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natflow_user.c
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natflow_user.c
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/*
* Author: Chen Minqiang <[email protected]>
* Date : Wed, 27 Jun 2018 22:13:17 +0800
*/
#include <linux/ctype.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/version.h>
#include <linux/spinlock.h>
#include <linux/seqlock.h>
#include <linux/netdevice.h>
#include <linux/bitops.h>
#include <linux/timer.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/netfilter.h>
#include <linux/netfilter_bridge.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <linux/if_pppox.h>
#include <linux/ppp_defs.h>
#include "natflow.h"
#include "natflow_common.h"
#include "natflow_user.h"
#include "natflow_zone.h"
struct userinfo {
struct list_head list;
unsigned int timeout;
union {
__be32 ip;
union nf_inet_addr ipv6;
};
uint8_t macaddr[ETH_ALEN];
uint8_t l2num:1; /* 0: ipv4, 1: ipv6 */
uint8_t auth_type:7;
uint8_t auth_status;
uint16_t auth_rule_id;
unsigned long long rx_packets;
unsigned long long rx_bytes;
unsigned long long tx_packets;
unsigned long long tx_bytes;
unsigned int rx_speed_packets;
unsigned int rx_speed_bytes;
unsigned int tx_speed_packets;
unsigned int tx_speed_bytes;
};
struct userinfo_event {
spinlock_t lock;
struct list_head head;
wait_queue_head_t wait;
#define USERINFO_EVENT_STOPPED 0
#define USERINFO_EVENT_RUNNING 1
unsigned int stage;
};
static struct userinfo_event userinfo_event_store;
static inline void userinfo_event_store_init(void)
{
spin_lock_init(&userinfo_event_store.lock);
INIT_LIST_HEAD(&userinfo_event_store.head);
init_waitqueue_head(&userinfo_event_store.wait);
userinfo_event_store.stage = USERINFO_EVENT_STOPPED;
}
static inline void userinfo_event_store_exit(void)
{
struct userinfo *user_i, *n;
list_for_each_entry_safe(user_i, n, &userinfo_event_store.head, list) {
list_del(&user_i->list);
kfree(user_i);
}
}
static int natflow_user_major = 0;
static int natflow_user_minor = 0;
static struct cdev natflow_user_cdev;
const char *natflow_user_dev_name = "natflow_user_ctl";
static struct class *natflow_user_class;
static struct device *natflow_user_dev;
static uint16_t auth_conf_magic = 0;
static inline void auth_conf_update_magic(int init)
{
if (init) {
auth_conf_magic = jiffies;
} else {
auth_conf_magic++;
}
}
static struct auth_conf *auth_conf = NULL;
static inline int auth_rule_add_one(struct auth_rule_t *rule)
{
if (auth_conf->num < MAX_AUTH) {
memcpy(&auth_conf->auth[auth_conf->num], rule, sizeof(struct auth_rule_t));
auth_conf->num++;
return 0;
}
return -ENOMEM;
}
static int disabled = 1;
void natflow_user_disabled_set(int v)
{
disabled = v;
}
int natflow_user_disabled_get(void)
{
return disabled;
}
static int qos_major = 0;
static int qos_minor = 0;
static struct cdev qos_cdev;
const char *qos_dev_name = "qos_ctl";
static struct class *qos_class;
static struct device *qos_dev;
#define QOS_TOKEN_CTRL_GROUP_MAX 64
static struct {
struct token_ctrl rx;
struct token_ctrl tx;
} qos_token_ctrl[QOS_TOKEN_CTRL_GROUP_MAX];
static struct qos_rule {
union {
unsigned char name[16];
__be32 ip;
struct {
__be32 ip;
__be32 mask;
} ipcidr;
} user;
union {
unsigned char name[16];
__be16 port;
} user_port;
union {
unsigned char name[16];
__be32 ip;
struct {
__be32 ip;
__be32 mask;
} ipcidr;
} remote;
union {
unsigned char name[16];
__be16 port;
} remote_port;
unsigned short proto;
#define USER_TYPE_IP BIT(0)
#define USER_TYPE_IPCIDR BIT(1)
#define USER_TYPE_SET BIT(2)
#define USER_TYPE_MASK (USER_TYPE_IP|USER_TYPE_IPCIDR|USER_TYPE_SET)
#define USER_PORT_TYPE_PORT BIT(3)
#define USER_PORT_TYPE_SET BIT(4)
#define USER_PORT_TYPE_MASK (USER_PORT_TYPE_PORT|USER_PORT_TYPE_SET)
#define REMOTE_TYPE_IP BIT(5)
#define REMOTE_TYPE_IPCIDR BIT(6)
#define REMOTE_TYPE_SET BIT(7)
#define REMOTE_TYPE_MASK (REMOTE_TYPE_IP|REMOTE_TYPE_IPCIDR|REMOTE_TYPE_SET)
#define REMOTE_PORT_TYPE_PORT BIT(8)
#define REMOTE_PORT_TYPE_SET BIT(9)
#define REMOTE_PORT_TYPE_MASK (REMOTE_PORT_TYPE_PORT|REMOTE_PORT_TYPE_SET)
unsigned short flag;
unsigned int rxbytes;
unsigned int txbytes;
} qos_token_ctrl_rule[QOS_TOKEN_CTRL_GROUP_MAX];
static unsigned int tc_classid_mode = 0;
static int qos_token_ctrl_num = 0;
static void qos_token_ctrl_init(void)
{
int i;
memset(&qos_token_ctrl, 0, sizeof(*qos_token_ctrl) * QOS_TOKEN_CTRL_GROUP_MAX);
memset(&qos_token_ctrl_rule, 0, sizeof(*qos_token_ctrl_rule) * QOS_TOKEN_CTRL_GROUP_MAX);
for (i = 0; i < QOS_TOKEN_CTRL_GROUP_MAX; i++) {
spin_lock_init(&qos_token_ctrl[i].rx.lock);
spin_lock_init(&qos_token_ctrl[i].tx.lock);
}
}
static int natflow_token_ctrl(struct sk_buff *skb, struct token_ctrl *tc)
{
int feed_jiffies = 0;
unsigned int current_jiffies = (unsigned int)jiffies;
int ret = 0;
int len = skb->len;
struct iphdr *iph = ip_hdr(skb);
void *l4 = (void *)iph + iph->ihl * 4;
switch (iph->protocol) {
case IPPROTO_TCP:
len -= iph->ihl * 4 + TCPH(l4)->doff * 4;
break;
case IPPROTO_UDP:
len -= iph->ihl * 4 + sizeof(struct udphdr);
break;
}
if (len <= 0) return 0;
if (tc->tokens_per_jiffy == 0) return 0;
spin_lock_bh(&tc->lock);
if (tc->tokens > 0) {
tc->tokens -= len;
ret = 0;
goto out;
}
current_jiffies = jiffies;
feed_jiffies = uintmindiff(current_jiffies, tc->jiffies);
if (feed_jiffies > HZ) {
feed_jiffies = HZ/8 + 1;
}
ret = tc->tokens + (int)(tc->tokens_per_jiffy * feed_jiffies);
if (feed_jiffies <= HZ) {
tc->tokens = ret;
} else {
if (ret <= 0) {
tc->tokens = ret;
} else {
tc->tokens = 0;
}
}
if (tc->tokens >= 0) {
tc->tokens -= len;
ret = 0;
}
tc->jiffies = current_jiffies;
out:
spin_unlock_bh(&tc->lock);
return ret;
}
int rx_token_ctrl(struct sk_buff *skb, struct fakeuser_data_t *fud, natflow_t *nf)
{
int ret = 0;
if (tc_classid_mode && nf && nf->qos_id) {
skb->mark = nf->qos_id * 2 - 1;
return 0;
}
if (nf && nf->qos_id && nf->qos_id <= qos_token_ctrl_num) {
ret = natflow_token_ctrl(skb, &qos_token_ctrl[nf->qos_id - 1].rx);
}
if (fud->tc.rx.tokens_per_jiffy == 0 || ret < 0) {
return ret;
}
return natflow_token_ctrl(skb, &fud->tc.rx);
}
int tx_token_ctrl(struct sk_buff *skb, struct fakeuser_data_t *fud, natflow_t *nf)
{
int ret = 0;
if (tc_classid_mode && nf && nf->qos_id) {
skb->mark = nf->qos_id * 2;
return 0;
}
if (nf && nf->qos_id && nf->qos_id <= qos_token_ctrl_num) {
ret = natflow_token_ctrl(skb, &qos_token_ctrl[nf->qos_id - 1].tx);
}
if (fud->tc.tx.tokens_per_jiffy == 0 || ret < 0) {
return ret;
}
return natflow_token_ctrl(skb, &fud->tc.tx);
}
static unsigned int auth_open_weixin_reply = 0;
static unsigned short https_redirect_port = __constant_htons(443);
