diff options
Diffstat (limited to 'kernel/net/6lowpan/iphc.c')
-rw-r--r-- | kernel/net/6lowpan/iphc.c | 707 |
1 files changed, 476 insertions, 231 deletions
diff --git a/kernel/net/6lowpan/iphc.c b/kernel/net/6lowpan/iphc.c index 94a375c04..346b5c1a9 100644 --- a/kernel/net/6lowpan/iphc.c +++ b/kernel/net/6lowpan/iphc.c @@ -48,38 +48,179 @@ #include <linux/bitops.h> #include <linux/if_arp.h> -#include <linux/module.h> #include <linux/netdevice.h> + #include <net/6lowpan.h> #include <net/ipv6.h> -#include <net/af_ieee802154.h> + +/* special link-layer handling */ +#include <net/mac802154.h> #include "nhc.h" +/* Values of fields within the IPHC encoding first byte */ +#define LOWPAN_IPHC_TF_MASK 0x18 +#define LOWPAN_IPHC_TF_00 0x00 +#define LOWPAN_IPHC_TF_01 0x08 +#define LOWPAN_IPHC_TF_10 0x10 +#define LOWPAN_IPHC_TF_11 0x18 + +#define LOWPAN_IPHC_NH 0x04 + +#define LOWPAN_IPHC_HLIM_MASK 0x03 +#define LOWPAN_IPHC_HLIM_00 0x00 +#define LOWPAN_IPHC_HLIM_01 0x01 +#define LOWPAN_IPHC_HLIM_10 0x02 +#define LOWPAN_IPHC_HLIM_11 0x03 + +/* Values of fields within the IPHC encoding second byte */ +#define LOWPAN_IPHC_CID 0x80 + +#define LOWPAN_IPHC_SAC 0x40 + +#define LOWPAN_IPHC_SAM_MASK 0x30 +#define LOWPAN_IPHC_SAM_00 0x00 +#define LOWPAN_IPHC_SAM_01 0x10 +#define LOWPAN_IPHC_SAM_10 0x20 +#define LOWPAN_IPHC_SAM_11 0x30 + +#define LOWPAN_IPHC_M 0x08 + +#define LOWPAN_IPHC_DAC 0x04 + +#define LOWPAN_IPHC_DAM_MASK 0x03 +#define LOWPAN_IPHC_DAM_00 0x00 +#define LOWPAN_IPHC_DAM_01 0x01 +#define LOWPAN_IPHC_DAM_10 0x02 +#define LOWPAN_IPHC_DAM_11 0x03 + +/* ipv6 address based on mac + * second bit-flip (Universe/Local) is done according RFC2464 + */ +#define is_addr_mac_addr_based(a, m) \ + ((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \ + (((a)->s6_addr[9]) == (m)[1]) && \ + (((a)->s6_addr[10]) == (m)[2]) && \ + (((a)->s6_addr[11]) == (m)[3]) && \ + (((a)->s6_addr[12]) == (m)[4]) && \ + (((a)->s6_addr[13]) == (m)[5]) && \ + (((a)->s6_addr[14]) == (m)[6]) && \ + (((a)->s6_addr[15]) == (m)[7])) + +/* check whether we can compress the IID to 16 bits, + * it's possible for unicast addresses with first 49 bits are zero only. + */ +#define lowpan_is_iid_16_bit_compressable(a) \ + ((((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr[10]) == 0) && \ + (((a)->s6_addr[11]) == 0xff) && \ + (((a)->s6_addr[12]) == 0xfe) && \ + (((a)->s6_addr[13]) == 0)) + +/* check whether the 112-bit gid of the multicast address is mappable to: */ + +/* 48 bits, FFXX::00XX:XXXX:XXXX */ +#define lowpan_is_mcast_addr_compressable48(a) \ + ((((a)->s6_addr16[1]) == 0) && \ + (((a)->s6_addr16[2]) == 0) && \ + (((a)->s6_addr16[3]) == 0) && \ + (((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr[10]) == 0)) + +/* 32 bits, FFXX::00XX:XXXX */ +#define lowpan_is_mcast_addr_compressable32(a) \ + ((((a)->s6_addr16[1]) == 0) && \ + (((a)->s6_addr16[2]) == 0) && \ + (((a)->s6_addr16[3]) == 0) && \ + (((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr16[5]) == 0) && \ + (((a)->s6_addr[12]) == 0)) + +/* 8 bits, FF02::00XX */ +#define lowpan_is_mcast_addr_compressable8(a) \ + ((((a)->s6_addr[1]) == 2) && \ + (((a)->s6_addr16[1]) == 0) && \ + (((a)->s6_addr16[2]) == 0) && \ + (((a)->s6_addr16[3]) == 0) && \ + (((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr16[5]) == 0) && \ + (((a)->s6_addr16[6]) == 0) && \ + (((a)->s6_addr[14]) == 0)) + +static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr, + const void *lladdr) +{ + /* fe:80::XXXX:XXXX:XXXX:XXXX + * \_________________/ + * hwaddr + */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN); + /* second bit-flip (Universe/Local) + * is done according RFC2464 + */ + ipaddr->s6_addr[8] ^= 0x02; +} + +static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr, + const void *lladdr) +{ + const struct ieee802154_addr *addr = lladdr; + u8 eui64[EUI64_ADDR_LEN] = { }; + + switch (addr->mode) { + case IEEE802154_ADDR_LONG: + ieee802154_le64_to_be64(eui64, &addr->extended_addr); + iphc_uncompress_eui64_lladdr(ipaddr, eui64); + 