Add RFC5424 syslog protocol support (VPP-1139)

[vpp.git] / src / vnet / syslog / syslog_udp.c

diff --git a/src/vnet/syslog/syslog_udp.c b/src/vnet/syslog/syslog_udp.c
new file mode 100644 (file)
index 0000000..f4fa1d0
--- /dev/null
+++ b/src/vnet/syslog/syslog_udp.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @file syslog protocol UDP transport layer implementation (RFC5426)
+ */
+
+#include <vnet/syslog/syslog_udp.h>
+#include <vnet/ip/ip4.h>
+#include <vnet/udp/udp_packet.h>
+
+void
+syslog_add_udp_transport (vlib_main_t * vm, u32 bi)
+{
+  syslog_main_t *sm = &syslog_main;
+  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  ip4_header_t *ip;
+  udp_header_t *udp;
+
+  vlib_buffer_advance (b, -(sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+  b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
+  vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
+  vnet_buffer (b)->sw_if_index[VLIB_TX] = sm->fib_index;
+
+  ip = vlib_buffer_get_current (b);
+  clib_memset (ip, 0, sizeof (*ip));
+  udp = (udp_header_t *) (ip + 1);
+  clib_memset (udp, 0, sizeof (*udp));
+
+  ip->ip_version_and_header_length = 0x45;
+  ip->flags_and_fragment_offset =
+    clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT);
+  ip->ttl = 255;
+  ip->protocol = IP_PROTOCOL_UDP;
+  ip->src_address.as_u32 = sm->src_address.as_u32;
+  ip->dst_address.as_u32 = sm->collector.as_u32;
+
+  udp->src_port = udp->dst_port = clib_host_to_net_u16 (sm->collector_port);
+
+  const u16 ip_length = vlib_buffer_length_in_chain (vm, b);
+  ip->length = clib_host_to_net_u16 (ip_length);
+  ip->checksum = ip4_header_checksum (ip);
+
+  const u16 udp_length = ip_length - (sizeof (ip4_header_t));
+  udp->length = clib_host_to_net_u16 (udp_length);
+  /* RFC5426 3.6. */
+  udp->checksum = ip4_tcp_udp_compute_checksum (vm, b, ip);
+  if (udp->checksum == 0)
+    udp->checksum = 0xffff;
+
+  b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */