/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <assert.h>
#include <errno.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sip.h>

#include "sip_msg.h"
#include "sip_miscdefs.h"
#include "sip_parse_generic.h"

sip_methods_t sip_methods[MAX_SIP_METHODS] = {
        {"UNKNOWN", 7},
        {"INVITE", 6},
        {"ACK", 3},
        {"OPTIONS", 7},
        {"BYE", 3},
        {"CANCEL", 6},
        {"REGISTER", 8},
        {"REFER", 5},
        {"INFO", 4},
        {"SUBSCRIBE", 9},
        {"NOTIFY", 6},
        {"PRACK", 5}
};

/*
 * Built-In Header function table
 */
sip_header_function_t sip_header_function_table[] = {
        {"Unknown", NULL, sip_parse_unknown_header, NULL, NULL, NULL},
        {"CONTACT", "m", sip_parse_cftr_header, NULL, NULL,
        sip_free_cftr_header},
        {"FROM", "F", sip_parse_cftr_header, NULL, NULL, sip_free_cftr_header},
        {"TO", "T", sip_parse_cftr_header, NULL, NULL, sip_free_cftr_header},
        {"CONTENT-LENGTH", "l", sip_parse_clen_header, NULL, NULL,
        sip_free_phdr},
        {"CONTENT-TYPE", "c", sip_parse_ctype_header, NULL, NULL,
        sip_free_phdr},
        {"CALL-ID", "i", sip_parse_cid_header, NULL, NULL, sip_free_phdr},
        {"CSEQ", NULL, sip_parse_cseq_header, NULL, NULL, sip_free_phdr},
        {"VIA", "v", sip_parse_via_header, NULL, NULL, sip_free_phdr},
        {"Max-Forwards", NULL, sip_parse_maxf_header, NULL, NULL,
        sip_free_phdr},
        {"RECORD-ROUTE", NULL, sip_parse_cftr_header, NULL, NULL,
        sip_free_cftr_header},
        {"ROUTE", NULL, sip_parse_cftr_header, NULL, NULL,
        sip_free_cftr_header},
        {"ACCEPT", NULL, sip_parse_acpt_header, NULL, NULL, sip_free_phdr},
        {"ACCEPT-ENCODING", NULL, sip_parse_acpt_encode_header, NULL, NULL,
        sip_free_phdr},
        {"ACCEPT-LANGUAGE", NULL, sip_parse_acpt_lang_header, NULL, NULL,
        sip_free_phdr},
        {"ALERT-INFO", NULL, sip_parse_alert_header, NULL, NULL, sip_free_phdr},
        {"ALLOW", NULL, sip_parse_allow_header, NULL, NULL, sip_free_phdr},
        {"CALL-INFO", NULL, sip_parse_callinfo_header, NULL, NULL,
        sip_free_phdr},
        {"CONTENT-DISPOSITION", NULL, sip_parse_contentdis_header, NULL, NULL,
        sip_free_phdr},
        {"CONTENT-ENCODING", "e", sip_parse_contentencode_header, NULL, NULL,
        sip_free_phdr},
        {"CONTENT-LANGUAGE", NULL, sip_parse_contentlang_header, NULL, NULL,
        sip_free_phdr},
        {"DATE", NULL, sip_parse_date_header, NULL, NULL, sip_free_phdr},
        {"ERROR-INFO", NULL, sip_parse_errorinfo_header, NULL, NULL,
        sip_free_phdr},
        {"EXPIRES", NULL, sip_parse_expire_header, NULL, NULL, sip_free_phdr},
        {"IN-REPLY-TO", NULL, sip_parse_inreplyto_header, NULL, NULL,
        sip_free_phdr},
        {"MIN-EXPIRES", NULL, sip_parse_minexpire_header, NULL, NULL,
        sip_free_phdr},
        {"MIME-VERSION", NULL, sip_parse_mimeversion_header, NULL, NULL,
        sip_free_phdr},
        {"ORGANIZATION", NULL, sip_parse_org_header, NULL, NULL, sip_free_phdr},
        {"PRIORITY", NULL, sip_parse_priority_header, NULL, NULL,
        sip_free_phdr},
        {"REQUIRE", NULL, sip_parse_require_header, NULL, NULL, sip_free_phdr},
        {"REPLY-TO", NULL, sip_parse_replyto_header, NULL, NULL, sip_free_phdr},
        {"RETRY-AFTER", NULL, sip_parse_retryaft_header, NULL, NULL,
        sip_free_phdr},
        {"SERVER", NULL, sip_parse_server_header, NULL, NULL, sip_free_phdr},
        {"SUBJECT", "s", sip_parse_subject_header, NULL, NULL, sip_free_phdr},
        {"TIMESTAMP", NULL, sip_parse_timestamp_header, NULL, NULL,
        sip_free_phdr},
        {"UNSUPPORTED", NULL, sip_parse_usupport_header, NULL, NULL,
        sip_free_phdr},
        {"SUPPORTED", "k", sip_parse_support_header, NULL, NULL, sip_free_phdr},
        {"USER-AGENT", NULL, sip_parse_useragt_header, NULL, NULL,
        sip_free_phdr},
        {"WARNING", NULL, sip_parse_warn_header, NULL, NULL, sip_free_phdr},
        {"ALLOW-EVENTS", "u", sip_parse_allow_events_header, NULL, NULL,
        sip_free_phdr},
        {"EVENT", "o", sip_parse_event_header, NULL, NULL, sip_free_phdr},
        {"SUBSCRIPTION-STATE", NULL, sip_parse_substate_header, NULL, NULL,
        sip_free_phdr},
        {"AUTHORIZATION", NULL, sip_parse_author_header, NULL, NULL,
        sip_free_phdr},
        {"AUTHENTICATION-INFO", NULL, sip_parse_ainfo_header, NULL, NULL,
        sip_free_phdr},
        {"PROXY-AUTHORIZATION", NULL, sip_parse_pauthor_header, NULL, NULL,
        sip_free_phdr},
        {"PROXY-AUTHENTICATE", NULL, sip_parse_pauthen_header, NULL, NULL,
        sip_free_phdr},
        {"PROXY-REQUIRE", NULL, sip_parse_preq_header, NULL, NULL,
        sip_free_phdr},
        {"WWW-AUTHENTICATE", NULL, sip_parse_wauthen_header, NULL, NULL,
        sip_free_phdr},
        {"RSEQ", NULL, sip_parse_rseq, NULL, NULL, sip_free_phdr},
        {"RACK", NULL, sip_parse_rack, NULL, NULL, sip_free_phdr},
        {"P-ASSERTED-IDENTITY", NULL, sip_parse_passertedid, NULL, NULL,
        sip_free_phdr},
        {"P-PREFERRED-IDENTITY", NULL, sip_parse_ppreferredid, NULL, NULL,
        sip_free_phdr},
        {"PRIVACY", NULL, sip_parse_privacy_header, NULL, NULL, sip_free_phdr},
        {NULL, NULL, NULL, NULL, NULL, NULL},
};

