blob: d27b3ae5768634857d7084f536002607bf0edfe5 [file] [log] [blame]
/*
* libxt_owner - iptables addon for xt_owner
*
* Copyright © CC Computer Consultants GmbH, 2007 - 2008
* Jan Engelhardt <jengelh@computergmbh.de>
*/
#include <getopt.h>
#include <grp.h>
#include <netdb.h>
#include <pwd.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <xtables.h>
#include <linux/netfilter/xt_owner.h>
#include <linux/netfilter_ipv4/ipt_owner.h>
#include <linux/netfilter_ipv6/ip6t_owner.h>
/*
* Note: "UINT32_MAX - 1" is used in the code because -1 is a reserved
* UID/GID value anyway.
*/
enum {
FLAG_UID_OWNER = 1 << 0,
FLAG_GID_OWNER = 1 << 1,
FLAG_SOCKET_EXISTS = 1 << 2,
FLAG_PID_OWNER = 1 << 3,
FLAG_SID_OWNER = 1 << 4,
FLAG_COMM = 1 << 5,
};
static void owner_mt_help_v0(void)
{
#ifdef IPT_OWNER_COMM
printf(
"owner match 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"
"[!] --cmd-owner name Match local command name\n"
"NOTE: PID, SID and command matching are broken on SMP\n");
#else
printf(
"owner match 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"
"NOTE: PID and SID matching are broken on SMP\n");
#endif /* IPT_OWNER_COMM */
}
static void owner_mt6_help_v0(void)
{
printf(
"owner match 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"
"NOTE: PID and SID matching are broken on SMP\n");
}
static void owner_mt_help(void)
{
printf(
"owner match options:\n"
"[!] --uid-owner userid[-userid] Match local UID\n"
"[!] --gid-owner groupid[-groupid] Match local GID\n"
"[!] --socket-exists Match if socket exists\n");
}
static const struct option owner_mt_opts_v0[] = {
{.name = "uid-owner", .has_arg = true, .val = 'u'},
{.name = "gid-owner", .has_arg = true, .val = 'g'},
{.name = "pid-owner", .has_arg = true, .val = 'p'},
{.name = "sid-owner", .has_arg = true, .val = 's'},
#ifdef IPT_OWNER_COMM
{.name = "cmd-owner", .has_arg = true, .val = 'c'},
#endif
{ .name = NULL }
};
static const struct option owner_mt6_opts_v0[] = {
{.name = "uid-owner", .has_arg = true, .val = 'u'},
{.name = "gid-owner", .has_arg = true, .val = 'g'},
{.name = "pid-owner", .has_arg = true, .val = 'p'},
{.name = "sid-owner", .has_arg = true, .val = 's'},
{ .name = NULL }
};
static const struct option owner_mt_opts[] = {
{.name = "uid-owner", .has_arg = true, .val = 'u'},
{.name = "gid-owner", .has_arg = true, .val = 'g'},
{.name = "socket-exists", .has_arg = false, .val = 'k'},
{ .name = NULL }
};
static int
owner_mt_parse_v0(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct ipt_owner_info *info = (void *)(*match)->data;
struct passwd *pwd;
struct group *grp;
unsigned int id;
switch (c) {
case 'u':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--uid-owner", *flags & FLAG_UID_OWNER);
if ((pwd = getpwnam(optarg)) != NULL)
id = pwd->pw_uid;
else if (!xtables_strtoui(optarg, NULL, &id, 0, UINT32_MAX - 1))
xtables_param_act(XTF_BAD_VALUE, "owner", "--uid-owner", optarg);
if (invert)
info->invert |= IPT_OWNER_UID;
info->match |= IPT_OWNER_UID;
info->uid = id;
*flags |= FLAG_UID_OWNER;
return true;
