diff options
Diffstat (limited to 'src/state/s6-linux-init-shutdownd.c')
| -rw-r--r-- | src/state/s6-linux-init-shutdownd.c | 278 |
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 ; +} |