netsnmp: fix static build failure due to missing -lssl and -lz

During configure some checking needing -lssl and -lz don't have them
appended to linker tail. Since we are building static this leads to
configure failure because of mandatory functions lack produces:
"configure: error: The DTLS based transports require the libssl library
from OpenSSL to be available and support DTLS"

- Add 1 patch to fix -lssl lack in configure and .ac modules:
upstreamed: https://sourceforge.net/p/net-snmp/code/ci/bd59be8e4e339870a1400f6866a7b73ca11f6460/
- Add 2 patches to fix -lz lack in configure and .ac modules:
1 upstreamed: https://sourceforge.net/p/net-snmp/code/ci/13da2bcde8e22dd0127a668374fdf79bed04d353/
1 in Merge Request: https://sourceforge.net/p/net-snmp/code/merge-requests/19/
- Add NETSNMP_AUTORECONF = YES

Fixes:
http://autobuild.buildroot.net/results/ece/ece7af756c910f65f618c1d04a5de70cc574b5f4/
http://autobuild.buildroot.net/results/2a7/2a7020de6a4095cf9991d09fbe8f6e364783f63b/
http://autobuild.buildroot.net/results/e27/e2787d15f72949cbb347e8a1d344f5f80b4d7697/
http://autobuild.buildroot.net/results/439/4393ce8ddee294f91bdc3e6fb53e08d56fe52184/
http://autobuild.buildroot.net/results/da6/da6bbbbb3a8d8193ec1389b9d976164181e88ae2/
http://autobuild.buildroot.net/results/cf5/cf57686e7620cc0ec361631a9ff906aa0123fdb4/
http://autobuild.buildroot.net/results/104/1043a958314529240627005d1bf21a76f4e6fcf5/
http://autobuild.buildroot.net/results/885/8855545bd09388e0da451a3cb53b312e13b29c2c/
http://autobuild.buildroot.net/results/a3d/a3dab9618a7ed88f94597418a5892c87adc23c66/
http://autobuild.buildroot.net/results/18e/18e70b88c9bcb3b8ede7308e54bba9417d1fd3fb/
http://autobuild.buildroot.net/results/ee3/ee34f65f26da20c0f2fdb9e86bcbddd389f59a29/
http://autobuild.buildroot.net/results/a1e/a1eb848079080ddf7cf2fc9e554cdd63ade0e9aa/
http://autobuild.buildroot.net/results/4dc/4dc8b53ff9f504c0a3dfc2d72c2609ad4d34559b/
http://autobuild.buildroot.net/results/9cc/9cc19e481de20ea0b4b5163e45c5aee525b81229/
http://autobuild.buildroot.net/results/f15/f15c22e0257d7498456049d8aae195ed6a265d2e/
http://autobuild.buildroot.net/results/1b3/1b30f9813a4605056963bfe4532374f725830fda/
http://autobuild.buildroot.net/results/d02/d02afc174ac4c9888f0a2cf725820cc1f05fc4bf/
http://autobuild.buildroot.net/results/57b/57b3f4663058d728987ef848e4b346656cae21d4/
http://autobuild.buildroot.net/results/ed4/ed4c27bdffccc4374ab7f951c30baba8171d30e1/

