diff options
Diffstat (limited to 'net/ieee802154/header_ops.c')
| -rw-r--r-- | net/ieee802154/header_ops.c | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/net/ieee802154/header_ops.c b/net/ieee802154/header_ops.c new file mode 100644 index 000000000..c7439f0fb --- /dev/null +++ b/net/ieee802154/header_ops.c @@ -0,0 +1,326 @@ +/* + * 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 <linux/ieee802154.h> + +#include <net/mac802154.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, struct ieee802154_hdr *hdr) +{ + u8 buf[IEEE802154_MAX_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); |