/*
 * $Id: cache_manager.c,v 1.30 2006/08/25 12:26:07 serassio Exp $
 *
 * DEBUG: section 16    Cache Manager Objects
 * AUTHOR: Duane Wessels
 *
 * SQUID Web Proxy Cache          http://www.squid-cache.org/
 * ----------------------------------------------------------
 *
 *  Squid is the result of efforts by numerous individuals from
 *  the Internet community; see the CONTRIBUTORS file for full
 *  details.   Many organizations have provided support for Squid's
 *  development; see the SPONSORS file for full details.  Squid is
 *  Copyrighted (C) 2001 by the Regents of the University of
 *  California; see the COPYRIGHT file for full details.  Squid
 *  incorporates software developed and/or copyrighted by other
 *  sources; see the CREDITS file for full details.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 */

#include "squid.h"

#define MGR_PASSWD_SZ 128

typedef struct {
    StoreEntry *entry;
    char *action;
    char *user_name;
    char *passwd;
} cachemgrStateData;

typedef struct _action_table {
    char *action;
    char *desc;
    OBJH *handler;
    struct {
	unsigned int pw_req:1;
	unsigned int atomic:1;
    } flags;
    struct _action_table *next;
} action_table;

static action_table *cachemgrFindAction(const char *action);
static cachemgrStateData *cachemgrParseUrl(const char *url);
static void cachemgrParseHeaders(cachemgrStateData * mgr, const request_t * request);
static int cachemgrCheckPassword(cachemgrStateData *);
static void cachemgrStateFree(cachemgrStateData * mgr);
static char *cachemgrPasswdGet(cachemgr_passwd *, const char *);
static const char *cachemgrActionProtection(const action_table * at);
static OBJH cachemgrShutdown;
static OBJH cachemgrMenu;
static OBJH cachemgrOfflineToggle;

action_table *ActionTable = NULL;

void
cachemgrRegister(const char *action, const char *desc, OBJH * handler, int pw_req_flag, int atomic)
{
    action_table *a;
    action_table **A;
    if (cachemgrFindAction(action) != NULL) {
	debug(16, 3) ("cachemgrRegister: Duplicate '%s'\n", action);
	return;
    }
    a = xcalloc(1, sizeof(action_table));
    a->action = xstrdup(action);
    a->desc = xstrdup(desc);
    a->handler = handler;
    a->flags.pw_req = pw_req_flag;
    a->flags.atomic = atomic;
    for (A = &ActionTable; *A; A = &(*A)->next);
    *A = a;
    debug(16, 3) ("cachemgrRegister: registered %s\n", action);
}

static action_table *
cachemgrFindAction(const char *action)
{
    action_table *a;
    for (a = ActionTable; a != NULL; a = a->next) {
	if (0 == strcmp(a->action, action))
	    return a;
    }
    return NULL;
}

static cachemgrStateData *
cachemgrParseUrl(const char *url)
{
    int t;
    LOCAL_ARRAY(char, host, MAX_URL);
    LOCAL_ARRAY(char, request, MAX_URL);
    LOCAL_ARRAY(char, password, MAX_URL);
    action_table *a;
    cachemgrStateData *mgr = NULL;
    const char *prot;
    t = sscanf(url, "cache_object://%[^/]/%[^@]@%s", host, request, password);
    if (t < 2) {
	xstrncpy(request, "menu", MAX_URL);
#ifdef _SQUID_OS2_
	/*
	 * emx's sscanf insists of returning 2 because it sets request
	 * to null
	 */
    } else if (request[0] == '\0') {
	xstrncpy(request, "menu", MAX_URL);
#endif
    }
    request[strcspn(request, "/")] = '\0';
    if ((a = cachemgrFindAction(request)) == NULL) {
	debug(16, 1) ("cachemgrParseUrl: action '%s' not found\n", request);
	return NULL;
    } else {
	prot = cachemgrActionProtection(a);
	if (!strcmp(prot, "disabled") || !strcmp(prot, "hidden")) {
	    debug(16, 1) ("cachemgrParseUrl: action '%s' is %s\n", request, prot);
	    return NULL;
	}
    }
    /* set absent entries to NULL so we can test if they are present later */
    mgr = xcalloc(1, sizeof(cachemgrStateData));
    mgr->user_name = NULL;
    mgr->passwd = t == 3 ? xstrdup(password) : NULL;
    mgr->action = xstrdup(request);
    return mgr;
}

