From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 15 Aug 2022 20:20:46 +0000 (+0100)
Subject: Revert "prefork-interp: Protocol work"
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=f4c97cbe0d8b7648d365c59669811f5121db7d3d;p=chiark-utils.git

Revert "prefork-interp: Protocol work"

This reverts commit 6ef8d3dd7e4490db0ce5c753e6b8c94c16fc2035.

Some of this is a bad idea.  Notably, changing the arg/env format is
just makework.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/cprogs/prefork-interp.c b/cprogs/prefork-interp.c
index 2e773d2..c62f00a 100644
--- a/cprogs/prefork-interp.c
+++ b/cprogs/prefork-interp.c
@@ -188,22 +188,20 @@ static void prepare_string(size_t *len, char **buf, const char *s) {
   prepare_data(len, buf, s, sl+1);
 }
 
-static void prepare_string_list(size_t *len, char **buf,
-				const char *const *list) {
+static void prepare_message(size_t *len, char **buf) {
   const char *s;
-  const char *const *p;
-  
-  size_t count = 0;
-  for (p = list; (s = *p++); ) count++;
-  char *count_s = m_asprintf("%zd", count);
 
-  prepare_string(len, buf, count_s);
-  for (p = list; (s = *p++); ) prepare_string(len, buf, s);
-}
+  const char *const *p = (void*)environ;
+  while ((s = *p++)) {
+    if (strchr(s, '='))
+      prepare_string(len, buf, s);
+  }
 
-static void prepare_message(size_t *len, char **buf) {
-  prepare_string_list(len, buf, (const char* const*)environ);
-  prepare_string_list(len, buf, executor_argv);
+  prepare_string(len, buf, "");
+
+  p = executor_argv;
+  while ((s = *p++))
+    prepare_string(len, buf, s);
 }
 
 static void send_fd(int payload_fd) {
@@ -256,14 +254,14 @@ static void send_request(void) {
   send_fd(1);
   send_fd(2);
 
-  size_t len = 0;
+  size_t len = 4;
   prepare_message(&len, 0);
-
-  char *m = xmalloc(len + 4);
+  char *m = malloc(len);
+  if (!m) diee("failed to allocate for message");
   char *p = m;
-  prepare_length(0, &p, len);
+  prepare_length(0, &p, len - 4);
   prepare_message(0, &p);
-  assert(p == m + len + 4);
+  assert(p == m + len);
 
   ssize_t sr = fwrite(p, len, 1, call_sock);
   if (sr != 1) diee("write request");
diff --git a/perl/Prefork.pm b/perl/Prefork.pm
index 10c7ec1..bb39265 100644
--- a/perl/Prefork.pm
+++ b/perl/Prefork.pm
@@ -36,10 +36,6 @@ sub server_quit ($) {
 
 # Returns in the executor process
 sub become_monitor () {
-  close LISTEN;
-  eval { protocol_exchange(); 1; }
-    or fail_log("protocol exchange failed: $@");
-
   my $child = fork // fail_log("fork executor: $!");
   if (!$child) {
     #---- executor ----
@@ -47,7 +43,6 @@ sub become_monitor () {
     open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
     open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
     close_call_fds();
-    $! = 0;
     return;
   }
 
@@ -59,8 +54,16 @@ sub become_monitor () {
   _exit(0);
 }
 
+sub forked_monitor () {
+  close LISTEN;
+  eval { protocol_exchange(); 1; }
+    or fail_log("protocol exchange failed: $@");
+  return become_monitor();
+}
+
 sub close_call_fds () {
   foreach (@call_fds) {
+    next if $_ <= 2;
     POSIX::close($_);
   }
   close CALL;
@@ -90,8 +93,7 @@ sub protocol_read_fail ($) {
 }
 
 sub protocol_exchange () {
-  my $greeting = "PFI\n\0\0\0\0";
-  protocol_write($greeting);
+  protocol_write("\n");
 
   @call_fds = map {
     my $r;
@@ -221,7 +223,7 @@ sub initialisation_complete {
 	$child = fork // fail_log("fork for accepted call failed: $!");
 	if (!$child) {
 	  #---- monitor [1] ----
-	  become_monitor();
+	  forked_monitor();
 	}
 	close(CALL);
 	$errcount = 0;