#define MAX_SIP_HEADERS \
        sizeof (sip_header_function_table) / sizeof (sip_header_function_t)

/*
 * External/application provided function table
 */
sip_header_function_t *sip_header_function_table_external = NULL;

/*
 * Free parameter list
 */
static void
sip_free_params(sip_param_t *param_list)
{
        sip_param_t *param, *next_param;

        param = param_list;

        while (param != NULL) {
                next_param = param->param_next;
                free(param);
                param = next_param;
        }
}

/*
 * Common header free routine
 */
void
sip_free_phdr(sip_parsed_header_t *header)
{
        sip_hdr_value_t *value;
        sip_hdr_value_t *next_value;

        if (header == NULL)
                return;
        value = (sip_hdr_value_t *)header->value;
        while (value != NULL) {
                sip_free_params(value->sip_param_list);
                next_value = value->sip_next_value;
                free(value);
                value = next_value;
        }
        free(header);
}

/*
 * Free Contact/From/To header
 */
void
sip_free_cftr_header(sip_parsed_header_t *header)
{
        sip_hdr_value_t *value;
        sip_hdr_value_t *next_value;

        if (header == NULL)
                return;
        value = (sip_hdr_value_t *)header->value;
        while (value != NULL) {
                next_value = value->sip_next_value;
                sip_free_params(value->sip_param_list);
                if (value->cftr_name != NULL)
                        free(value->cftr_name);
                if (value->sip_value_parsed_uri != NULL) {
                        sip_free_parsed_uri(value->sip_value_parsed_uri);
                        value->sip_value_parsed_uri = NULL;
                }
                free(value);
                value = next_value;
        }
        free(header);
}

