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/*
* test/tests-u32-with-actions.c Add ingress qdisc, create some hash filters, and add redirect action
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Stolen from tests/test-complex-HTB-with-hash-filters.c
*
* Copyright (c) 2013 Cong Wang <xiyou.wangcong@gmail.com>
*/
#include <netlink/route/link.h>
#include <netlink/route/tc.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/cls/u32.h>
#include <netlink/route/classifier.h>
#include <netlink/route/action.h>
#include <netlink/route/act/mirred.h>
#include <netlink/route/act/skbedit.h>
#include <netlink/route/class.h>
#include <linux/if_ether.h>
#include <netlink/attr.h>
#include <stdio.h>
#include <string.h>
#define TC_HANDLE(maj, min) (TC_H_MAJ((maj) << 16) | TC_H_MIN(min))
/* some functions are copied from iproute-tc tool */
static int get_u32(__u32 *val, const char *arg, int base)
{
unsigned long res;
char *ptr;
if (!arg || !*arg)
return -1;
res = strtoul(arg, &ptr, base);
if (!ptr || ptr == arg || *ptr || res > 0xFFFFFFFFUL)
return -1;
*val = res;
return 0;
}
static int get_u32_handle(__u32 *handle, const char *str)
{
__u32 htid=0, hash=0, nodeid=0;
char *tmp = strchr(str, ':');
if (tmp == NULL) {
if (memcmp("0x", str, 2) == 0)
return get_u32(handle, str, 16);
return -1;
}
htid = strtoul(str, &tmp, 16);
if (tmp == str && *str != ':' && *str != 0)
return -1;
if (htid>=0x1000)
return -1;
if (*tmp) {
str = tmp+1;
hash = strtoul(str, &tmp, 16);
if (tmp == str && *str != ':' && *str != 0)
return -1;
if (hash>=0x100)
return -1;
if (*tmp) {
str = tmp+1;
nodeid = strtoul(str, &tmp, 16);
if (tmp == str && *str != 0)
return -1;
if (nodeid>=0x1000)
return -1;
}
}
*handle = (htid<<20)|(hash<<12)|nodeid;
return 0;
}
static uint32_t get_u32_parse_handle(const char *cHandle)
{
uint32_t handle=0;
if(get_u32_handle(&handle, cHandle)) {
printf ("Illegal \"ht\"\n");
return -1;
}
if (handle && TC_U32_NODE(handle)) {
printf("\"link\" must be a hash table.\n");
return -1;
}
return handle;
}
/*
* Function that adds a new filter and attach it to a hash table
* and set next hash table link with hash mask
*
*/
static
int u32_add_filter_on_ht_with_hashmask(struct nl_sock *sock, struct rtnl_link *rtnlLink, uint32_t prio,
uint32_t keyval, uint32_t keymask, int keyoff, int keyoffmask,
uint32_t htid, uint32_t htlink, uint32_t hmask, uint32_t hoffset, struct rtnl_act *act, struct rtnl_act *act2)
{
struct rtnl_cls *cls;
int err;
cls=rtnl_cls_alloc();
if (!(cls)) {
printf("Can not allocate classifier\n");
nl_socket_free(sock);
exit(1);
}
rtnl_tc_set_link(TC_CAST(cls), rtnlLink);
if ((err = rtnl_tc_set_kind(TC_CAST(cls), "u32"))) {
printf("Can not set classifier as u32\n");
return 1;
}
rtnl_cls_set_prio(cls, prio);
rtnl_cls_set_protocol(cls, ETH_P_IP);
rtnl_tc_set_parent(TC_CAST(cls), TC_HANDLE(0xffff, 0));
if (htid)
rtnl_u32_set_hashtable(cls, htid);
rtnl_u32_add_key_uint32(cls, keyval, keymask, keyoff, keyoffmask);
rtnl_u32_set_hashmask(cls, hmask, hoffset);
rtnl_u32_set_link(cls, htlink);
rtnl_u32_add_action(cls, act);
rtnl_u32_add_action(cls, act2);
if ((err = rtnl_cls_add(sock, cls, NLM_F_CREATE))) {
printf("Can not add classifier: %s\n", nl_geterror(err));
return -1;
}
rtnl_cls_put(cls);
return 0;
}
/*
* function that creates a new hash table
