Save pending changes in 1.0.0.0 branch

1 files changed, 278 insertions, 0 deletions

diff --git a/src/state/s6-linux-init-shutdownd.c b/src/state/s6-linux-init-shutdownd.c
new file mode 100644
index 0000000..d4ecd4b
--- /dev/null
+++ b/src/state/s6-linux-init-shutdownd.c
@@ -0,0 +1,278 @@
+/* ISC license. */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/wait.h>
+
+#include <skalibs/posixplz.h>
+#include <skalibs/uint32.h>
+#include <skalibs/types.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/buffer.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/sig.h>
+#include <skalibs/tai.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/iopause.h>
+#include <skalibs/skamisc.h>
+
+#include "defaults.h"
+#include "initctl.h"
+#include "hpr.h"
+
+#define STAGE4_FILE "stage 4"
+
+#define USAGE "s6-linux-init-shutdownd [ -b bindir ] [ -c basedir ] [ -g gracetime ]"
+#define dieusage() strerr_dieusage(100, USAGE)
+
+static char const *basedir = BASEDIR ;
+
+static inline void prepare_shutdown (char c, unsigned int *what, tain_t *deadline, unsigned int *grace_time)
+{
+  uint32_t u ;
+  char pack[TAIN_PACK] ;
+  ssize_t r = sanitize_read(buffer_get(buffer_0small, pack, TAIN_PACK)) ;
+  if (r == -1) strerr_diefu1sys(111, "read from pipe") ;
+  if (r < TAIN_PACK + 4) strerr_dief1x(101, "bad shutdown protocol") ;
+  tain_unpack(pack, deadline) ;
+  uint32_unpack_big(pack + TAIN_PACK, &u) ;
+  if (u && u <= 300000) *grace_time = u ;
+  *what = byte_chr(" hpr", c, 4) ;
+}
+
+static inline void change_runlevels (char c)
+{
+  pid_t pid = doublefork() ;
+  if (pid == -1)
+    strerr_warnwu1sys("doublefork for runlevel change") ;
+  if (pid)
+  {
+    size_t basedirlen = strlen(basedir) ;
+    char fn[basedirlen + sizeof("/scripts/runlevel")] ;
+    char s[2] = { c, 0 } ;
+    char const *cargv[3] = { fn, s, 0 } ;
+    PROG = "s6-linux-init-shutdownd (grandchild)" ;
+    memcpy(fn, basedir, basedirlen) ;
+    memcpy(fn + basedirlen, "/scripts/runlevel", sizeof("/scripts/runlevel")) ;
+    xpathexec_run(cargv[0], cargv, (char const *const *)environ) ;
+  }
+}
+
+static inline void handle_stdin (unsigned int *what, tain_t *deadline, unsigned int *grace_time)
+{
+  char rl = 0 ;
+  for (;;)
+  {
+    char c ;
+    ssize_t r = sanitize_read(buffer_get(buffer_0small, &c, 1)) ;
+    if (r == -1) strerr_diefu1sys(111, "read from pipe") ;
+    else if (!r) break ;
+    switch (c)
+    {
+      case 'h' :
+      case 'p' :
+      case 'r' :
+        prepare_shutdown(c, what, deadline, grace_time) ;
+        break ;
+      case 'c' :
+        *what = 0 ;
+        rl = 0 ;
+        tain_add_g(deadline, &tain_infinite_relative) ;
+        break ;
+      case 'S' :
+        *what = 4 ;
+        tain_copynow(deadline) ;
+        break ;
+      case '0' :
+      case '1' :
+      case '2' :
+      case '3' :
+      case '4' :
+      case '5' :
+      case '6' :
+        *what = 0 ;
+        tain_add_g(deadline, &tain_infinite_relative) ;
+        rl = c  ;
+        break ;
+      default :
+      {
+        char s[2] = { c, 0 } ;
+        strerr_warnw2x("unknown command: ", s) ;
+      }
+      break ;
+    }
+  }
+  if (rl) change_runlevels(rl) ;
+}
+
+static inline void prepare_stage4 (char const *bindir, char const *basedir, unsigned int what)
+{
+  static char const *table[4] = { "single", "halt", "poweroff", "reboot" } ;
+  stralloc sa = STRALLOC_ZERO ;
+  buffer b ;
+  char buf[512] ;
+  int fd ;
+  unlink_void(STAGE4_FILE ".new") ;
+  fd = open_excl(STAGE4_FILE ".new") ;
+  if (fd == -1) strerr_diefu3sys(111, "open ", STAGE4_FILE ".new", " for writing") ;
+  buffer_init(&b, &buffer_write, fd, buf, 512) ;
+
+  if (buffer_puts(&b, "#!") == -1
+   || buffer_puts(&b, bindir) == -1
+   || buffer_puts(&b, "/execlineb -P\n\n") == -1)
+    strerr_diefu2sys(111, "write to ", STAGE4_FILE ".new") ;
+  if (!string_quote(&sa, basedir, strlen(basedir)))
+    strerr_diefu1sys(111, "string_quote") ;
+  if (buffer_put(&b, sa.s, sa.len) == -1
+   || buffer_puts(&b, "/bin/" STAGE4 " ") == -1
+   || buffer_puts(&b, table[what]) == -1
+   || buffer_putsflush(&b, "\n") == -1)
+    strerr_diefu2sys(111, "write to ", STAGE4_FILE ".new") ;
+  stralloc_free(&sa) ;
+  if (fchmod(fd, S_IRWXU) == -1)
