/*
 *   This program is is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License, version 2 if the
 *   License as published by the Free Software Foundation.
 *
 *   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
 */

/**
 * $Id: 9c4a2f0b402710c4d8ed7825043646870ed1c6db $
 * @file rlm_passwd.c
 * @brief Enables authentication against unix passwd files.
 *
 * @copyright 2000,2006  The FreeRADIUS server project
 */
RCSID("$Id: 9c4a2f0b402710c4d8ed7825043646870ed1c6db $")

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

struct mypasswd {
	struct mypasswd *next;
	char *listflag;
	char *field[1];
};

struct hashtable {
	int tablesize;
	int keyfield;
	int nfields;
	int islist;
	int ignorenis;
	char * filename;
	struct mypasswd **table;
	char buffer[1024];
	FILE *fp;
	char delimiter;
};


#ifdef TEST

#define rad_malloc(s) malloc(s)

void printpw(struct mypasswd *pw, int nfields){
	int i;
	if (pw) {
		for( i = 0; i < nfields; i++ ) printf("%s:", pw->field[i]);
		printf("\n");
	}
	else printf ("Not found\n");
	fflush(stdout);
}
#endif


static struct mypasswd * mypasswd_malloc(char const* buffer, int nfields, size_t* len)
{
	struct mypasswd *t;
	/* reserve memory for (struct mypasswd) + listflag (nfields * sizeof (char*)) +
	** fields (nfields * sizeof (char)) + strlen (inst->format) + 1 */

  	*len=sizeof (struct mypasswd) + nfields * sizeof (char*) + nfields * sizeof (char ) + strlen(buffer) + 1;
	t = (struct mypasswd *) rad_malloc(*len);
	if (t) memset(t, 0, *len);
  	return (t);
}

static int string_to_entry(char const* string, int nfields, char delimiter,
			   struct mypasswd *passwd, size_t bufferlen)
{
	char *str;
	size_t len, i;
	int fn=0;
	char *data_beg;


	len = strlen(string);
	if(!len) return 0;
	if (string[len-1] == '\n') len--;
	if(!len) return 0;
	if (string[len-1] == '\r') len--;
	if(!len) return 0;
	if (!len || !passwd ||
	    bufferlen < (len + nfields * sizeof (char*) + nfields * sizeof (char) + sizeof (struct mypasswd) + 1) ) return 0;
	passwd->next = NULL;
	data_beg=(char *)passwd + sizeof(struct mypasswd);
	str = data_beg + nfields * sizeof (char) + nfields * sizeof (char*);
	memcpy (str, string, len);
	str[len] = 0;
	passwd->field[fn++] = str;
	passwd->listflag = data_beg + nfields * sizeof (char *);
	for(i=0; i < len; i++){
		if (str[i] == delimiter) {
			str[i] = 0;
			passwd->field[fn++] = str + i + 1;
			if (fn == nfields) break;
		}
	}
	for (; fn < nfields; fn++) passwd->field[fn] = NULL;
	return len + nfields * sizeof (char) + nfields * sizeof (char*) + sizeof (struct mypasswd) + 1;
}


static void destroy_password (struct mypasswd * pass)
{
	struct mypasswd *p;
	while ((p=pass)!=NULL) {
		pass = pass->next;
		free(p);
	}
}


static unsigned int hash(char const * username, unsigned int tablesize)
{
	int h=1;
	while (*username) {
		h = h * 7907 + *username++;
	}
	return h%tablesize;
}

static void release_hash_table(struct hashtable * ht){
	int i;

	if (!ht) return;
	for (i = 0; i < ht->tablesize; i++)
 		if (ht->table[i])
 			destroy_password(ht->table[i]);
	if (ht->table) {
		free(ht->table);
		ht->table = NULL;
	}
	if (ht->fp) {
		fclose(ht->fp);
		ht->fp = NULL;
	}
	ht->tablesize = 0;
}

static void release_ht(struct hashtable * ht){
	if (!ht) return;
	release_hash_table(ht);
	if (ht->filename) {
		free(ht->filename);
		ht->filename = NULL;
	}
	free(ht);
}

