diff options
Diffstat (limited to 'net/ieee802154/header_ops.c')
| -rw-r--r-- | net/ieee802154/header_ops.c | 325 | 
1 files changed, 325 insertions, 0 deletions
diff --git a/net/ieee802154/header_ops.c b/net/ieee802154/header_ops.c new file mode 100644 index 00000000000..c09294e39ca --- /dev/null +++ b/net/ieee802154/header_ops.c @@ -0,0 +1,325 @@ +/* + * Copyright (C) 2014 Fraunhofer ITWM + * + * 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. + * + * Written by: + * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de> + */ + +#include <net/mac802154.h> +#include <net/ieee802154.h> +#include <net/ieee802154_netdev.h> + +static int +ieee802154_hdr_push_addr(u8 *buf, const struct ieee802154_addr *addr, +			 bool omit_pan) +{ +	int pos = 0; + +	if (addr->mode == IEEE802154_ADDR_NONE) +		return 0; + +	if (!omit_pan) { +		memcpy(buf + pos, &addr->pan_id, 2); +		pos += 2; +	} + +	switch (addr->mode) { +	case IEEE802154_ADDR_SHORT: +		memcpy(buf + pos, &addr->short_addr, 2); +		pos += 2; +		break; + +	case IEEE802154_ADDR_LONG: +		memcpy(buf + pos, &addr->extended_addr, IEEE802154_ADDR_LEN); +		pos += IEEE802154_ADDR_LEN; +		break; + +	default: +		return -EINVAL; +	} + +	return pos; +} + +static int +ieee802154_hdr_push_sechdr(u8 *buf, const struct ieee802154_sechdr *hdr) +{ +	int pos = 5; + +	memcpy(buf, hdr, 1); +	memcpy(buf + 1, &hdr->frame_counter, 4); + +	switch (hdr->key_id_mode) { +	case IEEE802154_SCF_KEY_IMPLICIT: +		return pos; + +	case IEEE802154_SCF_KEY_INDEX: +		break; + +	case IEEE802154_SCF_KEY_SHORT_INDEX: +		memcpy(buf + pos, &hdr->short_src, 4); +		pos += 4; +		break; + +	case IEEE802154_SCF_KEY_HW_INDEX: +		memcpy(buf + pos, &hdr->extended_src, IEEE802154_ADDR_LEN); +		pos += IEEE802154_ADDR_LEN; +		break; +	} + +	buf[pos++] = hdr->key_id; + +	return pos; +} + +int +ieee802154_hdr_push(struct sk_buff *skb, const struct ieee802154_hdr *hdr) +{ +	u8 buf[MAC802154_FRAME_HARD_HEADER_LEN]; +	int pos = 2; +	int rc; +	struct ieee802154_hdr_fc fc = hdr->fc; + +	buf[pos++] = hdr->seq; + +	fc.dest_addr_mode = hdr->dest.mode; + +	rc = ieee802154_hdr_push_addr(buf + pos, &hdr->dest, false); +	if (rc < 0) +		return -EINVAL; +	pos += rc; + +	fc.source_addr_mode = hdr->source.mode; + +	if (hdr->source.pan_id == hdr->dest.pan_id && +	    hdr->dest.mode != IEEE802154_ADDR_NONE) +		fc.intra_pan = true; + +	rc = ieee802154_hdr_push_addr(buf + pos, &hdr->source, fc.intra_pan); +	if (rc < 0) +		return -EINVAL; +	pos += rc; + +	if (fc.security_enabled) { +		fc.version = 1; + +		rc = ieee802154_hdr_push_sechdr(buf + pos, &hdr->sec); +		if (rc < 0) +			return -EINVAL; + +		pos += rc; +	} + +	memcpy(buf, &fc, 2); + +	memcpy(skb_push(skb, pos), buf, pos); + +	return pos; +} +EXPORT_SYMBOL_GPL(ieee802154_hdr_push); + +static int +ieee802154_hdr_get_addr(const u8 *buf, int mode, bool omit_pan, +			struct ieee802154_addr *addr) +{ +	int pos = 0; + +	addr->mode = mode; + +	if (mode == IEEE802154_ADDR_NONE) +		return 0; + +	if (!omit_pan) { +		memcpy(&addr->pan_id, buf + pos, 2); +		pos += 2; +	} + +	if (mode == IEEE802154_ADDR_SHORT) { +		memcpy(&addr->short_addr, buf + pos, 2); +		return pos + 2; +	} else { +		memcpy(&addr->extended_addr, buf + pos, IEEE802154_ADDR_LEN); +		return pos + IEEE802154_ADDR_LEN; +	} +} + +static int ieee802154_hdr_addr_len(int mode, bool omit_pan) +{ +	int pan_len = omit_pan ? 