -1) {
                if (best.base == -1 || cur.len > best.len)
                    best = cur;
                cur.base = -1;
            }
        }
    }
    if (cur.base != -1) {
        if (best.base == -1 || cur.len > best.len)
            best = cur;
    }
    if (best.base != -1 && best.len < 2)
        best.base = -1;
 
    /*
     * Format the result.
     */
    tp = tmp;
    for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
        /* Are we inside the best run of 0x00's? */
        if (best.base != -1 && i >= best.base &&
            i < (best.base + best.len)) {
            if (i == best.base)
                *tp++ = ':';
            continue;
        }
        /* Are we following an initial run of 0x00s or any real hex? */
        if (i != 0)
            *tp++ = ':';
        /* Is this address an encapsulated IPv4? */
        if (i == 6 && best.base == 0 &&
            (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
            if (!inet_ntop4(src + 12, tp,
                            sizeof(tmp) - (tp - tmp)))
                return (NULL);
            tp += strlen(tp);
            break;
        }
        tp += sprintf(tp, "%x", words[i]); /* XXX */
    }
    /* Was it a trailing run of 0x00's? */
    if (best.base != -1 && (best.base + best.len) ==
        (NS_IN6ADDRSZ / NS_INT16SZ))
        *tp++ = ':';
    *tp++ = '\0';
 
    /*
     * Check for overflow, copy, and we're done.
     */
    if ((size_t)(tp - tmp) > size) {
        /* errno = ENOSPC; */
        return (NULL);
    }
    strcpy(dst, tmp);
    return (dst);
}

Referenced by os_inet_ntop().

os_inet_ntop()

static const char* os_inet_ntop ( int  af, const void *  src, char *  dst, size_t  size  )

static

char * lwres_net_ntop(af, src, dst, size) convert a network format address to presentation format. return: pointer to presentation format address (‘dst’), or NULL (see errno). author: Paul Vixie, 1996.

Definition at line 40 of file inet_ntop.h.

{
    switch (af) {
    case AF_INET:
        return (inet_ntop4(src, dst, size));
    case AF_INET6:
        return (inet_ntop6(src, dst, size));
    default:
        /* errno = EAFNOSUPPORT; */
        return (NULL);
    }
    /* NOTREACHED */
}

Referenced by NET_BaseAdrToString().