/**
* Compare function which returns TRUE if the hosts are equal.
*
* @note For use in hash tables and sets.
*/
bool
gnet_host_equal(const void *v1, const void *v2)
{
const gnet_host_t *h1 = v1, *h2 = v2;
return gnet_host_get_port(h1) == gnet_host_get_port(h2) &&
host_addr_equal(gnet_host_get_addr(h1), gnet_host_get_addr(h2));
}
/**
* Alternative hash function for use in hash table and sets.
*/
uint G_HOT
gnet_host_hash2(const void *key)
{
const gnet_host_t *host = key;
host_addr_t addr;
uint16 port;
addr = gnet_host_get_addr(host);
port = gnet_host_get_port(host);
return host_addr_port_hash2(addr, port);
}
/**
* Prints the host address ` followed by ``port'' to ``buf''. The string
* written to ``buf'' is always NUL-terminated unless ``len'' is zero. If
* ``len'' is too small, the string will be truncated.
*
* @param h the packet IP:port address.
* @param buf the destination buffer; may be NULL iff ``len'' is zero.
* @param len the size of ``buf'' in bytes.
*
* @return The length of the resulting string assuming ``len'' is sufficient.
*/
size_t
gnet_host_to_string_buf(const gnet_host_t *h, void *buf, size_t len)
{
host_addr_t addr;
uint16 port;
g_assert(h != NULL);
packed_host_unpack_addr(&h->data, &addr);
port = gnet_host_get_port(h);
return host_addr_port_to_string_buf(addr, port, buf, len);
}
/**
* Dump locally-emitted message block sent via UDP.
*/
void
dump_tx_udp_packet(const gnet_host_t *to, const pmsg_t *mb)
{
if (GNET_PROPERTY(dump_transmitted_gnutella_packets)) {
struct gnutella_node udp;
g_assert(to != NULL);
g_assert(mb != NULL);
/*
* Fill only the fields which will be perused by
* dump_packet_from_to().
*/
udp.peermode = NODE_P_UDP;
udp.addr = gnet_host_get_addr(to);
udp.port = gnet_host_get_port(to);
dump_packet_from_to(&dump_tx, NULL, &udp, mb);
} else if (dump_tx.initialized) {
dump_disable(&dump_tx);
}
}
/**
* Send buffer datagram to specified destination `to'.
*
* @returns amount of bytes written, or -1 on error with errno set.
*/
static ssize_t
tx_dgram_sendto(txdrv_t *tx, const gnet_host_t *to,
gconstpointer data, size_t len)
{
ssize_t r;
struct attr *attr = tx->opaque;
if (gnet_host_get_port(to) > 0) {
r = bio_sendto(attr->bio, to, data, len);
} else {
errno = EINVAL;
r = -1;
}
if ((ssize_t) -1 == r)
return tx_dgram_write_error(tx, to, "tx_dgram_sendto");
if (attr->cb->add_tx_written != NULL)
attr->cb->add_tx_written(tx->owner, r);
inet_udp_record_sent(gnet_host_get_addr(to));
return r;
}
/*
* @return stringified host vector as newly allocated string via halloc()
*/
char *
gnet_host_vec_to_string(const gnet_host_vec_t *hvec)
{
str_t *s;
uint i, n;
g_return_val_if_fail(hvec, NULL);
s = str_new(0);
n = gnet_host_vec_count(hvec);
for (i = 0; i < n; i++) {
gnet_host_t host;
gchar buf[128];
if (i > 0) {
STR_CAT(s, ", ");
}
host = gnet_host_vec_get(hvec, i);
host_addr_port_to_string_buf(gnet_host_get_addr(&host),
gnet_host_get_port(&host), buf, sizeof buf);
str_cat(s, buf);
}
return str_s2c_null(&s);
}
/**
* Periodic host heartbeat timer.
*/
void
host_timer(void)
{
guint count;
int missing;
host_addr_t addr;
guint16 port;
host_type_t htype;
guint max_nodes;
gboolean empty_cache = FALSE;
if (in_shutdown || !GNET_PROPERTY(online_mode))
return;
max_nodes = settings_is_leaf() ?
