ipl_tools/system.c

   1 /*
   2  * Copyright IBM Corp 2008
   3  * Author: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
   4  *
   5  * Linux for System z shutdown actions
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the Free
   9  * Software Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  15  */
  16
  17 #include <ctype.h>
  18 #include <getopt.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <string.h>
  24 #include <fcntl.h>
  25 #include <sys/stat.h>
  26 #include <sys/wait.h>
  27 #include <sys/types.h>
  28 #include <signal.h>
  29 #include <syslog.h>
  30 #include <pthread.h>
  31 #include "chreipl.h"
  32
  33 /* check if we are running in an LPAR environment.
  34  * this functions return 0 if we run inside an lpar and -1 otherwise
  35  */
  36 int islpar(void)
  37 {
  38         int rc;
  39         FILE *filp;
  40         size_t bytes_read;
  41         char buffer[2048];
  42         char *contains_vm;
  43
  44         rc = -1;
  45         filp = fopen("/proc/cpuinfo", "r");
  46         if (!filp) {
  47                 fprintf(stderr, "%s: Can not open /proc/cpuinfo: %s \n"
  48                         , name, strerror(errno));
  49                 return rc;
  50         }
  51         bytes_read = fread(buffer, 1, sizeof(buffer), filp);
  52         if (bytes_read == 0) {
  53                 fprintf(stderr, "%s: Reading /proc/cpuinfo failed:", name);
  54                 fprintf(stderr, "%s\n", strerror(errno));
  55                 goto out;
  56         }
  57         buffer[bytes_read] = '\0';
  58         contains_vm = strstr(buffer, "version = FF");
  59         if (contains_vm == NULL) {
  60                 rc = 0;
  61                 if (verbose)
  62                         printf("Detected System running in LPAR mode\n");
  63                 goto out;
  64         } else {
  65                 if (verbose)
  66                         printf("Detected System running in z/VM mode\n");
  67         }
  68 out:
  69         fclose(filp);
  70         return rc;
  71 }
  72
  73 /* get a substring of a given source with fixed start, end and length */
  74 char *substring(size_t start, size_t stop, const char *src, char *dst,
  75                 size_t size)
  76 {
  77         unsigned int count;
  78
  79         count = stop - start;
  80         if (count >= --size)
  81                 count = size;
  82         sprintf(dst, "%.*s", count, src + start);
  83         return dst;
  84 }
  85
  86 /*
  87  * check whether we are started as root.
  88  * Return 0 if user is root, non-zero otherwise.
  89  */
  90 int check_for_root(void)
  91 {
  92         if (geteuid() != 0)
  93                 return -1;
  94         else
  95                 return 0;
  96 }
  97
  98 /*
  99  * check if a given string is composed of hex numbers soley.
 100  * return 0 if true and -1 otherwise
 101  */
 102 int ishex(char *cp)
 103 {
 104
 105         unsigned int i;
 106         char c;
 107
 108         for (i = 0; i <= strlen(cp); i++) {
 109                 c = cp[i];
 110                 if (isxdigit(cp[i]))
 111                         continue;
 112                 else
 113                         return -1;
 114         }
 115         return 0;
 116 }
 117
 118 /* convert a string to lower case */
 119 void strlow(char *s)
 120 {
 121         while (*s) {
 122                 *s = tolower(*s);
 123                 s++;
 124         }
 125 }
 126
 127 /*
 128  * write a string to a particular file
 129  */
 130 int strwrt(char *string, char *file)
 131 {
 132         FILE *filp;
 133         char path[4096];
 134         int rc;
 135
 136         strncpy(path, file, sizeof(path));
 137         if (access(path, W_OK) == 0) {
 138                 filp = fopen(path, "w");
 139                 if (!filp) {
 140                         fprintf(stderr, "%s: Can not open %s :", name, path);
 141                         fprintf(stderr, "%s\n", strerror(errno));
 142                         exit(1);
 143                 }
 144                 rc = fputs(string, filp);
 145                 fclose(filp);
 146                 if (rc < 0) {
 147                         fprintf(stderr, "%s: Failed to write %s "
 148                                 "into %s:", name, string, path);
 149                         fprintf(stderr, "%s\n", strerror(errno));
 150                         return -1;
 151                 } else
 152                         return 0;
 153         } else {
 154                 fprintf(stderr, "%s: Can not open %s :", name, path);
 155                 fprintf(stderr, "%s\n", strerror(errno));
 156         }
 157         return -1;
 158 }
 159
 160 /*
 161  * read a string from a particular file
 162  */
 163 int strrd(char *string, char *file)
 164 {
 165         FILE *filp;
 166         char path[4096];
 167         int rc;
 168
 169         strncpy(path, file, sizeof(path));
 170         if (access(path, R_OK) == 0) {
 171                 filp = fopen(path, "rb");
 172                 if (!filp) {
 173                         fprintf(stderr, "%s: Can not open %s: ", name, file);
 174                         fprintf(stderr, "%s\n", strerror(errno));
 175                         exit(1);
 176                 }
 177                 rc = fread(string, 1, 4096, filp);
 178                 fclose(filp);