case 'g':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--gid-owner", *flags & FLAG_GID_OWNER);
if ((grp = getgrnam(optarg)) != NULL)
id = grp->gr_gid;
else if (!xtables_strtoui(optarg, NULL, &id, 0, UINT32_MAX - 1))
xtables_param_act(XTF_BAD_VALUE, "owner", "--gid-owner", optarg);
if (invert)
info->invert |= IPT_OWNER_GID;
info->match |= IPT_OWNER_GID;
info->gid = id;
*flags |= FLAG_GID_OWNER;
return true;
case 'p':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--pid-owner", *flags & FLAG_PID_OWNER);
if (!xtables_strtoui(optarg, NULL, &id, 0, INT_MAX))
xtables_param_act(XTF_BAD_VALUE, "owner", "--pid-owner", optarg);
if (invert)
info->invert |= IPT_OWNER_PID;
info->match |= IPT_OWNER_PID;
info->pid = id;
*flags |= FLAG_PID_OWNER;
return true;
case 's':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--sid-owner", *flags & FLAG_SID_OWNER);
if (!xtables_strtoui(optarg, NULL, &id, 0, INT_MAX))
xtables_param_act(XTF_BAD_VALUE, "owner", "--sid-value", optarg);
if (invert)
info->invert |= IPT_OWNER_SID;
info->match |= IPT_OWNER_SID;
info->sid = id;
*flags |= FLAG_SID_OWNER;
return true;
#ifdef IPT_OWNER_COMM
case 'c':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--cmd-owner", *flags & FLAG_COMM);
if (strlen(optarg) > sizeof(info->comm))
xtables_error(PARAMETER_PROBLEM, "owner match: command "
"\"%s\" too long, max. %zu characters",
optarg, sizeof(info->comm));
info->comm[sizeof(info->comm)-1] = '\0';
strncpy(info->comm, optarg, sizeof(info->comm));
if (invert)
info->invert |= IPT_OWNER_COMM;
info->match |= IPT_OWNER_COMM;
*flags |= FLAG_COMM;
return true;
#endif
}
return false;
}
static int
owner_mt6_parse_v0(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct ip6t_owner_info *info = (void *)(*match)->data;
struct passwd *pwd;
struct group *grp;
unsigned int id;
switch (c) {
case 'u':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--uid-owner",
*flags & FLAG_UID_OWNER);
if ((pwd = getpwnam(optarg)) != NULL)
id = pwd->pw_uid;
else if (!xtables_strtoui(optarg, NULL, &id, 0, UINT32_MAX - 1))
xtables_param_act(XTF_BAD_VALUE, "owner", "--uid-owner", optarg);
if (invert)
info->invert |= IP6T_OWNER_UID;
info->match |= IP6T_OWNER_UID;
info->uid = id;
*flags |= FLAG_UID_OWNER;
return true;
case 'g':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--gid-owner",
*flags & FLAG_GID_OWNER);
if ((grp = getgrnam(optarg)) != NULL)
id = grp->gr_gid;
else if (!xtables_strtoui(optarg, NULL, &id, 0, UINT32_MAX - 1))
xtables_param_act(XTF_BAD_VALUE, "owner", "--gid-owner", optarg);
if (invert)
info->invert |= IP6T_OWNER_GID;
info->match |= IP6T_OWNER_GID;
info->gid = id;
*flags |= FLAG_GID_OWNER;
return true;
case 'p':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--pid-owner",
*flags & FLAG_PID_OWNER);
if (!xtables_strtoui(optarg, NULL, &id, 0, INT_MAX))
xtables_param_act(XTF_BAD_VALUE, "owner", "--pid-owner", optarg);
if (invert)
info->invert |= IP6T_OWNER_PID;
info->match |= IP6T_OWNER_PID;
info->pid = id;
*flags |= FLAG_PID_OWNER;
return true;
case 's':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--sid-owner",
*flags & FLAG_SID_OWNER);
