Fix DNSLookup memory leak (#422)

* Fix memory leak with shared_ptr and -fsanitize=address

* Replace addrinfo* by shared_ptr

* fsanitize=address only on Linux

* Add USE_WS Linux CI test

* Remove fsanitize from the cmake files

* Remove USE_WS in linux test suite

ixwebsocket/IXDNSLookup.cpp

@@ -23,6 +23,7 @@
 #include <chrono>
 #include <string.h>
 #include <thread>
+#include <utility>
 
 // mingw build quirks
 #if defined(_WIN32) && defined(__GNUC__)
@@ -44,7 +45,7 @@ namespace ix
         ;
     }
 
-    struct addrinfo* DNSLookup::getAddrInfo(const std::string& hostname,
+    DNSLookup::AddrInfoPtr DNSLookup::getAddrInfo(const std::string& hostname,
                                             int port,
                                             std::string& errMsg)
     {
@@ -63,10 +64,10 @@ namespace ix
             errMsg = gai_strerror(getaddrinfo_result);
             res = nullptr;
         }
-        return res;
+        return AddrInfoPtr{ res, freeaddrinfo };
     }
 
-    struct addrinfo* DNSLookup::resolve(std::string& errMsg,
+    DNSLookup::AddrInfoPtr DNSLookup::resolve(std::string& errMsg,
                                         const CancellationRequest& isCancellationRequested,
                                         bool cancellable)
     {
@@ -74,12 +75,7 @@ namespace ix
                            : resolveUnCancellable(errMsg, isCancellationRequested);
     }
 
-    void DNSLookup::release(struct addrinfo* addr)
+    DNSLookup::AddrInfoPtr DNSLookup::resolveUnCancellable(
-    {
-        freeaddrinfo(addr);
-    }
-
-    struct addrinfo* DNSLookup::resolveUnCancellable(
         std::string& errMsg, const CancellationRequest& isCancellationRequested)
     {
         errMsg = "no error";
@@ -94,7 +90,7 @@ namespace ix
         return getAddrInfo(_hostname, _port, errMsg);
     }
 
-    struct addrinfo* DNSLookup::resolveCancellable(
+    DNSLookup::AddrInfoPtr DNSLookup::resolveCancellable(
         std::string& errMsg, const CancellationRequest& isCancellationRequested)
     {
         errMsg = "no error";
@@ -157,7 +153,7 @@ namespace ix
         // gone, so we use temporary variables (res) or we pass in by copy everything that
         // getAddrInfo needs to work.
         std::string errMsg;
-        struct addrinfo* res = getAddrInfo(hostname, port, errMsg);
+        auto res = getAddrInfo(hostname, port, errMsg);
 
         if (auto lock = self.lock())
         {
@@ -181,13 +177,13 @@ namespace ix
         return _errMsg;
     }
 
-    void DNSLookup::setRes(struct addrinfo* addr)
+    void DNSLookup::setRes(DNSLookup::AddrInfoPtr addr)
     {
         std::lock_guard<std::mutex> lock(_resMutex);
-        _res = addr;
+        _res = std::move(addr);
     }
 
-    struct addrinfo* DNSLookup::getRes()
+    DNSLookup::AddrInfoPtr DNSLookup::getRes()
     {
         std::lock_guard<std::mutex> lock(_resMutex);
         return _res;

ixwebsocket/IXDNSLookup.h

@@ -24,22 +24,21 @@ namespace ix
     class DNSLookup : public std::enable_shared_from_this<DNSLookup>
     {
     public:
+        using AddrInfoPtr = std::shared_ptr<addrinfo>;
         DNSLookup(const std::string& hostname, int port, int64_t wait = DNSLookup::kDefaultWait);
         ~DNSLookup() = default;
 
-        struct addrinfo* resolve(std::string& errMsg,
+        AddrInfoPtr resolve(std::string& errMsg,
                                  const CancellationRequest& isCancellationRequested,
                                  bool cancellable = true);
 
