root/net/smc/smc_diag.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 * Monitoring SMC transport protocol sockets
 *
 * Copyright IBM Corp. 2016
 *
 * Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/sock_diag.h>
#include <linux/inet_diag.h>
#include <linux/smc_diag.h>
#include <net/netlink.h>
#include <net/smc.h>

#include "smc.h"
#include "smc_core.h"
#include "smc_ism.h"

struct smc_diag_dump_ctx {
        int pos[2];
};

static struct smc_diag_dump_ctx *smc_dump_context(struct netlink_callback *cb)
{
        return (struct smc_diag_dump_ctx *)cb->ctx;
}

static void smc_diag_msg_common_fill(struct smc_diag_msg *r, struct sock *sk)
{
        struct smc_sock *smc = smc_sk(sk);

        memset(r, 0, sizeof(*r));
        r->diag_family = sk->sk_family;
        sock_diag_save_cookie(sk, r->id.idiag_cookie);
        if (!smc->clcsock)
                return;
        r->id.idiag_sport = htons(smc->clcsock->sk->sk_num);
        r->id.idiag_dport = smc->clcsock->sk->sk_dport;
        r->id.idiag_if = smc->clcsock->sk->sk_bound_dev_if;
        if (sk->sk_protocol == SMCPROTO_SMC) {
                r->id.idiag_src[0] = smc->clcsock->sk->sk_rcv_saddr;
                r->id.idiag_dst[0] = smc->clcsock->sk->sk_daddr;
#if IS_ENABLED(CONFIG_IPV6)
        } else if (sk->sk_protocol == SMCPROTO_SMC6) {
                memcpy(&r->id.idiag_src, &smc->clcsock->sk->sk_v6_rcv_saddr,
                       sizeof(smc->clcsock->sk->sk_v6_rcv_saddr));
                memcpy(&r->id.idiag_dst, &smc->clcsock->sk->sk_v6_daddr,
                       sizeof(smc->clcsock->sk->sk_v6_daddr));
#endif
        }
}

static int smc_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
                                   struct smc_diag_msg *r,
                                   struct user_namespace *user_ns)
{
        if (nla_put_u8(skb, SMC_DIAG_SHUTDOWN, sk->sk_shutdown))
                return 1;

        r->diag_uid = from_kuid_munged(user_ns, sk_uid(sk));
        r->diag_inode = sock_i_ino(sk);
        return 0;
}

static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb,
                           struct netlink_callback *cb,
                           const struct smc_diag_req *req,
                           struct nlattr *bc)
{
        struct smc_sock *smc = smc_sk(sk);
        struct smc_diag_fallback fallback;
        struct user_namespace *user_ns;
        struct smc_diag_msg *r;
        struct nlmsghdr *nlh;

        nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
                        cb->nlh->nlmsg_type, sizeof(*r), NLM_F_MULTI);
        if (!nlh)
                return -EMSGSIZE;

        r = nlmsg_data(nlh);
        smc_diag_msg_common_fill(r, sk);
        r->diag_state = sk->sk_state;
        if (smc->use_fallback)
                r->diag_mode = SMC_DIAG_MODE_FALLBACK_TCP;
        else if (smc_conn_lgr_valid(&smc->conn) && smc->conn.lgr->is_smcd)
                r->diag_mode = SMC_DIAG_MODE_SMCD;
        else
                r->diag_mode = SMC_DIAG_MODE_SMCR;
        user_ns = sk_user_ns(NETLINK_CB(cb->skb).sk);
        if (smc_diag_msg_attrs_fill(sk, skb, r, user_ns))
                goto errout;

        fallback.reason = smc->fallback_rsn;
        fallback.peer_diagnosis = smc->peer_diagnosis;
        if (nla_put(skb, SMC_DIAG_FALLBACK, sizeof(fallback), &fallback) < 0)
                goto errout;

        if ((req->diag_ext & (1 << (SMC_DIAG_CONNINFO - 1))) &&
            smc->conn.alert_token_local) {
                struct smc_connection *conn = &smc->conn;
                struct smc_diag_conninfo cinfo = {
                        .token = conn->alert_token_local,
                        .sndbuf_size = conn->sndbuf_desc ?
                                conn->sndbuf_desc->len : 0,
                        .rmbe_size = conn->rmb_desc ? conn->rmb_desc->len : 0,
                        .peer_rmbe_size = conn->peer_rmbe_size,

                        .rx_prod.wrap = conn->local_rx_ctrl.prod.wrap,
                        .rx_prod.count = conn->local_rx_ctrl.prod.count,
                        .rx_cons.wrap = conn->local_rx_ctrl.cons.wrap,
                        .rx_cons.count = conn->local_rx_ctrl.cons.count,

                        .tx_prod.wrap = conn->local_tx_ctrl.prod.wrap,
                        .tx_prod.count = conn->local_tx_ctrl.prod.count,
                        .tx_cons.wrap = conn->local_tx_ctrl.cons.wrap,
                        .tx_cons.count = conn->local_tx_ctrl.cons.count,

                        .tx_prod_flags =
                                *(u8 *)&conn->local_tx_ctrl.prod_flags,
                        .tx_conn_state_flags =
                                *(u8 *)&conn->local_tx_ctrl.conn_state_flags,
                        .rx_prod_flags = *(u8 *)&conn->local_rx_ctrl.prod_flags,
                        .rx_conn_state_flags =
                                *(u8 *)&conn->local_rx_ctrl.conn_state_flags,

