diff --git a/net/6lowpan/Kconfig b/net/6lowpan/Kconfig index e4a02ef55102..e45c96321845 100644 --- a/net/6lowpan/Kconfig +++ b/net/6lowpan/Kconfig @@ -1,6 +1,23 @@ -config 6LOWPAN +menuconfig 6LOWPAN tristate "6LoWPAN Support" depends on IPV6 ---help--- This enables IPv6 over Low power Wireless Personal Area Network - "6LoWPAN" which is supported by IEEE 802.15.4 or Bluetooth stacks. + +menuconfig 6LOWPAN_NHC + tristate "Next Header Compression Support" + depends on 6LOWPAN + default y + ---help--- + Support for next header compression. + +if 6LOWPAN_NHC + +config 6LOWPAN_NHC_UDP + tristate "UDP Header Support" + default y + ---help--- + 6LoWPAN IPv6 UDP Header compression according to RFC6282. + +endif diff --git a/net/6lowpan/Makefile b/net/6lowpan/Makefile index 4215602a25bd..abf551d31881 100644 --- a/net/6lowpan/Makefile +++ b/net/6lowpan/Makefile @@ -1,3 +1,6 @@ -obj-$(CONFIG_6LOWPAN) := 6lowpan.o +obj-$(CONFIG_6LOWPAN) += 6lowpan.o 6lowpan-y := iphc.o nhc.o + +#rfc6282 nhcs +obj-$(CONFIG_6LOWPAN_NHC_UDP) += nhc_udp.o diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c index 32ffec6ef164..390bdd9677df 100644 --- a/net/6lowpan/iphc.c +++ b/net/6lowpan/iphc.c @@ -54,6 +54,8 @@ #include #include +#include "nhc.h" + /* Uncompress address function for source and * destination address(non-multicast). * @@ -224,77 +226,6 @@ static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, return 0; } -static int uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh) -{ - bool fail; - u8 tmp = 0, val = 0; - - fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp)); - - 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: - fail |= lowpan_fetch_skb(skb, &uh->source, - sizeof(uh->source)); - fail |= lowpan_fetch_skb(skb, &uh->dest, - sizeof(uh->dest)); - break; - case LOWPAN_NHC_UDP_CS_P_01: - fail |= lowpan_fetch_skb(skb, &uh->source, - sizeof(uh->source)); - fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); - uh->dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); - break; - case LOWPAN_NHC_UDP_CS_P_10: - fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); - uh->source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); - fail |= lowpan_fetch_skb(skb, &uh->dest, - sizeof(uh->dest)); - break; - case LOWPAN_NHC_UDP_CS_P_11: - fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); - uh->source = htons(LOWPAN_NHC_UDP_4BIT_PORT + - (val >> 4)); - uh->dest = htons(LOWPAN_NHC_UDP_4BIT_PORT + - (val & 0x0f)); - break; - default: - pr_debug("ERROR: unknown UDP format\n"); - goto err; - } - - pr_debug("uncompressed UDP ports: src = %d, dst = %d\n", - ntohs(uh->source), ntohs(uh->dest)); - - /* checksum */ - if (tmp & LOWPAN_NHC_UDP_CS_C) { - pr_debug_ratelimited("checksum elided currently not supported\n"); - goto err; - } else { - fail |= lowpan_fetch_skb(skb, &uh->check, - sizeof(uh->check)); - } - - /* UDP length 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", ntohs(uh->len)); - } else { - pr_debug("ERROR: unsupported NH format\n"); - goto err; - } - - if (fail) - goto err; - - return 0; -err: - return -EINVAL; -} - /* TTL uncompression values */ static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 }; @@ -425,29 +356,11 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev, return -EINVAL; } - /* UDP data uncompression */ + /* Next header data uncompression */ if (iphc0 & LOWPAN_IPHC_NH_C) { - struct udphdr uh; - const int needed = sizeof(struct udphdr) + sizeof(hdr); - - if (uncompress_udp_header(skb, &uh)) - return -EINVAL; - - /* replace the compressed UDP head by the uncompressed UDP - * header - */ - err = skb_cow(skb, needed); - if (unlikely(err)) + err = lowpan_nhc_do_uncompression(skb, dev, &hdr); + if (err < 0) return err; - - 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; } else { err = skb_cow(skb, sizeof(hdr)); if (unlikely(err)) @@ -500,71 +413,6 @@ static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift, return rol8(val, shift); } -static void compress_udp_header(u8 **hc_ptr, struct sk_buff *skb) -{ - struct udphdr *uh; - u8 tmp; - - /* In the case of RAW sockets the transport header is not set by - * the ip6 stack so we must set it ourselves - */ - if (skb->transport_header == skb->network_header) - skb_set_transport_header(skb, sizeof(struct ipv6hdr)); - - uh = udp_hdr(skb); - - if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) == - LOWPAN_NHC_UDP_4BIT_PORT) && - ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) == - LOWPAN_NHC_UDP_4BIT_PORT)) { - pr_debug("UDP header: both ports compression to 4 bits\n"); - /* compression value */ - tmp = LOWPAN_NHC_UDP_CS_P_11; - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - /* source and destination port */ - tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT + - ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4); - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - } else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) == - LOWPAN_NHC_UDP_8BIT_PORT) { - pr_debug("UDP header: remove 8 bits of dest\n"); - /* compression value */ - tmp = LOWPAN_NHC_UDP_CS_P_01; - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - /* source port */ - lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source)); - /* destination port */ - tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT; - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - } else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) == - LOWPAN_NHC_UDP_8BIT_PORT) { - pr_debug("UDP header: remove 8 bits of source\n"); - /* compression value */ - tmp = LOWPAN_NHC_UDP_CS_P_10; - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - /* source port */ - tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT; - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - /* destination port */ - lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest)); - } else { - pr_debug("UDP header: can't compress\n"); - /* compression value */ - tmp = LOWPAN_NHC_UDP_CS_P_00; - lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); - /* source port */ - lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source)); - /* destination