diff options
author | Chuck Lever <chuck.lever@oracle.com> | 2007-03-29 16:48:04 -0400 |
---|---|---|
committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-04-30 22:17:12 -0700 |
commit | a509050bd3b8e0aa269c2241aa10d74ca7701e2f (patch) | |
tree | 47860feb054c6c286fd10c7d19a5ed3c3efb5c32 /net | |
parent | c5a4dd8b7c15927a8fbff83171b57cad675a79b9 (diff) | |
download | linux-3.10-a509050bd3b8e0aa269c2241aa10d74ca7701e2f.tar.gz linux-3.10-a509050bd3b8e0aa269c2241aa10d74ca7701e2f.tar.bz2 linux-3.10-a509050bd3b8e0aa269c2241aa10d74ca7701e2f.zip |
SUNRPC: introduce rpcbind: replacement for in-kernel portmapper
Introduce a replacement for the in-kernel portmapper client that supports
all 3 versions of the rpcbind protocol. This code is not used yet.
Original code by Groupe Bull updated for the latest kernel, with multiple
bug fixes.
Note that rpcb_clnt.c does not yet support registering via versions 3 and
4 of the rpcbind protocol. That is planned for a later patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net')
-rw-r--r-- | net/sunrpc/Makefile | 2 | ||||
-rw-r--r-- | net/sunrpc/rpcb_clnt.c | 625 | ||||
-rw-r--r-- | net/sunrpc/xprt.c | 1 |
3 files changed, 627 insertions, 1 deletions
diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile index cdcab9ca4c6..3417a1ef1f9 100644 --- a/net/sunrpc/Makefile +++ b/net/sunrpc/Makefile @@ -9,7 +9,7 @@ obj-$(CONFIG_SUNRPC_GSS) += auth_gss/ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \ auth.o auth_null.o auth_unix.o \ svc.o svcsock.o svcauth.o svcauth_unix.o \ - pmap_clnt.o timer.o xdr.o \ + pmap_clnt.o rpcb_clnt.o timer.o xdr.o \ sunrpc_syms.o cache.o rpc_pipe.o sunrpc-$(CONFIG_PROC_FS) += stats.o sunrpc-$(CONFIG_SYSCTL) += sysctl.o diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c new file mode 100644 index 00000000000..6c7aa8a1f0c --- /dev/null +++ b/net/sunrpc/rpcb_clnt.c @@ -0,0 +1,625 @@ +/* + * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind + * protocol + * + * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and + * RFC 3530: "Network File System (NFS) version 4 Protocol" + * + * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net> + * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com> + * + * Descended from net/sunrpc/pmap_clnt.c, + * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> + */ + +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/kernel.h> +#include <linux/errno.h> + +#include <linux/sunrpc/clnt.h> +#include <linux/sunrpc/sched.h> + +#ifdef RPC_DEBUG +# define RPCDBG_FACILITY RPCDBG_BIND +#endif + +#define RPCBIND_PROGRAM (100000u) +#define RPCBIND_PORT (111u) + +enum { + RPCBPROC_NULL, + RPCBPROC_SET, + RPCBPROC_UNSET, + RPCBPROC_GETPORT, + RPCBPROC_GETADDR = 3, /* alias for GETPORT */ + RPCBPROC_DUMP, + RPCBPROC_CALLIT, + RPCBPROC_BCAST = 5, /* alias for CALLIT */ + RPCBPROC_GETTIME, + RPCBPROC_UADDR2TADDR, + RPCBPROC_TADDR2UADDR, + RPCBPROC_GETVERSADDR, + RPCBPROC_INDIRECT, + RPCBPROC_GETADDRLIST, + RPCBPROC_GETSTAT, +}; + +#define RPCB_HIGHPROC_2 RPCBPROC_CALLIT +#define RPCB_HIGHPROC_3 RPCBPROC_TADDR2UADDR +#define RPCB_HIGHPROC_4 RPCBPROC_GETSTAT + +/* + * r_addr + * + * Quoting RFC 3530, section 2.2: + * + * For TCP over