/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <pthread.h>
#include <strings.h>

#include "sip_parse_uri.h"
#include "sip_msg.h"
#include "sip_miscdefs.h"
#include "sip_xaction.h"
#include "sip_hash.h"

#define RFC_3261_BRANCH "z9hG4bK"

/*
 * The transaction hash table
 */
sip_hash_t      sip_xaction_hash[SIP_HASH_SZ];

int (*sip_xaction_ulp_trans_err)(sip_transaction_t, int, void *) = NULL;
void (*sip_xaction_ulp_state_cb)(sip_transaction_t, sip_msg_t, int, int) = NULL;

int sip_xaction_add(sip_xaction_t *, char *, _sip_msg_t *, sip_method_t);
static boolean_t sip_is_conn_obj_cache(sip_conn_object_t, void *);

/*
 * Get the md5 hash of the required fields
 */
int
sip_find_md5_digest(char *bid, _sip_msg_t *msg, uint16_t *hindex,
    sip_method_t method)
{
        boolean_t       is_2543;

        is_2543 = (bid == NULL ||
            strncmp(bid, RFC_3261_BRANCH, strlen(RFC_3261_BRANCH)) != 0);

        if (is_2543 && msg == NULL)
                return (EINVAL);
        if (is_2543) {
                _sip_header_t   *from = NULL;
                _sip_header_t   *cid = NULL;
                _sip_header_t   *via = NULL;
                const sip_str_t *to_uri = NULL;
                int             cseq;
                int             error = 0;

                /*
                 * Since the response might contain parameters not in the
                 * request, just use the to URI.
                 */
                to_uri = sip_get_to_uri_str((sip_msg_t)msg, &error);
                if (to_uri == NULL || error != 0)
                        return (EINVAL);
                cseq = sip_get_callseq_num((sip_msg_t)msg, &error);
                if (cseq < 0 || error != 0)
                        return (EINVAL);
                (void) pthread_mutex_lock(&msg->sip_msg_mutex);
                via = sip_search_for_header(msg, SIP_VIA, NULL);
                from = sip_search_for_header(msg, SIP_FROM, NULL);
                cid = sip_search_for_header(msg, SIP_CALL_ID, NULL);
                (void) pthread_mutex_unlock(&msg->sip_msg_mutex);
                if (via == NULL || from == NULL || cid == NULL)
                        return (EINVAL);
                sip_md5_hash(via->sip_hdr_start,
                    via->sip_hdr_end - via->sip_hdr_start,
                    cid->sip_hdr_start,
                    cid->sip_hdr_end - cid->sip_hdr_start,
                    from->sip_hdr_start,
                    from->sip_hdr_end - from->sip_hdr_start,
                    (char *)&cseq, sizeof (int),
                    (char *)&method, sizeof (sip_method_t),
                    to_uri->sip_str_ptr, to_uri->sip_str_len,
                    (uchar_t *)hindex);
        } else {
                sip_md5_hash(bid, strlen(bid), (char *)&method,
                    sizeof (sip_method_t), NULL, 0, NULL, 0, NULL, 0, NULL, 0,
                    (uchar_t *)hindex);
        }
        return (0);
}

/*
 * Add object to the connection cache object. Not checking for duplicates!!
 */
int
sip_add_conn_obj_cache(sip_conn_object_t obj, void *cobj)
{
        void                    **obj_val;
        sip_conn_obj_pvt_t      *pvt_data;
        sip_conn_cache_t        *xaction_list;
        sip_xaction_t           *sip_trans = (sip_xaction_t *)cobj;

