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authorUrsula Braun <ubraun@linux.vnet.ibm.com>2017-01-09 16:55:16 +0100
committerDavid S. Miller <davem@davemloft.net>2017-01-09 16:07:39 -0500
commita046d57da19f812216f393e7c535f5858f793ac3 (patch)
tree9b3c535ff6cd3da3cf06b3164cd727839df25f38 /net/smc/smc_clc.c
parent6812baabf24d5c299c13223366a23c269408f4d0 (diff)
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smc: CLC handshake (incl. preparation steps)
* CLC (Connection Layer Control) handshake Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/smc/smc_clc.c')
-rw-r--r--net/smc/smc_clc.c252
1 files changed, 252 insertions, 0 deletions
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
new file mode 100644
index 000000000000..b613b866a2ef
--- /dev/null
+++ b/net/smc/smc_clc.c
@@ -0,0 +1,252 @@
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * CLC (connection layer control) handshake over initial TCP socket to
+ * prepare for RDMA traffic
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/in.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+
+#include "smc.h"
+#include "smc_clc.h"
+#include "smc_ib.h"
+
+/* Wait for data on the tcp-socket, analyze received data
+ * Returns:
+ * 0 if success and it was not a decline that we received.
+ * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
+ * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
+ */
+int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
+ u8 expected_type)
+{
+ struct sock *clc_sk = smc->clcsock->sk;
+ struct smc_clc_msg_hdr *clcm = buf;
+ struct msghdr msg = {NULL, 0};
+ int reason_code = 0;
+ struct kvec vec;
+ int len, datlen;
+ int krflags;
+
+ /* peek the first few bytes to determine length of data to receive
+ * so we don't consume any subsequent CLC message or payload data
+ * in the TCP byte stream
+ */
+ vec.iov_base = buf;
+ vec.iov_len = buflen;
+ krflags = MSG_PEEK | MSG_WAITALL;
+ smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
+ len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1,
+ sizeof(struct smc_clc_msg_hdr), krflags);
+ if (signal_pending(current)) {
+ reason_code = -EINTR;
+ clc_sk->sk_err = EINTR;
+ smc->sk.sk_err = EINTR;
+ goto out;
+ }
+ if (clc_sk->sk_err) {
+ reason_code = -clc_sk->sk_err;
+ smc->sk.sk_err = clc_sk->sk_err;
+ goto out;
+ }
+ if (!len) { /* peer has performed orderly shutdown */
+ smc->sk.sk_err = ECONNRESET;
+ reason_code = -ECONNRESET;
+ goto out;
+ }
+ if (len < 0) {
+ smc->sk.sk_err = -len;
+ reason_code = len;
+ goto out;
+ }
+ datlen = ntohs(clcm->length);
+ if ((len < sizeof(struct smc_clc_msg_hdr)) ||
+ (datlen < sizeof(struct smc_clc_msg_decline)) ||
+ (datlen > sizeof(struct smc_clc_msg_accept_confirm)) ||
+ memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) ||
+ ((clcm->type != SMC_CLC_DECLINE) &&
+ (clcm->type != expected_type))) {
+ smc->sk.sk_err = EPROTO;
+ reason_code = -EPROTO;
+ goto out;
+ }
+
+ /* receive the complete CLC message */
+ vec.iov_base = buf;
+ vec.iov_len = buflen;
+ memset(&msg, 0, sizeof(struct msghdr));
+ krflags = MSG_WAITALL;
+ smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
+ len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1, datlen, krflags);
+ if (len < datlen) {
+ smc->sk.sk_err = EPROTO;
+ reason_code = -EPROTO;
+ goto out;
+ }
+ if (clcm->type == SMC_CLC_DECLINE)
+ reason_code = SMC_CLC_DECL_REPLY;
+out:
+ return reason_code;
+}
+
+/* send CLC DECLINE message across internal TCP socket */
+int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info,
+ u8 out_of_sync)
+{
+ struct smc_clc_msg_decline dclc;
+ struct msghdr msg;
+ struct kvec vec;
+ int len;
+
+ 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 = SMC_CLC_V1;
+ dclc.hdr.flag = out_of_sync ? 1 : 0;
+ 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));
+
+ 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 < sizeof(struct smc_clc_msg_decline))
