Return-Path: From: Jukka Rissanen To: linux-bluetooth@vger.kernel.org Subject: [RFC v2 4/7] Bluetooth: Enable 6LoWPAN support for BT LE devices Date: Wed, 30 Oct 2013 11:00:58 +0200 Message-Id: <1383123661-15087-5-git-send-email-jukka.rissanen@linux.intel.com> In-Reply-To: <1383123661-15087-1-git-send-email-jukka.rissanen@linux.intel.com> References: <1383123661-15087-1-git-send-email-jukka.rissanen@linux.intel.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Signed-off-by: Jukka Rissanen --- net/bluetooth/6lowpan.c | 1128 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 1127 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index aff478b..1cba7fd 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -11,6 +11,20 @@ GNU General Public License for more details. */ +/* + * The compression, uncompression and IPv6 packet fragmentation code + * is from net/ieee802154/6lowpan.c with these copyrights + * + * Copyright 2011, Siemens AG + * written by Alexander Smirnov + * + * Based on patches from Jon Smirl + * Copyright (c) 2011 Jon Smirl + * + * Jon's code is based on 6lowpan implementation for Contiki which is: + * Copyright (c) 2008, Swedish Institute of Computer Science. + */ + #include #include #include @@ -69,6 +83,9 @@ struct lowpan_fragment { struct list_head list; /* fragments list */ }; +static LIST_HEAD(lowpan_fragments); +static DEFINE_SPINLOCK(flist_lock); + #define DELETE_TIMEOUT msecs_to_jiffies(1) /* TTL uncompression values */ @@ -110,8 +127,723 @@ static inline void raw_dump_table(const char *caller, char *msg, #endif /* DEBUG */ } +static inline bool fetch_skb(struct sk_buff *skb, + void *data, const unsigned int len) +{ + if (unlikely(!pskb_may_pull(skb, len))) + return true; + + skb_copy_from_linear_data(skb, data, len); + skb_pull(skb, len); + + return false; +} + +/* + * Uncompress address function for source and + * destination address(non-multicast). + * + * address_mode is sam value or dam value. + */ +static int uncompress_addr(struct sk_buff *skb, + struct in6_addr *ipaddr, + const u8 address_mode, + const u8 *lladdr) +{ + bool fail; + + switch (address_mode) { + case LOWPAN_IPHC_ADDR_00: + /* for global link addresses */ + fail = fetch_skb(skb, ipaddr->s6_addr, 16); + break; + case LOWPAN_IPHC_ADDR_01: + /* fe:80::XXXX:XXXX:XXXX:XXXX */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + fail = fetch_skb(skb, &ipaddr->s6_addr[8], 8); + break; + case LOWPAN_IPHC_ADDR_02: + /* fe:80::ff:fe00:XXXX */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + ipaddr->s6_addr[11] = 0xFF; + ipaddr->s6_addr[12] = 0xFE; + fail = fetch_skb(skb, &ipaddr->s6_addr[14], 2); + break; + case LOWPAN_IPHC_ADDR_03: + fail = false; + /* XXX: support only normal addr (IEEE802154_ADDR_LONG) atm */ + + /* fe:80::XXXX:XXXX:XXXX:XXXX + * \_________________/ + * hwaddr + */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ADDR_LEN); + break; + default: + pr_debug("Invalid address mode value: 0x%x\n", address_mode); + return -EINVAL; + } + + if (fail) { + pr_debug("Failed to fetch skb data\n"); + return -EIO; + } + + raw_dump_inline(NULL, "Reconstructed ipv6 addr is", + ipaddr->s6_addr, 16); + + return 0; +} + +/* + * Uncompress address function for source context + * based address(non-multicast). + */ +static int uncompress_context_based_src_addr(struct sk_buff *skb, + struct in6_addr *ipaddr, + const u8 sam) +{ + switch (sam) { + case LOWPAN_IPHC_ADDR_00: + /* unspec address :: + * Do nothing, address is already :: + */ + break; + case LOWPAN_IPHC_ADDR_01: + /* TODO */ + case LOWPAN_IPHC_ADDR_02: + /* TODO */ + case LOWPAN_IPHC_ADDR_03: + /* TODO */ + netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam); + return -EINVAL; + default: + pr_debug("Invalid