// SPDX-License-Identifier: GPL-2.0
#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 init_protocol(struct ceph_auth_client *ac, int proto)
{
        dout("%s proto %d\n", __func__, proto);

        switch (proto) {
        case CEPH_AUTH_NONE:
                return ceph_auth_none_init(ac);
        case CEPH_AUTH_CEPHX:
                return ceph_x_init(ac);
        default:
                pr_err("bad auth protocol %d\n", proto);
                return -EINVAL;
        }
}

void ceph_auth_set_global_id(struct ceph_auth_client *ac, u64 global_id)
{
        dout("%s global_id %llu\n", __func__, global_id);

        if (!global_id)
                pr_err("got zero global_id\n");

        if (ac->global_id && global_id != ac->global_id)
                pr_err("global_id changed from %llu to %llu\n", ac->global_id,
                       global_id);

        ac->global_id = global_id;
}

/*
 * setup, teardown.
 */
struct ceph_auth_client *ceph_auth_init(const char *name,
                                        const struct ceph_crypto_key *key,
                                        const int *con_modes)
{
        struct ceph_auth_client *ac;

        ac = kzalloc_obj(*ac, GFP_NOFS);
        if (!ac)
                return ERR_PTR(-ENOMEM);

        mutex_init(&ac->mutex);
        ac->negotiating = true;
        if (name)
                ac->name = name;
        else
                ac->name = CEPH_AUTH_NAME_DEFAULT;
        ac->key = key;
        ac->preferred_mode = con_modes[0];
        ac->fallback_mode = con_modes[1];

        dout("%s name '%s' preferred_mode %d fallback_mode %d\n", __func__,
             ac->name, ac->preferred_mode, ac->fallback_mode);
        return ac;
}

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)
{
        mutex_lock(&ac->mutex);
        dout("auth_reset %p\n", ac);
        if (ac->ops && !ac->negotiating)
                ac->ops->reset(ac);
        ac->negotiating = true;
        mutex_unlock(&ac->mutex);
}

/*
 * EntityName, not to be confused with entity_name_t
 */
int ceph_auth_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;

        mutex_lock(&ac->mutex);
        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, CEPH_AUTH_UNKNOWN);  /* 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_auth_entity_name_encode(ac->name, &p, end);
        if (ret < 0)
                goto out;
        ceph_decode_need(&p, end, sizeof(u64), bad);
        ceph_encode_64(&p, ac->global_id);

        ceph_encode_32(&lenp, p - lenp - sizeof(u32));
        ret = p - buf;
out:
        mutex_unlock(&ac->mutex);
        return ret;

bad:
        ret = -ERANGE;
        goto out;
}

static int build_request(struct ceph_auth_client *ac, bool add_header,
                         void *buf, int buf_len)
{
        void *end = buf + buf_len;
        void *p;
        int ret;

        p = buf;
        if (add_header) {
                /* struct ceph_mon_request_header + protocol */
                ceph_encode_64_safe(&p, end, 0, e_range);
                ceph_encode_16_safe(&p, end, -1, e_range);
                ceph_encode_64_safe(&p, end, 0, e_range);
                ceph_encode_32_safe(&p, end, ac->protocol, e_range);
        }

        ceph_encode_need(&p, end, sizeof(u32), e_range);
        ret = ac->ops->build_request(ac, p + sizeof(u32), end);
        if (ret < 0) {
                pr_err("auth protocol '%s' building request failed: %d\n",
                       ceph_auth_proto_name(ac->protocol), ret);
                return ret;
        }
        dout(" built request %d bytes\n", ret);
        ceph_encode_32(&p, ret);
        return p + ret - buf;

e_range:
        return -ERANGE;
}

/*
 * 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;
        u32 payload_len;
        char *result_msg;
        u32 result_msg_len;
        int ret = -EINVAL;

        mutex_lock(&ac->mutex);
        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);
        ceph_decode_need(&p, end, payload_len, bad);
        payload = p;
        p += payload_len;
        ceph_decode_need(&p, end, sizeof(u32), bad);
        result_msg_len = ceph_decode_32(&p);
        ceph_decode_need(&p, end, result_msg_len, bad);
        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 (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 = init_protocol(ac, protocol);
                        if (ret) {
                                pr_err("auth protocol '%s' init failed: %d\n",
                                       ceph_auth_proto_name(protocol), ret);
                                goto out;
                        }
                }

                ac->negotiating = false;
        }

        if (result) {
                pr_err("auth protocol '%s' mauth authentication failed: %d\n",
                       ceph_auth_proto_name(ac->protocol), result);
                ret = result;
                goto out;
        }

