+/*********************************************************************
+ *
+ * File : $Source: /cvsroot/ijbswa/current/client-tags.c,v $
+ *
+ * Purpose : Functions related to client-specific tags.
+ *
+ * Copyright : Copyright (C) 2016 Fabian Keil <fk@fabiankeil.de>
+ *
+ * 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.
+ *
+ * The GNU General Public License should be included with
+ * this file. If not, you can view it at
+ * http://www.gnu.org/copyleft/gpl.html
+ * or write to the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ **********************************************************************/
+
+#include "config.h"
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <assert.h>
+
+#include "project.h"
+#include "list.h"
+#include "jcc.h"
+#include "miscutil.h"
+#include "errlog.h"
+
+struct client_specific_tag
+{
+ char *name;
+
+ time_t end_of_life;
+
+ struct client_specific_tag *next;
+ struct client_specific_tag *prev;
+};
+
+/**
+ * This struct represents tags that have been requested by clients
+ */
+struct requested_tags
+{
+ char *client; /**< The IP address of the client that requested the tag */
+
+ /**< List of tags the client requested .... */
+ struct client_specific_tag *tags;
+
+ struct requested_tags *next;
+ struct requested_tags *prev;
+};
+
+struct requested_tags *requested_tags;
+static void remove_tag_for_client(const char *client_address, const char *tag);
+
+/*********************************************************************
+ *
+ * Function : validate_tag_list
+ *
+ * Description : Validates the given tag list
+ *
+ * Parameters :
+ * 1 : enabled_tags = The tags to validate
+ *
+ * Returns : void
+ *
+ *********************************************************************/
+static void validate_tag_list(struct client_specific_tag *enabled_tags)
+{
+ while (enabled_tags != NULL)
+ {
+ if (enabled_tags->name == NULL)
+ {
+ assert(enabled_tags->name != NULL);
+ log_error(LOG_LEVEL_FATAL, "validate_tag_list(): Tag without name detected");
+ }
+ if (enabled_tags->next != NULL)
+ {
+ if (enabled_tags->next->prev != enabled_tags)
+ {
+ assert(enabled_tags->next->prev == enabled_tags);
+ log_error(LOG_LEVEL_FATAL, "validate_tag_list(): Invalid backlink detected");
+ }
+ }
+ enabled_tags = enabled_tags->next;
+ }
+}
+
+/*********************************************************************
+ *
+ * Function : validate_requested_tags
+ *
+ * Description : Validates the requested_tags list
+ *
+ * Parameters : N/A
+ *
+ * Returns : void
+ *
+ *********************************************************************/
+static jb_err validate_requested_tags()
+{
+ struct requested_tags *requested_tag;
+
+ for (requested_tag = requested_tags; requested_tag != NULL;
+ requested_tag = requested_tag->next)
+ {
+ if (requested_tag->client == NULL)
+ {
+ assert(requested_tag->client != NULL);
+ log_error(LOG_LEVEL_FATAL, "validate_tag_list(): Client not registered");
+ }
+ validate_tag_list(requested_tag->tags);
+ if (requested_tag->next != NULL)
+ {
+ if (requested_tag->next->prev != requested_tag)
+ {
+ assert(requested_tag->next->prev == requested_tag);
+ log_error(LOG_LEVEL_FATAL, "validate_requested_tags(): Invalid backlink detected");
+ }
+ }
+ }
+
+ return TRUE;
+}
+
+
+/*********************************************************************
+ *
+ * Function : get_client_specific_tag
+ *
+ * Description : Returns the data for a client-specific-tag specified
+ * by name.
+ *
+ * Parameters :
+ * 1 : tag_list = The tag list to check
+ * 2 : name = The tag name to look up
+ *
+ * Returns : Pointer to tag structure or NULL on error.
+ *
+ *********************************************************************/
+static struct client_tag_spec *get_client_specific_tag(
+ struct client_tag_spec *tag_list, const char *name)
+{
+ struct client_tag_spec *tag;
+
+ for (tag = tag_list; tag != NULL; tag = tag->next)
+ {
+ if (tag->name != NULL && !strcmp(tag->name, name))
+ {
+ return tag;
+ }
+ }
+
+ log_error(LOG_LEVEL_ERROR, "No such tag: '%s'", name);
+
+ return NULL;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : get_tags_for_client
+ *
+ * Description : Returns the list of tags the client opted-in.