sam value: 0x%x\n", sam); + return -EINVAL; + } + + raw_dump_inline(NULL, + "Reconstructed context based ipv6 src addr is", + ipaddr->s6_addr, 16); + + return 0; +} + +/* + * This func is called when the packet from BT LE device + * needs to be sent upper layers. + */ +static int give_skb_to_upper(struct sk_buff *skb, + struct net_device *dev) +{ + struct sk_buff *skb_cp; + int ret = NET_RX_SUCCESS; + + skb_cp = skb_copy(skb, GFP_ATOMIC); + if (!skb_cp) { + ret = -ENOMEM; + } else { + ret = netif_rx(skb_cp); + + BT_DBG("receive skb %d", ret); + if (ret < 0) + ret = NET_RX_DROP; + } + + return ret; +} + +static inline int fetch_skb_u8(struct sk_buff *skb, u8 *val) +{ + if (unlikely(!pskb_may_pull(skb, 1))) + return -EINVAL; + + *val = skb->data[0]; + skb_pull(skb, 1); + + return 0; +} + +static inline int fetch_skb_u16(struct sk_buff *skb, u16 *val) +{ + if (unlikely(!pskb_may_pull(skb, 2))) + return -EINVAL; + + *val = (skb->data[0] << 8) | skb->data[1]; + skb_pull(skb, 2); + + return 0; +} + +static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr, + struct net_device *dev) +{ + struct sk_buff *new; + int stat; + + new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb), + GFP_ATOMIC); + kfree_skb(skb); + + if (!new) + return -ENOMEM; + + skb_push(new, sizeof(struct ipv6hdr)); + skb_reset_network_header(new); + skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr)); + + new->protocol = htons(ETH_P_IPV6); + new->pkt_type = PACKET_HOST; + new->dev = dev; + + raw_dump_table(__func__, + "raw skb data dump before receiving", + new->data, new->len); + + stat = give_skb_to_upper(new, dev); + + kfree_skb(new); + + return stat; +} + +static void lowpan_fragment_timer_expired(unsigned long entry_addr) +{ + struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr; + + pr_debug("timer expired for frame with tag %d\n", entry->tag); + + list_del(&entry->list); + dev_kfree_skb(entry->skb); + kfree(entry); +} + +static struct lowpan_fragment *alloc_new_frame(struct sk_buff *skb, + u16 len, u16 tag) +{ + struct lowpan_fragment *frame; + + frame = kzalloc(sizeof(struct lowpan_fragment), + GFP_ATOMIC); + if (!frame) + goto frame_err; + + INIT_LIST_HEAD(&frame->list); + + frame->length = len; + frame->tag = tag; + + /* allocate buffer for frame assembling */ + frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length + + sizeof(struct ipv6hdr)); + + if (!frame->skb) + goto skb_err; + + frame->skb->priority = skb->priority; + frame->skb->dev = skb->dev; + + /* reserve headroom for uncompressed ipv6 header */ + skb_reserve(frame->skb, sizeof(struct ipv6hdr)); + skb_put(frame->skb, frame->length); + + /* copy the first control block to keep a + * trace of the link-layer addresses in case + * of a link-local compressed address + */ + memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb)); + + init_timer(&frame->timer); + /* time out is the same as for ipv6 - 60 sec */ + frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT; + frame->timer.data = (unsigned long)frame; + frame->timer.function = lowpan_fragment_timer_expired; + + add_timer(&frame->timer); + + list_add_tail(&frame->list, &lowpan_fragments); + + return frame; + +skb_err: + kfree(frame); +frame_err: + return NULL; +} + +/* Uncompress function for multicast destination address, + * when M bit is set. + */ +static int +lowpan_uncompress_multicast_daddr(struct sk_buff *skb, + struct in6_addr *ipaddr, + const u8 dam) +{ + bool fail; + + switch (dam) { + case LOWPAN_IPHC_DAM_00: + /* 00: 128 bits. The full address + * is carried in-line. + */ + fail = fetch_skb(skb, ipaddr->s6_addr, 16); + break; + case LOWPAN_IPHC_DAM_01: + /* 01: 48 bits. The address takes + * the form ffXX::00XX:XXXX:XXXX. + */ + ipaddr->s6_addr[0] = 