prefork-interp: fix exit status and signal handling

[chiark-utils.git] / cprogs / prefork-interp.c

diff --git a/cprogs/prefork-interp.c b/cprogs/prefork-interp.c
index 47ad3616a5e46b7bb7c7e546eb96deb9b31b8ae7..3a999ef4c629d0339f6a7ffab5cf7fe021fbfb79 100644 (file)
--- a/cprogs/prefork-interp.c
+++ b/cprogs/prefork-interp.c
@@ -7,11 +7,27 @@
  *   prefork-interp  [<option>,..],<interpreter>   <script> [<args> ...]
  *   prefork-interp '[<option> ..] <interpreter>'  <script> [<args> ...]
  *
- * Options must specify argument laundering mode.
- * Currently the only mode supported is:
+ * Options must specify argument mediation approach.
+ * Currently the only argument mediation supported is:
+ *
  *   -U    unlaundered: setup and executor both get all arguments and env vars
  *         ident covers only env vars specified  with -E
  *         ident covers only arguments interpreter and (if present) script
+ *
+ * Options for setting the operation mode:
+ *
+ *   (none)     Default: start new server if needed, then run service
+ *   -f         Force a fresh service (old one is terminated)
+ *   --kill     Kill any existing service; do not actually run anything
+ *
+ * Options for controlling whether different invocations share a server:
+ *
+ *   -E VAR      ident includes env var VAR (or its absence)
+ *   -G STRING   ident includes string STRING
+ *   -g IDENT    use IDENT rather than hex(SHA256(... identity things ...))
+ *
+ * (Ordering of -E and -G options is relevant; invocations with different
+ * -E -G options are different even if the env var settings are the same)
  */
 
 /*
@@ -363,6 +379,7 @@
 */
 
 #include <arpa/inet.h>
+#include <sys/utsname.h>
 
 #include <uv.h>
 
@@ -404,16 +421,34 @@ const struct cmdinfo cmdinfos[]= {
   { 0 }
 };
 
+static void ident_add_stat(const char *path) {
+  struct stat stab;
+  int r = stat(path, &stab);
+  if (r) diee("failed to stat %s", path);
+
+  IDENT_ADD_OBJ(path[0], stab.st_dev);
+  IDENT_ADD_OBJ('i',     stab.st_ino);
+}
+
 void ident_addinit(void) {
-  char ident_magic[1] = { 0 };
-  sha256_update(&identsc, sizeof(ident_magic), ident_magic);
+  ident_add_key_byte(1);
+
+  struct utsname uts = { };
+  size_t utslen = sizeof(uts);
+  int r = uname(&uts);
+  if (r) diee("uname failed!");
+  IDENT_ADD_OBJ('u', utslen);
+  IDENT_ADD_OBJ('u', uts);
+
+  ident_add_stat(".");
+  ident_add_stat("/");
 }
 
 static void propagate_exit_status(int status, const char *what) {
   int r;
 
   if (WIFEXITED(status)) {
-    _exit(status);
+    _exit(WEXITSTATUS(status));
   }
 
   if (WIFSIGNALED(status)) {
@@ -423,22 +458,25 @@ static void propagate_exit_status(int status, const char *what) {
 
     if (! WCOREDUMP(status) &&
        (sig == SIGINT ||
+        sig == SIGTERM ||
         sig == SIGHUP ||
         sig == SIGPIPE ||
         sig == SIGKILL)) {
       struct sigaction sa;
       FILLZERO(sa);
       sa.sa_handler = SIG_DFL;
-      r = sigaction(sig, &sa, 0);
-      if (r) diee("failed to reset signal handler while propagating %s",
-                 signame);
-
-      sigset_t sset;
-      sigemptyset(&sset);
-      sigaddset(&sset, sig);
-      r = sigprocmask(SIG_UNBLOCK, &sset, 0);
-      if (r) diee("failed to reset signal block while propagating %s",
-                 signame);
+      if (sig != SIGKILL) {
+        r = sigaction(sig, &sa, 0);
+        if (r) diee("failed to reset signal handler while propagating %s",
+                    signame);
+
+        sigset_t sset;
+        sigemptyset(&sset);
+        sigaddset(&sset, sig);
+        r = sigprocmask(SIG_UNBLOCK, &sset, 0);
+        if (r) diee("failed to reset signal block while propagating %s",
+                    signame);
+      }
 
       raise(sig);
       die("unexpectedly kept running after raising (to propagate) %s",
@@ -708,7 +746,8 @@ static const char *read_greeting(void) {
   char got_magic[sizeof(header_magic)];
 
   if (protocol_read_maybe(&got_magic, sizeof(got_magic)) < 0)
-    return "initial monitor process quit";
+    return "initial monitor process quit"
+      " (maybe script didn't call preform_initialisation_complete?)";
 
   if (memcmp(got_magic, header_magic, sizeof(header_magic)))
     die("got unexpected protocol magic 0x%02x%02x%02x%02x",