ebtablesu.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <fcntl.h>
   8 #include <errno.h>
   9
  10 static void print_help()
  11 {
  12         printf("ebtablesu v"PROGVERSION" ("PROGDATE")\n");
  13         printf(
  14 "Usage:\n"
  15 "ebtablesu open table         : copy the kernel table\n"
  16 "ebtablesu fopen table file   : copy the table from the specified file\n"
  17 "ebtablesu free table         : remove the table from memory\n"
  18 "ebtablesu commit table       : commit the table to the kernel\n"
  19 "ebtablesu fcommit table file : commit the table to the specified file\n\n"
  20 "ebtablesu <ebtables options> : the ebtables specifications\n"
  21 "                               use spaces only to separate options and commands\n"
  22 "For the ebtables options, see\n# ebtables -h\nor\n# man ebtables\n"
  23         );
  24 }
  25 int main(int argc, char *argv[])
  26 {
  27         char *arguments, *pos;
  28         int i, writefd, len = 0;
  29
  30         if (argc > EBTD_ARGC_MAX) {
  31                 fprintf(stderr, "ebtablesd accepts at most %d arguments, %d "
  32                         "arguments were specified. If you need this many "
  33                         "arguments, recompile this tool with a higher value for"
  34                         " EBTD_ARGC_MAX.\n", EBTD_ARGC_MAX - 1, argc - 1);
  35                 return -1;
  36         } else if (argc == 1) {
  37                 fprintf(stderr, "At least one argument is needed.\n");
  38                 print_help();
  39                 exit(0);
  40         }
  41
  42         for (i = 0; i < argc; i++)
  43                 len += strlen(argv[i]);
  44         /* Don't forget '\0' */
  45         len += argc;
  46         if (len > EBTD_CMDLINE_MAXLN) {
  47                 fprintf(stderr, "ebtablesd has a maximum command line argument "
  48                        "length of %d, an argument length of %d was received. "
  49                        "If a smaller length is unfeasible, recompile this tool "
  50                        "with a higher value for EBTD_CMDLINE_MAXLN.\n",
  51                        EBTD_CMDLINE_MAXLN, len);
  52                 return -1;
  53         }
  54
  55         if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
  56                 if (argc != 2) {
  57                         fprintf(stderr, "%s does not accept options.\n", argv[1]);
  58                         return -1;
  59                 }
  60                 print_help();
  61                 exit(0);
  62         }
  63
  64         if (!(arguments = (char *)malloc(len))) {
  65                 fprintf(stderr, "ebtablesu: out of memory.\n");
  66                 return -1;
  67         }
  68
  69         if ((writefd = open(EBTD_PIPE, O_WRONLY, 0)) == -1) {
  70                 fprintf(stderr, "Could not open the pipe, perhaps ebtablesd is "
  71                         "not running or you don't have write permission (try "
  72                         "running as root).\n");
  73                 return -1;
  74         }
  75
  76         pos = arguments;
  77         for (i = 0; i < argc; i++) {
  78                 strcpy(pos, argv[i]);
  79                 pos += strlen(argv[i]);
  80                 *(pos++) = ' ';
  81         }
  82
  83         *(pos-1) = '\n';
  84         if (write(writefd, arguments, len) == -1) {
  85                 perror("write");
  86                 return -1;
  87         }
  88         return 0;
  89 }