X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fbrowse.c;fp=src%2Fbrowse.c;h=d8f70e6a9ff492af4550003388b2c4cca857e89b;hb=f1de9dcaab953757252d51b4725cbfa36daa10a5;hp=0000000000000000000000000000000000000000;hpb=7a5b2f69af7d36d6cd4153142f125fa011784e03;p=catta

diff --git a/src/browse.c b/src/browse.c
new file mode 100644
index 0000000..d8f70e6
--- /dev/null
+++ b/src/browse.c
@@ -0,0 +1,613 @@
+/***
+  This file is part of catta.
+
+  catta is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+
+  catta 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 Lesser General
+  Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with catta; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+
+#include <catta/timeval.h>
+#include <catta/malloc.h>
+#include <catta/error.h>
+#include <catta/domain.h>
+#include <catta/rlist.h>
+#include <catta/address.h>
+#include <catta/log.h>
+
+#include "browse.h"
+#include "querier.h"
+#include "domain-util.h"
+#include "rr-util.h"
+
+#define CATTA_LOOKUPS_PER_BROWSER_MAX 15
+
+struct CattaSRBLookup {
+    CattaSRecordBrowser *record_browser;
+
+    unsigned ref;
+
+    CattaIfIndex iface;
+    CattaProtocol protocol;
+    CattaLookupFlags flags;
+
+    CattaKey *key;
+
+    CattaWideAreaLookup *wide_area;
+    CattaMulticastLookup *multicast;
+
+    CattaRList *cname_lookups;
+
+    CATTA_LLIST_FIELDS(CattaSRBLookup, lookups);
+};
+
+static void lookup_handle_cname(CattaSRBLookup *l, CattaIfIndex iface, CattaProtocol protocol, CattaLookupFlags flags, CattaRecord *r);
+static void lookup_drop_cname(CattaSRBLookup *l, CattaIfIndex iface, CattaProtocol protocol, CattaLookupFlags flags, CattaRecord *r);
+
+static void transport_flags_from_domain(CattaServer *s, CattaLookupFlags *flags, const char *domain) {
+    assert(flags);
+    assert(domain);
+
+    assert(!((*flags & CATTA_LOOKUP_USE_MULTICAST) && (*flags & CATTA_LOOKUP_USE_WIDE_AREA)));
+
+    if (*flags & (CATTA_LOOKUP_USE_MULTICAST|CATTA_LOOKUP_USE_WIDE_AREA))
+        return;
+
+    if (!s->wide_area_lookup_engine ||
+        !catta_wide_area_has_servers(s->wide_area_lookup_engine) ||
+        catta_domain_ends_with(domain, CATTA_MDNS_SUFFIX_LOCAL) ||
+        catta_domain_ends_with(domain, CATTA_MDNS_SUFFIX_ADDR_IPV4) ||
+        catta_domain_ends_with(domain, CATTA_MDNS_SUFFIX_ADDR_IPV6))
+        *flags |= CATTA_LOOKUP_USE_MULTICAST;
+    else
+        *flags |= CATTA_LOOKUP_USE_WIDE_AREA;
+}
+
+static CattaSRBLookup* lookup_new(
+    CattaSRecordBrowser *b,
+    CattaIfIndex iface,
+    CattaProtocol protocol,
+    CattaLookupFlags flags,
+    CattaKey *key) {
+
+    CattaSRBLookup *l;
+
+    assert(b);
+    assert(CATTA_IF_VALID(iface));
+    assert(CATTA_PROTO_VALID(protocol));
+
+    if (b->n_lookups >= CATTA_LOOKUPS_PER_BROWSER_MAX)
+        /* We don't like cyclic CNAMEs */
+        return NULL;
+
+    if (!(l = catta_new(CattaSRBLookup, 1)))
+        return NULL;
+
+    l->ref = 1;
+    l->record_browser = b;
+    l->iface = iface;
+    l->protocol = protocol;
+    l->key = catta_key_ref(key);
+    l->wide_area = NULL;
+    l->multicast = NULL;
+    l->cname_lookups = NULL;
+    l->flags = flags;
+
+    transport_flags_from_domain(b->server, &l->flags, key->name);
+
+    CATTA_LLIST_PREPEND(CattaSRBLookup, lookups, b->lookups, l);
+
+    b->n_lookups ++;
+
+    return l;
+}
+
+static void lookup_unref(CattaSRBLookup *l) {
+    assert(l);
+    assert(l->ref >= 1);
+
+    if (--l->ref >= 1)
+        return;
+
+    CATTA_LLIST_REMOVE(CattaSRBLookup, lookups, l->record_browser->lookups, l);
