6lowpan: Moving generic compression code into 6lowpan_iphc.c
authorJukka Rissanen <jukka.rissanen@linux.intel.com>
Wed, 11 Dec 2013 15:05:34 +0000 (17:05 +0200)
committerMarcel Holtmann <marcel@holtmann.org>
Wed, 11 Dec 2013 20:57:54 +0000 (12:57 -0800)
Because the IEEE 802154 and Bluetooth share the IP header compression
and uncompression code, the common code is moved to 6lowpan_iphc.c
file.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
net/ieee802154/6lowpan.c
net/ieee802154/6lowpan.h
net/ieee802154/6lowpan_iphc.c [new file with mode: 0644]
net/ieee802154/Makefile

index 459e200..53d0bd5 100644 (file)
@@ -62,9 +62,6 @@
 
 #include "6lowpan.h"
 
-/* TTL uncompression values */
-static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
-
 static LIST_HEAD(lowpan_devices);
 
 /* private device info */
@@ -135,347 +132,14 @@ static inline void lowpan_raw_dump_table(const char *caller, char *msg,
 #endif /* DEBUG */
 }
 
-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);
-}
-
-/*
- * Uncompress address function for source and
- * destination address(non-multicast).
- *
- * address_mode is sam value or dam value.
- */
-static int
-lowpan_uncompress_addr(struct sk_buff *skb,
-               struct in6_addr *ipaddr,
-               const u8 address_mode,
-               const struct ieee802154_addr *lladdr)
-{
-       bool fail;
-
-       switch (address_mode) {
-       case LOWPAN_IPHC_ADDR_00:
-               /* for global link addresses */
-               fail = lowpan_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 = lowpan_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 = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
-               break;
-       case LOWPAN_IPHC_ADDR_03:
-               fail = false;
-               switch (lladdr->addr_type) {
-               case IEEE802154_ADDR_LONG:
-                       /* fe:80::XXXX:XXXX:XXXX:XXXX
-                        *        \_________________/
-                        *              hwaddr
-                        */
-                       ipaddr->s6_addr[0] = 0xFE;
-                       ipaddr->s6_addr[1] = 0x80;
-                       memcpy(&ipaddr->s6_addr[8], lladdr->hwaddr,
-                                       IEEE802154_ADDR_LEN);
-                       /* second bit-flip (Universe/Local)
-                        * is done according RFC2464
-                        */
-                       ipaddr->s6_addr[8] ^= 0x02;
-                       break;
-               case IEEE802154_ADDR_SHORT:
-                       /* fe:80::ff:fe00:XXXX
-                        *                \__/
-                        *             short_addr
-                        *
-                        * Universe/Local bit is zero.
-                        */
-                       ipaddr->s6_addr[0] = 0xFE;
-                       ipaddr->s6_addr[1] = 0x80;
-                       ipaddr->s6_addr[11] = 0xFF;
-                       ipaddr->s6_addr[12] = 0xFE;
-                       ipaddr->s6_addr16[7] = htons(lladdr->short_addr);
-                       break;
-               default:
-                       pr_debug("Invalid addr_type set\n");
-                       return -EINVAL;
-               }
-               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;
-       }
-
-       lowpan_raw_dump_inline(NULL, "Reconstructed ipv6 addr is:\n",
-                       ipaddr->s6_addr, 16);
-
-       return 0;
-}
-
-/* Uncompress address function for source context
- * based address(non-multicast).
- */
-static int
-lowpan_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;
-       }
-
-       lowpan_raw_dump_inline(NULL,
-                       "Reconstructed context based ipv6 src addr is:\n",
-                       ipaddr->s6_addr, 16);
-
-       return 0;
-}
-
-/* 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 = lowpan_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 = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
-               fail |= lowpan_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 = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
-               fail |= lowpan_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 = lowpan_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;
-       }
-
-       lowpan_raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is:\n",
-                       ipaddr->s6_addr, 16);
-
-       return 0;
-}
-
-static void
-lowpan_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
-lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
-{
-       u8 tmp;
-
-       if (!uh)
-               goto err;
-
-       if (lowpan_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;
-               }
-
-               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 lowpan_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;
        const u8 *saddr = _saddr;
        const u8 *daddr = _daddr;
-       u8 head[100];
        struct ieee802154_addr sa, da;
 
        /* TODO:
@@ -485,181 +149,14 @@ static int lowpan_header_create(struct sk_buff *skb,
                return 0;
 
