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authorLaurent Bercot <ska-skaware@skarnet.org>2019-04-16 20:37:01 +0000
committerLaurent Bercot <ska-skaware@skarnet.org>2019-04-16 20:37:01 +0000
commit73cff35173dd75b0254ae7cf9098c32822859de0 (patch)
treefd1bb09611b2b7064967ca8d8b2aef98514e616b /src/shutdown/s6-linux-init-shutdown.c
parent5199738f4e32773f4f752a94998593e18e3af36f (diff)
downloads6-linux-init-73cff35173dd75b0254ae7cf9098c32822859de0.tar.xz
It builds! Tomorrow: skeletons for stage2, stage3 and runlevel scripts.
Diffstat (limited to 'src/shutdown/s6-linux-init-shutdown.c')
-rw-r--r--src/shutdown/s6-linux-init-shutdown.c268
1 files changed, 268 insertions, 0 deletions
diff --git a/src/shutdown/s6-linux-init-shutdown.c b/src/shutdown/s6-linux-init-shutdown.c
new file mode 100644
index 0000000..f534944
--- /dev/null
+++ b/src/shutdown/s6-linux-init-shutdown.c
@@ -0,0 +1,268 @@
+/* ISC license. */
+
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <time.h>
+#include <utmpx.h>
+
+#include <skalibs/uint32.h>
+#include <skalibs/types.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/sig.h>
+#include <skalibs/tai.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/djbtime.h>
+
+#include "defaults.h"
+#include "initctl.h"
+#include "hpr.h"
+
+#ifndef UT_NAMESIZE
+#define UT_NAMESIZE 32
+#endif
+
+#define USAGE "s6-linux-init-shutdown [ -h | -p | -r | -k ] [ -f | -F ] [ -a ] [ -t sec ] time [ message ] or s6-linux-init-shutdown -c [ message ]"
+#define dieusage() strerr_dieusage(100, USAGE)
+
+#define AC_FILE "/etc/shutdown.allow"
+#define AC_BUFSIZE 4096
+#define AC_MAX 64
+#define AC_SHORT_MESSAGE "no authorized users logged in\n"
+#define AC_MESSAGE "s6-linux-init-shutdown: " AC_SHORT_MESSAGE
+
+
+ /* shutdown 01:23: date/time format parsing */
+
+static inline void add_one_day (struct tm *tm)
+{
+ tm->tm_isdst = -1 ;
+ if (tm->tm_mday++ < 31) return ;
+ tm->tm_mday = 1 ;
+ if (tm->tm_mon++ < 11) return ;
+ tm->tm_mon = 0 ;
+ tm->tm_year++ ;
+}
+
+static inline void parse_hourmin (tain_t *when, char const *s)
+{
+ tai_t taithen ;
+ struct tm tmnow, tmthen ;
+ unsigned int hour, minute ;
+ size_t len = uint_scan(s, &hour) ;
+ if (!len || len > 2 || s[len] != ':' || hour > 23)
+ strerr_dief1x(100, "invalid time format") ;
+ s += len+1 ;
+ len = uint0_scan(s, &minute) ;
+ if (!len || len != 2 || minute > 59)
+ strerr_dief1x(100, "invalid time format") ;
+ if (!localtm_from_tai(&tmnow, tain_secp(&STAMP), 1))
+ strerr_diefu1sys(111, "break down current time into struct tm") ;
+ tmthen = tmnow ;
+ tmthen.tm_hour = hour ;
+ tmthen.tm_min = minute ;
+ if (!tai_from_localtm(&taithen, &tmthen))
+ strerr_diefu1sys(111, "assemble broken-down time into tain_t") ;
+ if (tai_less(&taithen, tain_secp(&STAMP)))
+ {
+ add_one_day(&tmthen) ;
+ if (!tai_from_localtm(&taithen, &tmthen))
+ strerr_diefu1sys(111, "assemble broken-down time into tain_t") ;
+ }
+ tai_sub(tain_secp(when), &taithen, tain_secp(&STAMP)) ;
+ when->nano = 0 ;
+}
+
+static inline void parse_time (tain_t *when, char const *s)
+{
+ if (!strcmp(s, "now")) tain_copynow(when) ;
+ else if (s[0] == '+')
+ {
+ unsigned int mins ;
+ if (!uint0_scan(s+1, &mins)) dieusage() ;
+ tain_addsec_g(when, mins * 60) ;
+ }
+ else if (strchr(s, ':')) parse_hourmin(when, s) ;
+ else
+ {
+ unsigned int mins ;
+ if (!uint0_scan(s, &mins)) dieusage() ;
+ tain_addsec_g(when, mins * 60) ;
+ }
+}
+
+
+ /* shutdown -a: access control */
+
+static inline unsigned char cclass (unsigned char c)
+{
+ switch (c)
+ {
+ case 0 : return 0 ;
+ case '\n' : return 1 ;
+ case '#' : return 2 ;
+ default : return 3 ;
+ }
+}
+
+static inline unsigned int parse_authorized_users (char *buf, char const **users, unsigned int max)
