In iftable.c, replace calls to functions in rtnetlink.c with inline code
(converted to use libmnl instead of libnfnetlink).
It is essential to offer *all* functions originally provided by
libnfnetlink so that a built program will either take its nlif_*()
functions from libnetfilter_queue or libnfnetlink (depending on the
build-time order in LIBS).
Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
v2: created from patches 19/32 & (some of) 32/32
src/Makefile.am | 1 +
src/iftable.c | 311 ++++++++++++++++++++++--------------------------
2 files changed, 141 insertions(+), 171 deletions(-)
diff --git a/src/Makefile.am b/src/Makefile.am
index 079853e..a6813e8 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -30,6 +30,7 @@ libnetfilter_queue_la_LDFLAGS = -Wc,-nostartfiles \
-version-info $(LIBVERSION)
libnetfilter_queue_la_SOURCES = libnetfilter_queue.c \
nlmsg.c \
+ iftable.c \
extra/checksum.c \
extra/icmp.c \
extra/ipv6.c \
diff --git a/src/iftable.c b/src/iftable.c
index 9884a52..54364b3 100644
--- a/src/iftable.c
+++ b/src/iftable.c
@@ -11,19 +11,29 @@
#include <unistd.h>
#include <stdlib.h>
+#include <time.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
-#include <assert.h>
#include <linux/netdevice.h>
-#include <libnfnetlink/libnfnetlink.h>
-#include "rtnl.h"
-#include "linux_list.h"
+#include <libmnl/libmnl.h>
+#include <linux/rtnetlink.h>
+#include <libnetfilter_queue/linux_list.h>
+#include <linux/netfilter/nfnetlink_queue.h>
+#include <libnetfilter_queue/libnetfilter_queue.h>
+
+#include "internal.h"
+
+#define NUM_NLIF_BITS 4
+#define NUM_NLIF_ENTRIES (1 << NUM_NLIF_BITS)
+#define NLIF_ENTRY_MASK (NUM_NLIF_ENTRIES - 1)
+
+static int data_cb(const struct nlmsghdr *nlh, void *data);
/**
* \defgroup iftable Functions to manage a table of network interfaces
@@ -86,117 +96,15 @@ struct ifindex_node {
uint32_t index;
uint32_t type;
- uint32_t alen;
uint32_t flags;
- char addr[8];
- char name[16];
+ char name[IFNAMSIZ];
};
struct nlif_handle {
- struct list_head ifindex_hash[16];
- struct rtnl_handle *rtnl_handle;
- struct rtnl_handler ifadd_handler;
- struct rtnl_handler ifdel_handler;
+ struct list_head ifindex_hash[NUM_NLIF_ENTRIES];
+ struct mnl_socket *nl;
};
-/* iftable_add - Add/Update an entry to/in the interface table
- * \param n: netlink message header of a RTM_NEWLINK message
- * \param arg: not used
- *
- * This function adds/updates an entry in the intrface table.
- * Returns -1 on error, 1 on success.
