Ticket #479: allow media transport framework to return transport specific info (for example, to know whether SRTP is enabled)

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@1860 74dad513-b988-da41-8d7b-12977e46ad98

6 files changed, 154 insertions, 21 deletions

diff --git a/pjmedia/include/pjmedia/config.h b/pjmedia/include/pjmedia/config.h
index 0640b184..38dd872c 100644
--- a/pjmedia/include/pjmedia/config.h
+++ b/pjmedia/include/pjmedia/config.h
@@ -525,6 +525,27 @@
 
 
 /**
+ * Transport info (pjmedia_transport_info) contains a socket info and list
+ * of transport specific info, since transports can be chained together 
+ * (for example, SRTP transport uses UDP transport as the underlying 
+ * transport). This constant specifies maximum number of transport specific
+ * infos that can be held in a transport info.
+ */
+#ifndef PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXCNT
+#   define PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXCNT   4
+#endif
+
+
+/**
+ * Maximum size in bytes of storage buffer of a transport specific info.
+ */
+#ifndef PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE
+#   define PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE  (12*sizeof(long))
+#endif
+
+
+
+/**
  * @}
  */
 
diff --git a/pjmedia/include/pjmedia/transport.h b/pjmedia/include/pjmedia/transport.h
index 2629cf87..fcf120da 100644
--- a/pjmedia/include/pjmedia/transport.h
+++ b/pjmedia/include/pjmedia/transport.h
@@ -207,12 +207,18 @@ PJ_BEGIN_DECL
 
 #include <pjmedia/sdp.h>
 
+
 /**
  * Forward declaration for media transport.
  */
 typedef struct pjmedia_transport pjmedia_transport;
 
 /**
+ * Forward declaration for media transport info.
+ */
+typedef struct pjmedia_transport_info pjmedia_transport_info;
+
+/**
  * This enumeration specifies the general behaviour of media processing
  */
 typedef enum pjmedia_tranport_media_option
@@ -228,6 +234,7 @@ typedef enum pjmedia_tranport_media_option
 
 } pjmedia_tranport_media_option;
 
+
 /**
  * This structure describes the operations for the stream transport.
  */
@@ -239,7 +246,7 @@ struct pjmedia_transport_op
      * Application should call #pjmedia_transport_get_info() instead
      */
     pj_status_t (*get_info)(pjmedia_transport *tp,
-			    pjmedia_sock_info *info);
+			    pjmedia_transport_info *info);
 
     /**
      * This function is called by the stream when the transport is about
@@ -368,7 +375,14 @@ typedef enum pjmedia_transport_type
     PJMEDIA_TRANSPORT_TYPE_UDP,
 
     /** Media transport using ICE */
-    PJMEDIA_TRANSPORT_TYPE_ICE
+    PJMEDIA_TRANSPORT_TYPE_ICE,
+
+    /** 
+     * Media transport SRTP, this transport is actually security adapter to be
+     * stacked with other transport to enable encryption on the underlying
+     * transport.
+     */
+    PJMEDIA_TRANSPORT_TYPE_SRTP
 
 } pjmedia_transport_type;
 
@@ -390,6 +404,56 @@ struct pjmedia_transport
     pjmedia_transport_op    *op;
 };
 
+/**
+ * This structure describes buffer storage of transport specific info.
+ * The actual transport specific info contents will be defined by transport
+ * implementation. Note that some transport implementations do not need to
+ * provide specific info, since the general socket info is enough.
+ */
+typedef struct pjmedia_transport_specific_info
+{
+    /**
+     * Specify media transport type.
+     */
+    pjmedia_transport_type   type;
+
+    /**
+     * Specify storage buffer size of transport specific info.
+     */
+    int			     cbsize;
+
+    /**
+     * Storage buffer of transport specific info.
+     */
+    char		     buffer[PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE];
+
+} pjmedia_transport_specific_info;
+
+
+/**
+ * This structure describes transport informations, including general 
+ * socket information and specific information of single transport or 
+ * stacked transports (e.g: SRTP stacked on top of UDP)
+ */
+struct pjmedia_transport_info
+{
+    /**
+     * General socket info.
+     */
+    pjmedia_sock_info sock_info;
+
+    /**
+     * Specifies number of transport specific info included.
+     */
+    int specific_info_cnt;
+
+    /**
+     * Buffer storage of transport specific info.
+     */
+    pjmedia_transport_specific_info spc_info[PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXCNT];
+
+};
+
 
