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772db4bb | 1 | /** @file\r |
3e8c18da | 2 | IP4 option support functions.\r |
d1102dba LG |
3 | \r |
4 | Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>\r | |
9d510e61 | 5 | SPDX-License-Identifier: BSD-2-Clause-Patent\r |
772db4bb | 6 | \r |
772db4bb | 7 | **/\r |
8 | \r | |
9 | #include "Ip4Impl.h"\r | |
10 | \r | |
772db4bb | 11 | /**\r |
12 | Validate the IP4 option format for both the packets we received\r | |
7538d536 | 13 | and will transmit.\r |
772db4bb | 14 | \r |
3e8c18da | 15 | @param[in] Option The first byte of the option\r |
16 | @param[in] OptionLen The length of the whole option\r | |
17 | @param[in] Rcvd The option is from the packet we received if TRUE,\r | |
772db4bb | 18 | otherwise the option we wants to transmit.\r |
19 | \r | |
96e1079f | 20 | @retval TRUE The option is properly formatted\r |
8d774c74 | 21 | @retval FALSE The option is malformatted\r |
772db4bb | 22 | \r |
23 | **/\r | |
24 | BOOLEAN\r | |
25 | Ip4OptionIsValid (\r | |
d1050b9d MK |
26 | IN UINT8 *Option,\r |
27 | IN UINT32 OptionLen,\r | |
28 | IN BOOLEAN Rcvd\r | |
772db4bb | 29 | )\r |
30 | {\r | |
d1050b9d MK |
31 | UINT32 Cur;\r |
32 | UINT32 Len;\r | |
33 | UINT32 Point;\r | |
772db4bb | 34 | \r |
d1050b9d | 35 | Cur = 0;\r |
772db4bb | 36 | \r |
37 | while (Cur < OptionLen) {\r | |
38 | switch (Option[Cur]) {\r | |
d1050b9d MK |
39 | case IP4_OPTION_NOP:\r |
40 | Cur++;\r | |
41 | break;\r | |
42 | \r | |
43 | case IP4_OPTION_EOP:\r | |
44 | Cur = OptionLen;\r | |
45 | break;\r | |
46 | \r | |
47 | case IP4_OPTION_LSRR:\r | |
48 | case IP4_OPTION_SSRR:\r | |
49 | case IP4_OPTION_RR:\r | |
50 | Len = Option[Cur + 1];\r | |
51 | Point = Option[Cur + 2];\r | |
52 | \r | |
53 | //\r | |
54 | // SRR/RR options are formatted as |Type|Len|Point|Ip1|Ip2|...\r | |
55 | //\r | |
56 | if ((OptionLen - Cur < Len) || (Len < 3) || ((Len - 3) % 4 != 0)) {\r | |
57 | return FALSE;\r | |
58 | }\r | |
59 | \r | |
60 | if ((Point > Len + 1) || (Point % 4 != 0)) {\r | |
61 | return FALSE;\r | |
62 | }\r | |
63 | \r | |
64 | //\r | |
65 | // The Point must point pass the last entry if the packet is received\r | |
66 | // by us. It must point to 4 if the packet is to be sent by us for\r | |
67 | // source route option.\r | |
68 | //\r | |
69 | if ((Option[Cur] != IP4_OPTION_RR) &&\r | |
70 | ((Rcvd && (Point != Len + 1)) || (!Rcvd && (Point != 4))))\r | |
71 | {\r | |
72 | return FALSE;\r | |
73 | }\r | |
74 | \r | |
75 | Cur += Len;\r | |
76 | break;\r | |
77 | \r | |
78 | default:\r | |
79 | Len = Option[Cur + 1];\r | |
80 | \r | |
81 | if ((OptionLen - Cur < Len) || (Len < 2)) {\r | |
82 | return FALSE;\r | |
83 | }\r | |
84 | \r | |
85 | Cur = Cur + Len;\r | |
86 | break;\r | |
772db4bb | 87 | }\r |
772db4bb | 88 | }\r |
89 | \r | |
90 | return TRUE;\r | |
91 | }\r | |
92 | \r | |
772db4bb | 93 | /**\r |
94 | Copy the option from the original option to buffer. It\r | |
95 | handles the details such as:\r | |
96 | 1. whether copy the single IP4 option to the first/non-first\r | |
96e1079f | 97 | fragments.\r |
98 | 2. Pad the options copied over to aligned to 4 bytes.\r | |
772db4bb | 99 | \r |
3e8c18da | 100 | @param[in] Option The original option to copy from\r |
101 | @param[in] OptionLen The length of the original option\r | |
