@@ -27,6 +27,9 @@ extern "C" int initializeWinsockIfNecessary();
2727#include < stdarg.h>
2828#include < time.h>
2929#include < sys/time.h>
30+ #if !defined(_WIN32)
31+ #include < netinet/tcp.h>
32+ #endif
3033#include < fcntl.h>
3134#define initializeWinsockIfNecessary () 1
3235#endif
@@ -217,8 +220,38 @@ Boolean makeSocketBlocking(int sock, unsigned writeTimeoutInMilliseconds) {
217220 return result;
218221}
219222
223+ Boolean setSocketKeepAlive (int sock) {
224+ #if defined(__WIN32__) || defined(_WIN32)
225+ // How do we do this in Windows? For now, just make this a no-op in Windows:
226+ #else
227+ int const keepalive_enabled = 1 ;
228+ if (setsockopt (sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&keepalive_enabled, sizeof keepalive_enabled) < 0 ) {
229+ return False;
230+ }
231+
232+ #ifdef TCP_KEEPIDLE
233+ int const keepalive_time = 180 ;
234+ if (setsockopt (sock, IPPROTO_TCP, TCP_KEEPIDLE, (void *)&keepalive_time, sizeof keepalive_time) < 0 ) {
235+ return False;
236+ }
237+ #endif
238+
239+ int const keepalive_count = 5 ;
240+ if (setsockopt (sock, IPPROTO_TCP, TCP_KEEPCNT, (void *)&keepalive_count, sizeof keepalive_count) < 0 ) {
241+ return False;
242+ }
243+
244+ int const keepalive_interval = 20 ;
245+ if (setsockopt (sock, IPPROTO_TCP, TCP_KEEPINTVL, (void *)&keepalive_interval, sizeof keepalive_interval) < 0 ) {
246+ return False;
247+ }
248+ #endif
249+
250+ return True;
251+ }
252+
220253int setupStreamSocket (UsageEnvironment& env,
221- Port port, Boolean makeNonBlocking) {
254+ Port port, Boolean makeNonBlocking, Boolean setKeepAlive ) {
222255 if (!initializeWinsockIfNecessary ()) {
223256 socketErr (env, " Failed to initialize 'winsock': "
224257 return -1 ;
@@ -284,6 +317,16 @@ int setupStreamSocket(UsageEnvironment& env,
284317 }
285318 }
286319
320+ // Set the keep alive mechanism for the TCP socket, to avoid "ghost sockets"
321+ // that remain after an interrupted communication.
322+ if (setKeepAlive) {
323+ if (!setSocketKeepAlive (newSocket)) {
324+ socketErr (env, " failed to set keep alive: "
325+ closeSocket (newSocket);
326+ return -1 ;
327+ }
328+ }
329+
287330 return newSocket;
288331}
289332
0 commit comments