From 8bd670430ae70d36c19cde01c0c43c1bd0dbf7f9 Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon@gmx.de>
Date: Thu, 16 Nov 2017 22:24:17 +0100
Subject: [PATCH] httpd: ssi: move checking file extensions against
 g_pcSSIExtensions array into its own function guarded by
 LWIP_HTTPD_SSI_BY_FILE_EXTENSION

---
 src/apps/httpd/httpd.c             | 70 ++++++++++++++++++------------
 src/include/lwip/apps/httpd_opts.h | 12 +++++
 2 files changed, 55 insertions(+), 27 deletions(-)

diff --git a/src/apps/httpd/httpd.c b/src/apps/httpd/httpd.c
index 36380ea4..b3ca15b4 100644
--- a/src/apps/httpd/httpd.c
+++ b/src/apps/httpd/httpd.c
@@ -2087,6 +2087,47 @@ badrequest:
   }
 }
 
+#if LWIP_HTTPD_SSI && (LWIP_HTTPD_SSI_BY_FILE_EXTENSION == 1)
+/* Check if SSI should be parsed for this file/URL
+ * (With LWIP_HTTPD_SSI_BY_FILE_EXTENSION == 2, this function can be
+ * overridden by an external implementation.)
+ *
+ * @return 1 for SSI, 0 for standard files
+ */
+static u8_t
+http_uri_is_ssi(struct fs_file *file, const char *uri)
+{
+  size_t loop;
+  u8_t tag_check = 0;
+  if (file != NULL) {
+    /* See if we have been asked for an shtml file and, if so,
+        enable tag checking. */
+    const char *ext = NULL, *sub;
+    char *param = (char *)strstr(uri, "?");
+    if (param != NULL) {
+      /* separate uri from parameters for now, set back later */
+      *param = 0;
+    }
+    sub = uri;
+    ext = uri;
+    for (sub = strstr(sub, "."); sub != NULL; sub = strstr(sub, ".")) {
+      ext = sub;
+      sub++;
+    }
+    for (loop = 0; loop < NUM_SHTML_EXTENSIONS; loop++) {
+      if (!lwip_stricmp(ext, g_pcSSIExtensions[loop])) {
+        tag_check = 1;
+        break;
+      }
+    }
+    if (param != NULL) {
+      *param = '?';
+    }
+  }
+  return tag_check;
+}
+#endif /* LWIP_HTTPD_SSI */
+
 /** Try to find the file specified by uri and, if found, initialize hs
  * accordingly.
  *
@@ -2193,33 +2234,8 @@ http_find_file(struct http_state *hs, const char *uri, int is_09)
     } else {
       file = http_get_404_file(hs, &uri);
     }
-#if LWIP_HTTPD_SSI
-    if (file != NULL) {
-      /* See if we have been asked for an shtml file and, if so,
-         enable tag checking. */
-      const char *ext = NULL, *sub;
-      char *param = (char *)strstr(uri, "?");
-      if (param != NULL) {
-        /* separate uri from parameters for now, set back later */
-        *param = 0;
-      }
-      sub = uri;
-      ext = uri;
-      for (sub = strstr(sub, "."); sub != NULL; sub = strstr(sub, ".")) {
-        ext = sub;
-        sub++;
-      }
-      tag_check = 0;
-      for (loop = 0; loop < NUM_SHTML_EXTENSIONS; loop++) {
-        if (!lwip_stricmp(ext, g_pcSSIExtensions[loop])) {
-          tag_check = 1;
-          break;
-        }
-      }
-      if (param != NULL) {
-        *param = '?';
-      }
-    }
+#if LWIP_HTTPD_SSI && LWIP_HTTPD_SSI_BY_FILE_EXTENSION
+    tag_check = http_uri_is_ssi(file, uri);
 #endif /* LWIP_HTTPD_SSI */
   }
   if (file == NULL) {
diff --git a/src/include/lwip/apps/httpd_opts.h b/src/include/lwip/apps/httpd_opts.h
index 2d2191be..a107ee7e 100644
--- a/src/include/lwip/apps/httpd_opts.h
+++ b/src/include/lwip/apps/httpd_opts.h
@@ -109,6 +109,18 @@
 #define LWIP_HTTPD_SSI_RAW        0
 #endif
 
+/** Set this to 0 to prevent parsing the file extension at runtime to decide
+ * if a file should be scanned for SSI tags or not.
+ * Default is 1 (file extensions are checked using the g_pcSSIExtensions array)
+ * Set to 2 to override this runtime test function.
+ *
+ * This is enabled by default, but if you only use a newer version of makefsdata
+ * supporting the "-ssi" option, this info is already present in
+ */
+#if !defined LWIP_HTTPD_SSI_BY_FILE_EXTENSION || defined __DOXYGEN__
+#define LWIP_HTTPD_SSI_BY_FILE_EXTENSION  1
+#endif
+
 /** Set this to 1 to support HTTP POST */
 #if !defined LWIP_HTTPD_SUPPORT_POST || defined __DOXYGEN__
 #define LWIP_HTTPD_SUPPORT_POST   0