nftables used to have a cache to speed up interface name <-> index, restore it
using libmnl.
This reduces netlink traffic since if_nametoindex() and if_indexto_name() open,
send request, receive 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.
We still need special handling for the nft -i case.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/iface.h | 13 ++++++
src/Makefile.am | 1 +
src/iface.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/meta.c | 5 ++-
4 files changed, 151 insertions(+), 2 deletions(-)
create mode 100644 include/iface.h
create mode 100644 src/iface.c
diff --git a/include/iface.h b/include/iface.h
new file mode 100644
index 0000000..62e6a33
--- /dev/null
+++ b/include/iface.h
@@ -0,0 +1,13 @@
+#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);
+
+#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..8c5f99c
--- /dev/null
+++ b/src/iface.c
@@ -0,0 +1,134 @@
+/*
+ * 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 = malloc(sizeof(struct iface));
+ if (iface == NULL)
+ memory_allocation_error();
+
+ 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;
+}
+
+static void __init iface_cache_init(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);
+}
+
+static void __exit iface_cache_fini(void)
+{
+ struct iface *iface, *next;
+
+ list_for_each_entry_safe(iface, next, &iface_list, list)
+ free(iface);
+}
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
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