IPv4 and for UDP over IPv4, the format of r_addr is the + * US-ASCII string: + * + * h1.h2.h3.h4.p1.p2 + * + * The prefix, "h1.h2.h3.h4", is the standard textual form for + * representing an IPv4 address, which is always four octets long. + * Assuming big-endian ordering, h1, h2, h3, and h4, are respectively, + * the first through fourth octets each converted to ASCII-decimal. + * Assuming big-endian ordering, p1 and p2 are, respectively, the first + * and second octets each converted to ASCII-decimal. For example, if a + * host, in big-endian order, has an address of 0x0A010307 and there is + * a service listening on, in big endian order, port 0x020F (decimal + * 527), then the complete universal address is "10.1.3.7.2.15". + * + * ... + * + * For TCP over IPv6 and for UDP over IPv6, the format of r_addr is the + * US-ASCII string: + * + * x1:x2:x3:x4:x5:x6:x7:x8.p1.p2 + * + * The suffix "p1.p2" is the service port, and is computed the same way + * as with universal addresses for TCP and UDP over IPv4. The prefix, + * "x1:x2:x3:x4:x5:x6:x7:x8", is the standard textual form for + * representing an IPv6 address as defined in Section 2.2 of [RFC2373]. + * Additionally, the two alternative forms specified in Section 2.2 of + * [RFC2373] are also acceptable. + * + * XXX: Currently this implementation does not explicitly convert the + * stored address to US-ASCII on non-ASCII systems. + */ +#define RPCB_MAXADDRLEN (128u) + +/* + * r_netid + * + * Quoting RFC 3530, section 2.2: + * + * For TCP over IPv4 the value of r_netid is the string "tcp". For UDP + * over IPv4 the value of r_netid is the string "udp". + * + * ... + * + * For TCP over IPv6 the value of r_netid is the string "tcp6". For UDP + * over IPv6 the value of r_netid is the string "udp6". + */ +#define RPCB_NETID_UDP "\165\144\160" /* "udp" */ +#define RPCB_NETID_TCP "\164\143\160" /* "tcp" */ +#define RPCB_NETID_UDP6 "\165\144\160\066" /* "udp6" */ +#define RPCB_NETID_TCP6 "\164\143\160\066" /* "tcp6" */ + +#define RPCB_MAXNETIDLEN (4u) + +/* + * r_owner + * + * The "owner" is allowed to unset a service in the rpcbind database. + * We always use the following (arbitrary) fixed string. + */ +#define RPCB_OWNER_STRING "rpcb" +#define RPCB_MAXOWNERLEN sizeof(RPCB_OWNER_STRING) + +static void rpcb_getport_done(struct rpc_task *, void *); +extern struct rpc_program rpcb_program; + +struct rpcbind_args { + struct rpc_xprt * r_xprt; + + u32 r_prog; + u32 r_vers; + u32 r_prot; + unsigned short r_port; + char * r_netid; + char r_addr[RPCB_MAXADDRLEN]; + char * r_owner; +}; + +static struct rpc_procinfo rpcb_procedures2[]; +static struct rpc_procinfo rpcb_procedures3[]; + +static struct rpcb_info { + int rpc_vers; + struct rpc_procinfo * rpc_proc; +} rpcb_next_version[]; + +static void rpcb_getport_prepare(struct rpc_task *task, void *calldata) +{ + struct rpcbind_args *map = calldata; + struct rpc_xprt *xprt = map->r_xprt; + struct rpc_message msg = { + .rpc_proc = rpcb_next_version[xprt->bind_index].rpc_proc, + .rpc_argp = map, + .rpc_resp = &map->r_port, + }; + + rpc_call_setup(task, &msg, 0); +} + +static void rpcb_map_release(void *data) +{ + struct rpcbind_args *map = data; + + xprt_put(map->r_xprt); + kfree(map); +} + +static const struct rpc_call_ops rpcb_getport_ops = { + .rpc_call_prepare = rpcb_getport_prepare, + .rpc_call_done = rpcb_getport_done, + .rpc_release = rpcb_map_release, +}; + +static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status) +{ + xprt_clear_binding(xprt); + rpc_wake_up_status(&xprt->binding, status); +} + +static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr, + int proto, int version, int privileged) +{ + struct rpc_create_args args = { + .protocol = proto, + .address = srvaddr, + .addrsize = sizeof(struct sockaddr_in), + .servername = hostname, + .program = &rpcb_program, + .version = version, + .authflavor = RPC_AUTH_UNIX, + .flags = (RPC_CLNT_CREATE_ONESHOT | + RPC_CLNT_CREATE_NOPING), + }; + + ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT); + if (!privileged) + args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; + return rpc_create(&args); +} + +/** + * rpcb_register - set or unset a port registration with the local rpcbind svc + * @prog: RPC program number to bind + * @vers: RPC version number to bind + * @prot: transport protocol to use to make this request + * @port: port value to register + * @okay: result code + * + * port == 0 means unregister, port != 0 means register. + * + * This routine supports only rpcbind version 2. + */ +int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay) +{ + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_LOOPBACK), + }; + struct rpcbind_args map = { + .r_prog = prog, + .r_vers = vers, + .r_prot = prot, + .r_port = port, + }; + struct rpc_message msg = { + .rpc_proc = &rpcb_procedures2[port ? + RPCBPROC_SET : RPCBPROC_UNSET], + .rpc_argp = &map, + .rpc_resp = okay, + }; + struct rpc_clnt *rpcb_clnt; + int error = 0; + + dprintk("RPC: %sregistering (%u, %u, %d, %u) with local " + "rpcbind\n", (port ? "" : "un"), + prog, vers, prot, port); + + rpcb_clnt = rpcb_create("localhost", (struct sockaddr *) &sin, + IPPROTO_UDP, 2, 1); + if (IS_ERR(rpcb_clnt)) + return PTR_ERR(rpcb_clnt); + + error = rpc_call_sync(rpcb_clnt, &msg, 0); + + if (error < 0) + printk(KERN_WARNING "RPC: failed to contact local rpcbind " + "server (errno %d).\n", -error); + dprintk("RPC: registration status %d/%d\n", error, *okay); + + return error; +} + +#ifdef CONFIG_ROOT_NFS +/** + * rpcb_getport_external - obtain the port for an RPC service on a given host + * @sin: address of remote peer + * @prog: RPC program number to bind + * @vers: RPC version number to bind + * @prot: transport protocol to use to make this request + * + * Called from outside the RPC client in a synchronous task context. + * + * For now, this supports only version 2 queries, but is used only by + * mount_clnt for NFS_ROOT. + */ +int rpcb_getport_external(struct sockaddr_in *sin, __u32 prog, + __u32 vers, int prot) +{ + struct rpcbind_args map = { + .r_prog = prog, + .r_vers = vers, + .r_prot = prot, + .r_port = 0, + }; + struct rpc_message msg = { + .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT], + .rpc_argp = &map, + .rpc_resp = &map.r_port, + }; + struct rpc_clnt *rpcb_clnt; + char hostname[40]; + int status; + + dprintk("RPC: rpcb_getport_external(%u.%u.%u.