cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ip6_offload.c (12707B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *	IPV6 GSO/GRO offload support
      4 *	Linux INET6 implementation
      5 */
      6
      7#include <linux/kernel.h>
      8#include <linux/socket.h>
      9#include <linux/netdevice.h>
     10#include <linux/skbuff.h>
     11#include <linux/printk.h>
     12
     13#include <net/protocol.h>
     14#include <net/ipv6.h>
     15#include <net/inet_common.h>
     16#include <net/tcp.h>
     17#include <net/udp.h>
     18#include <net/gro.h>
     19
     20#include "ip6_offload.h"
     21
     22/* All GRO functions are always builtin, except UDP over ipv6, which lays in
     23 * ipv6 module, as it depends on UDPv6 lookup function, so we need special care
     24 * when ipv6 is built as a module
     25 */
     26#if IS_BUILTIN(CONFIG_IPV6)
     27#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
     28#else
     29#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
     30#endif
     31
     32#define indirect_call_gro_receive_l4(f2, f1, cb, head, skb)	\
     33({								\
     34	unlikely(gro_recursion_inc_test(skb)) ?			\
     35		NAPI_GRO_CB(skb)->flush |= 1, NULL :		\
     36		INDIRECT_CALL_L4(cb, f2, f1, head, skb);	\
     37})
     38
     39static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
     40{
     41	const struct net_offload *ops = NULL;
     42
     43	for (;;) {
     44		struct ipv6_opt_hdr *opth;
     45		int len;
     46
     47		if (proto != NEXTHDR_HOP) {
     48			ops = rcu_dereference(inet6_offloads[proto]);
     49
     50			if (unlikely(!ops))
     51				break;
     52
     53			if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
     54				break;
     55		}
     56
     57		if (unlikely(!pskb_may_pull(skb, 8)))
     58			break;
     59
     60		opth = (void *)skb->data;
     61		len = ipv6_optlen(opth);
     62
     63		if (unlikely(!pskb_may_pull(skb, len)))
     64			break;
     65
     66		opth = (void *)skb->data;
     67		proto = opth->nexthdr;
     68		__skb_pull(skb, len);
     69	}
     70
     71	return proto;
     72}
     73
     74static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
     75	netdev_features_t features)
     76{
     77	struct sk_buff *segs = ERR_PTR(-EINVAL);
     78	struct ipv6hdr *ipv6h;
     79	const struct net_offload *ops;
     80	int proto, nexthdr;
     81	struct frag_hdr *fptr;
     82	unsigned int payload_len;
     83	u8 *prevhdr;
     84	int offset = 0;
     85	bool encap, udpfrag;
     86	int nhoff;
     87	bool gso_partial;
     88
     89	skb_reset_network_header(skb);
     90	nexthdr = ipv6_has_hopopt_jumbo(skb);
     91	if (nexthdr) {
     92		const int hophdr_len = sizeof(struct hop_jumbo_hdr);
     93		int err;
     94
     95		err = skb_cow_head(skb, 0);
     96		if (err < 0)
     97			return ERR_PTR(err);
     98
     99		/* remove the HBH header.