static void
cachemgrParseHeaders(cachemgrStateData * mgr, const request_t * request)
{
    const char *basic_cookie;	/* base 64 _decoded_ user:passwd pair */
    const char *passwd_del;
    assert(mgr && request);
    basic_cookie = httpHeaderGetAuth(&request->header, HDR_AUTHORIZATION, "Basic");
    if (!basic_cookie)
	return;
    if (!(passwd_del = strchr(basic_cookie, ':'))) {
	debug(16, 1) ("cachemgrParseHeaders: unknown basic_cookie format '%s'\n", basic_cookie);
	return;
    }
    /* found user:password pair, reset old values */
    safe_free(mgr->user_name);
    safe_free(mgr->passwd);
    mgr->user_name = xstrdup(basic_cookie);
    mgr->user_name[passwd_del - basic_cookie] = '\0';
    mgr->passwd = xstrdup(passwd_del + 1);
    /* warning: this prints decoded password which maybe not what you want to do @?@ @?@ */
    debug(16, 9) ("cachemgrParseHeaders: got user: '%s' passwd: '%s'\n", mgr->user_name, mgr->passwd);
}

/*
 * return 0 if mgr->password is good
 */
static int
cachemgrCheckPassword(cachemgrStateData * mgr)
{
    char *pwd = cachemgrPasswdGet(Config.passwd_list, mgr->action);
    action_table *a = cachemgrFindAction(mgr->action);
    assert(a != NULL);
    if (pwd == NULL)
	return a->flags.pw_req;
    if (strcmp(pwd, "disable") == 0)
	return 1;
    if (strcmp(pwd, "none") == 0)
	return 0;
    if (!mgr->passwd)
	return 1;
    return strcmp(pwd, mgr->passwd);
}

static void
cachemgrStateFree(cachemgrStateData * mgr)
{
    safe_free(mgr->action);
    safe_free(mgr->user_name);
    safe_free(mgr->passwd);
    storeUnlockObject(mgr->entry);
    xfree(mgr);
}

