From 9817fd7b0ac2fdd744bd39fdcabcbca94376b8e0 Mon Sep 17 00:00:00 2001
From: Patrick J Cherry <patrick@bytemark.co.uk>
Date: Fri, 9 Feb 2018 11:42:25 +0000
Subject: [PATCH] Final tidies, comments etc.

---
 tests/acceptance/ld_preload.rb                   | 10 +++++++++-
 tests/acceptance/ld_preloads/setsockopt_logger.c | 14 +++++++++-----
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/tests/acceptance/ld_preload.rb b/tests/acceptance/ld_preload.rb
index 8ce0a8f..405660e 100644
--- a/tests/acceptance/ld_preload.rb
+++ b/tests/acceptance/ld_preload.rb
@@ -1,7 +1,11 @@
 require 'tempfile'
 
-# LdPreload is a little wrapper for using LD_PRELOAD when testing flexnbd
+#
+# LdPreload is a little wrapper for using LD_PRELOAD loggers to pick up system
+# calls when testing flexnbd.
+#
 module LdPreload
+  #
   # This takes an object name, sets up a temporary log file, whose name is
   # recorded in the environment as OUTPUT_obj_name, where obj_name is the
   # name of the preload module to build and load.
@@ -34,6 +38,10 @@ module LdPreload
     lines
   end
 
+  #
+  # The next to methods assume the log file has one entry per line, and that
+  # each entry is a series of values separated by colons.
+  #
   def parse_ld_preload_logs(obj_name)
     read_ld_preload_log(obj_name).map do |l|
       l.split(':').map { |i| i =~ /^\d+$/ ? i.to_i : i }
diff --git a/tests/acceptance/ld_preloads/setsockopt_logger.c b/tests/acceptance/ld_preloads/setsockopt_logger.c
index 9a7bf60..d2cc021 100644
--- a/tests/acceptance/ld_preloads/setsockopt_logger.c
+++ b/tests/acceptance/ld_preloads/setsockopt_logger.c
@@ -5,6 +5,10 @@
 #include <stdlib.h>
 #include <sys/socket.h>
 
+/*
+ * Noddy LD_PRELOAD wrapper to catch setsockopt calls, and log them to a file.
+ */
+
 typedef int (*real_setsockopt_t)(int sockfd, int level, int optname, const void *optval, socklen_t optlen);
 
 int real_setsockopt(int sockfd, int level, int optname, const void *optval, socklen_t optlen)
@@ -12,10 +16,6 @@ int real_setsockopt(int sockfd, int level, int optname, const void *optval, sock
   return ((real_setsockopt_t)dlsym(RTLD_NEXT, "setsockopt"))(sockfd, level, optname, optval, optlen);
 }
 
-/*
- * Noddy LD_PRELOAD wrapper to catch setsockopt calls, and log them to a file.
- */
-
 int setsockopt(int sockfd, int level, int optname, const void *optval, socklen_t optlen)
 {
   FILE *fd;
@@ -24,9 +24,13 @@ int setsockopt(int sockfd, int level, int optname, const void *optval, socklen_t
   
   retval = real_setsockopt(sockfd, level, optname, optval, optlen);
   fn = getenv("OUTPUT_setsockopt_logger");
+
+  /* 
+   * Only interested in catching non-null 4-byte (integer) values 
+   */
   if ( fn != NULL && optval != NULL && optlen == 4) {
     fd = fopen(fn,"a");
-    fprintf(fd,"setsockopt:%d:%d:%d:%i:%d\n", sockfd, level, optname, *(int *)optval, retval);
+    fprintf(fd,"setsockopt:%i:%i:%i:%i:%i\n", sockfd, level, optname, *(int *)optval, retval);
     fclose(fd);
   }