+ smc->sk.sk_err = EPROTO;
+ if (len < 0)
+ smc->sk.sk_err = -len;
+ return len;
+}
+
+/* send CLC PROPOSAL message across internal TCP socket */
+int smc_clc_send_proposal(struct smc_sock *smc,
+ struct smc_ib_device *smcibdev,
+ u8 ibport)
+{
+ struct smc_clc_msg_proposal pclc;
+ int reason_code = 0;
+ struct msghdr msg;
+ struct kvec vec;
+ int len, rc;
+
+ /* send SMC Proposal CLC message */
+ memset(&pclc, 0, sizeof(pclc));
+ memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+ pclc.hdr.type = SMC_CLC_PROPOSAL;
+ pclc.hdr.length = htons(sizeof(pclc));
+ pclc.hdr.version = SMC_CLC_V1; /* SMC version */
+ memcpy(pclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
+ memcpy(&pclc.lcl.gid, &smcibdev->gid[ibport - 1], SMC_GID_SIZE);
+ memcpy(&pclc.lcl.mac, &smcibdev->mac[ibport - 1],
+ sizeof(smcibdev->mac[ibport - 1]));
+
+ /* determine subnet and mask from internal TCP socket */
+ rc = smc_netinfo_by_tcpsk(smc->clcsock, &pclc.outgoing_subnet,
+ &pclc.prefix_len);
+ if (rc)
+ return SMC_CLC_DECL_CNFERR; /* configuration error */
+ memcpy(pclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+ memset(&msg, 0, sizeof(msg));
+ vec.iov_base = &pclc;
+ vec.iov_len = sizeof(pclc);
+ /* due to the few bytes needed for clc-handshake this cannot block */
+ len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(pclc));
+ if (len < sizeof(pclc)) {
+ if (len >= 0) {
+ reason_code = -ENETUNREACH;
+ smc->sk.sk_err = -reason_code;
+ } else {
+ smc->sk.sk_err = smc->clcsock->sk->sk_err;
+ reason_code = -smc->sk.sk_err;
+ }
+ }
+
+ return reason_code;
+}
+
+/* send CLC CONFIRM message across internal TCP socket */
+int smc_clc_send_confirm(struct smc_sock *smc)
+{
+ struct smc_clc_msg_accept_confirm cclc;
+ int reason_code = 0;
+ struct msghdr msg;
+ struct kvec vec;
+ int len;
+
+ /* send SMC Confirm CLC msg */
+ memset(&cclc, 0, sizeof(cclc));
+ memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+ cclc.hdr.type = SMC_CLC_CONFIRM;
+ cclc.hdr.length = htons(sizeof(cclc));
+ cclc.hdr.version = SMC_CLC_V1; /* SMC version */
+ memcpy(cclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
+
+ /* tbd in follow-on patch: fill in link-related values */
+
+ /* tbd in follow-on patch: fill in rmb-related values */
+
+ cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
+
+ memcpy(cclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+
+ memset(&msg, 0, sizeof(msg));
+ vec.iov_base = &cclc;
+ vec.iov_len = sizeof(cclc);
+ len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(cclc));
+ if (len < sizeof(cclc)) {
+ if (len >= 0) {
+ reason_code = -ENETUNREACH;
+ smc->sk.sk_err = -reason_code;
+ } else {
+ smc->sk.sk_err = smc->clcsock->sk->sk_err;
+ reason_code = -smc->sk.sk_err;
+ }
+ }
+ return reason_code;
+}
+
+/* send CLC ACCEPT message across internal TCP socket */
+int smc_clc_send_accept(struct smc_sock *new_smc)
+{
+ struct smc_clc_msg_accept_confirm aclc;
+ struct msghdr msg;
+ struct kvec vec;
+ int rc = 0;
+ int len;
+
+ memset(&aclc, 0, sizeof(aclc));
+ memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+ aclc.hdr.type = SMC_CLC_ACCEPT;
+ aclc.hdr.length = htons(sizeof(aclc));
+ aclc.hdr.version = SMC_CLC_V1; /* SMC version */
+ memcpy(aclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
+
+ /* tbd in follow-on patch: fill in link-related values */
+
+ /* tbd in follow-on patch: fill in rmb-related values */
+
+ aclc.conn_idx = 1; /* as long as 1 RMB = 1 RMBE */
+ memcpy(aclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+
+ memset(&msg, 0, sizeof(msg));
+ vec.iov_base = &aclc;
+ vec.iov_len = sizeof(aclc);
+ len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1, sizeof(aclc));
+ if (len < sizeof(aclc)) {
+ if (len >= 0)
+ new_smc->sk.sk_err = EPROTO;
+ else
+ new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
+ rc = sock_error(&new_smc->sk);
+ }
+
+ return rc;
+}