src/oom/oomctl.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <getopt.h>
   4 #include <unistd.h>
   5
   6 #include "bus-error.h"
   7 #include "copy.h"
   8 #include "main-func.h"
   9 #include "pretty-print.h"
  10 #include "terminal-util.h"
  11 #include "verbs.h"
  12
  13 static PagerFlags arg_pager_flags = 0;
  14
  15 static int help(int argc, char *argv[], void *userdata) {
  16         _cleanup_free_ char *link = NULL;
  17         int r;
  18
  19         (void) pager_open(arg_pager_flags);
  20
  21         r = terminal_urlify_man("oomctl", "1", &link);
  22         if (r < 0)
  23                 return log_oom();
  24
  25         printf("%1$s [OPTIONS...] COMMAND ...\n\n"
  26                "%2$sManage or inspect the userspace OOM killer.%3$s\n"
  27                "\n%4$sCommands:%5$s\n"
  28                "  dump                        Output the current state of systemd-oomd\n"
  29                "\n%4$sOptions:%5$s\n"
  30                "  -h --help                   Show this help\n"
  31                "     --version                Show package version\n"
  32                "     --no-pager               Do not pipe output into a pager\n"
  33                "\nSee the %6$s for details.\n"
  34                , program_invocation_short_name
  35                , ansi_highlight(), ansi_normal()
  36                , ansi_underline(), ansi_normal()
  37                , link
  38         );
  39
  40         return 0;
  41 }
  42
  43 static int dump_state(int argc, char *argv[], void *userdata) {
  44         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
  45         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
  46         _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
  47         int fd = -1;
  48         int r;
  49
  50         r = sd_bus_open_system(&bus);
  51         if (r < 0)
  52                 return log_error_errno(r, "Failed to connect system bus: %m");
  53
  54         (void) pager_open(arg_pager_flags);
  55
  56         r = sd_bus_call_method(
  57                         bus,
  58                         "org.freedesktop.oom1",
  59                         "/org/freedesktop/oom1",
  60                         "org.freedesktop.oom1.Manager",
  61                         "DumpByFileDescriptor",
  62                         &error,
  63                         &reply,
  64                         NULL);
  65         if (r < 0)
  66                 return log_error_errno(r, "Failed to dump context: %s", bus_error_message(&error, r));
  67
  68         r = sd_bus_message_read(reply, "h", &fd);
  69         if (r < 0)
  70                 return bus_log_parse_error(r);
  71
  72         fflush(stdout);
  73         return copy_bytes(fd, STDOUT_FILENO, (uint64_t) -1, 0);
  74 }
  75
  76 static int parse_argv(int argc, char *argv[]) {
  77         enum {
  78                 ARG_VERSION = 0x100,
  79                 ARG_NO_PAGER,
  80         };
  81
  82         static const struct option options[] = {
  83                 { "help",     no_argument, NULL, 'h'          },
  84                 { "version",  no_argument, NULL, ARG_VERSION  },
  85                 { "no-pager", no_argument, NULL, ARG_NO_PAGER },
  86                 {}
  87         };
  88
  89         int c;
  90
  91         assert(argc >= 0);
  92         assert(argv);
  93
  94         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
  95
  96                 switch (c) {
  97
  98                         case 'h':
  99                                 return help(0, NULL, NULL);
 100
 101                         case ARG_VERSION:
 102                                 return version();
 103
 104                         case ARG_NO_PAGER:
 105                                 arg_pager_flags |= PAGER_DISABLE;
 106                                 break;
 107
 108                         case '?':
 109                                 return -EINVAL;
 110
 111                         default:
 112                                 assert_not_reached("Invalid option passed.");
 113                 }
 114
 115         return 1;
 116 }
 117
 118 static int run(int argc, char* argv[]) {
 119         static const Verb verbs[] = {
 120                 { "help", VERB_ANY, VERB_ANY, 0,            help       },
 121                 { "dump", VERB_ANY, 1,        VERB_DEFAULT, dump_state },
 122                 {}
 123         };
 124
 125         int r;
 126
 127         log_show_color(true);
 128         log_parse_environment();
 129         log_open();
 130
 131         r = parse_argv(argc, argv);
 132         if (r <= 0)
 133                 return r;
 134
 135         return dispatch_verb(argc, argv, verbs, NULL);
 136 }
 137
 138 DEFINE_MAIN_FUNCTION(run);