#include <net-snmp/net-snmp-config.h>

#include <stdio.h>
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>

#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif

#include <net-snmp/types.h>
#include <net-snmp/output_api.h>
#include <net-snmp/config_api.h>

#include <net-snmp/library/snmp_transport.h>
#include <net-snmp/library/snmpIPXDomain.h>

#define SNMP_IPX_DEFAULT_PORT	36879   /*  Specified in RFC 1420.  */
static netsnmp_tdomain ipxDomain;

/*
 * Return a string representing the address in data, or else the "far end"
 * address if data is NULL.  
 */

static char *
netsnmp_ipx_fmtaddr(netsnmp_transport *t, void *data, int len)
{
    struct sockaddr_ipx *to = NULL;

    if (data != NULL && len == sizeof(struct sockaddr_ipx)) {
        to = (struct sockaddr_ipx *) data;
    } else if (t != NULL && t->data != NULL) {
        to = (struct sockaddr_ipx *) t->data;
    }
    if (to == NULL) {
        return strdup("IPX: unknown");
    } else {
        char tmp[64];
        sprintf(tmp, "IPX: %08X:%02X%02X%02X%02X%02X%02X/%hu",
                ntohl(to->sipx_network), to->sipx_node[0],
                to->sipx_node[1], to->sipx_node[2], to->sipx_node[3],
                to->sipx_node[4], to->sipx_node[5], ntohs(to->sipx_port));
        return strdup(tmp);
    }
}


/*
 * You can write something into opaque that will subsequently get passed back 
 * to your send function if you like.  For instance, you might want to
 * remember where a PDU came from, so that you can send a reply there...  
 */

static int
netsnmp_ipx_recv(netsnmp_transport *t, void *buf, int size,
		 void **opaque, int *olength)
{
    int		     rc = -1;
    socklen_t	     fromlen = sizeof(struct sockaddr);
    struct sockaddr *from;

    if (t != NULL && t->sock >= 0) {
        from = (struct sockaddr *)malloc(sizeof(struct sockaddr_ipx));
        if (from == NULL) {
            *opaque = NULL;
            *olength = 0;
            return -1;
        } else {
            memset(from, 0, fromlen);
        }

	while (rc < 0) {
	  rc = recvfrom(t->sock, buf, size, 0, from, &fromlen);
	  if (rc < 0 && errno != EINTR) {
	    break;
	  }
	}

        if (rc >= 0) {
            char *str = netsnmp_ipx_fmtaddr(NULL, from, fromlen);
            DEBUGMSGTL(("netsnmp_ipx","recvfrom fd %d got %d bytes(from %s)\n",
			t->sock, rc, str));
            free(str);
        } else {
            DEBUGMSGTL(("netsnmp_ipx", "recvfrom fd %d err %d (\"%s\")\n",
                        t->sock, errno, strerror(errno)));
        }
        *opaque = (void *) from;
        *olength = sizeof(struct sockaddr_ipx);
    }
    return rc;
}


static int
netsnmp_ipx_send(netsnmp_transport *t, void *buf, int size,
		 void **opaque, int *olength)
{
    int rc = -1;
    struct sockaddr *to = NULL;

    if (opaque != NULL && *opaque != NULL &&
	*olength == sizeof(struct sockaddr_ipx)) {
        to = (struct sockaddr *) (*opaque);
    } else if (t != NULL && t->data != NULL &&
               t->data_length == sizeof(struct sockaddr_ipx)) {
        to = (struct sockaddr *) (t->data);
    }

    if (to != NULL && t != NULL && t->sock >= 0) {
        char *str = netsnmp_ipx_fmtaddr(NULL, (void *)to,
					sizeof(struct sockaddr_ipx));
        DEBUGMSGTL(("netsnmp_ipx", "send %d bytes from %p to %s on fd %d\n",
                    size, buf, str, t->sock));
        free(str);
	while (rc < 0) {
	    rc = sendto(t->sock, buf, size, 0, to, sizeof(struct sockaddr));
	    if (rc < 0 && errno != EINTR) {
		break;
	    }
	}
    }
    return rc;
}


static int
netsnmp_ipx_close(netsnmp_transport *t)
{
    int rc = -1;
    if (t->sock >= 0) {
#ifndef HAVE_CLOSESOCKET
        rc = close(t->sock);
#else
        rc = closesocket(t->sock);
#endif
        t->sock = -1;
    }
    return rc;
}


