/**
* DBMW foreach iterator to remove old entries.
* @return TRUE if entry must be deleted.
*/
static bool
guid_prune_old_entries(void *key, void *value, size_t u_len, void *u_data)
{
const guid_t *guid = key;
const struct guiddata *gd = value;
time_delta_t d;
double p = 0.0;
bool expired;
(void) u_len;
(void) u_data;
/*
* We reuse the statistical probability model of DHT nodes to project
* whether it makes sense to keep an entry.
*/
d = delta_time(tm_time(), gd->last_time);
if (gd->create_time == gd->last_time) {
expired = d > GUID_STABLE_LIFETIME;
} else {
p = stable_still_alive_probability(gd->create_time, gd->last_time);
expired = p < GUID_STABLE_PROBA;
}
if (GNET_PROPERTY(guid_debug) > 5) {
g_debug("GUID cached %s life=%s last_seen=%s, p=%.2f%%%s",
guid_hex_str(guid),
compact_time(delta_time(gd->last_time, gd->create_time)),
compact_time2(d), p * 100.0,
expired ? " [EXPIRED]" : "");
}
return expired;
}
/**
* Fill supplied buffer with the formatted string describing the message.
*
* @param data start of the G2 message
* @param len length of the message
* @param buf buffer where formatted string is written
* @param buflen length of the destination buffer
*
* @return the amount of bytes written.
*/
size_t
g2_msg_infostr_to_buf(const void *data, size_t len, char *buf, size_t buflen)
{
enum g2_msg m;
const guid_t *muid = NULL;
g_assert(size_is_non_negative(len));
g_assert(size_is_non_negative(buflen));
/*
* Check whether we need to decompile the packet to access the GUID, which
* is the payload of the root element in the tree. Given the way things
* are serialized, that would be the last 16 bytes of the message, so
* we don't have to deserialize everything just to access it.
*/
m = g2_msg_type(data, len);
switch (m) {
case G2_MSG_Q2:
case G2_MSG_QA:
case G2_MSG_QH2:
if (len > GUID_RAW_SIZE)
muid = const_ptr_add_offset(data, len - GUID_RAW_SIZE);
/* FALL THROUGH */
default:
break;
}
return str_bprintf(buf, buflen,
"/%s (%zu byte%s)%s%s",
g2_msg_type_name(m), len, plural(len),
NULL == muid ? "" : " #",
NULL == muid ? "" : guid_hex_str(muid));
}
/**
* Send a Gnutella ping to the specified host via UDP, using the
* specified MUID.
*/
void
udp_connect_back(const host_addr_t addr, uint16 port, const struct guid *muid)
{
if (udp_send_ping(muid, addr, port, FALSE)) {
if (GNET_PROPERTY(udp_debug) > 19)
g_debug("UDP queued connect-back PING #%s to %s\n",
guid_hex_str(muid), host_addr_port_to_string(addr, port));
}
}
/**
* Flush current /QH2.
*
* Depending how the QH2 builder is configured, this either sends the message
* to the target node or invokes a processing callback.
*/
static void
g2_build_qh2_flush(struct g2_qh2_builder *ctx)
{
pmsg_t *mb;
g_assert(ctx != NULL);
g_assert(ctx->t != NULL);
g_assert((ctx->n != NULL) ^ (ctx->cb != NULL));
/*
* Restore the order of children in the root packet to be the order we
* used when we added the nodes, since we prepend new children.
*/
g2_tree_reverse_children(ctx->t);
/*
* If sending over UDP, ask for reliable delivery of the query hit.
* To be able to monitor the fate of the message, we asssociate a free
* routine to it.
*/
if (ctx->to_udp) {
struct g2_qh2_pmsg_info *pmi;
WALLOC0(pmi);
pmi->magic = G2_QH2_PMI_MAGIC;
pmi->hub_id = nid_ref(NODE_ID(ctx->hub));
mb = g2_build_pmsg_extended(ctx->t, g2_qh2_pmsg_free, pmi);
pmsg_mark_reliable(mb);
} else {
mb = g2_build_pmsg(ctx->t);
}
if (GNET_PROPERTY(g2_debug) > 3) {
g_debug("%s(): flushing the following hit for "
"Q2 #%s to %s%s (%d bytes):",
G_STRFUNC, guid_hex_str(ctx->muid),
NULL == ctx->n ?
stacktrace_function_name(ctx->cb) : node_infostr(ctx->n),
NULL == ctx->n ? "()" : "", pmsg_size(mb));
g2_tfmt_tree_dump(ctx->t, stderr, G2FMT_O_PAYLOAD | G2FMT_O_PAYLEN);
}
if (ctx->n != NULL)
g2_node_send(ctx->n, mb);
else
(*ctx->cb)(mb, ctx->arg);
ctx->messages++;
ctx->current_size = 0;
g2_tree_free_null(&ctx->t);
}
/**
* Send an UDP ping to the host cache.
