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Wireformat rdata field iterator

This commit is contained in:
Willem Toorop 2015-02-14 21:42:25 +01:00
parent 2dcc0a0da6
commit 177ee2046a
4 changed files with 204 additions and 61 deletions
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5
src/Makefile.in
View File

@ -247,7 +247,8 @@ rr-dict.lo rr-dict.o: $(srcdir)/rr-dict.c $(srcdir)/rr-dict.h getdns/getdns.h $(
$(srcdir)/getdns/getdns_extra.h getdns/getdns.h $(srcdir)/util/rbtree.h $(srcdir)/context.h config.h \
$(srcdir)/extension/libmini_event.h config.h $(srcdir)/util/mini_event.h $(srcdir)/util/rbtree.h \
$(srcdir)/types-internal.h $(srcdir)/dict.h
rr-iter.lo rr-iter.o: $(srcdir)/rr-iter.c $(srcdir)/rr-iter.h getdns/getdns.h $(srcdir)/gldns/pkthdr.h
rr-iter.lo rr-iter.o: $(srcdir)/rr-iter.c $(srcdir)/rr-iter.h getdns/getdns.h $(srcdir)/rr-dict.h config.h \
$(srcdir)/gldns/pkthdr.h $(srcdir)/gldns/gbuffer.h
stub.lo stub.o: $(srcdir)/stub.c config.h $(srcdir)/stub.h getdns/getdns.h $(srcdir)/types-internal.h \
$(srcdir)/getdns/getdns_extra.h getdns/getdns.h $(srcdir)/util/rbtree.h $(srcdir)/gldns/gbuffer.h \
$(srcdir)/gldns/pkthdr.h $(srcdir)/context.h $(srcdir)/extension/libmini_event.h config.h \
@ -262,7 +263,7 @@ util-internal.lo util-internal.o: $(srcdir)/util-internal.c getdns/getdns.h $(sr
$(srcdir)/util-internal.h $(srcdir)/context.h config.h $(srcdir)/extension/libmini_event.h config.h \
$(srcdir)/util/mini_event.h $(srcdir)/util/rbtree.h $(srcdir)/types-internal.h $(srcdir)/rr-dict.h \
$(srcdir)/gldns/wire2str.h $(srcdir)/gldns/str2wire.h $(srcdir)/gldns/rrdef.h $(srcdir)/gldns/gbuffer.h \
$(srcdir)/gldns/pkthdr.h
$(srcdir)/gldns/pkthdr.h $(srcdir)/rr-iter.h
gbuffer.lo gbuffer.o: $(srcdir)/gldns/gbuffer.c config.h $(srcdir)/gldns/gbuffer.h
keyraw.lo keyraw.o: $(srcdir)/gldns/keyraw.c config.h $(srcdir)/gldns/keyraw.h $(srcdir)/gldns/rrdef.h
parse.lo parse.o: $(srcdir)/gldns/parse.c config.h $(srcdir)/gldns/parse.h $(srcdir)/gldns/parseutil.h \

