exclude route cacalate

exclude_route.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int _net_count = 0;
int _net_pref[25600];
int _net_list[25600];

int includeNetwork(int network, int prefix) {
        int i, j = 0;
        int net1, msk1;
        int net0, msk0 = (1<< (32 - prefix)) - 1;

        for (i = 0; i < _net_count; i++) {
                int pref = _net_pref[i];

                if (pref <= prefix) {
                        msk1 = (1 << (32 - pref)) - 1;
                        net0 = (network & ~msk1);

                        if (_net_list[i] == net0) {
                                for (int n = 0; n < _net_count - i; n++) {
                                        _net_list[j + n] = _net_list[i + n];
                                        _net_pref[j + n] = _net_pref[i + n];
                                }
                                _net_count -= (i - j);
                                return 0;
                        }

                        _net_list[j] = _net_list[i];
                        _net_pref[j] = _net_pref[i];
                        j++;
                        continue;
                }

                net1 = (_net_list[i] & ~msk0);
                if (net1 == network) {
                        continue;
                }

                _net_list[j] = _net_list[i];
                _net_pref[j] = _net_pref[i];
                j++;
        }

        _net_list[j] = (network & 0xffffffff);
        _net_pref[j] = prefix;
        _net_count = ++j;
        return 0;
}

int excludeNetwork(int network, int prefix) {
        int i, j = 0;
        int net1, msk1;
        int net0, msk0 = (1<< (32 - prefix)) - 1;

        for (i = 0; i < _net_count; i++) {
                int pref = _net_pref[i];

                // System.out.println("pref " + Long.toHexString(pref));
                if (pref <= prefix) {
                        msk1 = (1 << (32 - pref)) - 1;
                        net0 = (network & ~msk1) & 0xffffffff;

                        // System.out.println("net0 " + Long.toHexString(net0) + " " + Long.toHexString(_net_list[i]));
                        if (_net_list[i] == net0) {
                                net0 = _net_list[i];
                                for (int n = 0; n < _net_count - i - 1; n++) {
                                        _net_list[j + n] = _net_list[i + 1 + n];
                                        _net_pref[j + n] = _net_pref[i + 1 + n];
                                }
                                _net_count -= (i + 1 - j);

                                for (int k = pref + 1; k <= prefix; k++) {
                                        int newnet = network ^ (1 << (32 - k));
                                        msk1 = (1 << (32 - k)) - 1;
                                        newnet &= 0xffffffff;
                                        // System.out.println("newnet " + Long.toHexString(newnet));
                                        includeNetwork(newnet & ~msk1, (int)k);
                                }

                                return 0;
                        }

                        _net_list[j] = _net_list[i];
                        _net_pref[j] = _net_pref[i];
                        j++;
                        continue;
                }

                net1 = (_net_list[i] & ~msk0) & 0xffffffff;
                // System.out.println("net1 " + Long.toHexString(net1));
                // System.out.println("network " + Long.toHexString(network));
                if (net1 == network) {
                        continue;
                }

                _net_list[j] = _net_list[i];
                _net_pref[j] = _net_pref[i];
                j++;
        }

        _net_count = j;
        return 0;
}

#define ARRAY_SIZE(array) (sizeof(array)/ sizeof(*array))

int main(int argc, char *argv[])
{
#if 0
        String _include[] = {"0.0.0.0/1", "128.0.0.0/2", "192.0.0.0/3"};
        String _internal[] = {"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"};

        String _exclude[] = {"0.0.0.0/8", "10.0.0.0/8", "127.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16", "169.254.0.0/16", "100.64.0.0/10", "192.0.0.0/24", "192.0.2.0/24", "192.88.99.0/24", "198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24"};
        String _exclude[] = {"0.0.0.0/8", "127.0.0.0/8", "192.168.0.0/16", "169.254.0.0/16"};
#endif
        const char * _include[] = {"0.0.0.0/1", "128.0.0.0/2", "192.0.0.0/3"};
        const char * _exclude[] = {"0.0.0.0/8", "10.0.0.0/8", "127.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16", "169.254.0.0/16", "100.64.0.0/10", "192.0.0.0/24", "192.0.2.0/24", "192.88.99.0/24", "198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24"};

        char dummy[256];
        for (int i = 0; i < ARRAY_SIZE(_include); i++) {
                int len = 0;
                const char *domain = _include[i];
                const char *dotp = strchr(domain, '/');

                int prefix = atoi(dotp + 1);

                len = dotp - domain;
                memcpy(dummy, domain, len);
                dummy[len] = 0;

                int network = inet_addr(dummy);
                // printf("%s/%d %s\n", inet_ntoa(*(in_addr *)&network), prefix, domain);
                includeNetwork(htonl(network), prefix);
        }

        for (int i = 0; i < ARRAY_SIZE(_exclude); i++) {
                int len = 0;
                const char *domain = _exclude[i];
                const char *dotp = strchr(domain, '/');

                int prefix = atoi(dotp + 1);

                len = dotp - domain;
                memcpy(dummy, domain, len);
                dummy[len] = 0;

                int network = inet_addr(dummy);
                // printf("%s/%d %s\n", inet_ntoa(*(in_addr *)&network), prefix, domain);
                excludeNetwork(htonl(network), prefix);
        }

        char buf[256];
        while (fgets(buf, sizeof(buf), stdin) != NULL) {
                int len = 0;
                const char *domain = buf;
                const char *dotp = strchr(domain, '/');

                int prefix = atoi(dotp + 1);

                len = dotp - domain;
                memcpy(dummy, domain, len);
                dummy[len] = 0;

                int network = inet_addr(dummy);
                // printf("%s/%d %s\n", inet_ntoa(*(in_addr *)&network), prefix, domain);
                excludeNetwork(htonl(network), prefix);
        }

        for (int i = 0; i < _net_count; i++) {
                int nw = htonl(_net_list[i]);
                printf("%s/%d\n", inet_ntoa(*(in_addr *)&nw), _net_pref[i]);
        }

        return 0;
}