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| author |   Jesper Dangaard Brouer <brouer@redhat.com> | 2017-08-29 16:38:06 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-08-29 10:51:29 -0700 |
| commit | 306da4e685b415f5c875cef275001b5cdc182da9 (patch) | |
| tree | 76ba2be2cdb8d5a01fa43270a66fdbf758837f99 /samples/bpf/xdp_redirect_user.c | |
| parent | xdp: separate xdp_redirect tracepoint in map case (diff) | |
| download | linux-dev-306da4e685b415f5c875cef275001b5cdc182da9.tar.xz linux-dev-306da4e685b415f5c875cef275001b5cdc182da9.zip | |
samples/bpf: xdp_redirect load XDP dummy prog on TX device
For supporting XDP_REDIRECT, a device driver must (obviously)
implement the "TX" function ndo_xdp_xmit(). An additional requirement
is you cannot TX out a device, unless it also have a xdp bpf program
attached. This dependency is caused by the driver code need to setup
XDP resources before it can ndo_xdp_xmit.
Update bpf samples xdp_redirect and xdp_redirect_map to automatically
attach a dummy XDP program to the configured ifindex_out device. Use
the XDP flag XDP_FLAGS_UPDATE_IF_NOEXIST on the dummy load, to avoid
overriding an existing XDP prog on the device.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/bpf/xdp_redirect_user.c')
| -rw-r--r-- | samples/bpf/xdp_redirect_user.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c index f705a1905d2d..4475d837bf2c 100644 --- a/samples/bpf/xdp_redirect_user.c +++ b/samples/bpf/xdp_redirect_user.c @@ -16,6 +16,7 @@ #include <signal.h> #include <stdio.h> #include <stdlib.h> +#include <stdbool.h> #include <string.h> #include <unistd.h> #include <libgen.h> @@ -26,17 +27,18 @@ static int ifindex_in; static int ifindex_out; +static bool ifindex_out_xdp_dummy_attached = true; static __u32 xdp_flags; static void int_exit(int sig) { set_link_xdp_fd(ifindex_in, -1, xdp_flags); + if (ifindex_out_xdp_dummy_attached) + set_link_xdp_fd(ifindex_out, -1, xdp_flags); exit(0); } -/* simple per-protocol drop counter - */ static void poll_stats(int interval, int ifindex) { unsigned int nr_cpus = bpf_num_possible_cpus(); @@ -112,14 +114,21 @@ int main(int argc, char **argv) return 1; } - signal(SIGINT, int_exit); - signal(SIGTERM, int_exit); - if (set_link_xdp_fd(ifindex_in, prog_fd[0], xdp_flags) < 0) { - printf("link set xdp fd failed\n"); + printf("ERROR: link set xdp fd failed on %d\n", ifindex_in); return 1; } + /* Loading dummy XDP prog on out-device */ + if (set_link_xdp_fd(ifindex_out, prog_fd[1], + (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) { + printf("WARN: link set xdp fd failed on %d\n", ifindex_out); + ifindex_out_xdp_dummy_attached = false; + } + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + /* bpf redirect port */ ret = bpf_map_update_elem(map_fd[0], &key, &ifindex_out, 0); if (ret) { |