evaluate.c

使用最广泛的radius的linux的源码

/*
 * evaluate.c	Evaluate complex conditions
 *
 * Version:	$Id: evaluate.c,v 1.42 2008/05/02 09:11:18 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 2007  The FreeRADIUS server project
 * Copyright 2007  Alan DeKok <[e-mail]>
 */

#include <freeradius-devel/ident.h>
RCSID("$Id: evaluate.c,v 1.42 2008/05/02 09:11:18 aland Exp $")

#include <freeradius-devel/radiusd.h>
#include <freeradius-devel/modules.h>
#include <freeradius-devel/rad_assert.h>

#include <ctype.h>

#ifdef HAVE_REGEX_H
#include <regex.h>

/*
 *  For POSIX Regular expressions.
 *  (0) Means no extended regular expressions.
 *  REG_EXTENDED means use extended regular expressions.
 */
#ifndef REG_EXTENDED
#define REG_EXTENDED (0)
#endif

#ifndef REG_NOSUB
#define REG_NOSUB (0)
#endif
#endif


static int all_digits(const char *string)
{
	const char *p = string;

	if (*p == '-') p++;

	while (isdigit((int) *p)) p++;

	return (*p == '\0');
}

#ifndef NDEBUG
#ifndef DEBUG4
#define DEBUG4  if (debug_flag > 4)log_debug
#endif
#else
#define DEBUG4 if (0) log_debug
#endif

static const char *filler = "????????????????????????????????????????????????????????????????";

static const char *expand_string(char *buffer, size_t sizeof_buffer,
				 REQUEST *request,
				 FR_TOKEN value_type, const char *value)
{
	int result;
	char *p;

	switch (value_type) {
	default:
	case T_BARE_WORD:
	case T_SINGLE_QUOTED_STRING:
		return value;

	case T_BACK_QUOTED_STRING:
		result = radius_exec_program(value, request, 1,
					     buffer, sizeof_buffer, NULL,
					     NULL, 0);
		if (result != 0) {
			return NULL;
		}

		/*
		 *	The result should be ASCII.
		 */
		for (p = buffer; *p != '\0'; p++) {
			if (*p < ' ' ) {
				*p = '\0';
				return buffer;
			}
		}
		return buffer;

	case T_DOUBLE_QUOTED_STRING:
		if (!strchr(value, '%')) return value;

		radius_xlat(buffer, sizeof_buffer, value, request, NULL);
		return buffer;
	}

	return NULL;
}

#ifdef HAVE_REGEX_H
static FR_TOKEN getregex(const char **ptr, char *buffer, size_t buflen,
			 int *pcflags)
{
	const char *p = *ptr;
	char *q = buffer;

	if (*p != '/') return T_OP_INVALID;

	*pcflags = REG_EXTENDED;

	p++;
	while (*p) {
		if (buflen <= 1) break;

		if (*p == '/') {
			p++;

			/*
			 *	Check for case insensitivity
			 */
			if (*p == 'i') {
				p++;
				*pcflags |= REG_ICASE;
			}

			break;
		}

		if (*p == '\\') {
			int x;
			
			switch (p[1]) {
			case 'r':
				*q++ = '\r';
				break;
			case 'n':
				*q++ = '\n';
				break;
			case 't':
				*q++ = '\t';
				break;
			case '"':
				*q++ = '"';
				break;
			case '\'':
				*q++ = '\'';
				break;
			case '`':
				*q++ = '`';
				break;
				
				/*
				 *	FIXME: add 'x' and 'u'
				 */

			default:
				if ((p[1] >= '0') && (p[1] <= '9') &&
				    (sscanf(p, "%3o", &x) == 1)) {
					*q++ = x;
					p += 2;
				} else {
					*q++ = p[1];
				}
				break;
			}
			p += 2;
			buflen--;
			continue;
		}

		*(q++) = *(p++);
		buflen--;
	}
	*q = '\0';
	*ptr = p;

	return T_DOUBLE_QUOTED_STRING;
}
#endif

static const FR_NAME_NUMBER modreturn_table[] = {
	{ "reject",     RLM_MODULE_REJECT       },
	{ "fail",       RLM_MODULE_FAIL         },
	{ "ok",         RLM_MODULE_OK           },
	{ "handled",    RLM_MODULE_HANDLED      },
	{ "invalid",    RLM_MODULE_INVALID      },
	{ "userlock",   RLM_MODULE_USERLOCK     },
	{ "notfound",   RLM_MODULE_NOTFOUND     },
	{ "noop",       RLM_MODULE_NOOP         },
	{ "updated",    RLM_MODULE_UPDATED      },
	{ NULL, 0 }
};


static int radius_get_vp(REQUEST *request, const char *name, VALUE_PAIR **vp_p)
			
{
	const char *vp_name = name;
	REQUEST *myrequest = request;
	DICT_ATTR *da;
	VALUE_PAIR *vps = NULL;

	*vp_p = NULL;

	/*
	 *	Allow for tunneled sessions.
	 */
	if (strncmp(vp_name, "outer.", 6) == 0) {
		if (!myrequest->parent) return TRUE;
		vp_name += 6;
		myrequest = myrequest->parent;
	}

	if (strncmp(vp_name, "request:", 8) == 0) {
		vp_name += 8;
		vps = myrequest->packet->vps;

