doh: added HTTP library to configuration file (automake)

README.md

@@ -25,7 +25,7 @@ sudo apt-get install \
 #### Install optional packages:
 ```bash
 sudo apt-get install \
-  libcap-ng-dev libsystemd-dev libidn2-0-dev protobuf-c-compiler libfstrm-dev libmaxminddb-dev
+  libcap-ng-dev libsystemd-dev libidn2-0-dev protobuf-c-compiler libfstrm-dev libmaxminddb-dev libnghttp2-dev
 ```
 
 ### Fedora like distributions
@@ -49,7 +49,7 @@ dnf install \
 #### Install optional packages:
 ```bash
 dnf install \
-  libcap-ng-devel systemd-devel libidn2-devel protobuf-c-devel fstrm-devel libmaxminddb-devel
+  libcap-ng-devel systemd-devel libidn2-devel protobuf-c-devel fstrm-devel libmaxminddb-devel libnghttp2-devel
 ```
 
 When compiling on RHEL based system, the Fedora EPEL repository has to be

configure.ac

@@ -535,6 +535,13 @@ AC_ARG_WITH(libidn,
   with_libidn=yes
 )
 
+dnl Check for libnghttp2.
+AC_ARG_WITH(libnghttp2,
+  AC_HELP_STRING([--with-libnghttp2=[DIR]], [Support DoH (needs libnghttp2)]),
+  with_libnghttp2=$withval,
+  with_libnghttp2=yes
+)
+
 AS_IF([test "$enable_utilities" = "yes"], [
   AS_IF([test "$with_libidn" != "no"], [
     PKG_CHECK_MODULES([libidn2], [libidn2 >= 2.0.0], [
@@ -552,6 +559,16 @@ AS_IF([test "$enable_utilities" = "yes"], [
       ])
     ])
   ])
+
+  AS_IF([test "$with_libnghttp2" != "no"], [
+    PKG_CHECK_MODULES([libnghttp2], [libnghttp2], [
+      with_libnghttp2=libnghttp2
+      AC_DEFINE([LIBNGHTTP2], [1], [Define to 1 to enable DoH support])
+    ], [
+      with_libnghttp2=no
+      AC_MSG_WARN([libnghttp2 not found])
+    ])
+  ])
 ]) # Knot DNS utilities dependencies
 
 AC_ARG_ENABLE([cap-ng],
@@ -726,6 +743,7 @@ result_msg_base="  Knot DNS $VERSION
     Memory allocator:       ${with_memory_allocator}
     Fast zone parser:       ${enable_fastparser}
     Utilities with IDN:     ${with_libidn}
+    Utilities with DoH:     ${with_libnghttp2}
     Utilities with Dnstap:  ${enable_dnstap}
     MaxMind DB support:     ${enable_maxminddb}
     Systemd integration:    ${enable_systemd}

src/utils/Makefile.inc

@@ -5,10 +5,11 @@ if HAVE_LIBUTILS
 noinst_LTLIBRARIES += libknotus.la
 
 libknotus_la_CPPFLAGS = $(AM_CPPFLAGS) $(CFLAG_VISIBILITY) $(libidn2_CFLAGS) \
-                        $(libidn_CFLAGS) $(libedit_CFLAGS) $(gnutls_CFLAGS)
+                        $(libidn_CFLAGS) $(libedit_CFLAGS) $(libnghttp2_CFLAGS) \
+                        $(gnutls_CFLAGS)
 libknotus_la_LDFLAGS  = $(AM_LDFLAGS) $(LDFLAG_EXCLUDE_LIBS)
 libknotus_la_LIBADD   = libcontrib.la libknot.la $(libidn2_LIBS) $(libidn_LIBS) \
-                        $(libedit_LIBS) $(gnutls_LIBS)
+                        $(libedit_LIBS) $(libnghttp2_LIBS) $(gnutls_LIBS)
 
 libknotus_la_SOURCES = \
 	utils/common/cert.c			\