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      1 //
      2 // Copyright (C) 2012 The Android Open Source Project
      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 <errno.h>
     18 #include <stdio.h>
     19 #include <time.h>
     20 #include <unistd.h>
     21 
     22 #include <string>
     23 #include <vector>
     24 
     25 #include <base/bind.h>
     26 #include <base/command_line.h>
     27 #include <base/files/file_path.h>
     28 #include <base/strings/string_number_conversions.h>
     29 #include <base/strings/string_split.h>
     30 #include <brillo/minijail/minijail.h>
     31 #include <brillo/syslog_logging.h>
     32 
     33 #include "shill/daemon_task.h"
     34 #include "shill/error.h"
     35 #include "shill/logging.h"
     36 #include "shill/shill_config.h"
     37 #include "shill/shill_daemon.h"
     38 #include "shill/technology.h"
     39 
     40 using base::FilePath;
     41 using std::string;
     42 using std::vector;
     43 
     44 namespace switches {
     45 
     46 // Don't daemon()ize; run in foreground.
     47 static const char kForeground[] = "foreground";
     48 // Don't attempt to manage these devices.
     49 static const char kDeviceBlackList[] = "device-black-list";
     50 // Manage only these devices.
     51 static const char kDeviceWhiteList[] = "device-white-list";
     52 // Ignore Ethernet-like devices that don't have any driver information.
     53 static const char kIgnoreUnknownEthernet[] = "ignore-unknown-ethernet";
     54 // Technologies to enable for portal check at startup.
     55 static const char kPortalList[] = "portal-list";
     56 // When in passive mode, Shill will not manage any devices by default.
     57 // Remote service can instruct Shill to manage/unmanage devices through
     58 // org.chromium.flimflam.Manager's ClaimInterface/ReleaseInterface APIs.
     59 static const char kPassiveMode[] = "passive-mode";
     60 // Default priority order of the technologies.
     61 static const char kTechnologyOrder[] = "default-technology-order";
     62 // Comma-separated list of DNS servers to prepend to the resolver list.
     63 static const char kPrependDNSServers[] = "prepend-dns-servers";
     64 // The minimum MTU value that will be respected in DHCP responses.
     65 static const char kMinimumMTU[] = "minimum-mtu";
     66 // Accept hostname from the DHCP server for the specified devices.
     67 // eg. eth0 or eth*
     68 static const char kAcceptHostnameFrom[] = "accept-hostname-from";
     69 #ifndef DISABLE_DHCPV6
     70 // List of devices to enable DHCPv6.
     71 static const char kDhcpv6EnabledDevices[] = "dhcpv6-enabled-devices";
     72 #endif  // DISABLE_DHCPV6
     73 // Flag that causes shill to show the help message and exit.
     74 static const char kHelp[] = "help";
     75 
     76 // The help message shown if help flag is passed to the program.
     77 static const char kHelpMessage[] = "\n"
     78     "Available Switches: \n"
     79     "  --foreground\n"
     80     "    Don\'t daemon()ize; run in foreground.\n"
     81     "  --device-black-list=device1,device2\n"
     82     "    Do not manage devices named device1 or device2\n"
     83     "  --device-white-list=device1,device2\n"
     84     "    Manage only devices named device1 and device2\n"
     85     "  --ignore-unknown-ethernet\n"
     86     "    Ignore Ethernet-like devices that do not report a driver\n"
     87     "  --log-level=N\n"
     88     "    Logging level:\n"
     89     "      0 = LOG(INFO), 1 = LOG(WARNING), 2 = LOG(ERROR),\n"
     90     "      -1 = SLOG(..., 1), -2 = SLOG(..., 2), etc.\n"
     91     "  --log-scopes=\"*scope1+scope2\".\n"
     92     "    Scopes to enable for SLOG()-based logging.\n"
     93     "  --portal-list=technology1,technology2\n"
     94     "    Specify technologies to perform portal detection on at startup.\n"
     95     "  --passive-mode\n"
     96     "    Do not manage any devices by default\n"
     97     "  --default-technology-order=technology1,technology2\n"
     98     "    Specify the default priority order of the technologies.\n"
     99     "  --prepend-dns-servers=server1,server2,...\n"
    100     "    Prepend the provided DNS servers to the resolver list.\n"
    101     "  --accept-hostname-from=eth0 or --accept-hostname-from=eth*\n"
    102     "    Accept a hostname from the DHCP server for the matching devices.\n"
    103 #ifndef DISABLE_DHCPV6
    104     "  --dhcpv6-enabled-devices=device1,device2\n"
    105     "    Enable DHCPv6 for devices named device1 and device2\n"
    106 #endif  // DISABLE_DHCPV6
    107     "  --minimum-mtu=mtu\n"
    108     "    Set the minimum value to respect as the MTU from DHCP responses.\n";
    109 }  // namespace switches
    110 
    111 namespace {
    112 
    113 #if !defined(__ANDROID__)
    114 const char* kLoggerCommand = "/usr/bin/logger";
    115 const char* kLoggerUser = "syslog";
    116 #endif  // __ANDROID__
    117 
    118 const char* kDefaultTechnologyOrder = "vpn,ethernet,wifi,wimax,cellular";
    119 
    120 }  // namespace
    121 
    122 // Always logs to the syslog and logs to stderr if
    123 // we are running in the foreground.
    124 void SetupLogging(bool foreground, const char* daemon_name) {
    125   int log_flags = 0;
    126   log_flags |= brillo::kLogToSyslog;
    127   log_flags |= brillo::kLogHeader;
    128   if (foreground) {
    129     log_flags |= brillo::kLogToStderr;
    130   }
    131   brillo::InitLog(log_flags);
    132 
    133 #if !defined(__ANDROID__)
    134   // Logger utility doesn't exist on Android, so do not run it on Android.
