Initial commit

2 files changed, 378 insertions, 0 deletions

diff --git a/src/init/deps-exe/s6-linux-init-maker b/src/init/deps-exe/s6-linux-init-maker
new file mode 100644
index 0000000..e7187fe
--- /dev/null
+++ b/src/init/deps-exe/s6-linux-init-maker
@@ -0,0 +1 @@
+-lskarnet
diff --git a/src/init/s6-linux-init-maker.c b/src/init/s6-linux-init-maker.c
new file mode 100644
index 0000000..a965cc0
--- /dev/null
+++ b/src/init/s6-linux-init-maker.c
@@ -0,0 +1,377 @@
+/* ISC license. */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pwd.h>
+#include <skalibs/config.h>
+#include <skalibs/uint64.h>
+#include <skalibs/uint.h>
+#include <skalibs/gidstuff.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/buffer.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/skamisc.h>
+#include <execline/config.h>
+#include <s6-portable-utils/config.h>
+#include <s6-linux-utils/config.h>
+#include <s6/config.h>
+
+#define USAGE "s6-linux-init-maker [ -c basedir ] [ -l tmpfsdir ] [ -b execline_bindir ] [ -u log_user ] [ -g early_getty_cmd ] [ -2 stage2_script ] [ -3 stage3_script ] [ -p initial_path ] [ -m initial_umask ] [ -t timestamp_style ] [ -d dev_style ] [ -e initial_envvar ... ] dir"
+#define dieusage() strerr_dieusage(100, USAGE)
+#define dienomem() strerr_diefu1sys(111, "stralloc_catb") ;
+
+#define CRASH_SCRIPT \
+"#!" EXECLINE_EXTBINPREFIX "execlineb -P\n\n" \
+EXECLINE_EXTBINPREFIX "redirfd -r 0 /dev/console\n" \
+EXECLINE_EXTBINPREFIX "redirfd -w 1 /dev/console\n" \
+EXECLINE_EXTBINPREFIX "fdmove -c 2 1\n" \
+EXECLINE_EXTBINPREFIX "foreground { " \
+S6_PORTABLE_UTILS_EXTBINPREFIX "s6-echo -- " \
+"\"s6-svscan crashed. Dropping to an interactive shell.\" }\n" \
+"/bin/sh -i\n"
+
+#define BANNER1 "s6-init: stage 1"
+#define BANNER2 "s6-init: stage 2"
+
+static char const *slashrun = "/run" ;
+static char const *robase = "/etc/s6" ;
+static char const *init_script = "/etc/rc.init" ;
+static char const *shutdown_script = "/etc/rc.shutdown" ;
+static char const *bindir = "/bin" ;
+static char const *initial_path = SKALIBS_DEFAULTPATH ;
+static char const *early_getty = 0 ;
+static uid_t uncaught_logs_uid = 65534 ;
+static gid_t uncaught_logs_gid = 65534 ;
+static unsigned int initial_umask = 022 ;
+static unsigned int timestamp_style = 1 ;
+static unsigned int slashdev_style = 2 ;
+
+typedef int writetobuf_func_t (buffer *) ;
+typedef writetobuf_func_t *writetobuf_func_t_ref ;
+
+static int early_getty_script (buffer *b)
+{
+  if (buffer_puts(b, "#!" EXECLINE_EXTBINPREFIX "execlineb -P\n\n") < 0
+   || buffer_puts(b, early_getty) < 0
+   || buffer_put(b, "\n", 1) < 0)
+    return 0 ;
+  return 1 ;
+}
+
+static int s6_svscan_log_script (buffer *b)
+{
+  unsigned int sabase = satmp.len ;
+  char fmt[UINT64_FMT] ;
+  if (buffer_puts(b,
+    "#!" EXECLINE_EXTBINPREFIX "execlineb -P\n\n"
+    EXECLINE_EXTBINPREFIX "redirfd -rnb 0 fifo\n"
+    S6_EXTBINPREFIX "s6-applyuidgid -u ") < 0
+   || buffer_put(b, fmt, uint64_fmt(fmt, uncaught_logs_uid)) < 0
+   || buffer_puts(b, " -g ") < 0
+   || buffer_put(b, fmt, gid_fmt(fmt, uncaught_logs_gid)) < 0
+   || buffer_puts(b, " --\n" S6_EXTBINPREFIX "s6-log -bp -- ") < 0
+   || buffer_puts(b, timestamp_style & 1 ? "t " : "") < 0
+   || buffer_puts(b, timestamp_style & 2 ? "T " : "") < 0) return 0 ;
+  if (!string_quote(&satmp, slashrun, str_len(slashrun))) return 0 ;
+  if (buffer_put(b, satmp.s + sabase, satmp.len - sabase) < 0)
