GoodbyeDPI/blackwhitelist.c

111 lines
3.2 KiB
C

/*
* Blacklist for GoodbyeDPI HTTP DPI circumvention tricks
*
* This is a simple domain hash table.
* Domain records are added from a text file, where every
* domain is separated with a new line.
*/
#include <windows.h>
#include <stdio.h>
#include "goodbyedpi.h"
#include "uthash.h"
#include "getline.h"
typedef struct blackwhitelist_record {
const char *host;
UT_hash_handle hh; /* makes this structure hashable */
} blackwhitelist_record_t;
static blackwhitelist_record_t *blackwhitelist = NULL;
static int check_get_hostname(const char *host) {
blackwhitelist_record_t *tmp_record = NULL;
if (!blackwhitelist) return FALSE;
HASH_FIND_STR(blackwhitelist, host, tmp_record);
if (tmp_record) {
debug("check_get_hostname found host\n");
return TRUE;
}
debug("check_get_hostname host not found\n");
return FALSE;
}
static int add_hostname(const char *host) {
if (!host)
return FALSE;
int host_len = strlen(host);
blackwhitelist_record_t *tmp_record = malloc(sizeof(blackwhitelist_record_t));
char *host_c = malloc(host_len + 1);
if (!check_get_hostname(host)) {
strncpy(host_c, host, host_len);
host_c[host_len] = '\0';
tmp_record->host = host_c;
HASH_ADD_KEYPTR(hh, blackwhitelist, tmp_record->host,
strlen(tmp_record->host), tmp_record);
debug("Added host %s\n", host_c);
return TRUE;
}
debug("Not added host %s\n", host);
free(tmp_record);
free(host_c);
return FALSE;
}
int blackwhitelist_load_list(const char *filename) {
char *line = malloc(HOST_MAXLEN + 1);
size_t linelen = HOST_MAXLEN + 1;
int cnt = 0;
ssize_t read;
FILE *fp = fopen(filename, "r");
if (!fp) return FALSE;
while ((read = getline(&line, &linelen, fp)) != -1) {
/* works with both \n and \r\n */
line[strcspn(line, "\r\n")] = '\0';
if (strlen(line) > HOST_MAXLEN) {
printf("WARNING: host %s exceeds maximum host length and has not been added\n",
line);
continue;
}
if (strlen(line) < 4)
continue;
if (add_hostname(line))
cnt++;
}
free(line);
if (!blackwhitelist) return FALSE;
printf("Loaded %d hosts from file %s\n", cnt, filename);
fclose(fp);
return TRUE;
}
int blackwhitelist_check_hostname(const char *host_addr, int host_len) {
char current_host[HOST_MAXLEN + 1];
char *tokenized_host = NULL;
if (host_len > HOST_MAXLEN) return FALSE;
if (host_addr && host_len) {
memcpy(current_host, host_addr, host_len);
current_host[host_len] = '\0';
}
if (check_get_hostname(current_host))
return TRUE;
tokenized_host = strchr(current_host, '.');
while (tokenized_host != NULL && tokenized_host < (current_host + HOST_MAXLEN)) {
/* Search hostname only if there is next token */
if (strchr(tokenized_host + 1, '.') && check_get_hostname(tokenized_host + 1))
return TRUE;
tokenized_host = strchr(tokenized_host + 1, '.');
}
debug("____blackwhitelist_check_hostname FALSE: host %s\n", current_host);
return FALSE;
}