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path: root/src/shutdown/s6-linux-init-shutdownd.c
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Diffstat (limited to 'src/shutdown/s6-linux-init-shutdownd.c')
-rw-r--r--src/shutdown/s6-linux-init-shutdownd.c228
1 files changed, 228 insertions, 0 deletions
diff --git a/src/shutdown/s6-linux-init-shutdownd.c b/src/shutdown/s6-linux-init-shutdownd.c
new file mode 100644
index 0000000..c6d6316
--- /dev/null
+++ b/src/shutdown/s6-linux-init-shutdownd.c
@@ -0,0 +1,228 @@
+/* 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/sig.h>
+#include <skalibs/tai.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/iopause.h>
+#include <skalibs/skamisc.h>
+
+#include <execline/config.h>
+
+#include "defaults.h"
+#include "initctl.h"
+#include "hpr.h"
+
+#define STAGE4_FILE "stage 4"
+
+#define USAGE "s6-linux-init-shutdownd [ -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 = 1 + byte_chr("hpr", c, 3) ;
+}
+
+static inline void handle_stdin (unsigned int *what, tain_t *deadline, unsigned int *grace_time)
+{
+ 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 ;
+ tain_add_g(deadline, &tain_infinite_relative) ;
+ break ;
+ default :
+ {
+ char s[2] = { c, 0 } ;
+ strerr_warnw2x("unknown command: ", s) ;
+ }
+ break ;
+ }
+ }
+}
+
+static inline void prepare_stage4 (char const *basedir, unsigned int what)
+{
+ static char const *table[3] = { "halt", "poweroff", "reboot" } ;
+ buffer b ;
+ int fd ;
+ char buf[512] ;
+ 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,
+ "#!" EXECLINE_SHEBANGPREFIX "/execlineb -P\n\n"
+ EXECLINE_EXTBINPREFIX "foreground { "
+ S6_LINUX_INIT_LIBEXECPREFIX "s6-linux-init-umountall }\n"
+ S6_LINUX_INIT_LIBEXECPREFIX "s6-linux-init-") < 0
+ || buffer_puts(&b, table[what-1]) < 0
+ || buffer_putsflush(&b, " -f\n") < 0)
+ strerr_diefu2sys(111, "write to ", STAGE4_FILE ".new") ;
+ if (fchmod(fd, S_IRWXU) == -1)
+ strerr_diefu2sys(111, "fchmod ", 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 *const *envp)
+{
+ pid_t pid ;
+ tain_t deadline ;
+ unsigned int what = 0 ;
+ unsigned int grace_time = 3000 ;
+ PROG = "s6-linux-init-shutdownd" ;
+
+ {
+ subgetopt_t l = SUBGETOPT_ZERO ;
+ for (;;)
+ {
+ int opt = subgetopt_r(argc, argv, "c:g:", &l) ;
+ if (opt == -1) break ;
+ switch (opt)
+ {
+ 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 (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, envp) ;
+ 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) ;
+ }
+
+
+ /* 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)) ;
+ pid = child_spawn0(stage3_argv[0], stage3_argv, envp) ;
+ 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) ;
+ }
+ }
+ else strerr_warnwu2sys("spawn ", stage3) ;
+ }
+
+
+ /* The end is coming! */
+
+ prepare_stage4(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 ;
+}
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