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/*
* f_bpf.c BPF-based Classifier
*
* This program is free software; you can distribute 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: Daniel Borkmann <dborkman@redhat.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <linux/bpf.h>
#include "utils.h"
#include "tc_util.h"
#include "tc_bpf.h"
static const enum bpf_prog_type bpf_type = BPF_PROG_TYPE_SCHED_CLS;
static const int nla_tbl[BPF_NLA_MAX] = {
[BPF_NLA_OPS_LEN] = TCA_BPF_OPS_LEN,
[BPF_NLA_OPS] = TCA_BPF_OPS,
[BPF_NLA_FD] = TCA_BPF_FD,
[BPF_NLA_NAME] = TCA_BPF_NAME,
};
static void explain(void)
{
fprintf(stderr, "Usage: ... bpf ...\n");
fprintf(stderr, "\n");
fprintf(stderr, "BPF use case:\n");
fprintf(stderr, " bytecode BPF_BYTECODE\n");
fprintf(stderr, " bytecode-file FILE\n");
fprintf(stderr, "\n");
fprintf(stderr, "eBPF use case:\n");
fprintf(stderr, " object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]");
fprintf(stderr, " [ verbose ] [ direct-action ]\n");
fprintf(stderr, " object-pinned FILE [ direct-action ]\n");
fprintf(stderr, "\n");
fprintf(stderr, "Common remaining options:\n");
fprintf(stderr, " [ action ACTION_SPEC ]\n");
fprintf(stderr, " [ classid CLASSID ]\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n");
fprintf(stderr, "c,t,f,k and s are decimals; s denotes number of 4-tuples\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where FILE points to a file containing the BPF_BYTECODE string,\n");
fprintf(stderr, "an ELF file containing eBPF map definitions and bytecode, or a\n");
fprintf(stderr, "pinned eBPF program.\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where CLS_NAME refers to the section name containing the\n");
fprintf(stderr, "classifier (default \'%s\').\n", bpf_default_section(bpf_type));
fprintf(stderr, "\n");
fprintf(stderr, "Where UDS_FILE points to a unix domain socket file in order\n");
fprintf(stderr, "to hand off control of all created eBPF maps to an agent.\n");
fprintf(stderr, "\n");
fprintf(stderr, "ACTION_SPEC := ... look at individual actions\n");
fprintf(stderr, "NOTE: CLASSID is parsed as hexadecimal input.\n");
}
static int bpf_parse_opt(struct filter_util *qu, char *handle,
int argc, char **argv, struct nlmsghdr *n)
{
const char *bpf_obj = NULL, *bpf_uds_name = NULL;
struct tcmsg *t = NLMSG_DATA(n);
unsigned int bpf_flags = 0;
bool seen_run = false;
struct rtattr *tail;
int ret = 0;
if (argc == 0)
return 0;
if (handle) {
if (get_u32(&t->tcm_handle, handle, 0)) {
fprintf(stderr, "Illegal \"handle\"\n");
return -1;
}
}
tail = (struct rtattr *)(((void *)n) + NLMSG_ALIGN(n->nlmsg_len));
addattr_l(n, MAX_MSG, TCA_OPTIONS, NULL, 0);
while (argc > 0) {
if (matches(*argv, "run") == 0) {
NEXT_ARG();
opt_bpf:
seen_run = true;
if (bpf_parse_common(&argc, &argv, nla_tbl, bpf_type,
&bpf_obj, &bpf_uds_name, n)) {
fprintf(stderr, "Failed to retrieve (e)BPF data!\n");
return -1;
}
} else if (matches(*argv, "classid") == 0 ||
matches(*argv, "flowid") == 0) {
unsigned int handle;
NEXT_ARG();
if (get_tc_classid(&handle, *argv)) {
fprintf(stderr, "Illegal \"classid\"\n");
return -1;
}
addattr32(n, MAX_MSG, TCA_BPF_CLASSID, handle);
} else if (matches(*argv, "direct-action") == 0 ||
matches(*argv, "da") == 0) {
bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
} else if (matches(*argv, "action") == 0) {
NEXT_ARG();
if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) {
fprintf(stderr, "Illegal \"action\"\n");
return -1;
}
continue;
} else if (matches(*argv, "police") == 0) {
NEXT_ARG();
if (parse_police(&argc, &argv, TCA_BPF_POLICE, n)) {
fprintf(stderr, "Illegal \"police\"\n");
return -1;
}
continue;
} else if (matches(*argv, "help") == 0) {
explain();
return -1;
} else {
if (!seen_run)
goto opt_bpf;
fprintf(stderr, "What is \"%s\"?\n", *argv);
explain();
return -1;
}
NEXT_ARG_FWD();
}
if (bpf_obj && bpf_flags)
addattr32(n, MAX_MSG, TCA_BPF_FLAGS, bpf_flags);
tail->rta_len = (((void *)n) + n->nlmsg_len) - (void *)tail;
if (bpf_uds_name)
ret = bpf_send_map_fds(bpf_uds_name, bpf_obj);
return ret;
}
static int bpf_print_opt(struct filter_util *qu, FILE *f,
struct rtattr *opt, __u32 handle)
{
struct rtattr *tb[TCA_BPF_MAX + 1];
if (opt == NULL)
return 0;
parse_rtattr_nested(tb, TCA_BPF_MAX, opt);
if (handle)
fprintf(f, "handle 0x%x ", handle);
if (tb[TCA_BPF_CLASSID]) {
SPRINT_BUF(b1);
fprintf(f, "flowid %s ",
sprint_tc_classid(rta_getattr_u32(tb[TCA_BPF_CLASSID]), b1));
}
if (tb[TCA_BPF_NAME])
fprintf(f, "%s ", rta_getattr_str(tb[TCA_BPF_NAME]));
else if (tb[TCA_BPF_FD])
fprintf(f, "pfd %u ", rta_getattr_u32(tb[TCA_BPF_FD]));
if (tb[TCA_BPF_FLAGS]) {
unsigned int flags = rta_getattr_u32(tb[TCA_BPF_FLAGS]);
if (flags & TCA_BPF_FLAG_ACT_DIRECT)
fprintf(f, "direct-action ");
}
if (tb[TCA_BPF_OPS] && tb[TCA_BPF_OPS_LEN]) {
bpf_print_ops(f, tb[TCA_BPF_OPS],
rta_getattr_u16(tb[TCA_BPF_OPS_LEN]));
fprintf(f, "\n");
}
if (tb[TCA_BPF_POLICE]) {
fprintf(f, "\n");
tc_print_police(f, tb[TCA_BPF_POLICE]);
}
if (tb[TCA_BPF_ACT]) {
tc_print_action(f, tb[TCA_BPF_ACT]);
}
return 0;
}
struct filter_util bpf_filter_util = {
.id = "bpf",
.parse_fopt = bpf_parse_opt,
.print_fopt = bpf_print_opt,
};
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