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gossipd: clean up gossip_store offsets.
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gossmap offsets are to the beginning of the message, whereas
the gossip_store uses the header offset.  Convert the internals
of gossip_store to use gossmap-style uniformly, even where it's
a little less convenient.

Signed-off-by: Rusty Russell <[email protected]>
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@rustyrussell
rustyrussell committed Feb 3, 2024
1 parent 7efa0a4 commit c49fb2e
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Showing 3 changed files with 50 additions and 67 deletions.
91 changes: 39 additions & 52 deletions gossipd/gossip_store.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -377,9 +377,11 @@ u64 gossip_store_add(struct gossip_store *gs, const u8 *gossip_msg, u32 timestam
return 0;
}

return off;
/* By gossmap convention, offset is *after* hdr */
return off + sizeof(struct gossip_hdr);
}

/* Offsets are all gossmap-style: *after* hdr! */
static const u8 *gossip_store_get_with_hdr(const tal_t *ctx,
struct gossip_store *gs,
u64 offset,
Expand All @@ -388,92 +390,93 @@ static const u8 *gossip_store_get_with_hdr(const tal_t *ctx,
u32 msglen, checksum;
u8 *msg;

if (offset == 0)
if (offset <= sizeof(*hdr))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"gossip_store: can't access offset %"PRIu64,
offset);
if (pread(gs->fd, hdr, sizeof(*hdr), offset) != sizeof(*hdr)) {
if (pread(gs->fd, hdr, sizeof(*hdr), offset - sizeof(*hdr)) != sizeof(*hdr)) {
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"gossip_store: can't read hdr offset %"PRIu64
"/%"PRIu64": %s",
offset, gs->len, strerror(errno));
offset - sizeof(*hdr), gs->len, strerror(errno));
}

if (be16_to_cpu(hdr->flags) & GOSSIP_STORE_DELETED_BIT)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"gossip_store: get delete entry offset %"PRIu64
"/%"PRIu64"",
offset, gs->len);
offset - sizeof(*hdr), gs->len);

msglen = be16_to_cpu(hdr->len);
checksum = be32_to_cpu(hdr->crc);
msg = tal_arr(ctx, u8, msglen);
if (pread(gs->fd, msg, msglen, offset + sizeof(*hdr)) != msglen)
if (pread(gs->fd, msg, msglen, offset) != msglen)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"gossip_store: can't read len %u offset %"PRIu64
"/%"PRIu64, msglen, offset, gs->len);

if (checksum != crc32c(be32_to_cpu(hdr->timestamp), msg, msglen))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"gossip_store: bad checksum offset %"PRIu64": %s",
offset, tal_hex(tmpctx, msg));
offset - sizeof(*hdr), tal_hex(tmpctx, msg));

return msg;
}

static bool check_msg_type(struct gossip_store *gs, u32 index, int flag, int type)
static bool check_msg_type(struct gossip_store *gs, u64 offset, int flag, int type)
{
struct gossip_hdr hdr;
const u8 *msg = gossip_store_get_with_hdr(tmpctx, gs, index, &hdr);
const u8 *msg = gossip_store_get_with_hdr(tmpctx, gs, offset, &hdr);

if (fromwire_peektype(msg) == type)
return true;

status_broken("asked to flag-%u type %i @%u but store contains "
status_broken("asked to flag-%u type %i @%"PRIu64" but store contains "
"%i (gs->len=%"PRIu64"): %s",
flag, type, index, fromwire_peektype(msg),
flag, type, offset, fromwire_peektype(msg),
gs->len, tal_hex(tmpctx, msg));
return false;
}

/* Returns index of following entry. */
static u32 flag_by_index(struct gossip_store *gs, u32 index, int flag, int type)
/* Returns offset of following entry (i.e. after its header). */
u64 gossip_store_set_flag(struct gossip_store *gs,
u64 offset, u16 flag, int type)
{
struct {
beint16_t beflags;
beint16_t belen;
} hdr;
u64 hdr_off = offset - sizeof(struct gossip_hdr);

/* Should never get here during loading! */
assert(gs->writable);

/* Should never try to overwrite version */
assert(index);
assert(offset > sizeof(struct gossip_hdr));

/* FIXME: debugging a gs->len overrun issue reported in #6270 */
if (pread(gs->fd, &hdr, sizeof(hdr), index) != sizeof(hdr)) {
status_broken("gossip_store pread fail during flag %u @%u type: %i"
" gs->len: %"PRIu64, flag, index, type, gs->len);
return index;
if (pread(gs->fd, &hdr, sizeof(hdr), hdr_off) != sizeof(hdr)) {
status_broken("gossip_store pread fail during flag %u @%"PRIu64" type: %i"
" gs->len: %"PRIu64, flag, hdr_off, type, gs->len);
return offset;
}
if (index + sizeof(struct gossip_hdr) +
be16_to_cpu(hdr.belen) > gs->len) {
status_broken("gossip_store overrun during flag-%u @%u type: %i"
" gs->len: %"PRIu64, flag, index, type, gs->len);
return index;
if (offset + be16_to_cpu(hdr.belen) > gs->len) {
status_broken("gossip_store overrun during flag-%u @%"PRIu64" type: %i"
" gs->len: %"PRIu64, flag, hdr_off, type, gs->len);
return offset;
}

if (!check_msg_type(gs, index, flag, type))
return index;
if (!check_msg_type(gs, offset, flag, type))
return offset;