                        .tx_prep.wrap = conn->tx_curs_prep.wrap,
                        .tx_prep.count = conn->tx_curs_prep.count,
                        .tx_sent.wrap = conn->tx_curs_sent.wrap,
                        .tx_sent.count = conn->tx_curs_sent.count,
                        .tx_fin.wrap = conn->tx_curs_fin.wrap,
                        .tx_fin.count = conn->tx_curs_fin.count,
                };

                if (nla_put(skb, SMC_DIAG_CONNINFO, sizeof(cinfo), &cinfo) < 0)
                        goto errout;
        }

        if (smc_conn_lgr_valid(&smc->conn) && !smc->conn.lgr->is_smcd &&
            (req->diag_ext & (1 << (SMC_DIAG_LGRINFO - 1))) &&
            !list_empty(&smc->conn.lgr->list)) {
                struct smc_link *link = smc->conn.lnk;

                struct smc_diag_lgrinfo linfo = {
                        .role = smc->conn.lgr->role,
                        .lnk[0].ibport = link->ibport,
                        .lnk[0].link_id = link->link_id,
                };

                memcpy(linfo.lnk[0].ibname, link->smcibdev->ibdev->name,
                       sizeof(link->smcibdev->ibdev->name));
                smc_gid_be16_convert(linfo.lnk[0].gid, link->gid);
                smc_gid_be16_convert(linfo.lnk[0].peer_gid, link->peer_gid);

                if (nla_put(skb, SMC_DIAG_LGRINFO, sizeof(linfo), &linfo) < 0)
                        goto errout;
        }
        if (smc_conn_lgr_valid(&smc->conn) && smc->conn.lgr->is_smcd &&
            (req->diag_ext & (1 << (SMC_DIAG_DMBINFO - 1))) &&
            !list_empty(&smc->conn.lgr->list) && smc->conn.rmb_desc) {
                struct smc_connection *conn = &smc->conn;
                struct smcd_diag_dmbinfo dinfo;
                struct smcd_dev *smcd = conn->lgr->smcd;
                struct smcd_gid smcd_gid;

                memset(&dinfo, 0, sizeof(dinfo));

                dinfo.linkid = *((u32 *)conn->lgr->id);
                dinfo.peer_gid = conn->lgr->peer_gid.gid;
                dinfo.peer_gid_ext = conn->lgr->peer_gid.gid_ext;
                copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
                dinfo.my_gid = smcd_gid.gid;
                dinfo.my_gid_ext = smcd_gid.gid_ext;
                dinfo.token = conn->rmb_desc->token;
                dinfo.peer_token = conn->peer_token;

                if (nla_put(skb, SMC_DIAG_DMBINFO, sizeof(dinfo), &dinfo) < 0)
                        goto errout;
        }

        nlmsg_end(skb, nlh);
        return 0;

errout:
        nlmsg_cancel(skb, nlh);
        return -EMSGSIZE;
}

static int smc_diag_dump_proto(struct proto *prot, struct sk_buff *skb,
                               struct netlink_callback *cb, int p_type)
{
        struct smc_diag_dump_ctx *cb_ctx = smc_dump_context(cb);
        struct net *net = sock_net(skb->sk);
        int snum = cb_ctx->pos[p_type];
        struct nlattr *bc = NULL;
        struct hlist_head *head;
        int rc = 0, num = 0;
        struct sock *sk;

        read_lock(&prot->h.smc_hash->lock);
        head = &prot->h.smc_hash->ht;
        if (hlist_empty(head))
                goto out;

        sk_for_each(sk, head) {
                if (!net_eq(sock_net(sk), net))
                        continue;
                if (num < snum)
                        goto next;
                rc = __smc_diag_dump(sk, skb, cb, nlmsg_data(cb->nlh), bc);
                if (rc < 0)
                        goto out;
next:
                num++;
        }

out:
        read_unlock(&prot->h.smc_hash->lock);
        cb_ctx->pos[p_type] = num;
        return rc;
}

static int smc_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
        int rc = 0;

        rc = smc_diag_dump_proto(&smc_proto, skb, cb, SMCPROTO_SMC);
        if (!rc)
                smc_diag_dump_proto(&smc_proto6, skb, cb, SMCPROTO_SMC6);
        return skb->len;
}

static int smc_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
{
        struct net *net = sock_net(skb->sk);

        if (h->nlmsg_type == SOCK_DIAG_BY_FAMILY &&
            h->nlmsg_flags & NLM_F_DUMP) {
                {
                        struct netlink_dump_control c = {
                                .dump = smc_diag_dump,
                                .min_dump_alloc = SKB_WITH_OVERHEAD(32768),
                        };
                        return netlink_dump_start(net->diag_nlsk, skb, h, &c);
                }
        }
        return 0;
}

static const struct sock_diag_handler smc_diag_handler = {
        .owner = THIS_MODULE,
        .family = AF_SMC,
        .dump = smc_diag_handler_dump,
};

static int __init smc_diag_init(void)
{
        return sock_diag_register(&smc_diag_handler);
}

static void __exit smc_diag_exit(void)
{
        sock_diag_unregister(&smc_diag_handler);
}

module_init(smc_diag_init);
module_exit(smc_diag_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SMC socket monitoring via SOCK_DIAG");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 43 /* AF_SMC */);
MODULE_ALIAS_GENL_FAMILY(SMCR_GENL_FAMILY_NAME);