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// SPDX-License-Identifier: GPL-3.0-or-later
#include "debugfs_plugin.h"
#include "libnetdata/required_dummies.h"
static char *user_config_dir = CONFIG_DIR;
static char *stock_config_dir = LIBCONFIG_DIR;
static int update_every = 1;
static struct debugfs_module {
const char *name;
int enabled;
int (*func)(int update_every, const char *name);
} debugfs_modules[] = {
// Memory Fragmentation
{ .name = "/sys/kernel/debug/extfrag", .enabled = CONFIG_BOOLEAN_YES,
.func = do_debugfs_extfrag},
{ .name = "/sys/kernel/debug/zswap", .enabled = CONFIG_BOOLEAN_YES,
.func = do_debugfs_zswap},
// The terminator
{ .name = NULL, .enabled = CONFIG_BOOLEAN_NO, .func = NULL}
};
#ifdef HAVE_CAPABILITY
static int debugfs_check_capabilities()
{
cap_t caps = cap_get_proc();
if (!caps) {
error("Cannot get current capabilities.");
return 0;
}
int ret = 1;
cap_flag_value_t cfv = CAP_CLEAR;
if (cap_get_flag(caps, CAP_DAC_READ_SEARCH, CAP_EFFECTIVE, &cfv) == -1) {
error("Cannot find if CAP_DAC_READ_SEARCH is effective.");
ret = 0;
} else {
if (cfv != CAP_SET) {
error("debugfs.plugin should run with CAP_DAC_READ_SEARCH.");
ret = 0;
}
}
cap_free(caps);
return ret;
}
#else
static int debugfs_check_capabilities()
{
return 0;
}
#endif
// TODO: This is a function used by 3 different collector, we should do it global (next PR)
static int debugfs_am_i_running_as_root()
{
uid_t uid = getuid(), euid = geteuid();
if (uid == 0 || euid == 0) {
return 1;
}
return 0;
}
void debugfs2lower(char *name)
{
while (*name) {
*name = tolower(*name);
name++;
}
}
// Consiidering our goal to redce binaries, I preferred to copy function, instead to force link with unecessary libs
const char *debugfs_rrdset_type_name(RRDSET_TYPE chart_type) {
switch(chart_type) {
case RRDSET_TYPE_LINE:
default:
return RRDSET_TYPE_LINE_NAME;
case RRDSET_TYPE_AREA:
return RRDSET_TYPE_AREA_NAME;
case RRDSET_TYPE_STACKED:
return RRDSET_TYPE_STACKED_NAME;
}
}
const char *debugfs_rrd_algorithm_name(RRD_ALGORITHM algorithm) {
switch(algorithm) {
case RRD_ALGORITHM_ABSOLUTE:
default:
return RRD_ALGORITHM_ABSOLUTE_NAME;
case RRD_ALGORITHM_INCREMENTAL:
return RRD_ALGORITHM_INCREMENTAL_NAME;
case RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL:
return RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL_NAME;
case RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
return RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL_NAME;
}
}
int debugfs_check_sys_permission() {
int ret = 0;
char filename[FILENAME_MAX + 1];
snprintfz(filename, FILENAME_MAX, "%s/sys/kernel/debug/extfrag/extfrag_index", netdata_configured_host_prefix);
procfile *ff = procfile_open(filename, NULL, PROCFILE_FLAG_NO_ERROR_ON_FILE_IO);
if(!ff) goto dcsp_cleanup;
ff = procfile_readall(ff);
if(!ff) goto dcsp_cleanup;
ret = 1;
dcsp_cleanup:
if (!ret)
perror("Cannot open /sys/kernel/debug/extfrag/extfrag_index file");
procfile_close(ff);
return ret;
}
static void debugfs_parse_args(int argc, char **argv)
{
int i, freq = 0;
for(i = 1; i < argc; i++) {
if(!freq) {
int n = (int)str2l(argv[i]);
if(n > 0) {
freq = n;
continue;
}
}
if(strcmp("test-permissions", argv[i]) == 0 || strcmp("-t", argv[i]) == 0) {
if(!debugfs_check_sys_permission()) {
exit(2);
}
printf("OK\n");
exit(0);
}
}
if(freq > 0) update_every = freq;
}
int main(int argc, char **argv)
{
// debug_flags = D_PROCFILE;
stderror = stderr;
// set the name for logging
program_name = "debugfs.plugin";
// disable syslog for debugfs.plugin
error_log_syslog = 0;
netdata_configured_host_prefix = getenv("NETDATA_HOST_PREFIX");
if (verify_netdata_host_prefix() == -1)
exit(1);
user_config_dir = getenv("NETDATA_USER_CONFIG_DIR");
if (user_config_dir == NULL) {
user_config_dir = CONFIG_DIR;
}
stock_config_dir = getenv("NETDATA_STOCK_CONFIG_DIR");
if (stock_config_dir == NULL) {
// info("NETDATA_CONFIG_DIR is not passed from netdata");
stock_config_dir = LIBCONFIG_DIR;
}
// FIXME: should first check if /sys/kernel/debug is mounted
// FIXME: remove debugfs_check_sys_permission() after https://github.com/netdata/netdata/issues/15048 is fixed
if (!debugfs_check_capabilities() && !debugfs_am_i_running_as_root() && !debugfs_check_sys_permission()) {
uid_t uid = getuid(), euid = geteuid();
#ifdef HAVE_CAPABILITY
error(
"debugfs.plugin should either run as root (now running with uid %u, euid %u) or have special capabilities. "
"Without these, debugfs.plugin cannot access /sys/kernel/debug. "
"To enable capabilities run: sudo setcap cap_dac_read_search,cap_sys_ptrace+ep %s; "
"To enable setuid to root run: sudo chown root:netdata %s; sudo chmod 4750 %s; ",
uid,
euid,
argv[0],
argv[0],
argv[0]);
#else
error(
"debugfs.plugin should either run as root (now running with uid %u, euid %u) or have special capabilities. "
"Without these, debugfs.plugin cannot access /sys/kernel/debug."
"Your system does not support capabilities. "
"To enable setuid to root run: sudo chown root:netdata %s; sudo chmod 4750 %s; ",
uid,
euid,
argv[0],
argv[0]);
#endif
exit(1);
}
// if (!debugfs_check_sys_permission()) {
// exit(2);
// }
debugfs_parse_args(argc, argv);
size_t iteration;
usec_t step = update_every * USEC_PER_SEC;
heartbeat_t hb;
heartbeat_init(&hb);
for (iteration = 0; iteration < 86400; iteration++) {
heartbeat_next(&hb, step);
int enabled = 0;
for (int i = 0; debugfs_modules[i].name; i++) {
struct debugfs_module *pm = &debugfs_modules[i];
if (unlikely(!pm->enabled))
continue;
pm->enabled = !pm->func(update_every, pm->name);
if (likely(pm->enabled))
enabled++;
}
if (!enabled) {
info("all modules are disabled, exiting...");
return 1;
}
}
fprintf(stdout, "EXIT\n");
fflush(stdout);
return 0;
}
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