[mirror_ubuntu-bionic-kernel.git] / net / ieee802154 / 6lowpan / tx.c

/* This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <net/6lowpan.h>
#include <net/ieee802154_netdev.h>
#include <net/mac802154.h>

#include "6lowpan_i.h"

#define LOWPAN_FRAG1_HEAD_SIZE	0x4
#define LOWPAN_FRAGN_HEAD_SIZE	0x5

/* don't save pan id, it's intra pan */
struct lowpan_addr {
	u8 mode;
	union {
		/* IPv6 needs big endian here */
		__be64 extended_addr;
		__be16 short_addr;
	} u;
};

struct lowpan_addr_info {
	struct lowpan_addr daddr;
	struct lowpan_addr saddr;
};

static inline struct
lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
{
	WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
	return (struct lowpan_addr_info *)(skb->data -
			sizeof(struct lowpan_addr_info));
}

/* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET
 * sockets gives an 8 byte array for addresses only!
 *
 * TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no
 * sense here. We should disable it, the right use-case would be AF_INET6
 * RAW/DGRAM sockets.
 */
int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
			 unsigned short type, const void *_daddr,
			 const void *_saddr, unsigned int len)
{
	const u8 *saddr = _saddr;
	const u8 *daddr = _daddr;
	struct lowpan_addr_info *info;

	/* TODO:
	 * if this package isn't ipv6 one, where should it be routed?
	 */
	if (type != ETH_P_IPV6)
		return 0;

	if (!saddr)
		saddr = ldev->dev_addr;

	raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
	raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);

	info = lowpan_skb_priv(skb);

	/* TODO: Currently we only support extended_addr */
	info->daddr.mode = IEEE802154_ADDR_LONG;
	memcpy(&info->daddr.u.extended_addr, daddr,
	       sizeof(info->daddr.u.extended_addr));
	info->saddr.mode = IEEE802154_ADDR_LONG;
	memcpy(&info->saddr.u.extended_addr, saddr,
	       sizeof(info->daddr.u.extended_addr));

	return 0;
}

static struct sk_buff*
lowpan_alloc_frag(struct sk_buff *skb, int size,
		  const struct ieee802154_hdr *master_hdr, bool frag1)
{
	struct net_device *wdev = lowpan_dev_info(skb->dev)->wdev;
	struct sk_buff *frag;
	int rc;

	frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
			 GFP_ATOMIC);

	if (likely(frag)) {
		frag->dev = wdev;
		frag->priority = skb->priority;
		skb_reserve(frag, wdev->needed_headroom);
		skb_reset_network_header(frag);
		*mac_cb(frag) = *mac_cb(skb);

		if (frag1) {
			memcpy(skb_put(frag, skb->mac_len),
			       skb_mac_header(skb), skb->mac_len);
		} else {
			rc = wpan_dev_hard_header(frag, wdev,
						  &master_hdr->dest,
						  &master_hdr->source, size);
			if (rc < 0) {
				kfree_skb(frag);
				return ERR_PTR(rc);
			}
		}
	} else {
		frag = ERR_PTR(-ENOMEM);
	}

	return frag;
}

static int
lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
		     u8 *frag_hdr, int frag_hdrlen,
		     int offset, int len, bool frag1)
{
	struct sk_buff *frag;

	raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);

	frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
	if (IS_ERR(frag))
		return PTR_ERR(frag);

	memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
	memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);

	raw_dump_table(__func__, " fragment dump", frag->data, frag->len);

	return dev_queue_xmit(frag);
}

static int
lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
		       const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
		       u16 dgram_offset)
{
	__be16 frag_tag;
	u8 frag_hdr[5];
	int frag_cap, frag_len, payload_cap, rc;
	int skb_unprocessed, skb_offset;

	frag_tag = htons(lowpan_dev_info(ldev)->fragment_tag);
	lowpan_dev_info(ldev)->fragment_tag++;

	frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
	frag_hdr[1] = dgram_size & 0xff;
	memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));

