1 files changed, 121 insertions, 0 deletions
diff --git a/lib/xref.c b/lib/xref.c
new file mode 100644
index 0000000..fc0ba62
--- /dev/null
+++ b/lib/xref.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2017-20  David Lamparter, for NetDEF, Inc.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <pthread.h>
+#include <signal.h>
+#include <inttypes.h>
+
+#include "xref.h"
+#include "vty.h"
+#include "jhash.h"
+#include "sha256.h"
+#include "memory.h"
+#include "hash.h"
+
+struct xref_block *xref_blocks;
+static struct xref_block **xref_block_last = &xref_blocks;
+
+struct xrefdata_uid_head xrefdata_uid = INIT_RBTREE_UNIQ(xrefdata_uid);
+
+static void base32(uint8_t **inpos, int *bitpos,
+		   char *out, size_t n_chars)
+{
+	static const char base32ch[] = "0123456789ABCDEFGHJKMNPQRSTVWXYZ";
+
+	char *opos = out;
+	uint8_t *in = *inpos;
+	int bp = *bitpos;
+
+	while (opos < out + n_chars) {
+		uint32_t bits = in[0] | (in[1] << 8);
+
+		if (bp == -1)
+			bits |= 0x10;
+		else
+			bits >>= bp;
+
+		*opos++ = base32ch[bits & 0x1f];
+
+		bp += 5;
+		if (bp >= 8)
+			in++, bp -= 8;
+	}
+	*opos = '\0';
+	*inpos = in;
+	*bitpos = bp;
+}
+
+static void xref_add_one(const struct xref *xref)
+{
+	SHA256_CTX sha;
+	struct xrefdata *xrefdata;
+
+	const char *filename, *p, *q;
+	uint8_t hash[32], *h = hash;
+	uint32_t be_val;
+	int bitpos;
+
+	if (!xref || !xref->xrefdata)
+		return;
+
+	xrefdata = xref->xrefdata;
+	xrefdata->xref = xref;
+
+	if (!xrefdata->hashstr)
+		return;
+
+	/* as far as the unique ID is concerned, only use the last
+	 * directory name + filename, e.g. "bgpd/bgp_route.c".  This
+	 * gives a little leeway in moving things and avoids IDs being
+	 * screwed up by out of tree builds or absolute pathnames.
+	 */
+	filename = xref->file;
+	p = strrchr(filename, '/');
+	if (p) {
+		q = memrchr(filename, '/', p - filename);
+		if (q)
+			filename = q + 1;
+	}
+
+	SHA256_Init(&sha);
+	SHA256_Update(&sha, filename, strlen(filename));
+	SHA256_Update(&sha, xrefdata->hashstr,
+		      strlen(xrefdata->hashstr));
+	be_val = htonl(xrefdata->hashu32[0]);
+	SHA256_Update(&sha, &be_val, sizeof(be_val));
+	be_val = htonl(xrefdata->hashu32[1]);
+	SHA256_Update(&sha, &be_val, sizeof(be_val));
+	SHA256_Final(hash, &sha);
+
+	bitpos = -1;
+	base32(&h, &bitpos, &xrefdata->uid[0], 5);
+	xrefdata->uid[5] = '-';
+	base32(&h, &bitpos, &xrefdata->uid[6], 5);
+
+	xrefdata_uid_add(&xrefdata_uid, xrefdata);
+}
+
+void xref_gcc_workaround(const struct xref *xref)
+{
+	xref_add_one(xref);
+}
+
+void xref_block_add(struct xref_block *block)
+{
+	const struct xref * const *xrefp;
+
+	*xref_block_last = block;
+	xref_block_last = &block->next;
+
+	for (xrefp = block->start; xrefp < block->stop; xrefp++)
+		xref_add_one(*xrefp);
+}