+  {
+    satmp.len = sabase ;
+    return 0 ;
+  }
+  satmp.len = sabase ;
+  if (buffer_puts(b, "/uncaught-logs\n") < 0) return 0 ;
+  return 1 ;
+}
+
+static int finish_script (buffer *b)
+{
+  unsigned int sabase = satmp.len ;
+  if (buffer_puts(b, 
+    "#!" EXECLINE_EXTBINPREFIX "execlineb -S0\n\n"
+    EXECLINE_EXTBINPREFIX "cd /\n"
+    EXECLINE_EXTBINPREFIX "redirfd -w 2 /dev/console\n"
+    EXECLINE_EXTBINPREFIX "fdmove -c 1 2\n"
+    EXECLINE_EXTBINPREFIX "wait { }\n") < 0
+   || !string_quote(&satmp, shutdown_script, str_len(shutdown_script))) return 0 ;
+  if (buffer_put(b, satmp.s + sabase, satmp.len - sabase) < 0)
+  {
+    satmp.len = sabase ;
+    return 0 ;
+  }
+  satmp.len = sabase ;
+  if (buffer_puts(b, " ${@}\n") < 0) return 0 ;
+  return 1 ;
+}
+
+static void cleanup (char const *base)
+{
+  int e = errno ;
+  rm_rf(base) ;
+  errno = e ;
+}
+
+static void auto_dir (char const *base, char const *dir, uid_t uid, gid_t gid, unsigned int mode)
+{
+  unsigned int clen = str_len(base) ;
+  unsigned int dlen = str_len(dir) ;
+  char fn[clen + dlen + 2] ;
+  byte_copy(fn, clen, base) ;
+  fn[clen] = dlen ? '/' : 0 ;
+  byte_copy(fn + clen + 1, dlen + 1, dir) ;
+  if (mkdir(fn, mode) < 0
+   || ((uid || gid) && (chown(fn, uid, gid) < 0 || chmod(fn, mode) < 0)))
+  {
+    cleanup(base) ;
+    strerr_diefu2sys(111, "mkdir ", fn) ;
+  }
+}
+
+static void auto_file (char const *base, char const *file, char const *s, unsigned int n, int executable)
+{
+  unsigned int clen = str_len(base) ;
+  unsigned int flen = str_len(file) ;
+  char fn[clen + flen + 2] ;
+  byte_copy(fn, clen, base) ;
+  fn[clen] = '/' ;
+  byte_copy(fn + clen + 1, flen + 1, file) ;
+  if (!openwritenclose_unsafe(fn, s, n)
+   || (executable && chmod(fn, 0755) < 0))
+  {
+    cleanup(base) ;
+    strerr_diefu2sys(111, "write to ", fn) ;
+  }
+}
+
+static void auto_fifo (char const *base, char const *fifo)
+{
+  unsigned int baselen = str_len(base) ;
+  unsigned int fifolen = str_len(fifo) ;
+  char fn[baselen + fifolen + 2] ;
+  byte_copy(fn, baselen, base) ;
+  fn[baselen] = '/' ;
+  byte_copy(fn + baselen + 1, fifolen + 1, fifo) ;
+  if (mkfifo(fn, 0600) < 0)
+  {
+    cleanup(base) ;
+    strerr_diefu2sys(111, "mkfifo ", fn) ;
+  }
+}
+
+static void auto_script (char const *base, char const *file, writetobuf_func_t_ref scriptf)
+{
+  char buf[4096] ;
+  buffer b ;
+  int fd ;
+  unsigned int baselen = str_len(base) ;
+  unsigned int filelen = str_len(file) ;
+  char fn[baselen + filelen + 2] ;
+  byte_copy(fn, baselen, base) ;
+  fn[baselen] = '/' ;
+  byte_copy(fn + baselen + 1, filelen + 1, file) ;
+  fd = open_trunc(fn) ;
+  if (fd < 0 || ndelay_off(fd) < 0 || fchmod(fd, 0755) < 0)
+  {
+    cleanup(base) ;
+    strerr_diefu3sys(111, "open ", fn, " for script writing") ;
+  }
+  buffer_init(&b, &fd_writesv, fd, buf, 4096) ;
+  if (!(*scriptf)(&b) || !buffer_flush(&b))
+  {
+    cleanup(base) ;
+    strerr_diefu2sys(111, "write to ", fn) ;
+  }
+  close(fd) ;
+}
+
+static void make_image (char const *base)
+{
+  auto_dir(base, "run-image", 0, 0, 0755) ;
+  auto_dir(base, "run-image/uncaught-logs", uncaught_logs_uid, uncaught_logs_gid, 02700) ;
+  auto_dir(base, "run-image/service", 0, 0, 0755) ;
+  auto_dir(base, "run-image/service/.s6-svscan", 0, 0, 0755) ;
+  auto_file(base, "run-image/service/.s6-svscan/crash", CRASH_SCRIPT, sizeof(CRASH_SCRIPT) - 1, 1) ;
