config: allow for custom SSRC. Added thread safety

ultravideo · Dec 7, 2022 · 2806a1e · 2806a1e
1 parent c72b9ec
commit 2806a1e
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Showing 7 changed files with 49 additions and 29 deletions.
diff --git a/include/uvgrtp/media_stream.hh b/include/uvgrtp/media_stream.hh
@@ -5,7 +5,7 @@
 #include <unordered_map>
 #include <memory>
 #include <string>
-
+#include <atomic>
 
 #ifndef _WIN32
 #include <sys/socket.h>
@@ -315,6 +315,8 @@ namespace uvgrtp {
             std::shared_ptr<uvgrtp::rtp>    rtp_;
             std::shared_ptr<uvgrtp::rtcp>   rtcp_;
 
+            std::shared_ptr<std::atomic<std::uint32_t>> ssrc_;
+
             sockaddr_in remote_sockaddr_;
             std::string remote_address_;
             std::string local_address_;

diff --git a/include/uvgrtp/rtcp.hh b/include/uvgrtp/rtcp.hh
@@ -12,6 +12,7 @@
 #include <memory>
 #include <mutex>
 #include <deque>
+#include <atomic>
 
 namespace uvgrtp {
 
@@ -108,8 +109,8 @@ namespace uvgrtp {
     class rtcp {
         public:
             /// \cond DO_NOT_DOCUMENT
-            rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::string cname, int rce_flags);
-            rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::string cname, std::shared_ptr<uvgrtp::srtcp> srtcp, int rce_flags);
+            rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::shared_ptr<std::atomic<std::uint32_t>> ssrc, std::string cname, int rce_flags);
+            rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::shared_ptr<std::atomic<std::uint32_t>> ssrc, std::string cname, std::shared_ptr<uvgrtp::srtcp> srtcp, int rce_flags);
             ~rtcp();
 
             /* start the RTCP runner thread
@@ -512,7 +513,7 @@ namespace uvgrtp {
             bool initial_;
 
             /* Copy of our own current SSRC */
-            const uint32_t ssrc_;
+            std::shared_ptr<std::atomic_uint> ssrc_;
 
             /* NTP timestamp associated with initial RTP timestamp (aka t = 0) */
             uint64_t clock_start_;

diff --git a/include/uvgrtp/util.hh b/include/uvgrtp/util.hh
@@ -362,6 +362,13 @@ enum RTP_CTX_CONFIGURATION_FLAGS {
      * See RCC_FPS_NUMERATOR for more info.
      */
     RCC_FPS_DENOMINATOR  = 9,
+
+    /** Set the SSRC of the stream manually
+    *
+    * By default SSRC is generated randomly
+    */
+    RCC_SSRC = 10,
+
     /// \cond DO_NOT_DOCUMENT
     RCC_LAST
     /// \endcond

diff --git a/src/media_stream.cc b/src/media_stream.cc
@@ -45,7 +45,8 @@ uvgrtp::media_stream::media_stream(std::string cname, std::string remote_addr,
     holepuncher_(std::unique_ptr<uvgrtp::holepuncher>(new uvgrtp::holepuncher(socket_))),
     cname_(cname),
     fps_numerator_(30),
-    fps_denominator_(1)
+    fps_denominator_(1),
+    ssrc_(std::make_shared<std::atomic<std::uint32_t>>(uvgrtp::random::generate_32()))
 {}
 
 uvgrtp::media_stream::~media_stream()
@@ -257,8 +258,8 @@ rtp_error_t uvgrtp::media_stream::init()
 
     reception_flow_ = std::unique_ptr<uvgrtp::reception_flow> (new uvgrtp::reception_flow());
 
-    rtp_ = std::shared_ptr<uvgrtp::rtp> (new uvgrtp::rtp(fmt_));
-    rtcp_ = std::shared_ptr<uvgrtp::rtcp> (new uvgrtp::rtcp(rtp_, cname_, rce_flags_));
+    rtp_ = std::shared_ptr<uvgrtp::rtp> (new uvgrtp::rtp(fmt_, ssrc_));
+    rtcp_ = std::shared_ptr<uvgrtp::rtcp> (new uvgrtp::rtcp(rtp_, ssrc_, cname_, rce_flags_));
 
     socket_->install_handler(rtcp_.get(), rtcp_->send_packet_handler_vec);
 