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; + ieee802154_le16_to_be16(&ipaddr->s6_addr16[7], + &addr->short_addr); + break; + default: + /* should never handled and filtered by 802154 6lowpan */ + WARN_ON_ONCE(1); + break; + } +} + /* Uncompress address function for source and * destination address(non-multicast). * - * address_mode is sam value or dam value. + * address_mode is the masked value for sam 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) +static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev, + struct in6_addr *ipaddr, u8 address_mode, + const void *lladdr) { bool fail; switch (address_mode) { - case LOWPAN_IPHC_ADDR_00: + /* SAM and DAM are the same here */ + case LOWPAN_IPHC_DAM_00: /* for global link addresses */ fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); break; - case LOWPAN_IPHC_ADDR_01: + case LOWPAN_IPHC_SAM_01: + case LOWPAN_IPHC_DAM_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: + case LOWPAN_IPHC_SAM_10: + case LOWPAN_IPHC_DAM_10: /* fe:80::ff:fe00:XXXX */ ipaddr->s6_addr[0] = 0xFE; ipaddr->s6_addr[1] = 0x80; @@ -87,38 +228,16 @@ static int uncompress_addr(struct sk_buff *skb, ipaddr->s6_addr[12] = 0xFE; fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2); break; - case LOWPAN_IPHC_ADDR_03: + case LOWPAN_IPHC_SAM_11: + case LOWPAN_IPHC_DAM_11: 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)); + switch (lowpan_priv(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + iphc_uncompress_802154_lladdr(ipaddr, lladdr); break; default: - pr_debug("Invalid addr_type set\n"); - return -EINVAL; + iphc_uncompress_eui64_lladdr(ipaddr, lladdr); + break; } break; default: @@ -142,24 +261,25 @@ static int uncompress_addr(struct sk_buff *skb, */ static int uncompress_context_based_src_addr(struct sk_buff *skb, struct in6_addr *ipaddr, - const u8 sam) + u8 address_mode) { - switch (sam) { - case LOWPAN_IPHC_ADDR_00: + switch (address_mode) { + case LOWPAN_IPHC_SAM_00: /* unspec address :: * Do nothing, address is already :: */ break; - case LOWPAN_IPHC_ADDR_01: + case LOWPAN_IPHC_SAM_01: /* TODO */ - case LOWPAN_IPHC_ADDR_02: + case LOWPAN_IPHC_SAM_10: /* TODO */ - case LOWPAN_IPHC_ADDR_03: + case LOWPAN_IPHC_SAM_11: /* TODO */ - netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam); + netdev_warn(skb->dev, "SAM value 0x%x not supported\n", + address_mode); return -EINVAL; default: - pr_debug("Invalid sam value: 0x%x\n", sam); + pr_debug("Invalid sam value: 0x%x\n", address_mode); return -EINVAL; } @@ -175,11 +295,11 @@ static int uncompress_context_based_src_addr(struct sk_buff *skb, */ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, struct in6_addr *ipaddr, - const u8 dam) + u8 address_mode) { bool fail; - switch (dam) { + switch (address_mode) { case LOWPAN_IPHC_DAM_00: /* 00: 128 bits. The full address * is carried in-line. @@ -211,7 +331,7 @@ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1); break; default: - pr_debug("DAM value has a wrong value: 0x%x\n", dam); + pr_debug("DAM value has a wrong value: 0x%x\n", address_mode); return -EINVAL; } @@ -226,77 +346,142 @@ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, return 0; } -/* TTL uncompression values */ -static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 }; - -int -lowpan_header_decompress(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) +/* get the ecn values from iphc tf format and set it to ipv6hdr */ +static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf) { - struct ipv6hdr hdr = {}; - u8 tmp, num_context = 0; - int err; + /* get the two higher bits which is ecn */ + u8 ecn = tf[0] & 0xc0; - raw_dump_table(__func__, "raw skb data dump uncompressed", - skb->data, skb->len); + /* ECN takes 0x30 in hdr->flow_lbl[0] */ + hdr->flow_lbl[0] |= (ecn >> 2); +} - /* 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(skb, &num_context, sizeof(num_context))) - return -EINVAL; - } +/* get the dscp values from iphc tf format and set it to ipv6hdr */ +static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf) +{ + /* DSCP is at place after ECN */ + u8 dscp = tf[0] & 