Re: Ncat/Nsock notification of connection reset

diff --git a/ncat/ncat_connect.c b/ncat/ncat_connect.c
index b7773bd..5a38442 100644
--- a/ncat/ncat_connect.c
+++ b/ncat/ncat_connect.c
@@ -1265,7 +1265,7 @@ static void read_socket_handler(nsock_pool nsp, nsock_event evt, void *data)
     if (status == NSE_STATUS_EOF) {
         Close(STDOUT_FILENO);
         /* In --recv-only mode or non-TCP mode, exit after EOF on the socket. */
-        if (o.proto != IPPROTO_TCP || (o.proto == IPPROTO_TCP && o.recvonly))
+        //if (o.proto != IPPROTO_TCP || (o.proto == IPPROTO_TCP && o.recvonly))
             nsock_loop_quit(nsp);
         return;
     } else if (status == NSE_STATUS_ERROR) {
diff --git a/nsock/src/engine_epoll.c b/nsock/src/engine_epoll.c
index 00c28cb..af232d9 100644
--- a/nsock/src/engine_epoll.c
+++ b/nsock/src/engine_epoll.c
@@ -74,12 +74,12 @@
 
 #define EPOLL_R_FLAGS (EPOLLIN | EPOLLPRI)
 #define EPOLL_W_FLAGS EPOLLOUT
-#ifdef EPOLLRDHUP
-  #define EPOLL_X_FLAGS (EPOLLERR | EPOLLRDHUP| EPOLLHUP)
-#else
-  /* EPOLLRDHUP was introduced later and might be unavailable on older systems. */
-  #define EPOLL_X_FLAGS (EPOLLERR | EPOLLHUP)
-#endif /* EPOLLRDHUP */
+
+/* EPOLLRDHUP was introduced later and might be unavailable on older systems. */
+#ifndef EPOLLRDHUP
+  #define EPOLLRDHUP 0
+#endif
+#define EPOLL_X_FLAGS (EPOLLERR | EPOLLRDHUP| EPOLLHUP)
 
 
 /* --- ENGINE INTERFACE PROTOTYPES --- */
@@ -178,8 +178,6 @@ int epoll_iod_register(struct npool *nsp, struct niod *iod, struct nevent *nse,
     epev.events |= EPOLL_R_FLAGS;
   if (ev & EV_WRITE)
     epev.events |= EPOLL_W_FLAGS;
-  if (ev & EV_EXCEPT)
-    epev.events |= EPOLL_X_FLAGS;
 
   sd = nsock_iod_get_sd(iod);
   if (epoll_ctl(einfo->epfd, EPOLL_CTL_ADD, sd, &epev) < 0)
@@ -233,8 +231,6 @@ int epoll_iod_modify(struct npool *nsp, struct niod *iod, struct nevent *nse, in
     epev.events |= EPOLL_R_FLAGS;
   if (iod->watched_events & EV_WRITE)
     epev.events |= EPOLL_W_FLAGS;
-  if (iod->watched_events & EV_EXCEPT)
-    epev.events |= EPOLL_X_FLAGS;
 
   sd = nsock_iod_get_sd(iod);
 
@@ -328,7 +324,7 @@ static inline int get_evmask(struct epoll_engine_info *einfo, int n) {
   if (einfo->events[n].events & EPOLL_W_FLAGS)
     evmask |= EV_WRITE;
   if (einfo->events[n].events & EPOLL_X_FLAGS)
-    evmask |= (EV_READ | EV_WRITE | EV_EXCEPT);
+    evmask |= EV_EXCEPT;
 
   return evmask;
 }
diff --git a/nsock/src/engine_poll.c b/nsock/src/engine_poll.c
index 39d166e..62a8e9f 100644
--- a/nsock/src/engine_poll.c
+++ b/nsock/src/engine_poll.c
@@ -294,10 +294,6 @@ int poll_iod_modify(struct npool *nsp, struct niod *iod, struct nevent *nse, int
     pinfo->events[sd].events |= POLL_R_FLAGS;
   if (iod->watched_events & EV_WRITE)
     pinfo->events[sd].events |= POLL_W_FLAGS;
-#ifndef WIN32
-  if (iod->watched_events & EV_EXCEPT)
-    pinfo->events[sd].events |= POLL_X_FLAGS;
-#endif
 
   return 1;
 }
@@ -403,7 +399,7 @@ static inline int get_evmask(struct npool *nsp, struct niod *nsi) {
       if (pev->revents & POLL_W_FLAGS)
         evmask |= EV_WRITE;
       if (pev->events && (pev->revents & POLL_X_FLAGS))
-        evmask |= (EV_READ | EV_WRITE | EV_EXCEPT);
+        evmask |= EV_EXCEPT;
   }
   return evmask;
 }
diff --git a/nsock/src/engine_select.c b/nsock/src/engine_select.c
index 8b61482..fceb981 100644
--- a/nsock/src/engine_select.c
+++ b/nsock/src/engine_select.c
@@ -208,6 +208,9 @@ int select_iod_modify(struct npool *nsp, struct niod *iod, struct nevent *nse, i
   iod->watched_events |= ev_set;
   iod->watched_events &= ~ev_clr;
 
+  ev_set |= EV_EXCEPT;
+  ev_clr &= ~EV_EXCEPT;
+
   sd = nsock_iod_get_sd(iod);
 