        ret = ac->ops->handle_reply(ac, global_id, payload, payload_end,
                                    NULL, NULL, NULL, NULL);
        if (ret == -EAGAIN) {
                ret = build_request(ac, true, reply_buf, reply_len);
                goto out;
        } else if (ret) {
                goto out;
        }

out:
        mutex_unlock(&ac->mutex);
        return ret;

bad:
        pr_err("failed to decode auth msg\n");
        ret = -EINVAL;
        goto out;
}

int ceph_build_auth(struct ceph_auth_client *ac,
                    void *msg_buf, size_t msg_len)
{
        int ret = 0;

        mutex_lock(&ac->mutex);
        if (ac->ops->should_authenticate(ac))
                ret = build_request(ac, true, msg_buf, msg_len);
        mutex_unlock(&ac->mutex);
        return ret;
}

int ceph_auth_is_authenticated(struct ceph_auth_client *ac)
{
        int ret = 0;

        mutex_lock(&ac->mutex);
        if (ac->ops)
                ret = ac->ops->is_authenticated(ac);
        mutex_unlock(&ac->mutex);
        return ret;
}
EXPORT_SYMBOL(ceph_auth_is_authenticated);

int __ceph_auth_get_authorizer(struct ceph_auth_client *ac,
                               struct ceph_auth_handshake *auth,
                               int peer_type, bool force_new,
                               int *proto, int *pref_mode, int *fallb_mode)
{
        int ret;

        mutex_lock(&ac->mutex);
        if (force_new && auth->authorizer) {
                ceph_auth_destroy_authorizer(auth->authorizer);
                auth->authorizer = NULL;
        }
        if (!auth->authorizer)
                ret = ac->ops->create_authorizer(ac, peer_type, auth);
        else if (ac->ops->update_authorizer)
                ret = ac->ops->update_authorizer(ac, peer_type, auth);
        else
                ret = 0;
        if (ret)
                goto out;

        *proto = ac->protocol;
        if (pref_mode && fallb_mode) {
                *pref_mode = ac->preferred_mode;
                *fallb_mode = ac->fallback_mode;
        }

out:
        mutex_unlock(&ac->mutex);
        return ret;
}
EXPORT_SYMBOL(__ceph_auth_get_authorizer);

void ceph_auth_destroy_authorizer(struct ceph_authorizer *a)
{
        a->destroy(a);
}
EXPORT_SYMBOL(ceph_auth_destroy_authorizer);

int ceph_auth_add_authorizer_challenge(struct ceph_auth_client *ac,
                                       struct ceph_authorizer *a,
                                       void *challenge_buf,
                                       int challenge_buf_len)
{
        int ret = 0;

        mutex_lock(&ac->mutex);
        if (ac->ops && ac->ops->add_authorizer_challenge)
                ret = ac->ops->add_authorizer_challenge(ac, a, challenge_buf,
                                                        challenge_buf_len);
        mutex_unlock(&ac->mutex);
        return ret;
}
EXPORT_SYMBOL(ceph_auth_add_authorizer_challenge);

int ceph_auth_verify_authorizer_reply(struct ceph_auth_client *ac,
                                      struct ceph_authorizer *a,
                                      void *reply, int reply_len,
                                      u8 *session_key, int *session_key_len,
                                      u8 *con_secret, int *con_secret_len)
{
        int ret = 0;

        mutex_lock(&ac->mutex);
        if (ac->ops && ac->ops->verify_authorizer_reply)
                ret = ac->ops->verify_authorizer_reply(ac, a,
                        reply, reply_len, session_key, session_key_len,
                        con_secret, con_secret_len);
        mutex_unlock(&ac->mutex);
        return ret;
}
EXPORT_SYMBOL(ceph_auth_verify_authorizer_reply);

void ceph_auth_invalidate_authorizer(struct ceph_auth_client *ac, int peer_type)
{
        mutex_lock(&ac->mutex);
        if (ac->ops && ac->ops->invalidate_authorizer)
                ac->ops->invalidate_authorizer(ac, peer_type);
        mutex_unlock(&ac->mutex);
}
EXPORT_SYMBOL(ceph_auth_invalidate_authorizer);

