static char *
get_config(char *cmdline)
{
xenbus_transaction_t txn;
char *cfg;
int retry;
cfg = rumprun_config_path(cmdline);
if (cfg != NULL)
return cfg;
if (xenbus_transaction_start(&txn))
return jsonordie();
if (xenbus_read(txn, "rumprun/cfg", &cfg) != NULL)
cfg = jsonordie();
xenbus_transaction_end(txn, 0, &retry);
return cfg;
}
void
rumprun_config(char *cmdline)
{
char *cfg;
struct rumprun_exec *rre;
jsmn_parser p;
jsmntok_t *tokens = NULL;
jsmntok_t *t;
size_t cmdline_len;
unsigned int i;
int ntok;
/* is the config file on rootfs? if so, mount & dig it out */
cfg = rumprun_config_path(cmdline);
if (cfg != NULL) {
cmdline = getcmdlinefromroot(cfg);
if (cmdline == NULL)
errx(1, "could not get cfg from rootfs");
}
while (*cmdline != '{') {
if (*cmdline == '\0') {
warnx("could not find start of json. no config?");
makeargv(strdup("rumprun"));
return;
}
cmdline++;
}
cmdline_len = strlen(cmdline);
jsmn_init(&p);
ntok = jsmn_parse(&p, cmdline, cmdline_len, NULL, 0);
if (ntok <= 0) {
errx(1, "json parse failed 1");
}
tokens = malloc(ntok * sizeof(*t));
if (!tokens) {
errx(1, "failed to allocate jsmn tokens");
}
jsmn_init(&p);
if ((ntok = jsmn_parse(&p, cmdline, cmdline_len, tokens, ntok)) < 1) {
errx(1, "json parse failed 2");
}
T_CHECKTYPE(tokens, cmdline, JSMN_OBJECT, __func__);
for (t = &tokens[0]; t < &tokens[ntok]; ) {
/* allow multiple levels of object nesting */
if (t->type == JSMN_OBJECT) {
t++;
continue;
}
T_CHECKTYPE(t, cmdline, JSMN_STRING, __func__);
for (i = 0; i < __arraycount(parsers); i++) {
if (T_STREQ(t, cmdline, parsers[i].name)) {
int left;
t++;
left = &tokens[ntok] - t;
t += parsers[i].handler(t, left, cmdline);
break;
}
}
if (i == __arraycount(parsers))
errx(1, "no match for key \"%.*s\"",
T_PRINTFSTAR(t, cmdline));
}
/*
* Before we start running things, perform some sanity checks
*/
rre = TAILQ_LAST(&rumprun_execs, rumprun_execs);
if (rre == NULL) {
errx(1, "rumprun_config: no bins");
}
if (rre->rre_flags & RUMPRUN_EXEC_PIPE) {
errx(1, "rumprun_config: last bin may not output to pipe");
}
free(tokens);
}
