tools: bpftool: add JSON output for `bpftool batch file FILE` command

`bpftool batch file FILE` takes FILE as an argument and executes all the
bpftool commands it finds inside (or stops if an error occurs).

To obtain a consistent JSON output, create a root JSON array, then for
each command create a new object containing two fields: one with the
command arguments, the other with the output (which is the JSON object
that the command would have produced, if called on its own).

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 14bfc17..71b01bf 100644 (file)
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -155,6 +155,7 @@ static int do_batch(int argc, char **argv)
        int n_argc;
        FILE *fp;
        int err;
+       int i;
 
        if (argc < 2) {
                err("too few parameters for batch\n");
@@ -174,6 +175,8 @@ static int do_batch(int argc, char **argv)
                return -1;
        }
 
+       if (json_output)
+               jsonw_start_array(json_wtr);
        while (fgets(buf, sizeof(buf), fp)) {
                if (strlen(buf) == sizeof(buf) - 1) {
                        errno = E2BIG;
@@ -197,7 +200,21 @@ static int do_batch(int argc, char **argv)
                if (!n_argc)
                        continue;
 
+               if (json_output) {
+                       jsonw_start_object(json_wtr);
+                       jsonw_name(json_wtr, "command");
+                       jsonw_start_array(json_wtr);
+                       for (i = 0; i < n_argc; i++)
+                               jsonw_string(json_wtr, n_argv[i]);
+                       jsonw_end_array(json_wtr);
+                       jsonw_name(json_wtr, "output");
+               }
+
                err = cmd_select(cmds, n_argc, n_argv, do_help);
+
+               if (json_output)
+                       jsonw_end_object(json_wtr);
+
                if (err)
                        goto err_close;
 
@@ -214,6 +231,9 @@ static int do_batch(int argc, char **argv)
 err_close:
        fclose(fp);
 
+       if (json_output)
+               jsonw_end_array(json_wtr);
+
        return err;
 }