*/
static void
uhc_send_ping(void)
{
g_assert(uhc_connecting);
guid_random_muid(&uhc_ctx.muid);
if (udp_send_ping(&uhc_ctx.muid, uhc_ctx.addr, uhc_ctx.port, TRUE)) {
if (GNET_PROPERTY(bootstrap_debug) || GNET_PROPERTY(log_uhc_pings_tx)) {
g_debug("BOOT sent UDP SCP ping #%s to %s:%u",
guid_hex_str(&uhc_ctx.muid), uhc_ctx.host, uhc_ctx.port);
}
/*
* Give GUI feedback.
*/
{
char msg[256];
str_bprintf(msg, sizeof msg,
_("Sent ping to UDP host cache %s:%u"),
uhc_ctx.host, uhc_ctx.port);
gcu_statusbar_message(msg);
}
/*
* Arm a timer to see whether we should not try to ping another
* host cache if we don't get a timely reply.
*/
g_assert(uhc_ctx.timeout_ev == NULL);
uhc_ctx.timeout_ev = cq_main_insert(UHC_TIMEOUT,
uhc_ping_timeout, NULL);
} else {
g_warning("BOOT failed to send UDP SCP to %s",
host_addr_port_to_string(uhc_ctx.addr, uhc_ctx.port));
uhc_try_next();
}
}
/**
* Add GUID to the banned list or refresh the fact that we are still seeing
* it as being worth banning.
*/
void
guid_add_banned(const struct guid *guid)
{
struct guiddata *gd;
struct guiddata new_gd;
gd = get_guiddata(guid);
if (NULL == gd) {
gd = &new_gd;
gd->create_time = gd->last_time = tm_time();
gnet_stats_inc_general(GNR_BANNED_GUID_HELD);
if (GNET_PROPERTY(guid_debug)) {
g_debug("GUID banning %s", guid_hex_str(guid));
}
} else {
gd->last_time = tm_time();
}
dbmw_write(db_guid, guid, gd, sizeof *gd);
}
/**
* Called when a pong with an "IPP" extension was received.
*/
void
uhc_ipp_extract(gnutella_node_t *n, const char *payload, int paylen,
enum net_type type)
{
int i, cnt;
int len = NET_TYPE_IPV6 == type ? 18 : 6;
const void *p;
g_assert(0 == paylen % len);
cnt = paylen / len;
if (GNET_PROPERTY(bootstrap_debug))
g_debug("extracting %d host%s in UDP IPP pong #%s from %s",
cnt, plural(cnt),
guid_hex_str(gnutella_header_get_muid(&n->header)), node_addr(n));
for (i = 0, p = payload; i < cnt; i++, p = const_ptr_add_offset(p, len)) {
host_addr_t ha;
uint16 port;
host_ip_port_peek(p, type, &ha, &port);
hcache_add_caught(HOST_ULTRA, ha, port, "UDP-HC");
if (GNET_PROPERTY(bootstrap_debug) > 2)
g_debug("BOOT collected %s from UDP IPP pong from %s",
host_addr_port_to_string(ha, port), node_addr(n));
}
if (!uhc_connecting)
return;
/*
* Check whether this was a reply from our request.
*
* The reply could come well after we decided it timed out and picked
* another UDP host cache, which ended-up replying, so we must really
* check whether we're still in a probing cycle.
*/
if (!guid_eq(&uhc_ctx.muid, gnutella_header_get_muid(&n->header)))
return;
if (GNET_PROPERTY(bootstrap_debug)) {
g_debug("BOOT UDP cache \"%s\" replied: got %d host%s from %s",
uhc_ctx.host, cnt, plural(cnt), node_addr(n));
}
/*
* Terminate the probing cycle if we got hosts.
*/
if (cnt > 0) {
char msg[256];
cq_cancel(&uhc_ctx.timeout_ev);
uhc_connecting = FALSE;
str_bprintf(msg, sizeof(msg),
NG_("Got %d host from UDP host cache %s",
"Got %d hosts from UDP host cache %s",
cnt),
cnt, uhc_ctx.host);
gcu_statusbar_message(msg);
} else {
uhc_try_next();
}
}
/**
* Determine unique filename for `file' in `path', with optional trailing
* extension `ext'. If no `ext' is wanted, one must supply an empty string.
