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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <netinet/in.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/netfilter.h>
#include "sd-netlink.h"
#include "iovec-util.h"
#include "netlink-internal.h"
#include "netlink-types.h"
#include "netlink-util.h"
bool nfproto_is_valid(int nfproto) {
return IN_SET(nfproto,
NFPROTO_UNSPEC,
NFPROTO_INET,
NFPROTO_IPV4,
NFPROTO_ARP,
NFPROTO_NETDEV,
NFPROTO_BRIDGE,
NFPROTO_IPV6);
}
int sd_nfnl_message_new(sd_netlink *nfnl, sd_netlink_message **ret, int nfproto, uint16_t subsys, uint16_t msg_type, uint16_t flags) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
assert_return(nfnl, -EINVAL);
assert_return(ret, -EINVAL);
assert_return(nfproto_is_valid(nfproto), -EINVAL);
assert_return(NFNL_MSG_TYPE(msg_type) == msg_type, -EINVAL);
r = message_new(nfnl, &m, subsys << 8 | msg_type);
if (r < 0)
return r;
m->hdr->nlmsg_flags |= flags;
*(struct nfgenmsg*) NLMSG_DATA(m->hdr) = (struct nfgenmsg) {
.nfgen_family = nfproto,
.version = NFNETLINK_V0,
};
*ret = TAKE_PTR(m);
return 0;
}
static int nfnl_message_set_res_id(sd_netlink_message *m, uint16_t res_id) {
struct nfgenmsg *nfgen;
assert(m);
assert(m->hdr);
nfgen = NLMSG_DATA(m->hdr);
nfgen->res_id = htobe16(res_id);
return 0;
}
static int nfnl_message_get_subsys(sd_netlink_message *m, uint16_t *ret) {
uint16_t t;
int r;
assert(m);
assert(ret);
r = sd_netlink_message_get_type(m, &t);
if (r < 0)
return r;
*ret = NFNL_SUBSYS_ID(t);
return 0;
}
static int nfnl_message_new_batch(sd_netlink *nfnl, sd_netlink_message **ret, uint16_t subsys, uint16_t msg_type) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
assert_return(nfnl, -EINVAL);
assert_return(ret, -EINVAL);
assert_return(NFNL_MSG_TYPE(msg_type) == msg_type, -EINVAL);
r = sd_nfnl_message_new(nfnl, &m, NFPROTO_UNSPEC, NFNL_SUBSYS_NONE, msg_type, 0);
if (r < 0)
return r;
r = nfnl_message_set_res_id(m, subsys);
if (r < 0)
return r;
*ret = TAKE_PTR(m);
return 0;
}
int sd_nfnl_send_batch(
sd_netlink *nfnl,
sd_netlink_message **messages,
size_t n_messages,
uint32_t **ret_serials) {
/* iovs refs batch_begin and batch_end, hence, free iovs first, then free batch_begin and batch_end. */
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *batch_begin = NULL, *batch_end = NULL;
_cleanup_free_ struct iovec *iovs = NULL;
_cleanup_free_ uint32_t *serials = NULL;
uint16_t subsys;
ssize_t k;
size_t c = 0;
int r;
assert_return(nfnl, -EINVAL);
assert_return(!netlink_pid_changed(nfnl), -ECHILD);
assert_return(messages, -EINVAL);
assert_return(n_messages > 0, -EINVAL);
iovs = new(struct iovec, n_messages + 2);
if (!iovs)
return -ENOMEM;
if (ret_serials) {
serials = new(uint32_t, n_messages);
if (!serials)
return -ENOMEM;
}
r = nfnl_message_get_subsys(messages[0], &subsys);
if (r < 0)
return r;
r = nfnl_message_new_batch(nfnl, &batch_begin, subsys, NFNL_MSG_BATCH_BEGIN);
if (r < 0)
return r;
netlink_seal_message(nfnl, batch_begin);
iovs[c++] = IOVEC_MAKE(batch_begin->hdr, batch_begin->hdr->nlmsg_len);
for (size_t i = 0; i < n_messages; i++) {
uint16_t s;
r = nfnl_message_get_subsys(messages[i], &s);
if (r < 0)
return r;
if (s != subsys)
return -EINVAL;
netlink_seal_message(nfnl, messages[i]);
if (serials)
serials[i] = message_get_serial(messages[i]);
/* It seems that the kernel accepts an arbitrary number. Let's set the lower 16 bits of the
* serial of the first message. */
nfnl_message_set_res_id(messages[i], (uint16_t) (message_get_serial(batch_begin) & UINT16_MAX));
iovs[c++] = IOVEC_MAKE(messages[i]->hdr, messages[i]->hdr->nlmsg_len);
}
r = nfnl_message_new_batch(nfnl, &batch_end, subsys, NFNL_MSG_BATCH_END);
if (r < 0)
return r;
netlink_seal_message(nfnl, batch_end);
iovs[c++] = IOVEC_MAKE(batch_end->hdr, batch_end->hdr->nlmsg_len);
assert(c == n_messages + 2);
k = writev(nfnl->fd, iovs, n_messages + 2);
if (k < 0)
return -errno;
if (ret_serials)
*ret_serials = TAKE_PTR(serials);
return 0;
}
int sd_nfnl_call_batch(
sd_netlink *nfnl,
sd_netlink_message **messages,
size_t n_messages,
uint64_t usec,
sd_netlink_message ***ret_messages) {
_cleanup_free_ sd_netlink_message **replies = NULL;
_cleanup_free_ uint32_t *serials = NULL;
int r;
assert_return(nfnl, -EINVAL);
assert_return(!netlink_pid_changed(nfnl), -ECHILD);
assert_return(messages, -EINVAL);
assert_return(n_messages > 0, -EINVAL);
if (ret_messages) {
replies = new0(sd_netlink_message*, n_messages);
