evaluate.c

使用最广泛的radius的linux的源码

/*
 * evaluate.c		Evaluate a policy language
 *
 * Version:	$Id: evaluate.c,v 1.20 2008/03/07 10:03:35 aland Exp $
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * Copyright 2004  Alan DeKok <[e-mail]>
 * Copyright 2006  The FreeRADIUS server project
 */

#include <freeradius-devel/ident.h>
RCSID("$Id: evaluate.c,v 1.20 2008/03/07 10:03:35 aland Exp $")

#include "rlm_policy.h"

#ifdef HAVE_REGEX_H
#include <regex.h>
#endif

#define debug_evaluate if (0) printf

/*
 *	Print stuff we've parsed
 */
static void policy_print(const policy_item_t *item, int indent)
{
	if (!item) {
		if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
		fprintf(fr_log_fp, "[NULL]\n");
		return;
	}

	while (item) {
		switch (item->type) {
		case POLICY_TYPE_BAD:
			if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
			fprintf(fr_log_fp, "[BAD STATEMENT]");
			break;

		case POLICY_TYPE_PRINT:
			if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
			{
				const policy_print_t *this;

				this = (const policy_print_t *) item;

				if (this->rhs_type == POLICY_LEX_BARE_WORD) {
					fprintf(fr_log_fp, "print %s\n", this->rhs);
				} else {
					fprintf(fr_log_fp, "print \"%s\"\n", this->rhs);
				}
			}
			break;

		case POLICY_TYPE_ASSIGNMENT:
			{
				const policy_assignment_t *assign;

				assign = (const policy_assignment_t *) item;
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");

				fprintf(fr_log_fp, "\t%s %s ", assign->lhs,
				       fr_int2str(rlm_policy_tokens,
						    assign->assign, "?"));
				if (assign->rhs_type == POLICY_LEX_BARE_WORD) {
					fprintf(fr_log_fp, "%s\n", assign->rhs);
				} else {
					/*
					 *	FIXME: escape "
					 */
					fprintf(fr_log_fp, "\"%s\"\n", assign->rhs);
				}
			}
			break;

		case POLICY_TYPE_CONDITIONAL: /* no indentation here */
			{
				const policy_condition_t *condition;

				condition = (const policy_condition_t *) item;

				fprintf(fr_log_fp, "(");

				if (condition->sense) {
					fprintf(fr_log_fp, "!");
				}

				/*
				 *	Nested conditions.
				 */
				if (condition->compare == POLICY_LEX_L_BRACKET) {
					policy_print(condition->child, indent);
					fprintf(fr_log_fp, ")");
					break;
				}

				if (condition->compare == POLICY_LEX_L_NOT) {
					fprintf(fr_log_fp, "!");
					policy_print(condition->child, indent);
					fprintf(fr_log_fp, ")");
					break;
				}

				if (condition->compare == POLICY_LEX_CMP_TRUE) {
					fprintf(fr_log_fp, "%s)", condition->lhs);
					break;
				}

				if (condition->lhs_type == POLICY_LEX_FUNCTION) {
					fprintf(fr_log_fp, "%s()", condition->lhs);
				} else {
					/*
					 *	FIXME: escape ",
					 *	and move all of this logic
					 *	to a function.
					 */
					fprintf(fr_log_fp, "\"%s\"", condition->lhs);
				}

				/*
				 *	We always print this condition.
				 */
				fprintf(fr_log_fp, " %s ", fr_int2str(rlm_policy_tokens,
							    condition->compare,
							    "?"));
				if (condition->rhs_type == POLICY_LEX_BARE_WORD) {
					fprintf(fr_log_fp, "%s", condition->rhs);
				} else {
					/*
					 *	FIXME: escape ",
					 *	and move all of this logic
					 *	to a function.
					 */
					fprintf(fr_log_fp, "\"%s\"", condition->rhs);
				}
				fprintf(fr_log_fp, ")");

				if ((condition->child_condition != POLICY_LEX_BAD) &&
				    (condition->child_condition != POLICY_LEX_BARE_WORD)) {
					fprintf(fr_log_fp, " %s ", fr_int2str(rlm_policy_tokens, condition->child_condition, "?"));
					policy_print(condition->child, indent);
				}
			}
			break;

		case POLICY_TYPE_IF:
			{
				const policy_if_t *statement;

				statement = (const policy_if_t *) item;