+ *
+ * Parameters :
+ * 1 : client_address = Address of the client
+ *
+ * Returns : Pointer to tag structure or NULL on error.
+ *
+ *********************************************************************/
+static struct client_specific_tag *get_tags_for_client(const char *client_address)
+{
+ struct requested_tags *requested_tag;
+
+ for (requested_tag = requested_tags; requested_tag != NULL;
+ requested_tag = requested_tag->next)
+ {
+ if (!strcmp(requested_tag->client, client_address))
+ {
+ return requested_tag->tags;
+ }
+ }
+
+ return NULL;
+}
+
+
+/*********************************************************************
+ *
+ * Function : get_tag_list_for_client
+ *
+ * Description : Provides a list of tag names the client opted-in.
+ * Other tag attributes are not part of the list.
+ *
+ * Parameters :
+ * 1 : tag_list = The list to fill in.
+ * 2 : client_address = Address of the client
+ *
+ * Returns : Pointer to tag list.
+ *
+ *********************************************************************/
+void get_tag_list_for_client(struct list *tag_list,
+ const char *client_address)
+{
+ struct client_specific_tag *enabled_tags;
+ const time_t now = time(NULL);
+
+ privoxy_mutex_lock(&client_tags_mutex);
+
+ enabled_tags = get_tags_for_client(client_address);
+ while (enabled_tags != NULL)
+ {
+ if (enabled_tags->end_of_life && (enabled_tags->end_of_life < now))
+ {
+ struct client_specific_tag *next_tag = enabled_tags->next;
+ log_error(LOG_LEVEL_INFO,
+ "Tag '%s' for client %s expired %u seconds ago. Deleting it.",
+ enabled_tags->name, client_address,
+ (now - enabled_tags->end_of_life));
+ remove_tag_for_client(client_address, enabled_tags->name);
+ enabled_tags = next_tag;
+ continue;
+ }
+ else
+ {
+ enlist(tag_list, enabled_tags->name);
+ }
+ enabled_tags = enabled_tags->next;
+ }
+
+ privoxy_mutex_unlock(&client_tags_mutex);
+}
+
+
+/*********************************************************************
+ *
+ * Function : add_tag_for_client
+ *
+ * Description : Adds the tag for the client.
+ *
+ * Parameters :
+ * 1 : client_address = Address of the client
+ * 2 : tag = The tag to add.
+ * 3 : time_to_live = 0, or the number of seconds
+ * the tag remains activated.
+ *
+ * Returns : void
+ *
+ *********************************************************************/
+static void add_tag_for_client(const char *client_address,
+ const char *tag, const time_t time_to_live)
+{
+ struct requested_tags *clients_with_tags;
+ struct client_specific_tag *enabled_tags;
+
+ validate_requested_tags();
+
+ if (requested_tags == NULL)
+ {
+ /* XXX: Code duplication. */
+ requested_tags = zalloc_or_die(sizeof(struct requested_tags));
+ requested_tags->client = strdup_or_die(client_address);
+ requested_tags->tags = zalloc_or_die(sizeof(struct client_specific_tag));
+ requested_tags->tags->name = strdup_or_die(tag);
+ requested_tags->tags->end_of_life = time_to_live ?
+ (time(NULL) + time_to_live) : 0;
+
+ validate_requested_tags();
+ return;
+ }
+ else
+ {
+ clients_with_tags = requested_tags;
+ while (clients_with_tags->next != NULL)
+ {
+ if (!strcmp(clients_with_tags->client, client_address))
+ {
+ break;
+ }
+ clients_with_tags = clients_with_tags->next;
+ }
+ if (strcmp(clients_with_tags->client, client_address))
+ {
+ /* Client does not have tags yet, add new structure */
+ clients_with_tags->next = zalloc_or_die(sizeof(struct requested_tags));
+ clients_with_tags->next->prev = clients_with_tags;
+ clients_with_tags = clients_with_tags->next;
+ clients_with_tags->client = strdup_or_die(client_address);
+ clients_with_tags->tags = zalloc_or_die(sizeof(struct client_specific_tag));
+ clients_with_tags->tags->name = strdup_or_die(tag);
+ clients_with_tags->tags->end_of_life = time_to_live ?
