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gossmap.c
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#include "config.h"
#include <assert.h>
#include <ccan/crypto/siphash24/siphash24.h>
#include <ccan/err/err.h>
#include <ccan/htable/htable_type.h>
#include <ccan/ptrint/ptrint.h>
#include <ccan/tal/str/str.h>
#include <common/features.h>
#include <common/gossip_store.h>
#include <common/gossmap.h>
#include <common/pseudorand.h>
#include <common/sciddir_or_pubkey.h>
#include <errno.h>
#include <fcntl.h>
#include <gossipd/gossip_store_wiregen.h>
#include <inttypes.h>
#include <sys/mman.h>
#include <unistd.h>
#include <wire/peer_wire.h>
/* We need this global to decode indexes for hash functions */
static struct gossmap *map;
/* This makes an htable of indices into our array. */
static struct short_channel_id chanidx_id(const ptrint_t *pidx);
static bool chanidx_eq_id(const ptrint_t *pidx,
struct short_channel_id scid)
{
struct short_channel_id pidxid = chanidx_id(pidx);
return short_channel_id_eq(pidxid, scid);
}
static size_t scid_hash(const struct short_channel_id scid)
{
return siphash24(siphash_seed(), &scid, sizeof(scid));
}
HTABLE_DEFINE_TYPE(ptrint_t, chanidx_id, scid_hash, chanidx_eq_id,
chanidx_htable);
static struct node_id nodeidx_id(const ptrint_t *pidx);
static bool nodeidx_eq_id(const ptrint_t *pidx, const struct node_id id)
{
struct node_id pidxid = nodeidx_id(pidx);
return node_id_eq(&pidxid, &id);
}
static size_t nodeid_hash(const struct node_id id)
{
return siphash24(siphash_seed(), &id, PUBKEY_CMPR_LEN);
}
HTABLE_DEFINE_TYPE(ptrint_t, nodeidx_id, nodeid_hash, nodeidx_eq_id,
nodeidx_htable);
struct gossmap {
/* We updated this every time we reopen, so we know to update iterators! */
u64 generation;
/* The file descriptor and filename to monitor */
int fd;
/* NULL means we don't own fd */
const char *fname;
/* The memory map of the file: u8 for arithmetic portability */
u8 *mmap;
/* map_end is where we read to so far, map_size is total size */
u64 map_end, map_size;
/* Map of node id -> node */
struct nodeidx_htable *nodes;
/* Map of short_channel_id id -> channel */
struct chanidx_htable *channels;
/* Array of nodes, so we can use simple index. */
struct gossmap_node *node_arr;
/* This is tal_count(node_arr), which we call very often in assert() */
size_t num_node_arr;
/* Array of chans, so we can use simple index */
struct gossmap_chan *chan_arr;
/* This is tal_count(chan_arr), which we call very often in assert() */
size_t num_chan_arr;
/* Linked list of freed ones, if any. */
u32 freed_nodes, freed_chans;
/* local channel_announce messages, if any. */
const u8 *local_announces;
/* local channel_update messages, if any. */
u8 *local_updates;
/* Callbacks for different events: return false to fail. */
void (*cupdate_fail)(struct gossmap *map,
const struct short_channel_id_dir *scidd,
u16 cltv_expiry_delta,
u32 fee_base_msat,
u32 fee_proportional_millionths,
void *cb_arg);
bool (*unknown_record)(struct gossmap *map,
int type,
u64 off,
size_t msglen,
void *cb_arg);
void *cb_arg;
};
/* Accessors for the gossmap */
static void map_copy(const struct gossmap *map, u64 offset,
void *dst, size_t len)
{
/* After mmap, we place local channel_announcements then channel_updates */
if (offset >= map->map_size) {
u64 localannoff = offset - map->map_size;
