/*
* iprule.c "ip rule".
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <string.h>
#include <linux/fib_rules.h>
#include <errno.h>
#include "rt_names.h"
#include "utils.h"
#include "ip_common.h"
extern struct rtnl_handle rth;
static void usage(void) __attribute__((noreturn));
static void usage(void)
{
fprintf(stderr, "Usage: ip rule [ list | add | del | flush | save ] SELECTOR ACTION\n");
fprintf(stderr, " ip rule restore\n");
fprintf(stderr, "SELECTOR := [ not ] [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK[/MASK] ]\n");
fprintf(stderr, " [ iif STRING ] [ oif STRING ] [ pref NUMBER ] [ uidrange UID1-UID2 ]\n");
fprintf(stderr, "ACTION := [ table TABLE_ID ]\n");
fprintf(stderr, " [ realms [SRCREALM/]DSTREALM ]\n");
fprintf(stderr, " [ goto NUMBER ]\n");
fprintf(stderr, " SUPPRESSOR\n");
fprintf(stderr, "SUPPRESSOR := [ suppress_prefixlength NUMBER ]\n");
fprintf(stderr, " [ suppress_ifgroup DEVGROUP ]\n");
fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
exit(-1);
}
int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
FILE *fp = (FILE*)arg;
struct rtmsg *r = NLMSG_DATA(n);
int len = n->nlmsg_len;
int host_len = -1;
__u32 table;
struct rtattr * tb[FRA_MAX+1];
char abuf[256];
SPRINT_BUF(b1);
if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE)
return 0;
len -= NLMSG_LENGTH(sizeof(*r));
if (len < 0)
return -1;
parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
host_len = af_bit_len(r->rtm_family);
if (n->nlmsg_type == RTM_DELRULE)
fprintf(fp, "Deleted ");
if (tb[FRA_PRIORITY])
fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[FRA_PRIORITY]));
else
fprintf(fp, "0:\t");
if (r->rtm_flags & FIB_RULE_INVERT)
fprintf(fp, "not ");
if (tb[FRA_SRC]) {
if (r->rtm_src_len != host_len) {
fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
RTA_PAYLOAD(tb[FRA_SRC]),
RTA_DATA(tb[FRA_SRC]),
abuf, sizeof(abuf)),
r->rtm_src_len
);
} else {
fprintf(fp, "from %s ", format_host(r->rtm_family,
RTA_PAYLOAD(tb[FRA_SRC]),
RTA_DATA(tb[FRA_SRC]),
abuf, sizeof(abuf))
);
}
} else if (r->rtm_src_len) {
fprintf(fp, "from 0/%d ", r->rtm_src_len);
} else {
fprintf(fp, "from all ");
}
if (tb[FRA_DST]) {
if (r->rtm_dst_len != host_len) {
fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
RTA_PAYLOAD(tb[FRA_DST]),
RTA_DATA(tb[FRA_DST]),
abuf, sizeof(abuf)),
r->rtm_dst_len
);
} else {
fprintf(fp, "to %s ", format_host(r->rtm_family,
RTA_PAYLOAD(tb[FRA_DST]),
RTA_DATA(tb[FRA_DST]),
abuf, sizeof(abuf)));
}
} else if (r->rtm_dst_len) {
fprintf(fp, "to 0/%d ", r->rtm_dst_len);
}
if (r->rtm_tos) {
SPRINT_BUF(b1);
fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
}
if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
__u32 mark = 0, mask = 0;
if (tb[FRA_FWMARK])
mark = rta_getattr_u32(tb[FRA_FWMARK]);
if (tb[FRA_FWMASK] &&
(mask = rta_getattr_u32(tb[FRA_FWMASK])) != 0xFFFFFFFF)
fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
else
fprintf(fp, "fwmark 0x%x ", mark);
}
if (tb[FRA_IFNAME]) {
fprintf(fp, "iif %s ", rta_getattr_str(tb[FRA_IFNAME]));
if (r->rtm_flags & FIB_RULE_IIF_DETACHED)
fprintf(fp, "[detached] ");
}
if (tb[FRA_OIFNAME]) {
fprintf(fp, "oif %s ", rta_getattr_str(tb[FRA_OIFNAME]));
if (r->rtm_flags & FIB_RULE_OIF_DETACHED)
fprintf(fp, "[detached] ");
}
if (tb[FRA_UID_START] || tb[FRA_UID_END]) {
fprintf(fp, "uidrange ");
if (tb[FRA_UID_START])
fprintf(fp, "%u", rta_getattr_u32(tb[FRA_UID_START]));
