nftables used to have a cache to speed up interface name <-> index lookup,
restore it using libmnl.
This reduces netlink traffic since if_nametoindex() and if_indextoname() open,
send a request, receive the list of interface and close a netlink socket for
each call. I think this is also good for consistency since nft -f will operate
with the same index number when reloading the ruleset.
For the interactive mode, the cache is refreshed for each command to keep it
current in a poor man fashion. We can revisit this later to use events instead.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/Makefile.am | 1 +
include/iface.h | 16 +++++++
src/Makefile.am | 1 +
src/iface.c | 133 +++++++++++++++++++++++++++++++++++++++++++++++++++
src/main.c | 8 +++-
src/meta.c | 5 +-
6 files changed, 161 insertions(+), 3 deletions(-)
create mode 100644 include/iface.h
create mode 100644 src/iface.c
diff --git a/include/Makefile.am b/include/Makefile.am
index f22561b..465d804 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -4,6 +4,7 @@ noinst_HEADERS = cli.h \
datatype.h \
expression.h \
gmputil.h \
+ iface.h \
mnl.h \
nftables.h \
payload.h \
diff --git a/include/iface.h b/include/iface.h
new file mode 100644
index 0000000..4a6908c
--- /dev/null
+++ b/include/iface.h
@@ -0,0 +1,16 @@
+#ifndef _NFTABLES_IFACE_H_
+#define _NFTABLES_IFACE_H_
+
+struct iface {
+ struct list_head list;
+ char name[IFNAMSIZ];
+ uint32_t ifindex;
+};
+
+unsigned int nft_if_nametoindex(const char *name);
+int nft_if_indextoname(unsigned int ifindex, char *name);
+
+void iface_cache_update(void);
+void iface_cache_release(void);
+
+#endif
diff --git a/src/Makefile.am b/src/Makefile.am
index 2410fd3..fd63219 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -44,6 +44,7 @@ nft_SOURCES = main.c \
utils.c \
erec.c \
mnl.c \
+ iface.c \
scanner.l \
parser_bison.y
diff --git a/src/iface.c b/src/iface.c
new file mode 100644
index 0000000..7b34b3d
--- /dev/null
+++ b/src/iface.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2015 Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <net/if.h>
+#include <time.h>
+#include <string.h>
+#include <errno.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/rtnetlink.h>
+
+#include <list.h>
+#include <netlink.h>
+#include <iface.h>
+
+static LIST_HEAD(iface_list);
+
+unsigned int nft_if_nametoindex(const char *name)
+{
+ struct iface *iface;
+
+ list_for_each_entry(iface, &iface_list, list) {
+ if (strncmp(name, iface->name, IFNAMSIZ) == 0)
+ return iface->ifindex;
+ }
+ return 0;
+}
+
+int nft_if_indextoname(unsigned int ifindex, char *name)
+{
+ struct iface *iface;
+
+ list_for_each_entry(iface, &iface_list, list) {
+ if (iface->ifindex == ifindex) {
+ strncpy(name, iface->name, IFNAMSIZ);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int data_attr_cb(const struct nlattr *attr, void *data)
+{
+ const struct nlattr **tb = data;
+ int type = mnl_attr_get_type(attr);
+
+ if (mnl_attr_type_valid(attr, IFLA_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch(type) {
+ case IFLA_IFNAME:
+ if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
+ netlink_abi_error();
+ break;
+ default:
+ return MNL_CB_OK;
+ }
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static int data_cb(const struct nlmsghdr *nlh, void *data)
+{
+ struct nlattr *tb[IFLA_MAX + 1] = {};
+ struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh);
+ struct iface *iface;
+
+ iface = xmalloc(sizeof(struct iface));
+ iface->ifindex = ifm->ifi_index;
+ mnl_attr_parse(nlh, sizeof(*ifm), data_attr_cb, tb);
+ strncpy(iface->name, mnl_attr_get_str(tb[IFLA_IFNAME]), IFNAMSIZ);
+ list_add(&iface->list, &iface_list);
+
+ return MNL_CB_OK;
+}
+
+void iface_cache_update(void)
+{
+ char buf[MNL_SOCKET_BUFFER_SIZE];
+ struct mnl_socket *nl;
+ struct nlmsghdr *nlh;
+ struct rtgenmsg *rt;
+ uint32_t seq, portid;
+ int ret;
+
+ nlh = mnl_nlmsg_put_header(buf);
+ nlh->nlmsg_type = RTM_GETLINK;
+ nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+ nlh->nlmsg_seq = seq = time(NULL);
+ rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
+ rt->rtgen_family = AF_PACKET;
+
+ nl = mnl_socket_open(NETLINK_ROUTE);
+ if (nl == NULL)
+ netlink_init_error();
+
+ if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0)
+ netlink_init_error();
+
+ portid = mnl_socket_get_portid(nl);
+
+ if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0)
+ netlink_init_error();
+
+ ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+ while (ret > 0) {
+ ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
+ if (ret <= MNL_CB_STOP)
+ break;
+ ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+ }
+ if (ret == -1)
+ netlink_init_error();
+
+ mnl_socket_close(nl);
+}
+
+void iface_cache_release(void)
+{
+ struct iface *iface, *next;
+
+ list_for_each_entry_safe(iface, next, &iface_list, list) {
+ list_del(&iface->list);
+ free(iface);
+ }
+}
diff --git a/src/main.c b/src/main.c
index 4590c30..384fb34 100644
--- a/src/main.c
+++ b/src/main.c
@@ -17,6 +17,7 @@
#include <getopt.h>
#include <fcntl.h>
#include <sys/types.h>
+#include <net/if.h>
#include <nftables.h>
#include <utils.h>
@@ -25,6 +26,7 @@
#include <netlink.h>
#include <erec.h>
#include <mnl.h>
+#include <iface.h>
#include <cli.h>
unsigned int max_errors = 10;
@@ -228,9 +230,12 @@ int nft_run(void *scanner, struct parser_state *state, struct list_head *msgs)
struct cmd *cmd, *next;
int ret;
+ iface_cache_update();
ret = nft_parse(scanner, state);
- if (ret != 0 || state->nerrs > 0)
+ if (ret != 0 || state->nerrs > 0) {
+ iface_cache_release();
return -1;
+ }
retry:
ret = nft_netlink(state, msgs);
if (ret < 0 && errno == EINTR) {
@@ -242,6 +247,7 @@ retry:
list_del(&cmd->list);
cmd_free(cmd);
}
+ iface_cache_release();
return ret;
}
diff --git a/src/meta.c b/src/meta.c
index ad57228..bfc1258 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -30,6 +30,7 @@
#include <gmputil.h>
#include <utils.h>
#include <erec.h>
+#include <iface.h>
static struct symbol_table *realm_tbl;
static void __init realm_table_init(void)
@@ -138,7 +139,7 @@ static void ifindex_type_print(const struct expr *expr)
int ifindex;
ifindex = mpz_get_uint32(expr->value);
- if (if_indextoname(ifindex, name))
+ if (nft_if_indextoname(ifindex, name))
printf("%s", name);
else
printf("%d", ifindex);
@@ -149,7 +150,7 @@ static struct error_record *ifindex_type_parse(const struct expr *sym,
{
int ifindex;
- ifindex = if_nametoindex(sym->identifier);
+ ifindex = nft_if_nametoindex(sym->identifier);
if (ifindex == 0)
return error(&sym->location, "Interface does not exist");
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
