Bring image sniffing up-to-date with the MIMESNIFF speccontent-sniffing-update

5 files changed, 100 insertions, 101 deletions

diff --git a/libsoup/soup-content-sniffer.c b/libsoup/soup-content-sniffer.c
index 55ac5e8d..ee2c29be 100644
--- a/libsoup/soup-content-sniffer.c
+++ b/libsoup/soup-content-sniffer.c
@@ -40,7 +40,6 @@ static void soup_content_sniffer_session_feature_init (SoupSessionFeatureInterfa
 static SoupContentProcessorInterface *soup_content_sniffer_default_content_processor_interface;
 static void soup_content_sniffer_content_processor_init (SoupContentProcessorInterface *interface, gpointer interface_data);
 
-
 G_DEFINE_TYPE_WITH_CODE (SoupContentSniffer, soup_content_sniffer, G_TYPE_OBJECT,
 			 G_IMPLEMENT_INTERFACE (SOUP_TYPE_SESSION_FEATURE,
 						soup_content_sniffer_session_feature_init)
@@ -77,14 +76,99 @@ soup_content_sniffer_init (SoupContentSniffer *content_sniffer)
 {
 }
 
+typedef struct {
+	const guchar *mask;
+	const guchar *pattern;
+	guint         pattern_length;
+	const char   *sniffed_type;
+} SoupContentSnifferMediaPattern;
+
+static SoupContentSnifferMediaPattern image_types_table[] = {
+
+    /* Windows icon signature. */
+	{ (const guchar *)"\xFF\xFF\xFF\xFF",
+	  (const guchar *)"\x00\x00\x01\x00",
+	  4,
+	  "image/x-icon" },
+
+    /* Windows cursor signature. */
+	{ (const guchar *)"\xFF\xFF\xFF\xFF",
+	  (const guchar *)"\x00\x00\x02\x00",
+	  4,
+	  "image/x-icon" },
+
+    /* BMP. */
+	{ (const guchar *)"\xFF\xFF",
+	  (const guchar *)"BM",
+	  2,
+	  "image/bmp" },
+
+    /* GIFs. */
+    { (const guchar *)"\xFF\xFF\xFF\xFF\xFF\xFF",
+	  (const guchar *)"GIF87a",
+	  6,
+	  "image/gif" },
+
+	{ (const guchar *)"\xFF\xFF\xFF\xFF\xFF\xFF",
+	  (const guchar *)"GIF89a",
+	  6,
+	  "image/gif" },
+
+    /* WEBP. */
+	{ (const guchar *)"\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF\xFF\xFF",
+	  (const guchar *)"RIFF\x00\x00\x00\x00WEBPVP",
+	  14,
+	  "image/webp" },
+
+    /* PNG. */
+	{ (const guchar *)"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
+	  (const guchar *)"\x89PNG\x0D\x0A\x1A\x0A",
+	  8,
+	  "image/png" },
+
+    /* JPEG. */
+	{ (const guchar *)"\xFF\xFF\xFF",
+	  (const guchar *)"\xFF\xD8\xFF",
+	  3,
+	  "image/jpeg" },
+};
+
+static char*
+sniff_images (SoupContentSniffer *sniffer, SoupBuffer *buffer,
+	      const char *content_type)
+{
+	const guchar *resource = (const guchar *)buffer->data;
+	int resource_length = MIN (512, buffer->length);
+	int i;
+
+	for (i = 0; i < G_N_ELEMENTS (image_types_table); i++) {
+                SoupContentSnifferMediaPattern *type_row = &(image_types_table[i]);
+                int j;
+
+		if (resource_length < type_row->pattern_length)
+			continue;
+
+		for (j = 0; j < type_row->pattern_length; j++) {
+			if ((type_row->mask[j] & resource[j]) != type_row->pattern[j])
+				break;
+		}
+
+		/* This means our comparison above matched completely */
+		if (j == type_row->pattern_length)
+			return g_strdup (type_row->sniffed_type);
+	}
+
+	return g_strdup (content_type);
+}
+
 /* This table is based on the MIMESNIFF spec;
- * See 7.1 Identifying a resource with an unknown MIME type
- */
+  * See 7.1 Identifying a resource with an unknown MIME type
+   */
 typedef struct {
 	/* @has_ws is TRUE if @pattern contains "generic" whitespace */
 	gboolean      has_ws;
 	/* @has_tag_termination is TRUE if we should check for a tag-terminating
-	 * byte (0x20 " " or 0x3E ">") after the pattern match. */
+	 	 * byte (0x20 " " or 0x3E ">") after the pattern match. */
 	gboolean      has_tag_termination;
 	const guchar *mask;
 	const guchar *pattern;
@@ -93,7 +177,6 @@ typedef struct {
 	gboolean      scriptable;
 } SoupContentSnifferPattern;
 
