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74971473 JG |
1 | /* |
2 | * This file is part of the PCEPlib, a PCEP protocol library. | |
3 | * | |
4 | * Copyright (C) 2020 Volta Networks https://voltanet.io/ | |
5 | * | |
6 | * This library is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU Lesser General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * This library is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * Lesser General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU Lesser General Public License | |
17 | * along with this program. If not, see <https://www.gnu.org/licenses/>. | |
18 | * | |
19 | * Author : Brady Johnson <brady@voltanet.io> | |
20 | * | |
21 | */ | |
22 | ||
23 | ||
24 | /* | |
25 | * Encoding and decoding for PCEP messages. | |
26 | */ | |
27 | ||
28 | #include <stdlib.h> | |
29 | #include <string.h> | |
30 | #include <unistd.h> | |
31 | ||
32 | #include "pcep_msg_encoding.h" | |
33 | #include "pcep_msg_messages.h" | |
34 | #include "pcep_msg_objects.h" | |
35 | #include "pcep_msg_tools.h" | |
36 | #include "pcep_utils_logging.h" | |
37 | #include "pcep_utils_memory.h" | |
38 | ||
39 | #define ANY_OBJECT 0 | |
40 | #define NO_OBJECT -1 | |
41 | #define NUM_CHECKED_OBJECTS 4 | |
42 | /* It wont compile with this definition: | |
43 | static const int | |
44 | MANDATORY_MESSAGE_OBJECT_CLASSES[PCEP_TYPE_INITIATE+1][NUM_CHECKED_OBJECTS] | |
45 | */ | |
46 | static const enum pcep_object_classes MANDATORY_MESSAGE_OBJECT_CLASSES[13][4] = | |
47 | { | |
48 | {NO_OBJECT, NO_OBJECT, NO_OBJECT, | |
49 | NO_OBJECT}, /* unsupported message ID = 0 */ | |
50 | {PCEP_OBJ_CLASS_OPEN, NO_OBJECT, NO_OBJECT, | |
51 | NO_OBJECT}, /* PCEP_TYPE_OPEN = 1 */ | |
52 | {NO_OBJECT, NO_OBJECT, NO_OBJECT, | |
53 | NO_OBJECT}, /* PCEP_TYPE_KEEPALIVE = 2 */ | |
54 | {PCEP_OBJ_CLASS_RP, PCEP_OBJ_CLASS_ENDPOINTS, ANY_OBJECT, | |
55 | ANY_OBJECT}, /* PCEP_TYPE_PCREQ = 3 */ | |
56 | {PCEP_OBJ_CLASS_RP, ANY_OBJECT, ANY_OBJECT, | |
57 | ANY_OBJECT}, /* PCEP_TYPE_PCREP = 4 */ | |
58 | {PCEP_OBJ_CLASS_NOTF, ANY_OBJECT, ANY_OBJECT, | |
59 | ANY_OBJECT}, /* PCEP_TYPE_PCNOTF = 5 */ | |
60 | {PCEP_OBJ_CLASS_ERROR, ANY_OBJECT, ANY_OBJECT, | |
61 | ANY_OBJECT}, /* PCEP_TYPE_ERROR = 6 */ | |
62 | {PCEP_OBJ_CLASS_CLOSE, NO_OBJECT, NO_OBJECT, | |
63 | NO_OBJECT}, /* PCEP_TYPE_CLOSE = 7 */ | |
64 | {NO_OBJECT, NO_OBJECT, NO_OBJECT, | |
65 | NO_OBJECT}, /* unsupported message ID = 8 */ | |
66 | {NO_OBJECT, NO_OBJECT, NO_OBJECT, | |
67 | NO_OBJECT}, /* unsupported message ID = 9 */ | |
68 | {PCEP_OBJ_CLASS_SRP, PCEP_OBJ_CLASS_LSP, ANY_OBJECT, | |
69 | ANY_OBJECT}, /* PCEP_TYPE_REPORT = 10 */ | |
70 | {PCEP_OBJ_CLASS_SRP, PCEP_OBJ_CLASS_LSP, ANY_OBJECT, | |
71 | ANY_OBJECT}, /* PCEP_TYPE_UPDATE = 11 */ | |
72 | {PCEP_OBJ_CLASS_SRP, PCEP_OBJ_CLASS_LSP, ANY_OBJECT, | |
73 | ANY_OBJECT}, /* PCEP_TYPE_INITIATE = 12 */ | |
74 | }; | |
75 | ||
76 | /* PCEP Message Common Header, According to RFC 5440 | |
77 | * | |
78 | * 0 1 2 3 | |
79 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |
80 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
81 | * | Ver | Flags | Message-Type | Message-Length | | |
82 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
83 | * | |
