/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Authors: Michael Zucchi <notzed@ximian.com>
 * 	    Jeffrey Stedfast <fejj@ximian.com>
 *	    Chris Toshok <toshok@ximian.com>
 *
 * Copyright (C) 2004 Ximian Inc.
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of version 2 of the GNU General Public 
 * License as published by the Free Software Foundation.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/poll.h>
#include <pthread.h>
#include <stdio.h>
#include <errno.h>

#include <glib.h>

#include "camel-i18n.h"
#include "camel-operation.h"
#include "camel-exception.h"
#include "camel-net-utils.h"

#include "libedataserver/e-msgport.h"

#define d(x)

/* gethostbyname emulation code for emulating getaddrinfo code ...

This should probably go away */

#ifdef NEED_ADDRINFO

#if !defined (HAVE_GETHOSTBYNAME_R) || !defined (HAVE_GETHOSTBYADDR_R)
G_LOCK_DEFINE_STATIC (gethost_mutex);
#endif

#define ALIGN(x) (((x) + (sizeof (char *) - 1)) & ~(sizeof (char *) - 1))

#define GETHOST_PROCESS(h, host, buf, buflen, herr) G_STMT_START {     \
	int num_aliases = 0, num_addrs = 0;                            \
	int req_length;                                                \
	char *p;                                                       \
	int i;                                                         \
	                                                               \
	/* check to make sure we have enough room in our buffer */     \
	req_length = 0;                                                \
	if (h->h_aliases) {                                            \
		for (i = 0; h->h_aliases[i]; i++)                      \
			req_length += strlen (h->h_aliases[i]) + 1;    \
		num_aliases = i;                                       \
	}                                                              \
	                                                               \
	if (h->h_addr_list) {                                          \
		for (i = 0; h->h_addr_list[i]; i++)                    \
			req_length += h->h_length;                     \
		num_addrs = i;                                         \
	}                                                              \
	                                                               \
	req_length += sizeof (char *) * (num_aliases + 1);             \
	req_length += sizeof (char *) * (num_addrs + 1);               \
	req_length += strlen (h->h_name) + 1;                          \
	                                                               \
	if (buflen < req_length) {                                     \
		*herr = ERANGE;                                        \
		G_UNLOCK (gethost_mutex);                              \
		return ERANGE;                                         \
	}                                                              \
	                                                               \
	/* we store the alias/addr pointers in the buffer */           \
        /* their addresses here. */                                    \
	p = buf;                                                       \
	if (num_aliases) {                                             \
		host->h_aliases = (char **) p;                         \
		p += sizeof (char *) * (num_aliases + 1);              \
	} else                                                         \
		host->h_aliases = NULL;                                \
                                                                       \
	if (num_addrs) {                                               \
		host->h_addr_list = (char **) p;                       \
		p += sizeof (char *) * (num_addrs + 1);                \
	} else                                                         \
		host->h_addr_list = NULL;                              \
	                                                               \
	/* copy the host name into the buffer */                       \
	host->h_name = p;                                              \
	strcpy (p, h->h_name);                                         \
	p += strlen (h->h_name) + 1;                                   \
	host->h_addrtype = h->h_addrtype;                              \
	host->h_length = h->h_length;                                  \
	                                                               \
	/* copy the aliases/addresses into the buffer */               \
        /* and assign pointers into the hostent */                     \
	*p = 0;                                                        \
	if (num_aliases) {                                             \
		for (i = 0; i < num_aliases; i++) {                    \
			strcpy (p, h->h_aliases[i]);                   \
			host->h_aliases[i] = p;                        \
			p += strlen (h->h_aliases[i]);                 \
		}                                                      \
		host->h_aliases[num_aliases] = NULL;                   \
	}                                                              \
	                                                               \
	if (num_addrs) {                                               \
		for (i = 0; i < num_addrs; i++) {                      \
			memcpy (p, h->h_addr_list[i], h->h_length);    \
			host->h_addr_list[i] = p;                      \
			p += h->h_length;                              \
		}                                                      \
		host->h_addr_list[num_addrs] = NULL;                   \
	}                                                              \
} G_STMT_END


