From 306da4e685b415f5c875cef275001b5cdc182da9 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 29 Aug 2017 16:38:06 +0200 Subject: 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 Signed-off-by: David S. Miller --- samples/bpf/xdp_redirect_kern.c | 11 ++++++++++- samples/bpf/xdp_redirect_map_kern.c | 11 ++++++++++- samples/bpf/xdp_redirect_map_user.c | 22 +++++++++++++++------- samples/bpf/xdp_redirect_user.c | 21 +++++++++++++++------ 4 files changed, 50 insertions(+), 15 deletions(-) (limited to 'samples/bpf') diff --git a/samples/bpf/xdp_redirect_kern.c b/samples/bpf/xdp_redirect_kern.c index a34ad457a684..1c90288d0203 100644 --- a/samples/bpf/xdp_redirect_kern.c +++ b/samples/bpf/xdp_redirect_kern.c @@ -26,6 +26,9 @@ struct bpf_map_def SEC("maps") tx_port = { .max_entries = 1, }; +/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success + * feedback. Redirect TX errors can be caught via a tracepoint. + */ struct bpf_map_def SEC("maps") rxcnt = { .type = BPF_MAP_TYPE_PERCPU_ARRAY, .key_size = sizeof(u32), @@ -33,7 +36,6 @@ struct bpf_map_def SEC("maps") rxcnt = { .max_entries = 1, }; - static void swap_src_dst_mac(void *data) { unsigned short *p = data; @@ -78,4 +80,11 @@ int xdp_redirect_prog(struct xdp_md *ctx) return bpf_redirect(*ifindex, 0); } +/* Redirect require an XDP bpf_prog loaded on the TX device */ +SEC("xdp_redirect_dummy") +int xdp_redirect_dummy(struct xdp_md *ctx) +{ + return XDP_PASS; +} + char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/xdp_redirect_map_kern.c b/samples/bpf/xdp_redirect_map_kern.c index 2faf196e17ea..79795d41ad0d 100644 --- a/samples/bpf/xdp_redirect_map_kern.c +++ b/samples/bpf/xdp_redirect_map_kern.c @@ -26,6 +26,9 @@ struct bpf_map_def SEC("maps") tx_port = { .max_entries = 100, }; +/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success + * feedback. Redirect TX errors can be caught via a tracepoint. + */ struct bpf_map_def SEC("maps") rxcnt = { .type = BPF_MAP_TYPE_PERCPU_ARRAY, .key_size = sizeof(u32), @@ -33,7 +36,6 @@ struct bpf_map_def SEC("maps") rxcnt = { .max_entries = 1, }; - static void swap_src_dst_mac(void *data) { unsigned short *p = data; @@ -80,4 +82,11 @@ int xdp_redirect_map_prog(struct xdp_md *ctx) return bpf_redirect_map(&tx_port, vport, 0); } +/* Redirect require an XDP bpf_prog loaded on the TX device */ +SEC("xdp_redirect_dummy") +int xdp_redirect_dummy(struct xdp_md *ctx) +{ + return XDP_PASS; +} + char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/xdp_redirect_map_user.c b/samples/bpf/xdp_redirect_map_user.c index a1ad00fdaa8a..d4d86a273fba 100644 --- a/samples/bpf/xdp_redirect_map_user.c +++ b/samples/bpf/xdp_redirect_map_user.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -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(); @@ -70,7 +72,6 @@ static void usage(const char *prog) prog); } - int main(int argc, char **argv) { const char *optstr = "SN"; @@ -112,14 +113,21 @@ 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); + printf("map[0] (vports) = %i, map[1] (map) = %i, map[2] (count) = %i\n", map_fd[0], map_fd[1], map_fd[2]); 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 #include #include +#include #include #include #include @@ -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) { -- cgit v1.2.3