/*
 * Open a IPX-based transport for SNMP.  Local is TRUE if addr is the local
 * address to bind to (i.e. this is a server-type session); otherwise addr is 
 * the remote address to send things to.  
 */

netsnmp_transport *
netsnmp_ipx_transport(struct sockaddr_ipx *addr, int local)
{
    netsnmp_transport *t = NULL;
    int             rc = 0;
    char           *str = NULL;

    if (addr == NULL || addr->sipx_family != AF_IPX) {
        return NULL;
    }

    t = (netsnmp_transport *) malloc(sizeof(netsnmp_transport));
    if (t == NULL) {
        return NULL;
    }

    str = netsnmp_ipx_fmtaddr(NULL, (void *)addr, 
				 sizeof(struct sockaddr_ipx));
    DEBUGMSGTL(("netsnmp_ipx", "open %s %s\n", local ? "local" : "remote",
                str));
    free(str);

    memset(t, 0, sizeof(netsnmp_transport));

    t->domain = netsnmpIPXDomain;
    t->domain_length = netsnmpIPXDomain_len;

    t->sock = socket(AF_IPX, SOCK_DGRAM, AF_IPX);
    if (t->sock < 0) {
        netsnmp_transport_free(t);
        return NULL;
    }

    if (local) {
        t->local = (unsigned char*)malloc(12);
        if (t->local == NULL) {
            netsnmp_transport_free(t);
            return NULL;
        }
        memcpy(&(t->local[00]), (u_char *) & (addr->sipx_network), 4);
        memcpy(&(t->local[04]), (u_char *) & (addr->sipx_node), 6);
        memcpy(&(t->local[10]), (u_char *) & (addr->sipx_port), 2);
        t->local_length = 12;

        /*
         * This session is inteneded as a server, so we must bind on to the
         * given address (which may include a particular network and/or node
         * address, but definitely includes a port number).
         */

        rc = bind(t->sock, (struct sockaddr *) addr,
                  sizeof(struct sockaddr));
        if (rc != 0) {
            netsnmp_ipx_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }
        t->data = NULL;
        t->data_length = 0;
    } else {
        t->remote = (unsigned char*)malloc(12);
        if (t->remote == NULL) {
            netsnmp_transport_free(t);
            return NULL;
        }
        memcpy(&(t->remote[00]), (u_char *) & (addr->sipx_network), 4);
        memcpy(&(t->remote[04]), (u_char *) & (addr->sipx_node), 6);
        memcpy(&(t->remote[10]), (u_char *) & (addr->sipx_port), 2);
        t->remote_length = 12;

        /*
         * This is a client session.  Save the address in the
         * transport-specific data pointer for later use by snmp_ipx_send.
         */

        t->data = malloc(sizeof(struct sockaddr_ipx));
        if (t->data == NULL) {
            netsnmp_transport_free(t);
            return NULL;
        }
        memcpy(t->data, addr, sizeof(struct sockaddr_ipx));
        t->data_length = sizeof(struct sockaddr_ipx);
    }

    /*
     * Maximum size of an IPX PDU is 576 bytes including a 30-byte header.
     * Ridiculous!  
     */

    t->msgMaxSize = 576 - 30;
    t->f_recv     = netsnmp_ipx_recv;
    t->f_send     = netsnmp_ipx_send;
    t->f_close    = netsnmp_ipx_close;
    t->f_accept   = NULL;
    t->f_fmtaddr  = netsnmp_ipx_fmtaddr;

    return t;
}


/*
 * Attempt to parse a string of the form [%08x]:%12x[/%d] where the parts
 * are the network number, the node address and the port in that order.  
 */

int
netsnmp_sockaddr_ipx2(struct sockaddr_ipx *addr, const char *peername,
		      const char *default_target)
{
    char           *input = NULL, *def = NULL;
    const char     *network, *node, *port;
    char           *tmp;
    unsigned long   i;

    if (addr == NULL) {
        return 0;
    }
    memset(addr, 0, sizeof(struct sockaddr_ipx));

    DEBUGMSGTL(("netsnmp_sockaddr_ipx",
		"addr %p, peername \"%s\" default_target \"%s\"\n",
                addr, peername ? peername : "[NIL]",
		default_target ? default_target : "[NIL]"));

    addr->sipx_family = AF_IPX;
    addr->sipx_type = 4;        /*  Specified in RFC 1420.  */

    network = input = strdup(peername ? peername : "");
    tmp = strchr(network, ':');
    if (tmp != NULL) {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx", "Node identified\n"));
        *tmp++ = '\0';
	node = tmp;
        tmp = strchr(tmp, '/');
    } else {
        node = NULL;
        tmp = strchr(network, '/');
    }
    if (tmp != NULL) {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx", "Port identified\n"));
        *tmp++ = '\0';
        port = tmp;
    } else
        port = NULL;

