msg.c

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

/*
 * This file is part of the Sofia-SIP package
 *
 * Copyright (C) 2005 Nokia Corporation.
 *
 * Contact: Pekka Pessi <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

/**@internal @file msg.c Message object implementation.
 *
 * @author Pekka Pessi <[e-mail]>
 *
 * @date Created: Thu Jun  8 19:28:55 2000 ppessi
 */

#include "config.h"

#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <limits.h>
#include <errno.h>

#include <assert.h>

#include <sofia-sip/su_alloc.h>		/* XXX */
#include <sofia-sip/su.h>

#include "msg_internal.h"
#include "sofia-sip/msg_parser.h"
#include "sofia-sip/msg_mclass.h"

/**
 * Create a message.
 *
 * @relatesalso msg_s
 *
 * @param mc    message class
 * @param flags message control flags
 */
msg_t *msg_create(msg_mclass_t const *mc, int flags)
{
  msg_t *msg = su_home_new(sizeof(*msg) + mc->mc_msize);

  if (msg) {
    if ((flags & MSG_FLG_THRDSAFE) &&
	su_home_threadsafe(msg->m_home) < 0) {
      su_home_unref(msg->m_home);
      return NULL;
    }

    msg->m_refs++;
    msg->m_tail = &msg->m_chain;
    msg->m_addrinfo.ai_addrlen = sizeof(msg->m_addr);
    msg->m_addrinfo.ai_addr = &msg->m_addr->su_sa;
    msg->m_maxsize = 0;

    flags &= MSG_FLG_USERMASK;

    msg->m_class = mc;
    msg->m_oflags = flags;
    msg->m_object = (void *)(msg + 1);
    msg->m_object->msg_size = mc->mc_msize;
    msg->m_object->msg_flags = mc->mc_flags | flags;
    msg->m_object->msg_common->h_class = (void *)mc;
  }

  return msg;
}

/**Increment a message reference count.
 *
 * @relatesalso msg_s
 *
 * Creates a reference to a message.  The
 * referenced message is not freed until all the references have been
 * destroyed.
 *
 * @param msg   message of which a reference is created
 * 
 * @return
 * A pointer to a message.
 */
msg_t *msg_ref_create(msg_t *msg)
{
  if (msg) {
    su_home_mutex_lock(msg->m_home);
    msg->m_refs++;
    su_home_mutex_unlock(msg->m_home);
  }
  return msg;
}

/**Set a message parent.
 *
 * @relatesalso msg_s
 *
 * Set a parent for a message. The parent message is not destroyed until all
 * its kids have been destroyed - each kid keeps a reference to its parent
 * message.
 *
 * @param kid  child message
 * @param dad  parent message
 */
void msg_set_parent(msg_t *kid, msg_t *dad)
{
  if (kid) {
    msg_t *step_dad = kid->m_parent;

    if (dad && step_dad && step_dad != dad)
      msg_ref_destroy(step_dad);

    kid->m_parent = msg_ref_create(dad);
  }
}

/** Destroy a reference to a message.
 *
 * @relatesalso msg_s
 *
 * @param ref pointer to msg object
 * 
 * @deprecated Use msg_destroy() instead.
 */
void msg_ref_destroy(msg_t *ref)
{
  msg_destroy(ref);
}

/**Deinitialize and free a message.
 *
 * @relatesalso msg_s
 *
 * @param msg  message to be destroyed
 */
void msg_destroy(msg_t *msg)
{
  msg_t *parent;
  
  for (; msg; msg = parent) {
    int refs;
    su_home_mutex_lock(msg->m_home);
    parent = msg->m_parent;
    if (msg->m_refs)
      msg->m_refs--;
    refs = msg->m_refs;
    su_home_mutex_unlock(msg->m_home);
    if (refs)
      break;
    su_home_zap(msg->m_home);
  }
}

/* Message object routines */

/**Retrieve public message structure.
 *
 * Get a pointer to the public message structure.
 * 
 * @param msg pointer to msg object
 * 
 * @returns
 * A pointer to the public message structure, or NULL if none.
 */
msg_pub_t *msg_object(msg_t const *msg)
{
  if (msg)
    return msg->m_object;
  else
    return NULL;
}

/**Retrieve public message structure of given type.
 *
 * @relatesalso msg_s
 *
 * Get a pointer to the public message structure of the
 * given protocol.
 * 
 * @param msg pointer to msg object
 * @param tag tag of public message structure
 * 
 * @returns
 * A pointer to the public message structure, or NULL if there is none or
 * the message is not for desired protocol.
 */
msg_pub_t *msg_public(msg_t const *msg, void *tag)
{
  if (msg && msg->m_class->mc_tag == tag)
    return msg->m_object;
  else
    return NULL;
}

/**Retrieve message class.
 *
 * @relatesalso msg_s
 *
 * Get a pointer to the message class object
 * (factory object for the message).
 * 
 * @param msg pointer to msg object
 * 
 * @returns
 * A pointer to the message class, or NULL if none.
 */
msg_mclass_t const *msg_mclass(msg_t const *msg)
{
  if (msg)
    return msg->m_class;
  else
    return NULL;
}

/* Address management */

/** Zero the message address.
 *
 * @relatesalso msg_s
 *
 * Zero the address and addressinfo structures associated with the message.
 *
 * @sa msg_addrinfo(), msg_set_address(), msg_get_address(), msg_addr_copy().
 */ 
void msg_addr_zero(msg_t *msg)
{
  memset(&msg->m_addr, 0, sizeof(&msg->m_addr));
  memset(&msg->m_addrinfo, 0, sizeof(&msg->m_addrinfo));

  msg->m_addrinfo.ai_addrlen = sizeof(msg->m_addr);
  msg->m_addrinfo.ai_addr = &msg->m_addr->su_sa;
}

