Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2018 The WebRTC project authors. All Rights Reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
Steve Anton | 10542f2 | 2019-01-11 09:11:00 -0800 | [diff] [blame^] | 11 | #include "pc/sdp_serializer.h" |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 12 | |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 13 | #include <algorithm> |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 14 | #include <string> |
| 15 | #include <utility> |
| 16 | #include <vector> |
| 17 | |
| 18 | #include "api/jsep.h" |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 19 | #include "rtc_base/checks.h" |
Steve Anton | 10542f2 | 2019-01-11 09:11:00 -0800 | [diff] [blame^] | 20 | #include "rtc_base/string_encode.h" |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 21 | #include "rtc_base/string_to_number.h" |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 22 | #include "rtc_base/strings/string_builder.h" |
| 23 | |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 24 | using cricket::RidDescription; |
| 25 | using cricket::RidDirection; |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 26 | using cricket::SimulcastDescription; |
| 27 | using cricket::SimulcastLayer; |
| 28 | using cricket::SimulcastLayerList; |
| 29 | |
| 30 | namespace webrtc { |
| 31 | |
| 32 | namespace { |
| 33 | |
| 34 | // delimiters |
| 35 | const char kDelimiterComma[] = ","; |
| 36 | const char kDelimiterCommaChar = ','; |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 37 | const char kDelimiterEqual[] = "="; |
| 38 | const char kDelimiterEqualChar = '='; |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 39 | const char kDelimiterSemicolon[] = ";"; |
| 40 | const char kDelimiterSemicolonChar = ';'; |
| 41 | const char kDelimiterSpace[] = " "; |
| 42 | const char kDelimiterSpaceChar = ' '; |
| 43 | |
| 44 | // https://tools.ietf.org/html/draft-ietf-mmusic-sdp-simulcast-13#section-5.1 |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 45 | // https://tools.ietf.org/html/draft-ietf-mmusic-rid-15#section-10 |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 46 | const char kSimulcastPausedStream[] = "~"; |
| 47 | const char kSimulcastPausedStreamChar = '~'; |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 48 | const char kSendDirection[] = "send"; |
| 49 | const char kReceiveDirection[] = "recv"; |
| 50 | const char kPayloadType[] = "pt"; |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 51 | |
| 52 | RTCError ParseError(const std::string& message) { |
| 53 | return RTCError(RTCErrorType::SYNTAX_ERROR, message); |
| 54 | } |
| 55 | |
| 56 | // These methods serialize simulcast according to the specification: |
| 57 | // https://tools.ietf.org/html/draft-ietf-mmusic-sdp-simulcast-13#section-5.1 |
| 58 | rtc::StringBuilder& operator<<(rtc::StringBuilder& builder, |
| 59 | const SimulcastLayer& simulcast_layer) { |
| 60 | if (simulcast_layer.is_paused) { |
| 61 | builder << kSimulcastPausedStream; |
| 62 | } |
| 63 | builder << simulcast_layer.rid; |
| 64 | return builder; |
| 65 | } |
| 66 | |
| 67 | rtc::StringBuilder& operator<<( |
| 68 | rtc::StringBuilder& builder, |
| 69 | const std::vector<SimulcastLayer>& layer_alternatives) { |
| 70 | bool first = true; |
| 71 | for (const SimulcastLayer& rid : layer_alternatives) { |
| 72 | if (!first) { |
| 73 | builder << kDelimiterComma; |
| 74 | } |
| 75 | builder << rid; |
| 76 | first = false; |
| 77 | } |
