1 #ifndef __6LOWPAN_NHC_H 2 #define __6LOWPAN_NHC_H 3 4 #include <linux/skbuff.h> 5 #include <linux/rbtree.h> 6 #include <linux/module.h> 7 8 #include <net/6lowpan.h> 9 #include <net/ipv6.h> 10 11 #define LOWPAN_NHC_MAX_ID_LEN 1 12 13 /** 14 * LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct 15 * 16 * @__nhc: variable name of the lowpan_nhc struct. 17 * @_name: const char * of common header compression name. 18 * @_nexthdr: ipv6 nexthdr field for the header compression. 19 * @_nexthdrlen: ipv6 nexthdr len for the reserved space. 20 * @_idsetup: callback to setup id and mask values. 21 * @_idlen: len for the next header id and mask, should be always the same. 22 * @_uncompress: callback for uncompression call. 23 * @_compress: callback for compression call. 24 */ 25 #define LOWPAN_NHC(__nhc, _name, _nexthdr, \ 26 _hdrlen, _idsetup, _idlen, \ 27 _uncompress, _compress) \ 28 static u8 __nhc##_val[_idlen]; \ 29 static u8 __nhc##_mask[_idlen]; \ 30 static struct lowpan_nhc __nhc = { \ 31 .name = _name, \ 32 .nexthdr = _nexthdr, \ 33 .nexthdrlen = _hdrlen, \ 34 .id = __nhc##_val, \ 35 .idmask = __nhc##_mask, \ 36 .idlen = _idlen, \ 37 .idsetup = _idsetup, \ 38 .uncompress = _uncompress, \ 39 .compress = _compress, \ 40 } 41 42 #define module_lowpan_nhc(__nhc) \ 43 static int __init __nhc##_init(void) \ 44 { \ 45 return lowpan_nhc_add(&(__nhc)); \ 46 } \ 47 module_init(__nhc##_init); \ 48 static void __exit __nhc##_exit(void) \ 49 { \ 50 lowpan_nhc_del(&(__nhc)); \ 51 } \ 52 module_exit(__nhc##_exit); 53 54 /** 55 * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation 56 * 57 * @node: holder for the rbtree. 58 * @name: name of the specific next header compression 59 * @nexthdr: next header value of the protocol which should be compressed. 60 * @nexthdrlen: ipv6 nexthdr len for the reserved space. 61 * @id: array for nhc id. Note this need to be in network byteorder. 62 * @mask: array for nhc id mask. Note this need to be in network byteorder. 63 * @len: the length of the next header id and mask. 64 * @setup: callback to setup fill the next header id value and mask. 65 * @compress: callback to do the header compression. 66 * @uncompress: callback to do the header uncompression. 67 */ 68 struct lowpan_nhc { 69 struct rb_node node; 70 const char *name; 71 const u8 nexthdr; 72 const size_t nexthdrlen; 73 u8 *id; 74 u8 *idmask; 75 const size_t idlen; 76 77 void (*idsetup)(struct lowpan_nhc *nhc); 78 int (*uncompress)(struct sk_buff *skb, size_t needed); 79 int (*compress)(struct sk_buff *skb, u8 **hc_ptr); 80 }; 81 82 /** 83 * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr. 84 * 85 * @nexthdr: ipv6 nexthdr value. 86 */ 87 struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr); 88 89 /** 90 * lowpan_nhc_check_compression - checks if we support compression format. If 91 * we support the nhc by nexthdr field, the 6LoWPAN iphc NHC bit will be 92 * set. If we don't support nexthdr will be added as inline data to the 93 * 6LoWPAN header. 94 * 95 * @skb: skb of 6LoWPAN header to read nhc and replace header. 96 * @hdr: ipv6hdr to check the nexthdr value 97 * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of 98 * replaced header. 99 * @iphc0: iphc0 pointer to set the 6LoWPAN NHC bit 100 */ 101 int lowpan_nhc_check_compression(struct sk_buff *skb, 102 const struct ipv6hdr *hdr, u8 **hc_ptr, 103 u8 *iphc0); 104 105 /** 106 * lowpan_nhc_do_compression - calling compress callback for nhc 107 * 108 * @skb: skb of 6LoWPAN header to read nhc and replace header. 109 * @hdr: ipv6hdr to set the nexthdr value 110 * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of 111 * replaced header. 112 */ 113 int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, 114 u8 **hc_ptr); 115 116 /** 117 * lowpan_nhc_do_uncompression - calling uncompress callback for nhc 118 * 119 * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions. 120 * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value. 121 * @dev: netdevice for print logging information. 122 * @hdr: ipv6hdr for setting nexthdr value. 123 */ 124 int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev, 125 struct ipv6hdr *hdr); 126 127 /** 128 * lowpan_nhc_add - register a next header compression to framework 129 * 130 * @nhc: nhc which should be add. 131 */ 132 int lowpan_nhc_add(struct lowpan_nhc *nhc); 133 134 /** 135 * lowpan_nhc_del - delete a next header compression from framework 136 * 137 * @nhc: nhc which should be delete. 138 */ 139 void lowpan_nhc_del(struct lowpan_nhc *nhc); 140 141 /** 142 * lowpan_nhc_init - adding all default nhcs 143 */ 144 void lowpan_nhc_init(void); 145 146 #endif /* __6LOWPAN_NHC_H */ 147