/** Get pointer to socket address structure. 
 *
 * @relatesalso msg_s
 *
 * @deprecated Use msg_get_address() or msg_set_address() instead.
 */
su_sockaddr_t *msg_addr(msg_t *msg)
{
  return msg ? msg->m_addr : 0;
}

/** Get message address.
 *
 * @relatesalso msg_s
 *
 * Copy the socket address associated with the message to the supplied
 * socket address struture.
 *
 * @param msg pointer to msg object
 * @param su pointer to socket address structure
 * @param return_len return parameter value for length 
 *                    of socket address structure
 *
 * @sa msg_addrinfo(), msg_set_address(), msg_addr_zero(), msg_addr_copy().
 */
int msg_get_address(msg_t *msg, su_sockaddr_t *su, socklen_t *return_len)
{
  if (msg && return_len && *return_len >= msg->m_addrinfo.ai_addrlen) {
    *return_len = (socklen_t)msg->m_addrinfo.ai_addrlen;
    if (su)
      memcpy(su, msg->m_addr, msg->m_addrinfo.ai_addrlen);
    return 0;
  }
  if (msg)
    msg->m_errno = EFAULT;
  return -1;
}

/** Set message address. 
 *
 * @relatesalso msg_s
 *
 * Copy the supplied socket address to the socket address structure
 * associated with the message.
 * 
 * @param msg pointer to msg object
 * @param su pointer to socket address structure
 * @param sulen length of socket address structure
 *
 * @sa msg_addrinfo(), msg_get_address(), msg_addr_zero(), msg_addr_copy().
 */
int msg_set_address(msg_t *msg, su_sockaddr_t const *su, socklen_t sulen)
{
  if (sulen < (sizeof msg->m_addr) && msg && su) {
    memcpy(msg->m_addr, su, msg->m_addrinfo.ai_addrlen = sulen);
    msg->m_addrinfo.ai_family = su->su_family;
    return 0;
  }
  if (msg)
    msg->m_errno = EFAULT;
  return -1;
}

/** Get addrinfo structure.
 *
 * @relatesalso msg_s
 *
 * Get pointer to the addrinfo structure associated with the message.
 *
 * @param msg pointer to msg object
 *
 * @retval pointer to addrinfo structure
 * @retval NULL if msg is NULL
 *
 * @sa msg_get_address(), msg_set_address(), msg_addr_zero(), msg_addr_copy().
 */
su_addrinfo_t *msg_addrinfo(msg_t *msg)
{
  return msg ? &msg->m_addrinfo : 0;
}

/**Copy message address.
 *
 * @relatesalso msg_s
 *
 * Copy the addrinfo and socket address structures from @a src to the @a dst
 * message object.
 *
 * @param dst pointer to destination message object 
 * @param src pointer to source message object
 *
 * @sa msg_addrinfo(), msg_get_address(), msg_set_address(), msg_addr_zero().
 */
void msg_addr_copy(msg_t *dst, msg_t const *src)
{
  dst->m_addrinfo = src->m_addrinfo;
  dst->m_addrinfo.ai_next = NULL;
  dst->m_addrinfo.ai_canonname = NULL;
  memcpy(dst->m_addrinfo.ai_addr = &dst->m_addr->su_sa, 
	 src->m_addr, src->m_addrinfo.ai_addrlen);
  if (dst->m_addrinfo.ai_addrlen < sizeof(dst->m_addr))
    memset((char *)dst->m_addr + dst->m_addrinfo.ai_addrlen, 0, 
	   sizeof(dst->m_addr) - dst->m_addrinfo.ai_addrlen);
}


/** Get error classification flags.
 *
 * @relatesalso msg_s
 *
 * If the message parser fails to parse certain headers in the message, it
 * sets the corresponding extract error flags. The flags corresponding to
 * each header are stored in the message parser (msg_mclass_t) structure. 
 * They are set when the header is added to the parser table. 
 * 
 * The SIP flags are defined in <sofia-sip/sip_headers.h>. For well-known
 * SIP headers, the flags for each header are listed in a separate text file
 * (sip_bad_mask) read by msg_parser.awk.
 *
 * The flags can be used directly by NTA (the mask triggering 400 response
 * is set with NTATAG_BAD_REQ_MASK(), the mask triggering response messages
 * to be dropped is set with NTATAG_BAD_RESP_MASK()). Alternatively the
 * application can check them based on the method or required SIP features.
 *
 * @sa msg_mclass_insert_with_mask(), NTATAG_BAD_REQ_MASK(),
 * NTATAG_BAD_RESP_MASK().
 */
unsigned msg_extract_errors(msg_t const *msg)
{
  return msg ? msg->m_extract_err : (unsigned)-1;
}


/** Get error number associated with message.
 *
 * @relatesalso msg_s
 *
 * @param msg pointer to msg object
 *
 */
int msg_errno(msg_t const *msg)
{
  return msg ? msg->m_errno : EINVAL;
}

/** Set error number associated with message.
 *
 * @relatesalso msg_s
 *
 * @param msg pointer to msg object
 * @param err error value (as defined in <sofia-sip/su_errno.h>).
 *
 */
void msg_set_errno(msg_t *msg, int err)
{
  if (msg)
    msg->m_errno = err;
}