/*
 * Return new header
 */
_sip_header_t *
sip_new_header(int header_size)
{
        _sip_header_t *new_header;

        new_header = calloc(1, sizeof (_sip_header_t));
        if (new_header == NULL)
                return (NULL);

        /*
         * We are using snprintf which adds a null character
         * so allocate an extra byte which is not part of
         * the message header
         */
        new_header->sip_hdr_start = calloc(1, header_size + 1);
        if (new_header->sip_hdr_start == NULL) {
                free(new_header);
                return (NULL);
        }
        new_header->sip_hdr_end = new_header->sip_hdr_start + header_size;
        new_header->sip_hdr_current = new_header->sip_hdr_start;
        new_header->sip_hdr_allocated = B_TRUE;
        return (new_header);
}

/*
 * Free the given header
 */
void
sip_free_header(_sip_header_t *sip_header)
{
        if (sip_header->sip_hdr_allocated) {
                assert(sip_header->sip_hdr_start != NULL);
                free(sip_header->sip_hdr_start);
        }
        if (sip_header->sip_hdr_parsed != NULL) {
                assert(sip_header->sip_header_functions != NULL);
                if (sip_header->sip_header_functions->header_free != NULL) {
                        sip_header->sip_header_functions->header_free(
                            sip_header->sip_hdr_parsed);
                }
        }
        free(sip_header);
}

/*
 * Return a copy of the header passed in.
 */
_sip_header_t *
sip_dup_header(_sip_header_t *from)
{
        size_t          hdr_size;
        _sip_header_t   *to;

        hdr_size = from->sip_hdr_end - from->sip_hdr_start;
        to = sip_new_header(hdr_size);
        if (to == NULL)
                return (NULL);
        if (from->sip_header_state == SIP_HEADER_DELETED_VAL) {
                to->sip_hdr_end = to->sip_hdr_start +
                    sip_copy_values(to->sip_hdr_start, from);
        } else {
                (void) memcpy(to->sip_hdr_start, from->sip_hdr_start, hdr_size);
                to->sip_hdr_end = to->sip_hdr_start + hdr_size;
        }
        to->sip_header_functions = from->sip_header_functions;
        return (to);
}

/*
 * Copy header with extra_param, if any, to sip_msg
 */
int
_sip_copy_header(_sip_msg_t *sip_msg, _sip_header_t *header, char *extra_param,
    boolean_t skip_crlf)
{
        _sip_header_t   *new_header;
        int             hdrlen;
        int             extra_len = 0;
        int             ncrlf = 0;
        char            *p;

#ifdef  __solaris__
        assert(mutex_held(&sip_msg->sip_msg_mutex));
#endif
        if (extra_param != NULL) {
                extra_len = SIP_SPACE_LEN + sizeof (char) + SIP_SPACE_LEN +
                    strlen(extra_param);
        }
        /*
         * Just take one if there are more, i.e. if this is the last header
         * before the content.
         */
        if (skip_crlf) {
                if (header->sip_hdr_end - strlen(SIP_CRLF) <=
                    header->sip_hdr_start) {
                        goto proceed;
                }
                p = header->sip_hdr_end - strlen(SIP_CRLF);
                while (strncmp(SIP_CRLF, p, strlen(SIP_CRLF)) == 0) {
                        ncrlf++;
                        if (p - strlen(SIP_CRLF) < header->sip_hdr_start)
                                break;
                        p -= strlen(SIP_CRLF);
                }
                /*
                 * Take one CRLF.
                 */
                ncrlf = (ncrlf - 1) * strlen(SIP_CRLF);
        }
proceed:
        hdrlen = header->sip_hdr_end - header->sip_hdr_start - ncrlf;
        new_header = sip_new_header(hdrlen + extra_len);
        if (new_header == NULL)
                return (ENOMEM);
        if (header->sip_header_state == SIP_HEADER_DELETED_VAL) {
                int     len;

