mirror of
https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git
synced 2026-10-14 00:24:41 -04:00
Merge "net: netfilter: IRC DCC for private clients"
This commit is contained in:
qctecmdr
Gerrit - the friendly Code Review server
commit
313972cbb2
1 changed files with 393 additions and 72 deletions
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@ -15,6 +15,7 @@
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#include <linux/tcp.h>
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#include <linux/netfilter.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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@ -28,6 +29,18 @@ static unsigned int max_dcc_channels = 8;
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static unsigned int dcc_timeout __read_mostly = 300;
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/* This is slow, but it's simple. --RR */
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static char *irc_buffer;
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struct irc_client_info {
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char *nickname;
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bool conn_to_server;
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int nickname_len;
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__be32 server_ip;
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__be32 client_ip;
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struct list_head ptr;
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};
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static struct irc_client_info client_list;
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static unsigned int no_of_clients;
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static DEFINE_SPINLOCK(irc_buffer_lock);
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unsigned int (*nf_nat_irc_hook)(struct sk_buff *skb,
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@ -59,7 +72,7 @@ static const char *const dccprotos[] = {
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};
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#define MINMATCHLEN 5
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#define MINLENNICK 1
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/* tries to get the ip_addr and port out of a dcc command
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* return value: -1 on failure, 0 on success
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* data pointer to first byte of DCC command data
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@ -69,6 +82,20 @@ static const char *const dccprotos[] = {
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* ad_beg_p returns pointer to first byte of addr data
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* ad_end_p returns pointer to last byte of addr data
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*/
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static struct irc_client_info *search_client_by_ip(struct nf_conntrack_tuple *tuple)
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{
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struct irc_client_info *temp, *ret = NULL;
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struct list_head *obj_ptr, *prev_obj_ptr;
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list_for_each_safe(obj_ptr, prev_obj_ptr, &client_list.ptr) {
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temp = list_entry(obj_ptr, struct irc_client_info, ptr);
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if (temp->client_ip == tuple->src.u3.ip &&
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temp->server_ip == tuple->dst.u3.ip)
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ret = temp;
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}
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return ret;
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}
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static int parse_dcc(char *data, const char *data_end, __be32 *ip,
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u_int16_t *port, char **ad_beg_p, char **ad_end_p)
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{
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@ -103,6 +130,217 @@ static int parse_dcc(char *data, const char *data_end, __be32 *ip,
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return 0;
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}
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static bool mangle_ip(struct nf_conn *ct,
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int dir, char *nick_start)
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{
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char *nick_end;
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struct nf_conntrack_tuple *tuple;
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struct irc_client_info *temp;
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struct list_head *obj_ptr, *prev_obj_ptr;
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tuple = &ct->tuplehash[dir].tuple;
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nick_end = nick_start;
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while (*nick_end != ' ')
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nick_end++;
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list_for_each_safe(obj_ptr, prev_obj_ptr,
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&client_list.ptr) {
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temp = list_entry(obj_ptr,
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struct irc_client_info, ptr);
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/*If it is an internal client,
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*do not mangle the DCC Server IP
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*/
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if (temp->server_ip == tuple->dst.u3.ip &&
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(temp->nickname_len == nick_end - nick_start) &&
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(memcmp(nick_start, temp->nickname,
