From 77c500a0e28550a58cba618b7b69da6b6eabdce3 Mon Sep 17 00:00:00 2001
From: Tobias Schramm <t.schramm@t-sys.eu>
Date: Fri, 5 Feb 2021 16:14:42 +0100
Subject: [PATCH] Remove libmath dependency

Can be replaced by a few simple bitshifts
---
 Makefile | 1 -
 block.c  | 1 -
 main.c   | 5 +++--
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 74c32a9..2121302 100644
--- a/Makefile
+++ b/Makefile
@@ -37,7 +37,6 @@ CXXFLAGS+= \
 
 LFLAGS+= \
     -flto \
-    -lm \
     `pkg-config --libs libnl-3.0`
 
 ifeq ($(DEBUG),1)
diff --git a/block.c b/block.c
index 808b539..1b2d225 100644
--- a/block.c
+++ b/block.c
@@ -1,7 +1,6 @@
 #include "block.h"
 
 #include <errno.h>
-#include <math.h>
 
 #include "dhcp.h"
 #include "logger.h"
diff --git a/main.c b/main.c
index 9cb07a5..a3061c4 100644
--- a/main.c
+++ b/main.c
@@ -1,7 +1,6 @@
 #include <arpa/inet.h>
 #include <assert.h>
 #include <getopt.h>
-#include <math.h>
 #include <netinet/in.h>
 #include <sys/un.h>
 #include <sys/types.h>
@@ -408,7 +407,8 @@ int main(int argc, char** argv) {
     LOG("WARNING: Requested verbosity is higher than maximum supported by this build\n");
   }
 
-  config.number_of_blocks = (uint32_t)pow(2u, (32u - config.prefix_len - ceil(log2(config.block_size))));
+  unsigned long number_of_addresses = 1ul << (32 - config.prefix_len);
+  config.number_of_blocks = (uint32_t)number_of_addresses / config.block_size;
 
   if (config.disable_dhcp) {
     config.spare_leases_needed = 0;
@@ -423,6 +423,7 @@ int main(int argc, char** argv) {
   INFO("CONFIG: tentative_timeout=%i\n", config.tentative_timeout);
   INFO("CONFIG: client_interface=%s\n", interface_client);
   INFO("CONFIG: group_interface=%s\n", interface);
+  INFO("CONFIG: number_of_blocks=%lu\n", config.number_of_blocks);
 
   //Register signal handlers
   handle_signal(SIGHUP, SIG_IGN);