				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "if ");
				policy_print(statement->condition, indent);
				fprintf(fr_log_fp, " {\n");
				policy_print(statement->if_true, indent + 1);
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				if (statement->if_false) {
					fprintf(fr_log_fp, "} else ");
					if (statement->if_false->type == POLICY_TYPE_ASSIGNMENT) {
						fprintf(fr_log_fp, " { ");
						policy_print(statement->if_false, indent + 1);
						if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
						fprintf(fr_log_fp, " }");
					} else {
						policy_print(statement->if_false, indent + 1);
					}
				} else {
					fprintf(fr_log_fp, "}\n");
				}
			}
			break;

		case POLICY_TYPE_ATTRIBUTE_LIST:
			{
				const policy_attributes_t *this;

				this = (const policy_attributes_t *) item;

				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "%s %s {\n",
				       fr_int2str(policy_reserved_words,
						    this->where, "?"),
				       fr_int2str(rlm_policy_tokens,
						    this->how, "?"));
				policy_print(this->attributes, indent + 1);
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "}\n");
			}
			break;

		case POLICY_TYPE_NAMED_POLICY:
			{
				const policy_named_t *this;

				this = (const policy_named_t *) item;
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "policy %s {\n", this->name);
				policy_print(this->policy, indent + 1);
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "}\n");
			}
			break;

		case POLICY_TYPE_CALL:
			{
				const policy_call_t *this;

				this = (const policy_call_t *) item;
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "call %s\n", this->name);
			}
			break;

		case POLICY_TYPE_RETURN:
			{
				const policy_return_t *this;

				this = (const policy_return_t *) item;
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "return %s\n",
				       fr_int2str(policy_return_codes,
						    this->rcode, "???"));
			}
			break;

		case POLICY_TYPE_MODULE:
			{
				const policy_module_t *this;

				this = (const policy_module_t *) item;
				if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
				fprintf(fr_log_fp, "module %s <stuff>\n",
				       fr_int2str(policy_component_names,
						    this->component, "???"));
			}
			break;

		default:
			if (indent) fprintf(fr_log_fp, "%*s", indent, " ");
			fprintf(fr_log_fp, "[HUH?]\n");
			break;

		}

		item = item->next;
	}
}


void rlm_policy_print(const policy_item_t *item)
{
	if (!fr_log_fp) return;

	fprintf(fr_log_fp, "# rlm_policy \n");
	policy_print(item, 0);
}

/*
 *	Internal stack of things to do.  This lets us have function
 *	calls...
 *
 *	Yes, we should learn lex, yacc, etc.
 */
#define POLICY_MAX_STACK 16
typedef struct policy_state_t {
	rlm_policy_t	*inst;
	REQUEST		*request; /* so it's not passed on the C stack */
	int		rcode;	/* for functions, etc. */
	int		component; /* for calling other modules */
	int		depth;
	const policy_item_t *stack[POLICY_MAX_STACK];
} policy_state_t;


static int policy_evaluate_name(policy_state_t *state, const char *name);

/*
 *	Push an item onto the state.
 */
static int policy_stack_push(policy_state_t *state, const policy_item_t *item)
{
	rad_assert(state->depth >= 0);

	/*
	 *	Asked to push nothing.  Don't push it.
	 */
	if (!item) return 1;

	/*
	 *	State is full.  Die.
	 */
	if (state->depth >= POLICY_MAX_STACK) {
		return 0;
	}

