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(). ... --- net/ipv4/inet_fragment.c | 608 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 608 insertions(+) create mode 100644 net/ipv4/inet_fragment.c (limited to 'net/ipv4/inet_fragment.c') diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c new file mode 100644 index 000000000..7072fc078 --- /dev/null +++ b/net/ipv4/inet_fragment.c @@ -0,0 +1,608 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * inet fragments management + * + * Authors: Pavel Emelyanov + * Started as consolidation of ipv4/ip_fragment.c, + * ipv6/reassembly. and ipv6 nf conntrack reassembly + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +/* Use skb->cb to track consecutive/adjacent fragments coming at + * the end of the queue. Nodes in the rb-tree queue will + * contain "runs" of one or more adjacent fragments. + * + * Invariants: + * - next_frag is NULL at the tail of a "run"; + * - the head of a "run" has the sum of all fragment lengths in frag_run_len. + */ +struct ipfrag_skb_cb { + union { + struct inet_skb_parm h4; + struct inet6_skb_parm h6; + }; + struct sk_buff *next_frag; + int frag_run_len; +}; + +#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb)) + +static void fragcb_clear(struct sk_buff *skb) +{ + RB_CLEAR_NODE(&skb->rbnode); + FRAG_CB(skb)->next_frag = NULL; + FRAG_CB(skb)->frag_run_len = skb->len; +} + +/* Append skb to the last "run". */ +static void fragrun_append_to_last(struct inet_frag_queue *q, + struct sk_buff *skb) +{ + fragcb_clear(skb); + + FRAG_CB(q->last_run_head)->frag_run_len += skb->len; + FRAG_CB(q->fragments_tail)->next_frag = skb; + q->fragments_tail = skb; +} + +/* Create a new "run" with the skb. */ +static void fragrun_create(struct inet_frag_queue *q, struct sk_buff *skb) +{ + BUILD_BUG_ON(sizeof(struct ipfrag_skb_cb) > sizeof(skb->cb)); + fragcb_clear(skb); + + if (q->last_run_head) + rb_link_node(&skb->rbnode, &q->last_run_head->rbnode, + &q->last_run_head->rbnode.rb_right); + else + rb_link_node(&skb->rbnode, NULL, &q->rb_fragments.rb_node); + rb_insert_color(&skb->rbnode, &q->rb_fragments); + + q->fragments_tail = skb; + q->last_run_head = skb; +} + +/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements + * Value : 0xff if frame should be dropped. + * 0 or INET_ECN_CE value, to be ORed in to final iph->tos field + */ +const u8 ip_frag_ecn_table[16] = { + /* at least one fragment had CE, and others ECT_0 or ECT_1 */ + [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE, + [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE, + [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE, + + /* invalid combinations : drop frame */ + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff, +}; +EXPORT_SYMBOL(ip_frag_ecn_table); + +int inet_frags_init(struct inet_frags *f) +{ + f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0, + NULL); + if (!f->frags_cachep) + return -ENOMEM; + + refcount_set(&f->refcnt, 1); + init_completion(&f->completion); + return 0; +} +EXPORT_SYMBOL(inet_frags_init); + +void inet_frags_fini(struct inet_frags *f) +{ + if (refcount_dec_and_test(&f->refcnt)) + complete(&f->completion); + + wait_for_completion(&f->completion); + + kmem_cache_destroy(f->frags_cachep); + f->frags_cachep = NULL; +} +EXPORT_SYMBOL(inet_frags_fini); + +/* called from rhashtable_free_and_destroy() at netns_frags dismantle */ +static void inet_frags_free_cb(void *ptr, void *arg) +{ + struct inet_frag_queue *fq = ptr; + int count; + + count = del_timer_sync(&fq->timer) ? 1 : 0; + + spin_lock_bh(&fq->lock); + fq->flags |= INET_FRAG_DROP; + if (!