	payload_cap = ieee802154_max_payload(wpan_hdr);

	frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
			      skb_network_header_len(skb), 8);

	skb_offset = skb_network_header_len(skb);
	skb_unprocessed = skb->len - skb->mac_len - skb_offset;

	rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
				  LOWPAN_FRAG1_HEAD_SIZE, 0,
				  frag_len + skb_network_header_len(skb),
				  true);
	if (rc) {
		pr_debug("%s unable to send FRAG1 packet (tag: %d)",
			 __func__, ntohs(frag_tag));
		goto err;
	}

	frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
	frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
	frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);

	do {
		dgram_offset += frag_len;
		skb_offset += frag_len;
		skb_unprocessed -= frag_len;
		frag_len = min(frag_cap, skb_unprocessed);

		frag_hdr[4] = dgram_offset >> 3;

		rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
					  LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
					  frag_len, false);
		if (rc) {
			pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
				 __func__, ntohs(frag_tag), skb_offset);
			goto err;
		}
	} while (skb_unprocessed > frag_cap);

	ldev->stats.tx_packets++;
	ldev->stats.tx_bytes += dgram_size;
	consume_skb(skb);
	return NET_XMIT_SUCCESS;

err:
	kfree_skb(skb);
	return rc;
}

static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
			 u16 *dgram_size, u16 *dgram_offset)
{
	struct wpan_dev *wpan_dev = lowpan_dev_info(ldev)->wdev->ieee802154_ptr;
	struct ieee802154_addr sa, da;
	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
	struct lowpan_addr_info info;
	void *daddr, *saddr;

	memcpy(&info, lowpan_skb_priv(skb), sizeof(info));

	/* TODO: Currently we only support extended_addr */
	daddr = &info.daddr.u.extended_addr;
	saddr = &info.saddr.u.extended_addr;

	*dgram_size = skb->len;
	lowpan_header_compress(skb, ldev, daddr, saddr);
	/* dgram_offset = (saved bytes after compression) + lowpan header len */
	*dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);

	cb->type = IEEE802154_FC_TYPE_DATA;

	/* prepare wpan address data */
	sa.mode = IEEE802154_ADDR_LONG;
	sa.pan_id = wpan_dev->pan_id;
	sa.extended_addr = ieee802154_devaddr_from_raw(saddr);

	/* intra-PAN communications */
	da.pan_id = sa.pan_id;

	/* if the destination address is the broadcast address, use the
	 * corresponding short address
	 */
	if (lowpan_is_addr_broadcast((const u8 *)daddr)) {
		da.mode = IEEE802154_ADDR_SHORT;
		da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
		cb->ackreq = false;
	} else {
		da.mode = IEEE802154_ADDR_LONG;
		da.extended_addr = ieee802154_devaddr_from_raw(daddr);
		cb->ackreq = wpan_dev->ackreq;
	}

	return wpan_dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, &da, &sa,
				    0);
}

netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
{
	struct ieee802154_hdr wpan_hdr;
	int max_single, ret;
	u16 dgram_size, dgram_offset;

	pr_debug("package xmit\n");

	WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);

	/* We must take a copy of the skb before we modify/replace the ipv6
	 * header as the header could be used elsewhere
	 */
	skb = skb_unshare(skb, GFP_ATOMIC);
	if (!skb)
		return NET_XMIT_DROP;

	ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
	if (ret < 0) {
		kfree_skb(skb);
		return NET_XMIT_DROP;
	}

	if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
		kfree_skb(skb);
		return NET_XMIT_DROP;
	}

	max_single = ieee802154_max_payload(&wpan_hdr);

	if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
		skb->dev = lowpan_dev_info(ldev)->wdev;
		ldev->stats.tx_packets++;
		ldev->stats.tx_bytes += dgram_size;
		return dev_queue_xmit(skb);
	} else {
		netdev_tx_t rc;

		pr_debug("frame is too big, fragmentation is needed\n");
		rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
					    dgram_offset);

		return rc < 0 ? NET_XMIT_DROP : rc;
	}
}
Commit	Line	Data
4dc315e2 AA	1	/* This program is free software; you can redistribute it and/or modify
	2	* it under the terms of the GNU General Public License version 2
	3	* as published by the Free Software Foundation.
	4	*
	5	* This program is distributed in the hope that it will be useful,
	6	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	7	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	8	* GNU General Public License for more details.
	9	*/
	10
	11	#include <net/6lowpan.h>
	12	#include <net/ieee802154_netdev.h>
87a93e4e	13	#include <net/mac802154.h>
4dc315e2 AA	14
	15	#include "6lowpan_i.h"
	16
6350047e AA	17	#define LOWPAN_FRAG1_HEAD_SIZE 0x4
	18	#define LOWPAN_FRAGN_HEAD_SIZE 0x5
	19
4dc315e2 AA	20	/* don't save pan id, it's intra pan */
	21	struct lowpan_addr {
	22	u8 mode;
	23	union {
	24	/* IPv6 needs big endian here */
	25	__be64 extended_addr;
	26	__be16 short_addr;
	27	} u;
	28	};
	29
	30	struct lowpan_addr_info {
	31	struct lowpan_addr daddr;
	32	struct lowpan_addr saddr;
	33	};
	34
	35	static inline struct
	36	lowpan_addr_info lowpan_skb_priv(const struct sk_buff skb)
	37	{
	38	WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
	39	return (struct lowpan_addr_info *)(skb->data -
	40	sizeof(struct lowpan_addr_info));
	41	}
	42
87a93e4e AA	43	/* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET
	44	* sockets gives an 8 byte array for addresses only!
	45	*
	46	* TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no
	47	* sense here. We should disable it, the right use-case would be AF_INET6
	48	* RAW/DGRAM sockets.
	49	*/
f4606583	50	int lowpan_header_create(struct sk_buff skb, struct net_device ldev,
4dc315e2 AA	51	unsigned short type, const void *_daddr,
	52	const void *_saddr, unsigned int len)
	53	{
	54	const u8 *saddr = _saddr;
	55	const u8 *daddr = _daddr;
	56	struct lowpan_addr_info *info;
	57
	58	/* TODO:
	59	* if this package isn't ipv6 one, where should it be routed?
	60	*/
	61	if (type != ETH_P_IPV6)
	62	return 0;
	63
	64	if (!saddr)
f4606583	65	saddr = ldev->dev_addr;
4dc315e2 AA	66
	67	raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
	68	raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
	69
	70	info = lowpan_skb_priv(skb);
	71
	72	/* TODO: Currently we only support extended_addr */
	73	info->daddr.mode = IEEE802154_ADDR_LONG;
	74	memcpy(&info->daddr.u.extended_addr, daddr,
	75	sizeof(info->daddr.u.extended_addr));
	76	info->saddr.mode = IEEE802154_ADDR_LONG;
	77	memcpy(&info->saddr.u.extended_addr, saddr,
	78	sizeof(info->daddr.u.extended_addr));
	79
	80	return 0;
	81	}
	82
	83	static struct sk_buff*
	84	lowpan_alloc_frag(struct sk_buff *skb, int size,
4bc8fbc9	85	const struct ieee802154_hdr *master_hdr, bool frag1)
4dc315e2	86	{
f4606583	87	struct net_device *wdev = lowpan_dev_info(skb->dev)->wdev;