#ifdef ENABLE_IPv6
/* some helpful utils for IPv6 lookups */
#define IPv6_BUFLEN_MIN  (sizeof (char *) * 3)

static int
ai_to_herr (int error)
{
	switch (error) {
	case EAI_NONAME:
	case EAI_FAIL:
		return HOST_NOT_FOUND;
		break;
	case EAI_SERVICE:
		return NO_DATA;
		break;
	case EAI_ADDRFAMILY:
		return NO_ADDRESS;
		break;
	case EAI_NODATA:
		return NO_DATA;
		break;
	case EAI_MEMORY:
		return ENOMEM;
		break;
	case EAI_AGAIN:
		return TRY_AGAIN;
		break;
	case EAI_SYSTEM:
		return errno;
		break;
	default:
		return NO_RECOVERY;
		break;
	}
}

#endif /* ENABLE_IPv6 */

static int
camel_gethostbyname_r (const char *name, struct hostent *host,
		       char *buf, size_t buflen, int *herr)
{
#ifdef ENABLE_IPv6
	struct addrinfo hints, *res;
	int retval, len;
	char *addr;
	
	memset (&hints, 0, sizeof (struct addrinfo));
#ifdef HAVE_AI_ADDRCONFIG
	hints.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
#else
	hints.ai_flags = AI_CANONNAME;
#endif
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;
	
	if ((retval = getaddrinfo (name, NULL, &hints, &res)) != 0) {
		*herr = ai_to_herr (retval);
		return -1;
	}
	
	len = ALIGN (strlen (res->ai_canonname) + 1);
	if (buflen < IPv6_BUFLEN_MIN + len + res->ai_addrlen + sizeof (char *))
		return ERANGE;
	
	/* h_name */
	strcpy (buf, res->ai_canonname);
	host->h_name = buf;
	buf += len;
	
	/* h_aliases */
	((char **) buf)[0] = NULL;
	host->h_aliases = (char **) buf;
	buf += sizeof (char *);
	
	/* h_addrtype and h_length */
	host->h_length = res->ai_addrlen;
	if (res->ai_family == PF_INET6) {
		host->h_addrtype = AF_INET6;
		
		addr = (char *) &((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
	} else {
		host->h_addrtype = AF_INET;
		
		addr = (char *) &((struct sockaddr_in *) res->ai_addr)->sin_addr;
	}
	
	memcpy (buf, addr, host->h_length);
	addr = buf;
	buf += ALIGN (host->h_length);
	
	/* h_addr_list */
	((char **) buf)[0] = addr;
	((char **) buf)[1] = NULL;
	host->h_addr_list = (char **) buf;
	
	freeaddrinfo (res);
	
	return 0;
#else /* No support for IPv6 addresses */
#ifdef HAVE_GETHOSTBYNAME_R
#ifdef GETHOSTBYNAME_R_FIVE_ARGS
	if (gethostbyname_r (name, host, buf, buflen, herr))
		return 0;
	else
		return errno;
#else
	struct hostent *hp;
	int retval;
	
	retval = gethostbyname_r (name, host, buf, buflen, &hp, herr);
	if (hp != NULL) {
		*herr = 0;
	} else if (retval == 0) {
		/* glibc 2.3.2 workaround - it seems that
		 * gethostbyname_r will sometimes return 0 on fail and
		 * not set the hostent values (hence the crash in bug
		 * #56337).  Hopefully we can depend on @hp being NULL
		 * in this error case like we do with
		 * gethostbyaddr_r().
		 */
		retval = -1;
	}
	
	return retval;
#endif
#else /* No support for gethostbyname_r */
	struct hostent *h;
	