port */ - lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest)); - } - - /* checksum is always inline */ - lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check)); - - /* 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) @@ -572,7 +420,7 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, u8 tmp, iphc0, iphc1, *hc_ptr; struct ipv6hdr *hdr; u8 head[100] = {}; - int addr_type; + int ret, addr_type; if (type != ETH_P_IPV6) return -EINVAL; @@ -649,13 +497,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, /* 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) - lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr, - sizeof(hdr->nexthdr)); + /* 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; /* Hop limit * if 1: compress, encoding is 01 @@ -741,9 +588,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, } } - /* UDP header compression */ - if (hdr->nexthdr == UIP_PROTO_UDP) - compress_udp_header(&hc_ptr, skb); + /* next header compression */ + if (iphc0 & LOWPAN_IPHC_NH_C) { + ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr); + if (ret < 0) + return ret; + } head[0] = iphc0; head[1] = iphc1; @@ -761,4 +611,12 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, } EXPORT_SYMBOL_GPL(lowpan_header_compress); +static int __init lowpan_module_init(void) +{ + request_module_nowait("nhc_udp"); + + return 0; +} +module_init(lowpan_module_init); + MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_udp.c b/net/6lowpan/nhc_udp.c new file mode 100644 index 000000000000..c6bcaeb428ae --- /dev/null +++ b/net/6lowpan/nhc_udp.c @@ -0,0 +1,157 @@ +/* + * 6LoWPAN IPv6 UDP compression according to RFC6282 + * + * + * Authors: + * Alexander Aring + * + * Orignal written by: + * Alexander Smirnov + * Jon Smirl + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_UDP_IDLEN 1 + +static int udp_uncompress(struct sk_buff *skb, size_t needed) +{ + u8 tmp = 0, val = 0; + struct udphdr uh; + bool fail; + int err; + + fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp)); + + pr_debug("UDP header uncompression\n"); + switch (tmp & LOWPAN_NHC_UDP_CS_P_11) { + case LOWPAN_NHC_UDP_CS_P_00: + fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source)); + fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest)); + break; + case LOWPAN_NHC_UDP_CS_P_01: + fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source)); + fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); + uh.dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); + break; + case LOWPAN_NHC_UDP_CS_P_10: + fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); + uh.source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); + fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest)); + break; + case LOWPAN_NHC_UDP_CS_P_11: + fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); + uh.source = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val >> 4)); + uh.dest = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val & 0x0f)); + break; + default: + BUG(); + } + + pr_debug("uncompressed UDP ports: src = %d, dst = %d\n", + ntohs(uh.source), ntohs(uh.dest)); + + /* checksum */ + if (tmp & LOWPAN_NHC_UDP_CS_C) { + pr_debug_ratelimited("checksum elided currently not supported\n"); + fail = true; + } else { + fail |= lowpan_fetch_skb(skb, &uh.check, sizeof(uh.check)); + } + + if (fail) + return -EINVAL; + + /* UDP length 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", ntohs(uh.len)); + + /* replace the compressed UDP head by the uncompressed UDP + * header + */ + err = skb_cow(skb, needed); + if (unlikely(err)) + return err; + + skb_push(skb, sizeof(struct udphdr)); + skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr)); + + return 0; +} + +static int udp_compress(struct sk_buff *skb, u8 **hc_ptr) +{ + const struct udphdr *uh = udp_hdr(skb); + u8 tmp; + + if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) == + LOWPAN_NHC_UDP_4BIT_PORT) && + ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) == + LOWPAN_NHC_UDP_4BIT_PORT)) { + pr_debug("UDP header: both ports compression to 4 bits\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_11; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source and destination port */ + tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT + + ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4); + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + } else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) == + LOWPAN_NHC_UDP_8BIT_PORT) { + pr_debug("UDP header: remove 8 bits of dest\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_01; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source port */ + lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source)); + /* destination port */ + tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + } else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) == + LOWPAN_NHC_UDP_8BIT_PORT) { + pr_debug("UDP header: remove 8 bits of source\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_10; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source port */ + tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* destination port */ + lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest)); + } else { + pr_debug("UDP header: can't compress\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_00; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source port */ + lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source)); + /* destination port */ + lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest)); + } + + /* checksum is always inline */ + lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check)); + + return 0; +} + +static void udp_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_UDP_ID; + nhc->idmask[0] = LOWPAN_NHC_UDP_MASK; +} + +LOWPAN_NHC(nhc_udp, "RFC6282 UDP", NEXTHDR_UDP, sizeof(struct udphdr), + udp_nhid_setup, LOWPAN_NHC_UDP_IDLEN, udp_uncompress, udp_compress); + +module_lowpan_nhc(nhc_udp); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 UDP compression"); +MODULE_LICENSE("GPL");