@leroysheep / CrazyWebTemps / commits / 49c6b912e2

reftable/writer: ensure valid range for log's update_index

Each reftable addition has an associated update_index. While writing refs, the update_index is verified to be within the range of the reftable writer, i.e. `writer.min_update_index <= ref.update_index` and `writer.max_update_index => ref.update_index`. The corresponding check for reflogs in `reftable_writer_add_log` is however missing. Add a similar check, but only check for the upper limit. This is because reflogs are treated a bit differently than refs. Each reflog entry in reftable has an associated update_index and we also allow expiring entries in the middle, which is done by simply writing a new reflog entry with the same update_index. This means, writing reflog entries with update_index lesser than the writer's update_index is an expected scenario. Add a new unit test to check for the limits and fix some of the existing tests, which were setting arbitrary values for the update_index by ensuring they stay within the now checked limits. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Karthik Nayak committed Dec 6, 2024 at 14:13 UTC 49c6b912e2f4c49784d471f8c9364077c423dbf5
3 files changed +63 -4
reftable/writer.c
+12
index fd136794d5..f87086777c 100644 --- a/reftable/writer.c +++ b/reftable/writer.c @@ -412,6 +412,18 @@ int reftable_writer_add_log(struct reftable_writer *w, if (log->value_type == REFTABLE_LOG_DELETION) return reftable_writer_add_log_verbatim(w, log); + /* + * Verify only the upper limit of the update_index. Each reflog entry + * is tied to a specific update_index. Entries in the reflog can be + * replaced by adding a new entry with the same update_index, + * effectively canceling the old one. + * + * Consequently, reflog updates may include update_index values lower + * than the writer's min_update_index. + */ + if (log->update_index > w->max_update_index) + return REFTABLE_API_ERROR; + if (!log->refname) return REFTABLE_API_ERROR;
t/unit-tests/t-reftable-readwrite.c
+45 -2
index d279b86df0..7ffbd78c67 100644 --- a/t/unit-tests/t-reftable-readwrite.c +++ b/t/unit-tests/t-reftable-readwrite.c @@ -90,7 +90,7 @@ static void t_log_buffer_size(void) int i; struct reftable_log_record log = { .refname = (char *) "refs/heads/master", - .update_index = 0xa, + .update_index = update_index, .value_type = REFTABLE_LOG_UPDATE, .value = { .update = { .name = (char *) "Han-Wen Nienhuys", @@ -127,7 +127,7 @@ static void t_log_overflow(void) int err; struct reftable_log_record log = { .refname = (char *) "refs/heads/master", - .update_index = 0xa, + .update_index = update_index, .value_type = REFTABLE_LOG_UPDATE, .value = { .update = { @@ -151,6 +151,48 @@ static void t_log_overflow(void) reftable_buf_release(&buf); } +static void t_log_write_limits(void) +{ + struct reftable_write_options opts = { 0 }; + struct reftable_buf buf = REFTABLE_BUF_INIT; + struct reftable_writer *w = t_reftable_strbuf_writer(&buf, &opts); + struct reftable_log_record log = { + .refname = (char *)"refs/head/master", + .update_index = 0, + .value_type = REFTABLE_LOG_UPDATE, + .value = { + .update = { + .old_hash = { 1 }, + .new_hash = { 2 }, + .name = (char *)"Han-Wen Nienhuys", + .email = (char *)"hanwen@google.com", + .tz_offset = 100, + .time = 0x5e430672, + }, + }, + }; + int err; + + reftable_writer_set_limits(w, 1, 1); + + /* write with update_index (0) below set limits (1, 1) */ + err = reftable_writer_add_log(w, &log); + check_int(err, ==, 0); + + /* write with update_index (1) in the set limits (1, 1) */ + log.update_index = 1; + err = reftable_writer_add_log(w, &log); + check_int(err, ==, 0); + + /* write with update_index (3) above set limits (1, 1) */ + log.update_index = 3; + err = reftable_writer_add_log(w, &log); + check_int(err, ==, REFTABLE_API_ERROR); + + reftable_writer_free(w); + reftable_buf_release(&buf); +} + static void t_log_write_read(void) { struct reftable_write_options opts = { @@ -917,6 +959,7 @@ int cmd_main(int argc UNUSED, const char *argv[] UNUSED) TEST(t_corrupt_table_empty(), "read-write on an empty table"); TEST(t_log_buffer_size(), "buffer extension for log compression"); TEST(t_log_overflow(), "log overflow returns expected error"); + TEST(t_log_write_limits(), "writer limits for writing log records"); TEST(t_log_write_read(), "read-write on log records"); TEST(t_log_zlib_corruption(), "reading corrupted log record returns expected error"); TEST(t_table_read_api(), "read on a table");
t/unit-tests/t-reftable-stack.c
+6 -2
index 72f6747064..52b81475c3 100644 --- a/t/unit-tests/t-reftable-stack.c +++ b/t/unit-tests/t-reftable-stack.c @@ -770,8 +770,12 @@ static void t_reftable_stack_tombstone(void) } logs[i].refname = xstrdup(buf); - /* update_index is part of the key. */ - logs[i].update_index = 42; + /* + * update_index is part of the key so should be constant. + * The value itself should be less than the writer's upper + * limit. + */ + logs[i].update_index = 1; if (i % 2 == 0) { logs[i].value_type = REFTABLE_LOG_UPDATE; t_reftable_set_hash(logs[i].value.update.new_hash, i,