    135   // TODO(zqiu): add support to redirect stderr logs from child processes
    136   // to Android logging facility.
    137   if (!foreground) {
    138     vector<char*> logger_command_line;
    139     int logger_stdin_fd;
    140     logger_command_line.push_back(const_cast<char*>(kLoggerCommand));
    141     logger_command_line.push_back(const_cast<char*>("--priority"));
    142     logger_command_line.push_back(const_cast<char*>("daemon.err"));
    143     logger_command_line.push_back(const_cast<char*>("--tag"));
    144     logger_command_line.push_back(const_cast<char*>(daemon_name));
    145     logger_command_line.push_back(nullptr);
    146 
    147     brillo::Minijail* minijail = brillo::Minijail::GetInstance();
    148     struct minijail* jail = minijail->New();
    149     minijail->DropRoot(jail, kLoggerUser, kLoggerUser);
    150 
    151     if (!minijail->RunPipeAndDestroy(jail, logger_command_line, nullptr,
    152                                      &logger_stdin_fd)) {
    153       LOG(ERROR) << "Unable to spawn logger. "
    154                  << "Writes to stderr will be discarded.";
    155       return;
    156     }
    157 
    158     // Note that we don't set O_CLOEXEC here. This means that stderr
    159     // from any child processes will, by default, be logged to syslog.
    160     if (dup2(logger_stdin_fd, fileno(stderr)) != fileno(stderr)) {
    161       PLOG(ERROR) << "Failed to redirect stderr to syslog";
    162     }
    163     close(logger_stdin_fd);
    164   }
    165 #endif  // __ANDROID__
    166 }
    167 
    168 void OnStartup(const char *daemon_name, base::CommandLine* cl) {
    169   SetupLogging(cl->HasSwitch(switches::kForeground), daemon_name);
    170   shill::SetLogLevelFromCommandLine(cl);
    171 }
    172 
    173 int main(int argc, char** argv) {
    174   base::CommandLine::Init(argc, argv);
    175   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
    176 
    177   if (cl->HasSwitch(switches::kHelp)) {
    178     LOG(INFO) << switches::kHelpMessage;
    179     return 0;
    180   }
    181 
    182   shill::DaemonTask::Settings settings;
    183   if (cl->HasSwitch(switches::kTechnologyOrder)) {
    184     shill::Error error;
    185     string order_flag = cl->GetSwitchValueASCII(
    186         switches::kTechnologyOrder);
    187     vector<shill::Technology::Identifier> test_order_vector;
    188     if (shill::Technology::GetTechnologyVectorFromString(
    189         order_flag, &test_order_vector, &error)) {
    190       settings.default_technology_order = order_flag;
    191     }  else {
    192       LOG(ERROR) << "Invalid default technology order: [" << order_flag
    193                  << "] Error: " << error.message();
    194     }
    195   }
    196   if (settings.default_technology_order.empty()) {
    197     settings.default_technology_order = kDefaultTechnologyOrder;
    198   }
    199 
    200   if (cl->HasSwitch(switches::kDeviceBlackList)) {
    201     settings.device_blacklist = base::SplitString(
    202         cl->GetSwitchValueASCII(switches::kDeviceBlackList), ",",
    203         base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
    204   }
    205 
    206   if (cl->HasSwitch(switches::kDeviceWhiteList)) {
    207     settings.device_whitelist = base::SplitString(
    208         cl->GetSwitchValueASCII(switches::kDeviceWhiteList), ",",
    209         base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
    210   }
    211 
    212   settings.ignore_unknown_ethernet =
    213       cl->HasSwitch(switches::kIgnoreUnknownEthernet);
    214 
    215   if (cl->HasSwitch(switches::kPortalList)) {
    216     settings.use_portal_list = true;
    217     settings.portal_list = cl->GetSwitchValueASCII(switches::kPortalList);
    218   }
    219 
    220   settings.passive_mode = cl->HasSwitch(switches::kPassiveMode);
    221 
    222   if (cl->HasSwitch(switches::kPrependDNSServers)) {
    223     settings.prepend_dns_servers =
    224         cl->GetSwitchValueASCII(switches::kPrependDNSServers);
    225   }
    226 
    227   if (cl->HasSwitch(switches::kMinimumMTU)) {
    228     int mtu;
    229     std::string value = cl->GetSwitchValueASCII(switches::kMinimumMTU);
    230     if (!base::StringToInt(value, &mtu)) {
    231       LOG(FATAL) << "Could not convert '" << value << "' to integer.";
    232     }
    233     settings.minimum_mtu = mtu;
    234   }
    235 
    236   if (cl->HasSwitch(switches::kAcceptHostnameFrom)) {
    237     settings.accept_hostname_from =
    238         cl->GetSwitchValueASCII(switches::kAcceptHostnameFrom);
    239   }
    240 
    241 #ifndef DISABLE_DHCPV6
    242   if (cl->HasSwitch(switches::kDhcpv6EnabledDevices)) {
    243     settings.dhcpv6_enabled_devices = base::SplitString(
    244         cl->GetSwitchValueASCII(switches::kDhcpv6EnabledDevices), ",",
    245         base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
    246   }
    247 #endif  // DISABLE_DHCPV6
    248 
    249   shill::Config config;
    250 
    251   shill::ShillDaemon daemon(base::Bind(&OnStartup, argv[0], cl), settings,
    252                             &config);
    253   daemon.Run();
    254 
    255   LOG(INFO) << "Process exiting.";
    256 
    257   return 0;
    258 }
    259