	} else if (strncmp(vp_name, "reply:", 6) == 0) {
		vp_name += 6;
		vps = myrequest->reply->vps;

	} else if (strncmp(vp_name, "proxy-request:", 14) == 0) {
		vp_name += 14;
		if (request->proxy) vps = myrequest->proxy->vps;

	} else if (strncmp(vp_name, "proxy-reply:", 12) == 0) {
		vp_name += 12;
		if (request->proxy_reply) vps = myrequest->proxy_reply->vps;

	} else if (strncmp(vp_name, "config:", 7) == 0) {
		vp_name += 7;
		vps = myrequest->config_items;

	} else if (strncmp(vp_name, "control:", 8) == 0) {
		vp_name += 8;
		vps = myrequest->config_items;

	} else {
		vps = myrequest->packet->vps;
	}

	da = dict_attrbyname(vp_name);
	if (!da) return FALSE;	/* not a dictionary name */

	/*
	 *	May not may not be found, but it *is* a known name.
	 */
	*vp_p = pairfind(vps, da->attr);
	return TRUE;
}


/*
 *	*presult is "did comparison match or not"
 */
static int radius_do_cmp(REQUEST *request, int *presult,
			 FR_TOKEN lt, const char *pleft, FR_TOKEN token,
			 FR_TOKEN rt, const char *pright,
			 int cflags, int modreturn)
{
	int result;
	int lint, rint;
	VALUE_PAIR *vp = NULL;
	char buffer[1024];

	rt = rt;		/* -Wunused */

	if (lt == T_BARE_WORD) {
		/*
		 *	Maybe check the last return code.
		 */
		if (token == T_OP_CMP_TRUE) {
			int isreturn;

			/*
			 *	Looks like a return code, treat is as such.
			 */
			isreturn = fr_str2int(modreturn_table, pleft, -1);
			if (isreturn != -1) {
				*presult = (modreturn == isreturn);
				return TRUE;
			}
		}

		/*
		 *	Bare words on the left can be attribute names.
		 */
		if (radius_get_vp(request, pleft, &vp)) {
			VALUE_PAIR myvp;

			/*
			 *	VP exists, and that's all we're looking for.
			 */
			if (token == T_OP_CMP_TRUE) {
				*presult = (vp != NULL);
				return TRUE;
			}

			if (!vp) {
				DEBUG2("    (Attribute %s was not found)",
				       pleft);
				return FALSE;
			}

#ifdef HAVE_REGEX_H
			/*
			 * 	Regex comparisons treat everything as
			 *	strings.
			 */
			if ((token == T_OP_REG_EQ) ||
			    (token == T_OP_REG_NE)) {
				vp_prints_value(buffer, sizeof(buffer), vp, 0);
				pleft = buffer;
				goto do_checks;
			}
#endif

			memcpy(&myvp, vp, sizeof(myvp));
			if (!pairparsevalue(&myvp, pright)) {
				DEBUG2("Failed parsing \"%s\": %s",
				       pright, librad_errstr);
				return FALSE;
			}

			myvp.operator = token;
			*presult = paircmp(&myvp, vp);
			return TRUE;
		} /* else it's not a attribute in the dictionary */
	}

	do_checks:
	switch (token) {
	case T_OP_GE:
	case T_OP_GT:
	case T_OP_LE:
	case T_OP_LT:
		if (!all_digits(pright)) {
			DEBUG2("    (Right field is not a number at: %s)", pright);
			return FALSE;
		}
		rint = atoi(pright);
		if (!all_digits(pleft)) {
			DEBUG2("    (Left field is not a number at: %s)", pleft);
			return FALSE;
		}
		lint = atoi(pleft);
		break;
		
	default:
		lint = rint = 0;  /* quiet the compiler */
		break;
	}
	
	switch (token) {
	case T_OP_CMP_TRUE:
		/*
		 *	Check for truth or falsehood.
		 */
		if (all_digits(pleft)) {
			lint = atoi(pleft);
			result = (lint != 0);
			
		} else {
			result = (*pleft != '\0');
		}
		break;
		

	case T_OP_CMP_EQ:
		result = (strcmp(pleft, pright) == 0);
		break;
		
	case T_OP_NE:
		result = (strcmp(pleft, pright) != 0);
		break;
		
	case T_OP_GE:
		result = (lint >= rint);
		break;
		
	case T_OP_GT:
		result = (lint > rint);
		break;
		
	case T_OP_LE:
		result = (lint <= rint);
		break;
		
	case T_OP_LT:
		result = (lint < rint);
		break;

#ifdef HAVE_REGEX_H
	case T_OP_REG_EQ: {
		int i, compare;
		regex_t reg;
		regmatch_t rxmatch[REQUEST_MAX_REGEX + 1];
		
		/*
		 *	Include substring matches.
		 */
		regcomp(&reg, pright, cflags);
		compare = regexec(&reg, pleft,
				  REQUEST_MAX_REGEX + 1,
				  rxmatch, 0);
		regfree(&reg);
		
