#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_dnsparser_lib.h"
+#include "dnsparser.h"
-// DNS-Stuff
-GNUNET_NETWORK_STRUCT_BEGIN
-struct dns_header
-{
- uint16_t id GNUNET_PACKED;
- struct GNUNET_DNSPARSER_Flags flags;
- uint16_t query_count GNUNET_PACKED; // number of questions
- uint16_t answer_rcount GNUNET_PACKED; // number of answers
- uint16_t authority_rcount GNUNET_PACKED; // number of authority-records
- uint16_t additional_rcount GNUNET_PACKED; // number of additional records
-};
-
-struct query_line
-{
- uint16_t type GNUNET_PACKED;
- uint16_t class GNUNET_PACKED;
-};
-
-struct record_line
-{
- uint16_t type GNUNET_PACKED;
- uint16_t class GNUNET_PACKED;
- uint32_t ttl GNUNET_PACKED;
- uint16_t data_len GNUNET_PACKED;
-};
-
-struct soa_data
-{
- uint32_t serial GNUNET_PACKED;
- uint32_t refresh GNUNET_PACKED;
- uint32_t retry GNUNET_PACKED;
- uint32_t expire GNUNET_PACKED;
- uint32_t minimum GNUNET_PACKED;
-};
-
-GNUNET_NETWORK_STRUCT_END
-
/**
* Parse name inside of a DNS query or record.
struct soa_data soa;
uint16_t mxpref;
uint16_t data_len;
+ struct srv_data srv;
+ char *ndup;
+ char *tok;
name = parse_name (udp_payload,
udp_payload_length,
off, 0);
if ( (NULL == r->data.soa->mname) ||
(NULL == r->data.soa->rname) ||
- (*off + sizeof (soa) > udp_payload_length) )
+ (*off + sizeof (struct soa_data) > udp_payload_length) )
return GNUNET_SYSERR;
- memcpy (&soa, &udp_payload[*off], sizeof (soa));
+ memcpy (&soa, &udp_payload[*off], sizeof (struct soa_data));
r->data.soa->serial = ntohl (soa.serial);
r->data.soa->refresh = ntohl (soa.refresh);
r->data.soa->retry = ntohl (soa.retry);
r->data.soa->expire = ntohl (soa.expire);
r->data.soa->minimum_ttl = ntohl (soa.minimum);
- (*off) += sizeof (soa);
+ (*off) += sizeof (struct soa_data);
if (old_off + data_len != *off)
return GNUNET_SYSERR;
return GNUNET_OK;
if (old_off + data_len != *off)
return GNUNET_SYSERR;
return GNUNET_OK;
+ case GNUNET_DNSPARSER_TYPE_SRV:
+ if ('_' != *r->name)
+ return GNUNET_SYSERR; /* all valid srv names must start with "_" */
+ if (NULL == strstr (r->name, "._"))
+ return GNUNET_SYSERR; /* necessary string from "._$PROTO" not present */
+ old_off = *off;
+ if (*off + sizeof (struct srv_data) > udp_payload_length)
+ return GNUNET_SYSERR;
+ memcpy (&srv, &udp_payload[*off], sizeof (struct srv_data));
+ (*off) += sizeof (struct srv_data);
+ r->data.srv = GNUNET_malloc (sizeof (struct GNUNET_DNSPARSER_SrvRecord));
+ r->data.srv->priority = ntohs (srv.prio);
+ r->data.srv->weight = ntohs (srv.weight);
+ r->data.srv->port = ntohs (srv.port);
+ /* parse 'data.hostname' into components, which are
+ "_$SERVICE._$PROTO.$DOMAIN_NAME" */
+ ndup = GNUNET_strdup (r->name);
+ tok = strtok (ndup, ".");
+ GNUNET_assert (NULL != tok);
+ GNUNET_assert ('_' == *tok);
+ r->data.srv->service = GNUNET_strdup (&tok[1]);
+ tok = strtok (NULL, ".");
+ if ( (NULL == tok) || ('_' != *tok) )
+ {
+ GNUNET_free (r->data.srv);
+ GNUNET_free (ndup);
+ return GNUNET_SYSERR;
+ }
+ r->data.srv->proto = GNUNET_strdup (&tok[1]);
+ tok = strtok (NULL, ".");
+ if (NULL == tok)
+ {
+ GNUNET_free (r->data.srv);
+ GNUNET_free (ndup);
+ return GNUNET_SYSERR;
+ }
+ r->data.srv->domain_name = GNUNET_strdup (tok);
+ GNUNET_free (ndup);
+ r->data.srv->target = parse_name (udp_payload,
+ udp_payload_length,
+ off, 0);
+ if (old_off + data_len != *off)
+ return GNUNET_SYSERR;
+ return GNUNET_OK;
default:
r->data.raw.data = GNUNET_malloc (data_len);
r->data.raw.data_len = data_len;
size_t udp_payload_length)
{
struct GNUNET_DNSPARSER_Packet *p;
- const struct dns_header *dns;
+ const struct GNUNET_TUN_DnsHeader *dns;
size_t off;
unsigned int n;
unsigned int i;
- if (udp_payload_length < sizeof (struct dns_header))
+ if (udp_payload_length < sizeof (struct GNUNET_TUN_DnsHeader))
return NULL;
- dns = (const struct dns_header *) udp_payload;
- off = sizeof (struct dns_header);
+ dns = (const struct GNUNET_TUN_DnsHeader *) udp_payload;
+ off = sizeof (struct GNUNET_TUN_DnsHeader);
p = GNUNET_malloc (sizeof (struct GNUNET_DNSPARSER_Packet));
p->flags = dns->flags;
p->id = dns->id;
}
+/**
+ * Free SRV information record.