84 | * Ver (Version - 3 bits): PCEP version number. Current version is version 1. | |
85 | * | |
86 | * Flags (5 bits): No flags are currently defined. Unassigned bits are | |
87 | * considered as reserved. They MUST be set to zero on transmission | |
88 | * and MUST be ignored on receipt. | |
89 | */ | |
90 | void pcep_encode_message(struct pcep_message *message, | |
91 | struct pcep_versioning *versioning) | |
92 | { | |
93 | if (message == NULL) { | |
94 | return; | |
95 | } | |
96 | ||
97 | if (message->msg_header == NULL) { | |
98 | return; | |
99 | } | |
100 | ||
101 | /* Internal buffer used for the entire message. Later, once the entire | |
102 | * length is known, memory will be allocated and this buffer will be | |
103 | * copied. */ | |
104 | uint8_t message_buffer[PCEP_MESSAGE_LENGTH] = {0}; | |
105 | ||
106 | /* Write the message header. The message header length will be | |
107 | * written when the entire length is known. */ | |
108 | uint32_t message_length = MESSAGE_HEADER_LENGTH; | |
109 | uint16_t net_order_length = 0; | |
110 | message_buffer[0] = (message->msg_header->pcep_version << 5) & 0xf0; | |
111 | message_buffer[1] = message->msg_header->type; | |
112 | ||
113 | if (message->obj_list == NULL) { | |
114 | net_order_length = htons(message_length); | |
115 | memcpy(message_buffer + 2, &net_order_length, | |
116 | sizeof(net_order_length)); | |
117 | message->encoded_message = | |
118 | pceplib_malloc(PCEPLIB_MESSAGES, message_length); | |
119 | memcpy(message->encoded_message, message_buffer, | |
120 | message_length); | |
121 | message->encoded_message_length = message_length; | |
122 | ||
123 | return; | |
124 | } | |
125 | ||
126 | /* Encode each of the objects */ | |
127 | double_linked_list_node *node = message->obj_list->head; | |
128 | for (; node != NULL; node = node->next_node) { | |
129 | message_length += | |
130 | pcep_encode_object(node->data, versioning, | |
131 | message_buffer + message_length); | |
132 | if (message_length > PCEP_MESSAGE_LENGTH) { | |
133 | message->encoded_message = NULL; | |
134 | message->encoded_message_length = 0; | |
135 | return; | |
136 | } | |
137 | } | |
138 | ||
139 | net_order_length = htons(message_length); | |
140 | memcpy(message_buffer + 2, &net_order_length, sizeof(net_order_length)); | |
141 | message->encoded_message = | |
142 | pceplib_malloc(PCEPLIB_MESSAGES, message_length); | |
143 | memcpy(message->encoded_message, message_buffer, message_length); | |
144 | message->encoded_message_length = message_length; | |
145 | } | |
146 | ||
147 | /* | |
148 | * Decoding functions | |
149 | */ | |
150 | ||
151 | /* Expecting Host byte ordered header */ | |
152 | static bool validate_msg_header(uint8_t msg_version, uint8_t msg_flags, | |
153 | uint8_t msg_type, uint16_t msg_length) | |
154 | { | |
155 | /* Invalid message if the length is less than the header | |
156 | * size or if its not a multiple of 4 */ | |
157 | if (msg_length < MESSAGE_HEADER_LENGTH || (msg_length % 4) != 0) { | |
158 | pcep_log(LOG_INFO, | |
159 | "%s: Invalid PCEP message header length [%d]", | |
160 | __func__, msg_length); | |
161 | return false; | |
162 | } | |
163 | ||
164 | if (msg_version != PCEP_MESSAGE_HEADER_VERSION) { | |