                len = sip_copy_values(new_header->sip_hdr_start, header);
                new_header->sip_hdr_end = new_header->sip_hdr_start + len;
                hdrlen = hdrlen - len + extra_len;
        } else {
                (void) memcpy(new_header->sip_hdr_start, header->sip_hdr_start,
                    hdrlen);
                new_header->sip_hdr_end = new_header->sip_hdr_start + hdrlen;
                hdrlen = extra_len;
        }
        if (extra_param != NULL) {
                /*
                 * Find CR
                 */
                if (sip_find_cr(new_header) != 0) {
                        sip_free_header(new_header);
                        return (EINVAL);
                }
                hdrlen += new_header->sip_hdr_end - new_header->sip_hdr_current;
                (void) snprintf(new_header->sip_hdr_current, hdrlen + 1,
                    " %c %s%s", SIP_SEMI, extra_param, SIP_CRLF);
        }

        new_header->sip_hdr_end += extra_len;
        new_header->sip_header_functions = header->sip_header_functions;
        _sip_add_header(sip_msg, new_header, B_TRUE, B_FALSE, NULL);
        return (0);
}

/*
 * Copy all "header_name" headers from _old_msg to _new_msg
 */
int
_sip_find_and_copy_all_header(_sip_msg_t *_old_msg, _sip_msg_t *_new_msg,
    char *header_name)
{
        _sip_header_t   *header;
        int             ret = 0;

        if (_old_msg == NULL || _new_msg == NULL)
                return (EINVAL);
#ifdef  __solaris__
        assert(mutex_held(&_old_msg->sip_msg_mutex));
#endif
        if (_old_msg != _new_msg)
                (void) pthread_mutex_lock(&_new_msg->sip_msg_mutex);
        header = sip_search_for_header(_old_msg, header_name, NULL);
        while (header != NULL) {
                ret = _sip_copy_header(_new_msg, header, NULL, B_TRUE);
                if (ret != 0)
                        break;
                header = sip_search_for_header(_old_msg, header_name, header);
        }
        if (_old_msg != _new_msg)
                (void) pthread_mutex_unlock(&_new_msg->sip_msg_mutex);
        return (ret);
}

/*
 * Copy header_name from _old_msg to _new_msg with extra_parm.
 */
int
_sip_find_and_copy_header(sip_msg_t _old_msg, sip_msg_t _new_msg,
    char *header_name, char *extra_param, boolean_t lock_newmsg)
{
        _sip_header_t   *header;
        int             ret;

        if (_old_msg == NULL || _new_msg == NULL)
                return (EINVAL);
#ifdef  __solaris__
        assert(mutex_held(&_old_msg->sip_msg_mutex));
#endif
        header = sip_search_for_header(_old_msg, header_name, NULL);
        if (header == NULL)
                return (EINVAL);
        if (lock_newmsg)
                (void) pthread_mutex_lock(&_new_msg->sip_msg_mutex);
        ret = _sip_copy_header(_new_msg, header, extra_param, B_TRUE);
        if (lock_newmsg)
                (void) pthread_mutex_unlock(&_new_msg->sip_msg_mutex);
        return (ret);
}

/*
 * Copy all headers from old_msg to new_msg
 */
int
sip_copy_all_headers(sip_msg_t old_msg, sip_msg_t new_msg)
{
        _sip_header_t   *header;
        _sip_msg_t      *_old_msg;
        _sip_msg_t      *_new_msg;
        int             ret = 0;

        if (old_msg == NULL || new_msg == NULL)
                return (EINVAL);
        _old_msg = (_sip_msg_t *)old_msg;
        _new_msg = (_sip_msg_t *)new_msg;

        (void) pthread_mutex_lock(&_old_msg->sip_msg_mutex);
        (void) pthread_mutex_lock(&_new_msg->sip_msg_mutex);
        header = sip_search_for_header(_old_msg, NULL, NULL);
        while (header != NULL) {
                ret = _sip_copy_header(_new_msg, header, NULL, B_FALSE);
                if (ret != 0)
                        goto done;
                header = sip_search_for_header(_old_msg, NULL, header);
        }
done:
        (void) pthread_mutex_unlock(&_new_msg->sip_msg_mutex);
        (void) pthread_mutex_unlock(&_old_msg->sip_msg_mutex);
        return (ret);
}

/*
 * Copy start line from msg to sip_msg
 */
int
sip_copy_start_line(sip_msg_t msg, sip_msg_t sip_msg)
{
        int             len;
        _sip_header_t   *new_header;
        _sip_msg_t      *_old_msg;
        _sip_msg_t      *_sip_msg;

        if (msg == NULL || sip_msg == NULL)
                return (EINVAL);
        _old_msg = (_sip_msg_t *)msg;
        _sip_msg = (_sip_msg_t *)sip_msg;