        /*
         * Is already cached
         */
        if (sip_trans->sip_xaction_conn_obj != NULL) {
                if (sip_is_conn_obj_cache(sip_trans->sip_xaction_conn_obj,
                    (void *)sip_trans)) {
                        return (0);
                }
                /*
                 * Transaction has cached a different conn_obj, release it
                 */
                sip_del_conn_obj_cache(sip_trans->sip_xaction_conn_obj,
                    (void *)sip_trans);
        }

        xaction_list = malloc(sizeof (sip_conn_cache_t));
        if (xaction_list == NULL)
                return (ENOMEM);
        xaction_list->obj = cobj;
        xaction_list->next = xaction_list->prev = NULL;

        obj_val = (void *)obj;
        pvt_data = (sip_conn_obj_pvt_t *)*obj_val;
        if (pvt_data == NULL) {
                free(xaction_list);
                return (EINVAL);
        }
        (void) pthread_mutex_lock(&pvt_data->sip_conn_obj_cache_lock);

        if (pvt_data->sip_conn_obj_cache == NULL) {
                pvt_data->sip_conn_obj_cache = xaction_list;
        } else {
                xaction_list->next =  pvt_data->sip_conn_obj_cache;
                pvt_data->sip_conn_obj_cache->prev = xaction_list;
                pvt_data->sip_conn_obj_cache = xaction_list;
        }
        sip_refhold_conn(obj);
        sip_trans->sip_xaction_conn_obj = obj;
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_cache_lock);
        return (0);
}

/*
 * Walk thru the list of transactions that have cached this obj and
 * and return true if 'cobj' is one of them.
 */
static boolean_t
sip_is_conn_obj_cache(sip_conn_object_t obj, void *cobj)
{
        void                    **obj_val;
        sip_conn_obj_pvt_t      *pvt_data;
        sip_conn_cache_t        *xaction_list;
        sip_xaction_t           *trans;
        sip_xaction_t           *ctrans = (sip_xaction_t *)cobj;

        obj_val = (void *)obj;
        pvt_data = (sip_conn_obj_pvt_t *)*obj_val;
        if (pvt_data == NULL)
                return (B_FALSE);
        (void) pthread_mutex_lock(&pvt_data->sip_conn_obj_cache_lock);
        xaction_list = pvt_data->sip_conn_obj_cache;
        while (xaction_list != NULL) {
                trans = (sip_xaction_t *)xaction_list->obj;
                if (ctrans != trans) {
                        xaction_list = xaction_list->next;
                        continue;
                }
                (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_cache_lock);
                return (B_TRUE);
        }
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_cache_lock);
        return (B_FALSE);
}


/*
 * Walk thru the list of transactions that have cached this obj and
 * refrele the objs.
 */
void
sip_del_conn_obj_cache(sip_conn_object_t obj, void *cobj)
{
        void                    **obj_val;
        sip_conn_obj_pvt_t      *pvt_data;
        sip_conn_cache_t        *xaction_list;
        sip_conn_cache_t        *tmp_list;
        sip_xaction_t           *trans;
        sip_xaction_t           *ctrans = NULL;

        if (cobj != NULL)
                ctrans = (sip_xaction_t *)cobj;

        obj_val = (void *)obj;
        pvt_data = (sip_conn_obj_pvt_t *)*obj_val;
        if (pvt_data == NULL) { /* ASSERT FALSE if ctrans != NULL?? */
                if (ctrans != NULL) {
                        sip_refrele_conn(obj);
                        ctrans->sip_xaction_conn_obj = NULL;
                }
                return;
        }
        (void) pthread_mutex_lock(&pvt_data->sip_conn_obj_cache_lock);
        xaction_list = pvt_data->sip_conn_obj_cache;
        while (xaction_list != NULL) {
                tmp_list = xaction_list;
                trans = (sip_xaction_t *)xaction_list->obj;
                assert(trans != NULL);
                if (ctrans != NULL && ctrans != trans) {
                        xaction_list = xaction_list->next;
                        continue;
                }
                if (ctrans == NULL)
                        (void) pthread_mutex_lock(&trans->sip_xaction_mutex);
                assert(trans->sip_xaction_conn_obj == obj);
                sip_refrele_conn(obj);
                trans->sip_xaction_conn_obj = NULL;
                if (ctrans == NULL)
                        (void) pthread_mutex_unlock(&trans->sip_xaction_mutex);
                xaction_list = xaction_list->next;

