X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=b83ab8c61d34c3a52f8e0f35dfa63d05c3584f21;hp=6ab96215df880dc04eea0f6f90c48fd385720816;hb=e9e826f4fb415c4225ff5934fe42572ffa3b5ebc;hpb=7964fd8324c24679ca2ec85b6e9589f24079e089

diff --git a/net.c b/net.c
index 6ab96215..b83ab8c6 100644
--- a/net.c
+++ b/net.c
@@ -661,6 +661,33 @@ int para_accept(int fd, void *addr, socklen_t size)
 	return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd;
 }
 
+/**
+ * Probe the list of DCCP CCIDs supported locally by the host.
+ * \param ccids Array to be filled in.
+ * \param nccids Length of \a ccids.
+ * \return Pointer to \a ccids, NULL on failure.
+ *
+ * NB: This feature is only available on Linux > 2.6.30; on older kernels
+ * ENOPROTOOPT ("Protocol not available") will be returned.
+ */
+const uint8_t *dccp_available_ccids(uint8_t *ccids, uint8_t *nccids)
+{
+	int fd = makesock(AF_UNSPEC, IPPROTO_DCCP, 0, NULL, 0);
+
+	if (fd < 0)
+		return NULL;
+
+	if (getsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_AVAILABLE_CCIDS,
+					ccids, (socklen_t *)nccids) < 0) {
+		PARA_ERROR_LOG("No DCCP_SOCKOPT_AVAILABLE_CCIDS: %s\n",
+				strerror(errno));
+		*nccids = 0;
+	}
+	close(fd);
+
+	return *nccids ? ccids : NULL;
+}
+
 /**
  * Prepare a structure for \p AF_UNIX socket addresses.
  *