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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /net/netfilter/xt_l2tp.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'net/netfilter/xt_l2tp.c')
-rw-r--r--net/netfilter/xt_l2tp.c355
1 files changed, 355 insertions, 0 deletions
diff --git a/net/netfilter/xt_l2tp.c b/net/netfilter/xt_l2tp.c
new file mode 100644
index 000000000..a61eb81e9
--- /dev/null
+++ b/net/netfilter/xt_l2tp.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Kernel module to match L2TP header parameters. */
+
+/* (C) 2013 James Chapman <jchapman@katalix.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/if_ether.h>
+#include <net/ip.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+#include <net/udp.h>
+#include <linux/l2tp.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_tcpudp.h>
+#include <linux/netfilter/xt_l2tp.h>
+
+/* L2TP header masks */
+#define L2TP_HDR_T_BIT 0x8000
+#define L2TP_HDR_L_BIT 0x4000
+#define L2TP_HDR_VER 0x000f
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
+MODULE_DESCRIPTION("Xtables: L2TP header match");
+MODULE_ALIAS("ipt_l2tp");
+MODULE_ALIAS("ip6t_l2tp");
+
+/* The L2TP fields that can be matched */
+struct l2tp_data {
+ u32 tid;
+ u32 sid;
+ u8 type;
+ u8 version;
+};
+
+union l2tp_val {
+ __be16 val16[2];
+ __be32 val32;
+};
+
+static bool l2tp_match(const struct xt_l2tp_info *info, struct l2tp_data *data)
+{
+ if ((info->flags & XT_L2TP_TYPE) && (info->type != data->type))
+ return false;
+
+ if ((info->flags & XT_L2TP_VERSION) && (info->version != data->version))
+ return false;
+
+ /* Check tid only for L2TPv3 control or any L2TPv2 packets */
+ if ((info->flags & XT_L2TP_TID) &&
+ ((data->type == XT_L2TP_TYPE_CONTROL) || (data->version == 2)) &&
+ (info->tid != data->tid))
+ return false;
+
+ /* Check sid only for L2TP data packets */
+ if ((info->flags & XT_L2TP_SID) && (data->type == XT_L2TP_TYPE_DATA) &&
+ (info->sid != data->sid))
+ return false;
+
+ return true;
+}
+
+/* Parse L2TP header fields when UDP encapsulation is used. Handles
+ * L2TPv2 and L2TPv3. Note the L2TPv3 control and data packets have a
+ * different format. See
+ * RFC2661, Section 3.1, L2TPv2 Header Format
+ * RFC3931, Section 3.2.1, L2TPv3 Control Message Header
+ * RFC3931, Section 3.2.2, L2TPv3 Data Message Header
+ * RFC3931, Section 4.1.2.1, L2TPv3 Session Header over UDP
+ */
+static bool l2tp_udp_mt(const struct sk_buff *skb, struct xt_action_param *par, u16 thoff)
+{
+ const struct xt_l2tp_info *info = par->matchinfo;
+ int uhlen = sizeof(struct udphdr);
+ int offs = thoff + uhlen;
+ union l2tp_val *lh;
+ union l2tp_val lhbuf;
+ u16 flags;
+ struct l2tp_data data = { 0, };
+
+ if (par->fragoff != 0)
+ return false;
+
+ /* Extract L2TP header fields. The flags in the first 16 bits
+ * tell us where the other fields are.
+ */
+ lh = skb_header_pointer(skb, offs, 2, &lhbuf);
+ if (lh == NULL)
+ return false;
+
+ flags = ntohs(lh->val16[0]);
+ if (flags & L2TP_HDR_T_BIT)
+ data.type = XT_L2TP_TYPE_CONTROL;
+ else
+ data.type = XT_L2TP_TYPE_DATA;
+ data.version = (u8) flags & L2TP_HDR_VER;
+
+ /* Now extract the L2TP tid/sid. These are in different places
+ * for L2TPv2 (rfc2661) and L2TPv3 (rfc3931). For L2TPv2, we
+ * must also check to see if the length field is present,
+ * since this affects the offsets into the packet of the
+ * tid/sid fields.