                /*
                 * Take the obj out of the list
                 */
                if (tmp_list == pvt_data->sip_conn_obj_cache) {
                        if (xaction_list == NULL) {
                                pvt_data->sip_conn_obj_cache = NULL;
                        } else {
                                xaction_list->prev = NULL;
                                pvt_data->sip_conn_obj_cache = xaction_list;
                        }
                } else if (xaction_list == NULL) {
                        assert(tmp_list->prev != NULL);
                        tmp_list->prev->next = NULL;
                } else {
                        assert(tmp_list->prev != NULL);
                        tmp_list->prev->next = xaction_list;
                        xaction_list->prev = tmp_list->prev;
                }
                tmp_list->prev = NULL;
                tmp_list->next = NULL;
                tmp_list->obj = NULL;

                free(tmp_list);
        }
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_cache_lock);
}

/*
 * Check for a transaction match. Passed to sip_hash_find().
 */
boolean_t
sip_xaction_match(void *obj, void *hindex)
{
        sip_xaction_t   *tmp = (sip_xaction_t *)obj;

        tmp = (sip_xaction_t *)obj;

        if (SIP_IS_XACTION_TERMINATED(tmp->sip_xaction_state))
                return (B_FALSE);
        if (bcmp(tmp->sip_xaction_hash_digest, hindex,
            sizeof (tmp->sip_xaction_hash_digest)) == 0) {
                SIP_XACTION_REFCNT_INCR(tmp);
                return (B_TRUE);
        }
        return (B_FALSE);
}


/*
 * Find a transaction
 */
static sip_xaction_t *
sip_xaction_find(char *branchid, _sip_msg_t *msg, int which)
{
        sip_xaction_t           *tmp;
        uint16_t                hash_index[8];
        int                     hindex;
        sip_method_t            method;
        int                     error;
        sip_message_type_t      *sip_msg_info;

        sip_msg_info = msg->sip_msg_req_res;
        method = sip_get_callseq_method((sip_msg_t)msg, &error);
        if (error != 0)
                return (NULL);

        /*
         * If we are getting a ACK/CANCEL we need to match with the
         * corresponding INVITE, if any.
         */
        if (sip_msg_info->is_request && which == SIP_SERVER_TRANSACTION &&
            (method == ACK || method == CANCEL)) {
                method = INVITE;
        }
        if (sip_find_md5_digest(branchid, msg, hash_index, method) != 0)
                return (NULL);
        hindex = SIP_DIGEST_TO_HASH(hash_index);
        tmp = (sip_xaction_t *)sip_hash_find(sip_xaction_hash,
            (void *)hash_index, hindex, sip_xaction_match);
        return (tmp);
}

/*
 * create a transaction.
 */
static sip_xaction_t *
sip_xaction_create(sip_conn_object_t obj, _sip_msg_t *msg, char *branchid,
    int *error)
{
        sip_xaction_t           *trans;
        sip_message_type_t      *sip_msg_info;
        int                     state = 0;
        int                     prev_state = 0;
        sip_method_t            method;
        int                     ret;
        int                     timer1 = sip_timer_T1;
        int                     timer4 = sip_timer_T4;
        int                     timerd = sip_timer_TD;