	G_LOCK (gethost_mutex);
	
	h = gethostbyname (name);
	
	if (!h) {
		*herr = h_errno;
		G_UNLOCK (gethost_mutex);
		return -1;
	}
	
	GETHOST_PROCESS (h, host, buf, buflen, herr);
	
	G_UNLOCK (gethost_mutex);
	
	return 0;
#endif /* HAVE_GETHOSTBYNAME_R */
#endif /* ENABLE_IPv6 */
}

static int
camel_gethostbyaddr_r (const char *addr, int addrlen, int type, struct hostent *host,
		       char *buf, size_t buflen, int *herr)
{
#ifdef ENABLE_IPv6
	int retval, len;
	
	if ((retval = getnameinfo (addr, addrlen, buf, buflen, NULL, 0, NI_NAMEREQD)) != 0) {
		*herr = ai_to_herr (retval);
		return -1;
	}
	
	len = ALIGN (strlen (buf) + 1);
	if (buflen < IPv6_BUFLEN_MIN + len + addrlen + sizeof (char *))
		return ERANGE;
	
	/* h_name */
	host->h_name = buf;
	buf += len;
	
	/* h_aliases */
	((char **) buf)[0] = NULL;
	host->h_aliases = (char **) buf;
	buf += sizeof (char *);
	
	/* h_addrtype and h_length */
	host->h_length = addrlen;
	host->h_addrtype = type;
	
	memcpy (buf, addr, host->h_length);
	addr = buf;
	buf += ALIGN (host->h_length);
	
	/* h_addr_list */
	((char **) buf)[0] = addr;
	((char **) buf)[1] = NULL;
	host->h_addr_list = (char **) buf;
	
	return 0;
#else /* No support for IPv6 addresses */
#ifdef HAVE_GETHOSTBYADDR_R
#ifdef GETHOSTBYADDR_R_SEVEN_ARGS
	if (gethostbyaddr_r (addr, addrlen, type, host, buf, buflen, herr))
		return 0;
	else
		return errno;
#else
	struct hostent *hp;
	int retval;
	
	retval = gethostbyaddr_r (addr, addrlen, type, host, buf, buflen, &hp, herr);
	if (hp != NULL) {
		*herr = 0;
		retval = 0;
	} else if (retval == 0) {
		/* glibc 2.3.2 workaround - it seems that
		 * gethostbyaddr_r will sometimes return 0 on fail and
		 * fill @host with garbage strings from /etc/hosts
		 * (failure to parse the file? who knows). Luckily, it
		 * seems that we can rely on @hp being NULL on
		 * fail.
		 */
		retval = -1;
	}
	
	return retval;
#endif
#else /* No support for gethostbyaddr_r */
	struct hostent *h;
	
	G_LOCK (gethost_mutex);
	
	h = gethostbyaddr (addr, addrlen, type);
	
	if (!h) {
		*herr = h_errno;
		G_UNLOCK (gethost_mutex);
		return -1;
	}
	
	GETHOST_PROCESS (h, host, buf, buflen, herr);
	
	G_UNLOCK (gethost_mutex);
	
	return 0;
#endif /* HAVE_GETHOSTBYADDR_R */
#endif /* ENABLE_IPv6 */
}
#endif /* NEED_ADDRINFO */

/* ********************************************************************** */
struct _addrinfo_msg {
	EMsg msg;
	unsigned int cancelled:1;

	/* for host lookup */
	const char *name;
	const char *service;
	int result;
	const struct addrinfo *hints;
	struct addrinfo **res;

	/* for host lookup emulation */
#ifdef NEED_ADDRINFO
	struct hostent hostbuf;
	int hostbuflen;
	char *hostbufmem;
#endif

	/* for name lookup */
	const struct sockaddr *addr;
	socklen_t addrlen;
	char *host;
	int hostlen;
	char *serv;
	int servlen;
	int flags;
};

static void
cs_freeinfo(struct _addrinfo_msg *msg)
{
	g_free(msg->host);
	g_free(msg->serv);
#ifdef NEED_ADDRINFO
	g_free(msg->hostbufmem);
#endif
	g_free(msg);
}