+ (time(NULL) + time_to_live) : 0;
+
+ validate_requested_tags();
+
+ return;
+ }
+ }
+
+ enabled_tags = clients_with_tags->tags;
+ while (enabled_tags != NULL)
+ {
+ if (enabled_tags->next == NULL)
+ {
+ enabled_tags->next = zalloc_or_die(sizeof(struct client_specific_tag));
+ enabled_tags->next->name = strdup_or_die(tag);
+ clients_with_tags->tags->end_of_life = time_to_live ?
+ (time(NULL) + time_to_live) : 0;
+ enabled_tags->next->prev = enabled_tags;
+ break;
+ }
+ enabled_tags = enabled_tags->next;
+ }
+
+ validate_requested_tags();
+}
+
+
+/*********************************************************************
+ *
+ * Function : remove_tag_for_client
+ *
+ * Description : Removes the tag for the client.
+ *
+ * Parameters :
+ * 1 : client_address = Address of the client
+ * 2 : tag = The tag to remove.
+ *
+ * Returns : void
+ *
+ *********************************************************************/
+static void remove_tag_for_client(const char *client_address, const char *tag)
+{
+ struct requested_tags *clients_with_tags;
+ struct client_specific_tag *enabled_tags;
+
+ validate_requested_tags();
+
+ clients_with_tags = requested_tags;
+ while (clients_with_tags != NULL && clients_with_tags->client != NULL)
+ {
+ if (!strcmp(clients_with_tags->client, client_address))
+ {
+ break;
+ }
+ clients_with_tags = clients_with_tags->next;
+ }
+
+ enabled_tags = clients_with_tags->tags;
+ while (enabled_tags != NULL)
+ {
+ if (!strcmp(enabled_tags->name, tag))
+ {
+ if (enabled_tags->next != NULL)
+ {
+ enabled_tags->next->prev = enabled_tags->prev;
+ if (enabled_tags == clients_with_tags->tags)
+ {
+ /* Tag is first in line */
+ clients_with_tags->tags = enabled_tags->next;
+ }
+ }
+ if (enabled_tags->prev != NULL)
+ {
+ /* Tag has preceding tag */
+ enabled_tags->prev->next = enabled_tags->next;
+ }
+ if (enabled_tags->prev == NULL && enabled_tags->next == NULL)
+ {
+ /* Tag is the only one */
+ if (clients_with_tags->next != NULL)
+ {
+ /* Client has following client */
+ clients_with_tags->next->prev = clients_with_tags->prev;
+ }
+ if (clients_with_tags->prev != NULL)
+ {
+ /* Client has preceding client */
+ clients_with_tags->prev->next = clients_with_tags->next;
+ }
+ freez(clients_with_tags->client);
+ if (clients_with_tags == requested_tags)
+ {
+ /* Removing last tag */
+ freez(requested_tags);
+ clients_with_tags = requested_tags;
+ }
+ else
+ {
+ freez(clients_with_tags);
+ }
+ }
+ freez(enabled_tags->name);
+ freez(enabled_tags);
+ break;
+ }
+
+ enabled_tags = enabled_tags->next;
+ }
+
+ validate_requested_tags();
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : client_has_requested_tag
+ *
+ * Description : Checks whether or not the given client requested
+ * the tag.
+ *
+ * Parameters :
+ * 1 : client_address = Address of the client
+ * 2 : tag = Tag to check.
+ *
+ * Returns : TRUE or FALSE.
