From patchwork Fri Nov 10 11:37:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Hopps X-Patchwork-Id: 13452371 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5467D1A732 for ; Fri, 10 Nov 2023 11:45:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none X-Greylist: delayed 395 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 10 Nov 2023 03:45:10 PST Received: from smtp.chopps.org (smtp.chopps.org [54.88.81.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BB49A311A1 for ; Fri, 10 Nov 2023 03:45:10 -0800 (PST) Received: from labnh.int.chopps.org (172-222-091-149.res.spectrum.com [172.222.91.149]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by smtp.chopps.org (Postfix) with ESMTPSA id 9EFBF7D138; Fri, 10 Nov 2023 11:38:39 +0000 (UTC) From: Christian Hopps To: devel@linux-ipsec.org Cc: Steffen Klassert , netdev@vger.kernel.org, Christian Hopps Subject: [RFC ipsec-next 8/8] iptfs: impl: add new iptfs xfrm mode impl Date: Fri, 10 Nov 2023 06:37:19 -0500 Message-ID: <20231110113719.3055788-9-chopps@chopps.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231110113719.3055788-1-chopps@chopps.org> References: <20231110113719.3055788-1-chopps@chopps.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC From: Christian Hopps Add a new xfrm mode implementing AggFrag/IP-TFS from RFC9347. This utilizes the new xfrm_mode_cbs to implement demand-driven IP-TFS functionality. This functionality can be used to increase bandwidth utilization through small packet aggregation, as well as help solve PMTU issues through it's efficient use of fragmentation. Link: https://www.rfc-editor.org/rfc/rfc9347.txt Signed-off-by: Christian Hopps --- include/net/iptfs.h | 18 + net/xfrm/trace_iptfs.h | 226 ++++ net/xfrm/xfrm_iptfs.c | 2735 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 2979 insertions(+) create mode 100644 include/net/iptfs.h create mode 100644 net/xfrm/trace_iptfs.h create mode 100644 net/xfrm/xfrm_iptfs.c diff --git a/include/net/iptfs.h b/include/net/iptfs.h new file mode 100644 index 000000000000..d8f2e494f251 --- /dev/null +++ b/include/net/iptfs.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_IPTFS_H +#define _NET_IPTFS_H + +#include +#include + +#define IPTFS_SUBTYPE_BASIC 0 +#define IPTFS_SUBTYPE_CC 1 +#define IPTFS_SUBTYPE_LAST IPTFS_SUBTYPE_CC + +#define IPTFS_CC_FLAGS_ECN_CE 0x1 +#define IPTFS_CC_FLAGS_PLMTUD 0x2 + +extern void xfrm_iptfs_get_rtt_and_delays(struct ip_iptfs_cc_hdr *cch, u32 *rtt, + u32 *actual_delay, u32 *xmit_delay); + +#endif /* _NET_IPTFS_H */ diff --git a/net/xfrm/trace_iptfs.h b/net/xfrm/trace_iptfs.h new file mode 100644 index 000000000000..bade955942e3 --- /dev/null +++ b/net/xfrm/trace_iptfs.h @@ -0,0 +1,226 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* xfrm_trace_iptfs.h + * + * August 12 2023, Christian Hopps + * + * Copyright (c) 2023, LabN Consulting, L.L.C. + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM iptfs + +#if !defined(_TRACE_IPTFS_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_IPTFS_H + +#include +#include +#include +#include + +struct xfrm_iptfs_data; + +TRACE_EVENT(iptfs_egress_recv, + TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u16 blkoff), + TP_ARGS(skb, xtfs, blkoff), + TP_STRUCT__entry( + __field(struct sk_buff *, skb) + __field(void *, head) + __field(void *, head_pg_addr) + __field(void *, pg0addr) + __field(u32, skb_len) + __field(u32, data_len) + __field(u32, headroom) + __field(u32, tailroom) + __field(u32, tail) + __field(u32, end) + __field(u32, pg0off) + __field(u8, head_frag) + __field(u8, frag_list) + __field(u8, nr_frags) + __field(u16, blkoff)), + TP_fast_assign( + __entry->skb = skb; + __entry->head = skb->head; + __entry->skb_len = skb->len; + __entry->data_len = skb->data_len; + __entry->headroom = skb_headroom(skb); + __entry->tailroom = skb_tailroom(skb); + __entry->tail = skb->tail; + __entry->end = skb->end; + __entry->head_frag = skb->head_frag; + __entry->frag_list = (bool)skb_shinfo(skb)->frag_list; + __entry->nr_frags = skb_shinfo(skb)->nr_frags; + __entry->blkoff = blkoff; + __entry->head_pg_addr = page_address(virt_to_head_page(skb->head)); + __entry->pg0addr = (__entry->nr_frags ? page_address(skb_shinfo(skb)->frags[0].bv_page) : 0); + __entry->pg0off = (__entry->nr_frags ? skb_shinfo(skb)->frags[0].bv_offset : 0); + + ), + TP_printk("EGRESS: skb=%p len=%u data_len=%u headroom=%u head_frag=%u frag_list=%u nr_frags=%u blkoff=%u\n\t\ttailroom=%u tail=%u end=%u head=%p hdpgaddr=%p pg0->addr=%p pg0->data=%p pg0->off=%u", + __entry->skb, __entry->skb_len, __entry->data_len, __entry->headroom, + __entry->head_frag, __entry->frag_list, __entry->nr_frags, + __entry->blkoff, __entry->tailroom, __entry->tail, __entry->end, __entry->head, __entry->head_pg_addr, __entry->pg0addr, __entry->pg0addr + __entry->pg0off, __entry->pg0off) + ) + + +DECLARE_EVENT_CLASS(iptfs_ingress_preq_event, + TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso), + TP_ARGS(skb, xtfs, pmtu, was_gso), + TP_STRUCT__entry( + __field(struct sk_buff *, skb) + __field(u32, skb_len) + __field(u32, data_len) + __field(u32, pmtu) + __field(u32, queue_size) + __field(u32, proto_seq) + __field(u8, proto) + __field(u8, was_gso) + ), + TP_fast_assign( + __entry->skb = skb; + __entry->skb_len = skb->len; + __entry->data_len = skb->data_len; + __entry->queue_size = xtfs->cfg.max_queue_size - xtfs->queue_size; + __entry->proto = __trace_ip_proto(ip_hdr(skb)); + __entry->proto_seq = __trace_ip_proto_seq(ip_hdr(skb)); + __entry->pmtu = pmtu; + __entry->was_gso = was_gso; + ), + TP_printk("INGRPREQ: skb=%p len=%u data_len=%u qsize=%u proto=%u proto_seq=%u pmtu=%u was_gso=%u", + __entry->skb, __entry->skb_len, __entry->data_len, __entry->queue_size, + __entry->proto, __entry->proto_seq, __entry->pmtu, __entry->was_gso)); + +DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_enqueue, + TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso), + TP_ARGS(skb, xtfs, pmtu, was_gso)); + +DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_no_queue_space, + TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso), + TP_ARGS(skb, xtfs, pmtu, was_gso)); + +DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_too_big, + TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso), + TP_ARGS(skb, xtfs, pmtu, was_gso)); + +DECLARE_EVENT_CLASS( + iptfs_ingress_postq_event, + TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, struct iphdr *iph), + TP_ARGS(skb, mtu, blkoff, iph), + TP_STRUCT__entry(__field(struct sk_buff *, skb) + __field(u32, skb_len) + __field(u32, data_len) + __field(u32, mtu) + __field(u32, proto_seq) + __field(u16, blkoff) + __field(u8, proto)), + TP_fast_assign(__entry->skb = skb; + __entry->skb_len = skb->len; + __entry->data_len = skb->data_len; + __entry->mtu = mtu; + __entry->blkoff = blkoff; + __entry->proto = iph ? __trace_ip_proto(iph) : 0; + __entry->proto_seq = iph ? __trace_ip_proto_seq(iph) : 0; + ), + TP_printk( + "INGRPSTQ: skb=%p len=%u data_len=%u mtu=%u blkoff=%u proto=%u proto_seq=%u", + __entry->skb, __entry->skb_len, __entry->data_len, __entry->mtu, + __entry->blkoff, __entry->proto, __entry->proto_seq)); + +DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_dequeue, + TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, + struct iphdr *iph), + TP_ARGS(skb, mtu, blkoff, iph)); + +DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_fragmenting, + TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, + struct iphdr *iph), + TP_ARGS(skb, mtu, blkoff, iph)); + +DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_final_fragment, + TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, + struct iphdr *iph), + TP_ARGS(skb, mtu, blkoff, iph)); + +DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_toobig, + TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, + struct iphdr *iph), + TP_ARGS(skb, mtu, blkoff, iph)); + +TRACE_EVENT(iptfs_ingress_nth_peek, + TP_PROTO(struct sk_buff *skb, u32 remaining), + TP_ARGS(skb, remaining), + TP_STRUCT__entry(__field(struct sk_buff *, skb) + __field(u32, skb_len) + __field(u32, remaining)), + TP_fast_assign(__entry->skb = skb; + __entry->skb_len = skb->len; + __entry->remaining = remaining; + ), + TP_printk("INGRPSTQ: NTHPEEK: skb=%p len=%u remaining=%u", __entry->skb, + __entry->skb_len, __entry->remaining)); + +TRACE_EVENT(iptfs_ingress_nth_add, TP_PROTO(struct sk_buff *skb, u8 share_ok), + TP_ARGS(skb, share_ok), + TP_STRUCT__entry(__field(struct sk_buff *, skb) + __field(u32, skb_len) + __field(u32, data_len) + __field(u8, share_ok) + __field(u8, head_frag) + __field(u8, pp_recycle) + __field(u8, cloned) + __field(u8, shared) + __field(u8, nr_frags) + __field(u8, frag_list) + ), + TP_fast_assign(__entry->skb = skb; + __entry->skb_len = skb->len; + __entry->data_len = skb->data_len; + __entry->share_ok = share_ok; + __entry->head_frag = skb->head_frag; + __entry->pp_recycle = skb->pp_recycle; + __entry->cloned = skb_cloned(skb); + __entry->shared = skb_shared(skb); + __entry->nr_frags = skb_shinfo(skb)->nr_frags; + __entry->frag_list = (bool)skb_shinfo(skb)->frag_list; + ), + TP_printk("INGRPSTQ: NTHADD: skb=%p len=%u data_len=%u share_ok=%u head_frag=%u pp_recycle=%u cloned=%u shared=%u nr_frags=%u frag_list=%u", + __entry->skb, + __entry->skb_len, + __entry->data_len, + __entry->share_ok, + __entry->head_frag, + __entry->pp_recycle, + __entry->cloned, + __entry->shared, + __entry->nr_frags, + __entry->frag_list + )); + +DECLARE_EVENT_CLASS(iptfs_timer_event, + TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val), + TP_ARGS(xtfs, time_val), + TP_STRUCT__entry( + __field(u64, time_val) + __field(u64, set_time)), + TP_fast_assign( + __entry->time_val = time_val; + __entry->set_time = xtfs->iptfs_settime; + ), + TP_printk("TIMER: set_time=%llu time_val=%llu", __entry->set_time, __entry->time_val)); + +DEFINE_EVENT(iptfs_timer_event, iptfs_timer_start, + TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val), + TP_ARGS(xtfs, time_val)); + +DEFINE_EVENT(iptfs_timer_event, iptfs_timer_expire, + TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val), + TP_ARGS(xtfs, time_val)); + +#endif /* _TRACE_IPTFS_H */ + +/* This part must be outside protection */ +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH ../../net/xfrm +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace_iptfs +#include diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c new file mode 100644 index 000000000000..61d460dfb01a --- /dev/null +++ b/net/xfrm/xfrm_iptfs.c @@ -0,0 +1,2735 @@ +// SPDX-License-Identifier: GPL-2.0 +/* xfrm_iptfs: IPTFS encapsulation support + * + * April 21 2022, Christian Hopps + * + * Copyright (c) 2022, LabN Consulting, L.L.C. