From 76c3923a9f832dcd0a1952633c2a5a6eecd4646d Mon Sep 17 00:00:00 2001
From: Lubos Slovak <lubos.slovak@nic.cz>
Date: Wed, 4 May 2011 14:50:14 +0200
Subject: [PATCH] Dname parsing from wire format implemented.
- Added functions for checking and getting dname pointer.
refs #816 @0:45
---
src/dnslib/dname.c | 71 ++++++++++++++++++++++++++++++++++++++++++++--
src/dnslib/wire.h | 15 ++++++++++
2 files changed, 83 insertions(+), 3 deletions(-)
diff --git a/src/dnslib/dname.c b/src/dnslib/dname.c
index 622633e2fd..8dcb9c31ba 100644
--- a/src/dnslib/dname.c
+++ b/src/dnslib/dname.c
@@ -12,6 +12,7 @@
#include "dnslib/tolower.h"
#include "dnslib/debug.h"
#include "dnslib/utils.h"
+#include "dnslib/wire.h"
/*
* Memory cache.
@@ -432,10 +433,74 @@ dnslib_dname_t *dnslib_dname_new_from_wire(const uint8_t *name, uint size,
dnslib_dname_t *dnslib_dname_parse_from_wire(const uint8_t *wire,
size_t *pos, size_t size,
- struct dnslib_node *node)
+ dnslib_node_t *node)
{
- /*! @todo Implement! */
- return NULL;
+ uint8_t name[DNSLIB_MAX_DNAME_LENGTH];
+ uint8_t labels[DNSLIB_MAX_DNAME_LABELS];
+
+ short l = 0;
+ size_t i = 0, p = *pos;
+ int pointer_used = 0;
+
+ while (p < size && wire[p] != 0) {
+ labels[l] = i;
+
+ if (dnslib_wire_is_pointer(wire + p)) {
+ // pointer.
+ p = dnslib_wire_get_pointer(wire + p);
+ *pos += 2;
+ pointer_used = 1;
+ if (p >= size) {
+ return NULL;
+ }
+ } else {
+ // label; first byte is label length
+ uint8_t length = *(wire + p);
+ memcpy(name + i, wire + p, length + 1);
+ p += length + 1;
+ i += length + 1;
+ if (!pointer_used) {
+ *pos += length + 1;
+ }
+ ++l;
+ }
+ }
+ if (p >= size) {
+ return NULL;
+ }
+
+ name[i] = 0;
+
+ dnslib_dname_t *dname = dnslib_dname_alloc();
+
+ if (dname == NULL) {
+ ERR_ALLOC_FAILED;
+ return NULL;
+ }
+
+ dname->name = (uint8_t *)malloc((i + 1) * sizeof(uint8_t));
+ if (dname->name == NULL) {
+ ERR_ALLOC_FAILED;
+ dnslib_dname_free(&dname);
+ return NULL;
+ }
+
+ memcpy(dname->name, name, i + 1);
+ dname->size = i + 1;
+
+ dname->labels = (uint8_t *)malloc(l * sizeof(uint8_t));
+ if (dname->labels == NULL) {
+ ERR_ALLOC_FAILED;
+ dnslib_dname_free(&dname);
+ return NULL;
+ }
+ memcpy(dname->labels, labels, l);
+
+ dname->label_count = l - 1;
+
+ dname->node = node;
+
+ return dname;
}
/*----------------------------------------------------------------------------*/
diff --git a/src/dnslib/wire.h b/src/dnslib/wire.h
index 6affd7c352..3e0eff04bd 100644
--- a/src/dnslib/wire.h
+++ b/src/dnslib/wire.h
@@ -890,6 +890,21 @@ static inline void dnslib_wire_put_pointer(uint8_t *pos, size_t ptr)
pos[0] |= DNSLIB_WIRE_PTR;
}
+static inline int dnslib_wire_is_pointer(const uint8_t *pos)
+{
+ return ((pos[0] & DNSLIB_WIRE_PTR) != 0);
+}
+
+static inline size_t dnslib_wire_get_pointer(const uint8_t *pos)
+{
+ uint16_t p = 0;
+ memcpy(&p, pos, 2);
+ p &= ~DNSLIB_WIRE_PTR;
+
+ uint16_t p2 = dnslib_wire_read_u16(&p);
+ return p2;
+}
+
#endif /* _KNOT_DNSLIB_WIRE_H_ */
/*! @} */
--
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