/* returns -1 if cancelled */
static int
cs_waitinfo(void *(worker)(void *), struct _addrinfo_msg *msg, const char *error, CamelException *ex)
{
	EMsgPort *reply_port;
	pthread_t id;
	int err, cancel_fd, cancel = 0, fd;

	cancel_fd = camel_operation_cancel_fd(NULL);
	if (cancel_fd == -1) {
		worker(msg);
		return 0;
	}
	
	reply_port = msg->msg.reply_port = e_msgport_new();
	fd = e_msgport_fd(msg->msg.reply_port);
	if ((err = pthread_create(&id, NULL, worker, msg)) == 0) {
		struct pollfd polls[2];
		int status;

		polls[0].fd = fd;
		polls[0].events = POLLIN;
		polls[1].fd = cancel_fd;
		polls[1].events = POLLIN;

		d(printf("waiting for name return/cancellation in main process\n"));
		do {
			polls[0].revents = 0;
			polls[1].revents = 0;
			status = poll(polls, 2, -1);
		} while (status == -1 && errno == EINTR);

		if (status == -1 || (polls[1].revents & POLLIN)) {
			if (status == -1)
				camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, "%s: %s", error, g_strerror(errno));
			else
				camel_exception_setv(ex, CAMEL_EXCEPTION_USER_CANCEL, _("Cancelled"));
			
			/* We cancel so if the thread impl is decent it causes immediate exit.
			   We detach so we dont need to wait for it to exit if it isn't.
			   We check the reply port incase we had a reply in the mean time, which we free later */
			d(printf("Cancelling lookup thread and leaving it\n"));
			msg->cancelled = 1;
			pthread_detach(id);
			pthread_cancel(id);
			cancel = 1;
		} else {
			struct _addrinfo_msg *reply = (struct _addrinfo_msg *)e_msgport_get(reply_port);

			g_assert(reply == msg);
			d(printf("waiting for child to exit\n"));
			pthread_join(id, NULL);
			d(printf("child done\n"));
		}
	} else {
		camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, "%s: %s: %s", error, _("cannot create thread"), g_strerror(err));
	}
	e_msgport_destroy(reply_port);

	return cancel;
}

#ifdef NEED_ADDRINFO
static void *
cs_getaddrinfo(void *data)
{
	struct _addrinfo_msg *msg = data;
	int herr;
	struct hostent h;
	struct addrinfo *res, *last = NULL;
	struct sockaddr_in *sin;
	in_port_t port = 0;
	int i;

	/* This is a pretty simplistic emulation of getaddrinfo */

	while ((msg->result = camel_gethostbyname_r(msg->name, &h, msg->hostbufmem, msg->hostbuflen, &herr)) == ERANGE) {
		pthread_testcancel();
                msg->hostbuflen *= 2;
                msg->hostbufmem = g_realloc(msg->hostbufmem, msg->hostbuflen);
	}
	
	/* If we got cancelled, dont reply, just free it */
	if (msg->cancelled)
		goto cancel;

	/* FIXME: map error numbers across */
	if (msg->result != 0)
		goto reply;

	/* check hints matched */
	if (msg->hints && msg->hints->ai_family && msg->hints->ai_family != h.h_addrtype) {
		msg->result = EAI_FAMILY;
		goto reply;
	}

	/* we only support ipv4 for this interface, even if it could supply ipv6 */
	if (h.h_addrtype != AF_INET) {
		msg->result = EAI_FAMILY;
		goto reply;
	}