+ *
+ *********************************************************************/
+int client_has_requested_tag(const char *client_address, const char *tag)
+{
+ struct client_specific_tag *enabled_tags;
+
+ enabled_tags = get_tags_for_client(client_address);
+
+ while (enabled_tags != NULL)
+ {
+ if (!strcmp(enabled_tags->name, tag))
+ {
+ return TRUE;
+ }
+ enabled_tags = enabled_tags->next;
+ }
+
+ return FALSE;
+
+}
+
+/*********************************************************************
+ *
+ * Function : enable_client_specific_tag
+ *
+ * Description : Enables a client-specific-tag for the client
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : tag_name = The name of the tag to enable
+ * 3 : time_to_live = If not 0, the number of seconds the
+ * tag should stay enabled.
+ *
+ * Returns : JB_ERR_OK on success, JB_ERR_MEMORY or JB_ERR_PARSE.
+ *
+ *********************************************************************/
+jb_err enable_client_specific_tag(struct client_state *csp,
+ const char *tag_name, const time_t time_to_live)
+{
+ struct client_tag_spec *tag;
+
+ privoxy_mutex_lock(&client_tags_mutex);
+
+ tag = get_client_specific_tag(csp->config->client_tags, tag_name);
+ if (tag == NULL)
+ {
+ privoxy_mutex_unlock(&client_tags_mutex);
+ return JB_ERR_PARSE;
+ }
+
+ if (client_has_requested_tag(csp->ip_addr_str, tag_name))
+ {
+ log_error(LOG_LEVEL_ERROR,
+ "Tag '%s' already enabled for client '%s'", tag->name, csp->ip_addr_str);
+ }
+ else
+ {
+ add_tag_for_client(csp->ip_addr_str, tag_name, time_to_live);
+ log_error(LOG_LEVEL_INFO,
+ "Tag '%s' enabled for client '%s'", tag->name, csp->ip_addr_str);
+ }
+
+ privoxy_mutex_unlock(&client_tags_mutex);
+
+ return JB_ERR_OK;
+
+}
+
+/*********************************************************************
+ *
+ * Function : disable_client_specific_tag
+ *
+ * Description : Disables a client-specific-tag for the client
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : tag_name = The name of the tag to disable
+ *
+ * Returns : JB_ERR_OK on success, JB_ERR_MEMORY or JB_ERR_PARSE.
+ *
+ *********************************************************************/
+jb_err disable_client_specific_tag(struct client_state *csp, const char *tag_name)
+{
+ struct client_tag_spec *tag;
+
+ privoxy_mutex_lock(&client_tags_mutex);
+
+ tag = get_client_specific_tag(csp->config->client_tags, tag_name);
+ if (tag == NULL)
+ {
+ privoxy_mutex_unlock(&client_tags_mutex);
+ return JB_ERR_PARSE;
+ }
+
+ if (client_has_requested_tag(csp->ip_addr_str, tag_name))
+ {
+ remove_tag_for_client(csp->ip_addr_str, tag_name);
+ log_error(LOG_LEVEL_INFO,
+ "Tag '%s' disabled for client '%s'", tag->name, csp->ip_addr_str);
+ }
+ else
+ {
+ log_error(LOG_LEVEL_ERROR,
+ "Tag '%s' currently not set for client '%s'",
+ tag->name, csp->ip_addr_str);
+ }
+
+ privoxy_mutex_unlock(&client_tags_mutex);
+ return JB_ERR_OK;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : client_tag_match
+ *
+ * Description : Compare a client tag against a client tag pattern.
+ *
+ * Parameters :
+ * 1 : pattern = a TAG pattern
+ * 2 : tag = Client tag to match
+ *
+ * Returns : Nonzero if the tag matches the pattern, else 0.
+ *
+ *********************************************************************/
+int client_tag_match(const struct pattern_spec *pattern,
+ const struct list *tags)
+{
+ struct list_entry *tag;
+
+ if (!(pattern->flags & PATTERN_SPEC_CLIENT_TAG_PATTERN))
+ {
+ /*
+ * It's not a client pattern and thus shouldn't
+ * be matched against client tags.
+ */
+ return 0;
+ }
+
+ assert(tags);
+
+ for (tag = tags->first; tag != NULL; tag = tag->next)
+ {
+ if (0 == regexec(pattern->pattern.tag_regex, tag->str, 0, NULL, 0))
+ {
+ return 1;
+ }
+ }
+
+ return 0;
+
+}