GNET_PROPERTY(max_ultrapeers) : GNET_PROPERTY(max_connections);
count = node_count(); /* Established + connecting */
missing = node_keep_missing();
if (GNET_PROPERTY(host_debug) > 1)
g_debug("host_timer - count %u, missing %u", count, missing);
/*
* If we are not connected to the Internet, apparently, make sure to
* connect to at most one host, to avoid using all our hostcache.
* Also, we don't connect each time we are called.
*/
if (!GNET_PROPERTY(is_inet_connected)) {
static time_t last_try;
if (last_try && delta_time(tm_time(), last_try) < 20)
return;
last_try = tm_time();
if (GNET_PROPERTY(host_debug))
g_debug("host_timer - not connected, trying to connect");
}
/*
* Allow more outgoing connections than the maximum amount of
* established Gnet connection we can maintain, but not more
* than quick_connect_pool_size This is the "greedy mode".
*/
if (count >= GNET_PROPERTY(quick_connect_pool_size)) {
if (GNET_PROPERTY(host_debug) > 1)
g_debug("host_timer - count %u >= pool size %u",
count, GNET_PROPERTY(quick_connect_pool_size));
return;
}
if (count < max_nodes)
missing -= whitelist_connect();
/*
* If we are under the number of connections wanted, we add hosts
* to the connection list
*/
htype = HOST_ULTRA;
if (
settings_is_ultra() &&
GNET_PROPERTY(node_normal_count) < GNET_PROPERTY(normal_connections) &&
GNET_PROPERTY(node_ultra_count) >=
(GNET_PROPERTY(up_connections) - GNET_PROPERTY(normal_connections))
) {
htype = HOST_ANY;
}
if (hcache_size(htype) == 0)
htype = HOST_ANY;
if (hcache_size(htype) == 0)
empty_cache = TRUE;
if (GNET_PROPERTY(host_debug) && missing > 0)
g_debug("host_timer - missing %d host%s%s",
missing, missing == 1 ? "" : "s",
empty_cache ? " [empty caches]" : "");
if (!GNET_PROPERTY(stop_host_get)) {
if (missing > 0) {
static time_t last_try;
unsigned fan, max_pool, to_add;
max_pool = MAX(GNET_PROPERTY(quick_connect_pool_size), max_nodes);
fan = (missing * GNET_PROPERTY(quick_connect_pool_size))/ max_pool;
fan = MAX(1, fan);
to_add = GNET_PROPERTY(is_inet_connected) ? fan : (guint) missing;
/*
* Every so many calls, attempt to ping all our neighbours to
* get fresh pongs, in case our host cache is not containing
* sufficiently fresh hosts and we keep getting connection failures.
*/
if (
0 == last_try ||
delta_time(tm_time(), last_try) >= HOST_PINGING_PERIOD
) {
ping_all_neighbours();
last_try = tm_time();
}
/*
* Make sure that we never use more connections then the
* quick pool or the maximum number of hosts allow.
*/
if (to_add + count > max_pool)
to_add = max_pool - count;
if (GNET_PROPERTY(host_debug) > 2) {
g_debug("host_timer - connecting - "
"add: %d fan:%d miss:%d max_hosts:%d count:%d extra:%d",
to_add, fan, missing, max_nodes, count,
GNET_PROPERTY(quick_connect_pool_size));
}
missing = to_add;
if (missing > 0 && (0 == connected_nodes() || host_low_on_pongs)) {
gnet_host_t host[HOST_DHT_MAX];
int hcount;
int i;
hcount = dht_fill_random(host,
MIN(UNSIGNED(missing), G_N_ELEMENTS(host)));
missing -= hcount;
for (i = 0; i < hcount; i++) {
addr = gnet_host_get_addr(&host[i]);
port = gnet_host_get_port(&host[i]);
if (!hcache_node_is_bad(addr)) {
if (GNET_PROPERTY(host_debug) > 3) {
g_debug("host_timer - UHC pinging and connecting "
"to DHT node at %s",
host_addr_port_to_string(addr, port));
}
/* Try to use the host as an UHC before connecting */
udp_send_ping(NULL, addr, port, TRUE);
if (!host_gnutella_connect(addr, port)) {
missing++; /* Did not use entry */
}
} else {
missing++; /* Did not use entry */
}
}
}
while (hcache_size(htype) && missing-- > 0) {
if (hcache_get_caught(htype, &addr, &port)) {
if (!(hostiles_check(addr) || hcache_node_is_bad(addr))) {
if (!host_gnutella_connect(addr, port)) {
missing++; /* Did not use entry */
}
} else {
missing++; /* Did not use entry */
}
}
}
if (missing > 0 && (empty_cache || host_cache_allow_bypass())) {
if (!uhc_is_waiting()) {
if (GNET_PROPERTY(host_debug))
g_debug("host_timer - querying UDP host cache");
uhc_get_hosts(); /* Get new hosts from UHCs */
}
}
}
} else if (GNET_PROPERTY(use_netmasks)) {
/* Try to find better hosts */
if (hcache_find_nearby(htype, &addr, &port)) {
if (node_remove_worst(TRUE))
node_add(addr, port, 0);
else
hcache_add_caught(htype, addr, port, "nearby host");
}
}
}
/**
* Add file to the current query hit.