+    l->record_browser->n_lookups --;
+
+    if (l->wide_area) {
+        catta_wide_area_lookup_free(l->wide_area);
+        l->wide_area = NULL;
+    }
+
+    if (l->multicast) {
+        catta_multicast_lookup_free(l->multicast);
+        l->multicast = NULL;
+    }
+
+    while (l->cname_lookups) {
+        lookup_unref(l->cname_lookups->data);
+        l->cname_lookups = catta_rlist_remove_by_link(l->cname_lookups, l->cname_lookups);
+    }
+
+    catta_key_unref(l->key);
+    catta_free(l);
+}
+
+static CattaSRBLookup* lookup_ref(CattaSRBLookup *l) {
+    assert(l);
+    assert(l->ref >= 1);
+
+    l->ref++;
+    return l;
+}
+
+static CattaSRBLookup *lookup_find(
+    CattaSRecordBrowser *b,
+    CattaIfIndex iface,
+    CattaProtocol protocol,
+    CattaLookupFlags flags,
+    CattaKey *key) {
+
+    CattaSRBLookup *l;
+
+    assert(b);
+
+    for (l = b->lookups; l; l = l->lookups_next) {
+
+        if ((l->iface == CATTA_IF_UNSPEC || l->iface == iface) &&
+            (l->iface == CATTA_PROTO_UNSPEC || l->protocol == protocol) &&
+            l->flags == flags &&
+            catta_key_equal(l->key, key))
+
+            return l;
+    }
+
+    return NULL;
+}
+
+static void browser_cancel(CattaSRecordBrowser *b) {
+    assert(b);
+
+    if (b->root_lookup) {
+        lookup_unref(b->root_lookup);
+        b->root_lookup = NULL;
+    }
+
+    if (b->defer_time_event) {
+        catta_time_event_free(b->defer_time_event);
+        b->defer_time_event = NULL;
+    }
+}
+
+static void lookup_wide_area_callback(
+    CattaWideAreaLookupEngine *e,
+    CattaBrowserEvent event,
+    CattaLookupResultFlags flags,
+    CattaRecord *r,
+    void *userdata) {
+
+    CattaSRBLookup *l = userdata;
+    CattaSRecordBrowser *b;
+
+    assert(e);
+    assert(l);
+    assert(l->ref >= 1);
+
+    b = l->record_browser;
+
+    if (b->dead)
+        return;
+
+    lookup_ref(l);
+
+    switch (event) {
+        case CATTA_BROWSER_NEW:
+            assert(r);
+
+            if (r->key->clazz == CATTA_DNS_CLASS_IN &&
+                r->key->type == CATTA_DNS_TYPE_CNAME)
+                /* It's a CNAME record, so let's follow it. We only follow it on wide area DNS! */
+                lookup_handle_cname(l, CATTA_IF_UNSPEC, CATTA_PROTO_UNSPEC, CATTA_LOOKUP_USE_WIDE_AREA, r);
+            else {
+                /* It's a normal record, so let's call the user callback */
+                assert(catta_key_equal(r->key, l->key));
+
+                b->callback(b, CATTA_IF_UNSPEC, CATTA_PROTO_UNSPEC, event, r, flags, b->userdata);
+            }
+            break;
+
+        case CATTA_BROWSER_REMOVE:
+        case CATTA_BROWSER_CACHE_EXHAUSTED:
+            /* Not defined for wide area DNS */
+            abort();
+
+        case CATTA_BROWSER_ALL_FOR_NOW:
+        case CATTA_BROWSER_FAILURE:
+
+            b->callback(b, CATTA_IF_UNSPEC, CATTA_PROTO_UNSPEC, event, NULL, flags, b->userdata);
+            break;
+    }
+
+    lookup_unref(l);
+
+}
+
+static void lookup_multicast_callback(
+    CattaMulticastLookupEngine *e,
+    CattaIfIndex iface,
+    CattaProtocol protocol,
+    CattaBrowserEvent event,
+    CattaLookupResultFlags flags,
+    CattaRecord *r,
+    void *userdata) {
+
+    CattaSRBLookup *l = userdata;
+    CattaSRecordBrowser *b;
+
+    assert(e);
+    assert(l);
+
+    b = l->record_browser;
+
+    if (b->dead)
+        return;
+
+    lookup_ref(l);
+
+    switch (event) {
+        case CATTA_BROWSER_NEW:
+            assert(r);
+
