ceph/src/common/module.c

   1 /*
   2  * Ceph - scalable distributed file system
   3  *
   4  * Copyright (C) 2014 Inktank Storage, Inc.
   5  *
   6  * This is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License version 2.1, as published by the Free Software
   9  * Foundation.  See file COPYING.
  10  *
  11  */
  12
  13 #include "acconfig.h"
  14 #include <errno.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #if defined(__FreeBSD__)
  19 #include <sys/wait.h>
  20 #endif
  21
  22 /*
  23  * TODO: Switch to libkmod when we abandon older platforms.  The APIs
  24  * we want are:
  25  *
  26  * - kmod_module_new_from_name() for obtaining handles;
  27  * - kmod_module_probe_insert_module() for module_load();
  28  * - kmod_module_get_info(), kmod_module_info_get_{key,value}() for
  29  *   module_has_param().
  30  */
  31
  32 /*
  33  * Return command's exit status or -1 on error.
  34  */
  35 static int run_command(const char *command)
  36 {
  37         int status;
  38
  39         status = system(command);
  40         if (status >= 0 && WIFEXITED(status))
  41                 return WEXITSTATUS(status);
  42
  43         if (status < 0) {
  44                 char error_buf[80];
  45 #ifdef STRERROR_R_CHAR_P
  46                 char* dummy = strerror_r(errno, error_buf, sizeof(error_buf));
  47                 (void)dummy;
  48 #else
  49                 strerror_r(errno, error_buf, sizeof(error_buf));
  50 #endif
  51                 fprintf(stderr, "couldn't run '%s': %s\n", command,
  52                         error_buf);
  53         } else if (WIFSIGNALED(status)) {
  54                 fprintf(stderr, "'%s' killed by signal %d\n", command,
  55                         WTERMSIG(status));
  56         } else {
  57                 fprintf(stderr, "weird status from '%s': %d\n", command,
  58                         status);
  59         }
  60
  61         return -1;
  62 }
  63
  64 int module_has_param(const char *module, const char *param)
  65 {
  66         char command[128];
  67
  68         snprintf(command, sizeof(command),
  69                  "/sbin/modinfo -F parm %s | /bin/grep -q ^%s:",
  70                  module, param);
  71
  72         return run_command(command) == 0;
  73 }
  74
  75 int module_load(const char *module, const char *options)
  76 {
  77         char command[128];
  78
  79         snprintf(command, sizeof(command), "/sbin/modprobe %s %s",
  80                  module, (options ? options : ""));
  81
  82         return run_command(command);
  83 }