    DEBUGMSGTL(("netsnmp_sockaddr_ipx", "Address: %s:%s/%s\n",
                network ? network : "[NIL]", node ? node : "[NIL]",
                port ? port : "[NIL]"));

    def = strdup(default_target ? default_target : "");
    if (network == NULL || *network == '\0')
        network = def;
    tmp = strchr(def, ':');
    if (tmp != NULL) {
        *tmp++ = '\0';
	if (node == NULL || *node == '\0')
            node = tmp;
        tmp = strchr(tmp, '/');
    } else
        tmp = strchr(def, '/');
    if (tmp != NULL) {
        *tmp++ = '\0';
        if (port == NULL || *port == '\0')
            port = tmp;
    }

    DEBUGMSGTL(("netsnmp_sockaddr_ipx", "Address: %s:%s/%s\n",
                network ? network : "[NIL]", node ? node : "[NIL]",
                port ? port : "[NIL]"));

    if (network == NULL || *network == '\0')
        network = "0";

    if (node == NULL || *node == '\0')
        node = "000000000000";

    if (port == NULL || *port == '\0')
#define val(x) __STRING(x)
        port = val(SNMP_IPX_DEFAULT_PORT);
#undef val

    DEBUGMSGTL(("netsnmp_sockaddr_ipx", "Address: %s:%s/%s\n",
                network ? network : "[NIL]", node ? node : "[NIL]",
                port ? port : "[NIL]"));

    if(sscanf(network, "%8lx%*c", &i) == 1) {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx", "network parsed okay\n"));
        addr->sipx_network = htonl(i);
    } else {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx",
                    "failed to parse network part of address\n"));
        free(def);
        free(input);
        return 0;
    }

    if(sscanf(node, "%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%*c",
              &addr->sipx_node[0], &addr->sipx_node[1],
              &addr->sipx_node[2], &addr->sipx_node[3],
              &addr->sipx_node[4], &addr->sipx_node[5]) == 6) {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx", "node parsed okay\n"));
    } else {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx",
                    "failed to parse node part of address\n"));
        free(def);
        free(input);
        return 0;
    }

    if(sscanf(port, "%lu%*c", &i) == 1) {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx", "port parsed okay\n"));
        addr->sipx_port = htons(i);
    } else {
        DEBUGMSGTL(("netsnmp_sockaddr_ipx",
                    "failed to parse port part of address\n"));
        free(def);
        free(input);
        return 0;
    }

    free(def);
    free(input);
    return 1;
}


int
netsnmp_sockaddr_ipx(struct sockaddr_ipx *addr, const char *peername)
{
    return netsnmp_sockaddr_ipx2(addr, peername, NULL);
}


netsnmp_transport *
netsnmp_ipx_create_tstring(const char *str, int local,
			   const char *default_target)
{
    struct sockaddr_ipx addr;

    if (netsnmp_sockaddr_ipx2(&addr, str, default_target)) {
        return netsnmp_ipx_transport(&addr, local);
    } else {
        return NULL;
    }
}


netsnmp_transport *
netsnmp_ipx_create_ostring(const u_char * o, size_t o_len, int local)
{
    struct sockaddr_ipx addr;

    if (o_len == 12) {
        addr.sipx_family = AF_IPX;
        memcpy((u_char *) & (addr.sipx_network), &(o[00]), 4);
        memcpy((u_char *) & (addr.sipx_node), &(o[04]), 6);
        memcpy((u_char *) & (addr.sipx_port), &(o[10]), 2);
        return netsnmp_ipx_transport(&addr, local);
    }
    return NULL;
}


void
netsnmp_ipx_ctor(void)
{
    ipxDomain.name = netsnmpIPXDomain;
    ipxDomain.name_length = netsnmpIPXDomain_len;
    ipxDomain.prefix = (const char**)calloc(2, sizeof(char *));
    ipxDomain.prefix[0] = "ipx";

    ipxDomain.f_create_from_tstring     = NULL;
    ipxDomain.f_create_from_tstring_new = netsnmp_ipx_create_tstring;
    ipxDomain.f_create_from_ostring     = netsnmp_ipx_create_ostring;

    netsnmp_tdomain_register(&ipxDomain);
}