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-rw-r--r--include/linux/socket.h1
-rw-r--r--include/linux/tcp.h1
-rw-r--r--include/net/netns/smc.h2
-rw-r--r--include/uapi/linux/smc.h15
-rw-r--r--net/ipv4/tcp_input.c3
-rw-r--r--net/smc/af_smc.c184
-rw-r--r--net/smc/smc.h13
-rw-r--r--net/smc/smc_netlink.c15
-rw-r--r--net/smc/smc_pnet.c3
9 files changed, 233 insertions, 4 deletions
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 8ef26d89ef49..6f85f5d957ef 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -366,6 +366,7 @@ struct ucred {
#define SOL_XDP 283
#define SOL_MPTCP 284
#define SOL_MCTP 285
+#define SOL_SMC 286
/* IPX options */
#define IPX_TYPE 1
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 78b91bb92f0d..1168302b7927 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -394,6 +394,7 @@ struct tcp_sock {
bool is_mptcp;
#endif
#if IS_ENABLED(CONFIG_SMC)
+ bool (*smc_hs_congested)(const struct sock *sk);
bool syn_smc; /* SYN includes SMC */
#endif
diff --git a/include/net/netns/smc.h b/include/net/netns/smc.h
index ea8a9cf2619b..47b166684fd8 100644
--- a/include/net/netns/smc.h
+++ b/include/net/netns/smc.h
@@ -12,5 +12,7 @@ struct netns_smc {
/* protect fback_rsn */
struct mutex mutex_fback_rsn;
struct smc_stats_rsn *fback_rsn;
+
+ bool limit_smc_hs; /* constraint on handshake */
};
#endif
diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index 6c2874fd2c00..693f549f6966 100644
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -59,6 +59,9 @@ enum {
SMC_NETLINK_DUMP_SEID,
SMC_NETLINK_ENABLE_SEID,
SMC_NETLINK_DISABLE_SEID,
+ SMC_NETLINK_DUMP_HS_LIMITATION,
+ SMC_NETLINK_ENABLE_HS_LIMITATION,
+ SMC_NETLINK_DISABLE_HS_LIMITATION,
};
/* SMC_GENL_FAMILY top level attributes */
@@ -284,4 +287,16 @@ enum {
__SMC_NLA_SEID_TABLE_MAX,
SMC_NLA_SEID_TABLE_MAX = __SMC_NLA_SEID_TABLE_MAX - 1
};
+
+/* SMC_NETLINK_HS_LIMITATION attributes */
+enum {
+ SMC_NLA_HS_LIMITATION_UNSPEC,
+ SMC_NLA_HS_LIMITATION_ENABLED, /* u8 */
+ __SMC_NLA_HS_LIMITATION_MAX,
+ SMC_NLA_HS_LIMITATION_MAX = __SMC_NLA_HS_LIMITATION_MAX - 1
+};
+
+/* SMC socket options */
+#define SMC_LIMIT_HS 1 /* constraint on smc handshake */
+
#endif /* _UAPI_LINUX_SMC_H */
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index af94a6d22a9d..92e65d56dc2c 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6703,7 +6703,8 @@ static void tcp_openreq_init(struct request_sock *req,
ireq->ir_num = ntohs(tcp_hdr(skb)->dest);
ireq->ir_mark = inet_request_mark(sk, skb);
#if IS_ENABLED(CONFIG_SMC)
- ireq->smc_ok = rx_opt->smc_ok;
+ ireq->smc_ok = rx_opt->smc_ok && !(tcp_sk(sk)->smc_hs_congested &&
+ tcp_sk(sk)->smc_hs_congested(sk));
#endif
}
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 00b2e9deabb0..246c874de629 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -59,12 +59,52 @@ static DEFINE_MUTEX(smc_client_lgr_pending); /* serialize link group
* creation on client
*/
+static struct workqueue_struct *smc_tcp_ls_wq; /* wq for tcp listen work */
struct workqueue_struct *smc_hs_wq; /* wq for handshake work */
struct workqueue_struct *smc_close_wq; /* wq for close work */
static void smc_tcp_listen_work(struct work_struct *);
static void smc_connect_work(struct work_struct *);
+int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+ void *hdr;
+
+ if (cb_ctx->pos[0])
+ goto out;
+
+ hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+ &smc_gen_nl_family, NLM_F_MULTI,
+ SMC_NETLINK_DUMP_HS_LIMITATION);
+ if (!hdr)
+ return -ENOMEM;
+
+ if (nla_put_u8(skb, SMC_NLA_HS_LIMITATION_ENABLED,
+ sock_net(skb->sk)->smc.limit_smc_hs))
+ goto err;
+
+ genlmsg_end(skb, hdr);
+ cb_ctx->pos[0] = 1;
+out:
+ return skb->len;
+err:
+ genlmsg_cancel(skb, hdr);
+ return -EMSGSIZE;
+}
+
+int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
+{
+ sock_net(skb->sk)->smc.limit_smc_hs = true;
+ return 0;
+}
+
+int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
+{
+ sock_net(skb->sk)->smc.limit_smc_hs = false;
+ return 0;
+}
+
static void smc_set_keepalive(struct sock *sk, int val)
{
struct smc_sock *smc = smc_sk(sk);
@@ -72,6 +112,51 @@ static void smc_set_keepalive(struct sock *sk, int val)
smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
}
