/*
    Copyright (C) 2008 Andreas Baumann <abaumann@yahoo.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "port/netdb.h"

#if !defined HAVE_GETADDRINFO || defined TEST_GETADDRINFO

#include "port/string.h"			/* for memset, memcpy */
#include "port/stdlib.h"			/* for atoi, itoa, malloc, free, NULL */
#include "port/stdio.h"				/* for snprintf */
#include "port/unused.h"

#include <netinet/in.h>				/* for struct sockaddr_in */

int wolf_port_getaddrinfo(			const char *host_name,
						const char *service_name,
						const struct wolf_port_addrinfo *hintp,
						struct wolf_port_addrinfo **result ) {
	struct wolf_port_addrinfo *ai;
	struct sockaddr_in sin,
			   *psin;
	struct wolf_port_addrinfo hints;

	if( hintp == NULL ) {
		memset( &hints, 0, sizeof( struct wolf_port_addrinfo ) );
		hints.ai_family = AF_INET;
		hints.ai_socktype = SOCK_STREAM;
	} else {
		memcpy( &hints, hintp, sizeof( struct wolf_port_addrinfo ) );
	}

	if( hints.ai_family != AF_INET && hints.ai_family != AF_UNSPEC ) {
		return EAI_FAMILY;
	}

	if( hints.ai_socktype == 0 ) {
		hints.ai_socktype = SOCK_STREAM;
	}

	if( ( host_name == NULL ) && ( service_name == NULL ) ) {
		return EAI_NONAME;
	}

	memset( &sin, 0, sizeof( struct sockaddr_in) );

	sin.sin_family = AF_INET;

	if( host_name != NULL ) {
		if( host_name[0] == '\0' ) {
			sin.sin_addr.s_addr = htonl( INADDR_ANY );
		} else if( hints.ai_flags & AI_NUMERICHOST ) {
			if( !inet_aton( host_name, &sin.sin_addr ) ) {
				return EAI_FAIL;
			}
		} else {
			struct hostent *hp;

			hp = gethostbyname( host_name );
			
			if( hp == NULL ) {
				switch( h_errno ) {
					case HOST_NOT_FOUND:
					case NO_DATA:
						return EAI_NONAME;

					case TRY_AGAIN:
						return EAI_AGAIN;

					case NO_RECOVERY:
					default:
						return EAI_FAIL;
				}
			}

			if( hp->h_addrtype != AF_INET ) {
				return EAI_FAIL;
			}

			memcpy( &(sin.sin_addr), hp->h_addr, hp->h_length );
		}
	} else {
		if( hints.ai_flags & AI_PASSIVE ) {
			sin.sin_addr.s_addr = htonl( INADDR_ANY );
		} else {
			sin.sin_addr.s_addr = htonl( INADDR_LOOPBACK );
		}
	}

	if( service_name != NULL ) {
		sin.sin_port = htons( (unsigned short)atoi( service_name ) );
	}

	ai = (struct wolf_port_addrinfo *)malloc( sizeof( struct wolf_port_addrinfo ) );
	if( ai == NULL ) {
		return EAI_MEMORY;
	}

	psin = (struct sockaddr_in *)malloc( sizeof( struct sockaddr_in ) );
	if (!psin)
	{
		free(ai);
		return EAI_MEMORY;
	}

	memcpy( psin, &sin, sizeof( struct sockaddr_in ) );

	ai->ai_flags = 0;
	ai->ai_family = AF_INET;
	ai->ai_socktype = hints.ai_socktype;
	ai->ai_protocol = hints.ai_protocol;
	ai->ai_addrlen = sizeof(*psin);
	ai->ai_addr = (struct sockaddr *) psin;
	ai->ai_canonname = NULL;
	ai->ai_next = NULL;

	*result = ai;

	return 0;
}

void wolf_port_freeaddrinfo(			struct wolf_port_addrinfo *result ) {
	/* stub doesn't have more than one element in list, adapt if you change that! */
	if( result != NULL ) {
		if( result->ai_addr != NULL ) {
			free( result->ai_addr );
		}
		free( result );
	}
}

