/*
* Use the portmapper to discover whether or not the service we want is
* available. The lists 'versions' and 'protos' define ordered sequences
* of service versions and udp/tcp protocols to probe for.
*
* Returns 1 if the requested service port is unambiguous and pingable;
* @pmap is filled in with the version, port, and transport protocol used
* during the successful ping. Note that if a port is already specified
* in @pmap and it matches the rpcbind query result, nfs_probe_port() does
* not perform an RPC ping.
*
* If an error occurs or the requested service isn't available, zero is
* returned; rpccreateerr.cf_stat is set to reflect the nature of the error.
*/
static int nfs_probe_port(const struct sockaddr *sap, const socklen_t salen,
struct pmap *pmap, const unsigned long *versions,
const unsigned int *protos)
{
struct sockaddr_storage address;
struct sockaddr *saddr = (struct sockaddr *)&address;
const unsigned long prog = pmap->pm_prog, *p_vers;
const unsigned int prot = (u_int)pmap->pm_prot, *p_prot;
const u_short port = (u_short) pmap->pm_port;
unsigned long vers = pmap->pm_vers;
unsigned short p_port;
memcpy(saddr, sap, salen);
p_prot = prot ? &prot : protos;
p_vers = vers ? &vers : versions;
rpc_createerr.cf_stat = 0;
for (;;) {
p_port = nfs_getport(saddr, salen, prog, *p_vers, *p_prot);
if (p_port) {
if (!port || port == p_port) {
nfs_set_port(saddr, p_port);
nfs_pp_debug(saddr, salen, prog, *p_vers,
*p_prot, p_port);
if (nfs_rpc_ping(saddr, salen, prog,
*p_vers, *p_prot, NULL))
goto out_ok;
}
}
if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED &&
rpc_createerr.cf_stat != RPC_TIMEDOUT &&
rpc_createerr.cf_stat != RPC_CANTRECV &&
rpc_createerr.cf_stat != RPC_PROGVERSMISMATCH)
goto out_bad;
if (!prot) {
if (*++p_prot)
continue;
p_prot = protos;
}
if (rpc_createerr.cf_stat == RPC_TIMEDOUT ||
rpc_createerr.cf_stat == RPC_CANTRECV)
goto out_bad;
if (vers || !*++p_vers)
break;
}
out_bad:
return 0;
out_ok:
if (!vers)
pmap->pm_vers = *p_vers;
if (!prot)
pmap->pm_prot = *p_prot;
if (!port)
pmap->pm_port = p_port;
rpc_createerr.cf_stat = 0;
return 1;
}
/*
* If the port isn't already set, do an rpcbind query to the remote server
* using the program and version and get the port.
*
* Newer kernels send the value of the port= mount option in the "info"
* file for the upcall or '0' for NFSv2/3. For NFSv4 it sends the value
* of the port= option or '2049'. The port field in a new sockaddr should
* reflect the value that was sent by the kernel.
*/
static int
populate_port(struct sockaddr *sa, const socklen_t salen,
const rpcprog_t program, const rpcvers_t version,
const unsigned short protocol)
{
struct sockaddr_in *s4 = (struct sockaddr_in *) sa;
#ifdef IPV6_SUPPORTED
struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) sa;
#endif /* IPV6_SUPPORTED */
unsigned short port;
/*
* Newer kernels send the port in the upcall. If we already have
* the port, there's no need to look it up.
*/
switch (sa->sa_family) {
case AF_INET:
if (s4->sin_port != 0) {
printerr(4, "DEBUG: port already set to %d\n",
ntohs(s4->sin_port));
return 1;
}
break;
#ifdef IPV6_SUPPORTED
case AF_INET6:
if (s6->sin6_port != 0) {
printerr(4, "DEBUG: port already set to %d\n",
ntohs(s6->sin6_port));
return 1;
}
break;
#endif /* IPV6_SUPPORTED */
default:
printerr(0, "ERROR: unsupported address family %d\n",
sa->sa_family);
return 0;
}
/*
* Newer kernels that send the port in the upcall set the value to
* 2049 for NFSv4 mounts when one isn't specified. The check below is
* only for kernels that don't send the port in the upcall. For those
* we either have to do an rpcbind query or set it to the standard
* port. Doing a query could be problematic (firewalls, etc), so take
* the latter approach.
*/
if (program == 100003 && version == 4) {
port = 2049;
goto set_port;
}
port = nfs_getport(sa, salen, program, version, protocol);
if (!port) {
printerr(0, "ERROR: unable to obtain port for prog %ld "
"vers %ld\n", program, version);
return 0;
}
set_port:
printerr(2, "DEBUG: setting port to %hu for prog %lu vers %lu\n", port,
program, version);
switch (sa->sa_family) {
case AF_INET:
s4->sin_port = htons(port);
break;
#ifdef IPV6_SUPPORTED
case AF_INET6:
s6->sin6_port = htons(port);
break;
#endif /* IPV6_SUPPORTED */
}
return 1;
}