static unsigned int https_redirect_en = 0;
/*XXX: default redirect_ip 10.10.10.10 */
unsigned int redirect_ip = __constant_htonl((10<<24)|(10<<16)|(10<<8)|(10<<0));
/* user timeout 1800s */
static unsigned int natflow_user_timeout = 1800;
#define NATFLOW_USER_TIMEOUT 300
static DEFINE_PER_CPU(struct sk_buff *, natflow_user_uskbs);
#define NATFLOW_USKB_SIZE (sizeof(struct iphdr) + sizeof(struct ipv6hdr) + sizeof(struct udphdr))
#define NATFLOW_FAKEUSER_DADDR __constant_htonl(0x7fffffff)
static inline struct sk_buff *uskb_of_this_cpu(void)
{
struct sk_buff **ptr = this_cpu_ptr(&natflow_user_uskbs);
if (!*ptr) {
*ptr = __alloc_skb(NATFLOW_USKB_SIZE, GFP_ATOMIC, 0, numa_node_id());
}
return *ptr;
}
void natflow_user_timeout_touch(natflow_fakeuser_t *nfu)
{
struct fakeuser_data_t *fud;
fud = natflow_fakeuser_data(nfu);
if (fud->auth_type != AUTH_TYPE_UNKNOWN) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0)
unsigned long newtimeout = jiffies + natflow_user_timeout * HZ;
if (newtimeout - nfu->timeout.expires > HZ) {
mod_timer_pending(&nfu->timeout, newtimeout);
}
#else
nfu->timeout = jiffies + natflow_user_timeout * HZ;
#endif
} else {
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0)
unsigned long newtimeout = jiffies + NATFLOW_USER_TIMEOUT * HZ;
if (newtimeout - nfu->timeout.expires > HZ) {
mod_timer_pending(&nfu->timeout, newtimeout);
}
#else
nfu->timeout = jiffies + NATFLOW_USER_TIMEOUT * HZ;
#endif
}
}
natflow_fakeuser_t *natflow_user_get(struct nf_conn *ct)
{
natflow_fakeuser_t *user = NULL;
if (ct->master) {
if ((IPS_NATFLOW_USER & ct->master->status)) {
if (unlikely(nf_ct_is_dying(ct->master))) {
return NULL;
}
user = ct->master;
} else if (ct->master->master && (IPS_NATFLOW_USER & ct->master->master->status)) {
if (unlikely(nf_ct_is_dying(ct->master->master))) {
return NULL;
}
user = ct->master->master;
}
}
return user;
}
static natflow_fakeuser_t *natflow_user_find_get(__be32 ip)
{
natflow_fakeuser_t *user = NULL;
struct nf_conntrack_tuple tuple;
struct nf_conntrack_tuple_hash *h;
memset(&tuple, 0, sizeof(tuple));
tuple.src.u3.ip = ip;
tuple.src.u.udp.port = __constant_htons(0);
tuple.dst.u3.ip = NATFLOW_FAKEUSER_DADDR;
tuple.dst.u.udp.port = __constant_htons(65535);
tuple.src.l3num = PF_INET;
tuple.dst.protonum = IPPROTO_UDP;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)
h = nf_conntrack_find_get(&init_net, NF_CT_DEFAULT_ZONE, &tuple);
#else
h = nf_conntrack_find_get(&init_net, &nf_ct_zone_dflt, &tuple);
#endif
if (h) {
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
if (!(IPS_NATFLOW_USER & ct->status) || NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL) {
nf_ct_put(ct);
} else {
user = ct;
}
}
return user;
}
static natflow_fakeuser_t *natflow_user_find_get6(union nf_inet_addr *u3)
{
natflow_fakeuser_t *user = NULL;
struct nf_conntrack_tuple tuple;
struct nf_conntrack_tuple_hash *h;
memset(&tuple, 0, sizeof(tuple));
tuple.src.u3 = *u3;
tuple.src.u.udp.port = __constant_htons(0);
memset(&tuple.dst.u3, 0, sizeof(tuple.dst.u3));
tuple.dst.u3.in6.s6_addr16[0] = 0xffff; //NATFLOW_FAKEUSER_DADDR=ffff::
tuple.dst.u.udp.port = __constant_htons(65535);
tuple.src.l3num = AF_INET6;
tuple.dst.protonum = IPPROTO_UDP;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)
