diff options
| author | Jesper Dangaard Brouer <brouer@redhat.com> | 2018-06-25 16:27:48 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-06-28 23:50:20 +0200 |
| commit | 509fda105ba8f9a1a5c6f8b79e4c7fc50b35c1e3 (patch) | |
| tree | c71cfab13dad3b8bab03a29004d286dc514daf07 /samples | |
| parent | samples/bpf: extend xdp_rxq_info to read packet payload (diff) | |
| download | linux-509fda105ba8f9a1a5c6f8b79e4c7fc50b35c1e3.tar.xz linux-509fda105ba8f9a1a5c6f8b79e4c7fc50b35c1e3.zip | |
samples/bpf: xdp_rxq_info action XDP_TX must adjust MAC-addrs
XDP_TX requires also changing the MAC-addrs, else some hardware
may drop the TX packet before reaching the wire. This was
observed with driver mlx5.
If xdp_rxq_info select --action XDP_TX the swapmac functionality
is activated. It is also possible to manually enable via cmdline
option --swapmac. This is practical if wanting to measure the
overhead of writing/updating payload for other action types.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/xdp_rxq_info_kern.c | 26 | ||||
| -rw-r--r-- | samples/bpf/xdp_rxq_info_user.c | 11 |
2 files changed, 36 insertions, 1 deletions
diff --git a/samples/bpf/xdp_rxq_info_kern.c b/samples/bpf/xdp_rxq_info_kern.c index 61af6210df2f..222a83eed1cb 100644 --- a/samples/bpf/xdp_rxq_info_kern.c +++ b/samples/bpf/xdp_rxq_info_kern.c @@ -21,6 +21,7 @@ struct config { enum cfg_options_flags { NO_TOUCH = 0x0U, READ_MEM = 0x1U, + SWAP_MAC = 0x2U, }; struct bpf_map_def SEC("maps") config_map = { .type = BPF_MAP_TYPE_ARRAY, @@ -52,6 +53,23 @@ struct bpf_map_def SEC("maps") rx_queue_index_map = { .max_entries = MAX_RXQs + 1, }; +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]; +} + SEC("xdp_prog0") int xdp_prognum0(struct xdp_md *ctx) { @@ -98,7 +116,7 @@ int xdp_prognum0(struct xdp_md *ctx) rxq_rec->issue++; /* Default: Don't touch packet data, only count packets */ - if (unlikely(config->options & READ_MEM)) { + if (unlikely(config->options & (READ_MEM|SWAP_MAC))) { struct ethhdr *eth = data; if (eth + 1 > data_end) @@ -107,6 +125,12 @@ int xdp_prognum0(struct xdp_md *ctx) /* Avoid compiler removing this: Drop non 802.3 Ethertypes */ if (ntohs(eth->h_proto) < ETH_P_802_3_MIN) return XDP_ABORTED; + + /* XDP_TX requires changing MAC-addrs, else HW may drop. + * Can also be enabled with --swapmac (for test purposes) + */ + if (unlikely(config->options & SWAP_MAC)) + swap_src_dst_mac(data); } return config->action; diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c index 435485d4f49e..248a7eab9531 100644 --- a/samples/bpf/xdp_rxq_info_user.c +++ b/samples/bpf/xdp_rxq_info_user.c @@ -51,6 +51,7 @@ static const struct option long_options[] = { {"no-separators", no_argument, NULL, 'z' }, {"action", required_argument, NULL, 'a' }, {"readmem", no_argument, NULL, 'r' }, + {"swapmac", no_argument, NULL, 'm' }, {0, 0, NULL, 0 } }; @@ -72,6 +73,7 @@ struct config { enum cfg_options_flags { NO_TOUCH = 0x0U, READ_MEM = 0x1U, + SWAP_MAC = 0x2U, }; #define XDP_ACTION_MAX (XDP_TX + 1) #define XDP_ACTION_MAX_STRLEN 11 @@ -119,6 +121,8 @@ static char* options2str(enum cfg_options_flags flag) { if (flag == NO_TOUCH) return "no_touch"; + if (flag & SWAP_MAC) + return "swapmac"; if (flag & READ_MEM) return "read"; fprintf(stderr, "ERR: Unknown config option flags"); @@ -517,6 +521,9 @@ int main(int argc, char **argv) case 'r': cfg_options |= READ_MEM; break; + case 'm': + cfg_options |= SWAP_MAC; + break; case 'h': error: default: @@ -543,6 +550,10 @@ int main(int argc, char **argv) } } cfg.action = action; + + /* XDP_TX requires changing MAC-addrs, else HW may drop */ + if (action == XDP_TX) + cfg_options |= SWAP_MAC; cfg.options = cfg_options; /* Trick to pretty printf with thousands separators use %' */ |