static struct hashtable * build_hash_table (char const * file, int nfields,
					    int keyfield, int islist, int tablesize, int ignorenis, char delimiter)
{
	struct hashtable* ht;
	size_t len;
	unsigned int h;
	struct mypasswd *hashentry, *hashentry1;
	char *list;
	char *nextlist=0;
	int i;
	char buffer[1024];

	ht = (struct hashtable *) rad_malloc(sizeof(struct hashtable));
	if(!ht) {
		return NULL;
	}
	memset(ht, 0, sizeof(struct hashtable));
	ht->filename = strdup(file);
	if(!ht->filename) {
		free(ht);
		return NULL;
	}
	ht->tablesize = tablesize;
	ht->nfields = nfields;
	ht->keyfield = keyfield;
	ht->islist = islist;
	ht->ignorenis = ignorenis;
	if (delimiter) ht->delimiter = delimiter;
	else ht->delimiter = ':';
	if(!tablesize) return ht;
	if(!(ht->fp = fopen(file,"r"))) {
		free(ht->filename);
		free(ht);
		return NULL;
	}

	/*
	 *	@todo: This code is SHIT.  It's badly formatted.  It's
	 *	hard to understand.  It re-implements tons of things
	 *	which are already in the server core.
	 */
	memset(ht->buffer, 0, 1024);
	ht->table = (struct mypasswd **) rad_malloc (tablesize * sizeof(struct mypasswd *));
	if (!ht->table) {
		/*
		 * Unable allocate memory for hash table
		 * Still work without it
		 */
		ht->tablesize = 0;
		return ht;
	}
	memset(ht->table, 0, tablesize * sizeof(struct mypasswd *));
	while (fgets(buffer, 1024, ht->fp)) {
		if(*buffer && *buffer!='\n' && (!ignorenis || (*buffer != '+' && *buffer != '-')) ){
			if(!(hashentry = mypasswd_malloc(buffer, nfields, &len))){
				release_hash_table(ht);
				return ht;
			}
			len = string_to_entry(buffer, nfields, ht->delimiter, hashentry, len);
			if(!hashentry->field[keyfield] || *hashentry->field[keyfield] == '\0') {
				free(hashentry);
				continue;
			}

			if (islist) {
				list = hashentry->field[keyfield];
				for (nextlist = list; *nextlist && *nextlist!=','; nextlist++);
				if (*nextlist) *nextlist++ = 0;
				else nextlist = 0;
			}
			h = hash(hashentry->field[keyfield], tablesize);
			hashentry->next = ht->table[h];
			ht->table[h] = hashentry;
			if (islist) {
				for(list=nextlist; nextlist; list = nextlist){
					for (nextlist = list; *nextlist && *nextlist!=','; nextlist++);
					if (*nextlist) *nextlist++ = 0;
					else nextlist = 0;
					if(!(hashentry1 = mypasswd_malloc("", nfields, &len))){
						release_hash_table(ht);
						return ht;
					}
					for (i=0; i<nfields; i++) hashentry1->field[i] = hashentry->field[i];
					hashentry1->field[keyfield] = list;
					h = hash(list, tablesize);
					hashentry1->next = ht->table[h];
					ht->table[h] = hashentry1;
				}
			}
		}
	}
	fclose(ht->fp);
	ht->fp = NULL;
	return ht;
#undef passwd
}

static struct mypasswd * get_next(char *name, struct hashtable *ht,
				  struct mypasswd **last_found)
{
	struct mypasswd * passwd;
	struct mypasswd * hashentry;
	char buffer[1024];
	int len;
	char *list, *nextlist;

	if (ht->tablesize > 0) {
		/* get saved address of next item to check from buffer */
		hashentry = *last_found;
		for (; hashentry; hashentry = hashentry->next) {
			if (!strcmp(hashentry->field[ht->keyfield], name)) {
				/* save new address */
				*last_found = hashentry->next;
				return hashentry;
			}
		}
		return NULL;
	}
	/*	printf("try to find in file\n"); */
	if (!ht->fp) return NULL;

