static int
send_diffs (kadm5_server_context *server_context, slave *s, int log_fd,
const char *database, uint32_t current_version,
uint32_t current_tstamp)
{
krb5_context context = server_context->context;
krb5_storage *sp;
uint32_t ver, initial_version, initial_version2;
uint32_t initial_tstamp, initial_tstamp2;
enum kadm_ops op;
uint32_t len;
off_t right, left;
krb5_ssize_t bytes;
krb5_data data;
int ret = 0;
if (s->flags & SLAVE_F_DEAD) {
krb5_warnx(context, "not sending diffs to dead slave %s", s->name);
return 0;
}
if (s->version == current_version) {
char buf[4];
sp = krb5_storage_from_mem(buf, 4);
if (sp == NULL)
krb5_errx(context, IPROPD_RESTART, "krb5_storage_from_mem");
ret = krb5_store_uint32(sp, YOU_HAVE_LAST_VERSION);
krb5_storage_free(sp);
data.data = buf;
data.length = 4;
if (ret == 0) {
ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
if (ret) {
krb5_warn(context, ret, "send_diffs: failed to send to slave");
slave_dead(context, s);
}
krb5_warnx(context, "slave %s in sync already at version %ld",
s->name, (long)s->version);
}
return ret;
}
if (verbose)
krb5_warnx(context, "sending diffs to live-seeming slave %s", s->name);
/*
* XXX The code that makes the diffs should be made a separate function,
* then error handling (send_are_you_there() or slave_dead()) can be done
* here.
*/
if (flock(log_fd, LOCK_SH) == -1) {
krb5_warn(context, errno, "could not obtain shared lock on log file");
send_are_you_there(context, s);
return errno;
}
ret = kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_FIRST,
&initial_version, &initial_tstamp);
sp = kadm5_log_goto_end(server_context, log_fd);
flock(log_fd, LOCK_UN);
if (ret) {
if (sp != NULL)
krb5_storage_free(sp);
krb5_warn(context, ret, "send_diffs: failed to read log");
send_are_you_there(context, s);
return ret;
}
if (sp == NULL) {
send_are_you_there(context, s);
krb5_warn(context, errno ? errno : EINVAL,
"send_diffs: failed to read log");
return errno ? errno : EINVAL;
}
/*
* We're not holding any locks here, so we can't prevent truncations.
*
* We protect against this by re-checking that the initial version and
* timestamp are the same before and after this loop.
*/
right = krb5_storage_seek(sp, 0, SEEK_CUR);
if (right == (off_t)-1) {
krb5_storage_free(sp);
send_are_you_there(context, s);
return errno;
}
for (;;) {
ret = kadm5_log_previous (context, sp, &ver, NULL, &op, &len);
if (ret)
krb5_err(context, IPROPD_RESTART, ret,
"send_diffs: failed to find previous entry");
left = krb5_storage_seek(sp, -16, SEEK_CUR);
if (left == (off_t)-1) {
krb5_storage_free(sp);
send_are_you_there(context, s);
return errno;
}
if (ver == s->version + 1)
break;
/*
* We don't expect to reach the slave's version, except when it is
* starting empty with the uber record.
*/
if (ver == s->version && !(ver == 0 && op == kadm_nop)) {
/*
* This shouldn't happen, but recall we're not holding a lock on
* the log.
*/
krb5_storage_free(sp);
krb5_warnx(context, "iprop log truncated while sending diffs to "
"slave?? ver = %lu", (unsigned long)ver);
send_are_you_there(context, s);
return 0;
}
/* If we've reached the uber record, send the complete database */
if (left == 0 || (ver == 0 && op == kadm_nop)) {
krb5_storage_free(sp);
krb5_warnx(context,
"slave %s (version %lu) out of sync with master "
"(first version in log %lu), sending complete database",
s->name, (unsigned long)s->version, (unsigned long)ver);
return send_complete (context, s, database, current_version, ver,
initial_tstamp);
}
}
assert(ver == s->version + 1);
krb5_warnx(context,
"syncing slave %s from version %lu to version %lu",
s->name, (unsigned long)s->version,
(unsigned long)current_version);
ret = krb5_data_alloc (&data, right - left + 4);
if (ret) {
krb5_storage_free(sp);
krb5_warn (context, ret, "send_diffs: krb5_data_alloc");
send_are_you_there(context, s);
return 1;
}
bytes = krb5_storage_read(sp, (char *)data.data + 4, data.length - 4);
krb5_storage_free(sp);
if (bytes != data.length - 4) {
krb5_warnx(context, "iprop log truncated while sending diffs to "
"slave?? ver = %lu", (unsigned long)ver);
send_are_you_there(context, s);
return 1;
}
/*
* Check that we have the same log initial version and timestamp now as
* when we dropped the shared lock on the log file! Else we could be
* sending garbage to the slave.