h = nf_conntrack_find_get(&init_net, NF_CT_DEFAULT_ZONE, &tuple);
#else
h = nf_conntrack_find_get(&init_net, &nf_ct_zone_dflt, &tuple);
#endif
if (h) {
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
if (!(IPS_NATFLOW_USER & ct->status) || NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL) {
nf_ct_put(ct);
} else {
user = ct;
}
}
return user;
}
static void natflow_user_release_put(natflow_fakeuser_t *user)
{
nf_ct_put(user);
}
static natflow_fakeuser_t *natflow_user_lookup_in(struct nf_conn *ct, int dir)
{
natflow_fakeuser_t *user = NULL;
user = natflow_user_get(ct);
if (user)
return user;
/* FIXME: cannot use ct->master for user since destroy_gre_conntrack() may double free gre helper in master */
if (unlikely(nf_ct_protonum(ct) == IPPROTO_GRE)) {
return NULL;
}
if (!nf_ct_is_confirmed(ct) && !user && (!ct->master || !ct->master->master)) {
if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num == AF_INET) {
user = natflow_user_find_get(ct->tuplehash[dir].tuple.src.u3.ip);
} else {
user = natflow_user_find_get6(&ct->tuplehash[dir].tuple.src.u3);
}
if (user) {
natflow_user_timeout_touch(user);
if (ct->master && !(IPS_NATFLOW_USER & ct->master->status)) {
if (!test_and_set_bit(IPS_NATFLOW_MASTER_BIT, &ct->master->status)) {
nf_conntrack_get(&user->ct_general);
ct->master->master = user;
}
} else {
if (!test_and_set_bit(IPS_NATFLOW_MASTER_BIT, &ct->status)) {
nf_conntrack_get(&user->ct_general);
ct->master = user;
}
}
natflow_user_release_put(user);
} else {
return NULL;
}
}
return natflow_user_get(ct);
}
static natflow_fakeuser_t *natflow_user_in(struct nf_conn *ct, int dir)
{
natflow_fakeuser_t *user = NULL;
user = natflow_user_get(ct);
if (user)
return user;
/* FIXME: cannot use ct->master for user since destroy_gre_conntrack() may double free gre helper in master */
if (unlikely(nf_ct_protonum(ct) == IPPROTO_GRE)) {
return NULL;
}
if (!nf_ct_is_confirmed(ct) && !user && (!ct->master || !ct->master->master)) {
struct nf_ct_ext *new = NULL;
unsigned int newoff = 0;
int ret;
struct sk_buff *uskb;
struct iphdr *iph;
struct udphdr *udph;
enum ip_conntrack_info ctinfo;
uskb = uskb_of_this_cpu();
if (uskb == NULL) {
return NULL;
}
skb_reset_transport_header(uskb);
skb_reset_network_header(uskb);
skb_reset_mac_len(uskb);
if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num == AF_INET) {
uskb->protocol = __constant_htons(ETH_P_IP);
uskb->len = (sizeof(struct iphdr) + sizeof(struct udphdr));
skb_set_tail_pointer(uskb, uskb->len);
uskb->pkt_type = PACKET_HOST;
uskb->transport_header = uskb->network_header + sizeof(struct iphdr);
iph = ip_hdr(uskb);
iph->version = 4;
iph->ihl = 5;
iph->saddr = ct->tuplehash[dir].tuple.src.u3.ip;
iph->daddr = NATFLOW_FAKEUSER_DADDR;
iph->tos = 0;
iph->tot_len = htons(uskb->len);
iph->ttl=255;
iph->protocol = IPPROTO_UDP;
iph->id = __constant_htons(0xDEAD);
iph->frag_off = 0;
iph->check = 0;
iph->check = ip_fast_csum(iph, iph->ihl);
udph = (struct udphdr *)((char *)iph + sizeof(struct iphdr));
udph->source = __constant_htons(0);
udph->dest = __constant_htons(65535);
udph->len = __constant_htons(sizeof(struct udphdr));
udph->check = 0;
ret = nf_conntrack_in_compat(&init_net, PF_INET, NF_INET_PRE_ROUTING, uskb);
if (ret != NF_ACCEPT) {
return NULL;
}
user = nf_ct_get(uskb, &ctinfo);