*
* @return TRUE if we kept the file, FALSE if we did not include it in the hit.
*/
static bool
g2_build_qh2_add(struct g2_qh2_builder *ctx, const shared_file_t *sf)
{
const sha1_t *sha1;
g2_tree_t *h, *c;
shared_file_check(sf);
/*
* Make sure the file is still in the library.
*/
if (0 == shared_file_index(sf))
return FALSE;
/*
* On G2, the H/URN child is required, meaning we need the SHA1 at least.
*/
if (!sha1_hash_available(sf))
return FALSE;
/*
* Do not send duplicates, as determined by the SHA1 of the resource.
*
* A user may share several files with different names but the same SHA1,
* and if all of them are hits, we only want to send one instance.
*
* When generating hits for host-browsing, we do not care about duplicates
* and ctx->hs is NULL then.
*/
sha1 = shared_file_sha1(sf); /* This is an atom */
if (ctx->hs != NULL) {
if (hset_contains(ctx->hs, sha1))
return FALSE;
hset_insert(ctx->hs, sha1);
}
/*
* Create the "H" child and attach it to the current tree.
*/
if (NULL == ctx->t)
g2_build_qh2_start(ctx);
h = g2_tree_alloc_empty("H");
g2_tree_add_child(ctx->t, h);
/*
* URN -- Universal Resource Name
*
* If there is a known TTH, then we can generate a bitprint, otherwise
* we just convey the SHA1.
*/
{
const tth_t * const tth = shared_file_tth(sf);
char payload[SHA1_RAW_SIZE + TTH_RAW_SIZE + sizeof G2_URN_BITPRINT];
char *p = payload;
if (NULL == tth) {
p = mempcpy(p, G2_URN_SHA1, sizeof G2_URN_SHA1);
p += clamp_memcpy(p, sizeof payload - ptr_diff(p, payload),
sha1, SHA1_RAW_SIZE);
} else {
p = mempcpy(p, G2_URN_BITPRINT, sizeof G2_URN_BITPRINT);
p += clamp_memcpy(p, sizeof payload - ptr_diff(p, payload),
sha1, SHA1_RAW_SIZE);
p += clamp_memcpy(p, sizeof payload - ptr_diff(p, payload),
tth, TTH_RAW_SIZE);
}
g_assert(ptr_diff(p, payload) <= sizeof payload);
c = g2_tree_alloc_copy("URN", payload, ptr_diff(p, payload));
g2_tree_add_child(h, c);
}
/*
* URL -- empty to indicate that we share the file via uri-res.
*/
if (ctx->flags & QHIT_F_G2_URL) {
uint known;
uint16 csc;
c = g2_tree_alloc_empty("URL");
g2_tree_add_child(h, c);
/*
* CSC -- if we know alternate sources, indicate how many in "CSC".
*
* This child is only emitted when they requested "URL".
*/
known = dmesh_count(sha1);
csc = MIN(known, MAX_INT_VAL(uint16));
if (csc != 0) {
char payload[2];
poke_le16(payload, csc);
c = g2_tree_alloc_copy("CSC", payload, sizeof payload);
g2_tree_add_child(h, c);
}
/*
* PART -- if we only have a partial file, indicate how much we have.
*
* This child is only emitted when they requested "URL".