        (void) pthread_mutex_lock(&_old_msg->sip_msg_mutex);
        if (_old_msg->sip_msg_start_line == NULL) {
                (void) pthread_mutex_unlock(&_old_msg->sip_msg_mutex);
                return (EINVAL);
        }
        len = _old_msg->sip_msg_start_line->sip_hdr_end -
            _old_msg->sip_msg_start_line->sip_hdr_start;
        new_header = sip_new_header(len);
        if (new_header == NULL) {
                (void) pthread_mutex_unlock(&_old_msg->sip_msg_mutex);
                return (ENOMEM);
        }
        new_header->sip_hdr_sipmsg = _sip_msg;
        (void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
        _sip_msg->sip_msg_start_line = new_header;
        _sip_msg->sip_msg_len = len;
        (void) strncpy(_sip_msg->sip_msg_start_line->sip_hdr_start,
            _old_msg->sip_msg_start_line->sip_hdr_start, len);
        (void) sip_parse_first_line(_sip_msg->sip_msg_start_line,
            &_sip_msg->sip_msg_req_res);
        (void) pthread_mutex_unlock(&_old_msg->sip_msg_mutex);
        (void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
        return (0);
}

/*
 * Delete start line from sip_msg
 */
int
sip_delete_start_line_locked(_sip_msg_t *_sip_msg)
{
        _sip_header_t   *header;
        _sip_header_t   *next_header;

        if (_sip_msg->sip_msg_start_line == NULL)
                return (EINVAL);

        header = _sip_msg->sip_msg_start_line;
        while (header != NULL) {
                next_header = header->sip_hdr_next;
                _sip_msg->sip_msg_len -= (header->sip_hdr_end -
                    header->sip_hdr_start);
                sip_free_header(header);
                header = next_header;
        }
        _sip_msg->sip_msg_start_line = NULL;

        /*
         * Also delete the sip_msg_req_res info since we don't have a start
         * line.
         */
        while (_sip_msg->sip_msg_req_res != NULL) {
                sip_message_type_t      *sip_msg_type_ptr;

                sip_msg_type_ptr = _sip_msg->sip_msg_req_res->sip_next;
                if (_sip_msg->sip_msg_req_res->is_request) {
                        sip_request_t   *reqline;

                        reqline = &_sip_msg->sip_msg_req_res->U.sip_request;
                        if (reqline->sip_parse_uri != NULL) {
                                sip_free_parsed_uri(reqline->sip_parse_uri);
                                reqline->sip_parse_uri = NULL;
                        }
                }
                free(_sip_msg->sip_msg_req_res);
                _sip_msg->sip_msg_req_res = sip_msg_type_ptr;
        }
        return (0);
}


/*
 * Delete start line from sip_msg
 */
int
sip_delete_start_line(sip_msg_t sip_msg)
{
        _sip_msg_t      *_sip_msg;
        int             ret;

        if (sip_msg == NULL)
                return (EINVAL);

        _sip_msg = (_sip_msg_t *)sip_msg;
        (void) pthread_mutex_lock(&_sip_msg->sip_msg_mutex);
        ret = sip_delete_start_line_locked(_sip_msg);
        (void) pthread_mutex_unlock(&_sip_msg->sip_msg_mutex);

        return (ret);
}

/*
 * Delete all headers from _sip_msg
 */
void
sip_delete_all_headers(_sip_msg_t *_sip_msg)
{
        _sip_header_t *header;

#ifdef  __solaris__
        assert(mutex_held(&_sip_msg->sip_msg_mutex));
#endif

        header = _sip_msg->sip_msg_headers_start;
        while (header != NULL) {
                _sip_header_t *next_header;
                next_header = header->sip_hdr_next;
                sip_free_header(header);
                header = next_header;
        }
        _sip_msg->sip_msg_headers_start = NULL;
        _sip_msg->sip_msg_headers_end = NULL;
}

/*
 * Delete and free the named header. If header_name is null
 * free all headers.
 */
void
sip_delete_headers(sip_msg_t sip_msg, char *header_name)
{
        _sip_header_t *header;
        _sip_msg_t *_sip_msg;