| 78 | return builder; |
| 79 | } |
| 80 | |
| 81 | rtc::StringBuilder& operator<<(rtc::StringBuilder& builder, |
| 82 | const SimulcastLayerList& simulcast_layers) { |
| 83 | bool first = true; |
| 84 | for (auto alternatives : simulcast_layers) { |
| 85 | if (!first) { |
| 86 | builder << kDelimiterSemicolon; |
| 87 | } |
| 88 | builder << alternatives; |
| 89 | first = false; |
| 90 | } |
| 91 | return builder; |
| 92 | } |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 93 | // This method deserializes simulcast according to the specification: |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 94 | // https://tools.ietf.org/html/draft-ietf-mmusic-sdp-simulcast-13#section-5.1 |
| 95 | // sc-str-list = sc-alt-list *( ";" sc-alt-list ) |
| 96 | // sc-alt-list = sc-id *( "," sc-id ) |
| 97 | // sc-id-paused = "~" |
| 98 | // sc-id = [sc-id-paused] rid-id |
| 99 | // rid-id = 1*(alpha-numeric / "-" / "_") ; see: I-D.ietf-mmusic-rid |
| 100 | RTCErrorOr<SimulcastLayerList> ParseSimulcastLayerList(const std::string& str) { |
| 101 | std::vector<std::string> tokens; |
| 102 | rtc::tokenize_with_empty_tokens(str, kDelimiterSemicolonChar, &tokens); |
| 103 | if (tokens.empty()) { |
| 104 | return ParseError("Layer list cannot be empty."); |
| 105 | } |
| 106 | |
| 107 | SimulcastLayerList result; |
| 108 | for (const std::string& token : tokens) { |
| 109 | if (token.empty()) { |
| 110 | return ParseError("Simulcast alternative layer list is empty."); |
| 111 | } |
| 112 | |
| 113 | std::vector<std::string> rid_tokens; |
| 114 | rtc::tokenize_with_empty_tokens(token, kDelimiterCommaChar, &rid_tokens); |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 115 | |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 116 | if (rid_tokens.empty()) { |
| 117 | return ParseError("Simulcast alternative layer list is malformed."); |
| 118 | } |
| 119 | |
| 120 | std::vector<SimulcastLayer> layers; |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 121 | for (const std::string& rid_token : rid_tokens) { |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 122 | if (rid_token.empty() || rid_token == kSimulcastPausedStream) { |
| 123 | return ParseError("Rid must not be empty."); |
| 124 | } |
| 125 | |
| 126 | bool paused = rid_token[0] == kSimulcastPausedStreamChar; |
| 127 | std::string rid = paused ? rid_token.substr(1) : rid_token; |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 128 | layers.push_back(SimulcastLayer(rid, paused)); |
| 129 | } |
| 130 | |
| 131 | result.AddLayerWithAlternatives(layers); |
| 132 | } |
| 133 | |
| 134 | return std::move(result); |
| 135 | } |
| 136 | |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 137 | webrtc::RTCError ParseRidPayloadList(const std::string& payload_list, |
| 138 | RidDescription* rid_description) { |
| 139 | RTC_DCHECK(rid_description); |
| 140 | std::vector<int>& payload_types = rid_description->payload_types; |
| 141 | // Check that the description doesn't have any payload types or restrictions. |
| 142 | // If the pt= field is specified, it must be first and must not repeat. |
| 143 | if (!payload_types.empty()) { |
| 144 | return ParseError("Multiple pt= found in RID Description."); |
| 145 | } |
| 146 | if (!rid_description->restrictions.empty()) { |
| 147 | return ParseError("Payload list must appear first in the restrictions."); |
| 148 | } |
| 149 | |
| 150 | // If the pt= field is specified, it must have a value. |
| 151 | if (payload_list.empty()) { |