165 | pcep_log( | |
166 | LOG_INFO, | |
167 | "%s: Invalid PCEP message header version [0x%x] expected version [0x%x]", | |
168 | __func__, msg_version, PCEP_MESSAGE_HEADER_VERSION); | |
169 | return false; | |
170 | } | |
171 | ||
172 | if (msg_flags != 0) { | |
173 | pcep_log(LOG_INFO, | |
174 | "%s: Invalid PCEP message header flags [0x%x]", | |
175 | __func__, msg_flags); | |
176 | return false; | |
177 | } | |
178 | ||
179 | switch (msg_type) { | |
180 | /* Supported message types */ | |
181 | case PCEP_TYPE_OPEN: | |
182 | case PCEP_TYPE_KEEPALIVE: | |
183 | case PCEP_TYPE_PCREQ: | |
184 | case PCEP_TYPE_PCREP: | |
185 | case PCEP_TYPE_PCNOTF: | |
186 | case PCEP_TYPE_ERROR: | |
187 | case PCEP_TYPE_CLOSE: | |
188 | case PCEP_TYPE_REPORT: | |
189 | case PCEP_TYPE_UPDATE: | |
190 | case PCEP_TYPE_INITIATE: | |
191 | break; | |
192 | default: | |
193 | pcep_log(LOG_INFO, "%s: Invalid PCEP message header type [%d]", | |
194 | __func__, msg_type); | |
195 | return false; | |
196 | break; | |
197 | } | |
198 | ||
199 | return true; | |
200 | } | |
201 | ||
202 | /* Internal util function */ | |
203 | static uint16_t pcep_decode_msg_header(const uint8_t *msg_buf, | |
204 | uint8_t *msg_version, uint8_t *msg_flags, | |
205 | uint8_t *msg_type) | |
206 | { | |
207 | // Check RFC 5440 for version and flags position. | |
208 | // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |
209 | //+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
210 | //| Ver | Flags | Message-Type | Message-Length | | |
211 | //+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
212 | *msg_version = (msg_buf[0] >> 5) & 0x07; | |
213 | *msg_flags = (msg_buf[0] & 0x1f); | |
214 | *msg_type = msg_buf[1]; | |
215 | uint16_t host_order_length; | |
216 | memcpy(&host_order_length, msg_buf + 2, sizeof(host_order_length)); | |
217 | return ntohs(host_order_length); | |
218 | } | |
219 | ||
220 | /* Decode the message header and return the message length */ | |
221 | int32_t pcep_decode_validate_msg_header(const uint8_t *msg_buf) | |
222 | { | |
223 | uint8_t msg_version; | |
224 | uint8_t msg_flags; | |
225 | uint8_t msg_type; | |
226 | uint32_t msg_length; | |
227 | ||
228 | msg_length = pcep_decode_msg_header(msg_buf, &msg_version, &msg_flags, | |
229 | &msg_type); | |
230 | ||
231 | return ((validate_msg_header(msg_version, msg_flags, msg_type, | |
232 | msg_length) | |
233 | == false) | |
234 | ? -1 | |
235 | : (int32_t)msg_length); | |
236 | } | |
237 | ||
238 | bool validate_message_objects(struct pcep_message *msg) | |
239 | { | |
240 | if (msg->msg_header->type >= PCEP_TYPE_START_TLS) { | |
241 | pcep_log( | |
242 | LOG_INFO, | |
243 | "%s: Rejecting received message: Unknown message type [%d]", | |
244 | __func__, msg->msg_header->type); | |
245 | return false; | |
246 | } | |
247 | ||
248 | const enum pcep_object_classes *object_classes = | |
249 | MANDATORY_MESSAGE_OBJECT_CLASSES[msg->msg_header->type]; | |
250 | double_linked_list_node *node; | |
251 | int index; | |
252 | for (node = (msg->obj_list == NULL ? NULL : msg->obj_list->head), | |
253 | index = 0; | |
254 | index < NUM_CHECKED_OBJECTS; | |
255 | index++, (node = (node == NULL ? NULL : node->next_node))) { | |
256 | struct pcep_object_header *obj = | |
