1 /** 2 * Copyright 2017 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <fcntl.h> 18 #include <getopt.h> 19 #include <poll.h> 20 #include <unistd.h> 21 22 #include <array> 23 #include <cstdint> 24 #include <iostream> 25 #include <memory> 26 #include <thread> 27 28 #include "lpcsnoop/snoop.hpp" 29 30 static const char* snoopFilename = "/dev/aspeed-lpc-snoop0"; 31 32 /* 33 * 256 bytes is a nice amount. It's improbable we'd need this many, but its 34 * gives us leg room in the event the driver poll doesn't return in a timely 35 * fashion. So, mostly arbitrarily chosen. 36 */ 37 static constexpr size_t BUFFER_SIZE = 256; 38 39 /* 40 * Process any incoming dbus inquiries, which include introspection etc. 41 */ 42 void ProcessDbus(sdbusplus::bus::bus& bus) 43 { 44 while (true) 45 { 46 bus.process_discard(); 47 bus.wait(); // wait indefinitely 48 } 49 50 return; 51 } 52 53 static void usage(const char* name) 54 { 55 fprintf(stderr, 56 "Usage: %s [-d <DEVICE>]\n" 57 " -d, --device <DEVICE> use <DEVICE> file. Default is '%s'\n\n", 58 name, snoopFilename); 59 } 60 61 /* 62 * TODO(venture): this only listens one of the possible snoop ports, but 63 * doesn't share the namespace. 64 * 65 * This polls() the lpc snoop character device and it owns the dbus object 66 * whose value is the latest port 80h value. 67 */ 68 int main(int argc, char* argv[]) 69 { 70 int rc = 0; 71 int opt; 72 struct pollfd pollset; 73 int pollr; 74 int readb; 75 int postFd = -1; 76 std::array<uint8_t, BUFFER_SIZE> buffer; 77 78 /* 79 * These string constants are only used in this method within this object 80 * and this object is the only object feeding into the final binary. 81 * 82 * If however, another object is added to this binary it would be proper 83 * to move these declarations to be global and extern to the other object. 84 */ 85 const char* snoopObject = SNOOP_OBJECTPATH; 86 const char* snoopDbus = SNOOP_BUSNAME; 87 88 bool deferSignals = true; 89 90 static const struct option long_options[] = { 91 {"device", required_argument, NULL, 'd'}, {0, 0, 0, 0}}; 92 93 while ((opt = getopt_long(argc, argv, "d:", long_options, NULL)) != -1) 94 { 95 switch (opt) 96 { 97 case 0: 98 break; 99 case 'd': 100 snoopFilename = optarg; 101 break; 102 default: 103 usage(argv[0]); 104 exit(EXIT_FAILURE); 105 } 106 } 107 108 postFd = open(snoopFilename, 0); 109 if (postFd < 0) 110 { 111 fprintf(stderr, "Unable to open: %s\n", snoopFilename); 112 return -1; 113 } 114 115 pollset.fd = postFd; 116 pollset.events |= POLLIN; 117 118 auto bus = sdbusplus::bus::new_default(); 119 120 // Add systemd object manager. 121 sdbusplus::server::manager::manager(bus, snoopObject); 122 123 PostReporter reporter(bus, snoopObject, deferSignals); 124 reporter.emit_object_added(); 125 126 bus.request_name(snoopDbus); 127 128 /* 129 * I don't see a public interface for getting the underlying sd_bus* 130 * so instead of poll(bus, driver), I'll just create a separate thread. 131 * 132 * TODO(venture): There may be a way to use sdevent to poll both the file 133 * and the dbus in the same event loop. If I could get the sdbus pointer 134 * from bus directly, I'd grab a file handler from it, and then just poll on 135 * both in one loop. From a cursory look at sdevent, I should be able to do 136 * something similar with that at some point. 137 */ 138 std::thread lt(ProcessDbus, std::ref(bus)); 139 140 /* infinitely listen for POST codes and broadcast. */ 141 while (true) 142 { 143 pollr = poll(&pollset, 1, -1); /* polls indefinitely. */ 144 if (pollr < 0) 145 { 146 /* poll returned error. */ 147 rc = -errno; 148 goto exit; 149 } 150 151 if (pollr > 0) 152 { 153 if (pollset.revents & POLLIN) 154 { 155 readb = read(postFd, buffer.data(), buffer.size()); 156 if (readb < 0) 157 { 158 /* Read failure. */ 159 rc = readb; 160 goto exit; 161 } 162 else 163 { 164 /* Broadcast the bytes read. */ 165 for (int i = 0; i < readb; i++) 166 { 167 reporter.value(buffer[i]); 168 } 169 } 170 } 171 } 172 } 173 174 exit: 175 if (postFd > -1) 176 { 177 close(postFd); 178 } 179 180 lt.join(); 181 182 return rc; 183 } 184