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datastructure.c
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datastructure.c
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/* Pi-hole: A black hole for Internet advertisements
* (c) 2017 Pi-hole, LLC (https://pi-hole.net)
* Network-wide ad blocking via your own hardware.
*
* FTL Engine
* Query processing routines
*
* This file is copyright under the latest version of the EUPL.
* Please see LICENSE file for your rights under this license. */
#include "FTL.h"
// converts upper to lower case, and leaves other characters unchanged
void strtolower(char *str)
{
int i = 0;
while(str[i]){ str[i] = tolower(str[i]); i++; }
}
void gettimestamp(int *querytimestamp, int *overTimetimestamp)
{
// Get current time
*querytimestamp = (int)time(NULL);
// Floor timestamp to the beginning of 10 minutes interval
// and add 5 minutes to center it in the interval
*overTimetimestamp = *querytimestamp-(*querytimestamp%600)+300;
}
int findOverTimeID(int overTimetimestamp)
{
int timeidx = -1, i;
// Check struct size
memory_check(OVERTIME);
if(counters.overTime > 0)
validate_access("overTime", counters.overTime-1, true, __LINE__, __FUNCTION__, __FILE__);
for(i=0; i < counters.overTime; i++)
{
if(overTime[i].timestamp == overTimetimestamp)
return i;
}
// We loop over this to fill potential data holes with zeros
int nexttimestamp = 0;
if(counters.overTime != 0)
{
validate_access("overTime", counters.overTime-1, false, __LINE__, __FUNCTION__, __FILE__);
nexttimestamp = overTime[counters.overTime-1].timestamp + 600;
}
else
{
nexttimestamp = overTimetimestamp;
}
// Fill potential holes in the overTime struct (may happen
// if there haven't been any queries within a time interval)
while(overTimetimestamp >= nexttimestamp)
{
// Check struct size
memory_check(OVERTIME);
timeidx = counters.overTime;
validate_access("overTime", timeidx, false, __LINE__, __FUNCTION__, __FILE__);
// Set magic byte
overTime[timeidx].magic = MAGICBYTE;
overTime[timeidx].timestamp = nexttimestamp;
overTime[timeidx].total = 0;
overTime[timeidx].blocked = 0;
overTime[timeidx].cached = 0;
// overTime[timeidx].querytypedata is static
overTime[timeidx].clientnum = 0;
overTime[timeidx].clientdata = NULL;
counters.overTime++;
// Update time stamp for next loop interation
if(counters.overTime != 0)
{
validate_access("overTime", counters.overTime-1, false, __LINE__, __FUNCTION__, __FILE__);
nexttimestamp = overTime[counters.overTime-1].timestamp + 600;
}
}
// Ensure that we don't return negative time indices. This may happen
// when the system time is getting corrected backwards since FTL started
if(timeidx < 0)
timeidx = 0;
return timeidx;
}
int findForwardID(const char * forward, bool count)
{
int i, forwardID = -1;
if(counters.forwarded > 0)
validate_access("forwarded", counters.forwarded-1, true, __LINE__, __FUNCTION__, __FILE__);
// Go through already knows forward servers and see if we used one of those
for(i=0; i < counters.forwarded; i++)
{
if(strcmp(forwarded[i].ip, forward) == 0)
{
forwardID = i;
if(count) forwarded[forwardID].count++;
return forwardID;
}
}
// This forward server is not known
// Store ID
forwardID = counters.forwarded;
logg("New forward server: %s (%i/%u)", forward, forwardID, counters.forwarded_MAX);
// Check struct size
memory_check(FORWARDED);
validate_access("forwarded", forwardID, false, __LINE__, __FUNCTION__, __FILE__);
// Set magic byte
forwarded[forwardID].magic = MAGICBYTE;
// Initialize its counter
if(count)
forwarded[forwardID].count = 1;
else
forwarded[forwardID].count = 0;
// Save forward destination IP address
forwarded[forwardID].ip = strdup(forward);
forwarded[forwardID].failed = 0;
// Initialize forward hostname
// Due to the nature of us being the resolver,
// the actual resolving of the host name has
// to be done separately to be non-blocking
forwarded[forwardID].new = true;
forwarded[forwardID].name = NULL;
// Increase counter by one
counters.forwarded++;
return forwardID;
}
int findDomainID(const char *domain)
{
int i;
if(counters.domains > 0)
validate_access("domains", counters.domains-1, true, __LINE__, __FUNCTION__, __FILE__);
for(i=0; i < counters.domains; i++)
{
// Quick test: Does the domain start with the same character?