/*
 * msgr2 authentication
 */

static bool contains(const int *arr, int cnt, int val)
{
        int i;

        for (i = 0; i < cnt; i++) {
                if (arr[i] == val)
                        return true;
        }

        return false;
}

static int encode_con_modes(void **p, void *end, int pref_mode, int fallb_mode)
{
        WARN_ON(pref_mode == CEPH_CON_MODE_UNKNOWN);
        if (fallb_mode != CEPH_CON_MODE_UNKNOWN) {
                ceph_encode_32_safe(p, end, 2, e_range);
                ceph_encode_32_safe(p, end, pref_mode, e_range);
                ceph_encode_32_safe(p, end, fallb_mode, e_range);
        } else {
                ceph_encode_32_safe(p, end, 1, e_range);
                ceph_encode_32_safe(p, end, pref_mode, e_range);
        }

        return 0;

e_range:
        return -ERANGE;
}

/*
 * Similar to ceph_auth_build_hello().
 */
int ceph_auth_get_request(struct ceph_auth_client *ac, void *buf, int buf_len)
{
        int proto = ac->key ? CEPH_AUTH_CEPHX : CEPH_AUTH_NONE;
        void *end = buf + buf_len;
        void *lenp;
        void *p;
        int ret;

        mutex_lock(&ac->mutex);
        if (ac->protocol == CEPH_AUTH_UNKNOWN) {
                ret = init_protocol(ac, proto);
                if (ret) {
                        pr_err("auth protocol '%s' init failed: %d\n",
                               ceph_auth_proto_name(proto), ret);
                        goto out;
                }
        } else {
                WARN_ON(ac->protocol != proto);
                ac->ops->reset(ac);
        }

        p = buf;
        ceph_encode_32_safe(&p, end, ac->protocol, e_range);
        ret = encode_con_modes(&p, end, ac->preferred_mode, ac->fallback_mode);
        if (ret)
                goto out;

        lenp = p;
        p += 4;  /* space for len */

        ceph_encode_8_safe(&p, end, CEPH_AUTH_MODE_MON, e_range);
        ret = ceph_auth_entity_name_encode(ac->name, &p, end);
        if (ret)
                goto out;

        ceph_encode_64_safe(&p, end, ac->global_id, e_range);
        ceph_encode_32(&lenp, p - lenp - 4);
        ret = p - buf;

out:
        mutex_unlock(&ac->mutex);
        return ret;

e_range:
        ret = -ERANGE;
        goto out;
}

int ceph_auth_handle_reply_more(struct ceph_auth_client *ac, void *reply,
                                int reply_len, void *buf, int buf_len)
{
        int ret;

        mutex_lock(&ac->mutex);
        ret = ac->ops->handle_reply(ac, 0, reply, reply + reply_len,
                                    NULL, NULL, NULL, NULL);
        if (ret == -EAGAIN)
                ret = build_request(ac, false, buf, buf_len);
        else
                WARN_ON(ret >= 0);
        mutex_unlock(&ac->mutex);
        return ret;
}

int ceph_auth_handle_reply_done(struct ceph_auth_client *ac,
                                u64 global_id, void *reply, int reply_len,
                                u8 *session_key, int *session_key_len,
                                u8 *con_secret, int *con_secret_len)
{
        int ret;

        mutex_lock(&ac->mutex);
        ret = ac->ops->handle_reply(ac, global_id, reply, reply + reply_len,
                                    session_key, session_key_len,
                                    con_secret, con_secret_len);
        WARN_ON(ret == -EAGAIN || ret > 0);
        mutex_unlock(&ac->mutex);
        return ret;
}

bool ceph_auth_handle_bad_method(struct ceph_auth_client *ac,
                                 int used_proto, int result,
                                 const int *allowed_protos, int proto_cnt,
                                 const int *allowed_modes, int mode_cnt)
{
        mutex_lock(&ac->mutex);
        WARN_ON(used_proto != ac->protocol);

        if (result == -EOPNOTSUPP) {
                if (!contains(allowed_protos, proto_cnt, ac->protocol)) {
                        pr_err("auth protocol '%s' not allowed\n",
                               ceph_auth_proto_name(ac->protocol));
                        goto not_allowed;
                }
                if (!contains(allowed_modes, mode_cnt, ac->preferred_mode) &&
                    (ac->fallback_mode == CEPH_CON_MODE_UNKNOWN ||
                     !contains(allowed_modes, mode_cnt, ac->fallback_mode))) {
                        pr_err("preferred mode '%s' not allowed\n",
                               ceph_con_mode_name(ac->preferred_mode));
                        if (ac->fallback_mode == CEPH_CON_MODE_UNKNOWN)
                                pr_err("no fallback mode\n");
                        else
                                pr_err("fallback mode '%s' not allowed\n",
                                       ceph_con_mode_name(ac->fallback_mode));
                        goto not_allowed;
                }
        }

