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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 /lib/nlattr.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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 '')
-rw-r--r--lib/nlattr.c1137
1 files changed, 1137 insertions, 0 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c
new file mode 100644
index 000000000..489e15bde
--- /dev/null
+++ b/lib/nlattr.c
@@ -0,0 +1,1137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NETLINK Netlink attributes
+ *
+ * Authors: Thomas Graf <tgraf@suug.ch>
+ * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/nospec.h>
+#include <linux/skbuff.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <net/netlink.h>
+
+/* For these data types, attribute length should be exactly the given
+ * size. However, to maintain compatibility with broken commands, if the
+ * attribute length does not match the expected size a warning is emitted
+ * to the user that the command is sending invalid data and needs to be fixed.
+ */
+static const u8 nla_attr_len[NLA_TYPE_MAX+1] = {
+ [NLA_U8] = sizeof(u8),
+ [NLA_U16] = sizeof(u16),
+ [NLA_U32] = sizeof(u32),
+ [NLA_U64] = sizeof(u64),
+ [NLA_S8] = sizeof(s8),
+ [NLA_S16] = sizeof(s16),
+ [NLA_S32] = sizeof(s32),
+ [NLA_S64] = sizeof(s64),
+};
+
+static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
+ [NLA_U8] = sizeof(u8),
+ [NLA_U16] = sizeof(u16),
+ [NLA_U32] = sizeof(u32),
+ [NLA_U64] = sizeof(u64),
+ [NLA_MSECS] = sizeof(u64),
+ [NLA_NESTED] = NLA_HDRLEN,
+ [NLA_S8] = sizeof(s8),
+ [NLA_S16] = sizeof(s16),
+ [NLA_S32] = sizeof(s32),
+ [NLA_S64] = sizeof(s64),
+};
+
+/*
+ * Nested policies might refer back to the original
+ * policy in some cases, and userspace could try to
+ * abuse that and recurse by nesting in the right
+ * ways. Limit recursion to avoid this problem.
+ */
+#define MAX_POLICY_RECURSION_DEPTH 10
+
+static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy,
+ unsigned int validate,
+ struct netlink_ext_ack *extack,
+ struct nlattr **tb, unsigned int depth);
+
+static int validate_nla_bitfield32(const struct nlattr *nla,
+ const u32 valid_flags_mask)
+{
+ const struct nla_bitfield32 *bf = nla_data(nla);
+
+ if (!valid_flags_mask)
+ return -EINVAL;
+
+ /*disallow invalid bit selector */
+ if (bf->selector & ~valid_flags_mask)
+ return -EINVAL;
+
+ /*disallow invalid bit values */
+ if (bf->value & ~valid_flags_mask)
+ return -EINVAL;
+
+ /*disallow valid bit values that are not selected*/
+ if (bf->value & ~bf->selector)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int nla_validate_array(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack,
+ unsigned int validate, unsigned int depth)
+{
+ const struct nlattr *entry;
+ int rem;
+
+ nla_for_each_attr(entry, head, len, rem) {
+ int ret;
+
+ if (nla_len(entry) == 0)
+ continue;
+
+ if (nla_len(entry) < NLA_HDRLEN) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, entry, policy,
+ "Array element too short");
+ return -ERANGE;
+ }
+
+ ret = __nla_validate_parse(nla_data(entry), nla_len(entry),
+ maxtype, policy, validate, extack,
+ NULL, depth + 1);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+void nla_get_range_unsigned(const struct nla_policy *pt,
+ struct netlink_range_validation *range)
+{
+ WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
+ (pt->min < 0 || pt->max < 0));
+
+ range->min = 0;
+
+ switch (pt->type) {
+ case NLA_U8:
+ range->max = U8_MAX;
+ break;
+ case NLA_U16:
+ case NLA_BE16:
+ case NLA_BINARY:
+ range->max = U16_MAX;
+ break;
+ case NLA_U32:
+ case NLA_BE32:
+ range->max = U32_MAX;
+ break;
