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-rw-r--r--extensions/libipt_owner.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/extensions/libipt_owner.c b/extensions/libipt_owner.c
new file mode 100644
index 00000000..29311022
--- /dev/null
+++ b/extensions/libipt_owner.c
@@ -0,0 +1,219 @@
+/* Shared library add-on to iptables to add OWNER matching support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ipt_owner.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"OWNER match v%s options:\n"
+"[!] --uid-owner userid Match local uid\n"
+"[!] --gid-owner groupid Match local gid\n"
+"[!] --pid-owner processid Match local pid\n"
+"[!] --sid-owner sessionid Match local sid\n"
+"\n",
+NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+ { "uid-owner", 1, 0, '1' },
+ { "gid-owner", 1, 0, '2' },
+ { "pid-owner", 1, 0, '3' },
+ { "sid-owner", 1, 0, '4' },
+ {0}
+};
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+ /* Can't cache this. */
+ *nfcache |= NFC_UNKNOWN;
+}
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int
+parse(int c, char **argv, int invert, unsigned int *flags,
+ const struct ipt_entry *entry,
+ unsigned int *nfcache,
+ struct ipt_entry_match **match)
+{
+ struct ipt_owner_info *ownerinfo = (struct ipt_owner_info *)(*match)->data;
+
+ switch (c) {
+ char *end;
+ struct passwd *pwd;
+ struct group *grp;
+ case '1':
+ if (check_inverse(optarg, &invert))
+ optind++;
+
+ if ((pwd = getpwnam(optarg)))
+ ownerinfo->uid = pwd->pw_uid;
+ else {
+ ownerinfo->uid = strtoul(optarg, &end, 0);
+ if (*end != '\0' || end == optarg)
+ exit_error(PARAMETER_PROBLEM, "Bad OWNER UID value `%s'", optarg);
+ }
+ if (invert)
+ ownerinfo->invert |= IPT_OWNER_UID;
+ ownerinfo->match |= IPT_OWNER_UID;
+ *flags = 1;
+ break;
+
+ case '2':
+ if (check_inverse(optarg, &invert))
+ optind++;
+ if ((grp = getgrnam(optarg)))
+ ownerinfo->gid = grp->gr_gid;
+ else {
+ ownerinfo->gid = strtoul(optarg, &end, 0);
+ if (*end != '\0' || end == optarg)
+ exit_error(PARAMETER_PROBLEM, "Bad OWNER GID value `%s'", optarg);
+ }
+ if (invert)
+ ownerinfo->invert |= IPT_OWNER_GID;
+ ownerinfo->match |= IPT_OWNER_GID;
+ *flags = 1;
+ break;
+
+ case '3':
+ if (check_inverse(optarg, &invert))
+ optind++;
+ ownerinfo->pid = strtoul(optarg, &end, 0);
+ if (*end != '\0' || end == optarg)
+ exit_error(PARAMETER_PROBLEM, "Bad OWNER PID value `%s'", optarg);
+ if (invert)
+ ownerinfo->invert |= IPT_OWNER_PID;
+ ownerinfo->match |= IPT_OWNER_PID;
+ *flags = 1;
+ break;
+
+ case '4':
+ if (check_inverse(optarg, &invert))
+ optind++;
+ ownerinfo->sid = strtoul(optarg, &end, 0);
+ if (*end != '\0' || end == optarg)
+ exit_error(PARAMETER_PROBLEM, "Bad OWNER SID value `%s'", optarg);
+ if (invert)
+ ownerinfo->invert |= IPT_OWNER_SID;
+ ownerinfo->match |= IPT_OWNER_SID;
+ *flags = 1;
+ break;
+
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static void
+print_item(struct ipt_owner_info *info, u_int8_t flag, int numeric, char *label)
+{
+ if(info->match & flag) {
+
+ printf(label);
+
+ if (info->invert & flag)
+ fputc('!', stdout);
+
+ switch(info->match & flag) {
+ case IPT_OWNER_UID:
+ if(!numeric) {
+ struct passwd *pwd = getpwuid(info->uid);
+
+ if(pwd && pwd->pw_name) {
+ printf("%s ", pwd->pw_name);
+ break;
+ }
+ /* FALLTHROUGH */
+ }
+ printf("%u ", info->uid);
+ break;
+ case IPT_OWNER_GID:
+ if(!numeric) {
+ struct group *grp = getgrgid(info->gid);
+
+ if(grp && grp->gr_name) {
+ printf("%s ", grp->gr_name);
+ break;
+ }
+ /* FALLTHROUGH */
+ }
+ printf("%u ", info->gid);
+ break;
+ case IPT_OWNER_PID:
+ printf("%u ", info->pid);
+ break;
+ case IPT_OWNER_SID:
+ printf("%u ", info->sid);
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+/* Final check; must have specified --own. */
+static void
+final_check(unsigned int flags)
+{
+ if (!flags)
+ exit_error(PARAMETER_PROBLEM,
+ "OWNER match: You must specify one or more options");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_match *match,
+ int numeric)
+{
+ struct ipt_owner_info *info = (struct ipt_owner_info *)match->data;
+
+ print_item(info, IPT_OWNER_UID, numeric, "OWNER UID match ");
+ print_item(info, IPT_OWNER_GID, numeric, "OWNER GID match ");
+ print_item(info, IPT_OWNER_PID, numeric, "OWNER PID match ");
+ print_item(info, IPT_OWNER_SID, numeric, "OWNER SID match ");
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+ struct ipt_owner_info *info = (struct ipt_owner_info *)match->data;
+
+ print_item(info, IPT_OWNER_UID, 0, "--uid-owner ");
+ print_item(info, IPT_OWNER_GID, 0, "--gid-owner ");
+ print_item(info, IPT_OWNER_PID, 0, "--pid-owner ");
+ print_item(info, IPT_OWNER_SID, 0, "--sid-owner ");
+}
+
+struct iptables_match owner
+= { NULL,
+ "owner",
+ NETFILTER_VERSION,
+ sizeof(struct ipt_owner_info),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_match(&owner);
+}