if (!xtables_strtoui(optarg, NULL, &id, 0, INT_MAX))
xtables_param_act(XTF_BAD_VALUE, "owner", "--sid-owner", optarg);
if (invert)
info->invert |= IP6T_OWNER_SID;
info->match |= IP6T_OWNER_SID;
info->sid = id;
*flags |= FLAG_SID_OWNER;
return true;
}
return false;
}
static void owner_parse_range(const char *s, unsigned int *from,
unsigned int *to, const char *opt)
{
char *end;
/* -1 is reversed, so the max is one less than that. */
if (!xtables_strtoui(s, &end, from, 0, UINT32_MAX - 1))
xtables_param_act(XTF_BAD_VALUE, "owner", opt, s);
*to = *from;
if (*end == '-' || *end == ':')
if (!xtables_strtoui(end + 1, &end, to, 0, UINT32_MAX - 1))
xtables_param_act(XTF_BAD_VALUE, "owner", opt, s);
if (*end != '\0')
xtables_param_act(XTF_BAD_VALUE, "owner", opt, s);
}
static int owner_mt_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct xt_owner_match_info *info = (void *)(*match)->data;
struct passwd *pwd;
struct group *grp;
unsigned int from, to;
switch (c) {
case 'u':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--uid-owner",
*flags & FLAG_UID_OWNER);
if ((pwd = getpwnam(optarg)) != NULL)
from = to = pwd->pw_uid;
else
owner_parse_range(optarg, &from, &to, "--uid-owner");
if (invert)
info->invert |= XT_OWNER_UID;
info->match |= XT_OWNER_UID;
info->uid_min = from;
info->uid_max = to;
*flags |= FLAG_UID_OWNER;
return true;
case 'g':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--gid-owner",
*flags & FLAG_GID_OWNER);
if ((grp = getgrnam(optarg)) != NULL)
from = to = grp->gr_gid;
else
owner_parse_range(optarg, &from, &to, "--gid-owner");
if (invert)
info->invert |= XT_OWNER_GID;
info->match |= XT_OWNER_GID;
info->gid_min = from;
info->gid_max = to;
*flags |= FLAG_GID_OWNER;
return true;
case 'k':
xtables_param_act(XTF_ONLY_ONCE, "owner", "--socket-exists",
*flags & FLAG_SOCKET_EXISTS);
if (invert)
info->invert |= XT_OWNER_SOCKET;
info->match |= XT_OWNER_SOCKET;
*flags |= FLAG_SOCKET_EXISTS;
return true;
}
return false;
}
static void owner_mt_check(unsigned int flags)
{
if (flags == 0)
xtables_error(PARAMETER_PROBLEM, "owner: At least one of "
"--uid-owner, --gid-owner or --socket-exists "
"is required");
}
static void
owner_mt_print_item_v0(const struct ipt_owner_info *info, const char *label,
u_int8_t flag, bool numeric)
{
if (!(info->match & flag))
return;
if (info->invert & flag)
printf("! ");
printf("%s ", label);
switch (info->match & flag) {
case IPT_OWNER_UID:
if (!numeric) {
struct passwd *pwd = getpwuid(info->uid);
if (pwd != NULL && pwd->pw_name != NULL) {
printf("%s ", pwd->pw_name);
break;
}
}
printf("%u ", (unsigned int)info->uid);
break;
case IPT_OWNER_GID:
if (!numeric) {
struct group *grp = getgrgid(info->gid);
if (grp != NULL && grp->gr_name != NULL) {
printf("%s ", grp->gr_name);
break;
}
}
printf("%u ", (unsigned int)info->gid);
break;
case IPT_OWNER_PID:
printf("%u ", (unsigned int)info->pid);
break;
case IPT_OWNER_SID:
printf("%u ", (unsigned int)info->sid);
break;
#ifdef IPT_OWNER_COMM
case IPT_OWNER_COMM:
printf("%.*s ", (int)sizeof(info->comm), info->comm);
break;
#endif
}
}
