| Message ID | 20201111031213.25109-3-alexei.starovoitov@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9cc873e85800ccde80aa2e4b2bae9f1b5fa4c478 |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: Pointers beyond packet end. | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/source_inline | fail | Was 0 now: 2 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | fail | Errors and warnings before: 4 this patch: 4 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | fail | Link |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
Alexei Starovoitov wrote: > From: Alexei Starovoitov <ast@kernel.org> > > Add a test that currently makes LLVM generate assembly code: > > $ llvm-objdump -S skb_pkt_end.o > 0000000000000000 <main_prog>: > ; if (skb_shorter(skb, ETH_IPV4_TCP_SIZE)) > 0: 61 12 50 00 00 00 00 00 r2 = *(u32 *)(r1 + 80) > 1: 61 14 4c 00 00 00 00 00 r4 = *(u32 *)(r1 + 76) > 2: bf 43 00 00 00 00 00 00 r3 = r4 > 3: 07 03 00 00 36 00 00 00 r3 += 54 > 4: b7 01 00 00 00 00 00 00 r1 = 0 > 5: 2d 23 02 00 00 00 00 00 if r3 > r2 goto +2 <LBB0_2> > 6: 07 04 00 00 0e 00 00 00 r4 += 14 > ; if (skb_shorter(skb, ETH_IPV4_TCP_SIZE)) > 7: bf 41 00 00 00 00 00 00 r1 = r4 > 0000000000000040 <LBB0_2>: > 8: b4 00 00 00 ff ff ff ff w0 = -1 > ; if (!(ip = get_iphdr(skb))) > 9: 2d 23 05 00 00 00 00 00 if r3 > r2 goto +5 <LBB0_6> > ; proto = ip->protocol; > 10: 71 12 09 00 00 00 00 00 r2 = *(u8 *)(r1 + 9) > ; if (proto != IPPROTO_TCP) > 11: 56 02 03 00 06 00 00 00 if w2 != 6 goto +3 <LBB0_6> > ; if (tcp->dest != 0) > 12: 69 12 16 00 00 00 00 00 r2 = *(u16 *)(r1 + 22) > 13: 56 02 01 00 00 00 00 00 if w2 != 0 goto +1 <LBB0_6> > ; return tcp->urg_ptr; > 14: 69 10 26 00 00 00 00 00 r0 = *(u16 *)(r1 + 38) > 0000000000000078 <LBB0_6>: > ; } > 15: 95 00 00 00 00 00 00 00 exit > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > --- Acked-by: John Fastabend <john.fastabend@gmail.com>
diff --git a/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c b/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c new file mode 100644 index 000000000000..cf1215531920 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include <test_progs.h> +#include <network_helpers.h> +#include "skb_pkt_end.skel.h" + +static int sanity_run(struct bpf_program *prog) +{ + __u32 duration, retval; + int err, prog_fd; + + prog_fd = bpf_program__fd(prog); + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4), + NULL, NULL, &retval, &duration); + if (CHECK(err || retval != 123, "test_run", + "err %d errno %d retval %d duration %d\n", + err, errno, retval, duration)) + return -1; + return 0; +} + +void test_test_skb_pkt_end(void) +{ + struct skb_pkt_end *skb_pkt_end_skel = NULL; + __u32 duration = 0; + int err; + + skb_pkt_end_skel = skb_pkt_end__open_and_load(); + if (CHECK(!skb_pkt_end_skel, "skb_pkt_end_skel_load", "skb_pkt_end skeleton failed\n")) + goto cleanup; + + err = skb_pkt_end__attach(skb_pkt_end_skel); + if (CHECK(err, "skb_pkt_end_attach", "skb_pkt_end attach failed: %d\n", err)) + goto cleanup; + + if (sanity_run(skb_pkt_end_skel->progs.main_prog)) + goto cleanup; + +cleanup: + skb_pkt_end__destroy(skb_pkt_end_skel); +} diff --git a/tools/testing/selftests/bpf/progs/skb_pkt_end.c b/tools/testing/selftests/bpf/progs/skb_pkt_end.c new file mode 100644 index 000000000000..cf6823f42e80 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/skb_pkt_end.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 +#define BPF_NO_PRESERVE_ACCESS_INDEX +#include <vmlinux.h> +#include <bpf/bpf_core_read.h> +#include <bpf/bpf_helpers.h> + +#define NULL 0 +#define INLINE __always_inline + +#define skb_shorter(skb, len) ((void *)(long)(skb)->data + (len) > (void *)(long)skb->data_end) + +#define ETH_IPV4_TCP_SIZE (14 + sizeof(struct iphdr) + sizeof(struct tcphdr)) + +static INLINE struct iphdr *get_iphdr(struct __sk_buff *skb) +{ + struct iphdr *ip = NULL; + struct ethhdr *eth; + + if (skb_shorter(skb, ETH_IPV4_TCP_SIZE)) + goto out; + + eth = (void *)(long)skb->data; + ip = (void *)(eth + 1); + +out: + return ip; +} + +SEC("classifier/cls") +int main_prog(struct __sk_buff *skb) +{ + struct iphdr *ip = NULL; + struct tcphdr *tcp; + __u8 proto = 0; + + if (!(ip = get_iphdr(skb))) + goto out; + + proto = ip->protocol; + + if (proto != IPPROTO_TCP) + goto out; + + tcp = (void*)(ip + 1); + if (tcp->dest != 0) + goto out; + if (!tcp) + goto out; + + return tcp->urg_ptr; +out: + return -1; +} +char _license[] SEC("license") = "GPL";