assert((be16_to_cpu(hdr.beflags) & flag) == 0);
hdr.beflags |= cpu_to_be16(flag);
if (pwrite(gs->fd, &hdr.beflags, sizeof(hdr.beflags), index) != sizeof(hdr.beflags))
if (pwrite(gs->fd, &hdr.beflags, sizeof(hdr.beflags), hdr_off) != sizeof(hdr.beflags))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Failed writing flags to delete @%u: %s",
index, strerror(errno));
"Failed writing flags to delete @%"PRIu64": %s",
offset, strerror(errno));

return index + sizeof(struct gossip_hdr) + be16_to_cpu(hdr.belen);
return offset + be16_to_cpu(hdr.belen) + sizeof(struct gossip_hdr);
}

void gossip_store_del(struct gossip_store *gs,
Expand All @@ -483,25 +486,15 @@ void gossip_store_del(struct gossip_store *gs,
u32 next_index;

assert(offset > sizeof(struct gossip_hdr));
next_index = flag_by_index(gs, offset - sizeof(struct gossip_hdr),
GOSSIP_STORE_DELETED_BIT,
type);
next_index = gossip_store_set_flag(gs, offset,
GOSSIP_STORE_DELETED_BIT,
type);

/* For a channel_announcement, we need to delete amount too */
if (type == WIRE_CHANNEL_ANNOUNCEMENT)
flag_by_index(gs, next_index,
GOSSIP_STORE_DELETED_BIT,
WIRE_GOSSIP_STORE_CHANNEL_AMOUNT);
}

void gossip_store_flag(struct gossip_store *gs,
u64 offset,
u16 flag,
int type)
{
assert(offset > sizeof(struct gossip_hdr));

flag_by_index(gs, offset - sizeof(struct gossip_hdr), flag, type);
gossip_store_set_flag(gs, next_index,
GOSSIP_STORE_DELETED_BIT,
WIRE_GOSSIP_STORE_CHANNEL_AMOUNT);
}

u32 gossip_store_get_timestamp(struct gossip_store *gs, u64 offset)
Expand All @@ -524,13 +517,7 @@ void gossip_store_set_timestamp(struct gossip_store *gs, u64 offset, u32 timesta
struct gossip_hdr hdr;
const u8 *msg;

assert(offset > sizeof(struct gossip_hdr));
msg = gossip_store_get_with_hdr(tmpctx, gs, offset - sizeof(hdr), &hdr);
if (pread(gs->fd, &hdr, sizeof(hdr), offset - sizeof(hdr)) != sizeof(hdr)) {
status_broken("gossip_store overrun during set_timestamp @%"PRIu64
" gs->len: %"PRIu64, offset, gs->len);
return;
}
msg = gossip_store_get_with_hdr(tmpctx, gs, offset, &hdr);

/* Change timestamp and crc */
hdr.timestamp = cpu_to_be32(timestamp);
Expand Down
8 changes: 3 additions & 5 deletions gossipd/gossip_store.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,14 +51,12 @@ void gossip_store_del(struct gossip_store *gs,

/**
* Add a flag the record at this offset (offset is that of
* record, not header, unlike bcast->index!).
* record!). Returns offset of *next* record.
*
* In developer mode, checks that type is correct.
*/
void gossip_store_flag(struct gossip_store *gs,
u64 offset,
u16 flag,
int type);
u64 gossip_store_set_flag(struct gossip_store *gs,
u64 offset, u16 flag, int type);

/**
* Direct store accessor: get timestamp header for a record.
Expand Down
18 changes: 8 additions & 10 deletions gossipd/gossmap_manage.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1112,9 +1112,7 @@ void gossmap_manage_new_block(struct gossmap_manage *gm, u32 new_blockheight)

kill_spent_channel(gm, gossmap, gm->dying_channels[i].scid);
gossip_store_del(gm->daemon->gs,
/* FIXME: fix API to give us pre-hdr offsets! */
gm->dying_channels[i].gossmap_offset
+ sizeof(struct gossip_hdr),
gm->dying_channels[i].gossmap_offset,
WIRE_GOSSIP_STORE_CHAN_DYING);
tal_arr_remove(&gm->dying_channels, i);
}
Expand Down Expand Up @@ -1160,18 +1158,18 @@ void gossmap_manage_channel_spent(struct gossmap_manage *gm,
gossmap_manage_channel_dying(gm, off, deadline, scid);

/* Mark it dying, so we don't gossip it */
gossip_store_flag(gm->daemon->gs, chan->cann_off,
GOSSIP_STORE_DYING_BIT,
WIRE_CHANNEL_ANNOUNCEMENT);
gossip_store_set_flag(gm->daemon->gs, chan->cann_off,
GOSSIP_STORE_DYING_BIT,
WIRE_CHANNEL_ANNOUNCEMENT);
/* Channel updates too! */
for (int dir = 0; dir < 2; dir++) {
if (!gossmap_chan_set(chan, dir))
continue;

gossip_store_flag(gm->daemon->gs,
chan->cupdate_off[dir],
GOSSIP_STORE_DYING_BIT,
WIRE_CHANNEL_UPDATE);
gossip_store_set_flag(gm->daemon->gs,
chan->cupdate_off[dir],
GOSSIP_STORE_DYING_BIT,
WIRE_CHANNEL_UPDATE);
}
}

Expand Down

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