obs-webrtc: Do not use curl_easy_nextheader

API not available in Ubuntu 22.04 which ships 7.81 this API was first
available in 7.83

plugins/obs-webrtc/whip-output.cpp

@@ -362,7 +362,7 @@ bool WHIPOutput::Connect()
 	}
 
 	std::string read_buffer;
-	std::vector<std::string> location_headers;
+	std::vector<std::string> http_headers;
 
 	auto offer_sdp =
 		std::string(peer_connection->localDescription().value());
@@ -379,9 +379,8 @@ bool WHIPOutput::Connect()
 	CURL *c = curl_easy_init();
 	curl_easy_setopt(c, CURLOPT_WRITEFUNCTION, curl_writefunction);
 	curl_easy_setopt(c, CURLOPT_WRITEDATA, (void *)&read_buffer);
-	curl_easy_setopt(c, CURLOPT_HEADERFUNCTION,
-			 curl_header_location_function);
-	curl_easy_setopt(c, CURLOPT_HEADERDATA, (void *)&location_headers);
+	curl_easy_setopt(c, CURLOPT_HEADERFUNCTION, curl_header_function);
+	curl_easy_setopt(c, CURLOPT_HEADERDATA, (void *)&http_headers);
 	curl_easy_setopt(c, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(c, CURLOPT_URL, endpoint_url.c_str());
 	curl_easy_setopt(c, CURLOPT_POST, 1L);
@@ -428,7 +427,18 @@ bool WHIPOutput::Connect()
 	long redirect_count = 0;
 	curl_easy_getinfo(c, CURLINFO_REDIRECT_COUNT, &redirect_count);
 
-	if (location_headers.size() < static_cast<size_t>(redirect_count) + 1) {
+	std::string last_location_header;
+	size_t location_header_count = 0;
+	for (auto &http_header : http_headers) {
+		auto value = value_for_header("location", http_header);
+		if (value.empty())
+			continue;
+
+		location_header_count++;
+		last_location_header = value;
+	}
+
+	if (location_header_count < static_cast<size_t>(redirect_count) + 1) {
 		do_log(LOG_ERROR,
 		       "WHIP server did not provide a resource URL via the Location header");
 		cleanup();
@@ -437,25 +447,21 @@ bool WHIPOutput::Connect()
 	}
 
 	CURLU *url_builder = curl_url();
-	auto last_location_header = location_headers.back();
 
 	// Parse Link headers to extract STUN/TURN server configuration URLs
-	struct curl_header *prev = nullptr;
-	struct curl_header *h = nullptr;
 	std::vector<rtc::IceServer> iceServers;
-	while ((h = curl_easy_nextheader(c, CURLH_HEADER, 0, prev))) {
-		if (astrcmpi("Link", h->name) == 0) {
-			auto value = std::string(h->value);
-			// Parse multiple links separated by ','
-			for (auto end = value.find(",");
-			     end != std::string::npos; end = value.find(",")) {
-				this->ParseLinkHeader(value.substr(0, end),
-						      iceServers);
-				value = value.substr(end + 1);
-			}
-			this->ParseLinkHeader(value, iceServers);
+	for (auto &http_header : http_headers) {
+		auto value = value_for_header("link", http_header);
+		if (value.empty())
+			continue;
+
+		// Parse multiple links separated by ','
+		for (auto end = value.find(","); end != std::string::npos;
+		     end = value.find(",")) {
+			this->ParseLinkHeader(value.substr(0, end), iceServers);
+			value = value.substr(end + 1);
 		}
-		prev = h;
+		this->ParseLinkHeader(value, iceServers);
 	}
 
 	// If Location header doesn't start with `http` it is a relative URL.

plugins/obs-webrtc/whip-utils.h

@@ -26,6 +26,22 @@ static std::string trim_string(const std::string &source)
 	return ret;
 }
 
+static std::string value_for_header(const std::string &header,
+				    const std::string &val)
+{
+	if (val.size() <= header.size() ||
+	    astrcmpi_n(header.c_str(), val.c_str(), header.size()) != 0) {
+		return "";
+	}
+
+	auto delimiter = val.find_first_of(" ");
+	if (delimiter == std::string::npos) {
+		return "";
+	}
+
+	return val.substr(delimiter + 1);
+}
+
 static size_t curl_writefunction(char *data, size_t size, size_t nmemb,
 				 void *priv_data)
 {
@@ -37,28 +53,12 @@ static size_t curl_writefunction(char *data, size_t size, size_t nmemb,
 	return real_size;
 }
 
-#define LOCATION_HEADER_LENGTH 10
-
-static size_t curl_header_location_function(char *data, size_t size,
-					    size_t nmemb, void *priv_data)
+static size_t curl_header_function(char *data, size_t size, size_t nmemb,
+				   void *priv_data)
 {
 	auto header_buffer = static_cast<std::vector<std::string> *>(priv_data);
-
-	size_t real_size = size * nmemb;
-
-	if (real_size < LOCATION_HEADER_LENGTH)
-		return real_size;
-
-	if (!astrcmpi_n(data, "location: ", LOCATION_HEADER_LENGTH)) {
-		char *val = data + LOCATION_HEADER_LENGTH;
-		auto header_temp =
-			std::string(val, real_size - LOCATION_HEADER_LENGTH);
-
-		header_temp = trim_string(header_temp);
-		header_buffer->push_back(header_temp);
-	}
-
-	return real_size;
+	header_buffer->push_back(trim_string(std::string(data, size * nmemb)));
+	return size * nmemb;
 }
 
 static inline std::string generate_user_agent()