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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __6LOWPAN_NHC_H #define __6LOWPAN_NHC_H #include <linux/skbuff.h> #include <linux/rbtree.h> #include <linux/module.h> #include <net/6lowpan.h> #include <net/ipv6.h> /** * LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct * * @__nhc: variable name of the lowpan_nhc struct. * @_name: const char * of common header compression name. * @_nexthdr: ipv6 nexthdr field for the header compression. * @_nexthdrlen: ipv6 nexthdr len for the reserved space. * @_idsetup: callback to setup id and mask values. * @_idlen: len for the next header id and mask, should be always the same. * @_uncompress: callback for uncompression call. * @_compress: callback for compression call. */ #define LOWPAN_NHC(__nhc, _name, _nexthdr, \ _hdrlen, _idsetup, _idlen, \ _uncompress, _compress) \ static u8 __nhc##_val[_idlen]; \ static u8 __nhc##_mask[_idlen]; \ static struct lowpan_nhc __nhc = { \ .name = _name, \ .nexthdr = _nexthdr, \ .nexthdrlen = _hdrlen, \ .id = __nhc##_val, \ .idmask = __nhc##_mask, \ .idlen = _idlen, \ .idsetup = _idsetup, \ .uncompress = _uncompress, \ .compress = _compress, \ } #define module_lowpan_nhc(__nhc) \ static int __init __nhc##_init(void) \ { \ return lowpan_nhc_add(&(__nhc)); \ } \ module_init(__nhc##_init); \ static void __exit __nhc##_exit(void) \ { \ lowpan_nhc_del(&(__nhc)); \ } \ module_exit(__nhc##_exit); /** * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation * * @node: holder for the rbtree. * @name: name of the specific next header compression * @nexthdr: next header value of the protocol which should be compressed. * @nexthdrlen: ipv6 nexthdr len for the reserved space. * @id: array for nhc id. Note this need to be in network byteorder. * @mask: array for nhc id mask. Note this need to be in network byteorder. * @len: the length of the next header id and mask. * @setup: callback to setup fill the next header id value and mask. * @compress: callback to do the header compression. * @uncompress: callback to do the header uncompression. */ struct lowpan_nhc { struct rb_node node; const char *name; const u8 nexthdr; const size_t nexthdrlen; u8 *id; u8 *idmask; const size_t idlen; void (*idsetup)(struct lowpan_nhc *nhc); int (*uncompress)(struct sk_buff *skb, size_t needed); int (*compress)(struct sk_buff *skb, u8 **hc_ptr); }; /** * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr. * * @nexthdr: ipv6 nexthdr value. */ struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr); /** * lowpan_nhc_check_compression - checks if we support compression format. If * we support the nhc by nexthdr field, the function will return 0. If we * don't support the nhc by nexthdr this function will return -ENOENT. * * @skb: skb of 6LoWPAN header to read nhc and replace header. * @hdr: ipv6hdr to check the nexthdr value * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of * replaced header. */ int lowpan_nhc_check_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, u8 **hc_ptr); /** * lowpan_nhc_do_compression - calling compress callback for nhc * * @skb: skb of 6LoWPAN header to read nhc and replace header. * @hdr: ipv6hdr to set the nexthdr value * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of * replaced header. */ int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, u8 **hc_ptr); /** * lowpan_nhc_do_uncompression - calling uncompress callback for nhc * * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions. * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value. * @dev: netdevice for print logging information. * @hdr: ipv6hdr for setting nexthdr value. */ int lowpan_nhc_do_uncompression(struct sk_buff *skb, const struct net_device *dev, struct ipv6hdr *hdr); /** * lowpan_nhc_add - register a next header compression to framework * * @nhc: nhc which should be add. */ int lowpan_nhc_add(struct lowpan_nhc *nhc); /** * lowpan_nhc_del - delete a next header compression from framework * * @nhc: nhc which should be delete. */ void lowpan_nhc_del(struct lowpan_nhc *nhc); /** * lowpan_nhc_init - adding all default nhcs */ void lowpan_nhc_init(void); #endif /* __6LOWPAN_NHC_H */ |