[PATCH net-next 12/14] net/smc: CLC accept / confirm V2

Karsten Graul
2020-09-26T10:44:55Z

The new format of SMCD V2 CLC accept and confirm is introduced,
and building and checking of SMCD V2 CLC accepts / confirms is adapted
accordingly.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/af_smc.c | 101 ++++++++++++++++++++++++++++++++++++----------
net/smc/smc_clc.c | 99 +++++++++++++++++++++++++++++++--------------
net/smc/smc_clc.h | 27 ++++++++++---
3 files changed, 170 insertions(+), 57 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 3963a4d2b79f..da282a860cfb 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -660,9 +660,13 @@ static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
return 0;
}

+#define SMC_CLC_MAX_ACCEPT_LEN \
+ (sizeof(struct smc_clc_msg_accept_confirm_v2) + \
+ sizeof(struct smc_clc_msg_trail))
+
/* CLC handshake during connect */
static int smc_connect_clc(struct smc_sock *smc,
- struct smc_clc_msg_accept_confirm *aclc,
+ struct smc_clc_msg_accept_confirm_v2 *aclc2,
struct smc_init_info *ini)
{
int rc = 0;
@@ -672,8 +676,8 @@ static int smc_connect_clc(struct smc_sock *smc,
if (rc)
return rc;
/* receive SMC Accept CLC message */
- return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
- CLC_WAIT_TIME);
+ return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
+ SMC_CLC_ACCEPT, CLC_WAIT_TIME);
}

/* setup for RDMA connection of client */
@@ -747,7 +751,8 @@ static int smc_connect_rdma(struct smc_sock *smc,
}
smc_rmb_sync_sg_for_device(&smc->conn);

- reason_code = smc_clc_send_confirm(smc);
+ reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
+ SMC_V1);
if (reason_code)
return smc_connect_abort(smc, reason_code,
ini->first_contact_local);
@@ -773,6 +778,25 @@ static int smc_connect_rdma(struct smc_sock *smc,
return 0;
}

+/* The server has chosen one of the proposed ISM devices for the communication.
+ * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
+ */
+static int
+smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
+ struct smc_init_info *ini)
+{
+ int i;
+
+ for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
+ if (ini->ism_chid[i] == ntohs(aclc->chid)) {
+ ini->ism_selected = i;
+ return 0;
+ }
+ }
+
+ return -EPROTO;
+}
+
/* setup for ISM connection of client */
static int smc_connect_ism(struct smc_sock *smc,
struct smc_clc_msg_accept_confirm *aclc,
@@ -781,9 +805,18 @@ static int smc_connect_ism(struct smc_sock *smc,
int rc = 0;

ini->is_smcd = true;
- ini->ism_peer_gid[0] = aclc->d0.gid;
ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;

+ if (aclc->hdr.version == SMC_V2) {
+ struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
+ (struct smc_clc_msg_accept_confirm_v2 *)aclc;
+
+ rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
+ if (rc)
+ return rc;
+ }
+ ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
+
/* there is only one lgr role for SMC-D; use server lock */
mutex_lock(&smc_server_lgr_pending);
rc = smc_conn_create(smc, ini);
@@ -805,7 +838,8 @@ static int smc_connect_ism(struct smc_sock *smc,
smc_rx_init(smc);
smc_tx_init(smc);

- rc = smc_clc_send_confirm(smc);
+ rc = smc_clc_send_confirm(smc, ini->first_contact_local,
+ aclc->hdr.version);
if (rc)
return smc_connect_abort(smc, rc, ini->first_contact_local);
mutex_unlock(&smc_server_lgr_pending);
@@ -825,7 +859,12 @@ static int smc_connect_check_aclc(struct smc_init_info *ini,
if ((aclc->hdr.typev1 == SMC_TYPE_R &&
!smcr_indicated(ini->smc_type_v1)) ||
(aclc->hdr.typev1 == SMC_TYPE_D &&
- !smcd_indicated(ini->smc_type_v1)))
+ ((!smcd_indicated(ini->smc_type_v1) &&
+ !smcd_indicated(ini->smc_type_v2)) ||
+ (aclc->hdr.version == SMC_V1 &&
+ !smcd_indicated(ini->smc_type_v1)) ||
+ (aclc->hdr.version == SMC_V2 &&
+ !smcd_indicated(ini->smc_type_v2)))))
return SMC_CLC_DECL_MODEUNSUPP;

return 0;
@@ -834,8 +873,10 @@ static int smc_connect_check_aclc(struct smc_init_info *ini,
/* perform steps before actually connecting */
static int __smc_connect(struct smc_sock *smc)
{
- struct smc_clc_msg_accept_confirm aclc;
+ struct smc_clc_msg_accept_confirm_v2 *aclc2;
+ struct smc_clc_msg_accept_confirm *aclc;
struct smc_init_info *ini = NULL;
+ u8 *buf = NULL;
int rc = 0;

if (smc->use_fallback)
@@ -872,30 +913,40 @@ static int __smc_connect(struct smc_sock *smc)
if (rc)
goto fallback;

+ buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
+ if (!buf) {
+ rc = SMC_CLC_DECL_MEM;
+ goto fallback;
+ }
+ aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
+ aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
+
/* perform CLC handshake */
- rc = smc_connect_clc(smc, &aclc, ini);
+ rc = smc_connect_clc(smc, aclc2, ini);
if (rc)
goto vlan_cleanup;

/* check if smc modes and versions of CLC proposal and accept match */
- rc = smc_connect_check_aclc(ini, &aclc);
+ rc = smc_connect_check_aclc(ini, aclc);
if (rc)
goto vlan_cleanup;

/* depending on previous steps, connect using rdma or ism */
- if (aclc.hdr.typev1 == SMC_TYPE_R)
- rc = smc_connect_rdma(smc, &aclc, ini);
- else if (aclc.hdr.typev1 == SMC_TYPE_D)
- rc = smc_connect_ism(smc, &aclc, ini);
+ if (aclc->hdr.typev1 == SMC_TYPE_R)
+ rc = smc_connect_rdma(smc, aclc, ini);
+ else if (aclc->hdr.typev1 == SMC_TYPE_D)
+ rc = smc_connect_ism(smc, aclc, ini);
if (rc)
goto vlan_cleanup;

smc_connect_ism_vlan_cleanup(smc, ini);
+ kfree(buf);
kfree(ini);
return 0;

vlan_cleanup:
smc_connect_ism_vlan_cleanup(smc, ini);
+ kfree(buf);
fallback:
kfree(ini);
return smc_connect_decline_fallback(smc, rc);
@@ -1214,10 +1265,10 @@ static void smc_listen_out_err(struct smc_sock *new_smc)

/* listen worker: decline and fall back if possible */
static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
- bool local_first)
+ struct smc_init_info *ini)
{
/* RDMA setup failed, switch back to TCP */
- if (local_first)
+ if (ini->first_contact_local)
smc_lgr_cleanup_early(&new_smc->conn);
else
smc_conn_free(&new_smc->conn);
@@ -1560,7 +1611,8 @@ static void smc_listen_work(struct work_struct *work)
struct smc_sock *new_smc = container_of(work, struct smc_sock,
smc_listen_work);
struct socket *newclcsock = new_smc->clcsock;
- struct smc_clc_msg_accept_confirm cclc;
+ struct smc_clc_msg_accept_confirm_v2 *cclc2;
+ struct smc_clc_msg_accept_confirm *cclc;
struct smc_clc_msg_proposal_area *buf;
struct smc_clc_msg_proposal *pclc;
struct smc_init_info *ini = NULL;
@@ -1624,7 +1676,8 @@ static void smc_listen_work(struct work_struct *work)
goto out_unlock;

/* send SMC Accept CLC message */
- rc = smc_clc_send_accept(new_smc, ini->first_contact_local);
+ rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
+ ini->smcd_version == SMC_V2 ? SMC_V2 : SMC_V1);
if (rc)
goto out_unlock;

@@ -1633,7 +1686,11 @@ static void smc_listen_work(struct work_struct *work)
mutex_unlock(&smc_server_lgr_pending);

/* receive SMC Confirm CLC message */
- rc = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
+ cclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
+ cclc = (struct smc_clc_msg_accept_confirm *)cclc2;
+ memset(buf, 0, sizeof(struct smc_clc_msg_proposal_area));
+ rc = smc_clc_wait_msg(new_smc, cclc2,
+ sizeof(struct smc_clc_msg_proposal_area),
SMC_CLC_CONFIRM, CLC_WAIT_TIME);
if (rc) {
if (!ini->is_smcd)
@@ -1643,20 +1700,20 @@ static void smc_listen_work(struct work_struct *work)

/* finish worker */
if (!ini->is_smcd) {
- rc = smc_listen_rdma_finish(new_smc, &cclc,
+ rc = smc_listen_rdma_finish(new_smc, cclc,
ini->first_contact_local);
if (rc)
goto out_unlock;
mutex_unlock(&smc_server_lgr_pending);
}
- smc_conn_save_peer_info(new_smc, &cclc);
+ smc_conn_save_peer_info(new_smc, cclc);
smc_listen_out_connected(new_smc);
goto out_free;

out_unlock:
mutex_unlock(&smc_server_lgr_pending);
out_decl:
- smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0);
+ smc_listen_decline(new_smc, rc, ini);
out_free:
kfree(ini);
kfree(buf);
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 037c92a0c2b9..a2eb59dbcdb0 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -27,6 +27,7 @@