        if (error != NULL)
                *error = 0;
        /*
         * Make sure we are not creating a transaction for
         * an ACK request.
         */
        trans = (sip_xaction_t *)malloc(sizeof (sip_xaction_t));
        if (trans == NULL) {
                if (error != NULL)
                        *error = ENOMEM;
                return (NULL);
        }
        bzero(trans, sizeof (sip_xaction_t));
        if (branchid == NULL) {
                trans->sip_xaction_branch_id = (char *)sip_branchid(NULL);
                if (trans->sip_xaction_branch_id == NULL) {
                        free(trans);
                        if (error != NULL)
                                *error = ENOMEM;
                        return (NULL);
                }
        } else {
                trans->sip_xaction_branch_id = (char *)malloc(strlen(branchid)
                    + 1);
                if (trans->sip_xaction_branch_id == NULL) {
                        free(trans);
                        if (error != NULL)
                                *error = ENOMEM;
                        return (NULL);
                }
                (void) strncpy(trans->sip_xaction_branch_id, branchid,
                    strlen(branchid));
                trans->sip_xaction_branch_id[strlen(branchid)] = '\0';
        }
        (void) pthread_mutex_init(&trans->sip_xaction_mutex, NULL);
        SIP_MSG_REFCNT_INCR(msg);
        trans->sip_xaction_orig_msg = msg;
        assert(msg->sip_msg_req_res != NULL);
        sip_msg_info = msg->sip_msg_req_res;
        if (sip_msg_info->is_request) {
                method = sip_msg_info->sip_req_method;
        } else {
                method = sip_get_callseq_method((sip_msg_t)msg, &ret);
                if (ret != 0) {
                        free(trans->sip_xaction_branch_id);
                        free(trans);
                        if (error != NULL)
                                *error = ret;
                        return (NULL);
                }
                if (method == INVITE)
                        state = SIP_SRV_INV_PROCEEDING;
                else
                        state = SIP_SRV_TRYING;
        }
        trans->sip_xaction_method = method;
        trans->sip_xaction_state = state;

        /*
         * Get connection object specific timeouts, if present
         */
        if (sip_conn_timer1 != NULL)
                timer1 = sip_conn_timer1(obj);
        if (sip_conn_timer4 != NULL)
                timer4 = sip_conn_timer4(obj);
        if (sip_conn_timerd != NULL)
                timerd = sip_conn_timerd(obj);

        SIP_INIT_TIMER(trans->sip_xaction_TA, 2 * timer1);
        SIP_INIT_TIMER(trans->sip_xaction_TB, 64 * timer1)
        SIP_INIT_TIMER(trans->sip_xaction_TD,  timerd);
        SIP_INIT_TIMER(trans->sip_xaction_TE, timer1);
        SIP_INIT_TIMER(trans->sip_xaction_TF, 64 * timer1);
        SIP_INIT_TIMER(trans->sip_xaction_TG, 2 * timer1);
        SIP_INIT_TIMER(trans->sip_xaction_TH, 64 * timer1);
        SIP_INIT_TIMER(trans->sip_xaction_TI, timer4);
        SIP_INIT_TIMER(trans->sip_xaction_TJ, 64 * timer1);
        SIP_INIT_TIMER(trans->sip_xaction_TK, timer4);

        if ((ret = sip_xaction_add(trans, branchid, msg, method)) != 0) {
                (void) pthread_mutex_destroy(&trans->sip_xaction_mutex);
                free(trans->sip_xaction_branch_id);
                free(trans);
                if (error != NULL)
                        *error = ret;
                return (NULL);
        }
        if (sip_xaction_ulp_state_cb != NULL &&
            prev_state != trans->sip_xaction_state) {
                sip_xaction_ulp_state_cb((sip_transaction_t)trans,
                    (sip_msg_t)msg, prev_state, trans->sip_xaction_state);
        }
        return (trans);
}

/*
 * Find a transaction, create if asked for
 */
sip_xaction_t *
sip_xaction_get(sip_conn_object_t obj, sip_msg_t msg, boolean_t create,
    int which, int *error)
{
        char                    *branchid;
        sip_xaction_t           *sip_trans;
        _sip_msg_t              *_msg;
        sip_message_type_t      *sip_msg_info;

        if (error != NULL)
                *error = 0;