+ *
+ * @param srv record to free
+ */
+static void
+free_srv (struct GNUNET_DNSPARSER_SrvRecord *srv)
+{
+ if (NULL == srv)
+ return;
+ GNUNET_free_non_null (srv->target);
+ GNUNET_free_non_null (srv->domain_name);
+ GNUNET_free_non_null (srv->proto);
+ GNUNET_free_non_null (srv->service);
+ GNUNET_free (srv);
+}
+
+
/**
* Free MX information record.
*
case GNUNET_DNSPARSER_TYPE_SOA:
free_soa (r->data.soa);
break;
+ case GNUNET_DNSPARSER_TYPE_SRV:
+ free_srv (r->data.srv);
+ break;
case GNUNET_DNSPARSER_TYPE_NS:
case GNUNET_DNSPARSER_TYPE_CNAME:
case GNUNET_DNSPARSER_TYPE_PTR:
off,
soa->rname)) ) )
return ret;
- if (*off + sizeof (soa) > dst_len)
+ if (*off + sizeof (struct soa_data) > dst_len)
return GNUNET_NO;
sd.serial = htonl (soa->serial);
sd.refresh = htonl (soa->refresh);
}
+/**
+ * Add an SRV record to the UDP packet at the given location.
+ *
+ * @param dst where to write the SRV record
+ * @param dst_len number of bytes in dst
+ * @param off pointer to offset where to write the SRV information (increment by bytes used)
+ * can also change if there was an error
+ * @param srv SRV information to write
+ * @return GNUNET_SYSERR if 'srv' is invalid
+ * GNUNET_NO if 'srv' did not fit
+ * GNUNET_OK if 'srv' was added to 'dst'
+ */
+static int
+add_srv (char *dst,
+ size_t dst_len,
+ size_t *off,
+ const struct GNUNET_DNSPARSER_SrvRecord *srv)
+{
+ struct srv_data sd;
+ int ret;
+
+ if (*off + sizeof (struct srv_data) > dst_len)
+ return GNUNET_NO;
+ sd.prio = htons (srv->priority);
+ sd.weight = htons (srv->weight);
+ sd.port = htons (srv->port);
+ memcpy (&dst[*off], &sd, sizeof (sd));
+ (*off) += sizeof (sd);
+ if (GNUNET_OK != (ret = add_name (dst,
+ dst_len,
+ off,
+ srv->target)))
+ return ret;
+ return GNUNET_OK;
+}
+
+
/**
* Add a DNS record to the UDP packet at the given location.