189
src/rr-iter.c
View File

@ -34,46 +34,51 @@
#include <gldns/pkthdr.h>
#include <gldns/gbuffer.h>
static void
rr_iter_find_nxt(priv_getdns_rr_iter *i)
{
assert(i);
assert(i->rr_type);
i->nxt = i->n < GLDNS_QDCOUNT(i->pkt)
? i->rr_type + 4
: i->rr_type + 10 > i->pkt_end
? i->pkt_end
: i->rr_type + 10 + gldns_read_uint16(i->rr_type + 8) > i->pkt_end
? i->pkt_end
: i->rr_type + 10 + gldns_read_uint16(i->rr_type + 8);
}
static priv_getdns_rr_iter *
find_rrtype(priv_getdns_rr_iter *i)
{
size_t dlen;
uint8_t *pos;
assert(i);
assert(i->pos);
/* Past the last RR in the pkt */
if (GLDNS_QDCOUNT(i->pkt) + GLDNS_ANCOUNT(i->pkt) +
GLDNS_NSCOUNT(i->pkt) + GLDNS_ARCOUNT(i->pkt) <= i->n) {
GLDNS_NSCOUNT(i->pkt) + GLDNS_ARCOUNT(i->pkt) <= i->n)
goto done;
i->pos = NULL;
return NULL;
}
/* This iterator was already done */
if (!i->pos)
return NULL;
pos = i->pos;
dlen = i->pkt_len - (pos - i->pkt);
while (dlen >= 5) { /* At least space for type and class */
if (*pos == 0) {
for (pos = i->pos; pos + 4 < i->pkt_end; pos += *pos + 1)
if (!*pos) {
i->rr_type = pos + 1;
rr_iter_find_nxt(i);
return i;
}
if ((*pos & 0xC0) == 0xC0) {
} else if ((*pos & 0xC0) == 0xC0) {
if ( pos + 6 > i->pkt_end)
break; /* No space for class */
i->rr_type = pos + 2;
rr_iter_find_nxt(i);
return i;
}
if ((*pos & 0xC0) != 0)
} else if (*pos & 0xC0)
break; /* Unknown label type */
if (*pos > dlen)
break; /* Label size overflows packet size! */
dlen -= *pos + 1;
pos += *pos + 1;
}
done:
i->pos = NULL;
return NULL;
}
@ -81,11 +86,14 @@ find_rrtype(priv_getdns_rr_iter *i)
priv_getdns_rr_iter *
priv_getdns_rr_iter_init(priv_getdns_rr_iter *i, uint8_t *pkt, size_t pkt_len)
{
if (pkt_len < GLDNS_HEADER_SIZE + 5)
return NULL;
assert(i);
if (pkt_len < GLDNS_HEADER_SIZE + 5) {
i->pos = NULL;
return NULL;
}
i->pkt = pkt;
i->pkt_len = pkt_len;
i->pkt_end = pkt + pkt_len;
i->n = 0;
i->pos = pkt + GLDNS_HEADER_SIZE;
@ -96,31 +104,114 @@ priv_getdns_rr_iter_init(priv_getdns_rr_iter *i, uint8_t *pkt, size_t pkt_len)
priv_getdns_rr_iter *
priv_getdns_rr_iter_next(priv_getdns_rr_iter *i)
{
size_t dlen;
assert(i);
/* Already done */
if (!i->pos)
return NULL;
assert(i->rr_type);
i->n += 1;
if (i->n <= GLDNS_QDCOUNT(i->pkt)) {
i->pos = i->rr_type + 4;
return find_rrtype(i);
}
dlen = i->pkt_len - (i->rr_type - i->pkt);
if (dlen < 10)
goto garbage; /* No space for type, class, ttl & rdlength */
if (gldns_read_uint16(i->rr_type + 8) > dlen - 10)
goto garbage; /* RData size overflos packet size */
i->pos = i->rr_type + 10 + gldns_read_uint16(i->rr_type + 8);
i->n += 1;
i->pos = i->nxt;
return find_rrtype(i);
garbage:
}
static priv_getdns_rdf_iter *
rdf_iter_find_nxt(priv_getdns_rdf_iter *i)
{
uint8_t *pos;
assert(i);
assert(i->pos);
assert(i->rdd_pos);
if (!i->rdd_repeat && (i->rdd_pos->type & GETDNS_RDF_REPEAT)) {
if (i->rdd_pos->type == GETDNS_RDF_REPEAT &&
++i->rdd_pos == i->rdd_end)
goto done;
i->rdd_repeat = i->rdd_pos;
}
if (i->rdd_pos->type & GETDNS_RDF_FIXEDSZ)
i->nxt = i->pos + (i->rdd_pos->type & GETDNS_RDF_FIXEDSZ);
else if ((i->rdd_pos->type & GETDNS_RDF_LEN_VAL) == 0x100)
i->nxt = i->pos < i->end ? i->pos + *i->pos + 1 : i->end;
else if ((i->rdd_pos->type & GETDNS_RDF_LEN_VAL) == 0x200)
i->nxt = i->pos + 1 < i->end
? i->pos + gldns_read_uint16(i->pos) + 2 : i->end;
else if ((i->rdd_pos->type & GETDNS_RDF_DNAME) == GETDNS_RDF_DNAME)
for (pos = i->pos; pos < i->end; pos += *pos + 1) {
if (!*pos) {
i->nxt = pos + 1;
break;
} else if ((*pos & 0xC0) == 0xC0) {
i->nxt = pos + 2;
break;
} else if (*pos & 0xC0) /* Uknown label type */
goto done;
}
else
i->nxt = i->end;
if (i->nxt <= i->end)
return i;
done:
i->pos = NULL;
return NULL;
}
priv_getdns_rdf_iter *
priv_getdns_rdf_iter_init(priv_getdns_rdf_iter *i, priv_getdns_rr_iter *rr)
{
const priv_getdns_rr_def *rr_def;
assert(i);
assert(rr);
/* rr_iter already done or in question section */
if (!rr->pos || rr->n < GLDNS_QDCOUNT(rr->pkt))
goto done;
i->pkt = rr->pkt;
i->pkt_end = rr->pkt_end;
rr_def = priv_getdns_rr_def_lookup(gldns_read_uint16(rr->rr_type));
i->rdd_pos = rr_def->rdata;
i->rdd_end = rr_def->rdata + rr_def->n_rdata_fields;
/* No rdata */
if (i->rdd_pos == i->rdd_end)
goto done;
/* No space to read rdata len */
if (rr->rr_type + 10 >= rr->nxt)
goto done;
i->rdd_repeat = NULL;
i->pos = rr->rr_type + 10;
i->end = rr->nxt;
return rdf_iter_find_nxt(i);
done:
i->pos = NULL;
return NULL;
}
priv_getdns_rdf_iter *
priv_getdns_rdf_iter_next(priv_getdns_rdf_iter *i)
{
if (!i->pos)
return NULL;
i->rdd_pos += 1;
if ((i->pos = i->nxt) >= i->end)
goto done; /* Out of rdata */
if (i->rdd_pos >= i->rdd_end && !(i->rdd_pos = i->rdd_repeat))
goto done; /* Remaining rdata, but out of definitions! */
return rdf_iter_find_nxt(i);
done:
i->pos = NULL;
return NULL;
}