+            if (r->key->clazz == CATTA_DNS_CLASS_IN &&
+                r->key->type == CATTA_DNS_TYPE_CNAME)
+                /* It's a CNAME record, so let's follow it. We allow browsing on both multicast and wide area. */
+                lookup_handle_cname(l, iface, protocol, b->flags, r);
+            else {
+                /* It's a normal record, so let's call the user callback */
+
+                if (catta_server_is_record_local(b->server, iface, protocol, r))
+                    flags |= CATTA_LOOKUP_RESULT_LOCAL;
+
+                b->callback(b, iface, protocol, event, r, flags, b->userdata);
+            }
+            break;
+
+        case CATTA_BROWSER_REMOVE:
+            assert(r);
+
+            if (r->key->clazz == CATTA_DNS_CLASS_IN &&
+                r->key->type == CATTA_DNS_TYPE_CNAME)
+                /* It's a CNAME record, so let's drop that query! */
+                lookup_drop_cname(l, iface, protocol, 0, r);
+            else {
+                /* It's a normal record, so let's call the user callback */
+                assert(catta_key_equal(b->key, l->key));
+
+                b->callback(b, iface, protocol, event, r, flags, b->userdata);
+            }
+            break;
+
+        case CATTA_BROWSER_ALL_FOR_NOW:
+
+            b->callback(b, CATTA_IF_UNSPEC, CATTA_PROTO_UNSPEC, event, NULL, flags, b->userdata);
+            break;
+
+        case CATTA_BROWSER_CACHE_EXHAUSTED:
+        case CATTA_BROWSER_FAILURE:
+            /* Not defined for multicast DNS */
+            abort();
+
+    }
+
+    lookup_unref(l);
+}
+
+static int lookup_start(CattaSRBLookup *l) {
+    assert(l);
+
+    assert(!(l->flags & CATTA_LOOKUP_USE_WIDE_AREA) != !(l->flags & CATTA_LOOKUP_USE_MULTICAST));
+    assert(!l->wide_area && !l->multicast);
+
+    if (l->flags & CATTA_LOOKUP_USE_WIDE_AREA) {
+
+        if (!(l->wide_area = catta_wide_area_lookup_new(l->record_browser->server->wide_area_lookup_engine, l->key, lookup_wide_area_callback, l)))
+            return -1;
+
+    } else {
+        assert(l->flags & CATTA_LOOKUP_USE_MULTICAST);
+
+        if (!(l->multicast = catta_multicast_lookup_new(l->record_browser->server->multicast_lookup_engine, l->iface, l->protocol, l->key, lookup_multicast_callback, l)))
+            return -1;
+    }
+
+    return 0;
+}
+
+static int lookup_scan_cache(CattaSRBLookup *l) {
+    int n = 0;
+
+    assert(l);
+
+    assert(!(l->flags & CATTA_LOOKUP_USE_WIDE_AREA) != !(l->flags & CATTA_LOOKUP_USE_MULTICAST));
+
+
+    if (l->flags & CATTA_LOOKUP_USE_WIDE_AREA) {
+        n = (int) catta_wide_area_scan_cache(l->record_browser->server->wide_area_lookup_engine, l->key, lookup_wide_area_callback, l);
+
+    } else {
+        assert(l->flags & CATTA_LOOKUP_USE_MULTICAST);
+        n = (int) catta_multicast_lookup_engine_scan_cache(l->record_browser->server->multicast_lookup_engine, l->iface, l->protocol, l->key, lookup_multicast_callback, l);
+    }
+
+    return n;
+}
+
+static CattaSRBLookup* lookup_add(CattaSRecordBrowser *b, CattaIfIndex iface, CattaProtocol protocol, CattaLookupFlags flags, CattaKey *key) {
+    CattaSRBLookup *l;
+
+    assert(b);
+    assert(!b->dead);
+
+    if ((l = lookup_find(b, iface, protocol, flags, key)))
+        return lookup_ref(l);
+
+    if (!(l = lookup_new(b, iface, protocol, flags, key)))
+        return NULL;
+
+    return l;
+}
+
+static int lookup_go(CattaSRBLookup *l) {
+    int n = 0;
+    assert(l);
+
+    if (l->record_browser->dead)
+        return 0;
+
+    lookup_ref(l);
+
+    /* Browse the cache for the root request */