*/
if (shared_file_is_partial(sf) && !shared_file_is_finished(sf)) {
filesize_t available = shared_file_available(sf);
char payload[8]; /* If we have to encode file size as 64-bit */
uint32 av32;
time_t mtime = shared_file_modification_time(sf);
c = g2_tree_alloc_empty("PART");
g2_tree_add_child(h, c);
av32 = available;
if (av32 == available) {
/* Fits within a 32-bit quantity */
poke_le32(payload, av32);
g2_tree_set_payload(c, payload, sizeof av32, TRUE);
} else {
/* Encode as a 64-bit quantity then */
poke_le64(payload, available);
g2_tree_set_payload(c, payload, sizeof payload, TRUE);
}
/*
* GTKG extension: encode the last modification time of the
* partial file in an "MT" child. This lets the other party
* determine whether the host is still able to actively complete
* the file.
*/
poke_le32(payload, (uint32) mtime);
g2_tree_add_child(c,
g2_tree_alloc_copy("MT", payload, sizeof(uint32)));
}
/*
* CT -- creation time of the resource (GTKG extension).
*/
{
time_t create_time = shared_file_creation_time(sf);
if ((time_t) -1 != create_time) {
char payload[8];
int n;
create_time = MAX(0, create_time);
n = vlint_encode(create_time, payload);
g2_tree_add_child(h,
g2_tree_alloc_copy("CT", payload, n)); /* No trailing 0s */
}
}
}
/*
* DN -- distinguished name.
*
* Note that the presence of DN also governs the presence of SZ if the
* file length does not fit a 32-bit unsigned quantity.
*/
if (ctx->flags & QHIT_F_G2_DN) {
char payload[8]; /* If we have to encode file size as 64-bit */
uint32 fs32;
filesize_t fs = shared_file_size(sf);
const char *name;
const char *rp;
c = g2_tree_alloc_empty("DN");
fs32 = fs;
if (fs32 == fs) {
/* Fits within a 32-bit quantity */
poke_le32(payload, fs32);
g2_tree_set_payload(c, payload, sizeof fs32, TRUE);
} else {
/* Does not fit a 32-bit quantity, emit a SZ child */
poke_le64(payload, fs);
g2_tree_add_child(h,
g2_tree_alloc_copy("SZ", payload, sizeof payload));
}
name = shared_file_name_nfc(sf);
g2_tree_append_payload(c, name, shared_file_name_nfc_len(sf));
g2_tree_add_child(h, c);
/*
* GTKG extension: if there is a file path, expose it as a "P" child
* under the DN node.
*/
rp = shared_file_relative_path(sf);
if (rp != NULL) {
g2_tree_add_child(c, g2_tree_alloc_copy("P", rp, strlen(rp)));
}
}
/*
* GTKG extension: if they requested alt-locs in the /Q2/I with "A", then
* send them some known alt-locs in an "ALT" child.
*
* Note that these alt-locs can be for Gnutella hosts: since both Gnutella
* and G2 share a common HTTP-based file transfer mechanism with compatible
* extra headers, there is no need to handle them separately.
*/
if (ctx->flags & QHIT_F_G2_ALT) {
gnet_host_t hvec[G2_BUILD_QH2_MAX_ALT];
int hcnt = 0;
hcnt = dmesh_fill_alternate(sha1, hvec, N_ITEMS(hvec));
if (hcnt > 0) {
int i;
c = g2_tree_alloc_empty("ALT");
for (i = 0; i < hcnt; i++) {
host_addr_t addr;
uint16 port;
addr = gnet_host_get_addr(&hvec[i]);
port = gnet_host_get_port(&hvec[i]);
if (host_addr_is_ipv4(addr)) {
char payload[6];
host_ip_port_poke(payload, addr, port, NULL);
g2_tree_append_payload(c, payload, sizeof payload);
}
}
/*
* If the payload is still empty, then drop the "ALT" child.
* Otherwise, attach it to the "H" node.
*/
if (NULL == g2_tree_node_payload(c, NULL)) {
g2_tree_free_null(&c);
} else {
g2_tree_add_child(h, c);
}
}
}
/*
* Update the size of the query hit we're generating.
*/
ctx->current_size += g2_frame_serialize(h, NULL, 0);
return TRUE;
}
/**
* Send message block to IP:port.