        _sip_msg = (_sip_msg_t *)sip_msg;
#ifdef  __solaris__
        assert(mutex_held(&_sip_msg->sip_msg_mutex));
#endif
        header = sip_search_for_header(_sip_msg, header_name, NULL);
        if (header == NULL)
                return;
        while (header != NULL) {
                if (_sip_msg->sip_msg_headers_start == header) {
                        _sip_msg->sip_msg_headers_start = header->sip_hdr_next;
                } else {
                        header->sip_hdr_prev->sip_hdr_next =
                            header->sip_hdr_next;
                }
                if (_sip_msg->sip_msg_headers_end == header) {
                        _sip_msg->sip_msg_headers_end = header->sip_hdr_prev;
                } else {
                        header->sip_hdr_next->sip_hdr_prev =
                            header->sip_hdr_prev;
                }
                sip_free_header(header);
                if (header_name != NULL)
                        return;
                else
                        header = sip_search_for_header(_sip_msg, NULL, NULL);
        }
}

/*
 * Add a header to sip_msg. If header_name is provided then the new header
 * is added before that header, if first is set, or after. If append is
 * set, then the header is added to the end of the header list.
 */
void
_sip_add_header(_sip_msg_t *sip_msg, _sip_header_t *new_header,
    boolean_t append, boolean_t first, char *header_name)
{
        _sip_header_t   *header = NULL;

        if (sip_msg == NULL || new_header == NULL)
                return;
#ifdef  __solaris__
        assert(mutex_held(&sip_msg->sip_msg_mutex));
#endif
        new_header->sip_hdr_sipmsg = sip_msg;
        if (header_name != NULL) {
                _sip_header_t   *header_tmp;

                header = sip_search_for_header(sip_msg, header_name, NULL);
                header_tmp = header;
                if (!first) {
                        while (header != NULL) {
                                header_tmp = header;
                                header = sip_search_for_header(sip_msg,
                                    header_name, header);
                        }
                }
                header = header_tmp;
                if (header == NULL)
                        append =  B_TRUE;
        }

        if (header != NULL) {
                if (append) {
                        new_header->sip_hdr_prev = header;
                        if (sip_msg->sip_msg_headers_end == header) {
                                sip_msg->sip_msg_headers_end = new_header;
                                new_header->sip_hdr_next = NULL;
                        } else {
                                header->sip_hdr_next->sip_hdr_prev = new_header;
                                new_header->sip_hdr_next = header->sip_hdr_next;
                        }
                        header->sip_hdr_next = new_header;
                } else {
                        new_header->sip_hdr_next = header;
                        if (sip_msg->sip_msg_headers_start == header) {
                                sip_msg->sip_msg_headers_start = new_header;
                                new_header->sip_hdr_prev = NULL;
                        } else {
                                header->sip_hdr_prev->sip_hdr_next = new_header;
                                new_header->sip_hdr_prev = header->sip_hdr_prev;
                        }
                        header->sip_hdr_prev = new_header;
                }
        } else {
                if (append) {
                        if (sip_msg->sip_msg_headers_end != NULL) {
                                sip_msg->sip_msg_headers_end->sip_hdr_next =
                                    new_header;
                        } else {
                                sip_msg->sip_msg_headers_start = new_header;
                        }
                        new_header->sip_hdr_prev =
                            sip_msg->sip_msg_headers_end;
                        new_header->sip_hdr_next = NULL;
                        sip_msg->sip_msg_headers_end = new_header;
                } else {
                        if (sip_msg->sip_msg_headers_start != NULL) {
                                sip_msg->sip_msg_headers_start->sip_hdr_prev =
                                    new_header;
                        } else {
                                sip_msg->sip_msg_headers_end = new_header;
                        }
                        new_header->sip_hdr_next =
                            sip_msg->sip_msg_headers_start;
                        new_header->sip_hdr_prev = NULL;
                        sip_msg->sip_msg_headers_start = new_header;
                }
        }
        sip_msg->sip_msg_len += new_header->sip_hdr_end -
            new_header->sip_hdr_start;
}

/*
 * Scan through the function table and return the entry for the given header
 * type.
 */
sip_header_function_t *
_sip_get_header_functions(sip_header_function_t *sip_header_function_table,
    _sip_header_t *sip_header, char *header_name)
{
        int     len;
        int     i = 0;

        if (sip_header == NULL && header_name == NULL)
                return (NULL);