+static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
+ struct sk_buff *skb,
+ struct request_sock *req,
+ struct dst_entry *dst,
+ struct request_sock *req_unhash,
+ bool *own_req)
+{
+ struct smc_sock *smc;
+
+ smc = smc_clcsock_user_data(sk);
+
+ if (READ_ONCE(sk->sk_ack_backlog) + atomic_read(&smc->queued_smc_hs) >
+ sk->sk_max_ack_backlog)
+ goto drop;
+
+ if (sk_acceptq_is_full(&smc->sk)) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+ goto drop;
+ }
+
+ /* passthrough to original syn recv sock fct */
+ return smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash,
+ own_req);
+
+drop:
+ dst_release(dst);
+ tcp_listendrop(sk);
+ return NULL;
+}
+
+static bool smc_hs_congested(const struct sock *sk)
+{
+ const struct smc_sock *smc;
+
+ smc = smc_clcsock_user_data(sk);
+
+ if (!smc)
+ return true;
+
+ if (workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq))
+ return true;
+
+ return false;
+}
+
static struct smc_hashinfo smc_v4_hashinfo = {
.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
};
@@ -1594,6 +1679,9 @@ static void smc_listen_out(struct smc_sock *new_smc)
struct smc_sock *lsmc = new_smc->listen_smc;
struct sock *newsmcsk = &new_smc->sk;
+ if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
+ atomic_dec(&lsmc->queued_smc_hs);
+
if (lsmc->sk.sk_state == SMC_LISTEN) {
lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
smc_accept_enqueue(&lsmc->sk, newsmcsk);
@@ -2199,6 +2287,9 @@ static void smc_tcp_listen_work(struct work_struct *work)
if (!new_smc)
continue;
+ if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
+ atomic_inc(&lsmc->queued_smc_hs);
+
new_smc->listen_smc = lsmc;
new_smc->use_fallback = lsmc->use_fallback;
new_smc->fallback_rsn = lsmc->fallback_rsn;
@@ -2227,7 +2318,7 @@ static void smc_clcsock_data_ready(struct sock *listen_clcsock)
lsmc->clcsk_data_ready(listen_clcsock);
if (lsmc->sk.sk_state == SMC_LISTEN) {
sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
- if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
+ if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
sock_put(&lsmc->sk);
}
}
@@ -2265,6 +2356,18 @@ static int smc_listen(struct socket *sock, int backlog)
smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
smc->clcsock->sk->sk_user_data =
(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
+
+ /* save original ops */
+ smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
+
+ smc->af_ops = *smc->ori_af_ops;
+ smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
+
+ inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
+
+ if (smc->limit_smc_hs)
+ tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested;
+
rc = kernel_listen(smc->clcsock, backlog);
if (rc) {
smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
@@ -2558,6 +2661,67 @@ out:
return rc ? rc : rc1;
}
+static int __smc_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ struct smc_sock *smc;
+ int val, len;
+
+ smc = smc_sk(sock->sk);
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+
+ len = min_t(int, len, sizeof(int));
+
+ if (len < 0)
+ return -EINVAL;
+
+ switch (optname) {
+ case SMC_LIMIT_HS:
+ val = smc->limit_smc_hs;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (put_user(len, optlen))
+ return -EFAULT;
+ if (copy_to_user(optval, &val, len))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int __smc_setsockopt(struct socket *sock, int level, int optname,
+ sockptr_t optval, unsigned int optlen)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int val, rc;
+
+ smc = smc_sk(sk);
+
+ lock_sock(sk);
+ switch (optname) {
+ case SMC_LIMIT_HS:
+ if (optlen < sizeof(int))
+ return -EINVAL;
+ if (copy_from_sockptr(&val, optval, sizeof(int)))
+ return -EFAULT;
+
+ smc->limit_smc_hs = !!val;
+ rc = 0;
+ break;
+ default:
+ rc = -EOPNOTSUPP;
+ break;
+ }
+ release_sock(sk);
+
+ return rc;
+}
+
static int smc_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
@@ -2567,6 +2731,8 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
if (level == SOL_TCP && optname == TCP_ULP)
return -EOPNOTSUPP;
+ else if (level == SOL_SMC)
+ return __smc_setsockopt(sock, level, optname, optval, optlen);
smc = smc_sk(sk);
@@ -2649,6 +2815,9 @@ static int smc_getsockopt(struct socket *sock, int level, int optname,
