libsip/common/sip_reass.c

	sip_reass.c revision 40cb5e5daa7b80bb70fcf8dadfb20f9281566331
/*
 * 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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/socket.h>
#include <netinet/in.h>
#include "sip_miscdefs.h"

/*
 * Local version of case insensitive strstr().
 */
static char *
sip_reass_strstr(const char *as1, const char *as2)
{
    const char  *s1;
    const char  *s2;
    const char  *tptr;
    char    c;

    s1 = as1;
    s2 = as2;

    if (s2 == NULL || *s2 == '\0')
        return ((char *)s1);
    c = *s2;

    while (*s1)
        if (tolower(*s1++) == c) {
            tptr = s1;
            while ((c = *++s2) == tolower(*s1++) && c)
                ;
            if (c == 0)
                return ((char *)tptr - 1);
            s1 = tptr;
            s2 = as2;
            c = *s2;
        }

    return (NULL);
}

/*
 * Get the value in the content-length field and add it to the header length
 * and return the total length. returns -1 if the length cannot be determined
 * or if the message does not contain the entire message.
 */
static int
sip_get_msglen(char *p, size_t msglen)
{
    int value = 0;
    int     hlen;
    char    *c;
    char    *e;
    int base = 10;
    char    *edge;
    int digits = 0;

    edge = p + msglen;
    if ((c = sip_reass_strstr(p, "content-length")) == NULL)
        return (-1);
    hlen = c - p;
    if ((hlen +  strlen("content-length")) >= msglen)
        return (-1);
    c += strlen("content-length");
    e = c + 1;
    while (*e == ' ' || *e == ':') {
        e++;
        if (e == edge)
            return (-1);
    }
    while (*e  != '\r' && *e != ' ') {
        if (e == edge)
            return (-1);
        if (*e >= '0' && *e <= '9')
            digits = *e - '0';
        else
            return (-1);
        value = (value * base) + digits;
        e++;
    }
    while (*e != '\r') {
        e++;
        if (e == edge)
            return (-1);
    }
    hlen = e - p + 4;   /* 4 for 2 CRLFs ?? */
    value += hlen;

    return (value);
}

/*
 * We have determined that msg does not contain a *single* complete message.
 * Add it to the reassembly list and check if we have a complete message.
 * a NULL 'msg' means we are just checking if there are more complete
 * messages in the list that can be passed up.
 */
char *
sip_get_tcp_msg(sip_conn_object_t obj, char *msg, size_t *msglen)
{
    int         value;
    sip_conn_obj_pvt_t  *pvt_data;
    sip_reass_entry_t   *reass;
    void            **obj_val;
    char            *msgbuf = NULL;
    int         splitlen;
    char            *splitbuf;

    if (msg != NULL) {
        assert(*msglen > 0);
        msgbuf = (char *)malloc(*msglen + 1);
        if (msgbuf == NULL)
            return (NULL);
        (void) strncpy(msgbuf, msg, *msglen);
        msgbuf[*msglen] = '\0';
        msg = msgbuf;
    }
    obj_val = (void *)obj;
    pvt_data = (sip_conn_obj_pvt_t *)*obj_val;
    /*
     * connection object not initialized
     */
    if (pvt_data == NULL) {
        if (msg == NULL)
            return (NULL);
        value = sip_get_msglen(msg, *msglen);
        if (value == *msglen) {
            return (msg);
        } else {
            if (msgbuf != NULL)
                free(msgbuf);
            return (NULL);
        }
    }
    (void) pthread_mutex_lock(&pvt_data->sip_conn_obj_reass_lock);
    reass = pvt_data->sip_conn_obj_reass;
    assert(reass != NULL);
    if (reass->sip_reass_msg == NULL) {
        assert(reass->sip_reass_msglen == 0);
        if (msg == NULL) {
            (void) pthread_mutex_unlock(
                &pvt_data->sip_conn_obj_reass_lock);
            return (NULL);
        }
        value = sip_get_msglen(msg, *msglen);
        if (value == *msglen) {
            (void) pthread_mutex_unlock(
                &pvt_data->sip_conn_obj_reass_lock);
            return (msg);
        }
        reass->sip_reass_msg = msg;
        reass->sip_reass_msglen = *msglen;
        if (value != -1 && value < reass->sip_reass_msglen)
            goto tryone;
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_reass_lock);
        return (NULL);
    } else if (msg != NULL) {
        /*
         * Resize, not optimal
         */
        int newlen = reass->sip_reass_msglen + *msglen;
        char    *newmsg;

        assert(strlen(reass->sip_reass_msg) == reass->sip_reass_msglen);
        newmsg = malloc(newlen + 1);
        if (newmsg == NULL) {
            (void) pthread_mutex_unlock(
                &pvt_data->sip_conn_obj_reass_lock);
            if (msgbuf != NULL)
                free(msgbuf);
            return (NULL);
        }
        (void) strncpy(newmsg, reass->sip_reass_msg,
            reass->sip_reass_msglen);
        newmsg[reass->sip_reass_msglen] = '\0';
        (void) strncat(newmsg, msg, *msglen);
        newmsg[newlen] = '\0';
        assert(strlen(newmsg) == newlen);
        reass->sip_reass_msglen = newlen;
        free(msg);
        free(reass->sip_reass_msg);
        reass->sip_reass_msg = newmsg;
    }
    value = sip_get_msglen(reass->sip_reass_msg, reass->sip_reass_msglen);
    if (value == -1 || value >  reass->sip_reass_msglen) {
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_reass_lock);
        return (NULL);
    }
tryone:
    if (value == reass->sip_reass_msglen) {
        msg = reass->sip_reass_msg;
        *msglen = reass->sip_reass_msglen;
        reass->sip_reass_msg = NULL;
        reass->sip_reass_msglen = 0;
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_reass_lock);
        return (msg);
    }
    splitlen = reass->sip_reass_msglen - value;
    msg = (char *)malloc(value + 1);
    splitbuf = (char *)malloc(splitlen + 1);
    if (msg == NULL || splitbuf == NULL) {
        if (msg != NULL)
            free(msg);
        if (splitbuf != NULL)
            free(splitbuf);
        (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_reass_lock);
        return (NULL);
    }
    (void) strncpy(msg, reass->sip_reass_msg, value);
    msg[value] = '\0';
    (void) strncpy(splitbuf, reass->sip_reass_msg + value, splitlen);
    splitbuf[splitlen] = '\0';
    free(reass->sip_reass_msg);
    reass->sip_reass_msg = splitbuf;
    reass->sip_reass_msglen = splitlen;
    (void) pthread_mutex_unlock(&pvt_data->sip_conn_obj_reass_lock);
    *msglen = value;
    return (msg);
}