    100		 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
    101		 */
    102		memmove(skb_mac_header(skb) + hophdr_len,
    103			skb_mac_header(skb),
    104			ETH_HLEN + sizeof(struct ipv6hdr));
    105		skb->data += hophdr_len;
    106		skb->len -= hophdr_len;
    107		skb->network_header += hophdr_len;
    108		skb->mac_header += hophdr_len;
    109		ipv6h = (struct ipv6hdr *)skb->data;
    110		ipv6h->nexthdr = nexthdr;
    111	}
    112	nhoff = skb_network_header(skb) - skb_mac_header(skb);
    113	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
    114		goto out;
    115
    116	encap = SKB_GSO_CB(skb)->encap_level > 0;
    117	if (encap)
    118		features &= skb->dev->hw_enc_features;
    119	SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
    120
    121	ipv6h = ipv6_hdr(skb);
    122	__skb_pull(skb, sizeof(*ipv6h));
    123	segs = ERR_PTR(-EPROTONOSUPPORT);
    124
    125	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
    126
    127	if (skb->encapsulation &&
    128	    skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
    129		udpfrag = proto == IPPROTO_UDP && encap &&
    130			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
    131	else
    132		udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
    133			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
    134
    135	ops = rcu_dereference(inet6_offloads[proto]);
    136	if (likely(ops && ops->callbacks.gso_segment)) {
    137		skb_reset_transport_header(skb);
    138		segs = ops->callbacks.gso_segment(skb, features);
    139		if (!segs)
    140			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
    141	}
    142
    143	if (IS_ERR_OR_NULL(segs))
    144		goto out;
    145
    146	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
    147
    148	for (skb = segs; skb; skb = skb->next) {
    149		ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
    150		if (gso_partial && skb_is_gso(skb))
    151			payload_len = skb_shinfo(skb)->gso_size +
    152				      SKB_GSO_CB(skb)->data_offset +
    153				      skb->head - (unsigned char *)(ipv6h + 1);
    154		else
    155			payload_len = skb->len - nhoff - sizeof(*ipv6h);
    156		ipv6h->payload_len = htons(payload_len);
    157		skb->network_header = (u8 *)ipv6h - skb->head;
    158		skb_reset_mac_len(skb);
    159
    160		if (udpfrag) {
    161			int err = ip6_find_1stfragopt(skb, &prevhdr);
    162			if (err < 0) {
    163				kfree_skb_list(segs);
    164				return ERR_PTR(err);
    165			}
    166			fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
    167			fptr->frag_off = htons(offset);
    168			if (skb->next)
    169				fptr->frag_off |= htons(IP6_MF);
    170			offset += (ntohs(ipv6h->payload_len) -
    171				   sizeof(struct frag_hdr));
    172		}
    173		if (encap)
    174			skb_reset_inner_headers(skb);
    175	}
    176
    177out:
    178	return segs;
    179}
    180
    181/* Return the total length of all the extension hdrs, following the same
    182 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
    183 */
    184static int ipv6_exthdrs_len(struct ipv6hdr *iph,
    185			    const struct net_offload **opps)
    186{
    187	struct ipv6_opt_hdr *opth = (void *)iph;
    188	int len = 0, proto, optlen = sizeof(*iph);
    189
    190	proto = iph->nexthdr;
    191	for (;;) {
    192		if (proto != NEXTHDR_HOP) {
    193			*opps = rcu_dereference(inet6_offloads[proto]);
    194			if (unlikely(!(*opps)))
    195				break;
    196			if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
    197				break;
    198		}
    199		opth = (void *)opth + optlen;
    200		optlen = ipv6_optlen(opth);
    201		len += optlen;
    202		proto = opth->nexthdr;
    203	}
    204	return len;
    205}
    206
    207INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
    208							 struct sk_buff *skb)
    209{
    210	const struct net_offload *ops;
    211	struct sk_buff *pp = NULL;
    212	struct sk_buff *p;
    213	struct ipv6hdr *iph;
    214	unsigned int nlen;
    215	unsigned int hlen;
    216	unsigned int off;
    217	u16 flush = 1;
    218	int proto;
    219
    220	off = skb_gro_offset(skb);
    221	hlen = off + sizeof(*iph);
    222	iph = skb_gro_header_fast(skb, off);
    223	if (skb_gro_header_hard(skb, hlen)) {
    224		iph = skb_gro_header_slow(skb, hlen, off);
    225		if (unlikely(!iph))
    226			goto out;
    227	}
    228
    229	skb_set_network_header(skb, off);
    230	skb_gro_pull(skb, sizeof(*iph));
    231	skb_set_transport_header(skb, skb_gro_offset(skb));
    232
    233	flush += ntohs(iph->payload_len) != skb_gro_len(skb);
    234
    235	proto = iph->nexthdr;
    236	ops = rcu_dereference(inet6_offloads[proto]);
    237	if (!ops || !ops->callbacks.gro_receive) {
    238		__pskb_pull(skb, skb_gro_offset(skb));
    239		skb_gro_frag0_invalidate(skb);
    240		proto = ipv6_gso_pull_exthdrs(skb, proto);
    241		skb_gro_pull(skb, -skb_transport_offset(skb));
    242		skb_reset_transport_header(skb);
    243		__skb_push(skb, skb_gro_offset(skb));
    244
    245		ops = rcu_dereference(inet6_offloads[proto]);
    246		if (!ops || !ops->callbacks.gro_receive)
    247			goto out;
    248
    249		iph = ipv6_hdr(skb);
    250	}
    251
    252	NAPI_GRO_CB(skb)->proto = proto;
    253
    254	flush--;
    255	nlen = skb_network_header_len(skb);
    256
    257	list_for_each_entry(p, head, list) {
    258		const struct ipv6hdr *iph2;
    259		__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
    260
    261		if (!NAPI_GRO_CB(p)->same_flow)
    262			continue;
    263
    264		iph2 = (struct ipv6hdr *)(p->data + off);
    265		first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
    266
    267		/* All fields must match except length and Traffic Class.