@@ -277,7 +278,7 @@ rtp_error_t uvgrtp::media_stream::init(std::shared_ptr<uvgrtp::zrtp> zrtp)
 
     reception_flow_ = std::unique_ptr<uvgrtp::reception_flow> (new uvgrtp::reception_flow());
 
-    rtp_ = std::shared_ptr<uvgrtp::rtp> (new uvgrtp::rtp(fmt_));
+    rtp_ = std::shared_ptr<uvgrtp::rtp> (new uvgrtp::rtp(fmt_, ssrc_));
 
     bool perform_dh = !(rce_flags_ & RCE_ZRTP_MULTISTREAM_MODE);
     if (!perform_dh)
@@ -313,7 +314,7 @@ rtp_error_t uvgrtp::media_stream::init(std::shared_ptr<uvgrtp::zrtp> zrtp)
 
     zrtp->dh_has_finished(); // only after the DH stream has gotten its keys, do we let non-DH stream perform ZRTP
 
-    rtcp_ = std::shared_ptr<uvgrtp::rtcp> (new uvgrtp::rtcp(rtp_, cname_, srtcp_, rce_flags_));
+    rtcp_ = std::shared_ptr<uvgrtp::rtcp> (new uvgrtp::rtcp(rtp_, ssrc_, cname_, srtcp_, rce_flags_));
 
     socket_->install_handler(rtcp_.get(), rtcp_->send_packet_handler_vec);
     socket_->install_handler(srtp_.get(), srtp_->send_packet_handler);
@@ -345,7 +346,7 @@ rtp_error_t uvgrtp::media_stream::add_srtp_ctx(uint8_t *key, uint8_t *salt)
 
     reception_flow_ = std::unique_ptr<uvgrtp::reception_flow> (new uvgrtp::reception_flow());
 
-    rtp_ = std::shared_ptr<uvgrtp::rtp> (new uvgrtp::rtp(fmt_));
+    rtp_ = std::shared_ptr<uvgrtp::rtp> (new uvgrtp::rtp(fmt_, ssrc_));
 
     srtp_ = std::shared_ptr<uvgrtp::srtp> (new uvgrtp::srtp(rce_flags_));
 
@@ -362,7 +363,7 @@ rtp_error_t uvgrtp::media_stream::add_srtp_ctx(uint8_t *key, uint8_t *salt)
         return free_resources(ret);
     }
 
-    rtcp_ = std::shared_ptr<uvgrtp::rtcp> (new uvgrtp::rtcp(rtp_, cname_, srtcp_, rce_flags_));
+    rtcp_ = std::shared_ptr<uvgrtp::rtcp> (new uvgrtp::rtcp(rtp_, ssrc_, cname_, srtcp_, rce_flags_));
 
     socket_->install_handler(rtcp_.get(), rtcp_->send_packet_handler_vec);
     socket_->install_handler(srtp_.get(), srtp_->send_packet_handler);
@@ -660,7 +661,13 @@ rtp_error_t uvgrtp::media_stream::configure_ctx(int rcc_flag, ssize_t value)
             media_->set_fps(fps_numerator_, fps_denominator_);
             break;
         }           
+        case RCC_SSRC: {
+            if (value <= 0 || value > (ssize_t)UINT32_MAX)
+                return RTP_INVALID_VALUE;
 
+            *ssrc_ = (uint32_t)value;
+            break;
+        }
         default:
             return RTP_INVALID_VALUE;
     }
@@ -685,7 +692,7 @@ uint32_t uvgrtp::media_stream::get_ssrc() const
         return 0;
     }
 
-    return rtp_->get_ssrc();
+    return *ssrc_.get();
 }
 
 rtp_error_t uvgrtp::media_stream::init_srtp_with_zrtp(int rce_flags, int type, std::shared_ptr<uvgrtp::base_srtp> srtp,

diff --git a/src/rtcp.cc b/src/rtcp.cc
@@ -37,12 +37,12 @@ constexpr int ESTIMATED_MAX_RECEPTION_TIME_MS = 10;
 
 const uint32_t MAX_SUPPORTED_PARTICIPANTS = 31;
 
