static int nfs_verify_lock_option(struct mount_options *options)
{
if (po_rightmost(options, nfs_lock_opttbl) == 0)
return 1;
if (!start_statd()) {
nfs_error(_("%s: rpc.statd is not running but is "
"required for remote locking."), progname);
nfs_error(_("%s: Either use '-o nolock' to keep "
"locks local, or start statd."), progname);
return 0;
}
return 1;
}
static int nfsmount_start(struct nfsmount_info *mi)
{
if (!nfs_validate_options(mi))
return EX_FAIL;
/*
* Avoid retry and negotiation logic when remounting
*/
if (mi->flags & MS_REMOUNT)
return nfs_remount(mi);
if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
return nfsmount_bg(mi);
else
return nfsmount_fg(mi);
}
/*
* Returns the NFS transport protocol specified by the given mount options
*
* Returns the IPPROTO_ value specified by the given mount options, or
* IPPROTO_UDP if all fails.
*/
static unsigned short nfs_nfs_protocol(struct mount_options *options)
{
char *option;
switch (po_rightmost(options, nfs_transport_opttbl)) {
case 1: /* tcp */
return IPPROTO_TCP;
case 2: /* proto */
option = po_get(options, "proto");
if (option) {
if (strcmp(option, "tcp") == 0)
return IPPROTO_TCP;
if (strcmp(option, "udp") == 0)
return IPPROTO_UDP;
}
}
return IPPROTO_UDP;
}
/*
* Try a getsockname() on a connected datagram socket.
*
* Returns 1 and fills in @buf if successful; otherwise, zero.
*
* A connected datagram socket prevents leaving a socket in TIME_WAIT.
* This conserves the ephemeral port number space, helping reduce failed
* socket binds during mount storms.
*/
static int nfs_ca_sockname(const struct sockaddr *sap, const socklen_t salen,
struct sockaddr *buf, socklen_t *buflen)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_ANY),
};
struct sockaddr_in6 sin6 = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
};
int sock;
sock = socket(sap->sa_family, SOCK_DGRAM, IPPROTO_UDP);
if (sock < 0)
return 0;
switch (sap->sa_family) {
case AF_INET:
if (bind(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
close(sock);
return 0;
}
break;
case AF_INET6:
if (bind(sock, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
close(sock);
return 0;
}
break;
default:
errno = EAFNOSUPPORT;
return 0;
}
if (connect(sock, sap, salen) < 0) {
close(sock);
return 0;
}
return !getsockname(sock, buf, buflen);
}
/*
* Try to generate an address that prevents the server from calling us.
*
* Returns 1 and fills in @buf if successful; otherwise, zero.
*/
static int nfs_ca_gai(const struct sockaddr *sap, const socklen_t salen,
struct sockaddr *buf, socklen_t *buflen)
{
struct addrinfo *gai_results;
struct addrinfo gai_hint = {
.ai_family = sap->sa_family,
.ai_flags = AI_PASSIVE, /* ANYADDR */
};
if (getaddrinfo(NULL, "", &gai_hint, &gai_results))
return 0;
*buflen = gai_results->ai_addrlen;
memcpy(buf, gai_results->ai_addr, *buflen);
freeaddrinfo(gai_results);
return 1;
}
/**
* nfs_callback_address - acquire our local network address
* @sap: pointer to address of remote
* @sap_len: length of address
* @buf: pointer to buffer to be filled in with local network address
* @buflen: IN: length of buffer to fill in; OUT: length of filled-in address
*
* Discover a network address that an NFSv4 server can use to call us back.
* On multi-homed clients, this address depends on which NIC we use to
* route requests to the server.
*
* Returns 1 and fills in @buf if an unambiguous local address is
* available; returns 1 and fills in an appropriate ANYADDR address
* if a local address isn't available; otherwise, returns zero.
*/
int nfs_callback_address(const struct sockaddr *sap, const socklen_t salen,
struct sockaddr *buf, socklen_t *buflen)
{
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
if (nfs_ca_sockname(sap, salen, buf, buflen) == 0)
if (nfs_ca_gai(sap, salen, buf, buflen) == 0)
goto out_failed;
/*
* The server can't use an interface ID that was generated
* here on the client, so always clear sin6_scope_id.
*/
if (sin6->sin6_family == AF_INET6)
sin6->sin6_scope_id = 0;
return 1;
out_failed:
*buflen = 0;
if (verbose)
nfs_error(_("%s: failed to construct callback address"));
return 0;
}
/*
* "nfsprog" is only supported by the legacy mount command. The
* kernel mount client does not support this option.
*
* Returns the value set by the nfsprog= option, the value of
* the RPC NFS program specified in /etc/rpc, or a baked-in
* default program number, if all fails.
*/
static rpcprog_t nfs_nfs_program(struct mount_options *options)
{
long tmp;
if (po_get_numeric(options, "nfsprog", &tmp) == PO_FOUND)
if (tmp >= 0)
return tmp;
return nfs_getrpcbyname(NFSPROG, nfs_nfs_pgmtbl);
}
/*
* Returns the RPC version number specified by the given mount
* options for the NFS service, or zero if all fails.
*/
static rpcvers_t nfs_nfs_version(struct mount_options *options)
{
long tmp;
switch (po_rightmost(options, nfs_version_opttbl)) {
case 0: /* v2 */
return 2;
case 1: /* v3 */
return 3;
case 2: /* vers */
if (po_get_numeric(options, "vers", &tmp) == PO_FOUND)
if (tmp >= 2 && tmp <= 3)
return tmp;
break;
case 3: /* nfsvers */
if (po_get_numeric(options, "nfsvers", &tmp) == PO_FOUND)
if (tmp >= 2 && tmp <= 3)
return tmp;
break;
}
return 0;
}