| Message ID | 20240305053310.815877-1-kuba@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | tools: ynl: add --dbg-small-recv for easier kernel testing | expand |
Hello: This series was applied to netdev/net-next.git (main) by David S. Miller <davem@davemloft.net>: On Mon, 4 Mar 2024 21:33:06 -0800 you wrote: > When testing netlink dumps I usually hack some user space up > to constrain its user space buffer size (iproute2, ethtool or ynl). > Netlink will try to fill the messages up, so since these apps use > large buffers by default, the dumps are rarely fragmented. > > I was hoping to figure out a way to create a selftest for dump > testing, but so far I have no idea how to do that in a useful > and generic way. > > [...] Here is the summary with links: - [net-next,v2,1/4] tools: ynl: move the new line in NlMsg __repr__ https://git.kernel.org/netdev/net-next/c/7df7231d6a6b - [net-next,v2,2/4] tools: ynl: allow setting recv() size https://git.kernel.org/netdev/net-next/c/7c93a88785da - [net-next,v2,3/4] tools: ynl: support debug printing messages https://git.kernel.org/netdev/net-next/c/a6a41521f95e - [net-next,v2,4/4] tools: ynl: add --dbg-small-recv for easier kernel testing https://git.kernel.org/netdev/net-next/c/c0111878d45e You are awesome, thank you!
When testing netlink dumps I usually hack some user space up to constrain its user space buffer size (iproute2, ethtool or ynl). Netlink will try to fill the messages up, so since these apps use large buffers by default, the dumps are rarely fragmented. I was hoping to figure out a way to create a selftest for dump testing, but so far I have no idea how to do that in a useful and generic way. Until someone does that, make manual dump testing easier with YNL. Create a special option for limiting the buffer size, so I don't have to make the same edits each time, and maybe others will benefit, too :) Example: $ ./cli.py [...] --dbg-small-recv >/dev/null Recv: read 3712 bytes, 29 messages nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 [...] nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 Recv: read 3968 bytes, 31 messages nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 [...] nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 Recv: read 532 bytes, 5 messages nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 [...] nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 nl_len = 20 (4) nl_flags = 0x2 nl_type = 3 Now let's make the DONE not fit in the last message: $ ./cli.py [...] --dbg-small-recv 4499 >/dev/null Recv: read 3712 bytes, 29 messages nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 [...] nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 Recv: read 4480 bytes, 35 messages nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 [...] nl_len = 128 (112) nl_flags = 0x0 nl_type = 19 Recv: read 20 bytes, 1 messages nl_len = 20 (4) nl_flags = 0x2 nl_type = 3 A real test would also have to check the messages are complete and not duplicated. That part has to be done manually right now. Note that the first message is always conservatively sized by the kernel. Still, I think this is good enough to be useful. v2: - patch 2: - move the recv_size setting up - change the default to 0 so that cli.py doesn't have to worry what the "unset" value is v1: https://lore.kernel.org/all/20240301230542.116823-1-kuba@kernel.org/ Jakub Kicinski (4): tools: ynl: move the new line in NlMsg __repr__ tools: ynl: allow setting recv() size tools: ynl: support debug printing messages tools: ynl: add --dbg-small-recv for easier kernel testing tools/net/ynl/cli.py | 7 ++++++- tools/net/ynl/lib/ynl.py | 42 ++++++++++++++++++++++++++++++++++------ 2 files changed, 42 insertions(+), 7 deletions(-)