openwrt/package/openwrt/libshared/shutils.c

   1 /*
   2  * Shell-like utility functions
   3  *
   4  * Copyright 2004, Broadcom Corporation
   5  * All Rights Reserved.
   6  *
   7  * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
   8  * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
   9  * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
  10  * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
  11  *
  12  * $Id$
  13  */
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <stdarg.h>
  18 #include <errno.h>
  19 #include <error.h>
  20 #include <fcntl.h>
  21 #include <limits.h>
  22 #include <unistd.h>
  23 #include <signal.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <sys/wait.h>
  28 #include <termios.h>
  29 #include <sys/ioctl.h>
  30 #include <sys/time.h>
  31 #include <net/ethernet.h>
  32
  33 #include <shutils.h>
  34
  35 /*
  36  * Reads file and returns contents
  37  * @param       fd      file descriptor
  38  * @return      contents of file or NULL if an error occurred
  39  */
  40 char *
  41 fd2str(int fd)
  42 {
  43         char *buf = NULL;
  44         size_t count = 0, n;
  45
  46         do {
  47                 buf = realloc(buf, count + 512);
  48                 n = read(fd, buf + count, 512);
  49                 if (n < 0) {
  50                         free(buf);
  51                         buf = NULL;
  52                 }
  53                 count += n;
  54         } while (n == 512);
  55
  56         close(fd);
  57         if (buf)
  58                 buf[count] = '\0';
  59         return buf;
  60 }
  61
  62 /*
  63  * Reads file and returns contents
  64  * @param       path    path to file
  65  * @return      contents of file or NULL if an error occurred
  66  */
  67 char *
  68 file2str(const char *path)
  69 {
  70         int fd;
  71
  72         if ((fd = open(path, O_RDONLY)) == -1) {
  73                 perror(path);
  74                 return NULL;
  75         }
  76
  77         return fd2str(fd);
  78 }
  79
  80 /*
  81  * Waits for a file descriptor to change status or unblocked signal
  82  * @param       fd      file descriptor
  83  * @param       timeout seconds to wait before timing out or 0 for no timeout
  84  * @return      1 if descriptor changed status or 0 if timed out or -1 on error
  85  */
  86 int
  87 waitfor(int fd, int timeout)
  88 {
  89         fd_set rfds;
  90         struct timeval tv = { timeout, 0 };
  91
  92         FD_ZERO(&rfds);
  93         FD_SET(fd, &rfds);
  94         return select(fd + 1, &rfds, NULL, NULL, (timeout > 0) ? &tv : NULL);
  95 }
  96
  97 /*
  98  * Concatenates NULL-terminated list of arguments into a single
  99  * commmand and executes it
 100  * @param       argv    argument list
 101  * @param       path    NULL, ">output", or ">>output"
 102  * @param       timeout seconds to wait before timing out or 0 for no timeout
 103  * @param       ppid    NULL to wait for child termination or pointer to pid
 104  * @return      return value of executed command or errno
 105  */
 106 int
 107 _eval(char *const argv[], char *path, int timeout, int *ppid)
 108 {
 109         pid_t pid;
 110         int status;
 111         int fd;
 112         int flags;
 113         int sig;
 114         char buf[254]="";
 115         int i;
 116
 117         switch (pid = fork()) {
 118         case -1:        /* error */
 119                 perror("fork");
 120                 return errno;
 121         case 0:         /* child */
 122                 /* Reset signal handlers set for parent process */
 123                 for (sig = 0; sig < (_NSIG-1); sig++)
 124                         signal(sig, SIG_DFL);
 125
 126                 /* Clean up */
 127                 ioctl(0, TIOCNOTTY, 0);
 128                 close(STDIN_FILENO);
 129                 close(STDOUT_FILENO);
 130                 close(STDERR_FILENO);
 131                 setsid();
 132
 133                 /* We want to check the board if exist UART? , add by honor 2003-12-04 */
 134                 if ((fd = open("/dev/console", O_RDWR)) < 0) {
 135                         (void) open("/dev/null", O_RDONLY);
 136                         (void) open("/dev/null", O_WRONLY);
 137                         (void) open("/dev/null", O_WRONLY);
 138                 }
 139                 else{
 140                         close(fd);
 141                         (void) open("/dev/console", O_RDONLY);
 142                         (void) open("/dev/console", O_WRONLY);
 143                         (void) open("/dev/console", O_WRONLY);
 144                 }
 145
 146                 /* Redirect stdout to <path> */
 147                 if (path) {
 148                         flags = O_WRONLY | O_CREAT;
 149                         if (!strncmp(path, ">>", 2)) {
 150                                 /* append to <path> */
 151                                 flags |= O_APPEND;
 152                                 path += 2;
 153                         } else if (!strncmp(path, ">", 1)) {
 154                                 /* overwrite <path> */
 155                                 flags |= O_TRUNC;
 156                                 path += 1;
 157                         }
 158                         if ((fd = open(path, flags, 0644)) < 0)
 159                                 perror(path);
 160                         else {
 161                                 dup2(fd, STDOUT_FILENO);
 162                                 close(fd);
 163                         }
