It builds! Tomorrow: skeletons for stage2, stage3 and runlevel scripts.

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) ;
+}