From 56f1645aa881b8a4d3c2881acf376d0921faf206 Mon Sep 17 00:00:00 2001
From: Mark Rivers <rivers@cars.uchicago.edu>
Date: Tue, 5 Nov 2024 11:38:24 -0600
Subject: [PATCH] Changes to shorten connect() timeout when connecting to
 unavailable TCP ports

---
 asyn/asynDriver/asynDriver.h       |  1 +
 asyn/asynDriver/asynManager.c      | 11 +++++++++++
 asyn/drvAsynSerial/drvAsynIPPort.c | 18 ++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/asyn/asynDriver/asynDriver.h b/asyn/asynDriver/asynDriver.h
index 446bad350..dd1d1bd62 100644
--- a/asyn/asynDriver/asynDriver.h
+++ b/asyn/asynDriver/asynDriver.h
@@ -161,6 +161,7 @@ typedef struct asynManager {
     asynStatus (*isEnabled)(asynUser *pasynUser,int *yesNo);
     asynStatus (*isAutoConnect)(asynUser *pasynUser,int *yesNo);
     asynStatus (*setAutoConnectTimeout)(double timeout);
+    asynStatus (*getAutoConnectTimeout)(double *timeout);
     asynStatus (*waitConnect)(asynUser *pasynUser, double timeout);
     /*The following are methods for interrupts*/
     asynStatus (*registerInterruptSource)(const char *portName,
diff --git a/asyn/asynDriver/asynManager.c b/asyn/asynDriver/asynManager.c
index 2061131ed..856a8cc52 100644
--- a/asyn/asynDriver/asynManager.c
+++ b/asyn/asynDriver/asynManager.c
@@ -313,6 +313,7 @@ static asynStatus isConnected(asynUser *pasynUser,int *yesNo);
 static asynStatus isEnabled(asynUser *pasynUser,int *yesNo);
 static asynStatus isAutoConnect(asynUser *pasynUser,int *yesNo);
 static asynStatus setAutoConnectTimeout(double timeout);
+static asynStatus getAutoConnectTimeout(double *timeout);
 static asynStatus waitConnect(asynUser *pasynUser, double timeout);
 static asynStatus registerInterruptSource(const char *portName,
     asynInterface *pasynInterface, void **pasynPvt);
@@ -370,6 +371,7 @@ static asynManager manager = {
     isEnabled,
     isAutoConnect,
     setAutoConnectTimeout,
+    getAutoConnectTimeout,
     waitConnect,
     registerInterruptSource,
     getInterruptPvt,
@@ -2222,6 +2224,15 @@ static asynStatus setAutoConnectTimeout(double timeout)
     return asynSuccess;
 }
 
+static asynStatus getAutoConnectTimeout(double *timeout)
+{
+    if(!pasynBase) asynInit();
+    epicsMutexMustLock(pasynBase->lock);
+    *timeout = pasynBase->autoConnectTimeout;
+    epicsMutexUnlock(pasynBase->lock);
+    return asynSuccess;
+}
+
 static asynStatus setQueueLockPortTimeout(asynUser *pasynUser, double timeout)
 {
     userPvt    *puserPvt = asynUserToUserPvt(pasynUser);
diff --git a/asyn/drvAsynSerial/drvAsynIPPort.c b/asyn/drvAsynSerial/drvAsynIPPort.c
index a5fd1415f..da9e849cb 100644
--- a/asyn/drvAsynSerial/drvAsynIPPort.c
+++ b/asyn/drvAsynSerial/drvAsynIPPort.c
@@ -511,7 +511,22 @@ connectIt(void *drvPvt, asynUser *pasynUser)
          * problem is just that the device has DHCP'd itself an new number.
          */
         if (tty->socketType != SOCK_DGRAM) {
+            double connectTimeout;
+            struct timeval saveTV, connectTV;
+            socklen_t svlen = sizeof saveTV;
+            pasynManager->getAutoConnectTimeout(&connectTimeout);
+            connectTV.tv_sec = (time_t)connectTimeout;
+            connectTV.tv_usec = (suseconds_t)((connectTimeout - connectTV.tv_sec)*1000000);
+            asynPrint(pasynUser, ASYN_TRACE_ERROR, "Calling setsockopt SO_SNDTIMEO tv_sec=%d tv_usec=%d\n", connectTV.tv_sec, connectTV.tv_usec);
+            if (getsockopt (fd, SOL_SOCKET, SO_SNDTIMEO, (char *)&saveTV, &svlen) < 0) {
+                asynPrint(pasynUser, ASYN_TRACE_ERROR, "connectIt, error calling getsockopt for SO_RECVTIMEO: %s\n", strerror(SOCKERRNO));
+            }
+            if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, (char *)&connectTV, sizeof connectTV) < 0) {
+                 asynPrint(pasynUser, ASYN_TRACE_ERROR, "connectIt, error calling setsockopt for SO_RECVTIMEO: %s\n", strerror(SOCKERRNO));
+            }
+            asynPrint(pasynUser, ASYN_TRACE_ERROR, "connectIt, calling connect()\n");
             if (connect(fd, &tty->farAddr.oa.sa, (int)tty->farAddrSize) < 0) {
+                asynPrint(pasynUser, ASYN_TRACE_ERROR, "connectIt, connect returned error: %s\n", strerror(SOCKERRNO));
                 epicsSnprintf(pasynUser->errorMessage,pasynUser->errorMessageSize,
                               "Can't connect to %s: %s",
                               tty->IPDeviceName, strerror(SOCKERRNO));
@@ -520,6 +535,9 @@ connectIt(void *drvPvt, asynUser *pasynUser)
                     tty->flags |=  FLAG_NEED_LOOKUP;
                 return asynError;
             }
+            if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, (char *)&saveTV, sizeof saveTV) < 0) {
+                asynPrint(pasynUser, ASYN_TRACE_ERROR, "connectIt, error calling setsockopt for SO_RECVTIMEO: %s\n", strerror(SOCKERRNO));
+            }
         }
     }
     i = 1;