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>
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
new file mode 100644
index 0000000..6c7aa8a
--- /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,
+};