Re: [PATCH net-next v2 2/6] net/smc: add vendor unique experimental options area in clc handshake

Jan Karcher
2023-08-18T19:43:28Z

On 17/08/2023 15:20, Guangguan Wang wrote:
> Add vendor unique experimental options area in clc handshake. In clc
> accept and confirm msg, vendor unique experimental options use the
> 16-Bytes reserved field, which defined in struct smc_clc_fce_gid_ext
> in previous version. Because of the struct smc_clc_first_contact_ext
> is widely used and limit the scope of modification, this patch moves
> the 16-Bytes reserved field out of struct smc_clc_fce_gid_ext, and
> followed with the struct smc_clc_first_contact_ext in a new struct
> names struct smc_clc_first_contact_ext_v2x.
>
> For SMC-R first connection, in previous version, the struct smc_clc_
> first_contact_ext and the 16-Bytes reserved field has already been
> included in clc accept and confirm msg. Thus, this patch use struct
> smc_clc_first_contact_ext_v2x instead of the struct smc_clc_first_
> contact_ext and the 16-Bytes reserved field in SMC-R clc accept and
> confirm msg is compatible with previous version.
>
> For SMC-D first connection, in previous version, only the struct smc_
> clc_first_contact_ext is included in clc accept and confirm msg, and
> the 16-Bytes reserved field is not included. Thus, when the negotiated
> smc release version is the version before v2.1, we still use struct
> smc_clc_first_contact_ext for compatible consideration. If the negotiated
> smc release version is v2.1 or later, use struct smc_clc_first_contact_
> ext_v2x instead.
>
> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>

Thank you for your contribution, Guangguan.