37
src/rr-iter.h
View File

@ -33,13 +33,28 @@
#define RR_ITER_H_
#include "getdns/getdns.h"
#include "rr-dict.h"
typedef struct priv_getdns_rr_iter {
uint8_t *pkt;
size_t pkt_len;
size_t n; /* Which RR are we currently at */
uint8_t *pkt_end;
/* Which RR are we currently at */
size_t n;
/* pos points to start of the owner name the RR.
* Or is NULL when there are no RR's left.
*/
uint8_t *pos;
/* rr_type will point to the rr_type right after the RR's owner name.
* rr_type is guaranteed to have a value when pos has a value
*/
uint8_t *rr_type;
/* nxt point to the owner name of the next RR or to pkt_end */
uint8_t *nxt;
} priv_getdns_rr_iter;
priv_getdns_rr_iter *priv_getdns_rr_iter_init(priv_getdns_rr_iter *i,
@ -47,6 +62,20 @@ priv_getdns_rr_iter *priv_getdns_rr_iter_init(priv_getdns_rr_iter *i,
priv_getdns_rr_iter *priv_getdns_rr_iter_next(priv_getdns_rr_iter *i);
#endif
typedef struct piv_getdns_rdf_iter {
uint8_t *pkt;
uint8_t *pkt_end;
const priv_getdns_rdata_def *rdd_pos;
const priv_getdns_rdata_def *rdd_end;
const priv_getdns_rdata_def *rdd_repeat;
uint8_t *pos;
uint8_t *end;
uint8_t *nxt;
} priv_getdns_rdf_iter;
/* rrs.h */
priv_getdns_rdf_iter *priv_getdns_rdf_iter_init(priv_getdns_rdf_iter *i,
priv_getdns_rr_iter *rr);
priv_getdns_rdf_iter *priv_getdns_rdf_iter_next(priv_getdns_rdf_iter *i);
#endif

34
src/util-internal.c
View File

@ -504,8 +504,13 @@ create_getdns_response(getdns_dns_req *completed_request)
/* info (bools) about dns_req */
int dnssec_return_status;
#if defined(WIRE_DEBUG) && WIRE_DEBUG
char *str_pkt;
priv_getdns_rr_iter rr_iter_storage, *rr_iter;
priv_getdns_rdf_iter rdf_spc, *rdf_iter;
int i;
#endif
for ( netreq_p = completed_request->netreqs
; ! r && (netreq = *netreq_p)
@ -529,12 +534,29 @@ create_getdns_response(getdns_dns_req *completed_request)
; rr_iter
; rr_iter = priv_getdns_rr_iter_next(rr_iter)) {
fprintf( stderr, "n: %d, dname: %p, rr_type: %p "
"-> type: %d, class: %d\n"
, (int)rr_iter->n,rr_iter->pos,rr_iter->rr_type
, (int)gldns_read_uint16(rr_iter->rr_type)
, (int)gldns_read_uint16(rr_iter->rr_type + 2)
);
fprintf( stderr, "%d (%p): %s\n"
, (int)rr_iter->n, rr_iter->pos
, priv_getdns_rr_def_lookup(
(int)gldns_read_uint16(rr_iter->rr_type)
)->name);
i = 0;
for ( rdf_iter = priv_getdns_rdf_iter_init(&rdf_spc
, rr_iter)
; rdf_iter
; rdf_iter = priv_getdns_rdf_iter_next(rdf_iter)) {
fprintf( stderr, "\t%d (%p): "
"len: %3d, left: %3d, "
"name: %s\n"
, i++
, rdf_iter->pos
, (int)(rdf_iter->nxt - rdf_iter->pos)
, (int)(rdf_iter->end - rdf_iter->nxt)
, rdf_iter->rdd_pos->name
);
}
}
if ((str_pkt = gldns_wire2str_pkt(
netreq->response, netreq->response_len))) {