From c9ba348e1a7fa99a0b41a0e53f251309f2768187 Mon Sep 17 00:00:00 2001
From: Giuseppe Foti <foti.giuseppe@gmail.com>
Date: Mon, 31 Jul 2023 11:23:22 +0200
Subject: [PATCH] Fix: automagic dependency on netsnmp that is not required.
 (#1463)

When building openvas-scanner Cmake searches for SNMP and links to it but the dependency is not defined as required:
https://github.com/greenbone/openvas-scanner/blob/d1b7268a05eb81b5deab0febe7ac472a730815c0/nasl/CMakeLists.txt#L73-L80)

In source-based distributions (like gentoo) this can create an issue on system update.
Reading here you can have a more detailed description of the issue:
https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Automagic_dependencies#Why_automagic_dependencies_are_wrong

Please add a BUILD_WITH_NETSNMP variable in openvas-scanner/CMakeLists.txt and openvas-scanner/nasl/CMakeLists.txt as suggested here:
https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Automagic_dependencies#CMake
---
 CMakeLists.txt      |  4 ++++
 nasl/CMakeLists.txt | 18 +++++++++++-------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1389e9b75..9bc95ff57 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -145,6 +145,10 @@ if (NOT OPENVAS_RUN_DIR)
   set (OPENVAS_RUN_DIR "/run/ospd")
 endif (NOT OPENVAS_RUN_DIR)
 
+if (NOT BUILD_WITH_NETSNMP)
+  set (BUILD_WITH_NETSNMP TRUE)
+endif (NOT BUILD_WITH_NETSNMP)
+
 set (OPENVAS_DATA_DIR    "${DATADIR}/openvas")
 set (OPENVAS_STATE_DIR   "${LOCALSTATEDIR}/lib/openvas")
 
diff --git a/nasl/CMakeLists.txt b/nasl/CMakeLists.txt
index fa51196fe..975154ae9 100644
--- a/nasl/CMakeLists.txt
+++ b/nasl/CMakeLists.txt
@@ -70,14 +70,18 @@ if (NOT GPGME_FOUND)
     OUTPUT_STRIP_TRAILING_WHITESPACE)
 endif (NOT GPGME_FOUND)
 
-message (STATUS "Looking for netsnmp...")
-find_library (SNMP netsnmp)
-message (STATUS "Looking for netsnmp... ${SNMP}")
-if (SNMP)
+if (BUILD_WITH_NETSNMP)
+  message (STATUS "Looking for netsnmp...")
+  find_library (NETSNMP netsnmp)
+  message (STATUS "Looking for netsnmp... ${NETSNMP}")
+else (BUILD_WITH_NETSNMP)
+  message (STATUS "Netsnmp support disabled")
+endif (BUILD_WITH_NETSNMP)
+if (NETSNMP)
   execute_process (COMMAND net-snmp-config --libs
     OUTPUT_VARIABLE SNMP_LDFLAGS
     OUTPUT_STRIP_TRAILING_WHITESPACE)
-endif (SNMP)
+endif (NETSNMP)
 
 message (STATUS "Looking for libgcrypt...")
 find_library (GCRYPT gcrypt)
@@ -103,9 +107,9 @@ endif (NOT GCRYPT)
 
 
 ## Library
-if (SNMP)
+if (NETSNMP)
   add_definitions (-DHAVE_NETSNMP)
-endif (SNMP)
+endif (NETSNMP)
 
 
 # The "-fno-strict-aliasing" silences warnings caused by macros defined in byteorder.h.