Reviewed-by: Jan Karcher <jaka@linux.ibm.com>

> ---
> net/smc/af_smc.c | 2 +-
> net/smc/smc_clc.c | 44 +++++++++++++++++++++++---------------------
> net/smc/smc_clc.h | 15 +++++++++++++--
> 3 files changed, 37 insertions(+), 24 deletions(-)
>
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index c99ac371b5b1..10bec585983f 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -1113,7 +1113,7 @@ static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
>
> #define SMC_CLC_MAX_ACCEPT_LEN \
> (sizeof(struct smc_clc_msg_accept_confirm_v2) + \
> - sizeof(struct smc_clc_first_contact_ext) + \
> + sizeof(struct smc_clc_first_contact_ext_v2x) + \
> sizeof(struct smc_clc_msg_trail))
>
> /* CLC handshake during connect */
> diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
> index 7c5627c6abcc..728f88616266 100644
> --- a/net/smc/smc_clc.c
> +++ b/net/smc/smc_clc.c
> @@ -391,9 +391,7 @@ smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
> return false;
> } else {
> if (hdr->typev1 == SMC_TYPE_D &&
> - ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 &&
> - (ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 +
> - sizeof(struct smc_clc_first_contact_ext)))
> + ntohs(hdr->length) < SMCD_CLC_ACCEPT_CONFIRM_LEN_V2)
> return false;
> if (hdr->typev1 == SMC_TYPE_R &&
> ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
> @@ -420,13 +418,19 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
> return true;
> }
>
> -static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len, int release_nr)
> +static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
> + struct smc_init_info *ini)
> {
> + int ret = sizeof(*fce);
> +
> memset(fce, 0, sizeof(*fce));
> - fce->os_type = SMC_CLC_OS_LINUX;
> - fce->release = release_nr;
> - memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
> - (*len) += sizeof(*fce);
> + fce->fce_v2_base.os_type = SMC_CLC_OS_LINUX;
> + fce->fce_v2_base.release = ini->release_nr;
> + memcpy(fce->fce_v2_base.hostname, smc_hostname, sizeof(smc_hostname));
> + if (ini->is_smcd && ini->release_nr < SMC_RELEASE_1)
> + ret = sizeof(struct smc_clc_first_contact_ext);
> +
> + return ret;
> }
>
> /* check if received message has a correct header length and contains valid
> @@ -986,13 +990,13 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
> u8 *eid, struct smc_init_info *ini)
> {
> struct smc_connection *conn = &smc->conn;
> + struct smc_clc_first_contact_ext_v2x fce;
> struct smc_clc_msg_accept_confirm *clc;
> - struct smc_clc_first_contact_ext fce;
> struct smc_clc_fce_gid_ext gle;
> struct smc_clc_msg_trail trl;
> + int i, len, fce_len;
> struct kvec vec[5];
> struct msghdr msg;
> - int i, len;
>
> /* send SMC Confirm CLC msg */
> clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
> @@ -1018,8 +1022,10 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
> if (eid && eid[0])
> memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN);
> len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
> - if (first_contact)
> - smc_clc_fill_fce(&fce, &len, ini->release_nr);
> + if (first_contact) {
> + fce_len = smc_clc_fill_fce(&fce, ini);
> + len += fce_len;
> + }
> clc_v2->hdr.length = htons(len);
> }
> memcpy(trl.eyecatcher, SMCD_EYECATCHER,
> @@ -1063,15 +1069,14 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
> memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
> len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
> if (first_contact) {
> - smc_clc_fill_fce(&fce, &len, ini->release_nr);
> - fce.v2_direct = !link->lgr->uses_gateway;
> - memset(&gle, 0, sizeof(gle));
> + fce_len = smc_clc_fill_fce(&fce, ini);
> + len += fce_len;
> + fce.fce_v2_base.v2_direct = !link->lgr->uses_gateway;
> if (clc->hdr.type == SMC_CLC_CONFIRM) {
> + memset(&gle, 0, sizeof(gle));
> gle.gid_cnt = ini->smcrv2.gidlist.len;
> len += sizeof(gle);
> len += gle.gid_cnt * sizeof(gle.gid[0]);
> - } else {
> - len += sizeof(gle.reserved);
> }
> }
> clc_v2->hdr.length = htons(len);
> @@ -1094,7 +1099,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
> sizeof(trl);
> if (version > SMC_V1 && first_contact) {
> vec[i].iov_base = &fce;
> - vec[i++].iov_len = sizeof(fce);
> + vec[i++].iov_len = fce_len;
> if (!conn->lgr->is_smcd) {
> if (clc->hdr.type == SMC_CLC_CONFIRM) {
> vec[i].iov_base = &gle;
> @@ -1102,9 +1107,6 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
> vec[i].iov_base = &ini->smcrv2.gidlist.list;
> vec[i++].iov_len = gle.gid_cnt *
> sizeof(gle.gid[0]);
> - } else {
> - vec[i].iov_base = &gle.reserved;
> - vec[i++].iov_len = sizeof(gle.reserved);
> }
> }
> }
> diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
> index b923e89acafb..bd75382f374d 100644
> --- a/net/smc/smc_clc.h
> +++ b/net/smc/smc_clc.h
> @@ -147,7 +147,9 @@ struct smc_clc_msg_proposal_prefix { /* prefix part of clc proposal message*/
> struct smc_clc_msg_smcd { /* SMC-D GID information */
> struct smc_clc_smcd_gid_chid ism; /* ISM native GID+CHID of requestor */
> __be16 v2_ext_offset; /* SMC Version 2 Extension Offset */
> - u8 reserved[28];
> + u8 vendor_oui[3]; /* vendor organizationally unique identifier */
> + u8 vendor_exp_options[5];
> + u8 reserved[20];
> };
>
> struct smc_clc_smcd_v2_extension {
> @@ -231,8 +233,17 @@ struct smc_clc_first_contact_ext {
> u8 hostname[SMC_MAX_HOSTNAME_LEN];
> };
>
> +struct smc_clc_first_contact_ext_v2x {
> + struct smc_clc_first_contact_ext fce_v2_base;
> + u8 reserved3[4];
> + __be32 vendor_exp_options;
> + u8 reserved4[8];
> +} __packed; /* format defined in
> + * IBM Shared Memory Communications Version 2 (Third Edition)
> + * (https://www.ibm.com/support/pages/node/7009315)
> + */
> +
> struct smc_clc_fce_gid_ext {
> - u8 reserved[16];
> u8 gid_cnt;
> u8 reserved2[3];
> u8 gid[][SMC_GID_SIZE];