if (localannoff < tal_bytelen(map->local_announces)) {
assert(localannoff + len <= tal_bytelen(map->local_announces));
memcpy(dst, map->local_announces + localannoff, len);
} else {
u64 localchanoff = localannoff - tal_bytelen(map->local_announces);
assert(localchanoff + len <= tal_bytelen(map->local_updates));
memcpy(dst, map->local_updates + localchanoff, len);
}
} else {
assert(offset + len <= map->map_size);
if (map->mmap)
memcpy(dst, map->mmap + offset, len);
else {
/* Yeah, we'll crash on I/O errors. */
if (pread(map->fd, dst, len, offset) != len)
abort();
}
}
}
static u8 map_u8(const struct gossmap *map, u64 offset)
{
u8 u8;
map_copy(map, offset, &u8, sizeof(u8));
return u8;
}
static u16 map_be16(const struct gossmap *map, u64 offset)
{
be16 be16;
map_copy(map, offset, &be16, sizeof(be16));
return be16_to_cpu(be16);
}
static u32 map_be32(const struct gossmap *map, u64 offset)
{
be32 be32;
map_copy(map, offset, &be32, sizeof(be32));
return be32_to_cpu(be32);
}
static u64 map_be64(const struct gossmap *map, u64 offset)
{
be64 be64;
map_copy(map, offset, &be64, sizeof(be64));
return be64_to_cpu(be64);
}
static void map_nodeid(const struct gossmap *map, u64 offset,
struct node_id *id)
{
map_copy(map, offset, id, sizeof(*id));
}
/* Returns optional or compulsory feature if set, otherwise -1 */
static int map_feature_test(const struct gossmap *map,
int compulsory_bit,
u64 offset, size_t len)
{
size_t bytenum = compulsory_bit / 8;
u8 bits;
assert(COMPULSORY_FEATURE(compulsory_bit) == compulsory_bit);
if (bytenum >= len)
return -1;
/* Note reversed! */
bits = map_u8(map, offset + len - 1 - bytenum);
if (bits & (1 << (compulsory_bit % 8)))
return compulsory_bit;
if (bits & (1 << (OPTIONAL_FEATURE(compulsory_bit) % 8)))
return OPTIONAL_FEATURE(compulsory_bit);
return -1;
}
/* Helper callback which simply increments counter */
static void cupdate_fail_inc_ctr(struct gossmap *map,
const struct short_channel_id_dir *scidd,
u16 cltv_expiry_delta,
u32 fee_base_msat,
u32 fee_proportional_millionths,
void *cb_arg)
{
size_t *num = cb_arg;
(*num)++;
}
/* These values can change across calls to gossmap_check. */
u32 gossmap_max_node_idx(const struct gossmap *map)
{
assert(tal_count(map->node_arr) == map->num_node_arr);
return map->num_node_arr;
}
u32 gossmap_max_chan_idx(const struct gossmap *map)
{
assert(tal_count(map->chan_arr) == map->num_chan_arr);
return map->num_chan_arr;
}
/* Each channel has a unique (low) index. */
u32 gossmap_node_idx(const struct gossmap *map, const struct gossmap_node *node)
{
assert(node - map->node_arr < map->num_node_arr);
return node - map->node_arr;
}
u32 gossmap_chan_idx(const struct gossmap *map, const struct gossmap_chan *chan)
{
assert(chan - map->chan_arr < map->num_chan_arr);
return chan - map->chan_arr;
}
struct gossmap_node *gossmap_node_byidx(const struct gossmap *map, u32 idx)
{
assert(idx < gossmap_max_node_idx(map));
if (map->node_arr[idx].chan_idxs == NULL)
return NULL;
return &map->node_arr[idx];
}
struct gossmap_chan *gossmap_chan_byidx(const struct gossmap *map, u32 idx)
{
assert(idx < gossmap_max_chan_idx(map));
if (map->chan_arr[idx].plus_scid_off == 0)
return NULL;
return &map->chan_arr[idx];
}
/* htable can't handle NULL or 1 values, so we add 2 */
static struct gossmap_chan *ptrint2chan(const ptrint_t *pidx)
{
return map->chan_arr + ptr2int(pidx) - 2;
}