4dc315e2 AA	88	struct sk_buff *frag;
	89	int rc;
	90
87a93e4e	91	frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
4dc315e2 AA	92	GFP_ATOMIC);
	93
	94	if (likely(frag)) {
f4606583	95	frag->dev = wdev;
4dc315e2	96	frag->priority = skb->priority;
87a93e4e	97	skb_reserve(frag, wdev->needed_headroom);
4dc315e2 AA	98	skb_reset_network_header(frag);
	99	mac_cb(frag) = mac_cb(skb);
	100
4bc8fbc9 AA	101	if (frag1) {
	102	memcpy(skb_put(frag, skb->mac_len),
	103	skb_mac_header(skb), skb->mac_len);
	104	} else {
	105	rc = wpan_dev_hard_header(frag, wdev,
	106	&master_hdr->dest,
	107	&master_hdr->source, size);
	108	if (rc < 0) {
	109	kfree_skb(frag);
	110	return ERR_PTR(rc);
	111	}
4dc315e2 AA	112	}
	113	} else {
	114	frag = ERR_PTR(-ENOMEM);
	115	}
	116
	117	return frag;
	118	}
	119
	120	static int
	121	lowpan_xmit_fragment(struct sk_buff skb, const struct ieee802154_hdr wpan_hdr,
	122	u8 *frag_hdr, int frag_hdrlen,
4bc8fbc9	123	int offset, int len, bool frag1)
4dc315e2 AA	124	{
	125	struct sk_buff *frag;
	126
	127	raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
	128
4bc8fbc9	129	frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
4dc315e2	130	if (IS_ERR(frag))
8f8db918	131	return PTR_ERR(frag);
4dc315e2 AA	132
	133	memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
	134	memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);
	135
	136	raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
	137
	138	return dev_queue_xmit(frag);
	139	}
	140
	141	static int
f4606583	142	lowpan_xmit_fragmented(struct sk_buff skb, struct net_device ldev,
5f509239 AA	143	const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
5f509239 AA	144	u16 dgram_offset)
4dc315e2	145	{
4dc315e2 AA	146	__be16 frag_tag;
	147	u8 frag_hdr[5];
	148	int frag_cap, frag_len, payload_cap, rc;
	149	int skb_unprocessed, skb_offset;
	150
f4606583 AA	151	frag_tag = htons(lowpan_dev_info(ldev)->fragment_tag);
f4606583 AA	152	lowpan_dev_info(ldev)->fragment_tag++;
4dc315e2 AA	153
	154	frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 \| ((dgram_size >> 8) & 0x07);
	155	frag_hdr[1] = dgram_size & 0xff;
	156	memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
	157
	158	payload_cap = ieee802154_max_payload(wpan_hdr);
	159
	160	frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
	161	skb_network_header_len(skb), 8);
	162
	163	skb_offset = skb_network_header_len(skb);
	164	skb_unprocessed = skb->len - skb->mac_len - skb_offset;
	165
	166	rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
	167	LOWPAN_FRAG1_HEAD_SIZE, 0,
4bc8fbc9 AA	168	frag_len + skb_network_header_len(skb),
4bc8fbc9 AA	169	true);
4dc315e2 AA	170	if (rc) {
	171	pr_debug("%s unable to send FRAG1 packet (tag: %d)",
	172	__func__, ntohs(frag_tag));
	173	goto err;
	174	}
	175
	176	frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
	177	frag_hdr[0] \|= LOWPAN_DISPATCH_FRAGN;
	178	frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
	179
	180	do {
	181	dgram_offset += frag_len;
	182	skb_offset += frag_len;
	183	skb_unprocessed -= frag_len;
	184	frag_len = min(frag_cap, skb_unprocessed);
	185
	186	frag_hdr[4] = dgram_offset >> 3;
	187
	188	rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
	189	LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
4bc8fbc9	190	frag_len, false);
4dc315e2 AA	191	if (rc) {
	192	pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
	193	__func__, ntohs(frag_tag), skb_offset);
	194	goto err;
	195	}
	196	} while (skb_unprocessed > frag_cap);
	197