*
* @param path A directory path.
* @param file The basename for the resulting pathname.
* @param ext An optional filename extension to be appended to the basename.
* @param name_is_uniq An optional callback to decide whether a created
* pathname is uniq. If omitted, the default is file_does_not_exist().
*
* @returns the chosen unique complete filename as a pointer which must be
* freed via hfree().
*/
char *
filename_unique(const char *path, const char *name, const char *ext,
bool (*name_is_uniq)(const char *pathname))
{
char filename_buf[FILENAME_MAXBYTES];
char name_buf[FILENAME_MAXBYTES];
char mid_buf[32];
char ext_buf[32];
const char *mid;
char *pathname;
size_t name_len, mid_len, ext_len;
int i;
g_assert(path);
g_assert(name);
g_assert(ext);
g_assert(is_absolute_path(path));
STATIC_ASSERT(sizeof filename_buf >
sizeof mid_buf + sizeof ext_buf + GUID_HEX_SIZE);
/**
* NOTE: The generated filename must not exceed FILENAME_MAXBYTES
* because such a file cannot be created. In reality, it depends
* on the filesystem as well and the limit might be even smaller.
* In any case, we don't want to cut-off arbitrary bytes but
* at least preserve the filename extension and the (potential)
* UTF-8 encoding.
*/
/* Because "ext" can be an additional extension like .BAD rather than
* one that indicates the filetype, try to preserve the next "extension"
* as well, if there's any. */
mid = strrchr(name, '.');
if (NULL == mid || mid == name || strlen(mid) >= sizeof mid_buf) {
mid = strchr(name, '\0');
}
ext_len = strlen(ext);
mid_len = strlen(mid);
name_len = strlen(name) - mid_len;
ext_len = MIN(ext_len, sizeof ext_buf - 1);
mid_len = MIN(mid_len, sizeof mid_buf - 1);
name_len = MIN(name_len, sizeof name_buf - 1);
if (name_len + mid_len + ext_len >= sizeof filename_buf) {
g_assert(name_len >= ext_len);
name_len -= ext_len;
}
/* Truncate strings so that an UTF-8 encoding is preserved */
ext_len = utf8_truncate(ext, ext_buf, ext_len + 1);
mid_len = utf8_truncate(mid, mid_buf, mid_len + 1);
name_len = utf8_truncate(name, name_buf, name_len + 1);
str_bprintf(filename_buf, sizeof filename_buf, "%s%s%s",
name_buf, mid_buf, ext_buf);
pathname = unique_pathname(path, filename_buf, name_is_uniq);
if (pathname)
goto finish;
if (!is_directory(path))
return NULL;
/*
* Looks like we need to make the filename more unique. Append .00, then
* .01, etc... until .99.
*/
while (name_len + mid_len + ext_len + 3 >= sizeof filename_buf) {
g_assert(name_len > 0);
name_len--;
}
name_len = utf8_truncate(name, name_buf, name_len + 1);
for (i = 0; i < 100; i++) {
str_bprintf(filename_buf, sizeof filename_buf, "%s.%02u%s%s",
name_buf, i, mid_buf, ext_buf);
pathname = unique_pathname(path, filename_buf, name_is_uniq);
if (pathname)
goto finish;
}
/*
* OK, no luck. Try with a few random numbers then.
*/
while (name_len + mid_len + ext_len + 9 >= sizeof filename_buf) {
g_assert(name_len > 0);
name_len--;
}
name_len = utf8_truncate(name, name_buf, name_len + 1);
for (i = 0; i < 100; i++) {
str_bprintf(filename_buf, sizeof filename_buf, "%s.%x%s%s",
name_buf, (unsigned) random_u32(), mid_buf, ext_buf);
pathname = unique_pathname(path, filename_buf, name_is_uniq);
if (pathname)
goto finish;
}
/*
* Bad luck. Allocate a random GUID then.
*/
while (
name_len + mid_len + ext_len + GUID_HEX_SIZE + 1 >= sizeof filename_buf
) {
g_assert(name_len > 0);
name_len--;
}
name_len = utf8_truncate(name, name_buf, name_len + 1);
{
struct guid guid;
guid_random_fill(&guid);
str_bprintf(filename_buf, sizeof filename_buf, "%s.%s%s%s",
name_buf, guid_hex_str(&guid), mid_buf, ext_buf);
}
pathname = unique_pathname(path, filename_buf, name_is_uniq);
if (pathname)
goto finish;
/*
* This may also be the result of permission problems or inode
* exhaustion.
