/* * Copyright (C) ST-Ericsson AB 2010 * Authors: Sjur Brendeland * Daniel Martensson * License terms: GNU General Public License (GPL) version 2 */ #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ #include <linux/fs.h> #include <linux/hardirq.h> #include <linux/init.h> #include <linux/module.h> #include <linux/netdevice.h> #include <linux/if_ether.h> #include <linux/moduleparam.h> #include <linux/ip.h> #include <linux/sched.h> #include <linux/sockios.h> #include <linux/caif/if_caif.h> #include <net/rtnetlink.h> #include <net/caif/caif_layer.h> #include <net/caif/cfpkt.h> #include <net/caif/caif_dev.h> /* GPRS PDP connection has MTU to 1500 */ #define GPRS_PDP_MTU 1500 /* 5 sec. connect timeout */ #define CONNECT_TIMEOUT (5 * HZ) #define CAIF_NET_DEFAULT_QUEUE_LEN 500 #define UNDEF_CONNID 0xffffffff /*This list is protected by the rtnl lock. */ static LIST_HEAD(chnl_net_list); MODULE_LICENSE("GPL"); MODULE_ALIAS_RTNL_LINK("caif"); enum caif_states { CAIF_CONNECTED = 1, CAIF_CONNECTING, CAIF_DISCONNECTED, CAIF_SHUTDOWN }; struct chnl_net { struct cflayer chnl; struct net_device_stats stats; struct caif_connect_request conn_req; struct list_head list_field; struct net_device *netdev; char name[256]; wait_queue_head_t netmgmt_wq; /* Flow status to remember and control the transmission. */ bool flowenabled; enum caif_states state; }; static void robust_list_del(struct list_head *delete_node) { struct list_head *list_node; struct list_head *n; ASSERT_RTNL(); list_for_each_safe(list_node, n, &chnl_net_list) { if (list_node == delete_node) { list_del(list_node); return; } } WARN_ON(1); } static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt) { struct sk_buff *skb; struct chnl_net *priv; int pktlen; const u8 *ip_version; u8 buf; priv = container_of(layr, struct chnl_net, chnl); if (!priv) return -EINVAL; skb = (struct sk_buff *) cfpkt_tonative(pkt); /* Get length of CAIF packet. */ pktlen = skb->len; /* Pass some minimum information and * send the packet to the net stack. */ skb->dev = priv->netdev; /* check the version of IP */ ip_version = skb_header_pointer(skb, 0, 1, &buf); if (!ip_version) { kfree_skb(skb); return -EINVAL; } switch (*ip_version >> 4) { case 4: skb->protocol = htons(ETH_P_IP); break; case 6: skb->protocol = htons(ETH_P_IPV6); break; default: kfree_skb(skb); priv->netdev->stats.rx_errors++; return -EINVAL; } /* If we change the header in loop mode, the checksum is corrupted. */ if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) skb->ip_summed = CHECKSUM_UNNECESSARY; else skb->ip_summed = CHECKSUM_NONE; if (in_interrupt()) netif_rx(skb); else netif_rx_ni(skb); /* Update statistics. */ priv->netdev->stats.rx_packets++; priv->netdev->stats.rx_bytes += pktlen; return 0; } static int delete_device(struct chnl_net *dev) { ASSERT_RTNL(); if (dev->netdev) unregister_netdevice(dev->netdev); return 0; } static void close_work(struct work_struct *work) { struct chnl_net *dev = NULL; struct list_head *list_node; struct list_head *_tmp; rtnl_lock(); list_for_each_safe(list_node, _tmp, &chnl_net_list) { dev = list_entry(list_node, struct chnl_net, list_field); if (dev->state == CAIF_SHUTDOWN) dev_close(dev->netdev); } rtnl_unlock(); } static DECLARE_WORK(close_worker, close_work); static void chnl_hold(struct cflayer *lyr) { struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); dev_hold(priv->netdev); } static void chnl_put(struct cflayer *lyr) { struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); dev_put(priv->netdev); } static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, int phyid) { struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); pr_debug("NET flowctrl func called flow: %s\n", flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND"); switch (flow) { case CAIF_CTRLCMD_FLOW_OFF_IND: priv->flowenabled = false; netif_stop_queue(priv->netdev); break; case CAIF_CTRLCMD_DEINIT_RSP: priv->state = CAIF_DISCONNECTED; break; case CAIF_CTRLCMD_INIT_FAIL_RSP: priv->state = CAIF_DISCONNECTED; wake_up_interruptible(&priv->netmgmt_wq); break; case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: priv->state = CAIF_SHUTDOWN; netif_tx_disable(priv->netdev); schedule_work(&close_worker); break; case CAIF_CTRLCMD_FLOW_ON_IND: priv->flowenabled = true; netif_wake_queue(priv->netdev); break; case CAIF_CTRLCMD_INIT_RSP: caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put); priv->state = CAIF_CONNECTED; priv->flowenabled = true; netif_wake_queue(priv->netdev); wake_up_interruptible(&priv->netmgmt_wq); break; default: break; } } static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct chnl_net *priv; struct cfpkt *pkt = NULL; int len; int result = -1; /* Get our private data. */ priv = netdev_priv(dev); if (skb->len > priv->netdev->mtu) { pr_warn("Size of skb exceeded MTU\n"); kfree_skb(skb); dev->stats.tx_errors++; return NETDEV_TX_OK; } if (!priv->flowenabled) { pr_debug("dropping packets flow off\n"); kfree_skb(skb); dev->stats.tx_dropped++; return NETDEV_TX_OK; } if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); /* Store original SKB length. */ len = skb->len; pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); /* Send the packet down the stack. */ result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); if (result) { dev->stats.tx_dropped++; return NETDEV_TX_OK; } /* Update statistics. */ dev->stats.tx_packets++; dev->stats.tx_bytes += len; return NETDEV_TX_OK; } static int chnl_net_open(struct net_device *dev) { struct chnl_net *priv = NULL; int result = -1; int llifindex, headroom, tailroom, mtu; struct net_device *lldev; ASSERT_RTNL(); priv = netdev_priv(dev); if (!priv) { pr_debug("chnl_net_open: no priv\n"); return -ENODEV; } if (priv->state != CAIF_CONNECTING) { priv->state = CAIF_CONNECTING; result = caif_connect_client(dev_net(dev), &priv->conn_req, &priv->chnl, &llifindex, &headroom, &tailroom); if (result != 0) { pr_debug("err: " "Unable to register and open device," " Err:%d\n", result); goto error; } lldev = __dev_get_by_index(dev_net(dev), llifindex); if (lldev == NULL) { pr_debug("no interface?\n"); result = -ENODEV; goto error; } dev->needed_tailroom = tailroom + lldev->needed_tailroom; dev->hard_header_len = headroom + lldev->hard_header_len + lldev->needed_tailroom; /* * MTU, head-room etc is not know before we have a * CAIF link layer device available. MTU calculation may * override initial RTNL configuration. * MTU is minimum of current mtu, link layer mtu pluss * CAIF head and tail, and PDP GPRS contexts max MTU. */ mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); mtu = min_t(int, GPRS_PDP_MTU, mtu); dev_set_mtu(dev, mtu); if (mtu < 100) { pr_warn("CAIF Interface MTU too small (%d)\n", mtu); result = -ENODEV; goto error; } } rtnl_unlock(); /* Release RTNL lock during connect wait */ result = wait_event_interruptible_timeout(priv->netmgmt_wq, priv->state != CAIF_CONNECTING, CONNECT_TIMEOUT); rtnl_lock(); if (result == -ERESTARTSYS) { pr_debug("wait_event_interruptible woken by a signal\n"); result = -ERESTARTSYS; goto error; } if (result == 0) { pr_debug("connect timeout\n"); caif_disconnect_client(dev_net(dev), &priv->chnl); priv->state = CAIF_DISCONNECTED; pr_debug("state disconnected\n"); result = -ETIMEDOUT; goto error; } if (priv->state != CAIF_CONNECTED) { pr_debug("connect failed\n"); result = -ECONNREFUSED; goto error; } pr_debug("CAIF Netdevice connected\n"); return 0; error: caif_disconnect_client(dev_net(dev), &priv->chnl); priv->state = CAIF_DISCONNECTED; pr_debug("state disconnected\n"); return result; } static int chnl_net_stop(struct net_device *dev) { struct chnl_net *priv; ASSERT_RTNL(); priv = netdev_priv(dev); priv->state = CAIF_DISCONNECTED; caif_disconnect_client(dev_net(dev), &priv->chnl); return 0; } static int chnl_net_init(struct net_device *dev) { struct chnl_net *priv; ASSERT_RTNL(); priv = netdev_priv(dev); strncpy(priv->name, dev->name, sizeof(priv->name)); return 0; } static void chnl_net_uninit(struct net_device *dev) { struct chnl_net *priv; ASSERT_RTNL(); priv = netdev_priv(dev); robust_list_del(&priv->list_field); } static const struct net_device_ops netdev_ops = { .ndo_open = chnl_net_open, .ndo_stop = chnl_net_stop, .ndo_init = chnl_net_init, .ndo_uninit = chnl_net_uninit, .ndo_start_xmit = chnl_net_start_xmit, }; static void chnl_net_destructor(struct net_device *dev) { struct chnl_net *priv = netdev_priv(dev); caif_free_client(&priv->chnl); free_netdev(dev); } static void ipcaif_net_setup(struct net_device *dev) { struct chnl_net *priv; dev->netdev_ops = &netdev_ops; dev->destructor = chnl_net_destructor; dev->flags |= IFF_NOARP; dev->flags |= IFF_POINTOPOINT; dev->mtu = GPRS_PDP_MTU; dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; priv = netdev_priv(dev); priv->chnl.receive = chnl_recv_cb; priv->chnl.ctrlcmd = chnl_flowctrl_cb; priv->netdev = dev; priv->conn_req.protocol = CAIFPROTO_DATAGRAM; priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; priv->conn_req.priority = CAIF_PRIO_LOW; /* Insert illegal value */ priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID; priv->flowenabled = false; init_waitqueue_head(&priv->netmgmt_wq); } static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) { struct chnl_net *priv; u8 loop; priv = netdev_priv(dev); if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID, priv->conn_req.sockaddr.u.dgm.connection_id) || nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID, priv->conn_req.sockaddr.u.dgm.connection_id)) goto nla_put_failure; loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop)) goto nla_put_failure; return 0; nla_put_failure: return -EMSGSIZE; } static void caif_netlink_parms(struct nlattr *data[], struct caif_connect_request *conn_req) { if (!data) { pr_warn("no params data found\n"); return; } if (data[IFLA_CAIF_IPV4_CONNID]) conn_req->sockaddr.u.dgm.connection_id = nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); if (data[IFLA_CAIF_IPV6_CONNID]) conn_req->sockaddr.u.dgm.connection_id = nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); if (data[IFLA_CAIF_LOOPBACK]) { if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; else conn_req->protocol = CAIFPROTO_DATAGRAM; } } static int ipcaif_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { int ret; struct chnl_net *caifdev; ASSERT_RTNL(); caifdev = netdev_priv(dev); caif_netlink_parms(data, &caifdev->conn_req); ret = register_netdevice(dev); if (ret) pr_warn("device rtml registration failed\n"); else list_add(&caifdev->list_field, &chnl_net_list); /* Use ifindex as connection id, and use loopback channel default. */ if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) { caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP; } return ret; } static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct chnl_net *caifdev; ASSERT_RTNL(); caifdev = netdev_priv(dev); caif_netlink_parms(data, &caifdev->conn_req); netdev_state_change(dev); return 0; } static size_t ipcaif_get_size(const struct net_device *dev) { return /* IFLA_CAIF_IPV4_CONNID */ nla_total_size(4) + /* IFLA_CAIF_IPV6_CONNID */ nla_total_size(4) + /* IFLA_CAIF_LOOPBACK */ nla_total_size(2) + 0; } static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } }; static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { .kind = "caif", .priv_size = sizeof(struct chnl_net), .setup = ipcaif_net_setup, .maxtype = IFLA_CAIF_MAX, .policy = ipcaif_policy, .newlink = ipcaif_newlink, .changelink = ipcaif_changelink, .get_size = ipcaif_get_size, .fill_info = ipcaif_fill_info, }; static int __init chnl_init_module(void) { return rtnl_link_register(&ipcaif_link_ops); } static void __exit chnl_exit_module(void) { struct chnl_net *dev = NULL; struct list_head *list_node; struct list_head *_tmp; rtnl_link_unregister(&ipcaif_link_ops); rtnl_lock(); list_for_each_safe(list_node, _tmp, &chnl_net_list) { dev = list_entry(list_node, struct chnl_net, list_field); list_del(list_node); delete_device(dev); } rtnl_unlock(); } module_init(chnl_init_module); module_exit(chnl_exit_module);