if (!user) {
NATFLOW_ERROR("fakeuser create for ct[%pI4:%u->%pI4:%u %pI4:%u<-%pI4:%u] failed, ctinfo=%x\n",
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all),
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all), (unsigned int)ctinfo);
return NULL;
}
if (!user->ext) {
NATFLOW_ERROR("fakeuser create for ct[%pI4:%u->%pI4:%u %pI4:%u<-%pI4:%u] failed, user->ext is NULL\n",
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all),
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all));
skb_nfct_reset(uskb);
return NULL;
}
if (!nf_ct_is_confirmed(user) && !(IPS_NATFLOW_USER & user->status) && !test_and_set_bit(IPS_NATFLOW_USER_BIT, &user->status)) {
struct fakeuser_data_t *fud;
newoff = ALIGN(user->ext->len, __ALIGN_64BITS);
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 0)
new = __krealloc(user->ext, newoff + sizeof(struct fakeuser_data_t), GFP_ATOMIC);
#else
new = krealloc(user->ext, newoff + sizeof(struct fakeuser_data_t), GFP_ATOMIC);
#endif
if (!new) {
NATFLOW_ERROR("fakeuser create for ct[%pI4:%u->%pI4:%u %pI4:%u<-%pI4:%u] failed, realloc user->ext failed\n",
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all),
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all));
skb_nfct_reset(uskb);
return NULL;
}
if (user->ext != new) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0)
kfree_rcu(user->ext, rcu);
user->ext = new;
#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 0)
kfree_rcu(user->ext, rcu);
rcu_assign_pointer(user->ext, new);
#else
user->ext = new;
#endif
}
new->len = newoff;
memset((void *)new + newoff, 0, sizeof(struct fakeuser_data_t));
fud = (struct fakeuser_data_t *)((void *)new + newoff);
spin_lock_init(&fud->tc.rx.lock);
spin_lock_init(&fud->tc.tx.lock);
}
} else {
//FIXME ipv6
uskb->protocol = __constant_htons(ETH_P_IPV6);
uskb->len = (sizeof(struct ipv6hdr) + sizeof(struct udphdr));
skb_set_tail_pointer(uskb, uskb->len);
uskb->pkt_type = PACKET_HOST;
uskb->transport_header = uskb->network_header + sizeof(struct ipv6hdr);
iph = ip_hdr(uskb);
IPV6H->version = 6;
IPV6H->priority = 0;
IPV6H->flow_lbl[2] = IPV6H->flow_lbl[1] = IPV6H->flow_lbl[0] = 0;
IPV6H->payload_len = htons(sizeof(struct udphdr));
IPV6H->nexthdr = IPPROTO_UDP;
IPV6H->hop_limit = 255;
IPV6H->saddr = ct->tuplehash[dir].tuple.src.u3.in6;
memset(&IPV6H->daddr, 0x0, sizeof(IPV6H->daddr));
IPV6H->daddr.s6_addr16[0] = 0xffff; //NATFLOW_FAKEUSER_DADDR=ffff::
udph = (struct udphdr *)((char *)iph + sizeof(struct ipv6hdr));
udph->source = __constant_htons(0);
udph->dest = __constant_htons(65535);
udph->len = __constant_htons(sizeof(struct udphdr));
udph->check = 0;
ret = nf_conntrack_in_compat(&init_net, AF_INET6, NF_INET_PRE_ROUTING, uskb);
if (ret != NF_ACCEPT) {
return NULL;
}
user = nf_ct_get(uskb, &ctinfo);
if (!user) {
NATFLOW_ERROR("fakeuser create for ct[%pI6:%u->%pI6:%u %pI6:%u<-%pI6:%u] failed, ctinfo=%x\n",
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all),
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all), (unsigned int)ctinfo);
return NULL;
}
if (!user->ext) {
NATFLOW_ERROR("fakeuser create for ct[%pI6:%u->%pI6:%u %pI6:%u<-%pI6:%u] failed, user->ext is NULL\n",
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all),
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all));
