/*
 * $LynxId: HTRules.c,v 1.47 2017/07/02 19:45:22 tom Exp $
 *
 *	Configuration manager for Hypertext Daemon		HTRules.c
 *	==========================================
 *
 *
 * History:
 *	 3 Jun 91	Written TBL
 *	10 Aug 91	Authorisation added after Daniel Martin (pass, fail)
 *			Rule order in file changed
 *			Comments allowed with # on 1st char of rule line
 *	17 Jun 92	Bug fix: pass and fail failed if didn't contain '*' TBL
 *	 1 Sep 93	Bug fix: no memory check - Nathan Torkington
 *			BYTE_ADDRESSING removed - Arthur Secret
 *	11 Sep 93  MD	Changed %i into %d in debug printf.
 *			VMS does not recognize %i.
 *			Bug Fix: in case of PASS, only one parameter to printf.
 *	19 Sep 93  AL	Added Access Authorization stuff.
 *	 1 Nov 93  AL	Added htbin.
 *	25 May 99  KW	Added redirect for lynx.
 *
 */

#include <HTUtils.h>

/* (c) CERN WorldWideWeb project 1990,91. See Copyright.html for details */
#include <HTRules.h>

#include <HTFile.h>
#include <LYLeaks.h>
#include <HTAAProt.h>

#define LINE_LENGTH 256

typedef struct _rule {
    struct _rule *next;
    HTRuleOp op;
    char *pattern;
    char *equiv;
    char *condition_op;		/* as strings - may be inefficient, */
    char *condition;		/* but this is not for a server - kw */
} rule;

#ifndef NO_RULES

#include <HTTP.h>		/* for redirecting_url, indirectly HTPermitRedir - kw */
#include <LYGlobalDefs.h>	/* for LYUserSpecifiedURL - kw */
#include <LYStrings.h>		/* for LYscanFloat */
#include <LYUtils.h>		/* for LYFixCursesOn - kw */
#include <HTAlert.h>

/*	Global variables
 *	----------------
 */
char *HTBinDir = NULL;		/* Physical /htbin directory path.      */

				/* In future this should not be global. */
char *HTSearchScript = NULL;	/* Search script name.          */

/*	Module-wide variables
 *	---------------------
 */

static rule *rules = 0;		/* Pointer to first on list */

#ifndef PUT_ON_HEAD
static rule *rule_tail = 0;	/* Pointer to last on list */
#endif

/*	Add rule to the list					HTAddRule()
 *	--------------------
 *
 *  On entry,
 *	pattern		points to 0-terminated string containing a single "*"
 *	equiv		points to the equivalent string with * for the
 *			place where the text matched by * goes.
 *  On exit,
 *	returns		0 if success, -1 if error.
 */

int HTAddRule(HTRuleOp op, const char *pattern,
	      const char *equiv,
	      const char *cond_op,
	      const char *cond)
{				/* BYTE_ADDRESSING removed and memory check - AS - 1 Sep 93 */
    rule *temp;
    char *pPattern = NULL;

    temp = typecalloc(rule);
    if (temp == NULL)
	outofmem(__FILE__, "HTAddRule");

    if (equiv) {		/* Two operands */
	char *pEquiv = NULL;

	StrAllocCopy(pEquiv, equiv);
	temp->equiv = pEquiv;
    } else {
	temp->equiv = 0;
    }
    if (cond_op) {
	StrAllocCopy(temp->condition_op, cond_op);
	StrAllocCopy(temp->condition, cond);
    }
    StrAllocCopy(pPattern, pattern);
    temp->pattern = pPattern;
    temp->op = op;

    if (equiv) {
	CTRACE((tfp, "Rule: For `%s' op %d `%s'", pattern, (int) op, equiv));
    } else {
	CTRACE((tfp, "Rule: For `%s' op %d", pattern, (int) op));
    }
    if (cond_op) {
	CTRACE((tfp, "\t%s %s\n", cond_op, NONNULL(cond)));
    } else {
	CTRACE((tfp, "\n"));
    }

    if (!rules) {
#ifdef LY_FIND_LEAKS
	atexit(HTClearRules);
#endif
    }
#ifdef PUT_ON_HEAD
    temp->next = rules;
    rules = temp;
#else
    temp->next = 0;
    if (rule_tail)
	rule_tail->next = temp;
    else
	rules = temp;
    rule_tail = temp;
#endif

    return 0;
}

/*	Clear all rules						HTClearRules()
 *	---------------
 *
 * On exit,
 *	There are no rules
 *
 * See also
 *	HTAddRule()
 */
void HTClearRules(void)
{
    while (rules) {
	rule *temp = rules;

