A new command (--monitor-table-update or -T) is added to be able to monitor
netlink event that inform when a table is updated.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
---
include/linux/netfilter/nfnetlink_tables.h | 24 +++++++++
include/xtables.h | 10 ++++
iptables/ip6tables.c | 16 +++++-
iptables/iptables.c | 16 +++++-
libxtables/Makefile.am | 4 ++
libxtables/xtables.c | 87 ++++++++++++++++++++++++++++++
6 files changed, 153 insertions(+), 4 deletions(-)
create mode 100644 include/linux/netfilter/nfnetlink_tables.h
diff --git a/include/linux/netfilter/nfnetlink_tables.h b/include/linux/netfilter/nfnetlink_tables.h
new file mode 100644
index 0000000..bb70039
--- /dev/null
+++ b/include/linux/netfilter/nfnetlink_tables.h
@@ -0,0 +1,24 @@
+#ifndef _NFNETLINK_TABLES_H
+#define _NFNETLINK_TABLES_H
+
+/* This file describes the netlink messages (i.e. 'protocol packets'),
+ * and not any kind of function definitions. It is shared between kernel and
+ * userspace. Don't put kernel specific stuff in here */
+
+#include <linux/types.h>
+#include <linux/netfilter/nfnetlink.h>
+
+enum nftbl_types {
+ NFTBL_UPDATE,
+
+ NFTBL_MSG_MAX
+};
+
+enum nfnl_tables_attr_type {
+ NFTBLA_UNSPEC,
+ NFTBLA_TABLENAME,
+ __NFTBLA_MAX
+};
+#define NFTBLA_MAX (__NFTBLA_MAX - 1)
+
+#endif /* _NFNETLINK_TABLES_H */
diff --git a/include/xtables.h b/include/xtables.h
index 2cc1a02..32c42b1 100644
--- a/include/xtables.h
+++ b/include/xtables.h
@@ -18,6 +18,11 @@
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
+#ifdef HAVE_LIBNFNETLINK
+#include <libnfnetlink/libnfnetlink.h>
+#include <linux/netfilter/nfnetlink_tables.h>
+#endif
+
#ifndef IPPROTO_SCTP
#define IPPROTO_SCTP 132
#endif
@@ -432,8 +437,11 @@ extern u_int16_t xtables_parse_port(const char *port, const char *proto);
extern void
xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask);
+#ifndef HAVE_LIBNFNETLINK
+/* already defined libnfnetlink/libnfnetlink.h */
/* this is a special 64bit data type that is 8-byte aligned */
#define aligned_u64 u_int64_t __attribute__((aligned(8)))
+#endif
extern struct xtables_globals *xt_params;
#define xtables_error (xt_params->exit_err)
@@ -511,6 +519,8 @@ extern void xtables_lmap_free(struct xtables_lmap *);
extern int xtables_lmap_name2id(const struct xtables_lmap *, const char *);
extern const char *xtables_lmap_id2name(const struct xtables_lmap *, int);
+extern int nfnl_monitor_table_udpate(void);
+
#ifdef XTABLES_INTERNAL
/* Shipped modules rely on this... */
diff --git a/iptables/ip6tables.c b/iptables/ip6tables.c
index 3661216..408c91e 100644
--- a/iptables/ip6tables.c
+++ b/iptables/ip6tables.c
@@ -83,7 +83,8 @@
#define CMD_LIST_RULES 0x1000U
#define CMD_ZERO_NUM 0x2000U
#define CMD_CHECK 0x4000U
-#define NUMBER_OF_CMD 16
+#define CMD_MONITOR_TBLUPDT 0x8000U
+#define NUMBER_OF_CMD 17
static const char cmdflags[] = { 'I', 'D', 'D', 'R', 'A', 'L', 'F', 'Z',
'N', 'X', 'P', 'E', 'S', 'Z', 'C' };
@@ -105,6 +106,7 @@ static struct option original_opts[] = {
{.name = "delete-chain", .has_arg = 2, .val = 'X'},
{.name = "rename-chain", .has_arg = 1, .val = 'E'},
{.name = "policy", .has_arg = 1, .val = 'P'},
+ {.name = "monitor-table-update",.has_arg = 0, .val = 'T'},
{.name = "source", .has_arg = 1, .val = 's'},
{.name = "destination", .has_arg = 1, .val = 'd'},
{.name = "src", .has_arg = 1, .val = 's'}, /* synonym */
@@ -165,6 +167,7 @@ static const char commands_v_options[NUMBER_OF_CMD][NUMBER_OF_OPT] =