0xFF; + fail = fetch_skb(skb, &ipaddr->s6_addr[1], 1); + fail |= fetch_skb(skb, &ipaddr->s6_addr[11], 5); + break; + case LOWPAN_IPHC_DAM_10: + /* 10: 32 bits. The address takes + * the form ffXX::00XX:XXXX. + */ + ipaddr->s6_addr[0] = 0xFF; + fail = fetch_skb(skb, &ipaddr->s6_addr[1], 1); + fail |= fetch_skb(skb, &ipaddr->s6_addr[13], 3); + break; + case LOWPAN_IPHC_DAM_11: + /* 11: 8 bits. The address takes + * the form ff02::00XX. + */ + ipaddr->s6_addr[0] = 0xFF; + ipaddr->s6_addr[1] = 0x02; + fail = fetch_skb(skb, &ipaddr->s6_addr[15], 1); + break; + default: + pr_debug("DAM value has a wrong value: 0x%x\n", dam); + return -EINVAL; + } + + if (fail) { + pr_debug("Failed to fetch skb data\n"); + return -EIO; + } + + raw_dump_inline(NULL, + "Reconstructed ipv6 multicast addr is", + ipaddr->s6_addr, 16); + + return 0; +} + +static int +uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh) +{ + u8 tmp; + + if (!uh) + goto err; + + if (fetch_skb_u8(skb, &tmp)) + goto err; + + if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) { + pr_debug("UDP header uncompression\n"); + switch (tmp & LOWPAN_NHC_UDP_CS_P_11) { + case LOWPAN_NHC_UDP_CS_P_00: + memcpy(&uh->source, &skb->data[0], 2); + memcpy(&uh->dest, &skb->data[2], 2); + skb_pull(skb, 4); + break; + case LOWPAN_NHC_UDP_CS_P_01: + memcpy(&uh->source, &skb->data[0], 2); + uh->dest = + skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT; + skb_pull(skb, 3); + break; + case LOWPAN_NHC_UDP_CS_P_10: + uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT; + memcpy(&uh->dest, &skb->data[1], 2); + skb_pull(skb, 3); + break; + case LOWPAN_NHC_UDP_CS_P_11: + uh->source = + LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4); + uh->dest = + LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f); + skb_pull(skb, 1); + break; + default: + pr_debug("ERROR: unknown UDP format\n"); + goto err; + break; + } + + pr_debug("uncompressed UDP ports: src = %d, dst = %d\n", + uh->source, uh->dest); + + /* copy checksum */ + memcpy(&uh->check, &skb->data[0], 2); + skb_pull(skb, 2); + + /* + * UDP lenght needs to be infered from the lower layers + * here, we obtain the hint from the remaining size of the + * frame + */ + uh->len = htons(skb->len + sizeof(struct udphdr)); + pr_debug("uncompressed UDP length: src = %d", uh->len); + } else { + pr_debug("ERROR: unsupported NH format\n"); + goto err; + } + + return 0; +err: + return -EINVAL; +} + +static int process_data(struct sk_buff *skb, struct net_device *dev) +{ + struct ipv6hdr hdr = {}; + u8 tmp, iphc0, iphc1, num_context = 0; + const u8 *_saddr = NULL, *_daddr = NULL; + struct lowpan_info *info; + int err; + + raw_dump_table(__func__, "raw skb data dump uncompressed", + skb->data, skb->len); + + /* at least two bytes will be used for the encoding */ + if (skb->len < 2) + goto drop; + + if (fetch_skb_u8(skb, &iphc0)) + goto drop; + + info = lowpan_info(dev); + + /* fragments assembling */ + switch (iphc0 & LOWPAN_DISPATCH_MASK) { + case LOWPAN_DISPATCH_FRAG1: + case LOWPAN_DISPATCH_FRAGN: + { + struct lowpan_fragment *frame; + /* slen stores the rightmost 8 bits of the 11 bits length */ + u8 slen, offset = 0; + u16 len, tag; + bool found = false; + + if (fetch_skb_u8(skb, &slen) || /* frame length */ + fetch_skb_u16(skb, &tag)) /* fragment tag */ + goto drop; + + /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */ + len = ((iphc0 & 7) << 8) | slen; + + if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) { + pr_debug("%s received a FRAG1 packet (tag: %d, " + "size of the entire IP packet: %d)\n", + __func__, tag, len); + } else { /* FRAGN */ + if (fetch_skb_u8(skb, &offset)) + goto unlock_and_drop; + pr_debug("%s received a FRAGN packet (tag: %d, " + "size of the entire IP packet: %d, " + "offset: %d)\n", __func__, tag, len, + offset * 8); + } + + /* + * check if frame assembling with the same tag is + * already in progress + */ + spin_lock_bh(&flist_lock); + + list_for_each_entry(frame, &lowpan_fragments, list) + if (frame->tag == tag) { + found = true; + break; + } + + /* alloc new frame structure */ + if (!found) { + pr_debug("%s first fragment received for tag %d, " + "begin packet reassembly\n", __func__, tag); + frame = alloc_new_frame(skb, len, tag); + if (!frame) + goto unlock_and_drop; + } + + /* if payload fits buffer, copy it */ + if (likely((offset * 8 + skb->len) <= frame->length)) + skb_copy_to_linear_data_offset(frame->skb, offset * 8, + skb->data, skb->len); + else + goto unlock_and_drop; + + frame->bytes_rcv += skb->len; + + /* frame assembling complete */ + if ((frame->bytes_rcv == frame->length) && + frame->timer.expires > jiffies) { + /* if timer haven't expired - first of all delete it */ + del_timer_sync(&frame->timer); + list_del(&frame->list); + spin_unlock_bh(&flist_lock); + + pr_debug("%s successfully reassembled fragment " + "(tag %d)\n", __func__, tag); + + dev_kfree_skb(skb); + skb = frame->skb; + kfree(frame); + + if (fetch_skb_u8(skb, &iphc0)) + goto drop; + + break; + } + spin_unlock_bh(&flist_lock); + + return kfree_skb(skb), 0; + } + default: + break; + } + + if (fetch_skb_u8(skb, &iphc1)) + goto drop; + + _saddr = info->ieee802154_addr; + _daddr = info->net->dev_addr; + + /* another if the CID flag is set */ + if (iphc1 & LOWPAN_IPHC_CID) { + pr_debug("CID flag is set, increase header with one\n"); + if (fetch_skb_u8(skb, &num_context)) + goto drop; + } + + hdr.version = 6; + + /* Traffic Class and Flow Label */ + switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) { + /* + * Traffic Class and FLow Label carried in-line + * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) + */ + case 0: /* 00b */ + if (fetch_skb_u8(skb, &tmp)) + goto drop; + + memcpy(&hdr.flow_lbl, &skb->data[0], 3); + skb_pull(skb, 3); + hdr.priority = ((tmp >> 2) & 0x0f); + hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) | + (hdr.flow_lbl[0] & 0x0f); + break; + /* + * Traffic class carried in-line + * ECN + DSCP (1 byte), Flow Label is elided + */ + case 1: /* 10b */ + if (fetch_skb_u8(skb, &tmp)) + goto drop; + + hdr.priority = ((tmp >> 2) & 0x0f); + hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30); + break; + /* + * Flow Label carried in-line + * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided + */ + case 2: /* 01b */ + if (fetch_skb_u8(skb, &tmp)) + goto drop; + + hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30); + memcpy(&hdr.flow_lbl[1], &skb->data[0], 2); + skb_pull(skb, 2); + break; + /* Traffic Class and Flow Label are elided */ + case 3: /* 11b */ + break; + default: + break; + } + + /* Next Header */ + if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { + /* Next header is carried inline */ + if (fetch_skb_u8(skb, &(hdr.nexthdr))) + goto drop; + + pr_debug("NH flag is set, next header carried inline: %02x\n", + hdr.nexthdr); + } + + /* Hop Limit */ + if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) + hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03]; + else { + if (fetch_skb_u8(skb, &(hdr.hop_limit))) + goto drop; + } + + /* Extract SAM to the tmp variable */ + tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03; + + if (iphc1 & LOWPAN_IPHC_SAC) { + /* Source address context based uncompression */ + pr_debug("SAC bit is set. Handle context based source address.