4 char pidfile[FILENAME_MAX + 1] = "";
6 void sig_handler_exit(int signo)
9 error_log_limit_unlimited();
10 error("Received signal %d. Exiting...", signo);
15 void sig_handler_logrotate(int signo)
18 error_log_limit_unlimited();
19 info("Received signal %d to re-open the log files", signo);
20 reopen_all_log_files();
21 error_log_limit_reset();
25 void sig_handler_save(int signo)
28 error_log_limit_unlimited();
29 info("Received signal %d to save the database...", signo);
31 error_log_limit_reset();
35 void sig_handler_reload_health(int signo)
38 error_log_limit_unlimited();
39 info("Received signal %d to reload health configuration...", signo);
41 error_log_limit_reset();
45 static void chown_open_file(int fd, uid_t uid, gid_t gid) {
50 if(fstat(fd, &buf) == -1) {
51 error("Cannot fstat() fd %d", fd);
55 if((buf.st_uid != uid || buf.st_gid != gid) && S_ISREG(buf.st_mode)) {
56 if(fchown(fd, uid, gid) == -1)
57 error("Cannot fchown() fd %d.", fd);
61 void create_needed_dir(const char *dir, uid_t uid, gid_t gid)
63 if(mkdir(dir, 0755) == -1 && errno != EEXIST)
64 error("Cannot create directory '%s'", dir);
66 if(chown(dir, uid, gid) == -1)
67 error("Cannot chown directory '%s' to %u:%u", dir, (unsigned int)uid, (unsigned int)gid);
70 int become_user(const char *username, int pid_fd)
72 struct passwd *pw = getpwnam(username);
74 error("User %s is not present.", username);
78 uid_t uid = pw->pw_uid;
79 gid_t gid = pw->pw_gid;
81 create_needed_dir(CACHE_DIR, uid, gid);
82 create_needed_dir(VARLIB_DIR, uid, gid);
84 int ngroups = (int)sysconf(_SC_NGROUPS_MAX);
85 gid_t *supplementary_groups = NULL;
87 supplementary_groups = mallocz(sizeof(gid_t) * ngroups);
88 if(getgrouplist(username, gid, supplementary_groups, &ngroups) == -1) {
89 error("Cannot get supplementary groups of user '%s'.", username);
90 freez(supplementary_groups);
91 supplementary_groups = NULL;
96 chown_open_file(STDOUT_FILENO, uid, gid);
97 chown_open_file(STDERR_FILENO, uid, gid);
98 chown_open_file(stdaccess_fd, uid, gid);
99 chown_open_file(pid_fd, uid, gid);
101 if(supplementary_groups && ngroups) {
102 if(setgroups(ngroups, supplementary_groups) == -1)
103 error("Cannot set supplementary groups for user '%s'", username);
105 freez(supplementary_groups);
106 supplementary_groups = NULL;
110 if(setresgid(gid, gid, gid) != 0) {
111 error("Cannot switch to user's %s group (gid: %u).", username, gid);
115 if(setresuid(uid, uid, uid) != 0) {
116 error("Cannot switch to user %s (uid: %u).", username, uid);
120 if(setgid(gid) != 0) {
121 error("Cannot switch to user's %s group (gid: %u).", username, gid);
124 if(setegid(gid) != 0) {
125 error("Cannot effectively switch to user's %s group (gid: %u).", username, gid);
128 if(setuid(uid) != 0) {
129 error("Cannot switch to user %s (uid: %u).", username, uid);
132 if(seteuid(uid) != 0) {
133 error("Cannot effectively switch to user %s (uid: %u).", username, uid);
140 void oom_score_adj(int score) {
142 int fd = open("/proc/self/oom_score_adj", O_WRONLY);
145 ssize_t len = snprintfz(buf, 10, "%d", score);
146 if(write(fd, buf, len) == len) done = 1;
151 error("Cannot adjust my Out-Of-Memory score to %d.", score);
153 debug(D_SYSTEM, "Adjusted my Out-Of-Memory score to %d.", score);
156 int sched_setscheduler_idle(void) {
158 const struct sched_param param = {
162 int i = sched_setscheduler(0, SCHED_IDLE, ¶m);
164 error("Cannot adjust my scheduling priority to IDLE.");
166 debug(D_SYSTEM, "Adjusted my scheduling priority to IDLE.");
174 int become_daemon(int dont_fork, const char *user)
179 perror("cannot fork");
183 exit(0); // the parent
186 // become session leader
188 perror("Cannot become session leader.");
195 perror("cannot fork");
199 exit(0); // the parent
203 // generate our pid file
206 pidfd = open(pidfile, O_WRONLY | O_CREAT, 0644);
208 if(ftruncate(pidfd, 0) != 0)
209 error("Cannot truncate pidfile '%s'.", pidfile);
212 sprintf(b, "%d\n", getpid());
213 ssize_t i = write(pidfd, b, strlen(b));
215 error("Cannot write pidfile '%s'.", pidfile);
217 else error("Failed to open pidfile '%s'.", pidfile);
220 // Set new file permissions
223 // adjust my Out-Of-Memory score
226 // never become a problem
227 if(sched_setscheduler_idle() != 0) {
228 if(nice(19) == -1) error("Cannot lower my CPU priority.");
229 else debug(D_SYSTEM, "Set my nice value to 19.");
233 if(become_user(user, pidfd) != 0) {
234 error("Cannot become user '%s'. Continuing as we are.", user);
236 else debug(D_SYSTEM, "Successfully became user '%s'.", user);
239 create_needed_dir(CACHE_DIR, getuid(), getgid());
240 create_needed_dir(VARLIB_DIR, getuid(), getgid());