else
fprintf(fp, "???");
if (tb[FRA_UID_END])
fprintf(fp, "-%u ", rta_getattr_u32(tb[FRA_UID_END]));
else
fprintf(fp, "-??? ");
}
table = rtm_get_table(r, tb);
if (table) {
fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
if (tb[FRA_SUPPRESS_PREFIXLEN]) {
int pl = rta_getattr_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
if (pl != -1) {
fprintf(fp, "suppress_prefixlength %d ", pl);
}
}
if (tb[FRA_SUPPRESS_IFGROUP]) {
int group = rta_getattr_u32(tb[FRA_SUPPRESS_IFGROUP]);
if (group != -1) {
SPRINT_BUF(b1);
fprintf(fp, "suppress_ifgroup %s ", rtnl_group_n2a(group, b1, sizeof(b1)));
}
}
}
if (tb[FRA_FLOW]) {
__u32 to = rta_getattr_u32(tb[FRA_FLOW]);
__u32 from = to>>16;
to &= 0xFFFF;
if (from) {
fprintf(fp, "realms %s/",
rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
}
fprintf(fp, "%s ",
rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
}
if (r->rtm_type == RTN_NAT) {
if (tb[RTA_GATEWAY]) {
fprintf(fp, "map-to %s ",
format_host(r->rtm_family,
RTA_PAYLOAD(tb[RTA_GATEWAY]),
RTA_DATA(tb[RTA_GATEWAY]),
abuf, sizeof(abuf)));
} else
fprintf(fp, "masquerade");
} else if (r->rtm_type == FR_ACT_GOTO) {
fprintf(fp, "goto ");
if (tb[FRA_GOTO])
fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO]));
else
fprintf(fp, "none");
if (r->rtm_flags & FIB_RULE_UNRESOLVED)
fprintf(fp, " [unresolved]");
} else if (r->rtm_type == FR_ACT_NOP)
fprintf(fp, "nop");
else if (r->rtm_type != RTN_UNICAST)
fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
fprintf(fp, "\n");
fflush(fp);
return 0;
}
static __u32 rule_dump_magic = 0x71706986;
static int save_rule_prep(void)
{
int ret;
if (isatty(STDOUT_FILENO)) {
fprintf(stderr, "Not sending a binary stream to stdout\n");
return -1;
}
ret = write(STDOUT_FILENO, &rule_dump_magic, sizeof(rule_dump_magic));
if (ret != sizeof(rule_dump_magic)) {
fprintf(stderr, "Can't write magic to dump file\n");
return -1;
}
return 0;
}
static int save_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
int ret;
ret = write(STDOUT_FILENO, n, n->nlmsg_len);
if ((ret > 0) && (ret != n->nlmsg_len)) {
fprintf(stderr, "Short write while saving nlmsg\n");
ret = -EIO;
}
return ret == n->nlmsg_len ? 0 : ret;
}
static int iprule_list_or_save(int argc, char **argv, int save)
{
rtnl_filter_t filter = print_rule;
int af = preferred_family;
if (af == AF_UNSPEC)
af = AF_INET;
if (argc > 0) {
fprintf(stderr, "\"ip rule %s\" does not take any arguments.\n",
save ? "save" : "show");
return -1;
}
if (save) {
if (save_rule_prep())
return -1;
filter = save_rule;
}
if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
perror("Cannot send dump request");
return 1;
}
if (rtnl_dump_filter(&rth, filter, stdout) < 0) {
fprintf(stderr, "Dump terminated\n");
return 1;
}
return 0;
}
static int rule_dump_check_magic(void)
{
int ret;
__u32 magic = 0;
if (isatty(STDIN_FILENO)) {
fprintf(stderr, "Can't restore rule dump from a terminal\n");
return -1;
}
ret = fread(&magic, sizeof(magic), 1, stdin);
if (magic != rule_dump_magic) {
fprintf(stderr, "Magic mismatch (%d elems, %x magic)\n", ret, magic);
return -1;
}
return 0;
}
static int restore_handler(const struct sockaddr_nl *nl,
struct rtnl_ctrl_data *ctrl,
struct nlmsghdr *n, void *arg)
{
int ret;
n->nlmsg_flags |= NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK;
ll_init_map(&rth);
ret = rtnl_talk(&rth, n, n, sizeof(*n));
if ((ret < 0) && (errno == EEXIST))