%u, %u, %u, %d)\n", + NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot); + + sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(sin->sin_addr.s_addr)); + rpcb_clnt = rpcb_create(hostname, (struct sockaddr *)sin, prot, 2, 0); + if (IS_ERR(rpcb_clnt)) + return PTR_ERR(rpcb_clnt); + + status = rpc_call_sync(rpcb_clnt, &msg, 0); + + if (status >= 0) { + if (map.r_port != 0) + return map.r_port; + status = -EACCES; + } + return status; +} +#endif + +/** + * rpcb_getport - obtain the port for a given RPC service on a given host + * @task: task that is waiting for portmapper request + * + * This one can be called for an ongoing RPC request, and can be used in + * an async (rpciod) context. + */ +void rpcb_getport(struct rpc_task *task) +{ + struct rpc_clnt *clnt = task->tk_client; + int bind_version; + struct rpc_xprt *xprt = task->tk_xprt; + struct rpc_clnt *rpcb_clnt; + static struct rpcbind_args *map; + struct rpc_task *child; + struct sockaddr addr; + int status; + + dprintk("RPC: %5u rpcb_getport(%s, %u, %u, %d)\n", + task->tk_pid, clnt->cl_server, + clnt->cl_prog, clnt->cl_vers, xprt->prot); + + /* Autobind on cloned rpc clients is discouraged */ + BUG_ON(clnt->cl_parent != clnt); + + if (xprt_test_and_set_binding(xprt)) { + status = -EACCES; /* tell caller to check again */ + dprintk("RPC: %5u rpcb_getport waiting for another binder\n", + task->tk_pid); + goto bailout_nowake; + } + + /* Put self on queue before sending rpcbind request, in case + * rpcb_getport_done completes before we return from rpc_run_task */ + rpc_sleep_on(&xprt->binding, task, NULL, NULL); + + /* Someone else may have bound if we slept */ + if (xprt_bound(xprt)) { + status = 0; + dprintk("RPC: %5u rpcb_getport already bound\n", task->tk_pid); + goto bailout_nofree; + } + + if (rpcb_next_version[xprt->bind_index].rpc_proc == NULL) { + xprt->bind_index = 0; + status = -EACCES; /* tell caller to try again later */ + dprintk("RPC: %5u rpcb_getport no more getport versions " + "available\n", task->tk_pid); + goto bailout_nofree; + } + bind_version = rpcb_next_version[xprt->bind_index].rpc_vers; + + dprintk("RPC: %5u rpcb_getport trying rpcbind version %u\n", + task->tk_pid, bind_version); + + map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC); + if (!map) { + status = -ENOMEM; + dprintk("RPC: %5u rpcb_getport no memory available\n", + task->tk_pid); + goto bailout_nofree; + } + map->r_prog = clnt->cl_prog; + map->r_vers = clnt->cl_vers; + map->r_prot = xprt->prot; + map->r_port = 0; + map->r_xprt = xprt_get(xprt); + map->r_netid = (xprt->prot == IPPROTO_TCP) ? RPCB_NETID_TCP : + RPCB_NETID_UDP; + memcpy(&map->r_addr, rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR), + sizeof(map->r_addr)); + map->r_owner = RPCB_OWNER_STRING; /* ignored for GETADDR */ + + rpc_peeraddr(clnt, (void *)&addr, sizeof(addr)); + rpcb_clnt = rpcb_create(clnt->cl_server, &addr, xprt->prot, bind_version, 0); + if (IS_ERR(rpcb_clnt)) { + status = PTR_ERR(rpcb_clnt); + dprintk("RPC: %5u rpcb_getport rpcb_create failed, error %ld\n", + task->tk_pid, PTR_ERR(rpcb_clnt)); + goto bailout; + } + + child = rpc_run_task(rpcb_clnt, RPC_TASK_ASYNC, &rpcb_getport_ops, map); + if (IS_ERR(child)) { + status = -EIO; + dprintk("RPC: %5u rpcb_getport rpc_run_task failed\n", + task->tk_pid); + goto bailout_nofree; + } + rpc_put_task(child); + + task->tk_xprt->stat.bind_count++; + return; + +bailout: + kfree(map); + xprt_put(xprt); +bailout_nofree: + rpcb_wake_rpcbind_waiters(xprt, status); +bailout_nowake: + task->tk_status = status; +} + +/* + * Rpcbind child task calls this callback via tk_exit. + */ +static void rpcb_getport_done(struct rpc_task *child, void *data) +{ + struct rpcbind_args *map = data; + struct rpc_xprt *xprt = map->r_xprt; + int status = child->tk_status; + + /* rpcbind server doesn't support this rpcbind protocol version */ + if (status == -EPROTONOSUPPORT) + xprt->bind_index++; + + if (status < 0) { + /* rpcbind server not available on remote host? */ + xprt->ops->set_port(xprt, 0); + } else if (map->r_port == 0) { + /* Requested RPC service wasn't registered on remote host */ + xprt->ops->set_port(xprt, 0); + status = -EACCES; + } else { + /* Succeeded */ + xprt->ops->set_port(xprt, map->r_port); + xprt_set_bound(xprt); + status = 0; + } + + dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n", + child->tk_pid, status, map->r_port); + + rpcb_wake_rpcbind_waiters(xprt, status); +} + +static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p, + struct rpcbind_args *rpcb) +{ + dprintk("RPC: rpcb_encode_mapping(%u, %u, %d, %u)\n", + rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port); + *p++ = htonl(rpcb->r_prog); + *p++ = htonl(rpcb->r_vers); + *p++ = htonl(rpcb->r_prot); + *p++ = htonl(rpcb->r_port); + + req->rq_slen = xdr_adjust_iovec(req->rq_svec, p); + return 0; +} + +static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p, + unsigned short *portp) +{ + *portp = (unsigned short) ntohl(*p++); + dprintk("RPC: rpcb_decode_getport result %u\n", + *portp); + return 0; +} + +static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p, + unsigned int *boolp) +{ + *boolp = (unsigned int) ntohl(*p++); + dprintk("RPC: rpcb_decode_set result %u\n", + *boolp); + return 0; +} + +static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p, + struct rpcbind_args *rpcb) +{ + dprintk("RPC: rpcb_encode_getaddr(%u, %u, %s)\n", + rpcb->r_prog, rpcb->r_vers, rpcb->r_addr); + *p++ = htonl(rpcb->r_prog); + *p++ = htonl(rpcb->r_vers); + + p = xdr_encode_string(p, rpcb->r_netid); + p = xdr_encode_string(p, rpcb->r_addr); + p = xdr_encode_string(p, rpcb->r_owner); + + req->rq_slen = xdr_adjust_iovec(req->rq_svec, p); + + return 0; +} + +static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p, + unsigned short *portp) +{ + char *addr; + int addr_len, c, i, f, first, val; + + *portp = 0; + addr_len = (unsigned int) ntohl(*p++); + if (addr_len > RPCB_MAXADDRLEN) /* sanity */ + return -EINVAL; + + dprintk("RPC: rpcb_decode_getaddr returned string: '%s'\n", + (char *) p); + + addr = (char *)p; + val = 0; + first = 1; + f = 1; + for (i = addr_len - 1; i > 0; i--) { + c = addr[i]; + if (c >= '0' && c <= '9') { + val += (c - '0') * f; + f *= 10; + } else if (c == '.') { + if (first) { + *portp = val; + val = first = 0; + f = 1; + } else { + *portp |= (val << 8); + break; + } + } + } + + dprintk("RPC: rpcb_decode_getaddr