// Ada Milter API, a binding to Libmilter, the Sendmail mail filtering API
// Copyright 2012 - 2013 B. Persson, Bjorn@Rombobeorn.se
//
// This library is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License version 3, as published
// by the Free Software Foundation.


// This file contains helper functions for extracting address data from a
// sockaddr, because trying to access the fields of sockaddr structures from
// Ada in a portable way would get ugly fast.


#include <stdint.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>


// constants exported by milter_api.adb:
extern const uint8_t milter_api_address_type_ipv4;
extern const uint8_t milter_api_address_type_ipv6;
extern const uint8_t milter_api_address_type_unknown;


uint8_t milter_api_address_type(struct sockaddr const* const endpoint)
// milter_api_address_type returns a code to tell which type of address
// endpoint contains.
{
   if(endpoint->sa_family == AF_INET) {
      return milter_api_address_type_ipv4;
   } else if(endpoint->sa_family == AF_INET6) {
      return milter_api_address_type_ipv6;
   } else {
      return milter_api_address_type_unknown;
   }
}


void milter_api_ipv4_address(struct sockaddr_in const* const endpoint,  // in
                             uint8_t* const                  buffer)    // out
// milter_api_ipv4_address copies the IPv4 address from endpoint to buffer.
// buffer must be 4 bytes long.
{
   memcpy(buffer, &endpoint->sin_addr, 4);
}


void milter_api_ipv6_address(struct sockaddr_in6 const* const endpoint,  // in
                             uint8_t* const                   buffer)    // out
// milter_api_ipv6_address copies the IPv6 address from endpoint to buffer.
// buffer must be 16 bytes long.
{
   memcpy(buffer, &endpoint->sin6_addr, 16);
}


void milter_api_address_string(struct sockaddr const* const endpoint,  // in
                               char* const                  buffer,    // out
                               const uint8_t                size)      // in
// milter_api_address_string writes in buffer a textual representation of the
// IP address in endpoint. size is the length of buffer in bytes.
{
   char const* result = NULL;

   if(endpoint->sa_family == AF_INET) {
      result = inet_ntop(endpoint->sa_family,
                         &((struct sockaddr_in const*)endpoint)->sin_addr,
                         buffer, size);
   } else if(endpoint->sa_family == AF_INET6) {
      result = inet_ntop(endpoint->sa_family,
                         &((struct sockaddr_in6 const*)endpoint)->sin6_addr,
                         buffer, size);
   }
   if(result == NULL) {
      strncpy(buffer, "(error in address conversion)", size);
      buffer[size - 1] = '\0';
   }
}


uint16_t milter_api_port(struct sockaddr const* const endpoint)
// milter_api_port returns (in host byte order) the port number in endpoint.
{
   if(endpoint->sa_family == AF_INET) {
      return ntohs(((struct sockaddr_in const*)endpoint)->sin_port);
   } else if(endpoint->sa_family == AF_INET6) {
      return ntohs(((struct sockaddr_in6 const*)endpoint)->sin6_port);
   } else {
      return 0;
   }
}