More ticket #465: option to return UDP header in pj_pcap_read_udp(), and better RTP packet handling in pcaputil sample

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@1769 74dad513-b988-da41-8d7b-12977e46ad98

2 files changed, 29 insertions, 15 deletions

diff --git a/pjlib-util/include/pjlib-util/pcap.h b/pjlib-util/include/pjlib-util/pcap.h
index e27f5709..58d39a9f 100644
--- a/pjlib-util/include/pjlib-util/pcap.h
+++ b/pjlib-util/include/pjlib-util/pcap.h
@@ -60,9 +60,22 @@ typedef enum pj_pcap_proto_type
 
 
 /**
+ * This describes UDP header, which may optionally be returned in
+ * #pj_pcap_read_udp() function. All fields are in network byte order.
+ */
+typedef struct pj_pcap_udp_hdr
+{
+    pj_uint16_t	src_port;   /**< Source port.	    */
+    pj_uint16_t	dst_port;   /**< Destination port   */
+    pj_uint16_t	len;	    /**< Length.	    */
+    pj_uint16_t	csum;	    /**< Checksum.	    */
+} pj_pcap_udp_hdr;
+
+
+/**
  * This structure describes the filter to be used when reading packets from
- * a PCAP file. The filter is used to select what packets can be returned
- * to a read operation.
+ * a PCAP file. When a filter is configured, only packets matching all the
+ * filter specifications will be read from PCAP file.
  */
 typedef struct pj_pcap_filter
 {
@@ -142,7 +155,8 @@ PJ_DECL(pj_status_t) pj_pcap_open(pj_pool_t *pool,
 PJ_DECL(pj_status_t) pj_pcap_close(pj_pcap_file *file);
 
 /**
- * Configure filter for reading the file.
+ * Configure filter for reading the file. When filter is configured,
+ * only packets matching all the filter settings will be returned.
  *
  * @param file	    PCAP file handle.
  * @param filter    The filter.
@@ -153,9 +167,11 @@ PJ_DECL(pj_status_t) pj_pcap_set_filter(pj_pcap_file *file,
 				        const pj_pcap_filter *filter);
 
 /**
- * Read UDP payload from the next packet in the PCAP file.
+ * Read UDP payload from the next packet in the PCAP file. Optionally it
+ * can return the UDP header, if caller supplies it.
  *
  * @param file		    PCAP file handle.
+ * @param udp_hdr	    Optional buffer to receive UDP header.
  * @param udp_payload	    Buffer to receive the UDP payload.
  * @param udp_payload_size  On input, specify the size of the buffer.
  *			    On output, it will be filled with the actual size
@@ -164,6 +180,7 @@ PJ_DECL(pj_status_t) pj_pcap_set_filter(pj_pcap_file *file,
  * @return	    PJ_SUCCESS on success, or the appropriate error code.
  */
 PJ_DECL(pj_status_t) pj_pcap_read_udp(pj_pcap_file *file,
+				      pj_pcap_udp_hdr *udp_hdr,
 				      pj_uint8_t *udp_payload,
 				      pj_size_t *udp_payload_size);
 
diff --git a/pjlib-util/src/pjlib-util/pcap.c b/pjlib-util/src/pjlib-util/pcap.c
index 22d602d5..40ee7b3f 100644
--- a/pjlib-util/src/pjlib-util/pcap.c
+++ b/pjlib-util/src/pjlib-util/pcap.c
@@ -54,11 +54,12 @@ typedef struct pj_pcap_rec_hdr
 } pj_pcap_rec_hdr;
 
 #if 0
+/* gcc insisted on aligning this struct to 32bit on ARM */
 typedef struct pj_pcap_eth_hdr 
 {
     pj_uint8_t  dest[6];
     pj_uint8_t  src[6];
-    pj_uint8_t  len[2];	/* problem with struct size if pj_uint16_t */
+    pj_uint8_t  len[2];
 } pj_pcap_eth_hdr;
 #else
 typedef pj_uint8_t pj_pcap_eth_hdr[14];
@@ -78,16 +79,6 @@ typedef struct pj_pcap_ip_hdr
     pj_uint32_t	ip_dst;
 } pj_pcap_ip_hdr;
 
-typedef struct pj_pcap_udp_hdr
-{
-    pj_uint16_t	src_port;
-    pj_uint16_t	dst_port;
-    pj_uint16_t	len;
-    pj_uint16_t	csum;
-} pj_pcap_udp_hdr;
-
-#pragma pack()
-
 /* Implementation of pcap file */
 struct pj_pcap_file
 {
@@ -210,6 +201,7 @@ static pj_status_t skip(pj_oshandle_t fd, pj_off_t bytes)
 
 /* Read UDP packet */
 PJ_DEF(pj_status_t) pj_pcap_read_udp(pj_pcap_file *file,
+				     pj_pcap_udp_hdr *udp_hdr,
 				     pj_uint8_t *udp_payload,
 				     pj_size_t *udp_payload_size)
 {
@@ -342,6 +334,11 @@ PJ_DEF(pj_status_t) pj_pcap_read_udp(pj_pcap_file *file,
 		continue;
 	    }
 
+	    /* Copy UDP header if caller wants it */
+	    if (udp_hdr) {
+		pj_memcpy(udp_hdr, &tmp.udp, sizeof(*udp_hdr));
+	    }
+
 	    /* Calculate payload size */
 	    sz = pj_ntohs(tmp.udp.len) - sizeof(tmp.udp);
 	    break;