-        void release(struct addrinfo* addr);
-
     private:
-        struct addrinfo* resolveCancellable(std::string& errMsg,
+        AddrInfoPtr resolveCancellable(std::string& errMsg,
                                             const CancellationRequest& isCancellationRequested);
-        struct addrinfo* resolveUnCancellable(std::string& errMsg,
+        AddrInfoPtr resolveUnCancellable(std::string& errMsg,
                                               const CancellationRequest& isCancellationRequested);
 
-        static struct addrinfo* getAddrInfo(const std::string& hostname,
+        AddrInfoPtr getAddrInfo(const std::string& hostname,
                                             int port,
                                             std::string& errMsg);
 
@@ -48,15 +47,15 @@ namespace ix
         void setErrMsg(const std::string& errMsg);
         const std::string& getErrMsg();
 
-        void setRes(struct addrinfo* addr);
+        void setRes(AddrInfoPtr addr);
-        struct addrinfo* getRes();
+        AddrInfoPtr getRes();
 
         std::string _hostname;
         int _port;
         int64_t _wait;
         const static int64_t kDefaultWait;
 
-        struct addrinfo* _res;
+        AddrInfoPtr _res;
         std::mutex _resMutex;
 
         std::string _errMsg;

ixwebsocket/IXSocketConnect.cpp

@@ -102,7 +102,7 @@ namespace ix
         // First do DNS resolution
         //
         auto dnsLookup = std::make_shared<DNSLookup>(hostname, port);
-        struct addrinfo* res = dnsLookup->resolve(errMsg, isCancellationRequested);
+        auto res = dnsLookup->resolve(errMsg, isCancellationRequested);
         if (res == nullptr)
         {
             return -1;
@@ -112,7 +112,7 @@ namespace ix
 
         // iterate through the records to find a working peer
         struct addrinfo* address;
-        for (address = res; address != nullptr; address = address->ai_next)
+        for (address = res.get(); address != nullptr; address = address->ai_next)
         {
             //
             // Second try to connect to the remote host
@@ -124,7 +124,6 @@ namespace ix
             }
         }
 
-        freeaddrinfo(res);
         return sockfd;
     }
 

test/IXDNSLookupTest.cpp

@@ -19,13 +19,9 @@ TEST_CASE("dns", "[net]")
         auto dnsLookup = std::make_shared<DNSLookup>("www.google.com", 80);
 
         std::string errMsg;
-        struct addrinfo* res;
+        auto res = dnsLookup->resolve(errMsg, [] { return false; });
-
-        res = dnsLookup->resolve(errMsg, [] { return false; });
         std::cerr << "Error message: " << errMsg << std::endl;
         REQUIRE(res != nullptr);
-
-        dnsLookup->release(res);
     }
 
     SECTION("Test resolving a non-existing hostname")
@@ -33,7 +29,7 @@ TEST_CASE("dns", "[net]")
         auto dnsLookup = std::make_shared<DNSLookup>("wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww", 80);
 
         std::string errMsg;
-        struct addrinfo* res = dnsLookup->resolve(errMsg, [] { return false; });
+        auto res = dnsLookup->resolve(errMsg, [] { return false; });
         std::cerr << "Error message: " << errMsg << std::endl;
         REQUIRE(res == nullptr);
     }
@@ -44,7 +40,7 @@ TEST_CASE("dns", "[net]")
 
         std::string errMsg;
         // The callback returning true means we are requesting cancellation
-        struct addrinfo* res = dnsLookup->resolve(errMsg, [] { return true; });
+        auto res = dnsLookup->resolve(errMsg, [] { return true; });
         std::cerr << "Error message: " << errMsg << std::endl;
         REQUIRE(res == nullptr);
     }

ws/ws.cpp

@@ -892,9 +892,8 @@ namespace ix
         auto dnsLookup = std::make_shared<DNSLookup>(hostname, 80);
 
         std::string errMsg;
-        struct addrinfo* res;
 
-        res = dnsLookup->resolve(errMsg, [] { return false; });
+        auto res = dnsLookup->resolve(errMsg, [] { return false; });
 
         auto addr = res->ai_addr;