0 : 2; + +	switch (mode) { +	case IEEE802154_ADDR_NONE: return 0; +	case IEEE802154_ADDR_SHORT: return 2 + pan_len; +	case IEEE802154_ADDR_LONG: return IEEE802154_ADDR_LEN + pan_len; +	default: return -EINVAL; +	} +} + +static int +ieee802154_hdr_get_sechdr(const u8 *buf, struct ieee802154_sechdr *hdr) +{ +	int pos = 5; + +	memcpy(hdr, buf, 1); +	memcpy(&hdr->frame_counter, buf + 1, 4); + +	switch (hdr->key_id_mode) { +	case IEEE802154_SCF_KEY_IMPLICIT: +		return pos; + +	case IEEE802154_SCF_KEY_INDEX: +		break; + +	case IEEE802154_SCF_KEY_SHORT_INDEX: +		memcpy(&hdr->short_src, buf + pos, 4); +		pos += 4; +		break; + +	case IEEE802154_SCF_KEY_HW_INDEX: +		memcpy(&hdr->extended_src, buf + pos, IEEE802154_ADDR_LEN); +		pos += IEEE802154_ADDR_LEN; +		break; +	} + +	hdr->key_id = buf[pos++]; + +	return pos; +} + +static int ieee802154_sechdr_lengths[4] = { +	[IEEE802154_SCF_KEY_IMPLICIT] = 5, +	[IEEE802154_SCF_KEY_INDEX] = 6, +	[IEEE802154_SCF_KEY_SHORT_INDEX] = 10, +	[IEEE802154_SCF_KEY_HW_INDEX] = 14, +}; + +static int ieee802154_hdr_sechdr_len(u8 sc) +{ +	return ieee802154_sechdr_lengths[IEEE802154_SCF_KEY_ID_MODE(sc)]; +} + +static int ieee802154_hdr_minlen(const struct ieee802154_hdr *hdr) +{ +	int dlen, slen; + +	dlen = ieee802154_hdr_addr_len(hdr->fc.dest_addr_mode, false); +	slen = ieee802154_hdr_addr_len(hdr->fc.source_addr_mode, +				       hdr->fc.intra_pan); + +	if (slen < 0 || dlen < 0) +		return -EINVAL; + +	return 3 + dlen + slen + hdr->fc.security_enabled; +} + +static int +ieee802154_hdr_get_addrs(const u8 *buf, struct ieee802154_hdr *hdr) +{ +	int pos = 0; + +	pos += ieee802154_hdr_get_addr(buf + pos, hdr->fc.dest_addr_mode, +				       false, &hdr->dest); +	pos += ieee802154_hdr_get_addr(buf + pos, hdr->fc.source_addr_mode, +				       hdr->fc.intra_pan, &hdr->source); + +	if (hdr->fc.intra_pan) +		hdr->source.pan_id = hdr->dest.pan_id; + +	return pos; +} + +int +ieee802154_hdr_pull(struct sk_buff *skb, struct ieee802154_hdr *hdr) +{ +	int pos = 3, rc; + +	if (!pskb_may_pull(skb, 3)) +		return -EINVAL; + +	memcpy(hdr, skb->data, 3); + +	rc = ieee802154_hdr_minlen(hdr); +	if (rc < 0 || !pskb_may_pull(skb, rc)) +		return -EINVAL; + +	pos += ieee802154_hdr_get_addrs(skb->data + pos, hdr); + +	if (hdr->fc.security_enabled) { +		int want = pos + ieee802154_hdr_sechdr_len(skb->data[pos]); + +		if (!pskb_may_pull(skb, want)) +			return -EINVAL; + +		pos += ieee802154_hdr_get_sechdr(skb->data + pos, &hdr->sec); +	} + +	skb_pull(skb, pos); +	return pos; +} +EXPORT_SYMBOL_GPL(ieee802154_hdr_pull); + +int +ieee802154_hdr_peek_addrs(const struct sk_buff *skb, struct ieee802154_hdr *hdr) +{ +	const u8 *buf = skb_mac_header(skb); +	int pos = 3, rc; + +	if (buf + 3 > skb_tail_pointer(skb)) +		return -EINVAL; + +	memcpy(hdr, buf, 3); + +	rc = ieee802154_hdr_minlen(hdr); +	if (rc < 0 || buf + rc > skb_tail_pointer(skb)) +		return -EINVAL; + +	pos += ieee802154_hdr_get_addrs(buf + pos, hdr); +	return pos; +} +EXPORT_SYMBOL_GPL(ieee802154_hdr_peek_addrs); + +int +ieee802154_hdr_peek(const struct sk_buff *skb, struct ieee802154_hdr *hdr) +{ +	const u8 *buf = skb_mac_header(skb); +	int pos; + +	pos = ieee802154_hdr_peek_addrs(skb, hdr); +	if (pos < 0) +		return -EINVAL; + +	if (hdr->fc.security_enabled) { +		u8 key_id_mode = IEEE802154_SCF_KEY_ID_MODE(*(buf + pos)); +		int want = pos + ieee802154_sechdr_lengths[key_id_mode]; + +		if (buf + want > skb_tail_pointer(skb)) +			return -EINVAL; + +		pos += ieee802154_hdr_get_sechdr(buf + pos, &hdr->sec); +	} + +	return pos; +} +EXPORT_SYMBOL_GPL(ieee802154_hdr_peek); + +int ieee802154_max_payload(const struct ieee802154_hdr *hdr) +{ +	int hlen = ieee802154_hdr_minlen(hdr); + +	if (hdr->fc.security_enabled) { +		hlen += ieee802154_sechdr_lengths[hdr->sec.key_id_mode] - 1; +		hlen += ieee802154_sechdr_authtag_len(&hdr->sec); +	} + +	return IEEE802154_MTU - hlen - IEEE802154_MFR_SIZE; +} +EXPORT_SYMBOL_GPL(ieee802154_max_payload);  | 