static ptrint_t *chan2ptrint(const struct gossmap_chan *chan)
{
return int2ptr(chan - map->chan_arr + 2);
}
static struct gossmap_node *ptrint2node(const ptrint_t *pidx)
{
return map->node_arr + ptr2int(pidx) - 2;
}
static ptrint_t *node2ptrint(const struct gossmap_node *node)
{
return int2ptr(node - map->node_arr + 2);
}
static struct short_channel_id chanidx_id(const ptrint_t *pidx)
{
return gossmap_chan_scid(map, ptrint2chan(pidx));
}
static struct node_id nodeidx_id(const ptrint_t *pidx)
{
struct node_id id;
gossmap_node_get_id(map, ptrint2node(pidx), &id);
return id;
}
struct gossmap_node *gossmap_find_node(const struct gossmap *map,
const struct node_id *id)
{
ptrint_t *pi = nodeidx_htable_get(map->nodes, *id);
if (pi)
return ptrint2node(pi);
return NULL;
}
struct gossmap_chan *gossmap_find_chan(const struct gossmap *map,
const struct short_channel_id *scid)
{
ptrint_t *pi = chanidx_htable_get(map->channels, *scid);
if (pi)
return ptrint2chan(pi);
return NULL;
}
static u32 init_node_arr(struct gossmap_node *node_arr, size_t start)
{
size_t i;
for (i = start; i < tal_count(node_arr) - 1; i++) {
node_arr[i].nann_off = i + 1;
node_arr[i].chan_idxs = NULL;
}
node_arr[i].nann_off = UINT_MAX;
node_arr[i].chan_idxs = NULL;
return start;
}
/* Freelist links through node_off of unused entries. */
static struct gossmap_node *next_free_node(struct gossmap *map)
{
size_t f;
if (map->freed_nodes == UINT_MAX) {
/* Double in size, add second half to free list */
size_t n = tal_count(map->node_arr);
map->num_node_arr *= 2;
tal_resize(&map->node_arr, n * 2);
map->freed_nodes = init_node_arr(map->node_arr, n);
}
f = map->freed_nodes;
map->freed_nodes = map->node_arr[f].nann_off;
return &map->node_arr[f];
}
static u32 new_node(struct gossmap *map)
{
struct gossmap_node *node = next_free_node(map);
assert(node->chan_idxs == NULL);
node->nann_off = 0;
node->num_chans = 0;
return gossmap_node_idx(map, node);
}
static void remove_node(struct gossmap *map, struct gossmap_node *node)
{
u32 nodeidx = gossmap_node_idx(map, node);
if (!nodeidx_htable_del(map->nodes, node2ptrint(node)))
abort();
node->nann_off = map->freed_nodes;
free(node->chan_idxs);
node->chan_idxs = NULL;
node->num_chans = 0;
map->freed_nodes = nodeidx;
}
static void node_add_channel(struct gossmap_node *node, u32 chanidx)
{
node->num_chans++;
node->chan_idxs = realloc(node->chan_idxs,
node->num_chans * sizeof(*node->chan_idxs));
node->chan_idxs[node->num_chans-1] = chanidx;
}
static u32 init_chan_arr(struct gossmap_chan *chan_arr, size_t start)
{
size_t i;
for (i = start; i < tal_count(chan_arr) - 1; i++) {
chan_arr[i].cann_off = i + 1;
chan_arr[i].plus_scid_off = 0;
}
chan_arr[i].cann_off = UINT_MAX;
chan_arr[i].plus_scid_off = 0;
return start;
}
/* Freelist links through scid of unused entries. */
static struct gossmap_chan *next_free_chan(struct gossmap *map)
{
size_t f;
if (map->freed_chans == UINT_MAX) {
/* Double in size, add second half to free list */
size_t n = tal_count(map->chan_arr);
map->num_chan_arr *= 2;
tal_resize(&map->chan_arr, n * 2);
map->freed_chans = init_chan_arr(map->chan_arr, n);
}
f = map->freed_chans;
map->freed_chans = map->chan_arr[f].cann_off;
return &map->chan_arr[f];
}
static struct gossmap_chan *new_channel(struct gossmap *map,
u64 cannounce_off,
u64 plus_scid_off,
u32 n1idx, u32 n2idx)
{
struct gossmap_chan *chan = next_free_chan(map);
