SENDTO addresses now prefer IPv4 over IPv6 name resolution

CHANGES

@@ -11,6 +11,11 @@ Corrections:
 	Added Socat option -0 to allow version 1.8.0.0 behaviour (no preferred
 	IP version).
 
+	UDP-SENDTO, UDPLITE-SENDTO, and IP-SENDTO addresses now select an IPv4
+	address in case the server name resolves to both IPv4 and IPv6
+	addresses.
+	Tests: V1800_*_SENDTO_RESOLV_6_4
+
 	Guard applyopts_termios_value() with WITH_TERMIOS.
 	Thanks to Kush Upadhyay from Amazon Bottlerocket team for providing the
 	patch.

test.sh

@@ -13543,7 +13543,7 @@ te="$td/test$N.stderr"
 tdiff="$td/test$N.diff"
 da="test$N $(date) $RANDOM"
 newport udp6
-CMD0="$TRACE $SOCAT $opts UDP6-RECV:$PORT,ipv6-join-group=[ff02::2]:$MCINTERFACE /dev/null"
+CMD0="$TRACE $SOCAT $opts -T 0.001 -u UDP6-RECV:$PORT,ipv6-join-group=[ff02::2]:$MCINTERFACE /dev/null"
 printf "test $F_n $TEST... " $N
 $CMD0 >/dev/null 2>"${te}0"
 rc0=$?
@@ -17011,6 +17011,10 @@ elif ! A=$(testaddrs TCP-CONNECT GOPEN); then
     $PRINTF "test $F_n $TEST... ${YELLOW}Address $A not available in $SOCAT${NORMAL}\n" $N
     numCANT=$((numCANT+1))
     listCANT="$listCANT $N"
+elif ! o=$(testoptions ai-addrconfig) >/dev/null; then
+    $PRINTF "test $F_n $TEST... ${YELLOW}Option $o not available in $SOCAT${NORMAL}\n" $N
+    numCANT=$((numCANT+1))
+    listCANT="$listCANT $N"
 elif ! runsip4 >/dev/null; then
     $PRINTF "test $F_n $TEST... ${YELLOW}IPv4 not available${NORMAL}\n" $N
     numCANT=$((numCANT+1))
@@ -17858,7 +17862,6 @@ TEST="$NAME: sigint option with SHELL"
 # Send the parent a SIGINT; when the child gets SIGINT too (vs.SIGTERM)
 # the test succeeded
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! F=$(testfeats STDIO SHELL PIPE); then
     $PRINTF "test $F_n $TEST... ${YELLOW}Feature $F not configured in $SOCAT${NORMAL}\n" $N
     numCANT=$((numCANT+1))
@@ -18028,7 +18031,6 @@ TEST="$NAME: sigint option with SYSTEM"
 # the test succeeded
 # setsid is required so the initial SIGINT is not delivered to the sub process.
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif [ "$UNAME" = "NetBSD" ]; then
     # On NetBSD-4.0 and NetBSD-9.3 this test hangs (signal has no effect)
     # (other versions not tried)
@@ -18696,7 +18698,6 @@ TEST="$NAME: f-setpipe-sz on STDIN"
 # Start Socat in a shell pipe and have it calling Filan via EXEC and nofork
 # Check Filan output if pipe size of its input pipe is modified.
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! $(type true >/dev/null 2>&1); then
     $PRINTF "test $F_n $TEST... ${YELLOW}true not available${NORMAL}\n" $N
     numCANT=$((numCANT+1))
@@ -18763,7 +18764,6 @@ TEST="$NAME: f-setpipe-sz on EXEC with pipes"
 # Start Socat calling Filan via EXEC and pipes and f-setpipe-sz
 # Check Filan output if pipe size of both pipes is modified.
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! F=$(testfeats STDIO EXEC); then
     $PRINTF "test $F_n $TEST... ${YELLOW}Feature $F not configured in $SOCAT${NORMAL}\n" $N
     numCANT=$((numCANT+1))
@@ -18885,7 +18885,6 @@ case "$TESTS" in
 *%$N%*|*%functions%*|*%ip4%*|*%ipapp%*|*%udplite%*|*%$NAME%*)
 TEST="$NAME: echo via connection to UDP-Lite V4 socket"
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -18953,7 +18952,6 @@ case "$TESTS" in
 *%$N%*|*%functions%*|*%ip4%*|*%ipapp%*|*%udplite%*|*%$NAME%*)
 TEST="$NAME: echo via connection to UDP-Lite V4 socket"
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -19021,7 +19019,6 @@ case "$TESTS" in
 *%$N%*|*%functions%*|*%ip4%*|*%ipapp%*|*%udplite%*|*%$NAME%*)
 TEST="$NAME: echo via connection to UDP-Lite V4 socket"
 if ! eval $NUMCOND; then :;
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -19338,7 +19335,6 @@ TEST="$NAME: test socat-chain.sh with SOCKS4 over UNIX-socket"
 # Run a socks4 server on UNIX-listen
 # Connect with socat-chain.sh; check if data transfer is correct
 if ! eval $NUMCOND; then :
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -19410,7 +19406,6 @@ TEST="$NAME: test socat-chain.sh with SSL over PTY"
 # open the PTY with socat-chain.sh using SSL;
 # check if data transfer is correct
 if ! eval $NUMCOND; then :
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -19492,7 +19487,6 @@ TEST="$NAME: test the socat-mux.sh script"
 # Connect with two clients to mux, send different data records from both.
 # Check if both clients received both records in order.
 if ! eval $NUMCOND; then :
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -19604,7 +19598,6 @@ TEST="$NAME: test the socat-broker.sh script"
 # Connect with two clients, send different data records from both.
 # Check if both client received both records in order.
 if ! eval $NUMCOND; then :
-# Remove unneeded checks, adapt lists of the remaining ones
 elif ! cond=$(checkconds \
 		  "" \
 		  "" \
@@ -20195,6 +20188,75 @@ IP-DATAGRAM:1.2.3.4      ip4      PROTO .                    bind=127.0.0.1
 "
 
