proc_sys_kernel_random_entropy_avail.c

#include "common.h"

int do_proc_sys_kernel_random_entropy_avail(int update_every, usec_t dt) {
    (void)dt;

    static procfile *ff = NULL;

    if(unlikely(!ff)) {
        char filename[FILENAME_MAX + 1];
        snprintfz(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/sys/kernel/random/entropy_avail");
        ff = procfile_open(config_get("plugin:proc:/proc/sys/kernel/random/entropy_avail", "filename to monitor", filename), "", PROCFILE_FLAG_DEFAULT);
        if(unlikely(!ff)) return 1;
    }

    ff = procfile_readall(ff);
    if(unlikely(!ff)) return 0; // we return 0, so that we will retry to open it next time

    unsigned long long entropy = strtoull(procfile_lineword(ff, 0, 0), NULL, 10);

    RRDSET *st = rrdset_find_bytype("system", "entropy");
    if(unlikely(!st)) {
        st = rrdset_create("system", "entropy", NULL, "entropy", NULL, "Available Entropy", "entropy", 1000, update_every, RRDSET_TYPE_LINE);
        rrddim_add(st, "entropy", NULL, 1, 1, RRDDIM_ABSOLUTE);
    }
    else rrdset_next(st);

    rrddim_set(st, "entropy", entropy);
    rrdset_done(st);

    return 0;
}