chan->cann_off = cannounce_off;
chan->plus_scid_off = plus_scid_off;
chan->cupdate_off[0] = chan->cupdate_off[1] = 0;
memset(chan->half, 0, sizeof(chan->half));
chan->half[0].nodeidx = n1idx;
chan->half[1].nodeidx = n2idx;
node_add_channel(map->node_arr + n1idx, gossmap_chan_idx(map, chan));
node_add_channel(map->node_arr + n2idx, gossmap_chan_idx(map, chan));
chanidx_htable_add(map->channels, chan2ptrint(chan));
return chan;
}
static void remove_chan_from_node(struct gossmap *map,
struct gossmap_node *node,
u32 chanidx)
{
size_t i;
if (node->num_chans == 1) {
remove_node(map, node);
return;
}
for (i = 0; node->chan_idxs[i] != chanidx; i++)
assert(i < node->num_chans);
memmove(node->chan_idxs + i,
node->chan_idxs + i + 1,
sizeof(node->chan_idxs[0]) * (node->num_chans - i - 1));
node->num_chans--;
}
void gossmap_remove_chan(struct gossmap *map, struct gossmap_chan *chan)
{
u32 chanidx = gossmap_chan_idx(map, chan);
if (!chanidx_htable_del(map->channels, chan2ptrint(chan)))
abort();
remove_chan_from_node(map, gossmap_nth_node(map, chan, 0), chanidx);
remove_chan_from_node(map, gossmap_nth_node(map, chan, 1), chanidx);
chan->cann_off = map->freed_chans;
chan->plus_scid_off = 0;
map->freed_chans = chanidx;
}
void gossmap_remove_node(struct gossmap *map, struct gossmap_node *node)
{
while (node->num_chans != 0)
gossmap_remove_chan(map, gossmap_nth_chan(map, node, 0, NULL));
}
/* BOLT #7:
* 1. type: 256 (`channel_announcement`)
* 2. data:
* * [`signature`:`node_signature_1`]
* * [`signature`:`node_signature_2`]
* * [`signature`:`bitcoin_signature_1`]
* * [`signature`:`bitcoin_signature_2`]
* * [`u16`:`len`]
* * [`len*byte`:`features`]
* * [`chain_hash`:`chain_hash`]
* * [`short_channel_id`:`short_channel_id`]
* * [`point`:`node_id_1`]
* * [`point`:`node_id_2`]
*/
static struct gossmap_chan *add_channel(struct gossmap *map,
u64 cannounce_off,
size_t msglen)
{
/* Note that first two bytes are message type */
const u64 feature_len_off = 2 + (64 + 64 + 64 + 64);
size_t feature_len;
u64 plus_scid_off;
struct short_channel_id scid;
struct node_id node_id[2];
struct gossmap_node *n[2];
struct gossmap_chan *chan;
u32 nidx[2];
feature_len = map_be16(map, cannounce_off + feature_len_off);
plus_scid_off = feature_len_off + 2 + feature_len + 32;
map_nodeid(map, cannounce_off + plus_scid_off + 8, &node_id[0]);
map_nodeid(map, cannounce_off + plus_scid_off + 8 + PUBKEY_CMPR_LEN, &node_id[1]);
/* We should not get duplicates. */
scid.u64 = map_be64(map, cannounce_off + plus_scid_off);
chan = gossmap_find_chan(map, &scid);
if (chan) {
/* FIXME: Report this better! */
warnx("gossmap: redundant channel_announce for %s, offsets %"PRIu64" and %"PRIu64"!",
fmt_short_channel_id(tmpctx, scid),
chan->cann_off, cannounce_off);
return NULL;
}
/* gossipd writes WIRE_GOSSIP_STORE_CHANNEL_AMOUNT after this,
* so ignore channel_announcement until that appears */
if (msglen
&& (map->map_size < cannounce_off + msglen + sizeof(struct gossip_hdr) + sizeof(u16) + sizeof(u64)))
return NULL;
/* We carefully map pointers to indexes, since new_node can move them! */
n[0] = gossmap_find_node(map, &node_id[0]);
if (n[0])
nidx[0] = gossmap_node_idx(map, n[0]);
else
nidx[0] = new_node(map);
n[1] = gossmap_find_node(map, &node_id[1]);
if (n[1])
nidx[1] = gossmap_node_idx(map, n[1]);
else
nidx[1] = new_node(map);
chan = new_channel(map, cannounce_off, plus_scid_off,
