diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/xdping_kern.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/xdping_kern.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/xdping_kern.c b/tools/testing/selftests/bpf/progs/xdping_kern.c new file mode 100644 index 000000000..6b9ca40bd --- /dev/null +++ b/tools/testing/selftests/bpf/progs/xdping_kern.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. */ + +#define KBUILD_MODNAME "foo" +#include <stddef.h> +#include <string.h> +#include <linux/bpf.h> +#include <linux/icmp.h> +#include <linux/in.h> +#include <linux/if_ether.h> +#include <linux/if_packet.h> +#include <linux/if_vlan.h> +#include <linux/ip.h> + +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> + +#include "xdping.h" + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 256); + __type(key, __u32); + __type(value, struct pinginfo); +} ping_map SEC(".maps"); + +static __always_inline void swap_src_dst_mac(void *data) +{ + unsigned short *p = data; + unsigned short dst[3]; + + dst[0] = p[0]; + dst[1] = p[1]; + dst[2] = p[2]; + p[0] = p[3]; + p[1] = p[4]; + p[2] = p[5]; + p[3] = dst[0]; + p[4] = dst[1]; + p[5] = dst[2]; +} + +static __always_inline __u16 csum_fold_helper(__wsum sum) +{ + sum = (sum & 0xffff) + (sum >> 16); + return ~((sum & 0xffff) + (sum >> 16)); +} + +static __always_inline __u16 ipv4_csum(void *data_start, int data_size) +{ + __wsum sum; + + sum = bpf_csum_diff(0, 0, data_start, data_size, 0); + return csum_fold_helper(sum); +} + +#define ICMP_ECHO_LEN 64 + +static __always_inline int icmp_check(struct xdp_md *ctx, int type) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + struct ethhdr *eth = data; + struct icmphdr *icmph; + struct iphdr *iph; + + if (data + sizeof(*eth) + sizeof(*iph) + ICMP_ECHO_LEN > data_end) + return XDP_PASS; + + if (eth->h_proto != bpf_htons(ETH_P_IP)) + return XDP_PASS; + + iph = data + sizeof(*eth); + + if (iph->protocol != IPPROTO_ICMP) + return XDP_PASS; + + if (bpf_ntohs(iph->tot_len) - sizeof(*iph) != ICMP_ECHO_LEN) + return XDP_PASS; + + icmph = data + sizeof(*eth) + sizeof(*iph); + + if (icmph->type != type) + return XDP_PASS; + + return XDP_TX; +} + +SEC("xdpclient") +int xdping_client(struct xdp_md *ctx) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + struct pinginfo *pinginfo = NULL; + struct ethhdr *eth = data; + struct icmphdr *icmph; + struct iphdr *iph; + __u64 recvtime; + __be32 raddr; + __be16 seq; + int ret; + __u8 i; + + ret = icmp_check(ctx, ICMP_ECHOREPLY); + + if (ret != XDP_TX) + return ret; + + iph = data + sizeof(*eth); + icmph = data + sizeof(*eth) + sizeof(*iph); + raddr = iph->saddr; + + /* Record time reply received. */ + recvtime = bpf_ktime_get_ns(); + pinginfo = bpf_map_lookup_elem(&ping_map, &raddr); + if (!pinginfo || pinginfo->seq != icmph->un.echo.sequence) + return XDP_PASS; + + if (pinginfo->start) { +#pragma clang loop unroll(full) + for (i = 0; i < XDPING_MAX_COUNT; i++) { + if (pinginfo->times[i] == 0) + break; + } + /* verifier is fussy here... */ + if (i < XDPING_MAX_COUNT) { + pinginfo->times[i] = recvtime - + pinginfo->start; + pinginfo->start = 0; + i++; + } + /* No more space for values? */ + if (i == pinginfo->count || i == XDPING_MAX_COUNT) + return XDP_PASS; + } + + /* Now convert reply back into echo request. */ + swap_src_dst_mac(data); + iph->saddr = iph->daddr; + iph->daddr = raddr; + icmph->type = ICMP_ECHO; + seq = bpf_htons(bpf_ntohs(icmph->un.echo.sequence) + 1); + icmph->un.echo.sequence = seq; + icmph->checksum = 0; + icmph->checksum = ipv4_csum(icmph, ICMP_ECHO_LEN); + + pinginfo->seq = seq; + pinginfo->start = bpf_ktime_get_ns(); + + return XDP_TX; +} + +SEC("xdpserver") +int xdping_server(struct xdp_md *ctx) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + struct ethhdr *eth = data; + struct icmphdr *icmph; + struct iphdr *iph; + __be32 raddr; + int ret; + + ret = icmp_check(ctx, ICMP_ECHO); + + if (ret != XDP_TX) + return ret; + + iph = data + sizeof(*eth); + icmph = data + sizeof(*eth) + sizeof(*iph); + raddr = iph->saddr; + + /* Now convert request into echo reply. */ + swap_src_dst_mac(data); + iph->saddr = iph->daddr; + iph->daddr = raddr; + icmph->type = ICMP_ECHOREPLY; + icmph->checksum = 0; + icmph->checksum = ipv4_csum(icmph, ICMP_ECHO_LEN); + + return XDP_TX; +} + +char _license[] SEC("license") = "GPL"; |