From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- Documentation/security/SCTP.rst | 344 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 344 insertions(+) create mode 100644 Documentation/security/SCTP.rst (limited to 'Documentation/security/SCTP.rst') diff --git a/Documentation/security/SCTP.rst b/Documentation/security/SCTP.rst new file mode 100644 index 000000000..b73eb764a --- /dev/null +++ b/Documentation/security/SCTP.rst @@ -0,0 +1,344 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==== +SCTP +==== + +SCTP LSM Support +================ + +Security Hooks +-------------- + +For security module support, three SCTP specific hooks have been implemented:: + + security_sctp_assoc_request() + security_sctp_bind_connect() + security_sctp_sk_clone() + security_sctp_assoc_established() + +The usage of these hooks are described below with the SELinux implementation +described in the `SCTP SELinux Support`_ chapter. + + +security_sctp_assoc_request() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Passes the ``@asoc`` and ``@chunk->skb`` of the association INIT packet to the +security module. Returns 0 on success, error on failure. +:: + + @asoc - pointer to sctp association structure. + @skb - pointer to skbuff of association packet. + + +security_sctp_bind_connect() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Passes one or more ipv4/ipv6 addresses to the security module for validation +based on the ``@optname`` that will result in either a bind or connect +service as shown in the permission check tables below. +Returns 0 on success, error on failure. +:: + + @sk - Pointer to sock structure. + @optname - Name of the option to validate. + @address - One or more ipv4 / ipv6 addresses. + @addrlen - The total length of address(s). This is calculated on each + ipv4 or ipv6 address using sizeof(struct sockaddr_in) or + sizeof(struct sockaddr_in6). + + ------------------------------------------------------------------ + | BIND Type Checks | + | @optname | @address contains | + |----------------------------|-----------------------------------| + | SCTP_SOCKOPT_BINDX_ADD | One or more ipv4 / ipv6 addresses | + | SCTP_PRIMARY_ADDR | Single ipv4 or ipv6 address | + | SCTP_SET_PEER_PRIMARY_ADDR | Single ipv4 or ipv6 address | + ------------------------------------------------------------------ + + ------------------------------------------------------------------ + | CONNECT Type Checks | + | @optname | @address contains | + |----------------------------|-----------------------------------| + | SCTP_SOCKOPT_CONNECTX | One or more ipv4 / ipv6 addresses | + | SCTP_PARAM_ADD_IP | One or more ipv4 / ipv6 addresses | + | SCTP_SENDMSG_CONNECT | Single ipv4 or ipv6 address | + | SCTP_PARAM_SET_PRIMARY | Single ipv4 or ipv6 address | + ------------------------------------------------------------------ + +A summary of the ``@optname`` entries is as follows:: + + SCTP_SOCKOPT_BINDX_ADD - Allows additional bind addresses to be + associated after (optionally) calling + bind(3). + sctp_bindx(3) adds a set of bind + addresses on a socket. + + SCTP_SOCKOPT_CONNECTX - Allows the allocation of multiple + addresses for reaching a peer + (multi-homed). + sctp_connectx(3) initiates a connection + on an SCTP socket using multiple + destination addresses. + + SCTP_SENDMSG_CONNECT - Initiate a connection that is generated by a + sendmsg(2) or sctp_sendmsg(3) on a new asociation. + + SCTP_PRIMARY_ADDR - Set local primary address. + + SCTP_SET_PEER_PRIMARY_ADDR - Request peer sets address as + association primary. + + SCTP_PARAM_ADD_IP - These are used when Dynamic Address + SCTP_PARAM_SET_PRIMARY - Reconfiguration is enabled as explained below. + + +To support Dynamic Address Reconfiguration the following parameters must be +enabled on both endpoints (or use the appropriate **setsockopt**\(2)):: + + /proc/sys/net/sctp/addip_enable + /proc/sys/net/sctp/addip_noauth_enable + +then the following *_PARAM_*'s are sent to the peer in an +ASCONF chunk when the corresponding ``@optname``'s are present:: + + @optname ASCONF Parameter + ---------- ------------------ + SCTP_SOCKOPT_BINDX_ADD -> SCTP_PARAM_ADD_IP + SCTP_SET_PEER_PRIMARY_ADDR -> SCTP_PARAM_SET_PRIMARY + + +security_sctp_sk_clone() +~~~~~~~~~~~~~~~~~~~~~~~~ +Called whenever a new socket is created by **accept**\(2) +(i.e. a TCP style socket) or when