+    n = lookup_scan_cache(l);
+
+    /* Start the lookup */
+    if (!l->record_browser->dead && l->ref > 1) {
+
+        if ((l->flags & CATTA_LOOKUP_USE_MULTICAST) || n == 0)
+            /* We do no start a query if the cache contained entries and we're on wide area */
+
+            if (lookup_start(l) < 0)
+                n = -1;
+    }
+
+    lookup_unref(l);
+
+    return n;
+}
+
+static void lookup_handle_cname(CattaSRBLookup *l, CattaIfIndex iface, CattaProtocol protocol, CattaLookupFlags flags, CattaRecord *r) {
+    CattaKey *k;
+    CattaSRBLookup *n;
+
+    assert(l);
+    assert(r);
+
+    assert(r->key->clazz == CATTA_DNS_CLASS_IN);
+    assert(r->key->type == CATTA_DNS_TYPE_CNAME);
+
+    k = catta_key_new(r->data.ptr.name, l->record_browser->key->clazz, l->record_browser->key->type);
+    n = lookup_add(l->record_browser, iface, protocol, flags, k);
+    catta_key_unref(k);
+
+    if (!n) {
+        catta_log_debug(__FILE__": Failed to create SRBLookup.");
+        return;
+    }
+
+    l->cname_lookups = catta_rlist_prepend(l->cname_lookups, lookup_ref(n));
+
+    lookup_go(n);
+    lookup_unref(n);
+}
+
+static void lookup_drop_cname(CattaSRBLookup *l, CattaIfIndex iface, CattaProtocol protocol, CattaLookupFlags flags, CattaRecord *r) {
+    CattaKey *k;
+    CattaSRBLookup *n = NULL;
+    CattaRList *rl;
+
+    assert(r->key->clazz == CATTA_DNS_CLASS_IN);
+    assert(r->key->type == CATTA_DNS_TYPE_CNAME);
+
+    k = catta_key_new(r->data.ptr.name, l->record_browser->key->clazz, l->record_browser->key->type);
+
+    for (rl = l->cname_lookups; rl; rl = rl->rlist_next) {
+        n = rl->data;
+
+        assert(n);
+
+        if ((n->iface == CATTA_IF_UNSPEC || n->iface == iface) &&
+            (n->iface == CATTA_PROTO_UNSPEC || n->protocol == protocol) &&
+            n->flags == flags &&
+            catta_key_equal(n->key, k))
+            break;
+    }
+
+    catta_key_unref(k);
+
+    if (rl) {
+        l->cname_lookups = catta_rlist_remove_by_link(l->cname_lookups, rl);
+        lookup_unref(n);
+    }
+}
+
+static void defer_callback(CATTA_GCC_UNUSED CattaTimeEvent *e, void *userdata) {
+    CattaSRecordBrowser *b = userdata;
+    int n;
+
+    assert(b);
+    assert(!b->dead);
+
+    /* Remove the defer timeout */
+    if (b->defer_time_event) {
+        catta_time_event_free(b->defer_time_event);
+        b->defer_time_event = NULL;
+    }
+
+    /* Create initial query */
+    assert(!b->root_lookup);
+    b->root_lookup = lookup_add(b, b->iface, b->protocol, b->flags, b->key);
+    assert(b->root_lookup);
+
+    n = lookup_go(b->root_lookup);
+
+    if (b->dead)
+        return;
+
+    if (n < 0) {
+        /* sending of the initial query failed */
+
+        catta_server_set_errno(b->server, CATTA_ERR_FAILURE);
+
+        b->callback(
+            b, b->iface, b->protocol, CATTA_BROWSER_FAILURE, NULL,
+            b->flags & CATTA_LOOKUP_USE_WIDE_AREA ? CATTA_LOOKUP_RESULT_WIDE_AREA : CATTA_LOOKUP_RESULT_MULTICAST,
+            b->userdata);
+
+        browser_cancel(b);
+        return;
+    }
+
+    /* Tell the client that we're done with the cache */
+    b->callback(
+        b, b->iface, b->protocol, CATTA_BROWSER_CACHE_EXHAUSTED, NULL,
+        b->flags & CATTA_LOOKUP_USE_WIDE_AREA ? CATTA_LOOKUP_RESULT_WIDE_AREA : CATTA_LOOKUP_RESULT_MULTICAST,
+        b->userdata);
+
+    if (!b->dead && b->root_lookup && b->root_lookup->flags & CATTA_LOOKUP_USE_WIDE_AREA && n > 0) {
+
+        /* If we do wide area lookups and the the cache contained