#define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
#define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
+#define SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 78
#define SMC_CLC_RECV_BUF_LEN 100

/* eye catcher "SMCR" EBCDIC for CLC messages */
@@ -75,12 +76,34 @@ static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
return true;
}

+/* check arriving CLC accept or confirm */
+static bool
+smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
+{
+ struct smc_clc_msg_hdr *hdr = &clc_v2->hdr;
+
+ if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
+ return false;
+ if (hdr->version == SMC_V1) {
+ if ((hdr->typev1 == SMC_TYPE_R &&
+ ntohs(hdr->length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
+ (hdr->typev1 == SMC_TYPE_D &&
+ ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
+ return false;
+ } else {
+ if (hdr->typev1 == SMC_TYPE_D &&
+ ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2)
+ return false;
+ }
+ return true;
+}
+
/* check if received message has a correct header length and contains valid
* heading and trailing eyecatchers
*/
static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
{
- struct smc_clc_msg_accept_confirm *clc;
+ struct smc_clc_msg_accept_confirm_v2 *clc_v2;
struct smc_clc_msg_proposal *pclc;
struct smc_clc_msg_decline *dclc;
struct smc_clc_msg_trail *trl;
@@ -98,16 +121,12 @@ static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
break;
case SMC_CLC_ACCEPT:
case SMC_CLC_CONFIRM:
- if (clcm->typev1 != SMC_TYPE_R && clcm->typev1 != SMC_TYPE_D)
- return false;
- clc = (struct smc_clc_msg_accept_confirm *)clcm;
- if ((clcm->typev1 == SMC_TYPE_R &&
- ntohs(clc->hdr.length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
- (clcm->typev1 == SMC_TYPE_D &&
- ntohs(clc->hdr.length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
+ clc_v2 = (struct smc_clc_msg_accept_confirm_v2 *)clcm;
+ if (!smc_clc_msg_acc_conf_valid(clc_v2))
return false;
trl = (struct smc_clc_msg_trail *)
- ((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
+ ((u8 *)clc_v2 + ntohs(clc_v2->hdr.length) -
+ sizeof(*trl));
break;
case SMC_CLC_DECLINE:
dclc = (struct smc_clc_msg_decline *)clcm;
@@ -599,17 +618,19 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)

/* build and send CLC CONFIRM / ACCEPT message */
static int smc_clc_send_confirm_accept(struct smc_sock *smc,
- struct smc_clc_msg_accept_confirm *clc,
- int first_contact)
+ struct smc_clc_msg_accept_confirm_v2 *clc_v2,
+ int first_contact, u8 version)
{
struct smc_connection *conn = &smc->conn;
+ struct smc_clc_msg_accept_confirm *clc;
struct smc_clc_msg_trail trl;
struct kvec vec[2];
struct msghdr msg;
int i;

/* send SMC Confirm CLC msg */
- clc->hdr.version = SMC_V1; /* SMC version */
+ clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
+ clc->hdr.version = version; /* SMC version */
if (first_contact)
clc->hdr.typev2 |= SMC_FIRST_CONTACT_MASK;
if (conn->lgr->is_smcd) {
@@ -617,12 +638,23 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
sizeof(SMCD_EYECATCHER));
clc->hdr.typev1 = SMC_TYPE_D;
- clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
clc->d0.gid = conn->lgr->smcd->local_gid;
clc->d0.token = conn->rmb_desc->token;
clc->d0.dmbe_size = conn->rmbe_size_short;
clc->d0.dmbe_idx = 0;
memcpy(&clc->d0.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
+ if (version == SMC_V1) {
+ clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
+ } else {
+ u8 *eid = NULL;
+
+ clc_v2->chid = htons(smc_ism_get_chid(conn->lgr->smcd));
+ smc_ism_get_system_eid(conn->lgr->smcd, &eid);
+ if (eid)
+ memcpy(clc_v2->eid, eid, SMC_MAX_EID_LEN);
+ clc_v2->hdr.length =
+ htons(SMCD_CLC_ACCEPT_CONFIRM_LEN_V2);
+ }
memcpy(trl.eyecatcher, SMCD_EYECATCHER,
sizeof(SMCD_EYECATCHER));
} else {
@@ -661,11 +693,14 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,

memset(&msg, 0, sizeof(msg));
i = 0;
- vec[i].iov_base = clc;
- vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
- SMCD_CLC_ACCEPT_CONFIRM_LEN :
- SMCR_CLC_ACCEPT_CONFIRM_LEN) -
- sizeof(trl);
+ vec[i].iov_base = clc_v2;
+ if (version > SMC_V1)
+ vec[i++].iov_len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 - sizeof(trl);
+ else
+ vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
+ SMCD_CLC_ACCEPT_CONFIRM_LEN :
+ SMCR_CLC_ACCEPT_CONFIRM_LEN) -
+ sizeof(trl);
vec[i].iov_base = &trl;
vec[i++].iov_len = sizeof(trl);
return kernel_sendmsg(smc->clcsock, &msg, vec, 1,
@@ -673,17 +708,19 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
}

