From 74926f92dd3a65e378def1a3e7309a027b8efbd3 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Thu, 15 Nov 2012 22:33:23 +0100 Subject: link: Protect registration of af and link ops with rwlock Signed-off-by: Thomas Graf --- lib/route/link/api.c | 74 ++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 57 insertions(+), 17 deletions(-) diff --git a/lib/route/link/api.c b/lib/route/link/api.c index f7907a7..a12eb09 100644 --- a/lib/route/link/api.c +++ b/lib/route/link/api.c @@ -47,6 +47,9 @@ static NL_LIST_HEAD(info_ops); +/* lock protecting info_ops and af_ops */ +static NL_RW_LOCK(info_lock); + static struct rtnl_link_info_ops *__rtnl_link_info_ops_lookup(const char *name) { struct rtnl_link_info_ops *ops; @@ -75,8 +78,10 @@ struct rtnl_link_info_ops *rtnl_link_info_ops_lookup(const char *name) { struct rtnl_link_info_ops *ops; + nl_write_lock(&info_lock); if ((ops = __rtnl_link_info_ops_lookup(name))) ops->io_refcnt++; + nl_write_unlock(&info_lock); return ops; } @@ -105,17 +110,24 @@ void rtnl_link_info_ops_put(struct rtnl_link_info_ops *ops) */ int rtnl_link_register_info(struct rtnl_link_info_ops *ops) { + int err = 0; + if (ops->io_name == NULL) return -NLE_INVAL; - if (__rtnl_link_info_ops_lookup(ops->io_name)) - return -NLE_EXIST; + nl_write_lock(&info_lock); + if (__rtnl_link_info_ops_lookup(ops->io_name)) { + err = -NLE_EXIST; + goto errout; + } NL_DBG(1, "Registered link info operations %s\n", ops->io_name); nl_list_add_tail(&ops->io_list, &info_ops); +errout: + nl_write_unlock(&info_lock); - return 0; + return err; } /** @@ -134,22 +146,30 @@ int rtnl_link_register_info(struct rtnl_link_info_ops *ops) int rtnl_link_unregister_info(struct rtnl_link_info_ops *ops) { struct rtnl_link_info_ops *t; + int err = -NLE_OPNOTSUPP; + + nl_write_lock(&info_lock); nl_list_for_each_entry(t, &info_ops, io_list) { if (t == ops) { - if (t->io_refcnt > 0) - return -NLE_BUSY; + if (t->io_refcnt > 0) { + err = -NLE_BUSY; + goto errout; + } nl_list_del(&t->io_list); NL_DBG(1, "Unregistered link info operations %s\n", ops->io_name); - - return 0; + err = 0; + goto errout; } } - return -NLE_OPNOTSUPP; +errout: + nl_write_unlock(&info_lock); + + return err; } /** @} */ @@ -174,8 +194,10 @@ struct rtnl_link_af_ops *rtnl_link_af_ops_lookup(const unsigned int family) if (family == AF_UNSPEC || family >= AF_MAX) return NULL; + nl_write_lock(&info_lock); if (af_ops[family]) af_ops[family]->ao_refcnt++; + nl_write_unlock(&info_lock); return af_ops[family]; } @@ -262,11 +284,16 @@ void *rtnl_link_af_data(const struct rtnl_link *link, */ int rtnl_link_af_register(struct rtnl_link_af_ops *ops) { + int err = 0; + if (ops->ao_family == AF_UNSPEC || ops->ao_family >= AF_MAX) return -NLE_INVAL; - if (af_ops[ops->ao_family]) - return -NLE_EXIST; + nl_write_lock(&info_lock); + if (af_ops[ops->ao_family]) { + err = -NLE_EXIST; + goto errout; + } ops->ao_refcnt = 0; af_ops[ops->ao_family] = ops; @@ -274,7 +301,10 @@ int rtnl_link_af_register(struct rtnl_link_af_ops *ops) NL_DBG(1, "Registered link address family operations %u\n", ops->ao_family); - return 0; +errout: + nl_write_unlock(&info_lock); + + return err; } /** @@ -293,21 +323,31 @@ int rtnl_link_af_register(struct rtnl_link_af_ops *ops) */ int rtnl_link_af_unregister(struct rtnl_link_af_ops *ops) { + int err = -NLE_INVAL; + if (!ops) - return -NLE_INVAL; + goto errout; - if (!af_ops[ops->ao_family]) - return -NLE_OBJ_NOTFOUND; + nl_write_lock(&info_lock); + if (!af_ops[ops->ao_family]) { + err = -NLE_OBJ_NOTFOUND; + goto errout; + } - if (ops->ao_refcnt > 0) - return -NLE_BUSY; + if (ops->ao_refcnt > 0) { + err = -NLE_BUSY; + goto errout; + } af_ops[ops->ao_family] = NULL; NL_DBG(1, "Unregistered link address family operations %u\n", ops->ao_family); - return 0; +errout: + nl_write_lock(&info_lock); + + return err; } /** @} */ -- cgit v1.2.1