*/
static
int u32_add_ht(struct nl_sock *sock, struct rtnl_link *rtnlLink, uint32_t prio, uint32_t htid, uint32_t divisor)
{
int err;
struct rtnl_cls *cls;
cls=rtnl_cls_alloc();
if (!(cls)) {
printf("Can not allocate classifier\n");
nl_socket_free(sock);
exit(1);
}
rtnl_tc_set_link(TC_CAST(cls), rtnlLink);
if ((err = rtnl_tc_set_kind(TC_CAST(cls), "u32"))) {
printf("Can not set classifier as u32\n");
return 1;
}
rtnl_cls_set_prio(cls, prio);
rtnl_cls_set_protocol(cls, ETH_P_IP);
rtnl_tc_set_parent(TC_CAST(cls), TC_HANDLE(0xffff, 0));
rtnl_u32_set_handle(cls, htid, 0x0, 0x0);
//printf("htid: 0x%X\n", htid);
rtnl_u32_set_divisor(cls, divisor);
if ((err = rtnl_cls_add(sock, cls, NLM_F_CREATE))) {
printf("Can not add classifier: %s\n", nl_geterror(err));
return -1;
}
rtnl_cls_put(cls);
return 0;
}
/*
* function that adds a new ingress qdisc and set the default class for unclassified traffic
*/
static
int qdisc_add_ingress(struct nl_sock *sock, struct rtnl_link *rtnlLink)
{
struct rtnl_qdisc *qdisc;
int err;
/* Allocation of a qdisc object */
if (!(qdisc = rtnl_qdisc_alloc())) {
printf("Can not allocate Qdisc\n");
return -1;
}
//rtnl_tc_set_ifindex(TC_CAST(qdisc), master_index);
rtnl_tc_set_link(TC_CAST(qdisc), rtnlLink);
rtnl_tc_set_parent(TC_CAST(qdisc), TC_H_ROOT);
//printf("Delete current qdisc\n");
rtnl_qdisc_delete(sock, qdisc);
//rtnl_qdisc_put(qdisc);
rtnl_tc_set_handle(TC_CAST(qdisc), TC_HANDLE(0xffff, 0));
if ((err = rtnl_tc_set_kind(TC_CAST(qdisc), "ingress"))) {
printf("Can not allocate ingress\n");
return -1;
}
/* Submit request to kernel and wait for response */
if ((err = rtnl_qdisc_add(sock, qdisc, NLM_F_CREATE))) {
printf("Can not allocate ingress Qdisc\n");
return -1;
}
/* Return the qdisc object to free memory resources */
rtnl_qdisc_put(qdisc);
return 0;
}
int main(void)
{
struct nl_sock *sock;
struct rtnl_link *link;
uint32_t ht, htlink, htid, direction;
char chashlink[16]="";
int err;
struct nl_cache *link_cache;
struct rtnl_act *act, *act2;
if (!(sock = nl_socket_alloc())) {
printf("Unable to allocate netlink socket\n");
exit(1);
}
if ((err = nl_connect(sock, NETLINK_ROUTE)) < 0 ) {
printf("Nu s-a putut conecta la NETLINK!\n");
nl_socket_free(sock);
exit(1);
}
if ((err = rtnl_link_alloc_cache(sock, AF_UNSPEC, &link_cache)) < 0) {
printf("Unable to allocate link cache: %s\n",
nl_geterror(err));
nl_socket_free(sock);
exit(1);
}
/* lookup interface index of eth0 */
if (!(link = rtnl_link_get_by_name(link_cache, "eth0"))) {
/* error */
printf("Interface not found\n");
nl_socket_free(sock);
exit(1);
}
err=qdisc_add_ingress(sock, link);
//printf("Add main hash table\n");
/* create u32 first hash filter table
*
*/
/* formula calcul handle:
* uint32_t handle = (htid << 20) | (hash << 12) | nodeid;
*/
/*
* Upper limit of number of hash tables: 4096 (0xFFF)
* Number of hashes in a table: 256 values (0xFF)
*
*/
/* using 256 values for hash table
* each entry in hash table match a byte from IP address specified later by a hash key
*/
uint32_t i;
for (i = 1; i <= 0xf; i++)
u32_add_ht(sock, link, 1, i, 256);
/*
* attach a u32 filter to the first hash
* that redirects all traffic and make a hash key
* from the fist byte of the IP address
*
*/
//divisor=0x0; // unused here
