diff options
Diffstat (limited to 'src/daemon.c')
| -rw-r--r-- | src/daemon.c | 521 |
1 files changed, 218 insertions, 303 deletions
diff --git a/src/daemon.c b/src/daemon.c index 2a56ae0cc..bc4614f07 100644 --- a/src/daemon.c +++ b/src/daemon.c @@ -1,315 +1,230 @@ -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> -#include <fcntl.h> -#include <errno.h> -#include <signal.h> -#include <string.h> -#include <sys/types.h> -#include <pwd.h> -#include <grp.h> -#include <pthread.h> -#include <sys/wait.h> -#include <sys/stat.h> - #include "common.h" -#include "appconfig.h" -#include "log.h" -#include "web_client.h" -#include "plugins_d.h" -#include "rrd.h" -#include "popen.h" -#include "main.h" -#include "daemon.h" +#include <sched.h> char pidfile[FILENAME_MAX + 1] = ""; -int pidfd = -1; -void sig_handler(int signo) +void sig_handler_exit(int signo) +{ + if(signo) { + error_log_limit_unlimited(); + error("Received signal %d. Exiting...", signo); + netdata_exit = 1; + } +} + +void sig_handler_logrotate(int signo) { - if(signo) - netdata_exit = 1; + if(signo) { + error_log_limit_reset(); + info("Received signal %d to re-open the log files", signo); + reopen_all_log_files(); + } } -int become_user(const char *username) +void sig_handler_save(int signo) { - struct passwd *pw = getpwnam(username); - if(!pw) { - error("User %s is not present.", username); - return -1; - } - - uid_t uid = pw->pw_uid; - gid_t gid = pw->pw_gid; - - int ngroups = sysconf(_SC_NGROUPS_MAX); - gid_t *supplementary_groups = NULL; - if(ngroups) { - supplementary_groups = malloc(sizeof(gid_t) * ngroups); - if(supplementary_groups) { - if(getgrouplist(username, gid, supplementary_groups, &ngroups) == -1) { - error("Cannot get supplementary groups of user '%s'.", username); - free(supplementary_groups); - supplementary_groups = NULL; - ngroups = 0; - } - } - else fatal("Cannot allocate memory for %d supplementary groups", ngroups); - } - - if(pidfile[0] && getuid() != uid) { - // we are dropping privileges - if(chown(pidfile, uid, gid) != 0) - error("Cannot chown pidfile '%s' to user '%s'", pidfile, username); - - else if(pidfd != -1) { - // not need to keep it open - close(pidfd); - pidfd = -1; - } - } - else if(pidfd != -1) { - // not need to keep it open - close(pidfd); - pidfd = -1; - } - - if(supplementary_groups && ngroups) { - if(setgroups(ngroups, supplementary_groups) == -1) - error("Cannot set supplementary groups for user '%s'", username); - - free(supplementary_groups); - supplementary_groups = NULL; - ngroups = 0; - } - - if(setresgid(gid, gid, gid) != 0) { - error("Cannot switch to user's %s group (gid: %d).", username, gid); - return -1; - } - - if(setresuid(uid, uid, uid) != 0) { - error("Cannot switch to user %s (uid: %d).", username, uid); - return -1; - } - - if(setgid(gid) != 0) { - error("Cannot switch to user's %s group (gid: %d).", username, gid); - return -1; - } - if(setegid(gid) != 0) { - error("Cannot effectively switch to user's %s group (gid: %d).", username, gid); - return -1; - } - if(setuid(uid) != 0) { - error("Cannot switch to user %s (uid: %d).", username, uid); - return -1; - } - if(seteuid(uid) != 0) { - error("Cannot effectively switch to user %s (uid: %d).", username, uid); - return -1; - } - - return(0); + if(signo) { + error_log_limit_reset(); + info("Received signal %d to save the database...", signo); + rrdset_save_all(); + } +} + +void sig_handler_reload_health(int signo) +{ + if(signo) { + error_log_limit_reset(); + info("Received signal %d to reload health configuration...", signo); + health_reload(); + } +} + +static void chown_open_file(int fd, uid_t uid, gid_t gid) { + if(fd == -1) return; + + struct stat buf; + + if(fstat(fd, &buf) == -1) { + error("Cannot fstat() fd %d", fd); + return; + } + + if((buf.st_uid != uid || buf.st_gid != gid) && S_ISREG(buf.st_mode)) { + if(fchown(fd, uid, gid) == -1) + error("Cannot fchown() fd %d.", fd); + } +} + +int become_user(const char *username, int pid_fd) +{ + struct passwd *pw = getpwnam(username); + if(!pw) { + error("User %s is not present.", username); + return -1; + } + + uid_t uid = pw->pw_uid; + gid_t