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temp->nickname_len) == 0))
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return false;
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}
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return true;
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}
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static int handle_nickname(struct nf_conn *ct,
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int dir, char *nick_start)
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{
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char *nick_end;
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struct nf_conntrack_tuple *tuple;
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struct irc_client_info *temp;
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int i, j;
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bool add_entry = true;
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nick_end = nick_start;
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i = 0;
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while (*nick_end != '\n') {
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nick_end++;
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i++;
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}
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tuple = &ct->tuplehash[dir].tuple;
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/*Check if the entry is already
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* present for that client
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*/
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temp = search_client_by_ip(tuple);
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if (temp) {
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add_entry = false;
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/*Update nickname if the client is not already
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* connected to the server.If the client is
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* connected, wait for server to confirm
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* if nickname is valid
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*/
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if (!temp->conn_to_server) {
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kfree(temp->nickname);
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temp->nickname =
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kmalloc(i, GFP_ATOMIC);
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if (temp->nickname) {
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temp->nickname_len = i;
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memcpy(&temp->nickname,
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nick_start, temp->nickname_len);
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} else {
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list_del(&temp->ptr);
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no_of_clients--;
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kfree(temp);
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}
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}
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}
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/*Add client entry if not already present*/
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if (add_entry) {
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j = sizeof(struct irc_client_info);
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temp = kmalloc(j, GFP_ATOMIC);
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if (temp) {
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no_of_clients++;
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tuple = &ct->tuplehash[dir].tuple;
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temp->nickname_len = i;
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temp->nickname =
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kmalloc(temp->nickname_len, GFP_ATOMIC);
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if (!temp->nickname) {
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kfree(temp);
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return NF_DROP;
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}
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memcpy(temp->nickname, nick_start,
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temp->nickname_len);
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memcpy(&temp->client_ip,
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&tuple->src.u3.ip, sizeof(__be32));
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memcpy(&temp->server_ip,
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&tuple->dst.u3.ip, sizeof(__be32));
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temp->conn_to_server = false;
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list_add(&temp->ptr,
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&client_list.ptr);
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} else {
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return NF_DROP;
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}
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}
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return NF_ACCEPT;
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}
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static int check_for_motd_message_from_IRC_server(char *data, const char *data_limit,
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struct nf_conntrack_tuple *tuple,
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struct nf_conn *ct,
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int dir, struct irc_client_info *temp)
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{
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while (data < data_limit - 6) {
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if (memcmp(data, " MOTD ", 6)) {
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data++;