nidx[0], nidx[1]);
/* Now we have a channel, we can add nodes to htable */
if (!n[0])
nodeidx_htable_add(map->nodes,
node2ptrint(map->node_arr + nidx[0]));
if (!n[1])
nodeidx_htable_add(map->nodes,
node2ptrint(map->node_arr + nidx[1]));
return chan;
}
/* Does not set hc->nodeidx! */
static void fill_from_update(struct gossmap *map,
struct short_channel_id_dir *scidd,
struct half_chan *hc,
u64 cupdate_off,
void (*cupdate_fail)(struct gossmap *map,
const struct short_channel_id_dir *scidd,
u16 cltv_expiry_delta,
u32 fee_base_msat,
u32 fee_proportional_millionths,
void *cb_arg),
void *cb_arg)
{
/* Note that first two bytes are message type */
const u64 scid_off = cupdate_off + 2 + (64 + 32);
const u64 message_flags_off = scid_off + 8 + 4;
const u64 channel_flags_off = message_flags_off + 1;
const u64 cltv_expiry_delta_off = channel_flags_off + 1;
const u64 htlc_minimum_off = cltv_expiry_delta_off + 2;
const u64 fee_base_off = htlc_minimum_off + 8;
const u64 fee_prop_off = fee_base_off + 4;
const u64 htlc_maximum_off = fee_prop_off + 4;
u8 chanflags;
u32 base_fee, proportional_fee;
u16 delay;
/* We round this *down*, since too-low min is more conservative */
hc->htlc_min = u64_to_fp16(map_be64(map, htlc_minimum_off), false);
hc->htlc_max = u64_to_fp16(map_be64(map, htlc_maximum_off), true);
scidd->scid.u64 = map_be64(map, scid_off);
chanflags = map_u8(map, channel_flags_off);
scidd->dir = (chanflags & ROUTING_FLAGS_DIRECTION);
hc->enabled = !(chanflags & ROUTING_FLAGS_DISABLED);
base_fee = map_be32(map, fee_base_off);
proportional_fee = map_be32(map, fee_prop_off);
delay = map_be16(map, cltv_expiry_delta_off);
hc->base_fee = base_fee;
hc->proportional_fee = proportional_fee;
hc->delay = delay;
/* Check they fit: we turn off if not, call optional callback. */
if (hc->base_fee != base_fee
|| hc->proportional_fee != proportional_fee
|| hc->delay != delay) {
hc->htlc_max = 0;
hc->enabled = false;
if (cupdate_fail)
cupdate_fail(map, scidd,
delay, base_fee, proportional_fee,
cb_arg);
}
}
/* BOLT #7:
* 1. type: 258 (`channel_update`)
* 2. data:
* * [`signature`:`signature`]
* * [`chain_hash`:`chain_hash`]
* * [`short_channel_id`:`short_channel_id`]
* * [`u32`:`timestamp`]
* * [`byte`:`message_flags`]
* * [`byte`:`channel_flags`]
* * [`u16`:`cltv_expiry_delta`]
* * [`u64`:`htlc_minimum_msat`]
* * [`u32`:`fee_base_msat`]
* * [`u32`:`fee_proportional_millionths`]
* * [`u64`:`htlc_maximum_msat`]
*/
static void update_channel(struct gossmap *map, u64 cupdate_off)
{
struct short_channel_id_dir scidd;
struct gossmap_chan *chan;
struct half_chan hc;
fill_from_update(map, &scidd, &hc, cupdate_off,
map->cupdate_fail, map->cb_arg);
chan = gossmap_find_chan(map, &scidd.scid);
/* This can happen if channel gets deleted! */
if (!chan)
return;
/* Preserve this */
hc.nodeidx = chan->half[scidd.dir].nodeidx;
chan->half[scidd.dir] = hc;
chan->cupdate_off[scidd.dir] = cupdate_off;
}
static void remove_channel_by_deletemsg(struct gossmap *map, u64 del_off)
{
struct short_channel_id scid;
struct gossmap_chan *chan;
/* They can delete things we don't know about, since they also
* get their length marked with the deleted bit */
/* Note that first two bytes are message type */
scid.u64 = map_be64(map, del_off + 2);
chan = gossmap_find_chan(map, &scid);
if (!chan)
return;
gossmap_remove_chan(map, chan);
}