0x3f; - hdr.version = 6; + /* The four highest bits need to be set at hdr->priority */ + hdr->priority |= ((dscp & 0x3c) >> 2); + /* The two lower bits is part of hdr->flow_lbl[0] */ + hdr->flow_lbl[0] |= ((dscp & 0x03) << 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) +/* get the flow label values from iphc tf format and set it to ipv6hdr */ +static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl) +{ + /* flow label is always some array started with lower nibble of + * flow_lbl[0] and followed with two bytes afterwards. Inside inline + * data the flow_lbl position can be different, which will be handled + * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit + * shifted, the different lbl pointer will handle that. + * + * The flow label will started at lower nibble of flow_lbl[0], the + * higher nibbles are part of DSCP + ECN. */ - case 0: /* 00b */ - if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp))) + hdr->flow_lbl[0] |= lbl[0] & 0x0f; + memcpy(&hdr->flow_lbl[1], &lbl[1], 2); +} + +/* lowpan_iphc_tf_decompress - decompress the traffic class. + * This function will return zero on success, a value lower than zero if + * failed. + */ +static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr, + u8 val) +{ + u8 tf[4]; + + /* Traffic Class and Flow Label */ + switch (val) { + case LOWPAN_IPHC_TF_00: + /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */ + if (lowpan_fetch_skb(skb, tf, 4)) return -EINVAL; - 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); + /* 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN| DSCP | rsv | Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + lowpan_iphc_tf_set_ecn(hdr, tf); + lowpan_iphc_tf_set_dscp(hdr, tf); + lowpan_iphc_tf_set_lbl(hdr, &tf[1]); break; - /* Traffic class carried in-line - * ECN + DSCP (1 byte), Flow Label is elided - */ - case 2: /* 10b */ - if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp))) + case LOWPAN_IPHC_TF_01: + /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */ + if (lowpan_fetch_skb(skb, tf, 3)) return -EINVAL; - hdr.priority = ((tmp >> 2) & 0x0f); - hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30); + /* 1 2 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN|rsv| Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + lowpan_iphc_tf_set_ecn(hdr, tf); + lowpan_iphc_tf_set_lbl(hdr, &tf[0]); break; - /* Flow Label carried in-line - * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided - */ - case 1: /* 01b */ - if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp))) + case LOWPAN_IPHC_TF_10: + /* ECN + DSCP (1 byte), Flow Label is elided. */ + if (lowpan_fetch_skb(skb, tf, 1)) return -EINVAL; - hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30); - memcpy(&hdr.flow_lbl[1], &skb->data[0], 2); - skb_pull(skb, 2); + /* 0 1 2 3 4 5 6 7 + * +-+-+-+-+-+-+-+-+ + * |ECN| DSCP | + * +-+-+-+-+-+-+-+-+ + */ + lowpan_iphc_tf_set_ecn(hdr, tf); + lowpan_iphc_tf_set_dscp(hdr, tf); break; - /* Traffic Class and Flow Label are elided */ - case 3: /* 11b */ + case LOWPAN_IPHC_TF_11: + /* Traffic Class and Flow Label are elided */ break; default: - break; + WARN_ON_ONCE(1); + return -EINVAL; } + return 0; +} + +/* TTL uncompression values */ +static const u8 lowpan_ttl_values[] = { + [LOWPAN_IPHC_HLIM_01] = 1, + [LOWPAN_IPHC_HLIM_10] = 64, + [LOWPAN_IPHC_HLIM_11] = 255, +}; + +int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev, + const void *daddr, const void *saddr) +{ + struct ipv6hdr hdr = {}; + u8 iphc0, iphc1; + int err; + + raw_dump_table(__func__, "raw skb data dump uncompressed", + skb->data, skb->len); + + if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) || + lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1))) + return -EINVAL; + + /* another if the CID flag is set */ + if (iphc1 & LOWPAN_IPHC_CID) + return -ENOTSUPP; + + hdr.version = 6; + + err = lowpan_iphc_tf_decompress(skb, &hdr, + iphc0 & LOWPAN_IPHC_TF_MASK); + if (err < 0) + return err; + /* Next Header */ - if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { + if (!