		/*
		 *	Add new %{0}, %{1}, etc.
		 */
		if (compare == 0) for (i = 0; i <= REQUEST_MAX_REGEX; i++) {
			char *r;

			free(request_data_get(request, request,
					      REQUEST_DATA_REGEX | i));
			/*
			 *	No %{i}, skip it.
			 *	We MAY have %{2} without %{1}.
			 */
			if (rxmatch[i].rm_so == -1) continue;
			
			/*
			 *	Copy substring into buffer.
			 */
			memcpy(buffer, pleft + rxmatch[i].rm_so,
			       rxmatch[i].rm_eo - rxmatch[i].rm_so);
			buffer[rxmatch[i].rm_eo - rxmatch[i].rm_so] = '\0';
			
			/*
			 *	Copy substring, and add it to
			 *	the request.
			 *
			 *	Note that we don't check
			 *	for out of memory, which is
			 *	the only error we can get...
			 */
			r = strdup(buffer);
			request_data_add(request, request,
					 REQUEST_DATA_REGEX | i,
					 r, free);
		}
		result = (compare == 0);
	}
		break;
		
	case T_OP_REG_NE: {
		int compare;
		regex_t reg;
		regmatch_t rxmatch[REQUEST_MAX_REGEX + 1];
		
		/*
		 *	Include substring matches.
		 */
		regcomp(&reg, pright, cflags);
		compare = regexec(&reg, pleft,
				  REQUEST_MAX_REGEX + 1,
				  rxmatch, 0);
		regfree(&reg);
		
		result = (compare != 0);
	}
		break;
#endif
		
	default:
		DEBUG4(">>> NOT IMPLEMENTED %d", token);
		result = FALSE;
		break;
	}
	
	*presult = result;
	return TRUE;
}

int radius_evaluate_condition(REQUEST *request, int modreturn, int depth,
			      const char **ptr, int evaluate_it, int *presult)
{
	int found_condition = FALSE;
	int result = TRUE;
	int invert = FALSE;
	int evaluate_next_condition = evaluate_it;
	const char *p = *ptr;
	const char *q, *start;
	FR_TOKEN token, lt, rt;
	char left[1024], right[1024], comp[4];
	const char *pleft, *pright;
	char  xleft[1024], xright[1024];
#ifdef HAVE_REGEX_H
	int cflags = 0;
#endif

	if (!ptr || !*ptr || (depth >= 64)) {
		radlog(L_ERR, "Internal sanity check failed in evaluate condition");
		return FALSE;
	}

	while (*p) {
		while ((*p == ' ') || (*p == '\t')) p++;

		if (*p == '!') {
			DEBUG4(">>> INVERT");
			invert = TRUE;
			p++;
		}

		/*
		 *	It's a subcondition.
		 */
		if (*p == '(') {
			const char *end = p + 1;

			/*
			 *	Evaluate the condition, bailing out on
			 *	parse error.
			 */
			DEBUG4(">>> CALLING EVALUATE %s", end);
			if (!radius_evaluate_condition(request, modreturn,
						       depth + 1, &end,
						       evaluate_next_condition,
						       &result)) {
				return FALSE;
			}

			if (invert && evaluate_next_condition) {
				DEBUG2("%.*s Converting !%s -> %s",
				       depth, filler,
				       (result != FALSE) ? "TRUE" : "FALSE",
				       (result == FALSE) ? "TRUE" : "FALSE");

				       
				result = (result == FALSE);
				invert = FALSE;
			}

			/*
			 *	Start from the end of the previous
			 *	condition
			 */
			p = end;
			DEBUG4(">>> EVALUATE RETURNED ::%s::", end);
			
			if (!((*p == ')') || (*p == '!') ||
			      ((p[0] == '&') && (p[1] == '&')) ||
			      ((p[0] == '|') && (p[1] == '|')))) {

				radlog(L_ERR, "Parse error in condition at: %s", p);
				return FALSE;
			}
			if (*p == ')') p++;	/* skip it */
			found_condition = TRUE;
			
			while ((*p == ' ') || (*p == '\t')) p++;

			/*
			 *	EOL.  It's OK.
			 */
			if (!*p) {
				DEBUG4(">>> AT EOL");
				*ptr = p;
				*presult = result;
				return TRUE;
				
				/*
				 *	(A && B) means "evaluate B
				 *	only if A was true"
				 */
			} else if ((p[0] == '&') && (p[1] == '&')) {
				if (result == TRUE) {
					evaluate_next_condition = evaluate_it;
				} else {
					evaluate_next_condition = FALSE;
				}
				p += 2;
				
				/*
				 *	(A || B) means "evaluate B
				 *	only if A was false"
				 */
			} else if ((p[0] == '|') && (p[1] == '|')) {
				if (result == FALSE) {
					evaluate_next_condition = evaluate_it;
				} else {
					evaluate_next_condition = FALSE;
				}
				p += 2;

			} else if (*p == ')') {
				DEBUG4(">>> CLOSING BRACE");
				*ptr = p;
				*presult = result;
				return TRUE;

			} else {
				/*
				 *	Parse error
				 */