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continue;
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}
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/* MOTD message signifies successful
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* registration with server
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*/
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tuple = &ct->tuplehash[!dir].tuple;
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temp = search_client_by_ip(tuple);
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if (temp && !temp->conn_to_server)
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temp->conn_to_server = true;
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return NF_ACCEPT;
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}
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return NF_DROP;
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}
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static void process_nickname(struct irc_client_info *client_info, int i,
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char *data)
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{
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if (client_info && client_info->nickname) {
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kfree(client_info->nickname);
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client_info->nickname = kmalloc(i, GFP_ATOMIC);
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if (client_info->nickname) {
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client_info->nickname_len = i;
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memcpy(client_info->nickname, data,
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client_info->nickname_len);
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client_info->conn_to_server = true;
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} else {
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list_del(&client_info->ptr);
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no_of_clients--;
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kfree(client_info);
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}
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}
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}
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static int check_for_nick_message_from_IRC_server(char *data, const char *data_limit,
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char *nick_end,
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struct nf_conntrack_tuple *tuple,
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struct nf_conn *ct,
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int dir, struct irc_client_info *temp)
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{
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int i;
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while (data < data_limit - (6 + MINLENNICK)) {
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if (memcmp(data, "NICK :", 6)) {
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data++;
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continue;
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}
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data += 6;
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nick_end = data;
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i = 0;
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while ((*nick_end != 0x0d) &&
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(*(nick_end + 1) != '\n')) {
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nick_end++;
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i++;
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}
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tuple = &ct->tuplehash[!dir].tuple;
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temp = search_client_by_ip(tuple);
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process_nickname(temp, i, data);
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/*NICK during registration*/
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return NF_ACCEPT;
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}
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return NF_DROP;
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}
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static bool parse_nick_command_from_client(char *data, const char *data_limit,
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struct nf_conn *ct, int dir, int *ret)
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{
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while (data < data_limit - (5 + MINLENNICK)) {
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if (memcmp(data, "NICK ", 5)) {
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data++;
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continue;
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}
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data += 5;
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*ret = handle_nickname(ct, dir, data);
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return true;
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}
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return false;
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}
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static bool parse_quit(char *data, const char *data_limit,
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struct nf_conntrack_tuple *tuple, struct nf_conn *ct,
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int dir, struct irc_client_info *temp)
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{
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while (data < data_limit - 6) {
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if (memcmp(data, "QUIT :", 6)) {
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data++;
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continue;
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}