	/*
	 *	Walk back up the stack, looking for previous ocurrances
	 *	of this name.  If found, we have infinite recursion,
	 *	which we stop dead in the water!
	 *
	 *	This isn't strictly necessary right now, as we look up
	 *	policies by name when they're first referenced.  This
	 *	means that ALL references are backwards (to the start
	 *	of the file), which means that there are no circular
	 *	references.
	 */
	if (item->type == POLICY_TYPE_NAMED_POLICY) {
		int i;

		for (i = 0; i < state->depth; i++) {
			/*
			 *	Check for circular references, by seeing
			 *	if the function is already on the stack.
			 *
			 *	Hmmm... do we want to do this for any type?
			 */
			if (state->stack[i] == item) {
				debug_evaluate("Circular call to policy %s\n",
					       ((const policy_named_t *) item)->name);
				return 0;
			}
		}
	}

	debug_evaluate("push %d %p\n", state->depth, item);

	state->stack[state->depth] = item;
	state->depth++;		/* points to unused entry */

	return 1;
}


/*
 *	Pop an item from the state.
 */
static int policy_stack_pop(policy_state_t *state, const policy_item_t **pitem)
{
	rad_assert(pitem != NULL);
	rad_assert(state->depth >= 0);

 redo:
	if (state->depth == 0) {
		*pitem = NULL;
		return 0;
	}

	*pitem = state->stack[state->depth - 1];

	/*
	 *	Named policies are on the stack for catching recursion.
	 */
	if ((*pitem)->type == POLICY_TYPE_NAMED_POLICY) {
		state->depth--;
		goto redo;
	}

	/*
	 *	Process the whole item list.
	 */
	if ((*pitem)->next) {
		state->stack[state->depth - 1] = (*pitem)->next;
		debug_evaluate("pop/push %d %p\n", state->depth - 1, *pitem);
	} else {
		state->depth--;		/* points to unused entry */
		debug_evaluate("pop %d %p\n", state->depth, *pitem);
	}

	return 1;
}


/*
 *	Evaluate a print statement
 */
static int evaluate_print(policy_state_t *state, const policy_item_t *item)
{
	const policy_print_t *this;

	if (!fr_log_fp) return 1;

	this = (const policy_print_t *) item;

	if (this->rhs_type == POLICY_LEX_BARE_WORD) {
		fprintf(fr_log_fp, "%s\n", this->rhs);
	} else {
		char buffer[1024];

		radius_xlat(buffer, sizeof(buffer), this->rhs,
			    state->request, NULL);
		fprintf(fr_log_fp, "%s", buffer);
		if (!strchr(buffer, '\n')) fprintf(fr_log_fp, "\n");
	}

	/*
	 *	Doesn't change state->rcode
	 */

	return 1;
}

/*
 *	Return a VALUE_PAIR, given an attribute name.
 *
 *	FIXME: Have it return the N'th one, too, like
 *	doc/variables.txt?
 *
 *	The amount of duplicated code is getting annoying...
 */
static VALUE_PAIR *find_vp(REQUEST *request, const char *name)
{
	const char *p;
	const DICT_ATTR *dattr;
	VALUE_PAIR *vps;

	p = name;
	vps = request->packet->vps;;

	/*
	 *	FIXME: use names from reserved word list?
	 */
	if (strncasecmp(name, "request:", 8) == 0) {
		p += 8;
	} else if (strncasecmp(name, "reply:", 6) == 0) {
		p += 6;
		vps = request->reply->vps;
	} else if (strncasecmp(name, "proxy-request:", 14) == 0) {
		p += 14;
		if (request->proxy) {
			vps = request->proxy->vps;
		}
	} else if (strncasecmp(name, "proxy-reply:", 12) == 0) {
		p += 12;
		if (request->proxy_reply) {
			vps = request->proxy_reply->vps;
		}
	} else if (strncasecmp(name, "control:", 8) == 0) {
		p += 8;
		vps = request->config_items;
	} /* else it must be a bare attribute name */

	if (!vps) {
		return NULL;
	}

	dattr = dict_attrbyname(p);
	if (!dattr) {
		fprintf(stderr, "No such attribute %s\n", p);
		return NULL;	/* no such attribute */
	}

	return pairfind(vps, dattr->attr);
}


/*
 *	Evaluate an assignment
 *
 *	Not really used much...
 */
static int evaluate_assignment(UNUSED policy_state_t *state, const policy_item_t *item)
{
	const policy_assignment_t *this;
#if 0
	const DICT_ATTR *dattr;
#endif

	this = (const policy_assignment_t *) item;

	rad_assert(this->lhs != NULL);
	rad_assert(this->rhs != NULL);

