From ca374290aaade741a4781ae5f6e1ba7515e4e5fa Mon Sep 17 00:00:00 2001 From: Sergey Ryazanov Date: Tue, 22 Jun 2021 01:50:58 +0300 Subject: [PATCH] wwan: core: support default netdev creation Most, if not each WWAN device driver will create a netdev for the default data channel. Therefore, add an option for the WWAN netdev ops registration function to create a default netdev for the WWAN device. A WWAN device driver should pass a default data channel link id to the ops registering function to request the creation of a default netdev, or a special value WWAN_NO_DEFAULT_LINK to inform the WWAN core that the default netdev should not be created. For now, only wwan_hwsim utilize the default link creation option. Other drivers will be reworked next. Signed-off-by: Sergey Ryazanov CC: M Chetan Kumar CC: Intel Corporation Signed-off-by: David S. Miller --- drivers/net/mhi/net.c | 3 +- drivers/net/wwan/iosm/iosm_ipc_wwan.c | 3 +- drivers/net/wwan/wwan_core.c | 75 ++++++++++++++++++++++++++- drivers/net/wwan/wwan_hwsim.c | 2 +- include/linux/wwan.h | 8 ++- 5 files changed, 86 insertions(+), 5 deletions(-) diff --git a/drivers/net/mhi/net.c b/drivers/net/mhi/net.c index ffd1c01b3f35..f36ca5c0dfe9 100644 --- a/drivers/net/mhi/net.c +++ b/drivers/net/mhi/net.c @@ -397,7 +397,8 @@ static int mhi_net_probe(struct mhi_device *mhi_dev, struct net_device *ndev; int err; - err = wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_wwan_ops, mhi_dev); + err = wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_wwan_ops, mhi_dev, + WWAN_NO_DEFAULT_LINK); if (err) return err; diff --git a/drivers/net/wwan/iosm/iosm_ipc_wwan.c b/drivers/net/wwan/iosm/iosm_ipc_wwan.c index bee9b278223d..adb2bd40a404 100644 --- a/drivers/net/wwan/iosm/iosm_ipc_wwan.c +++ b/drivers/net/wwan/iosm/iosm_ipc_wwan.c @@ -317,7 +317,8 @@ struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev) ipc_wwan->dev = dev; ipc_wwan->ipc_imem = ipc_imem; - if (wwan_register_ops(ipc_wwan->dev, &iosm_wwan_ops, ipc_wwan)) { + if (wwan_register_ops(ipc_wwan->dev, &iosm_wwan_ops, ipc_wwan, + WWAN_NO_DEFAULT_LINK)) { kfree(ipc_wwan); return NULL; } diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index b634a0ba1196..ef6ec641d877 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -903,17 +903,81 @@ static struct rtnl_link_ops wwan_rtnl_link_ops __read_mostly = { .policy = wwan_rtnl_policy, }; +static void wwan_create_default_link(struct wwan_device *wwandev, + u32 def_link_id) +{ + struct nlattr *tb[IFLA_MAX + 1], *linkinfo[IFLA_INFO_MAX + 1]; + struct nlattr *data[IFLA_WWAN_MAX + 1]; + struct net_device *dev; + struct nlmsghdr *nlh; + struct sk_buff *msg; + + /* Forge attributes required to create a WWAN netdev. We first + * build a netlink message and then parse it. This looks + * odd, but such approach is less error prone. + */ + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (WARN_ON(!msg)) + return; + nlh = nlmsg_put(msg, 0, 0, RTM_NEWLINK, 0, 0); + if (WARN_ON(!nlh)) + goto free_attrs; + + if (nla_put_string(msg, IFLA_PARENT_DEV_NAME, dev_name(&wwandev->dev))) + goto free_attrs; + tb[IFLA_LINKINFO] = nla_nest_start(msg, IFLA_LINKINFO); + if (!tb[IFLA_LINKINFO]) + goto free_attrs; + linkinfo[IFLA_INFO_DATA] = nla_nest_start(msg, IFLA_INFO_DATA); + if (!linkinfo[IFLA_INFO_DATA]) + goto free_attrs; + if (nla_put_u32(msg, IFLA_WWAN_LINK_ID, def_link_id)) + goto free_attrs; + nla_nest_end(msg, linkinfo[IFLA_INFO_DATA]); + nla_nest_end(msg, tb[IFLA_LINKINFO]); + + nlmsg_end(msg, nlh); + + /* The next three parsing calls can not fail */ + nlmsg_parse_deprecated(nlh, 0, tb, IFLA_MAX, NULL, NULL); + nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO], + NULL, NULL); + nla_parse_nested_deprecated(data, IFLA_WWAN_MAX, + linkinfo[IFLA_INFO_DATA], NULL, NULL); + + rtnl_lock(); + + dev = rtnl_create_link(&init_net, "wwan%d", NET_NAME_ENUM, + &wwan_rtnl_link_ops, tb, NULL); + if (WARN_ON(IS_ERR(dev))) + goto unlock; + + if (WARN_ON(wwan_rtnl_newlink(&init_net, dev, tb, data, NULL))) { + free_netdev(dev); + goto unlock; + } + +unlock: + rtnl_unlock(); + +free_attrs: + nlmsg_free(msg); +} + /** * wwan_register_ops - register WWAN device ops * @parent: Device to use as parent and shared by all WWAN ports and * created netdevs * @ops: operations to register * @ctxt: context to pass to operations + * @def_link_id: id of the default link that will be automatically created by + * the WWAN core for the WWAN device. The default link will not be created + * if the passed value is WWAN_NO_DEFAULT_LINK. * * Returns: 0 on success, a negative error code on failure */ int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, - void *ctxt) + void *ctxt, u32 def_link_id) { struct wwan_device *wwandev; @@ -932,6 +996,15 @@ int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, wwandev->ops = ops; wwandev->ops_ctxt = ctxt; + /* NB: we do not abort ops registration in case of default link + * creation failure. Link ops is the management interface, while the + * default link creation is a service option. And we should not prevent + * a user from manually creating a link latter if service option failed + * now. + */ + if (def_link_id != WWAN_NO_DEFAULT_LINK) + wwan_create_default_link(wwandev, def_link_id); + return 0; } EXPORT_SYMBOL_GPL(wwan_register_ops); diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c index a8582a58a385..5b62cf3b3c42 100644 --- a/drivers/net/wwan/wwan_hwsim.c +++ b/drivers/net/wwan/wwan_hwsim.c @@ -288,7 +288,7 @@ static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void) INIT_WORK(&dev->del_work, wwan_hwsim_dev_del_work); - err = wwan_register_ops(&dev->dev, &wwan_hwsim_wwan_rtnl_ops, dev); + err = wwan_register_ops(&dev->dev, &wwan_hwsim_wwan_rtnl_ops, dev, 1); if (err) goto err_unreg_dev; diff --git a/include/linux/wwan.h b/include/linux/wwan.h index e1981ea3a2fd..91590db70a12 100644 --- a/include/linux/wwan.h +++ b/include/linux/wwan.h @@ -126,6 +126,12 @@ void wwan_port_txon(struct wwan_port *port); */ void *wwan_port_get_drvdata(struct wwan_port *port); +/* + * Used to indicate that the WWAN core should not create a default network + * link. + */ +#define WWAN_NO_DEFAULT_LINK U32_MAX + /** * struct wwan_ops - WWAN device ops * @priv_size: size of private netdev data area @@ -143,7 +149,7 @@ struct wwan_ops { }; int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, - void *ctxt); + void *ctxt, u32 def_link_id); void wwan_unregister_ops(struct device *parent);