Msquic Perf Lttng Library Issue

[victorstewart]

the zip folder nick sent me included libmsquic.lttng.so libmsquic.so secnetperf and running ldd on secnetperf gave me...

root@clr-df9e289c0de04eb2a0cfc75803a0b93e~/msquic # ldd secnetperf
	linux-vdso.so.1 (0x00007ffdc0595000)
	libmsquic.so => not found
	liblttng-ust.so.0 => not found
	libdl.so.2 => /usr/lib64/libdl.so.2 (0x00007f93b69d0000)
	libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f93b67c7000)
	libm.so.6 => /usr/lib64/haswell/libm.so.6 (0x00007f93b6681000)
	libgcc_s.so.1 => /usr/lib64/libgcc_s.so.1 (0x00007f93b6666000)
	libpthread.so.0 => /usr/lib64/libpthread.so.0 (0x00007f93b6640000)
	libc.so.6 => /usr/lib64/haswell/libc.so.6 (0x00007f93b6442000)
	/lib64/ld-linux-x86-64.so.2 => /usr/lib64/ld-linux-x86-64.so.2 (0x00007f93b94ae000)

so first issue, it wants liblttng-ust.so.0 not libmsquic.lttng.so?

i moved both libraries into /usr/lib64 and renamed libmsquic.lttng.so to liblttng-ust.so.0 now both found, but when i try to run the binary i still get a symbol error.

root@clr-df9e289c0de04eb2a0cfc75803a0b93e~/msquic # ./secnetperf
./secnetperf: symbol lookup error: ./secnetperf: undefined symbol: lttng_probe_register

[ThadHouse]

For secnetperf (and the other tools), it is correctly looking for liblttng-ust.so.0. To run the tools, you do need lttng installed.

For libmsquic.so, we dynamically load the lttng provider, so there is no explicit dependency on libmsquic.lttng.so. However, for the tools we are not able to do this, since they also do some logging internally, so those do require lttng installed on your test system.

[ThadHouse]

If you're on ubuntu, you can follow the instructions here to install lttng.

https://lttng.org/docs/v2.12/#doc-ubuntu-ppa

[nibanks]

It would be nice if we could make the lttng dependency optional or completely unnecessary for our tools. Ideas?

[ThadHouse]

The only way I can do that is to give each tool its own toolname.lttng.so library that it can load itself. That library would then be optional. Theres no way to hook it into the one we already generate for msquic. It's not too hard to do that however.

[victorstewart]

i installed lttng and it's working fine now. i'd assumed you needed some custom build of it since you provided me the library. we can close this issue unless you want to further this lttng or not discussion

[ThadHouse]

That library is specifically for libmsquic.so, and it allows it to dynamically load lttng. It's done that way so at least the library will run without lttng installed, and it just won't have logging.

[ThadHouse]

We'll do the discussion, so we can close this for now.