text: /*
   * net.h
   *
   * DNS Resolver definitions
   *
   * a Net::DNS like library for C
   *
   * (c) NLnet Labs, 2005-2006
   *
   * See the file LICENSE for the license
   */
  
  #ifndef LDNS_NET_H
  #define LDNS_NET_H
  
  #include <ldns/ldns.h>
  #include <sys/socket.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #define LDNS_DEFAULT_TIMEOUT_SEC 5
  #define LDNS_DEFAULT_TIMEOUT_USEC 0
  
  /**
   * \file
   *
   * Contains functions to send and receive packets over a network.
   */
  
  /**
   * Sends a buffer to an ip using udp and return the respons as a ldns_pkt
   * \param[in] qbin the ldns_buffer to be send
   * \param[in] to the ip addr to send to
   * \param[in] tolen length of the ip addr
   * \param[in] timeout the timeout value for the network
   * \param[out] answersize size of the packet
   * \param[out] result packet with the answer
   * \return status
   */
  ldns_status ldns_udp_send(uint8_t **result, ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen, struct timeval timeout, size_t *answersize);
  
  /**
   * Send an udp query and don't wait for an answer but return
   * the socket
   * \param[in] qbin the ldns_buffer to be send
   * \param[in] to the ip addr to send to
   * \param[in] tolen length of the ip addr
   * \param[in] timeout *unused*, was the timeout value for the network
   * \return the socket used
   */
  
  int ldns_udp_bgsend(ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen, struct timeval timeout);
  
  /**
   * Send an tcp query and don't wait for an answer but return
   * the socket
   * \param[in] qbin the ldns_buffer to be send
   * \param[in] to the ip addr to send to
   * \param[in] tolen length of the ip addr
   * \param[in] timeout the timeout value for the connect attempt
   * \return the socket used
   */
  int ldns_tcp_bgsend(ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen, struct timeval timeout);
  
  /**
   * Sends a buffer to an ip using tcp and return the respons as a ldns_pkt
   * \param[in] qbin the ldns_buffer to be send
   * \param[in] qbin the ldns_buffer to be send
   * \param[in] to the ip addr to send to
   * \param[in] tolen length of the ip addr
   * \param[in] timeout the timeout value for the network
   * \param[out] answersize size of the packet
   * \param[out] result packet with the answer
   * \return status
   */
  ldns_status ldns_tcp_send(uint8_t **result, ldns_buffer *qbin, const struct sockaddr_storage *to, socklen_t tolen, struct timeval timeout, size_t *answersize);
  
  /**
   * Sends ptk to the nameserver at the resolver object. Returns the data
   * as a ldns_pkt
   * 
   * \param[out] pkt packet received from the nameserver
   * \param[in] r the resolver to use 
   * \param[in] query_pkt the query to send
   * \return status
   */
  ldns_status ldns_send(ldns_pkt **pkt, ldns_resolver *r, const ldns_pkt *query_pkt);
  
  /**
   * Sends and ldns_buffer (presumably containing a packet to the nameserver at the resolver object. Returns the data
   * as a ldns_pkt
   * 
   * \param[out] pkt packet received from the nameserver
   * \param[in] r the resolver to use 
   * \param[in] qb the buffer to send
   * \param[in] tsig_mac the tsig MAC to authenticate the response with (NULL to do no TSIG authentication)
   * \return status
   */
  ldns_status ldns_send_buffer(ldns_pkt **pkt, ldns_resolver *r, ldns_buffer *qb, ldns_rdf *tsig_mac);
  
  /**
   * Create a tcp socket to the specified address
   * \param[in] to ip and family
   * \param[in] tolen length of to
   * \param[in] timeout timeout for the connect attempt
   * \return a socket descriptor
   */
  int ldns_tcp_connect(const struct sockaddr_storage *to, socklen_t tolen, struct timeval timeout);
  
  /**
   * Create a udp socket to the specified address
   * \param[in] to ip and family
   * \param[in] timeout *unused*, was timeout for the socket
   * \return a socket descriptor
   */
  int ldns_udp_connect(const struct sockaddr_storage *to, struct timeval timeout);
  
  /**
   * send a query via tcp to a server. Don't want for the answer
   *
   * \param[in] qbin the buffer to send
   * \param[in] sockfd the socket to use
   * \param[in] to which ip to send it
   * \param[in] tolen socketlen
   * \return number of bytes sent
   */
  ssize_t ldns_tcp_send_query(ldns_buffer *qbin, int sockfd, const struct sockaddr_storage *to, socklen_t tolen);
  
  /**
   * send a query via udp to a server. Don;t want for the answer
   *
   * \param[in] qbin the buffer to send
   * \param[in] sockfd the socket to use
   * \param[in] to which ip to send it
   * \param[in] tolen socketlen
   * \return number of bytes sent
   */
  ssize_t ldns_udp_send_query(ldns_buffer *qbin, int sockfd, const struct sockaddr_storage *to, socklen_t tolen);
  
  /**
   * Gives back a raw packet from the wire and reads the header data from the given
   * socket. Allocates the data (of size size) itself, so don't forget to free
   *
   * \param[in] sockfd the socket to read from
   * \param[out] size the number of bytes that are read
   * \param[in] timeout the time allowed between packets.
   * \return the data read
   */
  uint8_t *ldns_tcp_read_wire_timeout(int sockfd, size_t *size, struct timeval timeout);
  
  /**
   * This routine may block. Use ldns_tcp_read_wire_timeout, it checks timeouts.
   * Gives back a raw packet from the wire and reads the header data from the given
   * socket. Allocates the data (of size size) itself, so don't forget to free
   *
   * \param[in] sockfd the socket to read from
   * \param[out] size the number of bytes that are read
   * \return the data read
   */
  uint8_t *ldns_tcp_read_wire(int sockfd, size_t *size);
  
  /**
   * Gives back a raw packet from the wire and reads the header data from the given
   * socket. Allocates the data (of size size) itself, so don't forget to free
   *
   * \param[in] sockfd the socket to read from
   * \param[in] fr the address of the client (if applicable)
   * \param[in] *frlen the lenght of the client's addr (if applicable)
   * \param[out] size the number of bytes that are read
   * \return the data read
   */
  uint8_t *ldns_udp_read_wire(int sockfd, size_t *size, struct sockaddr_storage *fr, socklen_t *frlen);
  
  /**
   * returns the native sockaddr representation from the rdf.
   * \param[in] rd the ldns_rdf to operate on
   * \param[in] port what port to use. 0 means; use default (53)
   * \param[out] size what is the size of the sockaddr_storage
   * \return struct sockaddr* the address in the format so other
   * functions can use it (sendto)
   */
  struct sockaddr_storage * ldns_rdf2native_sockaddr_storage(const ldns_rdf *rd, uint16_t port, size_t *size);
  
  /**
   * returns an rdf with the sockaddr info. works for ip4 and ip6
   * \param[in] sock the struct sockaddr_storage to convert
   * \param[in] port what port was used. When NULL this is not set
   * \return ldns_rdf* wth the address
   */
  ldns_rdf * ldns_sockaddr_storage2rdf(struct sockaddr_storage *sock, uint16_t *port);
  
  /**
   * Prepares the resolver for an axfr query
   * The query is sent and the answers can be read with ldns_axfr_next
   * \param[in] resolver the resolver to use
   * \param[in] domain the domain to exfr
   * \param[in] c the class to use
   * \return ldns_status the status of the transfer
   */
  ldns_status ldns_axfr_start(ldns_resolver *resolver, ldns_rdf *domain, ldns_rr_class c);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif  /* LDNS_NET_H */
  