	/* check service mapping */
	if (msg->service) {
		const char *p = msg->service;

		while (*p) {
			if (*p < '0' || *p > '9')
				break;
			p++;
		}

		if (*p) {
			const char *socktype = NULL;
			struct servent *serv;

			if (msg->hints && msg->hints->ai_socktype) {
				if (msg->hints->ai_socktype == SOCK_STREAM)
					socktype = "tcp";
				else if (msg->hints->ai_socktype == SOCK_DGRAM)
					socktype = "udp";
			}

			serv = getservbyname(msg->service, socktype);
			if (serv == NULL) {
				msg->result = EAI_NONAME;
				goto reply;
			}
			port = serv->s_port;
		} else {
			port = htons(strtoul(msg->service, NULL, 10));
		}
	}

	for (i=0;h.h_addr_list[i];i++) {
		res = g_malloc0(sizeof(*res));
		if (msg->hints) {
			res->ai_flags = msg->hints->ai_flags;
			if (msg->hints->ai_flags & AI_CANONNAME)
				res->ai_canonname = g_strdup(h.h_name);
			res->ai_socktype = msg->hints->ai_socktype;
			res->ai_protocol = msg->hints->ai_protocol;
		} else {
			res->ai_flags = 0;
			res->ai_socktype = SOCK_STREAM;	/* fudge */
			res->ai_protocol = 0;	/* fudge */
		}
		res->ai_family = AF_INET;
		res->ai_addrlen = sizeof(*sin);
		res->ai_addr = g_malloc(sizeof(*sin));
		sin = (struct sockaddr_in *)res->ai_addr;
		sin->sin_family = AF_INET;
		sin->sin_port = port;
		memcpy(&sin->sin_addr, h.h_addr_list[i], sizeof(sin->sin_addr));

		if (last == NULL) {
			*msg->res = last = res;
		} else {
			last->ai_next = res;
			last = res;
		}
	}
reply:
	e_msgport_reply((EMsg *)msg);
	return NULL;
cancel:
	cs_freeinfo(msg);
	return NULL;
}
#else
static void *
cs_getaddrinfo(void *data)
{
	struct _addrinfo_msg *info = data;

	info->result = getaddrinfo(info->name, info->service, info->hints, info->res);
	
	if (info->cancelled) {
		g_free(info);
	} else {
		e_msgport_reply((EMsg *)info);
	}
	
	return NULL;
}
#endif /* NEED_ADDRINFO */

struct addrinfo *
camel_getaddrinfo(const char *name, const char *service, const struct addrinfo *hints, CamelException *ex)
{
	struct _addrinfo_msg *msg;
	struct addrinfo *res = NULL;
#ifndef ENABLE_IPv6
	struct addrinfo myhints;
#endif
	g_return_val_if_fail(name != NULL, NULL);
	
	if (camel_operation_cancel_check(NULL)) {
		camel_exception_set(ex, CAMEL_EXCEPTION_USER_CANCEL, _("Cancelled"));
		return NULL;
	}

	camel_operation_start_transient(NULL, _("Resolving: %s"), name);

	/* force ipv4 addresses only */
#ifndef ENABLE_IPv6
	if (hints == NULL)
		memset(&myhints, 0, sizeof(myhints));
	else
		memcpy (&myhints, hints, sizeof (myhints));
	
	myhints.ai_family = AF_INET;
	hints = &myhints;
#endif

	msg = g_malloc0(sizeof(*msg));
	msg->name = name;
	msg->service = service;
	msg->hints = hints;
	msg->res = &res;
#ifdef NEED_ADDRINFO
	msg->hostbuflen = 1024;
	msg->hostbufmem = g_malloc(msg->hostbuflen);
#endif	
	if (cs_waitinfo(cs_getaddrinfo, msg, _("Host lookup failed"), ex) == 0) {
		if (msg->result != 0)
			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM, _("Host lookup failed: %s: %s"),
					      name, gai_strerror (msg->result));
		
		cs_freeinfo(msg);
	} else
		res = NULL;
	
	camel_operation_end(NULL);

	return res;
}

void
camel_freeaddrinfo(struct addrinfo *host)
{
#ifdef NEED_ADDRINFO
	while (host) {
		struct addrinfo *next = host->ai_next;

		g_free(host->ai_canonname);
		g_free(host->ai_addr);
		g_free(host);
		host = next;
	}
#else
	freeaddrinfo(host);
#endif
}