+         * entries, we assume that it is complete, and tell the user
+         * so by firing ALL_FOR_NOW. */
+
+        b->callback(b, b->iface, b->protocol, CATTA_BROWSER_ALL_FOR_NOW, NULL, CATTA_LOOKUP_RESULT_WIDE_AREA, b->userdata);
+    }
+}
+
+void catta_s_record_browser_restart(CattaSRecordBrowser *b) {
+    assert(b);
+    assert(!b->dead);
+
+    browser_cancel(b);
+
+    /* Request a new iteration of the cache scanning */
+    if (!b->defer_time_event) {
+        b->defer_time_event = catta_time_event_new(b->server->time_event_queue, NULL, defer_callback, b);
+        assert(b->defer_time_event);
+    }
+}
+
+CattaSRecordBrowser *catta_s_record_browser_new(
+    CattaServer *server,
+    CattaIfIndex iface,
+    CattaProtocol protocol,
+    CattaKey *key,
+    CattaLookupFlags flags,
+    CattaSRecordBrowserCallback callback,
+    void* userdata) {
+
+    CattaSRecordBrowser *b;
+
+    assert(server);
+    assert(key);
+    assert(callback);
+
+    CATTA_CHECK_VALIDITY_RETURN_NULL(server, CATTA_IF_VALID(iface), CATTA_ERR_INVALID_INTERFACE);
+    CATTA_CHECK_VALIDITY_RETURN_NULL(server, CATTA_PROTO_VALID(protocol), CATTA_ERR_INVALID_PROTOCOL);
+    CATTA_CHECK_VALIDITY_RETURN_NULL(server, !catta_key_is_pattern(key), CATTA_ERR_IS_PATTERN);
+    CATTA_CHECK_VALIDITY_RETURN_NULL(server, catta_key_is_valid(key), CATTA_ERR_INVALID_KEY);
+    CATTA_CHECK_VALIDITY_RETURN_NULL(server, CATTA_FLAGS_VALID(flags, CATTA_LOOKUP_USE_WIDE_AREA|CATTA_LOOKUP_USE_MULTICAST), CATTA_ERR_INVALID_FLAGS);
+    CATTA_CHECK_VALIDITY_RETURN_NULL(server, !(flags & CATTA_LOOKUP_USE_WIDE_AREA) || !(flags & CATTA_LOOKUP_USE_MULTICAST), CATTA_ERR_INVALID_FLAGS);
+
+    if (!(b = catta_new(CattaSRecordBrowser, 1))) {
+        catta_server_set_errno(server, CATTA_ERR_NO_MEMORY);
+        return NULL;
+    }
+
+    b->dead = 0;
+    b->server = server;
+    b->iface = iface;
+    b->protocol = protocol;
+    b->key = catta_key_ref(key);
+    b->flags = flags;
+    b->callback = callback;
+    b->userdata = userdata;
+    b->n_lookups = 0;
+    CATTA_LLIST_HEAD_INIT(CattaSRBLookup, b->lookups);
+    b->root_lookup = NULL;
+
+    CATTA_LLIST_PREPEND(CattaSRecordBrowser, browser, server->record_browsers, b);
+
+    /* The currently cached entries are scanned a bit later, and than we will start querying, too */
+    b->defer_time_event = catta_time_event_new(server->time_event_queue, NULL, defer_callback, b);
+    assert(b->defer_time_event);
+
+    return b;
+}
+
+void catta_s_record_browser_free(CattaSRecordBrowser *b) {
+    assert(b);
+    assert(!b->dead);
+
+    b->dead = 1;
+    b->server->need_browser_cleanup = 1;
+
+    browser_cancel(b);
+}
+
+void catta_s_record_browser_destroy(CattaSRecordBrowser *b) {
+    assert(b);
+
+    browser_cancel(b);
+
+    CATTA_LLIST_REMOVE(CattaSRecordBrowser, browser, b->server->record_browsers, b);
+
+    catta_key_unref(b->key);
+
+    catta_free(b);
+}
+
+void catta_browser_cleanup(CattaServer *server) {
+    CattaSRecordBrowser *b;
+    CattaSRecordBrowser *n;
+
+    assert(server);
+
+    while (server->need_browser_cleanup) {
+        server->need_browser_cleanup = 0;
+
+        for (b = server->record_browsers; b; b = n) {
+            n = b->browser_next;
+
+            if (b->dead)
+                catta_s_record_browser_destroy(b);
+        }
+    }
+
+    if (server->wide_area_lookup_engine)
+        catta_wide_area_cleanup(server->wide_area_lookup_engine);
+    catta_multicast_lookup_engine_cleanup(server->multicast_lookup_engine);
+}
+