    268		 * XXX skbs on the gro_list have all been parsed and pulled
    269		 * already so we don't need to compare nlen
    270		 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
    271		 * memcmp() alone below is sufficient, right?
    272		 */
    273		 if ((first_word & htonl(0xF00FFFFF)) ||
    274		     !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
    275		     !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
    276		     iph->nexthdr != iph2->nexthdr) {
    277not_same_flow:
    278			NAPI_GRO_CB(p)->same_flow = 0;
    279			continue;
    280		}
    281		if (unlikely(nlen > sizeof(struct ipv6hdr))) {
    282			if (memcmp(iph + 1, iph2 + 1,
    283				   nlen - sizeof(struct ipv6hdr)))
    284				goto not_same_flow;
    285		}
    286		/* flush if Traffic Class fields are different */
    287		NAPI_GRO_CB(p)->flush |= !!((first_word & htonl(0x0FF00000)) |
    288			(__force __be32)(iph->hop_limit ^ iph2->hop_limit));
    289		NAPI_GRO_CB(p)->flush |= flush;
    290
    291		/* If the previous IP ID value was based on an atomic
    292		 * datagram we can overwrite the value and ignore it.
    293		 */
    294		if (NAPI_GRO_CB(skb)->is_atomic)
    295			NAPI_GRO_CB(p)->flush_id = 0;
    296	}
    297
    298	NAPI_GRO_CB(skb)->is_atomic = true;
    299	NAPI_GRO_CB(skb)->flush |= flush;
    300
    301	skb_gro_postpull_rcsum(skb, iph, nlen);
    302
    303	pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
    304					 ops->callbacks.gro_receive, head, skb);
    305
    306out:
    307	skb_gro_flush_final(skb, pp, flush);
    308
    309	return pp;
    310}
    311
    312static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
    313					      struct sk_buff *skb)
    314{
    315	/* Common GRO receive for SIT and IP6IP6 */
    316
    317	if (NAPI_GRO_CB(skb)->encap_mark) {
    318		NAPI_GRO_CB(skb)->flush = 1;
    319		return NULL;
    320	}
    321
    322	NAPI_GRO_CB(skb)->encap_mark = 1;
    323
    324	return ipv6_gro_receive(head, skb);
    325}
    326
    327static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
    328					  struct sk_buff *skb)
    329{
    330	/* Common GRO receive for SIT and IP6IP6 */
    331
    332	if (NAPI_GRO_CB(skb)->encap_mark) {
    333		NAPI_GRO_CB(skb)->flush = 1;
    334		return NULL;
    335	}
    336
    337	NAPI_GRO_CB(skb)->encap_mark = 1;
    338
    339	return inet_gro_receive(head, skb);
    340}
    341
    342INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
    343{
    344	const struct net_offload *ops;
    345	struct ipv6hdr *iph;
    346	int err = -ENOSYS;
    347	u32 payload_len;
    348
    349	if (skb->encapsulation) {
    350		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
    351		skb_set_inner_network_header(skb, nhoff);
    352	}
    353
    354	payload_len = skb->len - nhoff - sizeof(*iph);
    355	if (unlikely(payload_len > IPV6_MAXPLEN)) {
    356		struct hop_jumbo_hdr *hop_jumbo;
    357		int hoplen = sizeof(*hop_jumbo);
    358
    359		/* Move network header left */
    360		memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb),
    361			skb->transport_header - skb->mac_header);
    362		skb->data -= hoplen;
    363		skb->len += hoplen;
    364		skb->mac_header -= hoplen;
    365		skb->network_header -= hoplen;
    366		iph = (struct ipv6hdr *)(skb->data + nhoff);
    367		hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1);
    368
    369		/* Build hop-by-hop options */
    370		hop_jumbo->nexthdr = iph->nexthdr;
    371		hop_jumbo->hdrlen = 0;
    372		hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
    373		hop_jumbo->tlv_len = 4;
    374		hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
    375