void
cachemgrStart(int fd, request_t * request, StoreEntry * entry)
{
    cachemgrStateData *mgr = NULL;
    ErrorState *err = NULL;
    action_table *a;
    debug(16, 3) ("objectcacheStart: '%s'\n", storeUrl(entry));
    if ((mgr = cachemgrParseUrl(storeUrl(entry))) == NULL) {
	err = errorCon(ERR_INVALID_URL, HTTP_NOT_FOUND, request);
	err->url = xstrdup(storeUrl(entry));
	errorAppendEntry(entry, err);
	entry->expires = squid_curtime;
	return;
    }
    mgr->entry = entry;
    storeLockObject(entry);
    entry->expires = squid_curtime;
    debug(16, 5) ("CACHEMGR: %s requesting '%s'\n",
	fd_table[fd].ipaddr, mgr->action);
    /* get additional info from request headers */
    cachemgrParseHeaders(mgr, request);
    /* Check password */
    if (cachemgrCheckPassword(mgr) != 0) {
	/* build error message */
	ErrorState *err;
	HttpReply *rep;
	err = errorCon(ERR_CACHE_MGR_ACCESS_DENIED, HTTP_UNAUTHORIZED, request);
	/* warn if user specified incorrect password */
	if (mgr->passwd)
	    debug(16, 1) ("CACHEMGR: %s@%s: incorrect password for '%s'\n",
		mgr->user_name ? mgr->user_name : "<unknown>",
		fd_table[fd].ipaddr, mgr->action);
	else
	    debug(16, 1) ("CACHEMGR: %s@%s: password needed for '%s'\n",
		mgr->user_name ? mgr->user_name : "<unknown>",
		fd_table[fd].ipaddr, mgr->action);
	rep = errorBuildReply(err);
	errorStateFree(err);
	/*
	 * add Authenticate header, use 'action' as a realm because
	 * password depends on action
	 */
	httpHeaderPutAuth(&rep->header, "Basic", mgr->action);
	/* store the reply */
	httpReplySwapOut(rep, entry);
	entry->expires = squid_curtime;
	storeComplete(entry);
	cachemgrStateFree(mgr);
	return;
    }
    debug(16, 1) ("CACHEMGR: %s@%s requesting '%s'\n",
	mgr->user_name ? mgr->user_name : "<unknown>",
	fd_table[fd].ipaddr, mgr->action);
    /* retrieve object requested */
    a = cachemgrFindAction(mgr->action);
    assert(a != NULL);
    storeBuffer(entry);
    {
	http_version_t version;
	HttpReply *rep = entry->mem_obj->reply;
	/* prove there are no previous reply headers around */
	assert(0 == rep->sline.status);
	httpBuildVersion(&version, 1, 0);
	httpReplySetHeaders(rep,
	    version,
	    HTTP_OK,
	    NULL,
	    "text/plain",
	    -1,			/* C-Len */
	    squid_curtime,	/* LMT */
	    squid_curtime);
	httpReplySwapOut(rep, entry);
    }
    a->handler(entry);
    storeBufferFlush(entry);
    if (a->flags.atomic)
	storeComplete(entry);
    cachemgrStateFree(mgr);
}

static void
cachemgrShutdown(StoreEntry * entryunused)
{
    debug(16, 0) ("Shutdown by command.\n");
    shut_down(0);
}

static void
cachemgrOfflineToggle(StoreEntry * sentry)
{
    Config.onoff.offline = !Config.onoff.offline;
    debug(16, 0) ("offline_mode now %s.\n",
	Config.onoff.offline ? "ON" : "OFF");
    storeAppendPrintf(sentry, "offline_mode is now %s\n",
	Config.onoff.offline ? "ON" : "OFF");
}

static const char *
cachemgrActionProtection(const action_table * at)
{
    char *pwd;
    assert(at);
    pwd = cachemgrPasswdGet(Config.passwd_list, at->action);
    if (!pwd)
	return at->flags.pw_req ? "hidden" : "public";
    if (!strcmp(pwd, "disable"))
	return "disabled";
    if (strcmp(pwd, "none") == 0)
	return "public";
    return "protected";
}

static void
cachemgrMenu(StoreEntry * sentry)
{
    action_table *a;
    for (a = ActionTable; a != NULL; a = a->next) {
	storeAppendPrintf(sentry, " %-22s\t%s\t%s\n",
	    a->action, a->desc, cachemgrActionProtection(a));
    }
}

static char *
cachemgrPasswdGet(cachemgr_passwd * a, const char *action)
{
    wordlist *w;
    while (a != NULL) {
	for (w = a->actions; w != NULL; w = w->next) {
	    if (0 == strcmp(w->key, action))
		return a->passwd;
	    if (0 == strcmp(w->key, "all"))
		return a->passwd;
	}
	a = a->next;
    }
    return NULL;
}

void
cachemgrInit(void)
{
    cachemgrRegister("menu",
	"This Cachemanager Menu",
	cachemgrMenu, 0, 1);
    cachemgrRegister("shutdown",
	"Shut Down the Squid Process",
	cachemgrShutdown, 1, 1);
    cachemgrRegister("offline_toggle",
	"Toggle offline_mode setting",
	cachemgrOfflineToggle, 1, 1);
}