+ case NLA_U64:
+ case NLA_MSECS:
+ range->max = U64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_RANGE:
+ case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
+ range->min = pt->min;
+ range->max = pt->max;
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ *range = *pt->range;
+ break;
+ case NLA_VALIDATE_MIN:
+ range->min = pt->min;
+ break;
+ case NLA_VALIDATE_MAX:
+ range->max = pt->max;
+ break;
+ default:
+ break;
+ }
+}
+
+static int nla_validate_range_unsigned(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack,
+ unsigned int validate)
+{
+ struct netlink_range_validation range;
+ u64 value;
+
+ switch (pt->type) {
+ case NLA_U8:
+ value = nla_get_u8(nla);
+ break;
+ case NLA_U16:
+ value = nla_get_u16(nla);
+ break;
+ case NLA_U32:
+ value = nla_get_u32(nla);
+ break;
+ case NLA_U64:
+ value = nla_get_u64(nla);
+ break;
+ case NLA_MSECS:
+ value = nla_get_u64(nla);
+ break;
+ case NLA_BINARY:
+ value = nla_len(nla);
+ break;
+ case NLA_BE16:
+ value = ntohs(nla_get_be16(nla));
+ break;
+ case NLA_BE32:
+ value = ntohl(nla_get_be32(nla));
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ nla_get_range_unsigned(pt, &range);
+
+ if (pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG &&
+ pt->type == NLA_BINARY && value > range.max) {
+ pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
+ current->comm, pt->type);
+ if (validate & NL_VALIDATE_STRICT_ATTRS) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "invalid attribute length");
+ return -EINVAL;
+ }
+
+ /* this assumes min <= max (don't validate against min) */
+ return 0;
+ }
+
+ if (value < range.min || value > range.max) {
+ bool binary = pt->type == NLA_BINARY;
+
+ if (binary)
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "binary attribute size out of range");
+ else
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "integer out of range");
+
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+void nla_get_range_signed(const struct nla_policy *pt,
+ struct netlink_range_validation_signed *range)
+{
+ switch (pt->type) {
+ case NLA_S8:
+ range->min = S8_MIN;
+ range->max = S8_MAX;
+ break;
+ case NLA_S16:
+ range->min = S16_MIN;
+ range->max = S16_MAX;
+ break;
+ case NLA_S32:
+ range->min = S32_MIN;
+ range->max = S32_MAX;
+ break;
+ case NLA_S64:
+ range->min = S64_MIN;
+ range->max = S64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_RANGE:
+ range->min = pt->min;
+ range->max = pt->max;
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ *range = *pt->range_signed;
+ break;
+ case NLA_VALIDATE_MIN:
+ range->min = pt->min;
+ break;
+ case NLA_VALIDATE_MAX:
+ range->max = pt->max;
+ break;
+ default:
+ break;
+ }
+}
+
+static int nla_validate_int_range_signed(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ struct netlink_range_validation_signed range;
+ s64 value;
+
+ switch (pt->type) {
+ case NLA_S8:
+ value = nla_get_s8(nla);
+ break;
+ case NLA_S16:
+ value = nla_get_s16(nla);
+ break;
+ case NLA_S32:
+ value = nla_get_s32(nla);
+ break;
+ case NLA_S64:
+ value = nla_get_s64(nla);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ nla_get_range_signed(pt, &range);
+
+ if (value < range.min || value > range.max) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "integer out of range");
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+static int nla_validate_int_range(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack,
+ unsigned int validate)
+{
+ switch (pt->type) {
+ case NLA_U8:
+ case NLA_U16:
+ case NLA_U32:
+ case NLA_U64:
+ case NLA_MSECS:
+ case NLA_BINARY:
+ case NLA_BE16:
+ case NLA_BE32:
+ return nla_validate_range_unsigned(pt, nla, extack, validate);
+ case NLA_S8:
+ case NLA_S16:
+ case NLA_S32:
+ case NLA_S64:
+ return nla_validate_int_range_signed(pt, nla, extack);
+ default:
+ WARN_ON(1);
+ return -EINVAL;
+ }
+}
+
+static int nla_validate_mask(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ u64 value;
+
+ switch (pt->type) {
+ case NLA_U8:
+ value = nla_get_u8(nla);
+ break;
+ case NLA_U16:
+ value = nla_get_u16(nla);
+ break;
+ case NLA_U32:
+ value = nla_get_u32(nla);
+ break;
+ case NLA_U64:
+ value = nla_get_u64(nla);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (value & ~(u64)pt->mask) {
+ NL_SET_ERR_MSG_ATTR(extack, nla, "reserved bit set");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int validate_nla(const struct nlattr *nla, int maxtype,
+ const struct nla_policy *policy, unsigned int validate,
+ struct netlink_ext_ack *extack, unsigned int depth)
+{
+ u16 strict_start_type = policy[0].strict_start_type;
+ const struct nla_policy *pt;
+ int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
+ int err = -ERANGE;
+
+ if (strict_start_type && type >= strict_start_type)
+ validate |= NL_VALIDATE_STRICT;
+
+ if (type <= 0 || type > maxtype)
+ return 0;
+
+ type = array_index_nospec(type, maxtype + 1);
+ pt = &policy[type];
+
+ BUG_ON(pt->type > NLA_TYPE_MAX);
+
+ if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
+ pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
+ current->comm, type);
+ if (validate & NL_VALIDATE_STRICT_ATTRS) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "invalid attribute length");
+ return -EINVAL;
+ }
+ }
+
+ if (validate & NL_VALIDATE_NESTED) {
+ if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) &&
+ !(nla->nla_type & NLA_F_NESTED)) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "NLA_F_NESTED is missing");
+ return -EINVAL;
+ }
+ if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY &&
+ pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "NLA_F_NESTED not expected");
+ return -EINVAL;
+ }
+ }
+
+ switch (pt->type) {
+ case NLA_REJECT:
+ if (extack && pt->reject_message) {
+ NL_SET_BAD_ATTR(extack, nla);
+ extack->_msg = pt->reject_message;
+ return -EINVAL;
+ }
+ err = -EINVAL;
+ goto out_err;
+
+ case NLA_FLAG:
+ if (attrlen > 0)
+ goto out_err;
+ break;
+
+ case NLA_BITFIELD32:
+ if (attrlen != sizeof(struct nla_bitfield32))
+ goto out_err;
+
+ err = validate_nla_bitfield32(nla, pt->bitfield32_valid);
+ if (err)
+ goto out_err;
+ break;
+
+ case NLA_NUL_STRING:
+ if (pt->len)
+ minlen = min_t(int, attrlen, pt->len + 1);
+ else
+ minlen = attrlen;
+
+ if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) {
+ err = -EINVAL;
+ goto out_err;
+ }
+ fallthrough;
+
+ case NLA_STRING:
+ if (attrlen < 1)
+ goto out_err;
+
+ if (pt->len) {
+ char *buf = nla_data(nla);
+
+ if (buf[attrlen - 1] == '\0')
+ attrlen--;
+
+ if (attrlen > pt->len)
+ goto out_err;
+ }
+ break;
+
+ case NLA_BINARY:
+ if (pt->len && attrlen > pt->len)
+ goto out_err;
+ break;
+
+ case NLA_NESTED:
+ /* a nested attributes is allowed to be empty; if its not,
+ * it must have a size of at least NLA_HDRLEN.
+ */
+ if (attrlen == 0)
+ break;
+ if (attrlen < NLA_HDRLEN)
+ goto out_err;
+ if (pt->nested_policy) {
+ err = __nla_validate_parse(nla_data(nla), nla_len(nla),
+ pt->len, pt->nested_policy,
+ validate, extack, NULL,
+ depth + 1);
+ if (err < 0) {
+ /*
+ * return directly to preserve the inner
+ * error message/attribute pointer
+ */
+ return err;
+ }
+ }
+ break;
+ case NLA_NESTED_ARRAY:
+ /* a nested array attribute is allowed to be empty; if its not,
+ * it must have a size of at least NLA_HDRLEN.