-
 /* When has_ws is TRUE, spaces in the pattern will indicate where insignificant space
  * is allowed. Those spaces are marked with \x00 on the mask.
  */
@@ -261,66 +344,6 @@ static SoupContentSnifferPattern types_table[] = {
 	  4,
 	  "text/plain",
 	  FALSE },
-
-	/* Images. */
-
-	{ FALSE, FALSE, /* Windows icon signature. */
-	  (const guchar *)"\xFF\xFF\xFF\xFF",
-	  (const guchar *)"\x00\x00\x01\x00",
-	  4,
-	  "image/x-icon",
-	  FALSE },
-
-	{ FALSE, FALSE, /* Windows cursor signature. */
-	  (const guchar *)"\xFF\xFF\xFF\xFF",
-	  (const guchar *)"\x00\x00\x02\x00",
-	  4,
-	  "image/x-icon",
-	  FALSE },
-
-	{ FALSE, FALSE, /* BMP. */
-	  (const guchar *)"\xFF\xFF",
-	  (const guchar *)"BM",
-	  2,
-	  "image/bmp",
-	  FALSE },
-
-    { FALSE, FALSE, /* GIF. */
-	  (const guchar *)"\xFF\xFF\xFF\xFF\xFF\xFF",
-	  (const guchar *)"GIF87a",
-	  6,
-	  "image/gif",
-	  FALSE },
-
-	{ FALSE, FALSE, /* GIF. */
-	  (const guchar *)"\xFF\xFF\xFF\xFF\xFF\xFF",
-	  (const guchar *)"GIF89a",
-	  6,
-	  "image/gif",
-	  FALSE },
-
-	{ FALSE, FALSE, /* WEBP. */
-	  (const guchar *)"\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF\xFF\xFF",
-	  (const guchar *)"RIFF\x00\x00\x00\x00WEBPVP",
-	  14,
-	  "image/webp",
-	  FALSE },
-
-	{ FALSE, FALSE, /* PNG. */
-	  (const guchar *)"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
-	  (const guchar *)"\x89PNG\x0D\x0A\x1A\x0A",
-	  8,
-	  "image/png",
-	  FALSE },
-
-	{ FALSE, FALSE, /* JPEG. */
-	  (const guchar *)"\xFF\xFF\xFF",
-	  (const guchar *)"\xFF\xD8\xFF",
-	  3,
-	  "image/jpeg",
-	  FALSE },
-
-	/* TODO: audio/video, archive type. */
 };
 
 /* Whether a given byte looks like it might be part of binary content.
@@ -351,6 +374,7 @@ static char*
 sniff_unknown (SoupContentSniffer *sniffer, SoupBuffer *buffer,
 	       gboolean sniff_scriptable)
 {
+    char *sniffed_type = NULL;
 	const guchar *resource = (const guchar *)buffer->data;
 	int resource_length = MIN (512, buffer->length);
 	int i;
@@ -416,6 +440,13 @@ sniff_unknown (SoupContentSniffer *sniffer, SoupBuffer *buffer,
 		}
 	}
 
+    sniffed_type = sniff_images (sniffer, buffer, "unknown/unknown");
+
+    if (!g_str_equal (sniffed_type, "unknown/unknown"))
+        return sniffed_type;
+
+    g_free (sniffed_type);
+
 	for (i = 0; i < resource_length; i++) {
 		if (byte_looks_binary[resource[i]])
 			return g_strdup ("application/octet-stream");
@@ -463,33 +494,6 @@ sniff_text_or_binary (SoupContentSniffer *sniffer, SoupBuffer *buffer)
 	return sniff_unknown (sniffer, buffer, TRUE);
 }
 
-static char*
-sniff_images (SoupContentSniffer *sniffer, SoupBuffer *buffer,
-	      const char *content_type)
-{
-	const guchar *resource = (const guchar *)buffer->data;
-	int resource_length = MIN (512, buffer->length);
-	int i;
-
-	for (i = 0; i < G_N_ELEMENTS (types_table); i++) {
-		SoupContentSnifferPattern *type_row = &(types_table[i]);
-
-		if (resource_length < type_row->pattern_length)
-			continue;
-
-		if (!g_str_has_prefix (type_row->sniffed_type, "image/"))
-			continue;
-
-		/* All of the image types use all-\xFF for the mask,
-		 * so we can just memcmp.
-		 */
-		if (memcmp (type_row->pattern, resource, type_row->pattern_length) == 0)
-			return g_strdup (type_row->sniffed_type);
-	}
-
-	return g_strdup (content_type);
-}
-
 static gboolean skip_insignificant_space (const gchar *resource, int *pos, int resource_length)
 {
 	while ((resource[*pos] == '\x09') ||
@@ -684,15 +688,7 @@ soup_content_sniffer_real_sniff (SoupContentSniffer *sniffer, SoupMessage *msg,
 	if (!g_ascii_strcasecmp (content_type, "text/html"))
 		return sniff_feed_or_html (sniffer, buffer);
 
-	/* 2.7.5 Content-Type sniffing: image
-	 * The spec says:
-	 *
-	 *   If the resource's official type is "image/svg+xml", then
-	 *   the sniffed type of the resource is its official type (an
-	 *   XML type)
-	 *
-	 * The XML case is handled by the if above; if you refactor
-	 * this code, keep this in mind.
+	/* 6. Image types.
 	 */
 	if (!g_ascii_strncasecmp (content_type, "image/", 6))
 		return sniff_images (sniffer, buffer, content_type);
diff --git a/tests/resources/home.jpg b/tests/resources/home.jpg
new file mode 100644
index 00000000..ac1f3bbc
--- /dev/null
+++ b/tests/resources/home.jpg
diff --git a/tests/resources/home.png b/tests/resources/home.png
new file mode 100644
index 00000000..0bb82bac
--- /dev/null
+++ b/tests/resources/home.png
diff --git a/tests/resources/tux.webp b/tests/resources/tux.webp
new file mode 100644
index 00000000..8764f066
--- /dev/null
+++ b/tests/resources/tux.webp
diff --git a/tests/sniffing-test.c b/tests/sniffing-test.c
index c1fe56b9..d53d06f8 100644
--- a/tests/sniffing-test.c
+++ b/tests/sniffing-test.c
@@ -596,6 +596,9 @@ main (int argc, char **argv)
 	/* Test the image sniffing path */
 
 	test_sniffing ("/type/image_png/home.gif", "image/gif");
+	test_sniffing ("/type/image_gif/home.png", "image/png");
+	test_sniffing ("/type/image_png/home.jpg", "image/jpeg");
+	test_sniffing ("/type/image_png/tux.webp", "image/webp");
 
 	/* The spec tells us to only use the last Content-Type header */