-uvgrtp::rtcp::rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::string cname, int rce_flags):
-    rce_flags_(rce_flags), our_role_(RECEIVER),
+uvgrtp::rtcp::rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::shared_ptr<std::atomic_uint> ssrc, std::string cname, int rce_flags):
+    rce_flags_(rce_flags), our_role_(RECEIVER), ssrc_(ssrc),
     tp_(0), tc_(0), tn_(0), pmembers_(0),
     members_(0), senders_(0), rtcp_bandwidth_(0),
     we_sent_(false), avg_rtcp_pkt_pize_(0), rtcp_pkt_count_(0),
-    rtcp_pkt_sent_count_(0), initial_(true), ssrc_(rtp->get_ssrc()), 
+    rtcp_pkt_sent_count_(0), initial_(true), 
     num_receivers_(0),
     sender_hook_(nullptr),
     receiver_hook_(nullptr),
@@ -89,9 +89,9 @@ uvgrtp::rtcp::rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::string cname, int rce_
     }
 }
 
-uvgrtp::rtcp::rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::string cname, 
+uvgrtp::rtcp::rtcp(std::shared_ptr<uvgrtp::rtp> rtp, std::shared_ptr<std::atomic_uint> ssrc, std::string cname,
     std::shared_ptr<uvgrtp::srtcp> srtcp, int rce_flags):
-    rtcp(rtp, cname, rce_flags)
+    rtcp(rtp, ssrc, cname, rce_flags)
 {
     srtcp_ = srtcp;
 }
@@ -229,7 +229,7 @@ rtp_error_t uvgrtp::rtcp::stop()
     }
 
     /* Send BYE packet with our SSRC to all participants */
-    return uvgrtp::rtcp::send_bye_packet({ ssrc_ });
+    return uvgrtp::rtcp::send_bye_packet({ *ssrc_.get() });
 }
 
 void uvgrtp::rtcp::rtcp_runner(rtcp* rtcp, int interval)
@@ -1515,7 +1515,7 @@ rtp_error_t uvgrtp::rtcp::send_rtcp_packet_to_participants(uint8_t* frame, uint3
     rtp_error_t ret = RTP_OK;
 
     if (encrypt && srtcp_ && 
-        (ret = srtcp_->handle_rtcp_encryption(rce_flags_, rtcp_pkt_sent_count_, ssrc_, frame, frame_size)) != RTP_OK)
+        (ret = srtcp_->handle_rtcp_encryption(rce_flags_, rtcp_pkt_sent_count_, *ssrc_.get(), frame, frame_size)) != RTP_OK)
     {
         UVG_LOG_DEBUG("Encryption failed. Not sending packet");
         delete[] frame;
@@ -1640,6 +1640,7 @@ rtp_error_t uvgrtp::rtcp::generate_report()
     // see https://datatracker.ietf.org/doc/html/rfc3550#section-6.4.1
 
     size_t write_ptr = 0;
+    uint32_t ssrc = *ssrc_.get();
     if (sr_packet)
     {
         // sender reports have sender information in addition compared to receiver reports
@@ -1662,7 +1663,7 @@ rtp_error_t uvgrtp::rtcp::generate_report()
         uint64_t rtp_ts = expanded_ts_start + ts_since_start;
 
         if (!construct_rtcp_header(frame, write_ptr, sender_report_size, reports, uvgrtp::frame::RTCP_FT_SR) ||
-            !construct_ssrc(frame, write_ptr, ssrc_) ||
+            !construct_ssrc(frame, write_ptr, ssrc) ||
             !construct_sender_info(frame, write_ptr, ntp_ts, rtp_ts, our_stats.sent_pkts, our_stats.sent_bytes))
         {
             UVG_LOG_ERROR("Failed to construct SR");
@@ -1675,7 +1676,7 @@ rtp_error_t uvgrtp::rtcp::generate_report()
         size_t receiver_report_size = get_rr_packet_size(rce_flags_, reports);
 