- */
-static int iftable_add(struct nlmsghdr *n, void *arg)
-{
- unsigned int hash, found = 0;
- struct ifinfomsg *ifi_msg = NLMSG_DATA(n);
- struct ifindex_node *this;
- struct rtattr *cb[IFLA_MAX+1];
- struct nlif_handle *h = arg;
-
- if (n->nlmsg_type != RTM_NEWLINK)
- return -1;
-
- if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi_msg)))
- return -1;
-
- rtnl_parse_rtattr(cb, IFLA_MAX, IFLA_RTA(ifi_msg), IFLA_PAYLOAD(n));
-
- if (!cb[IFLA_IFNAME])
- return -1;
-
- hash = ifi_msg->ifi_index & 0xF;
- list_for_each_entry(this, &h->ifindex_hash[hash], head) {
- if (this->index == ifi_msg->ifi_index) {
- found = 1;
- break;
- }
- }
-
- if (!found) {
- this = malloc(sizeof(*this));
- if (!this)
- return -1;
-
- this->index = ifi_msg->ifi_index;
- }
-
- this->type = ifi_msg->ifi_type;
- this->flags = ifi_msg->ifi_flags;
- if (cb[IFLA_ADDRESS]) {
- unsigned int alen;
-
- this->alen = alen = RTA_PAYLOAD(cb[IFLA_ADDRESS]);
- if (alen > sizeof(this->addr))
- alen = sizeof(this->addr);
- memcpy(this->addr, RTA_DATA(cb[IFLA_ADDRESS]), alen);
- } else {
- this->alen = 0;
- memset(this->addr, 0, sizeof(this->addr));
- }
- strcpy(this->name, RTA_DATA(cb[IFLA_IFNAME]));
-
- if (!found)
- list_add(&this->head, &h->ifindex_hash[hash]);
-
- return 1;
-}
-
-/* iftable_del - Delete an entry from the interface table
- * \param n: netlink message header of a RTM_DELLINK nlmsg
- * \param arg: not used
- *
- * Delete an entry from the interface table.
- * Returns -1 on error, 0 if no matching entry was found or 1 on success.
- */
-static int iftable_del(struct nlmsghdr *n, void *arg)
-{
- struct ifinfomsg *ifi_msg = NLMSG_DATA(n);
- struct rtattr *cb[IFLA_MAX+1];
- struct nlif_handle *h = arg;
- struct ifindex_node *this, *tmp;
- unsigned int hash;
-
- if (n->nlmsg_type != RTM_DELLINK)
- return -1;
-
- if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi_msg)))
- return -1;
-
- rtnl_parse_rtattr(cb, IFLA_MAX, IFLA_RTA(ifi_msg), IFLA_PAYLOAD(n));
-
- hash = ifi_msg->ifi_index & 0xF;
- list_for_each_entry_safe(this, tmp, &h->ifindex_hash[hash], head) {
- if (this->index == ifi_msg->ifi_index) {
- list_del(&this->head);
- free(this);
- return 1;
- }
- }
-
- return 0;
-}
-
/**
* nlif_index2name - get the name for an ifindex
*
@@ -205,6 +113,7 @@ static int iftable_del(struct nlmsghdr *n, void *arg)
* \param name interface name, pass a buffer of IFNAMSIZ size
* \return -1 on error, 1 on success
*/
+EXPORT_SYMBOL
int nlif_index2name(struct nlif_handle *h,
unsigned int index,
char *name)
@@ -212,9 +121,6 @@ int nlif_index2name(struct nlif_handle *h,
unsigned int hash;
struct ifindex_node *this;
- assert(h != NULL);
- assert(name != NULL);
-
if (index == 0) {
strcpy(name, "*");
return 1;
@@ -240,6 +146,7 @@ int nlif_index2name(struct nlif_handle *h,
* \param flags pointer to variable used to store the interface flags
* \return -1 on error, 1 on success
*/
+EXPORT_SYMBOL
int nlif_get_ifflags(const struct nlif_handle *h,
unsigned int index,