(iphc0 & LOWPAN_IPHC_NH)) { /* Next header is carried inline */ if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr))) return -EINVAL; @@ -306,35 +491,30 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev, } /* Hop Limit */ - if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) { - hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03]; + if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) { + hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK]; } else { if (lowpan_fetch_skb(skb, &hdr.hop_limit, sizeof(hdr.hop_limit))) return -EINVAL; } - /* 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); + err = uncompress_context_based_src_addr(skb, &hdr.saddr, + iphc1 & LOWPAN_IPHC_SAM_MASK); } else { /* Source address uncompression */ pr_debug("source address stateless compression\n"); - err = uncompress_addr(skb, &hdr.saddr, tmp, saddr, - saddr_type, saddr_len); + err = uncompress_addr(skb, dev, &hdr.saddr, + iphc1 & LOWPAN_IPHC_SAM_MASK, saddr); } /* Check on error of previous branch */ if (err) return -EINVAL; - /* 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) { @@ -342,22 +522,22 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev, /* TODO: implement this */ } else { err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr, - tmp); + iphc1 & LOWPAN_IPHC_DAM_MASK); if (err) return -EINVAL; } } else { - err = uncompress_addr(skb, &hdr.daddr, tmp, daddr, - daddr_type, daddr_len); + err = uncompress_addr(skb, dev, &hdr.daddr, + iphc1 & LOWPAN_IPHC_DAM_MASK, daddr); pr_debug("dest: stateless compression mode %d dest %pI6c\n", - tmp, &hdr.daddr); + iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr); if (err) return -EINVAL; } /* Next header data uncompression */ - if (iphc0 & LOWPAN_IPHC_NH_C) { + if (iphc0 & LOWPAN_IPHC_NH) { err = lowpan_nhc_do_uncompression(skb, dev, &hdr); if (err < 0) return err; @@ -367,7 +547,18 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev, return err; } - hdr.payload_len = htons(skb->len); + switch (lowpan_priv(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + if (lowpan_802154_cb(skb)->d_size) + hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size - + sizeof(struct ipv6hdr)); + else + hdr.payload_len = htons(skb->len); + break; + default: + hdr.payload_len = htons(skb->len); + break; + } pr_debug("skb headroom size = %d, data length = %d\n", skb_headroom(skb), skb->len); @@ -387,42 +578,176 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev, } EXPORT_SYMBOL_GPL(lowpan_header_decompress); -static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift, - const struct in6_addr *ipaddr, - const unsigned char *lladdr) +static const u8 lowpan_iphc_dam_to_sam_value[] = { + [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00, + [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01, + [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10, + [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11, +}; + +static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr, + const unsigned char *lladdr, bool sam) { - u8 val = 0; + u8 dam = LOWPAN_IPHC_DAM_00; if (is_addr_mac_addr_based(ipaddr, lladdr)) { - val = 3; /* 0-bits */ + dam = LOWPAN_IPHC_DAM_11; /* 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 */ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2); - val = 2; /* 16-bits */ + dam = LOWPAN_IPHC_DAM_10; /* 16-bits */ raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)", *hc_ptr - 2, 2); } else { /* do not compress IID => xxxx::IID */ lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8); - val = 1; /* 64-bits */ + dam = LOWPAN_IPHC_DAM_01; /* 64-bits */ raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)", *hc_ptr - 8, 8); } - return rol8(val, shift); + if (sam) + return lowpan_iphc_dam_to_sam_value[dam]; + else + return dam; +} + +/* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */ +static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr) +{ + u8 dscp, ecn; + + /* hdr->priority contains the higher bits of dscp, lower are part of + * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr. + */ + dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6); + /* ECN is at the two lower bits from first nibble of flow_lbl[0] */ + ecn = (hdr->flow_lbl[0] & 0x30); + /* for pretty debug output, also shift ecn to get the ecn value */ + pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp); + /* ECN is at 0x30 now, shift it to have ECN + DCSP */ + return (ecn << 2) | dscp; +} + +/* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */ +static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr) +{ + return ((!