	passwd = (struct mypasswd *) ht->buffer;

	while (fgets(buffer, 1024,ht->fp)) {
		if(*buffer && *buffer!='\n' && (len = string_to_entry(buffer, ht->nfields, ht->delimiter, passwd, sizeof(ht->buffer)-1)) &&
		   (!ht->ignorenis || (*buffer !='-' && *buffer != '+') ) ){
			if(!ht->islist) {
				if(!strcmp(passwd->field[ht->keyfield], name))
					return passwd;
			}
			else {
				for (list = passwd->field[ht->keyfield], nextlist = list; nextlist; list = nextlist) {
					for(nextlist = list; *nextlist && *nextlist!=','; nextlist++);
					if(!*nextlist) {
						nextlist = 0;
					} else {
						*nextlist++ = 0;
					}
					if (!strcmp(list, name)) {
						return passwd;
					}
				}
			}

		}
	}
	fclose(ht->fp);
	ht->fp = NULL;
	return NULL;
}

static struct mypasswd * get_pw_nam(char * name, struct hashtable* ht,
				    struct mypasswd **last_found)
{
	int h;
	struct mypasswd * hashentry;

	if (!ht || !name || *name == '\0') return NULL;
	*last_found = NULL;
	if (ht->tablesize > 0) {
		h = hash (name, ht->tablesize);
		for (hashentry = ht->table[h]; hashentry; hashentry = hashentry->next) {
			if (!strcmp(hashentry->field[ht->keyfield], name)){
				/* save address of next item to check into buffer */
				*last_found=hashentry->next;
				return hashentry;
			}
		}

		return NULL;
	}
	if (ht->fp) {
		fclose(ht->fp);
		ht->fp = NULL;
	}
	if (!(ht->fp=fopen(ht->filename, "r"))) return NULL;
	return get_next(name, ht, last_found);
}

#ifdef TEST

#define MALLOC_CHECK_ 1

int main(void){
	struct hashtable *ht;
	char *buffer;
	struct mypasswd* pw, *last_found;
	int i;

	ht = build_hash_table("/etc/group", 4, 3, 1, 100, 0, ":");
	if(!ht) {
		printf("Hash table not built\n");
		return -1;
	}
	for (i = 0; i < ht->tablesize; i++) {
		if (ht->table[i]) {
			printf("%d:\n", i);
			for (pw = ht->table[i]; pw; pw = pw->next) {
				printpw(pw, 4);
			}
		}
	}

	while(fgets(buffer, 1024, stdin)){
		buffer[strlen(buffer)-1] = 0;
		pw = get_pw_nam(buffer, ht, &last_found);
		printpw(pw,4);
		while ((pw = get_next(buffer, ht, &last_found))) printpw(pw,4);
	}
	release_ht(ht);
}

#else  /* TEST */
struct passwd_instance {
	struct hashtable	*ht;
	struct mypasswd		*pwdfmt;
	char			*filename;
	char			*format;
	char			*delimiter;
	bool			allow_multiple;
	bool			ignore_nislike;
	int			hash_size;
	int			nfields;
	int			keyfield;
	int			listable;
	DICT_ATTR const		*keyattr;
	bool			ignore_empty;
};

static const CONF_PARSER module_config[] = {
	{ "filename",   PW_TYPE_FILE_INPUT | PW_TYPE_REQUIRED,
	  offsetof(struct passwd_instance, filename), NULL,  NULL },
	{ "format",   PW_TYPE_STRING_PTR | PW_TYPE_REQUIRED,
	  offsetof(struct passwd_instance, format), NULL,  NULL },
	{ "delimiter",   PW_TYPE_STRING_PTR,
	  offsetof(struct passwd_instance, delimiter), NULL,  ":" },

	{ "ignorenislike",   PW_TYPE_BOOLEAN | PW_TYPE_DEPRECATED,
	  offsetof(struct passwd_instance, ignore_nislike), NULL,  NULL },
	{ "ignore_nislike",   PW_TYPE_BOOLEAN,
	  offsetof(struct passwd_instance, ignore_nislike), NULL,  "yes" },

