Define macros to calculate (2^N)^M, and use them in more places.

Change-Id: I4df1b35d8d2233c301f0ba9e119d012aebe9cd17
Reviewed-on: https://code.wireshark.org/review/25913
Reviewed-by: Guy Harris <guy@alum.mit.edu>

7 files changed, 51 insertions, 17 deletions

diff --git a/epan/dissectors/packet-icmpv6.c b/epan/dissectors/packet-icmpv6.c
index b4d570e13f..56633a6ee3 100644
--- a/epan/dissectors/packet-icmpv6.c
+++ b/epan/dissectors/packet-icmpv6.c
@@ -34,6 +34,8 @@
 #include <epan/proto_data.h>
 #include <epan/strutil.h>
 
+#include <wsutil/pow2.h>
+
 #include "packet-ber.h"
 #include "packet-dns.h"
 #include "packet-x509af.h"
@@ -2995,7 +2997,7 @@ dissect_icmpv6_rpl_opt(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree
                             }
                         }
 
-                        proto_item_append_text(ti_opt_lifetime, " (%u sec)", 1U << ((lt_mr_nh & RPL_OPT_ROUTE_DISCOVERY_L) >> 6)*2);
+                        proto_item_append_text(ti_opt_lifetime, " (%u sec)", pow4(guint32, (lt_mr_nh & RPL_OPT_ROUTE_DISCOVERY_L) >> 6));
 
                         if (!(lt_mr_nh & RPL_OPT_ROUTE_DISCOVERY_MR_NH)) {
                             proto_item_append_text(ti_opt_mr_nh, " (Infinity)");
diff --git a/epan/dissectors/packet-iso14443.c b/epan/dissectors/packet-iso14443.c
index 76050832c9..4e2b3e5536 100644
--- a/epan/dissectors/packet-iso14443.c
+++ b/epan/dissectors/packet-iso14443.c
@@ -25,15 +25,16 @@
 
 
 #include "config.h"
-#include <math.h>
 #include <epan/packet.h>
 #include <epan/expert.h>
 #include <epan/conversation.h>
 #include <epan/tfs.h>
 #include <epan/reassemble.h>
-#include <wiretap/wtap.h>
 #include <epan/crc16-tvb.h>
 
+#include <wiretap/wtap.h>
+
+#include <wsutil/pow2.h>
 
 /* Proximity Integrated Circuit Card, i.e. the smartcard */
 #define ADDR_PICC "PICC"
@@ -541,8 +542,8 @@ dissect_iso14443_cmd_type_wupb(tvbuff_t *tvb, packet_info *pinfo,
         col_set_str(pinfo->cinfo, COL_INFO, msg_type);
         proto_item_append_text(ti, ": %s", msg_type);
         proto_tree_add_uint_bits_format_value(tree, hf_iso14443_n,
-                tvb, offset*8+5, 3, (guint8)pow(2, param&0x07),
-                "%d", (guint8)pow(2, param&0x07));
+                tvb, offset*8+5, 3, pow2(guint32, param&0x07),
+                "%u", pow2(guint32, param&0x07));
         offset++;
 
         if (!crc_dropped) {
diff --git a/epan/dissectors/packet-nas_eps.c b/epan/dissectors/packet-nas_eps.c
index 980779a421..63018053d4 100644
--- a/epan/dissectors/packet-nas_eps.c
+++ b/epan/dissectors/packet-nas_eps.c
@@ -14,13 +14,13 @@
 
 #include "config.h"
 
-#include <math.h>
 #include <epan/packet.h>
 #include <epan/asn1.h>
 #include <epan/prefs.h>
 #include <epan/expert.h>
 #include <epan/exceptions.h>
 #include <epan/show_exception.h>
+#include <wsutil/pow2.h>
 #include "packet-gsm_map.h"
 #include "packet-gsm_a_common.h"
 #include "packet-e212.h"
@@ -3538,16 +3538,16 @@ get_ext_ambr_unit(guint32 byte, const char **unit_str)
         mult = 0;
         *unit_str = "";
     } else if (byte <= 0x06) {
-        mult = (guint32)pow(4, byte-0x02);
+        mult = pow4(guint32, byte-0x02);
         *unit_str = "Mbps";
     } else if (byte <= 0x0b) {
-        mult = (guint32)pow(4, byte-0x07);
+        mult = pow4(guint32, byte-0x07);
         *unit_str = "Gbps";
     } else if (byte <= 0x10) {
-        mult = (guint32)pow(4, byte-0x0c);
+        mult = pow4(guint32, byte-0x0c);
         *unit_str = "Tbps";
     } else if (byte <= 0x15) {
-        mult = (guint32)pow(4, byte-0x11);
+        mult = pow4(guint32, byte-0x11);
         *unit_str = "Pbps";
     } else {
         mult = 256;
@@ -3622,16 +3622,16 @@ get_ext_eps_qos_unit(guint32 byte, const char **unit_str)
         mult = 200;
         *unit_str = "kbps";
     } else if (byte <= 0x06) {
-        mult = (guint32)pow(4, byte-0x02);
+        mult = pow4(guint32, byte-0x02);
         *unit_str = "Mbps";
     } else if (byte <= 0x0b) {
-        mult = (guint32)pow(4, byte-0x07);
+        mult = pow4(guint32, byte-0x07);
         *unit_str = "Gbps";
     } else if (byte <= 0x10) {
-        mult = (guint32)pow(4, byte-0x0c);
+        mult = pow4(guint32, byte-0x0c);
         *unit_str = "Tbps";
     } else if (byte <= 0x15) {
-        mult = (guint32)pow(4, byte-0x11);
+        mult = pow4(guint32, byte-0x11);
         *unit_str = "Pbps";
     } else {
         mult = 256;
diff --git a/epan/dissectors/packet-sigcomp.c b/epan/dissectors/packet-sigcomp.c
index 5c9f1adf18..cbd3eaf626 100644
--- a/epan/dissectors/packet-sigcomp.c
+++ b/epan/dissectors/packet-sigcomp.c
@@ -18,7 +18,6 @@
 