+ */
+ if (attrlen == 0)
+ break;
+ if (attrlen < NLA_HDRLEN)
+ goto out_err;
+ if (pt->nested_policy) {
+ int err;
+
+ err = nla_validate_array(nla_data(nla), nla_len(nla),
+ pt->len, pt->nested_policy,
+ extack, validate, depth);
+ if (err < 0) {
+ /*
+ * return directly to preserve the inner
+ * error message/attribute pointer
+ */
+ return err;
+ }
+ }
+ break;
+
+ case NLA_UNSPEC:
+ if (validate & NL_VALIDATE_UNSPEC) {
+ NL_SET_ERR_MSG_ATTR(extack, nla,
+ "Unsupported attribute");
+ return -EINVAL;
+ }
+ if (attrlen < pt->len)
+ goto out_err;
+ break;
+
+ default:
+ if (pt->len)
+ minlen = pt->len;
+ else
+ minlen = nla_attr_minlen[pt->type];
+
+ if (attrlen < minlen)
+ goto out_err;
+ }
+
+ /* further validation */
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_NONE:
+ /* nothing to do */
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ case NLA_VALIDATE_RANGE:
+ case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
+ case NLA_VALIDATE_MIN:
+ case NLA_VALIDATE_MAX:
+ err = nla_validate_int_range(pt, nla, extack, validate);
+ if (err)
+ return err;
+ break;
+ case NLA_VALIDATE_MASK:
+ err = nla_validate_mask(pt, nla, extack);
+ if (err)
+ return err;
+ break;
+ case NLA_VALIDATE_FUNCTION:
+ if (pt->validate) {
+ err = pt->validate(nla, extack);
+ if (err)
+ return err;
+ }
+ break;
+ }
+
+ return 0;
+out_err:
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "Attribute failed policy validation");
+ return err;
+}
+
+static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy,
+ unsigned int validate,
+ struct netlink_ext_ack *extack,
+ struct nlattr **tb, unsigned int depth)
+{
+ const struct nlattr *nla;
+ int rem;
+
+ if (depth >= MAX_POLICY_RECURSION_DEPTH) {
+ NL_SET_ERR_MSG(extack,
+ "allowed policy recursion depth exceeded");
+ return -EINVAL;
+ }
+
+ if (tb)
+ memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
+
+ nla_for_each_attr(nla, head, len, rem) {
+ u16 type = nla_type(nla);
+
+ if (type == 0 || type > maxtype) {
+ if (validate & NL_VALIDATE_MAXTYPE) {
+ NL_SET_ERR_MSG_ATTR(extack, nla,
+ "Unknown attribute type");
+ return -EINVAL;
+ }
+ continue;
+ }
+ type = array_index_nospec(type, maxtype + 1);
+ if (policy) {
+ int err = validate_nla(nla, maxtype, policy,
+ validate, extack, depth);
+
+ if (err < 0)
+ return err;
+ }
+
+ if (tb)
+ tb[type] = (struct nlattr *)nla;
+ }
+
+ if (unlikely(rem > 0)) {
+ pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n",
+ rem, current->comm);
+ NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes");
+ if (validate & NL_VALIDATE_TRAILING)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * __nla_validate - Validate a stream of attributes
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @maxtype: maximum attribute type to be expected
+ * @policy: validation policy
+ * @validate: validation strictness
+ * @extack: extended ACK report struct
+ *
+ * Validates all attributes in the specified attribute stream against the
+ * specified policy. Validation depends on the validate flags passed, see
+ * &enum netlink_validation for more details on that.
+ * See documentation of struct nla_policy for more details.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int __nla_validate(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy, unsigned int validate,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_validate_parse(head, len, maxtype, policy, validate,
+ extack, NULL, 0);
+}
+EXPORT_SYMBOL(__nla_validate);
+
+/**
+ * nla_policy_len - Determine the max. length of a policy
+ * @p: policy to use
+ * @n: number of policies
+ *
+ * Determines the max. length of the policy. It is currently used
+ * to allocated Netlink buffers roughly the size of the actual
+ * message.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int
+nla_policy_len(const struct nla_policy *p, int n)
+{
+ int i, len = 0;
+
+ for (i = 0; i < n; i++, p++) {
+ if (p->len)
+ len += nla_total_size(p->len);
+ else if (nla_attr_len[p->type])
+ len += nla_total_size(nla_attr_len[p->type]);
+ else if (nla_attr_minlen[p->type])
+ len += nla_total_size(nla_attr_minlen[p->type]);
+ }
+
+ return len;
+}
+EXPORT_SYMBOL(nla_policy_len);
+
+/**
+ * __nla_parse - Parse a stream of attributes into a tb buffer
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @policy: validation policy
+ * @validate: validation strictness
+ * @extack: extended ACK pointer
+ *
+ * Parses a stream of attributes and stores a pointer to each attribute in
+ * the tb array accessible via the attribute type.
+ * Validation is controlled by the @validate parameter.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int __nla_parse(struct nlattr **tb, int maxtype,
+ const struct nlattr *head, int len,
+ const struct nla_policy *policy, unsigned int validate,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_validate_parse(head, len, maxtype, policy, validate,
+ extack, tb, 0);
+}
+EXPORT_SYMBOL(__nla_parse);
+
+/**
+ * nla_find - Find a specific attribute in a stream of attributes
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @attrtype: type of attribute to look for
+ *
+ * Returns the first attribute in the stream matching the specified type.