 179                 /*
 180                  *  special handling is required for
 181                  *  /sys/firmware/reipl/ccw/loadparm
 182                  *  since this file can be empty
 183                  */
 184                 if (rc < 0 && strncmp(file,
 185                         "/sys/firmware/reipl/ccw/loadparm",
 186                         strlen(file)) == 0) {
 187                         string[0] = '\0';
 188                         return 0;
 189                 }
 190                 if (rc < 0) {
 191                         fprintf(stderr, "%s: Failed to read from %s:", name,
 192                                         file);
 193                         fprintf(stderr, "%s\n", strerror(errno));
 194                         return -1;
 195                 } else {
 196                         string[rc] = 0;
 197                         if (string[strlen(string) - 1] == '\n')
 198                                 string[strlen(string) - 1] = 0;
 199                         return 0;
 200                 }
 201         } else {
 202                 fprintf(stderr, "%s: Can not open %s: ", name, file);
 203                 fprintf(stderr, "%s\n", strerror(errno));
 204         }
 205         return -1;
 206 }
 207
 208 /*
 209  * read an integer from a particular file
 210  */
 211 int intrd(int *val, char *file)
 212 {
 213         FILE *filp;
 214         char path[4096];
 215         int rc;
 216
 217         strncpy(path, file, sizeof(path));
 218         if (access(path, R_OK) == 0) {
 219                 filp = fopen(path, "r");
 220                 if (!filp) {
 221                         fprintf(stderr, "%s: Can not open %s: ", name, file);
 222                         fprintf(stderr, "%s\n", strerror(errno));
 223                         exit(1);
 224                 }
 225                 rc = fscanf(filp, "%d", val);
 226                 fclose(filp);
 227                 if (rc < 0) {
 228                         /*
 229                          * supress error messages when called via lsreipl
 230                          *
 231                          */
 232                         if (strncmp(file, "/sys/firmware/reipl/ccw/loadparm",
 233                                 strlen(file)) >= 0)
 234                                         return -1;
 235                         fprintf(stderr, "%s: Failed to read from %s: ", name,
 236                                 file);
 237                         fprintf(stderr, "%s\n", strerror(errno));
 238                         return -1;
 239                 } else
 240                         return 0;
 241         } else {
 242                 fprintf(stderr, "%s: Can not open %s: ", name, file);
 243                 fprintf(stderr, "%s\n", strerror(errno));
 244         }
 245         return -1;
 246 }
 247
 248 /*
 249  * write an integer to a particular file
 250  */
 251 int intwrt(int val, char *file)
 252 {
 253         FILE *filp;
 254         char path[4096];
 255         int rc;
 256
 257         strncpy(path, file, sizeof(path));
 258         if (access(path, W_OK) == 0) {
 259                 filp = fopen(path, "w");
 260                 if (!filp) {
 261                         fprintf(stderr, "%s: Can not open %s :", name, path);
 262                         fprintf(stderr, "%s\n", strerror(errno));
 263                         exit(1);
 264                 }
 265                 rc = fprintf(filp, "%d\n", val);
 266                 fclose(filp);
 267                 if (rc < 0) {
 268                         fprintf(stderr, "%s: Failed to write %d into %s: ",
 269                                 name, val, path);
 270                         fprintf(stderr, "%s\n", strerror(errno));
 271                         return -1;
 272                 } else
 273                         return 0;
 274         } else {
 275                 fprintf(stderr, "%s: Can not open %s :", name, path);
 276                 fprintf(stderr, "%s\n", strerror(errno));
 277         }
 278         return -1;
 279 }
 280
 281 /*
 282  * write an unformated string to a particular file. this is needed to specify
 283  * multiple vmcmd commands
 284  */
 285 int ustrwrt(char *string, char *file)
 286 {
 287         char path[4096];
 288         int rc, fd;
 289
 290         strncpy(path, file, sizeof(path));
 291         if (access(path, W_OK) == 0) {
 292                 fd = open(file, O_WRONLY);
 293                 if (!fd) {
 294                         fprintf(stderr, "%s: Can not open %s : ", name, path);
 295                         fprintf(stderr, "%s\n", strerror(errno));
 296                         exit(1);
 297                 }
 298                 rc = write(fd, string, strlen(string));
 299                 close(fd);
 300                 if (rc < 0) {
 301                         fprintf(stderr, "%s: Failed to write %s into %s: ",
 302                                 name, string, path);
 303                         fprintf(stderr, "%s\n", strerror(errno));
 304                         return -1;
 305                 } else
 306                         return 0;
 307         } else {
 308                 fprintf(stderr, "%s: Can not open %s : ", name, path);
 309                 fprintf(stderr, "%s\n", strerror(errno));
 310         }
 311         return -1;
 312 }