busybox/networking/libiproute/iprule.c
Rui Salvaterra eecd6f7a6c ip rule: add support for fwmark/fwmask for policy routing
This adds support for fwmark/fwmask in ip rule which is needed, for example, in
OpenWrt's mwan3. Masks are supported since Linux 2.6.19.

Fixes: https://bugs.busybox.net/show_bug.cgi?id=11621

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-10-03 22:08:39 +02:00

372 lines
9.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* 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>
*
* Changes:
*
* Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
* initially integrated into busybox by Bernhard Reutner-Fischer
*/
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
/* from <linux/fib_rules.h>: */
#define FRA_FWMARK 10
#define FRA_SUPPRESS_IFGROUP 13
#define FRA_SUPPRESS_PREFIXLEN 14
#define FRA_FWMASK 16
#include "ip_common.h" /* #include "libbb.h" is inside */
#include "rt_names.h"
#include "utils.h"
#include <linux/version.h>
/* RTA_TABLE is not a define, can't test with ifdef. */
/* As a proxy, test which kernels toolchain expects: */
#define HAVE_RTA_TABLE (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19))
/* If you add stuff here, update iprule_full_usage */
static const char keywords[] ALIGN1 =
"from\0""to\0""preference\0""order\0""priority\0"
"tos\0""fwmark\0""realms\0""table\0""lookup\0"
"suppress_prefixlength\0""suppress_ifgroup\0"
"dev\0""iif\0""nat\0""map-to\0""type\0""help\0"
;
#define keyword_preference (keywords + sizeof("from") + sizeof("to"))
#define keyword_fwmark (keyword_preference + sizeof("preference") + sizeof("order") + sizeof("priority") + sizeof("tos"))
#define keyword_realms (keyword_fwmark + sizeof("fwmark"))
#define keyword_suppress_prefixlength (keyword_realms + sizeof("realms") + sizeof("table") + sizeof("lookup"))
#define keyword_suppress_ifgroup (keyword_suppress_prefixlength + sizeof("suppress_prefixlength"))
enum {
ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup,
ARG_suppress_prefixlength, ARG_suppress_ifgroup,
ARG_dev, ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help,
};
static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
struct nlmsghdr *n, void *arg UNUSED_PARAM)
{
struct rtmsg *r = NLMSG_DATA(n);
int len = n->nlmsg_len;
int host_len = -1;
struct rtattr * tb[RTA_MAX+1];
if (n->nlmsg_type != RTM_NEWRULE)
return 0;
len -= NLMSG_LENGTH(sizeof(*r));
if (len < 0)
return -1;
//memset(tb, 0, sizeof(tb)); - parse_rtattr does this
parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
if (r->rtm_family == AF_INET)
host_len = 32;
else if (r->rtm_family == AF_INET6)
host_len = 128;
/* else if (r->rtm_family == AF_DECnet)
host_len = 16;
else if (r->rtm_family == AF_IPX)
host_len = 80;
*/
printf("%u:\t", tb[RTA_PRIORITY] ?
*(unsigned*)RTA_DATA(tb[RTA_PRIORITY])
: 0);
printf("from ");
if (tb[RTA_SRC]) {
if (r->rtm_src_len != host_len) {
printf("%s/%u",
rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_SRC])),
r->rtm_src_len
);
} else {
fputs(format_host(r->rtm_family,
RTA_PAYLOAD(tb[RTA_SRC]),
RTA_DATA(tb[RTA_SRC])),
stdout
);
}
} else if (r->rtm_src_len) {
printf("0/%d", r->rtm_src_len);
} else {
printf("all");
}
bb_putchar(' ');
if (tb[RTA_DST]) {
if (r->rtm_dst_len != host_len) {
printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
RTA_DATA(tb[RTA_DST])),
r->rtm_dst_len
);
} else {
printf("to %s ", format_host(r->rtm_family,
RTA_PAYLOAD(tb[RTA_DST]),
RTA_DATA(tb[RTA_DST])));
}
} else if (r->rtm_dst_len) {
printf("to 0/%d ", r->rtm_dst_len);
}
if (r->rtm_tos) {
printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos));
}
if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
uint32_t mark = 0, mask = 0;
if (tb[FRA_FWMARK])
mark = *(uint32_t*)RTA_DATA(tb[FRA_FWMARK]);
if (tb[FRA_FWMASK]
&& (mask = *(uint32_t*)RTA_DATA(tb[FRA_FWMASK])) != 0xFFFFFFFF
)
printf("fwmark %#x/%#x ", mark, mask);
else
printf("fwmark %#x ", mark);
}
if (tb[RTA_IIF]) {
printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
}
#if HAVE_RTA_TABLE
if (tb[RTA_TABLE])
printf("lookup %s ", rtnl_rttable_n2a(*(uint32_t*)RTA_DATA(tb[RTA_TABLE])));
else
#endif
if (r->rtm_table)
printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table));
if (tb[FRA_SUPPRESS_PREFIXLEN]) {
int pl = *(uint32_t*)RTA_DATA(tb[FRA_SUPPRESS_PREFIXLEN]);
if (pl != -1)
printf("%s %d ", keyword_suppress_prefixlength, pl);
}
if (tb[FRA_SUPPRESS_IFGROUP]) {
int grp = *(uint32_t*)RTA_DATA(tb[FRA_SUPPRESS_IFGROUP]);
if (grp != -1)
printf("%s %d ", keyword_suppress_ifgroup, grp);
}
if (tb[RTA_FLOW]) {
uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
uint32_t from = to>>16;
to &= 0xFFFF;
if (from) {
printf("realms %s/",
rtnl_rtrealm_n2a(from));
}
printf("%s ",
rtnl_rtrealm_n2a(to));
}
if (r->rtm_type == RTN_NAT) {
if (tb[RTA_GATEWAY]) {
printf("map-to %s ",
format_host(r->rtm_family,
RTA_PAYLOAD(tb[RTA_GATEWAY]),
RTA_DATA(tb[RTA_GATEWAY]))
);
} else
printf("masquerade");
} else if (r->rtm_type != RTN_UNICAST)
fputs(rtnl_rtntype_n2a(r->rtm_type), stdout);
bb_putchar('\n');
/*fflush_all();*/
return 0;
}
/* Return value becomes exitcode. It's okay to not return at all */
static int iprule_list(char **argv)
{
struct rtnl_handle rth;
int af = preferred_family;
if (af == AF_UNSPEC)
af = AF_INET;
if (*argv) {
//bb_error_msg("\"rule show\" needs no arguments");
bb_warn_ignoring_args(*argv);
return -1;
}
xrtnl_open(&rth);
xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
xrtnl_dump_filter(&rth, print_rule, NULL);
return 0;
}
/* Return value becomes exitcode. It's okay to not return at all */
static int iprule_modify(int cmd, char **argv)
{
bool table_ok = 0;
struct rtnl_handle rth;
struct {
struct nlmsghdr n;
struct rtmsg r;
char buf[1024];
} req;
smalluint key;
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;
if (RT_SCOPE_UNIVERSE != 0)
req.r.rtm_scope = RT_SCOPE_UNIVERSE;
/*req.r.rtm_table = 0; - already is */
if (RTN_UNSPEC != 0)
req.r.rtm_type = RTN_UNSPEC;
if (cmd == RTM_NEWRULE) {
req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
req.r.rtm_type = RTN_UNICAST;
}
while (*argv) {
key = index_in_substrings(keywords, *argv) + 1;
if (key == 0) /* no match found in keywords array, bail out. */
invarg_1_to_2(*argv, applet_name);
if (key == ARG_from) {
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), RTA_SRC, &dst.data, dst.bytelen);
} else if (key == ARG_to) {
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), RTA_DST, &dst.data, dst.bytelen);
} else if (key == ARG_preference ||
key == ARG_order ||
key == ARG_priority
) {
uint32_t pref;
NEXT_ARG();
pref = get_u32(*argv, keyword_preference);
addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
} else if (key == ARG_tos) {
uint32_t tos;
NEXT_ARG();
if (rtnl_dsfield_a2n(&tos, *argv))
invarg_1_to_2(*argv, "TOS");
req.r.rtm_tos = tos;
} else if (key == ARG_fwmark) {
char *slash;
uint32_t fwmark, fwmask;
NEXT_ARG();
slash = strchr(*argv, '/');
if (slash)
*slash = '\0';
fwmark = get_u32(*argv, keyword_fwmark);
addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
if (slash) {
fwmask = get_u32(slash + 1, "fwmask");
addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
}
} else if (key == ARG_realms) {
uint32_t realm;
NEXT_ARG();
if (get_rt_realms(&realm, *argv))
invarg_1_to_2(*argv, keyword_realms);
addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
} else if (key == ARG_table ||
key == ARG_lookup
) {
uint32_t tid;
NEXT_ARG();
if (rtnl_rttable_a2n(&tid, *argv))
invarg_1_to_2(*argv, "table ID");
#if HAVE_RTA_TABLE
if (tid > 255) {
req.r.rtm_table = RT_TABLE_UNSPEC;
addattr32(&req.n, sizeof(req), RTA_TABLE, tid);
} else
#endif
req.r.rtm_table = tid;
table_ok = 1;
} else if (key == ARG_suppress_prefixlength) {
int prefix_length;
NEXT_ARG();
prefix_length = get_u32(*argv, keyword_suppress_prefixlength);
addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, prefix_length);
} else if (key == ARG_suppress_ifgroup) {
int grp;
NEXT_ARG();
grp = get_u32(*argv, keyword_suppress_ifgroup);
addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, grp);
} else if (key == ARG_dev ||
key == ARG_iif
) {
NEXT_ARG();
addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
} else if (key == ARG_nat ||
key == ARG_map_to
) {
NEXT_ARG();
addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
req.r.rtm_type = RTN_NAT;
} else {
int type;
if (key == ARG_type) {
NEXT_ARG();
}
if (key == ARG_help)
bb_show_usage();
if (rtnl_rtntype_a2n(&type, *argv))
invarg_1_to_2(*argv, "type");
req.r.rtm_type = type;
}
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;
xrtnl_open(&rth);
if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
return 2;
return 0;
}
/* Return value becomes exitcode. It's okay to not return at all */
int FAST_FUNC do_iprule(char **argv)
{
static const char ip_rule_commands[] ALIGN1 =
"add\0""delete\0""list\0""show\0";
if (*argv) {
int cmd = index_in_substrings(ip_rule_commands, *argv);
if (cmd < 0)
invarg_1_to_2(*argv, applet_name);
argv++;
if (cmd < 2)
return iprule_modify((cmd == 0) ? RTM_NEWRULE : RTM_DELRULE, argv);
}
return iprule_list(argv);
}