ne_locks.c

linux subdivision ying gai ke yi le ba

/* 
   WebDAV Class 2 locking operations
   Copyright (C) 1999-2004, Joe Orton <[e-mail]>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
   
   This library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA

*/

#include "config.h"

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif

#include <ctype.h> /* for isdigit() */

#include "ne_alloc.h"

#include "ne_request.h"
#include "ne_xml.h"
#include "ne_locks.h"
#include "ne_uri.h"
#include "ne_basic.h"
#include "ne_props.h"
#include "ne_207.h"
#include "ne_i18n.h"

#define HOOK_ID "http://webdav.org/neon/hooks/webdav-locking"

/* A list of lock objects. */
struct lock_list {
    struct ne_lock *lock;
    struct lock_list *next, *prev;
};

struct ne_lock_store_s {
    struct lock_list *locks;
    struct lock_list *cursor; /* current position in 'locks' */
};

struct lh_req_cookie {
    const ne_lock_store *store;
    struct lock_list *submit;
};

/* Context for PROPFIND/lockdiscovery callbacks */
struct discover_ctx {
    ne_session *session;
    ne_lock_result results;
    void *userdata;
    ne_buffer *cdata;
};

/* Context for handling LOCK response */
struct lock_ctx {
    struct ne_lock active; /* activelock */
    char *token; /* the token we're after. */
    int found;
    ne_buffer *cdata;
};

/* use the "application" state space. */
#define ELM_LOCK_FIRST (NE_PROPS_STATE_TOP + 66)

#define ELM_lockdiscovery (ELM_LOCK_FIRST)
#define ELM_activelock (ELM_LOCK_FIRST + 1)
#define ELM_lockscope (ELM_LOCK_FIRST + 2)
#define ELM_locktype (ELM_LOCK_FIRST + 3)
#define ELM_depth (ELM_LOCK_FIRST + 4)
#define ELM_owner (ELM_LOCK_FIRST + 5)
#define ELM_timeout (ELM_LOCK_FIRST + 6)
#define ELM_locktoken (ELM_LOCK_FIRST + 7)
#define ELM_lockinfo (ELM_LOCK_FIRST + 8)
#define ELM_write (ELM_LOCK_FIRST + 9)
#define ELM_exclusive (ELM_LOCK_FIRST + 10)
#define ELM_shared (ELM_LOCK_FIRST + 11)
#define ELM_href (ELM_LOCK_FIRST + 12)
#define ELM_prop (NE_207_STATE_PROP)

static const struct ne_xml_idmap element_map[] = {
#define ELM(x) { "DAV:", #x, ELM_ ## x }
    ELM(lockdiscovery), ELM(activelock), ELM(prop), ELM(lockscope),
    ELM(locktype), ELM(depth), ELM(owner), ELM(timeout), ELM(locktoken),
    ELM(lockinfo), ELM(lockscope), ELM(locktype), ELM(write), ELM(exclusive),
    ELM(shared), ELM(href)
    /* no "lockentry" */
#undef ELM
};

static const ne_propname lock_props[] = {
    { "DAV:", "lockdiscovery" },
    { NULL }
};

/* this simply registers the accessor for the function. */
static void lk_create(ne_request *req, void *session, 
		       const char *method, const char *uri)
{
    struct lh_req_cookie *lrc = ne_malloc(sizeof *lrc);
    lrc->store = session;
    lrc->submit = NULL;
    ne_set_request_private(req, HOOK_ID, lrc);
}

static void lk_pre_send(ne_request *r, void *userdata, ne_buffer *req)
{
    struct lh_req_cookie *lrc = ne_get_request_private(r, HOOK_ID);

    if (lrc->submit != NULL) {
	struct lock_list *item;

	/* Add in the If header */
	ne_buffer_zappend(req, "If:");
	for (item = lrc->submit; item != NULL; item = item->next) {
	    char *uri = ne_uri_unparse(&item->lock->uri);
	    ne_buffer_concat(req, " <", uri, "> (<",
			     item->lock->token, ">)", NULL);
	    ne_free(uri);
	}
	ne_buffer_zappend(req, EOL);
    }
}