*
* @param us the UDP scheduler
* @param mb the message to send
* @param to the IP:port destination of the message
* @param tx the TX stack sending the message
* @param cb callback actions on the datagram
*
* @return TRUE if message was sent or dropped, FALSE if there is no more
* bandwidth to send anything.
*/
static bool
udp_sched_mb_sendto(udp_sched_t *us, pmsg_t *mb, const gnet_host_t *to,
const txdrv_t *tx, const struct tx_dgram_cb *cb)
{
ssize_t r;
int len = pmsg_size(mb);
bio_source_t *bio = NULL;
if (0 == gnet_host_get_port(to))
return TRUE;
/*
* Check whether message still needs to be sent.
*/
if (!pmsg_hook_check(mb))
return TRUE; /* Dropped */
/*
* Select the proper I/O source depending on the network address type.
*/
switch (gnet_host_get_net(to)) {
case NET_TYPE_IPV4:
bio = us->bio[UDP_SCHED_IPv4];
break;
case NET_TYPE_IPV6:
bio = us->bio[UDP_SCHED_IPv6];
break;
case NET_TYPE_NONE:
case NET_TYPE_LOCAL:
g_assert_not_reached();
}
/*
* If there is no I/O source, then the socket to send that type of traffic
* was cleared, hence we simply need to discard the message.
*/
if (NULL == bio) {
udp_sched_log(4, "%p: discarding mb=%p (%d bytes) to %s",
us, mb, pmsg_size(mb), gnet_host_to_string(to));
return udp_tx_drop(tx, cb); /* TRUE, for "sent" */
}
/*
* OK, proceed if we have bandwidth.
*/
r = bio_sendto(bio, to, pmsg_start(mb), len);
if (r < 0) { /* Error, or no bandwidth */
if (udp_sched_write_error(us, to, mb, G_STRFUNC)) {
udp_sched_log(4, "%p: dropped mb=%p (%d bytes): %m",
us, mb, pmsg_size(mb));
return udp_tx_drop(tx, cb); /* TRUE, for "sent" */
}
udp_sched_log(3, "%p: no bandwidth for mb=%p (%d bytes)",
us, mb, pmsg_size(mb));
us->used_all = TRUE;
return FALSE;
}
if (r != len) {
g_warning("%s: partial UDP write (%zd bytes) to %s "
"for %d-byte datagram",
G_STRFUNC, r, gnet_host_to_string(to), len);
} else {
udp_sched_log(5, "%p: sent mb=%p (%d bytes) prio=%u",
us, mb, pmsg_size(mb), pmsg_prio(mb));
pmsg_mark_sent(mb);
if (cb->msg_account != NULL)
(*cb->msg_account)(tx->owner, mb);
inet_udp_record_sent(gnet_host_get_addr(to));
}
return TRUE; /* Message sent */
}
/**
* Start a G2 RPC with the specified host.
*
* @param host the host to which message is sent
* @param mb the message to send
* @param cb if non-NULL, callback to invoke on reply or timeout
* @param arg additional callback argument
* @param timeout amount of seconds before timeout
*
* @return TRUE if we initiated the RPC, FALSE if another of the same
* kind was already in progress with the host.
*/
bool
g2_rpc_launch(const gnet_host_t *host, pmsg_t *mb,
g2_rpc_cb_t cb, void *arg, unsigned timeout)
{
struct g2_rpc *gr;
struct g2_rpc_key key;
gnutella_node_t *n;
key.type = g2_msg_type_mb(mb);
key.addr = gnet_host_get_addr(host);
/*
* Because there is no MUID in /PI and /QKR messages, we cannot use that
* as a key to detect the RPC reply. Therefore, we use the message type
* and the IP address of the host. When a /PO or /QKA comes back, we'll
* be able to see whether we had a pending RPC from that host for that
* type of transaction.
*
* The downside is that we can only have one pending RPC at a time of
* a given kind towards a given IP address. We don't use the port in
* the key because we cannot assume the reply will come from the same port
* we sent the message to, if the remote host is behind NAT or does not
* use its listening UDP socket to reply.