*
size_t start;
size_t pos;
struct record_line rl;
-
+ char *name;
+
start = *off;
- ret = add_name (dst, dst_len - sizeof (struct record_line), off, record->name);
- if (ret != GNUNET_OK)
+ /* for SRV records, we can create the name from the details
+ of the record if needed */
+ name = record->name;
+ if ( (GNUNET_DNSPARSER_TYPE_SRV == record->type) &&
+ (NULL == name) )
+ GNUNET_asprintf (&name,
+ "_%s._%s.%s",
+ record->data.srv->service,
+ record->data.srv->proto,
+ record->data.srv->domain_name);
+ ret = add_name (dst, dst_len - sizeof (struct record_line), off, name);
+ if (name != record->name)
+ GNUNET_free (name);
+ if (GNUNET_OK != ret)
return ret;
/* '*off' is now the position where we will need to write the record line */
case GNUNET_DNSPARSER_TYPE_PTR:
ret = add_name (dst, dst_len, &pos, record->data.hostname);
break;
+ case GNUNET_DNSPARSER_TYPE_SRV:
+ ret = add_srv (dst, dst_len, &pos, record->data.srv);
+ break;
default:
if (pos + record->data.raw.data_len > dst_len)
{
ret = GNUNET_OK;
break;
}
- if (ret != GNUNET_OK)
+ if (GNUNET_OK != ret)
{
*off = start;
return GNUNET_NO;
char **buf,
size_t *buf_length)
{
- struct dns_header dns;
+ struct GNUNET_TUN_DnsHeader dns;
size_t off;
char tmp[max];
unsigned int i;
dns.authority_rcount = htons (p->num_authority_records);
dns.additional_rcount = htons (p->num_additional_records);
- off = sizeof (struct dns_header);
+ off = sizeof (struct GNUNET_TUN_DnsHeader);
trc = GNUNET_NO;
for (i=0;i<p->num_queries;i++)
{
if (GNUNET_YES == trc)
dns.flags.message_truncated = 1;
- memcpy (tmp, &dns, sizeof (struct dns_header));
+ memcpy (tmp, &dns, sizeof (struct GNUNET_TUN_DnsHeader));
*buf = GNUNET_malloc (off);
*buf_length = off;
return GNUNET_OK;
}
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-/* legacy code follows */
-
-/**
- * Parse a name from DNS to a normal .-delimited, 0-terminated string.
- *
- * @param d The destination of the name. Should have at least 255 bytes allocated.
- * @param src The DNS-Packet
- * @param idx The offset inside the Packet from which on the name should be read
- * @returns The offset of the first unparsed byte (the byte right behind the name)
- */
-static unsigned int
-parse_dns_name (char *d, const unsigned char *src, unsigned short idx)
-{ /*{{{ */
- char *dest = d;
-
- int len = src[idx++];
-
- while (len != 0)
- {
- if (len & 0xC0)
- { /* Compressed name, offset in this and the next octet */
- unsigned short offset = ((len & 0x3F) << 8) | src[idx++];
-
- parse_dns_name (dest, src, offset - 12); /* 12 for the Header of the DNS-Packet, idx starts at 0 which is 12 bytes from the start of the packet */
- return idx;
- }
- memcpy (dest, src + idx, len);
- idx += len;
- dest += len;
- *dest = '.';
- dest++;
- len = src[idx++];
- };
- *dest = 0;
-
- return idx;
-}
-
-/*}}}*/
-
-/**
- * Parse a complete DNS-Record from raw DNS-data to a struct dns_record
- *
- * @param data The DNS-data
- * @param dst Pointer to count pointers; individual pointers will be allocated
- * @param count Number of records to parse
- * @param idx The offset inside the Packet from which on the name should be read
- * @returns The offset of the first unparsed byte (the byte right behind the last record)
- */
-static unsigned short
-parse_dns_record (unsigned char *data, /*{{{ */
- struct dns_record **dst, unsigned short count,
- unsigned short idx)
-{
- int i;
- unsigned short _idx;
-
- for (i = 0; i < count; i++)
- {
- dst[i] = GNUNET_malloc (sizeof (struct dns_record));
- dst[i]->name = alloca (255); // see RFC1035, no name can be longer than this.
