[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 "6lowpan_i.h"

/* 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));
}

int lowpan_header_create(struct sk_buff *skb, struct net_device *dev,
			 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 = dev->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)
{
	struct net_device *real_dev = lowpan_dev_info(skb->dev)->real_dev;
	struct sk_buff *frag;
	int rc;

	frag = alloc_skb(real_dev->hard_header_len +
			 real_dev->needed_tailroom + size,
			 GFP_ATOMIC);

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

		rc = dev_hard_header(frag, real_dev, 0, &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)
{
	struct sk_buff *frag;

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

	frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr);
	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 *dev,
		       const struct ieee802154_hdr *wpan_hdr)
{
	u16 dgram_size, dgram_offset;
	__be16 frag_tag;
	u8 frag_hdr[5];
	int frag_cap, frag_len, payload_cap, rc;
	int skb_unprocessed, skb_offset;

	dgram_size = lowpan_uncompress_size(skb, &dgram_offset) -
		     skb->mac_len;
	frag_tag = htons(lowpan_dev_info(dev)->fragment_tag);
	lowpan_dev_info(dev)->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));
	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);
		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);

	consume_skb(skb);
	return NET_XMIT_SUCCESS;

err:
	kfree_skb(skb);
	return rc;
}

static int lowpan_header(struct sk_buff *skb, struct net_device *dev)
{
	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;

	lowpan_header_compress(skb, dev, ETH_P_IPV6, daddr, saddr, skb->len);

	cb->type = IEEE802154_FC_TYPE_DATA;

	/* prepare wpan address data */
	sa.mode = IEEE802154_ADDR_LONG;
	sa.pan_id = lowpan_dev_info(dev)->real_dev->ieee802154_ptr->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 = true;
	}

	return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
			ETH_P_IPV6, (void *)&da, (void *)&sa, 0);
}

netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct ieee802154_hdr wpan_hdr;
	int max_single, ret;

	pr_debug("package xmit\n");

	/* 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, dev);
	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(dev)->real_dev;
		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, dev, &wpan_hdr);