257 | ((node == NULL) | |
258 | ? NULL | |
259 | : (struct pcep_object_header *)node->data); | |
260 | ||
261 | if ((int)object_classes[index] == NO_OBJECT) { | |
262 | if (node != NULL) { | |
263 | pcep_log( | |
264 | LOG_INFO, | |
265 | "%s: Rejecting received message: Unexpected object [%d] present", | |
266 | __func__, obj->object_class); | |
267 | return false; | |
268 | } | |
269 | } else if (object_classes[index] != ANY_OBJECT) { | |
270 | if (node == NULL) { | |
271 | pcep_log( | |
272 | LOG_INFO, | |
273 | "%s: Rejecting received message: Expecting object in position [%d], but none received", | |
274 | __func__, index); | |
275 | return false; | |
276 | } else if (object_classes[index] != obj->object_class) { | |
277 | pcep_log( | |
278 | LOG_INFO, | |
279 | "%s: Rejecting received message: Unexpected Object Class received [%d]", | |
280 | __func__, object_classes[index]); | |
281 | return false; | |
282 | } | |
283 | } | |
284 | } | |
285 | ||
286 | return true; | |
287 | } | |
288 | ||
289 | struct pcep_message *pcep_decode_message(const uint8_t *msg_buf) | |
290 | { | |
291 | uint8_t msg_version; | |
292 | uint8_t msg_flags; | |
293 | uint8_t msg_type; | |
294 | uint16_t msg_length; | |
295 | ||
296 | msg_length = pcep_decode_msg_header(msg_buf, &msg_version, &msg_flags, | |
297 | &msg_type); | |
298 | ||
299 | struct pcep_message *msg = | |
300 | pceplib_calloc(PCEPLIB_MESSAGES, sizeof(struct pcep_message)); | |
301 | ||
302 | msg->msg_header = pceplib_malloc(PCEPLIB_MESSAGES, | |
303 | sizeof(struct pcep_message_header)); | |
304 | msg->msg_header->pcep_version = msg_version; | |
305 | msg->msg_header->type = msg_type; | |
306 | ||
307 | msg->obj_list = dll_initialize(); | |
308 | msg->encoded_message = pceplib_malloc(PCEPLIB_MESSAGES, msg_length); | |
309 | memcpy(msg->encoded_message, msg_buf, msg_length); | |
310 | msg->encoded_message_length = msg_length; | |
311 | ||
312 | uint16_t bytes_read = MESSAGE_HEADER_LENGTH; | |
313 | while ((msg_length - bytes_read) >= OBJECT_HEADER_LENGTH) { | |
314 | struct pcep_object_header *obj_hdr = | |
315 | pcep_decode_object(msg_buf + bytes_read); | |
316 | ||
317 | if (obj_hdr == NULL) { | |
318 | pcep_log(LOG_INFO, "%s: Discarding invalid message", | |
319 | __func__); | |
320 | pcep_msg_free_message(msg); | |
321 | ||
322 | return NULL; | |
323 | } | |
324 | ||
325 | dll_append(msg->obj_list, obj_hdr); | |
326 | bytes_read += obj_hdr->encoded_object_length; | |
327 | } | |
328 | ||
329 | if (validate_message_objects(msg) == false) { | |
330 | pcep_log(LOG_INFO, "%s: Discarding invalid message", __func__); | |
331 | pcep_msg_free_message(msg); | |
332 | ||
333 | return NULL; | |
334 | } | |
335 | ||
336 | return msg; | |
337 | } | |
338 | ||
339 | struct pcep_versioning *create_default_pcep_versioning() | |
340 | { | |
341 | struct pcep_versioning *versioning = | |
342 | pceplib_malloc(PCEPLIB_INFRA, sizeof(struct pcep_versioning)); | |
343 | memset(versioning, 0, sizeof(struct pcep_versioning)); | |
344 | ||
345 | return versioning; | |
346 | } | |
347 | ||
348 | void destroy_pcep_versioning(struct pcep_versioning *versioning) | |
349 | { | |
350 | pceplib_free(PCEPLIB_INFRA, versioning); | |
351 | } |