/* Insert 'lock' into lock list *list. */
static void insert_lock(struct lock_list **list, struct ne_lock *lock)
{
    struct lock_list *item = ne_malloc(sizeof *item);
    if (*list != NULL) {
	(*list)->prev = item;
    }
    item->prev = NULL;
    item->next = *list;
    item->lock = lock;
    *list = item;
}

static void free_list(struct lock_list *list, int destroy)
{
    struct lock_list *next;

    while (list != NULL) {
	next = list->next;
	if (destroy)
	    ne_lock_destroy(list->lock);
	ne_free(list);
	list = next;
    }
}

static void lk_destroy(ne_request *req, void *userdata)
{
    struct lh_req_cookie *lrc = ne_get_request_private(req, HOOK_ID);
    free_list(lrc->submit, 0);
    ne_free(lrc);
}

void ne_lockstore_destroy(ne_lock_store *store)
{
    free_list(store->locks, 1);
    ne_free(store);
}

ne_lock_store *ne_lockstore_create(void)
{
    return ne_calloc(sizeof(ne_lock_store));
}

#define CURSOR_RET(s) ((s)->cursor?(s)->cursor->lock:NULL)

struct ne_lock *ne_lockstore_first(ne_lock_store *store)
{
    store->cursor = store->locks;
    return CURSOR_RET(store);
}

struct ne_lock *ne_lockstore_next(ne_lock_store *store)
{
    store->cursor = store->cursor->next;
    return CURSOR_RET(store);
}

void ne_lockstore_register(ne_lock_store *store, ne_session *sess)
{
    /* Register the hooks */
    ne_hook_create_request(sess, lk_create, store);
    ne_hook_pre_send(sess, lk_pre_send, store);
    ne_hook_destroy_request(sess, lk_destroy, store);
}

/* Submit the given lock for the given URI */
static void submit_lock(struct lh_req_cookie *lrc, struct ne_lock *lock)
{
    struct lock_list *item;

    /* Check for dups */
    for (item = lrc->submit; item != NULL; item = item->next) {
	if (strcasecmp(item->lock->token, lock->token) == 0)
	    return;
    }

    insert_lock(&lrc->submit, lock);
}

struct ne_lock *ne_lockstore_findbyuri(ne_lock_store *store,
				       const ne_uri *uri)
{
    struct lock_list *cur;

    for (cur = store->locks; cur != NULL; cur = cur->next) {
	if (ne_uri_cmp(&cur->lock->uri, uri) == 0) {
	    return cur->lock;
	}
    }

    return NULL;
}

void ne_lock_using_parent(ne_request *req, const char *path)
{
    struct lh_req_cookie *lrc = ne_get_request_private(req, HOOK_ID);
    ne_uri u;
    struct lock_list *item;
    char *parent;

    if (lrc == NULL)
	return;
    
    parent = ne_path_parent(path);
    if (parent == NULL)
	return;
    
    u.authinfo = NULL;
    ne_fill_server_uri(ne_get_session(req), &u);

    for (item = lrc->store->locks; item != NULL; item = item->next) {

	/* Only care about locks which are on this server. */
	u.path = item->lock->uri.path;
	if (ne_uri_cmp(&u, &item->lock->uri))
	    continue;
	
	/* This lock is needed if it is an infinite depth lock which
	 * covers the parent, or a lock on the parent itself. */
	if ((item->lock->depth == NE_DEPTH_INFINITE && 
	     ne_path_childof(item->lock->uri.path, parent)) ||
	    ne_path_compare(item->lock->uri.path, parent) == 0) {
	    NE_DEBUG(NE_DBG_LOCKS, "Locked parent, %s on %s\n",
		     item->lock->token, item->lock->uri.path);
	    submit_lock(lrc, item->lock);
	}
    }

    u.path = parent; /* handy: makes u.path valid and ne_free(parent). */
    ne_uri_free(&u);
}

void ne_lock_using_resource(ne_request *req, const char *uri, int depth)
{
    struct lh_req_cookie *lrc = ne_get_request_private(req, HOOK_ID);
    struct lock_list *item;
    int match;

    if (lrc == NULL)
	return;	