+ */
+struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
+{
+ const struct nlattr *nla;
+ int rem;
+
+ nla_for_each_attr(nla, head, len, rem)
+ if (nla_type(nla) == attrtype)
+ return (struct nlattr *)nla;
+
+ return NULL;
+}
+EXPORT_SYMBOL(nla_find);
+
+/**
+ * nla_strscpy - Copy string attribute payload into a sized buffer
+ * @dst: Where to copy the string to.
+ * @nla: Attribute to copy the string from.
+ * @dstsize: Size of destination buffer.
+ *
+ * Copies at most dstsize - 1 bytes into the destination buffer.
+ * Unlike strlcpy the destination buffer is always padded out.
+ *
+ * Return:
+ * * srclen - Returns @nla length (not including the trailing %NUL).
+ * * -E2BIG - If @dstsize is 0 or greater than U16_MAX or @nla length greater
+ * than @dstsize.
+ */
+ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize)
+{
+ size_t srclen = nla_len(nla);
+ char *src = nla_data(nla);
+ ssize_t ret;
+ size_t len;
+
+ if (dstsize == 0 || WARN_ON_ONCE(dstsize > U16_MAX))
+ return -E2BIG;
+
+ if (srclen > 0 && src[srclen - 1] == '\0')
+ srclen--;
+
+ if (srclen >= dstsize) {
+ len = dstsize - 1;
+ ret = -E2BIG;
+ } else {
+ len = srclen;
+ ret = len;
+ }
+
+ memcpy(dst, src, len);
+ /* Zero pad end of dst. */
+ memset(dst + len, 0, dstsize - len);
+
+ return ret;
+}
+EXPORT_SYMBOL(nla_strscpy);
+
+/**
+ * nla_strdup - Copy string attribute payload into a newly allocated buffer
+ * @nla: attribute to copy the string from
+ * @flags: the type of memory to allocate (see kmalloc).
+ *
+ * Returns a pointer to the allocated buffer or NULL on error.
+ */
+char *nla_strdup(const struct nlattr *nla, gfp_t flags)
+{
+ size_t srclen = nla_len(nla);
+ char *src = nla_data(nla), *dst;
+
+ if (srclen > 0 && src[srclen - 1] == '\0')
+ srclen--;
+
+ dst = kmalloc(srclen + 1, flags);
+ if (dst != NULL) {
+ memcpy(dst, src, srclen);
+ dst[srclen] = '\0';
+ }
+ return dst;
+}
+EXPORT_SYMBOL(nla_strdup);
+
+/**
+ * nla_memcpy - Copy a netlink attribute into another memory area
+ * @dest: where to copy to memcpy
+ * @src: netlink attribute to copy from
+ * @count: size of the destination area
+ *
+ * Note: The number of bytes copied is limited by the length of
+ * attribute's payload. memcpy
+ *
+ * Returns the number of bytes copied.
+ */
+int nla_memcpy(void *dest, const struct nlattr *src, int count)
+{
+ int minlen = min_t(int, count, nla_len(src));
+
+ memcpy(dest, nla_data(src), minlen);
+ if (count > minlen)
+ memset(dest + minlen, 0, count - minlen);
+
+ return minlen;
+}
+EXPORT_SYMBOL(nla_memcpy);
+
+/**
+ * nla_memcmp - Compare an attribute with sized memory area
+ * @nla: netlink attribute
+ * @data: memory area
+ * @size: size of memory area
+ */
+int nla_memcmp(const struct nlattr *nla, const void *data,
+ size_t size)
+{
+ int d = nla_len(nla) - size;
+
+ if (d == 0)
+ d = memcmp(nla_data(nla), data, size);
+
+ return d;
+}
+EXPORT_SYMBOL(nla_memcmp);
+
+/**
+ * nla_strcmp - Compare a string attribute against a string
+ * @nla: netlink string attribute
+ * @str: another string
+ */
+int nla_strcmp(const struct nlattr *nla, const char *str)
+{
+ int len = strlen(str);
+ char *buf = nla_data(nla);
+ int attrlen = nla_len(nla);
+ int d;
+
+ while (attrlen > 0 && buf[attrlen - 1] == '\0')
+ attrlen--;
+
+ d = attrlen - len;
+ if (d == 0)
+ d = memcmp(nla_data(nla), str, len);
+
+ return d;
+}
+EXPORT_SYMBOL(nla_strcmp);
+
+#ifdef CONFIG_NET
+/**
+ * __nla_reserve - reserve room for attribute on the skb
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
+{
+ struct nlattr *nla;
+
+ nla = skb_put(skb, nla_total_size(attrlen));
+ nla->nla_type = attrtype;
+ nla->nla_len = nla_attr_size(attrlen);
+
+ memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
+
+ return nla;
+}
+EXPORT_SYMBOL(__nla_reserve);
+
+/**
+ * __nla_reserve_64bit - reserve room for attribute on the skb and align it
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @padattr: attribute type for the padding
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it. It also ensure that this
+ * attribute will have a 64-bit aligned nla_data() area.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
+ int attrlen, int padattr)
+{
+ nla_align_64bit(skb, padattr);
+
+ return __nla_reserve(skb, attrtype, attrlen);
+}
+EXPORT_SYMBOL(__nla_reserve_64bit);
+
+/**
+ * __nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the payload.
