Re: [PATCH net-next 2/6] net/smc: add vendor unique experimental options area in clc handshake
From: Jan Karcher
Date: Wed Aug 16 2023 - 17:50:47 EST
Hi Guangguan Wang,
thank you, some minor thoughts on this one.
On 16/08/2023 10:33, 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@xxxxxxxxxxxxxxxxx>
Reviewed-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx>
---
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 97265691bc95..7b54c153bd0d 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..624dc970d187 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_v20.os_type = SMC_CLC_OS_LINUX;
+ fce->fce_v20.release = ini->release_nr;
I don't like that this is called fce_v20.release which can be set to
v2.1 here although the struct is named v20. Maybe let us call the struct
something like fce_v2_base or fce_base_v2.
+ memcpy(fce->fce_v20.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_v20.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..6133276a8839 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];
+ u8 vendor_exp_options[5];
+ u8 reserved[20];
Could we either make those variables a bit more self explaining via
their name (e.g. vendor_organization_uid) or adding a comment /* vendor
organizationally unique identifier */
};
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_v20;
as stated at the top where the release is assigned i'm not completly
happy with the naming.
+ 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];