msg_parser_util.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
 *
 */

/**@ingroup msg_parser
 * @CFILE msg_parser_util.c
 *
 * Text-message parser helper functions.
 *
 * @author Pekka Pessi <[e-mail]>
 *
 * @date Created: Tue Aug 28 16:26:34 2001 ppessi
 *
 */

#include "config.h"

#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <limits.h>

#include <stdarg.h>
#include <sofia-sip/su_tagarg.h>

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

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

#include "sofia-sip/url.h"

static issize_t msg_comma_scanner(char *start);

/**
 * Parse first line.
 *
 * Splits the first line from a message into three whitespace-separated
 * parts.
 */
int msg_firstline_d(char *s, char **return_part2, char **return_part3)
{
  char *s1 = s, *s2, *s3;
  size_t n;

  /* Split line into three segments separated by whitespace */
  if (s1[n = span_non_ws(s1)]) {
    s1[n] = '\0';
    s2 = s1 + n + 1;
    while (IS_WS(*s2))
      s2++;
  }
  else {
    /* Hopeless - no WS in first line */
    return -1;
  }

  n = span_non_ws(s2);

  if (s2[n]) {
    s2[n++] = '\0';
    while (IS_WS(s2[n]))
      n++;
  }

  s3 = s2 + n;

  *return_part2 = s2;

  *return_part3 = s3;

  return 0;
}

/**Parse a token.
 *
 * Parses a token from string pointed by @a *ss. It stores the token value
 * in @a return_token, and updates the @a ss to the end of token and
 * possible whitespace.
 */
issize_t msg_token_d(char **ss, char const **return_token) 
{
  char *s = *ss;
  size_t n = span_token(s);
  if (n) {
    for (; IS_LWS(s[n]); n++)
      s[n] = '\0';
    *return_token = s;
    *ss = s + n;
    return n;
  }
  else
    return -1;
}

/** Parse a 32-bit unsigned int.
 *
 * The function msg_uint32_d() parses a 32-bit unsigned integer in string
 * pointed by @a *ss. It stores the value in @a return_token and updates the
 * @a ss to the end of integer and possible whitespace.
 *
 * @retval length of parsed integer, or -1 upon an error.
 */
issize_t msg_uint32_d(char **ss, uint32_t *return_value)
{
  char const *s = *ss, *s0 = s;
  uint32_t value;
  unsigned digit;

  if (!IS_DIGIT(*s))	
    return -1;

  for (value = 0; IS_DIGIT(*s); s++) {
    digit = *s - '0';
    if (value > 429496729U)
      return -1;
    else if (value == 429496729U && digit > 5)
      return -1;
    value = 10 * value + digit;
  }

  if (*s) {
    if (!IS_LWS(*s))
      return (issize_t)-1;
    skip_lws(&s);
  }

  *ss = (char *)s;
  *return_value = value;

  return s - s0;
}


/** Parse any list.
 *
 * Parses a list of items, separated by @a sep. The parsed string is passed
 * in @a *ss, which is updated to point to the first non-linear-whitespace
 * character after the list. The function modifies the string as it parses
 * it.
 *
 * The parsed items are appended to the list @a *append_list. If there the
 * list in @a *append_list is NULL, allocate a new list and return it in @a
 * *append_list. Empty list items are ignored, and are not appended to the
 * list.
 *
 * The function @b must be passed a scanning function @a scanner. The
 * scanning function scans for a legitimate list item, for example, a token. 
 * It should also compact the list item, for instance, if the item consists
 * of @c name=value parameter definitions it should remove whitespace around
 * "=" sign. The scanning function returns the length of the scanned item,
 * including any linear whitespace after it.
 *
 * @param[in]     home    memory home for allocating list pointers 
 * @param[in,out] ss      pointer to pointer to string to be parsed 
 * @param[in,out] append_list  pointer to list
 *                             where parsed list items are appended
 * @param[in]     sep     separator character 
 * @param[in]     scanner pointer to function for scanning a single item
 * 
 * @retval 0  if successful.
 * @retval -1 upon an error.
 */
issize_t msg_any_list_d(su_home_t *home, 
			char **ss, 
			msg_param_t **append_list,
			issize_t (*scanner)(char *s), 
			int sep)
{
  char const *stack[MSG_N_PARAMS];
  char const **list = stack, **re_list;
  size_t N = MSG_N_PARAMS, n = 0;
  issize_t tlen;
  char *s = *ss;
  char const **start;

