extensions/libipt_owner.c

   1 /* Shared library add-on to iptables to add OWNER matching support. */
   2 #include <stdio.h>
   3 #include <netdb.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <getopt.h>
   7 #include <pwd.h>
   8 #include <grp.h>
   9
  10 #include <iptables.h>
  11 #include <linux/netfilter_ipv4/ipt_owner.h>
  12
  13 /* Function which prints out usage message. */
  14 static void
  15 help(void)
  16 {
  17 #ifdef IPT_OWNER_COMM
  18         printf(
  19 "OWNER match v%s options:\n"
  20 "[!] --uid-owner userid     Match local uid\n"
  21 "[!] --gid-owner groupid    Match local gid\n"
  22 "[!] --pid-owner processid  Match local pid\n"
  23 "[!] --sid-owner sessionid  Match local sid\n"
  24 "[!] --cmd-owner name       Match local command name\n"
  25 "\n",
  26 IPTABLES_VERSION);
  27 #else
  28         printf(
  29 "OWNER match v%s options:\n"
  30 "[!] --uid-owner userid     Match local uid\n"
  31 "[!] --gid-owner groupid    Match local gid\n"
  32 "[!] --pid-owner processid  Match local pid\n"
  33 "[!] --sid-owner sessionid  Match local sid\n"
  34 "\n",
  35 IPTABLES_VERSION);
  36 #endif /* IPT_OWNER_COMM */
  37 }
  38
  39 static struct option opts[] = {
  40         { "uid-owner", 1, 0, '1' },
  41         { "gid-owner", 1, 0, '2' },
  42         { "pid-owner", 1, 0, '3' },
  43         { "sid-owner", 1, 0, '4' },
  44 #ifdef IPT_OWNER_COMM
  45         { "cmd-owner", 1, 0, '5' },
  46 #endif
  47         {0}
  48 };
  49
  50 /* Initialize the match. */
  51 static void
  52 init(struct ipt_entry_match *m, unsigned int *nfcache)
  53 {
  54         /* Can't cache this. */
  55         *nfcache |= NFC_UNKNOWN;
  56 }
  57
  58 /* Function which parses command options; returns true if it
  59    ate an option */
  60 static int
  61 parse(int c, char **argv, int invert, unsigned int *flags,
  62       const struct ipt_entry *entry,
  63       unsigned int *nfcache,
  64       struct ipt_entry_match **match)
  65 {
  66         struct ipt_owner_info *ownerinfo = (struct ipt_owner_info *)(*match)->data;
  67
  68         switch (c) {
  69                 char *end;
  70                 struct passwd *pwd;
  71                 struct group *grp;
  72         case '1':
  73                 check_inverse(optarg, &invert, &optind, 0);
  74                 if ((pwd = getpwnam(optarg)))
  75                         ownerinfo->uid = pwd->pw_uid;
  76                 else {
  77                         ownerinfo->uid = strtoul(optarg, &end, 0);
  78                         if (*end != '\0' || end == optarg)
  79                                 exit_error(PARAMETER_PROBLEM, "Bad OWNER UID value `%s'", optarg);
  80                 }
  81                 if (invert)
  82                         ownerinfo->invert |= IPT_OWNER_UID;
  83                 ownerinfo->match |= IPT_OWNER_UID;
  84                 *flags = 1;
  85                 break;
  86
  87         case '2':
  88                 check_inverse(optarg, &invert, &optind, 0);
  89                 if ((grp = getgrnam(optarg)))
  90                         ownerinfo->gid = grp->gr_gid;
  91                 else {
  92                         ownerinfo->gid = strtoul(optarg, &end, 0);
  93                         if (*end != '\0' || end == optarg)
  94                                 exit_error(PARAMETER_PROBLEM, "Bad OWNER GID value `%s'", optarg);
  95                 }
  96                 if (invert)
  97                         ownerinfo->invert |= IPT_OWNER_GID;
  98                 ownerinfo->match |= IPT_OWNER_GID;
  99                 *flags = 1;
 100                 break;
 101
 102         case '3':
 103                 check_inverse(optarg, &invert, &optind, 0);
 104                 ownerinfo->pid = strtoul(optarg, &end, 0);
 105                 if (*end != '\0' || end == optarg)
 106                         exit_error(PARAMETER_PROBLEM, "Bad OWNER PID value `%s'", optarg);
 107                 if (invert)
 108                         ownerinfo->invert |= IPT_OWNER_PID;
 109                 ownerinfo->match |= IPT_OWNER_PID;
 110                 *flags = 1;
 111                 break;
 112
 113         case '4':
 114                 check_inverse(optarg, &invert, &optind, 0);
 115                 ownerinfo->sid = strtoul(optarg, &end, 0);
 116                 if (*end != '\0' || end == optarg)
 117                         exit_error(PARAMETER_PROBLEM, "Bad OWNER SID value `%s'", optarg);
 118                 if (invert)
 119                         ownerinfo->invert |= IPT_OWNER_SID;
 120                 ownerinfo->match |= IPT_OWNER_SID;
 121                 *flags = 1;
 122                 break;
 123
 124 #ifdef IPT_OWNER_COMM
 125         case '5':