		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>
	13
	14	#include "6lowpan_i.h"
	15
	16	/* don't save pan id, it's intra pan */
	17	struct lowpan_addr {
	18	u8 mode;
	19	union {
	20	/* IPv6 needs big endian here */
	21	__be64 extended_addr;
	22	__be16 short_addr;
	23	} u;
	24	};
	25
	26	struct lowpan_addr_info {
	27	struct lowpan_addr daddr;
	28	struct lowpan_addr saddr;
	29	};
	30
	31	static inline struct
	32	lowpan_addr_info lowpan_skb_priv(const struct sk_buff skb)
	33	{
	34	WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
	35	return (struct lowpan_addr_info *)(skb->data -
	36	sizeof(struct lowpan_addr_info));
	37	}
	38
	39	int lowpan_header_create(struct sk_buff skb, struct net_device dev,
	40	unsigned short type, const void *_daddr,
	41	const void *_saddr, unsigned int len)
	42	{
	43	const u8 *saddr = _saddr;
	44	const u8 *daddr = _daddr;
	45	struct lowpan_addr_info *info;
	46
	47	/* TODO:
	48	* if this package isn't ipv6 one, where should it be routed?
	49	*/
	50	if (type != ETH_P_IPV6)
	51	return 0;
	52
	53	if (!saddr)
	54	saddr = dev->dev_addr;
	55
	56	raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
	57	raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
	58
	59	info = lowpan_skb_priv(skb);
	60
	61	/* TODO: Currently we only support extended_addr */
	62	info->daddr.mode = IEEE802154_ADDR_LONG;
	63	memcpy(&info->daddr.u.extended_addr, daddr,
	64	sizeof(info->daddr.u.extended_addr));
65	info->saddr.mode = IEEE802154_ADDR_LONG;
66	memcpy(&info->saddr.u.extended_addr, saddr,
67	sizeof(info->daddr.u.extended_addr));
68
69	return 0;
70	}
71
72	static struct sk_buff*
73	lowpan_alloc_frag(struct sk_buff *skb, int size,
74	const struct ieee802154_hdr *master_hdr)
75	{
76	struct net_device *real_dev = lowpan_dev_info(skb->dev)->real_dev;
77	struct sk_buff *frag;
78	int rc;
79
80	frag = alloc_skb(real_dev->hard_header_len +
81	real_dev->needed_tailroom + size,
82	GFP_ATOMIC);
83
84	if (likely(frag)) {
85	frag->dev = real_dev;
86	frag->priority = skb->priority;
87	skb_reserve(frag, real_dev->hard_header_len);
88	skb_reset_network_header(frag);
89	mac_cb(frag) = mac_cb(skb);
90
91	rc = dev_hard_header(frag, real_dev, 0, &master_hdr->dest,
92	&master_hdr->source, size);
93	if (rc < 0) {
94	kfree_skb(frag);
95	return ERR_PTR(rc);
96	}
97	} else {
98	frag = ERR_PTR(-ENOMEM);
99	}
100
101	return frag;
102	}
103
104	static int
105	lowpan_xmit_fragment(struct sk_buff skb, const struct ieee802154_hdr wpan_hdr,
106	u8 *frag_hdr, int frag_hdrlen,
107	int offset, int len)
108	{
109	struct sk_buff *frag;
110
111	raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
112
113	frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr);
114	if (IS_ERR(frag))
115	return -PTR_ERR(frag);
116
117	memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
118	memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);
119
120	raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
121
122	return dev_queue_xmit(frag);
123	}
124
125	static int
126	lowpan_xmit_fragmented(struct sk_buff skb, struct net_device dev,
127	const struct ieee802154_hdr *wpan_hdr)
128	{
129	u16 dgram_size, dgram_offset;
130	__be16 frag_tag;
131	u8 frag_hdr[5];
132	int frag_cap, frag_len, payload_cap, rc;
133	int skb_unprocessed, skb_offset;
134
135	dgram_size = lowpan_uncompress_size(skb, &dgram_offset) -
136	skb->mac_len;
137	frag_tag = htons(lowpan_dev_info(dev)->fragment_tag);
138	lowpan_dev_info(dev)->fragment_tag++;
139
140	frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 \| ((dgram_size >> 8) & 0x07);
141	frag_hdr[1] = dgram_size & 0xff;
142	memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
143
144	payload_cap = ieee802154_max_payload(wpan_hdr);
145
146	frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
147	skb_network_header_len(skb), 8);
148
149	skb_offset = skb_network_header_len(skb);
150	skb_unprocessed = skb->len - skb->mac_len - skb_offset;
151
152	rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
153	LOWPAN_FRAG1_HEAD_SIZE, 0,
154	frag_len + skb_network_header_len(skb));
155	if (rc) {
156	pr_debug("%s unable to send FRAG1 packet (tag: %d)",
157	__func__, ntohs(frag_tag));
158	goto err;
159	}
160
161	frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
162	frag_hdr[0] \|= LOWPAN_DISPATCH_FRAGN;
163	frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
164
165	do {
166	dgram_offset += frag_len;
167	skb_offset += frag_len;
168	skb_unprocessed -= frag_len;
169	frag_len = min(frag_cap, skb_unprocessed);
170
171	frag_hdr[4] = dgram_offset >> 3;
172
173	rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
174	LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
175	frag_len);
176	if (rc) {
177	pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
178	__func__, ntohs(frag_tag), skb_offset);
179	goto err;
180	}
181	} while (skb_unprocessed > frag_cap);
182
183	consume_skb(skb);
184	return NET_XMIT_SUCCESS;
185
186	err:
187	kfree_skb(skb);
188	return rc;
189	}
190
191	static int lowpan_header(struct sk_buff skb, struct net_device dev)
192	{
193	struct ieee802154_addr sa, da;
194	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
195	struct lowpan_addr_info info;
196	void daddr, saddr;
197
198	memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
199
200	/* TODO: Currently we only support extended_addr */
201	daddr = &info.daddr.u.extended_addr;
202	saddr = &info.saddr.u.extended_addr;
203
204	lowpan_header_compress(skb, dev, ETH_P_IPV6, daddr, saddr, skb->len);
205
206	cb->type = IEEE802154_FC_TYPE_DATA;
207
208	/* prepare wpan address data */
209	sa.mode = IEEE802154_ADDR_LONG;
c947f7e1	210	sa.pan_id = lowpan_dev_info(dev)->real_dev->ieee802154_ptr->pan_id;
4dc315e2 AA	211	sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
	212
	213	/* intra-PAN communications */
	214	da.pan_id = sa.pan_id;
	215
	216	/* if the destination address is the broadcast address, use the
	217	* corresponding short address
	218	*/
	219	if (lowpan_is_addr_broadcast((const u8 *)daddr)) {
	220	da.mode = IEEE802154_ADDR_SHORT;
	221	da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
	222	cb->ackreq = false;
	223	} else {
	224	da.mode = IEEE802154_ADDR_LONG;
	225	da.extended_addr = ieee802154_devaddr_from_raw(daddr);
	226	cb->ackreq = true;
	227	}
	228
	229	return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
	230	ETH_P_IPV6, (void )&da, (void )&sa, 0);
	231	}
	232
	233	netdev_tx_t lowpan_xmit(struct sk_buff skb, struct net_device dev)
	234	{
	235	struct ieee802154_hdr wpan_hdr;
	236	int max_single, ret;
	237
	238	pr_debug("package xmit\n");
	239
	240	/* We must take a copy of the skb before we modify/replace the ipv6
	241	* header as the header could be used elsewhere
	242	*/
	243	skb = skb_unshare(skb, GFP_ATOMIC);
	244	if (!skb)
	245	return NET_XMIT_DROP;
	246
	247	ret = lowpan_header(skb, dev);
	248	if (ret < 0) {
	249	kfree_skb(skb);
	250	return NET_XMIT_DROP;
	251	}
	252
	253	if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
	254	kfree_skb(skb);
	255	return NET_XMIT_DROP;
	256	}
	257
	258	max_single = ieee802154_max_payload(&wpan_hdr);
	259
	260	if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
	261	skb->dev = lowpan_dev_info(dev)->real_dev;
	262	return dev_queue_xmit(skb);
	263	} else {
	264	netdev_tx_t rc;
	265
	266	pr_debug("frame is too big, fragmentation is needed\n");
	267	rc = lowpan_xmit_fragmented(skb, dev, &wpan_hdr);
	268
	269	return rc < 0 ? NET_XMIT_DROP : rc;
	270	}
	271	}