geoip2_dump.c

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <byteswap.h>
#include <maxminddb.h>
#define STR_MAX 256

void usage(char *progname) {
    fprintf(stderr,
        "Usage:\n%s <mmdb file> <start ip_address> <end ip_address>\n", progname);
    exit(6);
}

void emit_range(in_addr_t start, in_addr_t end, char *value) {
    in_addr_t base = start, step;
    while (base <= end)
    {
        step = 0;
        while ((base | (1 << step)) != base) {
           if ((base | (((~0) & 0xffffffff) >> (31-step))) > end) {
               break;
           }
           step++;
        }

        struct in_addr base_s;
        base_s.s_addr = bswap_32(base);
        
        printf("%s/%d %s;\n", inet_ntoa(base_s), 32-step, value);
        base += 1 << step;
    }
}

int main(int argc, char **argv)
{
    //Validate arguments count
    if (argc != 4) usage(argv[0]);
    char *mmdbfname = argv[1], *startipstr = argv[2], *endipstr = argv[3];

    //Parse arguments
    struct in_addr s_startip, s_endip;
    if ( ! (inet_aton(startipstr, &s_startip) && inet_aton(endipstr, &s_endip)) ) {
        fprintf(stderr, "Garbage input: ipaddress is not recognized.\n");
        return 7;
    }
    //Convert network address form to normal byte order and validate range
    in_addr_t startip = bswap_32(s_startip.s_addr), endip = bswap_32(s_endip.s_addr);
    if (startip > endip) {
        fprintf(stderr, "Garbage input: startip is higher than endip.\n");
        return 8;
    }

    //Open MaxMind database
    MMDB_s mmdb;
    int status = MMDB_open(mmdbfname, MMDB_MODE_MMAP, &mmdb);

    if (MMDB_SUCCESS != status) {
        fprintf(stderr, "\n  Can't open %s - %s\n",
                mmdbfname, MMDB_strerror(status));

        if (MMDB_IO_ERROR == status) {
            fprintf(stderr, "    IO error: %s\n", strerror(errno));
        }
        return 1;
    }

    //Query all range
    struct sockaddr_in curr_sa;
    curr_sa.sin_family = AF_INET;

    in_addr_t i=startip, rangestart=startip;
    char lastisocode[] = "\0\0", isocode[] = "\0\0";

    for (; i <= endip ; i++) {
        *isocode = '\0';
        curr_sa.sin_addr.s_addr = bswap_32(i);
        int mmdb_error;

        MMDB_lookup_result_s result =
            MMDB_lookup_sockaddr(&mmdb, (struct sockaddr*)&curr_sa, &mmdb_error);
        if (MMDB_SUCCESS == mmdb_error) {

            MMDB_entry_data_s entry_data;

            status =
                MMDB_get_value(&result.entry, &entry_data, "country", "iso_code", NULL);

            if (
                MMDB_SUCCESS == status &&
                entry_data.has_data &&
                entry_data.type == MMDB_DATA_TYPE_UTF8_STRING
            ) {
                strncpy(isocode, entry_data.utf8_string, sizeof(isocode)-1);
                if (strcmp(isocode, "UA") == 0) {
                    status =
                        MMDB_get_value(&result.entry, &entry_data, "subdivisions", "0", "names", "en", NULL);

                    if (
                        MMDB_SUCCESS == status &&
                        entry_data.has_data &&
                        entry_data.type == MMDB_DATA_TYPE_UTF8_STRING
                    ) {
                        char subdiv[STR_MAX];
                        size_t border = (entry_data.data_size > sizeof(subdiv)-1) ? sizeof(subdiv)-1 : entry_data.data_size;
                        strncpy(subdiv, entry_data.utf8_string, border);
                        subdiv[border] = '\0';
                        if (
                            strstr(subdiv, "Sevastopol") ||
                            strstr(subdiv, "Crimea")
                            ) strcpy(isocode, "RU");
                    }
                }
            }

        }

        if (strcmp(isocode, lastisocode)) {
            if (*lastisocode) emit_range(rangestart, i-1, lastisocode);
            strcpy(lastisocode, isocode);
            rangestart = i;
        }
        if (i == endip) break;
    }
    if (*lastisocode) emit_range(rangestart, endip, lastisocode);

    MMDB_close(&mmdb);
    return 0;
}