a socket is 'peeled off' e.g userspace +calls **sctp_peeloff**\(3). +:: + + @asoc - pointer to current sctp association structure. + @sk - pointer to current sock structure. + @newsk - pointer to new sock structure. + + +security_sctp_assoc_established() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Called when a COOKIE ACK is received, and the peer secid will be +saved into ``@asoc->peer_secid`` for client:: + + @asoc - pointer to sctp association structure. + @skb - pointer to skbuff of the COOKIE ACK packet. + + +Security Hooks used for Association Establishment +------------------------------------------------- + +The following diagram shows the use of ``security_sctp_bind_connect()``, +``security_sctp_assoc_request()``, ``security_sctp_assoc_established()`` when +establishing an association. +:: + + SCTP endpoint "A" SCTP endpoint "Z" + ================= ================= + sctp_sf_do_prm_asoc() + Association setup can be initiated + by a connect(2), sctp_connectx(3), + sendmsg(2) or sctp_sendmsg(3). + These will result in a call to + security_sctp_bind_connect() to + initiate an association to + SCTP peer endpoint "Z". + INIT ---------------------------------------------> + sctp_sf_do_5_1B_init() + Respond to an INIT chunk. + SCTP peer endpoint "A" is asking + for a temporary association. + Call security_sctp_assoc_request() + to set the peer label if first + association. + If not first association, check + whether allowed, IF so send: + <----------------------------------------------- INIT ACK + | ELSE audit event and silently + | discard the packet. + | + COOKIE ECHO ------------------------------------------> + sctp_sf_do_5_1D_ce() + Respond to an COOKIE ECHO chunk. + Confirm the cookie and create a + permanent association. + Call security_sctp_assoc_request() to + do the same as for INIT chunk Response. + <------------------------------------------- COOKIE ACK + | | + sctp_sf_do_5_1E_ca | + Call security_sctp_assoc_established() | + to set the peer label. | + | | + | If SCTP_SOCKET_TCP or peeled off + | socket security_sctp_sk_clone() is + | called to clone the new socket. + | | + ESTABLISHED ESTABLISHED + | | + ------------------------------------------------------------------ + | Association Established | + ------------------------------------------------------------------ + + +SCTP SELinux Support +==================== + +Security Hooks +-------------- + +The `SCTP LSM Support`_ chapter above describes the following SCTP security +hooks with the SELinux specifics expanded below:: + + security_sctp_assoc_request() + security_sctp_bind_connect() + security_sctp_sk_clone() + security_sctp_assoc_established() + + +security_sctp_assoc_request() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Passes the ``@asoc`` and ``@chunk->skb`` of the association INIT packet to the +security module. Returns 0 on success, error on failure. +:: + + @asoc - pointer to sctp association structure. + @skb - pointer to skbuff of association packet. + +The security module performs the following operations: + IF this is the first association on ``@asoc->base.sk``, then set the peer + sid to that in ``@skb``. This will ensure there is only one peer sid + assigned to ``@asoc->base.sk`` that may support multiple associations. + + ELSE validate the ``@asoc->base.sk peer_sid`` against the ``@skb peer sid`` + to determine whether the association should be allowed or denied. + + Set the sctp ``@asoc sid`` to socket's sid (from ``asoc->base.sk``) with + MLS portion taken from ``@skb peer sid``. This will be used by SCTP + TCP style sockets and peeled off connections as they cause a new socket + to be generated. + + If IP security options are configured (CIPSO/CALIPSO), then the ip + options are set on the socket. + + +security_sctp_bind_connect() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Checks permissions required for ipv4/ipv6 addresses based on the ``@optname`` +as follows:: + + ------------------------------------------------------------------ + | BIND Permission Checks | + | @optname | @address contains | + |----------------------------|-----------------------------------| + | SCTP_SOCKOPT_BINDX_ADD | One or more ipv4 / ipv6 addresses | + | SCTP_PRIMARY_ADDR | Single ipv4 or ipv6 address | + | SCTP_SET_PEER_PRIMARY_ADDR | Single ipv4 or ipv6 address | + ------------------------------------------------------------------ + + ------------------------------------------------------------------ + | CONNECT Permission Checks | + | @optname | @address contains | + |----------------------------|-----------------------------------| + | SCTP_SOCKOPT_CONNECTX | One or more ipv4 / ipv6 addresses | + | SCTP_PARAM_ADD_IP | One or more ipv4 / ipv6 addresses | + | SCTP_SENDMSG_CONNECT | Single ipv4 or ipv6 address | + | SCTP_PARAM_SET_PRIMARY | Single ipv4 or ipv6 address | + ------------------------------------------------------------------ + + +`SCTP LSM Support`_ gives a summary of the ``@optname`` +entries and also describes ASCONF chunk processing when Dynamic Address +Reconfiguration is enabled. + + +security_sctp_sk_clone() +~~~~~~~~~~~~~~~~~~~~~~~~ +Called whenever a new socket is created by **accept**\(2) (i.e. a TCP style +socket) or when a socket is 'peeled off' e.g userspace calls +**sctp_peeloff**\(3). ``security_sctp_sk_clone()`` will set the new +sockets sid and peer sid to that contained in the ``@asoc sid`` and +``@asoc peer sid`` respectively. +:: + + @asoc - pointer to current sctp association structure. + @sk - pointer to current sock structure. + @newsk - pointer to new sock structure. + + +security_sctp_assoc_established() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Called when a COOKIE ACK is received where it sets the connection's peer sid +to that in ``@skb``:: + + @asoc - pointer to sctp association structure. + @skb - pointer to skbuff of the COOKIE ACK packet. + + +Policy Statements +----------------- +The following class and permissions to support SCTP are available within the +kernel:: + + class sctp_socket inherits socket { node_bind } + +whenever the following policy capability is enabled:: + + policycap extended_socket_class; + +SELinux SCTP support adds the ``name_connect`` permission for connecting +to a specific port type and the ``association`` permission that is explained +in the section below. + +If userspace tools have been updated, SCTP will support the ``portcon`` +statement as shown in the following example:: + + portcon sctp 1024-1036 system_u:object_r:sctp_ports_t:s0 + + +SCTP Peer Labeling +------------------ +An SCTP socket will only have one peer label assigned to it. This will be +assigned during the establishment of the first association. Any further +associations on this socket will have their packet peer label compared to +the sockets peer label, and only if they are different will the +``association`` permission be validated. This is validated by checking the +socket peer sid against the received packets peer sid to determine whether +the association should be allowed or denied. + +NOTES: + 1) If peer labeling is not enabled, then the peer context will always be + ``SECINITSID_UNLABELED`` (``unlabeled_t`` in Reference Policy). + + 2) As SCTP can support more than one transport address per endpoint + (multi-homing) on a single socket, it is possible to configure policy + and NetLabel to provide different peer labels for each of these. As the + socket peer label is determined by the first associations transport + address, it is recommended that all peer labels are consistent. + + 3) **getpeercon**\(3) may be used by userspace to retrieve the sockets peer + context. + + 4) While not SCTP specific, be aware when using NetLabel that if a label + is assigned to a specific interface, and that interface 'goes down', + then the NetLabel service will remove the entry. Therefore ensure that + the network startup scripts call **netlabelctl**\(8) to set the required + label (see **netlabel-config**\(8) helper script for details). + + 5) The NetLabel SCTP peer labeling rules apply as discussed in the following + set of posts tagged "netlabel" at: https://www.paul-moore.com/blog/t. + + 6) CIPSO is only supported for IPv4 addressing: ``socket(AF_INET, ...)`` + CALIPSO is only supported for IPv6 addressing: ``socket(AF_INET6, ...)`` + + Note the following when testing CIPSO/CALIPSO: + a) CIPSO will send an ICMP packet if an SCTP packet cannot be + delivered because of an invalid label. + b) CALIPSO does not send an ICMP packet, just silently discards it. + + 7) IPSEC is not supported as RFC 3554 - sctp/ipsec support has not been + implemented in userspace (**racoon**\(8) or **ipsec_pluto**\(8)), + although the kernel supports SCTP/IPSEC. -- cgit v1.2.3