 
+# Test if datagram SENDTO to a server name that resolves to IPv6 first and IPv4
+# as second address, binding to an IPv4 address, uses IPv4
+# This failed in Socat 1.8.0.0
+while read ADDR protov IPPORT _; do
+if [ -z "$ADDR" ] || [[ "$ADDR" == \#* ]]; then continue; fi
+FEATS=
+ADDR_="$(echo $ADDR |tr - _)" 	# UDP_SENDTO
+PROTO="${ADDR%%-*}" 		# UDP
+proto=$(tolower $PROTO) 	# udp
+FEATS="$FEATS $PROTO"
+NAME="$(echo "V1800_${ADDR_}_RESOLV_6_4" |sed 's/:[.0-8]*//')"
+case "$TESTS" in
+*%$N%*|*%functions%*|*%bugs%*|*%ip4%*|*%$protov%*|*%$proto%*|*%socket%*|*%$NAME%*)
+TEST="$NAME: test regression of $ADDR with IPv6,4 and binding to IPv4"
+# Start a SENDTO command to (internal) test name localhost-6-4.dest-unreach.net
+# and bind to an IPv4 address, and terminate immediately.
+# When no error occurs the test succeeded.
+if ! eval $NUMCOND; then :
+elif ! cond=$(checkconds \
+		  "" \
+		  "$([ $IPPORT = PROTO ] && echo root)" \
+		  "" \
+		  "$FEATS DEVTESTS IP4" \
+		  "$ADDR GOPEN" \
+		  "bind" \
+		  "$protov" ); then
+    $PRINTF "test $F_n $TEST... ${YELLOW}$cond${NORMAL}\n" $N
+    numCANT=$((numCANT+1))
+    listCANT="$listCANT $N"
+    namesCANT="$namesCANT $NAME"
+else
+    tf="$td/test$N.stdout"
+    te="$td/test$N.stderr"
+    tdiff="$td/test$N.diff"
+    da="test$N $(date) $RANDOM"
+    case X$IPPORT in
+	XPORT)  newport $(tolower $PROTO); _PORT=$PORT ;;
+	XPROTO) echo "IPPROTO=\"$IPPROTO\""
+		_PORT=$IPPROTO ;;
+    esac
+    CMD0="$TRACE $SOCAT $opts -u /dev/null $ADDR:localhost-6-4.dest-unreach.net:$_PORT,bind=127.0.0.1"
+    printf "test $F_n $TEST... " $N
+    $CMD0 2>"${te}0" </dev/null
+    rc0=$?
+    if [ "$rc0" -ne 0 ]; then
+	$PRINTF "$FAILED (rc0=$rc0)\n"
+	echo "$CMD0 &"
+	cat "${te}0" >&2
+	numFAIL=$((numFAIL+1))
+	listFAIL="$listFAIL $N"
+	namesFAIL="$namesFAIL $NAME"
+    else
+	$PRINTF "$OK\n"
+	if [ "$VERBOSE" ]; then echo "$CMD0 &"; fi
+	if [ "$DEBUG" ];   then cat "${te}0" >&2; fi
+	numOK=$((numOK+1))
+	listOK="$listOK $N"
+    fi
+fi # NUMCOND
+ ;;
+esac
+PORT=$((PORT+1))
+N=$((N+1))
+done <<<"
+UDP-SENDTO               udp4     PORT
+UDPLITE-SENDTO           udplite4 PORT
+IP-SENDTO                ip4      PROTO
+"
+
 # end of common tests
 
