| Message ID | 20210426171947.99233-12-olga.kornievskaia@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | create sysfs files for changing IP address | expand |
On Mon, 2021-04-26 at 13:19 -0400, Olga Kornievskaia wrote: > From: Olga Kornievskaia <kolga@netapp.com> > > Allow to query and set the destination's address of a transport. > Setting of the destination address is allowed only for TCP or RDMA > based connections. > > Signed-off-by: Olga Kornievskaia <kolga@netapp.com> > --- > net/sunrpc/sysfs.c | 72 > ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 72 insertions(+) > > diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c > index 682def4293f2..076f777db3cd 100644 > --- a/net/sunrpc/sysfs.c > +++ b/net/sunrpc/sysfs.c > @@ -4,6 +4,9 @@ > */ > #include <linux/sunrpc/clnt.h> > #include <linux/kobject.h> > +#include <linux/sunrpc/addr.h> > +#include <linux/sunrpc/xprtsock.h> > + > #include "sysfs.h" > > static struct kset *rpc_sunrpc_kset; > @@ -42,6 +45,66 @@ static struct kobject > *rpc_sysfs_object_alloc(const char *name, > return NULL; > } > > +static inline struct rpc_xprt * > +rpc_sysfs_xprt_kobj_get_xprt(struct kobject *kobj) > +{ > + struct rpc_sysfs_xprt_switch_xprt *x = container_of(kobj, > + struct rpc_sysfs_xprt_switch_xprt, kobject); > + > + return xprt_get(x->xprt); > +} > + > +static ssize_t rpc_sysfs_xprt_dstaddr_show(struct kobject *kobj, > + struct kobj_attribute > *attr, > + char *buf) > +{ > + struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj); > + ssize_t ret; > + > + if (!xprt) > + return 0; > + if (xprt->xprt_class->ident == XPRT_TRANSPORT_LOCAL) > + ret = sprintf(buf, "localhost"); This makes it look like it is a loopback socket, whereas in reality it is a named socket. Why not just use the xprt- >address_strings[RPC_DISPLAY_ADDR] here? > + else > + ret = rpc_ntop((struct sockaddr *)&xprt->addr, buf, > PAGE_SIZE); > + buf[ret] = '\n'; > + xprt_put(xprt); > + return ret + 1; > +} > + > +static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj, > + struct kobj_attribute > *attr, > + const char *buf, size_t > count) > +{ > + struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj); > + struct sockaddr *saddr; > + int port; > + > + if (!xprt) > + return 0; > + if (!(xprt->xprt_class->ident == XPRT_TRANSPORT_TCP || > + xprt->xprt_class->ident == XPRT_TRANSPORT_RDMA)) { > + xprt_put(xprt); > + return -EOPNOTSUPP; > + } > + > + wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE); > + saddr = (struct sockaddr *)&xprt->addr; > + port = rpc_get_port(saddr); > + > + kfree(xprt->address_strings[RPC_DISPLAY_ADDR]); This is not allowed. The xprt->address_strings can only be freed in a manner that is safe w.r.t. the rcu_read_lock(). Otherwise, various users of rpc_peeraddr2str() are prone to crash. So if you're going to replace these strings, then you have to replace them using something like rcu_replace_pointer(), then you have to free them using call_rcu() or kfree_rcu}(). > + xprt->address_strings[RPC_DISPLAY_ADDR] = kstrndup(buf, count > - 1, > + > GFP_KERNEL); > + xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, > saddr, > + sizeof(*saddr)); > + rpc_set_port(saddr, port); The above is also a bit dodgy w.r.t. rpc_peeraddr() since it is non- atomic. However it looks like it should be OK in practice. > + > + xprt->ops->connect(xprt, NULL); > + clear_bit(XPRT_LOCKED, &xprt->state); > + xprt_put(xprt); > + return count; > +} > + > int rpc_sysfs_init(void) > { > rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, > kernel_kobj); > @@ -105,6 +168,14 @@ static const void > *rpc_sysfs_xprt_switch_xprt_namespace(struct kobject *kobj) > kobject)->net; > } > > +static struct kobj_attribute rpc_sysfs_xprt_dstaddr = > __ATTR(dstaddr, > + 0644, rpc_sysfs_xprt_dstaddr_show, > rpc_sysfs_xprt_dstaddr_store); > + > +static struct attribute *rpc_sysfs_xprt_attrs[] = { > + &rpc_sysfs_xprt_dstaddr.attr, > + NULL, > +}; > + > static struct kobj_type rpc_sysfs_client_type = { > .release = rpc_sysfs_client_release, > .sysfs_ops = &kobj_sysfs_ops, > @@ -119,6 +190,7 @@ static struct kobj_type > rpc_sysfs_xprt_switch_type = { > > static struct kobj_type rpc_sysfs_xprt_switch_xprt_type = { > .release = rpc_sysfs_xprt_switch_xprt_release, > + .default_attrs = rpc_sysfs_xprt_attrs, > .sysfs_ops = &kobj_sysfs_ops, > .namespace = rpc_sysfs_xprt_switch_xprt_namespace, > };
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c index 682def4293f2..076f777db3cd 100644 --- a/net/sunrpc/sysfs.c +++ b/net/sunrpc/sysfs.c @@ -4,6 +4,9 @@ */ #include <linux/sunrpc/clnt.h> #include <linux/kobject.h> +#include <linux/sunrpc/addr.h> +#include <linux/sunrpc/xprtsock.h> + #include "sysfs.h" static struct kset *rpc_sunrpc_kset; @@ -42,6 +45,66 @@ static struct kobject *rpc_sysfs_object_alloc(const char *name, return NULL; } +static inline struct rpc_xprt * +rpc_sysfs_xprt_kobj_get_xprt(struct kobject *kobj) +{ + struct rpc_sysfs_xprt_switch_xprt *x = container_of(kobj, + struct rpc_sysfs_xprt_switch_xprt, kobject); + + return xprt_get(x->xprt); +} + +static ssize_t rpc_sysfs_xprt_dstaddr_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj); + ssize_t ret; + + if (!xprt) + return 0; + if (xprt->xprt_class->ident == XPRT_TRANSPORT_LOCAL) + ret = sprintf(buf, "localhost"); + else + ret = rpc_ntop((struct sockaddr *)&xprt->addr, buf, PAGE_SIZE); + buf[ret] = '\n'; + xprt_put(xprt); + return ret + 1; +} + +static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj); + struct sockaddr *saddr; + int port; + + if (!xprt) + return 0; + if (!(xprt->xprt_class->ident == XPRT_TRANSPORT_TCP || + xprt->xprt_class->ident == XPRT_TRANSPORT_RDMA)) { + xprt_put(xprt); + return -EOPNOTSUPP; + } + + wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE); + saddr = (struct sockaddr *)&xprt->addr; + port = rpc_get_port(saddr); + + kfree(xprt->address_strings[RPC_DISPLAY_ADDR]); + xprt->address_strings[RPC_DISPLAY_ADDR] = kstrndup(buf, count - 1, + GFP_KERNEL); + xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, saddr, + sizeof(*saddr)); + rpc_set_port(saddr, port); + + xprt->ops->connect(xprt, NULL); + clear_bit(XPRT_LOCKED, &xprt->state); + xprt_put(xprt); + return count; +} + int rpc_sysfs_init(void) { rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj); @@ -105,6 +168,14 @@ static const void *rpc_sysfs_xprt_switch_xprt_namespace(struct kobject *kobj) kobject)->net; } +static struct kobj_attribute rpc_sysfs_xprt_dstaddr = __ATTR(dstaddr, + 0644, rpc_sysfs_xprt_dstaddr_show, rpc_sysfs_xprt_dstaddr_store); + +static struct attribute *rpc_sysfs_xprt_attrs[] = { + &rpc_sysfs_xprt_dstaddr.attr, + NULL, +}; + static struct kobj_type rpc_sysfs_client_type = { .release = rpc_sysfs_client_release, .sysfs_ops = &kobj_sysfs_ops, @@ -119,6 +190,7 @@ static struct kobj_type rpc_sysfs_xprt_switch_type = { static struct kobj_type rpc_sysfs_xprt_switch_xprt_type = { .release = rpc_sysfs_xprt_switch_xprt_release, + .default_attrs = rpc_sysfs_xprt_attrs, .sysfs_ops = &kobj_sysfs_ops, .namespace = rpc_sysfs_xprt_switch_xprt_namespace, };