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heimdal/lib/kadm5/ipropd_master.c
Viktor Dukhovni d0211ef475 Refactor send_diffs making it progressive 
When a slave is many diffs behind, send these in batches of up to
50, then handle other slaves.

This also implements a fast-path that makes incremental diffs faster
when the log has not rolled over.

Related code cleanup.
2019-10-03 15:52:15 -05:00

1865 lines
53 KiB
C
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/*
* Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "iprop.h"
#include <rtbl.h>
static krb5_log_facility *log_facility;
static int verbose;
static const char *slave_stats_file;
static const char *slave_stats_temp_file;
static const char *slave_time_missing = "2 min";
static const char *slave_time_gone = "5 min";
static int time_before_missing;
static int time_before_gone;
const char *master_hostname;
static krb5_socket_t
make_signal_socket (krb5_context context)
{
#ifndef NO_UNIX_SOCKETS
struct sockaddr_un addr;
const char *fn;
krb5_socket_t fd;
fn = kadm5_log_signal_socket(context);
fd = socket (AF_UNIX, SOCK_DGRAM, 0);
if (fd < 0)
krb5_err (context, 1, errno, "socket AF_UNIX");
memset (&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
strlcpy (addr.sun_path, fn, sizeof(addr.sun_path));
unlink (addr.sun_path);
if (bind (fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
krb5_err (context, 1, errno, "bind %s", addr.sun_path);
return fd;
#else
struct addrinfo *ai = NULL;
krb5_socket_t fd;
kadm5_log_signal_socket_info(context, 1, &ai);
fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (rk_IS_BAD_SOCKET(fd))
krb5_err (context, 1, rk_SOCK_ERRNO, "socket AF=%d", ai->ai_family);
if (rk_IS_SOCKET_ERROR( bind (fd, ai->ai_addr, ai->ai_addrlen) ))
krb5_err (context, 1, rk_SOCK_ERRNO, "bind");
return fd;
#endif
}
static krb5_socket_t
make_listen_socket (krb5_context context, const char *port_str)
{
krb5_socket_t fd;
int one = 1;
struct sockaddr_in addr;
fd = socket (AF_INET, SOCK_STREAM, 0);
if (rk_IS_BAD_SOCKET(fd))
krb5_err (context, 1, rk_SOCK_ERRNO, "socket AF_INET");
setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
memset (&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
if (port_str) {
addr.sin_port = krb5_getportbyname (context,
port_str, "tcp",
0);
if (addr.sin_port == 0) {
char *ptr;
long port;
port = strtol (port_str, &ptr, 10);
if (port == 0 && ptr == port_str)
krb5_errx (context, 1, "bad port `%s'", port_str);
addr.sin_port = htons(port);
}
} else {
addr.sin_port = krb5_getportbyname (context, IPROP_SERVICE,
"tcp", IPROP_PORT);
}
if(bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
krb5_err (context, 1, errno, "bind");
if (listen(fd, SOMAXCONN) < 0)
krb5_err (context, 1, errno, "listen");
return fd;
}
struct slave {
krb5_socket_t fd;
struct sockaddr_in addr;
char *name;
krb5_auth_context ac;
uint32_t version;
uint32_t version_tstamp;
uint32_t version_ack;
time_t seen;
unsigned long flags;
#define SLAVE_F_DEAD 0x1
#define SLAVE_F_AYT 0x2
#define SLAVE_F_READY 0x4
/*
* We'll use non-blocking I/O so no slave can hold us back.
*
* We call the state left over from a partial write a "tail".
*
* The krb5_data holding an KRB-PRIV will be the write buffer.
*/
struct {
/* Every message we send is a KRB-PRIV with a 4-byte length prefixed */
uint8_t header_buf[4];
krb5_data header;
krb5_data packet;
size_t packet_off;
/* For send_complete() we need an sp as part of the tail */
krb5_storage *dump;
uint32_t vno;
} tail;
struct {
uint8_t header_buf[4];
krb5_data packet;
size_t offset;
int hlen;
} input;
/*
* Continuation for fair diff sending we send N entries at a time.
*/
struct {
off_t off_next_version; /* offset in log of next diff */
uint32_t initial_version; /* at time of previous diff */
uint32_t initial_tstamp; /* at time of previous diff */
uint32_t last_version_sent;
int more; /* need to send more diffs */
} next_diff;
struct slave *next;
};
typedef struct slave slave;
static int
check_acl (krb5_context context, const char *name)
{
const char *fn;
FILE *fp;
char buf[256];
int ret = 1;
char *slavefile = NULL;
if (asprintf(&slavefile, "%s/slaves", hdb_db_dir(context)) == -1
|| slavefile == NULL)
errx(1, "out of memory");
fn = krb5_config_get_string_default(context,
NULL,
slavefile,
"kdc",
"iprop-acl",
NULL);
fp = fopen (fn, "r");
free(slavefile);
if (fp == NULL)
return 1;
while (fgets(buf, sizeof(buf), fp) != NULL) {
buf[strcspn(buf, "\r\n")] = '\0';
if (strcmp (buf, name) == 0) {
ret = 0;
break;
}
}
fclose (fp);
return ret;
}
static void
slave_seen(slave *s)
{
s->flags &= ~SLAVE_F_AYT;
s->seen = time(NULL);
}
static int
slave_missing_p (slave *s)
{
if (time(NULL) > s->seen + time_before_missing)
return 1;
return 0;
}
static int
slave_gone_p (slave *s)
{
if (time(NULL) > s->seen + time_before_gone)
return 1;
return 0;
}
static void
slave_dead(krb5_context context, slave *s)
{
krb5_warnx(context, "slave %s dead", s->name);
if (!rk_IS_BAD_SOCKET(s->fd)) {
rk_closesocket (s->fd);
s->fd = rk_INVALID_SOCKET;
}
s->flags |= SLAVE_F_DEAD;
slave_seen(s);
}
static void
remove_slave (krb5_context context, slave *s, slave **root)
{
slave **p;
if (!rk_IS_BAD_SOCKET(s->fd))
rk_closesocket (s->fd);
if (s->name)
free (s->name);
if (s->ac)
krb5_auth_con_free (context, s->ac);
/* Free any pending input/output state */
krb5_data_free(&s->input.packet);
krb5_data_free(&s->tail.packet);
krb5_storage_free(s->tail.dump);
for (p = root; *p; p = &(*p)->next)
if (*p == s) {
*p = s->next;
break;
}
free (s);
}
static void
add_slave (krb5_context context, krb5_keytab keytab, slave **root,
krb5_socket_t fd)
{
krb5_principal server;
krb5_error_code ret;
slave *s;
socklen_t addr_len;
krb5_ticket *ticket = NULL;
char hostname[128];
s = calloc(1, sizeof(*s));
if (s == NULL) {
krb5_warnx (context, "add_slave: no memory");
return;
}
s->name = NULL;
s->ac = NULL;
s->input.packet.data = NULL;
s->tail.header.data = NULL;
s->tail.packet.data = NULL;
s->tail.dump = NULL;
addr_len = sizeof(s->addr);
s->fd = accept (fd, (struct sockaddr *)&s->addr, &addr_len);
if (rk_IS_BAD_SOCKET(s->fd)) {
krb5_warn (context, rk_SOCK_ERRNO, "accept");
goto error;
}
if (master_hostname)
strlcpy(hostname, master_hostname, sizeof(hostname));
else
gethostname(hostname, sizeof(hostname));
ret = krb5_sname_to_principal (context, hostname, IPROP_NAME,
KRB5_NT_SRV_HST, &server);
if (ret) {
krb5_warn (context, ret, "krb5_sname_to_principal");
goto error;
}
ret = krb5_recvauth (context, &s->ac, &s->fd,
IPROP_VERSION, server, 0, keytab, &ticket);
/*
* We'll be doing non-blocking I/O only after authentication. We don't
* want to get stuck talking to any one slave.
