auth.c

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#include <linux/ceph/ceph_debug.h>

#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>

#include <linux/ceph/types.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/libceph.h>
#include <linux/ceph/messenger.h>
#include "auth_none.h"
#include "auth_x.h"


/*
 * get protocol handler
 */
static u32 supported_protocols[] = {
    CEPH_AUTH_NONE,
    CEPH_AUTH_CEPHX
};

static 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 struct ceph_crypto_key *key)
{
    struct ceph_auth_client *ac;
    int ret;

    dout("auth_init name '%s'\n", name);

    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\n", ac->name);
    ac->key = key;
    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;
}

static 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 auth method %s request\n", ret,
               ac->ops->name);
        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("auth method '%s' error %d\n", ac->ops->name, 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->should_authenticate(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);
}