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navi-desunavi-desu
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supervise-daemon: poc refactor
1 parent 7f74c93 commit 49d3772

6 files changed

Lines changed: 1169 additions & 1201 deletions

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‎src/supervise-daemon/daemon.c‎

Lines changed: 364 additions & 0 deletions
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#ifdef __linux__
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#include <sys/capability.h>
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#include <sys/prctl.h>
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#endif
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#include <sys/resource.h>
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#include <errno.h>
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#include <pwd.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <string.h>
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#include <syslog.h>
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#include <unistd.h>
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#include <einfo.h>
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#include <rc.h>
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#include "daemon.h"
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#include "rc_exec.h"
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#include "helpers.h"
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#include "misc.h"
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#if !defined(SYS_ioprio_set) && defined(__NR_ioprio_set)
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# define SYS_ioprio_set __NR_ioprio_set
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#endif
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#if !defined(__DragonFly__)
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static inline int ioprio_set(int which RC_UNUSED, int who RC_UNUSED,
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int ioprio RC_UNUSED)
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{
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#ifdef SYS_ioprio_set
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return syscall(SYS_ioprio_set, which, who, ioprio);
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#else
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return 0;
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#endif
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}
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#endif
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extern const char *applet;
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static bool
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set_nicelevel(const char *option)
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{
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int nicelevel;
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FILE *fp;
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if (sscanf(option, "%d", &nicelevel) != 1 || setpriority(PRIO_PROCESS, getpid(), nicelevel)) {
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syslog(LOG_ERR, "setpriority %d: %s", nicelevel, strerror(errno));
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return false;
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}
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if ((fp = fopen("/proc/self/autogroup", "r+"))) {
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fprintf(fp, "%d\n", nicelevel);
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fclose(fp);
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} else if (errno != ENOENT) {
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syslog(LOG_ERR, "autogroup nice %d: %s", nicelevel, strerror(errno));
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return false;
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}
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return true;
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}
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static bool
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set_ionice(const char *option)
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{
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int ionicec, ioniced;
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if (sscanf(option, "%d:%d", &ionicec, &ioniced) == 0) {
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syslog(LOG_ERR, "invalid ionice '%s'", optarg);
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return false;
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}
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if (ionicec == 0)
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ioniced = 0;
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else if (ionicec == 3)
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ioniced = 7;
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ionicec <<= 13; /* class shift */
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if (ioprio_set(1, getpid(), ionicec | ioniced) == -1) {
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syslog(LOG_ERR, "ioprio_set %d %d: %s", ionicec, ioniced, strerror(errno));
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return false;
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}
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return true;
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}
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static bool
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set_oom_score(const char *option)
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{
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int score;
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FILE *fp;
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if (sscanf(option, "%d", &score) != 1) {
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syslog(LOG_ERR, "invalid oom-score-adj '%s'", option);
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return false;
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}
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if (!(fp = fopen("/proc/self/oom_score_adj", "w"))) {
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syslog(LOG_ERR, "oom_score_adj %d: %s", score, strerror(errno));
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return false;
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}
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fprintf(fp, "%d\n", score);
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fclose(fp);
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return true;
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}
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static bool
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set_capabilities(const char *option)
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{
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#ifdef __linux__
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cap_iab_t cap_iab;
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if (!(cap_iab = cap_iab_from_text(option)) || cap_iab_set_proc(cap_iab) != 0 || cap_free(cap_iab) != 0) {
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syslog(LOG_ERR, "failed to set capabilities");
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return false;
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}
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return true;
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#endif
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syslog(LOG_ERR, "capabilities are not supported");
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errno = ENOSYS;
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return false;
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}
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static bool
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set_secbits(const char *option)
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{
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#ifdef __linux__
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unsigned secbits;
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char *end;
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if (*option == '\0') {
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syslog(LOG_ERR, "secbits are empty");
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return false;
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}
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secbits = strtoul(option, &end, 0);
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if (option == end) {
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syslog(LOG_ERR, "could not parse secbits: %s", option);
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return false;
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}
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if (cap_set_secbits(secbits) < 0) {
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syslog(LOG_ERR, "could not set securebits to 0x%x: %s", secbits, strerror(errno));
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return false;
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}
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return true;
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#endif
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syslog(LOG_ERR, "secbits are not supported");
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errno = ENOSYS;
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return false;
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}
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static bool
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set_no_new_privs(const char *option)
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{
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if (!rc_yesno(option))
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return true;
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#ifdef PR_SET_NO_NEW_PRIVS
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if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1) {
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syslog(LOG_ERR, "prctl: %s", strerror(errno));
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return false;
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}
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return true;
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#endif
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syslog(LOG_ERR, "no-new-privs are not supported");
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errno = ENOSYS;
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return false;
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}
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static bool
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set_umask(const char *option)
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{
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mode_t mask = 022;
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if (parse_mode(&mask, option)) {
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syslog(LOG_ERR, "%s: invalid mode '%s'", applet, optarg);
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return false;
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}
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umask(mask);
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return true;
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}
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static bool
