]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - fs/lockd/mon.c
Merge git://git.infradead.org/iommu-2.6
[linux-2.6-omap-h63xx.git] / fs / lockd / mon.c
index 315ca07715c7b9d819481dd7d0c004c12fab3e8b..5e2c4d5ac82774011072c05f5f039ec466fca59e 100644 (file)
@@ -9,12 +9,12 @@
 #include <linux/types.h>
 #include <linux/utsname.h>
 #include <linux/kernel.h>
+#include <linux/ktime.h>
+
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/xprtsock.h>
 #include <linux/sunrpc/svc.h>
 #include <linux/lockd/lockd.h>
-#include <linux/lockd/sm_inter.h>
-
 
 #define NLMDBG_FACILITY                NLMDBG_MONITOR
 #define NSM_PROGRAM            100024
@@ -44,8 +44,6 @@ struct nsm_res {
        u32                     state;
 };
 
-static struct rpc_clnt *       nsm_create(void);
-
 static struct rpc_program      nsm_program;
 static                         LIST_HEAD(nsm_handles);
 static                         DEFINE_SPINLOCK(nsm_lock);
@@ -53,7 +51,13 @@ static                               DEFINE_SPINLOCK(nsm_lock);
 /*
  * Local NSM state
  */
-int                            nsm_local_state;
+int    __read_mostly           nsm_local_state;
+int    __read_mostly           nsm_use_hostnames;
+
+static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
+{
+       return (struct sockaddr *)&nsm->sm_addr;
+}
 
 static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf,
                                     const size_t len)
@@ -92,11 +96,26 @@ static void nsm_display_address(const struct sockaddr *sap,
        }
 }
 
-/*
- * Common procedure for NSMPROC_MON/NSMPROC_UNMON calls
- */
-static int
-nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
+static struct rpc_clnt *nsm_create(void)
+{
+       struct sockaddr_in sin = {
+               .sin_family             = AF_INET,
+               .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
+       };
+       struct rpc_create_args args = {
+               .protocol               = XPRT_TRANSPORT_UDP,
+               .address                = (struct sockaddr *)&sin,
+               .addrsize               = sizeof(sin),
+               .servername             = "rpc.statd",
+               .program                = &nsm_program,
+               .version                = NSM_VERSION,
+               .authflavor             = RPC_AUTH_NULL,
+       };
+
+       return rpc_create(&args);
+}
+
+static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
 {
        struct rpc_clnt *clnt;
        int             status;
@@ -213,6 +232,16 @@ static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
        return NULL;
 }
 
+static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
+{
+       struct nsm_handle *nsm;
+
+       list_for_each_entry(nsm, &nsm_handles, sm_link)
+               if (nlm_cmp_addr(nsm_addr(nsm), sap))
+                       return nsm;
+       return NULL;
+}
+
 static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
 {
        struct nsm_handle *nsm;
@@ -230,13 +259,25 @@ static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
  * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
  * requests.
  *
- * Linux provides the raw IP address of the monitored host,
- * left in network byte order.
+ * The NSM protocol requires that these cookies be unique while the
+ * system is running.  We prefer a stronger requirement of making them
+ * unique across reboots.  If user space bugs cause a stale cookie to
+ * be sent to the kernel, it could cause the wrong host to lose its
+ * lock state if cookies were not unique across reboots.
+ *
+ * The cookies are exposed only to local user space via loopback.  They
+ * do not appear on the physical network.  If we want greater security
+ * for some reason, nsm_init_private() could perform a one-way hash to
+ * obscure the contents of the cookie.
  */
 static void nsm_init_private(struct nsm_handle *nsm)
 {
-       __be32 *p = (__be32 *)&nsm->sm_priv.data;
-       *p = nsm_addr_in(nsm)->sin_addr.s_addr;
+       u64 *p = (u64 *)&nsm->sm_priv.data;
+       struct timespec ts;
+
+       ktime_get_ts(&ts);
+       *p++ = timespec_to_ns(&ts);
+       *p = (unsigned long)nsm;
 }
 