    /* Iterate over the list of stored locks to see if any of them
     * apply to this resource */
    for (item = lrc->store->locks; item != NULL; item = item->next) {
	
	match = 0;
	
	if (depth == NE_DEPTH_INFINITE &&
	    ne_path_childof(uri, item->lock->uri.path)) {
	    /* Case 1: this is a depth-infinity request which will 
	     * modify a lock somewhere inside the collection. */
	    NE_DEBUG(NE_DBG_LOCKS, "Has child: %s\n", item->lock->token);
	    match = 1;
	} 
	else if (ne_path_compare(uri, item->lock->uri.path) == 0) {
	    /* Case 2: this request is directly on a locked resource */
	    NE_DEBUG(NE_DBG_LOCKS, "Has direct lock: %s\n", item->lock->token);
	    match = 1;
	}
	else if (item->lock->depth == NE_DEPTH_INFINITE && 
		 ne_path_childof(item->lock->uri.path, uri)) {
	    /* Case 3: there is a higher-up infinite-depth lock which
	     * covers the resource that this request will modify. */
	    NE_DEBUG(NE_DBG_LOCKS, "Is child of: %s\n", item->lock->token);
	    match = 1;
	}
	
	if (match) {
	    submit_lock(lrc, item->lock);
	}
    }

}

void ne_lockstore_add(ne_lock_store *store, struct ne_lock *lock)
{
    insert_lock(&store->locks, lock);
}

void ne_lockstore_remove(ne_lock_store *store, struct ne_lock *lock)
{
    struct lock_list *item;

    /* Find the lock */
    for (item = store->locks; item != NULL; item = item->next)
	if (item->lock == lock)
	    break;
    
    if (item->prev != NULL) {
	item->prev->next = item->next;
    } else {
	store->locks = item->next;
    }
    if (item->next != NULL) {
	item->next->prev = item->prev;
    }
    ne_free(item);
}

struct ne_lock *ne_lock_copy(const struct ne_lock *lock)
{
    struct ne_lock *ret = ne_calloc(sizeof *ret);

    ret->uri.path = ne_strdup(lock->uri.path);
    ret->uri.host = ne_strdup(lock->uri.host);
    ret->uri.scheme = ne_strdup(lock->uri.scheme);
    ret->uri.port = lock->uri.port;
    ret->token = ne_strdup(lock->token);
    ret->depth = lock->depth;
    ret->type = lock->type;
    ret->scope = lock->scope;
    if (lock->owner) ret->owner = ne_strdup(lock->owner);
    ret->timeout = lock->timeout;

    return ret;
}

struct ne_lock *ne_lock_create(void)
{
    struct ne_lock *lock = ne_calloc(sizeof *lock);
    lock->depth = NE_DEPTH_ZERO;
    lock->type = ne_locktype_write;
    lock->scope = ne_lockscope_exclusive;
    lock->timeout = NE_TIMEOUT_INVALID;
    return lock;
}

void ne_lock_free(struct ne_lock *lock)
{
    ne_uri_free(&lock->uri);
    NE_FREE(lock->owner);
    NE_FREE(lock->token);
}

void ne_lock_destroy(struct ne_lock *lock)
{
    ne_lock_free(lock);
    ne_free(lock);
}

int ne_unlock(ne_session *sess, const struct ne_lock *lock)
{
    ne_request *req = ne_request_create(sess, "UNLOCK", lock->uri.path);
    int ret;
    
    ne_print_request_header(req, "Lock-Token", "<%s>", lock->token);
    
    /* UNLOCK of a lock-null resource removes the resource from the
     * parent collection; so an UNLOCK may modify the parent
     * collection. (somewhat counter-intuitive, and not easily derived
     * from 2518.) */
    ne_lock_using_parent(req, lock->uri.path);

    ret = ne_request_dispatch(req);
    
    if (ret == NE_OK && ne_get_status(req)->klass == 2) {
	ret = NE_OK;    
    } else {
	ret = NE_ERROR;
    }

    ne_request_destroy(req);
    
    return ret;
}