prefix4.cc

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#include "prefix4.h"
#include "value-op.h"
#include <arpa/inet.h>

namespace libbgp {

const uint32_t CIDR_MASK_MAP[33] = { 
    0x00000000, 0x00000080, 0x000000c0, 0x000000e0, 0x000000f0, 0x000000f8, 
    0x000000fc, 0x000000fe, 0x000000ff, 0x000080ff, 0x0000c0ff, 0x0000e0ff, 
    0x0000f0ff, 0x0000f8ff, 0x0000fcff, 0x0000feff, 0x0000ffff, 0x0080ffff, 
    0x00c0ffff, 0x00e0ffff, 0x00f0ffff, 0x00f8ffff, 0x00fcffff, 0x00feffff, 
    0x00ffffff, 0x80ffffff, 0xc0ffffff, 0xe0ffffff, 0xf0ffffff, 0xf8ffffff, 
    0xfcffffff, 0xfeffffff, 0xffffffff
};

uint32_t cidr_to_mask(uint8_t cidr) {
    if (cidr > 32) throw "bad_route_length";
    return CIDR_MASK_MAP[cidr];
}

Prefix4::Prefix4() {
    afi = IPV4;
    prefix = length = 0;
}

Prefix4::Prefix4(uint32_t prefix, uint8_t length) {
    if (length > 32) throw "bad_route_length";
    afi = IPV4;
    this->prefix = prefix;
    this->length = length;
}

Prefix4::Prefix4(const char* prefix, uint8_t length) {
    if (length > 32) throw "bad_route_length";
    afi = IPV4;
    this->length = length;
    inet_pton(AF_INET, prefix, &(this->prefix));
}

ssize_t Prefix4::parse(const uint8_t *buffer, size_t buf_sz) {
    if (buf_sz < 1) return -1;
    length = getValue<uint8_t>(&buffer);
    size_t prefix_buf_len = (length + 7) / 8;
    if (prefix_buf_len + 1 > buf_sz) return -1;
    prefix = 0;
    memcpy(&prefix, buffer, prefix_buf_len);
    return prefix_buf_len + 1;
}

ssize_t Prefix4::write(uint8_t *buffer, size_t buf_sz) const {
    size_t prefix_buf_len = (length + 7) / 8;
    if (buf_sz < 1 + prefix_buf_len) return -1;
    putValue<uint8_t>(&buffer, length);
    memcpy(buffer, &prefix, prefix_buf_len);
    return prefix_buf_len + 1;
}

bool Prefix4::Includes (uint32_t prefix, uint8_t length, uint32_t address) {
    if (length > 32) return false;
    return (address & CIDR_MASK_MAP[length]) == prefix;
}

bool Prefix4::Includes (uint32_t prefix_a, uint8_t length_a, uint32_t prefix_b, uint8_t length_b) {
    if (length_a > 32 || length_b > 32) return false;
    if (length_b < length_a) return false;
    return (prefix_b & CIDR_MASK_MAP[length_a]) == prefix_a;
}

bool Prefix4::includes (uint32_t address) const {
    return (address & CIDR_MASK_MAP[length]) == prefix;
}

bool Prefix4::includes (const char* address) const {
    uint32_t address_int = 0;
    if (inet_pton(AF_INET, address, &address_int) <= 0) return false;
    return includes (address_int);
}

bool Prefix4::includes (uint32_t prefix, uint8_t length) const {
    if (length > 32) return false;
    if (length < this->length) return false;
    return (prefix & CIDR_MASK_MAP[this->length]) == this->prefix;
}

bool Prefix4::includes (const Prefix &other) const {
    if (other.afi != IPV4) return false;
    const Prefix4 &other_4 = dynamic_cast<const Prefix4 &>(other);
    return includes (other_4.prefix, other_4.length);
}

bool Prefix4::includes (const char* prefix, uint8_t length) const {
    uint32_t prefix_int = 0;
    if (inet_pton(AF_INET, prefix, &prefix_int) <= 0) return false;
    return includes(prefix_int, length);
}

bool Prefix4::operator== (const Prefix &other) const {
    if (other.afi != IPV4) return false;
    const Prefix4 &other_4 = dynamic_cast<const Prefix4 &>(other);
    return other_4.prefix == prefix && other_4.length == length;
}

bool Prefix4::operator> (const Prefix &other) const {
    if (other.afi != IPV4) return false;
    const Prefix4 &other_4 = dynamic_cast<const Prefix4 &>(other);
    return length < other_4.length;
}

bool Prefix4::operator< (const Prefix &other) const {
    if (other.afi != IPV4) return false;
    const Prefix4 &other_4 = dynamic_cast<const Prefix4 &>(other);
    return length > other_4.length;
}

bool Prefix4::operator>= (const Prefix &other) const {
    return !(*this < other);
}

bool Prefix4::operator<= (const Prefix &other) const {
    return !(*this > other);
}

bool Prefix4::operator!= (const Prefix &other) const {
    return !(*this == other);
}

bool Prefix4::set(uint32_t prefix, uint8_t length) {
    if (length > 32) return false;
    this->length = length;
    this->prefix = prefix;
    return true;
}

bool Prefix4::setPrefix(uint32_t prefix) {
    this->prefix = prefix;
    return true;
}

bool Prefix4::setLength(uint8_t length) {
    if (length > 32) return false;
    this->length = length;
    return true;
}

uint32_t Prefix4::getPrefix() const {
    return prefix;
}

uint8_t Prefix4::getLength() const {
    return length;
}

uint32_t Prefix4::getMask() const {
    if (length > 32) throw "bad_route_length";
    return CIDR_MASK_MAP[length];
}

}