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "xfrm_inout.h" +#include "trace_iptfs.h" + +/* 1) skb->head should be cache aligned. + * 2) when resv is for L2 headers (i.e., ethernet) we want the cacheline to + * start -16 from data. + * 3) when resv is for L3+L2 headers IOW skb->data points at the IPTFS payload + * we want data to be cache line aligned so all the pushed headers will be in + * another cacheline. + */ +#define XFRM_IPTFS_MIN_L3HEADROOM 128 +#define XFRM_IPTFS_MIN_L2HEADROOM (64 + 16) +#define IPTFS_FRAG_COPY_MAX 256 /* max for copying to create iptfs frags */ +#define IPTFS_PKT_SHARE_MIN 129 /* min to try to share vs copy pkt data */ +#define NSECS_IN_USEC 1000 + +#define IPTFS_TYPE_NOCC 0 +#define IPTFS_TYPE_CC 1 + +#define IPTFS_HRTIMER_MODE HRTIMER_MODE_REL_SOFT + +struct skb_wseq { + struct sk_buff *skb; + u64 drop_time; +}; + +struct xfrm_iptfs_config { + bool dont_frag : 1; + u16 reorder_win_size; + u32 pkt_size; /* outer_packet_size or 0 */ + u32 max_queue_size; /* octets */ + u64 init_delay_us; /* microseconds */ + u32 drop_time_us; /* microseconds */ +}; + +struct xfrm_iptfs_data { + struct xfrm_iptfs_config cfg; + + /* Ingress User Input */ + struct xfrm_state *x; /* owning state */ + struct sk_buff_head queue; /* output queue */ + u32 queue_size; /* octets */ + u32 ecn_queue_size; /* octets above which ECN mark */ + u64 init_delay_ns; /* nanoseconds */ + struct hrtimer iptfs_timer; /* output timer */ + time64_t iptfs_settime; /* time timer was set */ + u32 payload_mtu; /* max payload size */ + + /* Tunnel input reordering */ + bool w_seq_set; /* true after first seq received */ + u64 w_wantseq; /* expected next sequence */ + struct skb_wseq *w_saved; /* the saved buf array */ + u32 w_savedlen; /* the saved len (not size) */ + spinlock_t drop_lock; + struct hrtimer drop_timer; + u64 drop_time_ns; + + /* Tunnel input reassembly */ + struct sk_buff *ra_newskb; /* new pkt being reassembled */ + u64 ra_wantseq; /* expected next sequence */ + u8 ra_runt[6]; /* last pkt bytes from last skb */ + u8 ra_runtlen; /* count of ra_runt */ +}; + +static u32 __iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu); +static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me); +static enum hrtimer_restart iptfs_drop_timer(struct hrtimer *me); + +/* ================= */ +/* Utility Functions */ +/* ================= */ + +static inline u32 __trace_ip_proto(struct iphdr *iph) +{ + if (iph->version == 4) + return iph->protocol; + return ((struct ipv6hdr *)iph)->nexthdr; +} + +static u32 __trace_ip_proto_seq(struct iphdr *iph) +{ + void *nexthdr; + u32 protocol = 0; + + if (iph->version == 4) { + nexthdr = (void *)(iph + 1); + protocol = iph->protocol; + } else if (iph->version == 6) { + nexthdr = (void *)(((struct ipv6hdr *)(iph)) + 1); + protocol = ((struct ipv6hdr *)(iph))->nexthdr; + } + switch (protocol) { + case IPPROTO_ICMP: + return ntohs(((struct icmphdr *)nexthdr)->un.echo.sequence); + case IPPROTO_ICMPV6: + return ntohs(((struct icmp6hdr *)nexthdr)->icmp6_sequence); + case IPPROTO_TCP: + return ntohl(((struct tcphdr *)nexthdr)->seq); + case IPPROTO_UDP: + return ntohs(((struct udphdr *)nexthdr)->source); + default: + return 0; + } +} + +static inline u64 __esp_seq(struct sk_buff *skb) +{ + u64 seq = ntohl(XFRM_SKB_CB(skb)->seq.input.low); + + return seq | (u64)ntohl(XFRM_SKB_CB(skb)->seq.input.hi) << 32; +} + +/* ================= */ +/* SK_BUFF Functions */ +/* ================= */ + +/** + * iptfs_alloc_skb() - Allocate a new `skb` using a meta-data template. + * @tpl: the template to copy the new `skb`s meta-data from. + * @len: the linear length of the head data, zero is fine. + * @l3resv: true if reserve needs to support pushing L3 headers + * + * A new `skb` is allocated and it's meta-data is initialized from `tpl`, the + * head data is sized to `len` + reserved space set according to the @l3resv + * boolean. When @l3resv is false, resv is XFRM_IPTFS_MIN_L2HEADROOM which + * arranges for `skb->data - 16` (etherhdr space) to be the start of a cacheline. + * Otherwise, @l3resv is true and resv is either the size of headroom from `tpl` or + * XFRM_IPTFS_MIN_L3HEADROOM whichever is greater, which tries to align + * skb->data to a cacheline as all headers will be pushed on the previous + * cacheline bytes. + * + * When copying meta-data from the @tpl, the sk_buff->headers are not copied. + * + * Zero length skbs are allocated when we only need a head skb to hold new + * packet headers (basically the mac header) that sit on top of existing shared + * packet data. + * + * Return: the new skb or NULL. + */ +static struct sk_buff *iptfs_alloc_skb(struct sk_buff *tpl, u32 len, + bool l3resv) +{ + struct sk_buff *skb; + u32 resv; + + if (!l3resv) { + resv = XFRM_IPTFS_MIN_L2HEADROOM; + } else { + resv = skb_headroom(tpl); + if (resv < XFRM_IPTFS_MIN_L3HEADROOM) + resv = XFRM_IPTFS_MIN_L3HEADROOM; + } + + skb = alloc_skb(len + resv, GFP_ATOMIC); + if (!skb) { + XFRM_INC_STATS(dev_net(tpl->dev), LINUX_MIB_XFRMINERROR); + return NULL; + } + + skb_reserve(skb, resv); + + /* Code from __copy_skb_header() -- we do not want any of the + * tpl->headers copied over, so we aren't using `skb_copy_header()`. + */ + skb->tstamp = tpl->tstamp; + skb->dev = tpl->dev; + memcpy(skb->cb, tpl->cb, sizeof(skb->cb)); + skb_dst_copy(skb, tpl); + __skb_ext_copy(skb, tpl); + __nf_copy(skb, tpl, false); + + return skb; +} + +/** + * skb_head_to_frag() - initialize a skb_frag_t based on skb head data + */ +static void skb_head_to_frag(const struct sk_buff *skb, skb_frag_t *frag) +{ + struct page *page = virt_to_head_page(skb->data); + unsigned char *addr = (unsigned char *)page_address(page); + + BUG_ON(!skb->head_frag); + skb_frag_fill_page_desc(frag, page, skb->data - addr, skb_headlen(skb)); +} + +/** + * struct skb_frag_walk - use to track a walk through fragments + * @fragi: current fragment index + * @past: length of data in fragments before @fragi + * @total: length of data in all fragments + * @nr_frags: number of fragments present in array + * @initial_offset: the value passed in to skb_prepare_frag_walk() + * @pp_recycle: copy of skb->pp_recycle + * @frags: the page fragments inc. room for head page + */ +struct skb_frag_walk { + u32 fragi; + u32 past; + u32 total; + u32 nr_frags; + u32 initial_offset; + bool pp_recycle; + skb_frag_t frags[MAX_SKB_FRAGS + 1]; +}; + +/** + * skb_prepare_frag_walk() - initialize a frag walk over an skb. + * @skb: the skb to walk. + * @initial_offset: start the walk @initial_offset into the skb. + * @walk: the walk to initialize + * + * Future calls to skb_add_frags() will expect the @offset value to be at + * least @initial_offset large. + */ +static void skb_prepare_frag_walk(struct sk_buff *skb, u32 initial_offset, + struct skb_frag_walk *walk) +{ + struct skb_shared_info *shinfo = skb_shinfo(skb); + skb_frag_t *frag, *from; + u32 i; + + walk->initial_offset = initial_offset; + walk->fragi = 0; + walk->past = 0; + walk->total = 0; + walk->nr_frags = 0; + walk->pp_recycle = skb->pp_recycle; + + if (skb->head_frag) { + if (initial_offset >= skb_headlen(skb)) { + initial_offset -= skb_headlen(skb); + } else { + frag = &walk->frags[walk->nr_frags++]; + skb_head_to_frag(skb, frag); + frag->bv_offset += initial_offset; + frag->bv_len -= initial_offset; + walk->total += frag->bv_len; + initial_offset = 0; + } + } else { + BUG_ON(skb_headlen(skb) > initial_offset); + initial_offset -= skb_headlen(skb); + } + + for (i = 0; i < shinfo->nr_frags; i++) { + from = &shinfo->frags[i]; + if (initial_offset >= from->bv_len) { + initial_offset -= from->bv_len; + continue; + } + frag = &walk->frags[walk->nr_frags++]; + *frag = *from; + if (initial_offset) { + frag->bv_offset += initial_offset; + frag->bv_len -= initial_offset; + initial_offset = 0; + } + walk->total += frag->bv_len; + } + BUG_ON(initial_offset != 0); +} + +static u32 __skb_reset_frag_walk(struct skb_frag_walk *walk, u32 offset) +{ + /* Adjust offset to refer to internal walk values */ + BUG_ON(offset < walk->initial_offset); + offset -= walk->initial_offset; + + /* Get to the correct fragment for offset */ + while (offset < walk->past) { + walk->past -= walk->frags[--walk->fragi].bv_len; + if (offset >= walk->past) + break; + BUG_ON(walk->fragi == 0); + } + while (offset >= walk->past + walk->frags[walk->fragi].bv_len) + walk->past += walk->frags[walk->fragi++].bv_len; + + /* offset now relative to this current frag */ + offset -= walk->past; + return offset; +} + +/** + * skb_can_add_frags() - check if ok to add frags from walk to skb + * @skb: skb to check for adding frags to + * @walk: the walk that will be used as source for frags. + * @offset: offset from beginning of original skb to start from. + * @len: amount of data to add frag references to in @skb. + */ +static bool skb_can_add_frags(const struct sk_buff *skb, + struct skb_frag_walk *walk, u32 offset, u32 len) +{ + struct skb_shared_info *shinfo = skb_shinfo(skb); + u32 fragi, nr_frags, fraglen; + + if (skb_has_frag_list(skb) || skb->pp_recycle != walk->pp_recycle) + return false; + + /* Make offset relative to current frag after setting that */ + offset = __skb_reset_frag_walk(walk, offset); + + /* Verify we have array space for the fragments we need to add */ + fragi = walk->fragi; + nr_frags = shinfo->nr_frags; + while (len && fragi < walk->nr_frags) { + skb_frag_t *frag = &walk->frags[fragi]; + + fraglen = frag->bv_len; + if (offset) { + fraglen -= offset; + offset = 0; + } + if (++nr_frags > MAX_SKB_FRAGS) + return false; + if (len <= fraglen) + return true; + len -= fraglen; + fragi++; + } + /* We may not copy all @len but what we have will fit. */ + return true; +} + +/** + * skb_add_frags() - add a range of fragment references into an skb + * @skb: skb to add references into + * @walk: the walk to add referenced fragments from. + * @offset: offset from beginning of original skb to start from. + * @len: amount of data to add frag references to in @skb. + * + * skb_can_add_frags() should be called before this function to verify that the + * destination @skb is compatible with the walk and has space in the array for + * the to be added frag refrences. + * + * Return: The number of bytes not added to @skb b/c we reached the end of the + * walk before adding all of @len. + */ +static int skb_add_frags(struct sk_buff *skb, struct skb_frag_walk *walk, + u32 offset, u32 len) +{ + struct skb_shared_info *shinfo = skb_shinfo(skb); + u32 fraglen; + + BUG_ON(skb->pp_recycle != walk->pp_recycle); + if (!walk->nr_frags || offset >= walk->total + walk->initial_offset) + return len; + + /* make offset relative to current frag after setting that */ + offset = __skb_reset_frag_walk(walk, offset); + BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); + + while (len && walk->fragi < walk->nr_frags) { + skb_frag_t *frag = &walk->frags[walk->fragi]; + skb_frag_t *tofrag = &shinfo->frags[shinfo->nr_frags]; + + *tofrag = *frag; + if (offset) { + tofrag->bv_offset += offset; + tofrag->bv_len -= offset; + offset = 0; + } + __skb_frag_ref(tofrag); + shinfo->nr_frags++; + BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS); + + /* see if we are done */ + fraglen = tofrag->bv_len; + if (len < fraglen) { + tofrag->bv_len = len; + skb->len += len; + skb->data_len += len; + return 0; + } + /* advance to next source fragment */ + len -= fraglen; /* careful, use dst bv_len */ + skb->len += fraglen; /* careful, " " " */ + skb->data_len += fraglen; /* careful, " " " */ + walk->past += + frag->bv_len; /* careful, use