Re: [PATCH bpf-next v2 4/5] samples: bpf: use libbpf where easy

[Andrii Nakryiko <andrii.nakryiko@gmail.com>]

On Wed, Feb 27, 2019 at 7:04 PM Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
>
> Some samples don't really need the magic of bpf_load,
> switch them to libbpf.
>
> v2: - specify program types.

thanks!

Acked-by: Andrii Nakryiko <andriin@fb.com>

>
> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
> ---
>  samples/bpf/Makefile       |  6 +++---
>  samples/bpf/fds_example.c  | 10 +++++++---
>  samples/bpf/sockex1_user.c | 23 +++++++++++++----------
>  samples/bpf/sockex2_user.c | 21 ++++++++++++---------
>  4 files changed, 35 insertions(+), 25 deletions(-)
>
> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> index 4dd98100678e..0c62ac39c697 100644
> --- a/samples/bpf/Makefile
> +++ b/samples/bpf/Makefile
> @@ -59,9 +59,9 @@ LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
>  CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
>  TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
>
> -fds_example-objs := bpf_load.o fds_example.o
> -sockex1-objs := bpf_load.o sockex1_user.o
> -sockex2-objs := bpf_load.o sockex2_user.o
> +fds_example-objs := fds_example.o
> +sockex1-objs := sockex1_user.o
> +sockex2-objs := sockex2_user.o
>  sockex3-objs := bpf_load.o sockex3_user.o
>  tracex1-objs := bpf_load.o tracex1_user.o
>  tracex2-objs := bpf_load.o tracex2_user.o
> diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
> index 9854854f05d1..e51eb060244e 100644
> --- a/samples/bpf/fds_example.c
> +++ b/samples/bpf/fds_example.c
> @@ -14,8 +14,8 @@
>
>  #include <bpf/bpf.h>
>
> +#include "bpf/libbpf.h"
>  #include "bpf_insn.h"
> -#include "bpf_load.h"
>  #include "sock_example.h"
>
>  #define BPF_F_PIN      (1 << 0)
> @@ -57,10 +57,14 @@ static int bpf_prog_create(const char *object)
>                 BPF_EXIT_INSN(),
>         };
>         size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
> +       char bpf_log_buf[BPF_LOG_BUF_SIZE];
> +       struct bpf_object *obj;
> +       int prog_fd;
>
>         if (object) {
> -               assert(!load_bpf_file((char *)object));
> -               return prog_fd[0];
> +               assert(!bpf_prog_load(object, BPF_PROG_TYPE_UNSPEC,
> +                                     &obj, &prog_fd));
> +               return prog_fd;
>         } else {
>                 return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
>                                         insns, insns_cnt, "GPL", 0,
> diff --git a/samples/bpf/sockex1_user.c b/samples/bpf/sockex1_user.c
> index be8ba5686924..7f90796ae15a 100644
> --- a/samples/bpf/sockex1_user.c
> +++ b/samples/bpf/sockex1_user.c
> @@ -3,28 +3,31 @@
>  #include <assert.h>
>  #include <linux/bpf.h>
>  #include <bpf/bpf.h>
> -#include "bpf_load.h"
> +#include "bpf/libbpf.h"
>  #include "sock_example.h"
>  #include <unistd.h>
>  #include <arpa/inet.h>
>
>  int main(int ac, char **argv)
>  {
> +       struct bpf_object *obj;
> +       int map_fd, prog_fd;
>         char filename[256];
> -       FILE *f;
>         int i, sock;
> +       FILE *f;
>
>         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
>
> -       if (load_bpf_file(filename)) {
> -               printf("%s", bpf_log_buf);
> +       if (bpf_prog_load(filename, BPF_PROG_TYPE_SOCKET_FILTER,
> +                         &obj, &prog_fd))
>                 return 1;
> -       }
> +
> +       map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
>
>         sock = open_raw_sock("lo");
>
> -       assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, prog_fd,
> -                         sizeof(prog_fd[0])) == 0);
> +       assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
> +                         sizeof(prog_fd)) == 0);
>
>         f = popen("ping -4 -c5 localhost", "r");
>         (void) f;
> @@ -34,13 +37,13 @@ int main(int ac, char **argv)
>                 int key;
>
>                 key = IPPROTO_TCP;
> -               assert(bpf_map_lookup_elem(map_fd[0], &key, &tcp_cnt) == 0);
> +               assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
>
>                 key = IPPROTO_UDP;
> -               assert(bpf_map_lookup_elem(map_fd[0], &key, &udp_cnt) == 0);
> +               assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
>
>                 key = IPPROTO_ICMP;
> -               assert(bpf_map_lookup_elem(map_fd[0], &key, &icmp_cnt) == 0);
> +               assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
>
>                 printf("TCP %lld UDP %lld ICMP %lld bytes\n",
>                        tcp_cnt, udp_cnt, icmp_cnt);
> diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c
> index 125ee6efc913..bc257333ad92 100644
> --- a/samples/bpf/sockex2_user.c
> +++ b/samples/bpf/sockex2_user.c
> @@ -3,7 +3,7 @@
>  #include <assert.h>
>  #include <linux/bpf.h>
>  #include <bpf/bpf.h>
> -#include "bpf_load.h"
> +#include "bpf/libbpf.h"
>  #include "sock_example.h"
>  #include <unistd.h>
>  #include <arpa/inet.h>
> @@ -17,22 +17,25 @@ struct pair {
>  int main(int ac, char **argv)
>  {
>         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
> +       struct bpf_object *obj;
> +       int map_fd, prog_fd;
>         char filename[256];
> -       FILE *f;
>         int i, sock;
> +       FILE *f;
>
>         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
>         setrlimit(RLIMIT_MEMLOCK, &r);
>
> -       if (load_bpf_file(filename)) {
> -               printf("%s", bpf_log_buf);
> +       if (bpf_prog_load(filename, BPF_PROG_TYPE_SOCKET_FILTER,
> +                         &obj, &prog_fd))
>                 return 1;
> -       }
> +
> +       map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
>
>         sock = open_raw_sock("lo");
>
> -       assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, prog_fd,
> -                         sizeof(prog_fd[0])) == 0);
> +       assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
> +                         sizeof(prog_fd)) == 0);
>
>         f = popen("ping -4 -c5 localhost", "r");
>         (void) f;
> @@ -41,8 +44,8 @@ int main(int ac, char **argv)
>                 int key = 0, next_key;
>                 struct pair value;
>
> -               while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) {
> -                       bpf_map_lookup_elem(map_fd[0], &next_key, &value);
> +               while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
> +                       bpf_map_lookup_elem(map_fd, &next_key, &value);
>                         printf("ip %s bytes %lld packets %lld\n",
>                                inet_ntoa((struct in_addr){htonl(next_key)}),
>                                value.bytes, value.packets);
> --
> 2.19.2
>