1c64f147 AA	198	ldev->stats.tx_packets++;
1c64f147 AA	199	ldev->stats.tx_bytes += dgram_size;
4dc315e2 AA	200	consume_skb(skb);
	201	return NET_XMIT_SUCCESS;
	202
	203	err:
	204	kfree_skb(skb);
	205	return rc;
	206	}
	207
187625e1	208	static int lowpan_header(struct sk_buff skb, struct net_device ldev,
5f509239	209	u16 dgram_size, u16 dgram_offset)
4dc315e2	210	{
f4606583	211	struct wpan_dev *wpan_dev = lowpan_dev_info(ldev)->wdev->ieee802154_ptr;
4dc315e2 AA	212	struct ieee802154_addr sa, da;
	213	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
	214	struct lowpan_addr_info info;
	215	void daddr, saddr;
	216
	217	memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
	218
	219	/* TODO: Currently we only support extended_addr */
	220	daddr = &info.daddr.u.extended_addr;
	221	saddr = &info.saddr.u.extended_addr;
	222
187625e1	223	*dgram_size = skb->len;
a6f77389	224	lowpan_header_compress(skb, ldev, daddr, saddr);
187625e1 AA	225	/* dgram_offset = (saved bytes after compression) + lowpan header len */
187625e1 AA	226	dgram_offset = (dgram_size - skb->len) + skb_network_header_len(skb);
4dc315e2 AA	227
	228	cb->type = IEEE802154_FC_TYPE_DATA;
	229
	230	/* prepare wpan address data */
	231	sa.mode = IEEE802154_ADDR_LONG;
1caf6f47	232	sa.pan_id = wpan_dev->pan_id;
4dc315e2 AA	233	sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
	234
	235	/* intra-PAN communications */
	236	da.pan_id = sa.pan_id;
	237
	238	/* if the destination address is the broadcast address, use the
	239	* corresponding short address
	240	*/
	241	if (lowpan_is_addr_broadcast((const u8 *)daddr)) {
	242	da.mode = IEEE802154_ADDR_SHORT;
	243	da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
	244	cb->ackreq = false;
	245	} else {
	246	da.mode = IEEE802154_ADDR_LONG;
	247	da.extended_addr = ieee802154_devaddr_from_raw(daddr);
c91208d8	248	cb->ackreq = wpan_dev->ackreq;
4dc315e2 AA	249	}
4dc315e2 AA	250
838b83d6 AA	251	return wpan_dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, &da, &sa,
838b83d6 AA	252	0);
4dc315e2 AA	253	}
4dc315e2 AA	254
f4606583	255	netdev_tx_t lowpan_xmit(struct sk_buff skb, struct net_device ldev)
4dc315e2 AA	256	{
	257	struct ieee802154_hdr wpan_hdr;
	258	int max_single, ret;
5f509239	259	u16 dgram_size, dgram_offset;
4dc315e2 AA	260
	261	pr_debug("package xmit\n");
	262
5f509239 AA	263	WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
5f509239 AA	264
4dc315e2 AA	265	/* We must take a copy of the skb before we modify/replace the ipv6
	266	* header as the header could be used elsewhere
	267	*/
	268	skb = skb_unshare(skb, GFP_ATOMIC);
	269	if (!skb)
	270	return NET_XMIT_DROP;
	271
187625e1	272	ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
4dc315e2 AA	273	if (ret < 0) {
	274	kfree_skb(skb);
	275	return NET_XMIT_DROP;
	276	}
	277
	278	if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
	279	kfree_skb(skb);
	280	return NET_XMIT_DROP;
	281	}
	282
	283	max_single = ieee802154_max_payload(&wpan_hdr);
	284
	285	if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
f4606583	286	skb->dev = lowpan_dev_info(ldev)->wdev;
1c64f147 AA	287	ldev->stats.tx_packets++;
1c64f147 AA	288	ldev->stats.tx_bytes += dgram_size;
4dc315e2 AA	289	return dev_queue_xmit(skb);
	290	} else {
	291	netdev_tx_t rc;
	292
	293	pr_debug("frame is too big, fragmentation is needed\n");
187625e1 AA	294	rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
187625e1 AA	295	dgram_offset);
4dc315e2 AA	296
	297	return rc < 0 ? NET_XMIT_DROP : rc;
	298	}
	299	}