+  auto_script(base, "run-image/service/.s6-svscan/finish", &finish_script) ;
+  auto_dir(base, "run-image/service/s6-svscan-log", 0, 0, 0755) ;
+  auto_fifo(base, "run-image/service/s6-svscan-log/fifo") ;
+  auto_script(base, "run-image/service/s6-svscan-log/run", &s6_svscan_log_script) ;
+  if (early_getty)
+  {
+    auto_dir(base, "run-image/service/early-getty", 0, 0, 0755) ;
+    auto_script(base, "run-image/service/early-getty/run", &early_getty_script) ;
+  }
+}
+
+static void make_env (char const *base, char const *modif, unsigned int modiflen)
+{
+  auto_dir(base, "env", 0, 0, 0755) ;
+  while (modiflen)
+  {
+    unsigned int len = str_len(modif) ;
+    unsigned int pos = byte_chr(modif, len, '=') ;
+    char fn[5 + pos] ;
+    byte_copy(fn, 4, "env/") ;
+    byte_copy(fn + 4, pos, modif) ;
+    fn[4 + pos] = 0 ;
+    
+    if (pos + 1 < len) auto_file(base, fn, modif + pos + 1, len - pos - 1, 0) ;
+    else if (pos + 1 == len) auto_file(base, fn, "\n", 1, 0) ;
+    else auto_file(base, fn, "", 0, 0) ;
+    modif += len+1 ; modiflen -= len+1 ;
+  }
+}
+
+static int make_init_script (buffer *b)
+{
+  unsigned int sabase = satmp.len, pos, pos2 ;
+  char fmt[UINT_OFMT] ;
+  if (buffer_puts(b, "#!") < 0
+   || buffer_puts(b, bindir) < 0
+   || buffer_puts(b, "/execlineb -P\n\n") < 0
+   || buffer_puts(b, bindir) < 0
+   || buffer_puts(b, "/export PATH ") < 0
+   || !string_quote(&satmp, initial_path, str_len(initial_path))) return 0 ;
+  if (buffer_put(b, satmp.s + sabase, satmp.len - sabase) < 0) goto err ;
+  satmp.len = sabase ;
+  if (buffer_put(b, "\n", 1) < 0
+   || buffer_puts(b, bindir) < 0
+   || buffer_puts(b, "/cd /\n"
+    EXECLINE_EXTBINPREFIX "umask 0") < 0
+   || buffer_put(b, fmt, uint_ofmt(fmt, initial_umask)) < 0
+   || buffer_puts(b, "\n"
+    EXECLINE_EXTBINPREFIX "if { "
+    S6_PORTABLE_UTILS_EXTBINPREFIX "s6-echo -- \"" BANNER1 "\" }\n"
+    EXECLINE_EXTBINPREFIX "if { "
+    S6_LINUX_UTILS_EXTBINPREFIX "s6-mount -nwt tmpfs -o mode=0755 tmpfs ") < 0
+   || !string_quote(&satmp, slashrun, str_len(slashrun))) return 0 ;
+  pos = satmp.len ;
+  if (buffer_put(b, satmp.s + sabase, pos - sabase) < 0
+   || buffer_puts(b, " }\n"
+    EXECLINE_EXTBINPREFIX "if { "
+    S6_PORTABLE_UTILS_EXTBINPREFIX "s6-hiercopy ") < 0
+   || !string_quote(&satmp, robase, str_len(robase))) return 0 ;
+  pos2 = satmp.len ;
+  if (buffer_put(b, satmp.s + pos, pos2 - pos) < 0
+   || buffer_puts(b, "/run-image ") < 0
+   || buffer_put(b, satmp.s + sabase, pos - sabase) < 0
+   || buffer_puts(b, " }\n") < 0) goto err ;
+  if (slashdev_style == 1)
+  {
+    if (buffer_puts(b,
+      EXECLINE_EXTBINPREFIX "if { "
+      S6_LINUX_UTILS_EXTBINPREFIX "s6-mount -nt devtmpfs dev /dev }\n") < 0)
+      goto err ;
+  }
+  if (buffer_puts(b,
+        EXECLINE_EXTBINPREFIX "redirfd -r 0 /dev/null\n"
+        S6_EXTBINPREFIX "s6-envdir -I -- ") < 0
+   || buffer_put(b, satmp.s + pos, pos2 - pos) < 0
+   || buffer_puts(b, "/env\n"
+        EXECLINE_EXTBINPREFIX "background\n{\n  "
+        S6_EXTBINPREFIX "s6-setsid --\n  "
+        EXECLINE_EXTBINPREFIX "redirfd -w 2 ") < 0
+   || buffer_put(b, satmp.s + sabase, pos - sabase) < 0
+   || buffer_puts(b, "/service/s6-svscan-log/fifo\n  "
+        EXECLINE_EXTBINPREFIX "if { "
+        S6_PORTABLE_UTILS_EXTBINPREFIX "s6-echo -- \"" BANNER2 "\" }\n  "
+        EXECLINE_EXTBINPREFIX "fdmove -c 1 2\n  ") < 0