 /**
  * Get media socket info from the specified transport. The socket info
@@ -403,7 +467,7 @@ struct pjmedia_transport
  * @return	    PJ_SUCCESS on success.
  */
 PJ_INLINE(pj_status_t) pjmedia_transport_get_info(pjmedia_transport *tp,
-						  pjmedia_sock_info *info)
+						  pjmedia_transport_info *info)
 {
     if (tp->op->get_info)
 	return (*tp->op->get_info)(tp, info);
diff --git a/pjmedia/include/pjmedia/transport_srtp.h b/pjmedia/include/pjmedia/transport_srtp.h
index a04e28b6..d2b6a015 100644
--- a/pjmedia/include/pjmedia/transport_srtp.h
+++ b/pjmedia/include/pjmedia/transport_srtp.h
@@ -160,6 +160,30 @@ typedef struct pjmedia_srtp_setting
 
 
 /**
+ * This structure specifies SRTP transport specific info. This will fit
+ * into \a buffer field of pjmedia_transport_specific_info.
+ */
+typedef struct pjmedia_srtp_info
+{
+    /**
+     * Specify whether the SRTP transport is active for SRTP session.
+     */
+    pj_bool_t			active;
+
+    /**
+     * Specify the policy used by the SRTP session for receive direction.
+     */
+    pjmedia_srtp_crypto		rx_policy;
+
+    /**
+     * Specify the policy used by the SRTP session for transmit direction.
+     */
+    pjmedia_srtp_crypto		tx_policy;
+
+} pjmedia_srtp_info;
+
+
+/**
  * Initialize SRTP setting with its default values.
  *
  * @param opt	SRTP setting to be initialized.
diff --git a/pjmedia/src/pjmedia/transport_ice.c b/pjmedia/src/pjmedia/transport_ice.c
index 8a6124f3..0534ad4b 100644
--- a/pjmedia/src/pjmedia/transport_ice.c
+++ b/pjmedia/src/pjmedia/transport_ice.c
@@ -55,7 +55,7 @@ struct transport_ice
  * These are media transport operations.
  */
 static pj_status_t transport_get_info (pjmedia_transport *tp,
-				       pjmedia_sock_info *info);
+				       pjmedia_transport_info *info);
 static pj_status_t transport_attach   (pjmedia_transport *tp,
 				       void *user_data,
 				       const pj_sockaddr_t *rem_addr,
@@ -673,20 +673,20 @@ static pj_status_t transport_media_stop(pjmedia_transport *tp)
 
 
 static pj_status_t transport_get_info(pjmedia_transport *tp,
-				      pjmedia_sock_info *info)
+				      pjmedia_transport_info *info)
 {
     struct transport_ice *tp_ice = (struct transport_ice*)tp;
     pj_ice_strans *ice_st = tp_ice->ice_st;
     pj_ice_strans_comp *comp;
 
-    pj_bzero(info, sizeof(*info));
-    info->rtp_sock = info->rtcp_sock = PJ_INVALID_SOCKET;
+    pj_bzero(&info->sock_info, sizeof(info->sock_info));
+    info->sock_info.rtp_sock = info->sock_info.rtcp_sock = PJ_INVALID_SOCKET;
 
     /* Retrieve address of default candidate for component 1 (RTP) */
     comp = ice_st->comp[0];
     pj_assert(comp->default_cand >= 0);
-    info->rtp_sock = comp->sock;
-    pj_memcpy(&info->rtp_addr_name, 
+    info->sock_info.rtp_sock = comp->sock;
+    pj_memcpy(&info->sock_info.rtp_addr_name, 
 	      &comp->cand_list[comp->default_cand].addr,
 	      sizeof(pj_sockaddr_in));
 
@@ -694,12 +694,13 @@ static pj_status_t transport_get_info(pjmedia_transport *tp,
     if (ice_st->comp_cnt > 1) {
 	comp = ice_st->comp[1];
 	pj_assert(comp->default_cand >= 0);
-	info->rtp_sock = comp->sock;
-	pj_memcpy(&info->rtcp_addr_name, 
+	info->sock_info.rtp_sock = comp->sock;
+	pj_memcpy(&info->sock_info.rtcp_addr_name, 
 		  &comp->cand_list[comp->default_cand].addr,
 		  sizeof(pj_sockaddr_in));
     }
 