 static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
@@ -281,8 +322,7 @@ struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
                                  const size_t salen, const char *hostname,
                                  const size_t hostname_len)
 {
-       struct nsm_handle *nsm = NULL;
-       struct nsm_handle *pos;
+       struct nsm_handle *cached, *new = NULL;
 
        if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
                if (printk_ratelimit()) {
@@ -295,38 +335,37 @@ struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
 
 retry:
        spin_lock(&nsm_lock);
-       list_for_each_entry(pos, &nsm_handles, sm_link) {
-
-               if (hostname && nsm_use_hostnames) {
-                       if (strlen(pos->sm_name) != hostname_len
-                        || memcmp(pos->sm_name, hostname, hostname_len))
-                               continue;
-               } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
-                       continue;
-               atomic_inc(&pos->sm_count);
-               kfree(nsm);
-               nsm = pos;
-               dprintk("lockd: found nsm_handle for %s (%s), cnt %d\n",
-                               pos->sm_name, pos->sm_addrbuf,
-                               atomic_read(&pos->sm_count));
-               goto found;
+
+       if (nsm_use_hostnames && hostname != NULL)
+               cached = nsm_lookup_hostname(hostname, hostname_len);
+       else
+               cached = nsm_lookup_addr(sap);
+
+       if (cached != NULL) {
+               atomic_inc(&cached->sm_count);
+               spin_unlock(&nsm_lock);
+               kfree(new);
+               dprintk("lockd: found nsm_handle for %s (%s), "
+                               "cnt %d\n", cached->sm_name,
+                               cached->sm_addrbuf,
+                               atomic_read(&cached->sm_count));
+               return cached;
        }
-       if (nsm) {
-               list_add(&nsm->sm_link, &nsm_handles);
+
+       if (new != NULL) {
+               list_add(&new->sm_link, &nsm_handles);
+               spin_unlock(&nsm_lock);
                dprintk("lockd: created nsm_handle for %s (%s)\n",
-                               nsm->sm_name, nsm->sm_addrbuf);
-               goto found;
+                               new->sm_name, new->sm_addrbuf);
+               return new;
        }
+
        spin_unlock(&nsm_lock);
 
-       nsm = nsm_create_handle(sap, salen, hostname, hostname_len);
-       if (unlikely(nsm == NULL))
+       new = nsm_create_handle(sap, salen, hostname, hostname_len);
+       if (unlikely(new == NULL))
                return NULL;
        goto retry;
-
-found:
-       spin_unlock(&nsm_lock);
-       return nsm;
 }
 
 /**
@@ -343,11 +382,7 @@ struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
 
        spin_lock(&nsm_lock);
 
-       if (nsm_use_hostnames && info->mon != NULL)
-               cached = nsm_lookup_hostname(info->mon, info->len);
-       else
-               cached = nsm_lookup_priv(&info->priv);
-
+       cached = nsm_lookup_priv(&info->priv);
        if (unlikely(cached == NULL)) {
                spin_unlock(&nsm_lock);
                dprintk("lockd: never saw rebooted peer '%.*s' before\n",
@@ -386,30 +421,6 @@ void nsm_release(struct nsm_handle *nsm)
        }
 }
 
-/*
- * Create NSM client for the local host
- */
-static struct rpc_clnt *
-nsm_create(void)
-{
-       struct sockaddr_in      sin = {
-               .sin_family     = AF_INET,
-               .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
-               .sin_port       = 0,
-       };
-       struct rpc_create_args args = {
-               .protocol       = XPRT_TRANSPORT_UDP,
-               .address        = (struct sockaddr *)&sin,
-               .addrsize       = sizeof(sin),
-               .servername     = "localhost",
-               .program        = &nsm_program,
-               .version        = NSM_VERSION,
-               .authflavor     = RPC_AUTH_NULL,
-       };
-
-       return rpc_create(&args);
-}
-
 /*
  * XDR functions for NSM.
  *