src bv_len */ + walk->fragi++; + } + return len; +} + +/** + * skb_copy_bits_seq - copy bits from a skb_seq_state to kernel buffer + * @st: source skb_seq_state + * @offset: offset in source + * @to: destination buffer + * @len: number of bytes to copy + * + * Copy @len bytes from @offset bytes into the source @st to the destination + * buffer @to. `offset` should increase (or be unchanged) with each subsequent + * call to this function. If offset needs to decrease from the previous use `st` + * should be reset first. + */ +static int skb_copy_bits_seq(struct skb_seq_state *st, int offset, void *to, int len) +{ + const u8 *data; + u32 sqlen; + + for (;;) { + sqlen = skb_seq_read(offset, &data, st); + if (sqlen == 0) + return -ENOMEM; + if (sqlen >= len) { + memcpy(to, data, len); + return 0; + } + memcpy(to, data, sqlen); + to += sqlen; + offset += sqlen; + len -= sqlen; + } +} + +/* ================================== */ +/* IPTFS Trace Event Definitions */ +/* ================================== */ + +#define CREATE_TRACE_POINTS +#include "trace_iptfs.h" + +/* ================================== */ +/* IPTFS Receiving (egress) Functions */ +/* ================================== */ + +/** + * iptfs_pskb_add_frags() - Create and add frags into a new sk_buff. + * @tpl: template to create new skb from. + * @walk: The source for fragments to add. + * @off: The offset into @walk to add frags from, also used with @st and + * @copy_len. + * @len: The length of data to add covering frags from @walk into @skb. + * This must be <= @skblen. + * @st: The sequence state to copy from into the new head skb. + * @copy_len: Copy @copy_len bytes from @st at offset @off into the new skb + * linear space. + * + * Create a new sk_buff `skb` using the template @tpl. Copy @copy_len bytes from + * @st into the new skb linear space, and then add shared fragments from the + * frag walk for the remaining @len of data (i.e., @len - @copy_len bytes). + * + * Return: The newly allocated sk_buff `skb` or NULL if an error occurs. + */ +struct sk_buff *iptfs_pskb_add_frags(struct sk_buff *tpl, + struct skb_frag_walk *walk, u32 off, + u32 len, struct skb_seq_state *st, + u32 copy_len) +{ + struct sk_buff *skb; + + skb = iptfs_alloc_skb(tpl, copy_len, false); + if (!skb) + return NULL; + + /* this should not normally be happening */ + if (!skb_can_add_frags(skb, walk, off + copy_len, len - copy_len)) { + kfree_skb(skb); + return NULL; + } + + if (copy_len && + skb_copy_bits_seq(st, off, skb_put(skb, copy_len), copy_len)) { + XFRM_INC_STATS(dev_net(st->root_skb->dev), + LINUX_MIB_XFRMINERROR); + kfree_skb(skb); + return NULL; + } + + skb_add_frags(skb, walk, off + copy_len, len - copy_len); + return skb; +} + +/** + * iptfs_pskb_extract_seq() - Create and load data into a new sk_buff. + * @skblen: the total data size for `skb`. + * @st: The source for the rest of the data to copy into `skb`. + * @off: The offset into @st to copy data from. + * @len: The length of data to copy from @st into `skb`. This must be <= + * @skblen. + * + * Create a new sk_buff `skb` with @skblen of packet data space. If non-zero, + * copy @rlen bytes of @runt into `skb`. Then using seq functions copy @len + * bytes from @st into `skb` starting from @off. + * + * It is an error for @len to be greater than the amount of data left in @st. + * + * Return: The newly allocated sk_buff `skb` or NULL if an error occurs. + */ +static struct sk_buff * +iptfs_pskb_extract_seq(u32 skblen, struct skb_seq_state *st, u32 off, int len) +{ + struct sk_buff *skb = iptfs_alloc_skb(st->root_skb, skblen, false); + + if (!skb) + return NULL; + if (skb_copy_bits_seq(st, off, skb_put(skb, len), len)) { + XFRM_INC_STATS(dev_net(st->root_skb->dev), + LINUX_MIB_XFRMINERROR); + kfree_skb(skb); + return NULL; + } + return skb; +} + +/** + * iptfs_input_save_runt() - save data in xtfs runt space. + * + * Save the small (`len`) start of a fragmented packet in `buf` in the xtfs data + * runt space. + */ +static inline void iptfs_input_save_runt(struct xfrm_iptfs_data *xtfs, u64 seq, + u8 *buf, int len) +{ + BUG_ON(xtfs->ra_newskb); /* we won't have a new SKB yet */ + + memcpy(xtfs->ra_runt, buf, len); + + xtfs->ra_runtlen = len; + xtfs->ra_wantseq = seq + 1; +} + +/** + * __iptfs_iphlen() - return the v4/v6 header length using packet data. + * + * The version data is expected to be valid (i.e., either 4 or 6). + */ +static u32 __iptfs_iphlen(u8 *data) +{ + struct iphdr *iph = (struct iphdr *)data; + + if (iph->version == 0x4) + return sizeof(*iph); + BUG_ON(iph->version != 0x6); + return sizeof(struct ipv6hdr); +} + +/** + * __iptfs_iplen() - return the v4/v6 length using packet data. + * + * Grab the IPv4 or IPv6 length value in the start of the inner packet header + * pointed to by `data`. Assumes data len is enough for the length field only. + * + * The version data is expected to be valid (i.e., either 4 or 6). + */ +static u32 __iptfs_iplen(u8 *data) +{ + struct iphdr *iph = (struct iphdr *)data; + + if (iph->version == 0x4) + return ntohs(iph->tot_len); + BUG_ON(iph->version != 0x6); + return ntohs(((struct ipv6hdr *)iph)->payload_len) + + sizeof(struct ipv6hdr); +} + +/** + * iptfs_complete_inner_skb() - finish preparing the inner packet for gro recv. + * + * Finish the standard xfrm processing on the inner packet prior to sending back + * through gro_cells_receive. We do this separately b/c we are building a list + * of packets in the hopes that one day a list will be taken by + * xfrm_input. + */ +static void iptfs_complete_inner_skb(struct xfrm_state *x, struct sk_buff *skb) +{ + skb_reset_network_header(skb); + + /* The packet is going back through gro_cells_receive no need to + * set this. + */ + skb_reset_transport_header(skb); + + /* Packet already has checksum value set. */ + skb->ip_summed = CHECKSUM_NONE; + + /* Our skb will contain the header data copied when this outer packet + * which contained the start of this inner packet. This is true + * when we allocate a new skb as well as when we reuse the existing skb. + */ + if (ip_hdr(skb)->version == 0x4) { + struct iphdr *iph = ip_hdr(skb); + + if (x->props.flags & XFRM_STATE_DECAP_DSCP) + ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, iph); + if (!(x->props.flags & XFRM_STATE_NOECN)) + if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos)) + IP_ECN_set_ce(iph); + + skb->protocol = htons(ETH_P_IP); + } else { + struct ipv6hdr *iph = ipv6_hdr(skb); + + if (x->props.flags & XFRM_STATE_DECAP_DSCP) + ipv6_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, iph); + if (!(x->props.flags & XFRM_STATE_NOECN)) + if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos)) + IP6_ECN_set_ce(skb, iph); + + skb->protocol = htons(ETH_P_IPV6); + } +} + +static inline void __iptfs_reassem_done(struct xfrm_iptfs_data *xtfs, bool free) +{ + int ret; + + assert_spin_locked(&xtfs->drop_lock); + + /* We don't care if it works locking takes care of things */ + ret = hrtimer_try_to_cancel(&xtfs->drop_timer); + if (free) + kfree_skb(xtfs->ra_newskb); + xtfs->ra_newskb = NULL; +} + +/** + * iptfs_reassem_done() - In-progress packet is aborted free the state. + */ +static inline void iptfs_reassem_abort(struct xfrm_iptfs_data *xtfs) +{ + __iptfs_reassem_done(xtfs, true); +} + +/** + * iptfs_reassem_done() - In-progress packet is complete, clear the state. + */ +static inline void iptfs_reassem_done(struct xfrm_iptfs_data *xtfs) +{ + __iptfs_reassem_done(xtfs, false); +} + +/** + * iptfs_reassem_cont() - Continue the reassembly of an inner packets. + * + * Process an IPTFS payload that has a non-zero `blkoff` or when we are + * expecting the continuation b/c we have a runt or in-progress packet. + */ +static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq, + struct skb_seq_state *st, struct sk_buff *skb, + u32 data, u32 blkoff, struct list_head *list) +{ + struct skb_frag_walk _fragwalk; + struct skb_frag_walk *fragwalk = NULL; + struct sk_buff *newskb = xtfs->ra_newskb; + u32 remaining = skb->len - data; + u32 runtlen = xtfs->ra_runtlen; + u32 copylen, fraglen, ipremain, iphlen, iphremain, rrem; + + /* Handle packet fragment we aren't expecting */ + if (!runtlen && !xtfs->ra_newskb) + return data + min(blkoff, remaining); + + /* Important to remember that input to this function is an ordered + * packet stream (unless the user disabled the reorder window). Thus if + * we are waiting for, and expecting the next packet so we can continue + * assembly, a newer sequence number indicates older ones are not coming + * (or if they do should be ignored). Technically we can receive older + * ones when the reorder window is disabled; however, the user should + * have disabled fragmentation in this case, and regardless we don't + * deal with it. + * + * blkoff could be zero if the stream is messed up (or it's an all pad + * insertion) be careful to handle that case in each of the below + */ + + /* Too old case: This can happen when the reorder window is disabled so + * ordering isn't actually guaranteed. + */ + if (seq < xtfs->ra_wantseq) + return data + remaining; + + /* Too new case: We missed what we wanted cleanup. */ + if (seq > xtfs->ra_wantseq) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINIPTFSERROR); + goto abandon; + } + + if (blkoff == 0) { + if ((*skb->data & 0xF0) != 0) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINIPTFSERROR); + goto abandon; + } + /* Handle all pad case, advance expected sequence number. + * (RFC 9347 S2.2.3) + */ + xtfs->ra_wantseq++; + /* will end parsing */ + return data + remaining; + } + + if (runtlen) { + BUG_ON(xtfs->ra_newskb); + + /* Regardless of what happens we're done with the runt */ + xtfs->ra_runtlen = 0; + + /* The start of this inner packet was at the very end of the last + * iptfs payload which didn't include enough for the ip header + * length field. We must have *at least* that now. + */ + rrem = sizeof(xtfs->ra_runt) - runtlen; + if (remaining < rrem || blkoff < rrem) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINIPTFSERROR); + goto abandon; + } + + /* fill in the runt data */ + if (skb_copy_bits_seq(st, data, &xtfs->ra_runt[runtlen], + rrem)) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINBUFFERERROR); + goto abandon; + } + + /* We have enough data to get the ip length value now, + * allocate an in progress skb + */ + ipremain = __iptfs_iplen(xtfs->ra_runt); + if (ipremain < sizeof(xtfs->ra_runt)) { + /* length has to be at least runtsize large */ + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINIPTFSERROR); + goto abandon; + } + + /* For the runt case we don't attempt sharing currently. NOTE: + * Currently, this IPTFS implementation will not create runts. + */ + + newskb = iptfs_alloc_skb(skb, ipremain, false); + if (!newskb) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINERROR); + goto abandon; + } + xtfs->ra_newskb = newskb; + + /* Copy the runt data into the buffer, but leave data + * pointers the same as normal non-runt case. The extra `rrem` + * recopied bytes are basically cacheline free. Allows using + * same logic below to complete. + */ + memcpy(skb_put(newskb, runtlen), xtfs->ra_runt, + sizeof(xtfs->ra_runt)); + } + + /* Continue reassembling the packet */ + ipremain = __iptfs_iplen(newskb->data); + iphlen = __iptfs_iphlen(newskb->data); + + /* Sanity check, we created the newskb knowing the IP length so the IP + * length can't now be shorter. + */ + BUG_ON(newskb->len > ipremain); + + ipremain -= newskb->len; + if (blkoff < ipremain) { + /* Corrupt data, we don't have enough to complete the packet */ + XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMINIPTFSERROR); + goto abandon; + } + + /* We want the IP header in linear space */ + if (newskb->len < iphlen) { + iphremain = iphlen - newskb->len; + if (blkoff < iphremain) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINIPTFSERROR); + goto abandon; + } + fraglen = min(blkoff, remaining); + copylen = min(fraglen, iphremain); + BUG_ON(skb_tailroom(newskb) < copylen); + if (skb_copy_bits_seq(st, data, skb_put(newskb, copylen), copylen)) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINBUFFERERROR); + goto abandon; + } + /* this is a silly condition that might occur anyway */ + if (copylen < iphremain) { + xtfs->ra_wantseq++; + return data + fraglen; + } + /* update data and things derived from it */ + data += copylen; + blkoff -= copylen; + remaining -= copylen; + ipremain -= copylen; + } + + fraglen = min(blkoff, remaining); + copylen = min(fraglen, ipremain); + + /* If we may have the opportunity to share prepare a fragwalk. */ + if (!skb_has_frag_list(skb) && !skb_has_frag_list(newskb) && + (skb->head_frag || skb->len == skb->data_len) && + skb->pp_recycle == newskb->pp_recycle) { + fragwalk = &_fragwalk; + skb_prepare_frag_walk(skb, data, fragwalk); + } + + /* Try share then copy. */ + if (fragwalk && skb_can_add_frags(newskb, fragwalk, data, copylen)) { + u32 leftover; + + leftover = skb_add_frags(newskb, fragwalk, data, copylen); + BUG_ON(leftover != 0); + } else { + /* We verified this was true in the main receive routine */ + BUG_ON(skb_tailroom(newskb) < copylen); + + /* copy fragment data into newskb */ + if (skb_copy_bits_seq(st, data, skb_put(newskb, copylen), copylen)) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINBUFFERERROR); + goto abandon; + } + } + + if (copylen < ipremain) { + xtfs->ra_wantseq++; + } else { + /* We are done with packet reassembly! */ + BUG_ON(copylen != ipremain); + iptfs_reassem_done(xtfs); + iptfs_complete_inner_skb(xtfs->x, newskb); + list_add_tail(&newskb->list, list); + } + + /* will continue on to new data block or end */ + return data + fraglen; + +abandon: + if (xtfs->ra_newskb) { + iptfs_reassem_abort(xtfs); + } else { + xtfs->ra_runtlen = 0; + xtfs->ra_wantseq = 0; + } + /* skip past fragment, maybe to end */ + return data + min(blkoff, remaining); +} + +/** + * iptfs_input_ordered() - handle next in order IPTFS payload. + * + * Process the IPTFS payload in `skb` and consume it afterwards. + */ +static int iptfs_input_ordered(struct xfrm_state *x, struct sk_buff *skb) +{ + u8 hbytes[sizeof(struct ipv6hdr)]; + struct ip_iptfs_cc_hdr iptcch; + struct skb_seq_state skbseq; + struct skb_frag_walk _fragwalk; + struct skb_frag_walk *fragwalk = NULL; + struct list_head sublist; /* rename this it's just a list */ + struct sk_buff *first_skb, *defer, *next; + const unsigned char *old_mac; + struct xfrm_iptfs_data *xtfs; + struct ip_iptfs_hdr *ipth; + struct iphdr *iph; + struct net *net; + u32 remaining, first_iplen, iplen, iphlen, data, tail; + u32 blkoff, capturelen; + u64 seq; + + xtfs = x->mode_data; + net = dev_net(skb->dev); + first_skb = NULL; + defer = NULL; + + seq = __esp_seq(skb); + + /* Large enough to hold both types of header */ + ipth = (struct ip_iptfs_hdr *)&iptcch; + + /* Save the old mac header if set */ + old_mac = skb_mac_header_was_set(skb) ? skb_mac_header(skb) : NULL; + + skb_prepare_seq_read(skb, 0, skb->len, &skbseq); + + /* Get the IPTFS header and validate it */ + + if (skb_copy_bits_seq(&skbseq, 0, ipth, sizeof(*ipth))) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR); + goto done; + } + data = sizeof(*ipth); + + trace_iptfs_egress_recv(skb, xtfs, htons(ipth->block_offset)); + + /* Set data past the basic header */ + if (ipth->subtype == IPTFS_SUBTYPE_CC) { + /* Copy the rest of the CC header */ + remaining = sizeof(iptcch) - sizeof(*ipth); + if (skb_copy_bits_seq(&skbseq, data, ipth + 1, remaining)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR); + goto done; + } + data += remaining; + } else if (ipth->subtype != IPTFS_SUBTYPE_BASIC) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR); + goto done; + } + + if (ipth->flags != 0) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR); + goto done; + } + + INIT_LIST_HEAD(&sublist); + + /* Handle fragment at start of payload, and/or waiting reassembly. */ + + blkoff = ntohs(ipth->block_offset); + /* check before locking i.e., maybe */ + if (blkoff || xtfs->ra_runtlen || xtfs->ra_newskb) { + spin_lock(&xtfs->drop_lock); + + /* check again after lock */ + if (blkoff || xtfs->ra_runtlen || xtfs->ra_newskb) { + data = iptfs_reassem_cont(xtfs, seq, &skbseq, skb, data, + blkoff, &sublist); + } + + spin_unlock(&xtfs->drop_lock); + } + + /* New packets */ + + tail = skb->len; + BUG_ON(xtfs->ra_newskb && data < tail); + + while (data < tail) { + u32 protocol = 0; + + /* Gather information on the next data block. + * `data` points to the start of the data block. + */ + remaining = tail - data; + + /* try and copy enough bytes to read length from ipv4/ipv6 */ + iphlen = min_t(u32, remaining, 6); + if (skb_copy_bits_seq(&skbseq, data, hbytes, iphlen)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR); + goto done; + } + + iph = (struct iphdr *)hbytes; + if (iph->version == 0x4) { + /* must have at least tot_len field present */ + if (remaining < 4) { + /* save the bytes we have, advance data and exit */ + iptfs_input_save_runt(xtfs, seq, hbytes, + remaining); + data += remaining; + break; + } + + iplen = htons(iph->tot_len); + iphlen = iph->ihl << 2; + protocol = htons(ETH_P_IP); + XFRM_MODE_SKB_CB(skbseq.root_skb)->tos = iph->tos; + } else if (iph->version == 0x6) { + /* must have at least payload_len field present */ + if (remaining < 6) { + /* save the bytes we have, advance data and exit */ + iptfs_input_save_runt(xtfs, seq, hbytes, + remaining); + data += remaining; + break; + } + + iplen = htons(((struct ipv6hdr *)hbytes)->payload_len); + iplen += sizeof(struct ipv6hdr); + iphlen = sizeof(struct ipv6hdr); + protocol = htons(ETH_P_IPV6); + XFRM_MODE_SKB_CB(skbseq.root_skb)->tos = + ipv6_get_dsfield((struct ipv6hdr *)iph); + } else if (iph->version == 0x0) { + /* pad */ + data = tail; + break; + } else { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR); + goto done; + } + + if (unlikely(skbseq.stepped_offset)) { + /* We need to reset our seq read, it can't backup at + * this point. + */ + struct sk_buff *save = skbseq.root_skb; + + skb_abort_seq_read(&skbseq); + skb_prepare_seq_read(save, data, tail, &skbseq); + } + + if (first_skb) { + skb = NULL; + } else { + first_skb = skb; + first_iplen = iplen; + fragwalk = NULL; + + /* We are going to skip over `data` bytes to reach the + * start of the IP header of `iphlen` len for `iplen` + * inner packet. + */ + + if (skb_has_frag_list(skb)) { + defer = skb; + skb = NULL; +#if 0 + } else if (data < skb_headlen(skb)) { + /* NOTE: Instead of pskb_pull we could just drop + * the head bytes and as many pages as necessary + * to get us pointing at the correct thing. + */ + pskb_pull(skb, data); + /* Reuse fist skb. Need to move past the initial + * iptfs header as well as any initial fragment + * for previous inner packet reassembly. + */ + skb_pull(skb, data); + data = 0; + tail = skb->len; + remaining = skb->len; + + skb->protocol = protocol; + skb_mac_header_rebuild(skb); + if (skb->mac_len) + eth_hdr(skb)->h_proto = skb->protocol; + + /* all pointers could be changed now -- reset walk */ + skb_abort_seq_read(&skbseq); + skb_prepare_seq_read(skb, data, tail, &skbseq); + + } else if (skb->data_len == 0 && + skb_tailroom(skb) + (skb->len - data) >= iplen) { +#endif + } else if (data + iphlen <= skb_headlen(skb) && + /* make sure our header is 32-bit aligned? */ + /* ((uintptr_t)(skb->data + data) & 0x3) == 0 && */ + skb_tailroom(skb) + tail - data >= iplen) { + /* Reuse the received skb. + * + * We have enough headlen to pull past any + * initial fragment data, leaving at least the + * IP header in the linear buffer space. + * + * For linear buffer space we only require that + * linear buffer space is large enough to + * eventually hold the entire reassembled + * packet (by including tailroom in the check). + * + * For non-linear tailroom is 0 and so we only + * re-use if the entire packet is present + * already. + * + * NOTE: there are many more options for + * sharing, KISS for now. Also, this can produce + * skb's with the IP header unaligned to 32 + * bits. If that ends up being a problem then a + * check should be added to the conditional + * above that the header lies on a 32-bit + * boundary as well. + */ + skb_pull(skb, data); + + /* our range just changed */ + data = 0; + tail = skb->len; + remaining = skb->len; + + skb->protocol = protocol; + skb_mac_header_rebuild(skb); + if (skb->mac_len) + eth_hdr(skb)->h_proto = skb->protocol; + + /* all pointers could be changed now reset walk */ + skb_abort_seq_read(&skbseq); + skb_prepare_seq_read(skb, data, tail, &skbseq); + } else if (skb->head_frag && + /* We have the IP header right now */ + remaining >= iphlen) { + fragwalk = &_fragwalk; + skb_prepare_frag_walk(skb, data, fragwalk); + defer = skb; + skb = NULL; + } else { + /* We couldn't reuse the input skb so allocate a + * new one. + */ + defer = skb; + skb = NULL; + } + + /* Don't trim `first_skb` until the end as we are + * walking that data now. + */ + } + + capturelen = min(iplen, remaining); + if (!skb) { + if (!fragwalk || + /* Large enough to be worth sharing */ + iplen < IPTFS_PKT_SHARE_MIN || + /* Have IP header + some data to share. */ + capturelen <= iphlen || + /* Try creating skb and adding frags */ + !