On Thu, Oct 18, 2018 at 1:48 PM Matteo Croce <mcr...@redhat.com> wrote:
>
> Find the ifindex via ioctl(SIOCGIFINDEX) instead of requiring the
> numeric ifindex.
Maybe use if_nametoindex which is simpler?
>
> Signed-off-by: Matteo Croce <mcr...@redhat.com>
> ---
> samples/bpf/xdp1_user.c | 26 ++++++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/samples/bpf/xdp1_user.c b/samples/bpf/xdp1_user.c
> index 4f3d824fc044..a1d0c5dcee9c 100644
> --- a/samples/bpf/xdp1_user.c
> +++ b/samples/bpf/xdp1_user.c
> @@ -15,6 +15,9 @@
> #include <unistd.h>
> #include <libgen.h>
> #include <sys/resource.h>
> +#include <sys/ioctl.h>
> +#include <sys/socket.h>
> +#include <linux/if.h>
>
> #include "bpf_util.h"
> #include "bpf/bpf.h"
> @@ -59,7 +62,7 @@ static void poll_stats(int map_fd, int interval)
> static void usage(const char *prog)
> {
> fprintf(stderr,
> - "usage: %s [OPTS] IFINDEX\n\n"
> + "usage: %s [OPTS] IFACE\n\n"
> "OPTS:\n"
> " -S use skb-mode\n"
> " -N enforce native mode\n",
> @@ -74,9 +77,11 @@ int main(int argc, char **argv)
> };
> const char *optstr = "SN";
> int prog_fd, map_fd, opt;
> + struct ifreq ifr = { 0 };
> struct bpf_object *obj;
> struct bpf_map *map;
> char filename[256];
> + int sock;
>
> while ((opt = getopt(argc, argv, optstr)) != -1) {
> switch (opt) {
> @@ -102,7 +107,24 @@ int main(int argc, char **argv)
> return 1;
> }
>
> - ifindex = strtoul(argv[optind], NULL, 0);
> + sock = socket(AF_UNIX, SOCK_DGRAM, 0);
> + if (sock == -1) {
> + perror("socket");
> + return 1;
> + }
> +
> + if (strlen(argv[optind]) >= IFNAMSIZ) {
> + printf("invalid ifname '%s'\n", argv[optind]);
> + return 1;
> + }
> +
> + strcpy(ifr.ifr_name, argv[optind]);
> + if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0) {
> + perror("SIOCGIFINDEX");
> + return 1;
> + }
> + close(sock);
> + ifindex = ifr.ifr_ifindex;
>
> snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
> prog_load_attr.file = filename;
> --
> 2.19.1
>