   /* -- set events -- */
@@ -233,7 +236,7 @@ int select_iod_modify(struct npool *nsp, struct niod *iod, struct nevent *nse, i
 
   /* -- update max_sd -- */
   if (ev_set != EV_NONE)
-    sinfo->max_sd = MAX(sinfo->max_sd,sd);
+    sinfo->max_sd = MAX(sinfo->max_sd, sd);
   else if (ev_clr != EV_NONE && iod->events_pending == 1 && (sinfo->max_sd == sd))
     sinfo->max_sd--;
 
diff --git a/nsock/src/nsock_core.c b/nsock/src/nsock_core.c
index b8aa352..6914bd9 100644
--- a/nsock/src/nsock_core.c
+++ b/nsock/src/nsock_core.c
@@ -168,6 +168,18 @@ static int socket_count_dec_ssl_desire(struct nevent *nse) {
 }
 #endif
 
+static int should_stop_watch_read(const struct niod *iod, int ev_set) {
+  return (ev_set & EV_READ) &&
+#if HAVE_PCAP
+         !iod->readpcapsd_count &&
+#endif
+         !iod->readsd_count;
+}
+
+static int should_stop_watch_write(const struct niod *iod, int ev_set) {
+  return (ev_set & EV_WRITE) && !iod->writesd_count;
+}
+
 /* Update the events that the IO engine should watch for a given IOD.
  *
  * ev_inc is a set of events for which the event counters should be increased.
@@ -188,18 +200,18 @@ static void update_events(struct niod * iod, struct npool *ms, struct nevent *ns
   setmask = ev_inc;
   clrmask = EV_NONE;
 
-  if ((ev_dec & EV_READ) &&
-#if HAVE_PCAP
-      !iod->readpcapsd_count &&
-#endif
-      !iod->readsd_count)
+  if (should_clear_ev_read(iod, ev_dec))
     clrmask |= EV_READ;
 
-  if ((ev_dec & EV_WRITE) && !iod->writesd_count)
+  if (should_clear_ev_write(iod, ev_dec))
     clrmask |= EV_WRITE;
 
+  /* EV_EXCEPT is systematically set and cannot be removed */
+  if (ev_inc & EV_EXCEPT)
+    nsock_log_info("Invalid event set, no need to specify EV_EXCEPT");
+
   if (ev_dec & EV_EXCEPT)
-    clrmask |= EV_EXCEPT;
+    nsock_log_info("Invalid event set, refusing to clear EV_EXCEPT");
 
   if (!IOD_PROPGET(iod, IOD_REGISTERED)) {
     assert(clrmask == EV_NONE);
@@ -426,7 +438,6 @@ void handle_connect_result(struct npool *ms, struct nevent *nse, enum nse_status
 
     ev |= socket_count_read_dec(iod);
     ev |= socket_count_write_dec(iod);
-    ev |= EV_EXCEPT;
     update_events(iod, ms, nse, EV_NONE, ev);
   }
 
@@ -951,7 +962,9 @@ enum nsock_loopstatus nsock_loop(nsock_pool nsp, int msec_timeout) {
 }
 
 void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int ev) {
-  int match_r = 0, match_w = 0;
+  int match_r = ev & EV_READ;
+  int match_w = ev & EV_WRITE;
+  int match_x = ev & EV_EXCEPT;
 #if HAVE_OPENSSL
   int desire_r = 0, desire_w = 0;
 #endif
@@ -972,8 +985,6 @@ void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int
         break;
 
       case NSE_TYPE_READ:
-        match_r = ev & EV_READ;
-        match_w = ev & EV_WRITE;
 #if HAVE_OPENSSL
         desire_r = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ;
         desire_w = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_WRITE;
@@ -981,16 +992,15 @@ void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int
           handle_read_result(nsp, nse, NSE_STATUS_SUCCESS);
         else
 #endif
-        if (!nse->iod->ssl && match_r)
+        if ((!nse->iod->ssl && match_r) || match_x)
           handle_read_result(nsp, nse, NSE_STATUS_SUCCESS);
 
         if (event_timedout(nse))
           handle_read_result(nsp, nse, NSE_STATUS_TIMEOUT);
+
         break;
 
       case NSE_TYPE_WRITE:
-        match_r = ev & EV_READ;
-        match_w = ev & EV_WRITE;
 #if HAVE_OPENSSL
         desire_r = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ;
         desire_w = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_WRITE;
@@ -998,8 +1008,8 @@ void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int
           handle_write_result(nsp, nse, NSE_STATUS_SUCCESS);
         else
 #endif
-          if (!nse->iod->ssl && match_w)
-            handle_write_result(nsp, nse, NSE_STATUS_SUCCESS);
+        if ((!nse->iod->ssl && match_w) || match_x)
+          handle_write_result(nsp, nse, NSE_STATUS_SUCCESS);
 
         if (event_timedout(nse))
           handle_write_result(nsp, nse, NSE_STATUS_TIMEOUT);
@@ -1263,7 +1273,7 @@ void nsock_pool_add_event(struct npool *nsp, struct nevent *nse) {
         assert(nse->iod->sd >= 0);
         socket_count_read_inc(nse->iod);
         socket_count_write_inc(nse->iod);
-        update_events(nse->iod, nsp, nse, EV_READ|EV_WRITE|EV_EXCEPT, EV_NONE);
+        update_events(nse->iod, nsp, nse, EV_READ|EV_WRITE, EV_NONE);
       }
       iod_add_event(nse->iod, nse);
       break;