unsigned int *flags)
@@ -247,9 +154,6 @@ int nlif_get_ifflags(const struct nlif_handle *h,
unsigned int hash;
struct ifindex_node *this;
- assert(h != NULL);
- assert(flags != NULL);
-
if (index == 0) {
errno = ENOENT;
return -1;
@@ -269,11 +173,12 @@ int nlif_get_ifflags(const struct nlif_handle *h,
/**
* nlif_open - initialize interface table
*
- * Initialize rtnl interface and interface table
- * Call this before any nlif_* function
+ * Open a netlink socket and initialize interface table
+ * Call this before any other nlif_* function
*
- * \return file descriptor to netlink socket
+ * \return NULL on error, else valid pointer to an nlif_handle structure
*/
+EXPORT_SYMBOL
struct nlif_handle *nlif_open(void)
{
int i;
@@ -283,32 +188,21 @@ struct nlif_handle *nlif_open(void)
if (h == NULL)
goto err;
- for (i = 0; i < 16; i++)
+ for (i = 0; i < NUM_NLIF_ENTRIES; i++)
INIT_LIST_HEAD(&h->ifindex_hash[i]);
- h->ifadd_handler.nlmsg_type = RTM_NEWLINK;
- h->ifadd_handler.handlefn = iftable_add;
- h->ifadd_handler.arg = h;
- h->ifdel_handler.nlmsg_type = RTM_DELLINK;
- h->ifdel_handler.handlefn = iftable_del;
- h->ifdel_handler.arg = h;
+ h->nl = mnl_socket_open(NETLINK_ROUTE);
+ if (!h->nl)
+ goto err_free;
- h->rtnl_handle = rtnl_open();
- if (h->rtnl_handle == NULL)
- goto err;
-
- if (rtnl_handler_register(h->rtnl_handle, &h->ifadd_handler) < 0)
+ if (mnl_socket_bind(h->nl, RTMGRP_LINK, MNL_SOCKET_AUTOPID) < 0)
goto err_close;
- if (rtnl_handler_register(h->rtnl_handle, &h->ifdel_handler) < 0)
- goto err_unregister;
-
return h;
-err_unregister:
- rtnl_handler_unregister(h->rtnl_handle, &h->ifadd_handler);
err_close:
- rtnl_close(h->rtnl_handle);
+ mnl_socket_close(h->nl);
+err_free:
free(h);
err:
return NULL;
@@ -319,18 +213,15 @@ err:
*
* \param h pointer to nlif_handle created by nlif_open()
*/
+EXPORT_SYMBOL
void nlif_close(struct nlif_handle *h)
{
int i;
struct ifindex_node *this, *tmp;
- assert(h != NULL);
+ mnl_socket_close(h->nl);
- rtnl_handler_unregister(h->rtnl_handle, &h->ifadd_handler);
- rtnl_handler_unregister(h->rtnl_handle, &h->ifdel_handler);
- rtnl_close(h->rtnl_handle);
-
- for (i = 0; i < 16; i++) {
+ for (i = 0; i < NUM_NLIF_ENTRIES; i++) {
list_for_each_entry_safe(this, tmp, &h->ifindex_hash[i], head) {
list_del(&this->head);
free(this);
@@ -344,61 +235,139 @@ void nlif_close(struct nlif_handle *h)
/**
* nlif_catch - receive message from netlink and update interface table
*
- * FIXME - elaborate a bit
- *
* \param h pointer to nlif_handle created by nlif_open()
* \return 0 if OK
*/
+EXPORT_SYMBOL
int nlif_catch(struct nlif_handle *h)
{
- assert(h != NULL);
-
- if (h->rtnl_handle)
- return rtnl_receive(h->rtnl_handle);
-
- return -1;
-}
-
-static int nlif_catch_multi(struct nlif_handle *h)
-{
- assert(h != NULL);
-
- if (h->rtnl_handle)
- return rtnl_receive_multi(h->rtnl_handle);
+ /*
+ * Use MNL_SOCKET_BUFFER_SIZE instead of MNL_SOCKET_DUMP_SIZE
+ * to keep memory footprint same as it was.