        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);
-
-       lowpan_raw_dump_table(__func__, "raw skb network header dump",
-               skb_network_header(skb), sizeof(struct ipv6hdr));
 
        if (!saddr)
                saddr = dev->dev_addr;
 
        lowpan_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 */
-
        lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 
-       /*
-        * 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)
-               lowpan_compress_udp_header(&hc06_ptr, skb);
-
-       head[0] = iphc0;
-       head[1] = iphc1;
-
-       skb_pull(skb, sizeof(struct ipv6hdr));
-       skb_reset_transport_header(skb);
-       memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
-       skb_reset_network_header(skb);
-
-       lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
-                               skb->len);
+       lowpan_header_compress(skb, dev, type, daddr, saddr, len);
 
        /*
         * NOTE1: I'm still unsure about the fact that compression and WPAN
@@ -671,39 +168,38 @@ static int lowpan_header_create(struct sk_buff *skb,
         * from MAC subif of the 'dev' and 'real_dev' network devices, but
         * this isn't implemented in mainline yet, so currently we assign 0xff
         */
-       {
-               mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
-               mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
+       mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+       mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
 
-               /* prepare wpan address data */
-               sa.addr_type = IEEE802154_ADDR_LONG;
-               sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
+       /* prepare wpan address data */
+       sa.addr_type = IEEE802154_ADDR_LONG;
+       sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 
-               memcpy(&(sa.hwaddr), saddr, 8);
-               /* intra-PAN communications */
-               da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
+       memcpy(&(sa.hwaddr), saddr, 8);
+       /* intra-PAN communications */
+       da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 
-               /*
-                * if the destination address is the broadcast address, use the
-                * corresponding short address
-                */
-               if (lowpan_is_addr_broadcast(daddr)) {
-                       da.addr_type = IEEE802154_ADDR_SHORT;
-                       da.short_addr = IEEE802154_ADDR_BROADCAST;
-               } else {
-                       da.addr_type = IEEE802154_ADDR_LONG;
-                       memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
-
-                       /* request acknowledgment */
-                       mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
-               }
+       /*
+        * if the destination address is the broadcast address, use the
+        * corresponding short address
+        */
+       if (lowpan_is_addr_broadcast(daddr)) {
+               da.addr_type = IEEE802154_ADDR_SHORT;
+               da.short_addr = IEEE802154_ADDR_BROADCAST;
+       } else {
+               da.addr_type = IEEE802154_ADDR_LONG;
+               memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
 
-               return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
-                               type, (void *)&da, (void *)&sa, skb->len);
+               /* request acknowledgment */
+               mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
        }
+
+       return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
+                       type, (void *)&da, (void *)&sa, skb->len);
 }
 
-static int lowpan_give_skb_to_devices(struct sk_buff *skb)
+static int lowpan_give_skb_to_devices(struct sk_buff *skb,
+                                       struct net_device *dev)
 {
        struct lowpan_dev_record *entry;
        struct sk_buff *skb_cp;
@@ -726,31 +222,6 @@ static int lowpan_give_skb_to_devices(struct sk_buff *skb)
        return stat;
 }
 
-static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
-{
-       struct sk_buff *new;
-       int stat = NET_RX_SUCCESS;
-
-       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_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
-
-       new->protocol = htons(ETH_P_IPV6);
-       new->pkt_type = PACKET_HOST;
-
-       stat = lowpan_give_skb_to_devices(new);
-
-       kfree_skb(new);
-
-       return stat;
-}
-
 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 {
        struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
@@ -814,13 +285,10 @@ frame_err:
        return NULL;
 }
 
-static int
-lowpan_process_data(struct sk_buff *skb)
+static int process_data(struct sk_buff *skb)
 {
-       struct ipv6hdr hdr = {};
-       u8 tmp, iphc0, iphc1, num_context = 0;
+       u8 iphc0, iphc1;
        const struct ieee802154_addr *_saddr, *_daddr;
-       int err;
 
        lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
                                skb->len);
@@ -925,162 +393,11 @@ lowpan_process_data(struct sk_buff *skb)
        _saddr = &mac_cb(skb)->sa;
        _daddr = &mac_cb(skb)->da;
 
