diff options
Diffstat (limited to 'net/l2tp/l2tp_eth.c')
| -rw-r--r-- | net/l2tp/l2tp_eth.c | 76 |
1 files changed, 64 insertions, 12 deletions
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c index 6fd41d7afe1e..8b21af7321b9 100644 --- a/net/l2tp/l2tp_eth.c +++ b/net/l2tp/l2tp_eth.c @@ -30,6 +30,9 @@ #include <net/xfrm.h> #include <net/net_namespace.h> #include <net/netns/generic.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/udp.h> #include "l2tp_core.h" @@ -127,8 +130,13 @@ static const struct net_device_ops l2tp_eth_netdev_ops = { .ndo_set_mac_address = eth_mac_addr, }; +static struct device_type l2tpeth_type = { + .name = "l2tpeth", +}; + static void l2tp_eth_dev_setup(struct net_device *dev) { + SET_NETDEV_DEVTYPE(dev, &l2tpeth_type); ether_setup(dev); dev->priv_flags &= ~IFF_TX_SKB_SHARING; dev->features |= NETIF_F_LLTX; @@ -204,8 +212,58 @@ static void l2tp_eth_show(struct seq_file *m, void *arg) } #endif +static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel, + struct l2tp_session *session, + struct net_device *dev) +{ + unsigned int overhead = 0; + struct dst_entry *dst; + u32 l3_overhead = 0; + + /* if the encap is UDP, account for UDP header size */ + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { + overhead += sizeof(struct udphdr); + dev->needed_headroom += sizeof(struct udphdr); + } + if (session->mtu != 0) { + dev->mtu = session->mtu; + dev->needed_headroom += session->hdr_len; + return; + } + lock_sock(tunnel->sock); + l3_overhead = kernel_sock_ip_overhead(tunnel->sock); + release_sock(tunnel->sock); + if (l3_overhead == 0) { + /* L3 Overhead couldn't be identified, this could be + * because tunnel->sock was NULL or the socket's + * address family was not IPv4 or IPv6, + * dev mtu stays at 1500. + */ + return; + } + /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr + * UDP overhead, if any, was already factored in above. + */ + overhead += session->hdr_len + ETH_HLEN + l3_overhead; + + /* If PMTU discovery was enabled, use discovered MTU on L2TP device */ + dst = sk_dst_get(tunnel->sock); + if (dst) { + /* dst_mtu will use PMTU if found, else fallback to intf MTU */ + u32 pmtu = dst_mtu(dst); + + if (pmtu != 0) + dev->mtu = pmtu; + dst_release(dst); + } + session->mtu = dev->mtu - overhead; + dev->mtu = session->mtu; + dev->needed_headroom += session->hdr_len; +} + static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) { + unsigned char name_assign_type; struct net_device *dev; char name[IFNAMSIZ]; struct l2tp_tunnel *tunnel; @@ -222,15 +280,12 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p } if (cfg->ifname) { - dev = dev_get_by_name(net, cfg->ifname); - if (dev) { - dev_put(dev); - rc = -EEXIST; - goto out; - } strlcpy(name, cfg->ifname, IFNAMSIZ); - } else + name_assign_type = NET_NAME_USER; + } else { strcpy(name, L2TP_ETH_DEV_NAME); + name_assign_type = NET_NAME_ENUM; + } session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, peer_session_id, cfg); @@ -239,7 +294,7 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p goto out; } - dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, + dev = alloc_netdev(sizeof(*priv), name, name_assign_type, l2tp_eth_dev_setup); if (!dev) { rc = -ENOMEM; @@ -247,12 +302,9 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p } dev_net_set(dev, net); - if (session->mtu == 0) - session->mtu = dev->mtu - session->hdr_len; - dev->mtu = session->mtu; - dev->needed_headroom += session->hdr_len; dev->min_mtu = 0; dev->max_mtu = ETH_MAX_MTU; + l2tp_eth_adjust_mtu(tunnel, session, dev); priv = netdev_priv(dev); priv->dev = dev; |