//! Show a term and its type, on single lines
void
xmlTermType (const Term t)
{
Term substbuf;
if (realTermVariable (t))
{
substbuf = t->subst;
t->subst = NULL;
}
xmlindent++;
xmlPrint ("<term>");
xmlindent++;
xmlIndentPrint ();
xmlTermPrint (t);
eprintf ("\n");
xmlindent--;
xmlPrint ("</term>");
xmlPrint ("<type>");
xmlindent++;
xmlTermlistPrint (t->stype);
xmlindent--;
xmlPrint ("</type>");
xmlindent--;
if (realTermVariable (t))
{
t->subst = substbuf;
}
}
/**
* Show the instantiations of all variables. Maybe we need to restrict this,
* and scan only for those variables that actually occur in the semitrace.
*/
void
xmlVariables (const System sys)
{
int prev_mode; // buffer for show mode
int run; // for loop
prev_mode = show_substitution_path;
show_substitution_path = true;
xmlPrint ("<variables>");
xmlindent++;
run = 0;
while (run < sys->maxruns)
{
if (sys->runs[run].protocol != INTRUDER)
{
Termlist varlist;
varlist = sys->runs[run].locals;
while (varlist != NULL)
{
if (realTermVariable (varlist->term))
{
xmlVariable (sys, varlist->term, run);
}
varlist = varlist->next;
}
}
run++;
}
xmlindent--;
xmlPrint ("</variables>");
show_substitution_path = prev_mode;
}
//! Show a single variable instantiation
void
xmlVariable (const System sys, const Term variable, const int run)
{
if (realTermVariable (variable))
{
xmlIndentPrint ();
eprintf ("<variable typeflaw=\"");
/* TODO this is now wrong, because it does not switch the matching more
* anymore */
if (!checkTypeTerm (variable))
{
eprintf ("true");
}
else
{
eprintf ("false");
}
eprintf ("\" run=\"%i\">\n", run);
xmlindent++;
xmlPrint ("<name>");
xmlTermType (variable);
xmlPrint ("</name>");
if (variable->subst != NULL)
{
xmlPrint ("<substitution>");
xmlTermType (deVar (variable));
xmlPrint ("</substitution>");
}
xmlindent--;
xmlPrint ("</variable>");
}
}
//! Determine whether this is a leaf construct with a ticket in it
int
isTicketTerm (Term t)
{
if (t != NULL)
{
if (realTermLeaf (t))
{
if (inTermlist (t->stype, TERM_Ticket))
{
return true;
}
else
{
if (realTermVariable (t))
{
return isTicketTerm (t->subst);
}
}
}
}
return false;
}
//! Print a term in XML form (iteration inner)
void
xmlTermPrintInner (Term term)
{
if (term != NULL)
{
if (!show_substitution_path)
{
/* In a normal situation, variables are immediately substituted, and
* only the result is output.
*/
term = deVar (term);
}
if (realTermLeaf (term))
{
// Variable?
if (realTermVariable (term))
{
Term substbuffer;
eprintf ("<var name=\"");
if (term->subst == NULL)
{
// Free variable
termPrint (term); // Must be a normal termPrint
eprintf ("\" free=\"true\" />");
}
else
{
// Bound variable
substbuffer = term->subst; // Temporarily unsubst for printing
term->subst = NULL;
termPrint (term); // Must be a normal termPrint
term->subst = substbuffer;
eprintf ("\">");
xmlTermPrintInner (term->subst);
eprintf ("</var>");
}
}
else
{
// Constant
eprintf ("<const>");
termPrint (term); // Must be a normal termPrint
eprintf ("</const>");
}
}
else
{
// Node
if (realTermEncrypt (term))
{
if (isTermLeaf (TermKey (term))
&& inTermlist (TermKey (term)->stype, TERM_Function))
{
/* function application */
eprintf ("<apply><function>");
xmlTermPrintInner (TermKey (term));
eprintf ("</function><arg>");
xmlTermPrintInner (TermOp (term));
eprintf ("</arg></apply>");
}
else
{
eprintf ("<encrypt><op>");
xmlTermPrintInner (TermOp (term));
eprintf ("</op><key>");
xmlTermPrintInner (TermKey (term));
eprintf ("</key></encrypt>");
}
}
else
{
// Assume tuple
eprintf ("<tuple><op1>");
xmlTermPrintInner (TermOp1 (term));
eprintf ("</op1><op2>");
xmlTermPrintInner (TermOp2 (term));
eprintf ("</op2></tuple>");
}
}
}
}
/**
* Try to determine the most general unifier of two terms.
* Resulting termlist must be termlistDelete'd.
*
*@return Returns a list of variables, that were previously open, but are now closed
* in such a way that the two terms unify. Returns \ref MGUFAIL if it is impossible.
* The termlist should be deleted.
*
* @TODO this code should be removed, as it duplicates 'unify' code, and is
* ill-suited for adaption later on with multiple unifiers.
*/
Termlist
termMguTerm (Term t1, Term t2)
{
/* added for speed */
t1 = deVar (t1);
t2 = deVar (t2);
if (t1 == t2)
return NULL;
if (!(hasTermVariable (t1) || hasTermVariable (t2)))
{
if (isTermEqual (t1, t2))
{
return NULL;
}
else
{
return MGUFAIL;
}
}
/*
* Distinguish a special case where both are unbound variables that will be
* connected, and I want to give one priority over the other for readability.