+{
+ static unsigned char const table[3][4] =
+ {
+ { 0x03, 0x00, 0x01, 0x12 },
+ { 0x03, 0x00, 0x01, 0x01 },
+ { 0x23, 0x20, 0x02, 0x02 }
+ } ;
+ size_t pos = 0 ;
+ size_t mark = 0 ;
+ unsigned int n = 0 ;
+ unsigned int state = 0 ;
+ for (; state < 3 ; pos++)
+ {
+ unsigned char what = table[state][cclass(buf[pos])] ;
+ state = what & 3 ;
+ if (what & 0x10) mark = pos ;
+ if (what & 0x20)
+ {
+ if (n >= max)
+ {
+ char fmt[UINT32_MAX] ;
+ fmt[uint32_fmt(fmt, AC_MAX)] = 0 ;
+ strerr_warnw4x(AC_FILE, " lists more than ", fmt, " authorized users - ignoring the extra ones") ;
+ break ;
+ }
+ buf[pos] = 0 ;
+ users[n++] = buf + mark ;
+ }
+ }
+ return n ;
+}
+
+static inline int match_users_with_utmp (char const *const *users, unsigned int n)
+{
+ setutxent() ;
+ for (;;)
+ {
+ struct utmpx *utx ;
+ errno = 0 ;
+ utx = getutxent() ;
+ if (!utx) break ;
+ if (utx->ut_type != USER_PROCESS) continue ;
+ for (unsigned int i = 0 ; i < n ; i++)
+ if (!strncmp(utx->ut_user, users[i], UT_NAMESIZE)) goto yes ;
+ }
+ if (errno) strerr_warnwu1sys("getutxent") ;
+ endutxent() ;
+ return 0 ;
+
+ yes:
+ endutxent() ;
+ return 1 ;
+}
+
+static inline void access_control (void)
+{
+ char buf[AC_BUFSIZE] ;
+ char const *users[AC_MAX] ;
+ unsigned int n ;
+ struct stat st ;
+ int fd = open_readb(AC_FILE) ;
+ if (fd == -1)
+ {
+ if (errno == ENOENT) return ;
+ strerr_diefu2sys(111, "open ", AC_FILE) ;
+ }
+ if (fstat(fd, &st) == -1)
+ strerr_diefu2sys(111, "stat ", AC_FILE) ;
+ if (st.st_size >= AC_BUFSIZE)
+ {
+ char fmt[UINT32_FMT] ;
+ fmt[uint32_fmt(fmt, AC_BUFSIZE - 1)] = 0 ;
+ strerr_dief4x(1, AC_FILE, " is too big: it needs to be ", fmt, " bytes or less") ;
+ }
+ if (allread(fd, buf, st.st_size) < st.st_size)
+ strerr_diefu2sys(111, "read ", AC_FILE) ;
+ fd_close(fd) ;
+ buf[st.st_size] = 0 ;
+ n = parse_authorized_users(buf, users, AC_MAX) ;
+ if (!n || !match_users_with_utmp(users, n))
+ {
+ fd = open_append("/dev/console") ;
+ if (fd == -1)
+ strerr_diefu1sys(111, "open /dev/console") ;
+ if (allwrite(fd, AC_MESSAGE, sizeof(AC_MESSAGE) - 1) < sizeof(AC_MESSAGE) - 1)
+ strerr_diefu1sys(111, "write to /dev/console") ;
+ strerr_dief1x(1, AC_SHORT_MESSAGE) ;
+ }
+}
+
+
+ /* main */
+
+int main (int argc, char const *const *argv)
+{
+ unsigned int gracetime = 0 ;
+ int what = 0 ;
+ int doactl = 0 ;
+ int docancel = 0 ;
+ tain_t when ;
+ PROG = "s6-linux-init-shutdown" ;
+
+ {
+ subgetopt_t l = SUBGETOPT_ZERO ;
+ for (;;)
+ {
+ int opt = subgetopt_r(argc, argv, "hprkafFct:", &l) ;
+ if (opt == -1) break ;
+ switch (opt)
+ {
+ case 'h' : what = 1 ; break ;
+ case 'p' : what = 2 ; break ;
+ case 'r' : what = 3 ; break ;
+ case 'k' : what = 4 ; break ;
+ case 'a' : doactl = 1 ; break ;
+ case 'f' : /* talk to the hand */ break ;
+ case 'F' : /* no, the other hand */ break ;
+ case 'c' : docancel = 1 ; break ;
+ case 't' : if (!uint0_scan(l.arg, &gracetime)) dieusage() ; break ;
+ default : strerr_dieusage(100, USAGE) ;
+ }
+ }
+ argc -= l.ind ; argv += l.ind ;
+ }
+
+ if (geteuid())
+ {
+ errno = EPERM ;
+ strerr_diefu1sys(111, "shutdown") ;
+ }
+ if (doactl) access_control() ;
+ if (!tain_now_g()) strerr_warnw1sys("get current time") ;
+ if (docancel)
+ {
+ if (argv[0]) hpr_wall(argv[0]) ;
+ if (!hpr_cancel()) goto err ;
+ return 0 ;
+ }
+ if (!argc) dieusage() ;
+ parse_time(&when, argv[0]) ;
+ if (argv[1]) hpr_wall(argv[1]) ;
+ if (what < 4)
+ {
+ if (gracetime > 300)
+ {
+ gracetime = 300 ;
+ strerr_warnw1x("delay between SIGTERM and SIGKILL is capped to 300 seconds") ;
+ }
+ if (!hpr_shutdown(what, &when, gracetime * 1000)) goto err ;
+ }
+ return 0 ;
+
+ err:
+ strerr_diefu2sys(111, "write to ", INITCTL) ;
+}