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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2019 Netronome Systems, Inc. */
#include <errno.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include "bpf.h"
#include "libbpf.h"
static int get_kernel_version(void)
{
int version, subversion, patchlevel;
struct utsname utsn;
/* Return 0 on failure, and attempt to probe with empty kversion */
if (uname(&utsn))
return 0;
if (sscanf(utsn.release, "%d.%d.%d",
&version, &subversion, &patchlevel) != 3)
return 0;
return (version << 16) + (subversion << 8) + patchlevel;
}
static void
probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns,
size_t insns_cnt, char *buf, size_t buf_len, __u32 ifindex)
{
struct bpf_load_program_attr xattr = {};
int fd;
switch (prog_type) {
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
xattr.expected_attach_type = BPF_CGROUP_INET4_CONNECT;
break;
case BPF_PROG_TYPE_KPROBE:
xattr.kern_version = get_kernel_version();
break;
case BPF_PROG_TYPE_UNSPEC:
case BPF_PROG_TYPE_SOCKET_FILTER:
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
case BPF_PROG_TYPE_TRACEPOINT:
case BPF_PROG_TYPE_XDP:
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_CGROUP_SKB:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_LWT_IN:
case BPF_PROG_TYPE_LWT_OUT:
case BPF_PROG_TYPE_LWT_XMIT:
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_RAW_TRACEPOINT:
case BPF_PROG_TYPE_LWT_SEG6LOCAL:
case BPF_PROG_TYPE_LIRC_MODE2:
case BPF_PROG_TYPE_SK_REUSEPORT:
case BPF_PROG_TYPE_FLOW_DISSECTOR:
default:
break;
}
xattr.prog_type = prog_type;
xattr.insns = insns;
xattr.insns_cnt = insns_cnt;
xattr.license = "GPL";
xattr.prog_ifindex = ifindex;
fd = bpf_load_program_xattr(&xattr, buf, buf_len);
if (fd >= 0)
close(fd);
}
bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex)
{
struct bpf_insn insns[2] = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN()
};
if (ifindex && prog_type == BPF_PROG_TYPE_SCHED_CLS)
/* nfp returns -EINVAL on exit(0) with TC offload */
insns[0].imm = 2;
errno = 0;
probe_load(prog_type, insns, ARRAY_SIZE(insns), NULL, 0, ifindex);
return errno != EINVAL && errno != EOPNOTSUPP;
}
bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex)
{
int key_size, value_size, max_entries, map_flags;
struct bpf_create_map_attr attr = {};
int fd = -1, fd_inner;
key_size = sizeof(__u32);
value_size = sizeof(__u32);
max_entries = 1;
map_flags = 0;
switch (map_type) {
case BPF_MAP_TYPE_STACK_TRACE:
value_size = sizeof(__u64);
break;
case BPF_MAP_TYPE_LPM_TRIE:
key_size = sizeof(__u64);
value_size = sizeof(__u64);
map_flags = BPF_F_NO_PREALLOC;
break;
case BPF_MAP_TYPE_CGROUP_STORAGE:
case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
key_size = sizeof(struct bpf_cgroup_storage_key);
value_size = sizeof(__u64);
max_entries = 0;
break;
case BPF_MAP_TYPE_QUEUE:
case BPF_MAP_TYPE_STACK:
key_size = 0;
break;
case BPF_MAP_TYPE_UNSPEC:
case BPF_MAP_TYPE_HASH:
case BPF_MAP_TYPE_ARRAY:
case BPF_MAP_TYPE_PROG_ARRAY:
case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
case BPF_MAP_TYPE_PERCPU_HASH:
case BPF_MAP_TYPE_PERCPU_ARRAY:
case BPF_MAP_TYPE_CGROUP_ARRAY:
case BPF_MAP_TYPE_LRU_HASH:
case BPF_MAP_TYPE_LRU_PERCPU_HASH:
case BPF_MAP_TYPE_ARRAY_OF_MAPS:
case BPF_MAP_TYPE_HASH_OF_MAPS:
case BPF_MAP_TYPE_DEVMAP:
case BPF_MAP_TYPE_SOCKMAP:
case BPF_MAP_TYPE_CPUMAP:
case BPF_MAP_TYPE_XSKMAP:
case BPF_MAP_TYPE_SOCKHASH:
case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
default:
break;
}
if (map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
/* TODO: probe for device, once libbpf has a function to create
* map-in-map for offload
*/
if (ifindex)
return false;
fd_inner = bpf_create_map(BPF_MAP_TYPE_HASH,
sizeof(__u32), sizeof(__u32), 1, 0);
if (fd_inner < 0)
return false;
fd = bpf_create_map_in_map(map_type, NULL, sizeof(__u32),
fd_inner, 1, 0);
close(fd_inner);
} else {
/* Note: No other restriction on map type probes for offload */
attr.map_type = map_type;
attr.key_size = key_size;
attr.value_size = value_size;
attr.max_entries = max_entries;
attr.map_flags = map_flags;
attr.map_ifindex = ifindex;
fd = bpf_create_map_xattr(&attr);
}
if (fd >= 0)
close(fd);
return fd >= 0;
}
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