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

#include <net-snmp/library/snmpAAL5PVCDomain.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

#include <atm.h>

#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/tools.h>

oid netsnmp_AAL5PVCDomain[10] = { NETSNMP_ENTERPRISE_MIB, 3, 3, 3 };

static netsnmp_tdomain aal5pvcDomain;

/*

 * Return a string representing the address in data, or else the "far end"

 * address if data is NULL.  

 */

static char *

netsnmp_aal5pvc_fmtaddr(netsnmp_transport *t, const void *data, int len)

{

    const struct sockaddr_atmpvc *to = NULL;

    if (data != NULL && len == sizeof(struct sockaddr_atmpvc)) {

        to = (const struct sockaddr_atmpvc *) data;

    } else if (t != NULL && t->data != NULL &&

               t->data_length == sizeof(struct sockaddr_atmpvc)) {

        to = (const struct sockaddr_atmpvc *) t->data;

    }

    if (to == NULL) {

        return strdup("AAL5 PVC: unknown");

    } else {

        char *tmp;

        if (asprintf(&tmp, "AAL5 PVC: %hd.%hd.%d", to->sap_addr.itf,

		     to->sap_addr.vpi, to->sap_addr.vci) < 0)

            tmp = NULL;

        return tmp;

    }

}

static void

netsnmp_aal5pvc_get_taddr(netsnmp_transport *t, void **addr, size_t *addr_len)

{

    struct sockaddr_atmpvc *sa = t->remote;

    unsigned char *p;

    *addr_len = 8;

    if (!(*addr = malloc(*addr_len)))

        return;

    p = *addr;

    p[0] = sa->sap_addr.itf >> 8;

    p[1] = sa->sap_addr.itf >> 0;

    p[2] = sa->sap_addr.vpi >> 8;

    p[3] = sa->sap_addr.vpi >> 0;

    p[4] = sa->sap_addr.vci >> 24;

    p[5] = sa->sap_addr.vci >> 16;

    p[6] = sa->sap_addr.vci >> 8;

    p[7] = sa->sap_addr.vci >> 0;

}

/*

 * 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_aal5pvc_recv(netsnmp_transport *t, void *buf, int size,

		     void **opaque, int *olength)

{

    int rc = -1;

    if (t != NULL && t->sock >= 0) {

	while (rc < 0) {

	    rc = recvfrom(t->sock, buf, size, 0, NULL, NULL);

	    if (rc < 0 && errno != EINTR) {

		break;

	    }

	}

        if (rc >= 0) {

            DEBUGIF("netsnmp_aal5pvc") {

                char *str = netsnmp_aal5pvc_fmtaddr(t, NULL, 0);

                DEBUGMSGTL(("netsnmp_aal5pvc",

                            "recv on fd %d got %d bytes (from %s)\n", t->sock,

                            rc, str));

                free(str);

            }

        } else {

            DEBUGMSGTL(("netsnmp_aal5pvc", "recv on fd %d err %d (\"%s\")\n", 

			t->sock, errno, strerror(errno)));

        }

        *opaque = NULL;

        *olength = 0;

    }

    return rc;

}

static int

netsnmp_aal5pvc_send(netsnmp_transport *t, const void *buf, int size,

                     void **opaque, int *olength)

{

    int rc = -1;

    const struct sockaddr *to = NULL;

    if (opaque != NULL && *opaque != NULL &&

        *olength == sizeof(struct sockaddr_atmpvc)) {

        to = (const struct sockaddr *) (*opaque);

    } else if (t != NULL && t->data != NULL &&

               t->data_length == sizeof(struct sockaddr_atmpvc)) {

        to = (const struct sockaddr *) (t->data);

    }

    if (to != NULL && t != NULL && t->sock >= 0) {

        DEBUGIF("netsnmp_aal5pvc") {

            char *str = netsnmp_aal5pvc_fmtaddr(NULL, to,

                                                sizeof(struct sockaddr_atmpvc));

            DEBUGMSGTL(("netsnmp_aal5pvc",

                        "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, NULL, 0);

	    if (rc < 0 && errno != EINTR) {

		break;