(fq->flags & INET_FRAG_COMPLETE)) { + fq->flags |= INET_FRAG_COMPLETE; + count++; + } else if (fq->flags & INET_FRAG_HASH_DEAD) { + count++; + } + spin_unlock_bh(&fq->lock); + + if (refcount_sub_and_test(count, &fq->refcnt)) + inet_frag_destroy(fq); +} + +static LLIST_HEAD(fqdir_free_list); + +static void fqdir_free_fn(struct work_struct *work) +{ + struct llist_node *kill_list; + struct fqdir *fqdir, *tmp; + struct inet_frags *f; + + /* Atomically snapshot the list of fqdirs to free */ + kill_list = llist_del_all(&fqdir_free_list); + + /* We need to make sure all ongoing call_rcu(..., inet_frag_destroy_rcu) + * have completed, since they need to dereference fqdir. + * Would it not be nice to have kfree_rcu_barrier() ? :) + */ + rcu_barrier(); + + llist_for_each_entry_safe(fqdir, tmp, kill_list, free_list) { + f = fqdir->f; + if (refcount_dec_and_test(&f->refcnt)) + complete(&f->completion); + + kfree(fqdir); + } +} + +static DECLARE_WORK(fqdir_free_work, fqdir_free_fn); + +static void fqdir_work_fn(struct work_struct *work) +{ + struct fqdir *fqdir = container_of(work, struct fqdir, destroy_work); + + rhashtable_free_and_destroy(&fqdir->rhashtable, inet_frags_free_cb, NULL); + + if (llist_add(&fqdir->free_list, &fqdir_free_list)) + queue_work(system_wq, &fqdir_free_work); +} + +int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net) +{ + struct fqdir *fqdir = kzalloc(sizeof(*fqdir), GFP_KERNEL); + int res; + + if (!fqdir) + return -ENOMEM; + fqdir->f = f; + fqdir->net = net; + res = rhashtable_init(&fqdir->rhashtable, &fqdir->f->rhash_params); + if (res < 0) { + kfree(fqdir); + return res; + } + refcount_inc(&f->refcnt); + *fqdirp = fqdir; + return 0; +} +EXPORT_SYMBOL(fqdir_init); + +static struct workqueue_struct *inet_frag_wq; + +static int __init inet_frag_wq_init(void) +{ + inet_frag_wq = create_workqueue("inet_frag_wq"); + if (!inet_frag_wq) + panic("Could not create inet frag workq"); + return 0; +} + +pure_initcall(inet_frag_wq_init); + +void fqdir_exit(struct fqdir *fqdir) +{ + INIT_WORK(&fqdir->destroy_work, fqdir_work_fn); + queue_work(inet_frag_wq, &fqdir->destroy_work); +} +EXPORT_SYMBOL(fqdir_exit); + +void inet_frag_kill(struct inet_frag_queue *fq) +{ + if (del_timer(&fq->timer)) + refcount_dec(&fq->refcnt); + + if (!(fq->flags & INET_FRAG_COMPLETE)) { + struct fqdir *fqdir = fq->fqdir; + + fq->flags |= INET_FRAG_COMPLETE; + rcu_read_lock(); + /* The RCU read lock provides a memory barrier + * guaranteeing that if fqdir->dead is false then + * the hash table destruction will not start until + * after we unlock. Paired with fqdir_pre_exit(). + */ + if (!READ_ONCE(fqdir->dead)) { + rhashtable_remove_fast(&fqdir->rhashtable, &fq->node, + fqdir->f->rhash_params); + refcount_dec(&fq->refcnt); + } else { + fq->flags |= INET_FRAG_HASH_DEAD; + } + rcu_read_unlock(); + } +} +EXPORT_SYMBOL(inet_frag_kill); + +static void inet_frag_destroy_rcu(struct rcu_head *head) +{ + struct inet_frag_queue *q = container_of(head, struct inet_frag_queue, + rcu); + struct inet_frags *f = q->fqdir->f; + + if (f->destructor) + f->destructor(q); + kmem_cache_free(f->frags_cachep, q); +} + +unsigned int inet_frag_rbtree_purge(struct rb_root *root, + enum skb_drop_reason reason) +{ + struct rb_node *p = rb_first(root); + unsigned int sum = 0; + + while (p) { + struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode); + + p = rb_next(p); + rb_erase(&skb->rbnode, root); + while (skb) { + struct sk_buff *next = FRAG_CB(skb)->next_frag; + + sum += skb->truesize; + kfree_skb_reason(skb, reason); + skb = next; + } + } + return sum; +} +EXPORT_SYMBOL(inet_frag_rbtree_purge); + +void inet_frag_destroy(struct inet_frag_queue *q) +{ + unsigned int sum, sum_truesize = 0; + enum skb_drop_reason reason; + struct inet_frags *f; + struct fqdir *fqdir; + + WARN_ON(!