rfc822.c

广泛使用的邮件服务器！同时

      string = NIL;
      (adr = mail_newaddr ())->mailbox = cpystr ("INVALID_ADDRESS");
      adr->host = cpystr (errhst);
      if (last) last = last->next = adr;
      else *lst = last = adr;
      break;
    }
  }
}

/* Parse RFC 2822 address
 * Accepts: address list to write to
 *	    tail of address list
 *	    pointer to input string
 *	    default host name
 *	    group nesting depth
 * Returns: new list tail
 */

ADDRESS *rfc822_parse_address (ADDRESS **lst,ADDRESS *last,char **string,
			       char *defaulthost,unsigned long depth)
{
  ADDRESS *adr;
  if (!*string) return NIL;	/* no string */
  rfc822_skipws (string);	/* skip leading WS */
  if (!**string) return NIL;	/* empty string */
  if (adr = rfc822_parse_group (lst,last,string,defaulthost,depth)) last = adr;
				/* got an address? */
  else if (adr = rfc822_parse_mailbox (string,defaulthost)) {
    if (!*lst) *lst = adr;	/* yes, first time through? */
    else last->next = adr;	/* no, append to the list */
				/* set for subsequent linking */
    for (last = adr; last->next; last = last->next);
  }
  else if (*string) return NIL;
  return last;
}

/* Parse RFC 2822 group
 * Accepts: address list to write to
 *	    pointer to tail of address list
 *	    pointer to input string
 *	    default host name
 *	    group nesting depth
 */

ADDRESS *rfc822_parse_group (ADDRESS **lst,ADDRESS *last,char **string,
			     char *defaulthost,unsigned long depth)
{
  char tmp[MAILTMPLEN];
  char *p,*s;
  ADDRESS *adr;
  if (depth > MAXGROUPDEPTH) {	/* excessively deep recursion? */
    MM_LOG ("Ignoring excessively deep group recursion",PARSE);
    return NIL;			/* probably abusive */
  }
  if (!*string) return NIL;	/* no string */
  rfc822_skipws (string);	/* skip leading WS */
  if (!**string ||		/* trailing whitespace or not group */
      ((*(p = *string) != ':') && !(p = rfc822_parse_phrase (*string))))
    return NIL;
  s = p;			/* end of candidate phrase */
  rfc822_skipws (&s);		/* find delimiter */
  if (*s != ':') return NIL;	/* not really a group */
  *p = '\0';			/* tie off group name */
  p = ++s;			/* continue after the delimiter */
  rfc822_skipws (&p);		/* skip subsequent whitespace */
				/* write as address */
  (adr = mail_newaddr ())->mailbox = rfc822_cpy (*string);
  if (!*lst) *lst = adr;	/* first time through? */
  else last->next = adr;	/* no, append to the list */
  last = adr;			/* set for subsequent linking */
  *string = p;			/* continue after this point */
  while (*string && **string && (**string != ';')) {
    if (adr = rfc822_parse_address (lst,last,string,defaulthost,depth+1)) {
      last = adr;		/* new tail address */
      if (*string) {		/* anything more? */
	rfc822_skipws (string);	/* skip whitespace */
	switch (**string) {	/* see what follows */
	case ',':		/* another address? */
	  ++*string;		/* yes, skip past the comma */
	case ';':		/* end of group? */
	case '\0':		/* end of string */
	  break;
	default:
	  sprintf (tmp,"Unexpected characters after address in group: %.80s",
		   *string);
	  MM_LOG (tmp,PARSE);
	  *string = NIL;	/* cancel remainder of parse */
	  last = last->next = mail_newaddr ();
	  last->mailbox = cpystr ("UNEXPECTED_DATA_AFTER_ADDRESS_IN_GROUP");
	  last->host = cpystr (errhst);
	}
      }
    }
    else {			/* bogon */
      sprintf (tmp,"Invalid group mailbox list: %.80s",*string);
      MM_LOG (tmp,PARSE);
      *string = NIL;		/* cancel remainder of parse */
      (adr = mail_newaddr ())->mailbox = cpystr ("INVALID_ADDRESS_IN_GROUP");
      adr->host = cpystr (errhst);
      last = last->next = adr;
    }
  }
  if (*string) {		/* skip close delimiter */
    if (**string == ';') ++*string;
    rfc822_skipws (string);
  }
				/* append end of address mark to the list */
  last->next = (adr = mail_newaddr ());
  last = adr;			/* set for subsequent linking */
  return last;			/* return the tail */
}

/* Parse RFC 2822 mailbox
 * Accepts: pointer to string pointer
 *	    default host
 * Returns: address list
 *
 * Updates string pointer
 */