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

1 files changed, 142 insertions, 0 deletions

diff --git a/package/netsnmp/0001-configure-static-linking-Fix-SSL-checks.patch b/package/netsnmp/0001-configure-static-linking-Fix-SSL-checks.patch
new file mode 100644
index 0000000000..8431d46868
--- /dev/null
+++ b/package/netsnmp/0001-configure-static-linking-Fix-SSL-checks.patch
@@ -0,0 +1,142 @@
+From bd59be8e4e339870a1400f6866a7b73ca11f6460 Mon Sep 17 00:00:00 2001
+From: Giulio Benetti <giulio.benetti@micronovasrl.com>
+Date: Wed, 12 Sep 2018 20:16:39 +0200
+Subject: [PATCH 1/3] configure, static linking: Fix SSL checks
+
+During checking of DTLS_method, the stub program is linked only with -ssl
+libssl.a lacks some function from -lcrypto:
+RAND_*()
+ERR_*()
+BUF_MEM_*()
+etc.
+and -lz:
+- inflate()
+- deflate()
+
+Append -lcrypto and -lz to LIBS variable when checking DTLS_method.
+
+See also https://sourceforge.net/p/net-snmp/patches/1374/.
+
+Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
+[bvanassche: Edited subject / rewrote this patch]
+---
+ configure                   | 52 ++++++++++++++++++++++++++++++++++---
+ configure.d/config_os_libs2 | 14 +++++++---
+ 2 files changed, 58 insertions(+), 8 deletions(-)
+
+diff --git a/configure b/configure
+index 6504a8e58..1116cecaa 100755
+--- a/configure
++++ b/configure
+@@ -23228,16 +23228,60 @@ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_crypto_EVP_md5" >&5
+ $as_echo "$ac_cv_lib_crypto_EVP_md5" >&6; }
+ if test "x$ac_cv_lib_crypto_EVP_md5" = xyes; then :
+-  CRYPTO="crypto"
++  CRYPTO="crypto"; LIBCRYPTO="-lcrypto"
++else
++
++		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for EVP_md5 in -lcrypto" >&5
++$as_echo_n "checking for EVP_md5 in -lcrypto... " >&6; }
++if ${ac_cv_lib_crypto_EVP_md5+:} false; then :
++  $as_echo_n "(cached) " >&6
++else
++  ac_check_lib_save_LIBS=$LIBS
++LIBS="-lcrypto -lz $LIBS"
++cat confdefs.h - <<_ACEOF >conftest.$ac_ext
++/* end confdefs.h.  */
++
++/* Override any GCC internal prototype to avoid an error.
++   Use char because int might match the return type of a GCC
++   builtin and then its argument prototype would still apply.  */
++#ifdef __cplusplus
++extern "C"
++#endif
++char EVP_md5 ();
++int
++main ()
++{
++return EVP_md5 ();
++  ;
++  return 0;
++}
++_ACEOF
++if ac_fn_c_try_link "$LINENO"; then :
++  ac_cv_lib_crypto_EVP_md5=yes
++else
++  ac_cv_lib_crypto_EVP_md5=no
++fi
++rm -f core conftest.err conftest.$ac_objext \
++    conftest$ac_exeext conftest.$ac_ext
++LIBS=$ac_check_lib_save_LIBS
++fi
++{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_crypto_EVP_md5" >&5
++$as_echo "$ac_cv_lib_crypto_EVP_md5" >&6; }
++if test "x$ac_cv_lib_crypto_EVP_md5" = xyes; then :
++  CRYPTO="crypto"; LIBCRYPTO="-lcrypto -lz"
+ fi
+ 
+-        fi
++
++fi
++
++	else
++	    LIBCRYPTO="-l${CRYPTO}"
++	fi
+ 
+         if test x$CRYPTO != x; then
+ 
+ $as_echo "#define HAVE_LIBCRYPTO 1" >>confdefs.h
+ 
+-            LIBCRYPTO="-l${CRYPTO}"
+             netsnmp_save_LIBS="$LIBS"
+             LIBS="$LIBCRYPTO"
+             for ac_func in AES_cfb128_encrypt                           EVP_sha224        EVP_sha384                                   EVP_MD_CTX_create EVP_MD_CTX_destroy                           EVP_MD_CTX_new    EVP_MD_CTX_free                              DH_set0_pqg DH_get0_pqg DH_get0_key                           ASN1_STRING_get0_data X509_NAME_ENTRY_get_object                           X509_NAME_ENTRY_get_data X509_get_signature_nid
+@@ -23291,7 +23335,7 @@ _ACEOF
+             LIBS="$netsnmp_save_LIBS"
+         fi
+         netsnmp_save_LIBS="$LIBS"
+-        LIBS="-lssl"
++        LIBS="-lssl $LIBCRYPTO"
+         for ac_func in TLS_method TLSv1_method DTLS_method DTLSv1_method                       SSL_library_init SSL_load_error_strings
+ do :
+   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+diff --git a/configure.d/config_os_libs2 b/configure.d/config_os_libs2
+index 4a1ad1551..75214cfff 100644
+--- a/configure.d/config_os_libs2
++++ b/configure.d/config_os_libs2
+@@ -306,13 +306,19 @@ if test "x$tryopenssl" != "xno" -a "x$tryopenssl" != "xinternal"; then
+         LIBS="$netsnmp_save_LIBS"
+ 
+         if test x$CRYPTO = x; then
+-            AC_CHECK_LIB([crypto], [EVP_md5], [CRYPTO="crypto"])
+-        fi
++            AC_CHECK_LIB([crypto], [EVP_md5],
++			 [CRYPTO="crypto"; LIBCRYPTO="-lcrypto"], [
++		AC_CHECK_LIB([crypto], [EVP_md5],
++			     [CRYPTO="crypto"; LIBCRYPTO="-lcrypto -lz"], [],
++			     [-lz])
++	    ])
++	else
++	    LIBCRYPTO="-l${CRYPTO}"
++	fi
+ 
+         if test x$CRYPTO != x; then
+             AC_DEFINE(HAVE_LIBCRYPTO, 1,
+                 [Define to 1 if you have the OpenSSL library (-lcrypto or -leay32).])
+-            LIBCRYPTO="-l${CRYPTO}"
+             netsnmp_save_LIBS="$LIBS"
+             LIBS="$LIBCRYPTO"
+             AC_CHECK_FUNCS([AES_cfb128_encrypt]dnl
+@@ -342,7 +348,7 @@ if test "x$tryopenssl" != "xno" -a "x$tryopenssl" != "xinternal"; then
+             LIBS="$netsnmp_save_LIBS"
+         fi
+         netsnmp_save_LIBS="$LIBS"
+-        LIBS="-lssl"
++        LIBS="-lssl $LIBCRYPTO"
+         AC_CHECK_FUNCS([TLS_method TLSv1_method DTLS_method DTLSv1_method]dnl
+                        [SSL_library_init SSL_load_error_strings])
+         LIBS="$netsnmp_save_LIBS"
+-- 
+2.17.1
+