//handle = 0x0; // unused here
//hash = 0x0; // unused here
//htid = 0x0; // unused here
//nodeid = 0x0; // unused here
// direction = 12 -> source IP
// direction = 16 -> destination IP
direction = 16;
/*
* which hash table will use
* in our case is hash table no 1 defined previous
*
* There are 2 posibilities to set the the hash table:
* 1. Using function get_u32_handle and sent a string in
* format 10: where 10 is number of the hash table
* 2. Create your own value in format: 0xa00000
*
*/
strcpy(chashlink, "1:");
//printf("Hash Link: %s\n", chashlink);
//chashlink=malloc(sizeof(char) *
htlink = 0x0; // is used by get_u32_handle to return the correct value of hash table (link)
if(get_u32_handle(&htlink, chashlink)) {
printf ("Illegal \"link\"");
nl_socket_free(sock);
exit(1);
}
//printf ("hash link : 0x%X\n", htlink);
//printf ("hash link test : %u\n", (htlink && TC_U32_NODE(htlink)));
if (htlink && TC_U32_NODE(htlink)) {
printf("\"link\" must be a hash table.\n");
nl_socket_free(sock);
exit(1);
}
/* the hash mask will hit the hash table (link) no 1: in our case
*/
/* set the hash key mask */
//hashmask = 0xFF000000UL; // the mask that is used to match the hash in specific table, in our case for example 1:a with mean the first byte which is 10 in hash table 1
/* Here we add a hash filter which match the first byte (see the hashmask value)
* of the source IP (offset 12 in the packet header)
* You can use also offset 16 to match the destination IP
*/
/*
* Also we need a filter to match our rule
* This mean that we will put a 0.0.0.0/0 filter in our first rule
* that match the offset 12 (source IP)
* Also you can put offset 16 to match the destination IP
*/
u32_add_filter_on_ht_with_hashmask(sock, link, 1,
0x0, 0x0, direction, 0,
0, htlink, 0xff000000, direction, NULL, NULL);
/*
* For each first byte that we need to match we will create a new hash table
* For example: you have those clases: 10.0.0.0/24 and 172.16.0.0/23
* For byte 10 and byte 172 will create a separate hash table that will match the second
* byte from each class.
*
*/
/*
* Now we will create other filter under (ATENTION) our first hash table (link) 1:
* Previous rule redirects the trafic according the hash mask to hash table (link) no 1:
* Here we will match the hash tables from 1:0 to 1:ff. Under each hash table we will attach
* other rules that matches next byte from IP source/destination IP and we will repeat the
* previous steps.
*
*/
act = rtnl_act_alloc();
if (!act) {
printf("rtnl_act_alloc() returns %p\n", act);
return -1;
}
rtnl_tc_set_kind(TC_CAST(act), "skbedit");
rtnl_skbedit_set_queue_mapping(act, 4);
rtnl_skbedit_set_action(act, TC_ACT_PIPE);
act2 = rtnl_act_alloc();
if (!act2) {
printf("rtnl_act_alloc() returns %p\n", act2);
return -1;
}
rtnl_tc_set_kind(TC_CAST(act2), "mirred");
rtnl_mirred_set_action(act2, TCA_EGRESS_REDIR);
rtnl_mirred_set_policy(act2, TC_ACT_STOLEN);
rtnl_mirred_set_ifindex(act2, rtnl_link_name2i(link_cache, "eth1"));
// /8 check
// 10.0.0.0/8
ht=get_u32_parse_handle("1:a:");
htid = (ht&0xFFFFF000);
htlink=get_u32_parse_handle("2:");
u32_add_filter_on_ht_with_hashmask(sock, link, 1,
0x0a000000, 0xff000000, direction, 0,
htid, htlink, 0x00ff0000, direction, act, act2);
rtnl_act_put(act);
nl_socket_free(sock);
return 0;
}