 164                 }
 165
 166                 /* execute command */
 167                 for(i=0 ; argv[i] ; i++)
 168                         snprintf(buf+strlen(buf), sizeof(buf), "%s ", argv[i]);
 169                 dprintf("cmd=[%s]\n", buf);
 170                 setenv("PATH", "/sbin:/bin:/usr/sbin:/usr/bin", 1);
 171                 alarm(timeout);
 172                 execvp(argv[0], argv);
 173                 perror(argv[0]);
 174                 exit(errno);
 175         default:        /* parent */
 176                 if (ppid) {
 177                         *ppid = pid;
 178                         return 0;
 179                 } else {
 180                         waitpid(pid, &status, 0);
 181                         if (WIFEXITED(status))
 182                                 return WEXITSTATUS(status);
 183                         else
 184                                 return status;
 185                 }
 186         }
 187 }
 188
 189 /*
 190  * Concatenates NULL-terminated list of arguments into a single
 191  * commmand and executes it
 192  * @param       argv    argument list
 193  * @return      stdout of executed command or NULL if an error occurred
 194  */
 195 char *
 196 _backtick(char *const argv[])
 197 {
 198         int filedes[2];
 199         pid_t pid;
 200         int status;
 201         char *buf = NULL;
 202
 203         /* create pipe */
 204         if (pipe(filedes) == -1) {
 205                 perror(argv[0]);
 206                 return NULL;
 207         }
 208
 209         switch (pid = fork()) {
 210         case -1:        /* error */
 211                 return NULL;
 212         case 0:         /* child */
 213                 close(filedes[0]);      /* close read end of pipe */
 214                 dup2(filedes[1], 1);    /* redirect stdout to write end of pipe */
 215                 close(filedes[1]);      /* close write end of pipe */
 216                 execvp(argv[0], argv);
 217                 exit(errno);
 218                 break;
 219         default:        /* parent */
 220                 close(filedes[1]);      /* close write end of pipe */
 221                 buf = fd2str(filedes[0]);
 222                 waitpid(pid, &status, 0);
 223                 break;
 224         }
 225
 226         return buf;
 227 }
 228
 229 /*
 230  * Kills process whose PID is stored in plaintext in pidfile
 231  * @param       pidfile PID file
 232  * @return      0 on success and errno on failure
 233  */
 234 int
 235 kill_pidfile(char *pidfile)
 236 {
 237         FILE *fp = fopen(pidfile, "r");
 238         char buf[256];
 239
 240         if (fp && fgets(buf, sizeof(buf), fp)) {
 241                 pid_t pid = strtoul(buf, NULL, 0);
 242                 fclose(fp);
 243                 return kill(pid, SIGTERM);
 244         } else
 245                 return errno;
 246 }
 247
 248 /*
 249  * fread() with automatic retry on syscall interrupt
 250  * @param       ptr     location to store to
 251  * @param       size    size of each element of data
 252  * @param       nmemb   number of elements
 253  * @param       stream  file stream
 254  * @return      number of items successfully read
 255  */
 256 int
 257 safe_fread(void *ptr, size_t size, size_t nmemb, FILE *stream)
 258 {
 259         size_t ret = 0;
 260
 261         do {
 262                 clearerr(stream);
 263                 ret += fread((char *)ptr + (ret * size), size, nmemb - ret, stream);
 264         } while (ret < nmemb && ferror(stream) && errno == EINTR);
 265
 266         return ret;
 267 }
 268
 269 /*
 270  * fwrite() with automatic retry on syscall interrupt
 271  * @param       ptr     location to read from
 272  * @param       size    size of each element of data
 273  * @param       nmemb   number of elements
 274  * @param       stream  file stream
 275  * @return      number of items successfully written
 276  */
 277 int
 278 safe_fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 279 {
 280         size_t ret = 0;
 281
 282         do {
 283                 clearerr(stream);
 284                 ret += fwrite((char *)ptr + (ret * size), size, nmemb - ret, stream);
 285         } while (ret < nmemb && ferror(stream) && errno == EINTR);
 286
 287         return ret;
 288 }
 289
 290 /*
 291  * Convert Ethernet address string representation to binary data
 292  * @param       a       string in xx:xx:xx:xx:xx:xx notation
 293  * @param       e       binary data
 294  * @return      TRUE if conversion was successful and FALSE otherwise
 295  */
 296 int
 297 ether_atoe(const char *a, unsigned char *e)
 298 {
 299         char *c = (char *) a;
 300         int i = 0;
 301
 302         memset(e, 0, ETHER_ADDR_LEN);
 303         for (;;) {
 304                 e[i++] = (unsigned char) strtoul(c, &c, 16);
 305                 if (!*c++ || i == ETHER_ADDR_LEN)
 306                         break;
 307         }
 308         return (i == ETHER_ADDR_LEN);
 309 }
 310
 311 /*
 312  * Convert Ethernet address binary data to string representation
 313  * @param       e       binary data
 314  * @param       a       string in xx:xx:xx:xx:xx:xx notation
 315  * @return      a
 316  */
 317 char *
 318 ether_etoa(const unsigned char *e, char *a)
 319 {
 320         char *c = a;
 321         int i;
 322
 323         for (i = 0; i < ETHER_ADDR_LEN; i++) {
 324                 if (i)
 325                         *c++ = ':';
 326                 c += sprintf(c, "%02X", e[i] & 0xff);
 327         }
 328         return a;
 329 }