	    }

	}

    }

    return rc;

}

static int

netsnmp_aal5pvc_close(netsnmp_transport *t)

{

    int rc = -1;

    if (t->sock >= 0) {

        DEBUGMSGTL(("netsnmp_aal5pvc", "close fd %d\n", t->sock));

#ifndef HAVE_CLOSESOCKET

        rc = close(t->sock);

#else

        rc = closesocket(t->sock);

#endif

        t->sock = -1;

    }

    return rc;

}

/*

 * Open an AAL5 PVC transport for SNMP.  Local is TRUE if addr is the local 

 * NSAP to bind to (i.e. this is a server-type session); otherwise addr is 

 * the remote NSAP to send things to.  

 */

netsnmp_transport *

netsnmp_aal5pvc_transport(const struct sockaddr_atmpvc *addr, int local)

{

    netsnmp_transport *t = NULL;

#ifdef NETSNMP_NO_LISTEN_SUPPORT

    if (local)

        return NULL;

#endif /* NETSNMP_NO_LISTEN_SUPPORT */

    if (addr == NULL || addr->sap_family != AF_ATMPVC) {

        return NULL;

    }

    t = SNMP_MALLOC_TYPEDEF(netsnmp_transport);

    if (t == NULL) {

        return NULL;

    }

    DEBUGIF("netsnmp_aal5pvc") {

        char *str = netsnmp_aal5pvc_fmtaddr(NULL, addr,

                                            sizeof(struct sockaddr_atmpvc));

        DEBUGMSGTL(("netsnmp_aal5pvc", "open %s %s\n",

                    local ? "local" : "remote", str));

        free(str);

    }

    t->domain = netsnmp_AAL5PVCDomain;

    t->domain_length =

        sizeof(netsnmp_AAL5PVCDomain) / sizeof(netsnmp_AAL5PVCDomain[0]);

    t->sock = socket(PF_ATMPVC, SOCK_DGRAM, 0);

    if (t->sock < 0) {

        DEBUGMSGTL(("netsnmp_aal5pvc","socket failed (%s)\n",strerror(errno)));

        netsnmp_transport_free(t);

        return NULL;

    }

    DEBUGMSGTL(("netsnmp_aal5pvc", "fd %d opened\n", t->sock));

    {

        /*

         * Set up the QOS parameters.

         */

        struct atm_qos qos = { 0 };

        qos.aal = ATM_AAL5;

        qos.rxtp.traffic_class = ATM_UBR;

        qos.rxtp.max_sdu = SNMP_MAX_LEN;    /*  Hmm -- this is a bit small?  */

        qos.txtp = qos.rxtp;

        if (setsockopt(t->sock, SOL_ATM, SO_ATMQOS, &qos, sizeof(qos)) < 0) {

            DEBUGMSGTL(("netsnmp_aal5pvc", "setsockopt failed (%s)\n",

                        strerror(errno)));

            netsnmp_aal5pvc_close(t);

            netsnmp_transport_free(t);

            return NULL;

        }

    }

    if (local) {

#ifndef NETSNMP_NO_LISTEN_SUPPORT

        t->local_length = sizeof(*addr);

        t->local = netsnmp_memdup(addr, sizeof(*addr));

        if (t->local == NULL) {

            netsnmp_transport_free(t);

            return NULL;

        }

        if (bind(t->sock, (const struct sockaddr *)addr,

                 sizeof(struct sockaddr_atmpvc)) < 0) {

            DEBUGMSGTL(("netsnmp_aal5pvc", "bind failed (%s)\n",

                        strerror(errno)));

            netsnmp_aal5pvc_close(t);

            netsnmp_transport_free(t);

            return NULL;

        }

#else /* NETSNMP_NO_LISTEN_SUPPORT */

        return NULL;

#endif /* NETSNMP_NO_LISTEN_SUPPORT */

    } else {

        t->remote_length = sizeof(*addr);

        t->remote = netsnmp_memdup(addr, sizeof(*addr));

        if (t->remote == NULL) {

            netsnmp_transport_free(t);

            return NULL;

