From: Trond Myklebust trond.myklebust@hammerspace.com

mainline inclusion from mainline-v5.5-rc1 commit e6237b6feb37582fbd6bd7a8336d1256a6b4b4f9 category: bugfix bugzilla: NA CVE: NA

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NFSv2, v3 and NFSv4 servers often have duplicate replay caches that look at the source port when deciding whether or not an RPC call is a replay of a previous call. This requires clients to perform strange TCP gymnastics in order to ensure that when they reconnect to the server, they bind to the same source port.

NFSv4.1 and NFSv4.2 have sessions that provide proper replay semantics, that do not look at the source port of the connection. This patch therefore ensures they can ignore the rebind requirement.

Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com

Conflicts: fs/lockd/host.c fs/nfs/client.c fs/nfs/nfs4client.c include/linux/nfs_fs_sb.h include/linux/sunrpc/clnt.h

Signed-off-by: Zhang Xiaoxu zhangxiaoxu5@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/lockd/host.c | 3 ++- fs/nfs/client.c | 3 +++ fs/nfs/nfs4client.c | 3 +++ include/linux/nfs_fs_sb.h | 1 + include/linux/sunrpc/clnt.h | 1 + include/linux/sunrpc/xprt.h | 3 ++- net/sunrpc/clnt.c | 7 ++++++- net/sunrpc/xprtsock.c | 2 +- 8 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/fs/lockd/host.c b/fs/lockd/host.c index 3f6ba0cd2bd9c..6d58f53555893 100644 --- a/fs/lockd/host.c +++ b/fs/lockd/host.c @@ -452,7 +452,8 @@ nlm_bind_host(struct nlm_host *host) .version = host->h_version, .authflavor = RPC_AUTH_UNIX, .flags = (RPC_CLNT_CREATE_NOPING | - RPC_CLNT_CREATE_AUTOBIND), + RPC_CLNT_CREATE_AUTOBIND | + RPC_CLNT_CREATE_REUSEPORT), };

/* diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 07c5ddd5d6d50..d25230de31364 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -522,6 +522,8 @@ int nfs_create_rpc_client(struct nfs_client *clp, args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags)) args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS; + if (test_bit(NFS_CS_REUSEPORT, &clp->cl_flags)) + args.flags |= RPC_CLNT_CREATE_REUSEPORT;

if (!IS_ERR(clp->cl_rpcclient)) return 0; @@ -663,6 +665,7 @@ static int nfs_init_server(struct nfs_server *server, .proto = data->nfs_server.protocol, .net = data->net, .timeparms = &timeparms, + .init_flags = (1UL << NFS_CS_REUSEPORT), }; struct nfs_client *clp; int error; diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index faaabbedc891d..48a1892f05854 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -872,6 +872,9 @@ static int nfs4_set_client(struct nfs_server *server, }; struct nfs_client *clp;

+ if (minorversion == 0) + __set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags); + if (server->flags & NFS_MOUNT_NORESVPORT) set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags); if (server->options & NFS_OPTION_MIGRATION) diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index bf39d9c92201f..7023ae64e3d7c 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -45,6 +45,7 @@ struct nfs_client { #define NFS_CS_INFINITE_SLOTS 3 /* - don't limit TCP slots */ #define NFS_CS_NO_RETRANS_TIMEOUT 4 /* - Disable retransmit timeouts */ #define NFS_CS_TSM_POSSIBLE 5 /* - Maybe state migration */ +#define NFS_CS_REUSEPORT 8 /* - reuse src port on reconnect */ struct sockaddr_storage cl_addr; /* server identifier */ size_t cl_addrlen; char * cl_hostname; /* hostname of server */ diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 73d5c4a870fae..60b6489e5ac1b 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -143,6 +143,7 @@ struct rpc_add_xprt_test { #define RPC_CLNT_CREATE_INFINITE_SLOTS (1UL << 7) #define RPC_CLNT_CREATE_NO_IDLE_TIMEOUT (1UL << 8) #define RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT (1UL << 9) +#define RPC_CLNT_CREATE_REUSEPORT (1UL << 11)

struct rpc_clnt *rpc_create(struct rpc_create_args *args); struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *, diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 69fed13e633b7..36a944dda1957 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -200,7 +200,8 @@ struct rpc_xprt { unsigned int min_reqs; /* min number of slots */ unsigned int num_reqs; /* total slots */ unsigned long state; /* transport state */ - unsigned char resvport : 1; /* use a reserved port */ + unsigned char resvport : 1, /* use a reserved port */ + reuseport : 1; /* reuse port on reconnect */ atomic_t swapper; /* we're swapping over this transport */ unsigned int bind_index; /* bind function index */ diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 227bf32f2476b..9ac94c774335e 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -583,6 +583,9 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args) xprt->resvport = 1; if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT) xprt->resvport = 0; + xprt->reuseport = 0; + if (args->flags & RPC_CLNT_CREATE_REUSEPORT) + xprt->reuseport = 1;

return rpc_create_xprt(args, xprt); } @@ -2730,7 +2733,7 @@ int rpc_clnt_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt; unsigned long connect_timeout; unsigned long reconnect_timeout; - unsigned char resvport; + unsigned char resvport, reuseport; int ret = 0;

rcu_read_lock(); @@ -2742,6 +2745,7 @@ int rpc_clnt_add_xprt(struct rpc_clnt *clnt, return -EAGAIN; } resvport = xprt->resvport; + reuseport = xprt->reuseport; connect_timeout = xprt->connect_timeout; reconnect_timeout = xprt->max_reconnect_timeout; rcu_read_unlock(); @@ -2752,6 +2756,7 @@ int rpc_clnt_add_xprt(struct rpc_clnt *clnt, goto out_put_switch; } xprt->resvport = resvport; + xprt->reuseport = reuseport; if (xprt->ops->set_connect_timeout != NULL) xprt->ops->set_connect_timeout(xprt, connect_timeout, diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 60ebb402ba61f..f93d386ae9232 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1839,7 +1839,7 @@ static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)

static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock) { - if (transport->srcport == 0) + if (transport->srcport == 0 && transport->xprt.reuseport) transport->srcport = xs_sock_getport(sock); }