#if 0
	dattr = dict_attrbyname(this->lhs);
	if (!dattr) {
		fprintf(stderr, "HUH?\n");
		return 0;
	}
#endif

	return 1;
}


/*
 *	Evaluate a condition
 */
static int evaluate_condition(policy_state_t *state, const policy_item_t *item)
{
	int rcode;
	const policy_condition_t *this;
	VALUE_PAIR *vp = NULL;
	const char *data = NULL;
	int compare;
#ifdef HAVE_REGEX_H
	regex_t reg;
#endif
	char buffer[256];
	char lhs_buffer[2048];

	this = (const policy_condition_t *) item;

 redo:
	/*
	 *	FIXME: Don't always do this...
	 */
	if (this->compare != POLICY_LEX_L_BRACKET) {
		if (this->lhs_type == POLICY_LEX_FUNCTION) {
			/*
			 *	We can't call evaluate_call here,
			 *	because that just pushes stuff onto
			 *	the stack, and we want to actually
			 *	evaluate all of it...
			 */
			rcode = policy_evaluate_name(state, this->lhs);
			data = fr_int2str(policy_return_codes, rcode, "???");
			strlcpy(lhs_buffer, data, sizeof(lhs_buffer)); /* FIXME: yuck */
		} else if (this->lhs_type == POLICY_LEX_DOUBLE_QUOTED_STRING) {
			if (radius_xlat(lhs_buffer, sizeof(lhs_buffer), this->lhs,
					state->request, NULL) > 0) {
				data = lhs_buffer;
			}
		}
	}

	switch (this->compare) {
	case POLICY_LEX_L_BRACKET: /* nested brackets are a special case */
		rcode = evaluate_condition(state, this->child);
		break;

	case POLICY_LEX_L_NOT:
		rcode = evaluate_condition(state, this->child);
		rcode = (rcode == FALSE); /* reverse sense of test */
		break;

	case POLICY_LEX_CMP_FALSE: /* non-existence */
		if (this->lhs_type == POLICY_LEX_BARE_WORD) {
			vp = find_vp(state->request, this->lhs);
			rcode = (vp == NULL);
		} else {
			rcode = (data == NULL);
		}
		break;

	case POLICY_LEX_CMP_TRUE: /* existence */
		if (this->lhs_type == POLICY_LEX_BARE_WORD) {
			vp = find_vp(state->request, this->lhs);
			rcode = (vp != NULL);
		} else {
			rcode = (data != NULL);
		}
		break;

	default:		/* process other comparisons */
		if ((this->compare != POLICY_LEX_CMP_EQUALS) &&
#ifdef HAVE_REGEX_H
		    (this->compare != POLICY_LEX_RX_EQUALS) &&
		    (this->compare != POLICY_LEX_RX_NOT_EQUALS) &&
#endif
		    (this->compare != POLICY_LEX_LT) &&
		    (this->compare != POLICY_LEX_GT) &&
		    (this->compare != POLICY_LEX_LE) &&
		    (this->compare != POLICY_LEX_GE) &&
		    (this->compare != POLICY_LEX_CMP_NOT_EQUALS)) {
			fprintf(stderr, "%d: bad comparison\n",
				this->item.lineno);
			return FALSE;
		}

		if (this->lhs_type == POLICY_LEX_BARE_WORD) {
			VALUE_PAIR *myvp;

			vp = find_vp(state->request, this->lhs);

			/*
			 *	A op B is FALSE if A doesn't
			 *	exist.
			 */
			if (!vp) {
				rcode = FALSE;
				break;
			}

			/*
			 *	FIXME: Move sanity checks to
			 *	post-parse code, so we don't do
			 *	it on every packet.
			 */
			vp_prints_value(buffer, sizeof(buffer), vp, 0);
			myvp = pairmake(vp->name, this->rhs, T_OP_EQ);
			if (!myvp) return FALSE; /* memory failure */
			data = buffer;

			/*
			 *	FIXME: What to do about comparisons
			 *	where vp doesn't exist?  Right now,
			 *	"simplepaircmp" returns -1, which is
			 *	probably a bad idea.  it should