	rules = temp->next;
	FREE(temp->pattern);
	FREE(temp->equiv);
	FREE(temp->condition_op);
	FREE(temp->condition);
	FREE(temp);
    }
#ifndef PUT_ON_HEAD
    rule_tail = 0;
#endif
}

static BOOL rule_cond_ok(rule * r)
{
    BOOL result;

    if (!r->condition_op)
	return YES;
    if (strcmp(r->condition_op, "if") && strcmp(r->condition_op, "unless")) {
	CTRACE((tfp, "....... rule ignored, unrecognized `%s'!\n",
		r->condition_op));
	return NO;
    }
    if (!strcmp(r->condition, "redirected"))
	result = (BOOL) (redirection_attempts > 0);
    else if (!strcmp(r->condition, "userspec"))
	result = LYUserSpecifiedURL;
    else {
	CTRACE((tfp, "....... rule ignored, unrecognized `%s %s'!\n",
		r->condition_op, NONNULL(r->condition)));
	return NO;
    }
    if (!strcmp(r->condition_op, "if"))
	return result;
    else
	return (BOOL) (!result);

}

/*	Translate by rules					HTTranslate()
 *	------------------
 *
 *	The most recently defined rules are applied first.
 *
 * On entry,
 *	required	points to a string whose equivalent value is needed
 * On exit,
 *	returns		the address of the equivalent string allocated from
 *			the heap which the CALLER MUST FREE. If no translation
 *			occurred, then it is a copy of the original.
 * NEW FEATURES:
 *			When a "protect" or "defprot" rule is matched,
 *			a call to HTAA_setCurrentProtection() or
 *			HTAA_setDefaultProtection() is made to notify
 *			the Access Authorization module that the file is
 *			protected, and so it knows how to handle it.
 *								-- AL
 */
char *HTTranslate(const char *required)
{
    rule *r;
    char *current = NULL;
    char *msgtmp = NULL;
    const char *pMsg;
    int proxy_none_flag = 0;
    int permitredir_flag = 0;

    StrAllocCopy(current, required);

    HTAA_clearProtections();	/* Reset from previous call -- AL */

    for (r = rules; r; r = r->next) {
	char *p = r->pattern;
	int m = 0;		/* Number of characters matched against wildcard */
	const char *q = current;

	for (; *p && *q; p++, q++) {	/* Find first mismatch */
	    if (*p != *q)
		break;
	}

	if (*p == '*') {	/* Match up to wildcard */
	    m = (int) strlen(q) - (int) strlen(p + 1);	/* Amount to match to wildcard */
	    if (m < 0)
		continue;	/* tail is too short to match */
	    if (0 != strcmp(q + m, p + 1))
		continue;	/* Tail mismatch */
	} else
	    /* Not wildcard */ if (*p != *q)
	    continue;		/* plain mismatch: go to next rule */

	if (!rule_cond_ok(r))	/* check condition, next rule if false - kw */
	    continue;

	switch (r->op) {	/* Perform operation */

	case HT_DefProt:
	case HT_Protect:
#ifdef ACCESS_AUTH
	    {
		char *local_copy = NULL;
		char *p2;
		char *eff_ids = NULL;
		char *prot_file = NULL;

		CTRACE((tfp, "HTRule: `%s' matched %s %s: `%s'\n",
			current,
			(r->op == HT_Protect ? "Protect" : "DefProt"),
			"rule, setup",
			(r->equiv ? r->equiv :
			 (r->op == HT_Protect ? "DEFAULT" : "NULL!!"))));

		if (r->equiv) {
		    StrAllocCopy(local_copy, r->equiv);
		    p2 = local_copy;
		    prot_file = HTNextField(&p2);
		    eff_ids = HTNextField(&p2);
		}

		if (r->op == HT_Protect)
		    HTAA_setCurrentProtection(current, prot_file, eff_ids);
		else
		    HTAA_setDefaultProtection(current, prot_file, eff_ids);

		FREE(local_copy);