*
* If we get a partial write, we'll finish writing when the socket becomes
* writable.
*
* Partial reads will be treated as EOF, causing the slave to be marked
* dead.
*
* To do non-blocking I/O for authentication we'll have to implement our
* own krb5_recvauth().
*/
socket_set_nonblocking(s->fd, 1);
/*
* We write message lengths separately from the payload, and may do
* back-to-back small writes when flushing pending input and then a new
* update. Avoid Nagle delays.
*/
#if defined(IPPROTO_TCP) && defined(TCP_NODELAY)
{
int nodelay = 1;
(void) setsockopt(s->fd, IPPROTO_TCP, TCP_NODELAY,
(void *)&nodelay, sizeof(nodelay));
}
#endif
krb5_free_principal (context, server);
if (ret) {
krb5_warn (context, ret, "krb5_recvauth");
goto error;
}
ret = krb5_unparse_name (context, ticket->client, &s->name);
krb5_free_ticket (context, ticket);
if (ret) {
krb5_warn (context, ret, "krb5_unparse_name");
goto error;
}
if (check_acl (context, s->name)) {
krb5_warnx (context, "%s not in acl", s->name);
goto error;
}
{
slave *l = *root;
while (l) {
if (strcmp(l->name, s->name) == 0)
break;
l = l->next;
}
if (l) {
if (l->flags & SLAVE_F_DEAD) {
remove_slave(context, l, root);
} else {
krb5_warnx (context, "second connection from %s", s->name);
goto error;
}
}
}
krb5_warnx (context, "connection from %s", s->name);
s->version = 0;
s->version_ack = 0;
s->flags = 0;
slave_seen(s);
s->next = *root;
*root = s;
return;
error:
remove_slave(context, s, root);
}
static int
dump_one (krb5_context context, HDB *db, hdb_entry_ex *entry, void *v)
{
krb5_error_code ret;
krb5_storage *dump = (krb5_storage *)v;
krb5_storage *sp;
krb5_data data;
ret = hdb_entry2value (context, &entry->entry, &data);
if (ret)
return ret;
ret = krb5_data_realloc (&data, data.length + 4);
if (ret)
goto done;
memmove ((char *)data.data + 4, data.data, data.length - 4);
sp = krb5_storage_from_data(&data);
if (sp == NULL) {
ret = krb5_enomem(context);
goto done;
}
ret = krb5_store_uint32(sp, ONE_PRINC);
krb5_storage_free(sp);
if (ret == 0)
ret = krb5_store_data(dump, data);
done:
krb5_data_free (&data);
return ret;
}
static int
write_dump (krb5_context context, krb5_storage *dump,
const char *database, uint32_t current_version)
{
krb5_error_code ret;
krb5_storage *sp;
HDB *db;
krb5_data data;
char buf[8];
/* we assume that the caller has obtained an exclusive lock */
ret = krb5_storage_truncate(dump, 0);
if (ret)
return ret;
if (krb5_storage_seek(dump, 0, SEEK_SET) != 0)
return errno;
/*
* First we store zero as the HDB version, this will indicate to a
* later reader that the dumpfile is invalid. We later write the
* correct version in the file after we have written all of the
* messages. A dump with a zero version will not be considered
* to be valid.
*/
ret = krb5_store_uint32(dump, 0);
ret = hdb_create (context, &db, database);
if (ret)
krb5_err (context, IPROPD_RESTART, ret, "hdb_create: %s", database);
ret = db->hdb_open (context, db, O_RDONLY, 0);
if (ret)
krb5_err (context, IPROPD_RESTART, ret, "db->open");
sp = krb5_storage_from_mem (buf, 4);
if (sp == NULL)
krb5_errx (context, IPROPD_RESTART, "krb5_storage_from_mem");
krb5_store_uint32 (sp, TELL_YOU_EVERYTHING);
krb5_storage_free (sp);
data.data = buf;
data.length = 4;
ret = krb5_store_data(dump, data);
if (ret) {
krb5_warn (context, ret, "write_dump");
return ret;
}
ret = hdb_foreach (context, db, HDB_F_ADMIN_DATA, dump_one, dump);
if (ret) {
krb5_warn (context, ret, "write_dump: hdb_foreach");
return ret;
}
(*db->hdb_close)(context, db);
(*db->hdb_destroy)(context, db);
sp = krb5_storage_from_mem (buf, 8);
if (sp == NULL)
krb5_errx (context, IPROPD_RESTART, "krb5_storage_from_mem");
ret = krb5_store_uint32(sp, NOW_YOU_HAVE);
if (ret == 0)
krb5_store_uint32(sp, current_version);
krb5_storage_free (sp);
data.length = 8;
if (ret == 0)
ret = krb5_store_data(dump, data);
/*
* We must ensure that the entire valid dump is written to disk
* before we write the current version at the front thus making
* it a valid dump file. If we crash around here, this can be
* important upon reboot.
*/
if (ret == 0)
ret = krb5_storage_fsync(dump);
if (ret == 0 && krb5_storage_seek(dump, 0, SEEK_SET) == -1)
ret = errno;
/* Write current version at the front making the dump valid */
if (ret == 0)
ret = krb5_store_uint32(dump, current_version);
/*
* We don't need to fsync(2) after the real version is written as
* it is not a disaster if it doesn't make it to disk if we crash.