+    info->specific_info_cnt = 0;
 
     return PJ_SUCCESS;
 }
diff --git a/pjmedia/src/pjmedia/transport_srtp.c b/pjmedia/src/pjmedia/transport_srtp.c
index 5dadb207..3bd95c88 100644
--- a/pjmedia/src/pjmedia/transport_srtp.c
+++ b/pjmedia/src/pjmedia/transport_srtp.c
@@ -125,7 +125,7 @@ static void srtp_rtcp_cb( void *user_data, void *pkt, pj_ssize_t size);
  * These are media transport operations.
  */
 static pj_status_t transport_get_info (pjmedia_transport *tp,
-				       pjmedia_sock_info *info);
+				       pjmedia_transport_info *info);
 static pj_status_t transport_attach   (pjmedia_transport *tp,
 				       void *user_data,
 				       const pj_sockaddr_t *rem_addr,
@@ -551,12 +551,34 @@ PJ_DEF(pjmedia_transport *) pjmedia_transport_srtp_get_member(
 
 
 static pj_status_t transport_get_info(pjmedia_transport *tp,
-				      pjmedia_sock_info *info)
+				      pjmedia_transport_info *info)
 {
     transport_srtp *srtp = (transport_srtp*) tp;
+    pjmedia_srtp_info srtp_info;
+    int spc_info_idx;
+    pj_status_t status;
+
+    PJ_ASSERT_RETURN(tp && info, PJ_EINVAL);
+    PJ_ASSERT_RETURN(info->specific_info_cnt <
+		     PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXCNT, PJ_ETOOMANY);
+    PJ_ASSERT_RETURN(sizeof(pjmedia_srtp_info) <=
+		     PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE, PJ_ENOMEM);
+
+    status = pjmedia_transport_get_info(srtp->real_tp, info);
+    if (status != PJ_SUCCESS)
+	return status;
+
+    srtp_info.active = srtp->session_inited;
+    srtp_info.rx_policy = srtp->rx_policy;
+    srtp_info.tx_policy = srtp->tx_policy;
 
-    /* put SRTP info as well? */
-    return pjmedia_transport_get_info(srtp->real_tp, info);
+    spc_info_idx = info->specific_info_cnt++;
+    info->spc_info[spc_info_idx].type = PJMEDIA_TRANSPORT_TYPE_SRTP;
+    info->spc_info[spc_info_idx].cbsize = sizeof(srtp_info);
+    pj_memcpy(&info->spc_info[spc_info_idx].buffer, &srtp_info, 
+	      sizeof(srtp_info));
+
+    return PJ_SUCCESS;
 }
 
 static pj_status_t transport_attach(pjmedia_transport *tp,
diff --git a/pjmedia/src/pjmedia/transport_udp.c b/pjmedia/src/pjmedia/transport_udp.c
index a341d44a..f4e12cd1 100644
--- a/pjmedia/src/pjmedia/transport_udp.c
+++ b/pjmedia/src/pjmedia/transport_udp.c
@@ -101,7 +101,7 @@ static void on_rx_rtcp(pj_ioqueue_key_t *key,
  * These are media transport operations.
  */
 static pj_status_t transport_get_info (pjmedia_transport *tp,
-				       pjmedia_sock_info *info);
+				       pjmedia_transport_info *info);
 static pj_status_t transport_attach   (pjmedia_transport *tp,
 				       void *user_data,
 				       const pj_sockaddr_t *rem_addr,
@@ -584,15 +584,16 @@ static void on_rx_rtcp(pj_ioqueue_key_t *key,
 
 /* Called to get the transport info */
 static pj_status_t transport_get_info(pjmedia_transport *tp,
-				      pjmedia_sock_info *info)
+				      pjmedia_transport_info *info)
 {
     struct transport_udp *udp = (struct transport_udp*)tp;
     PJ_ASSERT_RETURN(tp && info, PJ_EINVAL);
 
-    info->rtp_sock = udp->rtp_sock;
-    info->rtp_addr_name = udp->rtp_addr_name;
-    info->rtcp_sock = udp->rtcp_sock;
-    info->rtcp_addr_name = udp->rtcp_addr_name;
+    info->sock_info.rtp_sock = udp->rtp_sock;
+    info->sock_info.rtp_addr_name = udp->rtp_addr_name;
+    info->sock_info.rtcp_sock = udp->rtcp_sock;
+    info->sock_info.rtcp_addr_name = udp->rtcp_addr_name;
+    info->specific_info_cnt = 0;
 
     return PJ_SUCCESS;
 }