        _msg = (_sip_msg_t *)msg;
        sip_msg_info = ((_sip_msg_t *)msg)->sip_msg_req_res;

        branchid = sip_get_branchid(msg, NULL);
        sip_trans = sip_xaction_find(branchid, _msg, which);
        if (sip_trans == NULL && create) {
                /*
                 * If we are sending a request, must be conformant to RFC 3261.
                 */
                if (sip_msg_info->is_request &&
                    (branchid == NULL || strncmp(branchid,
                    RFC_3261_BRANCH, strlen(RFC_3261_BRANCH) != 0))) {
                        if (error != NULL)
                                *error = EINVAL;
                        if (branchid != NULL)
                                free(branchid);
                        return (NULL);
                }
                sip_trans = sip_xaction_create(obj, _msg, branchid, error);
                if (sip_trans != NULL)
                        SIP_XACTION_REFCNT_INCR(sip_trans);
        }
        if (branchid != NULL)
                free(branchid);
        return (sip_trans);
}


/*
 * Delete a transaction if the reference count is 0. Passed to
 * sip_hash_delete().
 */
boolean_t
sip_xaction_remove(void *obj, void *hindex, int *found)
{
        sip_xaction_t   *tmp = (sip_xaction_t *)obj;
        int             count = 0;
        sip_msg_chain_t *msg_chain;
        sip_msg_chain_t *nmsg_chain;

        *found = 0;
        tmp = (sip_xaction_t *)obj;
        (void) pthread_mutex_lock(&tmp->sip_xaction_mutex);
        if (bcmp(tmp->sip_xaction_hash_digest, hindex,
            sizeof (tmp->sip_xaction_hash_digest)) == 0) {
                *found = 1;
                if (tmp->sip_xaction_ref_cnt != 0) {
                        (void) pthread_mutex_unlock(&tmp->sip_xaction_mutex);
                        return (B_FALSE);
                }
                (void) pthread_mutex_destroy(&tmp->sip_xaction_mutex);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TA);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TB);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TD);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TE);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TF);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TG);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TH);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TI);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TJ);
                SIP_CANCEL_TIMER(tmp->sip_xaction_TK);
                sip_write_to_log((void *)tmp, SIP_TRANSACTION_LOG, NULL, 0);
                free(tmp->sip_xaction_branch_id);
                if (tmp->sip_xaction_last_msg != NULL) {
                        SIP_MSG_REFCNT_DECR(tmp->sip_xaction_last_msg);
                        tmp->sip_xaction_last_msg = NULL;
                }
                if (tmp->sip_xaction_orig_msg != NULL) {
                        SIP_MSG_REFCNT_DECR(tmp->sip_xaction_orig_msg);
                        tmp->sip_xaction_orig_msg = NULL;
                }
                if (tmp->sip_xaction_conn_obj != NULL) {
                        sip_del_conn_obj_cache(tmp->sip_xaction_conn_obj,
                            (void *)tmp);
                }
                /*
                 * If the transaction logging is disabled before we could
                 * write the captured messages into the transaction log, then
                 * we need to free those captured messsages
                 */
                for (count = 0; count <= SIP_SRV_NONINV_TERMINATED; count++) {
                        msg_chain = tmp->sip_xaction_log[count].sip_msgs;
                        while (msg_chain != NULL) {
                                nmsg_chain = msg_chain->next;
                                if (msg_chain->sip_msg != NULL)
                                        free(msg_chain->sip_msg);
                                free(msg_chain);
                                msg_chain = nmsg_chain;
                        }
                }
                free(tmp);
                return (B_TRUE);
        }
        (void) pthread_mutex_unlock(&tmp->sip_xaction_mutex);
        return (B_FALSE);
}

/*
 * Delete a SIP transaction
 */
void
sip_xaction_delete(sip_xaction_t *trans)
{
        int     hindex;

        (void) pthread_mutex_lock(&trans->sip_xaction_mutex);
        hindex = SIP_DIGEST_TO_HASH(trans->sip_xaction_hash_digest);
        if (trans->sip_xaction_ref_cnt != 0) {
                (void) pthread_mutex_unlock(&trans->sip_xaction_mutex);
                return;
        }
        (void) pthread_mutex_unlock(&trans->sip_xaction_mutex);
        sip_hash_delete(sip_xaction_hash, trans->sip_xaction_hash_digest,
            hindex, sip_xaction_remove);
}

