Added checks for correct values specified for connection memory limits

2 files changed, 35 insertions, 2 deletions

diff --git a/src/include/microhttpd.h b/src/include/microhttpd.h
index 4976b071..8745367c 100644
--- a/src/include/microhttpd.h
+++ b/src/include/microhttpd.h
@@ -96,7 +96,7 @@ extern "C"
  * they are parsed as decimal numbers.
  * Example: 0x01093001 = 1.9.30-1.
  */
-#define MHD_VERSION 0x00097702
+#define MHD_VERSION 0x00097703
 
 /* If generic headers don't work on your platform, include headers
    which define 'va_list', 'size_t', 'ssize_t', 'intptr_t', 'off_t',
@@ -1626,6 +1626,7 @@ enum MHD_OPTION
    * Values above 128k are unlikely to result in much benefit, as half
    * of the memory will be typically used for IO, and TCP buffers are
    * unlikely to support window sizes above 64k on most systems.
+   * Values below 64 bytes are completely unusable.
    */
   MHD_OPTION_CONNECTION_MEMORY_LIMIT = 1,
 
@@ -1864,7 +1865,8 @@ enum MHD_OPTION
 
   /**
    * Increment to use for growing the read buffer (followed by a
-   * `size_t`). Must fit within #MHD_OPTION_CONNECTION_MEMORY_LIMIT.
+   * `size_t`).
+   * Must not be higher than 1/4 of #MHD_OPTION_CONNECTION_MEMORY_LIMIT.
    */
   MHD_OPTION_CONNECTION_MEMORY_INCREMENT = 21,
 
diff --git a/src/microhttpd/daemon.c b/src/microhttpd/daemon.c
index f310e1c7..c403d02b 100644
--- a/src/microhttpd/daemon.c
+++ b/src/microhttpd/daemon.c
@@ -6250,10 +6250,41 @@ parse_options_va (struct MHD_Daemon *daemon,
     case MHD_OPTION_CONNECTION_MEMORY_LIMIT:
       daemon->pool_size = va_arg (ap,
                                   size_t);
+      if (64 > daemon->pool_size)
+      {
+#ifdef HAVE_MESSAGES
+        MHD_DLOG (daemon,
+                  _ ("Warning: specified MHD_OPTION_CONNECTION_MEMORY_LIMIT " \
+                     "value is too small and rounded up to 64.\n"));
+#endif /* HAVE_MESSAGES */
+        daemon->pool_size = 64;
+      }
+      if (daemon->pool_size / 4 < daemon->pool_increment)
+        daemon->pool_increment = daemon->pool_size / 4;
       break;
     case MHD_OPTION_CONNECTION_MEMORY_INCREMENT:
       daemon->pool_increment = va_arg (ap,
                                        size_t);
+      if (0 == daemon->pool_increment)
+      {
+#ifdef HAVE_MESSAGES
+        MHD_DLOG (daemon,
+                  _ ("The MHD_OPTION_CONNECTION_MEMORY_INCREMENT value " \
+                     "cannot be zero.\n"));
+#endif /* HAVE_MESSAGES */
+        return MHD_NO;
+      }
+      if (daemon->pool_size / 4 < daemon->pool_increment)
+      {
+#ifdef HAVE_MESSAGES
+        MHD_DLOG (daemon,
+                  _ ("Warning: specified " \
+                     "MHD_OPTION_CONNECTION_MEMORY_INCREMENT value is too " \
+                     "large and rounded down to 1/4 of " \
+                     "MHD_OPTION_CONNECTION_MEMORY_LIMIT.\n"));
+#endif /* HAVE_MESSAGES */
+        daemon->pool_increment = daemon->pool_size / 4;
+      }
       break;
     case MHD_OPTION_CONNECTION_LIMIT:
       daemon->connection_limit = va_arg (ap,