if (!replies)
return -ENOMEM;
}
r = sd_nfnl_send_batch(nfnl, messages, n_messages, &serials);
if (r < 0)
return r;
for (size_t i = 0; i < n_messages; i++)
RET_GATHER(r,
sd_netlink_read(nfnl, serials[i], usec, ret_messages ? replies + i : NULL));
if (r < 0)
return r;
if (ret_messages)
*ret_messages = TAKE_PTR(replies);
return 0;
}
int sd_nfnl_nft_message_new_basechain(
sd_netlink *nfnl,
sd_netlink_message **ret,
int nfproto,
const char *table,
const char *chain,
const char *type,
uint8_t hook,
int prio) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
r = sd_nfnl_message_new(nfnl, &m, nfproto, NFNL_SUBSYS_NFTABLES, NFT_MSG_NEWCHAIN, NLM_F_CREATE);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_CHAIN_TABLE, table);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_CHAIN_NAME, chain);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_CHAIN_TYPE, type);
if (r < 0)
return r;
r = sd_netlink_message_open_container(m, NFTA_CHAIN_HOOK);
if (r < 0)
return r;
r = sd_netlink_message_append_u32(m, NFTA_HOOK_HOOKNUM, htobe32(hook));
if (r < 0)
return r;
r = sd_netlink_message_append_u32(m, NFTA_HOOK_PRIORITY, htobe32(prio));
if (r < 0)
return r;
r = sd_netlink_message_close_container(m);
if (r < 0)
return r;
*ret = TAKE_PTR(m);
return 0;
}
int sd_nfnl_nft_message_new_table(
sd_netlink *nfnl,
sd_netlink_message **ret,
int nfproto,
const char *table) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
r = sd_nfnl_message_new(nfnl, &m, nfproto, NFNL_SUBSYS_NFTABLES, NFT_MSG_NEWTABLE, NLM_F_CREATE | NLM_F_EXCL);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_TABLE_NAME, table);
if (r < 0)
return r;
*ret = TAKE_PTR(m);
return r;
}
int sd_nfnl_nft_message_new_rule(
sd_netlink *nfnl,
sd_netlink_message **ret,
int nfproto,
const char *table,
const char *chain) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
r = sd_nfnl_message_new(nfnl, &m, nfproto, NFNL_SUBSYS_NFTABLES, NFT_MSG_NEWRULE, NLM_F_CREATE);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_RULE_TABLE, table);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_RULE_CHAIN, chain);
if (r < 0)
return r;
*ret = TAKE_PTR(m);
return r;
}
int sd_nfnl_nft_message_new_set(
sd_netlink *nfnl,
sd_netlink_message **ret,
int nfproto,
const char *table,
const char *set_name,
uint32_t set_id,
uint32_t klen) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
r = sd_nfnl_message_new(nfnl, &m, nfproto, NFNL_SUBSYS_NFTABLES, NFT_MSG_NEWSET, NLM_F_CREATE);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_SET_TABLE, table);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_SET_NAME, set_name);
if (r < 0)
return r;
r = sd_netlink_message_append_u32(m, NFTA_SET_ID, ++set_id);
if (r < 0)
return r;
r = sd_netlink_message_append_u32(m, NFTA_SET_KEY_LEN, htobe32(klen));
if (r < 0)
return r;
*ret = TAKE_PTR(m);
return r;
}
int sd_nfnl_nft_message_new_setelems(
sd_netlink *nfnl,
sd_netlink_message **ret,
int add, /* boolean */
int nfproto,
const char *table,
const char *set_name) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
int r;
if (add)
r = sd_nfnl_message_new(nfnl, &m, nfproto, NFNL_SUBSYS_NFTABLES, NFT_MSG_NEWSETELEM, NLM_F_CREATE);
else
r = sd_nfnl_message_new(nfnl, &m, nfproto, NFNL_SUBSYS_NFTABLES, NFT_MSG_DELSETELEM, 0);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_SET_ELEM_LIST_TABLE, table);
if (r < 0)
return r;
r = sd_netlink_message_append_string(m, NFTA_SET_ELEM_LIST_SET, set_name);
if (r < 0)
return r;
*ret = TAKE_PTR(m);
return r;
}
int sd_nfnl_nft_message_append_setelem(
sd_netlink_message *m,
uint32_t index,
const void *key,
size_t key_len,
const void *data,
size_t data_len,
uint32_t flags) {
int r;
r = sd_netlink_message_open_array(m, index);
if (r < 0)
return r;
r = sd_netlink_message_append_container_data(m, NFTA_SET_ELEM_KEY, NFTA_DATA_VALUE, key, key_len);
if (r < 0)
goto cancel;
if (data) {
r = sd_netlink_message_append_container_data(m, NFTA_SET_ELEM_DATA, NFTA_DATA_VALUE, data, data_len);
if (r < 0)
goto cancel;
}
if (flags != 0) {
r = sd_netlink_message_append_u32(m, NFTA_SET_ELEM_FLAGS, htobe32(flags));
if (r < 0)
goto cancel;
}
return sd_netlink_message_close_container(m); /* array */
cancel:
(void) sd_netlink_message_cancel_array(m);
return r;
}
int sd_nfnl_socket_open(sd_netlink **ret) {
return netlink_open_family(ret, NETLINK_NETFILTER);
}
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