+    strerr_diefu2sys(111, "fchmod ", STAGE4_FILE ".new") ;
+  if (fsync(fd) == -1)
+    strerr_diefu2sys(111, "fsync ", STAGE4_FILE ".new") ;
+  fd_close(fd) ;
+  if (rename(STAGE4_FILE ".new", STAGE4_FILE) == -1)
+    strerr_diefu4sys(111, "rename ", STAGE4_FILE ".new", " to ", STAGE4_FILE) ;
+}
+
+int main (int argc, char const *const *argv)
+{
+  char const *bindir = BINDIR ;
+  pid_t pid ;
+  tain_t deadline ;
+  unsigned int what = 0 ;
+  unsigned int grace_time = 3000 ;
+  int notif = 0 ;
+  PROG = "s6-linux-init-shutdownd" ;
+
+  {
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      int opt = subgetopt_r(argc, argv, "b:c:g:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'b' : bindir = l.arg ; break ;
+        case 'c' : basedir = l.arg ; break ;
+        case 'g' : if (!uint0_scan(l.arg, &grace_time)) dieusage() ; break ;
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
+  }
+  if (bindir[0] != '/')
+    strerr_dief2x(100, "bindir", " must be an absolute path") ;
+  if (basedir[0] != '/')
+    strerr_dief2x(100, "basedir", " must be an absolute path") ;
+  if (grace_time > 300000) grace_time = 300000 ;
+
+ /* if we're in stage 4, exec it immediately */
+  {
+    char const *stage4_argv[2] = { STAGE4_FILE, 0 } ;
+    pathexec_run(stage4_argv[0], stage4_argv, (char const *const *)environ) ;
+    if (errno != ENOENT)
+      strerr_warnwu2sys("exec ", stage4_argv[0]) ;
+  }
+
+  fd_close(1) ;
+  fd_close(0) ;
+
+  if (open_read(SHUTDOWND_FIFO))
+    strerr_diefu3sys(111, "open ", SHUTDOWND_FIFO, " for reading") ;
+  if (open_write(SHUTDOWND_FIFO) != 1)
+    strerr_diefu3sys(111, "open ", SHUTDOWND_FIFO, " for writing") ;
+  if (sig_ignore(SIGPIPE) == -1)
+    strerr_diefu1sys(111, "sig_ignore SIGPIPE") ;
+  tain_now_g() ;
+  tain_add_g(&deadline, &tain_infinite_relative) ;
+
+  for (;;)
+  {
+    iopause_fd x = { .fd = 0, .events = IOPAUSE_READ } ;
+    int r = iopause_g(&x, 1, &deadline) ;
+    if (r == -1) strerr_diefu1sys(111, "iopause") ;
+    if (!r)
+    {
+      if (what) break ;
+      tain_add_g(&deadline, &tain_infinite_relative) ;
+      continue ;
+    }
+    if (x.revents & IOPAUSE_READ)
+      handle_stdin(&what, &deadline, &grace_time) ;
+  }
+
+  if (what == 4) what = 0 ;
+
+ /* Stage 3 */
+
+  fd_close(1) ;
+  fd_close(0) ;
+  if (open_readb("/dev/null"))
+    strerr_diefu1sys(111, "open /dev/null for reading") ;
+  if (open_write("/dev/console") != 1 || ndelay_off(1) == -1)
+    strerr_diefu1sys(111, "open /dev/console for writing") ;
+  {
+    size_t basedirlen = strlen(basedir) ;
+    char stage3[basedirlen + sizeof("/" STAGE3)] ;
+    char const *stage3_argv[2] = { stage3, 0 } ;
+    memcpy(stage3, basedir, basedirlen) ;
+    memcpy(stage3 + basedirlen, "/" STAGE3, sizeof("/" STAGE3)) ;
+    sig_block(SIGCHLD) ;
+    pid = child_spawn0(stage3_argv[0], stage3_argv, (char const *const *)environ) ;
+    if (!pid) strerr_warnwu2sys("spawn ", stage3) ;
+    sig_unblock(SIGCHLD) ;
+    if (pid)
+    {
+      int wstat ;
+      if (wait_pid(pid, &wstat) == -1) strerr_diefu1sys(111, "waitpid") ;
+      if (WIFSIGNALED(wstat))
+      {
+        char fmt[UINT_FMT] ;
+        fmt[uint_fmt(fmt, WTERMSIG(wstat))] = 0 ;
+        strerr_warnw3x(stage3, " was killed by signal ", fmt) ;
+      }
+      else if (WEXITSTATUS(wstat))
+      {
+        char fmt[UINT_FMT] ;
+        fmt[uint_fmt(fmt, WTERMSIG(wstat))] = 0 ;
+        strerr_warnw3x(stage3, " was killed by signal ", fmt) ;
+      }
+      else if (WEXITSTATUS(wstat))
+      {
+        char fmt[UINT_FMT] ;
+        fmt[uint_fmt(fmt, WEXITSTATUS(wstat))] = 0 ;
+        strerr_warnw3x(stage3, " exited ", fmt) ;
+      }
+    }
+  }
+
+
+ /* The end is coming! */
+
+  prepare_stage4(bindir, basedir, what) ;
+  if (fd_move(2, 1) == -1) strerr_warnwu1sys("fd_move") ;
+  sync() ;
+  if (sig_ignore(SIGTERM) == -1) strerr_warnwu1sys("sig_ignore SIGTERM") ;
+  strerr_warni1x("sending all processes the TERM signal...") ;
+  kill(-1, SIGTERM) ;
+  kill(-1, SIGCONT) ;
+  tain_from_millisecs(&deadline, grace_time) ;
+  tain_add_g(&deadline, &deadline) ;
+  deepsleepuntil_g(&deadline) ;
+  sync() ;
+  strerr_warni1x("sending all processes the KILL signal...") ;
+  kill(-1, SIGKILL) ;
+  return 0 ;
+}