* After all, we'll just create a new dumpfile.
*/
if (ret == 0)
krb5_warnx(context, "wrote new dumpfile (version %u)",
current_version);
else
krb5_warn(context, ret, "failed to write new dumpfile (version %u)",
current_version);
return ret;
}
static int
mk_priv_tail(krb5_context context, slave *s, krb5_data *data)
{
uint32_t len;
int ret;
ret = krb5_mk_priv(context, s->ac, data, &s->tail.packet, NULL);
if (ret)
return ret;
len = s->tail.packet.length;
_krb5_put_int(s->tail.header_buf, len, sizeof(s->tail.header_buf));
s->tail.header.length = sizeof(s->tail.header_buf);
s->tail.header.data = s->tail.header_buf;
return 0;
}
static int
have_tail(slave *s)
{
return s->tail.header.length || s->tail.packet.length || s->tail.dump;
}
static int
more_diffs(slave *s)
{
return s->next_diff.more;
}
#define SEND_COMPLETE_MAX_RECORDS 50
#define SEND_DIFFS_MAX_RECORDS 50
static int
send_tail(krb5_context context, slave *s)
{
krb5_data data;
ssize_t bytes = 0;
size_t rem = 0;
size_t n;
int ret;
if (! have_tail(s))
return 0;
/*
* For the case where we're continuing a send_complete() send up to
* SEND_COMPLETE_MAX_RECORDS records now, and the rest asynchronously
* later. This ensures that sending a complete dump to a slow-to-drain
* client does not prevent others from getting serviced.
*/
for (n = 0; n < SEND_COMPLETE_MAX_RECORDS; n++) {
if (! have_tail(s))
return 0;
if (s->tail.header.length) {
bytes = krb5_net_write(context, &s->fd,
s->tail.header.data,
s->tail.header.length);
if (bytes < 0)
goto err;
s->tail.header.length -= bytes;
s->tail.header.data = (char *)s->tail.header.data + bytes;
rem = s->tail.header.length;
if (rem)
goto ewouldblock;
}
if (s->tail.packet.length) {
bytes = krb5_net_write(context, &s->fd,
(char *)s->tail.packet.data + s->tail.packet_off,
s->tail.packet.length - s->tail.packet_off);
if (bytes < 0)
goto err;
s->tail.packet_off += bytes;
if (bytes)
slave_seen(s);
rem = s->tail.packet.length - s->tail.packet_off;
if (rem)
goto ewouldblock;
krb5_data_free(&s->tail.packet);
s->tail.packet_off = 0;
}
if (s->tail.dump == NULL)
return 0;
/*
* We're in the middle of a send_complete() that was interrupted by
* EWOULDBLOCK. Continue the sending of the dump.
*/
ret = krb5_ret_data(s->tail.dump, &data);
if (ret == HEIM_ERR_EOF) {
krb5_storage_free(s->tail.dump);
s->tail.dump = NULL;
s->version = s->tail.vno;
return 0;
}
if (ret) {
krb5_warn(context, ret, "failed to read entry from dump!");
} else {
ret = mk_priv_tail(context, s, &data);
krb5_data_free(&data);
if (ret == 0)
continue;
krb5_warn(context, ret, "failed to make and send a KRB-PRIV to %s",
s->name);
}
slave_dead(context, s);
return ret;
}
if (ret == 0 && s->tail.dump != NULL)
return EWOULDBLOCK;
err:
if (errno != EAGAIN && errno != EWOULDBLOCK) {
krb5_warn(context, ret = errno,
"error sending diffs to now-dead slave %s", s->name);
slave_dead(context, s);
return ret;
}
ewouldblock:
if (verbose)
krb5_warnx(context, "would block writing %llu bytes to slave %s",
(unsigned long long)rem, s->name);
return EWOULDBLOCK;
}
static int
send_complete(krb5_context context, slave *s, const char *database,
uint32_t current_version, uint32_t oldest_version,
uint32_t initial_log_tstamp)
{
krb5_error_code ret;
krb5_storage *dump = NULL;
uint32_t vno = 0;
int fd = -1;
struct stat st;
char *dfn;
ret = asprintf(&dfn, "%s/ipropd.dumpfile", hdb_db_dir(context));
if (ret == -1 || !dfn)
return krb5_enomem(context);
fd = open(dfn, O_CREAT|O_RDWR, 0600);
if (fd == -1) {
ret = errno;
krb5_warn(context, ret, "Cannot open/create iprop dumpfile %s", dfn);
free(dfn);
return ret;
}
free(dfn);
dump = krb5_storage_from_fd(fd);
if (!dump) {
ret = errno;
krb5_warn(context, ret, "krb5_storage_from_fd");
goto done;
}
for (;;) {
ret = flock(fd, LOCK_SH);
if (ret == -1) {
ret = errno;
krb5_warn(context, ret, "flock(fd, LOCK_SH)");
goto done;
}
if (krb5_storage_seek(dump, 0, SEEK_SET) == (off_t)-1) {
ret = errno;
krb5_warn(context, ret, "krb5_storage_seek(dump, 0, SEEK_SET)");
goto done;
}
vno = 0;
ret = krb5_ret_uint32(dump, &vno);
if (ret && ret != HEIM_ERR_EOF) {
krb5_warn(context, ret, "krb5_ret_uint32(dump, &vno)");
goto done;
}
if (fstat(fd, &st) == -1) {
ret = errno;
krb5_warn(context, ret, "send_complete: could not stat dump file");
goto done;
}
/*
* If the current dump has an appropriate version, then we can
* break out of the loop and send the file below.
*/
if (ret == 0 && vno != 0 && st.st_mtime > initial_log_tstamp &&
vno >= oldest_version && vno <= current_version)
break;
if (verbose)
krb5_warnx(context, "send_complete: dumping HDB");
/*
* Otherwise, we may need to write a new dump file. We
* obtain an exclusive lock on the fd. Because this is
* not guaranteed to be an upgrade of our existing shared
* lock, someone else may have written a new dumpfile while
* we were waiting and so we must first check the vno of
* the dump to see if that happened. If it did, we need
* to go back to the top of the loop so that we can downgrade
* our lock to a shared one.