+ */
+ char buf[MNL_SOCKET_BUFFER_SIZE];
+ int ret;
+
+ if (!h->nl) /* The old library had this test */
+ return -1;
- return -1;
+ ret = mnl_socket_recvfrom(h->nl, buf, sizeof(buf));
+ if (ret == -1)
+ return -1;
+ return mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(h->nl),
+ data_cb, h) == -1 ? -1 : 0;
}
/**
* nlif_query - request a dump of interfaces available in the system
* \param h: pointer to a valid nlif_handler
+ * \return -1 on error with errno set, else >=0
*/
+EXPORT_SYMBOL
int nlif_query(struct nlif_handle *h)
{
- assert(h != NULL);
-
- if (rtnl_dump_type(h->rtnl_handle, RTM_GETLINK) < 0)
+ char buf[MNL_SOCKET_BUFFER_SIZE];
+ struct nlmsghdr *nlh;
+ uint32_t seq;
+ int ret;
+ struct rtgenmsg *rt;
+
+ 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;
+ if (mnl_socket_sendto(h->nl, nlh, nlh->nlmsg_len) < 0)
return -1;
-
- return nlif_catch_multi(h);
+ ret = mnl_socket_recvfrom(h->nl, buf, sizeof(buf));
+ while (ret > 0) {
+ ret = mnl_cb_run(buf, ret, seq, mnl_socket_get_portid(h->nl),
+ data_cb, h);
+ if (ret <= MNL_CB_STOP)
+ break;
+ ret = mnl_socket_recvfrom(h->nl, buf, sizeof(buf));
+ }
+ return ret;
}
/**
* nlif_fd - get file descriptor for the netlink socket
*
* \param h pointer to nlif_handle created by nlif_open()
- * \return The fd or -1 if there's an error
+ * \return socket fd or -1 on error
*/
+EXPORT_SYMBOL
int nlif_fd(struct nlif_handle *h)
{
- assert(h != NULL);
-
- if (h->rtnl_handle)
- return h->rtnl_handle->rtnl_fd;
-
- return -1;
+ return h->nl ? mnl_socket_get_fd(h->nl) : -1;
}
/**
* @}
*/
+
+/*
+ * data_cb - callback for rtnetlink messages
+ * caller will put nlif_handle in data
+ */
+
+static int data_cb(const struct nlmsghdr *nlh, void *data)
+{
+ struct ifinfomsg *ifi_msg = mnl_nlmsg_get_payload(nlh);
+ struct nlif_handle *h = data;
+ struct nlattr *attr;
+ uint32_t hash;
+ struct ifindex_node *this, *tmp;
+
+ if (nlh->nlmsg_type != RTM_NEWLINK && nlh->nlmsg_type != RTM_DELLINK) {
+ errno = EPROTO;
+ return MNL_CB_ERROR;
+ }
+ hash = ifi_msg->ifi_index & NLIF_ENTRY_MASK;
+
+ /* RTM_DELLINK is simple, do it first for less indenting */
+ if (nlh->nlmsg_type == RTM_DELLINK) {
+ /*
+ * The original code used list_for_each_entry_safe when deleting
+ * and list_for_each_entry when adding.
+ * The code is only ever going to delete one entry
+ * so what does the safe variant achieve?
+ * In a multi-threaded app,
+ * I'd suggest a pthread rwlock on all nlif accesses.
+ */
+ list_for_each_entry_safe(this, tmp, &h->ifindex_hash[hash],
+ head) {
+ if (this->index == ifi_msg->ifi_index) {
+ list_del(&this->head);
+ free(this);
+ }
+ }
+ return MNL_CB_OK;
+ }
+
+ list_for_each_entry(this, &h->ifindex_hash[hash], head) {
+ if (this->index == ifi_msg->ifi_index)
+ goto found;
+ }
+ this = calloc(1, sizeof(*this));
+ if (!this)
+ return MNL_CB_ERROR;
+ this->index = ifi_msg->ifi_index;
+ this->type = ifi_msg->ifi_type;
+ this->flags = ifi_msg->ifi_flags;
+ list_add(&this->head, &h->ifindex_hash[hash]);
+found:
+ mnl_attr_for_each(attr, nlh, sizeof(*ifi_msg)) {
+ /* All we want is the interface name */
+ if (mnl_attr_get_type(attr) == IFLA_IFNAME) {
+ if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
+ perror("mnl_attr_validate");
+ return MNL_CB_ERROR;
+ }
+ strcpy(this->name, mnl_attr_get_str(attr));
+ break;
+ }
+ }
+ return MNL_CB_OK;
+}
--
2.35.8
