[PATCH 009 of 9] knfsd: Allow sockets to be passed to nfsd via 'portlist'

From: NeilBrown
Date: Mon Jul 24 2006 - 21:55:05 EST

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Userspace should create and bind a socket (but not connectted)
and write the 'fd' to portlist. This will cause the nfs server
to listen on that socket.

To close a socket, the name of the socket - as read from 'portlist'
can be written to 'portlist' with a preceding '-'.

Signed-off-by: Neil Brown <neilb@xxxxxxx>

### Diffstat output
./fs/nfsd/nfsctl.c | 59 +++++++++++++++++++++++++++++++++------
./fs/nfsd/nfssvc.c | 4 --
./include/linux/nfsd/nfsd.h | 1
./include/linux/sunrpc/svcsock.h | 6 +++
./net/sunrpc/svcsock.c | 49 +++++++++++++++++++++++++++++---
5 files changed, 102 insertions(+), 17 deletions(-)

diff .prev/fs/nfsd/nfsctl.c ./fs/nfsd/nfsctl.c
--- .prev/fs/nfsd/nfsctl.c 2006-07-24 15:49:51.000000000 +1000
+++ ./fs/nfsd/nfsctl.c 2006-07-24 17:24:17.000000000 +1000
@@ -23,9 +23,11 @@
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/string.h>
+#include <linux/ctype.h>

#include <linux/nfs.h>
#include <linux/nfsd_idmap.h>
+#include <linux/lockd/bind.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfsd/nfsd.h>
@@ -425,16 +427,55 @@ static ssize_t write_versions(struct fil

static ssize_t write_ports(struct file *file, char *buf, size_t size)
{
- /* for now, ignore what was written and just
- * return known ports
- * AF proto address port
+ if (size == 0) {
+ int len = 0;
+ lock_kernel();
+ if (nfsd_serv)
+ len = svc_sock_names(buf, nfsd_serv, NULL);
+ unlock_kernel();
+ return len;
+ }
+ /* Either a single 'fd' number is written, in which
+ * case it must be for a socket of a supported family/protocol,
+ * and we use it as an nfsd socket, or
+ * A '-' followed by the 'name' of a socket in which case
+ * we close the socket.
*/
- int len = 0;
- lock_kernel();
- if (nfsd_serv)
- len = svc_sock_names(buf, nfsd_serv);
- unlock_kernel();
- return len;
+ if (isdigit(buf[0])) {
+ char *mesg = buf;
+ int fd;
+ int err;
+ err = get_int(&mesg, &fd);
+ if (err)
+ return -EINVAL;
+ if (fd < 0)
+ return -EINVAL;
+ err = nfsd_create_serv();
+ if (!err) {
+ int proto = 0;
+ err = svc_addsock(nfsd_serv, fd, buf, &proto);
+ /* Decrease the count, but don't shutdown the
+ * the service
+ */
+ if (err >= 0)
+ lockd_up(proto);
+ nfsd_serv->sv_nrthreads--;
+ }
+ return err;
+ }
+ if (buf[0] == '-') {
+ char *toclose = kstrdup(buf+1, GFP_KERNEL);
+ int len = 0;
+ if (!toclose)
+ return -ENOMEM;
+ lock_kernel();
+ if (nfsd_serv)
+ len = svc_sock_names(buf, nfsd_serv, toclose);
+ unlock_kernel();
+ kfree(toclose);
+ return len;
+ }
+ return -EINVAL;
}

#ifdef CONFIG_NFSD_V4

diff .prev/fs/nfsd/nfssvc.c ./fs/nfsd/nfssvc.c
--- .prev/fs/nfsd/nfssvc.c 2006-07-24 15:49:51.000000000 +1000
+++ ./fs/nfsd/nfssvc.c 2006-07-24 15:53:37.000000000 +1000
@@ -196,7 +196,7 @@ void nfsd_reset_versions(void)
}

-static inline int nfsd_create_serv(void)
+int nfsd_create_serv(void)
{
int err = 0;
lock_kernel();
@@ -211,8 +211,6 @@ static inline int nfsd_create_serv(void)
nfsd_last_thread);
if (nfsd_serv == NULL)
err = -ENOMEM;
- else
- nfsd_serv->sv_nrthreads++;
unlock_kernel();
do_gettimeofday(&nfssvc_boot); /* record boot time */
return err;

diff .prev/include/linux/nfsd/nfsd.h ./include/linux/nfsd/nfsd.h
--- .prev/include/linux/nfsd/nfsd.h 2006-07-24 15:49:51.000000000 +1000
+++ ./include/linux/nfsd/nfsd.h 2006-07-24 15:22:49.000000000 +1000
@@ -143,6 +143,7 @@ int nfsd_set_posix_acl(struct svc_fh *,
enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
int nfsd_vers(int vers, enum vers_op change);
void nfsd_reset_versions(void);
+int nfsd_create_serv(void);