*/
ret = flock(fd, LOCK_EX);
if (ret == -1) {
ret = errno;
krb5_warn(context, ret, "flock(fd, LOCK_EX)");
goto done;
}
ret = krb5_storage_seek(dump, 0, SEEK_SET);
if (ret == -1) {
ret = errno;
krb5_warn(context, ret, "krb5_storage_seek(dump, 0, SEEK_SET)");
goto done;
}
vno = 0;
ret = krb5_ret_uint32(dump, &vno);
if (ret && ret != HEIM_ERR_EOF) {
krb5_warn(context, ret, "krb5_ret_uint32(dump, &vno)");
goto done;
}
if (fstat(fd, &st) == -1) {
ret = errno;
krb5_warn(context, ret, "send_complete: could not stat dump file");
goto done;
}
/* check if someone wrote a better version for us */
if (ret == 0 && vno != 0 && st.st_mtime > initial_log_tstamp &&
vno >= oldest_version && vno <= current_version)
continue;
/* Now, we know that we must write a new dump file. */
ret = write_dump(context, dump, database, current_version);
if (ret)
goto done;
/*
* And we must continue to the top of the loop so that we can
* downgrade to a shared lock.
*/
}
/*
* Leaving the above loop, dump should have a ptr right after the initial
* 4 byte DB version number and we should have a shared lock on the file
* (which we may have just created), so we are reading to start sending
* the data down the wire.
*
* Note: (krb5_storage_from_fd() dup()'s the fd)
*/
s->tail.dump = dump;
s->tail.vno = vno;
dump = NULL;
ret = send_tail(context, s);
done:
if (fd != -1)
close(fd);
if (dump)
krb5_storage_free(dump);
return ret;
}
static int
send_are_you_there (krb5_context context, slave *s)
{
krb5_storage *sp;
krb5_data data;
char buf[4];
int ret;
if (s->flags & (SLAVE_F_DEAD|SLAVE_F_AYT))
return 0;
/*
* Write any remainder of previous write, if we can. If we'd block we'll
* return EWOULDBLOCK.
*/
ret = send_tail(context, s);
if (ret)
return ret;
krb5_warnx(context, "slave %s missing, sending AYT", s->name);
s->flags |= SLAVE_F_AYT;
data.data = buf;
data.length = 4;
sp = krb5_storage_from_mem (buf, 4);
if (sp == NULL) {
krb5_warnx (context, "are_you_there: krb5_data_alloc");
slave_dead(context, s);
return ENOMEM;
}
ret = krb5_store_uint32(sp, ARE_YOU_THERE);
krb5_storage_free (sp);
if (ret == 0)
ret = mk_priv_tail(context, s, &data);
if (ret == 0)
ret = send_tail(context, s);
if (ret && ret != EWOULDBLOCK) {
krb5_warn(context, ret, "are_you_there");
slave_dead(context, s);
}
return ret;
}
static int
diffready(krb5_context context, slave *s)
{
/*
* Don't send any diffs until slave has sent an I_HAVE telling us the
* initial version number!
*/
if ((s->flags & SLAVE_F_READY) == 0)
return 0;
if (s->flags & SLAVE_F_DEAD) {
if (verbose)
krb5_warnx(context, "not sending diffs to dead slave %s", s->name);
return 0;
}
/* Write any remainder of previous write, if we can. */
if (send_tail(context, s) != 0)
return 0;
return 1;
}
static int
nodiffs(krb5_context context, slave *s, uint32_t current_version)
{
krb5_storage *sp;
krb5_data data;
int ret;
if (s->version < current_version)
return 0;
/*
* If we had sent a partial diff, and now they're caught up, then there's
* no more.
*/
s->next_diff.more = 0;
if (verbose)
krb5_warnx(context, "slave %s version %ld already sent", s->name,
(long)s->version);
sp = krb5_storage_emem();
if (sp == NULL)
krb5_errx(context, IPROPD_RESTART, "krb5_storage_from_mem");
ret = krb5_store_uint32(sp, YOU_HAVE_LAST_VERSION);
if (ret == 0) {
krb5_data_zero(&data);
ret = krb5_storage_to_data(sp, &data);
}
krb5_storage_free(sp);
if (ret == 0) {
ret = mk_priv_tail(context, s, &data);
krb5_data_free(&data);
}
if (ret == 0)
send_tail(context, s);
return 1;
}
/*
* Lock the log and return initial version and timestamp
*/
static int
get_first(kadm5_server_context *server_context, int log_fd,
uint32_t *initial_verp, uint32_t *initial_timep)
{
krb5_context context = server_context->context;
int ret;
/*
* We don't want to perform tight retry loops on log access errors, so on
* error mark the slave dead. The slave reconnect after a delay...
*/
if (flock(log_fd, LOCK_SH) == -1) {
krb5_warn(context, errno, "could not obtain shared lock on log file");
return -1;
}
ret = kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_FIRST,
initial_verp, initial_timep);
if (ret != 0) {
flock(log_fd, LOCK_UN);
krb5_warnx(context, "could not read initial log entry");
return -1;
}
return 0;
}
/*-
* Find the left end of the diffs in the log we want to send.
*
* - On success, return a positive offset to the first new entry, retaining
* a read lock on the log file.
* - On error, return a negative offset, with the lock released.
* - If we simply find no successor entry in the log, return zero
* with the lock released, which indicates that fallback to send_complete()
* is needed.
*/
static off_t
get_left(kadm5_server_context *server_context, slave *s, krb5_storage *sp,
int log_fd, uint32_t current_version,
uint32_t *initial_verp, uint32_t *initial_timep)
{
krb5_context context = server_context->context;
off_t pos;
off_t left;
int ret;
for (;;) {
uint32_t ver = s->version;
/* This acquires a read lock on success */
ret = get_first(server_context, log_fd,
initial_verp, initial_timep);
if (ret != 0)
return -1;
/* When the slave version is out of range, send the whole database. */
if (ver == 0 || ver < *initial_verp || ver > current_version) {
flock(log_fd, LOCK_UN);
return 0;
}
/* Avoid seeking past the last committed record */
if (kadm5_log_goto_end(server_context, sp) != 0 ||
(pos = krb5_storage_seek(sp, 0, SEEK_CUR)) < 0)
goto err;
/*
* First try to see if we can find it quickly by seeking to the right
* end of the previous diff sent.
*/
if (s->next_diff.last_version_sent > 0 &&
s->next_diff.off_next_version > 0 &&
s->next_diff.off_next_version < pos &&
s->next_diff.initial_version == *initial_verp &&
s->next_diff.initial_tstamp == *initial_timep) {
/*
* Sanity check that the left version matches what we wanted, the
* log may have been truncated since.
*/
left = s->next_diff.off_next_version;
if (krb5_storage_seek(sp, left, SEEK_SET) != left)
goto err;
if (kadm5_log_next(context, sp, &ver, NULL, NULL, NULL) == 0 &&
ver == s->next_diff.last_version_sent + 1)
return left;
}
if (krb5_storage_seek(sp, pos, SEEK_SET) != pos)
goto err;
/*
* Drop the lock and try to find the left entry by seeking backward
* from the end of the end of the log. If we succeed, re-acquire the
* lock, update "next_diff", and retry the fast-path.