	{ "ignoreempty",   PW_TYPE_BOOLEAN | PW_TYPE_DEPRECATED,
	  offsetof(struct passwd_instance, ignore_empty), NULL,  NULL },
	{ "ignore_empty",   PW_TYPE_BOOLEAN,
	  offsetof(struct passwd_instance, ignore_empty), NULL,  "yes" },

	{ "allowmultiplekeys",   PW_TYPE_BOOLEAN | PW_TYPE_DEPRECATED,
	  offsetof(struct passwd_instance, allow_multiple), NULL,  NULL },
	{ "allow_multiple_keys",   PW_TYPE_BOOLEAN,
	  offsetof(struct passwd_instance, allow_multiple), NULL,  "no" },

	{ "hashsize",   PW_TYPE_INTEGER | PW_TYPE_DEPRECATED,
	  offsetof(struct passwd_instance, hash_size), NULL,  NULL },
	{ "hash_size",   PW_TYPE_INTEGER,
	  offsetof(struct passwd_instance, hash_size), NULL,  "100" },

	{ NULL, -1, 0, NULL, NULL }
};

static int mod_instantiate(CONF_SECTION *conf, void *instance)
{
	int nfields=0, keyfield=-1, listable=0;
	char *s;
	char *lf=NULL; /* destination list flags temporary */
	size_t len;
	int i;
	DICT_ATTR const * da;
	struct passwd_instance *inst = instance;

	rad_assert(inst->filename && *inst->filename);
	rad_assert(inst->format && *inst->format);

	if (inst->hash_size == 0) {
		cf_log_err_cs(conf, "Invalid value '0' for hash_size");
		return -1;
	}

	lf = talloc_strdup(inst, inst->format);
	if ( !lf) {
		ERROR("rlm_passwd: memory allocation failed for lf");
		return -1;
	}
	memset(lf, 0, strlen(inst->format));
	s = inst->format - 1;
	do {
		if(s == inst->format - 1 || *s == ':'){
			if(*(s+1) == '*'){
				keyfield = nfields;
				s++;
			}
			if(*(s+1) == ','){
				listable = 1;
				s++;
			}
			if(*(s+1) == '='){
				lf[nfields]=1;
				s++;
			}
			if(*(s+1) == '~'){
				lf[nfields]=2;
				s++;
			}
			nfields++;
		}
		s++;
	}while(*s);
	if(keyfield < 0) {
		cf_log_err_cs(conf, "no field marked as key in format: %s",
			      inst->format);
		return -1;
	}
	if (! (inst->ht = build_hash_table (inst->filename, nfields, keyfield, listable, inst->hash_size, inst->ignore_nislike, *inst->delimiter)) ){
		ERROR("rlm_passwd: can't build hashtable from passwd file");
		return -1;
	}
	if (! (inst->pwdfmt = mypasswd_malloc(inst->format, nfields, &len)) ){
		ERROR("rlm_passwd: memory allocation failed");
		release_ht(inst->ht);
		inst->ht = NULL;
		return -1;
	}
	if (!string_to_entry(inst->format, nfields, ':', inst->pwdfmt , len)) {
		ERROR("rlm_passwd: unable to convert format entry");
		release_ht(inst->ht);
		inst->ht = NULL;
		return -1;
	}

	memcpy(inst->pwdfmt->listflag, lf, nfields);

	talloc_free(lf);
	for (i=0; i<nfields; i++) {
		if (*inst->pwdfmt->field[i] == '*') inst->pwdfmt->field[i]++;
		if (*inst->pwdfmt->field[i] == ',') inst->pwdfmt->field[i]++;
		if (*inst->pwdfmt->field[i] == '=') inst->pwdfmt->field[i]++;
		if (*inst->pwdfmt->field[i] == '~') inst->pwdfmt->field[i]++;
	}
	if (!*inst->pwdfmt->field[keyfield]) {
		cf_log_err_cs(conf, "key field is empty");
		release_ht(inst->ht);
		inst->ht = NULL;
		return -1;
	}
	if (! (da = dict_attrbyname (inst->pwdfmt->field[keyfield])) ) {
		ERROR("rlm_passwd: unable to resolve attribute: %s", inst->pwdfmt->field[keyfield]);
		release_ht(inst->ht);
		inst->ht = NULL;
		return -1;
	}
	inst->keyattr = da;
	inst->nfields = nfields;
	inst->keyfield = keyfield;
	inst->listable = listable;
	DEBUG2("rlm_passwd: nfields: %d keyfield %d(%s) listable: %s", nfields, keyfield, inst->pwdfmt->field[keyfield], listable?"yes":"no");
	return 0;

