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 /** 12 * LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct 13 * 14 * @__nhc: variable name of the lowpan_nhc struct. 15 * @_name: const char * of common header compression name. 16 * @_nexthdr: ipv6 nexthdr field for the header compression. 17 * @_nexthdrlen: ipv6 nexthdr len for the reserved space. 18 * @_idsetup: callback to setup id and mask values. 19 * @_idlen: len for the next header id and mask, should be always the same. 20 * @_uncompress: callback for uncompression call. 21 * @_compress: callback for compression call. 22 */ 23 #define LOWPAN_NHC(__nhc, _name, _nexthdr, \ 24 _hdrlen, _idsetup, _idlen, \ 25 _uncompress, _compress) \ 26 static u8 __nhc##_val[_idlen]; \ 27 static u8 __nhc##_mask[_idlen]; \ 28 static struct lowpan_nhc __nhc = { \ 29 .name = _name, \ 30 .nexthdr = _nexthdr, \ 31 .nexthdrlen = _hdrlen, \ 32 .id = __nhc##_val, \ 33 .idmask = __nhc##_mask, \ 34 .idlen = _idlen, \ 35 .idsetup = _idsetup, \ 36 .uncompress = _uncompress, \ 37 .compress = _compress, \ 38 } 39 40 #define module_lowpan_nhc(__nhc) \ 41 static int __init __nhc##_init(void) \ 42 { \ 43 return lowpan_nhc_add(&(__nhc)); \ 44 } \ 45 module_init(__nhc##_init); \ 46 static void __exit __nhc##_exit(void) \ 47 { \ 48 lowpan_nhc_del(&(__nhc)); \ 49 } \ 50 module_exit(__nhc##_exit); 51 52 /** 53 * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation 54 * 55 * @node: holder for the rbtree. 56 * @name: name of the specific next header compression 57 * @nexthdr: next header value of the protocol which should be compressed. 58 * @nexthdrlen: ipv6 nexthdr len for the reserved space. 59 * @id: array for nhc id. Note this need to be in network byteorder. 60 * @mask: array for nhc id mask. Note this need to be in network byteorder. 61 * @len: the length of the next header id and mask. 62 * @setup: callback to setup fill the next header id value and mask. 63 * @compress: callback to do the header compression. 64 * @uncompress: callback to do the header uncompression. 65 */ 66 struct lowpan_nhc { 67 struct rb_node node; 68 const char *name; 69 const u8 nexthdr; 70 const size_t nexthdrlen; 71 u8 *id; 72 u8 *idmask; 73 const size_t idlen; 74 75 void (*idsetup)(struct lowpan_nhc *nhc); 76 int (*uncompress)(struct sk_buff *skb, size_t needed); 77 int (*compress)(struct sk_buff *skb, u8 **hc_ptr); 78 }; 79 80 /** 81 * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr. 82 * 83 * @nexthdr: ipv6 nexthdr value. 84 */ 85 struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr); 86 87 /** 88 * lowpan_nhc_check_compression - checks if we support compression format. If 89 * we support the nhc by nexthdr field, the function will return 0. If we 90 * don't support the nhc by nexthdr this function will return -ENOENT. 91 * 92 * @skb: skb of 6LoWPAN header to read nhc and replace header. 93 * @hdr: ipv6hdr to check the nexthdr value 94 * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of 95 * replaced header. 96 */ 97 int lowpan_nhc_check_compression(struct sk_buff *skb, 98 const struct ipv6hdr *hdr, u8 **hc_ptr); 99 100 /** 101 * lowpan_nhc_do_compression - calling compress callback for nhc 102 * 103 * @skb: skb of 6LoWPAN header to read nhc and replace header. 104 * @hdr: ipv6hdr to set the nexthdr value 105 * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of 106 * replaced header. 107 */ 108 int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, 109 u8 **hc_ptr); 110 111 /** 112 * lowpan_nhc_do_uncompression - calling uncompress callback for nhc 113 * 114 * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions. 115 * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value. 116 * @dev: netdevice for print logging information. 117 * @hdr: ipv6hdr for setting nexthdr value. 118 */ 119 int lowpan_nhc_do_uncompression(struct sk_buff *skb, 120 const struct net_device *dev, 121 struct ipv6hdr *hdr); 122 123 /** 124 * lowpan_nhc_add - register a next header compression to framework 125 * 126 * @nhc: nhc which should be add. 127 */ 128 int lowpan_nhc_add(struct lowpan_nhc *nhc); 129 130 /** 131 * lowpan_nhc_del - delete a next header compression from framework 132 * 133 * @nhc: nhc which should be delete. 134 */ 135 void lowpan_nhc_del(struct lowpan_nhc *nhc); 136 137 /** 138 * lowpan_nhc_init - adding all default nhcs 139 */ 140 void lowpan_nhc_init(void); 141 142 #endif /* __6LOWPAN_NHC_H */ 143