*/
flock(log_fd, LOCK_UN);
/* Slow path: seek backwards, entry by entry, from the end */
for (;;) {
enum kadm_ops op;
uint32_t len;
ret = kadm5_log_previous(context, sp, &ver, NULL, &op, &len);
if (ret)
return -1;
left = krb5_storage_seek(sp, -16, SEEK_CUR);
if (left < 0)
return left;
if (ver == s->version + 1)
break;
/*
* We don't expect to reach the slave's version, unless the log
* has been modified after we released the lock.
*/
if (ver == s->version) {
krb5_warnx(context, "iprop log truncated while sending diffs "
"to slave?? ver = %lu", (unsigned long)ver);
return -1;
}
/* If we've reached the uber record, send the complete database */
if (left == 0 || (ver == 0 && op == kadm_nop))
return 0;
}
assert(ver == s->version + 1);
/* Set up the fast-path pre-conditions */
s->next_diff.last_version_sent = s->version;
s->next_diff.off_next_version = left;
s->next_diff.initial_version = *initial_verp;
s->next_diff.initial_tstamp = *initial_timep;
/*
* If we loop then we're hoping to hit the fast path so we can return a
* non-zero, positive left offset with the lock held.
*
* We just updated the fast path pre-conditions, so unless a log
* truncation event happens between the point where we dropped the lock
* and the point where we rearcuire it above, we will hit the fast
* path.
*/
}
return left;
err:
flock(log_fd, LOCK_UN);
return -1;
}
static off_t
get_right(krb5_context context, int log_fd, krb5_storage *sp,
int lastver, slave *s, off_t left, uint32_t *verp)
{
int ret = 0;
int i = 0;
uint32_t ver = s->version;
off_t right = krb5_storage_seek(sp, left, SEEK_SET);
if (right <= 0) {
flock(log_fd, LOCK_UN);
return -1;
}
/* The "lastver" bound should preclude us reaching EOF */
for (; ret == 0 && i < SEND_DIFFS_MAX_RECORDS && ver < lastver; ++i) {
uint32_t logver;
ret = kadm5_log_next(context, sp, &logver, NULL, NULL, NULL);
if (logver != ++ver)
ret = KADM5_LOG_CORRUPT;
}
if (ret == 0)
right = krb5_storage_seek(sp, 0, SEEK_CUR);
else
right = -1;
if (right <= 0) {
flock(log_fd, LOCK_UN);
return -1;
}
*verp = ver;
return right;
}
static void
send_diffs(kadm5_server_context *server_context, slave *s, int log_fd,
const char *database, uint32_t current_version)
{
krb5_context context = server_context->context;
krb5_storage *sp;
uint32_t initial_version;
uint32_t initial_tstamp;
uint32_t ver;
off_t left = 0;
off_t right = 0;
krb5_ssize_t bytes;
krb5_data data;
int ret = 0;
if (!diffready(context, s) || nodiffs(context, s, current_version))
return;
if (verbose)
krb5_warnx(context, "sending diffs to live-seeming slave %s", s->name);
sp = krb5_storage_from_fd(log_fd);
if (sp == NULL)
krb5_err(context, IPROPD_RESTART_SLOW, ENOMEM,
"send_diffs: out of memory");
left = get_left(server_context, s, sp, log_fd, current_version,
&initial_version, &initial_tstamp);
if (left < 0) {
krb5_storage_free(sp);
slave_dead(context, s);
return;
}
if (left == 0) {
/* Slave's version is not in the log, fall back on send_complete() */
krb5_storage_free(sp);
send_complete(context, s, database, current_version,
initial_version, initial_tstamp);
return;
}
/* We still hold the read lock, if right > 0 */
right = get_right(server_context->context, log_fd, sp, current_version,
s, left, &ver);
if (right == left) {
flock(log_fd, LOCK_UN);
krb5_storage_free(sp);
return;
}
if (right < left) {
assert(right < 0);
krb5_storage_free(sp);
slave_dead(context, s);
return;
}
if (krb5_storage_seek(sp, left, SEEK_SET) != left) {
ret = errno ? errno : EIO;
flock(log_fd, LOCK_UN);
krb5_warn(context, ret, "send_diffs: krb5_storage_seek");
krb5_storage_free(sp);
slave_dead(context, s);
return;
}
ret = krb5_data_alloc(&data, right - left + 4);
if (ret) {
flock(log_fd, LOCK_UN);
krb5_warn(context, ret, "send_diffs: krb5_data_alloc");
krb5_storage_free(sp);
slave_dead(context, s);
return;
}
bytes = krb5_storage_read(sp, (char *)data.data + 4, data.length - 4);
flock(log_fd, LOCK_UN);
krb5_storage_free(sp);
if (bytes != data.length - 4)
krb5_errx(context, IPROPD_RESTART, "locked log truncated???");
sp = krb5_storage_from_data(&data);
if (sp == NULL) {
krb5_err(context, IPROPD_RESTART_SLOW, ENOMEM, "out of memory");
krb5_warnx(context, "send_diffs: krb5_storage_from_data");
return;
}
krb5_store_uint32(sp, FOR_YOU);
krb5_storage_free(sp);
ret = mk_priv_tail(context, s, &data);
krb5_data_free(&data);
if (ret == 0) {
/* Save the fast-path continuation */
s->next_diff.last_version_sent = ver;
s->next_diff.off_next_version = right;
s->next_diff.initial_version = initial_version;
s->next_diff.initial_tstamp = initial_tstamp;
s->next_diff.more = ver < current_version;
ret = send_tail(context, s);
krb5_warnx(context,
"syncing slave %s from version %lu to version %lu",
s->name, (unsigned long)s->version,
(unsigned long)ver);
s->version = ver;
}
if (ret && ret != EWOULDBLOCK) {
krb5_warn(context, ret, "send_diffs: making or sending "
"KRB-PRIV message");
slave_dead(context, s);
return;
}
slave_seen(s);
return;
}
/* Sensible bound on slave message size */
#define SLAVE_MSG_MAX 65536
static int
fill_input(krb5_context context, slave *s)
{
krb5_error_code ret;
if (s->input.hlen < 4) {
uint8_t *buf = s->input.header_buf + s->input.hlen;
size_t len = 4 - s->input.hlen;
krb5_ssize_t bytes = krb5_net_read(context, &s->fd, buf, len);
if (bytes == 0)
return HEIM_ERR_EOF;
if (bytes < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN)
return EWOULDBLOCK;
return errno ? errno : EIO;
}
