Error: Unable to load auth plugin "/usr/lib/auth-plug.so"

[gallog]

Hi,
I've a problem running your library on a x86 machine:

./mosquitto -c mosquitto.conf1412605004: mosquitto version 1.3.4 (build date 2014-10-06 16:14:36+0200) starting
1412605004: Config loaded from mosquitto.conf.
1412605004: Error: Unable to load auth plugin "/usr/lib/auth-plug.so".

I've succesfully compiled the library without modify your makefile (I've only changed the MOSQUITTO_SRC) and moved to /usr/lib/auth.plugin.so.

I'm using mosquitto 1.3.4 compiled by myself and here is my mosquitto.conf:

autosave_interval 1800
connection_messages true
log_timestamp true
listener 1883
auth_plugin /usr/lib/auth-plug.so
auth_opt_backends mysql
auth_opt_host 127.0.0.1
auth_opt_port 3306
auth_opt_dbname mqtt
auth_opt_user mqttauth
auth_opt_pass mqttauthpassword
auth_opt_userquery SELECT password FROM USERS WHERE id_user = %s
auth_opt_superquery SELECT IFNULL(COUNT(), 0) FROM USERS WHERE id_user = %s AND superuser = 1
auth_opt_superusers S

[jpmens]

You've compiled yourself, so you've probably also made install in Mosquitto. Did you remember to run ldconfig so that your system picks up new libs? Also, check ldd /usr/lib/auth-plug.so to see whether all paths can be resolved.

[gallog]

I've made
sudo make install
sudo ldconfig

ldd output:
ldd /usr/lib/auth-plug.so
linux-gate.so.1 => (0xb777b000)
libmysqlclient.so.18 => /usr/lib/i386-linux-gnu/libmysqlclient.so.18 (0xb743b000)
libcrypto.so.1.0.0 => /lib/i386-linux-gnu/libcrypto.so.1.0.0 (0xb7290000)
libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb70ea000)
libz.so.1 => /lib/i386-linux-gnu/libz.so.1 (0xb70d4000)
libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xb70cf000)
libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb70b4000)
libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xb7088000)
libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0xb7069000)
/lib/ld-linux.so.2 (0xb777c000)

ldd mosquitto
linux-gate.so.1 => (0xb7708000)
libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xb76eb000)
libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xb76bf000)
librt.so.1 => /lib/i386-linux-gnu/librt.so.1 (0xb76b5000)
libssl.so.1.0.0 => /lib/i386-linux-gnu/libssl.so.1.0.0 (0xb765d000)
libcrypto.so.1.0.0 => /lib/i386-linux-gnu/libcrypto.so.1.0.0 (0xb74b2000)
libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb730d000)
/lib/ld-linux.so.2 (0xb7709000)
libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb72f2000)
libz.so.1 => /lib/i386-linux-gnu/libz.so.1 (0xb72db000)

[jpmens]

In Mosquitto's src/security.c, on line 56, can you add this after the call to LIB_LOAD?

if (!lib){
       printf("LOADERROR %s\n", dlerror());

[gallog]

Output:
LOADERROR /usr/lib/auth-plug.so: undefined symbol: ares_library_init

[jpmens]

There you go. :)
Mosquitto requires the cares for DNS SRV records, but you can safely change Mosquitto's config.mk to set WITH_SRV:=no. Then:

make clean
make

[gallog]

Solved, thanks :)
Also need to rebuild you plugin after changing WITH_SRV:=no and recompiling mosquitto.

[jpmens]

Because of the linkage with Mosquitto, yes. Sorry: I forgot to say that. Glad it works now.

[zhangshexin]

Hello, I am using is 1.3.5, I tried in accordance with the above method, but it's still an error like that

[hkverma310]

Access denied for user 'xxxx'@'localhost' (using password: NO)
i am getting the above error

any help

auth_opt_backends mysql
auth_opt_db_host 192.168.1.95
auth_opt_db_port 3307
auth_opt_db_username root
auth_opt_db_password root
auth_opt_dbname test
auth_opt_anonusername AnonymouS
auth_opt_userquery SELECT pw FROM users WHERE username = '%s'
auth_opt_superquery SELECT IFNULL(COUNT(*), 0) FROM users WHERE username = '%s' AND super = 1

[jpmens]

Why are you commenting on a closed issue with something that has nothing to do with the original issue?! The plugin isn't allowed to connect to mysql. are you sure root is your db password?

[hkverma310]

yeah my db password is root

[mahesh-balumuri]

I have changed WITH_SRV:=no and recompiled both mosquitto and mqtt-auth-plugin. I am getting the below error.

./mosquitto -c ../local.conf
1457697662: mosquitto version 1.4.8 (build date 2016-03-11 03:59:19-0800) starting
1457697662: Config loaded from ../local.conf.
1457697662: |-- *** auth-plug: startup
|-- No backends configured.
|-- *** ABORT.