struct short_channel_id gossmap_chan_scid(const struct gossmap *map,
const struct gossmap_chan *c)
{
struct short_channel_id scid;
scid.u64 = map_be64(map, c->cann_off + c->plus_scid_off);
return scid;
}
/* BOLT #7:
* 1. type: 257 (`node_announcement`)
* 2. data:
* * [`signature`:`signature`]
* * [`u16`:`flen`]
* * [`flen*byte`:`features`]
* * [`u32`:`timestamp`]
* * [`point`:`node_id`]
* * [`3*byte`:`rgb_color`]
* * [`32*byte`:`alias`]
* * [`u16`:`addrlen`]
* * [`addrlen*byte`:`addresses`]
*/
static void node_announcement(struct gossmap *map, u64 nann_off)
{
const u64 feature_len_off = 2 + 64;
size_t feature_len;
struct gossmap_node *n;
struct node_id id;
feature_len = map_be16(map, nann_off + feature_len_off);
map_nodeid(map, nann_off + feature_len_off + 2 + feature_len + 4, &id);
if ((n = gossmap_find_node(map, &id)))
n->nann_off = nann_off;
}
static bool reopen_store(struct gossmap *map, u64 ended_off)
{
int fd;
if (!map->fname)
errx(1, "Need to reopen, but not fname!");
fd = open(map->fname, O_RDONLY);
if (fd < 0)
err(1, "Failed to reopen %s", map->fname);
/* This tells us the equivalent offset in new map */
map->map_end = map_be64(map, ended_off + 2);
close(map->fd);
map->fd = fd;
map->generation++;
return gossmap_refresh_mayfail(map, NULL);
}
/* Returns false only if unknown_cb returns false */
static bool map_catchup(struct gossmap *map, bool *changed)
{
size_t reclen;
if (changed)
*changed = false;
for (; map->map_end + sizeof(struct gossip_hdr) < map->map_size;
map->map_end += reclen) {
struct gossip_hdr ghdr;
u64 off;
u16 type, flags;
map_copy(map, map->map_end, &ghdr, sizeof(ghdr));
reclen = be16_to_cpu(ghdr.len) + sizeof(ghdr);
flags = be16_to_cpu(ghdr.flags);
if (flags & GOSSIP_STORE_DELETED_BIT)
continue;
/* Partial write, this can happen. */
if (map->map_end + reclen > map->map_size)
break;
off = map->map_end + sizeof(ghdr);
type = map_be16(map, off);
if (type == WIRE_CHANNEL_ANNOUNCEMENT) {
/* Don't read yet if amount field is not there! */
if (!add_channel(map, off, be16_to_cpu(ghdr.len)))
break;
} else if (type == WIRE_CHANNEL_UPDATE)
update_channel(map, off);
else if (type == WIRE_GOSSIP_STORE_DELETE_CHAN)
remove_channel_by_deletemsg(map, off);
else if (type == WIRE_NODE_ANNOUNCEMENT)
node_announcement(map, off);
else if (type == WIRE_GOSSIP_STORE_ENDED && map->fname) {
/* This can recurse! */
if (!reopen_store(map, off))
return false;
} else {
if (map->unknown_record
&& !map->unknown_record(map, type, off,
reclen - sizeof(ghdr),
map->cb_arg)) {
return false;
}
continue;
}
if (changed)
*changed = true;
}
return true;
}
static bool load_gossip_store(struct gossmap *map)
{
map->map_size = lseek(map->fd, 0, SEEK_END);
map->local_announces = NULL;
map->local_updates = NULL;
/* gossipd uses pwritev(), which is not consistent with mmap on OpenBSD! */
#ifndef __OpenBSD__
/* If this fails, we fall back to read */
map->mmap = mmap(NULL, map->map_size, PROT_READ, MAP_SHARED, map->fd, 0);
if (map->mmap == MAP_FAILED)
#endif /* __OpenBSD__ */
map->mmap = NULL;
/* We only support major version 0 */
if (GOSSIP_STORE_MAJOR_VERSION(map_u8(map, 0)) != 0) {
errno = EINVAL;
return false;
}
/* Since channel_announcement is ~430 bytes, and channel_update is 136,
* node_announcement is 144, and current topology has 35000 channels
* and 10000 nodes, let's assume each channel gets about 750 bytes.