skb_nfct_reset(uskb);
return NULL;
}
if (!nf_ct_is_confirmed(user) && !(IPS_NATFLOW_USER & user->status) && !test_and_set_bit(IPS_NATFLOW_USER_BIT, &user->status)) {
struct fakeuser_data_t *fud;
newoff = ALIGN(user->ext->len, __ALIGN_64BITS);
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 0)
new = __krealloc(user->ext, newoff + sizeof(struct fakeuser_data_t), GFP_ATOMIC);
#else
new = krealloc(user->ext, newoff + sizeof(struct fakeuser_data_t), GFP_ATOMIC);
#endif
if (!new) {
NATFLOW_ERROR("fakeuser create for ct[%pI6:%u->%pI6:%u %pI6:%u<-%pI6:%u] failed, realloc user->ext failed\n",
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all),
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all),
&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in6, ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all));
skb_nfct_reset(uskb);
return NULL;
}
if (user->ext != new) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0)
kfree_rcu(user->ext, rcu);
user->ext = new;
#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 0)
kfree_rcu(user->ext, rcu);
rcu_assign_pointer(user->ext, new);
#else
user->ext = new;
#endif
}
new->len = newoff;
memset((void *)new + newoff, 0, sizeof(struct fakeuser_data_t));
fud = (struct fakeuser_data_t *)((void *)new + newoff);
spin_lock_init(&fud->tc.rx.lock);
spin_lock_init(&fud->tc.tx.lock);
}
}
#ifdef CONFIG_NF_CONNTRACK_EVENTS
do {
struct nf_conntrack_ecache *e = nf_ct_ecache_find(user);
if (e) {
user->ext->offset[NF_CT_EXT_ECACHE] = 0;
}
} while (0);
#endif
ret = nf_conntrack_confirm(uskb);
if (ret != NF_ACCEPT) {
skb_nfct_reset(uskb);
return NULL;
}
/* XXX: in race loser_ct may be replaced in nf_conntrack_confirm,
* here reload ct(user) from uskb, and it can't be NULL
*/
user = nf_ct_get(uskb, &ctinfo);
if (!user || nf_ct_is_dying(user)) {
skb_nfct_reset(uskb);
return NULL;
}
natflow_user_timeout_touch(user);
if (ct->master && !(IPS_NATFLOW_USER & ct->master->status)) {
if (!test_and_set_bit(IPS_NATFLOW_MASTER_BIT, &ct->master->status)) {
nf_conntrack_get(&user->ct_general);
ct->master->master = user;
}
} else {
if (!test_and_set_bit(IPS_NATFLOW_MASTER_BIT, &ct->status)) {
nf_conntrack_get(&user->ct_general);
ct->master = user;
}
}
skb_nfct_reset(uskb);
}
return natflow_user_get(ct);
}
static inline void natflow_auth_reply_payload_fin(const char *payload, int payload_len, struct sk_buff *oskb, const struct net_device *dev, int pppoe_hdr)
{
struct sk_buff *nskb;
struct ethhdr *neth, *oeth;
struct iphdr *niph, *oiph;
struct tcphdr *otcph, *ntcph;
int len;
unsigned int csum;
int offset, header_len;
char *data;
int pppoe_len = 0;
if (pppoe_hdr) {
pppoe_len = PPPOE_SES_HLEN;
skb_push(oskb, PPPOE_SES_HLEN);
oskb->protocol = __constant_htons(ETH_P_PPP_SES);
}
oeth = (struct ethhdr *)skb_mac_header(oskb);
oiph = ip_hdr(oskb);
otcph = (struct tcphdr *)((void *)oiph + oiph->ihl*4);
offset = pppoe_len + sizeof(struct iphdr) + sizeof(struct tcphdr) + payload_len - oskb->len;
header_len = offset < 0 ? 0 : offset;
nskb = skb_copy_expand(oskb, skb_headroom(oskb), header_len, GFP_ATOMIC);
if (!nskb) {
NATFLOW_ERROR("alloc_skb fail\n");
goto out;
}
if (offset <= 0) {
if (pskb_trim(nskb, nskb->len + offset)) {
NATFLOW_ERROR("pskb_trim fail: len=%d, offset=%d\n", nskb->len, offset);
consume_skb(nskb);