/* send CLC CONFIRM message across internal TCP socket */
-int smc_clc_send_confirm(struct smc_sock *smc)
+int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
+ u8 version)
{
- struct smc_clc_msg_accept_confirm cclc;
+ struct smc_clc_msg_accept_confirm_v2 cclc_v2;
int reason_code = 0;
int len;

/* send SMC Confirm CLC msg */
- memset(&cclc, 0, sizeof(cclc));
- cclc.hdr.type = SMC_CLC_CONFIRM;
- len = smc_clc_send_confirm_accept(smc, &cclc, 0);
- if (len < ntohs(cclc.hdr.length)) {
+ memset(&cclc_v2, 0, sizeof(cclc_v2));
+ cclc_v2.hdr.type = SMC_CLC_CONFIRM;
+ len = smc_clc_send_confirm_accept(smc, &cclc_v2, clnt_first_contact,
+ version);
+ if (len < ntohs(cclc_v2.hdr.length)) {
if (len >= 0) {
reason_code = -ENETUNREACH;
smc->sk.sk_err = -reason_code;
@@ -696,15 +733,17 @@ int smc_clc_send_confirm(struct smc_sock *smc)
}

/* send CLC ACCEPT message across internal TCP socket */
-int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact)
+int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
+ u8 version)
{
- struct smc_clc_msg_accept_confirm aclc;
+ struct smc_clc_msg_accept_confirm_v2 aclc_v2;
int len;

- memset(&aclc, 0, sizeof(aclc));
- aclc.hdr.type = SMC_CLC_ACCEPT;
- len = smc_clc_send_confirm_accept(new_smc, &aclc, srv_first_contact);
- if (len < ntohs(aclc.hdr.length))
+ memset(&aclc_v2, 0, sizeof(aclc_v2));
+ aclc_v2.hdr.type = SMC_CLC_ACCEPT;
+ len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,
+ version);
+ if (len < ntohs(aclc_v2.hdr.length))
len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;

return len > 0 ? 0 : len;
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 5cefb0a09eaf..926b86cce68f 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -184,7 +184,7 @@ struct smcr_clc_msg_accept_confirm { /* SMCR accept/confirm */
u8 psn[3]; /* packet sequence number */
} __packed;

-struct smcd_clc_msg_accept_confirm { /* SMCD accept/confirm */
+struct smcd_clc_msg_accept_confirm_common { /* SMCD accept/confirm */
u64 gid; /* Sender GID */
u64 token; /* DMB token */
u8 dmbe_idx; /* DMBE index */
@@ -197,17 +197,32 @@ struct smcd_clc_msg_accept_confirm { /* SMCD accept/confirm */
#endif
u16 reserved4;
__be32 linkid; /* Link identifier */
- u32 reserved5[3];
} __packed;

struct smc_clc_msg_accept_confirm { /* clc accept / confirm message */
struct smc_clc_msg_hdr hdr;
union {
struct smcr_clc_msg_accept_confirm r0; /* SMC-R */
- struct smcd_clc_msg_accept_confirm d0; /* SMC-D */
+ struct { /* SMC-D */
+ struct smcd_clc_msg_accept_confirm_common d0;
+ u32 reserved5[3];
+ };
};
} __packed; /* format defined in RFC7609 */

+struct smc_clc_msg_accept_confirm_v2 { /* clc accept / confirm message */
+ struct smc_clc_msg_hdr hdr;
+ union {
+ struct smcr_clc_msg_accept_confirm r0; /* SMC-R */
+ struct { /* SMC-D */
+ struct smcd_clc_msg_accept_confirm_common d0;
+ __be16 chid;
+ u8 eid[SMC_MAX_EID_LEN];
+ u8 reserved5[8];
+ };
+ };
+};
+
struct smc_clc_msg_decline { /* clc decline message */
struct smc_clc_msg_hdr hdr;
u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
@@ -285,7 +300,9 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
u8 expected_type, unsigned long timeout);
int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini);
-int smc_clc_send_confirm(struct smc_sock *smc);
-int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact);
+int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
+ u8 version);
+int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
+ u8 version);

#endif
--
2.17.1