-       pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
-
-       /* another if the CID flag is set */
-       if (iphc1 & LOWPAN_IPHC_CID) {
-               pr_debug("CID flag is set, increase header with one\n");
-               if (lowpan_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 (lowpan_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 2: /* 10b */
-               if (lowpan_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 1: /* 01b */
-               if (lowpan_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 (lowpan_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 (lowpan_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 = lowpan_uncompress_context_based_src_addr(
-                               skb, &hdr.saddr, tmp);
-       } else {
-               /* Source address uncompression */
-               pr_debug("source address stateless compression\n");
-               err = lowpan_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 = lowpan_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 (lowpan_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_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
-
-               lowpan_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);
-
-       lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
-                                                       sizeof(hdr));
-       return lowpan_skb_deliver(skb, &hdr);
+       return lowpan_process_data(skb, skb->dev, (u8 *)_saddr->hwaddr,
+                               _saddr->addr_type, IEEE802154_ADDR_LEN,
+                               (u8 *)_daddr->hwaddr, _daddr->addr_type,
+                               IEEE802154_ADDR_LEN, iphc0, iphc1,
+                               lowpan_give_skb_to_devices);
 
 unlock_and_drop:
        spin_unlock_bh(&flist_lock);
@@ -1316,7 +633,7 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
                /* Pull off the 1-byte of 6lowpan header. */
                skb_pull(local_skb, 1);
 
-               lowpan_give_skb_to_devices(local_skb);
+               lowpan_give_skb_to_devices(local_skb, NULL);
 
                kfree_skb(local_skb);
                kfree_skb(skb);
@@ -1328,7 +645,7 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
                        local_skb = skb_clone(skb, GFP_ATOMIC);
                        if (!local_skb)
                                goto drop;
-                       lowpan_process_data(local_skb);
+                       process_data(local_skb);
 
                        kfree_skb(skb);
                        break;
index 2869c05..535606d 100644 (file)
                                        dest = 16 bit inline */
 #define LOWPAN_NHC_UDP_CS_P_11 0xF3 /* source & dest = 0xF0B + 4bit inline */
 
+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 inline bool lowpan_fetch_skb(struct sk_buff *skb,
                void *data, const unsigned int len)
 {
@@ -244,4 +266,14 @@ static inline bool lowpan_fetch_skb(struct sk_buff *skb,
        return false;
 }
 
+typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);
+
+int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
+               const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
+               const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
+               u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
+int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
+                       unsigned short type, const void *_daddr,
+                       const void *_saddr, unsigned int len);
+
 #endif /* __6LOWPAN_H__ */
diff --git a/net/ieee802154/6lowpan_iphc.c b/net/ieee802154/6lowpan_iphc.c
new file mode 100644 (file)
index 0000000..57c0b7a
--- /dev/null
@@ -0,0 +1,807 @@
+/*
+ * Copyright 2011, Siemens AG
+ * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+/*
+ * Based on patches from Jon Smirl <jonsmirl@gmail.com>
+ * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* Jon's code is based on 6lowpan implementation for Contiki which is:
+ * Copyright (c) 2008, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <linux/bitops.h>
+#include <linux/if_arp.h>
+#include <linux/netdevice.h>
+#include <net/ipv6.h>
+#include <net/af_ieee802154.h>
+
+#include "6lowpan.h"
+
+/* print data in line */
+static inline void raw_dump_inline(const char *caller, char *msg,
+                                  unsigned char *buf, int len)
+{
+       if (msg)
+               pr_debug("%s():%s: ", caller, msg);
+       print_hex_dump_debug("", DUMP_PREFIX_NONE,
+                      16, 1, buf, len, false);
+}
+
+/*
+ * print data in a table format:
+ *
+ * addr: xx xx xx xx xx xx
+ * addr: xx xx xx xx xx xx
+ * ...
+ */
+static inline void raw_dump_table(const char *caller, char *msg,
+                               unsigned char *buf, int len)
+{
+       if (msg)
+               pr_debug("%s():%s:\n", caller, msg);
+       print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET,
+                      16, 1, buf, len, 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, const u8 addr_type,
+                               const u8 addr_len)
+{
+       bool fail;
+
+       switch (address_mode) {
+       case LOWPAN_IPHC_ADDR_00:
+               /* for global link addresses */
+               fail = lowpan_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 = lowpan_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 = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
+               break;
+       case LOWPAN_IPHC_ADDR_03:
+               fail = false;
+               switch (addr_type) {
+               case IEEE802154_ADDR_LONG:
+                       /* fe:80::XXXX:XXXX:XXXX:XXXX
+                        *        \_________________/
+                        *              hwaddr
+                        */
+                       ipaddr->s6_addr[0] = 0xFE;
+                       ipaddr->s6_addr[1] = 0x80;
+                       memcpy(&ipaddr->s6_addr[8], lladdr, addr_len);
+                       /* second bit-flip (Universe/Local)
+                        * is done according RFC2464
+                        */
+                       ipaddr->s6_addr[8] ^= 0x02;
+                       break;
+               case IEEE802154_ADDR_SHORT:
+                       /* fe:80::ff:fe00:XXXX
+                        *                \__/
+                        *             short_addr
+                        *
+                        * Universe/Local bit is zero.
+                        */
+                       ipaddr->s6_addr[0] = 0xFE;
+                       ipaddr->s6_addr[1] = 0x80;
+                       ipaddr->s6_addr[11] = 0xFF;
+                       ipaddr->s6_addr[12] = 0xFE;
+                       ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr));
+                       break;
+               default:
+                       pr_debug("Invalid addr_type set\n");
+                       return -EINVAL;
+               }
+               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;
+}
+
+static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr,
+               struct net_device *dev, skb_delivery_cb deliver_skb)
+{
+       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 = deliver_skb(new, dev);
+
+       kfree_skb(new);
+
+       return stat;
+}
+
+/* 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 = lowpan_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 = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
+               fail |= lowpan_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 = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
+               fail |= lowpan_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 = lowpan_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 (lowpan_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;
+}
+
+/* TTL uncompression values */
+static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
+
+int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
+               const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
+               const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
+               u8 iphc0, u8 iphc1, skb_delivery_cb deliver_skb)
+{
+       struct ipv6hdr hdr = {};
+       u8 tmp, num_context = 0;
+       int err;
+
+       raw_dump_table(__func__, "raw skb data dump uncompressed",
+                               skb->data, skb->len);
+
+       /* another if the CID flag is set */
+       if (iphc1 & LOWPAN_IPHC_CID) {
+               pr_debug("CID flag is set, increase header with one\n");
+               if (lowpan_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 (lowpan_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 2: /* 10b */
+               if (lowpan_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 1: /* 01b */
+               if (lowpan_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 (lowpan_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 (lowpan_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,
+                                       saddr_type, saddr_len);
+       }
+
+       /* 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 {
+               err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
+                                       daddr_type, daddr_len);
+               pr_debug("dest: stateless compression mode %d dest %pI6c\n",
+                       tmp, &hdr.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;
+       }
+
+       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\tdest    = %pI6c\n",
+               hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
+               hdr.hop_limit, &hdr.daddr);
+
+       raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
+                                                       sizeof(hdr));
+
+       return skb_deliver(skb, &hdr, dev, deliver_skb);
+
+drop:
+       kfree_skb(skb);
+       return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(lowpan_process_data);
+
+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 */
+               pr_debug("address compression 0 bits\n");
+       } 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 */
+               raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
+                       *hc06_ptr - 2, 2);
+       } else {
+               /* do not compress IID => xxxx::IID */
+               memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
+               *hc06_ptr += 8;
+               val = 1; /* 64-bits */
+               raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
+                       *hc06_ptr - 8, 8);
+       }
+
+       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));
+}
+
+int lowpan_header_compress(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 head[100] = {};
+
+       if (type != ETH_P_IPV6)
+               return -EINVAL;
+
+       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\tdest    = %pI6c\n",
+               hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
+               hdr->hop_limit, &hdr->daddr);
+
+       raw_dump_table(__func__, "raw skb network header dump",
+               skb_network_header(skb), sizeof(struct ipv6hdr));
+
+       /*
+        * 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__, "saddr",
+                       (unsigned char *)_saddr, IEEE802154_ADDR_LEN);
+       raw_dump_inline(__func__, "daddr",
+                       (unsigned char *)_daddr, IEEE802154_ADDR_LEN);
+
+       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)) {
+               iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
+                               LOWPAN_IPHC_SAM_BIT, &hdr->saddr, _saddr);
+               pr_debug("source address unicast link-local %pI6c "
+                       "iphc1 0x%02x\n", &hdr->saddr, iphc1);
+       } 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)) {
+                       iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
+                               LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
+                       pr_debug("dest address unicast link-local %pI6c "
+                               "iphc1 0x%02x\n", &hdr->daddr, iphc1);
+               } else {
+                       pr_debug("dest address unicast %pI6c\n", &hdr->daddr);
+                       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));
+       skb_reset_transport_header(skb);
+       memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
+       skb_reset_network_header(skb);
+
+       pr_debug("header len %d skb %u\n", (int)(hc06_ptr - head), skb->len);
+
+       raw_dump_table(__func__, "raw skb data dump compressed",
+                               skb->data, skb->len);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(lowpan_header_compress);
index d7716d6..951a83e 100644 (file)
@@ -1,5 +1,5 @@
 obj-$(CONFIG_IEEE802154) += ieee802154.o af_802154.o
-obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o
+obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o 6lowpan_iphc.o
 
 ieee802154-y := netlink.o nl-mac.o nl-phy.o nl_policy.o wpan-class.o
 af_802154-y := af_ieee802154.o raw.o dgram.o