    376		iph->nexthdr = NEXTHDR_HOP;
    377		iph->payload_len = 0;
    378	} else {
    379		iph = (struct ipv6hdr *)(skb->data + nhoff);
    380		iph->payload_len = htons(payload_len);
    381	}
    382
    383	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
    384	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
    385		goto out;
    386
    387	err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
    388			       udp6_gro_complete, skb, nhoff);
    389
    390out:
    391	return err;
    392}
    393
    394static int sit_gro_complete(struct sk_buff *skb, int nhoff)
    395{
    396	skb->encapsulation = 1;
    397	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
    398	return ipv6_gro_complete(skb, nhoff);
    399}
    400
    401static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
    402{
    403	skb->encapsulation = 1;
    404	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
    405	return ipv6_gro_complete(skb, nhoff);
    406}
    407
    408static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
    409{
    410	skb->encapsulation = 1;
    411	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
    412	return inet_gro_complete(skb, nhoff);
    413}
    414
    415static struct packet_offload ipv6_packet_offload __read_mostly = {
    416	.type = cpu_to_be16(ETH_P_IPV6),
    417	.callbacks = {
    418		.gso_segment = ipv6_gso_segment,
    419		.gro_receive = ipv6_gro_receive,
    420		.gro_complete = ipv6_gro_complete,
    421	},
    422};
    423
    424static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
    425				       netdev_features_t features)
    426{
    427	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
    428		return ERR_PTR(-EINVAL);
    429
    430	return ipv6_gso_segment(skb, features);
    431}
    432
    433static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
    434					  netdev_features_t features)
    435{
    436	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
    437		return ERR_PTR(-EINVAL);
    438
    439	return inet_gso_segment(skb, features);
    440}
    441
    442static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
    443					  netdev_features_t features)
    444{
    445	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
    446		return ERR_PTR(-EINVAL);
    447
    448	return ipv6_gso_segment(skb, features);
    449}
    450
    451static const struct net_offload sit_offload = {
    452	.callbacks = {
    453		.gso_segment	= sit_gso_segment,
    454		.gro_receive    = sit_ip6ip6_gro_receive,
    455		.gro_complete   = sit_gro_complete,
    456	},
    457};
    458
    459static const struct net_offload ip4ip6_offload = {
    460	.callbacks = {
    461		.gso_segment	= ip4ip6_gso_segment,
    462		.gro_receive    = ip4ip6_gro_receive,
    463		.gro_complete   = ip4ip6_gro_complete,
    464	},
    465};
    466
    467static const struct net_offload ip6ip6_offload = {
    468	.callbacks = {
    469		.gso_segment	= ip6ip6_gso_segment,
    470		.gro_receive    = sit_ip6ip6_gro_receive,
    471		.gro_complete   = ip6ip6_gro_complete,
    472	},
    473};
    474static int __init ipv6_offload_init(void)
    475{
    476
    477	if (tcpv6_offload_init() < 0)
    478		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
    479	if (ipv6_exthdrs_offload_init() < 0)
    480		pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
    481
    482	dev_add_offload(&ipv6_packet_offload);
    483
    484	inet_add_offload(&sit_offload, IPPROTO_IPV6);
    485	inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
    486	inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
    487
    488	return 0;
    489}
    490
    491fs_initcall(ipv6_offload_init);