| 152 | return ParseError("Payload list must have at least one value."); |
| 153 | } |
| 154 | |
| 155 | // Tokenize the ',' delimited list |
| 156 | std::vector<std::string> string_payloads; |
| 157 | rtc::tokenize(payload_list, kDelimiterCommaChar, &string_payloads); |
| 158 | if (string_payloads.empty()) { |
| 159 | return ParseError("Payload list must have at least one value."); |
| 160 | } |
| 161 | |
| 162 | for (const std::string& payload_type : string_payloads) { |
| 163 | absl::optional<int> value = rtc::StringToNumber<int>(payload_type); |
| 164 | if (!value.has_value()) { |
| 165 | return ParseError("Invalid payload type: " + payload_type); |
| 166 | } |
| 167 | |
| 168 | // Check if the value already appears in the payload list. |
| 169 | if (std::find(payload_types.begin(), payload_types.end(), value.value()) != |
| 170 | payload_types.end()) { |
| 171 | return ParseError("Duplicate payload type in list: " + payload_type); |
| 172 | } |
| 173 | payload_types.push_back(value.value()); |
| 174 | } |
| 175 | |
| 176 | return RTCError::OK(); |
| 177 | } |
| 178 | |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 179 | } // namespace |
| 180 | |
| 181 | std::string SdpSerializer::SerializeSimulcastDescription( |
| 182 | const cricket::SimulcastDescription& simulcast) const { |
| 183 | rtc::StringBuilder sb; |
| 184 | std::string delimiter; |
| 185 | |
| 186 | if (!simulcast.send_layers().empty()) { |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 187 | sb << kSendDirection << kDelimiterSpace << simulcast.send_layers(); |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 188 | delimiter = kDelimiterSpace; |
| 189 | } |
| 190 | |
| 191 | if (!simulcast.receive_layers().empty()) { |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 192 | sb << delimiter << kReceiveDirection << kDelimiterSpace |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 193 | << simulcast.receive_layers(); |
| 194 | } |
| 195 | |
| 196 | return sb.str(); |
| 197 | } |
| 198 | |
| 199 | // https://tools.ietf.org/html/draft-ietf-mmusic-sdp-simulcast-13#section-5.1 |
| 200 | // a:simulcast:<send> <streams> <recv> <streams> |
| 201 | // Formal Grammar |
| 202 | // sc-value = ( sc-send [SP sc-recv] ) / ( sc-recv [SP sc-send] ) |
| 203 | // sc-send = %s"send" SP sc-str-list |
| 204 | // sc-recv = %s"recv" SP sc-str-list |
| 205 | // sc-str-list = sc-alt-list *( ";" sc-alt-list ) |
| 206 | // sc-alt-list = sc-id *( "," sc-id ) |
| 207 | // sc-id-paused = "~" |
| 208 | // sc-id = [sc-id-paused] rid-id |
| 209 | // rid-id = 1*(alpha-numeric / "-" / "_") ; see: I-D.ietf-mmusic-rid |
| 210 | RTCErrorOr<SimulcastDescription> SdpSerializer::DeserializeSimulcastDescription( |
| 211 | absl::string_view string) const { |
| 212 | std::vector<std::string> tokens; |
| 213 | rtc::tokenize(std::string(string), kDelimiterSpaceChar, &tokens); |
| 214 | |
| 215 | if (tokens.size() != 2 && tokens.size() != 4) { |
| 216 | return ParseError("Must have one or two <direction, streams> pairs."); |
| 217 | } |
| 218 | |
| 219 | bool bidirectional = tokens.size() == 4; // indicates both send and recv |
| 220 | |
| 221 | // Tokens 0, 2 (if exists) should be send / recv |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 222 | if ((tokens[0] != kSendDirection && tokens[0] != kReceiveDirection) || |
| 223 | (bidirectional && tokens[2] != kSendDirection && |
| 224 | tokens[2] != kReceiveDirection) || |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 225 | (bidirectional && tokens[0] == tokens[2])) { |
