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df00f20e4a
We use the high bit of the length field: this way we can still check that the checksums are valid on deleted fields. Once this is done, serially reading the gossip_store file will result in a complete, ordered, minimal gossip broadcast. Also, the horrible corner case where we might try to delete things from the store during load time is completely gone: we only load non-deleted things. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
#include <ccan/crc/crc.h>
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#include <ccan/endian/endian.h>
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#include <common/gossip_store.h>
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#include <common/status.h>
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#include <common/utils.h>
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#include <errno.h>
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#include <inttypes.h>
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#include <unistd.h>
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u8 *gossip_store_read(const tal_t *ctx, int gossip_store_fd, u64 offset)
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{
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beint32_t hdr[2];
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u32 msglen, checksum;
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u8 *msg;
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if (offset == 0)
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status_failed(STATUS_FAIL_INTERNAL_ERROR,
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"gossip_store: can't access offset %"PRIu64,
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offset);
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if (pread(gossip_store_fd, hdr, sizeof(hdr), offset) != sizeof(hdr)) {
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status_failed(STATUS_FAIL_INTERNAL_ERROR,
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"gossip_store: can't read hdr offset %"PRIu64
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": %s",
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offset, strerror(errno));
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}
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/* FIXME: We should skip over these deleted entries! */
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msglen = be32_to_cpu(hdr[0]) & ~GOSSIP_STORE_LEN_DELETED_BIT;
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checksum = be32_to_cpu(hdr[1]);
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msg = tal_arr(ctx, u8, msglen);
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if (pread(gossip_store_fd, msg, msglen, offset + sizeof(hdr)) != msglen)
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status_failed(STATUS_FAIL_INTERNAL_ERROR,
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"gossip_store: can't read len %u offset %"PRIu64,
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msglen, offset);
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if (checksum != crc32c(0, msg, msglen))
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status_failed(STATUS_FAIL_INTERNAL_ERROR,
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"gossip_store: bad checksum offset %"PRIu64": %s",
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offset, tal_hex(tmpctx, msg));
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return msg;
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}
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