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 int become_user(const char *username, int pid_fd)
63 struct passwd *pw = getpwnam(username);
65 error("User %s is not present.", username);
69 uid_t uid = pw->pw_uid;
70 gid_t gid = pw->pw_gid;
72 int ngroups = (int)sysconf(_SC_NGROUPS_MAX);
73 gid_t *supplementary_groups = NULL;
75 supplementary_groups = mallocz(sizeof(gid_t) * ngroups);
76 if(getgrouplist(username, gid, supplementary_groups, &ngroups) == -1) {
77 error("Cannot get supplementary groups of user '%s'.", username);
78 freez(supplementary_groups);
79 supplementary_groups = NULL;
84 chown_open_file(STDOUT_FILENO, uid, gid);
85 chown_open_file(STDERR_FILENO, uid, gid);
86 chown_open_file(stdaccess_fd, uid, gid);
87 chown_open_file(pid_fd, uid, gid);
89 if(supplementary_groups && ngroups) {
90 if(setgroups(ngroups, supplementary_groups) == -1)
91 error("Cannot set supplementary groups for user '%s'", username);
93 freez(supplementary_groups);
94 supplementary_groups = NULL;
98 if(setresgid(gid, gid, gid) != 0) {
99 error("Cannot switch to user's %s group (gid: %u).", username, gid);
103 if(setresuid(uid, uid, uid) != 0) {
104 error("Cannot switch to user %s (uid: %u).", username, uid);
108 if(setgid(gid) != 0) {
109 error("Cannot switch to user's %s group (gid: %u).", username, gid);
112 if(setegid(gid) != 0) {
113 error("Cannot effectively switch to user's %s group (gid: %u).", username, gid);
116 if(setuid(uid) != 0) {
117 error("Cannot switch to user %s (uid: %u).", username, uid);
120 if(seteuid(uid) != 0) {
121 error("Cannot effectively switch to user %s (uid: %u).", username, uid);
128 void oom_score_adj(int score) {
130 int fd = open("/proc/self/oom_score_adj", O_WRONLY);
133 ssize_t len = snprintfz(buf, 10, "%d", score);
134 if(write(fd, buf, len) == len) done = 1;
139 error("Cannot adjust my Out-Of-Memory score to %d.", score);
141 info("Adjusted my Out-Of-Memory score to %d.", score);
144 int sched_setscheduler_idle(void) {
146 const struct sched_param param = {
150 int i = sched_setscheduler(0, SCHED_IDLE, ¶m);
152 error("Cannot adjust my scheduling priority to IDLE.");
154 info("Adjusted my scheduling priority to IDLE.");
162 int become_daemon(int dont_fork, const char *user)
167 perror("cannot fork");
171 exit(0); // the parent
174 // become session leader
176 perror("Cannot become session leader.");
183 perror("cannot fork");
187 exit(0); // the parent
191 // generate our pid file
194 pidfd = open(pidfile, O_WRONLY | O_CREAT, 0644);
196 if(ftruncate(pidfd, 0) != 0)
197 error("Cannot truncate pidfile '%s'.", pidfile);
200 sprintf(b, "%d\n", getpid());
201 ssize_t i = write(pidfd, b, strlen(b));
203 error("Cannot write pidfile '%s'.", pidfile);
205 else error("Failed to open pidfile '%s'.", pidfile);
208 // Set new file permissions
211 // adjust my Out-Of-Memory score
214 // never become a problem
215 if(sched_setscheduler_idle() != 0) {
216 if(nice(19) == -1) error("Cannot lower my CPU priority.");
217 else info("Set my nice value to 19.");
221 if(become_user(user, pidfd) != 0) {
222 error("Cannot become user '%s'. Continuing as we are.", user);
224 else info("Successfully became user '%s'.", user);