linux/net/smc/smc_clc.c
Ursula Braun 263eec9b2a smc: switch to usage of IB_PD_UNSAFE_GLOBAL_RKEY
Currently, SMC enables remote access to physical memory when a user
has successfully configured and established an SMC-connection until ten
minutes after the last SMC connection is closed. Because this is considered
a security risk, drivers are supposed to use IB_PD_UNSAFE_GLOBAL_RKEY in
such a case.

This patch changes the current SMC code to use IB_PD_UNSAFE_GLOBAL_RKEY.
This improves user awareness, but does not remove the security risk itself.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-16 14:49:42 -04:00

283 lines
8.5 KiB
C

/*
* 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 (ntohl(((struct smc_clc_msg_decline *)buf)->peer_diagnosis)
== SMC_CLC_DECL_SYNCERR)
smc->conn.lgr->sync_err = true;
}
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], 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->rkey[SMC_SINGLE_LINK]);
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)conn->rmb_desc->dma_addr[SMC_SINGLE_LINK]);
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->rkey[SMC_SINGLE_LINK]);
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)conn->rmb_desc->dma_addr[SMC_SINGLE_LINK]);
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;
}