options.c: fix broken unary minus usage

In Visual Studio when unary minus is applied to unsigned,
result is still unsigned. This means that when we use result
as function formal parameter, we pass incorrect value.

Fix by introducing frame_remove_from_extra_frame(),
which makes code semantically more clear and eliminates
the need in negative value and cast.

Since GCC didn't complain (and users too :), it probably performed
cast to signed automatically.

Signed-off-by: Lev Stipakov <lev@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1539258702-15427-1-git-send-email-lstipakov@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg17739.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index e81399b7c532ed02f0b0c261c2f2f4edc7845f65..e9bf22b001474e8dc6afdd492fe5d1fe296ae378 100644 (file)
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -700,7 +700,7 @@ crypto_adjust_frame_parameters(struct frame *frame,
                                bool packet_id,
                                bool packet_id_long_form)
 {
-    size_t crypto_overhead = 0;
+    unsigned int crypto_overhead = 0;
 
     if (packet_id)
     {
@@ -725,10 +725,10 @@ crypto_adjust_frame_parameters(struct frame *frame,
     frame_add_to_extra_frame(frame, crypto_overhead);
 
     msg(D_MTU_DEBUG, "%s: Adjusting frame parameters for crypto by %u bytes",
-        __func__, (unsigned int) crypto_overhead);
+        __func__, crypto_overhead);
 }
 
-size_t
+unsigned int
 crypto_max_overhead(void)
 {
     return packet_id_size(true) + OPENVPN_MAX_IV_LENGTH

diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 795643c54b74b3790fce15cf39d998fff7b378a9..96ba8586832b719d68f27d04aa7011568517f995 100644 (file)
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -418,7 +418,7 @@ void crypto_adjust_frame_parameters(struct frame *frame,
                                     bool packet_id_long_form);
 
 /** Return the worst-case OpenVPN crypto overhead (in bytes) */
-size_t crypto_max_overhead(void);
+unsigned int crypto_max_overhead(void);
 
 /* Minimum length of the nonce used by the PRNG */
 #define NONCE_SECRET_LEN_MIN 16

diff --git a/src/openvpn/mtu.h b/src/openvpn/mtu.h
index a82154af98012c5ecfb434e67fdd037687afd025..cfa8d2f7df0d5b109a6b7622a8c67015ec44dbb8 100644 (file)
--- a/src/openvpn/mtu.h
+++ b/src/openvpn/mtu.h
@@ -271,11 +271,17 @@ frame_add_to_link_mtu(struct frame *frame, const int increment)
 }
 
 static inline void
-frame_add_to_extra_frame(struct frame *frame, const int increment)
+frame_add_to_extra_frame(struct frame *frame, const unsigned int increment)
 {
     frame->extra_frame += increment;
 }
 
+static inline void
+frame_remove_from_extra_frame(struct frame *frame, const unsigned int decrement)
+{
+    frame->extra_frame -= decrement;
+}
+
 static inline void
 frame_add_to_extra_tun(struct frame *frame, const int increment)
 {

diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index b65a456fe3621711c3117e0f147827f1ad30e4ac..0421185f98352a7026cb1d356bcd2b9d2b948340 100644 (file)
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -3511,7 +3511,7 @@ calc_options_string_link_mtu(const struct options *o, const struct frame *frame)
         struct key_type fake_kt;
         init_key_type(&fake_kt, o->ciphername, o->authname, o->keysize, true,
                       false);
-        frame_add_to_extra_frame(&fake_frame, -(crypto_max_overhead()));
+        frame_remove_from_extra_frame(&fake_frame, crypto_max_overhead());
         crypto_adjust_frame_parameters(&fake_frame, &fake_kt, o->replay,
                                        cipher_kt_mode_ofb_cfb(fake_kt.cipher));
         frame_finalize(&fake_frame, o->ce.link_mtu_defined, o->ce.link_mtu,

diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
index 42261bdfb81e820792d5652b6634604b38746b5a..4ec85f501748e95e2e3feec45dbe358aca106a66 100644 (file)
--- a/src/openvpn/ssl.c
+++ b/src/openvpn/ssl.c
@@ -1984,7 +1984,7 @@ tls_session_update_crypto_params(struct tls_session *session,
     }
 
     /* Update frame parameters: undo worst-case overhead, add actual overhead */
-    frame_add_to_extra_frame(frame, -(crypto_max_overhead()));
+    frame_remove_from_extra_frame(frame, crypto_max_overhead());
     crypto_adjust_frame_parameters(frame, &session->opt->key_type,
                                    options->replay, packet_id_long_form);
     frame_finalize(frame, options->ce.link_mtu_defined, options->ce.link_mtu,