		/* continue translating rules */
	    }
#endif /* ACCESS_AUTH */
	    break;

	case HT_UserMsg:	/* Produce message immediately */
	    LYFixCursesOn("show rule message:");
	    HTUserMsg2((r->equiv ? r->equiv : "Rule: %s"), current);
	    break;
	case HT_InfoMsg:	/* Produce messages immediately */
	case HT_Progress:
	case HT_Alert:
	    LYFixCursesOn("show rule message:");	/* and fall through */
	    /* FALLTHRU */
	case HT_AlwaysAlert:
	    pMsg = r->equiv ? r->equiv :
		(r->op == HT_AlwaysAlert) ? "%s" : "Rule: %s";
	    if (StrChr(pMsg, '%')) {
		HTSprintf0(&msgtmp, pMsg, current);
		pMsg = msgtmp;
	    }
	    switch (r->op) {	/* Actually produce message */
	    case HT_InfoMsg:
		HTInfoMsg(pMsg);
		break;
	    case HT_Progress:
		HTProgress(pMsg);
		break;
	    case HT_Alert:
		HTAlert(pMsg);
		break;
	    case HT_AlwaysAlert:
		HTAlwaysAlert("Rule alert:", pMsg);
		break;
	    default:
		break;
	    }
	    FREE(msgtmp);
	    break;

	case HT_PermitRedir:	/* Set special flag */
	    permitredir_flag = 1;
	    CTRACE((tfp, "HTRule: Mark for redirection permitted\n"));
	    break;

	case HT_Pass:		/* Authorised */
	    if (!r->equiv) {
		if (proxy_none_flag) {
		    char *temp = NULL;

		    StrAllocCopy(temp, "NoProxy=");
		    StrAllocCat(temp, current);
		    FREE(current);
		    current = temp;
		}
		CTRACE((tfp, "HTRule: Pass `%s'\n", current));
		return current;
	    }
	    /* FALLTHRU */

	case HT_Map:
	case HT_Redirect:
	case HT_RedirectPerm:
	    if (*p == *q) {	/* End of both strings, no wildcard */
		CTRACE((tfp, "For `%s' using `%s'\n", current, r->equiv));
		StrAllocCopy(current, r->equiv);	/* use entire translation */
	    } else {
		char *ins = StrChr(r->equiv, '*');	/* Insertion point */

		if (ins) {	/* Consistent rule!!! */
		    char *temp = NULL;

		    HTSprintf0(&temp, "%.*s%.*s%s",
			       (int) (ins - r->equiv),
			       r->equiv,
			       m,
			       q,
			       ins + 1);
		    CTRACE((tfp, "For `%s' using `%s'\n",
			    current, temp));
		    FREE(current);
		    current = temp;	/* Use this */

		} else {	/* No insertion point */
		    char *temp = NULL;

		    StrAllocCopy(temp, r->equiv);
		    CTRACE((tfp, "For `%s' using `%s'\n",
			    current, temp));
		    FREE(current);
		    current = temp;	/* Use this */
		}		/* If no insertion point exists */
	    }
	    if (r->op == HT_Pass) {
		if (proxy_none_flag) {
		    char *temp = NULL;

		    StrAllocCopy(temp, "NoProxy=");
		    StrAllocCat(temp, current);
		    FREE(current);
		    current = temp;
		}
		CTRACE((tfp, "HTRule: ...and pass `%s'\n",
			current));
		return current;
	    } else if (r->op == HT_Redirect) {
		CTRACE((tfp, "HTRule: ...and redirect to `%s'\n",
			current));
		redirecting_url = current;
		HTPermitRedir = (BOOL) (permitredir_flag == 1);
		return (char *) 0;
	    } else if (r->op == HT_RedirectPerm) {
		CTRACE((tfp, "HTRule: ...and redirect like 301 to `%s'\n",
			current));
		redirecting_url = current;
		permanent_redirection = TRUE;
		HTPermitRedir = (BOOL) (permitredir_flag == 1);
		return (char *) 0;
	    }
	    break;

	case HT_UseProxy:
	    if (r->equiv && 0 == strcasecomp(r->equiv, "none")) {
		CTRACE((tfp, "For `%s' will not use proxy\n", current));
		proxy_none_flag = 1;
	    } else if (proxy_none_flag) {
		CTRACE((tfp, "For `%s' proxy server ignored: %s\n",
			current,
			NONNULL(r->equiv)));
	    } else {
		char *temp = NULL;

		StrAllocCopy(temp, "Proxied=");
		StrAllocCat(temp, r->equiv);
		StrAllocCat(temp, current);
		CTRACE((tfp, "HTRule: proxy server found: %s\n",
			NONNULL(r->equiv)));
		FREE(current);
		return temp;
	    }
	    break;

	case HT_Invalid:
	case HT_Fail:		/* Unauthorised */
	    CTRACE((tfp, "HTRule: *** FAIL `%s'\n", current));
	    FREE(current);
	    return (char *) 0;
	}			/* if tail matches ... switch operation */

    }				/* loop over rules */

    if (proxy_none_flag) {
	char *temp = NULL;