ret = 0;
return ret;
}
static int iprule_restore(void)
{
if (rule_dump_check_magic())
exit(-1);
exit(rtnl_from_file(stdin, &restore_handler, NULL));
}
static int iprule_modify(int cmd, int argc, char **argv)
{
int table_ok = 0;
struct {
struct nlmsghdr n;
struct rtmsg r;
char buf[1024];
} req;
memset(&req, 0, sizeof(req));
req.n.nlmsg_type = cmd;
req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
req.n.nlmsg_flags = NLM_F_REQUEST;
req.r.rtm_family = preferred_family;
req.r.rtm_protocol = RTPROT_BOOT;
req.r.rtm_scope = RT_SCOPE_UNIVERSE;
req.r.rtm_table = 0;
req.r.rtm_type = RTN_UNSPEC;
req.r.rtm_flags = 0;
if (cmd == RTM_NEWRULE) {
req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
req.r.rtm_type = RTN_UNICAST;
}
while (argc > 0) {
if (strcmp(*argv, "not") == 0) {
req.r.rtm_flags |= FIB_RULE_INVERT;
} else if (strcmp(*argv, "from") == 0) {
inet_prefix dst;
NEXT_ARG();
get_prefix(&dst, *argv, req.r.rtm_family);
req.r.rtm_src_len = dst.bitlen;
addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
} else if (strcmp(*argv, "to") == 0) {
inet_prefix dst;
NEXT_ARG();
get_prefix(&dst, *argv, req.r.rtm_family);
req.r.rtm_dst_len = dst.bitlen;
addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
} else if (matches(*argv, "preference") == 0 ||
matches(*argv, "order") == 0 ||
matches(*argv, "priority") == 0) {
__u32 pref;
NEXT_ARG();
if (get_u32(&pref, *argv, 0))
invarg("preference value is invalid\n", *argv);
addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
} else if (strcmp(*argv, "tos") == 0 ||
matches(*argv, "dsfield") == 0) {
__u32 tos;
NEXT_ARG();
if (rtnl_dsfield_a2n(&tos, *argv))
invarg("TOS value is invalid\n", *argv);
req.r.rtm_tos = tos;
} else if (strcmp(*argv, "fwmark") == 0) {
char *slash;
__u32 fwmark, fwmask;
NEXT_ARG();
if ((slash = strchr(*argv, '/')) != NULL)
*slash = '\0';
if (get_u32(&fwmark, *argv, 0))
invarg("fwmark value is invalid\n", *argv);
addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
if (slash) {
if (get_u32(&fwmask, slash+1, 0))
invarg("fwmask value is invalid\n", slash+1);
addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
}
} else if (matches(*argv, "realms") == 0) {
__u32 realm;
NEXT_ARG();
if (get_rt_realms_or_raw(&realm, *argv))
invarg("invalid realms\n", *argv);
addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
} else if (matches(*argv, "table") == 0 ||
strcmp(*argv, "lookup") == 0) {
__u32 tid;
NEXT_ARG();
if (rtnl_rttable_a2n(&tid, *argv))
invarg("invalid table ID\n", *argv);
if (tid < 256)
req.r.rtm_table = tid;
else {
req.r.rtm_table = RT_TABLE_UNSPEC;
addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
}
table_ok = 1;
} else if (matches(*argv, "suppress_prefixlength") == 0 ||
strcmp(*argv, "sup_pl") == 0) {
int pl;
NEXT_ARG();
if (get_s32(&pl, *argv, 0) || pl < 0)
invarg("suppress_prefixlength value is invalid\n", *argv);
addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, pl);
} else if (matches(*argv, "suppress_ifgroup") == 0 ||
strcmp(*argv, "sup_group") == 0) {
NEXT_ARG();
int group;
if (rtnl_group_a2n(&group, *argv))
invarg("Invalid \"suppress_ifgroup\" value\n", *argv);
addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, group);
} else if (strcmp(*argv, "dev") == 0 ||
strcmp(*argv, "iif") == 0) {
NEXT_ARG();
addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
} else if (strcmp(*argv, "oif") == 0) {
NEXT_ARG();
addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1);
} else if (strcmp(*argv, "nat") == 0 ||
matches(*argv, "map-to") == 0) {
NEXT_ARG();
fprintf(stderr, "Warning: route NAT is deprecated\n");
addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
req.r.rtm_type = RTN_NAT;
} else if (strcmp(*argv, "uidrange") == 0) {
__u32 uid_start, uid_end;
NEXT_ARG();
if (sscanf(*argv, "%u-%u", &uid_start, &uid_end) != 2)
invarg("UID range is invalid\n", *argv);
addattr32(&req.n, sizeof(req), FRA_UID_START, uid_start);
addattr32(&req.n, sizeof(req), FRA_UID_END, uid_end);
} else {
int type;
if (strcmp(*argv, "type") == 0) {
NEXT_ARG();
}
if (matches(*argv, "help") == 0)
usage();
else if (matches(*argv, "goto") == 0) {
__u32 target;
type = FR_ACT_GOTO;
NEXT_ARG();
if (get_u32(&target, *argv, 0))
invarg("invalid target\n", *argv);
addattr32(&req.n, sizeof(req), FRA_GOTO, target);
} else if (matches(*argv, "nop") == 0)
type = FR_ACT_NOP;
else if (rtnl_rtntype_a2n(&type, *argv))
invarg("Failed to parse rule type", *argv);
req.r.rtm_type = type;
table_ok = 1;
}
argc--;
argv++;
}
if (req.r.rtm_family == AF_UNSPEC)
req.r.rtm_family = AF_INET;
if (!table_ok && cmd == RTM_NEWRULE)
req.r.rtm_table = RT_TABLE_MAIN;
if (rtnl_talk(&rth, &req.n, NULL, 0) < 0)
return -2;
return 0;
}
static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
struct rtnl_handle rth2;
struct rtmsg *r = NLMSG_DATA(n);
int len = n->nlmsg_len;
struct rtattr * tb[FRA_MAX+1];
len -= NLMSG_LENGTH(sizeof(*r));
if (len < 0)
return -1;
parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
if (tb[FRA_PRIORITY]) {
n->nlmsg_type = RTM_DELRULE;
n->nlmsg_flags = NLM_F_REQUEST;
if (rtnl_open(&rth2, 0) < 0)
return -1;
if (rtnl_talk(&rth2, n, NULL, 0) < 0)
return -2;
rtnl_close(&rth2);
}
return 0;
}
static int iprule_flush(int argc, char **argv)
{
int af = preferred_family;
if (af == AF_UNSPEC)
af = AF_INET;
if (argc > 0) {
fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
return -1;
}
if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
perror("Cannot send dump request");
return 1;
}
if (rtnl_dump_filter(&rth, flush_rule, NULL) < 0) {
fprintf(stderr, "Flush terminated\n");
return 1;
}
return 0;
}
int do_iprule(int argc, char **argv)
{
if (argc < 1) {
return iprule_list_or_save(0, NULL, 0);
} else if (matches(argv[0], "list") == 0 ||
matches(argv[0], "lst") == 0 ||
matches(argv[0], "show") == 0) {
return iprule_list_or_save(argc-1, argv+1, 0);
} else if (matches(argv[0], "save") == 0) {
return iprule_list_or_save(argc-1, argv+1, 1);
} else if (matches(argv[0], "restore") == 0) {
return iprule_restore();
} else if (matches(argv[0], "add") == 0) {
return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
} else if (matches(argv[0], "delete") == 0) {
return iprule_modify(RTM_DELRULE, argc-1, argv+1);
} else if (matches(argv[0], "flush") == 0) {
return iprule_flush(argc-1, argv+1);
} else if (matches(argv[0], "help") == 0)
usage();
fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
exit(-1);
}
int do_multirule(int argc, char **argv)
{
switch (preferred_family) {
case AF_UNSPEC:
case AF_INET:
preferred_family = RTNL_FAMILY_IPMR;
break;
case AF_INET6:
preferred_family = RTNL_FAMILY_IP6MR;
break;
case RTNL_FAMILY_IPMR:
case RTNL_FAMILY_IP6MR:
break;
default:
fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n",
preferred_family);
exit(-1);
}
return do_iprule(argc, argv);
}