 ##################################################################################

xio-ip.c

@@ -516,8 +516,11 @@ int xiogetaddrinfo(const char *node, const char *service,
 	   continue;
 	}
       if ((error_num = Getaddrinfo(node, service, &hints, res)) != 0) {
-	 if (*res != NULL)
+	 Warn7("getaddrinfo(\"%s\", \"%s\", {0x%02x,%d,%d,%d}, {}): %d",
-	    freeaddrinfo(*res);
+		node?node:"NULL", service?service:"NULL",
+		hints.ai_flags, hints.ai_family,
+		hints.ai_socktype, hints.ai_protocol,
+		error_num);
 	 if (numnode)
 	    free(numnode);
 
@@ -664,7 +667,7 @@ void xiofreeaddrinfo(struct addrinfo *res) {
 }
 
 /* A simple resolver interface that just returns one address,
-   the first found by calling xiogetaddrinfo().
+   the first found by calling xiogetaddrinfo(), but ev.respects preferred_ip;
    pf may be AF_INET, AF_INET6, or AF_UNSPEC;
    on failure logs error message;
    returns STAT_OK, STAT_RETRYLATER, STAT_NORETRY
@@ -683,13 +686,11 @@ int xioresolve(const char *node, const char *service,
    if (rc == EAI_AGAIN) {
       Warn3("xioresolve(node=\"%s\", pf=%d, ...): %s",
 	     node?node:"NULL", pf, gai_strerror(rc));
-      xiofreeaddrinfo(res);
       return STAT_RETRYLATER;
    } else if (rc != 0) {
       Error3("xioresolve(node=\"%s\", pf=%d, ...): %s",
 	     node?node:"NULL", pf,
 	     (rc == EAI_SYSTEM)?strerror(errno):gai_strerror(rc));
-      xiofreeaddrinfo(res);
       return STAT_NORETRY;
    }
    if (res == NULL) {

xio-ipapp.c

@@ -230,16 +230,22 @@ int
 	   bool *lowport,
 	   int socktype) {
    uint16_t port;
-   int result;
+   int rc;
 
    retropt_socket_pf(opts, pf);
 
    if (hostname != NULL || portname != NULL) {
-    if ((result =
+      rc = xiogetaddrinfo(hostname, portname, *pf, socktype, protocol,
-	xiogetaddrinfo(hostname, portname,
+			  themlist, ai_flags);
-		       *pf, socktype, protocol,
+      if (rc == EAI_AGAIN) {
-		       themlist, ai_flags))
+	 Warn4("_xioopen_ipapp_prepare(node=\"%s\", service=\"%s\", pf=%d, ...): %s",
-       != STAT_OK) {
+	       hostname?hostname:"NULL", portname?portname:"NULL",
+	       *pf, gai_strerror(rc));
+	 return STAT_RETRYLATER;
+      } else if (rc != 0) {
+	 Error4("_xioopen_ipapp_prepare(node=\"%s\", service=\"%s\", pf=%d, ...): %s",
+		hostname?hostname:"NULL", portname?portname:"NULL",
+		*pf, (rc == EAI_SYSTEM)?strerror(errno):gai_strerror(rc));
 	 return STAT_NORETRY;	/*! STAT_RETRYLATER? */
       }
    }