*/
if (flock(log_fd, LOCK_SH) == -1) {
krb5_warn(context, errno, "could not obtain shared lock on log file");
send_are_you_there(context, s);
return 1;
}
ret = kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_FIRST,
&initial_version2, &initial_tstamp2);
flock(log_fd, LOCK_UN);
if (ret) {
krb5_warn(context, ret,
"send_diffs: failed to read log while producing diffs");
send_are_you_there(context, s);
return 1;
}
if (initial_version != initial_version2 ||
initial_tstamp != initial_tstamp2) {
krb5_warn(context, ret,
"send_diffs: log truncated while producing diffs");
send_are_you_there(context, s);
return 1;
}
sp = krb5_storage_from_data (&data);
if (sp == NULL) {
krb5_warnx (context, "send_diffs: krb5_storage_from_data");
send_are_you_there(context, s);
return 1;
}
krb5_store_uint32 (sp, FOR_YOU);
krb5_storage_free(sp);
ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
krb5_data_free(&data);
if (ret) {
krb5_warn (context, ret, "send_diffs: krb5_write_priv_message");
slave_dead(context, s);
return 1;
}
slave_seen(s);
s->version = current_version;
krb5_warnx(context, "slave %s is now up to date (%u)", s->name, s->version);
return 0;
}
static int
send_diffs (krb5_context context, slave *s, int log_fd,
const char *database, u_int32_t current_version)
{
krb5_storage *sp;
u_int32_t ver;
time_t timestamp;
enum kadm_ops op;
u_int32_t len;
off_t right, left;
krb5_data data;
int ret = 0;
if (s->version == current_version)
return 0;
if (s->flags & SLAVE_F_DEAD)
return 0;
sp = kadm5_log_goto_end (log_fd);
right = krb5_storage_seek(sp, 0, SEEK_CUR);
for (;;) {
if (kadm5_log_previous (sp, &ver, ×tamp, &op, &len))
abort ();
left = krb5_storage_seek(sp, -16, SEEK_CUR);
if (ver == s->version)
return 0;
if (ver == s->version + 1)
break;
if (left == 0)
return send_complete (context, s, database, current_version);
}
ret = krb5_data_alloc (&data, right - left + 4);
if (ret) {
krb5_warn (context, ret, "send_diffs: krb5_data_alloc");
slave_dead(s);
return 1;
}
krb5_storage_read (sp, (char *)data.data + 4, data.length - 4);
krb5_storage_free(sp);
sp = krb5_storage_from_data (&data);
if (sp == NULL) {
krb5_warnx (context, "send_diffs: krb5_storage_from_data");
slave_dead(s);
return 1;
}
krb5_store_int32 (sp, FOR_YOU);
krb5_storage_free(sp);
ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
krb5_data_free(&data);
if (ret) {
krb5_warn (context, ret, "send_diffs: krb5_write_priv_message");
slave_dead(s);
return 1;
}
slave_seen(s);
return 0;
}
static int
send_diffs (krb5_context context, slave *s, int log_fd,
const char *database, uint32_t current_version)
{
krb5_storage *sp;
uint32_t ver;
time_t timestamp;
enum kadm_ops op;
uint32_t len;
off_t right, left;
krb5_data data;
int ret = 0;
if (s->version == current_version) {
krb5_warnx(context, "slave %s in sync already at version %ld",
s->name, (long)s->version);
return 0;
}
if (s->flags & SLAVE_F_DEAD)
return 0;
/* if slave is a fresh client, starting over */
if (s->version == 0) {
krb5_warnx(context, "sending complete log to fresh slave %s",
s->name);
return send_complete (context, s, database, current_version);
}
sp = kadm5_log_goto_end (log_fd);
right = krb5_storage_seek(sp, 0, SEEK_CUR);
for (;;) {
ret = kadm5_log_previous (context, sp, &ver, ×tamp, &op, &len);
if (ret)
krb5_err(context, 1, ret,
"send_diffs: failed to find previous entry");
left = krb5_storage_seek(sp, -16, SEEK_CUR);
if (ver == s->version)
return 0;
if (ver == s->version + 1)
break;
if (left == 0) {
krb5_storage_free(sp);
krb5_warnx(context,
"slave %s (version %lu) out of sync with master "
"(first version in log %lu), sending complete database",
s->name, (unsigned long)s->version, (unsigned long)ver);
return send_complete (context, s, database, current_version);
}
}
krb5_warnx(context,
"syncing slave %s from version %lu to version %lu",
s->name, (unsigned long)s->version,
(unsigned long)current_version);
ret = krb5_data_alloc (&data, right - left + 4);
if (ret) {
krb5_storage_free(sp);
krb5_warn (context, ret, "send_diffs: krb5_data_alloc");
slave_dead(context, s);
return 1;
}
krb5_storage_read (sp, (char *)data.data + 4, data.length - 4);
krb5_storage_free(sp);
sp = krb5_storage_from_data (&data);
if (sp == NULL) {
krb5_warnx (context, "send_diffs: krb5_storage_from_data");
slave_dead(context, s);
return 1;
}
krb5_store_int32 (sp, FOR_YOU);
krb5_storage_free(sp);
ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
krb5_data_free(&data);
if (ret) {
krb5_warn (context, ret, "send_diffs: krb5_write_priv_message");
slave_dead(context, s);
return 1;
}
slave_seen(s);
s->version = current_version;
return 0;
}