  if (!scanner)
    return -1;

  if (*append_list) {
    list = *append_list;
    while (list[n])
      n++;
    N = MSG_PARAMS_NUM(n + 1);
  }

  start = &list[n];

  skip_lws(&s);

  while (*s) {
    tlen = scanner(s);

    if (tlen < 0 || (s[tlen] && s[tlen] != sep && s[tlen] != ','))
      goto error;

    if (tlen > 0) {
      if (n + 1 == N) {		/* Reallocate list? */
	N = MSG_PARAMS_NUM(N + 1);
	if (list == stack || list == *append_list) {
	  re_list = su_alloc(home, N * sizeof(*list));
	  if (re_list)
	    memcpy(re_list, list, n * sizeof(*list));
	}
	else
	  re_list = su_realloc(home, list, N * sizeof(*list));
	if (!re_list)
	  goto error;
	list = re_list;
      }
      
      list[n++] = s;
      s += tlen;
    }

    if (*s == sep) {
      *s++ = '\0';
      skip_lws(&s);
    } 
    else if (*s)
      break;
  }

  *ss = s;

  if (n == 0) {
    *append_list = NULL;
    return 0;
  }

  if (list == stack) {
    size_t size = sizeof(*list) * MSG_PARAMS_NUM(n + 1);
    list = su_alloc(home, size);
    if (!list) return -1;
    memcpy((void *)list, stack, n * sizeof(*list));
  }

  list[n] = NULL;
  *append_list = list;
  return 0;

 error:
  *start = NULL;
  if (list != stack && list != *append_list)
    su_free(home, list);
  return -1;
}

/** Scan an attribute (name [= value]) pair.
 *
 * The attribute consists of name (a token) and optional value, separated by
 * equal sign. The value can be a token or quoted string.
 *
 * This function compacts the scanned value. It removes the
 * whitespace around equal sign "=" by moving the equal sign character and
 * value towards name.
 * 
 * If there is whitespace within the scanned value or after it, 
 * NUL-terminates the scanned attribute.
 *
 * @retval > 0 number of characters scanned, 
 *             including the whitespace within the value
 * @retval -1 upon an error
 */
issize_t msg_attribute_value_scanner(char *s)
{
  char *p = s;
  size_t tlen;

  skip_token(&s);

  if (s == p)		/* invalid parameter name */
    return -1;

  tlen = s - p;

  if (IS_LWS(*s)) { *s++ = '\0'; skip_lws(&s); }

  if (*s == '=') {
    char *v;
    s++;
    skip_lws(&s);

    /* get value */
    if (*s == '"') {
      size_t qlen = span_quoted(s);
      if (!qlen)
	return -1;
      v = s; s += qlen;
    }
    else {
      v = s; 
      skip_param(&s);
      if (s == v) 
	return -1;
    }

    if (p + tlen + 1 != v) {
      memmove(p + tlen + 1, v, s - v);
      p[tlen] = '=';
      p[tlen + 1 + (s - v)] = '\0';
    }
  }