(hdr->flow_lbl[0] & 0x0f)) && + !hdr->flow_lbl[1] && !hdr->flow_lbl[2]); +} + +/* lowpan_iphc_tf_compress - compress the traffic class which is set by + * ipv6hdr. Return the corresponding format identifier which is used. + */ +static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr) +{ + /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */ + u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val; + + /* printout the traffic class in hc format */ + pr_debug("tc 0x%02x\n", tc); + + if (lowpan_iphc_is_flow_lbl_zero(hdr)) { + if (!tc) { + /* 11: Traffic Class and Flow Label are elided. */ + val = LOWPAN_IPHC_TF_11; + } else { + /* 10: ECN + DSCP (1 byte), Flow Label is elided. + * + * 0 1 2 3 4 5 6 7 + * +-+-+-+-+-+-+-+-+ + * |ECN| DSCP | + * +-+-+-+-+-+-+-+-+ + */ + lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc)); + val = LOWPAN_IPHC_TF_10; + } + } else { + /* check if dscp is zero, it's after the first two bit */ + if (!(tc & 0x3f)) { + /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided + * + * 1 2 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN|rsv| Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + memcpy(&tf[0], &hdr->flow_lbl[0], 3); + /* zero the highest 4-bits, contains DCSP + ECN */ + tf[0] &= ~0xf0; + /* set ECN */ + tf[0] |= (tc & 0xc0); + + lowpan_push_hc_data(hc_ptr, tf, 3); + val = LOWPAN_IPHC_TF_01; + } else { + /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) + * + * 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN| DSCP | rsv | Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + memcpy(&tf[0], &tc, sizeof(tc)); + /* highest nibble of flow_lbl[0] is part of DSCP + ECN + * which will be the 4-bit pad and will be filled with + * zeros afterwards. + */ + memcpy(&tf[1], &hdr->flow_lbl[0], 3); + /* zero the 4-bit pad, which is reserved */ + tf[1] &= ~0xf0; + + lowpan_push_hc_data(hc_ptr, tf, 4); + val = LOWPAN_IPHC_TF_00; + } + } + + return val; } -int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, - unsigned short type, const void *_daddr, - const void *_saddr, unsigned int len) +static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr, + const struct in6_addr *ipaddr) { - u8 tmp, iphc0, iphc1, *hc_ptr; + u8 val; + + if (lowpan_is_mcast_addr_compressable8(ipaddr)) { + pr_debug("compressed to 1 octet\n"); + /* use last byte */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1); + val = LOWPAN_IPHC_DAM_11; + } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) { + pr_debug("compressed to 4 octets\n"); + /* second byte + the last three */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1); + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3); + val = LOWPAN_IPHC_DAM_10; + } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) { + pr_debug("compressed to 6 octets\n"); + /* second byte + the last five */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1); + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5); + val = LOWPAN_IPHC_DAM_01; + } else { + pr_debug("using full address\n"); + lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16); + val = LOWPAN_IPHC_DAM_00; + } + + return val; +} + +int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev, + const void *daddr, const void *saddr) +{ + u8 iphc0, iphc1, *hc_ptr; struct ipv6hdr *hdr; - u8 head[100] = {}; + u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {}; int ret, addr_type; - if (type != ETH_P_IPV6) + if (skb->protocol != htons(ETH_P_IPV6)) return -EINVAL; hdr = ipv6_hdr(skb); @@ -446,63 +771,26 