        WARN_ON(result == -EOPNOTSUPP || result >= 0);
        pr_err("auth protocol '%s' msgr authentication failed: %d\n",
               ceph_auth_proto_name(ac->protocol), result);

        mutex_unlock(&ac->mutex);
        return true;

not_allowed:
        mutex_unlock(&ac->mutex);
        return false;
}

int ceph_auth_get_authorizer(struct ceph_auth_client *ac,
                             struct ceph_auth_handshake *auth,
                             int peer_type, void *buf, int *buf_len)
{
        void *end = buf + *buf_len;
        int pref_mode, fallb_mode;
        int proto;
        void *p;
        int ret;

        ret = __ceph_auth_get_authorizer(ac, auth, peer_type, true, &proto,
                                         &pref_mode, &fallb_mode);
        if (ret)
                return ret;

        p = buf;
        ceph_encode_32_safe(&p, end, proto, e_range);
        ret = encode_con_modes(&p, end, pref_mode, fallb_mode);
        if (ret)
                return ret;

        ceph_encode_32_safe(&p, end, auth->authorizer_buf_len, e_range);
        *buf_len = p - buf;
        return 0;

e_range:
        return -ERANGE;
}
EXPORT_SYMBOL(ceph_auth_get_authorizer);

int ceph_auth_handle_svc_reply_more(struct ceph_auth_client *ac,
                                    struct ceph_auth_handshake *auth,
                                    void *reply, int reply_len,
                                    void *buf, int *buf_len)
{
        void *end = buf + *buf_len;
        void *p;
        int ret;

        ret = ceph_auth_add_authorizer_challenge(ac, auth->authorizer,
                                                 reply, reply_len);
        if (ret)
                return ret;

        p = buf;
        ceph_encode_32_safe(&p, end, auth->authorizer_buf_len, e_range);
        *buf_len = p - buf;
        return 0;

e_range:
        return -ERANGE;
}
EXPORT_SYMBOL(ceph_auth_handle_svc_reply_more);

int ceph_auth_handle_svc_reply_done(struct ceph_auth_client *ac,
                                    struct ceph_auth_handshake *auth,
                                    void *reply, int reply_len,
                                    u8 *session_key, int *session_key_len,
                                    u8 *con_secret, int *con_secret_len)
{
        return ceph_auth_verify_authorizer_reply(ac, auth->authorizer,
                reply, reply_len, session_key, session_key_len,
                con_secret, con_secret_len);
}
EXPORT_SYMBOL(ceph_auth_handle_svc_reply_done);

bool ceph_auth_handle_bad_authorizer(struct ceph_auth_client *ac,
                                     int peer_type, int used_proto, int result,
                                     const int *allowed_protos, int proto_cnt,
                                     const int *allowed_modes, int mode_cnt)
{
        mutex_lock(&ac->mutex);
        WARN_ON(used_proto != ac->protocol);

        if (result == -EOPNOTSUPP) {
                if (!contains(allowed_protos, proto_cnt, ac->protocol)) {
                        pr_err("auth protocol '%s' not allowed by %s\n",
                               ceph_auth_proto_name(ac->protocol),
                               ceph_entity_type_name(peer_type));
                        goto not_allowed;
                }
                if (!contains(allowed_modes, mode_cnt, ac->preferred_mode) &&
                    (ac->fallback_mode == CEPH_CON_MODE_UNKNOWN ||
                     !contains(allowed_modes, mode_cnt, ac->fallback_mode))) {
                        pr_err("preferred mode '%s' not allowed by %s\n",
                               ceph_con_mode_name(ac->preferred_mode),
                               ceph_entity_type_name(peer_type));
                        if (ac->fallback_mode == CEPH_CON_MODE_UNKNOWN)
                                pr_err("no fallback mode\n");
                        else
                                pr_err("fallback mode '%s' not allowed by %s\n",
                                       ceph_con_mode_name(ac->fallback_mode),
                                       ceph_entity_type_name(peer_type));
                        goto not_allowed;
                }
        }

        WARN_ON(result == -EOPNOTSUPP || result >= 0);
        pr_err("auth protocol '%s' authorization to %s failed: %d\n",
               ceph_auth_proto_name(ac->protocol),
               ceph_entity_type_name(peer_type), result);

        if (ac->ops->invalidate_authorizer)
                ac->ops->invalidate_authorizer(ac, peer_type);

        mutex_unlock(&ac->mutex);
        return true;

not_allowed:
        mutex_unlock(&ac->mutex);
        return false;
}
EXPORT_SYMBOL(ceph_auth_handle_bad_authorizer);