#ifdef NEED_ADDRINFO
static void *
cs_getnameinfo(void *data)
{
	struct _addrinfo_msg *msg = data;
	int herr;
	struct hostent h;
	struct sockaddr_in *sin = (struct sockaddr_in *)msg->addr;

	/* FIXME: error code */
	if (msg->addr->sa_family != AF_INET) {
		msg->result = -1;
		return NULL;
	}

	/* FIXME: honour getnameinfo flags: do we care, not really */

	while ((msg->result = camel_gethostbyaddr_r((const char *)&sin->sin_addr, sizeof(sin->sin_addr), AF_INET, &h,
						    msg->hostbufmem, msg->hostbuflen, &herr)) == ERANGE) {
		pthread_testcancel ();
                msg->hostbuflen *= 2;
                msg->hostbufmem = g_realloc(msg->hostbufmem, msg->hostbuflen);
	}
	
	if (msg->cancelled)
		goto cancel;

	if (msg->host) {
		g_free(msg->host);
		if (msg->result == 0 && h.h_name && h.h_name[0]) {
			msg->host = g_strdup(h.h_name);
		} else {
			unsigned char *in = (unsigned char *)&sin->sin_addr;
			
			/* sin_addr is always network order which is big-endian */
			msg->host = g_strdup_printf("%u.%u.%u.%u", in[0], in[1], in[2], in[3]);
		}
	}

	/* we never actually use this anyway */
	if (msg->serv)
		sprintf(msg->serv, "%d", sin->sin_port);

	e_msgport_reply((EMsg *)msg);
	return NULL;
cancel:
	cs_freeinfo(msg);
	return NULL;
}
#else
static void *
cs_getnameinfo(void *data)
{
	struct _addrinfo_msg *msg = data;

	/* there doens't appear to be a return code which says host or serv buffers are too short, lengthen them */
	msg->result = getnameinfo(msg->addr, msg->addrlen, msg->host, msg->hostlen, msg->serv, msg->servlen, msg->flags);
	
	if (msg->cancelled)
		cs_freeinfo(msg);
	else
		e_msgport_reply((EMsg *)msg);

	return NULL;
}
#endif

int
camel_getnameinfo(const struct sockaddr *sa, socklen_t salen, char **host, char **serv, int flags, CamelException *ex)
{
	struct _addrinfo_msg *msg;
	int result;

	if (camel_operation_cancel_check(NULL)) {
		camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL, _("Cancelled"));
		return -1;
	}

	camel_operation_start_transient(NULL, _("Resolving address"));

	msg = g_malloc0(sizeof(*msg));
	msg->addr = sa;
	msg->addrlen = salen;
	if (host) {
		msg->hostlen = NI_MAXHOST;
		msg->host = g_malloc(msg->hostlen);
		msg->host[0] = 0;
	}
	if (serv) {
		msg->servlen = NI_MAXSERV;
		msg->serv = g_malloc(msg->servlen);
		msg->serv[0] = 0;
	}
	msg->flags = flags;
#ifdef NEED_ADDRINFO
	msg->hostbuflen = 1024;
	msg->hostbufmem = g_malloc(msg->hostbuflen);
#endif
	cs_waitinfo(cs_getnameinfo, msg, _("Name lookup failed"), ex);

	if ((result = msg->result) != 0)
		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM, _("Name lookup failed: %s"),
				      gai_strerror (result));

	if (host)
		*host = g_strdup(msg->host);
	if (serv)
		*serv = g_strdup(msg->serv);

	g_free(msg->host);
	g_free(msg->serv);
	g_free(msg);

	camel_operation_end(NULL);

	return result;
}