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, /* 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_inline(__func__, "saddr", saddr, EUI64_ADDR_LEN); + raw_dump_inline(__func__, "daddr", daddr, EUI64_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 - */ - - /* hc 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 */ - *hc_ptr = tmp; - hc_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; - *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F); - memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2); - hc_ptr += 3; - } else { - /* compress nothing */ - memcpy(hc_ptr, hdr, 4); - /* replace the top byte with new ECN | DSCP format */ - *hc_ptr = tmp; - hc_ptr += 4; - } - } + /* Traffic Class, Flow Label compression */ + iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr); /* NOTE: payload length is always compressed */ /* Check if we provide the nhc format for nexthdr and compression * functionality. If not nexthdr is handled inline and not compressed. */ - ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr, &iphc0); - if (ret < 0) - return ret; + ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr); + if (ret == -ENOENT) + lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr, + sizeof(hdr->nexthdr)); + else + iphc0 |= LOWPAN_IPHC_NH; /* Hop limit * if 1: compress, encoding is 01 @@ -512,13 +800,13 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, */ switch (hdr->hop_limit) { case 1: - iphc0 |= LOWPAN_IPHC_TTL_1; + iphc0 |= LOWPAN_IPHC_HLIM_01; break; case 64: - iphc0 |= LOWPAN_IPHC_TTL_64; + iphc0 |= LOWPAN_IPHC_HLIM_10; break; case 255: - iphc0 |= LOWPAN_IPHC_TTL_255; + iphc0 |= LOWPAN_IPHC_HLIM_11; break; default: lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit, @@ -532,9 +820,8 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, iphc1 |= LOWPAN_IPHC_SAC; } else { if (addr_type & IPV6_ADDR_LINKLOCAL) { - iphc1 |= lowpan_compress_addr_64(&hc_ptr, - LOWPAN_IPHC_SAM_BIT, - &hdr->saddr, _saddr); + iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->saddr, + saddr, true); pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n", &hdr->saddr, iphc1); } else { @@ -548,38 +835,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, if (addr_type & IPV6_ADDR_MULTICAST) { 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 */ - lowpan_push_hc_data(&hc_ptr, - &hdr->daddr.s6_addr[15], 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 */ - lowpan_push_hc_data(&hc_ptr, - &hdr->daddr.s6_addr[1], 1); - lowpan_push_hc_data(&hc_ptr, - &hdr->daddr.s6_addr[13], 3); - } 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 */ - lowpan_push_hc_data(&hc_ptr, - &hdr->daddr.s6_addr[1], 1); - lowpan_push_hc_data(&hc_ptr, - &hdr->daddr.s6_addr[11], 5); - } else { - pr_debug("using full address\n"); - iphc1 |= LOWPAN_IPHC_DAM_00; - lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); - } + iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr, &hdr->daddr); } else { if (addr_type & IPV6_ADDR_LINKLOCAL) { /* TODO: context lookup */ - iphc1 |= lowpan_compress_addr_64(&hc_ptr, - LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr); + iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->daddr, + daddr, false); pr_debug("dest address unicast link-local %pI6c " "iphc1 0x%02x\n", &hdr->daddr, iphc1); } else { @@ -589,7 +850,7 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, } /* next header compression */ - if (iphc0 & LOWPAN_IPHC_NH_C) { + if (iphc0 & LOWPAN_IPHC_NH) { ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr); if (ret < 0) return ret; @@ -610,19 +871,3 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, return 0; } EXPORT_SYMBOL_GPL(lowpan_header_compress); - -static int __init lowpan_module_init(void) -{ - request_module_nowait("nhc_dest"); - request_module_nowait("nhc_fragment"); - request_module_nowait("nhc_hop"); - request_module_nowait("nhc_ipv6"); - request_module_nowait("nhc_mobility"); - request_module_nowait("nhc_routing"); - request_module_nowait("nhc_udp"); - - return 0; -} -module_init(lowpan_module_init); - -MODULE_LICENSE("GPL"); |