ADDRESS *rfc822_parse_mailbox (char **string,char *defaulthost)
{
  ADDRESS *adr = NIL;
  char *s,*end;
  parsephrase_t pp = (parsephrase_t) mail_parameters (NIL,GET_PARSEPHRASE,NIL);
  if (!*string) return NIL;	/* no string */
  rfc822_skipws (string);	/* flush leading whitespace */
  if (!**string) return NIL;	/* empty string */
  if (*(s = *string) == '<') 	/* note start, handle case of phraseless RA */
    adr = rfc822_parse_routeaddr (s,string,defaulthost);
				/* otherwise, expect at least one word */
  else if (end = rfc822_parse_phrase (s)) {
    if ((adr = rfc822_parse_routeaddr (end,string,defaulthost))) {
				/* phrase is a personal name */
      if (adr->personal) fs_give ((void **) &adr->personal);
      *end = '\0';		/* tie off phrase */
      adr->personal = rfc822_cpy (s);
    }
				/* call external phraseparser if phrase only */
    else if (pp && rfc822_phraseonly (end) &&
	     (adr = (*pp) (s,end,defaulthost))) {
      *string = end;		/* update parse pointer */
      rfc822_skipws (string);	/* skip WS in the normal way */
    }
    else adr = rfc822_parse_addrspec (s,string,defaulthost);
  }
  return adr;			/* return the address */
}


/* Check if address is a phrase only
 * Accepts: pointer to end of phrase
 * Returns: T if phrase only, else NIL;
 */

long rfc822_phraseonly (char *end)
{
  while (*end == ' ') ++end;	/* call rfc822_skipws() instead?? */
  switch (*end) {
  case '\0': case ',': case ';':
    return LONGT;		/* is a phrase only */
  }
  return NIL;			/* something other than phase is here */
}

/* Parse RFC 2822 route-address
 * Accepts: string pointer
 *	    pointer to string pointer to update
 * Returns: address
 *
 * Updates string pointer
 */

ADDRESS *rfc822_parse_routeaddr (char *string,char **ret,char *defaulthost)
{
  char tmp[MAILTMPLEN];
  ADDRESS *adr;
  char *s,*t,*adl;
  size_t adllen,i;
  if (!string) return NIL;
  rfc822_skipws (&string);	/* flush leading whitespace */
				/* must start with open broket */
  if (*string != '<') return NIL;
  t = ++string;			/* see if A-D-L there */
  rfc822_skipws (&t);		/* flush leading whitespace */
  for (adl = NIL,adllen = 0;	/* parse possible A-D-L */
       (*t == '@') && (s = rfc822_parse_domain (t+1,&t));) {
    i = strlen (s) + 2;		/* @ plus domain plus delimiter or NUL */
    if (adl) {			/* have existing A-D-L? */
      fs_resize ((void **) &adl,adllen + i);
      sprintf (adl + adllen - 1,",@%s",s);
    }
				/* write initial A-D-L */
    else sprintf (adl = (char *) fs_get (i),"@%s",s);
    adllen += i;		/* new A-D-L length */
    fs_give ((void **) &s);	/* don't need domain any more */
    rfc822_skipws (&t);		/* skip WS */
    if (*t != ',') break;	/* put if not comma */
    t++;			/* skip the comma */
    rfc822_skipws (&t);		/* skip WS */
  }
  if (adl) {			/* got an A-D-L? */
    if (*t != ':') {		/* make sure syntax good */
      sprintf (tmp,"Unterminated at-domain-list: %.80s%.80s",adl,t);
      MM_LOG (tmp,PARSE);
    }
    else string = ++t;		/* continue parse from this point */
  }

				/* parse address spec */
  if (!(adr = rfc822_parse_addrspec (string,ret,defaulthost))) {
    if (adl) fs_give ((void **) &adl);
    return NIL;
  }
  if (adl) adr->adl = adl;	/* have an A-D-L? */
  if (*ret) if (**ret == '>') {	/* make sure terminated OK */
    ++*ret;			/* skip past the broket */
    rfc822_skipws (ret);	/* flush trailing WS */
    if (!**ret) *ret = NIL;	/* wipe pointer if at end of string */
    return adr;			/* return the address */
  }
  sprintf (tmp,"Unterminated mailbox: %.80s@%.80s",adr->mailbox,
	   *adr->host == '@' ? "<null>" : adr->host);
  MM_LOG (tmp,PARSE);
  adr->next = mail_newaddr ();
  adr->next->mailbox = cpystr ("MISSING_MAILBOX_TERMINATOR");
  adr->next->host = cpystr (errhst);
  return adr;			/* return the address */
}

/* Parse RFC 2822 address-spec
 * Accepts: string pointer
 *	    pointer to string pointer to update
 *	    default host
 * Returns: address
 *
 * Updates string pointer
 */

