[linux.git] / net / sctp / offload.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * sctp_offload - GRO/GSO Offloading for SCTP
 *
 * Copyright (C) 2015, Marcelo Ricardo Leitner <[email protected]>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/socket.h>
#include <linux/sctp.h>
#include <linux/proc_fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/kfifo.h>
#include <linux/time.h>
#include <net/net_namespace.h>

#include <linux/skbuff.h>
#include <net/sctp/sctp.h>
#include <net/sctp/checksum.h>
#include <net/protocol.h>

static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
{
	skb->ip_summed = CHECKSUM_NONE;
	skb->csum_not_inet = 0;
	/* csum and csum_start in GSO CB may be needed to do the UDP
	 * checksum when it's a UDP tunneling packet.
	 */
	SKB_GSO_CB(skb)->csum = (__force __wsum)~0;
	SKB_GSO_CB(skb)->csum_start = skb_headroom(skb) + skb->len;
	return sctp_compute_cksum(skb, skb_transport_offset(skb));
}

static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
					netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct sctphdr *sh;

	if (!skb_is_gso_sctp(skb))
		goto out;

	sh = sctp_hdr(skb);
	if (!pskb_may_pull(skb, sizeof(*sh)))
		goto out;

	__skb_pull(skb, sizeof(*sh));

	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
		/* Packet is from an untrusted source, reset gso_segs. */
		struct skb_shared_info *pinfo = skb_shinfo(skb);
		struct sk_buff *frag_iter;

		pinfo->gso_segs = 0;
		if (skb->len != skb->data_len) {
			/* Means we have chunks in here too */
			pinfo->gso_segs++;
		}

		skb_walk_frags(skb, frag_iter)
			pinfo->gso_segs++;

		segs = NULL;
		goto out;
	}

	segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG);
	if (IS_ERR(segs))
		goto out;

	/* All that is left is update SCTP CRC if necessary */
	if (!(features & NETIF_F_SCTP_CRC)) {
		for (skb = segs; skb; skb = skb->next) {
			if (skb->ip_summed == CHECKSUM_PARTIAL) {
				sh = sctp_hdr(skb);
				sh->checksum = sctp_gso_make_checksum(skb);
			}
		}
	}

out:
	return segs;
}

static const struct net_offload sctp_offload = {
	.callbacks = {
		.gso_segment = sctp_gso_segment,
	},
};

static const struct net_offload sctp6_offload = {
	.callbacks = {
		.gso_segment = sctp_gso_segment,
	},
};

int __init sctp_offload_init(void)
{
	int ret;

	ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
	if (ret)
		goto out;

	ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
	if (ret)
		goto ipv4;

	crc32c_csum_stub = &sctp_csum_ops;
	return ret;

ipv4:
	inet_del_offload(&sctp_offload, IPPROTO_SCTP);
out:
	return ret;
}
Commit	Line	Data
c942fddf	1	// SPDX-License-Identifier: GPL-2.0-or-later
90017acc MRL	2	/*
	3	* sctp_offload - GRO/GSO Offloading for SCTP
	4	*
	5	* Copyright (C) 2015, Marcelo Ricardo Leitner <[email protected]>
90017acc MRL	6	*/
	7
	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	9
	10	#include <linux/kernel.h>
	11	#include <linux/kprobes.h>
	12	#include <linux/socket.h>
	13	#include <linux/sctp.h>
	14	#include <linux/proc_fs.h>
	15	#include <linux/vmalloc.h>
	16	#include <linux/module.h>
	17	#include <linux/kfifo.h>
	18	#include <linux/time.h>
	19	#include <net/net_namespace.h>
	20
	21	#include <linux/skbuff.h>
	22	#include <net/sctp/sctp.h>
	23	#include <net/sctp/checksum.h>
	24	#include <net/protocol.h>
	25
	26	static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
	27	{
	28	skb->ip_summed = CHECKSUM_NONE;
dba00306	29	skb->csum_not_inet = 0;
527beb8e XL	30	/* csum and csum_start in GSO CB may be needed to do the UDP
	31	* checksum when it's a UDP tunneling packet.
	32	*/
	33	SKB_GSO_CB(skb)->csum = (__force __wsum)~0;
	34	SKB_GSO_CB(skb)->csum_start = skb_headroom(skb) + skb->len;
90017acc MRL	35	return sctp_compute_cksum(skb, skb_transport_offset(skb));
	36	}
	37
	38	static struct sk_buff sctp_gso_segment(struct sk_buff skb,
	39	netdev_features_t features)
	40	{
	41	struct sk_buff *segs = ERR_PTR(-EINVAL);
	42	struct sctphdr *sh;
	43
1dd27cde	44	if (!skb_is_gso_sctp(skb))
121d57af WB	45	goto out;
121d57af WB	46
90017acc MRL	47	sh = sctp_hdr(skb);
	48	if (!pskb_may_pull(skb, sizeof(*sh)))
	49	goto out;
	50
	51	__skb_pull(skb, sizeof(*sh));
	52
	53	if (skb_gso_ok(skb, features \| NETIF_F_GSO_ROBUST)) {
	54	/* Packet is from an untrusted source, reset gso_segs. */
	55	struct skb_shared_info *pinfo = skb_shinfo(skb);
	56	struct sk_buff *frag_iter;
	57
	58	pinfo->gso_segs = 0;
	59	if (skb->len != skb->data_len) {
	60	/* Means we have chunks in here too */
	61	pinfo->gso_segs++;
	62	}
	63
	64	skb_walk_frags(skb, frag_iter)
	65	pinfo->gso_segs++;
	66
	67	segs = NULL;
	68	goto out;
	69	}
	70
5207f399	71	segs = skb_segment(skb, features \| NETIF_F_HW_CSUM \| NETIF_F_SG);
90017acc MRL	72	if (IS_ERR(segs))
	73	goto out;
	74
	75	/* All that is left is update SCTP CRC if necessary */
	76	if (!(features & NETIF_F_SCTP_CRC)) {
	77	for (skb = segs; skb; skb = skb->next) {
	78	if (skb->ip_summed == CHECKSUM_PARTIAL) {
	79	sh = sctp_hdr(skb);
	80	sh->checksum = sctp_gso_make_checksum(skb);
	81	}
	82	}
	83	}
	84
	85	out:
	86	return segs;
	87	}
	88
	89	static const struct net_offload sctp_offload = {
	90	.callbacks = {
	91	.gso_segment = sctp_gso_segment,
	92	},
	93	};
	94
c5c4e45c MRL	95	static const struct net_offload sctp6_offload = {
	96	.callbacks = {
	97	.gso_segment = sctp_gso_segment,
	98	},
	99	};
	100
90017acc MRL	101	int __init sctp_offload_init(void)
90017acc MRL	102	{
c5c4e45c MRL	103	int ret;
	104
	105	ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
	106	if (ret)
	107	goto out;
	108
	109	ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
	110	if (ret)
	111	goto ipv4;
	112
c3e933a5	113	crc32c_csum_stub = &sctp_csum_ops;
c5c4e45c MRL	114	return ret;
	115
	116	ipv4:
	117	inet_del_offload(&sctp_offload, IPPROTO_SCTP);
	118	out:
	119	return ret;
90017acc	120	}