/*RENAME*/ {'x','x','x','x','x',' ','x','x','x','x','x'},
/*LIST_RULES*/{'x','x','x','x','x',' ','x','x','x','x','x'},
/*CHECK*/ {'x',' ',' ',' ',' ',' ','x',' ',' ','x','x'},
+/*MONITOR*/ {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '},
};
static const unsigned int inverse_for_options[NUMBER_OF_OPT] =
@@ -248,6 +251,7 @@ exit_printhelp(const struct xtables_rule_match *matches)
" --rename-chain\n"
" -E old-chain new-chain\n"
" Change chain name, (moving any references)\n"
+" --monitor-table-update Monitor table update\n"
"Options:\n"
" --ipv4 -4 Error (line is ignored by ip6tables-restore)\n"
@@ -1381,7 +1385,7 @@ int do_command6(int argc, char *argv[], char **table, struct xtc_handle **handle
opts = xt_params->orig_opts;
while ((cs.c = getopt_long(argc, argv,
- "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:bvnt:m:xc:g:46",
+ "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:VTh::o:p:s:d:j:i:bvnt:m:xc:g:46",
opts, NULL)) != -1) {
switch (cs.c) {
/*
@@ -1530,6 +1534,11 @@ int do_command6(int argc, char *argv[], char **table, struct xtc_handle **handle
cmd2char(CMD_SET_POLICY));
break;
+ case 'T':
+ add_command(&command, CMD_MONITOR_TBLUPDT, CMD_NONE,
+ cs.invert);
+ break;
+
case 'h':
if (!optarg)
optarg = argv[optind];
@@ -1777,6 +1786,9 @@ int do_command6(int argc, char *argv[], char **table, struct xtc_handle **handle
"chain name `%s' too long (must be under %u chars)",
chain, XT_EXTENSION_MAXNAMELEN);
+ if (command == CMD_MONITOR_TBLUPDT)
+ ret = nfnl_monitor_table_udpate();
+
/* only allocate handle if we weren't called with a handle */
if (!*handle)
*handle = ip6tc_init(*table);
diff --git a/iptables/iptables.c b/iptables/iptables.c
index e935f65..b8a99ab 100644
--- a/iptables/iptables.c
+++ b/iptables/iptables.c
@@ -79,7 +79,8 @@
#define CMD_LIST_RULES 0x1000U
#define CMD_ZERO_NUM 0x2000U
#define CMD_CHECK 0x4000U
-#define NUMBER_OF_CMD 16
+#define CMD_MONITOR_TBLUPDT 0x8000U
+#define NUMBER_OF_CMD 17
static const char cmdflags[] = { 'I', 'D', 'D', 'R', 'A', 'L', 'F', 'Z',
'N', 'X', 'P', 'E', 'S', 'Z', 'C' };
@@ -102,6 +103,7 @@ static struct option original_opts[] = {
{.name = "delete-chain", .has_arg = 2, .val = 'X'},
{.name = "rename-chain", .has_arg = 1, .val = 'E'},
{.name = "policy", .has_arg = 1, .val = 'P'},
+ {.name = "monitor-table-update",.has_arg = 0, .val = 'T'},
{.name = "source", .has_arg = 1, .val = 's'},
{.name = "destination", .has_arg = 1, .val = 'd'},
{.name = "src", .has_arg = 1, .val = 's'}, /* synonym */
@@ -164,6 +166,7 @@ static const char commands_v_options[NUMBER_OF_CMD][NUMBER_OF_OPT] =
/*RENAME*/ {'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*LIST_RULES*/{'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*CHECK*/ {'x',' ',' ',' ',' ',' ','x',' ',' ','x','x',' '},
+/*MONITOR*/ {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '},
};
static const int inverse_for_options[NUMBER_OF_OPT] =
@@ -258,6 +261,7 @@ exit_printhelp(const struct xtables_rule_match *matches)
" --rename-chain\n"
" -E old-chain new-chain\n"
" Change chain name, (moving any references)\n"
+" --monitor-table-update Monitor table update\n"
"Options:\n"
" --ipv4 -4 Nothing (line is ignored by ip6tables-restore)\n"
@@ -1394,7 +1398,7 @@ int do_command4(int argc, char *argv[], char **table, struct xtc_handle **handle
opts = xt_params->orig_opts;
while ((cs.c = getopt_long(argc, argv,
