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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/net/wan/hdlc_x25.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/net/wan/hdlc_x25.c')
-rw-r--r-- | drivers/net/wan/hdlc_x25.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c new file mode 100644 index 000000000..f72c92c24 --- /dev/null +++ b/drivers/net/wan/hdlc_x25.c @@ -0,0 +1,384 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic HDLC support routines for Linux + * X.25 support + * + * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl> + */ + +#include <linux/errno.h> +#include <linux/gfp.h> +#include <linux/hdlc.h> +#include <linux/if_arp.h> +#include <linux/inetdevice.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/lapb.h> +#include <linux/module.h> +#include <linux/pkt_sched.h> +#include <linux/poll.h> +#include <linux/rtnetlink.h> +#include <linux/skbuff.h> +#include <net/x25device.h> + +struct x25_state { + x25_hdlc_proto settings; + bool up; + spinlock_t up_lock; /* Protects "up" */ + struct sk_buff_head rx_queue; + struct tasklet_struct rx_tasklet; +}; + +static int x25_ioctl(struct net_device *dev, struct if_settings *ifs); + +static struct x25_state *state(hdlc_device *hdlc) +{ + return hdlc->state; +} + +static void x25_rx_queue_kick(struct tasklet_struct *t) +{ + struct x25_state *x25st = from_tasklet(x25st, t, rx_tasklet); + struct sk_buff *skb = skb_dequeue(&x25st->rx_queue); + + while (skb) { + netif_receive_skb_core(skb); + skb = skb_dequeue(&x25st->rx_queue); + } +} + +/* These functions are callbacks called by LAPB layer */ + +static void x25_connect_disconnect(struct net_device *dev, int reason, int code) +{ + struct x25_state *x25st = state(dev_to_hdlc(dev)); + struct sk_buff *skb; + unsigned char *ptr; + + skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC); + if (!skb) + return; + + ptr = skb_put(skb, 1); + *ptr = code; + + skb->protocol = x25_type_trans(skb, dev); + + skb_queue_tail(&x25st->rx_queue, skb); + tasklet_schedule(&x25st->rx_tasklet); +} + +static void x25_connected(struct net_device *dev, int reason) +{ + x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT); +} + +static void x25_disconnected(struct net_device *dev, int reason) +{ + x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT); +} + +static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) +{ + struct x25_state *x25st = state(dev_to_hdlc(dev)); + unsigned char *ptr; + + if (skb_cow(skb, 1)) { + kfree_skb(skb); + return NET_RX_DROP; + } + + skb_push(skb, 1); + + ptr = skb->data; + *ptr = X25_IFACE_DATA; + + skb->protocol = x25_type_trans(skb, dev); + + skb_queue_tail(&x25st->rx_queue, skb); + tasklet_schedule(&x25st->rx_tasklet); + return NET_RX_SUCCESS; +} + +static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + + skb_reset_network_header(skb); + skb->protocol = hdlc_type_trans(skb, dev); + + if (dev_nit_active(dev)) + dev_queue_xmit_nit(skb, dev); + + hdlc->xmit(skb, dev); /* Ignore return value :-( */ +} + +static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + struct x25_state *x25st = state(hdlc); + int result; + + /* There should be a pseudo header of 1 byte added by upper layers. + * Check to make sure it is there before reading it. + */ + if (skb->len < 1) { + kfree_skb(skb); + return NETDEV_TX_OK; + } + + spin_lock_bh(&x25st->up_lock); + if (!x25st->up) { + spin_unlock_bh(&x25st->up_lock); + kfree_skb(skb); + return NETDEV_TX_OK; + } + + switch (skb->data[0]) { + case X25_IFACE_DATA: /* Data to be transmitted */ + skb_pull(skb, 1); + result = lapb_data_request(dev, skb); + if (result != LAPB_OK) + dev_kfree_skb(skb); + spin_unlock_bh(&x25st->up_lock); + return NETDEV_TX_OK; + + case X25_IFACE_CONNECT: + result = lapb_connect_request(dev); + if (result != LAPB_OK) { + if (result == LAPB_CONNECTED) + /* Send connect confirm. msg to level 3 */ + x25_connected(dev, 0); + else + netdev_err(dev, "LAPB connect request failed, error code = %i\n", + result); + } + break; + + case X25_IFACE_DISCONNECT: + result = lapb_disconnect_request(dev); + if (result != LAPB_OK) { + if (result == LAPB_NOTCONNECTED) + /* Send disconnect confirm. msg to level 3 */ + x25_disconnected(dev, 0); + else + netdev_err(dev, "LAPB disconnect request failed, error code = %i\n", + result); + } + break; + + default: /* to be defined */ + break; + } + + spin_unlock_bh(&x25st->up_lock); + dev_kfree_skb(skb); + return NETDEV_TX_OK; +} + +static int x25_open(struct net_device *dev) +{ + static const struct lapb_register_struct cb = { + .connect_confirmation = x25_connected, + .connect_indication = x25_connected, + .disconnect_confirmation = x25_disconnected, + .disconnect_indication = x25_disconnected, + .data_indication = x25_data_indication, + .data_transmit = x25_data_transmit, + }; + hdlc_device *hdlc = dev_to_hdlc(dev); + struct x25_state *x25st = state(hdlc); + struct lapb_parms_struct params; + int result; + + result = lapb_register(dev, &cb); + if (result != LAPB_OK) + return -ENOMEM; + + result = lapb_getparms(dev, ¶ms); + if (result != LAPB_OK) + return -EINVAL; + + if (state(hdlc)->settings.dce) + params.mode = params.mode | LAPB_DCE; + + if (state(hdlc)->settings.modulo == 128) + params.mode = params.mode | LAPB_EXTENDED; + + params.window = state(hdlc)->settings.window; + params.t1 = state(hdlc)->settings.t1; + params.t2 = state(hdlc)->settings.t2; + params.n2 = state(hdlc)->settings.n2; + + result = lapb_setparms(dev, ¶ms); + if (result != LAPB_OK) + return -EINVAL; + + spin_lock_bh(&x25st->up_lock); + x25st->up = true; + spin_unlock_bh(&x25st->up_lock); + + return 0; +} + +static void x25_close(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + struct x25_state *x25st = state(hdlc); + + spin_lock_bh(&x25st->up_lock); + x25st->up = false; + spin_unlock_bh(&x25st->up_lock); + + lapb_unregister(dev); + tasklet_kill(&x25st->rx_tasklet); +} + +static int x25_rx(struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + hdlc_device *hdlc = dev_to_hdlc(dev); + struct x25_state *x25st = state(hdlc); + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) { + dev->stats.rx_dropped++; + return NET_RX_DROP; + } + + spin_lock_bh(&x25st->up_lock); + if (!x25st->up) { + spin_unlock_bh(&x25st->up_lock); + kfree_skb(skb); + dev->stats.rx_dropped++; + return NET_RX_DROP; + } + + if (lapb_data_received(dev, skb) == LAPB_OK) { + spin_unlock_bh(&x25st->up_lock); + return NET_RX_SUCCESS; + } + + spin_unlock_bh(&x25st->up_lock); + dev->stats.rx_errors++; + dev_kfree_skb_any(skb); + return NET_RX_DROP; +} + +static struct hdlc_proto proto = { + .open = x25_open, + .close = x25_close, + .ioctl = x25_ioctl, + .netif_rx = x25_rx, + .xmit = x25_xmit, + .module = THIS_MODULE, +}; + +static int x25_ioctl(struct net_device *dev, struct if_settings *ifs) +{ + x25_hdlc_proto __user *x25_s = ifs->ifs_ifsu.x25; + const size_t size = sizeof(x25_hdlc_proto); + hdlc_device *hdlc = dev_to_hdlc(dev); + x25_hdlc_proto new_settings; + int result; + + switch (ifs->type) { + case IF_GET_PROTO: + if (dev_to_hdlc(dev)->proto != &proto) + return -EINVAL; + ifs->type = IF_PROTO_X25; + if (ifs->size < size) { + ifs->size = size; /* data size wanted */ + return -ENOBUFS; + } + if (copy_to_user(x25_s, &state(hdlc)->settings, size)) + return -EFAULT; + return 0; + + case IF_PROTO_X25: + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + if (dev->flags & IFF_UP) + return -EBUSY; + + /* backward compatibility */ + if (ifs->size == 0) { + new_settings.dce = 0; + new_settings.modulo = 8; + new_settings.window = 7; + new_settings.t1 = 3; + new_settings.t2 = 1; + new_settings.n2 = 10; + } else { + if (copy_from_user(&new_settings, x25_s, size)) + return -EFAULT; + + if ((new_settings.dce != 0 && + new_settings.dce != 1) || + (new_settings.modulo != 8 && + new_settings.modulo != 128) || + new_settings.window < 1 || + (new_settings.modulo == 8 && + new_settings.window > 7) || + (new_settings.modulo == 128 && + new_settings.window > 127) || + new_settings.t1 < 1 || + new_settings.t1 > 255 || + new_settings.t2 < 1 || + new_settings.t2 > 255 || + new_settings.n2 < 1 || + new_settings.n2 > 255) + return -EINVAL; + } + + result = hdlc->attach(dev, ENCODING_NRZ, + PARITY_CRC16_PR1_CCITT); + if (result) + return result; + + result = attach_hdlc_protocol(dev, &proto, + sizeof(struct x25_state)); + if (result) + return result; + + memcpy(&state(hdlc)->settings, &new_settings, size); + state(hdlc)->up = false; + spin_lock_init(&state(hdlc)->up_lock); + skb_queue_head_init(&state(hdlc)->rx_queue); + tasklet_setup(&state(hdlc)->rx_tasklet, x25_rx_queue_kick); + + /* There's no header_ops so hard_header_len should be 0. */ + dev->hard_header_len = 0; + /* When transmitting data: + * first we'll remove a pseudo header of 1 byte, + * then we'll prepend an LAPB header of at most 3 bytes. + */ + dev->needed_headroom = 3 - 1; + + dev->type = ARPHRD_X25; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); + netif_dormant_off(dev); + return 0; + } + + return -EINVAL; +} + +static int __init hdlc_x25_init(void) +{ + register_hdlc_protocol(&proto); + return 0; +} + +static void __exit hdlc_x25_exit(void) +{ + unregister_hdlc_protocol(&proto); +} + +module_init(hdlc_x25_init); +module_exit(hdlc_x25_exit); + +MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); +MODULE_DESCRIPTION("X.25 protocol support for generic HDLC"); +MODULE_LICENSE("GPL v2"); |