*/
g_warning("%s(): no luck with random number generator", G_STRFUNC);
finish:
return pathname;
}
/**
* Route query hits from one node to the other.
*/
void
dh_route(gnutella_node_t *src, gnutella_node_t *dest, int count)
{
pmsg_t *mb;
struct dh_pmsg_info *pmi;
const struct guid *muid;
dqhit_t *dh;
mqueue_t *mq;
g_assert(
gnutella_header_get_function(&src->header) == GTA_MSG_SEARCH_RESULTS);
g_assert(count >= 0);
if (!NODE_IS_WRITABLE(dest))
goto drop_shutdown;
muid = gnutella_header_get_muid(&src->header);
dh = dh_locate(muid);
g_assert(dh != NULL); /* Must have called dh_got_results() first! */
if (GNET_PROPERTY(dh_debug) > 19) {
g_debug("DH #%s got %d hit%s: "
"msg=%u, hits_recv=%u, hits_sent=%u, hits_queued=%u",
guid_hex_str(muid), count, plural(count),
dh->msg_recv, dh->hits_recv, dh->hits_sent,
dh->hits_queued);
}
mq = dest->outq;
/*
* Can we forward the message?
*/
switch (dh_can_forward(dh, mq, FALSE)) {
case DH_DROP_FC:
goto drop_flow_control;
case DH_DROP_THROTTLE:
goto drop_throttle;
case DH_DROP_TRANSIENT:
goto drop_transient;
case DH_FORWARD:
default:
break;
}
/*
* Allow message through.
*/
WALLOC(pmi);
pmi->hits = count;
dh->hits_queued += count;
dh->msg_queued++;
g_assert(dh->hits_queued >= UNSIGNED(count));
/*
* Magic: we create an extended version of a pmsg_t that contains a
* free routine, which will be invoked when the message queue frees
* the message.
*
* This enables us to track how much results we already queued/sent.
*/
if (NODE_IS_UDP(dest)) {
gnet_host_t to;
pmsg_t *mbe;
gnet_host_set(&to, dest->addr, dest->port);
/*
* With GUESS we may route back a query hit to an UDP node.
*/
if (GNET_PROPERTY(guess_server_debug) > 19) {
g_debug("GUESS sending %d hit%s (%s) for #%s to %s",
count, plural(count),
NODE_CAN_SR_UDP(dest) ? "reliably" :
NODE_CAN_INFLATE(dest) ? "possibly deflated" : "uncompressed",
guid_hex_str(muid), node_infostr(dest));
}
/*
* Attempt to compress query hit if the destination supports it.
*
* If we're going to send the hit using semi-reliable UDP, there's
* no need to compress beforehand, since the transport layer will
* attempt its own compression anyway.
*/
if (!NODE_CAN_SR_UDP(dest) && NODE_CAN_INFLATE(dest)) {
mb = gmsg_split_to_deflated_pmsg(&src->header, src->data,
src->size + GTA_HEADER_SIZE);
if (gnutella_header_get_ttl(pmsg_start(mb)) & GTA_UDP_DEFLATED)
gnet_stats_inc_general(GNR_UDP_TX_COMPRESSED);
} else {
mb = gmsg_split_to_pmsg(&src->header, src->data,
src->size + GTA_HEADER_SIZE);
}
mbe = pmsg_clone_extend(mb, dh_pmsg_free, pmi);
pmsg_free(mb);
if (NODE_CAN_SR_UDP(dest))
pmsg_mark_reliable(mbe);
mq_udp_putq(mq, mbe, &to);
} else {
mb = gmsg_split_to_pmsg_extend(&src->header, src->data,
src->size + GTA_HEADER_SIZE, dh_pmsg_free, pmi);
mq_tcp_putq(mq, mb, src);
if (GNET_PROPERTY(dh_debug) > 19) {
g_debug("DH enqueued %d hit%s for #%s to %s",
count, plural(count), guid_hex_str(muid),
node_infostr(dest));
}
}
return;
drop_shutdown:
gnet_stats_count_dropped(src, MSG_DROP_SHUTDOWN);
return;
drop_flow_control:
gnet_stats_count_dropped(src, MSG_DROP_FLOW_CONTROL);
gnet_stats_count_flowc(&src->header, TRUE);
return;
drop_throttle:
gnet_stats_count_dropped(src, MSG_DROP_THROTTLE);
return;
drop_transient:
gnet_stats_count_dropped(src, MSG_DROP_TRANSIENT);
return;
}