s->input.hlen += bytes;
if (bytes < len)
return EWOULDBLOCK;
buf = s->input.header_buf;
len = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
if (len > SLAVE_MSG_MAX)
return EINVAL;
ret = krb5_data_alloc(&s->input.packet, len);
if (ret != 0)
return ret;
}
if (s->input.offset < s->input.packet.length) {
u_char *buf = (u_char *)s->input.packet.data + s->input.offset;
size_t len = s->input.packet.length - s->input.offset;
krb5_ssize_t bytes = krb5_net_read(context, &s->fd, buf, len);
if (bytes == 0)
return HEIM_ERR_EOF;
if (bytes < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN)
return EWOULDBLOCK;
return errno ? errno : EIO;
}
s->input.offset += bytes;
if (bytes != len)
return EWOULDBLOCK;
}
return 0;
}
static int
read_msg(krb5_context context, slave *s, krb5_data *out)
{
int ret = fill_input(context, s);
if (ret != 0)
return ret;
ret = krb5_rd_priv(context, s->ac, &s->input.packet, out, NULL);
/* Prepare for next packet */
krb5_data_free(&s->input.packet);
s->input.offset = 0;
s->input.hlen = 0;
return ret;
}
static int
process_msg(kadm5_server_context *server_context, slave *s, int log_fd,
const char *database, uint32_t current_version)
{
krb5_context context = server_context->context;
int ret = 0;
krb5_data out;
krb5_storage *sp;
uint32_t tmp;
ret = read_msg(context, s, &out);
if (ret) {
if (ret != EWOULDBLOCK)
krb5_warn(context, ret, "error reading message from %s", s->name);
return ret;
}
sp = krb5_storage_from_mem(out.data, out.length);
if (sp == NULL) {
krb5_warnx(context, "process_msg: no memory");
krb5_data_free(&out);
return 1;
}
if (krb5_ret_uint32(sp, &tmp) != 0) {
krb5_warnx(context, "process_msg: client send too short command");
krb5_data_free(&out);
return 1;
}
switch (tmp) {
case I_HAVE :
ret = krb5_ret_uint32(sp, &tmp);
if (ret != 0) {
krb5_warnx(context, "process_msg: client send too little I_HAVE data");
break;
}
/*
* XXX Make the slave send the timestamp as well, and try to get it
* here, and pass it to send_diffs().
*/
/*
* New slave whose version number we've not yet seen. If the version
* number is zero, the slave has no data, and we'll send a complete
* database (that happens in send_diffs()). Otherwise, we'll record a
* non-zero initial version and attempt an incremental update.
*
* NOTE!: Once the slave is "ready" (its first I_HAVE has conveyed its
* initial version), we MUST NOT update s->version to the slave's
* I_HAVE version, since we may already have sent later updates, and
* MUST NOT send them again, otherwise we can get further and further
* out of sync resending larger and larger diffs. The "not yet ready"
* is an essential precondition for setting s->version to the value
* in the I_HAVE message. This happens only once when the slave
* first connects.
*/
if (!(s->flags & SLAVE_F_READY)) {
if (current_version < tmp) {
krb5_warnx(context, "Slave %s (version %u) has later version "
"than the master (version %u) OUT OF SYNC",
s->name, tmp, current_version);
/* Force send_complete() */
tmp = 0;
}
/*
* Mark the slave as ready for updates based on incoming signals.
* Prior to the initial I_HAVE, we don't know the slave's version
* number, and MUST not send it anything, since we'll needlessly
* attempt to send the whole database!
*/
s->version = tmp;
s->flags |= SLAVE_F_READY;
if (verbose)
krb5_warnx(context, "slave %s ready for updates from version %u",
s->name, tmp);
}
if ((s->version_ack = tmp) < s->version)
break;
send_diffs(server_context, s, log_fd, database, current_version);
break;
case I_AM_HERE :
if (verbose)
krb5_warnx(context, "slave %s is there", s->name);
break;
case ARE_YOU_THERE:
case FOR_YOU :
default :
krb5_warnx(context, "Ignoring command %d", tmp);
break;
}
krb5_data_free(&out);
krb5_storage_free(sp);
slave_seen(s);
return ret;
}
#define SLAVE_NAME "Name"
#define SLAVE_ADDRESS "Address"
#define SLAVE_VERSION "Version"
#define SLAVE_STATUS "Status"
#define SLAVE_SEEN "Last Seen"
static void
init_stats_names(krb5_context context)
{
const char *fn = NULL;
char *buf = NULL;
if (slave_stats_file)
fn = slave_stats_file;
else if ((fn = krb5_config_get_string(context, NULL, "kdc",
"iprop-stats", NULL)) == NULL) {
if (asprintf(&buf, "%s/slaves-stats", hdb_db_dir(context)) != -1
&& buf != NULL)
fn = buf;
buf = NULL;
}
if (fn != NULL) {
slave_stats_file = fn;
if (asprintf(&buf, "%s.tmp", fn) != -1 && buf != NULL)
slave_stats_temp_file = buf;
}
}
static void
write_master_down(krb5_context context)
{
char str[100];
time_t t = time(NULL);
FILE *fp = NULL;
if (slave_stats_temp_file != NULL)
fp = fopen(slave_stats_temp_file, "w");
if (fp == NULL)
return;
krb5_format_time(context, t, str, sizeof(str), TRUE);
fprintf(fp, "master down at %s\n", str);
if (fclose(fp) != EOF)
rk_rename(slave_stats_temp_file, slave_stats_file);
}
static void
write_stats(krb5_context context, slave *slaves, uint32_t current_version)
{
char str[100];
rtbl_t tbl;
time_t t = time(NULL);
FILE *fp = NULL;
if (slave_stats_temp_file != NULL)
fp = fopen(slave_stats_temp_file, "w");
if (fp == NULL)
return;
krb5_format_time(context, t, str, sizeof(str), TRUE);
fprintf(fp, "Status for slaves, last updated: %s\n\n", str);
fprintf(fp, "Master version: %lu\n\n", (unsigned long)current_version);
tbl = rtbl_create();
if (tbl == NULL) {
fclose(fp);
return;
}
rtbl_add_column(tbl, SLAVE_NAME, 0);
rtbl_add_column(tbl, SLAVE_ADDRESS, 0);
rtbl_add_column(tbl, SLAVE_VERSION, RTBL_ALIGN_RIGHT);
rtbl_add_column(tbl, SLAVE_STATUS, 0);
rtbl_add_column(tbl, SLAVE_SEEN, 0);
rtbl_set_prefix(tbl, " ");
rtbl_set_column_prefix(tbl, SLAVE_NAME, "");
while (slaves) {
krb5_address addr;
krb5_error_code ret;
rtbl_add_column_entry(tbl, SLAVE_NAME, slaves->name);
ret = krb5_sockaddr2address (context,
(struct sockaddr*)&slaves->addr, &addr);
if(ret == 0) {
krb5_print_address(&addr, str, sizeof(str), NULL);
krb5_free_address(context, &addr);
rtbl_add_column_entry(tbl, SLAVE_ADDRESS, str);
} else
rtbl_add_column_entry(tbl, SLAVE_ADDRESS, "<unknown>");
snprintf(str, sizeof(str), "%u", (unsigned)slaves->version_ack);
rtbl_add_column_entry(tbl, SLAVE_VERSION, str);
if (slaves->flags & SLAVE_F_DEAD)
rtbl_add_column_entry(tbl, SLAVE_STATUS, "Down");
else
rtbl_add_column_entry(tbl, SLAVE_STATUS, "Up");
ret = krb5_format_time(context, slaves->seen, str, sizeof(str), TRUE);
rtbl_add_column_entry(tbl, SLAVE_SEEN, str);
slaves = slaves->next;
}
rtbl_format(tbl, fp);
rtbl_destroy(tbl);
if (fclose(fp) != EOF)
rk_rename(slave_stats_temp_file, slave_stats_file);
}
static char sHDB[] = "HDBGET:";
static char *realm;
static int version_flag;
static int help_flag;
static char *keytab_str = sHDB;
static char *database;
static char *config_file;
static char *port_str;
static int detach_from_console;
static int daemon_child = -1;
static struct getargs args[] = {
{ "config-file", 'c', arg_string, &config_file, NULL, NULL },
{ "realm", 'r', arg_string, &realm, NULL, NULL },
{ "keytab", 'k', arg_string, &keytab_str,
"keytab to get authentication from", "kspec" },
{ "database", 'd', arg_string, &database, "database", "file"},
{ "slave-stats-file", 0, arg_string, rk_UNCONST(&slave_stats_file),
"file for slave status information", "file"},
{ "time-missing", 0, arg_string, rk_UNCONST(&slave_time_missing),
"time before slave is polled for presence", "time"},
{ "time-gone", 0, arg_string, rk_UNCONST(&slave_time_gone),
"time of inactivity after which a slave is considered gone", "time"},
{ "port", 0, arg_string, &port_str,
"port ipropd will listen to", "port"},
{ "detach", 0, arg_flag, &detach_from_console,
"detach from console", NULL },
{ "daemon-child", 0 , arg_integer, &daemon_child,
"private argument, do not use", NULL },
{ "hostname", 0, arg_string, rk_UNCONST(&master_hostname),
"hostname of master (if not same as hostname)", "hostname" },
{ "verbose", 0, arg_flag, &verbose, NULL, NULL },
{ "version", 0, arg_flag, &version_flag, NULL, NULL },
{ "help", 0, arg_flag, &help_flag, NULL, NULL }
};
static int num_args = sizeof(args) / sizeof(args[0]);
int
main(int argc, char **argv)
{
krb5_error_code ret;
krb5_context context;
void *kadm_handle;
kadm5_server_context *server_context;
kadm5_config_params conf;
krb5_socket_t signal_fd, listen_fd;
int log_fd;
slave *slaves = NULL;
uint32_t current_version = 0, old_version = 0;
krb5_keytab keytab;
char **files;
int aret;
int optidx = 0;
int restarter_fd = -1;
struct stat st;
setprogname(argv[0]);
if (getarg(args, num_args, argc, argv, &optidx))
krb5_std_usage(1, args, num_args);
if (help_flag)
krb5_std_usage(0, args, num_args);
if (version_flag) {
print_version(NULL);
exit(0);
}
if (detach_from_console && daemon_child == -1)
daemon_child = roken_detach_prep(argc, argv, "--daemon-child");
rk_pidfile(NULL);
ret = krb5_init_context(&context);
if (ret)
errx(1, "krb5_init_context failed: %d", ret);
setup_signal();
if (config_file == NULL) {
aret = asprintf(&config_file, "%s/kdc.conf", hdb_db_dir(context));
if (aret == -1 || config_file == NULL)
errx(1, "out of memory");
}
ret = krb5_prepend_config_files_default(config_file, &files);
if (ret)
krb5_err(context, 1, ret, "getting configuration files");
ret = krb5_set_config_files(context, files);
krb5_free_config_files(files);
if (ret)
krb5_err(context, 1, ret, "reading configuration files");
init_stats_names(context);
time_before_gone = parse_time (slave_time_gone, "s");
if (time_before_gone < 0)
krb5_errx (context, 1, "couldn't parse time: %s", slave_time_gone);
time_before_missing = parse_time (slave_time_missing, "s");
if (time_before_missing < 0)
krb5_errx (context, 1, "couldn't parse time: %s", slave_time_missing);
krb5_openlog(context, "ipropd-master", &log_facility);
krb5_set_warn_dest(context, log_facility);
ret = krb5_kt_register(context, &hdb_get_kt_ops);
if(ret)
krb5_err(context, 1, ret, "krb5_kt_register");
ret = krb5_kt_resolve(context, keytab_str, &keytab);
if(ret)
krb5_err(context, 1, ret, "krb5_kt_resolve: %s", keytab_str);
memset(&conf, 0, sizeof(conf));
if(realm) {
conf.mask |= KADM5_CONFIG_REALM;
conf.realm = realm;
}
ret = kadm5_init_with_skey_ctx (context,
KADM5_ADMIN_SERVICE,
NULL,
KADM5_ADMIN_SERVICE,
&conf, 0, 0,
&kadm_handle);
if (ret)
krb5_err (context, 1, ret, "kadm5_init_with_password_ctx");
server_context = (kadm5_server_context *)kadm_handle;
log_fd = open (server_context->log_context.log_file, O_RDONLY, 0);
if (log_fd < 0)
krb5_err (context, 1, errno, "open %s",
server_context->log_context.log_file);
if (fstat(log_fd, &st) == -1)
krb5_err(context, 1, errno, "stat %s",
server_context->log_context.log_file);
if (flock(log_fd, LOCK_SH) == -1)
krb5_err(context, 1, errno, "shared flock %s",
server_context->log_context.log_file);
kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_LAST,
&current_version, NULL);
flock(log_fd, LOCK_UN);
signal_fd = make_signal_socket (context);
listen_fd = make_listen_socket (context, port_str);