         if (!construct_rtcp_header(frame, write_ptr, receiver_report_size, reports, uvgrtp::frame::RTCP_FT_RR) ||
-            !construct_ssrc(frame, write_ptr, ssrc_))
+            !construct_ssrc(frame, write_ptr, ssrc))
         {
             UVG_LOG_ERROR("Failed to construct RR");
             return RTP_GENERIC_ERROR;
@@ -1724,7 +1725,7 @@ rtp_error_t uvgrtp::rtcp::generate_report()
         // add the SDES packet after the SR/RR, mandatory, must contain CNAME
         if (!construct_rtcp_header(frame, write_ptr, get_sdes_packet_size(ourItems_), num_receivers_,
             uvgrtp::frame::RTCP_FT_SDES) ||
-            !construct_sdes_chunk(frame, write_ptr, { ssrc_, ourItems_ }))
+            !construct_sdes_chunk(frame, write_ptr, { ssrc, ourItems_ }))
         {
             UVG_LOG_ERROR("Failed to add SDES packet");
             delete[] frame;
@@ -1750,7 +1751,7 @@ rtp_error_t uvgrtp::rtcp::generate_report()
 
                 if (!construct_rtcp_header(frame, write_ptr, packet_size, secondField,
                     uvgrtp::frame::RTCP_FT_APP) ||
-                    !construct_ssrc(frame, write_ptr, ssrc_) ||
+                    !construct_ssrc(frame, write_ptr, ssrc) ||
                     !construct_app_packet(frame, write_ptr, next_packet.name, next_packet.payload, next_packet.payload_len))
                 {
                     UVG_LOG_ERROR("Failed to construct APP packet");

diff --git a/src/rtp.cc b/src/rtp.cc
@@ -17,8 +17,8 @@
 
 #define INVALID_TS UINT64_MAX
 
-uvgrtp::rtp::rtp(rtp_format_t fmt):
-    ssrc_(uvgrtp::random::generate_32()),
+uvgrtp::rtp::rtp(rtp_format_t fmt, std::shared_ptr<std::atomic<std::uint32_t>> ssrc):
+    ssrc_(ssrc),
     ts_(uvgrtp::random::generate_32()),
     seq_(uvgrtp::random::generate_32() & 0xffff),
     fmt_(fmt),
@@ -40,7 +40,7 @@ uvgrtp::rtp::~rtp()
 
 uint32_t uvgrtp::rtp::get_ssrc() const
 {
-    return ssrc_;
+    return *ssrc_.get();
 }
 
 uint16_t uvgrtp::rtp::get_sequence() const
@@ -145,7 +145,7 @@ void uvgrtp::rtp::fill_header(uint8_t *buffer)
     buffer[1] = (payload_ & 0x7f) | (0 << 7);
 
     *(uint16_t *)&buffer[2] = htons(seq_);
-    *(uint32_t *)&buffer[8] = htonl(ssrc_);
+    *(uint32_t *)&buffer[8] = htonl(*ssrc_.get());
 
     if (timestamp_ == INVALID_TS) {
 

diff --git a/src/rtp.hh b/src/rtp.hh
@@ -4,6 +4,8 @@
 #include "uvgrtp/util.hh"
 
 #include <chrono>
+#include <memory>
+#include <atomic>
 
 namespace uvgrtp {
 
@@ -14,7 +16,7 @@ namespace uvgrtp {
 
     class rtp {
         public:
-            rtp(rtp_format_t fmt);
+            rtp(rtp_format_t fmt, std::shared_ptr<std::atomic<std::uint32_t>> ssrc);
             ~rtp();
 
             uint32_t     get_ssrc()          const;
@@ -44,7 +46,7 @@ namespace uvgrtp {
 
             void set_default_clock_rate(rtp_format_t fmt);
 
-            uint32_t ssrc_;
+            std::shared_ptr<std::atomic<std::uint32_t>> ssrc_;
             uint32_t ts_;
             uint16_t seq_;
             rtp_format_t fmt_;