/*
 * Convert an ipv4 address to a hostname.
 *
 * Bugs:	- Only supports NI_NUMERICHOST and NI_NUMERICSERV
 *		  It will never resolv a hostname.
 *		- No IPv6 support.
 */
extern int getnameinfo(				const struct sockaddr *sa, socklen_t salen,
						char *host, size_t hostlen,
						char *serv, size_t servlen,	
						int flags ) {
	WOLF_UNUSED( salen );

	/* Invalid arguments. */
	if( sa == NULL || ( host == NULL && serv == NULL ) ) {
		return EAI_FAIL;
	}

	/* We don't support those. */
	if( ( host && !( flags & NI_NUMERICHOST ) )
		|| ( serv && !( flags & NI_NUMERICSERV ) ) ) {
		return EAI_FAIL;
	}

#ifdef	HAVE_IPV6
	/* no IPV6 here */
	if( sa->sa_family == AF_INET6 ) {
		return EAI_FAMILY;
	}
#endif

	if( host != NULL ) {
		if( sa->sa_family == AF_INET ) {
			char *p;

			/* maximal size of an IP4 addres 255.255.255.255.255 */
			if( hostlen < 16 ) {
				return EAI_MEMORY;
			}

			p = inet_ntoa( ( (const struct sockaddr_in * ) sa)->sin_addr );
			
			strlcpy( host, p, hostlen );
		}
	}

	if( serv != NULL ) {
		if (sa->sa_family == AF_INET ) {
			/* maximal number of digits in an unsigned short */
			if( servlen < 10 ) {
				return EAI_MEMORY;
			}
			(void)itoa( ntohs( ( (const struct sockaddr_in * )sa)->sin_port ), serv, 10 );
		}
	}

	return 0;
}

const char *wolf_port_gai_strerror(		int errcode ) {
	static char buf[256];

	switch( errcode ) {
		case EAI_NONAME:
			return "host nor service provided, or not known";

		case EAI_AGAIN:
			return "temporary failure in name resolution";

		case EAI_FAIL:
			return "non-recoverable failure in name resultion";

		case EAI_FAMILY:
			return "socket family not supported";

		case EAI_MEMORY:
			return "memory allocation failure";

		default:
			snprintf( buf, 256, "Unknown GAI error %d", errcode );
			return buf;
	}
}

#endif /* !defined HAVE_GETADDRINFO || defined TEST_GETADDRINFO */

#if !defined HAVE_GAI_STRERROR_R || defined TEST_GAI_STRERROR_R

#include "threads/mutex.h"	/* for mutexes */
#include "port/stdio.h"		/* for snprintf */
#include "port/stdbool.h"	/* for bool */
#include "port/string.h"	/* for strncmp */ 
#include <errno.h>		/* for errno */

#ifdef HAVE_THREADS
static bool mutex_initialized = false;
static wolf_mutex_t mutex;
#endif

int wolf_port_gai_strerror_r( int errcode, char *buf, size_t buflen ) {
	int safe_errno = errno;
	const char *msg;

	/* critical section as gai_strerror is not thread-safe */
#ifdef HAVE_THREADS
	if( !mutex_initialized ) {
		wolf_mutex_init( &mutex );
		mutex_initialized = true;
	}
	wolf_mutex_lock( &mutex );
#endif

	msg = gai_strerror( errcode );
	if( strncmp( msg, "Unknown GAI errror", strlen( "Unknown GAI error" ) ) == 0 /* our own stub implementation */ ) {
		(void)snprintf( buf, buflen, "Unknown GAI error %d", errcode );
		errno = EINVAL;
#ifdef HAVE_THREADS
		wolf_mutex_unlock( &mutex );
#endif
		return -1;
	}

	strncpy( buf, msg, buflen-1 );
	errno = safe_errno;
#ifdef HAVE_THREADS
	wolf_mutex_unlock( &mutex );
#endif
	return 0;
}

#endif /* !defined HAVE_GAI_STRERROR_R || defined TEST_GAI_STRERROR_R */