struct smc_sock *smc;
int rc;
+ if (level == SOL_SMC)
+ return __smc_getsockopt(sock, level, optname, optval, optlen);
+
smc = smc_sk(sock->sk);
mutex_lock(&smc->clcsock_release_lock);
if (!smc->clcsock) {
@@ -2877,6 +3046,9 @@ static int __smc_create(struct net *net, struct socket *sock, int protocol,
smc->use_fallback = false; /* assume rdma capability first */
smc->fallback_rsn = 0;
+ /* default behavior from limit_smc_hs in every net namespace */
+ smc->limit_smc_hs = net->smc.limit_smc_hs;
+
rc = 0;
if (!clcsock) {
rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
@@ -3024,9 +3196,14 @@ static int __init smc_init(void)
goto out_nl;
rc = -ENOMEM;
+
+ smc_tcp_ls_wq = alloc_workqueue("smc_tcp_ls_wq", 0, 0);
+ if (!smc_tcp_ls_wq)
+ goto out_pnet;
+
smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
if (!smc_hs_wq)
- goto out_pnet;
+ goto out_alloc_tcp_ls_wq;
smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
if (!smc_close_wq)
@@ -3097,6 +3274,8 @@ out_alloc_wqs:
destroy_workqueue(smc_close_wq);
out_alloc_hs_wq:
destroy_workqueue(smc_hs_wq);
+out_alloc_tcp_ls_wq:
+ destroy_workqueue(smc_tcp_ls_wq);
out_pnet:
smc_pnet_exit();
out_nl:
@@ -3115,6 +3294,7 @@ static void __exit smc_exit(void)
smc_core_exit();
smc_ib_unregister_client();
destroy_workqueue(smc_close_wq);
+ destroy_workqueue(smc_tcp_ls_wq);
destroy_workqueue(smc_hs_wq);
proto_unregister(&smc_proto6);
proto_unregister(&smc_proto);
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 37b2001a0255..a096d8af21a0 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -14,6 +14,7 @@
#include <linux/socket.h>
#include <linux/types.h>
#include <linux/compiler.h> /* __aligned */
+#include <net/genetlink.h>
#include <net/sock.h>
#include "smc_ib.h"
@@ -249,9 +250,14 @@ struct smc_sock { /* smc sock container */
struct work_struct smc_listen_work;/* prepare new accept socket */
struct list_head accept_q; /* sockets to be accepted */
spinlock_t accept_q_lock; /* protects accept_q */
+ bool limit_smc_hs; /* put constraint on handshake */
bool use_fallback; /* fallback to tcp */
int fallback_rsn; /* reason for fallback */
u32 peer_diagnosis; /* decline reason from peer */
+ atomic_t queued_smc_hs; /* queued smc handshakes */
+ struct inet_connection_sock_af_ops af_ops;
+ const struct inet_connection_sock_af_ops *ori_af_ops;
+ /* original af ops */
int sockopt_defer_accept;
/* sockopt TCP_DEFER_ACCEPT
* value
@@ -276,7 +282,7 @@ static inline struct smc_sock *smc_sk(const struct sock *sk)
return (struct smc_sock *)sk;
}
-static inline struct smc_sock *smc_clcsock_user_data(struct sock *clcsk)
+static inline struct smc_sock *smc_clcsock_user_data(const struct sock *clcsk)
{
return (struct smc_sock *)
((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
@@ -331,4 +337,9 @@ void smc_fill_gid_list(struct smc_link_group *lgr,
struct smc_gidlist *gidlist,
struct smc_ib_device *known_dev, u8 *known_gid);
+/* smc handshake limitation interface for netlink */
+int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb);
+int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
+int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
+
#endif /* __SMC_H */
diff --git a/net/smc/smc_netlink.c b/net/smc/smc_netlink.c
index f13ab0661ed5..c5a62f6f52ba 100644
--- a/net/smc/smc_netlink.c
+++ b/net/smc/smc_netlink.c
@@ -111,6 +111,21 @@ static const struct genl_ops smc_gen_nl_ops[] = {
.flags = GENL_ADMIN_PERM,
.doit = smc_nl_disable_seid,
},
+ {
+ .cmd = SMC_NETLINK_DUMP_HS_LIMITATION,
+ /* can be retrieved by unprivileged users */
+ .dumpit = smc_nl_dump_hs_limitation,
+ },
+ {
+ .cmd = SMC_NETLINK_ENABLE_HS_LIMITATION,
+ .flags = GENL_ADMIN_PERM,
+ .doit = smc_nl_enable_hs_limitation,
+ },
+ {
+ .cmd = SMC_NETLINK_DISABLE_HS_LIMITATION,
+ .flags = GENL_ADMIN_PERM,
+ .doit = smc_nl_disable_hs_limitation,
+ },
};
static const struct nla_policy smc_gen_nl_policy[2] = {
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index 0599246c0376..ff61b7b95875 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -870,6 +870,9 @@ int smc_pnet_net_init(struct net *net)
smc_pnet_create_pnetids_list(net);
+ /* disable handshake limitation by default */
+ net->smc.limit_smc_hs = 0;
+
return 0;
}