dco_linux: Fix -Wconversion warnings

Combination of using the correct types and some
unavoidable safe size_t->int casts.

Change-Id: I473d345d10fc406f76fbdb131c28cc4fc54822fd
Signed-off-by: Frank Lichtenheld <[email protected]>
Acked-by: Antonio Quartulli <[email protected]>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1220
Message-Id: <[email protected]>
URL: https://sourceforge.net/p/openvpn/mailman/message/59239172/
Signed-off-by: Gert Doering <[email protected]>

Author: flichtenheld

src/openvpn/dco_linux.c

@@ -62,11 +62,6 @@ void dco_check_key_ctx(const struct key_ctx_bi *key);
 
 typedef int (*ovpn_nl_cb)(struct nl_msg *msg, void *arg);
 
-#if defined(__GNUC__) || defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wconversion"
-#endif
-
 /**
  * @brief resolves the netlink ID for ovpn-dco
  *
@@ -110,7 +105,7 @@ resolve_ovpn_netlink_id(msglvl_t msglevel)
 }
 
 static struct nl_msg *
-ovpn_dco_nlmsg_create(dco_context_t *dco, int cmd)
+ovpn_dco_nlmsg_create(dco_context_t *dco, uint8_t cmd)
 {
     struct nl_msg *nl_msg = nlmsg_alloc();
     if (!nl_msg)
@@ -346,7 +341,7 @@ ovpn_nl_cb_error(struct sockaddr_nl(*nla) __attribute__((unused)), struct nlmsge
 
     if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
     {
-        ack_len += err->msg.nlmsg_len - sizeof(*nlh);
+        ack_len += err->msg.nlmsg_len - (int)sizeof(*nlh);
     }
 
     if (len <= ack_len)
@@ -360,8 +355,8 @@ ovpn_nl_cb_error(struct sockaddr_nl(*nla) __attribute__((unused)), struct nlmsge
     nla_parse(tb_msg, OVPN_NLMSGERR_ATTR_MAX, attrs, len, NULL);
     if (tb_msg[NLMSGERR_ATTR_MSG])
     {
-        len = strnlen((char *)nla_data(tb_msg[NLMSGERR_ATTR_MSG]),
-                      nla_len(tb_msg[NLMSGERR_ATTR_MSG]));
+        len = (int)strnlen((char *)nla_data(tb_msg[NLMSGERR_ATTR_MSG]),
+                           nla_len(tb_msg[NLMSGERR_ATTR_MSG]));
         msg(M_WARN, "kernel error: %*s", len, (char *)nla_data(tb_msg[NLMSGERR_ATTR_MSG]));
     }
 
@@ -606,7 +601,7 @@ dco_new_key(dco_context_t *dco, unsigned int peerid, int keyid, dco_key_slot_t s
     msg(D_DCO_DEBUG, "%s: slot %d, key-id %d, peer-id %d, cipher %s", __func__, slot, keyid, peerid,
         ciphername);
 
-    const size_t key_len = cipher_kt_key_size(ciphername);
+    const int key_len = cipher_kt_key_size(ciphername);
     const int nonce_tail_len = 8;
 
     struct nl_msg *nl_msg = ovpn_dco_nlmsg_create(dco, OVPN_CMD_KEY_NEW);
@@ -1303,8 +1298,4 @@ dco_get_supported_ciphers(void)
     return "AES-128-GCM:AES-256-GCM:AES-192-GCM:CHACHA20-POLY1305";
 }
 
-#if defined(__GNUC__) || defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
-
 #endif /* defined(ENABLE_DCO) && defined(TARGET_LINUX) */