102 | @param[in] FirstFragment Whether it is the first fragment\r | |
d1102dba | 103 | @param[in, out] Buf The buffer to copy options to. NULL\r |
3e8c18da | 104 | @param[in, out] BufLen The length of the buffer\r |
772db4bb | 105 | \r |
106 | @retval EFI_SUCCESS The options are copied over\r | |
96e1079f | 107 | @retval EFI_BUFFER_TOO_SMALL Buf is NULL or BufLen provided is too small.\r |
772db4bb | 108 | \r |
109 | **/\r | |
110 | EFI_STATUS\r | |
111 | Ip4CopyOption (\r | |
d1050b9d MK |
112 | IN UINT8 *Option,\r |
113 | IN UINT32 OptionLen,\r | |
114 | IN BOOLEAN FirstFragment,\r | |
115 | IN OUT UINT8 *Buf OPTIONAL,\r | |
116 | IN OUT UINT32 *BufLen\r | |
772db4bb | 117 | )\r |
118 | {\r | |
d1050b9d MK |
119 | UINT8 OptBuf[40];\r |
120 | UINT32 Cur;\r | |
121 | UINT32 Next;\r | |
122 | UINT8 Type;\r | |
123 | UINT32 Len;\r | |
772db4bb | 124 | \r |
125 | ASSERT ((BufLen != NULL) && (OptionLen <= 40));\r | |
126 | \r | |
d1050b9d MK |
127 | Cur = 0;\r |
128 | Next = 0;\r | |
772db4bb | 129 | \r |
130 | while (Cur < OptionLen) {\r | |
d1050b9d MK |
131 | Type = Option[Cur];\r |
132 | Len = Option[Cur + 1];\r | |
772db4bb | 133 | \r |
134 | if (Type == IP4_OPTION_NOP) {\r | |
135 | //\r | |
136 | // Keep the padding, in case that the sender wants to align\r | |
137 | // the option, say, to 4 bytes\r | |
138 | //\r | |
139 | OptBuf[Next] = IP4_OPTION_NOP;\r | |
140 | Next++;\r | |
141 | Cur++;\r | |
772db4bb | 142 | } else if (Type == IP4_OPTION_EOP) {\r |
143 | //\r | |
144 | // Don't append the EOP to avoid including only a EOP option\r | |
145 | //\r | |
146 | break;\r | |
772db4bb | 147 | } else {\r |
148 | //\r | |
149 | // don't copy options that is only valid for the first fragment\r | |
150 | //\r | |
d1050b9d | 151 | if (FirstFragment || ((Type & IP4_OPTION_COPY_MASK) != 0)) {\r |
e48e37fc | 152 | CopyMem (OptBuf + Next, Option + Cur, Len);\r |
772db4bb | 153 | Next += Len;\r |
154 | }\r | |
155 | \r | |
156 | Cur += Len;\r | |
157 | }\r | |
158 | }\r | |
159 | \r | |
160 | //\r | |
161 | // Don't append an EOP only option.\r | |
162 | //\r | |
163 | if (Next == 0) {\r | |
164 | *BufLen = 0;\r | |
165 | return EFI_SUCCESS;\r | |
166 | }\r | |
167 | \r | |
168 | //\r | |
169 | // Append an EOP if the end of option doesn't coincide with the\r | |
170 | // end of the IP header, that is, isn't aligned to 4 bytes..\r | |
171 | //\r | |
172 | if ((Next % 4) != 0) {\r | |
173 | OptBuf[Next] = IP4_OPTION_EOP;\r | |
174 | Next++;\r | |
175 | }\r | |
176 | \r | |
177 | //\r | |
178 | // Head length is in the unit of 4 bytes. Now, Len is the\r | |
6c585b52 | 179 | // actual option length to appear in the IP header.\r |
772db4bb | 180 | //\r |
181 | Len = ((Next + 3) &~0x03);\r | |
182 | \r | |
183 | //\r | |
184 | // If the buffer is too small, set the BufLen then return\r | |
185 | //\r | |
186 | if ((Buf == NULL) || (*BufLen < Len)) {\r | |
187 | *BufLen = Len;\r | |
188 | return EFI_BUFFER_TOO_SMALL;\r | |
189 | }\r | |
190 | \r | |
191 | //\r | |
192 | // Copy the option to the Buf, zero the buffer first to pad\r | |
193 | // the options with NOP to align to 4 bytes.\r | |
194 | //\r | |
e48e37fc | 195 | ZeroMem (Buf, Len);\r |
196 | CopyMem (Buf, OptBuf, Next);\r | |
772db4bb | 197 | *BufLen = Len;\r |
198 | return EFI_SUCCESS;\r | |
199 | }\r |