        /*
         * If header_name is NULL we first have to locate the name
         */
        if (header_name == NULL) {
                if (sip_skip_white_space(sip_header) != 0) {
                        return (NULL);
                }
                header_name = sip_header->sip_hdr_current;
                if (sip_find_separator(sip_header, SIP_HCOLON, 0,
                    0, B_FALSE) != 0) {
                        return (NULL);
                }
                len = sip_header->sip_hdr_current - header_name;
        } else {
                len = strlen(header_name);
        }

        if (len > 0) {
                while (sip_header_function_table[i].header_name != NULL ||
                    sip_header_function_table[i].header_short_name != NULL) {
                        if (sip_header_function_table[i].header_name != NULL &&
                            len ==
                            strlen(sip_header_function_table[i].header_name)) {
                                if (strncasecmp(header_name,
                                    sip_header_function_table[i].
                                    header_name, len) == 0) {
                                        break;
                                }
                        } else if (sip_header_function_table[i].
                            header_short_name != NULL && len ==
                            strlen(sip_header_function_table[i].
                            header_short_name)) {
                                if (strncasecmp(header_name,
                                    sip_header_function_table[i].
                                    header_short_name, len) == 0) {
                                        break;
                                }
                        }
                        i++;
                }
        }

        if (sip_header != NULL)
                sip_header->sip_hdr_current = sip_header->sip_hdr_start;
        if (sip_header_function_table[i].header_name == NULL)
                return (NULL);
        return (&sip_header_function_table[i]);
}

/*
 * Return the entry from the function table for the given header
 */
sip_header_function_t *
sip_get_header_functions(_sip_header_t *sip_header, char *header_name)
{
        sip_header_function_t   *func;
        sip_header_function_t   *header_f_table = NULL;

        if (sip_header_function_table_external != NULL) {
                header_f_table = _sip_get_header_functions(
                    sip_header_function_table_external,
                    sip_header, header_name);
                if (header_f_table != NULL)
                        return (header_f_table);
        }
        func = _sip_get_header_functions(sip_header_function_table, sip_header,
            header_name);
        return (func);
}

/*
 * Search for the header name passed in.
 */
_sip_header_t *
sip_search_for_header(_sip_msg_t *sip_msg, char *header_name,
    _sip_header_t *old_header)
{
        int                     len = 0;
        int                     full_len = 0;
        int                     compact_len = 0;
        _sip_header_t           *header = NULL;
        char                    *compact_name = NULL;
        char                    *full_name = NULL;
        sip_header_function_t   *header_f_table = NULL;

        if (sip_msg == NULL)
                return (NULL);
#ifdef  __solaris__
        assert(mutex_held(&sip_msg->sip_msg_mutex));
#endif

        if (header_name != NULL) {
                header_f_table = sip_get_header_functions(NULL, header_name);
                if (header_f_table != NULL) {
                        full_name = header_f_table->header_name;
                        compact_name = header_f_table->header_short_name;
                        if (full_name != NULL)
                                full_len = strlen(full_name);
                        if (compact_name != NULL)
                                compact_len = strlen(compact_name);
                } else {
                        header_f_table = &sip_header_function_table[0];
                        full_name = header_name;
                        full_len  = strlen(full_name);
                }
        }

        if (old_header != NULL)
                header = old_header->sip_hdr_next;
        else
                header = sip_msg->sip_msg_headers_start;

        while (header != NULL) {

                if (header->sip_header_state == SIP_HEADER_DELETED) {
                        header = header->sip_hdr_next;
                        continue;
                }

                if (compact_len == 0 && full_len == 0)
                        break;

                header->sip_hdr_current = header->sip_hdr_start;

                if (sip_skip_white_space(header)) {
                        header = header->sip_hdr_next;
                        continue;
                }

                len = header->sip_hdr_end - header->sip_hdr_current;

                if (full_name != NULL && (full_len <= len) &&
                    strncasecmp(header->sip_hdr_current, full_name,
                    full_len) == 0) {
                        header->sip_hdr_current += full_len;
                        if (sip_skip_white_space(header)) {
                                header = header->sip_hdr_next;
                                continue;
                        }

