google-ipmi-sys: initial commit: OEM IPMI handler
This implements a set of OEM IPMI commands built as sub-commands under
one OEM IPMI command registered in the Google OEM Namespace.
Change-Id: I65ff6f35838b501ac6ac67f7765bbc474b808660
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/cable.cpp b/cable.cpp
new file mode 100644
index 0000000..025b228
--- /dev/null
+++ b/cable.cpp
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * 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.
+ */
+
+#include "cable.hpp"
+
+#include "main.hpp"
+
+#include <cstdint>
+#include <experimental/filesystem>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <system_error>
+
+namespace google
+{
+namespace ipmi
+{
+namespace fs = std::experimental::filesystem;
+
+struct CableRequest
+{
+ uint8_t subcommand;
+ uint8_t if_name_len;
+ uint8_t if_name[0];
+} __attribute__((packed));
+
+struct CableReply
+{
+ uint8_t subcommand;
+ uint8_t value;
+} __attribute__((packed));
+
+ipmi_ret_t CableCheck(const uint8_t* reqBuf, uint8_t* replyBuf, size_t* dataLen)
+{
+ // There is an IPMI LAN channel statistics command which could be used for
+ // this type of check, however, we're not able to wait for the OpenBMC
+ // implementation to stabilize related to the network management.
+ //
+ // There is a link status file, but it is "unknown" to start with...
+ // The path we're checking: /sys/class/net/eth1/statistics/rx_packets
+
+ // This command is expecting: [0x00][len][if_name]
+ if ((*dataLen) < sizeof(struct CableRequest) + sizeof(uint8_t))
+ {
+ fprintf(stderr, "Invalid command length: %lu\n", (*dataLen));
+ return IPMI_CC_INVALID;
+ }
+
+ const auto request =
+ reinterpret_cast<const struct CableRequest*>(&reqBuf[0]);
+
+ // Sanity check the object contents.
+ if (request->if_name_len == 0)
+ {
+ fprintf(stderr, "Invalid string length: %d\n", request->if_name_len);
+ return IPMI_CC_INVALID;
+ }
+
+ // Verify the request buffer contains the object and the string.
+ if ((*dataLen) < (sizeof(struct CableRequest) + request->if_name_len))
+ {
+ fprintf(stderr, "*dataLen too small: %lu\n", (*dataLen));
+ return IPMI_CC_INVALID;
+ }
+
+ // Maximum length one can specify, plus null terminator.
+ char nameBuf[256] = {};
+ std::ostringstream opath;
+
+ // Copy the string out of the request buffer.
+ memcpy(&nameBuf[0], request->if_name, request->if_name_len);
+ std::string name = nameBuf;
+
+ // Minor sanity & security check (of course, I'm less certain if unicode
+ // comes into play here.
+ //
+ // Basically you can't easily inject ../ or /../ into the path below.
+ if (name.find("/") != std::string::npos)
+ {
+ fprintf(stderr, "Invalid or illegal name: '%s'\n", nameBuf);
+ return IPMI_CC_INVALID;
+ }
+
+ opath << "/sys/class/net/" << name << "/statistics/rx_packets";
+ std::string path = opath.str();
+
+ std::error_code ec;
+ if (!fs::exists(path, ec))
+ {
+ fprintf(stderr, "Path: '%s' doesn't exist.\n", path.c_str());
+ return IPMI_CC_INVALID;
+ }
+ // We're uninterested in the state of ec.
+
+ // Read the file and check the result.
+ int64_t count = 0;
+ std::ifstream ifs;
+ ifs.exceptions(std::ifstream::failbit);
+ try
+ {
+ ifs.open(path);
+ ifs >> count;
+ }
+ catch (std::ios_base::failure& fail)
+ {
+ return IPMI_CC_INVALID;
+ }
+
+ struct CableReply reply;
+ reply.subcommand = SysCableCheck;
+ reply.value = 0x00; // Default false
+
+ // If we have received packets then there is a cable present.
+ reply.value = (count > 0) ? 1 : 0;
+
+ // Return the subcommand and the result.
+ memcpy(&replyBuf[0], &reply, sizeof(struct CableReply));
+ (*dataLen) = sizeof(struct CableReply);
+
+ return IPMI_CC_OK;
+}
+
+} // namespace ipmi
+} // namespace google