diff options
Diffstat (limited to 'src/include/gnunet_dnsparser_lib.h')
| -rw-r--r-- | src/include/gnunet_dnsparser_lib.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/src/include/gnunet_dnsparser_lib.h b/src/include/gnunet_dnsparser_lib.h index 28cc4c0..daeb420 100644 --- a/src/include/gnunet_dnsparser_lib.h +++ b/src/include/gnunet_dnsparser_lib.h @@ -31,6 +31,17 @@ #include "gnunet_common.h" /** + * Maximum length of a label in DNS. + */ +#define GNUNET_DNSPARSER_MAX_LABEL_LENGTH 63 + +/** + * Maximum length of a name in DNS. + */ +#define GNUNET_DNSPARSER_MAX_NAME_LENGTH 253 + + +/** * A few common DNS types. */ #define GNUNET_DNSPARSER_TYPE_A 1 @@ -41,6 +52,8 @@ #define GNUNET_DNSPARSER_TYPE_MX 15 #define GNUNET_DNSPARSER_TYPE_TXT 16 #define GNUNET_DNSPARSER_TYPE_AAAA 28 +#define GNUNET_DNSPARSER_TYPE_SRV 33 +#define GNUNET_DNSPARSER_TYPE_TLSA 52 /** * A few common DNS classes (ok, only one is common, but I list a @@ -78,6 +91,7 @@ */ struct GNUNET_DNSPARSER_Flags { +#if __BYTE_ORDER == __LITTLE_ENDIAN /** * Set to 1 if recursion is desired (client -> server) */ @@ -127,6 +141,61 @@ struct GNUNET_DNSPARSER_Flags * Set to 1 if recursion is available (server -> client) */ unsigned int recursion_available : 1 GNUNET_PACKED; +#elif __BYTE_ORDER == __BIG_ENDIAN + + /** + * query:0, response:1 + */ + unsigned int query_or_response : 1 GNUNET_PACKED; + + /** + * See GNUNET_DNSPARSER_OPCODE_ defines. + */ + unsigned int opcode : 4 GNUNET_PACKED; + + /** + * Set to 1 if this is an authoritative answer + */ + unsigned int authoritative_answer : 1 GNUNET_PACKED; + + /** + * Set to 1 if message is truncated + */ + unsigned int message_truncated : 1 GNUNET_PACKED; + + /** + * Set to 1 if recursion is desired (client -> server) + */ + unsigned int recursion_desired : 1 GNUNET_PACKED; + + + /** + * Set to 1 if recursion is available (server -> client) + */ + unsigned int recursion_available : 1 GNUNET_PACKED; + + /** + * Always zero. + */ + unsigned int zero : 1 GNUNET_PACKED; + + /** + * Response has been cryptographically verified, RFC 4035. + */ + unsigned int authenticated_data : 1 GNUNET_PACKED; + + /** + * See RFC 4035. + */ + unsigned int checking_disabled : 1 GNUNET_PACKED; + + /** + * See GNUNET_DNSPARSER_RETURN_CODE_ defines. + */ + unsigned int return_code : 4 GNUNET_PACKED; +#else + #error byteorder undefined +#endif } GNUNET_GCC_STRUCT_LAYOUT; @@ -139,6 +208,10 @@ struct GNUNET_DNSPARSER_Query /** * Name of the record that the query is for (0-terminated). + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. */ char *name; @@ -168,11 +241,85 @@ struct GNUNET_DNSPARSER_MxRecord /** * Name of the mail server. + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. */ char *mxhost; }; + +/** + * Information from SRV records (RFC 2782). The 'service', 'proto' + * and 'domain_name' fields together give the DNS-name which for SRV + * records is of the form "_$SERVICE._$PROTO.$DOMAIN_NAME". The DNS + * parser provides the full name in 'struct DNSPARSER_Record' and the + * individual components in the respective fields of this struct. + * When serializing, you CAN set the 'name' field of 'struct + * GNUNET_DNSPARSER_Record' to NULL, in which case the DNSPARSER code + * will populate 'name' from the 'service', 'proto' and 'domain_name' + * fields in this struct. + */ +struct GNUNET_DNSPARSER_SrvRecord +{ + + /** + * Service name without the underscore (!). Note that RFC 6335 clarifies the + * set of legal characters for service names. + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. + */ + char *service; + + /** + * Transport protocol (typcially "tcp" or "udp", but others might be allowed). + * Without the underscore (!). + */ + char *proto; + + /** + * Domain name for which the record is valid + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. + */ + char *domain_name; + + /** + * Hostname offering the service. + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. + */ + char *target; + + /** + * Preference for this entry (lower value is higher preference). Clients + * will contact hosts from the lowest-priority group first and fall back + * to higher priorities if the low-priority entries are unavailable. + */ + uint16_t priority; + + /** + * Relative weight for records with the same priority. Clients will use + * the hosts of the same (lowest) priority with a probability proportional + * to the weight given. + */ + uint16_t weight; + + /** + * TCP or UDP port of the service. + */ + uint16_t port; + +}; + /** * Information from SOA records (RFC 1035). @@ -183,12 +330,20 @@ struct GNUNET_DNSPARSER_SoaRecord /** *The domainname of the name server that was the * original or primary source of data for this zone. + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. */ char *mname; /** * A domainname which specifies the mailbox of the * person responsible for this zone. + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. */ char *rname; @@ -249,14 +404,25 @@ struct GNUNET_DNSPARSER_Record /** * Name of the record that the query is for (0-terminated). + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. */ char *name; + /** + * Payload of the record (which one of these is valid depends on the 'type'). + */ union { /** * For NS, CNAME and PTR records, this is the uncompressed 0-terminated hostname. + * In UTF-8 format. The library will convert from and to DNS-IDNA + * as necessary. Use 'GNUNET_DNSPARSER_check_label' to test if an + * individual label is well-formed. If a given name is not well-formed, + * creating the DNS packet will fail. */ char *hostname; @@ -271,6 +437,11 @@ struct GNUNET_DNSPARSER_Record struct GNUNET_DNSPARSER_MxRecord *mx; /** + * SRV data for SRV records. + */ + struct GNUNET_DNSPARSER_SrvRecord *srv; + + /** * Raw data for all other types. */ struct GNUNET_DNSPARSER_RawRecord raw; @@ -355,6 +526,31 @@ struct GNUNET_DNSPARSER_Packet /** + * Check if a label in UTF-8 format can be coded into valid IDNA. + * This can fail if the ASCII-conversion becomes longer than 63 characters. + * + * @param label label to check (UTF-8 string) + * @return GNUNET_OK if the label can be converted to IDNA, + * GNUNET_SYSERR if the label is not valid for DNS names + */ +int +GNUNET_DNSPARSER_check_label (const char *label); + + +/** + * Check if a hostname in UTF-8 format can be coded into valid IDNA. + * This can fail if a label becomes longer than 63 characters or if + * the entire name exceeds 253 characters. + * + * @param name name to check (UTF-8 string) + * @return GNUNET_OK if the label can be converted to IDNA, + * GNUNET_SYSERR if the label is not valid for DNS names + */ +int +GNUNET_DNSPARSER_check_name (const char *name); + + +/** * Parse a UDP payload of a DNS packet in to a nice struct for further * processing and manipulation. * |