*
* We halve this, since often some records are deleted. */
map->channels = tal(map, struct chanidx_htable);
chanidx_htable_init_sized(map->channels, map->map_size / 750 / 2);
map->nodes = tal(map, struct nodeidx_htable);
nodeidx_htable_init_sized(map->nodes, map->map_size / 2500 / 2);
map->num_chan_arr = map->map_size / 750 / 2 + 1;
map->chan_arr = tal_arr(map, struct gossmap_chan, map->num_chan_arr);
map->freed_chans = init_chan_arr(map->chan_arr, 0);
map->num_node_arr = map->map_size / 2500 / 2 + 1;
map->node_arr = tal_arr(map, struct gossmap_node, map->num_node_arr);
map->freed_nodes = init_node_arr(map->node_arr, 0);
map->map_end = 1;
map_catchup(map, NULL);
return true;
}
static void destroy_map(struct gossmap *map)
{
if (map->mmap)
munmap(map->mmap, map->map_size);
for (size_t i = 0; i < tal_count(map->node_arr); i++)
free(map->node_arr[i].chan_idxs);
if (map->fname)
close(map->fd);
}
/* Local modifications. We only expect a few, so we use a simple
* array. If this changes, use a hashtable and a storage area for all
* those pointers to avoid dynamic allocation overhead! */
struct localmod {
struct short_channel_id scid;
/* If this is an entirely-local channel, here's its offset.
* Otherwise, 0xFFFFFFFFFFFFFFFF. */
u64 local_off;
/* Non-NULL values mean change existing ones */
struct localmod_changes {
const bool *enabled;
const struct amount_msat *htlc_min, *htlc_max;
const u32 *base_fee, *proportional_fee;
const u16 *delay;
} changes[2];
/* orig[n] defined if local_off == 0xFFFFFFFFFFFFFFFF */
struct half_chan orig[2];
/* Original update offsets */
u64 orig_cupdate_off[2];
};
static bool localmod_is_local_chan(const struct localmod *mod)
{
return mod->local_off != 0xFFFFFFFFFFFFFFFFULL;
}
struct gossmap_localmods {
struct localmod *mods;
/* This is the local announcement to be used by the gossmap */
u8 *local_announces;
};
struct gossmap_localmods *gossmap_localmods_new(const tal_t *ctx)
{
struct gossmap_localmods *localmods;
localmods = tal(ctx, struct gossmap_localmods);
localmods->mods = tal_arr(localmods, struct localmod, 0);
localmods->local_announces = tal_arr(localmods, u8, 0);
return localmods;
}
/* Create space at end of local map, return offset it was added at. */
static size_t insert_local_space(u8 **localspace, size_t msglen)
{
size_t oldlen = tal_bytelen(*localspace);
tal_resize(localspace, oldlen + msglen);
return oldlen;
}
static struct localmod *find_localmod(struct gossmap_localmods *localmods,
struct short_channel_id scid)
{
for (size_t i = 0; i < tal_count(localmods->mods); i++)
if (short_channel_id_eq(localmods->mods[i].scid, scid))
return &localmods->mods[i];
return NULL;
}
bool gossmap_local_addchan(struct gossmap_localmods *localmods,
const struct node_id *n1,
const struct node_id *n2,
struct short_channel_id scid,
struct amount_msat capacity,
const u8 *features)
{
be16 be16;
be64 be64;
u64 off;
struct localmod mod;
/* Don't create duplicate channels. */
if (find_localmod(localmods, scid))
return false;
/* BOLT #7:
*
* - MUST set `node_id_1` and `node_id_2` to the public keys
* of the two nodes operating the channel, such that
* `node_id_1` is the lexicographically-lesser of the two
* compressed keys sorted in ascending lexicographic order.