if(domains[i].domain[0] != domain[0])
continue;
// If so, compare the full domain using strcmp
if(strcmp(domains[i].domain, domain) == 0)
{
domains[i].count++;
return i;
}
}
// If we did not return until here, then this domain is not known
// Store ID
int domainID = counters.domains;
// Check struct size
memory_check(DOMAINS);
validate_access("domains", domainID, false, __LINE__, __FUNCTION__, __FILE__);
// Set magic byte
domains[domainID].magic = MAGICBYTE;
// Set its counter to 1
domains[domainID].count = 1;
// Set blocked counter to zero
domains[domainID].blockedcount = 0;
// Store domain name - no need to check for NULL here as it doesn't harm
domains[domainID].domain = strdup(domain);
// RegEx needs to be evaluated for this new domain
domains[domainID].regexmatch = REGEX_UNKNOWN;
// Increase counter by one
counters.domains++;
return domainID;
}
int findClientID(const char *client)
{
int i;
// Compare content of client against known client IP addresses
if(counters.clients > 0)
validate_access("clients", counters.clients-1, true, __LINE__, __FUNCTION__, __FILE__);
for(i=0; i < counters.clients; i++)
{
// Quick test: Does the clients IP start with the same character?
if(clients[i].ip[0] != client[0])
continue;
// If so, compare the full IP using strcmp
if(strcmp(clients[i].ip, client) == 0)
{
clients[i].count++;
return i;
}
}
// If we did not return until here, then this client is definitely new
// Store ID
int clientID = counters.clients;
// Check struct size
memory_check(CLIENTS);
validate_access("clients", clientID, false, __LINE__, __FUNCTION__, __FILE__);
// Set magic byte
clients[clientID].magic = MAGICBYTE;
// Set its counter to 1
clients[clientID].count = 1;
// Initialize blocked count to zero
clients[clientID].blockedcount = 0;
// Store client IP - no need to check for NULL here as it doesn't harm
clients[clientID].ip = strdup(client);
// Initialize client hostname
// Due to the nature of us being the resolver,
// the actual resolving of the host name has
// to be done separately to be non-blocking
clients[clientID].new = true;
clients[clientID].name = NULL;
// Increase counter by one
counters.clients++;
return clientID;
}
bool isValidIPv4(const char *addr)
{
struct sockaddr_in sa;
return inet_pton(AF_INET, addr, &(sa.sin_addr)) != 0;
}
bool isValidIPv6(const char *addr)
{
struct sockaddr_in6 sa;
return inet_pton(AF_INET6, addr, &(sa.sin6_addr)) != 0;
}
// Privacy-level sensitive subroutine that returns the domain name
// only when appropriate for the requested query
char *getDomainString(int queryID)
{
if(queries[queryID].privacylevel < PRIVACY_HIDE_DOMAINS)
{
validate_access("domains", queries[queryID].domainID, true, __LINE__, __FUNCTION__, __FILE__);
return domains[queries[queryID].domainID].domain;
}
else
return HIDDEN_DOMAIN;
}
// Privacy-level sensitive subroutine that returns the client IP
// only when appropriate for the requested query
char *getClientIPString(int queryID)
{
if(queries[queryID].privacylevel < PRIVACY_HIDE_DOMAINS_CLIENTS)
{
validate_access("clients", queries[queryID].clientID, true, __LINE__, __FUNCTION__, __FILE__);
return clients[queries[queryID].clientID].ip;
}
else
return HIDDEN_CLIENT;
}