From 1e6c93250172946eeb38e94a92a1fd12c9d3011e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 7 Nov 2018 13:22:44 +0100 Subject: Merging upstream version 1.11.0+dfsg. Signed-off-by: Daniel Baumann --- src/daemon.c | 396 ----------------------------------------------------------- 1 file changed, 396 deletions(-) delete mode 100644 src/daemon.c (limited to 'src/daemon.c') diff --git a/src/daemon.c b/src/daemon.c deleted file mode 100644 index 471c62c6e..000000000 --- a/src/daemon.c +++ /dev/null @@ -1,396 +0,0 @@ -#include "common.h" -#include - -char pidfile[FILENAME_MAX + 1] = ""; - -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); - } -} - -void create_needed_dir(const char *dir, uid_t uid, gid_t gid) -{ - // attempt to create the directory - if(mkdir(dir, 0755) == 0) { - // we created it - - // chown it to match the required user - if(chown(dir, uid, gid) == -1) - error("Cannot chown directory '%s' to %u:%u", dir, (unsigned int)uid, (unsigned int)gid); - } - else if(errno != EEXIST) - // log an error only if the directory does not exist - error("Cannot create directory '%s'", dir); -} - -int become_user(const char *username, int pid_fd) { - int am_i_root = (getuid() == 0)?1:0; - - 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; - - create_needed_dir(netdata_configured_cache_dir, uid, gid); - create_needed_dir(netdata_configured_varlib_dir, uid, gid); - - if(pidfile[0]) { - if(chown(pidfile, uid, gid) == -1) - error("Cannot chown '%s' to %u:%u", pidfile, (unsigned int)uid, (unsigned int)gid); - } - - int ngroups = (int)sysconf(_SC_NGROUPS_MAX); - gid_t *supplementary_groups = NULL; - if(ngroups > 0) { - supplementary_groups = mallocz(sizeof(gid_t) * ngroups); - if(getgrouplist(username, gid, supplementary_groups, &ngroups) == -1) { - if(am_i_root) - error("Cannot get supplementary groups of user '%s'.", username); - - 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 > 0) { - if(setgroups((size_t)ngroups, supplementary_groups) == -1) { - if(am_i_root) - error("Cannot set supplementary groups for user '%s'", username); - } - ngroups = 0; - } - - if(supplementary_groups) - freez(supplementary_groups); - -#ifdef __APPLE__ - if(setregid(gid, gid) != 0) { -#else - if(setresgid(gid, gid, gid) != 0) { -#endif /* __APPLE__ */ - error("Cannot switch to user's %s group (gid: %u).", username, gid); - return -1; - } - -#ifdef __APPLE__ - if(setreuid(uid, uid) != 0) { -#else - if(setresuid(uid, uid, uid) != 0) { -#endif /* __APPLE__ */ - 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); -} - -#ifndef OOM_SCORE_ADJ_MAX -#define OOM_SCORE_ADJ_MAX (1000) -#endif -#ifndef OOM_SCORE_ADJ_MIN -#define OOM_SCORE_ADJ_MIN (-1000) -#endif - -static void oom_score_adj(void) { - char buf[30 + 1]; - long long int old_score, wanted_score = OOM_SCORE_ADJ_MAX, final_score = 0; - - // read the existing score - if(read_single_signed_number_file("/proc/self/oom_score_adj", &old_score)) { - error("Out-Of-Memory (OOM) score setting is not supported on this system."); - return; - } - - if(old_score != 0) - wanted_score = old_score; - - // check the environment - char *s = getenv("OOMScoreAdjust"); - if(!s || !*s) { - snprintfz(buf, 30, "%d", (int)wanted_score); - s = buf; - } - - // check netdata.conf configuration - s = config_get(CONFIG_SECTION_GLOBAL, "OOM score", s); - if(s && *s && (isdigit(*s) || *s == '-' || *s == '+')) - wanted_score = atoll(s); - else { - info("Out-Of-Memory (OOM) score not changed due to non-numeric setting: '%s' (running with %d)", s, (int)old_score); - return; - } - - if(wanted_score < OOM_SCORE_ADJ_MIN) { - error("Wanted Out-Of-Memory (OOM) score %d is too small. Using %d", (int)wanted_score, (int)OOM_SCORE_ADJ_MIN); - wanted_score = OOM_SCORE_ADJ_MIN; - } - - if(wanted_score > OOM_SCORE_ADJ_MAX) { - error("Wanted Out-Of-Memory (OOM) score %d is too big. Using %d", (int)wanted_score, (int)OOM_SCORE_ADJ_MAX); - wanted_score = OOM_SCORE_ADJ_MAX; - } - - if(old_score == wanted_score) { - info("Out-Of-Memory (OOM) score is already set to the wanted value %d", (int)old_score); - return; - } - - int written = 0; - int fd = open("/proc/self/oom_score_adj", O_WRONLY); - if(fd != -1) { - snprintfz(buf, 30, "%d", (int)wanted_score); - ssize_t len = strlen(buf); - if(len > 0 && write(fd, buf, (size_t)len) == len) written = 1; - close(fd); - - if(written) { - if(read_single_signed_number_file("/proc/self/oom_score_adj", &final_score)) - error("Adjusted my Out-Of-Memory (OOM) score to %d, but cannot verify it.", (int)wanted_score); - else if(final_score == wanted_score) - info("Adjusted my Out-Of-Memory (OOM) score from %d to %d.", (int)old_score, (int)final_score); - else - error("Adjusted my Out-Of-Memory (OOM) score from %d to %d, but it has been set to %d.", (int)old_score, (int)wanted_score, (int)final_score); - } - else - error("Failed to adjust my Out-Of-Memory (OOM) score to %d. Running with %d. (systemd systems may change it via netdata.service)", (int)wanted_score, (int)old_score); - } - else - error("Failed to adjust my Out-Of-Memory (OOM) score. Cannot open /proc/self/oom_score_adj for writing."); -} - -static void process_nice_level(void) { -#ifdef HAVE_NICE - int nice_level = (int)config_get_number(CONFIG_SECTION_GLOBAL, "process nice level", 19); - if(nice(nice_level) == -1) error("Cannot set netdata CPU nice level to %d.", nice_level); - else debug(D_SYSTEM, "Set netdata nice level to %d.", nice_level); -#endif // HAVE_NICE -}; - -#ifdef HAVE_SCHED_SETSCHEDULER - -#define SCHED_FLAG_NONE 0x00 -#define SCHED_FLAG_PRIORITY_CONFIGURABLE 0x01 // the priority is user configurable -#define SCHED_FLAG_KEEP_AS_IS 0x04 // do not attempt to set policy, priority or nice() -#define SCHED_FLAG_USE_NICE 0x08 // use nice() after setting this policy - -struct sched_def { - char *name; - int policy; - int priority; - uint8_t flags; -} scheduler_defaults[] = { - - // the order of array members is important! - // the first defined is the default used by netdata - - // the available members are important too! - // these are all the possible scheduling policies supported by netdata - -#ifdef SCHED_IDLE - { "idle", SCHED_IDLE, 0, SCHED_FLAG_NONE }, -#endif - -#ifdef SCHED_OTHER - { "nice", SCHED_OTHER, 0, SCHED_FLAG_USE_NICE }, - { "other", SCHED_OTHER, 0, SCHED_FLAG_USE_NICE }, -#endif - -#ifdef SCHED_RR - { "rr", SCHED_RR, 0, SCHED_FLAG_PRIORITY_CONFIGURABLE }, -#endif - -#ifdef SCHED_FIFO - { "fifo", SCHED_FIFO, 0, SCHED_FLAG_PRIORITY_CONFIGURABLE }, -#endif - -#ifdef SCHED_BATCH - { "batch", SCHED_BATCH, 0, SCHED_FLAG_USE_NICE }, -#endif - - // do not change the scheduling priority - { "keep", 0, 0, SCHED_FLAG_KEEP_AS_IS }, - { "none", 0, 0, SCHED_FLAG_KEEP_AS_IS }, - - // array termination - { NULL, 0, 0, 0 } -}; - -static void sched_setscheduler_set(void) { - - if(scheduler_defaults[0].name) { - const char *name = scheduler_defaults[0].name; - int policy = scheduler_defaults[0].policy, priority = scheduler_defaults[0].priority; - uint8_t flags = scheduler_defaults[0].flags; - int found = 0; - - // read the configuration - name = config_get(CONFIG_SECTION_GLOBAL, "process scheduling policy", name); - int i; - for(i = 0 ; scheduler_defaults[i].name ; i++) { - if(!strcmp(name, scheduler_defaults[i].name)) { - found = 1; - policy = scheduler_defaults[i].policy; - priority = scheduler_defaults[i].priority; - flags = scheduler_defaults[i].flags; - - if(flags & SCHED_FLAG_KEEP_AS_IS) - return; - - if(flags & SCHED_FLAG_PRIORITY_CONFIGURABLE) - priority = (int)config_get_number(CONFIG_SECTION_GLOBAL, "process scheduling priority", priority); - -#ifdef HAVE_SCHED_GET_PRIORITY_MIN - errno = 0; - if(priority < sched_get_priority_min(policy)) { - error("scheduler %s (%d) priority %d is below the minimum %d. Using the minimum.", name, policy, priority, sched_get_priority_min(policy)); - priority = sched_get_priority_min(policy); - } -#endif -#ifdef HAVE_SCHED_GET_PRIORITY_MAX - errno = 0; - if(priority > sched_get_priority_max(policy)) { - error("scheduler %s (%d) priority %d is above the maximum %d. Using the maximum.", name, policy, priority, sched_get_priority_max(policy)); - priority = sched_get_priority_max(policy); - } -#endif - break; - } - } - - if(!found) { - error("Unknown scheduling policy '%s' - falling back to nice", name); - goto fallback; - } - - const struct sched_param param = { - .sched_priority = priority - }; - - errno = 0; - i = sched_setscheduler(0, policy, ¶m); - if(i != 0) { - error("Cannot adjust netdata scheduling policy to %s (%d), with priority %d. Falling back to nice.", name, policy, priority); - } - else { - info("Adjusted netdata scheduling policy to %s (%d), with priority %d.", name, policy, priority); - if(!(flags & SCHED_FLAG_USE_NICE)) - return; - } - } - -fallback: - process_nice_level(); -} -#else -static void sched_setscheduler_set(void) { - process_nice_level(); -} -#endif - -int become_daemon(int dont_fork, const char *user) -{ - 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(0007); - - // adjust my Out-Of-Memory score - oom_score_adj(); - - // never become a problem - sched_setscheduler_set(); - - if(user && *user) { - if(become_user(user, pidfd) != 0) { - error("Cannot become user '%s'. Continuing as we are.", user); - } - else debug(D_SYSTEM, "Successfully became user '%s'.", user); - } - else { - create_needed_dir(netdata_configured_cache_dir, getuid(), getgid()); - create_needed_dir(netdata_configured_varlib_dir, getuid(), getgid()); - } - - if(pidfd != -1) - close(pidfd); - - return(0); -} -- cgit v1.2.3