#2697 Cannot configure with DTLS Transport

[Jean-christophe Manciot]

Hello,
On Ubuntu 4.2.0-27-generic #32-Ubuntu SMP Fri Jan 22 04:49:08 UTC 2016 x86_64 GNU/Linux, I'm trying to configure stable 5.7.3 with the following options:
./configure --enable-ipv6 \ --with-transports="UDPIPv6 TCPIPv6 DTLSUDP TLSTCP" \ --with-security-modules="usm ksm tsm" \ --with-mib-modules="ucd-snmp/lmSensors ip-mib/ipv4InterfaceTable ip-mib/ipv6InterfaceTable tunnel misc/ipfwacc ipfwchains/ipfwchains" \ --with-python-modules \
--with-openssl=/usr/local/ssl \ --prefix=/usr --sysconfdir=/etc --localstatedir=/var

The script complains with the following:
checking for DTLSv1_method in -lssl... no
configure: error: The DTLS based transports require the libssl library from OpenSSL to be available and support DTLS

Actually, DTLS is present by default in openssl.

There is also another error:
./build-net-snmp-stable.sh: line 19: --with-openssl=/usr/local/ssl: No such file or directory
whereas:
root@samsung-ubuntu:/usr/local/ssl# ll
total 48
drwxr-xr-x 9 root root 4096 Feb 23 14:44 ./
drwxr-xr-x 12 root root 4096 Jan 3 11:55 ../
drwxr-xr-x 2 root root 4096 Feb 23 14:44 bin/
drwxr-xr-x 2 root root 4096 May 5 2015 certs/
drwxr-xr-x 3 root root 4096 May 5 2015 include/
drwxr-xr-x 4 root root 4096 Feb 23 14:44 lib/
drwxr-xr-x 6 root root 4096 May 5 2015 man/
drwxr-xr-x 2 root root 4096 Feb 23 14:44 misc/
-rw-r--r-- 1 root root 10835 Feb 23 14:43 openssl.cnf
drwxr-xr-x 2 root root 4096 May 5 2015 private/

Something is badly broken in your configure.

[Niels Baggesen]

./build-net-snmp-stable.sh: line 19: --with-openssl=/usr/local/ssl: No such file or directory

you seem to have bug in your script ...

What version of OpenSSL do you have in /usr/local/lib?

[Jean-christophe Manciot]

I have found the ssl issue: it is in the ssl comment that comes with "configure --help":

--with-openssl=PATH             Look for openssl in **PATH/lib**,

should have been displayed as:

--with-openssl=PATH             Look for openssl **lib in PATH**,

because the following configure openssl option passes:

    ./configure     --prefix=/usr --sysconfdir=/etc --localstatedir=/var \
            **--with-openssl=/usr/local/ssl/lib** \
            --with-systemd \
            --enable-ipv6 \
            --with-transports="UDP UDPIPv6 TCP TCPIPv6 TLSTCP" \
            --with-security-modules="usm ksm tsm" \
            --with-mib-modules="ip-mib/ipv4InterfaceTable ip-mib/ipv6InterfaceTable tunnel misc/ipfwacc agentx" \
            --with-python-modules 

[Jean-christophe Manciot]

However, there is still an issue with DTLS and even TLS:
The previous configure options lead to:

---------------------------------------------------------
            Net-SNMP configuration summary:
---------------------------------------------------------

  SNMP Versions Supported:    1 2c 3
  Building for:               linux
  Net-SNMP Version:           5.7.3
  Network transport support:  Callback Unix Alias TCP UDP TCPIPv6 UDPIPv6 IPv4Base SocketBase TCPBase UDPIPv4Base UDPBase IPv6Base
  SNMPv3 Security Modules:     usm
  Agent MIB code:            default_modules =>  snmpv3mibs mibII ucd_snmp notification notification-log-mib target agent_mibs agentx disman/event disman/schedule utilities host
  MYSQL Trap Logging:         unavailable
  Embedded Perl support:      disabled
  SNMP Perl modules:          building -- not embeddable
  SNMP Python modules:        disabled
  Crypto support from:        crypto
  Authentication support:     MD5 SHA1
  Encryption support:         DES AES
  Local DNSSEC validation:    disabled

---------------------------------------------------------

**./build-net-snmp-stable.sh: line 18: --with-transports=UDP UDPIPv6 TCP TCPIPv6 DTLSUDP TLSTCP: command not found**
./build-net-snmp-stable.sh: line 21: --with-python-modules: command not found

Where is the issue this time?

[Bill Fenner]

Can you upload your build-net-snmp-stable.sh? These errors that you are seeing from the shell while parsing your script sound like the script itself is what is causing you trouble (e.g., missing backslashes?)

[Jean-christophe Manciot]

OK, after removing some comments within the list of options which confuses configure, here's the issue:

configure: error: Cannot find file ./snmplib/transports/snmpDTLSDomain.c to support SNMP transport domain DTLS.

The filename is different:

-rw-r--r-- 1 root root 63591 Dec  8  2014 snmpDTLSUDPDomain.c

This means I'm the first one to compile with the option DTLSUDP in 1 year & a half...

[Niels Baggesen]

You are surely not the first to do this. I do it, if not daily then at least weekly, for several Linux and BSD distributions and several branches of net-snmp.