- char *name = dst[i]->name;
-
- _idx = parse_dns_name (name, data, idx);
- dst[i]->namelen = _idx - idx;
-
- dst[i]->name = GNUNET_malloc (dst[i]->namelen);
- memcpy (dst[i]->name, name, dst[i]->namelen);
-
- idx = _idx;
-
- dst[i]->type = *((unsigned short *) (data + idx));
- idx += 2;
- dst[i]->class = *((unsigned short *) (data + idx));
- idx += 2;
- dst[i]->ttl = *((unsigned int *) (data + idx));
- idx += 4;
- dst[i]->data_len = *((unsigned short *) (data + idx));
- idx += 2;
- dst[i]->data = GNUNET_malloc (ntohs (dst[i]->data_len));
- memcpy (dst[i]->data, data + idx, ntohs (dst[i]->data_len));
- idx += ntohs (dst[i]->data_len);
- }
- return idx;
-} /*}}} */
-
-/**
- * Parse a raw DNS-Packet into an usable struct
- */
-struct dns_pkt_parsed *
-parse_dns_packet (struct dns_pkt *pkt)
-{ /*{{{ */
- struct dns_pkt_parsed *ppkt = GNUNET_malloc (sizeof (struct dns_pkt_parsed));
-
- memcpy (&ppkt->s, &pkt->s, sizeof pkt->s);
-
- unsigned short qdcount = ntohs (ppkt->s.qdcount);
- unsigned short ancount = ntohs (ppkt->s.ancount);
- unsigned short nscount = ntohs (ppkt->s.nscount);
- unsigned short arcount = ntohs (ppkt->s.arcount);
-
- ppkt->queries = GNUNET_malloc (qdcount * sizeof (struct dns_query *));
- ppkt->answers = GNUNET_malloc (ancount * sizeof (struct dns_record *));
- ppkt->nameservers = GNUNET_malloc (nscount * sizeof (struct dns_record *));
- ppkt->additional = GNUNET_malloc (arcount * sizeof (struct dns_record *));
-
- unsigned short idx = 0, _idx; /* This keeps track how far we have parsed the data */
-
- /* Parse the Query */
- int i;
-
- for (i = 0; i < qdcount; i++)
- { /*{{{ */
- ppkt->queries[i] = GNUNET_malloc (sizeof (struct dns_query));
- char *name = alloca (255); /* see RFC1035, it can't be more than this. */
-
- _idx = parse_dns_name (name, pkt->data, idx);
- ppkt->queries[i]->namelen = _idx - idx;
- idx = _idx;
-
- ppkt->queries[i]->name = GNUNET_malloc (ppkt->queries[i]->namelen);
- memcpy (ppkt->queries[i]->name, name, ppkt->queries[i]->namelen);
-
- ppkt->queries[i]->qtype = *((unsigned short *) (pkt->data + idx));
- idx += 2;
- ppkt->queries[i]->qclass = *((unsigned short *) (pkt->data + idx));
- idx += 2;
- }
- /*}}} */
- idx = parse_dns_record (pkt->data, ppkt->answers, ancount, idx);
- idx = parse_dns_record (pkt->data, ppkt->nameservers, nscount, idx);
- idx = parse_dns_record (pkt->data, ppkt->additional, arcount, idx);
- return ppkt;
-} /*}}} */
-
-static void
-unparse_dns_name (char *dest, char *src, size_t len)
-{
- char *b = dest;
- char cnt = 0;
-
- dest++;
- while (*src != 0)
- {
- while (*src != '.' && *src != 0)
- {
- *dest = *src;
- src++;
- dest++;
- cnt++;
- }
- *b = cnt;
- cnt = 0;
- b = dest;
- dest++;
- src++;
- }
- *b = 0;
-}
-
-struct dns_pkt *
-unparse_dns_packet (struct dns_pkt_parsed *ppkt)
-{
- size_t size = sizeof (struct dns_pkt) - 1;
- int i;
-
- for (i = 0; i < ntohs (ppkt->s.qdcount); i++)
- size += ppkt->queries[i]->namelen + 1;
-
- for (i = 0; i < ntohs (ppkt->s.ancount); i++)
- {
- size += ppkt->answers[i]->namelen + 1;
- size += ppkt->answers[i]->data_len;
- }
- for (i = 0; i < ntohs (ppkt->s.nscount); i++)
- {
- size += ppkt->nameservers[i]->namelen + 1;
- size += ppkt->nameservers[i]->data_len;
- }
- for (i = 0; i < ntohs (ppkt->s.arcount); i++)
- {
- size += ppkt->additional[i]->namelen + 1;
- size += ppkt->additional[i]->data_len;
- }
-
- size +=
- 4 * ntohs (ppkt->s.qdcount) + 10 * (ntohs (ppkt->s.ancount) +
