On Tue, 10 Dec 2019 17:06:42 +0100, Paul Chaignon wrote:
> When working with frequently modified BPF programs, both the ID and the
> tag may change. bpftool currently doesn't provide a "stable" way to match
> such programs.
>
> This patch implements lookup by name for programs. The show and dump
> commands will return all programs with the given name, whereas other
> commands will error out if several programs have the same name.
>
> Signed-off-by: Paul Chaignon <paul.chaignon@xxxxxxxxxx>
> @@ -164,7 +165,7 @@ prog_parse_fds(int *argc, char ***argv, int *fds)
> }
> return 1;
> } else if (is_prefix(**argv, "tag")) {
> - unsigned char tag[BPF_TAG_SIZE];
> + char tag[BPF_TAG_SIZE];
Perhaps better to change the argument to prog_fd_by_nametag() to void *?
>
> NEXT_ARGP();
>
> @@ -176,7 +177,20 @@ prog_parse_fds(int *argc, char ***argv, int *fds)
> }
> NEXT_ARGP();
>
> - return prog_fd_by_tag(tag, fds);
> + return prog_fd_by_nametag(tag, fds, true);
> + } else if (is_prefix(**argv, "name")) {
> + char *name;
> +
> + NEXT_ARGP();
> +
> + name = **argv;
> + if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
Is this needed? strncmp will simply never match, is it preferred to
hard error?
> + p_err("can't parse name");
> + return -1;
> + }
> + NEXT_ARGP();
> +
> + return prog_fd_by_nametag(name, fds, false);
> } else if (is_prefix(**argv, "pinned")) {
> char *path;
>
> @@ -191,7 +205,7 @@ prog_parse_fds(int *argc, char ***argv, int *fds)
> return 1;
> }
>
> - p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);
> + p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);
> return -1;
> }
>