*/
if (hevset_contains(g2_rpc_pending, &key)) {
if (GNET_PROPERTY(g2_rpc_debug)) {
g_debug("%s(): cannot issue /%s RPC to %s: concurrent request",
G_STRFUNC, g2_msg_type_name(key.type),
gnet_host_to_string(host));
}
return FALSE;
}
/*
* Make sure the node is valid.
*/
n = node_udp_g2_get_addr_port(key.addr, gnet_host_get_port(host));
if (NULL == n) {
if (GNET_PROPERTY(g2_rpc_debug)) {
g_debug("%s(): cannot issue /%s RPC to %s: cannot get G2 node",
G_STRFUNC, g2_msg_type_name(key.type),
gnet_host_to_string(host));
}
return FALSE; /* Invalid node, or G2 disabled */
}
/*
* Good, we can issue the RPC.
*/
WALLOC(gr);
gr->magic = G2_RPC_MAGIC;
gr->key = key; /* struct copy */
gr->cb = cb;
gr->arg = arg;
gr->timeout_ev = cq_main_insert(timeout * 1000, g2_rpc_timeout, gr);
hevset_insert(g2_rpc_pending, gr);
if (GNET_PROPERTY(g2_rpc_debug) > 1) {
g_debug("%s(): issuing /%s RPC to %s, timeout %u sec%s",
G_STRFUNC, g2_msg_type_name(key.type),
gnet_host_to_string(host), timeout, plural(timeout));
}
/*
* Do not send RPCs reliably: this can cause problems if we don't receive
* the ACK backm yet the message was received and processed remotely: the
* remote host will send a reply back and the message will still appear to
* be "unsent" locally.
*
* Furthermore, this alleviates the need for the remote side to actually
* acknowledge the request: targeted hosts can be busy so it's best to
* make the RPC "unreliable" to limit processing and bandwidth requirements.
*/
g2_node_send(n, mb);
return TRUE;
}
/**
* Create a new Gnutella host vector out of a sequence of gnet_host_t items.
*/
static gnet_host_vec_t *
gnet_host_vec_from_sequence(sequence_t *s)
{
sequence_iter_t *iter;
gnet_host_vec_t *vec;
uint n_ipv6 = 0, n_ipv4 = 0, hcnt;
if (sequence_is_empty(s))
return NULL;
hcnt = 0;
iter = sequence_forward_iterator(s);
while (sequence_iter_has_next(iter)) {
const gnet_host_t *host = sequence_iter_next(iter);
switch (gnet_host_get_net(host)) {
case NET_TYPE_IPV4:
n_ipv4++;
hcnt++;
break;
case NET_TYPE_IPV6:
n_ipv6++;
hcnt++;
break;
case NET_TYPE_LOCAL:
case NET_TYPE_NONE:
break;
}
}
sequence_iterator_release(&iter);
if (0 == hcnt)
return NULL;
vec = gnet_host_vec_alloc();
vec->n_ipv4 = MIN(n_ipv4, 255);
vec->n_ipv6 = MIN(n_ipv6, 255);
if (vec->n_ipv4 > 0)
WALLOC_ARRAY(vec->hvec_v4, vec->n_ipv4);
if (vec->n_ipv6 > 0)
WALLOC_ARRAY(vec->hvec_v6, vec->n_ipv6);
n_ipv4 = 0;
n_ipv6 = 0;
iter = sequence_forward_iterator(s);
while (sequence_iter_has_next(iter)) {
const gnet_host_t *host = sequence_iter_next(iter);
host_addr_t addr = gnet_host_get_addr(host);
uint16 port = gnet_host_get_port(host);
switch (gnet_host_get_net(host)) {
case NET_TYPE_IPV4:
if (n_ipv4 < vec->n_ipv4) {
char *dest = cast_to_pointer(&vec->hvec_v4[n_ipv4++]);
poke_be32(&dest[0], host_addr_ipv4(addr));
poke_le16(&dest[4], port);
}
break;
case NET_TYPE_IPV6:
if (n_ipv6 < vec->n_ipv6) {
char *dest = cast_to_pointer(&vec->hvec_v6[n_ipv6++]);
dest = mempcpy(dest, host_addr_ipv6(&addr), 16);
poke_le16(dest, port);
}
break;
case NET_TYPE_LOCAL:
case NET_TYPE_NONE:
break;
}
}
sequence_iterator_release(&iter);
return vec;
}