gid = pw->pw_gid; + + int ngroups = (int)sysconf(_SC_NGROUPS_MAX); + gid_t *supplementary_groups = NULL; + if(ngroups) { + supplementary_groups = mallocz(sizeof(gid_t) * ngroups); + if(getgrouplist(username, gid, supplementary_groups, &ngroups) == -1) { + error("Cannot get supplementary groups of user '%s'.", username); + freez(supplementary_groups); + supplementary_groups = NULL; + ngroups = 0; + } + } + + chown_open_file(STDOUT_FILENO, uid, gid); + chown_open_file(STDERR_FILENO, uid, gid); + chown_open_file(stdaccess_fd, uid, gid); + chown_open_file(pid_fd, uid, gid); + + if(supplementary_groups && ngroups) { + if(setgroups(ngroups, supplementary_groups) == -1) + error("Cannot set supplementary groups for user '%s'", username); + + freez(supplementary_groups); + supplementary_groups = NULL; + ngroups = 0; + } + + if(setresgid(gid, gid, gid) != 0) { + error("Cannot switch to user's %s group (gid: %u).", username, gid); + return -1; + } + + if(setresuid(uid, uid, uid) != 0) { + error("Cannot switch to user %s (uid: %u).", username, uid); + return -1; + } + + if(setgid(gid) != 0) { + error("Cannot switch to user's %s group (gid: %u).", username, gid); + return -1; + } + if(setegid(gid) != 0) { + error("Cannot effectively switch to user's %s group (gid: %u).", username, gid); + return -1; + } + if(setuid(uid) != 0) { + error("Cannot switch to user %s (uid: %u).", username, uid); + return -1; + } + if(seteuid(uid) != 0) { + error("Cannot effectively switch to user %s (uid: %u).", username, uid); + return -1; + } + + return(0); +} + +void oom_score_adj(int score) { + int done = 0; + int fd = open("/proc/self/oom_score_adj", O_WRONLY); + if(fd != -1) { + char buf[10 + 1]; + ssize_t len = snprintfz(buf, 10, "%d", score); + if(write(fd, buf, len) == len) done = 1; + close(fd); + } + + if(!done) + error("Cannot adjust my Out-Of-Memory score to %d.", score); + else + info("Adjusted my Out-Of-Memory score to %d.", score); +} + +int sched_setscheduler_idle(void) { +#ifdef SCHED_IDLE + const struct sched_param param = { + .sched_priority = 0 + }; + + int i = sched_setscheduler(0, SCHED_IDLE, ¶m); + if(i != 0) + error("Cannot adjust my scheduling priority to IDLE."); + else + info("Adjusted my scheduling priority to IDLE."); + + return i; +#else + return -1; +#endif } -int become_daemon(int dont_fork, int close_all_files, const char *user, const char *input, const char *output, const char *error, const char *access, int *access_fd, FILE **access_fp) +int become_daemon(int dont_fork, const char *user) { - fflush(NULL); - - // open the files before forking - int input_fd = -1, output_fd = -1, error_fd = -1, dev_null; - - if(input && *input) { - if((input_fd = open(input, O_RDONLY, 0666)) == -1) { - error("Cannot open input file '%s'.", input); - return -1; - } - } - - if(output && *output) { - if((output_fd = open(output, O_RDWR | O_APPEND | O_CREAT, 0666)) == -1) { - error("Cannot open output log file '%s'", output); - if(input_fd != -1) close(input_fd); - return -1; - } - } - - if(error && *error) { - if((error_fd = open(error, O_RDWR | O_APPEND | O_CREAT, 0666)) == -1) { - error("Cannot open error log file '%s'.", error); - if(input_fd != -1) close(input_fd); - if(output_fd != -1) close(output_fd); - return -1; - } - } - - if(access && *access && access_fd) { - if((*access_fd = open(access, O_RDWR | O_APPEND | O_CREAT, 0666)) == -1) { - error("Cannot open access log file '%s'", access); - if(input_fd != -1) close(input_fd); - if(output_fd != -1) close(output_fd); - if(error_fd != -1) close(error_fd); - return -1; - } - - if(access_fp) { - *access_fp = fdopen(*access_fd, "w"); - if(!