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/* Parsing QUIT to free the list entry
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*/
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tuple = &ct->tuplehash[dir].tuple;
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temp = search_client_by_ip(tuple);
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if (temp) {
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list_del(&temp->ptr);
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no_of_clients--;
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kfree(temp->nickname);
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kfree(temp);
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}
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return true;
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}
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return false;
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}
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static int help(struct sk_buff *skb, unsigned int protoff,
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struct nf_conn *ct, enum ip_conntrack_info ctinfo)
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{
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@ -111,20 +349,18 @@ static int help(struct sk_buff *skb, unsigned int protoff,
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const struct tcphdr *th;
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struct tcphdr _tcph;
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const char *data_limit;
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char *data, *ib_ptr;
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char *data, *ib_ptr, *for_print, *nick_end = NULL;
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int dir = CTINFO2DIR(ctinfo);
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struct nf_conntrack_expect *exp;
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struct nf_conntrack_tuple *tuple;
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struct nf_conntrack_tuple *tuple = NULL;
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__be32 dcc_ip;
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u_int16_t dcc_port;
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__be16 port;
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int i, ret = NF_ACCEPT;
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char *addr_beg_p, *addr_end_p;
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typeof(nf_nat_irc_hook) nf_nat_irc;
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/* If packet is coming from IRC server */
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if (dir == IP_CT_DIR_REPLY)
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return NF_ACCEPT;
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typeof(nf_nat_irc_hook) nf_nat_irc __kernel;
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struct irc_client_info *temp = NULL;
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bool mangle = true;
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/* Until there's been traffic both ways, don't look in packets. */
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if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
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@ -148,78 +384,162 @@ static int help(struct sk_buff *skb, unsigned int protoff,
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data = ib_ptr;
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data_limit = ib_ptr + skb->len - dataoff;
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/* strlen("\1DCC SENT t AAAAAAAA P\1\n")=24
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* 5+MINMATCHLEN+strlen("t AAAAAAAA P\1\n")=14 */
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while (data < data_limit - (19 + MINMATCHLEN)) {
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if (memcmp(data, "\1DCC ", 5)) {
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data++;
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continue;
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/* If packet is coming from IRC server
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* parse the packet for different type of
|
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* messages (MOTD,NICK etc) and process
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* accordingly
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*/
|
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if (dir == IP_CT_DIR_REPLY) {
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/* strlen("NICK xxxxxx")
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* 5+strlen("xxxxxx")=1 (minimum length of nickname)
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*/
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if (check_for_motd_message_from_IRC_server(data, data_limit, tuple,
|
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ct, dir, temp) == NF_ACCEPT) {
|
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ret = NF_ACCEPT;
|
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goto out;
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}
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data += 5;
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/* we have at least (19+MINMATCHLEN)-5 bytes valid data left */
|
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|
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iph = ip_hdr(skb);
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pr_debug("DCC found in master %pI4:%u %pI4:%u\n",
|
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&iph->saddr, ntohs(th->source),
|
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&iph->daddr, ntohs(th->dest));
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||||
data = ib_ptr;
|
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data_limit = ib_ptr + skb->len - dataoff;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(dccprotos); i++) {
|
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if (memcmp(data, dccprotos[i], strlen(dccprotos[i]))) {