+ */
+ if (data.version == 3) {
+ lh = skb_header_pointer(skb, offs + 4, 4, &lhbuf);
+ if (lh == NULL)
+ return false;
+ if (data.type == XT_L2TP_TYPE_CONTROL)
+ data.tid = ntohl(lh->val32);
+ else
+ data.sid = ntohl(lh->val32);
+ } else if (data.version == 2) {
+ if (flags & L2TP_HDR_L_BIT)
+ offs += 2;
+ lh = skb_header_pointer(skb, offs + 2, 4, &lhbuf);
+ if (lh == NULL)
+ return false;
+ data.tid = (u32) ntohs(lh->val16[0]);
+ data.sid = (u32) ntohs(lh->val16[1]);
+ } else
+ return false;
+
+ return l2tp_match(info, &data);
+}
+
+/* Parse L2TP header fields for IP encapsulation (no UDP header).
+ * L2TPv3 data packets have a different form with IP encap. See
+ * RC3931, Section 4.1.1.1, L2TPv3 Session Header over IP.
+ * RC3931, Section 4.1.1.2, L2TPv3 Control and Data Traffic over IP.
+ */
+static bool l2tp_ip_mt(const struct sk_buff *skb, struct xt_action_param *par, u16 thoff)
+{
+ const struct xt_l2tp_info *info = par->matchinfo;
+ union l2tp_val *lh;
+ union l2tp_val lhbuf;
+ struct l2tp_data data = { 0, };
+
+ /* For IP encap, the L2TP sid is the first 32-bits. */
+ lh = skb_header_pointer(skb, thoff, sizeof(lhbuf), &lhbuf);
+ if (lh == NULL)
+ return false;
+ if (lh->val32 == 0) {
+ /* Must be a control packet. The L2TP tid is further
+ * into the packet.
+ */
+ data.type = XT_L2TP_TYPE_CONTROL;
+ lh = skb_header_pointer(skb, thoff + 8, sizeof(lhbuf),
+ &lhbuf);
+ if (lh == NULL)
+ return false;
+ data.tid = ntohl(lh->val32);
+ } else {
+ data.sid = ntohl(lh->val32);
+ data.type = XT_L2TP_TYPE_DATA;
+ }
+
+ data.version = 3;
+
+ return l2tp_match(info, &data);
+}
+
+static bool l2tp_mt4(const struct sk_buff *skb, struct xt_action_param *par)
+{
+ struct iphdr *iph = ip_hdr(skb);
+ u8 ipproto = iph->protocol;
+
+ /* l2tp_mt_check4 already restricts the transport protocol */
+ switch (ipproto) {
+ case IPPROTO_UDP:
+ return l2tp_udp_mt(skb, par, par->thoff);
+ case IPPROTO_L2TP:
+ return l2tp_ip_mt(skb, par, par->thoff);
+ }
+
+ return false;
+}
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+static bool l2tp_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+{
+ unsigned int thoff = 0;
+ unsigned short fragoff = 0;
+ int ipproto;
+
+ ipproto = ipv6_find_hdr(skb, &thoff, -1, &fragoff, NULL);
+ if (fragoff != 0)
+ return false;
+
+ /* l2tp_mt_check6 already restricts the transport protocol */
+ switch (ipproto) {
+ case IPPROTO_UDP:
+ return l2tp_udp_mt(skb, par, thoff);
+ case IPPROTO_L2TP:
+ return l2tp_ip_mt(skb, par, thoff);
+ }
+
+ return false;
+}
+#endif
+
+static int l2tp_mt_check(const struct xt_mtchk_param *par)
+{
+ const struct xt_l2tp_info *info = par->matchinfo;
+
+ /* Check for invalid flags */
+ if (info->flags & ~(XT_L2TP_TID | XT_L2TP_SID | XT_L2TP_VERSION |
+ XT_L2TP_TYPE)) {
+ pr_info_ratelimited("unknown flags: %x\n", info->flags);
+ return -EINVAL;
+ }
+
+ /* At least one of tid, sid or type=control must be specified */
+ if ((!(info->flags & XT_L2TP_TID)) &&
+ (!(info->flags & XT_L2TP_SID)) &&
+ ((!(info->flags & XT_L2TP_TYPE)) ||