*access_fp) { - error("Cannot migrate file's '%s' fd %d.", access, *access_fd); - if(input_fd != -1) close(input_fd); - if(output_fd != -1) close(output_fd); - if(error_fd != -1) close(error_fd); - close(*access_fd); - *access_fd = -1; - return -1; - } - if(setvbuf(*access_fp, NULL, _IOLBF, 0) != 0) - error("Cannot set line buffering on access.log"); - } - } - - if((dev_null = open("/dev/null", O_RDWR, 0666)) == -1) { - perror("Cannot open /dev/null"); - if(input_fd != -1) close(input_fd); - if(output_fd != -1) close(output_fd); - if(error_fd != -1) close(error_fd); - if(access && access_fd && *access_fd != -1) { - close(*access_fd); - *access_fd = -1; - if(access_fp) { - fclose(*access_fp); - *access_fp = NULL; - } - } - return -1; - } - - // all files opened - // lets do it - - if(!dont_fork) { - int i = fork(); - if(i == -1) { - perror("cannot fork"); - exit(1); - } - if(i != 0) { - exit(0); // the parent - } - - // become session leader - if (setsid() < 0) { - perror("Cannot become session leader."); - exit(2); - } - } - - // fork() again - if(!dont_fork) { - int i = fork(); - if(i == -1) { - perror("cannot fork"); - exit(1); - } - if(i != 0) { - exit(0); // the parent - } - } - - // Set new file permissions - umask(0); - - // close all files - if(close_all_files) { - int i; - for(i = (int) (sysconf(_SC_OPEN_MAX) - 1); i > 0; i--) - if( - ((access_fd && i != *access_fd) || !access_fd) - && i != dev_null - && i != input_fd - && i != output_fd - && i != error_fd - && fd_is_valid(i) - ) close(i); - } - else { - close(STDIN_FILENO); - close(STDOUT_FILENO); - close(STDERR_FILENO); - } - - // put the opened files - // to our standard file descriptors - if(input_fd != -1) { - if(input_fd != STDIN_FILENO) { - dup2(input_fd, STDIN_FILENO); - close(input_fd); - } - input_fd = -1; - } - else dup2(dev_null, STDIN_FILENO); - - if(output_fd != -1) { - if(output_fd != STDOUT_FILENO) { - dup2(output_fd, STDOUT_FILENO); - close(output_fd); - } - - if(setvbuf(stdout, NULL, _IOLBF, 0) != 0) - error("Cannot set line buffering on debug.log"); - - output_fd = -1; - } - else dup2(dev_null, STDOUT_FILENO); - - if(error_fd != -1) { - if(error_fd != STDERR_FILENO) { - dup2(error_fd, STDERR_FILENO); - close(error_fd); - } - - if(setvbuf(stderr, NULL, _IOLBF, 0) != 0) - error("Cannot set line buffering on error.log"); - - error_fd = -1; - } - else dup2(dev_null, STDERR_FILENO); - - // close /dev/null - if(dev_null != STDIN_FILENO && dev_null != STDOUT_FILENO && dev_null != STDERR_FILENO) - close(dev_null); - - // generate our pid file - if(pidfile[0]) { - pidfd = open(pidfile, O_RDWR | O_CREAT, 0644); - if(pidfd >= 0) { - if(ftruncate(pidfd, 0) != 0) - error("Cannot truncate pidfile '%s'.", pidfile); - - char b[100]; - sprintf(b, "%d\n", getpid()); - ssize_t i = write(pidfd, b, strlen(b)); - if(i <= 0) - error("Cannot write pidfile '%s'.", pidfile); - - // don't close it, we might need it at exit - // close(pidfd); - } - else error("Failed to open pidfile '%s'.", pidfile); - } - - if(user && *user) { - if(become_user(user) != 0) { - error("Cannot become user '%s'. Continuing as we are.", user); - } - else info("Successfully became user '%s'.", user); - } - else if(pidfd != -1) - close(pidfd); - - return(0); + if(!dont_fork) { + int i = fork(); + if(i == -1) { + perror("cannot fork"); + exit(1); + } + if(i != 0) { + exit(0); // the parent + } + + // become session leader + if (setsid() < 0) { + perror("Cannot become session leader."); + exit(2); + } + + // fork() again + i = fork(); + if(i == -1) { + perror("cannot fork"); + exit(1); + } + if(i != 0) { + exit(0); // the parent + } + } + + // generate our pid file + int pidfd = -1; + if(pidfile[0]) { + pidfd = open(pidfile, O_WRONLY | O_CREAT, 0644); + if(pidfd >= 0) { + if(ftruncate(pidfd, 0) != 0) + error("Cannot truncate pidfile '%s'.", pidfile); + + char b[100]; + sprintf(b, "%d\n", getpid()); + ssize_t i = write(pidfd, b, strlen(b)); + if(i <= 0) + error("Cannot write pidfile '%s'.", pidfile); + } + else error("Failed to open pidfile '%s'.", pidfile); + } + + // Set new file permissions + umask(0002); + + // adjust my Out-Of-Memory score + oom_score_adj(1000); + + // never become a problem + if(sched_setscheduler_idle() != 0) { + if(nice(19) == -1) error("Cannot lower my CPU priority."); + else info("Set my nice value to 19."); + } + + if(user && *user) { + if(become_user(user, pidfd) != 0) { + error("Cannot become user '%s'. Continuing as we are.", user); + } + else info("Successfully became user '%s'.", user); + } + + if(pidfd != -1) { + close(pidfd); + pidfd = -1; + } + + return(0); } |