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-rw-r--r--libc/inet/resolv.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c
index 6bfe52c79..011cd5e56 100644
--- a/libc/inet/resolv.c
+++ b/libc/inet/resolv.c
@@ -3886,6 +3886,201 @@ void ns_put32(unsigned long src, unsigned char *dst)
}
#endif /* L_ns_netint */
+#ifdef L_ns_parse
+/* These need to be in the same order as the nres.h:ns_flag enum. */
+const struct _ns_flagdata _ns_flagdata[16] = {
+ { 0x8000, 15 }, /*%< qr. */
+ { 0x7800, 11 }, /*%< opcode. */
+ { 0x0400, 10 }, /*%< aa. */
+ { 0x0200, 9 }, /*%< tc. */
+ { 0x0100, 8 }, /*%< rd. */
+ { 0x0080, 7 }, /*%< ra. */
+ { 0x0040, 6 }, /*%< z. */
+ { 0x0020, 5 }, /*%< ad. */
+ { 0x0010, 4 }, /*%< cd. */
+ { 0x000f, 0 }, /*%< rcode. */
+ { 0x0000, 0 }, /*%< expansion (1/6). */
+ { 0x0000, 0 }, /*%< expansion (2/6). */
+ { 0x0000, 0 }, /*%< expansion (3/6). */
+ { 0x0000, 0 }, /*%< expansion (4/6). */
+ { 0x0000, 0 }, /*%< expansion (5/6). */
+ { 0x0000, 0 }, /*%< expansion (6/6). */
+};
+
+static void setsection(ns_msg *msg, ns_sect sect)
+{
+ msg->_sect = sect;
+ if (sect == ns_s_max) {
+ msg->_rrnum = -1;
+ msg->_ptr = NULL;
+ } else {
+ msg->_rrnum = 0;
+ msg->_ptr = msg->_sections[(int)sect];
+ }
+}
+
+int ns_skiprr(const unsigned char *ptr,
+ const unsigned char *eom,
+ ns_sect section, int count)
+{
+ const u_char *optr = ptr;
+
+ for (; count > 0; count--) {
+ int b, rdlength;
+
+ b = dn_skipname(ptr, eom);
+ if (b < 0) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
+ if (section != ns_s_qd) {
+ if (ptr + NS_INT32SZ + NS_INT16SZ > eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ ptr += NS_INT32SZ/*TTL*/;
+ NS_GET16(rdlength, ptr);
+ ptr += rdlength/*RData*/;
+ }
+ }
+
+ if (ptr > eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ return ptr - optr;
+}
+
+int
+ns_initparse(const unsigned char *msg, int msglen, ns_msg *handle)
+{
+ const u_char *eom = msg + msglen;
+ int i;
+
+ handle->_msg = msg;
+ handle->_eom = eom;
+ if (msg + NS_INT16SZ > eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ NS_GET16(handle->_id, msg);
+ if (msg + NS_INT16SZ > eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ NS_GET16(handle->_flags, msg);
+ for (i = 0; i < ns_s_max; i++) {
+ if (msg + NS_INT16SZ > eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ NS_GET16(handle->_counts[i], msg);
+ }
+ for (i = 0; i < ns_s_max; i++)
+ if (handle->_counts[i] == 0)
+ handle->_sections[i] = NULL;
+ else {
+ int b = ns_skiprr(msg, eom, (ns_sect)i,
+ handle->_counts[i]);
+
+ if (b < 0)
+ return -1;
+ handle->_sections[i] = msg;
+ msg += b;
+ }
+
+ if (msg != eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ setsection(handle, ns_s_max);
+ return 0;
+}
+
+int
+ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr)
+{
+ int b;
+ int tmp;
+
+ /* Make section right. */
+ tmp = section;
+ if (tmp < 0 || section >= ns_s_max) {
+ errno = ENODEV;
+ return -1;
+ }
+
+ if (section != handle->_sect)
+ setsection(handle, section);
+
+ /* Make rrnum right. */
+ if (rrnum == -1)
+ rrnum = handle->_rrnum;
+ if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) {
+ errno = ENODEV;
+ return -1;
+ }
+ if (rrnum < handle->_rrnum)
+ setsection(handle, section);
+ if (rrnum > handle->_rrnum) {
+ b = ns_skiprr(handle->_ptr, handle->_eom, section,
+ rrnum - handle->_rrnum);
+
+ if (b < 0)
+ return (-1);
+ handle->_ptr += b;
+ handle->_rrnum = rrnum;
+ }
+
+ /* Do the parse. */
+ b = dn_expand(handle->_msg, handle->_eom,
+ handle->_ptr, rr->name, NS_MAXDNAME);
+ if (b < 0)
+ return (-1);
+ handle->_ptr += b;
+ if (handle->_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+ NS_GET16(rr->type, handle->_ptr);
+ NS_GET16(rr->rr_class, handle->_ptr);
+ if (section == ns_s_qd) {
+ rr->ttl = 0;
+ rr->rdlength = 0;
+ rr->rdata = NULL;
+ } else {
+ if (handle->_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+ NS_GET32(rr->ttl, handle->_ptr);
+ NS_GET16(rr->rdlength, handle->_ptr);
+ if (handle->_ptr + rr->rdlength > handle->_eom) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+ rr->rdata = handle->_ptr;
+ handle->_ptr += rr->rdlength;
+ }
+ if (++handle->_rrnum > handle->_counts[(int)section])
+ setsection(handle, (ns_sect)((int)section + 1));
+
+ return 0;
+}
+
+int ns_msg_getflag(ns_msg handle, int flag) {
+ return ((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift;
+}
+#endif /* L_ns_parse */
+
/* Unimplemented: */
/* res_mkquery */
/* res_send */