(skb = iptfs_pskb_add_frags(first_skb, fragwalk, + data, capturelen, + &skbseq, iphlen))) { + skb = iptfs_pskb_extract_seq(iplen, &skbseq, + data, capturelen); + } + if (!skb) { + /* skip to next packet or done */ + data += capturelen; + continue; + } + BUG_ON(skb->len != capturelen); + + skb->protocol = protocol; + if (old_mac) { + /* rebuild the mac header */ + skb_set_mac_header(skb, -first_skb->mac_len); + memcpy(skb_mac_header(skb), old_mac, + first_skb->mac_len); + eth_hdr(skb)->h_proto = skb->protocol; + } + } + + data += capturelen; + + if (skb->len < iplen) { + BUG_ON(data != tail); + BUG_ON(xtfs->ra_newskb); + + /* Start reassembly */ + spin_lock(&xtfs->drop_lock); + + xtfs->ra_newskb = skb; + xtfs->ra_wantseq = seq + 1; + if (!hrtimer_is_queued(&xtfs->drop_timer)) { + /* softirq blocked lest the timer fire and interrupt us */ + BUG_ON(!in_interrupt()); + hrtimer_start(&xtfs->drop_timer, + xtfs->drop_time_ns, + IPTFS_HRTIMER_MODE); + } + + spin_unlock(&xtfs->drop_lock); + + break; + } + + iptfs_complete_inner_skb(x, skb); + list_add_tail(&skb->list, &sublist); + } + + if (data != tail) + /* this should not happen from the above code */ + XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMINIPTFSERROR); + + if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb) { + /* first_skb is queued b/c !defer and not partial */ + if (pskb_trim(first_skb, first_iplen)) { + /* error trimming */ + list_del(&first_skb->list); + defer = first_skb; + } + first_skb->ip_summed = CHECKSUM_NONE; + } + + /* Send the packets! */ + list_for_each_entry_safe(skb, next, &sublist, list) { + BUG_ON(skb == defer); + skb_list_del_init(skb); + if (xfrm_input(skb, 0, 0, -3)) + kfree_skb(skb); + } + +done: + skb = skbseq.root_skb; + skb_abort_seq_read(&skbseq); + + if (defer) { + consume_skb(defer); + } else if (!first_skb) { + /* skb is the original passed in skb, but we didn't get far + * enough to process it as the first_skb, if we had it would + * either be save in ra_newskb, trimmed and sent on as an skb or + * placed in defer to be freed. + */ + BUG_ON(!skb); + kfree_skb(skb); + } + + return 0; +} + +/* ------------------------------- */ +/* Input (Egress) Re-ordering Code */ +/* ------------------------------- */ + +static void __vec_shift(struct xfrm_iptfs_data *xtfs, u32 shift) +{ + u32 savedlen = xtfs->w_savedlen; + + if (shift > savedlen) + shift = savedlen; + if (shift != savedlen) + memcpy(xtfs->w_saved, xtfs->w_saved + shift, + (savedlen - shift) * sizeof(*xtfs->w_saved)); + memset(xtfs->w_saved + savedlen - shift, 0, + shift * sizeof(*xtfs->w_saved)); + xtfs->w_savedlen -= shift; +} + +static int __reorder_past(struct xfrm_iptfs_data *xtfs, struct sk_buff *inskb, + struct list_head *freelist, u32 *fcount) +{ + list_add_tail(&inskb->list, freelist); + (*fcount)++; + return 0; +} + +static u32 __reorder_drop(struct xfrm_iptfs_data *xtfs, struct list_head *list) + +{ + struct skb_wseq *s, *se; + const u32 savedlen = xtfs->w_savedlen; + u64 wantseq = xtfs->w_wantseq; + time64_t now = ktime_get_raw_fast_ns(); + u32 count = 0; + u32 scount = 0; + + BUG_ON(!savedlen); + if (xtfs->w_saved[0].drop_time > now) + goto set_timer; + + wantseq = ++xtfs->w_wantseq; + + /* Keep flushing packets until we reach a drop time greater than now. */ + s = xtfs->w_saved; + se = s + savedlen; + do { + /* Walking past empty slots until we reach a packet */ + for (; s < se && !s->skb; s++) + if (s->drop_time > now) + goto outerdone; + /* Sending packets until we hit another empty slot. */ + for (; s < se && s->skb; scount++, s++) + list_add_tail(&s->skb->list, list); + } while (s < se); +outerdone: + + count = s - xtfs->w_saved; + if (count) { + xtfs->w_wantseq += count; + + /* Shift handled slots plus final empty slot into slot 0. */ + __vec_shift(xtfs, count); + } + + if (xtfs->w_savedlen) { +set_timer: + /* Drifting is OK */ + hrtimer_start(&xtfs->drop_timer, + xtfs->w_saved[0].drop_time - now, + IPTFS_HRTIMER_MODE); + } + return scount; +} + +static u32 __reorder_this(struct xfrm_iptfs_data *xtfs, struct sk_buff *inskb, + struct list_head *list) + +{ + struct skb_wseq *s, *se; + const u32 savedlen = xtfs->w_savedlen; + u64 wantseq = xtfs->w_wantseq; + u32 count = 0; + + /* Got what we wanted. */ + list_add_tail(&inskb->list, list); + wantseq = ++xtfs->w_wantseq; + if (!savedlen) + return 1; + + /* Flush remaining consecutive packets. */ + + /* Keep sending until we hit another missed pkt. */ + for (s = xtfs->w_saved, se = s + savedlen; s < se && s->skb; s++) + list_add_tail(&s->skb->list, list); + count = s - xtfs->w_saved; + if (count) + xtfs->w_wantseq += count; + + /* Shift handled slots plus final empty slot into slot 0. */ + __vec_shift(xtfs, count + 1); + + return count + 1; +} + +/* Set the slot's drop time and all the empty slots below it until reaching a + * filled slot which will already be set. + */ +static void iptfs_set_window_drop_times(struct xfrm_iptfs_data *xtfs, int index) +{ + const u32 savedlen = xtfs->w_savedlen; + struct skb_wseq *s = xtfs->w_saved; + time64_t drop_time; + + assert_spin_locked(&xtfs->drop_lock); + + if (savedlen > index + 1) { + /* we are below another, our drop time and the timer are already set */ + BUG_ON(xtfs->w_saved[index + 1].drop_time != + xtfs->w_saved[index].drop_time); + return; + } + /* we are the most future so get a new drop time. */ + drop_time = ktime_get_raw_fast_ns(); + drop_time += xtfs->drop_time_ns; + + /* Walk back through the array setting drop times as we go */ + s[index].drop_time = drop_time; + while (index-- > 0 && !s[index].skb) + s[index].drop_time = drop_time; + + /* If we walked all the way back, schedule the drop timer if needed */ + if (index == -1 && !hrtimer_is_queued(&xtfs->drop_timer)) + hrtimer_start(&xtfs->drop_timer, xtfs->drop_time_ns, + IPTFS_HRTIMER_MODE); +} + +static u32 __reorder_future_fits(struct xfrm_iptfs_data *xtfs, + struct sk_buff *inskb, + struct list_head *freelist, u32 *fcount) +{ + const u32 nslots = xtfs->cfg.reorder_win_size + 1; + const u64 inseq = __esp_seq(inskb); + const u64 wantseq = xtfs->w_wantseq; + const u64 distance = inseq - wantseq; + const u32 savedlen = xtfs->w_savedlen; + const u32 index = distance - 1; + + BUG_ON(distance >= nslots); + + /* Handle future sequence number received which fits in the window. + * + * We know we don't have the seq we want so we won't be able to flush + * anything. + */ + + /* slot count is 4, saved size is 3 savedlen is 2 + * + * "window boundary" is based on the fixed window size + * distance is also slot number + * index is an array index (i.e., - 1 of slot) + * : : - implicit NULL after array len + * + * +--------- used length (savedlen == 2) + * | +----- array size (nslots - 1 == 3) + * | | + window boundary (nslots == 4) + * V V | V + * | + * 0 1 2 3 | slot number + * --- 0 1 2 | array index + * [-] [b] : :| array + * + * "2" "3" "4" *5*| seq numbers + * + * We receive seq number 5 + * distance == 3 [inseq(5) - w_wantseq(2)] + * index == 2 [distance(6) - 1] + */ + + if (xtfs->w_saved[index].skb) { + /* a dup of a future */ + list_add_tail(&inskb->list, freelist); + (*fcount)++; + return 0; + } + + xtfs->w_saved[index].skb = inskb; + xtfs->w_savedlen = max(savedlen, index + 1); + iptfs_set_window_drop_times(xtfs, index); + + return 0; +} + +static u32 __reorder_future_shifts(struct xfrm_iptfs_data *xtfs, + struct sk_buff *inskb, + struct list_head *list, + struct list_head *freelist, u32 *fcount) +{ + const u32 nslots = xtfs->cfg.reorder_win_size + 1; + const u64 inseq = __esp_seq(inskb); + u32 savedlen = xtfs->w_savedlen; + u64 wantseq = xtfs->w_wantseq; + struct sk_buff *slot0 = NULL; + u64 last_drop_seq = xtfs->w_wantseq; + u64 distance, extra_drops, missed, s0seq; + u32 count = 0; + struct skb_wseq *wnext; + u32 beyond, shifting, slot; + + BUG_ON(inseq <= wantseq); + distance = inseq - wantseq; + BUG_ON(distance <= nslots - 1); + beyond = distance - (nslots - 1); + missed = 0; + + /* Handle future sequence number received. + * + * IMPORTANT: we are at least advancing w_wantseq (i.e., wantseq) by 1 + * b/c we are beyond the window boundary. + * + * We know we don't have the wantseq so that counts as a drop. + */ + + /* ex: slot count is 4, array size is 3 savedlen is 2, slot 0 is the + * missing sequence number. + * + * the final slot at savedlen (index savedlen - 1) is always occupied. + * + * beyond is "beyond array size" not savedlen. + * + * +--------- array length (savedlen == 2) + * | +----- array size (nslots - 1 == 3) + * | | +- window boundary (nslots == 4) + * V V | V + * | + * 0 1 2 3 | slot number + * --- 0 1 2 | array index + * [b] [c] : :| array + * | + * "2" "3" "4" "5"|*6* seq numbers + * + * We receive seq number 6 + * distance == 4 [inseq(6) - w_wantseq(2)] + * newslot == distance + * index == 3 [distance(4) - 1] + * beyond == 1 [newslot(4) - lastslot((nslots(4) - 1))] + * shifting == 1 [min(savedlen(2), beyond(1)] + * slot0_skb == [b], and should match w_wantseq + * + * +--- window boundary (nslots == 4) + * 0 1 2 3 | 4 slot number + * --- 0 1 2 | 3 array index + * [b] : : : :| array + * "2" "3" "4" "5" *6* seq numbers + * + * We receive seq number 6 + * distance == 4 [inseq(6) - w_wantseq(2)] + * newslot == distance + * index == 3 [distance(4) - 1] + * beyond == 1 [newslot(4) - lastslot((nslots(4) - 1))] + * shifting == 1 [min(savedlen(1), beyond(1)] + * slot0_skb == [b] and should match w_wantseq + * + * +-- window boundary (nslots == 4) + * 0 1 2 3 | 4 5 6 slot number + * --- 0 1 2 | 3 4 5 array index + * [-] [c] : :| array + * "2" "3" "4" "5" "6" "7" *8* seq numbers + * + * savedlen = 2, beyond = 3 + * iter 1: slot0 == NULL, missed++, lastdrop = 2 (2+1-1), slot0 = [-] + * iter 2: slot0 == NULL, missed++, lastdrop = 3 (2+2-1), slot0 = [c] + * 2 < 3, extra = 1 (3-2), missed += extra, lastdrop = 4 (2+2+1-1) + * + * We receive seq number 8 + * distance == 6 [inseq(8) - w_wantseq(2)] + * newslot == distance + * index == 5 [distance(6) - 1] + * beyond == 3 [newslot(6) - lastslot((nslots(4) - 1))] + * shifting == 2 [min(savedlen(2), beyond(3)] + * + * slot0_skb == NULL changed from [b] when "savedlen < beyond" is true. + */ + + /* Now send any packets that are being shifted out of saved, and account + * for missing packets that are exiting the window as we shift it. + */ + + /* If savedlen > beyond we are shifting some, else all. */ + shifting = min(savedlen, beyond); + + /* slot0 is the buf that just shifted out and into slot0 */ + slot0 = NULL; + s0seq = wantseq; + last_drop_seq = s0seq; + wnext = xtfs->w_saved; + for (slot = 1; slot <= shifting; slot++, wnext++) { + /* handle what was in slot0 before we occupy it */ + if (!slot0) { + last_drop_seq = s0seq; + missed++; + } else { + list_add_tail(&slot0->list, list); + count++; + } + s0seq++; + slot0 = wnext->skb; + wnext->skb = NULL; + } + + /* slot0 is now either NULL (in which case it's what we now are waiting + * for, or a buf in which case we need to handle it like we received it; + * however, we may be advancing past that buffer as well.. + */ + + /* Handle case where we need to shift more than we had saved, slot0 will + * be NULL iff savedlen is 0, otherwise slot0 will always be + * non-NULL b/c we shifted the final element, which is always set if + * there is any saved, into slot0. + */ + if (savedlen < beyond) { + extra_drops = beyond - savedlen; + if (savedlen == 0) { + BUG_ON(slot0); + s0seq += extra_drops; + last_drop_seq = s0seq - 1; + } else { + extra_drops--; /* we aren't dropping what's in slot0 */ + BUG_ON(!slot0); + list_add_tail(&slot0->list, list); + /* if extra_drops then we are going past this slot0 + * so we can safely advance last_drop_seq + */ + if (extra_drops) + last_drop_seq = s0seq + extra_drops; + s0seq += extra_drops + 1; + count++; + } + missed += extra_drops; + slot0 = NULL; + /* slot0 has had an empty slot pushed into it */ + } + + /* Remove the entries */ + __vec_shift(xtfs, beyond); + + /* Advance want seq */ + xtfs->w_wantseq += beyond; + + /* Process drops here when implementing congestion control */ + + /* We've shifted. plug the packet in at the end. */ + xtfs->w_savedlen = nslots - 1; + xtfs->w_saved[xtfs->w_savedlen - 1].skb = inskb; + iptfs_set_window_drop_times(xtfs, xtfs->w_savedlen - 1); + + /* if we don't have a slot0 then we must wait for it */ + if (!slot0) + return count; + + /* If slot0, seq must match new want seq */ + BUG_ON(xtfs->w_wantseq != __esp_seq(slot0)); + + /* slot0 is valid, treat like we received expected. */ + count += __reorder_this(xtfs, slot0, list); + return count; +} + +/* Receive a new packet into the reorder window. Return a list of ordered + * packets from the window. + */ +static u32 iptfs_input_reorder(struct xfrm_iptfs_data *xtfs, + struct sk_buff *inskb, struct list_head *list, + struct list_head *freelist, u32 *fcount) +{ + const u32 nslots = xtfs->cfg.reorder_win_size + 1; + u64 inseq = __esp_seq(inskb); + u64 wantseq; + + assert_spin_locked(&xtfs->drop_lock); + + if (unlikely(!xtfs->w_seq_set)) { + xtfs->w_seq_set = true; + xtfs->w_wantseq = inseq; + } + wantseq = xtfs->w_wantseq; + + if (likely(inseq == wantseq)) + return __reorder_this(xtfs, inskb, list); + else if (inseq < wantseq) + return __reorder_past(xtfs, inskb, freelist, fcount); + else if ((inseq - wantseq) < nslots) + return __reorder_future_fits(xtfs, inskb, freelist, fcount); + else + return __reorder_future_shifts(xtfs, inskb, list, freelist, + fcount); +} + +/** + * iptfs_drop_timer() - Handle drop timer expiry. + * + * This is similar to our input function. + * + * The drop timer is set when we start an in progress reassembly, and also when + * we save a future packet in the window saved array. + * + * NOTE packets in the save window are always newer WRT drop times as + * they get further in the future. i.e. for: + * + * if slots (S0, S1, ... Sn) and `Dn` is the drop time for slot `Sn`, + * then D(n-1) <= D(n). + * + * So, regardless of why the timer is firing we can always discard any inprogress + * fragment; either it's the reassembly timer, or slot 0 is going to be + * dropped as S0 must have the most recent drop time, and slot 0 holds the + * continuation fragment of the in progress packet. + */ +static enum hrtimer_restart iptfs_drop_timer(struct hrtimer *me) +{ + struct sk_buff *skb, *next; + struct list_head freelist, list; + struct xfrm_iptfs_data *xtfs; + struct xfrm_state *x; + u32 count, fcount; + + xtfs = container_of(me, typeof(*xtfs), drop_timer); + x = xtfs->x; + + spin_lock(&xtfs->drop_lock); + + INIT_LIST_HEAD(&list); + INIT_LIST_HEAD(&freelist); + fcount = 0; + + /* Drop any in progress packet */ + + if (xtfs->ra_newskb) { + kfree_skb(xtfs->ra_newskb); + xtfs->ra_newskb = NULL; + } + + /* Now drop as many packets as we should from the reordering window + * saved array + */ + count = xtfs->w_savedlen ? __reorder_drop(xtfs, &list) : 0; + + spin_unlock(&xtfs->drop_lock); + + if (count) { + list_for_each_entry_safe(skb, next, &list, list) { + skb_list_del_init(skb); + (void)iptfs_input_ordered(x, skb); + } + } + return HRTIMER_NORESTART; +} + +/** + * iptfs_input() - handle receipt of iptfs payload + * @x: xfrm state. + * @skb: the packet. + * + * We have an IPTFS payload order it if needed, then process newly in order + * packetsA. + */ +static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb) +{ + struct list_head freelist, list; + struct xfrm_iptfs_data *xtfs = x->mode_data; + struct sk_buff *next; + u32 count, fcount; + + /* Fast path for no reorder window. */ + if (xtfs->cfg.reorder_win_size == 0) { + iptfs_input_ordered(x, skb); + goto done; + } + + /* Fetch list of in-order packets from the reordering window as well as + * a list of buffers we need to now free. + */ + INIT_LIST_HEAD(&list); + INIT_LIST_HEAD(&freelist); + fcount = 0; + + spin_lock(&xtfs->drop_lock); + count = iptfs_input_reorder(xtfs, skb, &list, &freelist, &fcount); + spin_unlock(&xtfs->drop_lock); + + if (count) { + list_for_each_entry_safe(skb, next, &list, list) { + skb_list_del_init(skb); + (void)iptfs_input_ordered(x, skb); + } + } + + if (fcount) { + list_for_each_entry_safe(skb, next, &freelist, list) { + skb_list_del_init(skb); + kfree_skb(skb); + } + } +done: + /* We always have dealt with the input SKB, either we are re-using it, + * or we have freed it. Return EINPROGRESS so that xfrm_input stops + * processing it. + */ + return -EINPROGRESS; +} + +/* ================================= */ +/* IPTFS Sending (ingress) Functions */ +/* ================================= */ + +/* ------------------------- */ +/* Enqueue to send functions */ +/* ------------------------- */ + +/** + * iptfs_enqueue() - enqueue packet if ok to send. + * @xtfs: xtfs state + * @skb: the packet + * + * Return: true if packet enqueued. + */ +static bool iptfs_enqueue(struct xfrm_iptfs_data *xtfs, struct sk_buff *skb) +{ + u64 newsz = xtfs->queue_size + skb->len; + struct iphdr *iph; + + assert_spin_locked(&xtfs->x->lock); + + if (newsz > xtfs->cfg.max_queue_size) + return false; + + /* Set ECN CE if we are above our ECN queue threshold */ + if (newsz > xtfs->ecn_queue_size) { + iph = ip_hdr(skb); + if (iph->version == 4) + IP_ECN_set_ce(iph); + else if (iph->version == 6) + IP6_ECN_set_ce(skb, ipv6_hdr(skb)); + } + + __skb_queue_tail(&xtfs->queue, skb); + xtfs->queue_size += skb->len; + return true; +} + +static int iptfs_get_cur_pmtu(struct xfrm_state *x, struct xfrm_iptfs_data *xtfs, + struct sk_buff *skb) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)skb_dst(skb); + u32 payload_mtu = xtfs->payload_mtu; + u32 pmtu = __iptfs_get_inner_mtu(x, xdst->child_mtu_cached); + + if (payload_mtu && payload_mtu < pmtu) + pmtu = payload_mtu; + + return pmtu; +} + +static int iptfs_is_too_big(struct sock *sk, struct sk_buff *skb, u32 pmtu) +{ + struct flowi6 fl6; + + if (skb->len <= pmtu) + return 0; + + /* We only send ICMP too big if the user has configured us as + * dont-fragment. We need to adjust something in the + * stack as we are never getting here (good) even when + * our no DF config is set (bad). + */ + XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMOUTERROR); + + if (sk) { + if (ip_hdr(skb)->version == 4) { + xfrm_local_error(skb, pmtu); + } else { + WARN_ON_ONCE(ip_hdr(skb)->version != 6); + + memset(&fl6, 0, sizeof(fl6)); + ipv6_local_error(skb->sk, EMSGSIZE, &fl6, pmtu); + } + } else if (ip_hdr(skb)->version == 4) { + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(pmtu)); + } else { + WARN_ON_ONCE(ip_hdr(skb)->version != 6); + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, pmtu); + } + return 1; +} + +/* IPv4/IPv6 packet ingress to IPTFS tunnel, arrange to send in IPTFS payload + * (i.e., aggregating or fragmenting as appropriate). + * This is set in dst->output for an SA. + */ +static int iptfs_output_collect(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct xfrm_state *x = dst->xfrm; + struct xfrm_iptfs_data *xtfs = x->mode_data; + struct sk_buff *segs, *nskb; + u32 count, qcount; + u32 pmtu = 0; + bool ok = true; + bool was_gso; + + /* We have hooked into dst_entry->output which means we have skipped the + * protocol specific netfilter (see xfrm4_output, xfrm6_output). + * when our timer runs we will end up calling xfrm_output directly on + * the encapsulated traffic. + * + * For both cases this is the NF_INET_POST_ROUTING hook which allows + * changing the skb->dst entry which then may not be xfrm based anymore + * in which case a REROUTED flag is set. and dst_output is called. + * + * For IPv6 we are also skipping fragmentation handling for local + * sockets, which may or may not be good depending on our tunnel DF + * setting. Normally with fragmentation supported we want to skip this + * fragmentation. + */ + + BUG_ON(!xtfs); + + if (xtfs->cfg.dont_frag) + pmtu = iptfs_get_cur_pmtu(x, xtfs, skb); + + /* Break apart GSO skbs. If the queue is nearing full then we want the + * accounting and queuing to be based on the individual packets not on the + * aggregate GSO buffer. + */ + was_gso = skb_is_gso(skb); + if (!was_gso) { + segs = skb; + } else { + segs = skb_gso_segment(skb, 0); + if (IS_ERR_OR_NULL(segs)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); + kfree_skb(skb); + return PTR_ERR(segs); + } + consume_skb(skb); + skb = NULL; + } + + count = 0; + qcount = 0; + + /* We can be running on multiple cores and from the network softirq or + * from user context depending on where the packet is coming from. + */ + spin_lock_bh(&x->lock); + + skb_list_walk_safe(segs, skb, nskb) { + skb_mark_not_on_list(skb); + count++; + + /* Once we drop due to no queue space we continue to drop the + * rest of the packets from that GRO. + */ + if (!ok) { +nospace: + trace_iptfs_no_queue_space(skb, xtfs, pmtu, was_gso); + XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMOUTNOQSPACE); + kfree_skb_reason(skb, SKB_DROP_REASON_FULL_RING); + continue; + } + + /* If the user indicated no iptfs fragmenting check before + * enqueue. + */ + if (xtfs->cfg.dont_frag && iptfs_is_too_big(sk, skb, pmtu)) { + trace_iptfs_too_big(skb, xtfs, pmtu, was_gso); + kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG); + continue; + } + + /* Enqueue to send in tunnel */ + + ok = iptfs_enqueue(xtfs, skb); + if (!ok) + goto nospace; + + trace_iptfs_enqueue(skb, xtfs, pmtu, was_gso); + qcount++; + } + + /* Start a delay timer if we don't have one yet */ + if (!hrtimer_is_queued(&xtfs->iptfs_timer)) { + /* softirq blocked lest the timer fire and interrupt us */ + BUG_ON(!in_interrupt()); + hrtimer_start(&xtfs->iptfs_timer, xtfs->init_delay_ns, + IPTFS_HRTIMER_MODE); + + xtfs->iptfs_settime = ktime_get_raw_fast_ns(); + trace_iptfs_timer_start(xtfs, xtfs->init_delay_ns); + } + + spin_unlock_bh(&x->lock); + return 0; +} + +/* -------------------------- */ +/* Dequeue and send functions */ +/* -------------------------- */ + +static void iptfs_output_prepare_skb(struct sk_buff *skb, u32 blkoff) +{ + struct ip_iptfs_hdr *h; + size_t hsz = sizeof(*h); + + /* now reset values to be pointing at the rest of the packets */ + h = skb_push(skb, hsz); + memset(h, 0, hsz); + if (blkoff) + h->block_offset = htons(blkoff); + + /* network_header current points at the inner IP packet + * move it to the iptfs header + */ + skb->transport_header = skb->network_header; + skb->network_header -= hsz; + + IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE; + + /* xfrm[46]_prepare_output sets skb->protocol here, but the resulting + * called ip[6]_output functions also set this value as appropriate so + * seems unnecessary + * + * skb->protocol = htons(ETH_P_IP) or htons(ETH_P_IPV6); + */ +} + +/** + * iptfs_copy_create_frag() - create an inner fragment skb. + * @st: The source packet data. + * @offset: offset in @st of the new fragment data. + * @copy_len: the amount of data to copy from @st. + * + * Create a new skb holding a single IPTFS inner packet fragment. @copy_len must + * not be greater than the max fragment size. + * + * Return: the new fragment skb or an ERR_PTR(). + */ +static struct sk_buff *iptfs_copy_create_frag(struct skb_seq_state *st, + u32 offset, u32 copy_len) +{ + struct sk_buff *src = st->root_skb; + struct sk_buff *skb; + int err; + + skb = iptfs_alloc_skb(src, copy_len, true); + if (!skb) + return ERR_PTR(-ENOMEM); + + /* Now copy `copy_len` data from src */ + err = skb_copy_bits_seq(st, offset, skb_put(skb, copy_len), copy_len); + if (err) { + XFRM_INC_STATS(dev_net(src->dev), LINUX_MIB_XFRMOUTERROR); + kfree_skb(skb); + return ERR_PTR(err); + } + + return skb; +} + +/** + * iptfs_copy_create_frags() - create and send N-1 fragments of a larger skb. + * @skbp: the source packet skb (IN), skb holding the last fragment in + * the fragment stream (OUT). + * @xtfs: IPTFS SA state. + * @mtu: the max IPTFS fragment size. + * + * This function is responsible for fragmenting a larger inner packet into a + * sequence of IPTFS payload packets. The last fragment is returned rather than + * being sent so that the caller can append more inner packets (aggregation) if + * there is room. + */ +static int iptfs_copy_create_frags(struct sk_buff **skbp, + struct xfrm_iptfs_data *xtfs, u32 mtu) +{ + struct skb_seq_state skbseq; + struct list_head sublist; + struct sk_buff *skb = *skbp; + struct sk_buff *nskb = *skbp; + u32 copy_len, offset; + u32 to_copy = skb->len - mtu; + u32 blkoff = 0; + int err = 0; + + INIT_LIST_HEAD(&sublist); + + BUG_ON(skb->len <= mtu); + skb_prepare_seq_read(skb, 0, skb->len, &skbseq); + + /* A trimmed `skb` will be sent as the first fragment, later. */ + offset = mtu; + to_copy = skb->len - offset; + while (to_copy) { + /* Send all but last fragment to allow agg. append */ + trace_iptfs_first_fragmenting(nskb, mtu, to_copy, NULL); + list_add_tail(&nskb->list, &sublist); + + /* FUTURE: if the packet has an odd/non-aligning length we could + * send less data in the penultimate fragment so that the last + * fragment then ends on an aligned boundary. + */ + copy_len = to_copy <= mtu ? to_copy : mtu; + nskb = iptfs_copy_create_frag(&skbseq, offset, copy_len); + if (IS_ERR(nskb)) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMOUTERROR); + skb_abort_seq_read(&skbseq); + err = PTR_ERR(nskb); + nskb = NULL; + break; + } + iptfs_output_prepare_skb(nskb, to_copy); + offset += copy_len; + to_copy -= copy_len; + blkoff = to_copy; + } + skb_abort_seq_read(&skbseq); + + /* return last fragment that will be unsent (or NULL) */ + *skbp = nskb; + if (nskb) + trace_iptfs_first_final_fragment(nskb, mtu, blkoff, NULL); + + /* trim the original skb to MTU */ + if (!err) + err = pskb_trim(skb, mtu); + + if (err) { + /* Free all frags. Don't bother sending a partial packet we will + * never complete. + */ + kfree_skb(nskb); + list_for_each_entry_safe(skb, nskb, &sublist, list) { + skb_list_del_init(skb); + kfree_skb(skb); + } + return err; + } + + /* prepare the initial fragment with an iptfs header */ + iptfs_output_prepare_skb(skb, 0); + + /* Send all but last fragment. */ + list_for_each_entry_safe(skb, nskb, &sublist, list) { + skb_list_del_init(skb); + xfrm_output(NULL, skb); + } + + return 0; +} + +/** + * iptfs_first_should_copy() - determine if we should copy packet data. + * @first_skb: the first skb in the packet + * @mtu: the MTU. + * + * Determine if we should create subsequent skbs to hold the remaining data from + * a large inner packet by copying the packet data, or cloning the original skb + * and adjusting the offsets. + */ +static bool iptfs_first_should_copy(struct sk_buff *first_skb, u32 mtu) +{ + u32 frag_copy_max; + + /* If we have less than frag_copy_max for remaining packet we copy + * those tail bytes as it is more efficient. + */ + frag_copy_max = mtu <= IPTFS_FRAG_COPY_MAX ? mtu : IPTFS_FRAG_COPY_MAX; + if ((int)first_skb->len - (int)mtu < (int)frag_copy_max) + return true; + + /* If we have non-linear skb just use copy */ + if (skb_is_nonlinear(first_skb)) + return true; + + /* So we have a simple linear skb, easy to clone and share */ + return false; +} + +/** + * iptfs_first_skb() - handle the first dequeued inner packet for output + * @skbp: the source packet skb (IN), skb holding the last fragment in + * the fragment stream (OUT). + * @xtfs: IPTFS SA state. + * @mtu: the max IPTFS fragment size. + * + * This function is responsible for fragmenting a larger inner packet into a + * sequence of IPTFS payload packets. If it needs to fragment into subsequent + * skb's, it will either do so by copying or cloning. + * + * The last fragment is returned rather than being sent so that the caller can + * append more inner packets (aggregation) if there is room. + * + */ +static int iptfs_first_skb(struct sk_buff **skbp, struct xfrm_iptfs_data *xtfs, + u32 mtu) +{ + struct sk_buff *skb = *skbp; + int err; + + /* Classic ESP skips the don't fragment ICMP error if DF is clear on + * the inner packet or ignore_df is set. Otherwise it will send an ICMP + * or local error if the inner packet won't fit it's MTU. + * + * With IPTFS we do not care about the inner packet DF bit. If the + * tunnel is configured to "don't fragment" we error back if things + * don't fit in our max packet size. Otherwise we iptfs-fragment as + * normal. + */ + + /* The opportunity for HW offload has ended */ + if (skb->ip_summed == CHECKSUM_PARTIAL) { + err = skb_checksum_help(skb); + if (err) + return err; + } + + /* We've split these up before queuing */ + BUG_ON(skb_is_gso(skb)); + + trace_iptfs_first_dequeue(skb, mtu, 0, ip_hdr(skb)); + + /* Simple case -- it fits. `mtu` accounted for all the overhead + * including the basic IPTFS header. + */ + if (skb->len <= mtu) { + iptfs_output_prepare_skb(skb, 0); + return 0; + } + + BUG_ON(xtfs->cfg.dont_frag); + + if (iptfs_first_should_copy(skb, mtu)) + return iptfs_copy_create_frags(skbp, xtfs, mtu); + + /* For now we always copy */ + return iptfs_copy_create_frags(skbp, xtfs, mtu); +} + +static struct sk_buff **iptfs_rehome_fraglist(struct sk_buff **nextp, + struct sk_buff *child) +{ + u32 fllen = 0; + + BUG_ON(!skb_has_frag_list(child)); + + /* It might be possible to account for a frag list in addition to page + * fragment if it's a valid state to be in. The page fragments size + * should be kept as data_len so only the frag_list size is removed, + * this must be done above as well took + */ + BUG_ON(skb_shinfo(child)->nr_frags); + *nextp = skb_shinfo(child)->frag_list; + while (*nextp) { + fllen += (*nextp)->len; + nextp = &(*nextp)->next; + } + skb_frag_list_init(child); + BUG_ON(fllen > child->data_len); + child->len -= fllen; + child->data_len -= fllen; + + return nextp; +} + +static void iptfs_consume_frags(struct sk_buff *to, struct sk_buff *from) +{ + struct skb_shared_info *fromi = skb_shinfo(from); + struct skb_shared_info *toi = skb_shinfo(to); + unsigned int new_truesize; + + /* If we have data in a head page, grab it */ + if (!skb_headlen(from)) { + new_truesize = SKB_TRUESIZE(skb_end_offset(from)); + } else { + skb_head_to_frag(from, &toi->frags[toi->nr_frags]); + skb_frag_ref(to, toi->nr_frags++); + new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff)); + } + + /* Move any other page fragments rather than copy */ + memcpy(&toi->frags[toi->nr_frags], fromi->frags, + sizeof(fromi->frags[0]) * fromi->nr_frags); + toi->nr_frags += fromi->nr_frags; + fromi->nr_frags = 0; + from->data_len = 0; + from->len = 0; + to->truesize += from->truesize - new_truesize; + from->truesize = new_truesize; + + /* We are done with this SKB */ + consume_skb(from); +} + +static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list) +{ + struct xfrm_iptfs_data *xtfs = x->mode_data; + u32 payload_mtu = xtfs->payload_mtu; + struct sk_buff *skb, *skb2, **nextp; + struct skb_shared_info *shi, *shi2; + + /* For now we are just outputting packets as fast as we can, so if we + * are fragmenting we will do so until the last inner packet has been + * consumed. + * + * When we are fragmenting we need to output all outer packets that + * contain the fragments of a single inner packet, consecutively (ESP + * seq-wise). So we need a lock to keep another CPU from sending the + * next batch of packets (it's `list`) and trying to output those, while + * we output our `list` resuling with interleaved non-spec-client inner + * packet streams. Thus we need to lock the IPTFS output on a per SA + * basis while we process this list. + */ + + /* NOTE: for the future, for timed packet sends, if our queue is not + * growing longer (i.e., we are keeping up) and a packet we are about to + * fragment will not fragment in then next outer packet, we might consider + * holding on to it to send whole in the next slot. The question then is + * does this introduce a continuous delay in the inner packet stream + * with certain packet rates and sizes? + */ + + /* and send them on their way */ + + while ((skb = __skb_dequeue(list))) { + struct xfrm_dst *xdst = (struct xfrm_dst *)skb_dst(skb); + u32 mtu = __iptfs_get_inner_mtu(x, xdst->child_mtu_cached); + bool share_ok = true; + int remaining; + + /* protocol comes to us cleared sometimes */ + skb->protocol = x->outer_mode.family == AF_INET ? + htons(ETH_P_IP) : + htons(ETH_P_IPV6); + + if (payload_mtu && payload_mtu < mtu) + mtu = payload_mtu; + + if (skb->len > mtu && xtfs->cfg.dont_frag) { + /* We handle this case before enqueueing so we are only + * here b/c MTU changed after we enqueued before we + * dequeued, just drop these. + */ + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMOUTERROR); + + trace_iptfs_first_toobig(skb, mtu, 0, ip_hdr(skb)); + kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG); + continue; + } + + /* iptfs_first_skb will free skb on error as well */ + if (iptfs_first_skb(&skb, xtfs, mtu)) + continue; + + /* The returned skb is the last IPTFS fragment, it has it's + * IPTFS header included and it's blkoff set just past the end + * fragment data if needed. The space remaining to send more + * inner packet data is `mtu` - (skb->len - sizeof iptfs + * header). This is b/c the `mtu` value has the basic IPTFS + * header len accounted for, and we added that header to the skb + * so it is a part of skb->len, thus we subtract it from the skb + * length. + */ + remaining = mtu - (skb->len - sizeof(struct ip_iptfs_hdr)); + + /* Re-home nested fragment lists. */ + shi = skb_shinfo(skb); + nextp = &shi->frag_list; + while (*nextp) { + if (skb_has_frag_list(*nextp)) + nextp = iptfs_rehome_fraglist(&(*nextp)->next, + *nextp); + else + nextp = &(*nextp)->next; + } + + if (shi->frag_list || skb_cloned(skb) || skb_shared(skb)) + share_ok = false; + + /* See if we have enough space to simply append. + * + * NOTE: Maybe do not append if we will be mis-aligned, + * SW-based endpoints will probably have to copy in this + * case. + */ + while ((skb2 = skb_peek(list))) { + trace_iptfs_ingress_nth_peek(skb2, remaining); + if (skb2->len > remaining) + break; + + __skb_unlink(skb2, list); + + /* The opportunity for HW offload has ended, if we + * don't have a cksum in the packet we need to add one + * before encap and transmit. + */ + if (skb2->ip_summed == CHECKSUM_PARTIAL) { + if (skb_checksum_help(skb2)) { + XFRM_INC_STATS(dev_net(skb_dst(skb2)->dev), + LINUX_MIB_XFRMOUTERROR); + kfree_skb(skb2); + continue; + } + } + + /* skb->pp_recycle is passed to __skb_flag_unref for all + * frag pages so we can only share pages with skb's who + * match ourselves. + */ + shi2 = skb_shinfo(skb2); + if (share_ok && + (shi2->frag_list || + (!skb2->head_frag && skb_headlen(skb)) || + skb->pp_recycle != skb2->pp_recycle || + skb_zcopy(skb2) || + (shi->nr_frags + shi2->nr_frags + 1 > MAX_SKB_FRAGS))) + share_ok = false; + + /* do acct so we can free skb2 in share case */ + skb->data_len += skb2->len; + skb->len += skb2->len; + remaining -= skb2->len; + + trace_iptfs_ingress_nth_add(skb2, share_ok); + + if (share_ok) { + iptfs_consume_frags(skb, skb2); + } else { + /* link on the frag_list */ + *nextp = skb2; + nextp = &skb2->next; + BUG_ON(*nextp); + if (skb_has_frag_list(skb2)) + nextp = iptfs_rehome_fraglist(nextp, + skb2); + skb->truesize += skb2->truesize; + } + } + + /* Consider fragmenting this skb2 that didn't fit. For demand + * driven variable sized IPTFS pkts, though this isn't buying + * a whole lot, especially if we are doing a copy which waiting + * to send in a new pkt would not. + */ + + xfrm_output(NULL, skb); + } +} + +static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me) +{ + struct sk_buff_head list; + struct xfrm_iptfs_data *xtfs; + struct xfrm_state *x; + time64_t settime; + size_t osize; + + xtfs = container_of(me, typeof(*xtfs), iptfs_timer); + x = xtfs->x; + + /* Process all the queued packets + * + * softirq execution order: timer > tasklet > hrtimer + * + * Network rx will have run before us giving one last chance to queue + * ingress packets for us to process and transmit. + */ + + spin_lock(&x->lock); + __skb_queue_head_init(&list); + skb_queue_splice_init(&xtfs->queue, &list); + osize = xtfs->queue_size; + xtfs->queue_size = 0; + settime = xtfs->iptfs_settime; + spin_unlock(&x->lock); + + /* After the above unlock, packets can begin queuing again, and the + * timer can be set again, from another CPU either in softirq or user + * context (not from this one since we are running at softirq level + * already). + */ + + trace_iptfs_timer_expire(xtfs, + (unsigned long long)(ktime_get_raw_fast_ns() - settime)); + + iptfs_output_queued(x, &list); + + return HRTIMER_NORESTART; +} + +/** + * iptfs_encap_add_ipv4() - add outer encaps + * + * This was originally taken from xfrm4_tunnel_encap_add. The reason for the + * copy is that IP-TFS/AGGFRAG can have different functionality for how to set + * the TOS/DSCP bits. Sets the protocol to a different value and doesn't do + * anything with inner headers as they aren't pointing into a normal IP + * singleton inner packet. + */ +static int iptfs_encap_add_ipv4(struct xfrm_state *x, struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct iphdr *top_iph; + int flags; + + skb_reset_inner_network_header(skb); + skb_reset_inner_transport_header(skb); + + skb_set_network_header(skb, -(x->props.header_len - x->props.enc_hdr_len)); + skb->mac_header = skb->network_header + offsetof(struct iphdr, protocol); + skb->transport_header = skb->network_header + sizeof(*top_iph); + + top_iph = ip_hdr(skb); + top_iph->ihl = 5; + top_iph->version = 4; + top_iph->protocol = IPPROTO_AGGFRAG; + + /* As we have 0, fractional, 1 or N inner packets there's no obviously + * correct DSCP mapping to inherit. ECN should be cleared per RFC9347 + * 3.1. + */ + top_iph->tos = 0; + + flags = x->props.flags; + top_iph->frag_off = htons(IP_DF); + top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst)); + top_iph->saddr = x->props.saddr.a4; + top_iph->daddr = x->id.daddr.a4; + ip_select_ident(dev_net(dst->dev), skb, NULL); + + return 0; +} + +/** + * iptfs_encap_add_ipv6() - add outer encaps + * + * This was originally taken from xfrm6_tunnel_encap_add. The reason for the + * copy is that IP-TFS/AGGFRAG can have different functionality for how to set + * the flow label and TOS/DSCP bits. It also sets the protocol to a different + * value and doesn't do anything with inner headers as they aren't pointing into + * a normal IP singleton inner packet. + */ +static int iptfs_encap_add_ipv6(struct xfrm_state *x, struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct ipv6hdr *top_iph; + int dsfield; + + skb_reset_inner_network_header(skb); + skb_reset_inner_transport_header(skb); + + skb_set_network_header(skb, + -x->props.header_len + x->props.enc_hdr_len); + skb->mac_header = skb->network_header + + offsetof(struct ipv6hdr, nexthdr); + skb->transport_header = skb->network_header + sizeof(*top_iph); + + top_iph = ipv6_hdr(skb); + top_iph->version = 6; + top_iph->priority = 0; + memset(top_iph->flow_lbl, 0, sizeof(top_iph->flow_lbl)); + top_iph->nexthdr = IPPROTO_AGGFRAG; + + /* As we have 0, fractional, 1 or N inner packets there's no obviously + * correct DSCP mapping to inherit. ECN should be cleared per RFC9347 + * 3.1. + */ + dsfield = 0; + ipv6_change_dsfield(top_iph, 0, dsfield); + + top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst)); + top_iph->saddr = *(struct in6_addr *)&x->props.saddr; + top_iph->daddr = *(struct in6_addr *)&x->id.daddr; + + return 0; +} + +/** + * iptfs_prepare_output() - prepare the skb for output + * + * Return: Error value, if 0 then skb values should be as follows: + * - transport_header should point at ESP header + * - network_header should point at Outer IP header + * - mac_header should point at protocol/nexthdr of the outer IP + */ +static int iptfs_prepare_output(struct xfrm_state *x, struct sk_buff *skb) +{ + if (x->outer_mode.family == AF_INET) + return iptfs_encap_add_ipv4(x, skb); + if (x->outer_mode.family == AF_INET6) { +#if IS_ENABLED(CONFIG_IPV6) + return iptfs_encap_add_ipv6(x, skb); +#else + WARN_ON_ONCE(1); + return -EAFNOSUPPORT; +#endif + } + WARN_ON_ONCE(1); + return -EOPNOTSUPP; +} + +/* ========================== */ +/* State Management Functions */ +/* ========================== */ + +/** + * __iptfs_get_inner_mtu() - return inner MTU with no fragmentation. + */ +static u32 __iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu) +{ + struct crypto_aead *aead; + u32 blksize; + + aead = x->data; + blksize = ALIGN(crypto_aead_blocksize(aead), 4); + return ((outer_mtu - x->props.header_len - crypto_aead_authsize(aead)) & + ~(blksize - 1)) - 2; +} + +/** + * iptfs_get_mtu() - return the inner MTU for an IPTFS xfrm. + * @x: XFRM state. + * @outer_mtu: Outer MTU for the encapsulated packet. + * + * Return: Correct MTU taking in to account the encap overhead. + */ +static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu) +{ + struct xfrm_iptfs_data *xtfs = x->mode_data; + + /* If not dont-frag we have no MTU */ + if (!xtfs->cfg.dont_frag) + return x->outer_mode.family == AF_INET ? IP_MAX_MTU : + IP6_MAX_MTU; + return __iptfs_get_inner_mtu(x, outer_mtu); +} + +/** + * iptfs_user_init() - initialize the SA with IPTFS options from netlink. + */ +static int iptfs_user_init(struct net *net, struct xfrm_state *x, + struct nlattr **attrs) +{ + struct xfrm_iptfs_data *xtfs = x->mode_data; + struct xfrm_iptfs_config *xc; + + if (x->props.mode != XFRM_MODE_IPTFS) + return -EINVAL; + + xc = &xtfs->cfg; + xc->reorder_win_size = net->xfrm.sysctl_iptfs_rewin; + xc->max_queue_size = net->xfrm.sysctl_iptfs_maxqsize; + xc->init_delay_us = net->xfrm.sysctl_iptfs_idelay; + xc->drop_time_us = net->xfrm.sysctl_iptfs_drptime; + + if (attrs[XFRMA_IPTFS_DONT_FRAG]) + xc->dont_frag = true; + if (attrs[XFRMA_IPTFS_REORD_WIN]) + xc->reorder_win_size = + nla_get_u16(attrs[XFRMA_IPTFS_REORD_WIN]); + /* saved array is for saving 1..N seq nums from wantseq */ + if (xc->reorder_win_size) + xtfs->w_saved = kcalloc(xc->reorder_win_size, + sizeof(*xtfs->w_saved), GFP_KERNEL); + if (attrs[XFRMA_IPTFS_PKT_SIZE]) { + xc->pkt_size = nla_get_u32(attrs[XFRMA_IPTFS_PKT_SIZE]); + if (!xc->pkt_size) + xtfs->payload_mtu = 0; + else if (xc->pkt_size > x->props.header_len) + xtfs->payload_mtu = xc->pkt_size - x->props.header_len; + else + return -EINVAL; + } + if (attrs[XFRMA_IPTFS_MAX_QSIZE]) + xc->max_queue_size = nla_get_u32(attrs[XFRMA_IPTFS_MAX_QSIZE]); + if (attrs[XFRMA_IPTFS_DROP_TIME]) + xc->drop_time_us = nla_get_u32(attrs[XFRMA_IPTFS_DROP_TIME]); + if (attrs[XFRMA_IPTFS_IN_DELAY]) + xc->init_delay_us = nla_get_u32(attrs[XFRMA_IPTFS_IN_DELAY]); + + xtfs->ecn_queue_size = (u64)xc->max_queue_size * 95 / 100; + xtfs->drop_time_ns = xc->drop_time_us * NSECS_IN_USEC; + xtfs->init_delay_ns = xc->init_delay_us * NSECS_IN_USEC; + + return 0; +} + +static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb) +{ + struct xfrm_iptfs_data *xtfs = x->mode_data; + struct xfrm_iptfs_config *xc = &xtfs->cfg; + int ret; + + if (xc->dont_frag) { + ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG); + if (ret) + return ret; + } + ret = nla_put_u16(skb, XFRMA_IPTFS_REORD_WIN, xc->reorder_win_size); + if (ret) + return ret; + ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size); + if (ret) + return ret; + ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, xc->max_queue_size); + if (ret) + return ret; + ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, xc->drop_time_us); + if (ret) + return ret; + ret = nla_put_u32(skb, XFRMA_IPTFS_IN_DELAY, xc->init_delay_us); + return ret; +} + +static int iptfs_create_state(struct xfrm_state *x) +{ + struct xfrm_iptfs_data *xtfs; + + xtfs = kzalloc(sizeof(*xtfs), GFP_KERNEL); + if (!xtfs) + return -ENOMEM; + x->mode_data = xtfs; + + xtfs->x = x; + + __skb_queue_head_init(&xtfs->queue); + xtfs->init_delay_ns = xtfs->cfg.init_delay_us * NSECS_IN_USEC; + hrtimer_init(&xtfs->iptfs_timer, CLOCK_MONOTONIC, IPTFS_HRTIMER_MODE); + xtfs->iptfs_timer.function = iptfs_delay_timer; + + xtfs->drop_time_ns = xtfs->cfg.drop_time_us * NSECS_IN_USEC; + spin_lock_init(&xtfs->drop_lock); + hrtimer_init(&xtfs->drop_timer, CLOCK_MONOTONIC, IPTFS_HRTIMER_MODE); + xtfs->drop_timer.function = iptfs_drop_timer; + + /* Modify type (esp) adjustment values */ + + if (x->props.family == AF_INET) + x->props.header_len += sizeof(struct iphdr) + sizeof(struct ip_iptfs_hdr); + else if (x->props.family == AF_INET6) + x->props.header_len += sizeof(struct ipv6hdr) + sizeof(struct ip_iptfs_hdr); + x->props.enc_hdr_len = sizeof(struct ip_iptfs_hdr); + + return 0; +} + +static void iptfs_delete_state(struct xfrm_state *x) +{ + struct xfrm_iptfs_data *xtfs = x->mode_data; + + if (IS_ERR_OR_NULL(xtfs)) + return; + + spin_lock(&xtfs->drop_lock); + hrtimer_cancel(&xtfs->iptfs_timer); + hrtimer_cancel(&xtfs->drop_timer); + spin_unlock(&xtfs->drop_lock); + + kfree_sensitive(xtfs->w_saved); + kfree_sensitive(xtfs); +} + +static const struct xfrm_mode_cbs iptfs_mode_cbs = { + .owner = THIS_MODULE, + .create_state = iptfs_create_state, + .delete_state = iptfs_delete_state, + .user_init = iptfs_user_init, + .copy_to_user = iptfs_copy_to_user, + .get_inner_mtu = iptfs_get_inner_mtu, + .input = iptfs_input, + .output = iptfs_output_collect, + .prepare_output = iptfs_prepare_output, +}; + +static int __init xfrm_iptfs_init(void) +{ + int err; + + pr_info("xfrm_iptfs: IPsec IP-TFS tunnel mode module\n"); + + err = xfrm_register_mode_cbs(XFRM_MODE_IPTFS, &iptfs_mode_cbs); + if (err < 0) + pr_info("%s: can't register IP-TFS\n", __func__); + + return err; +} + +static void __exit xfrm_iptfs_fini(void) +{ + xfrm_unregister_mode_cbs(XFRM_MODE_IPTFS); +} + +module_init(xfrm_iptfs_init); +module_exit(xfrm_iptfs_fini); +MODULE_LICENSE("GPL");