+ */
+void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+ return skb_put_zero(skb, NLA_ALIGN(attrlen));
+}
+EXPORT_SYMBOL(__nla_reserve_nohdr);
+
+/**
+ * nla_reserve - reserve room for attribute on the skb
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
+{
+ if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
+ return NULL;
+
+ return __nla_reserve(skb, attrtype, attrlen);
+}
+EXPORT_SYMBOL(nla_reserve);
+
+/**
+ * nla_reserve_64bit - reserve room for attribute on the skb and align it
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @padattr: attribute type for the padding
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it. It also ensure that this
+ * attribute will have a 64-bit aligned nla_data() area.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, int attrlen,
+ int padattr)
+{
+ size_t len;
+
+ if (nla_need_padding_for_64bit(skb))
+ len = nla_total_size_64bit(attrlen);
+ else
+ len = nla_total_size(attrlen);
+ if (unlikely(skb_tailroom(skb) < len))
+ return NULL;
+
+ return __nla_reserve_64bit(skb, attrtype, attrlen, padattr);
+}
+EXPORT_SYMBOL(nla_reserve_64bit);
+
+/**
+ * nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return NULL;
+
+ return __nla_reserve_nohdr(skb, attrlen);
+}
+EXPORT_SYMBOL(nla_reserve_nohdr);
+
+/**
+ * __nla_put - Add a netlink attribute to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
+ const void *data)
+{
+ struct nlattr *nla;
+
+ nla = __nla_reserve(skb, attrtype, attrlen);
+ memcpy(nla_data(nla), data, attrlen);
+}
+EXPORT_SYMBOL(__nla_put);
+
+/**
+ * __nla_put_64bit - Add a netlink attribute to a socket buffer and align it
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ * @padattr: attribute type for the padding
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
+ const void *data, int padattr)
+{
+ struct nlattr *nla;
+
+ nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr);
+ memcpy(nla_data(nla), data, attrlen);
+}
+EXPORT_SYMBOL(__nla_put_64bit);
+
+/**
+ * __nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute payload.
+ */
+void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+ void *start;
+
+ start = __nla_reserve_nohdr(skb, attrlen);
+ memcpy(start, data, attrlen);
+}
+EXPORT_SYMBOL(__nla_put_nohdr);
+
+/**
+ * nla_put - Add a netlink attribute to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
+ return -EMSGSIZE;
+
+ __nla_put(skb, attrtype, attrlen, data);
+ return 0;
+}
+EXPORT_SYMBOL(nla_put);
+
+/**
+ * nla_put_64bit - Add a netlink attribute to a socket buffer and align it
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ * @padattr: attribute type for the padding
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
+ const void *data, int padattr)
+{
+ size_t len;
+
+ if (nla_need_padding_for_64bit(skb))
+ len = nla_total_size_64bit(attrlen);
+ else
+ len = nla_total_size(attrlen);
+ if (unlikely(skb_tailroom(skb) < len))
+ return -EMSGSIZE;
+
+ __nla_put_64bit(skb, attrtype, attrlen, data, padattr);
+ return 0;
+}
+EXPORT_SYMBOL(nla_put_64bit);
+
+/**
+ * nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return -EMSGSIZE;
+
+ __nla_put_nohdr(skb, attrlen, data);
+ return 0;
+}
+EXPORT_SYMBOL(nla_put_nohdr);
+
+/**
+ * nla_append - Add a netlink attribute without header or padding
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_append(struct sk_buff *skb, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return -EMSGSIZE;
+
+ skb_put_data(skb, data, attrlen);
+ return 0;
+}
+EXPORT_SYMBOL(nla_append);
+#endif