DNSCache Class Reference

#include <dns_cache.hpp>

Classes
struct	DNSResult

Public Member Functions
bool	lookup (const std::string &host, std::vector< std::string > &out)
std::string	lookup_one (const std::string &host)
void	store (const std::string &host, const std::vector< std::string > &addrs, int ttl_seconds=-1)
void	set_default_ttl (int seconds)
void	clear ()
size_t	size () const

Static Public Member Functions
static DNSCache &	instance ()

Private Member Functions
	DNSCache ()=default
	DNSCache (const DNSCache &)=delete
DNSCache &	operator= (const DNSCache &)=delete

Private Attributes
std::mutex	mu_
std::unordered_map< std::string, DNSResult >	map_
int	default_ttl_ = 60

Detailed Description

Definition at line 28 of file dns_cache.hpp.

Constructor & Destructor Documentation

DNSCache() [1/2]

DNSCache::DNSCache ( )

privatedefault

Referenced by DNSCache(), instance(), and operator=().

DNSCache() [2/2]

DNSCache::DNSCache ( const DNSCache & )

privatedelete

References DNSCache().

Member Function Documentation

clear()

void DNSCache::clear

(

)

Definition at line 73 of file dns_cache.cpp.

                     {
    std::lock_guard<std::mutex> lk(mu_);
    map_.clear();
}

References map_, and mu_.

instance()

DNSCache & DNSCache::instance ( )

static

Definition at line 26 of file dns_cache.cpp.

                             {
    static DNSCache inst;
    return inst;
}

References DNSCache().

Referenced by resolve_with_cache().

lookup()

bool DNSCache::lookup	(	const std::string &	host,
		std::vector< std::string > &	out )

Definition at line 31 of file dns_cache.cpp.

                                                                      {
    std::lock_guard<std::mutex> lk(mu_);
    auto it = map_.find(host);
    if (it == map_.end()) return false;
 
    auto now = std::chrono::steady_clock::now();
    if (now > it->second.expires) {
        map_.erase(it);
        return false;
    }
 
    out = it->second.addrs;
    return true;
}

References map_, and mu_.

Referenced by lookup_one().

lookup_one()

std::string DNSCache::lookup_one

(

const std::string &

host

)

Definition at line 46 of file dns_cache.cpp.

                                                    {
    std::vector<std::string> addrs;
    if (lookup(host, addrs) && !addrs.empty())
        return addrs.front();
    return {};
}

References lookup().

operator=()

DNSCache & DNSCache::operator= ( const DNSCache & )

privatedelete

References DNSCache().

set_default_ttl()

void DNSCache::set_default_ttl

(

int

seconds

)

Definition at line 68 of file dns_cache.cpp.

                                          {
    std::lock_guard<std::mutex> lk(mu_);
    default_ttl_ = (seconds > 0) ? seconds : 60;
}

References default_ttl_, and mu_.

size()

size_t DNSCache::size

(

)

const

Definition at line 78 of file dns_cache.cpp.

                            {
    std::lock_guard<std::mutex> lk(mu_);
    return map_.size();
}

References map_, and mu_.

store()

void DNSCache::store	(	const std::string &	host,
		const std::vector< std::string > &	addrs,
		int	ttl_seconds = -1 )

Definition at line 53 of file dns_cache.cpp.

                                      {
    if (host.empty() || addrs.empty()) return;
 
    DNSResult r;
    r.addrs = addrs;
    int ttl = (ttl_seconds > 0) ? ttl_seconds : default_ttl_;
    auto now = std::chrono::steady_clock::now();
    r.expires = now + std::chrono::seconds(ttl);
 
    std::lock_guard<std::mutex> lk(mu_);
    map_[host] = std::move(r);
}

References default_ttl_, map_, and mu_.

Referenced by resolve_with_cache().

Member Data Documentation

default_ttl_

int DNSCache::default_ttl_ = 60

private

Definition at line 53 of file dns_cache.hpp.

Referenced by set_default_ttl(), and store().

map_

std::unordered_map<std::string, DNSResult> DNSCache::map_

private

Definition at line 52 of file dns_cache.hpp.

Referenced by clear(), lookup(), size(), and store().

mu_

std::mutex DNSCache::mu_

mutableprivate

Definition at line 51 of file dns_cache.hpp.

Referenced by clear(), lookup(), set_default_ttl(), size(), and store().

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The documentation for this class was generated from the following files:

• BastionGuard/src/phishing/dns_cache.hpp
• BastionGuard/src/phishing/dns_cache.cpp