- ntohs (ppkt->s.arcount) +
- ntohs (ppkt->s.nscount));
-
- struct dns_pkt *pkt = GNUNET_malloc (size);
- char *pkt_c = (char *) pkt;
-
- memcpy (&pkt->s, &ppkt->s, sizeof ppkt->s);
- size_t idx = sizeof ppkt->s;
-
- for (i = 0; i < ntohs (ppkt->s.qdcount); i++)
- {
- unparse_dns_name (&pkt_c[idx], ppkt->queries[i]->name,
- ppkt->queries[i]->namelen);
- idx += ppkt->queries[i]->namelen;
- struct dns_query_line *d = (struct dns_query_line *) &pkt_c[idx];
-
- d->class = ppkt->queries[i]->qclass;
- d->type = ppkt->queries[i]->qtype;
- idx += sizeof (struct dns_query_line);
- }
-
- for (i = 0; i < ntohs (ppkt->s.ancount); i++)
- {
- unparse_dns_name (&pkt_c[idx], ppkt->answers[i]->name,
- ppkt->answers[i]->namelen);
- idx += ppkt->answers[i]->namelen;
- struct dns_record_line *r = (struct dns_record_line *) &pkt_c[idx];
-
- r->type = ppkt->answers[i]->type;
- r->class = ppkt->answers[i]->class;
- r->ttl = ppkt->answers[i]->ttl;
- r->data_len = ppkt->answers[i]->data_len;
- idx += sizeof (struct dns_record_line);
- memcpy (&r->data, ppkt->answers[i]->data, ppkt->answers[i]->data_len);
- idx += ppkt->answers[i]->data_len;
- }
-
- for (i = 0; i < ntohs (ppkt->s.nscount); i++)
- {
- unparse_dns_name (&pkt_c[idx], ppkt->nameservers[i]->name,
- ppkt->nameservers[i]->namelen);
- idx += ppkt->nameservers[i]->namelen;
- struct dns_record_line *r = (struct dns_record_line *) &pkt_c[idx];
-
- r->type = ppkt->nameservers[i]->type;
- r->class = ppkt->nameservers[i]->class;
- r->ttl = ppkt->nameservers[i]->ttl;
- r->data_len = ppkt->nameservers[i]->data_len;
- idx += sizeof (struct dns_record_line);
- memcpy (&r->data, ppkt->nameservers[i]->data,
- ppkt->nameservers[i]->data_len);
- idx += ppkt->nameservers[i]->data_len;
- }
-
- for (i = 0; i < ntohs (ppkt->s.arcount); i++)
- {
- unparse_dns_name (&pkt_c[idx], ppkt->additional[i]->name,
- ppkt->additional[i]->namelen);
- idx += ppkt->additional[i]->namelen;
- struct dns_record_line *r = (struct dns_record_line *) &pkt_c[idx];
-
- r->type = ppkt->additional[i]->type;
- r->class = ppkt->additional[i]->class;
- r->ttl = ppkt->additional[i]->ttl;
- r->data_len = ppkt->additional[i]->data_len;
- idx += sizeof (struct dns_record_line);
- memcpy (&r->data, ppkt->additional[i]->data, ppkt->additional[i]->data_len);
- idx += ppkt->additional[i]->data_len;
- }
-
- return pkt;
-}
-
-void
-free_parsed_dns_packet (struct dns_pkt_parsed *ppkt)
-{
- unsigned short qdcount = ntohs (ppkt->s.qdcount);
- unsigned short ancount = ntohs (ppkt->s.ancount);
- unsigned short nscount = ntohs (ppkt->s.nscount);
- unsigned short arcount = ntohs (ppkt->s.arcount);
-
- int i;
-
- for (i = 0; i < qdcount; i++)
- {
- GNUNET_free (ppkt->queries[i]->name);
- GNUNET_free (ppkt->queries[i]);
- }
- GNUNET_free (ppkt->queries);
- for (i = 0; i < ancount; i++)
- {
- GNUNET_free (ppkt->answers[i]->name);
- GNUNET_free (ppkt->answers[i]->data);
- GNUNET_free (ppkt->answers[i]);
- }
- GNUNET_free (ppkt->answers);
- for (i = 0; i < nscount; i++)
- {
- GNUNET_free (ppkt->nameservers[i]->name);
- GNUNET_free (ppkt->nameservers[i]->data);
- GNUNET_free (ppkt->nameservers[i]);
- }
- GNUNET_free (ppkt->nameservers);
- for (i = 0; i < arcount; i++)
- {
- GNUNET_free (ppkt->additional[i]->name);
- GNUNET_free (ppkt->additional[i]->data);
- GNUNET_free (ppkt->additional[i]);
- }
- GNUNET_free (ppkt->additional);
- GNUNET_free (ppkt);
-}
+/* end of dnsparser.c */
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