summaryrefslogtreecommitdiffstats
path: root/net/smc/smc_clc.c
blob: b7dd2743fb5c0cfa11228b6c36b3a7fe3c53498e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
/*
 *  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 <linux/if_ether.h>
#include <linux/sched/signal.h>

#include <net/sock.h>
#include <net/tcp.h>

#include "smc.h"
#include "smc_core.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;
		if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
			smc->conn.lgr->sync_err = true;
			smc_lgr_terminate(smc->conn.lgr);
		}
	}

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)
{
	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 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 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], ETH_ALEN);

	/* 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_connection *conn = &smc->conn;
	struct smc_clc_msg_accept_confirm cclc;
	struct smc_link *link;
	int reason_code = 0;
	struct msghdr msg;
	struct kvec vec;
	int len;

	link = &conn->lgr->lnk[SMC_SINGLE_LINK];
	/* 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));
	memcpy(&cclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
	       SMC_GID_SIZE);
	memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
	hton24(cclc.qpn, link->roce_qp->qp_num);
	cclc.rmb_rkey =
		htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
	cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
	cclc.rmbe_alert_token = htonl(conn->alert_token_local);
	cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
	cclc.rmbe_size = conn->rmbe_size_short;
	cclc.rmb_dma_addr = cpu_to_be64(
		(u64)sg_dma_address(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
	hton24(cclc.psn, link->psn_initial);

	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, int srv_first_contact)
{
	struct smc_connection *conn = &new_smc->conn;
	struct smc_clc_msg_accept_confirm aclc;
	struct smc_link *link;
	struct msghdr msg;
	struct kvec vec;
	int rc = 0;
	int len;

	link = &conn->lgr->lnk[SMC_SINGLE_LINK];
	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 */
	if (srv_first_contact)
		aclc.hdr.flag = 1;
	memcpy(aclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
	memcpy(&aclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
	       SMC_GID_SIZE);
	memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
	hton24(aclc.qpn, link->roce_qp->qp_num);
	aclc.rmb_rkey =
		htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
	aclc.conn_idx = 1;			/* as long as 1 RMB = 1 RMBE */
	aclc.rmbe_alert_token = htonl(conn->alert_token_local);
	aclc.qp_mtu = link->path_mtu;
	aclc.rmbe_size = conn->rmbe_size_short,
	aclc.rmb_dma_addr = cpu_to_be64(
		(u64)sg_dma_address(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
	hton24(aclc.psn, link->psn_initial);
	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;
}