illumos gate

libumem discovered following memory leaks in libndmp when setting NDMP property:

umem_alloc_16 leak: 2 buffers, 16 bytes each, 32 bytes total
            ADDR          BUFADDR        TIMESTAMP           THREAD
                            CACHE          LASTLOG         CONTENTS
         8f135c8          8f109e0   1ab5d260512cf5                6
                          8ef5290                0                0
                 libumem.so.1`umem_cache_alloc_debug+0x1fe
                 libumem.so.1`umem_cache_alloc+0x99
                 libumem.so.1`umem_alloc+0x50
                 libumem.so.1`umem_malloc+0x36
                 libc_hwcap1.so.1`strdup+0x2e
                 libscf.so.1`smf_get_state+0x69
                 libndmp.so.1`ndmp_service_refresh+0x1f
                 ndmp.node`_ZN4ndmp13EnableAuthJob8beginJobEv+0x380
                 ndmp.node`_ZN3nef8AsyncJob10onBeginJobEP9uv_work_s+0x2c
                 worker+0x77
                 uv__thread_start+0x1d
                 libc_hwcap1.so.1`_thrp_setup+0x88
                 libc_hwcap1.so.1`_lwp_start

umem_alloc_32 leak: 1 buffer, 32 bytes
            ADDR          BUFADDR        TIMESTAMP           THREAD
                            CACHE          LASTLOG         CONTENTS
         9145698          9143ca0   1ab5d25be11282                6
                          8ef5790                0                0
                 libumem.so.1`umem_cache_alloc_debug+0x1fe
                 libumem.so.1`umem_cache_alloc+0x99
                 libumem.so.1`umem_alloc+0x50
                 libumem.so.1`umem_malloc+0x36
                 libuutil.so.1`uu_zalloc+0x1e
                 libscf.so.1`scf_snapshot_create+0x1b
                 libscf.so.1`scf_handle_create+0x189
                 libndmp.so.1`ndmp_smf_scf_init+0x3b
                 libndmp.so.1`ndmp_set_prop+0x24
                 ndmp.node`_ZN4ndmp13EnableAuthJob8beginJobEv+0x3f
                 ndmp.node`_ZN3nef8AsyncJob10onBeginJobEP9uv_work_s+0x2c
                 worker+0x77
                 uv__thread_start+0x1d
                 libc_hwcap1.so.1`_thrp_setup+0x88
                 libc_hwcap1.so.1`_lwp_start

The first one was easy to find and fix. Eliminating useless call to smf_get_state() in ndmp_service_refresh() fixes it.

The second one was more difficult to find. scf handle which is used for getting/setting SMF properties was leaked because one of the references to it wasn't properly released. The leaked reference belongs to "property" object allocated in ndmp_smf_set_property() (call to scf_property_create()), which isn't properly destroyed by calling scf_property_destroy(). Furthermore the code in ndmp_smf_set_property is badly structured which is the reason why the leak wasn't apparent. I took this opportunity to restructure it in better way.

There are also a couple of apparent memory leaks in error paths which are going to be fixed too on behalf of this ticket.