From c0111878d45e3bb8779886fbf956b574bac8a3aa Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 4 Mar 2024 21:33:10 -0800 Subject: [PATCH] tools: ynl: add --dbg-small-recv for easier kernel testing Most "production" netlink clients use large buffers to make dump efficient, which means that handling of dump continuation in the kernel is not very well tested. Add an option for debugging / testing handling of dumps. It enables printing of extra netlink-level debug and lowers the recv() buffer size in one go. When used without any argument (--dbg-small-recv) it picks a very small default (4000), explicit size can be set, too (--dbg-small-recv 5000). Example: $ ./cli.py [...] --dbg-small-recv 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 (the [...] are edits to shorten the commit message). Note that the first message of the dump is sized conservatively by the kernel. Signed-off-by: Jakub Kicinski Reviewed-by: Donald Hunter Signed-off-by: David S. Miller --- tools/net/ynl/cli.py | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/net/ynl/cli.py b/tools/net/ynl/cli.py index 0f8239979670b..e8a65fbc36981 100755 --- a/tools/net/ynl/cli.py +++ b/tools/net/ynl/cli.py @@ -38,6 +38,8 @@ def main(): const=Netlink.NLM_F_APPEND) parser.add_argument('--process-unknown', action=argparse.BooleanOptionalAction) parser.add_argument('--output-json', action='store_true') + parser.add_argument('--dbg-small-recv', default=0, const=4000, + action='store', nargs='?', type=int) args = parser.parse_args() def output(msg): @@ -53,7 +55,10 @@ def main(): if args.json_text: attrs = json.loads(args.json_text) - ynl = YnlFamily(args.spec, args.schema, args.process_unknown) + ynl = YnlFamily(args.spec, args.schema, args.process_unknown, + recv_size=args.dbg_small_recv) + if args.dbg_small_recv: + ynl.set_recv_dbg(True) if args.ntf: ynl.ntf_subscribe(args.ntf) -- 2.39.5