From: Eelco Chaudron <echaudro@xxxxxxxxxx> This patch adds support for multi-buffer for the following helpers: - bpf_xdp_output() - bpf_perf_event_output() Signed-off-by: Eelco Chaudron <echaudro@xxxxxxxxxx> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> --- net/core/filter.c | 60 ++++++++- .../selftests/bpf/prog_tests/xdp_bpf2bpf.c | 127 ++++++++++++------ .../selftests/bpf/progs/test_xdp_bpf2bpf.c | 3 +- 3 files changed, 146 insertions(+), 44 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 18b2c9bacba1..a607ea8321bd 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4549,10 +4549,53 @@ static const struct bpf_func_proto bpf_sk_ancestor_cgroup_id_proto = { }; #endif -static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff, +static unsigned long bpf_xdp_copy(void *dst_buff, const void *ctx, unsigned long off, unsigned long len) { - memcpy(dst_buff, src_buff + off, len); + struct xdp_buff *xdp = (struct xdp_buff *)ctx; + struct xdp_shared_info *xdp_sinfo; + unsigned long base_len; + const void *src_buff; + + if (likely(!xdp->mb)) { + src_buff = xdp->data; + memcpy(dst_buff, src_buff + off, len); + + return 0; + } + + base_len = xdp->data_end - xdp->data; + xdp_sinfo = xdp_get_shared_info_from_buff(xdp); + do { + unsigned long copy_len; + + if (off < base_len) { + src_buff = xdp->data + off; + copy_len = min(len, base_len - off); + } else { + unsigned long frag_off_total = base_len; + int i; + + for (i = 0; i < xdp_sinfo->nr_frags; i++) { + skb_frag_t *frag = &xdp_sinfo->frags[i]; + unsigned long frag_len = xdp_get_frag_size(frag); + unsigned long frag_off = off - frag_off_total; + + if (frag_off < frag_len) { + src_buff = xdp_get_frag_address(frag) + + frag_off; + copy_len = min(len, frag_len - frag_off); + break; + } + frag_off_total += frag_len; + } + } + memcpy(dst_buff, src_buff, copy_len); + off += copy_len; + len -= copy_len; + dst_buff += copy_len; + } while (len); + return 0; } @@ -4564,10 +4607,19 @@ BPF_CALL_5(bpf_xdp_event_output, struct xdp_buff *, xdp, struct bpf_map *, map, if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK))) return -EINVAL; if (unlikely(!xdp || - xdp_size > (unsigned long)(xdp->data_end - xdp->data))) + (likely(!xdp->mb) && + xdp_size > (unsigned long)(xdp->data_end - xdp->data)))) return -EFAULT; + if (unlikely(xdp->mb)) { + struct xdp_shared_info *xdp_sinfo; + + xdp_sinfo = xdp_get_shared_info_from_buff(xdp); + if (unlikely(xdp_size > ((int)(xdp->data_end - xdp->data) + + xdp_sinfo->data_length))) + return -EFAULT; + } - return bpf_event_output(map, flags, meta, meta_size, xdp->data, + return bpf_event_output(map, flags, meta, meta_size, xdp, xdp_size, bpf_xdp_copy); } diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c index 2c6c570b21f8..355e64526f3f 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c @@ -10,11 +10,20 @@ struct meta { int pkt_len; }; +struct test_ctx_s { + bool passed; + int pkt_size; +}; + +struct test_ctx_s test_ctx; + static void on_sample(void *ctx, int cpu, void *data, __u32 size) { - int duration = 0; struct meta *meta = (struct meta *)data; struct ipv4_packet *trace_pkt_v4 = data + sizeof(*meta); + unsigned char *raw_pkt = data + sizeof(*meta); + struct test_ctx_s *tst_ctx = ctx; + int duration = 0; if (CHECK(size < sizeof(pkt_v4) + sizeof(*meta), "check_size", "size %u < %zu\n", @@ -25,25 +34,90 @@ static void on_sample(void *ctx, int cpu, void *data, __u32 size) "meta->ifindex = %d\n", meta->ifindex)) return; - if (CHECK(meta->pkt_len != sizeof(pkt_v4), "check_meta_pkt_len", - "meta->pkt_len = %zd\n", sizeof(pkt_v4))) + if (CHECK(meta->pkt_len != tst_ctx->pkt_size, "check_meta_pkt_len", + "meta->pkt_len = %d\n", tst_ctx->pkt_size)) return; if (CHECK(memcmp(trace_pkt_v4, &pkt_v4, sizeof(pkt_v4)), "check_packet_content", "content not the same\n")) return; - *(bool *)ctx = true; + if (meta->pkt_len > sizeof(pkt_v4)) { + for (int i = 0; i < (meta->pkt_len - sizeof(pkt_v4)); i++) { + if (raw_pkt[i + sizeof(pkt_v4)] != (unsigned char)i) { + CHECK(true, "check_packet_content", + "byte %zu does not match %u != %u\n", + i + sizeof(pkt_v4), + raw_pkt[i + sizeof(pkt_v4)], + (unsigned char)i); + break; + } + } + } + + tst_ctx->passed = true; } -void test_xdp_bpf2bpf(void) +static int run_xdp_bpf2bpf_pkt_size(int pkt_fd, struct perf_buffer *pb, + struct test_xdp_bpf2bpf *ftrace_skel, + int pkt_size) { __u32 duration = 0, retval, size; - char buf[128]; + unsigned char buf_in[9000]; + unsigned char buf[9000]; + int err; + + if (pkt_size > sizeof(buf_in) || pkt_size < sizeof(pkt_v4)) + return -EINVAL; + + test_ctx.passed = false; + test_ctx.pkt_size = pkt_size; + + memcpy(buf_in, &pkt_v4, sizeof(pkt_v4)); + if (pkt_size > sizeof(pkt_v4)) { + for (int i = 0; i < (pkt_size - sizeof(pkt_v4)); i++) + buf_in[i + sizeof(pkt_v4)] = i; + } + + /* Run test program */ + err = bpf_prog_test_run(pkt_fd, 1, buf_in, pkt_size, + buf, &size, &retval, &duration); + + if (CHECK(err || retval != XDP_PASS || size != pkt_size, + "ipv4", "err %d errno %d retval %d size %d\n", + err, errno, retval, size)) + return -1; + + /* Make sure bpf_xdp_output() was triggered and it sent the expected + * data to the perf ring buffer. + */ + err = perf_buffer__poll(pb, 100); + if (CHECK(err <= 0, "perf_buffer__poll", "err %d\n", err)) + return -1; + + if (CHECK_FAIL(!test_ctx.passed)) + return -1; + + /* Verify test results */ + if (CHECK(ftrace_skel->bss->test_result_fentry != if_nametoindex("lo"), + "result", "fentry failed err %llu\n", + ftrace_skel->bss->test_result_fentry)) + return -1; + + if (CHECK(ftrace_skel->bss->test_result_fexit != XDP_PASS, "result", + "fexit failed err %llu\n", + ftrace_skel->bss->test_result_fexit)) + return -1; + + return 0; +} + +void test_xdp_bpf2bpf(void) +{ int err, pkt_fd, map_fd; - bool passed = false; - struct iphdr *iph = (void *)buf + sizeof(struct ethhdr); - struct iptnl_info value4 = {.family = AF_INET}; + __u32 duration = 0; + int pkt_sizes[] = {sizeof(pkt_v4), 1024, 4100, 8200}; + struct iptnl_info value4 = {.family = AF_INET6}; struct test_xdp *pkt_skel = NULL; struct test_xdp_bpf2bpf *ftrace_skel = NULL; struct vip key4 = {.protocol = 6, .family = AF_INET}; @@ -87,40 +161,15 @@ void test_xdp_bpf2bpf(void) /* Set up perf buffer */ pb_opts.sample_cb = on_sample; - pb_opts.ctx = &passed; + pb_opts.ctx = &test_ctx; pb = perf_buffer__new(bpf_map__fd(ftrace_skel->maps.perf_buf_map), - 1, &pb_opts); + 8, &pb_opts); if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb))) goto out; - /* Run test program */ - err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4), - buf, &size, &retval, &duration); - - if (CHECK(err || retval != XDP_TX || size != 74 || - iph->protocol != IPPROTO_IPIP, "ipv4", - "err %d errno %d retval %d size %d\n", - err, errno, retval, size)) - goto out; - - /* Make sure bpf_xdp_output() was triggered and it sent the expected - * data to the perf ring buffer. - */ - err = perf_buffer__poll(pb, 100); - if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err)) - goto out; - - CHECK_FAIL(!passed); - - /* Verify test results */ - if (CHECK(ftrace_skel->bss->test_result_fentry != if_nametoindex("lo"), - "result", "fentry failed err %llu\n", - ftrace_skel->bss->test_result_fentry)) - goto out; - - CHECK(ftrace_skel->bss->test_result_fexit != XDP_TX, "result", - "fexit failed err %llu\n", ftrace_skel->bss->test_result_fexit); - + for (int i = 0; i < ARRAY_SIZE(pkt_sizes); i++) + run_xdp_bpf2bpf_pkt_size(pkt_fd, pb, ftrace_skel, + pkt_sizes[i]); out: if (pb) perf_buffer__free(pb); diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c index a038e827f850..d5a5f603d252 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c @@ -27,6 +27,7 @@ struct xdp_buff { void *data_hard_start; unsigned long handle; struct xdp_rxq_info *rxq; + __u32 frame_length; } __attribute__((preserve_access_index)); struct meta { @@ -49,7 +50,7 @@ int BPF_PROG(trace_on_entry, struct xdp_buff *xdp) void *data = (void *)(long)xdp->data; meta.ifindex = xdp->rxq->dev->ifindex; - meta.pkt_len = data_end - data; + meta.pkt_len = xdp->frame_length; bpf_xdp_output(xdp, &perf_buf_map, ((__u64) meta.pkt_len << 32) | BPF_F_CURRENT_CPU, -- 2.30.2