/*

diff .prev/include/linux/sunrpc/svcsock.h ./include/linux/sunrpc/svcsock.h
--- .prev/include/linux/sunrpc/svcsock.h 2006-07-24 15:49:51.000000000 +1000
+++ ./include/linux/sunrpc/svcsock.h 2006-07-24 15:22:49.000000000 +1000
@@ -61,6 +61,10 @@ int svc_recv(struct svc_serv *, struct
int svc_send(struct svc_rqst *);
void svc_drop(struct svc_rqst *);
void svc_sock_update_bufs(struct svc_serv *serv);
-int svc_sock_names(char *buf, struct svc_serv *serv);
+int svc_sock_names(char *buf, struct svc_serv *serv, char *toclose);
+int svc_addsock(struct svc_serv *serv,
+ int fd,
+ char *name_return,
+ int *proto);

#endif /* SUNRPC_SVCSOCK_H */

diff .prev/net/sunrpc/svcsock.c ./net/sunrpc/svcsock.c
--- .prev/net/sunrpc/svcsock.c 2006-07-24 15:49:51.000000000 +1000
+++ ./net/sunrpc/svcsock.c 2006-07-25 11:25:50.000000000 +1000
@@ -31,6 +31,7 @@
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
+#include <linux/file.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/ip.h>
@@ -449,18 +450,23 @@ int one_sock_name(char *buf, struct svc_
}

int
-svc_sock_names(char *buf, struct svc_serv *serv)
+svc_sock_names(char *buf, struct svc_serv *serv, char *toclose)
{
- struct svc_sock *svsk;
+ struct svc_sock *svsk, *closesk = NULL;
int len = 0;

if (!serv) return 0;
spin_lock(&serv->sv_lock);
list_for_each_entry(svsk, &serv->sv_permsocks, sk_list) {
int onelen = one_sock_name(buf+len, svsk);
- len += onelen;
+ if (toclose && strcmp(toclose, buf+len) == 0)
+ closesk = svsk;
+ else
+ len += onelen;
}
spin_unlock(&serv->sv_lock);
+ if (closesk)
+ svc_delete_socket(closesk);
return len;
}
EXPORT_SYMBOL(svc_sock_names);
@@ -1415,6 +1421,38 @@ svc_setup_socket(struct svc_serv *serv,
return svsk;
}

+int svc_addsock(struct svc_serv *serv,
+ int fd,
+ char *name_return,
+ int *proto)
+{
+ int err = 0;
+ struct socket *so = sockfd_lookup(fd, &err);
+ struct svc_sock *svsk = NULL;
+
+ if (!so)
+ return err;
+ if (so->sk->sk_family != AF_INET)
+ err = -EAFNOSUPPORT;
+ else if (so->sk->sk_protocol != IPPROTO_TCP &&
+ so->sk->sk_protocol != IPPROTO_UDP)
+ err = -EPROTONOSUPPORT;
+ else if (so->state > SS_UNCONNECTED)
+ err = -EISCONN;
+ else {
+ svsk = svc_setup_socket(serv, so, &err, 1);
+ if (svsk)
+ err = 0;
+ }
+ if (err) {
+ sockfd_put(so);
+ return err;
+ }
+ if (proto) *proto = so->sk->sk_protocol;
+ return one_sock_name(name_return, svsk);
+}
+EXPORT_SYMBOL_GPL(svc_addsock);
+
/*
* Create socket for RPC service.
*/
@@ -1492,7 +1530,10 @@ svc_delete_socket(struct svc_sock *svsk)

if (!svsk->sk_inuse) {
spin_unlock_bh(&serv->sv_lock);
- sock_release(svsk->sk_sock);
+ if (svsk->sk_sock->file)
+ sockfd_put(svsk->sk_sock);
+ else
+ sock_release(svsk->sk_sock);
kfree(svsk);
} else {
spin_unlock_bh(&serv->sv_lock);
-
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Next message: Andrew Morton: "Re: Bad ext3/nfs DoS bug"
Previous message: NeilBrown: "[PATCH 003 of 9] knfsd: knfsd: Remove an unused variable from auth_unix_lookup()"
In reply to: NeilBrown: "[PATCH 003 of 9] knfsd: knfsd: Remove an unused variable from auth_unix_lookup()"
Next in thread: Andrew Morton: "Re: [PATCH 009 of 9] knfsd: Allow sockets to be passed to nfsd via'portlist'"
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