+ (info->type != XT_L2TP_TYPE_CONTROL))) {
+ pr_info_ratelimited("invalid flags combination: %x\n",
+ info->flags);
+ return -EINVAL;
+ }
+
+ /* If version 2 is specified, check that incompatible params
+ * are not supplied
+ */
+ if (info->flags & XT_L2TP_VERSION) {
+ if ((info->version < 2) || (info->version > 3)) {
+ pr_info_ratelimited("wrong L2TP version: %u\n",
+ info->version);
+ return -EINVAL;
+ }
+
+ if (info->version == 2) {
+ if ((info->flags & XT_L2TP_TID) &&
+ (info->tid > 0xffff)) {
+ pr_info_ratelimited("v2 tid > 0xffff: %u\n",
+ info->tid);
+ return -EINVAL;
+ }
+ if ((info->flags & XT_L2TP_SID) &&
+ (info->sid > 0xffff)) {
+ pr_info_ratelimited("v2 sid > 0xffff: %u\n",
+ info->sid);
+ return -EINVAL;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int l2tp_mt_check4(const struct xt_mtchk_param *par)
+{
+ const struct xt_l2tp_info *info = par->matchinfo;
+ const struct ipt_entry *e = par->entryinfo;
+ const struct ipt_ip *ip = &e->ip;
+ int ret;
+
+ ret = l2tp_mt_check(par);
+ if (ret != 0)
+ return ret;
+
+ if ((ip->proto != IPPROTO_UDP) &&
+ (ip->proto != IPPROTO_L2TP)) {
+ pr_info_ratelimited("missing protocol rule (udp|l2tpip)\n");
+ return -EINVAL;
+ }
+
+ if ((ip->proto == IPPROTO_L2TP) &&
+ (info->version == 2)) {
+ pr_info_ratelimited("v2 doesn't support IP mode\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+static int l2tp_mt_check6(const struct xt_mtchk_param *par)
+{
+ const struct xt_l2tp_info *info = par->matchinfo;
+ const struct ip6t_entry *e = par->entryinfo;
+ const struct ip6t_ip6 *ip = &e->ipv6;
+ int ret;
+
+ ret = l2tp_mt_check(par);
+ if (ret != 0)
+ return ret;
+
+ if ((ip->proto != IPPROTO_UDP) &&
+ (ip->proto != IPPROTO_L2TP)) {
+ pr_info_ratelimited("missing protocol rule (udp|l2tpip)\n");
+ return -EINVAL;
+ }
+
+ if ((ip->proto == IPPROTO_L2TP) &&
+ (info->version == 2)) {
+ pr_info_ratelimited("v2 doesn't support IP mode\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+#endif
+
+static struct xt_match l2tp_mt_reg[] __read_mostly = {
+ {
+ .name = "l2tp",
+ .revision = 0,
+ .family = NFPROTO_IPV4,
+ .match = l2tp_mt4,
+ .matchsize = XT_ALIGN(sizeof(struct xt_l2tp_info)),
+ .checkentry = l2tp_mt_check4,
+ .hooks = ((1 << NF_INET_PRE_ROUTING) |
+ (1 << NF_INET_LOCAL_IN) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_FORWARD)),
+ .me = THIS_MODULE,
+ },
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+ {
+ .name = "l2tp",
+ .revision = 0,
+ .family = NFPROTO_IPV6,
+ .match = l2tp_mt6,
+ .matchsize = XT_ALIGN(sizeof(struct xt_l2tp_info)),
+ .checkentry = l2tp_mt_check6,
+ .hooks = ((1 << NF_INET_PRE_ROUTING) |
+ (1 << NF_INET_LOCAL_IN) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_FORWARD)),
+ .me = THIS_MODULE,
+ },
+#endif
+};
+
+static int __init l2tp_mt_init(void)
+{
+ return xt_register_matches(&l2tp_mt_reg[0], ARRAY_SIZE(l2tp_mt_reg));
+}
+
+static void __exit l2tp_mt_exit(void)
+{
+ xt_unregister_matches(&l2tp_mt_reg[0], ARRAY_SIZE(l2tp_mt_reg));
+}
+
+module_init(l2tp_mt_init);
+module_exit(l2tp_mt_exit);