 #include "config.h"
 
-#include <math.h>
 #include <epan/packet.h>
 #include <epan/prefs.h>
 #include <epan/expert.h>
@@ -28,6 +27,7 @@
 
 #include <wsutil/wsgcrypt.h>
 #include <wsutil/crc16.h>
+#include <wsutil/pow2.h>
 
 void proto_register_sigcomp(void);
 void proto_reg_handoff_sigcomp(void);
@@ -6340,7 +6340,7 @@ dissect_udvm_multitype_operand(tvbuff_t *udvm_tvb, proto_tree *sigcomp_udvm_tree
                     if ( display_udvm_bytecode )
                         proto_tree_add_uint(sigcomp_udvm_tree, hf_udvm_multitype_bytecode,
                                 udvm_tvb, offset, 1, display_bytecode);
-                    result = (guint32)pow(2,( bytecode & 0x07) + 8);
+                    result = pow2(guint32, (bytecode & 0x07) + 8);
                     operand = result & 0xffff;
                     *start_offset = offset;
                     *value = operand;
@@ -6355,7 +6355,7 @@ dissect_udvm_multitype_operand(tvbuff_t *udvm_tvb, proto_tree *sigcomp_udvm_tree
                         if ( display_udvm_bytecode )
                             proto_tree_add_uint(sigcomp_udvm_tree, hf_udvm_multitype_bytecode,
                                 udvm_tvb, offset, 1, display_bytecode);
-                        result = (guint32)pow(2,( bytecode & 0x01) + 6);
+                        result = pow2(guint32, (bytecode & 0x01) + 6);
                         operand = result & 0xffff;
                         *start_offset = offset;
                         *value = operand;
diff --git a/wsutil/CMakeLists.txt b/wsutil/CMakeLists.txt
index bb75fd4dfd..c8e685e2da 100644
--- a/wsutil/CMakeLists.txt
+++ b/wsutil/CMakeLists.txt
@@ -61,6 +61,7 @@ set(WSUTIL_PUBLIC_HEADERS
 	os_version_info.h
 	pint.h
 	plugins.h
+	pow2.h
 	privileges.h
 	processes.h
 	report_message.h
diff --git a/wsutil/Makefile.am b/wsutil/Makefile.am
index 008a50110d..0ce957f4ce 100644
--- a/wsutil/Makefile.am
+++ b/wsutil/Makefile.am
@@ -68,6 +68,7 @@ WSUTIL_PUBLIC_INCLUDES = \
 	os_version_info.h	\
 	pint.h			\
 	plugins.h		\
+	pow2.h			\
 	privileges.h		\
 	processes.h		\
 	report_message.h	\
diff --git a/wsutil/pow2.h b/wsutil/pow2.h
new file mode 100644
index 0000000000..f72b09133e
--- /dev/null
+++ b/wsutil/pow2.h
@@ -0,0 +1,29 @@
+/* ws_pow2.h
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef __WS_POW2_H__
+#define __WS_POW2_H__
+
+/*
+ * Macros to calculate pow2^M, for various power-of-2 values and positive
+ * integer values of M.  That's (2^N)^M, i.e. 2^(N*M).
+ *
+ * The first argument is the type of the desired result; the second
+ * argument is M.
+ */
+#define pow2(type, m)     (((type)1U) << (m))
+#define pow4(type, m)     (((type)1U) << (2*(m)))
+#define pow8(type, m)     (((type)1U) << (3*(m)))
+#define pow16(type, m)    (((type)1U) << (4*(m)))
+#define pow32(type, m)    (((type)1U) << (5*(m)))
+#define pow64(type, m)    (((type)1U) << (6*(m)))
+#define pow128(type, m)   (((type)1U) << (7*(m)))
+#define pow256(type, m)   (((type)1U) << (8*(m)))
+
+#endif /* __WS_POW2_H__ */