[PATCH net-next v2 06/11] net/smc: add v2 format of CLC decline message

Karsten Graul
2021-10-14T16:48:52Z

The CLC decline message changed with SMC-Rv2 and supports up to
4 additional diagnosis codes.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/smc_clc.c | 47 +++++++++++++++++++++++++++++++++++++----------
net/smc/smc_clc.h | 18 ++++++++++++++++++
2 files changed, 55 insertions(+), 10 deletions(-)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 5cc2e2dc7417..8409ab71a5e4 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -400,6 +400,24 @@ smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
return true;
}

+/* check arriving CLC decline */
+static bool
+smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
+{
+ struct smc_clc_msg_hdr *hdr = &dclc->hdr;
+
+ if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
+ return false;
+ if (hdr->version == SMC_V1) {
+ if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
+ return false;
+ } else {
+ if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline_v2))
+ return false;
+ }
+ return true;
+}
+
static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len)
{
memset(fce, 0, sizeof(*fce));
@@ -441,9 +459,9 @@ static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
break;
case SMC_CLC_DECLINE:
dclc = (struct smc_clc_msg_decline *)clcm;
- if (ntohs(dclc->hdr.length) != sizeof(*dclc))
+ if (!smc_clc_msg_decl_valid(dclc))
return false;
- trl = &dclc->trl;
+ check_trl = false;
break;
default:
return false;
@@ -742,15 +760,16 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
/* send CLC DECLINE message across internal TCP socket */
int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
{
- struct smc_clc_msg_decline dclc;
+ struct smc_clc_msg_decline *dclc_v1;
+ struct smc_clc_msg_decline_v2 dclc;
struct msghdr msg;
+ int len, send_len;
struct kvec vec;
- int len;

+ dclc_v1 = (struct smc_clc_msg_decline *)&dclc;
memset(&dclc, 0, sizeof(dclc));
memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
dclc.hdr.type = SMC_CLC_DECLINE;
- dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
dclc.hdr.version = version;
dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
@@ -760,14 +779,22 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
memcpy(dclc.id_for_peer, local_systemid,
sizeof(local_systemid));
dclc.peer_diagnosis = htonl(peer_diag_info);
- memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+ if (version == SMC_V1) {
+ memcpy(dclc_v1->trl.eyecatcher, SMC_EYECATCHER,
+ sizeof(SMC_EYECATCHER));
+ send_len = sizeof(*dclc_v1);
+ } else {
+ memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER,
+ sizeof(SMC_EYECATCHER));
+ send_len = sizeof(dclc);
+ }
+ dclc.hdr.length = htons(send_len);

memset(&msg, 0, sizeof(msg));
vec.iov_base = &dclc;
- vec.iov_len = sizeof(struct smc_clc_msg_decline);
- len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
- sizeof(struct smc_clc_msg_decline));
- if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
+ vec.iov_len = send_len;
+ len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, send_len);
+ if (len < 0 || len < send_len)
len = -EPROTO;
return len > 0 ? 0 : len;
}
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 22c079ed77a9..83f02f131fc0 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -281,6 +281,24 @@ struct smc_clc_msg_decline { /* clc decline message */
struct smc_clc_msg_trail trl; /* eye catcher "SMCD" or "SMCR" EBCDIC */
} __aligned(4);

+#define SMC_DECL_DIAG_COUNT_V2 4 /* no. of additional peer diagnosis codes */
+
+struct smc_clc_msg_decline_v2 { /* clc decline message */
+ struct smc_clc_msg_hdr hdr;
+ u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
+ __be32 peer_diagnosis; /* diagnosis information */
+#if defined(__BIG_ENDIAN_BITFIELD)
+ u8 os_type : 4,
+ reserved : 4;
+#elif defined(__LITTLE_ENDIAN_BITFIELD)
+ u8 reserved : 4,
+ os_type : 4;
+#endif
+ u8 reserved2[3];
+ __be32 peer_diagnosis_v2[SMC_DECL_DIAG_COUNT_V2];
+ struct smc_clc_msg_trail trl; /* eye catcher "SMCD" or "SMCR" EBCDIC */
+} __aligned(4);
+
/* determine start of the prefix area within the proposal message */
static inline struct smc_clc_msg_proposal_prefix *
smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
--
2.25.1