  if (IS_LWS(*s)) { *s++ = '\0'; skip_lws(&s); }

  return s - p;
}

/**Parse an attribute-value list.
 *
 * Parses an attribute-value list, which has syntax as follows:
 * @code
 *  av-list = (av-pair *(";" av-pair)
 *  av-pair = token ["=" ( value / quoted-string) ]        ; optional value
 * @endcode
 *
 * @param[in]     home      pointer to a memory home 
 * @param[in,out] ss        pointer to string at the start of parameter list 
 * @param[in,out] append_list  pointer to list
 *                             where parsed list items are appended
 *
 * @retval >= 0 if successful
 * @retval -1 upon an error
 */
issize_t msg_avlist_d(su_home_t *home, 
		      char **ss, 
		      msg_param_t const **append_list)
{
  char const *stack[MSG_N_PARAMS];
  char const **params;
  size_t n = 0, N;
  char *s = *ss;

  if (!*s)
    return -1;

  if (*append_list) {
    params = (char const **)*append_list;
    for (n = 0; params[n]; n++)
      ;
    N = MSG_PARAMS_NUM(n + 1);
  }
  else {
    params = stack;
    N = MSG_PARAMS_NUM(1);
  }
  
  for (;;) {
    char *p;
    size_t tlen;

    /* XXX - we should handle also quoted parameters */

    skip_lws(&s);
    p = s;
    skip_token(&s);
    tlen = s - p;
    if (!tlen)		/* invalid parameter name */
      goto error;

    if (IS_LWS(*s)) { *s++ = '\0'; skip_lws(&s); }

    if (*s == '=') {
      char *v;
      s++;
      skip_lws(&s);

      /* get value */
      if (*s == '"') {
	size_t qlen = span_quoted(s);
	if (!qlen)
	  goto error;
	v = s; s += qlen;
      }
      else {
	v = s; 
	skip_param(&s);
	if (s == v) 
	  goto error;
      }
      if (p + tlen + 1 != v) {
	p = memmove(v - tlen - 1, p, tlen);
	p[tlen] = '=';
      }

    }

    if (IS_LWS(*s)) { *s++ = '\0'; skip_lws(&s); }

    if (n == N) {
      /* Reallocate params */
      char **nparams = su_alloc(home,
				(N = MSG_PARAMS_NUM(N + 1)) * sizeof(*params));
      if (!nparams) {
	goto error;
      }
      params = memcpy(nparams, params, n * sizeof(*params));
    }

    params[n++] = p;

    if (*s != ';')
      break;

    *s++ = '\0';
  }

  *ss = s;

  if (params == stack) {
    size_t size = sizeof(*params) * MSG_PARAMS_NUM(n + 1);
    params = su_alloc(home, size);
    if (!params) return -1;
    memcpy((void *)params, stack, n * sizeof(*params));
  }
  else if (n == N) {
    /* Reallocate params */
    char **nparams = su_alloc(home, 
			      (N = MSG_PARAMS_NUM(N + 1)) * sizeof(*params));
    if (!nparams) {
      goto error;
    }
    params = memcpy(nparams, params, n * sizeof(*params));
  }

  params[n] = NULL;

  *append_list = params;

  return 0;

 error:
  if (params != stack)
    su_free(home, params);
  return -1;
}

/**Parse a semicolon-separated parameter list starting with semicolon.
 *
 * Parse a parameter list, which has syntax as follows:
 * @code
 *  *(";" token [ "=" (token | quoted-string)]).
 * @endcode
 *
 * @param[in]     home      pointer to a memory home 
 * @param[in,out] ss        pointer to string at the start of parameter list 
 * @param[in,out] append_list  pointer to list
 *                             where parsed list items are appended
 *
 * @retval >= 0 if successful
 * @retval -1 upon an error
 *
 * @sa msg_avlist_d()
 */
issize_t msg_params_d(su_home_t *home, 
		      char **ss, 
		      msg_param_t const **append_list)
{
  if (**ss == ';') {
    *(*ss)++ = '\0';
    *append_list = NULL;
    return msg_avlist_d(home, ss, append_list);
  }

  if (IS_LWS(**ss)) { 
    *(*ss)++ = '\0'; skip_lws(ss);
  }

  return 0;
}

/** Encode a list of parameters */
isize_t msg_params_e(char b[], isize_t bsiz, msg_param_t const pparams[])
{
  int i;