        }

        if (connect(t->sock, (const struct sockaddr *)addr,

                    sizeof(struct sockaddr_atmpvc)) < 0) {

            DEBUGMSGTL(("netsnmp_aal5pvc", "connect failed (%s)\n",

                        strerror(errno)));

            netsnmp_aal5pvc_close(t);

            netsnmp_transport_free(t);

            return NULL;

        }

    }

    t->data = malloc(sizeof(struct sockaddr_atmpvc));

    if (t->data == NULL) {

        netsnmp_transport_free(t);

        return NULL;

    }

    memcpy(t->data, addr, sizeof(struct sockaddr_atmpvc));

    t->data_length = sizeof(struct sockaddr_atmpvc);

    /*

     * 16-bit length field in the trailer, no headers.  

     */

    t->msgMaxSize = 0xffff;

    t->f_recv     = netsnmp_aal5pvc_recv;

    t->f_send     = netsnmp_aal5pvc_send;

    t->f_close    = netsnmp_aal5pvc_close;

    t->f_accept   = NULL;

    t->f_fmtaddr  = netsnmp_aal5pvc_fmtaddr;

    t->f_get_taddr = netsnmp_aal5pvc_get_taddr;

    return t;

}

netsnmp_transport *

netsnmp_aal5pvc_create_tstring(const char *str, int local,

			       const char *default_target)

{

    struct sockaddr_atmpvc addr;

    if (str == NULL || *str == '\0')

	str = default_target;

    if (str != NULL) {

        addr.sap_family = AF_ATMPVC;

        if (sscanf(str, "%hd.%hd.%d", &(addr.sap_addr.itf),

                   &(addr.sap_addr.vpi), &(addr.sap_addr.vci)) == 3) {

            return netsnmp_aal5pvc_transport(&addr, local);

        } else if (sscanf(str, "%hd.%d", &(addr.sap_addr.vpi),

                          &(addr.sap_addr.vci)) == 2) {

            addr.sap_addr.itf = 0;

            return netsnmp_aal5pvc_transport(&addr, local);

        } else if (sscanf(str, "%d", &(addr.sap_addr.vci)) == 1) {

            addr.sap_addr.itf = 0;

            addr.sap_addr.vpi = 0;

            return netsnmp_aal5pvc_transport(&addr, local);

        } else {

            return NULL;

        }

    } else {

        return NULL;

    }

}

static int netsnmp_aal5pvc_ostring_to_sockaddr(struct sockaddr_atmpvc *sa,

                                               const void *o, size_t o_len)

{

    const unsigned char *p = o;

    if (o_len != 8)

        return 0;

    memset(sa, 0, sizeof(*sa));

    sa->sap_family = AF_ATMPVC;

    sa->sap_addr.itf = (p[0] << 8) + (p[1] << 0);

    sa->sap_addr.vpi = (p[2] << 8) + (p[3] << 0);

    sa->sap_addr.vci = (p[4] << 24) + (p[5] << 16) + (p[6] << 8) + (p[7] << 0);

    return 1;

}

netsnmp_transport *

netsnmp_aal5pvc_create_ostring(const void *o, size_t o_len, int local)

{

    struct sockaddr_atmpvc sa;

    if (netsnmp_aal5pvc_ostring_to_sockaddr(&sa, o, o_len))

        return netsnmp_aal5pvc_transport(&sa, local);

    return NULL;

}

void

netsnmp_aal5pvc_ctor(void)

{

    aal5pvcDomain.name = netsnmp_AAL5PVCDomain;

    aal5pvcDomain.name_length = sizeof(netsnmp_AAL5PVCDomain) / sizeof(oid);

    aal5pvcDomain.prefix = (const char**)calloc(3, sizeof(char *));

    aal5pvcDomain.prefix[0] = "aal5pvc";

    aal5pvcDomain.prefix[1] = "pvc";

    aal5pvcDomain.f_create_from_tstring     = NULL;

    aal5pvcDomain.f_create_from_tstring_new = netsnmp_aal5pvc_create_tstring;

    aal5pvcDomain.f_create_from_ostring     = netsnmp_aal5pvc_create_ostring;

    netsnmp_tdomain_register(&aal5pvcDomain);

}