finish udp-ttl and udp-set-ttl!

Add tests, documentation, and fixes for rktio and Racket CS.

pkgs/racket-doc/scribblings/reference/networking.scrbl

@@ -619,6 +619,20 @@ or @racket[0] if the socket is unconnected.
 If the given port has been closed, the @exnraise[exn:fail:network].}
 
 
+@deftogether[(
+@defproc[(udp-set-ttl! [udp-socket udp?] [ttl byte?]) void?]
+@defproc[(udp-ttl [udp-socket udp?]) byte?]
+)]{
+
+@margin-note{Time-to-live settings correspond to the
+@as-index{@tt{IP_TTL}} setting of the socket.}
+
+Sets or retrieves the current time-to-live setting of
+@racket[udp-socket].
+
+@history[#:added "7.5.0.5"]}
+
+
 @deftogether[(
 @defproc[(udp-multicast-join-group! [udp-socket udp?]
 				    [multicast-addr string?]

pkgs/racket-test-core/tests/racket/udp.rktl

@@ -55,6 +55,20 @@
 (test #f udp-bound? udp1)
 (test #f udp-connected? udp1)
 
+(define original-ttl (udp-ttl udp1))
+(test #t byte? original-ttl)
+(test (void) udp-set-ttl! udp1 255)
+(test 255 udp-ttl udp1)
+(test (void) udp-set-ttl! udp1 0)
+(test 0 udp-ttl udp1)
+(test (void) udp-set-ttl! udp1 original-ttl)
+(err/rt-test (udp-ttl 0))
+(err/rt-test (udp-ttl 'no))
+(err/rt-test (udp-set-ttl! 0 64))
+(err/rt-test (udp-set-ttl! udp1 -1))
+(err/rt-test (udp-set-ttl! udp1 256))
+(err/rt-test (udp-set-ttl! udp1 'x))
+
 (err/rt-test (udp-set-receive-buffer-size! udp1 -1))
 (err/rt-test (udp-set-receive-buffer-size! udp1 0))
 (err/rt-test (udp-set-receive-buffer-size! udp1 (expt 2 300))

racket/src/io/network/error.rkt

@@ -3,7 +3,8 @@
          "../host/error.rkt")
 
 (provide raise-network-error
-         raise-network-arguments-error)
+         raise-network-arguments-error
+         raise-network-option-error)
 
 (define (raise-network-error who orig-err base-msg)
   (define err (remap-rktio-error orig-err))
@@ -37,3 +38,6 @@
                    "\n  socket: "
                    ((error-value->string-handler) u (error-print-width)))
     (current-continuation-marks))))
+
+(define (raise-network-option-error who mode v)
+  (raise-network-error who v (string-append mode "sockopt failed")))

racket/src/io/network/udp-multicast.rkt

@@ -67,7 +67,7 @@
 
 (define (raise-option-error who mode v)
   (end-atomic)
-  (raise-network-error who v (string-append mode "sockopt failed")))
+  (raise-network-option-error who mode v))
 
 ;; ----------------------------------------
 

racket/src/io/network/udp-socket.rkt

@@ -17,6 +17,9 @@
          udp-bind!
          udp-connect!
 
+         udp-ttl
+         udp-set-ttl!
+
          check-udp-closed
          handle-error-immediately
          udp-default-family
@@ -158,10 +161,11 @@
   (check who udp? u)
   (atomically
    (check-udp-closed who u)
-   (define v (rktio_udp_ttl rktio (udp-s u)))
+   (define v (rktio_udp_get_ttl rktio (udp-s u)))
    (cond
      [(rktio-error? v)
-      (raise-option-error who "get" v)]
+      (end-atomic)
+      (raise-network-option-error who "get" v)]
      [else v])))
 
 (define/who (udp-set-ttl! u ttl)
@@ -171,4 +175,5 @@
    (check-udp-closed who u)
    (define r (rktio_udp_set_ttl rktio (udp-s u) ttl))
    (when (rktio-error? r)
-     (raise-option-error who "set" r))))
+     (end-atomic)
+     (raise-network-option-error who "set" r))))

racket/src/io/network/udp.rkt

@@ -11,6 +11,8 @@
          udp-connected?
          udp-bind!
          udp-connect!
+         udp-ttl
+         udp-set-ttl!
 
          udp-send
          udp-send*

racket/src/rktio/rktio.rktl

@@ -596,6 +596,18 @@
  rktio_ok_t
  rktio_udp_set_receive_buffer_size
  (((ref rktio_t) rktio) ((ref rktio_fd_t) rfd) (int size)))
+(define-function/errno
+ #f
+ ()
+ rktio_ok_t
+ rktio_udp_set_ttl
+ (((ref rktio_t) rktio) ((ref rktio_fd_t) rfd) (int ttl_val)))
+(define-function/errno
+ RKTIO_PROP_ERROR
+ ()
+ rktio_tri_t
+ rktio_udp_get_ttl
+ (((ref rktio_t) rktio) ((ref rktio_fd_t) rfd)))
 (define-function/errno
  RKTIO_PROP_ERROR
  ()

racket/src/rktio/rktio_network.c

@@ -1955,7 +1955,7 @@ int rktio_udp_set_multicast_loopback(rktio_t *rktio, rktio_fd_t *rfd, int on)
 int rktio_udp_get_ttl(rktio_t *rktio, rktio_fd_t *rfd)
 {
   rktio_socket_t s = rktio_fd_socket(rktio, rfd);
-  u_char ttl;
+  int ttl;
   rktio_sockopt_len_t ttl_len = sizeof(ttl);
   int status;
 
@@ -1971,7 +1971,7 @@ int rktio_udp_get_ttl(rktio_t *rktio, rktio_fd_t *rfd)
 int rktio_udp_set_ttl(rktio_t *rktio, rktio_fd_t *rfd, int ttl_val)
 {
   rktio_socket_t s = rktio_fd_socket(rktio, rfd);
-  u_char ttl = ttl_val;
+  int ttl = ttl_val;
   rktio_sockopt_len_t ttl_len = sizeof(ttl);
   int status;