goto out;
}
} else {
nskb->len += offset;
nskb->tail += offset;
}
//setup mac header
neth = eth_hdr(nskb);
niph = ip_hdr(nskb);
if ((char *)niph - (char *)neth >= ETH_HLEN) {
memcpy(neth->h_dest, oeth->h_source, ETH_ALEN);
memcpy(neth->h_source, oeth->h_dest, ETH_ALEN);
//neth->h_proto = htons(ETH_P_IP);
}
//setup ip header
memset(niph, 0, sizeof(struct iphdr));
niph->saddr = oiph->daddr;
niph->daddr = oiph->saddr;
niph->version = oiph->version;
niph->ihl = 5;
niph->tos = 0;
niph->tot_len = htons(nskb->len - pppoe_len);
niph->ttl = 0x80;
niph->protocol = oiph->protocol;
niph->id = __constant_htons(0xDEAD);
niph->frag_off = 0x0;
ip_send_check(niph);
//setup payload
data = (char *)ip_hdr(nskb) + sizeof(struct iphdr) + sizeof(struct tcphdr);
memcpy(data, payload, payload_len);
//setup tcp header
ntcph = (struct tcphdr *)((char *)ip_hdr(nskb) + sizeof(struct iphdr));
memset(ntcph, 0, sizeof(struct tcphdr));
ntcph->source = otcph->dest;
ntcph->dest = otcph->source;
ntcph->seq = otcph->ack_seq;
ntcph->ack_seq = htonl(ntohl(otcph->seq) + ntohs(oiph->tot_len) - (oiph->ihl<<2) - (otcph->doff<<2));
ntcph->doff = 5;
ntcph->ack = 1;
ntcph->psh = 1;
ntcph->fin = 1;
ntcph->window = 65535;
//sum check
len = ntohs(niph->tot_len) - (niph->ihl<<2);
csum = csum_partial((char*)ntcph, len, 0);
ntcph->check = tcp_v4_check(len, niph->saddr, niph->daddr, csum);
//ready to send out
skb_push(nskb, (char *)niph - (char *)neth - pppoe_len);
if (pppoe_hdr) {
struct pppoe_hdr *ph = (struct pppoe_hdr *)((void *)eth_hdr(nskb) + ETH_HLEN);
ph->length = htons(ntohs(ip_hdr(nskb)->tot_len) + 2);
}
nskb->dev = (struct net_device *)dev;
nskb->ip_summed = CHECKSUM_UNNECESSARY;
dev_queue_xmit(nskb);
out:
if (pppoe_hdr) {
oskb->protocol = __constant_htons(ETH_P_IP);
skb_pull(oskb, PPPOE_SES_HLEN);
}
}
static void natflow_auth_http_302(const struct net_device *dev, struct sk_buff *skb, natflow_fakeuser_t *user, int pppoe_hdr)
{
struct fakeuser_data_t *fud = natflow_fakeuser_data(user);
const char *http_header_fmt = ""
"HTTP/1.1 302 Moved Temporarily\r\n"
"Connection: close\r\n"
"Cache-Control: no-cache\r\n"
"Content-Type: text/html; charset=UTF-8\r\n"
"Location: %s\r\n"
"Content-Length: %u\r\n"
"\r\n";
const char *http_data_fmt = ""
"<HTML><HEAD><meta http-equiv=\"content-type\" content=\"text/html;charset=utf-8\">\r\n"
"<TITLE>302 Moved</TITLE></HEAD><BODY>\r\n"
"<H1>302 Moved</H1>\r\n"
"The document has moved\r\n"
"<A HREF=\"%s\">here</A>.\r\n"
"</BODY></HTML>\r\n";
int n = 0;
struct {
char location[128];
char data[384];
char header[384];
char payload[0];
} *http = kmalloc(2048, GFP_ATOMIC);
if (!http)
return;
snprintf(http->location, sizeof(http->location), "http://%pI4/index.html?ip=%pI4&mac=%02X-%02X-%02X-%02X-%02X-%02X&rid=%u&_t=%lu",
&redirect_ip, &user->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip,
fud->macaddr[0], fud->macaddr[1], fud->macaddr[2],
fud->macaddr[3], fud->macaddr[4], fud->macaddr[5],
fud->auth_rule_id, jiffies);
http->location[sizeof(http->location) - 1] = 0;
n = snprintf(http->data, sizeof(http->data), http_data_fmt, http->location);
http->data[sizeof(http->data) - 1] = 0;
snprintf(http->header, sizeof(http->header), http_header_fmt, http->location, n);
http->header[sizeof(http->header) - 1] = 0;