static void
owner_mt6_print_item_v0(const struct ip6t_owner_info *info, const char *label,
u_int8_t flag, bool numeric)
{
if (!(info->match & flag))
return;
if (info->invert & flag)
printf("! ");
printf("%s ", label);
switch (info->match & flag) {
case IP6T_OWNER_UID:
if (!numeric) {
struct passwd *pwd = getpwuid(info->uid);
if (pwd != NULL && pwd->pw_name != NULL) {
printf("%s ", pwd->pw_name);
break;
}
}
printf("%u ", (unsigned int)info->uid);
break;
case IP6T_OWNER_GID:
if (!numeric) {
struct group *grp = getgrgid(info->gid);
if (grp != NULL && grp->gr_name != NULL) {
printf("%s ", grp->gr_name);
break;
}
}
printf("%u ", (unsigned int)info->gid);
break;
case IP6T_OWNER_PID:
printf("%u ", (unsigned int)info->pid);
break;
case IP6T_OWNER_SID:
printf("%u ", (unsigned int)info->sid);
break;
}
}
static void
owner_mt_print_item(const struct xt_owner_match_info *info, const char *label,
u_int8_t flag, bool numeric)
{
if (!(info->match & flag))
return;
if (info->invert & flag)
printf("! ");
printf("%s ", label);
switch (info->match & flag) {
case XT_OWNER_UID:
if (info->uid_min != info->uid_max) {
printf("%u-%u ", (unsigned int)info->uid_min,
(unsigned int)info->uid_max);
break;
} else if (!numeric) {
const struct passwd *pwd = getpwuid(info->uid_min);
if (pwd != NULL && pwd->pw_name != NULL) {
printf("%s ", pwd->pw_name);
break;
}
}
printf("%u ", (unsigned int)info->uid_min);
break;
case XT_OWNER_GID:
if (info->gid_min != info->gid_max) {
printf("%u-%u ", (unsigned int)info->gid_min,
(unsigned int)info->gid_max);
break;
} else if (!numeric) {
const struct group *grp = getgrgid(info->gid_min);
if (grp != NULL && grp->gr_name != NULL) {
printf("%s ", grp->gr_name);
break;
}
}
printf("%u ", (unsigned int)info->gid_min);
break;
}
}
static void
owner_mt_print_v0(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct ipt_owner_info *info = (void *)match->data;
owner_mt_print_item_v0(info, "owner UID match", IPT_OWNER_UID, numeric);
owner_mt_print_item_v0(info, "owner GID match", IPT_OWNER_GID, numeric);
owner_mt_print_item_v0(info, "owner PID match", IPT_OWNER_PID, numeric);
owner_mt_print_item_v0(info, "owner SID match", IPT_OWNER_SID, numeric);
#ifdef IPT_OWNER_COMM
owner_mt_print_item_v0(info, "owner CMD match", IPT_OWNER_COMM, numeric);
#endif
}
static void
owner_mt6_print_v0(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct ip6t_owner_info *info = (void *)match->data;
owner_mt6_print_item_v0(info, "owner UID match", IPT_OWNER_UID, numeric);
owner_mt6_print_item_v0(info, "owner GID match", IPT_OWNER_GID, numeric);
owner_mt6_print_item_v0(info, "owner PID match", IPT_OWNER_PID, numeric);
owner_mt6_print_item_v0(info, "owner SID match", IPT_OWNER_SID, numeric);
}
static void owner_mt_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct xt_owner_match_info *info = (void *)match->data;
owner_mt_print_item(info, "owner socket exists", XT_OWNER_SOCKET, numeric);
owner_mt_print_item(info, "owner UID match", XT_OWNER_UID, numeric);
owner_mt_print_item(info, "owner GID match", XT_OWNER_GID, numeric);
}
static void
