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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2018 Facebook */
#include <stdlib.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/bpf.h>
#include <linux/types.h>
#include <linux/if_ether.h>
#include <bpf/bpf_endian.h>
#include <bpf/bpf_helpers.h>
#include "test_select_reuseport_common.h"
int _version SEC("version") = 1;
#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif
struct {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__uint(max_entries, 1);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(__u32));
} outer_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, NR_RESULTS);
__type(key, __u32);
__type(value, __u32);
} result_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, int);
} tmp_index_ovr_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, __u32);
} linum_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, struct data_check);
} data_check_map SEC(".maps");
#define GOTO_DONE(_result) ({ \
result = (_result); \
linum = __LINE__; \
goto done; \
})
SEC("sk_reuseport")
int _select_by_skb_data(struct sk_reuseport_md *reuse_md)
{
__u32 linum, index = 0, flags = 0, index_zero = 0;
__u32 *result_cnt, *linum_value;
struct data_check data_check = {};
struct cmd *cmd, cmd_copy;
void *data, *data_end;
void *reuseport_array;
enum result result;
int *index_ovr;
int err;
data = reuse_md->data;
data_end = reuse_md->data_end;
data_check.len = reuse_md->len;
data_check.eth_protocol = reuse_md->eth_protocol;
data_check.ip_protocol = reuse_md->ip_protocol;
data_check.hash = reuse_md->hash;
data_check.bind_inany = reuse_md->bind_inany;
if (data_check.eth_protocol == bpf_htons(ETH_P_IP)) {
if (bpf_skb_load_bytes_relative(reuse_md,
offsetof(struct iphdr, saddr),
data_check.skb_addrs, 8,
BPF_HDR_START_NET))
GOTO_DONE(DROP_MISC);
} else {
if (bpf_skb_load_bytes_relative(reuse_md,
offsetof(struct ipv6hdr, saddr),
data_check.skb_addrs, 32,
BPF_HDR_START_NET))
GOTO_DONE(DROP_MISC);
}
/*
* The ip_protocol could be a compile time decision
* if the bpf_prog.o is dedicated to either TCP or
* UDP.
*
* Otherwise, reuse_md->ip_protocol or
* the protocol field in the iphdr can be used.
*/
if (data_check.ip_protocol == IPPROTO_TCP) {
struct tcphdr *th = data;
if (th + 1 > data_end)
GOTO_DONE(DROP_MISC);
data_check.skb_ports[0] = th->source;
data_check.skb_ports[1] = th->dest;
if (th->fin)
/* The connection is being torn down at the end of a
* test. It can't contain a cmd, so return early.
*/
return SK_PASS;
if ((th->doff << 2) + sizeof(*cmd) > data_check.len)
GOTO_DONE(DROP_ERR_SKB_DATA);
if (bpf_skb_load_bytes(reuse_md, th->doff << 2, &cmd_copy,
sizeof(cmd_copy)))
GOTO_DONE(DROP_MISC);
cmd = &cmd_copy;
} else if (data_check.ip_protocol == IPPROTO_UDP) {
struct udphdr *uh = data;
if (uh + 1 > data_end)
GOTO_DONE(DROP_MISC);
data_check.skb_ports[0] = uh->source;
data_check.skb_ports[1] = uh->dest;
if (sizeof(struct udphdr) + sizeof(*cmd) > data_check.len)
GOTO_DONE(DROP_ERR_SKB_DATA);
if (data + sizeof(struct udphdr) + sizeof(*cmd) > data_end) {
if (bpf_skb_load_bytes(reuse_md, sizeof(struct udphdr),
&cmd_copy, sizeof(cmd_copy)))
GOTO_DONE(DROP_MISC);
cmd = &cmd_copy;
} else {
cmd = data + sizeof(struct udphdr);
}
} else {
GOTO_DONE(DROP_MISC);
}
reuseport_array = bpf_map_lookup_elem(&outer_map, &index_zero);
if (!reuseport_array)
GOTO_DONE(DROP_ERR_INNER_MAP);
index = cmd->reuseport_index;
index_ovr = bpf_map_lookup_elem(&tmp_index_ovr_map, &index_zero);
if (!index_ovr)
GOTO_DONE(DROP_MISC);
if (*index_ovr != -1) {
index = *index_ovr;
*index_ovr = -1;
}
err = bpf_sk_select_reuseport(reuse_md, reuseport_array, &index,
flags);
if (!err)
GOTO_DONE(PASS);
if (cmd->pass_on_failure)
GOTO_DONE(PASS_ERR_SK_SELECT_REUSEPORT);
else
GOTO_DONE(DROP_ERR_SK_SELECT_REUSEPORT);
done:
result_cnt = bpf_map_lookup_elem(&result_map, &result);
if (!result_cnt)
return SK_DROP;
bpf_map_update_elem(&linum_map, &index_zero, &linum, BPF_ANY);
bpf_map_update_elem(&data_check_map, &index_zero, &data_check, BPF_ANY);
(*result_cnt)++;
return result < PASS ? SK_DROP : SK_PASS;
}
char _license[] SEC("license") = "GPL";
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