#undef inst
}

static int mod_detach (void *instance) {
#define inst ((struct passwd_instance *)instance)
	if(inst->ht) {
		release_ht(inst->ht);
		inst->ht = NULL;
	}
	free(inst->pwdfmt);
	return 0;
#undef inst
}

static void addresult (struct passwd_instance * inst, REQUEST *request, TALLOC_CTX *ctx, VALUE_PAIR **vps, struct mypasswd * pw, char when, char const *listname)
{
	int i;
	VALUE_PAIR *vp;

	for (i=0; i<inst->nfields; i++) {
		if (inst->pwdfmt->field[i] && *inst->pwdfmt->field[i] && pw->field[i] && i != inst->keyfield  && inst->pwdfmt->listflag[i] == when) {
			if ( !inst->ignore_empty || pw->field[i][0] != 0 ) { /* if value in key/value pair is not empty */
				vp = pairmake(ctx, vps, inst->pwdfmt->field[i], pw->field[i], T_OP_EQ);
				if (vp) {
					RDEBUG("Added %s: '%s' to %s ", inst->pwdfmt->field[i], pw->field[i], listname);
				}
			} else
				RDEBUG("NOOP %s: '%s' to %s ", inst->pwdfmt->field[i], pw->field[i], listname);
		}
	}
}

static rlm_rcode_t passwd_map(void *instance, REQUEST *request)
{
#define inst ((struct passwd_instance *)instance)
	char buffer[1024];
	VALUE_PAIR *key, *i;
	struct mypasswd * pw, *last_found;
	vp_cursor_t cursor;

	key = pairfind(request->packet->vps, inst->keyattr->attr, inst->keyattr->vendor, TAG_ANY);
	if (!key) {
		return RLM_MODULE_NOTFOUND;
	}

	for (i = fr_cursor_init(&cursor, &key);
	     i;
	     i = fr_cursor_next_by_num(&cursor, inst->keyattr->attr, inst->keyattr->vendor, TAG_ANY)) {
		/*
		 *	Ensure we have the string form of the attribute
		 */
		vp_prints_value(buffer, sizeof(buffer), i, 0);
		if (!(pw = get_pw_nam(buffer, inst->ht, &last_found)) ) {
			continue;
		}
		do {
			addresult(inst, request, request, &request->config_items, pw, 0, "config_items");
			addresult(inst, request, request->reply, &request->reply->vps, pw, 1, "reply_items");
			addresult(inst, request, request->packet, &request->packet->vps, pw, 2, "request_items");
		} while ((pw = get_next(buffer, inst->ht, &last_found)));

		if (!inst->allow_multiple) {
			break;
		}
	}

	return RLM_MODULE_OK;

#undef inst
}

module_t rlm_passwd = {
	RLM_MODULE_INIT,
	"passwd",
	RLM_TYPE_CHECK_CONFIG_SAFE | RLM_TYPE_HUP_SAFE,   	/* type */
	sizeof(struct passwd_instance),
	module_config,
	mod_instantiate,		/* instantiation */
	mod_detach,			/* detach */
	{
		NULL,			/* authentication */
		passwd_map,		/* authorization */
		NULL,			/* pre-accounting */
		passwd_map,		/* accounting */
		NULL,			/* checksimul */
		NULL,			/* pre-proxy */
		NULL,			/* post-proxy */
		passwd_map	       	/* post-auth */
#ifdef WITH_COA
		, passwd_map,
		passwd_map
#endif
	},
};
#endif /* TEST */