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set_scheduler(RC_UNUSED const char *option)
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{
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/* TODO */
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return true;
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}
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static char *expand_home(const char *path)
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{
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char *expanded = NULL;
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struct passwd *pw;
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const char *home;
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size_t size;
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FILE *fp;
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if (path[0] == '\\' && path[1] == '~')
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return xstrdup(path + 1);
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else if (path[0] != '~')
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return xstrdup(path);
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fp = xopen_memstream(&expanded, &size);
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path++;
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if (path[0] == '/' || path[0] == '\0') {
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if ((home = getenv("HOME"))) {
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fputs(home, fp);
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} else if ((pw = getpwuid(getuid()))) {
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fputs(pw->pw_dir, fp);
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} else {
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syslog(LOG_ERR, "getpwuid: %s", strerror(errno));
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goto err;
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}
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} else {
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char *username;
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if ((home = strchr(path, '/'))) {
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username = xstrndup(path, home - path);
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path = home + 1;
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} else {
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username = xstrdup(path);
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path = NULL;
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}
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if (!(pw = getpwnam(username))) {
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syslog(LOG_ERR, "user %s not found", username);
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goto err;
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}
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fputs(pw->pw_dir, fp);
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free(username);
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}
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if (path)
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fputs(path, fp);
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xclose_memstream(fp);
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return expanded;
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err:
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xclose_memstream(fp);
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free(expanded);
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return NULL;
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}
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static bool
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set_dir(const char *option)
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{
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char *expand_path = expand_home(option);
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if (!expand_path)
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return false;
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if (chdir(expand_path) == -1) {
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syslog(LOG_ERR, "chdir(%s): %s", expand_path, strerror(errno));
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return false;
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}
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free(expand_path);
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return true;
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}
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static bool
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set_root(const char *option)
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{
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char *expand_path = expand_home(option);
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if (!expand_path)
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return false;
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if (chroot(expand_path) == -1) {
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syslog(LOG_ERR, "chroot(%s): %s", expand_path, strerror(errno));
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return false;
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}
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free(expand_path);
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return true;
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}
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enum open_type { READONLY, CREATE, REDIRECT };
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static bool
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do_open(const char *option, enum open_type type, int target)
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{
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int flags = type == CREATE ? O_WRONLY | O_CREAT | O_APPEND : O_RDONLY;
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int fd;
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if (type == REDIRECT) {
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if ((fd = rc_pipe_command(option)) == -1) {
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syslog(LOG_ERR, "failed to pipe command to %s", option);
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return false;
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}
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} else {
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if ((fd = open(option, flags, S_IRUSR | S_IWUSR)) == -1) {
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syslog(LOG_ERR, "failed to open %s", option);
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return false;
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}
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}
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if (dup2(fd, target) != -1) {
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syslog(LOG_ERR, "dup2: %s", strerror(errno));
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return false;
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}
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return true;
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}
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RC_NORETURN void
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child_process(const char *svcname, struct notify *notify, char **argv)
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{
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/* the order of the options matter, as they're applied
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* in order so earlier options affect later ones! */
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static const struct {
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const char * const name;
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bool (*handler)(const char *option);
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enum open_type type;
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int target;
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} options[] = {
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{ "umask", set_umask, 0, 0 },
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{ "nicelevel", set_nicelevel, 0, 0 },
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{ "ionice", set_ionice, 0, 0 },
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{ "oom-score-adj", set_oom_score, 0, 0 },
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{ "scheduler", set_scheduler, 0, 0 },
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{ "scheduler-priority", set_scheduler, 0, 0 },
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{ "capabilities", set_capabilities, 0, 0 },
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{ "secbits", set_secbits, 0, 0 },
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{ "no-new-privs", set_no_new_privs, 0, 0 },
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/* chdir must be relative to the chroot */
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{ "chroot", set_root, 0, 0 },
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{ "chdir", set_dir, 0, 0 },
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{ "stdin", NULL, READONLY, STDIN_FILENO },
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{ "stdout", NULL, CREATE, STDOUT_FILENO },
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{ "stderr", NULL, CREATE, STDERR_FILENO },
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{ "stdout-logger", NULL, REDIRECT, STDOUT_FILENO },
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{ "stderr-logger", NULL, REDIRECT, STDERR_FILENO },
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};
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char *exec;
338+
if (!(exec = rc_service_value_get(svcname, "exec")))
339+
exec = argv[0];
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setsid();
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for (size_t i = 0; i < ARRAY_SIZE(options); i++) {
344+
char *option;
345+
if (!(option = rc_service_value_get(svcname, options[i].name)))
346+
continue;
347+
if (options[i].handler ? !options[i].handler(option)
348+
: do_open(options[i].name, options[i].type, options[i].target))
349+
exit(EXIT_FAILURE);
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free(option);
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}
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cloexec_fds_from(3);
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if (notify->type == NOTIFY_FD && dup2(notify->pipe[1], notify->fd) == -1) {
356+
syslog(LOG_ERR, "Failed to initialize ready fd.");
357+
exit(EXIT_FAILURE);
358+
}
359+
360+
execvp(*argv, argv);
361+
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syslog(LOG_ERR, "%s: failed to exec '%s': %s", applet, *argv, strerror(errno));
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exit(EXIT_FAILURE);
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}

‎src/supervise-daemon/daemon.h‎

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#ifndef __DAEMON_H__
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#define __DAEMON_H__
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#include "misc.h"
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#include "helpers.h"
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RC_NORETURN void supervise(const char *svcname);
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RC_NORETURN void child_process(const char *svcname, struct notify *notify, char **argv);
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#endif

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