When displaying sizes of various sorts, tc commonly uses the function
sprint_size() to format the size into a buffer as a human-readable string.
This string is then displayed either using print_string(), or in some code
even fprintf(). As a result, a typical sequence of code when formatting a
size is something like the following:
SPRINT_BUF(b);
print_uint(PRINT_JSON, "foo", NULL, foo);
print_string(PRINT_FP, NULL, "foo %s ", sprint_size(foo, b));
For a concept as broadly useful as size, it would be better to have a
dedicated function in json_print.
To that end, move sprint_size() from tc_util to json_print. Add helpers
print_size() and print_color_size() that wrap arount sprint_size() and
provide the JSON dispatch as appropriate.
Since print_size() should be the preferred interface, convert vast majority
of uses of sprint_size() to print_size(). Two notable exceptions are:
- q_tbf, which does not show the size as such, but uses the string
"$human_readable_size/$cell_size" even in JSON. There is simply no way to
have print_size() emit the same text, because print_size() in JSON mode
should of course just use the raw number, without human-readable frills.
- q_cake, which relies on the existence of sprint_size() in its macro-based
formatting helpers. There might be ways to convert this particular case,
but given q_tbf simply cannot be converted, leave it as is.
Signed-off-by: Petr Machata <me@pmachata.org>
Signed-off-by: David Ahern <dsahern@gmail.com>
We have helper routines to support nested attribute addition into
netlink buffer: use them instead of open coding.
Use addattr_nest_compat()/addattr_nest_compat_end() where appropriate.
Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
This patch adapts the tc command line interface to allow bandwidth limits
to be specified as a percentage of the interface's capacity.
Adding this functionality requires passing the specified device string to
each class/qdisc which changes the prototype for a couple of functions: the
.parse_qopt and .parse_copt interfaces. The device string is a required
parameter for tc-qdisc and tc-class, and when not specified, the kernel
returns ENODEV. In this patch, if the user tries to specify a bandwidth
percentage without naming the device, we return an error from userspace.
Signed-off-by: Nishanth Devarajan<ndev2021@gmail.com>