+   || !string_quote(&satmp, init_script, str_len(init_script))
+   || buffer_put(b, satmp.s + pos2, satmp.len - pos2) < 0
+   || buffer_puts(b, "\n}\n"
+        EXECLINE_EXTBINPREFIX "unexport !\n"
+        EXECLINE_EXTBINPREFIX "redirfd -wnb 1 ") < 0
+   || buffer_put(b, satmp.s + sabase, pos - sabase) < 0
+   || buffer_puts(b,
+        "/service/s6-svscan-log/fifo\n"
+        EXECLINE_EXTBINPREFIX "fdmove -c 2 1\n"
+        EXECLINE_EXTBINPREFIX "cd ") < 0
+   || buffer_put(b, satmp.s + sabase, pos - sabase) < 0
+   || buffer_puts(b, "/service\n") < 0) goto err ;
+  if (sizeof(S6_EXTBINPREFIX) > 1)
+  {
+    if (buffer_puts(b, EXECLINE_EXTBINPREFIX "exec -a s6-svscan --\n") < 0)
+      goto err ;
+  }
+  if (buffer_puts(b, S6_EXTBINPREFIX "s6-svscan -t0\n") < 0) goto err ;
+  return 1 ;
+ err:
+  satmp.len = sabase ;
+  return 0 ;
+}
+
+int main (int argc, char const *const *argv)
+{
+  char const *catchall_user = "nobody" ;
+  stralloc modif = STRALLOC_ZERO ;
+  PROG = "s6-linux-init-maker" ;
+  {
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      register int opt = subgetopt_r(argc, argv, "c:l:b:u:g:2:3:p:m:t:d:e:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'c' : robase = l.arg ; break ;
+        case 'l' : slashrun = l.arg ; break ;
+        case 'b' : bindir = l.arg ; break ;
+        case 'u' : catchall_user = l.arg ; break ;
+        case 'g' : early_getty = l.arg ; break ;
+        case '2' : init_script = l.arg ; break ;
+        case '3' : shutdown_script = l.arg ; break ;
+        case 'p' : initial_path = l.arg ; break ;
+        case 'm' : if (!uint0_oscan(l.arg, &initial_umask)) dieusage() ; break ;
+        case 't' : if (!uint0_scan(l.arg, &timestamp_style)) dieusage() ; break ;
+        case 'd' : if (!uint0_scan(l.arg, &slashdev_style)) dieusage() ; break ;
+        case 'e' : if (!stralloc_catb(&modif, l.arg, str_len(l.arg) + 1)) dienomem() ; break ;
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
+  }
+  if (!argc) dieusage() ;
+
+  if (robase[0] != '/')
+    strerr_dief3x(100, "base directory ", robase, " is not absolute") ;
+  if (slashrun[0] != '/')
+    strerr_dief3x(100, "tmpfs directory ", slashrun, " is not absolute") ;
+  if (bindir[0] != '/')
+    strerr_dief3x(100, "initial location for binaries ", bindir, " is not absolute") ;
+  if (init_script[0] != '/')
+    strerr_dief3x(100, "stage 2 script location ", init_script, " is not absolute") ;
+  if (shutdown_script[0] != '/')
+    strerr_dief3x(100, "stage 3 script location ", shutdown_script, " is not absolute") ;
+  if (timestamp_style > 3)
+    strerr_dief1x(100, "-t timestamp_style must be 0, 1, 2 or 3") ;
+  if (slashdev_style > 2)
+    strerr_dief1x(100, "-d dev_style must be 0, 1 or 2") ;
+
+
+  {
+    struct passwd *pw = getpwnam(catchall_user) ;
+    if (!pw)
+    {
+      if (errno)
+        strerr_diefu2sys(111, "getpwnam for ", catchall_user) ;
+      else
+        strerr_dief3x(100, "getpwnam for ", catchall_user, ": no such user") ;
+    }
+    uncaught_logs_uid = pw->pw_uid ;
+    uncaught_logs_gid = pw->pw_gid ;
+  }
+
+  if (mkdir(argv[0], 0755) < 0)
+    strerr_diefu2sys(111, "mkdir ", argv[0]) ;
+
+  make_env(argv[0], modif.s, modif.len) ;
+  stralloc_free(&modif) ;
+  make_image(argv[0]) ;
+  if (!make_init_script(buffer_1) || !buffer_flush(buffer_1))
+    strerr_diefu1sys(111, "write to stdout") ;
+  return 0 ;
+}