                        if (*header->sip_hdr_current == SIP_HCOLON) {
                                header_name = full_name;
                                break;
                        }
                }

                if (compact_name != NULL && (compact_len <= len) &&
                    strncasecmp(header->sip_hdr_current, compact_name,
                    compact_len) == 0) {
                        header->sip_hdr_current += compact_len;
                        if (sip_skip_white_space(header)) {
                                header = header->sip_hdr_next;
                                continue;
                        }
                        if (*header->sip_hdr_current == SIP_HCOLON) {
                                header_name = compact_name;
                                break;
                        }
                }
                header = header->sip_hdr_next;
        }

        if (header != NULL) {
                header->sip_hdr_current = header->sip_hdr_start;
                if (header_f_table == NULL) {
                        header_f_table =
                            sip_get_header_functions(header, header_name);
                        if (header_f_table == NULL)
                                header_f_table = &sip_header_function_table[0];
                }

                header->sip_header_functions = header_f_table;
        }
        return (header);
}

/*
 * Return the start line as a string. Caller frees string
 */
char *
_sip_startline_to_str(_sip_msg_t *sip_msg, int *error)
{
        char            *slstr;
        int             len;

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

        if (sip_msg == NULL || sip_msg->sip_msg_start_line == NULL) {
                if (error != NULL)
                        *error = EINVAL;
                return (NULL);
        }
        (void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
        len = sip_msg->sip_msg_start_line->sip_hdr_end -
            sip_msg->sip_msg_start_line->sip_hdr_start - 2;
        if ((slstr = malloc(len + 1)) == NULL) {
                (void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
                if (error != NULL)
                        *error = ENOMEM;
                return (NULL);
        }
        (void) strncpy(slstr, sip_msg->sip_msg_start_line->sip_hdr_start, len);
        (void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
        slstr[len] = '\0';
        return (slstr);
}

/*
 * Return the given header as a string. Caller frees string
 */
char *
sip_hdr_to_str(sip_header_t sip_header, int *error)
{
        char            *hdrstr;
        char            *tmpptr;
        _sip_header_t   *_sip_header;
        int             len;

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

        if (sip_header == NULL) {
                if (error != NULL)
                        *error = EINVAL;
                return (NULL);
        }
        _sip_header = (_sip_header_t *)sip_header;
        if (_sip_header->sip_header_state == SIP_HEADER_DELETED) {
                if (_sip_header->sip_hdr_sipmsg != NULL) {
                        (void) pthread_mutex_unlock(
                            &_sip_header->sip_hdr_sipmsg->sip_msg_mutex);
                }
                if (error != NULL)
                        *error = EINVAL;
                return (NULL);
        }
        if (_sip_header->sip_hdr_sipmsg != NULL) {
                (void) pthread_mutex_lock(
                    &_sip_header->sip_hdr_sipmsg->sip_msg_mutex);
        }
        len = _sip_header->sip_hdr_end - _sip_header->sip_hdr_start;
        hdrstr = malloc(len);
        if (hdrstr == NULL) {
                if (_sip_header->sip_hdr_sipmsg != NULL) {
                        (void) pthread_mutex_unlock(
                            &_sip_header->sip_hdr_sipmsg->sip_msg_mutex);
                }
                if (error != NULL)
                        *error = ENOMEM;
                return (NULL);
        }
        if (_sip_header->sip_header_state == SIP_HEADER_DELETED_VAL) {
                len = sip_copy_values(hdrstr, _sip_header);
        } else {
                (void) strncpy(hdrstr, _sip_header->sip_hdr_start, len);
        }
        if (_sip_header->sip_hdr_sipmsg != NULL) {
                (void) pthread_mutex_unlock(
                    &_sip_header->sip_hdr_sipmsg->sip_msg_mutex);
        }
        tmpptr = hdrstr + len;
        while (*tmpptr-- != '\n') {
                if (tmpptr == _sip_header->sip_hdr_start) {
                        free(hdrstr);
                        if (error != NULL)
                                *error = EINVAL;
                        return (NULL);
                }
        }
        *tmpptr = '\0';
        return (hdrstr);
}

/*
 * Given a param list find the named parameter.
 * Returns a pointer to the value or NULL.
 */
sip_param_t *
sip_get_param_from_list(sip_param_t *param_list, char *param_name)
{
        while (param_list != NULL) {
                if (param_list->param_name.sip_str_len == strlen(param_name) &&
                    strncasecmp(param_list->param_name.sip_str_ptr, param_name,
                    strlen(param_name)) == 0) {
                        return (param_list);
                }
                param_list = param_list->param_next;
        }
        return (NULL);
}