port=%u\n", *portp); + return 0; +} + +#define RPCB_program_sz (1u) +#define RPCB_version_sz (1u) +#define RPCB_protocol_sz (1u) +#define RPCB_port_sz (1u) +#define RPCB_boolean_sz (1u) + +#define RPCB_netid_sz (1+XDR_QUADLEN(RPCB_MAXNETIDLEN)) +#define RPCB_addr_sz (1+XDR_QUADLEN(RPCB_MAXADDRLEN)) +#define RPCB_ownerstring_sz (1+XDR_QUADLEN(RPCB_MAXOWNERLEN)) + +#define RPCB_mappingargs_sz RPCB_program_sz+RPCB_version_sz+ \ + RPCB_protocol_sz+RPCB_port_sz +#define RPCB_getaddrargs_sz RPCB_program_sz+RPCB_version_sz+ \ + RPCB_netid_sz+RPCB_addr_sz+ \ + RPCB_ownerstring_sz + +#define RPCB_setres_sz RPCB_boolean_sz +#define RPCB_getportres_sz RPCB_port_sz + +/* + * Note that RFC 1833 does not put any size restrictions on the + * address string returned by the remote rpcbind database. + */ +#define RPCB_getaddrres_sz RPCB_addr_sz + +#define PROC(proc, argtype, restype) \ + [RPCBPROC_##proc] = { \ + .p_proc = RPCBPROC_##proc, \ + .p_encode = (kxdrproc_t) rpcb_encode_##argtype, \ + .p_decode = (kxdrproc_t) rpcb_decode_##restype, \ + .p_arglen = RPCB_##argtype##args_sz, \ + .p_replen = RPCB_##restype##res_sz, \ + .p_statidx = RPCBPROC_##proc, \ + .p_timer = 0, \ + .p_name = #proc, \ + } + +/* + * Not all rpcbind procedures described in RFC 1833 are implemented + * since the Linux kernel RPC code requires only these. + */ +static struct rpc_procinfo rpcb_procedures2[] = { + PROC(SET, mapping, set), + PROC(UNSET, mapping, set), + PROC(GETADDR, mapping, getport), +}; + +static struct rpc_procinfo rpcb_procedures3[] = { + PROC(SET, mapping, set), + PROC(UNSET, mapping, set), + PROC(GETADDR, getaddr, getaddr), +}; + +static struct rpc_procinfo rpcb_procedures4[] = { + PROC(SET, mapping, set), + PROC(UNSET, mapping, set), + PROC(GETVERSADDR, getaddr, getaddr), +}; + +static struct rpcb_info rpcb_next_version[] = { +#ifdef CONFIG_SUNRPC_BIND34 + { 4, &rpcb_procedures4[RPCBPROC_GETVERSADDR] }, + { 3, &rpcb_procedures3[RPCBPROC_GETADDR] }, +#endif + { 2, &rpcb_procedures2[RPCBPROC_GETPORT] }, + { 0, NULL }, +}; + +static struct rpc_version rpcb_version2 = { + .number = 2, + .nrprocs = RPCB_HIGHPROC_2, + .procs = rpcb_procedures2 +}; + +static struct rpc_version rpcb_version3 = { + .number = 3, + .nrprocs = RPCB_HIGHPROC_3, + .procs = rpcb_procedures3 +}; + +static struct rpc_version rpcb_version4 = { + .number = 4, + .nrprocs = RPCB_HIGHPROC_4, + .procs = rpcb_procedures4 +}; + +static struct rpc_version *rpcb_version[] = { + NULL, + NULL, + &rpcb_version2, + &rpcb_version3, + &rpcb_version4 +}; + +static struct rpc_stat rpcb_stats; + +struct rpc_program rpcb_program = { + .name = "rpcbind", + .number = RPCBIND_PROGRAM, + .nrvers = ARRAY_SIZE(rpcb_version), + .version = rpcb_version, + .stats = &rpcb_stats, +}; diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 81fe830da8a..5b05b73e4c1 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -927,6 +927,7 @@ struct rpc_xprt *xprt_create_transport(int proto, struct sockaddr *ap, size_t si xprt->timer.data = (unsigned long) xprt; xprt->last_used = jiffies; xprt->cwnd = RPC_INITCWND; + xprt->bind_index = 0; rpc_init_wait_queue(&xprt->binding, "xprt_binding"); rpc_init_wait_queue(&xprt->pending, "xprt_pending"); |