(q->flags & INET_FRAG_COMPLETE)); + reason = (q->flags & INET_FRAG_DROP) ? + SKB_DROP_REASON_FRAG_REASM_TIMEOUT : + SKB_CONSUMED; + WARN_ON(del_timer(&q->timer) != 0); + + /* Release all fragment data. */ + fqdir = q->fqdir; + f = fqdir->f; + sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments, reason); + sum = sum_truesize + f->qsize; + + call_rcu(&q->rcu, inet_frag_destroy_rcu); + + sub_frag_mem_limit(fqdir, sum); +} +EXPORT_SYMBOL(inet_frag_destroy); + +static struct inet_frag_queue *inet_frag_alloc(struct fqdir *fqdir, + struct inet_frags *f, + void *arg) +{ + struct inet_frag_queue *q; + + q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC); + if (!q) + return NULL; + + q->fqdir = fqdir; + f->constructor(q, arg); + add_frag_mem_limit(fqdir, f->qsize); + + timer_setup(&q->timer, f->frag_expire, 0); + spin_lock_init(&q->lock); + refcount_set(&q->refcnt, 3); + + return q; +} + +static struct inet_frag_queue *inet_frag_create(struct fqdir *fqdir, + void *arg, + struct inet_frag_queue **prev) +{ + struct inet_frags *f = fqdir->f; + struct inet_frag_queue *q; + + q = inet_frag_alloc(fqdir, f, arg); + if (!q) { + *prev = ERR_PTR(-ENOMEM); + return NULL; + } + mod_timer(&q->timer, jiffies + fqdir->timeout); + + *prev = rhashtable_lookup_get_insert_key(&fqdir->rhashtable, &q->key, + &q->node, f->rhash_params); + if (*prev) { + q->flags |= INET_FRAG_COMPLETE; + inet_frag_kill(q); + inet_frag_destroy(q); + return NULL; + } + return q; +} + +/* TODO : call from rcu_read_lock() and no longer use refcount_inc_not_zero() */ +struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key) +{ + /* This pairs with WRITE_ONCE() in fqdir_pre_exit(). */ + long high_thresh = READ_ONCE(fqdir->high_thresh); + struct inet_frag_queue *fq = NULL, *prev; + + if (!high_thresh || frag_mem_limit(fqdir) > high_thresh) + return NULL; + + rcu_read_lock(); + + prev = rhashtable_lookup(&fqdir->rhashtable, key, fqdir->f->rhash_params); + if (!prev) + fq = inet_frag_create(fqdir, key, &prev); + if (!IS_ERR_OR_NULL(prev)) { + fq = prev; + if (!refcount_inc_not_zero(&fq->refcnt)) + fq = NULL; + } + rcu_read_unlock(); + return fq; +} +EXPORT_SYMBOL(inet_frag_find); + +int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, + int offset, int end) +{ + struct sk_buff *last = q->fragments_tail; + + /* RFC5722, Section 4, amended by Errata ID : 3089 + * When reassembling an IPv6 datagram, if + * one or more its constituent fragments is determined to be an + * overlapping fragment, the entire datagram (and any constituent + * fragments) MUST be silently discarded. + * + * Duplicates, however, should be ignored (i.e. skb dropped, but the + * queue/fragments kept for later reassembly). + */ + if (!last) + fragrun_create(q, skb); /* First fragment. */ + else if (last->ip_defrag_offset + last->len < end) { + /* This is the common case: skb goes to the end. */ + /* Detect and discard overlaps. */ + if (offset < last->ip_defrag_offset + last->len) + return IPFRAG_OVERLAP; + if (offset == last->ip_defrag_offset + last->len) + fragrun_append_to_last(q, skb); + else + fragrun_create(q, skb); + } else { + /* Binary search. Note that skb can become the first fragment, + * but not the last (covered above). + */ + struct rb_node **rbn, *parent; + + rbn = &q->rb_fragments.rb_node; + do { + struct sk_buff *curr; + int curr_run_end; + + parent = *rbn; + curr = rb_to_skb(parent); + curr_run_end = curr->ip_defrag_offset + + FRAG_CB(curr)->frag_run_len; + if (end <= curr->ip_defrag_offset) + rbn = &parent->rb_left; + else if (offset >= curr_run_end) + rbn = &parent->rb_right; + else if (offset >= curr->ip_defrag_offset && + end <= curr_run_end) + return IPFRAG_DUP; + else + return IPFRAG_OVERLAP; + } while (*rbn); + /* Here we have parent properly set, and rbn pointing to + * one of its NULL left/right children. Insert skb. + */ + fragcb_clear(skb); + rb_link_node(&skb->rbnode, parent, rbn); + rb_insert_color(&skb->rbnode, &q->rb_fragments); + } + + skb->ip_defrag_offset = offset; + + return IPFRAG_OK; +} +EXPORT_SYMBOL(inet_frag_queue_insert); + +void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, + struct sk_buff *parent) +{ + struct sk_buff *fp, *head = skb_rb_first(&q->rb_fragments); + struct sk_buff **nextp; + int delta; + + if (head != skb) { + fp = skb_clone(skb, GFP_ATOMIC); + if (!fp) + return NULL; + FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag; + if (RB_EMPTY_NODE(&skb->rbnode)) + FRAG_CB(parent)->next_frag = fp; + else + rb_replace_node(&skb->rbnode, &fp->rbnode, + &q->rb_fragments); + if (q->fragments_tail == skb) + q->fragments_tail = fp; + skb_morph(skb, head); + FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag; + rb_replace_node(&head->rbnode, &skb->rbnode, + &q->rb_fragments); + consume_skb(head); + head = skb; + } + WARN_ON(head->ip_defrag_offset != 0); + + delta = -head->truesize; + + /* Head of list must not be cloned. */ + if (skb_unclone(head, GFP_ATOMIC)) + return NULL; + + delta += head->truesize; + if (delta) + add_frag_mem_limit(q->fqdir, delta); + + /* If the first fragment is fragmented itself, we split + * it to two chunks: the first with data and paged part + * and the second, holding only fragments. + */ + if (skb_has_frag_list(head)) { + struct sk_buff *clone; + int i, plen = 0; + + clone = alloc_skb(0, GFP_ATOMIC); + if (!clone) + return NULL; + skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; + skb_frag_list_init(head); + for (i = 0; i < skb_shinfo(head)->nr_frags; i++) + plen += skb_frag_size(&skb_shinfo(head)->frags[i]); + clone->data_len = head->data_len - plen; + clone->len = clone->data_len; + head->truesize += clone->truesize; + clone->csum = 0; + clone->ip_summed = head->ip_summed; + add_frag_mem_limit(q->fqdir, clone->truesize); + skb_shinfo(head)->frag_list = clone; + nextp = &clone->next; + } else { + nextp = &skb_shinfo(head)->frag_list; + } + + return nextp; +} +EXPORT_SYMBOL(inet_frag_reasm_prepare); + +void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, + void *reasm_data, bool try_coalesce) +{ + struct sk_buff **nextp = reasm_data; + struct rb_node *rbn; + struct sk_buff *fp; + int sum_truesize; + + skb_push(head, head->data - skb_network_header(head)); + + /* Traverse the tree in order, to build frag_list. */ + fp = FRAG_CB(head)->next_frag; + rbn = rb_next(&head->rbnode); + rb_erase(&head->rbnode, &q->rb_fragments); + + sum_truesize = head->truesize; + while (rbn || fp) { + /* fp points to the next sk_buff in the current run; + * rbn points to the next run. + */ + /* Go through the current run. */ + while (fp) { + struct sk_buff *next_frag = FRAG_CB(fp)->next_frag; + bool stolen; + int delta; + + sum_truesize += fp->truesize; + if (head->ip_summed != fp->ip_summed) + head->ip_summed = CHECKSUM_NONE; + else if (head->ip_summed == CHECKSUM_COMPLETE) + head->csum = csum_add(head->csum, fp->csum); + + if (try_coalesce && skb_try_coalesce(head, fp, &stolen, + &delta)) { + kfree_skb_partial(fp, stolen); + } else { + fp->prev = NULL; + memset(&fp->rbnode, 0, sizeof(fp->rbnode)); + fp->sk = NULL; + + head->data_len += fp->len; + head->len += fp->len; + head->truesize += fp->truesize; + + *nextp = fp; + nextp = &fp->next; + } + + fp = next_frag; + } + /* Move to the next run. */ + if (rbn) { + struct rb_node *rbnext = rb_next(rbn); + + fp = rb_to_skb(rbn); + rb_erase(rbn, &q->rb_fragments); + rbn = rbnext; + } + } + sub_frag_mem_limit(q->fqdir, sum_truesize); + + *nextp = NULL; + skb_mark_not_on_list(head); + head->prev = NULL; + head->tstamp = q->stamp; + head->mono_delivery_time = q->mono_delivery_time; +} +EXPORT_SYMBOL(inet_frag_reasm_finish); + +struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q) +{ + struct sk_buff *head, *skb; + + head = skb_rb_first(&q->rb_fragments); + if (!head) + return NULL; + skb = FRAG_CB(head)->next_frag; + if (skb) + rb_replace_node(&head->rbnode, &skb->rbnode, + &q->rb_fragments); + else + rb_erase(&head->rbnode, &q->rb_fragments); + memset(&head->rbnode, 0, sizeof(head->rbnode)); + barrier(); + + if (head == q->fragments_tail) + q->fragments_tail = NULL; + + sub_frag_mem_limit(q->fqdir, head->truesize); + + return head; +} +EXPORT_SYMBOL(inet_frag_pull_head); -- cgit v1.2.3