- "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:Vh::o:p:s:d:j:i:fbvnt:m:xc:g:46",
+ "-:A:C:D:R:I:L::S::M:F::Z::N:X::E:P:VTh::o:p:s:d:j:i:fbvnt:m:xc:g:46",
opts, NULL)) != -1) {
switch (cs.c) {
/*
@@ -1543,6 +1547,11 @@ int do_command4(int argc, char *argv[], char **table, struct xtc_handle **handle
cmd2char(CMD_SET_POLICY));
break;
+ case 'T':
+ add_command(&command, CMD_MONITOR_TBLUPDT, CMD_NONE,
+ cs.invert);
+ break;
+
case 'h':
if (!optarg)
optarg = argv[optind];
@@ -1791,6 +1800,9 @@ int do_command4(int argc, char *argv[], char **table, struct xtc_handle **handle
"chain name `%s' too long (must be under %u chars)",
chain, XT_EXTENSION_MAXNAMELEN);
+ if (command == CMD_MONITOR_TBLUPDT)
+ ret = nfnl_monitor_table_udpate();
+
/* only allocate handle if we weren't called with a handle */
if (!*handle)
*handle = iptc_init(*table);
diff --git a/libxtables/Makefile.am b/libxtables/Makefile.am
index c5795fe..b6b83a1 100644
--- a/libxtables/Makefile.am
+++ b/libxtables/Makefile.am
@@ -18,3 +18,7 @@ libxtables_la_LIBADD += -ldl
else
libxtables_la_CFLAGS = ${AM_CFLAGS} -DNO_SHARED_LIBS=1
endif
+if HAVE_LIBNFNETLINK
+libxtables_la_CFLAGS += ${libnfnetlink_CFLAGS} -DHAVE_LIBNFNETLINK
+libxtables_la_LIBADD += ${libnfnetlink_LIBS} -lnfnetlink
+endif
diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 82c3643..348fcb1 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -1904,3 +1904,90 @@ void get_kernel_version(void)
sscanf(uts.release, "%d.%d.%d", &x, &y, &z);
kernel_version = LINUX_VERSION(x, y, z);
}
+
+#ifdef HAVE_LIBNFNETLINK
+static int nfnl_monitor_table_udpate_cb(struct nlmsghdr *nlh,
+ struct nfattr *nfa[], void *data)
+{
+ struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
+
+ printf("Update table: family: ");
+ switch (nfmsg->nfgen_family) {
+ case NFPROTO_UNSPEC:
+ printf("unspec");
+ break;
+ case NFPROTO_IPV4:
+ printf("ipv4");
+ break;
+ case NFPROTO_ARP:
+ printf("arp");
+ break;
+ case NFPROTO_BRIDGE:
+ printf("bridge");
+ break;
+ case NFPROTO_IPV6:
+ printf("ipv6");
+ break;
+ case NFPROTO_DECNET:
+ printf("decnet");
+ break;
+ default:
+ printf("unknown");
+ break;
+ }
+
+ if (nfa[NFTBLA_TABLENAME-1] != NULL)
+ printf(", table: %s\n", (char *)NFA_DATA(nfa[NFTBLA_TABLENAME-1]));
+ else
+ printf(", NFTBLA_TABLENAME not set\n");
+
+ return NFNL_CB_CONTINUE;
+}
+#endif
+
+int nfnl_monitor_table_udpate(void)
+{
+#ifdef HAVE_LIBNFNETLINK
+ struct nfnl_handle *nfnlh;
+ struct nfnl_subsys_handle *nfnlsh;
+ struct nfnl_callback cb;
+ int err;
+
+ cb.call = nfnl_monitor_table_udpate_cb;
+ cb.data = NULL;
+ cb.attr_count = NFTBLA_MAX;
+
+ nfnlh = nfnl_open();
+ if (!nfnlh) {
+ err = -EINVAL;
+ perror("nfnl_open()");
+ goto err_out_exit;
+ }
+
+ nfnlsh = nfnl_subsys_open(nfnlh, NFNL_SUBSYS_TABLES, NFTBL_MSG_MAX,
+ NF_NETLINK_TABLES);
+ if (!nfnlsh) {
+ err = -EINVAL;
+ perror("nfnl_subsys_open()");
+ goto err_out_close;
+ }
+
+ if ((err = nfnl_callback_register(nfnlsh, NFTBL_UPDATE, &cb)) < 0) {
+ perror("nfnl_callback_register()");
+ goto err_out_close_subsys;
+ }
+
+ if ((err = nfnl_catch(nfnlh)) < 0)
+ perror("nfnl_catch()");
+
+err_out_close_subsys:
+ nfnl_subsys_close(nfnlsh);
+err_out_close:
+ nfnl_close(nfnlh);
+err_out_exit:
+ return err;
+#else
+ fprintf(stderr, "tools compiled without nfnetlink support\n");
+ return -ENOTSUP;
+#endif
+}
--
1.7.12
--
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