 126                 check_inverse(optarg, &invert, &optind, 0);
 127                 if(strlen(optarg) > sizeof(ownerinfo->comm))
 128                         exit_error(PARAMETER_PROBLEM, "OWNER CMD `%s' too long, max %d characters", optarg, sizeof(ownerinfo->comm));
 129
 130                 strncpy(ownerinfo->comm, optarg, sizeof(ownerinfo->comm));
 131
 132                 if (invert)
 133                         ownerinfo->invert |= IPT_OWNER_COMM;
 134                 ownerinfo->match |= IPT_OWNER_COMM;
 135                 *flags = 1;
 136                 break;
 137 #endif
 138
 139         default:
 140                 return 0;
 141         }
 142         return 1;
 143 }
 144
 145 static void
 146 print_item(struct ipt_owner_info *info, u_int8_t flag, int numeric, char *label)
 147 {
 148         if(info->match & flag) {
 149
 150                 if (info->invert & flag)
 151                         printf("! ");
 152
 153                 printf(label);
 154
 155                 switch(info->match & flag) {
 156                 case IPT_OWNER_UID:
 157                         if(!numeric) {
 158                                 struct passwd *pwd = getpwuid(info->uid);
 159
 160                                 if(pwd && pwd->pw_name) {
 161                                         printf("%s ", pwd->pw_name);
 162                                         break;
 163                                 }
 164                                 /* FALLTHROUGH */
 165                         }
 166                         printf("%u ", info->uid);
 167                         break;
 168                 case IPT_OWNER_GID:
 169                         if(!numeric) {
 170                                 struct group *grp = getgrgid(info->gid);
 171
 172                                 if(grp && grp->gr_name) {
 173                                         printf("%s ", grp->gr_name);
 174                                         break;
 175                                 }
 176                                 /* FALLTHROUGH */
 177                         }
 178                         printf("%u ", info->gid);
 179                         break;
 180                 case IPT_OWNER_PID:
 181                         printf("%u ", info->pid);
 182                         break;
 183                 case IPT_OWNER_SID:
 184                         printf("%u ", info->sid);
 185                         break;
 186 #ifdef IPT_OWNER_COMM
 187                 case IPT_OWNER_COMM:
 188                         printf("%.*s ", (int)sizeof(info->comm), info->comm);
 189                         break;
 190 #endif
 191                 default:
 192                         break;
 193                 }
 194         }
 195 }
 196
 197 /* Final check; must have specified --own. */
 198 static void
 199 final_check(unsigned int flags)
 200 {
 201         if (!flags)
 202                 exit_error(PARAMETER_PROBLEM,
 203                            "OWNER match: You must specify one or more options");
 204 }
 205
 206 /* Prints out the matchinfo. */
 207 static void
 208 print(const struct ipt_ip *ip,
 209       const struct ipt_entry_match *match,
 210       int numeric)
 211 {
 212         struct ipt_owner_info *info = (struct ipt_owner_info *)match->data;
 213
 214         print_item(info, IPT_OWNER_UID, numeric, "OWNER UID match ");
 215         print_item(info, IPT_OWNER_GID, numeric, "OWNER GID match ");
 216         print_item(info, IPT_OWNER_PID, numeric, "OWNER PID match ");
 217         print_item(info, IPT_OWNER_SID, numeric, "OWNER SID match ");
 218 #ifdef IPT_OWNER_COMM
 219         print_item(info, IPT_OWNER_COMM, numeric, "OWNER CMD match ");
 220 #endif
 221 }
 222
 223 /* Saves the union ipt_matchinfo in parsable form to stdout. */
 224 static void
 225 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 226 {
 227         struct ipt_owner_info *info = (struct ipt_owner_info *)match->data;
 228
 229         print_item(info, IPT_OWNER_UID, 0, "--uid-owner ");
 230         print_item(info, IPT_OWNER_GID, 0, "--gid-owner ");
 231         print_item(info, IPT_OWNER_PID, 0, "--pid-owner ");
 232         print_item(info, IPT_OWNER_SID, 0, "--sid-owner ");
 233 #ifdef IPT_OWNER_COMM
 234         print_item(info, IPT_OWNER_COMM, 0, "--cmd-owner ");
 235 #endif
 236 }
 237
 238 static
 239 struct iptables_match owner
 240 = { NULL,
 241     "owner",
 242     IPTABLES_VERSION,
 243     IPT_ALIGN(sizeof(struct ipt_owner_info)),
 244     IPT_ALIGN(sizeof(struct ipt_owner_info)),
 245     &help,
 246     &init,
 247     &parse,
 248     &final_check,
 249     &print,
 250     &save,
 251     opts
 252 };
 253
 254 void _init(void)
 255 {
 256         register_match(&owner);
 257 }