| 226 | return ParseError("Valid values: send / recv."); |
| 227 | } |
| 228 | |
| 229 | // Tokens 1, 3 (if exists) should be alternative layer lists |
| 230 | RTCErrorOr<SimulcastLayerList> list1, list2; |
| 231 | list1 = ParseSimulcastLayerList(tokens[1]); |
| 232 | if (!list1.ok()) { |
| 233 | return list1.MoveError(); |
| 234 | } |
| 235 | |
| 236 | if (bidirectional) { |
| 237 | list2 = ParseSimulcastLayerList(tokens[3]); |
| 238 | if (!list2.ok()) { |
| 239 | return list2.MoveError(); |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | // Set the layers so that list1 is for send and list2 is for recv |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 244 | if (tokens[0] != kSendDirection) { |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 245 | std::swap(list1, list2); |
| 246 | } |
| 247 | |
| 248 | // Set the layers according to which pair is send and which is recv |
| 249 | // At this point if the simulcast is unidirectional then |
| 250 | // either |list1| or |list2| will be in 'error' state indicating that |
| 251 | // the value should not be used. |
| 252 | SimulcastDescription simulcast; |
| 253 | if (list1.ok()) { |
| 254 | simulcast.send_layers() = list1.MoveValue(); |
| 255 | } |
| 256 | |
| 257 | if (list2.ok()) { |
| 258 | simulcast.receive_layers() = list2.MoveValue(); |
| 259 | } |
| 260 | |
| 261 | return std::move(simulcast); |
| 262 | } |
| 263 | |
Amit Hilbuch | c57d573 | 2018-12-11 15:30:11 -0800 | [diff] [blame] | 264 | std::string SdpSerializer::SerializeRidDescription( |
| 265 | const RidDescription& rid_description) const { |
| 266 | RTC_DCHECK(!rid_description.rid.empty()); |
| 267 | RTC_DCHECK(rid_description.direction == RidDirection::kSend || |
| 268 | rid_description.direction == RidDirection::kReceive); |
| 269 | |
| 270 | rtc::StringBuilder builder; |
| 271 | builder << rid_description.rid << kDelimiterSpace |
| 272 | << (rid_description.direction == RidDirection::kSend |
| 273 | ? kSendDirection |
| 274 | : kReceiveDirection); |
| 275 | |
| 276 | const auto& payload_types = rid_description.payload_types; |
| 277 | const auto& restrictions = rid_description.restrictions; |
| 278 | |
| 279 | // First property is separated by ' ', the next ones by ';'. |
| 280 | const char* propertyDelimiter = kDelimiterSpace; |
| 281 | |
| 282 | // Serialize any codecs in the description. |
| 283 | if (!payload_types.empty()) { |
| 284 | builder << propertyDelimiter << kPayloadType << kDelimiterEqual; |
| 285 | propertyDelimiter = kDelimiterSemicolon; |
| 286 | const char* formatDelimiter = ""; |
| 287 | for (int payload_type : payload_types) { |
| 288 | builder << formatDelimiter << payload_type; |
| 289 | formatDelimiter = kDelimiterComma; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | // Serialize any restrictions in the description. |
| 294 | for (const auto& pair : restrictions) { |
| 295 | // Serialize key=val pairs. =val part is ommitted if val is empty. |
| 296 | builder << propertyDelimiter << pair.first; |
| 297 | if (!pair.second.empty()) { |
| 298 | builder << kDelimiterEqual << pair.second; |
| 299 | } |
| 300 | |
| 301 | propertyDelimiter = kDelimiterSemicolon; |
| 302 | } |
| 303 | |
| 304 | return builder.str(); |
| 305 | } |
| 306 | |
| 307 | // https://tools.ietf.org/html/draft-ietf-mmusic-rid-15#section-10 |
| 308 | // Formal Grammar |
| 309 | // rid-syntax = %s"a=rid:" rid-id SP rid-dir |