/*
 * Add a SIP transaction into the hash list.
 */
int
sip_xaction_add(sip_xaction_t *trans, char *branchid, _sip_msg_t *msg,
    sip_method_t method)
{
        uint16_t        hash_index[8];

        if (sip_find_md5_digest(branchid, msg, hash_index, method) != 0)
                return (EINVAL);

        /*
         * trans is not in the list as yet, so no need to hold the lock
         */
        bcopy(hash_index, trans->sip_xaction_hash_digest, sizeof (hash_index));

        if (sip_hash_add(sip_xaction_hash, (void *)trans,
            SIP_DIGEST_TO_HASH(hash_index)) != 0) {
                return (ENOMEM);
        }
        return (0);
}


/*
 * Given a state, return the  string - This is mostly for debug purposes
 */
char *
sip_get_xaction_state(int state)
{
        switch (state) {
                case SIP_NEW_TRANSACTION:
                        return ("SIP_NEW_TRANSACTION");
                case SIP_CLNT_CALLING:
                        return ("SIP_CLNT_CALLING");
                case SIP_CLNT_INV_PROCEEDING:
                        return ("SIP_CLNT_INV_PROCEEDING");
                case SIP_CLNT_INV_TERMINATED:
                        return ("SIP_CLNT_INV_TERMINATED");
                case SIP_CLNT_INV_COMPLETED:
                        return ("SIP_CLNT_INV_COMPLETED");
                case SIP_CLNT_TRYING:
                        return ("SIP_CLNT_TRYING");
                case SIP_CLNT_NONINV_PROCEEDING:
                        return ("SIP_CLNT_NONINV_PROCEEDING");
                case SIP_CLNT_NONINV_TERMINATED:
                        return ("SIP_CLNT_NONINV_TERMINATED");
                case SIP_CLNT_NONINV_COMPLETED:
                        return ("SIP_CLNT_NONINV_COMPLETED");
                case SIP_SRV_INV_PROCEEDING:
                        return ("SIP_SRV_INV_PROCEEDING");
                case SIP_SRV_INV_COMPLETED:
                        return ("SIP_SRV_INV_COMPLETED");
                case SIP_SRV_CONFIRMED:
                        return ("SIP_SRV_CONFIRMED");
                case SIP_SRV_INV_TERMINATED:
                        return ("SIP_SRV_INV_TERMINATED");
                case SIP_SRV_TRYING:
                        return ("SIP_SRV_TRYING");
                case SIP_SRV_NONINV_PROCEEDING:
                        return ("SIP_SRV_NONINV_PROCEEDING");
                case SIP_SRV_NONINV_COMPLETED:
                        return ("SIP_SRV_NONINV_COMPLETED");
                case SIP_SRV_NONINV_TERMINATED:
                        return ("SIP_SRV_NONINV_TERMINATED");
                default :
                        return ("UNKNOWN");
        }
}

/*
 * Initialize the hash table etc.
 */
void
sip_xaction_init(int (*ulp_trans_err)(sip_transaction_t, int, void *),
    void (*ulp_state_cb)(sip_transaction_t, sip_msg_t, int, int))
{
        int     cnt;

        for (cnt = 0; cnt < SIP_HASH_SZ; cnt++) {
                sip_xaction_hash[cnt].hash_count = 0;
                sip_xaction_hash[cnt].hash_head = NULL;
                sip_xaction_hash[cnt].hash_tail = NULL;
                (void) pthread_mutex_init(
                    &sip_xaction_hash[cnt].sip_hash_mutex, NULL);
        }
        if (ulp_trans_err != NULL)
                sip_xaction_ulp_trans_err = ulp_trans_err;
        if (ulp_state_cb != NULL)
                sip_xaction_ulp_state_cb = ulp_state_cb;
}