1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_GUE_H 2 #ifndef __NET_GUE_H
3 #define __NET_GUE_H 3 #define __NET_GUE_H
4 4
5 /* Definitions for the GUE header, standard an 5 /* Definitions for the GUE header, standard and private flags, lengths
6 * of optional fields are below. 6 * of optional fields are below.
7 * 7 *
8 * Diagram of GUE header: 8 * Diagram of GUE header:
9 * 9 *
10 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
11 * |Ver|C| Hlen | Proto/ctype | St 11 * |Ver|C| Hlen | Proto/ctype | Standard flags |P|
12 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 12 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
13 * | 13 * | |
14 * ~ Fields (optional) 14 * ~ Fields (optional) ~
15 * | 15 * | |
16 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 16 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
17 * | Private flags (optional, P bit 17 * | Private flags (optional, P bit is set) |
18 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 18 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
19 * | 19 * | |
20 * ~ Private fields (optiona 20 * ~ Private fields (optional) ~
21 * | 21 * | |
22 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 22 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
23 * 23 *
24 * C bit indicates control message when set, d 24 * C bit indicates control message when set, data message when unset.
25 * For a control message, proto/ctype is inter 25 * For a control message, proto/ctype is interpreted as a type of
26 * control message. For data messages, proto/c 26 * control message. For data messages, proto/ctype is the IP protocol
27 * of the next header. 27 * of the next header.
28 * 28 *
29 * P bit indicates private flags field is pres 29 * P bit indicates private flags field is present. The private flags
30 * may refer to options placed after this fiel 30 * may refer to options placed after this field.
31 */ 31 */
32 32
33 #include <asm/byteorder.h> 33 #include <asm/byteorder.h>
34 #include <linux/types.h> 34 #include <linux/types.h>
35 35
36 struct guehdr { 36 struct guehdr {
37 union { 37 union {
38 struct { 38 struct {
39 #if defined(__LITTLE_ENDIAN_BITFIELD) 39 #if defined(__LITTLE_ENDIAN_BITFIELD)
40 __u8 hlen:5, 40 __u8 hlen:5,
41 control:1, 41 control:1,
42 version:2; 42 version:2;
43 #elif defined (__BIG_ENDIAN_BITFIELD) 43 #elif defined (__BIG_ENDIAN_BITFIELD)
44 __u8 version:2, 44 __u8 version:2,
45 control:1, 45 control:1,
46 hlen:5; 46 hlen:5;
47 #else 47 #else
48 #error "Please fix <asm/byteorder.h>" 48 #error "Please fix <asm/byteorder.h>"
49 #endif 49 #endif
50 __u8 proto_ctype; 50 __u8 proto_ctype;
51 __be16 flags; 51 __be16 flags;
52 }; 52 };
53 __be32 word; 53 __be32 word;
54 }; 54 };
55 }; 55 };
56 56
57 /* Standard flags in GUE header */ 57 /* Standard flags in GUE header */
58 58
59 #define GUE_FLAG_PRIV htons(1<<0) /* Pri 59 #define GUE_FLAG_PRIV htons(1<<0) /* Private flags are in options */
60 #define GUE_LEN_PRIV 4 60 #define GUE_LEN_PRIV 4
61 61
62 #define GUE_FLAGS_ALL (GUE_FLAG_PRIV) 62 #define GUE_FLAGS_ALL (GUE_FLAG_PRIV)
63 63
64 /* Private flags in the private option extensi 64 /* Private flags in the private option extension */
65 65
66 #define GUE_PFLAG_REMCSUM htonl(1U << 31 66 #define GUE_PFLAG_REMCSUM htonl(1U << 31)
67 #define GUE_PLEN_REMCSUM 4 67 #define GUE_PLEN_REMCSUM 4
68 68
69 #define GUE_PFLAGS_ALL (GUE_PFLAG_REMCSUM) 69 #define GUE_PFLAGS_ALL (GUE_PFLAG_REMCSUM)
70 70
71 /* Functions to compute options length corresp 71 /* Functions to compute options length corresponding to flags.
72 * If we ever have a lot of flags this can be 72 * If we ever have a lot of flags this can be potentially be
73 * converted to a more optimized algorithm (ta 73 * converted to a more optimized algorithm (table lookup
74 * for instance). 74 * for instance).
75 */ 75 */
76 static inline size_t guehdr_flags_len(__be16 f 76 static inline size_t guehdr_flags_len(__be16 flags)
77 { 77 {
78 return ((flags & GUE_FLAG_PRIV) ? GUE_ 78 return ((flags & GUE_FLAG_PRIV) ? GUE_LEN_PRIV : 0);
79 } 79 }
80 80
81 static inline size_t guehdr_priv_flags_len(__b 81 static inline size_t guehdr_priv_flags_len(__be32 flags)
82 { 82 {
83 return 0; 83 return 0;
84 } 84 }
85 85
86 /* Validate standard and private flags. Return 86 /* Validate standard and private flags. Returns non-zero (meaning invalid)
87 * if there is an unknown standard or private 87 * if there is an unknown standard or private flags, or the options length for
88 * the flags exceeds the options length specif 88 * the flags exceeds the options length specific in hlen of the GUE header.
89 */ 89 */
90 static inline int validate_gue_flags(struct gu 90 static inline int validate_gue_flags(struct guehdr *guehdr, size_t optlen)
91 { 91 {
92 __be16 flags = guehdr->flags; 92 __be16 flags = guehdr->flags;
93 size_t len; 93 size_t len;
94 94
95 if (flags & ~GUE_FLAGS_ALL) 95 if (flags & ~GUE_FLAGS_ALL)
96 return 1; 96 return 1;
97 97
98 len = guehdr_flags_len(flags); 98 len = guehdr_flags_len(flags);
99 if (len > optlen) 99 if (len > optlen)
100 return 1; 100 return 1;
101 101
102 if (flags & GUE_FLAG_PRIV) { 102 if (flags & GUE_FLAG_PRIV) {
103 /* Private flags are last four 103 /* Private flags are last four bytes accounted in
104 * guehdr_flags_len 104 * guehdr_flags_len
105 */ 105 */
106 __be32 pflags = *(__be32 *)((v 106 __be32 pflags = *(__be32 *)((void *)&guehdr[1] +
107 le 107 len - GUE_LEN_PRIV);
108 108
109 if (pflags & ~GUE_PFLAGS_ALL) 109 if (pflags & ~GUE_PFLAGS_ALL)
110 return 1; 110 return 1;
111 111
112 len += guehdr_priv_flags_len(p 112 len += guehdr_priv_flags_len(pflags);
113 if (len > optlen) 113 if (len > optlen)
114 return 1; 114 return 1;
115 } 115 }
116 116
117 return 0; 117 return 0;
118 } 118 }
119 119
120 #endif 120 #endif
121 121
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