Partially revert "net/smc: Add netlink net namespace support"

The change of sizeof(struct smc_diag_linkinfo) by commit 79d39fc503
("net/smc: Add netlink net namespace support") introduced an ABI
regression: since struct smc_diag_lgrinfo contains an object of
type "struct smc_diag_linkinfo", offset of all subsequent members
of struct smc_diag_lgrinfo was changed by that change.

As result, applications compiled with the old version
of struct smc_diag_linkinfo will receive garbage in
struct smc_diag_lgrinfo.role if the kernel implements
this new version of struct smc_diag_linkinfo.

Fix this regression by reverting the part of commit 79d39fc503 that
changes struct smc_diag_linkinfo.  After all, there is SMC_GEN_NETLINK
interface which is good enough, so there is probably no need to touch
the smc_diag ABI in the first place.

Fixes: 79d39fc503 ("net/smc: Add netlink net namespace support")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20220202030904.GA9742@altlinux.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Dmitry V. Levin 2022-02-02 06:09:04 +03:00 committed by Jakub Kicinski
parent c8ff576e4e
commit c86d86131a
2 changed files with 5 additions and 8 deletions

View File

@ -89,7 +89,6 @@ struct smc_diag_linkinfo {
__u8 ibport; /* RDMA device port number */ __u8 ibport; /* RDMA device port number */
__u8 gid[40]; /* local GID */ __u8 gid[40]; /* local GID */
__u8 peer_gid[40]; /* peer GID */ __u8 peer_gid[40]; /* peer GID */
__aligned_u64 net_cookie; /* RDMA device net namespace */
}; };
struct smc_diag_lgrinfo { struct smc_diag_lgrinfo {

View File

@ -146,13 +146,11 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb,
(req->diag_ext & (1 << (SMC_DIAG_LGRINFO - 1))) && (req->diag_ext & (1 << (SMC_DIAG_LGRINFO - 1))) &&
!list_empty(&smc->conn.lgr->list)) { !list_empty(&smc->conn.lgr->list)) {
struct smc_link *link = smc->conn.lnk; struct smc_link *link = smc->conn.lnk;
struct net *net = read_pnet(&link->smcibdev->ibdev->coredev.rdma_net);
struct smc_diag_lgrinfo linfo = { struct smc_diag_lgrinfo linfo = {
.role = smc->conn.lgr->role, .role = smc->conn.lgr->role,
.lnk[0].ibport = link->ibport, .lnk[0].ibport = link->ibport,
.lnk[0].link_id = link->link_id, .lnk[0].link_id = link->link_id,
.lnk[0].net_cookie = net->net_cookie,
}; };
memcpy(linfo.lnk[0].ibname, memcpy(linfo.lnk[0].ibname,