\n"); + err = uncompress_context_based_src_addr( + skb, &hdr.saddr, tmp); + } else { + /* Source address uncompression */ + pr_debug("source address stateless compression\n"); + err = uncompress_addr(skb, &hdr.saddr, tmp, _saddr); + } + + /* Check on error of previous branch */ + if (err) + goto drop; + + /* Extract DAM to the tmp variable */ + tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03; + + /* check for Multicast Compression */ + if (iphc1 & LOWPAN_IPHC_M) { + if (iphc1 & LOWPAN_IPHC_DAC) { + pr_debug("dest: context-based mcast compression\n"); + /* TODO: implement this */ + } else { + err = lowpan_uncompress_multicast_daddr( + skb, &hdr.daddr, tmp); + if (err) + goto drop; + } + } else { + pr_debug("dest: stateless compression\n"); + err = uncompress_addr(skb, &hdr.daddr, tmp, _daddr); + if (err) + goto drop; + } + + /* UDP data uncompression */ + if (iphc0 & LOWPAN_IPHC_NH_C) { + struct udphdr uh; + struct sk_buff *new; + if (uncompress_udp_header(skb, &uh)) + goto drop; + + /* + * replace the compressed UDP head by the uncompressed UDP + * header + */ + new = skb_copy_expand(skb, sizeof(struct udphdr), + skb_tailroom(skb), GFP_ATOMIC); + kfree_skb(skb); + + if (!new) + return -ENOMEM; + + skb = new; + + skb_push(skb, sizeof(struct udphdr)); + skb_reset_transport_header(skb); + skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr)); + + raw_dump_table(__func__, "raw UDP header dump", + (u8 *)&uh, sizeof(uh)); + + hdr.nexthdr = UIP_PROTO_UDP; + } + + /* Not fragmented package */ + hdr.payload_len = htons(skb->len); + + pr_debug("skb headroom size = %d, data length = %d\n", + skb_headroom(skb), skb->len); + + pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t" + "nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version, + ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit); + + raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, + sizeof(hdr)); + + return skb_deliver(skb, &hdr, dev); + +unlock_and_drop: + spin_unlock_bh(&flist_lock); +drop: + kfree_skb(skb); + return -EINVAL; +} + static int recv_pkt(struct sk_buff *skb, struct net_device *dev) { + struct sk_buff *local_skb; + + if (!netif_running(dev)) + goto drop; + + if (dev->type != ARPHRD_RAWIP) + goto drop; + + raw_dump_table(__func__, "raw recv dump", skb->head, + skb->len); + + /* check that it's our buffer */ + if (skb->data[0] == LOWPAN_DISPATCH_IPV6) { + /* Copy the packet so that the IPv6 header is + * properly aligned. + */ + local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, + skb_tailroom(skb), GFP_ATOMIC); + if (!local_skb) + goto drop; + + local_skb->protocol = htons(ETH_P_IPV6); + local_skb->pkt_type = PACKET_HOST; + + skb_reset_network_header(local_skb); + skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); + + if (give_skb_to_upper(local_skb, + dev) != NET_RX_SUCCESS) { + kfree_skb(local_skb); + goto drop; + } + + dev->stats.rx_bytes += skb->len; + dev->stats.rx_packets++; + + kfree_skb(local_skb); + kfree_skb(skb); + } else { + switch (skb->data[0] & 0xe0) { + case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */ + case LOWPAN_DISPATCH_FRAG1: /* first fragment header */ + case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */ + local_skb = skb_clone(skb, GFP_ATOMIC); + if (!local_skb) + goto drop; + if (process_data(local_skb, + dev) != NET_RX_SUCCESS) + goto drop; + + dev->stats.rx_bytes += skb->len; + dev->stats.rx_packets++; + + kfree_skb(skb); + break; + default: + break; + } + } + + return NET_RX_SUCCESS; + +drop: kfree_skb(skb); return NET_RX_DROP; } @@ -147,19 +879,408 @@ static void do_send(struct l2cap_conn *conn, struct sk_buff *skb) BT_DBG("conn %p, skb %p len %d priority %u", conn, skb, skb->len, skb->priority); + hci_send_acl(conn->hchan, skb, ACL_START); return; } +static inline int skbuff_copy(void *msg, int len, + int count, int mtu, + struct sk_buff *skb, + struct net_device *dev) +{ + struct sk_buff **frag; + int sent = 0; + + memcpy(skb_put(skb, count), msg, count); + + sent += count; + msg += count; + len -= count; + + dev->stats.tx_bytes += count; + dev->stats.tx_packets++; + + raw_dump_table(__func__, "Sending", skb->data, skb->len); + + /* Continuation fragments (no L2CAP header) */ + frag = &skb_shinfo(skb)->frag_list; + while (len > 0) { + struct sk_buff *tmp; + + count = min_t(unsigned int, mtu, len); + + tmp = bt_skb_alloc(count, GFP_KERNEL); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); + + *frag = tmp; + + memcpy(skb_put(*frag, count), msg, count); + + raw_dump_table(__func__, "Sending fragment", + (*frag)->data, count); + + (*frag)->priority = skb->priority; + + sent += count; + msg += count; + len -= count; + + skb->len += (*frag)->len; + skb->data_len += (*frag)->len; + + frag = &(*frag)->next; + + dev->stats.tx_bytes += count; + dev->stats.tx_packets++; + } + + return sent; +} + +static struct sk_buff *create_pdu(struct l2cap_conn *conn, + void *msg, size_t len, + u32 priority, + struct net_device *dev) +{ + struct sk_buff *skb; + int err, count; + struct l2cap_hdr *lh; + + if (conn->mtu > (L2CAP_LE_MIN_MTU + L2CAP_HDR_SIZE)) + /* XXX: This should be not needed and atm is only used for + * testing purposes */ + conn->mtu = L2CAP_LE_MIN_MTU + L2CAP_HDR_SIZE; + + count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len); + + BT_DBG("conn %p len %zu mtu %d count %d", conn, len, conn->mtu, count); + + skb = bt_skb_alloc(count + L2CAP_HDR_SIZE, GFP_KERNEL); + if (IS_ERR(skb)) + return skb; + + skb->priority = priority; + + lh = (struct l2cap_hdr *)skb_put(skb, L2CAP_HDR_SIZE); + lh->cid = cpu_to_le16(L2CAP_FC_6LOWPAN); + lh->len = cpu_to_le16(len); + + err = skbuff_copy(msg, len, count, conn->mtu, skb, dev); + if (unlikely(err < 0)) { + kfree_skb(skb); + BT_DBG("skbuff copy %d failed", err); + return ERR_PTR(err); + } + + return skb; +} + static int conn_send(struct l2cap_conn *conn, void *msg, size_t len, u32 priority, struct net_device *dev) { - struct sk_buff *skb = {0}; + struct sk_buff *skb; + + skb = create_pdu(conn, msg, len, priority, dev); + if (IS_ERR(skb)) + return -EINVAL; do_send(conn, skb); return 0; } +static u8 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, + const struct in6_addr *ipaddr, + const unsigned char *lladdr) +{ + u8 val = 0; + + if (is_addr_mac_addr_based(ipaddr, lladdr)) + val = 3; /* 0-bits */ + else if (lowpan_is_iid_16_bit_compressable(ipaddr)) { + /* compress IID to 16 bits xxxx::XXXX */ + memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2); + *hc06_ptr += 2; + val = 2; /* 16-bits */ + } else { + /* do not compress IID => xxxx::IID */ + memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8); + *hc06_ptr += 8; + val = 1; /* 64-bits */ + } + + return rol8(val, shift); +} + +static void compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb) +{ + struct udphdr *uh = udp_hdr(skb); + + if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) == + LOWPAN_NHC_UDP_4BIT_PORT) && + ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) == + LOWPAN_NHC_UDP_4BIT_PORT)) { + pr_debug("UDP header: both ports compression to 4 bits\n"); + **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11; + **(hc06_ptr + 1) = /* subtraction is faster */ + (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) + + ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4)); + *hc06_ptr += 2; + } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) == + LOWPAN_NHC_UDP_8BIT_PORT) { + pr_debug("UDP header: remove 8 bits of dest\n"); + **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01; + memcpy(*hc06_ptr + 1, &uh->source, 2); + **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT); + *hc06_ptr += 4; + } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) == + LOWPAN_NHC_UDP_8BIT_PORT) { + pr_debug("UDP header: remove 8 bits of source\n"); + **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10; + memcpy(*hc06_ptr + 1, &uh->dest, 2); + **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT); + *hc06_ptr += 4; + } else { + pr_debug("UDP header: can't compress\n"); + **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00; + memcpy(*hc06_ptr + 1, &uh->source, 2); + memcpy(*hc06_ptr + 3, &uh->dest, 2); + *hc06_ptr += 5; + } + + /* checksum is always inline */ + memcpy(*hc06_ptr, &uh->check, 2); + *hc06_ptr += 2; + + /* skip the UDP header */ + skb_pull(skb, sizeof(struct udphdr)); +} + +static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val) +{ + if (unlikely(!pskb_may_pull(skb, 1))) + return -EINVAL; + + *val = skb->data[0]; + skb_pull(skb, 1); + + return 0; +} + +static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val) +{ + if (unlikely(!pskb_may_pull(skb, 2))) + return -EINVAL; + + *val = (skb->data[0] << 8) | skb->data[1]; + skb_pull(skb, 2); + + return 0; +} + +static int header_create(struct sk_buff *skb, struct net_device *dev, + unsigned short type, const void *_daddr, + const void *_saddr, unsigned int len) +{ + u8 tmp, iphc0, iphc1, *hc06_ptr; + struct ipv6hdr *hdr; + u8 *saddr, *daddr; + u8 head[100]; + struct lowpan_info *info; + + if (type != ETH_P_IPV6) + return -EINVAL; + + info = lowpan_info(dev); + daddr = info->ieee802154_addr; + saddr = info->net->dev_addr; + + hdr = ipv6_hdr(skb); + hc06_ptr = head + 2; + + pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n" + "\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version, + ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit); + + raw_dump_table(__func__, "raw skb network header dump", + skb_network_header(skb), sizeof(struct ipv6hdr)); + + raw_dump_inline(__func__, "saddr", + (unsigned char *)saddr, 8); + + /* + * As we copy some bit-length fields, in the IPHC encoding bytes, + * we sometimes use |= + * If the field is 0, and the current bit value in memory is 1, + * this does not work. We therefore reset the IPHC encoding here + */ + iphc0 = LOWPAN_DISPATCH_IPHC; + iphc1 = 0; + + /* TODO: context lookup */ + + raw_dump_inline(__func__, "daddr", + (unsigned char *)daddr, 8); + + raw_dump_table(__func__, + "sending raw skb network uncompressed packet", + skb->data, skb->len); + + /* + * Traffic class, flow label + * If flow label is 0, compress it. If traffic class is 0, compress it + * We have to process both in the same time as the offset of traffic + * class depends on the presence of version and flow label + */ + + /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */ + tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4); + tmp = ((tmp & 0x03) << 6) | (tmp >> 2); + + if (((hdr->flow_lbl[0] & 0x0F) == 0) && + (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) { + /* flow label can be compressed */ + iphc0 |= LOWPAN_IPHC_FL_C; + if ((hdr->priority == 0) && + ((hdr->flow_lbl[0] & 0xF0) == 0)) { + /* compress (elide) all */ + iphc0 |= LOWPAN_IPHC_TC_C; + } else { + /* compress only the flow label */ + *hc06_ptr = tmp; + hc06_ptr += 1; + } + } else { + /* Flow label cannot be compressed */ + if ((hdr->priority == 0) && + ((hdr->flow_lbl[0] & 0xF0) == 0)) { + /* compress only traffic class */ + iphc0 |= LOWPAN_IPHC_TC_C; + *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F); + memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2); + hc06_ptr += 3; + } else { + /* compress nothing */ + memcpy(hc06_ptr, &hdr, 4); + /* replace the top byte with new ECN | DSCP format */ + *hc06_ptr = tmp; + hc06_ptr += 4; + } + } + + /* NOTE: payload