| 310 | // [ rid-pt-param-list / rid-param-list ] |
| 311 | // rid-id = 1*(alpha-numeric / "-" / "_") |
| 312 | // rid-dir = %s"send" / %s"recv" |
| 313 | // rid-pt-param-list = SP rid-fmt-list *( ";" rid-param ) |
| 314 | // rid-param-list = SP rid-param *( ";" rid-param ) |
| 315 | // rid-fmt-list = %s"pt=" fmt *( "," fmt ) |
| 316 | // rid-param = 1*(alpha-numeric / "-") [ "=" param-val ] |
| 317 | // param-val = *( %x20-58 / %x60-7E ) |
| 318 | // ; Any printable character except semicolon |
| 319 | RTCErrorOr<RidDescription> SdpSerializer::DeserializeRidDescription( |
| 320 | absl::string_view string) const { |
| 321 | std::vector<std::string> tokens; |
| 322 | rtc::tokenize(std::string(string), kDelimiterSpaceChar, &tokens); |
| 323 | |
| 324 | if (tokens.size() < 2) { |
| 325 | return ParseError("RID Description must contain <RID> <direction>."); |
| 326 | } |
| 327 | |
| 328 | if (tokens.size() > 3) { |
| 329 | return ParseError("Invalid RID Description format. Too many arguments."); |
| 330 | } |
| 331 | |
| 332 | if (tokens[1] != kSendDirection && tokens[1] != kReceiveDirection) { |
| 333 | return ParseError("Invalid RID direction. Supported values: send / recv."); |
| 334 | } |
| 335 | |
| 336 | RidDirection direction = tokens[1] == kSendDirection ? RidDirection::kSend |
| 337 | : RidDirection::kReceive; |
| 338 | |
| 339 | RidDescription rid_description(tokens[0], direction); |
| 340 | |
| 341 | // If there is a third argument it is a payload list and/or restriction list. |
| 342 | if (tokens.size() == 3) { |
| 343 | std::vector<std::string> restrictions; |
| 344 | rtc::tokenize(tokens[2], kDelimiterSemicolonChar, &restrictions); |
| 345 | |
| 346 | // Check for malformed restriction list, such as ';' or ';;;' etc. |
| 347 | if (restrictions.empty()) { |
| 348 | return ParseError("Invalid RID restriction list: " + tokens[2]); |
| 349 | } |
| 350 | |
| 351 | // Parse the restrictions. The payload indicator (pt) can only appear first. |
| 352 | for (const std::string& restriction : restrictions) { |
| 353 | std::vector<std::string> parts; |
| 354 | rtc::tokenize(restriction, kDelimiterEqualChar, &parts); |
| 355 | if (parts.empty() || parts.size() > 2) { |
| 356 | return ParseError("Invalid format for restriction: " + restriction); |
| 357 | } |
| 358 | |
| 359 | // |parts| contains at least one value and it does not contain a space. |
| 360 | // Note: |parts| and other values might still contain tab, newline, |
| 361 | // unprintable characters, etc. which will not generate errors here but |
| 362 | // will (most-likely) be ignored by components down stream. |
| 363 | if (parts[0] == kPayloadType) { |
| 364 | RTCError error = ParseRidPayloadList( |
| 365 | parts.size() > 1 ? parts[1] : std::string(), &rid_description); |
| 366 | if (!error.ok()) { |
| 367 | return std::move(error); |
| 368 | } |
| 369 | |
| 370 | continue; |
| 371 | } |
| 372 | |
| 373 | // Parse |parts| as a key=value pair which allows unspecified values. |
| 374 | if (rid_description.restrictions.find(parts[0]) != |
| 375 | rid_description.restrictions.end()) { |
| 376 | return ParseError("Duplicate restriction specified: " + parts[0]); |
| 377 | } |
| 378 | |
| 379 | rid_description.restrictions[parts[0]] = |
| 380 | parts.size() > 1 ? parts[1] : std::string(); |
| 381 | } |
| 382 | } |
| 383 | |
| 384 | return std::move(rid_description); |
| 385 | } |
| 386 | |
Amit Hilbuch | a201204 | 2018-12-03 11:35:05 -0800 | [diff] [blame] | 387 | } // namespace webrtc |