From 366bb249b58381bc415a83608859019736b23766 Mon Sep 17 00:00:00 2001 From: Hans Wippel Date: Tue, 25 Feb 2020 22:41:21 +0100 Subject: [PATCH 1/2] net/smc: rework peer ID handling This patch initializes the peer ID to a random instance ID and a zero MAC address. If a RoCE device is in the host, the MAC address part of the peer ID is overwritten with the respective address. Also, a function for checking if the peer ID is valid is added. A peer ID is considered valid if the MAC address part contains a non-zero MAC address. Signed-off-by: Hans Wippel Signed-off-by: David S. Miller --- net/smc/smc_ib.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index 6756bd5a3fe4b..e0592d337a948 100644 --- a/net/smc/smc_ib.c +++ b/net/smc/smc_ib.c @@ -37,11 +37,7 @@ struct smc_ib_devices smc_ib_devices = { /* smc-registered ib devices */ .list = LIST_HEAD_INIT(smc_ib_devices.list), }; -#define SMC_LOCAL_SYSTEMID_RESET "%%%%%%%" - -u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system - * identifier - */ +u8 local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */ static int smc_ib_modify_qp_init(struct smc_link *lnk) { @@ -168,6 +164,15 @@ static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev, { memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1], sizeof(smcibdev->mac[ibport - 1])); +} + +static bool smc_ib_is_valid_local_systemid(void) +{ + return !is_zero_ether_addr(&local_systemid[2]); +} + +static void smc_ib_init_local_systemid(void) +{ get_random_bytes(&local_systemid[0], 2); } @@ -224,8 +229,7 @@ static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport) rc = smc_ib_fill_mac(smcibdev, ibport); if (rc) goto out; - if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET, - sizeof(local_systemid)) && + if (!smc_ib_is_valid_local_systemid() && smc_ib_port_active(smcibdev, ibport)) /* create unique system identifier */ smc_ib_define_local_systemid(smcibdev, ibport); @@ -605,6 +609,7 @@ static struct ib_client smc_ib_client = { int __init smc_ib_register_client(void) { + smc_ib_init_local_systemid(); return ib_register_client(&smc_ib_client); } From a082ec897ffed754aae39a9665af161f1a6fa44b Mon Sep 17 00:00:00 2001 From: Hans Wippel Date: Tue, 25 Feb 2020 22:41:22 +0100 Subject: [PATCH 2/2] net/smc: improve peer ID in CLC decline for SMC-R According to RFC 7609, all CLC messages contain a peer ID that consists of a unique instance ID and the MAC address of one of the host's RoCE devices. But if a SMC-R connection cannot be established, e.g., because no matching pnet table entry is found, the current implementation uses a zero value in the CLC decline message although the host's peer ID is set to a proper value. If no RoCE and no ISM device is usable for a connection, there is no LGR and the LGR check in smc_clc_send_decline() prevents that the peer ID is copied into the CLC decline message for both SMC-D and SMC-R. So, this patch modifies the check to also accept the case of no LGR. Also, only a valid peer ID is copied into the decline message. Signed-off-by: Hans Wippel Signed-off-by: David S. Miller --- net/smc/smc_clc.c | 3 ++- net/smc/smc_ib.c | 2 +- net/smc/smc_ib.h | 1 + 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index 3e16b887cfcf1..ea0068f0173c1 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -372,7 +372,8 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info) 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; - if (smc->conn.lgr && !smc->conn.lgr->is_smcd) + if ((!smc->conn.lgr || !smc->conn.lgr->is_smcd) && + smc_ib_is_valid_local_systemid()) memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid)); dclc.peer_diagnosis = htonl(peer_diag_info); diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index e0592d337a948..3444de27fecd0 100644 --- a/net/smc/smc_ib.c +++ b/net/smc/smc_ib.c @@ -166,7 +166,7 @@ static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev, sizeof(smcibdev->mac[ibport - 1])); } -static bool smc_ib_is_valid_local_systemid(void) +bool smc_ib_is_valid_local_systemid(void) { return !is_zero_ether_addr(&local_systemid[2]); } diff --git a/net/smc/smc_ib.h b/net/smc/smc_ib.h index 255db87547d32..5c2b115d36daa 100644 --- a/net/smc/smc_ib.h +++ b/net/smc/smc_ib.h @@ -84,4 +84,5 @@ void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev, enum dma_data_direction data_direction); int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport, unsigned short vlan_id, u8 gid[], u8 *sgid_index); +bool smc_ib_is_valid_local_systemid(void); #endif