|
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/* no match */
|
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/* strlen("NICK :xxxxxx")
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* 6+strlen("xxxxxx")=1 (minimum length of nickname)
|
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* Parsing the server reply to get nickname
|
||||
* of the client
|
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*/
|
||||
|
||||
if (check_for_nick_message_from_IRC_server(data, data_limit, nick_end, tuple,
|
||||
ct, dir, temp) == NF_ACCEPT) {
|
||||
ret = NF_ACCEPT;
|
||||
goto out;
|
||||
}
|
||||
} else {
|
||||
/*Parsing NICK command from client to create an entry
|
||||
* strlen("NICK xxxxxx")
|
||||
* 5+strlen("xxxxxx")=1 (minimum length of nickname)
|
||||
*/
|
||||
data = ib_ptr;
|
||||
data_limit = ib_ptr + skb->len - dataoff;
|
||||
if (parse_nick_command_from_client(data, data_limit, ct, dir, &ret))
|
||||
goto out;
|
||||
|
||||
data = ib_ptr;
|
||||
if (parse_quit(data, data_limit, tuple, ct, dir, temp)) {
|
||||
ret = NF_ACCEPT;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* strlen("\1DCC SENT t AAAAAAAA P\1\n")=24
|
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* 5+MINMATCHLEN+strlen("t AAAAAAAA P\1\n")=14
|
||||
*/
|
||||
data = ib_ptr;
|
||||
while (data < data_limit - (19 + MINMATCHLEN)) {
|
||||
if (memcmp(data, "\1DCC ", 5)) {
|
||||
data++;
|
||||
continue;
|
||||
}
|
||||
data += strlen(dccprotos[i]);
|
||||
pr_debug("DCC %s detected\n", dccprotos[i]);
|
||||
data += 5;
|
||||
/* we have at least (19+MINMATCHLEN)-5
|
||||
*bytes valid data left
|
||||
*/
|
||||
iph = ip_hdr(skb);
|
||||
pr_debug("DCC found in master %pI4:%u %pI4:%u\n",
|
||||
&iph->saddr, ntohs(th->source),
|
||||
&iph->daddr, ntohs(th->dest));
|
||||
|
||||
/* we have at least
|
||||
* (19+MINMATCHLEN)-5-dccprotos[i].matchlen bytes valid
|
||||
* data left (== 14/13 bytes) */
|
||||
if (parse_dcc(data, data_limit, &dcc_ip,
|
||||
&dcc_port, &addr_beg_p, &addr_end_p)) {
|
||||
pr_debug("unable to parse dcc command\n");
|
||||
continue;
|
||||
}
|
||||
for (i = 0; i < ARRAY_SIZE(dccprotos); i++) {
|
||||
if (memcmp(data, dccprotos[i],
|
||||
strlen(dccprotos[i]))) {
|
||||
/* no match */
|
||||
continue;
|
||||
}
|
||||
data += strlen(dccprotos[i]);
|
||||
pr_debug("DCC %s detected\n", dccprotos[i]);
|
||||
|
||||
pr_debug("DCC bound ip/port: %pI4:%u\n",
|
||||
&dcc_ip, dcc_port);
|
||||
/* we have at least
|
||||
* (19+MINMATCHLEN)-5-dccprotos[i].matchlen
|
||||
*bytes valid data left (== 14/13 bytes)
|
||||
*/
|
||||
if (parse_dcc(data, data_limit, &dcc_ip,
|
||||
&dcc_port, &addr_beg_p,
|
||||
&addr_end_p)) {
|
||||
pr_debug("unable to parse dcc command\n");
|
||||
continue;
|
||||
}
|
||||
|
||||
/* dcc_ip can be the internal OR external (NAT'ed) IP */
|
||||
tuple = &ct->tuplehash[dir].tuple;
|
||||
if (tuple->src.u3.ip != dcc_ip &&
|
||||
tuple->dst.u3.ip != dcc_ip) {
|
||||
net_warn_ratelimited("Forged DCC command from %pI4: %pI4:%u\n",
|
||||
&tuple->src.u3.ip,
|
||||
&dcc_ip, dcc_port);
|
||||
continue;
|
||||
}
|
||||
pr_debug("DCC bound ip/port: %pI4:%u\n",
|
||||
&dcc_ip, dcc_port);
|
||||
|
||||
exp = nf_ct_expect_alloc(ct);
|
||||
if (exp == NULL) {
|
||||
nf_ct_helper_log(skb, ct,
|
||||
"cannot alloc expectation");
|
||||
ret = NF_DROP;
|
||||
/* dcc_ip can be the internal OR
|
||||
*external (NAT'ed) IP
|
||||
*/
|
||||
tuple = &ct->tuplehash[dir].tuple;
|
||||
if (tuple->src.u3.ip != dcc_ip &&
|
||||
tuple->dst.u3.ip != dcc_ip) {
|
||||
net_warn_ratelimited("Forged DCC command from %pI4: %pI4:%u\n",
|
||||
&tuple->src.u3.ip,
|
||||
&dcc_ip, dcc_port);
|
||||
continue;
|
||||
}
|
||||
|
||||
exp = nf_ct_expect_alloc(ct);
|
||||
if (!exp) {
|
||||
nf_ct_helper_log(skb, ct,
|
||||
"cannot alloc expectation");
|
||||
ret = NF_DROP;
|
||||
goto out;
|
||||
}
|
||||
tuple = &ct->tuplehash[!dir].tuple;
|
||||
port = htons(dcc_port);
|
||||
nf_ct_expect_init(exp,
|
||||
NF_CT_EXPECT_CLASS_DEFAULT,
|
||||
tuple->src.l3num,
|
||||
NULL, &tuple->dst.u3,
|
||||
IPPROTO_TCP, NULL, &port);
|
||||
|
||||
nf_nat_irc = rcu_dereference(nf_nat_irc_hook);
|
||||
|
||||
tuple = &ct->tuplehash[dir].tuple;
|
||||
for_print = ib_ptr;
|
||||
/* strlen("PRIVMSG xxxx :\1DCC
|
||||
*SENT t AAAAAAAA P\1\n")=26
|
||||
* 8+strlen(xxxx) = 1(min length)+7+
|
||||
*MINMATCHLEN+strlen("t AAAAAAAA P\1\n")=14
|
||||
*Parsing DCC command to get client name and
|
||||
*check whether it is an internal client
|
||||
*/
|
||||
while (for_print <
|
||||
data_limit - (25 + MINMATCHLEN)) {
|
||||
if (memcmp(for_print, "PRIVMSG ", 8)) {
|
||||
for_print++;
|
||||
continue;
|
||||
}
|
||||
for_print += 8;
|
||||
mangle = mangle_ip(ct,
|
||||
dir, for_print);
|
||||
break;
|
||||
}
|
||||
if (mangle &&
|
||||
nf_nat_irc &&
|
||||
ct->status & IPS_NAT_MASK)
|
||||
ret = nf_nat_irc(skb, ctinfo,
|
||||
protoff,
|
||||
addr_beg_p - ib_ptr,
|
||||
addr_end_p
|
||||
- addr_beg_p,
|
||||
exp);
|
||||
|
||||
else if (mangle &&
|
||||
nf_ct_expect_related(exp, 0)
|
||||
!= 0) {
|
||||
nf_ct_helper_log(skb, ct,
|
||||
"cannot add expectation");
|
||||
ret = NF_DROP;
|
||||
}
|
||||
nf_ct_expect_put(exp);
|
||||
goto out;
|
||||
}
|
||||
tuple = &ct->tuplehash[!dir].tuple;
|
||||
port = htons(dcc_port);
|
||||
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
|
||||
tuple->src.l3num,
|
||||
NULL, &tuple->dst.u3,
|
||||
IPPROTO_TCP, NULL, &port);
|
||||
|
||||
nf_nat_irc = rcu_dereference(nf_nat_irc_hook);
|
||||
if (nf_nat_irc && ct->status & IPS_NAT_MASK)
|
||||
ret = nf_nat_irc(skb, ctinfo, protoff,
|
||||
addr_beg_p - ib_ptr,
|
||||
addr_end_p - addr_beg_p,
|
||||
exp);
|
||||
else if (nf_ct_expect_related(exp, 0) != 0) {
|
||||
nf_ct_helper_log(skb, ct,
|
||||
"cannot add expectation");
|
||||
ret = NF_DROP;
|
||||
}
|
||||
nf_ct_expect_put(exp);
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
out:
|
||||
|
|
@ -268,7 +588,8 @@ static int __init nf_conntrack_irc_init(void)
|
|||
kfree(irc_buffer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
no_of_clients = 0;
|
||||
INIT_LIST_HEAD(&client_list.ptr);
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue