linux/fs/ceph/auth.c
Sage Weil ec0994e48e ceph: add support for auth_x authentication protocol
The auth_x protocol implements support for a kerberos-like mutual
authentication infrastructure used by Ceph.  We do not simply use vanilla
kerberos because of scalability and performance issues when dealing with
a large cluster of nodes providing a single logical service.

Auth_x provides mutual authentication of client and server and protects
against replay and man in the middle attacks.  It does not encrypt
the full session over the wire, however, so data payload may still be
snooped.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
2010-02-11 11:48:45 -08:00

258 lines
5.5 KiB
C

#include "ceph_debug.h"
#include <linux/module.h>
#include <linux/err.h>
#include "types.h"
#include "auth_none.h"
#include "auth_x.h"
#include "decode.h"
#include "super.h"
#include "messenger.h"
/*
* get protocol handler
*/
static u32 supported_protocols[] = {
CEPH_AUTH_NONE,
CEPH_AUTH_CEPHX
};
int ceph_auth_init_protocol(struct ceph_auth_client *ac, int protocol)
{
switch (protocol) {
case CEPH_AUTH_NONE:
return ceph_auth_none_init(ac);
case CEPH_AUTH_CEPHX:
return ceph_x_init(ac);
default:
return -ENOENT;
}
}
/*
* setup, teardown.
*/
struct ceph_auth_client *ceph_auth_init(const char *name, const char *secret)
{
struct ceph_auth_client *ac;
int ret;
dout("auth_init name '%s' secret '%s'\n", name, secret);
ret = -ENOMEM;
ac = kzalloc(sizeof(*ac), GFP_NOFS);
if (!ac)
goto out;
ac->negotiating = true;
if (name)
ac->name = name;
else
ac->name = CEPH_AUTH_NAME_DEFAULT;
dout("auth_init name %s secret %s\n", ac->name, secret);
ac->secret = secret;
return ac;
out:
return ERR_PTR(ret);
}
void ceph_auth_destroy(struct ceph_auth_client *ac)
{
dout("auth_destroy %p\n", ac);
if (ac->ops)
ac->ops->destroy(ac);
kfree(ac);
}
/*
* Reset occurs when reconnecting to the monitor.
*/
void ceph_auth_reset(struct ceph_auth_client *ac)
{
dout("auth_reset %p\n", ac);
if (ac->ops && !ac->negotiating)
ac->ops->reset(ac);
ac->negotiating = true;
}
int ceph_entity_name_encode(const char *name, void **p, void *end)
{
int len = strlen(name);
if (*p + 2*sizeof(u32) + len > end)
return -ERANGE;
ceph_encode_32(p, CEPH_ENTITY_TYPE_CLIENT);
ceph_encode_32(p, len);
ceph_encode_copy(p, name, len);
return 0;
}
/*
* Initiate protocol negotiation with monitor. Include entity name
* and list supported protocols.
*/
int ceph_auth_build_hello(struct ceph_auth_client *ac, void *buf, size_t len)
{
struct ceph_mon_request_header *monhdr = buf;
void *p = monhdr + 1, *end = buf + len, *lenp;
int i, num;
int ret;
dout("auth_build_hello\n");
monhdr->have_version = 0;
monhdr->session_mon = cpu_to_le16(-1);
monhdr->session_mon_tid = 0;
ceph_encode_32(&p, 0); /* no protocol, yet */
lenp = p;
p += sizeof(u32);
ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
ceph_encode_8(&p, 1);
num = ARRAY_SIZE(supported_protocols);
ceph_encode_32(&p, num);
ceph_decode_need(&p, end, num * sizeof(u32), bad);
for (i = 0; i < num; i++)
ceph_encode_32(&p, supported_protocols[i]);
ret = ceph_entity_name_encode(ac->name, &p, end);
if (ret < 0)
return ret;
ceph_decode_need(&p, end, sizeof(u64), bad);
ceph_encode_64(&p, ac->global_id);
ceph_encode_32(&lenp, p - lenp - sizeof(u32));
return p - buf;
bad:
return -ERANGE;
}
int ceph_build_auth_request(struct ceph_auth_client *ac,
void *msg_buf, size_t msg_len)
{
struct ceph_mon_request_header *monhdr = msg_buf;
void *p = monhdr + 1;
void *end = msg_buf + msg_len;
int ret;
monhdr->have_version = 0;
monhdr->session_mon = cpu_to_le16(-1);
monhdr->session_mon_tid = 0;
ceph_encode_32(&p, ac->protocol);
ret = ac->ops->build_request(ac, p + sizeof(u32), end);
if (ret < 0) {
pr_err("error %d building request\n", ret);
return ret;
}
dout(" built request %d bytes\n", ret);
ceph_encode_32(&p, ret);
return p + ret - msg_buf;
}
/*
* Handle auth message from monitor.
*/
int ceph_handle_auth_reply(struct ceph_auth_client *ac,
void *buf, size_t len,
void *reply_buf, size_t reply_len)
{
void *p = buf;
void *end = buf + len;
int protocol;
s32 result;
u64 global_id;
void *payload, *payload_end;
int payload_len;
char *result_msg;
int result_msg_len;
int ret = -EINVAL;
dout("handle_auth_reply %p %p\n", p, end);
ceph_decode_need(&p, end, sizeof(u32) * 3 + sizeof(u64), bad);
protocol = ceph_decode_32(&p);
result = ceph_decode_32(&p);
global_id = ceph_decode_64(&p);
payload_len = ceph_decode_32(&p);
payload = p;
p += payload_len;
ceph_decode_need(&p, end, sizeof(u32), bad);
result_msg_len = ceph_decode_32(&p);
result_msg = p;
p += result_msg_len;
if (p != end)
goto bad;
dout(" result %d '%.*s' gid %llu len %d\n", result, result_msg_len,
result_msg, global_id, payload_len);
payload_end = payload + payload_len;
if (global_id && ac->global_id != global_id) {
dout(" set global_id %lld -> %lld\n", ac->global_id, global_id);
ac->global_id = global_id;
}
if (ac->negotiating) {
/* server does not support our protocols? */
if (!protocol && result < 0) {
ret = result;
goto out;
}
/* set up (new) protocol handler? */
if (ac->protocol && ac->protocol != protocol) {
ac->ops->destroy(ac);
ac->protocol = 0;
ac->ops = NULL;
}
if (ac->protocol != protocol) {
ret = ceph_auth_init_protocol(ac, protocol);
if (ret) {
pr_err("error %d on auth protocol %d init\n",
ret, protocol);
goto out;
}
}
ac->negotiating = false;
}
ret = ac->ops->handle_reply(ac, result, payload, payload_end);
if (ret == -EAGAIN) {
return ceph_build_auth_request(ac, reply_buf, reply_len);
} else if (ret) {
pr_err("authentication error %d\n", ret);
return ret;
}
return 0;
bad:
pr_err("failed to decode auth msg\n");
out:
return ret;
}
int ceph_build_auth(struct ceph_auth_client *ac,
void *msg_buf, size_t msg_len)
{
if (!ac->protocol)
return ceph_auth_build_hello(ac, msg_buf, msg_len);
BUG_ON(!ac->ops);
if (!ac->ops->is_authenticated(ac))
return ceph_build_auth_request(ac, msg_buf, msg_len);
return 0;
}
int ceph_auth_is_authenticated(struct ceph_auth_client *ac)
{
if (!ac->ops)
return 0;
return ac->ops->is_authenticated(ac);
}