	StrAllocCopy(temp, "NoProxy=");
	StrAllocCat(temp, current);
	FREE(current);
	return temp;
    }

    return current;
}

/*	Load one line of configuration
 *	------------------------------
 *
 *	Call this, for example, to load a X resource with config info.
 *
 * returns	0 OK, < 0 syntax error.
 */
int HTSetConfiguration(char *config)
{
    HTRuleOp op;
    char *line = NULL;
    char *pointer = NULL;
    char *word1;
    const char *word2;
    const char *word3;
    const char *cond_op = NULL;
    const char *cond = NULL;
    float quality, secs, secs_per_byte;
    long maxbytes;
    int status;

    StrAllocCopy(line, config);
    if (line != NULL) {
	char *p = line;

	/* Chop off comments */
	while ((p = StrChr(p, '#'))) {
	    if (p == line || isspace(UCH(*(p - 1)))) {
		*p = 0;
		break;
	    } else {
		p++;
	    }
	}
    }
    pointer = line;
    word1 = HTNextField(&pointer);
    if (!word1) {
	FREE(line);
	return 0;
    };				/* Comment only or blank */

    word2 = HTNextField(&pointer);

    if (0 == strcasecomp(word1, "defprot") ||
	0 == strcasecomp(word1, "protect"))
	word3 = pointer;	/* The rest of the line to be parsed by AA module */
    else
	word3 = HTNextField(&pointer);	/* Just the next word */

    if (!word2) {
	fprintf(stderr, "HTRule: %s %s\n", RULE_NEEDS_DATA, line);
	FREE(line);
	return -2;		/*syntax error */
    }

    if (0 == strcasecomp(word1, "suffix")) {
	char *encoding = HTNextField(&pointer);

	status = 0;
	if (pointer)
	    status = LYscanFloat(pointer, &quality);

	HTSetSuffix(word2, word3,
		    encoding ? encoding : "binary",
		    status >= 1 ? quality : (float) 1.0);

    } else if (0 == strcasecomp(word1, "presentation")) {
	status = 0;
	if (pointer) {
	    const char *temp = pointer;

	    if (LYscanFloat2(&temp, &quality)) {
		status = 1;
		if (LYscanFloat2(&temp, &secs)) {
		    status = 2;
		    if (LYscanFloat2(&temp, &secs_per_byte)) {
			status = 3;
			if (sscanf(temp, "%ld", &maxbytes)) {
			    status = 4;
			}
		    }
		}
	    }
	}

	HTSetPresentation(word2, word3, NULL,
			  status >= 1 ? quality : 1.0,
			  status >= 2 ? secs : 0.0,
			  status >= 3 ? secs_per_byte : 0.0,
			  status >= 4 ? maxbytes : 0,
			  mediaCFG);

    } else if (0 == strncasecomp(word1, "htbin", 5) ||
	       0 == strncasecomp(word1, "bindir", 6)) {
	StrAllocCopy(HTBinDir, word2);	/* Physical /htbin location */

    } else if (0 == strncasecomp(word1, "search", 6)) {
	StrAllocCopy(HTSearchScript, word2);	/* Search script name */

    } else {
	op = 0 == strcasecomp(word1, "map") ? HT_Map
	    : 0 == strcasecomp(word1, "pass") ? HT_Pass
	    : 0 == strcasecomp(word1, "fail") ? HT_Fail
	    : 0 == strcasecomp(word1, "redirect") ? HT_Redirect
	    : 0 == strncasecomp(word1, "redirectperm", 12) ? HT_RedirectPerm
	    : 0 == strcasecomp(word1, "redirecttemp") ? HT_Redirect
	    : 0 == strcasecomp(word1, "permitredirection") ? HT_PermitRedir
	    : 0 == strcasecomp(word1, "useproxy") ? HT_UseProxy
	    : 0 == strcasecomp(word1, "alert") ? HT_Alert
	    : 0 == strcasecomp(word1, "alwaysalert") ? HT_AlwaysAlert
	    : 0 == strcasecomp(word1, "progress") ? HT_Progress
	    : 0 == strcasecomp(word1, "usermsg") ? HT_UserMsg
	    : 0 == strcasecomp(word1, "infomsg") ? HT_InfoMsg
	    : 0 == strcasecomp(word1, "defprot") ? HT_DefProt
	    : 0 == strcasecomp(word1, "protect") ? HT_Protect
	    : HT_Invalid;
	if (op == HT_Invalid) {
	    fprintf(stderr, "HTRule: %s '%s'\n", RULE_INCORRECT, config);
	} else {
	    switch (op) {
	    case HT_Fail:	/* never a or other 2nd parameter */
	    case HT_PermitRedir:
		cond_op = word3;
		if (cond_op && *cond_op) {
		    word3 = NULL;
		    cond = HTNextField(&pointer);
		}
		break;

