Initial revision

1 files changed, 208 insertions, 0 deletions

diff --git a/src/runit.c b/src/runit.c
new file mode 100644
index 0000000..adfab62
--- /dev/null
+++ b/src/runit.c
@@ -0,0 +1,208 @@
+/* this requires: */
+#include <poll.h>
+
+#include <sys/types.h>
+#include <sys/reboot.h>
+#include <signal.h>
+#include <unistd.h>
+
+#include "sig.h"
+#include "strerr.h"
+#include "error.h"
+#include "pathexec.h"
+#include "iopause.h"
+#include "coe.h"
+#include "ndelay.h"
+#include "wait.h"
+#include "open.h"
+
+/* #define DEBUG */
+
+#define INFO "- runit: "
+#define WARNING "- runit: warning: "
+#define FATAL "- runit: fatal: "
+
+#define STOPIT "/etc/runit/stopit"
+#define CTRLALTDEL "/etc/runit/ctrlaltdel"
+
+const char * const take[3] ={
+  "/etc/runit/1",
+  "/etc/runit/2",
+  "/etc/runit/3" };
+const char *progname;
+int selfpipe[2];
+int sigc =0;
+int sigi =0;
+
+void sig_cont_handler(void) {
+  sigc++;
+  write(selfpipe[1], "", 1);
+}
+void sig_int_handler(void) {
+  sigi++;
+  write(selfpipe[1], "", 1);
+}
+void sig_child_handler(void) {
+  write(selfpipe[1], "", 1);
+}
+
+int main (int argc, const char * const *argv, const char * const *envp) {
+  int pid, pid2;
+  int wstat;
+  int fd;
+  int i;
+  int stopit =0;
+  iopause_fd x;
+  char ch;
+
+  setsid();
+
+  sig_block(sig_alarm);
+  sig_block(sig_child);
+  sig_catch(sig_child, sig_child_handler);
+  sig_block(sig_cont);
+  sig_catch(sig_cont, sig_cont_handler);
+  sig_block(sig_hangup);
+  sig_block(sig_int);
+  sig_catch(sig_int, sig_int_handler);
+  sig_block(sig_pipe);
+  sig_block(sig_term);
+
+  /* create selfpipe */
+  while (pipe(selfpipe) == -1) {
+    strerr_warn2(FATAL, "unable to create selfpipe, pausing: ", &strerr_sys);
+    sleep(5);
+  }
+  coe(selfpipe[0]);
+  coe(selfpipe[1]);
+  ndelay_on(selfpipe[0]);
+  ndelay_on(selfpipe[1]);
+
+  /* activate ctrlaltdel handling */
+  reboot(0);
+
+  strerr_warn3(INFO, "$Id$", ": booting.", 0);
+
+  /* runit */
+  for (i =0; i < 3; i++) {
+    while ((pid =fork()) == -1) {
+      strerr_warn4(FATAL, "unable to fork for \"", take[i], "\" pausing: ",
+		   &strerr_sys);
+      sleep(5);
+    }
+    if (!pid) {
+      /* child */
+      const char * prog[2];
+
+      prog[0] =take[i];
+      prog[1] =0;
+
+      setsid();
+
+      sig_unblock(sig_alarm);
+      sig_unblock(sig_child);
+      sig_uncatch(sig_child);
+      sig_unblock(sig_cont);
+      sig_ignore(sig_cont);
+      sig_unblock(sig_hangup);
+      sig_unblock(sig_int);
+      sig_uncatch(sig_int);
+      sig_unblock(sig_pipe);
+      sig_unblock(sig_term);
+            
+      strerr_warn3(INFO, "enter stage: ", take[i], 0);
+      pathexec_run(*prog, (const char* const *) prog, envp);
+      strerr_warn3(FATAL, "could not start child: ", take[i], &strerr_sys);
+    }
+
+    x.fd =selfpipe[0];
+    x.events =IOPAUSE_READ;
+
+    for (;;) {
+      sig_unblock(sig_child);
+      sig_unblock(sig_cont);
+      sig_unblock(sig_int);
+      poll(&x, 1, -1);
+      sig_block(sig_cont);
+      sig_block(sig_child);
+      sig_block(sig_int);
+
+      while (read(selfpipe[0], &ch, 1) == 1) {}
+      
+      if (wait_nohang(&wstat) == pid) {
+	if (wait_crashed(wstat) && !stopit) {
+	  strerr_warn3(WARNING, "child crashed: ", take[i], 0);
+	  if (i == 1) {
+	    kill(-pid, SIGTERM);
+	    sleep(1);
+	    strerr_warn2(WARNING, "restarting.", 0);
+	    i--;
+	    break;
+	  }
+	}
+	if (stopit) stopit =0;
+	strerr_warn3(INFO, "leave stage: ", take[i], 0);
+	break;
+      }
+      
+      /* sig */
+      if ((sigc == 0) && (sigi == 0)) {
+#ifdef DEBUG
+	strerr_warn2(WARNING, "poll: ", &strerr_sys);
+#endif
+	continue;
+      }
+      if ((i != 1) || stopit) {
+	strerr_warn2(WARNING, "sigs only work in stage 2.", 0);
+	sigc =sigi =0;
+	continue;
+      }
+      if (sigc && ((fd =open_write(STOPIT)) != -1)) {
+	close(fd);
+	unlink(STOPIT);
+	kill(pid, SIGTERM);
+	sigc =sigi =0;
+	stopit =1;
+	continue;
+      }
+      if (sigi && ((fd =open_write(CTRLALTDEL)) != -1)) {
+	close(fd);
+	strerr_warn2(INFO, "ctrl-alt-del request...", 0);
+	while ((pid2 =fork()) == -1) {
+	  strerr_warn4(FATAL,
+		       "unable to fork for \"", CTRLALTDEL, "\" pausing: ",
+		       &strerr_sys);
+	  sleep(5);
+	}
+	if (!pid2) {
+	  /* child */
+	  const char * prog[2];
+
+	  prog[0] =CTRLALTDEL;
+	  prog[1] =0;
+            
+	  strerr_warn3(INFO, "enter stage: ", prog[0], 0);
+	  pathexec_run(*prog, (const char* const *) prog, envp);
+	  strerr_warn3(FATAL, "could not start child: ", prog[0], &strerr_sys);
+	}
+	if (wait_pid(&wstat, pid2) == -1) {
+	  strerr_warn2(FATAL, "wait_pid: ", &strerr_sys);
+	}
+	if (wait_crashed(wstat)) {
+	  strerr_warn3(WARNING, "child crashed: ", CTRLALTDEL, 0);
+	}
+	kill(pid, SIGTERM);
+	sigc =sigi =0;
+	stopit =1;
+	continue;
+      }
+      
+#ifdef DEBUG
+      strerr_warn2(WARNING, "no request.", 0);
+#endif
+    }
+  }
+  /* not reached */
+  strerr_warn2(INFO, "exit.", 0);
+  exit(0);
+}