iproute2/tc/q_skbprio.c
Nishanth Devarajan 141b55f854 Add SKB Priority qdisc support in tc(8)
sch_skbprio is a qdisc that prioritizes packets according to their skb->priority
field. Under congestion, it drops already-enqueued lower priority packets to
make space available for higher priority packets. Skbprio was conceived as a
solution for denial-of-service defenses that need to route packets with
different priorities as a means to overcome DoS attacks.

Signed-off-by: Nishanth Devarajan <ndev2021@gmail.com>
Reviewed-by: Michel Machado <michel@digirati.com.br>
Signed-off-by: David Ahern <dsahern@gmail.com>
2018-08-14 07:06:43 -07:00

85 lines
1.7 KiB
C

/*
* q_skbprio.c SKB PRIORITY QUEUE.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Nishanth Devarajan, <ndev2021@gmail.com>
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include "utils.h"
#include "tc_util.h"
static void explain(void)
{
fprintf(stderr, "Usage: ... <skbprio> [ limit NUMBER ]\n");
}
static int skbprio_parse_opt(struct qdisc_util *qu, int argc, char **argv,
struct nlmsghdr *n, const char *dev)
{
int ok = 0;
struct tc_skbprio_qopt opt = {};
while (argc > 0) {
if (strcmp(*argv, "limit") == 0) {
NEXT_ARG();
if (get_size(&opt.limit, *argv)) {
fprintf(stderr,
"%s: Illegal \"limit\" value:\"%s\"\n",
qu->id, *argv);
return -1;
}
ok++;
}
else if (strcmp(*argv, "help") == 0) {
explain();
return -1;
} else {
fprintf(stderr,
"%s: unknown parameter \"%s\"\n",
qu->id, *argv);
explain();
return -1;
}
argc--; argv++;
}
if (ok)
addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
return 0;
}
static int skbprio_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
{
struct tc_skbprio_qopt *qopt;
if (opt == NULL)
return 0;
if (RTA_PAYLOAD(opt) < sizeof(*qopt))
return -1;
qopt = RTA_DATA(opt);
fprintf(f, "limit %u ", qopt->limit);
return 0;
}
struct qdisc_util skbprio_qdisc_util = {
.id = "skbprio",
.parse_qopt = skbprio_parse_opt,
.print_qopt = skbprio_print_opt,
};