owner_mt_save_v0(const void *ip, const struct xt_entry_match *match)
{
const struct ipt_owner_info *info = (void *)match->data;
owner_mt_print_item_v0(info, "--uid-owner", IPT_OWNER_UID, true);
owner_mt_print_item_v0(info, "--gid-owner", IPT_OWNER_GID, true);
owner_mt_print_item_v0(info, "--pid-owner", IPT_OWNER_PID, true);
owner_mt_print_item_v0(info, "--sid-owner", IPT_OWNER_SID, true);
#ifdef IPT_OWNER_COMM
owner_mt_print_item_v0(info, "--cmd-owner", IPT_OWNER_COMM, true);
#endif
}
static void
owner_mt6_save_v0(const void *ip, const struct xt_entry_match *match)
{
const struct ip6t_owner_info *info = (void *)match->data;
owner_mt6_print_item_v0(info, "--uid-owner", IPT_OWNER_UID, true);
owner_mt6_print_item_v0(info, "--gid-owner", IPT_OWNER_GID, true);
owner_mt6_print_item_v0(info, "--pid-owner", IPT_OWNER_PID, true);
owner_mt6_print_item_v0(info, "--sid-owner", IPT_OWNER_SID, true);
}
static void owner_mt_save(const void *ip, const struct xt_entry_match *match)
{
const struct xt_owner_match_info *info = (void *)match->data;
owner_mt_print_item(info, "--socket-exists", XT_OWNER_SOCKET, false);
owner_mt_print_item(info, "--uid-owner", XT_OWNER_UID, false);
owner_mt_print_item(info, "--gid-owner", XT_OWNER_GID, false);
}
static struct xtables_match owner_mt_reg_v0 = {
.version = XTABLES_VERSION,
.name = "owner",
.revision = 0,
.family = NFPROTO_IPV4,
.size = XT_ALIGN(sizeof(struct ipt_owner_info)),
.userspacesize = XT_ALIGN(sizeof(struct ipt_owner_info)),
.help = owner_mt_help_v0,
.parse = owner_mt_parse_v0,
.final_check = owner_mt_check,
.print = owner_mt_print_v0,
.save = owner_mt_save_v0,
.extra_opts = owner_mt_opts_v0,
};
static struct xtables_match owner_mt6_reg_v0 = {
.version = XTABLES_VERSION,
.name = "owner",
.revision = 0,
.family = NFPROTO_IPV6,
.size = XT_ALIGN(sizeof(struct ip6t_owner_info)),
.userspacesize = XT_ALIGN(sizeof(struct ip6t_owner_info)),
.help = owner_mt6_help_v0,
.parse = owner_mt6_parse_v0,
.final_check = owner_mt_check,
.print = owner_mt6_print_v0,
.save = owner_mt6_save_v0,
.extra_opts = owner_mt6_opts_v0,
};
static struct xtables_match owner_mt_reg = {
.version = XTABLES_VERSION,
.name = "owner",
.revision = 1,
.family = NFPROTO_IPV4,
.size = XT_ALIGN(sizeof(struct xt_owner_match_info)),
.userspacesize = XT_ALIGN(sizeof(struct xt_owner_match_info)),
.help = owner_mt_help,
.parse = owner_mt_parse,
.final_check = owner_mt_check,
.print = owner_mt_print,
.save = owner_mt_save,
.extra_opts = owner_mt_opts,
};
static struct xtables_match owner_mt6_reg = {
.version = XTABLES_VERSION,
.name = "owner",
.revision = 1,
.family = NFPROTO_IPV6,
.size = XT_ALIGN(sizeof(struct xt_owner_match_info)),
.userspacesize = XT_ALIGN(sizeof(struct xt_owner_match_info)),
.help = owner_mt_help,
.parse = owner_mt_parse,
.final_check = owner_mt_check,
.print = owner_mt_print,
.save = owner_mt_save,
.extra_opts = owner_mt_opts,
};
void _init(void)
{
xtables_register_match(&owner_mt_reg_v0);
xtables_register_match(&owner_mt6_reg_v0);
xtables_register_match(&owner_mt_reg);
xtables_register_match(&owner_mt6_reg);
}