*/
if (node_id_cmp(n1, n2) > 0)
return gossmap_local_addchan(localmods, n2, n1, scid, capacity,
features);
mod.scid = scid;
memset(&mod.changes, 0, sizeof(mod.changes));
/* We create amount, then fake local channel_announcement */
off = insert_local_space(&localmods->local_announces,
8 + 2 + 64 * 4 + 2 + tal_bytelen(features)
+ 32 + 8 + 33 + 33);
/* Write amount */
be64 = be64_to_cpu(capacity.millisatoshis / 1000 /* Raw: gossmap */);
memcpy(localmods->local_announces + off, &be64, sizeof(be64));
off += sizeof(be64);
/* From here is a channel-announcment, with only the fields we use */
mod.local_off = off;
/* Set type to be kosher. */
be16 = CPU_TO_BE16(WIRE_CHANNEL_ANNOUNCEMENT);
memcpy(localmods->local_announces + off, &be16, sizeof(be16));
off += sizeof(be16);
/* Skip sigs */
off += 64 * 4;
/* Set length and features */
be16 = cpu_to_be16(tal_bytelen(features));
memcpy(localmods->local_announces + off, &be16, sizeof(be16));
off += sizeof(be16);
/* Damn you, C committee! */
if (features)
memcpy(localmods->local_announces + off, features, tal_bytelen(features));
off += tal_bytelen(features);
/* Skip chain_hash */
off += 32;
/* Set scid */
be64 = be64_to_cpu(scid.u64);
memcpy(localmods->local_announces + off, &be64, sizeof(be64));
off += sizeof(be64);
/* set node_ids */
memcpy(localmods->local_announces + off, n1->k, sizeof(n1->k));
off += sizeof(n1->k);
memcpy(localmods->local_announces + off, n2->k, sizeof(n2->k));
off += sizeof(n2->k);
assert(off == tal_bytelen(localmods->local_announces));
tal_arr_expand(&localmods->mods, mod);
return true;
};
/* Insert a local-only channel_update: false if can't represent. */
bool gossmap_local_updatechan(struct gossmap_localmods *localmods,
const struct short_channel_id_dir *scidd,
const bool *enabled,
const struct amount_msat *htlc_min,
const struct amount_msat *htlc_max,
const struct amount_msat *base_fee,
const u32 *proportional_fee,
const u16 *delay)
{
struct localmod *mod;
struct localmod_changes *lc;
struct half_chan test;
/* Check fit before making any changes. */
if (base_fee) {
test.base_fee = base_fee->millisatoshis /* Raw: localmod */;
if (!amount_msat_eq(amount_msat(test.base_fee), *base_fee))
return false;
}
if (proportional_fee) {
test.proportional_fee = *proportional_fee;
if (test.proportional_fee != *proportional_fee)
return false;
}
if (delay) {
test.delay = *delay;
if (test.delay != *delay)
return false;
}
mod = find_localmod(localmods, scidd->scid);
if (!mod) {
/* Create new reference to (presumably) existing channel. */
size_t nmods = tal_count(localmods->mods);
tal_resize(&localmods->mods, nmods + 1);
mod = &localmods->mods[nmods];
mod->scid = scidd->scid;
memset(&mod->changes, 0, sizeof(mod->changes));
mod->local_off = 0xFFFFFFFFFFFFFFFFULL;
}
lc = &mod->changes[scidd->dir];
if (enabled) {
tal_free(lc->enabled);
lc->enabled = tal_dup(localmods, bool, enabled);
}
if (htlc_min) {
tal_free(lc->htlc_min);
lc->htlc_min = tal_dup(localmods, struct amount_msat, htlc_min);
}
if (htlc_max) {
tal_free(lc->htlc_max);
lc->htlc_max = tal_dup(localmods, struct amount_msat, htlc_max);
}
if (base_fee) {
u32 base_as_u32 = base_fee->millisatoshis; /* Raw: localmod */
tal_free(lc->base_fee);
lc->base_fee = tal_dup(localmods, u32, &base_as_u32);
}
if (proportional_fee) {
tal_free(lc->proportional_fee);
lc->proportional_fee = tal_dup(localmods, u32, proportional_fee);
}
if (delay) {