length is always compressed */ + + /* Next Header is compress if UDP */ + if (hdr->nexthdr == UIP_PROTO_UDP) + iphc0 |= LOWPAN_IPHC_NH_C; + + if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { + *hc06_ptr = hdr->nexthdr; + hc06_ptr += 1; + } + + /* + * Hop limit + * if 1: compress, encoding is 01 + * if 64: compress, encoding is 10 + * if 255: compress, encoding is 11 + * else do not compress + */ + switch (hdr->hop_limit) { + case 1: + iphc0 |= LOWPAN_IPHC_TTL_1; + break; + case 64: + iphc0 |= LOWPAN_IPHC_TTL_64; + break; + case 255: + iphc0 |= LOWPAN_IPHC_TTL_255; + break; + default: + *hc06_ptr = hdr->hop_limit; + hc06_ptr += 1; + break; + } + + /* source address compression */ + if (is_addr_unspecified(&hdr->saddr)) { + pr_debug("source address is unspecified, setting SAC\n"); + iphc1 |= LOWPAN_IPHC_SAC; + /* TODO: context lookup */ + } else if (is_addr_link_local(&hdr->saddr)) { + pr_debug("source address is link-local\n"); + iphc1 |= lowpan_compress_addr_64(&hc06_ptr, + LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr); + } else { + pr_debug("send the full source address\n"); + memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16); + hc06_ptr += 16; + } + + /* destination address compression */ + if (is_addr_mcast(&hdr->daddr)) { + pr_debug("destination address is multicast: "); + iphc1 |= LOWPAN_IPHC_M; + if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) { + pr_debug("compressed to 1 octet\n"); + iphc1 |= LOWPAN_IPHC_DAM_11; + /* use last byte */ + *hc06_ptr = hdr->daddr.s6_addr[15]; + hc06_ptr += 1; + } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) { + pr_debug("compressed to 4 octets\n"); + iphc1 |= LOWPAN_IPHC_DAM_10; + /* second byte + the last three */ + *hc06_ptr = hdr->daddr.s6_addr[1]; + memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3); + hc06_ptr += 4; + } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) { + pr_debug("compressed to 6 octets\n"); + iphc1 |= LOWPAN_IPHC_DAM_01; + /* second byte + the last five */ + *hc06_ptr = hdr->daddr.s6_addr[1]; + memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5); + hc06_ptr += 6; + } else { + pr_debug("using full address\n"); + iphc1 |= LOWPAN_IPHC_DAM_00; + memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16); + hc06_ptr += 16; + } + } else { + /* TODO: context lookup */ + if (is_addr_link_local(&hdr->daddr)) { + pr_debug("dest address is unicast and link-local\n"); + iphc1 |= lowpan_compress_addr_64(&hc06_ptr, + LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr); + } else { + pr_debug("dest address is unicast: using full one\n"); + memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16); + hc06_ptr += 16; + } + } + + /* UDP header compression */ + if (hdr->nexthdr == UIP_PROTO_UDP) + compress_udp_header(&hc06_ptr, skb); + + head[0] = iphc0; + head[1] = iphc1; + + skb_pull(skb, sizeof(struct ipv6hdr)); + + memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head); + + BT_DBG("header len %d skb %u", (int)(hc06_ptr - head), skb->len); + + skb_reset_network_header(skb); + + raw_dump_table(__func__, "raw skb data dump compressed", + skb->data, skb->len); + return 0; +} + /* Packet to BT LE device */ static int send_pkt(struct l2cap_conn *conn, const void *saddr, const void *daddr, struct sk_buff *skb, @@ -198,6 +1319,10 @@ static const struct net_device_ops netdev_ops = { .ndo_start_xmit = xmit, }; +static struct header_ops header_ops = { + .create = header_create, +}; + static void setup(struct net_device *dev) { dev->addr_len = IEEE802154_ADDR_LEN; @@ -211,6 +1336,7 @@ static void setup(struct net_device *dev) dev->watchdog_timeo = 0; dev->netdev_ops = &netdev_ops; + dev->header_ops = &header_ops; dev->destructor = free_netdev; } -- 1.7.11.7