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Message-Id: <0b66dc13c157f4d34518c06dd774ef39be0df271.1628790091.git.aclaudi@redhat.com>
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From: Andrea Claudi <aclaudi@redhat.com>
Date: Thu, 12 Aug 2021 18:26:39 +0200
Subject: [PATCH] tc: htb: improve burst error messages

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1910745
Upstream Status: iproute2.git commit e44786b2

commit e44786b26934e4fbf337b0af73a9e6f53d458a25
Author: Andrea Claudi <aclaudi@redhat.com>
Date:   Thu May 6 12:42:06 2021 +0200

    tc: htb: improve burst error messages

    When a wrong value is provided for "burst" or "cburst" parameters, the
    resulting error message is unclear and can be misleading:

    $ tc class add dev dummy0 parent 1: classid 1:1 htb rate 100KBps burst errtrigger
    Illegal "buffer"

    The message claims an illegal "buffer" is provided, but neither the
    inline help nor the man page list "buffer" among the htb parameters, and
    the only way to know that "burst", "maxburst" and "buffer" are synonyms
    is to look into tc/q_htb.c.

    This commit tries to improve this simply changing the error string to
    the parameter name provided in the user-given command, clearly pointing
    out where the wrong value is.

    $ tc class add dev dummy0 parent 1: classid 1:1 htb rate 100KBps burst errtrigger
    Illegal "burst"

    $ tc class add dev dummy0 parent 1: classid 1:1 htb rate 100Kbps maxburst errtrigger
    Illegal "maxburst"

    Reported-by: Sebastian Mitterle <smitterl@redhat.com>
    Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
    Signed-off-by: David Ahern <dsahern@kernel.org>

Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
---
 tc/q_htb.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tc/q_htb.c b/tc/q_htb.c
index 42566355..b5f95f67 100644
--- a/tc/q_htb.c
+++ b/tc/q_htb.c
@@ -125,6 +125,7 @@ static int htb_parse_class_opt(struct qdisc_util *qu, int argc, char **argv, str
 	unsigned int linklayer  = LINKLAYER_ETHERNET; /* Assume ethernet */
 	struct rtattr *tail;
 	__u64 ceil64 = 0, rate64 = 0;
+	char *param;
 
 	while (argc > 0) {
 		if (matches(*argv, "prio") == 0) {
@@ -160,17 +161,19 @@ static int htb_parse_class_opt(struct qdisc_util *qu, int argc, char **argv, str
 		} else if (matches(*argv, "burst") == 0 ||
 			   strcmp(*argv, "buffer") == 0 ||
 			   strcmp(*argv, "maxburst") == 0) {
+			param = *argv;
 			NEXT_ARG();
 			if (get_size_and_cell(&buffer, &cell_log, *argv) < 0) {
-				explain1("buffer");
+				explain1(param);
 				return -1;
 			}
 		} else if (matches(*argv, "cburst") == 0 ||
 			   strcmp(*argv, "cbuffer") == 0 ||
 			   strcmp(*argv, "cmaxburst") == 0) {
+			param = *argv;
 			NEXT_ARG();
 			if (get_size_and_cell(&cbuffer, &ccell_log, *argv) < 0) {
-				explain1("cbuffer");
+				explain1(param);
 				return -1;
 			}
 		} else if (strcmp(*argv, "ceil") == 0) {
-- 
2.31.1