n = sprintf(http->payload, "%s%s", http->header, http->data);
natflow_auth_reply_payload_fin(http->payload, n, skb, dev, pppoe_hdr);
kfree(http);
}
static inline void natflow_auth_open_weixin_reply(const struct net_device *dev, struct sk_buff *skb, int pppoe_hdr)
{
const char *http_header_fmt = ""
"HTTP/1.1 200 OK\r\n"
"Connection: close\r\n"
"Cache-Control: no-cache\r\n"
"Content-Type: text/html; charset=UTF-8\r\n"
"Content-Length: %u\r\n"
"\r\n";
const char *http_data_fmt = ""
"<!DOCTYPE html>\r\n"
"<html class='no-js'>\r\n"
"<head>\r\n"
"<meta charset='utf-8'>\r\n"
"<meta name='viewport' content='initial-scale=1.0, maximum-scale=1.0, user-scalable=no'>\r\n"
"<script type='text/javascript' src='http://%pI4/admin/js/guanzhu.js?%u'></script>\r\n"
"</head>\r\n"
"<body>\r\n"
"</body>\r\n"
"</html>\r\n";
int n = 0;
struct {
char data[384];
char header[384];
char payload[0];
} *http = kmalloc(2048, GFP_ATOMIC);
if (!http)
return;
n = snprintf(http->data, sizeof(http->data), http_data_fmt, &redirect_ip, jiffies);
http->data[sizeof(http->data) - 1] = 0;
snprintf(http->header, sizeof(http->header), http_header_fmt, n);
http->header[sizeof(http->header) - 1] = 0;
n = sprintf(http->payload, "%s%s", http->header, http->data);
natflow_auth_reply_payload_fin(http->payload, n, skb, dev, pppoe_hdr);
kfree(http);
}
static inline void natflow_auth_convert_tcprst(struct sk_buff *skb)
{
int offset = 0;
int len;
struct iphdr *iph;
struct tcphdr *tcph;
iph = ip_hdr(skb);
if (iph->protocol != IPPROTO_TCP)
return;
if (skb->len < ntohs(iph->tot_len))
return;
tcph = (struct tcphdr *)((void *)iph + iph->ihl * 4);
offset = iph->ihl * 4 + sizeof(struct tcphdr) - skb->len;
if (offset > 0)
return;
if (pskb_trim(skb, skb->len + offset))
return;
tcph->res1 = 0;
tcph->doff = 5;
tcph->syn = 0;
tcph->rst = 1;
tcph->psh = 0;
tcph->ack = 0;
tcph->fin = 0;
tcph->urg = 0;
tcph->ece = 0;
tcph->cwr = 0;
tcph->window = __constant_htons(0);
tcph->check = 0;
tcph->urg_ptr = 0;
iph->tot_len = htons(skb->len);
iph->id = __constant_htons(0xDEAD);
iph->frag_off = 0;
len = ntohs(iph->tot_len);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
iph->check = 0;
iph->check = ip_fast_csum(iph, iph->ihl);
tcph->check = 0;
tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len - iph->ihl * 4, IPPROTO_TCP, 0);
skb->csum_start = (unsigned char *)tcph - skb->head;
skb->csum_offset = offsetof(struct tcphdr, check);
} else {
iph->check = 0;
iph->check = ip_fast_csum(iph, iph->ihl);
skb->csum = 0;
tcph->check = 0;
skb->csum = skb_checksum(skb, iph->ihl * 4, len - iph->ihl * 4, 0);
tcph->check = csum_tcpudp_magic(iph->saddr, iph->daddr, len - iph->ihl * 4, iph->protocol, skb->csum);
}
}
static inline void natflow_auth_tcp_reply_finack(const struct net_device *dev, struct sk_buff *oskb, int pppoe_hdr)
{
struct sk_buff *nskb;
struct ethhdr *neth, *oeth;
struct iphdr *niph, *oiph;
struct tcphdr *otcph, *ntcph;
int len;
unsigned int csum;
int offset, header_len;
int pppoe_len = 0;
if (pppoe_hdr) {
pppoe_len = PPPOE_SES_HLEN;
skb_push(oskb, PPPOE_SES_HLEN);
oskb->protocol = __constant_htons(ETH_P_PPP_SES);
}
oeth = (struct ethhdr *)skb_mac_header(oskb);
oiph = ip_hdr(oskb);
otcph = (struct tcphdr *)((void *)oiph + oiph->ihl*4);
offset = pppoe_len + sizeof(struct iphdr) + sizeof(struct tcphdr) - oskb->len;