Add a "fork" of musl as //fusl.

fusl/src/network/ns_parse.c

Index: fusl/src/network/ns_parse.c
diff --git a/fusl/src/network/ns_parse.c b/fusl/src/network/ns_parse.c
new file mode 100644
index 0000000000000000000000000000000000000000..d01da47a3d41112ab50c0239b9bff63c9cbe5963
--- /dev/null
+++ b/fusl/src/network/ns_parse.c
@@ -0,0 +1,171 @@
+#define _BSD_SOURCE
+#include <errno.h>
+#include <stddef.h>
+#include <resolv.h>
+#include <arpa/nameser.h>
+
+const struct _ns_flagdata _ns_flagdata[16] = {
+	{ 0x8000, 15 },
+	{ 0x7800, 11 },
+	{ 0x0400, 10 },
+	{ 0x0200, 9 },
+	{ 0x0100, 8 },
+	{ 0x0080, 7 },
+	{ 0x0040, 6 },
+	{ 0x0020, 5 },
+	{ 0x0010, 4 },
+	{ 0x000f, 0 },
+	{ 0x0000, 0 },
+	{ 0x0000, 0 },
+	{ 0x0000, 0 },
+	{ 0x0000, 0 },
+	{ 0x0000, 0 },
+	{ 0x0000, 0 },
+};
+
+unsigned ns_get16(const unsigned char *cp)
+{
+	return cp[0]<<8 | cp[1];
+}
+
+unsigned long ns_get32(const unsigned char *cp)
+{
+	return (unsigned)cp[0]<<24 | cp[1]<<16 | cp[2]<<8 | cp[3];
+}
+
+void ns_put16(unsigned s, unsigned char *cp)
+{
+	*cp++ = s>>8;
+	*cp++ = s;
+}
+
+void ns_put32(unsigned long l, unsigned char *cp)
+{
+	*cp++ = l>>24;
+	*cp++ = l>>16;
+	*cp++ = l>>8;
+	*cp++ = l;
+}
+
+int ns_initparse(const unsigned char *msg, int msglen, ns_msg *handle)
+{
+	int i, r;
+
+	handle->_msg = msg;
+	handle->_eom = msg + msglen;
+	if (msglen < (2 + ns_s_max) * NS_INT16SZ) goto bad;
+	NS_GET16(handle->_id, msg);
+	NS_GET16(handle->_flags, msg);
+	for (i = 0; i < ns_s_max; i++) NS_GET16(handle->_counts[i], msg);
+	for (i = 0; i < ns_s_max; i++) {
+		if (handle->_counts[i]) {
+			handle->_sections[i] = msg;
+			r = ns_skiprr(msg, handle->_eom, i, handle->_counts[i]);
+			if (r < 0) return -1;
+			msg += r;
+		} else {
+			handle->_sections[i] = NULL;
+		}
+	}
+	if (msg != handle->_eom) goto bad;
+	handle->_sect = ns_s_max;
+	handle->_rrnum = -1;
+	handle->_msg_ptr = NULL;
+	return 0;
+bad:
+	errno = EMSGSIZE;
+	return -1;
+}
+
+int ns_skiprr(const unsigned char *ptr, const unsigned char *eom, ns_sect section, int count)
+{
+	const unsigned char *p = ptr;
+	int r;
+
+	while (count--) {
+		r = dn_skipname(p, eom);
+		if (r < 0) goto bad;
+		if (r + 2 * NS_INT16SZ > eom - p) goto bad;
+		p += r + 2 * NS_INT16SZ;
+		if (section != ns_s_qd) {
+			if (NS_INT32SZ + NS_INT16SZ > eom - p) goto bad;
+			p += NS_INT32SZ;
+			NS_GET16(r, p);
+			if (r > eom - p) goto bad;
+			p += r;
+		}
+	}
+	return p - ptr;
+bad:
+	errno = EMSGSIZE;
+	return -1;
+}
+
+int ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr)
+{
+	int r;
+
+	if (section < 0 || section >= ns_s_max) goto bad;
+	if (section != handle->_sect) {
+		handle->_sect = section;
+		handle->_rrnum = 0;
+		handle->_msg_ptr = handle->_sections[section];
+	}
+	if (rrnum == -1) rrnum = handle->_rrnum;
+	if (rrnum < 0 || rrnum >= handle->_counts[section]) goto bad;
+	if (rrnum < handle->_rrnum) {
+		handle->_rrnum = 0;
+		handle->_msg_ptr = handle->_sections[section];
+	}
+	if (rrnum > handle->_rrnum) {
+		r = ns_skiprr(handle->_msg_ptr, handle->_eom, section, rrnum - handle->_rrnum);
+		if (r < 0) return -1;
+		handle->_msg_ptr += r;
+		handle->_rrnum = rrnum;
+	}
+	r = ns_name_uncompress(handle->_msg, handle->_eom, handle->_msg_ptr, rr->name, NS_MAXDNAME);
+	if (r < 0) return -1;
+	handle->_msg_ptr += r;
+	if (2 * NS_INT16SZ > handle->_eom - handle->_msg_ptr) goto size;
+	NS_GET16(rr->type, handle->_msg_ptr);
+	NS_GET16(rr->rr_class, handle->_msg_ptr);
+	if (section != ns_s_qd) {
+		if (NS_INT32SZ + NS_INT16SZ > handle->_eom - handle->_msg_ptr) goto size;
+		NS_GET32(rr->ttl, handle->_msg_ptr);
+		NS_GET16(rr->rdlength, handle->_msg_ptr);
+		if (rr->rdlength > handle->_eom - handle->_msg_ptr) goto size;
+		rr->rdata = handle->_msg_ptr;
+		handle->_msg_ptr += rr->rdlength;
+	} else {
+		rr->ttl = 0;
+		rr->rdlength = 0;
+		rr->rdata = NULL;
+	}
+	handle->_rrnum++;
+	if (handle->_rrnum > handle->_counts[section]) {
+		handle->_sect = section + 1;
+		if (handle->_sect == ns_s_max) {
+			handle->_rrnum = -1;
+			handle->_msg_ptr = NULL;
+		} else {
+			handle->_rrnum = 0;
+		}
+	}
+	return 0;
+bad:
+	errno = ENODEV;
+	return -1;
+size:
+	errno = EMSGSIZE;
+	return -1;
+}
+
+int ns_name_uncompress(const unsigned char *msg, const unsigned char *eom,
+                       const unsigned char *src, char *dst, size_t dstsiz)
+{
+	int r;
+	r = dn_expand(msg, eom, src, dst, dstsiz);
+	if (r < 0) errno = EMSGSIZE;
+	return r;
+}
+