ADDRESS *rfc822_parse_addrspec (char *string,char **ret,char *defaulthost)
{
  ADDRESS *adr;
  char c,*s,*t,*v,*end;
  if (!string) return NIL;	/* no string */
  rfc822_skipws (&string);	/* flush leading whitespace */
  if (!*string) return NIL;	/* empty string */
				/* find end of mailbox */
  if (!(t = rfc822_parse_word (string,wspecials))) return NIL;
  adr = mail_newaddr ();	/* create address block */
  c = *t;			/* remember delimiter */
  *t = '\0';			/* tie off mailbox */
				/* copy mailbox */
  adr->mailbox = rfc822_cpy (string);
  *t = c;			/* restore delimiter */
  end = t;			/* remember end of mailbox */
  rfc822_skipws (&t);		/* skip whitespace */
  while (*t == '.') {		/* some cretin taking RFC 822 too seriously? */
    string = ++t;		/* skip past the dot and any WS */
    rfc822_skipws (&string);
				/* get next word of mailbox */
    if (t = rfc822_parse_word (string,wspecials)) {
      end = t;			/* remember new end of mailbox */
      c = *t;			/* remember delimiter */
      *t = '\0';		/* tie off word */
      s = rfc822_cpy (string);	/* copy successor part */
      *t = c;			/* restore delimiter */
				/* build new mailbox */
      sprintf (v = (char *) fs_get (strlen (adr->mailbox) + strlen (s) + 2),
	       "%s.%s",adr->mailbox,s);
      fs_give ((void **) &adr->mailbox);
      adr->mailbox = v;		/* new host name */
      rfc822_skipws (&t);	/* skip WS after mailbox */
    }
    else {			/* barf */
      MM_LOG ("Invalid mailbox part after .",PARSE);
      break;
    }
  }
  t = end;			/* remember delimiter in case no host */

  rfc822_skipws (&end);		/* sniff ahead at what follows */
#if RFC733			/* RFC 733 used "at" instead of "@" */
  if (((*end == 'a') || (*end == 'A')) &&
      ((end[1] == 't') || (end[1] == 'T')) &&
      ((end[2] == ' ') || (end[2] == '\t') || (end[2] == '\015') ||
       (end[2] == '\012') || (end[2] == '(')))
    *++end = '@';
#endif
  if (*end != '@') end = t;	/* host name missing */
				/* otherwise parse host name */
  else if (!(adr->host = rfc822_parse_domain (++end,&end)))
    adr->host = cpystr (errhst);
				/* default host if missing */
  if (!adr->host) adr->host = cpystr (defaulthost);
				/* try person name in comments if missing */
  if (end && !(adr->personal && *adr->personal)) {
    while (*end == ' ') ++end;	/* see if we can find a person name here */
    if ((*end == '(') && (s = rfc822_skip_comment (&end,LONGT)) && strlen (s))
      adr->personal = rfc822_cpy (s);
    rfc822_skipws (&end);	/* skip any other WS in the normal way */
  }
				/* set return to end pointer */
  *ret = (end && *end) ? end : NIL;
  return adr;			/* return the address we got */
}

/* Parse RFC 2822 domain
 * Accepts: string pointer
 *	    pointer to return end of domain
 * Returns: domain name or NIL if failure
 */

char *rfc822_parse_domain (char *string,char **end)
{
  char *ret = NIL;
  char c,*s,*t,*v;
  rfc822_skipws (&string);	/* skip whitespace */
  if (*string == '[') {		/* domain literal? */
    if (!(*end = rfc822_parse_word (string + 1,"]\\")))
      MM_LOG ("Empty domain literal",PARSE);
    else if (**end != ']') MM_LOG ("Unterminated domain literal",PARSE);
    else {
      size_t len = ++*end - string;
      strncpy (ret = (char *) fs_get (len + 1),string,len);
      ret[len] = '\0';		/* tie off literal */
    }
  }
				/* search for end of host */
  else if (t = rfc822_parse_word (string,wspecials)) {
    c = *t;			/* remember delimiter */
    *t = '\0';			/* tie off host */
    ret = rfc822_cpy (string);	/* copy host */
    *t = c;			/* restore delimiter */
    *end = t;			/* remember end of domain */
    rfc822_skipws (&t);		/* skip WS after host */
    while (*t == '.') {		/* some cretin taking RFC 822 too seriously? */
      string = ++t;		/* skip past the dot and any WS */
      rfc822_skipws (&string);
      if (string = rfc822_parse_domain (string,&t)) {
	*end = t;		/* remember new end of domain */
	c = *t;			/* remember delimiter */
	*t = '\0';		/* tie off host */
	s = rfc822_cpy (string);/* copy successor part */
	*t = c;			/* restore delimiter */
				/* build new domain */
	sprintf (v = (char *) fs_get (strlen (ret) + strlen (s) + 2),
		 "%s.%s",ret,s);
	fs_give ((void **) &ret);
	ret = v;		/* new host name */
	rfc822_skipws (&t);	/* skip WS after domain */
      }
      else {			/* barf */
	MM_LOG ("Invalid domain part after .",PARSE);
	break;
      }
    }
  }
  else MM_LOG ("Missing or invalid host name after @",PARSE);
  return ret;
}

/* Parse RFC 2822 phrase
 * Accepts: string pointer
 * Returns: pointer to end of phrase
 */

char *rfc822_parse_phrase (char *s)
{
  char *curpos;
  if (!s) return NIL;		/* no-op if no string */
				/* find first word of phrase */
  curpos = rfc822_parse_word (s,NIL);
  if (!curpos) return NIL;	/* no words means no phrase */
  if (!*curpos) return curpos;	/* check if string ends with word */
  s = curpos;			/* sniff past the end of this word and WS */
  rfc822_skipws (&s);		/* skip whitespace */
				/* recurse to see if any more */
  return (s = rfc822_parse_phrase (s)) ? s : curpos;
}