krb5_warnx(context, "ipropd-master started at version: %lu",
(unsigned long)current_version);
roken_detach_finish(NULL, daemon_child);
restarter_fd = restarter(context, NULL);
while (exit_flag == 0){
slave *p;
fd_set readset, writeset;
int max_fd = 0;
struct timeval to = {30, 0};
uint32_t vers;
struct stat st2;;
#ifndef NO_LIMIT_FD_SETSIZE
if (signal_fd >= FD_SETSIZE || listen_fd >= FD_SETSIZE ||
restarter_fd >= FD_SETSIZE)
krb5_errx (context, IPROPD_RESTART, "fd too large");
#endif
FD_ZERO(&readset);
FD_ZERO(&writeset);
FD_SET(signal_fd, &readset);
max_fd = max(max_fd, signal_fd);
FD_SET(listen_fd, &readset);
max_fd = max(max_fd, listen_fd);
if (restarter_fd > -1) {
FD_SET(restarter_fd, &readset);
max_fd = max(max_fd, restarter_fd);
}
for (p = slaves; p != NULL; p = p->next) {
if (p->flags & SLAVE_F_DEAD)
continue;
FD_SET(p->fd, &readset);
if (have_tail(p) || more_diffs(p))
FD_SET(p->fd, &writeset);
max_fd = max(max_fd, p->fd);
}
ret = select(max_fd + 1, &readset, &writeset, NULL, &to);
if (ret < 0) {
if (errno == EINTR)
continue;
else
krb5_err (context, IPROPD_RESTART, errno, "select");
}
if (stat(server_context->log_context.log_file, &st2) == -1) {
krb5_warn(context, errno, "could not stat log file by path");
st2 = st;
}
if (st2.st_dev != st.st_dev || st2.st_ino != st.st_ino) {
(void) close(log_fd);
log_fd = open(server_context->log_context.log_file, O_RDONLY, 0);
if (log_fd < 0)
krb5_err(context, IPROPD_RESTART_SLOW, errno, "open %s",
server_context->log_context.log_file);
if (fstat(log_fd, &st) == -1)
krb5_err(context, IPROPD_RESTART_SLOW, errno, "stat %s",
server_context->log_context.log_file);
if (flock(log_fd, LOCK_SH) == -1)
krb5_err(context, IPROPD_RESTART, errno, "shared flock %s",
server_context->log_context.log_file);
kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_LAST,
&current_version, NULL);
flock(log_fd, LOCK_UN);
}
if (ret == 0) {
/* Recover from failed transactions */
if (kadm5_log_init_nb(server_context) == 0)
kadm5_log_end(server_context);
if (flock(log_fd, LOCK_SH) == -1)
krb5_err(context, IPROPD_RESTART, errno,
"could not lock log file");
kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_LAST,
&current_version, NULL);
flock(log_fd, LOCK_UN);
if (current_version > old_version) {
if (verbose)
krb5_warnx(context,
"Missed a signal, updating slaves %lu to %lu",
(unsigned long)old_version,
(unsigned long)current_version);
for (p = slaves; p != NULL; p = p->next) {
if (p->flags & SLAVE_F_DEAD)
continue;
send_diffs(server_context, p, log_fd, database,
current_version);
}
old_version = current_version;
}
}
if (ret && FD_ISSET(restarter_fd, &readset)) {
exit_flag = SIGTERM;
break;
}
if (ret && FD_ISSET(signal_fd, &readset)) {
#ifndef NO_UNIX_SOCKETS
struct sockaddr_un peer_addr;
#else
struct sockaddr_storage peer_addr;
#endif
socklen_t peer_len = sizeof(peer_addr);
if(recvfrom(signal_fd, (void *)&vers, sizeof(vers), 0,
(struct sockaddr *)&peer_addr, &peer_len) < 0) {
krb5_warn (context, errno, "recvfrom");
continue;
}
--ret;
assert(ret >= 0);
old_version = current_version;
if (flock(log_fd, LOCK_SH) == -1)
krb5_err(context, IPROPD_RESTART, errno, "shared flock %s",
server_context->log_context.log_file);
kadm5_log_get_version_fd(server_context, log_fd, LOG_VERSION_LAST,
&current_version, NULL);
flock(log_fd, LOCK_UN);
if (current_version != old_version) {
/*
* If current_version < old_version then the log got
* truncated and we'll end up doing full propagations.
*
* Truncating the log when the current version is
* numerically small can lead to race conditions.
* Ideally we should identify log versions as
* {init_or_trunc_time, vno}, then we could not have any
* such race conditions, but this would either require
* breaking backwards compatibility for the protocol or
* adding new messages to it.
*/
if (verbose)
krb5_warnx(context,
"Got a signal, updating slaves %lu to %lu",
(unsigned long)old_version,
(unsigned long)current_version);
for (p = slaves; p != NULL; p = p->next) {
if (p->flags & SLAVE_F_DEAD)
continue;
send_diffs(server_context, p, log_fd, database,
current_version);
}
} else {
if (verbose)
krb5_warnx(context,
"Got a signal, but no update in log version %lu",
(unsigned long)current_version);
}
}
for (p = slaves; p != NULL; p = p->next) {
if (!(p->flags & SLAVE_F_DEAD) &&
FD_ISSET(p->fd, &writeset) &&
((have_tail(p) && send_tail(context, p) == 0) ||
(!have_tail(p) && more_diffs(p)))) {
send_diffs(server_context, p, log_fd, database,
current_version);
}
}
for(p = slaves; p != NULL; p = p->next) {
if (p->flags & SLAVE_F_DEAD)
continue;
if (ret && FD_ISSET(p->fd, &readset)) {
--ret;
assert(ret >= 0);
ret = process_msg(server_context, p, log_fd, database,
current_version);
if (ret && ret != EWOULDBLOCK)
slave_dead(context, p);
} else if (slave_gone_p (p))
slave_dead(context, p);
else if (slave_missing_p (p))
send_are_you_there (context, p);
}
if (ret && FD_ISSET(listen_fd, &readset)) {
add_slave (context, keytab, &slaves, listen_fd);
--ret;
assert(ret >= 0);
}
write_stats(context, slaves, current_version);
}
if(exit_flag == SIGINT || exit_flag == SIGTERM)
krb5_warnx(context, "%s terminated", getprogname());
#ifdef SIGXCPU
else if(exit_flag == SIGXCPU)
krb5_warnx(context, "%s CPU time limit exceeded", getprogname());
#endif
else
krb5_warnx(context, "%s unexpected exit reason: %ld",
getprogname(), (long)exit_flag);
write_master_down(context);
return 0;
}
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