	    case HT_Pass:	/* possibly a URL2 */
		if (word3 && (!strcasecomp(word3, "if") ||
			      !strcasecomp(word3, "unless"))) {
		    cond_op = word3;
		    word3 = NULL;
		    cond = HTNextField(&pointer);
		    break;
		}
		/* else fall through */
	    case HT_Map:	/* always a URL2 (or other 2nd parameter) */
	    case HT_Redirect:
	    case HT_RedirectPerm:
	    case HT_UseProxy:
		cond_op = HTNextField(&pointer);
		/* check for extra status word in "Redirect" */
		if (op == HT_Redirect && 0 == strcasecomp(word1, "redirect") &&
		    cond_op &&
		    strcasecomp(cond_op, "if") &&
		    strcasecomp(cond_op, "unless")) {
		    if (0 == strcmp(word2, "301") ||
			0 == strcasecomp(word2, "permanent")) {
			op = HT_RedirectPerm;
		    } else if (!(0 == strcmp(word2, "302") ||
				 0 == strcmp(word2, "303") ||
				 0 == strcasecomp(word2, "temp") ||
				 0 == strcasecomp(word2, "seeother"))) {
			CTRACE((tfp, "Rule: Ignoring `%s' in Redirect\n", word2));
		    }
		    word2 = word3;
		    word3 = cond_op;	/* cond_op isn't condition op after all */
		    cond_op = HTNextField(&pointer);
		}
		if (cond_op && *cond_op)
		    cond = HTNextField(&pointer);
		break;

	    case HT_Progress:
	    case HT_InfoMsg:
	    case HT_UserMsg:
	    case HT_Alert:
	    case HT_AlwaysAlert:
		cond_op = HTNextField(&pointer);
		if (cond_op && *cond_op)
		    cond = HTNextField(&pointer);
		if (word3) {	/* Fix string with too may %s - kw */
		    const char *cp = word3;
		    char *cp1, *cp2;

		    while ((cp1 = StrChr(cp, '%'))) {
			if (cp1[1] == '\0') {
			    *cp1 = '\0';
			    break;
			} else if (cp1[1] == '%') {
			    cp = cp1 + 2;
			    continue;
			} else
			    while ((cp2 = StrChr(cp1 + 2, '%'))) {
				if (cp2[1] == '\0') {
				    *cp2 = '\0';
				    break;
				} else if (cp2[1] == '%') {
				    cp1 = cp2;
				} else {
				    *cp2 = '?';		/* replace bad % */
				    cp1 = cp2;
				}
			    }
			break;
		    }
		}
		break;

	    default:
		break;
	    }
	    if (cond_op && cond && *cond && !strcasecomp(cond_op, "unless")) {
		cond_op = "unless";
	    } else if (cond_op && cond && *cond &&
		       !strcasecomp(cond_op, "if")) {
		cond_op = "if";
	    } else if (cond_op || cond) {
		fprintf(stderr, "HTRule: %s '%s'\n", RULE_INCORRECT, config);
		FREE(line);	/* syntax error, condition is a mess - kw */
		return -2;	/* NB unrecognized cond passes here - kw */
	    }
	    if (cond && !strncasecomp(cond, "redirected", (int) strlen(cond))) {
		cond = "redirected";	/* recognized, canonical case - kw */
	    } else if (cond && strlen(cond) >= 8 &&
		       !strncasecomp(cond, "userspecified", (int) strlen(cond))) {
		cond = "userspec";	/* also allow abbreviation - kw */
	    }
	    HTAddRule(op, word2, word3, cond_op, cond);
	}
    }
    FREE(line);
    return 0;
}

/*	Load the rules from a file				HTLoadRules()
 *	--------------------------
 *
 * On entry,
 *	Rules can be in any state
 * On exit,
 *	Any existing rules will have been kept.
 *	Any new rules will have been loaded.
 *	Returns		0 if no error, 0 if error!
 *
 * Bugs:
 *	The strings may not contain spaces.
 */

int HTLoadRules(const char *filename)
{
    FILE *fp = fopen(filename, TXT_R);
    char line[LINE_LENGTH + 1];

    if (!fp) {
	CTRACE((tfp, "HTRules: Can't open rules file %s\n", filename));
	return -1;		/* File open error */
    }
    for (;;) {
	if (!fgets(line, LINE_LENGTH + 1, fp))
	    break;		/* EOF or error */
	(void) HTSetConfiguration(line);
    }
    fclose(fp);
    return 0;			/* No error or syntax errors ignored */
}

#endif /* NO_RULES */