Initial working library

1 files changed, 128 insertions, 0 deletions

diff --git a/src/nspsl.c b/src/nspsl.c
new file mode 100644
index 0000000..2e6e4dd
--- /dev/null
+++ b/src/nspsl.c
@@ -0,0 +1,128 @@
+/*
+ * Copyright 2016 Vincent Sanders <vince@netsurf-browser.org>
+ *
+ * This file is part of libnspsl
+ *
+ * Licensed under the MIT License,
+ *                http://www.opensource.org/licenses/mit-license.php
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include "nspsl.h"
+
+#include "psl.inc"
+
+#define DOMSEP '.'
+
+static int matchlabel(int parent, const char *start, int len)
+{
+	int clast = pnodes[parent].child_index + pnodes[parent].child_count;
+	int cidx; /*child node index */
+	int ridx = -1; /* index of match or -1 */
+
+	if (pnodes[parent].child_count != 0) {
+		/* there are child nodes present to scan */
+
+		for (cidx = pnodes[parent].child_index; cidx < clast; cidx++) {
+			if (pnodes[cidx].label == STAB_WILDCARD) {
+				/* wildcard match */
+				ridx = cidx;
+			} else {
+				if ((pnodes[cidx].label_len == len) &&
+				    (strncasecmp(&stab[pnodes[cidx].label],
+						 start,
+						 len) == 0)) {
+
+					if ((pnodes[cidx].child_count == 1) &&
+					    (pnodes[pnodes[cidx].child_index].label == STAB_EXCEPTION)) {
+						/* exception to previous */
+						ridx = -1;
+					} else {
+						ridx = cidx;
+					}
+					break;
+				}
+			}
+		}
+	}
+	return ridx;
+}
+
+/*
+ * Exported public API 
+ */
+const char *nspsl_getpublicsuffix(const char *hostname)
+{
+	int treeidx = 0; /* index to current tree node */
+	const char *elem_start;
+	const char *elem_end;
+	int lab_count = 0;
+
+	/* deal with obviously bad hostname */
+	if ((hostname == NULL) ||
+	    (hostname[0]) == 0 ||
+	    (hostname[0] == DOMSEP)) {
+		return NULL;
+	}
+
+	/* hostnames are ass backwards and we need to consider elemets
+	 * from the end first.
+	 */
+	 elem_end = hostname + strlen(hostname);
+	 /* fqdn have a separator on the end */
+	 if (elem_end[-1] == DOMSEP) {
+		 elem_end--;
+	 }
+	 elem_start = elem_end;
+
+	 /* extract the element and check for a match in our tree */
+	 for(;;) {
+		 /* find the start of the element */
+		 while ((elem_start > hostname) && (*elem_start != DOMSEP)) {
+			 elem_start--;
+		 }
+		 if (*elem_start == DOMSEP) {
+			 elem_start++;
+		 }
+
+		 lab_count++;
+
+		 /* search child nodes for label */
+		 treeidx = matchlabel(treeidx, elem_start, elem_end - elem_start);
+		 if (treeidx == -1) {
+			 break;
+		 }
+
+		 if (elem_start == hostname) {
+			 /* not valid */
+			 return NULL;
+		 }
+
+		 elem_end = elem_start - 1;
+		 elem_start = elem_end - 1;
+	 }
+
+	 /* The public suffix algorithm says: "the domain must match
+	  * the public suffix plus one additional label." This
+	  * requires there to be at least two labels so we need to
+	  * check
+	  */
+	 if (lab_count == 1) {
+		 if (elem_start == hostname) {
+			 elem_start = NULL;
+		 } else {
+			 /* strip the non matching part */
+			 elem_start -= 2;
+			 while (elem_start > hostname && *elem_start != DOMSEP) {
+				 elem_start--;
+			 }
+			 if (*elem_start == DOMSEP)
+				 elem_start++;
+		 }
+	 }
+
+
+	 return elem_start;
+}