*
* Because t1 and t2 have been deVar'd means that if they are variables, they
* are also unbound.
*/
if (realTermVariable (t1) && realTermVariable (t2) && goodsubst (t1, t2))
{
/* Both are unbound variables. Decide.
*
* The plan: t1->subst will point to t2. But maybe we prefer the other
* way around?
*/
if (preferSubstitutionOrder (t2, t1))
{
Term t3;
// Swappy.
t3 = t1;
t1 = t2;
t2 = t3;
}
t1->subst = t2;
#ifdef DEBUG
showSubst (t1);
#endif
return termlistAdd (NULL, t1);
}
/* symmetrical tests for single variable.
*/
if (realTermVariable (t2))
{
if (termSubTerm (t1, t2) || !goodsubst (t2, t1))
return MGUFAIL;
else
{
t2->subst = t1;
#ifdef DEBUG
showSubst (t2);
#endif
return termlistAdd (NULL, t2);
}
}
if (realTermVariable (t1))
{
if (termSubTerm (t2, t1) || !goodsubst (t1, t2))
return MGUFAIL;
else
{
t1->subst = t2;
#ifdef DEBUG
showSubst (t1);
#endif
return termlistAdd (NULL, t1);
}
}
/* left & right are compounds with variables */
if (t1->type != t2->type)
return MGUFAIL;
/* identical compounds */
/* encryption first */
if (realTermEncrypt (t1))
{
Termlist tl1, tl2;
tl1 = termMguTerm (TermKey (t1), TermKey (t2));
if (tl1 == MGUFAIL)
{
return MGUFAIL;
}
else
{
tl2 = termMguTerm (TermOp (t1), TermOp (t2));
if (tl2 == MGUFAIL)
{
termlistSubstReset (tl1);
termlistDelete (tl1);
return MGUFAIL;
}
else
{
return termlistConcat (tl1, tl2);
}
}
}
/* tupling second
non-associative version ! TODO other version */
if (isTermTuple (t1))
{
Termlist tl1, tl2;
tl1 = termMguTerm (TermOp1 (t1), TermOp1 (t2));
if (tl1 == MGUFAIL)
{
return MGUFAIL;
}
else
{
tl2 = termMguTerm (TermOp2 (t1), TermOp2 (t2));
if (tl2 == MGUFAIL)
{
termlistSubstReset (tl1);
termlistDelete (tl1);
return MGUFAIL;
}
else
{
return termlistConcat (tl1, tl2);
}
}
}
return MGUFAIL;
}
/**
* Try to determine the most general unifier of two terms, if so calls function.
*
* int callback(Termlist, *state)
*
* The callback receives a list of variables, that were previously open, but are now closed
* in such a way that the two terms unify.
*
* The callback must return true for the iteration to proceed: if it returns false, a single call would abort the scan.
* The return value shows this: it is false if the scan was aborted, and true if not.
*/
int
unify (Term t1, Term t2, Termlist tl, int (*callback) (), void *state)
{
/* added for speed */
t1 = deVar (t1);
t2 = deVar (t2);
if (t1 == t2)
{
return callback (tl, state);
}
if (!(hasTermVariable (t1) || hasTermVariable (t2)))
{
// None has a variable
if (isTermEqual (t1, t2))
{
// Equal!
return callback (tl, state);
}
else
{
// Can never be fixed, no variables
return true;
}
}
/*
* Distinguish a special case where both are unbound variables that will be
* connected, and I want to give one priority over the other for readability.
*
* Because t1 and t2 have been deVar'd means that if they are variables, they
* are also unbound.
*/
if (realTermVariable (t1) && realTermVariable (t2) && goodsubst (t1, t2))
{
/* Both are unbound variables. Decide.
*
* The plan: t1->subst will point to t2. But maybe we prefer the other
* way around?
*/
if (preferSubstitutionOrder (t2, t1))
{
Term t3;
// Swappy.
t3 = t1;
t1 = t2;
t2 = t3;
}
return callsubst (callback, state, tl, t1, t2);
}
/* symmetrical tests for single variable.
*/
if (realTermVariable (t2))
{
if (termSubTerm (t1, t2) || !goodsubst (t2, t1))
return true;
else
{
return callsubst (callback, state, tl, t2, t1);
}
}
if (realTermVariable (t1))
{
if (termSubTerm (t2, t1) || !goodsubst (t1, t2))
return true;
else
{
return callsubst (callback, state, tl, t1, t2);
}
}
/* left & right are compounds with variables */
if (t1->type != t2->type)
return true;
/* identical compound types */
/* encryption first */
if (realTermEncrypt (t1))
{
struct state_mgu_tmp tmpstate;
tmpstate.oldstate = state;
tmpstate.oldcallback = callback;
tmpstate.unifyt1 = TermOp (t1);
tmpstate.unifyt2 = TermOp (t2);
return unify (TermKey (t1), TermKey (t2), tl, unify_callback_wrapper,
&tmpstate);
}
/* tupling second
non-associative version ! TODO other version */
if (isTermTuple (t1))
{
struct state_mgu_tmp tmpstate;
tmpstate.oldstate = state;
tmpstate.oldcallback = callback;
tmpstate.unifyt1 = TermOp2 (t1);
tmpstate.unifyt2 = TermOp2 (t2);
return unify (TermOp1 (t1), TermOp1 (t2), tl, unify_callback_wrapper,
&tmpstate);
}
return true;
}
