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/*
* tcp_diag.c Module for monitoring TCP sockets.
*
* Version: $Id: tcp_diag.c,v 1.2 2001/11/05 09:42:22 davem Exp $
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/random.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <net/icmp.h>
#include <net/tcp.h>
#include <net/ipv6.h>
#include <net/inet_common.h>
#include <linux/inet.h>
#include <linux/stddef.h>
#include <linux/tcp_diag.h>
static struct sock *tcpnl;
#define TCPDIAG_PUT(skb, attrtype, attrlen) \
({ int rtalen = RTA_LENGTH(attrlen); \
struct rtattr *rta; \
if (skb_tailroom(skb) < RTA_ALIGN(rtalen)) goto nlmsg_failure; \
rta = (void*)__skb_put(skb, RTA_ALIGN(rtalen)); \
rta->rta_type = attrtype; \
rta->rta_len = rtalen; \
RTA_DATA(rta); })
static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
int ext, u32 pid, u32 seq)
{
struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
struct tcpdiagmsg *r;
struct nlmsghdr *nlh;
struct tcp_info *info = NULL;
struct tcpdiag_meminfo *minfo = NULL;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r));
r = NLMSG_DATA(nlh);
if (sk->state != TCP_TIME_WAIT) {
if (ext & (1<<(TCPDIAG_MEMINFO-1)))
minfo = TCPDIAG_PUT(skb, TCPDIAG_MEMINFO, sizeof(*minfo));
if (ext & (1<<(TCPDIAG_INFO-1)))
info = TCPDIAG_PUT(skb, TCPDIAG_INFO, sizeof(*info));
}
r->tcpdiag_family = sk->family;
r->tcpdiag_state = sk->state;
r->tcpdiag_timer = 0;
r->tcpdiag_retrans = 0;
r->id.tcpdiag_sport = sk->sport;
r->id.tcpdiag_dport = sk->dport;
r->id.tcpdiag_src[0] = sk->rcv_saddr;
r->id.tcpdiag_dst[0] = sk->daddr;
r->id.tcpdiag_if = sk->bound_dev_if;
*((struct sock **)&r->id.tcpdiag_cookie) = sk;
if (r->tcpdiag_state == TCP_TIME_WAIT) {
struct tcp_tw_bucket *tw = (struct tcp_tw_bucket*)sk;
long tmo = tw->ttd - jiffies;
if (tmo < 0)
tmo = 0;
r->tcpdiag_state = tw->substate;
r->tcpdiag_timer = 3;
r->tcpdiag_expires = (tmo*1000+HZ-1)/HZ;
r->tcpdiag_rqueue = 0;
r->tcpdiag_wqueue = 0;
r->tcpdiag_uid = 0;
r->tcpdiag_inode = 0;
#ifdef CONFIG_IPV6
if (r->tcpdiag_family == AF_INET6) {
memcpy(r->id.tcpdiag_src, &tw->v6_rcv_saddr, 16);
memcpy(r->id.tcpdiag_dst, &tw->v6_daddr, 16);
}
#endif
nlh->nlmsg_len = skb->tail - b;
return skb->len;
}
#ifdef CONFIG_IPV6
if (r->tcpdiag_family == AF_INET6) {
memcpy(r->id.tcpdiag_src, &sk->net_pinfo.af_inet6.rcv_saddr, 16);
memcpy(r->id.tcpdiag_dst, &sk->net_pinfo.af_inet6.daddr, 16);
}
#endif
#define EXPIRES_IN_MS(tmo) ((tmo-jiffies)*1000+HZ-1)/HZ
if (tp->pending == TCP_TIME_RETRANS) {
r->tcpdiag_timer = 1;
r->tcpdiag_retrans = tp->retransmits;
r->tcpdiag_expires = EXPIRES_IN_MS(tp->timeout);
} else if (tp->pending == TCP_TIME_PROBE0) {
r->tcpdiag_timer = 4;
r->tcpdiag_retrans = tp->probes_out;
r->tcpdiag_expires = EXPIRES_IN_MS(tp->timeout);
} else if (timer_pending(&sk->timer)) {
r->tcpdiag_timer = 2;
r->tcpdiag_retrans = tp->probes_out;
r->tcpdiag_expires = EXPIRES_IN_MS(sk->timer.expires);
} else {
r->tcpdiag_timer = 0;
r->tcpdiag_expires = 0;
}
#undef EXPIRES_IN_MS
r->tcpdiag_rqueue = tp->rcv_nxt - tp->copied_seq;
r->tcpdiag_wqueue = tp->write_seq - tp->snd_una;
r->tcpdiag_uid = sock_i_uid(sk);
r->tcpdiag_inode = sock_i_ino(sk);
if (minfo) {
minfo->tcpdiag_rmem = atomic_read(&sk->rmem_alloc);
minfo->tcpdiag_wmem = sk->wmem_queued;
minfo->tcpdiag_fmem = sk->forward_alloc;
minfo->tcpdiag_tmem = atomic_read(&sk->wmem_alloc);
}
if (info) {
u32 now = tcp_time_stamp;
info->tcpi_state = sk->state;
info->tcpi_ca_state = tp->ca_state;
info->tcpi_retransmits = tp->retransmits;
info->tcpi_probes = tp->probes_out;
info->tcpi_backoff = tp->backoff;
info->tcpi_options = 0;
if (tp->tstamp_ok)
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
if (tp->sack_ok)
info->tcpi_options |= TCPI_OPT_SACK;
if (tp->wscale_ok) {
info->tcpi_options |= TCPI_OPT_WSCALE;
info->tcpi_snd_wscale = tp->snd_wscale;
info->tcpi_rcv_wscale = tp->rcv_wscale;
} else {
info->tcpi_snd_wscale = 0;
info->tcpi_rcv_wscale = 0;
}
#ifdef CONFIG_INET_ECN
if (tp->ecn_flags&TCP_ECN_OK)
info->tcpi_options |= TCPI_OPT_ECN;
#endif
info->tcpi_rto = (1000000*tp->rto)/HZ;
info->tcpi_ato = (1000000*tp->ack.ato)/HZ;
info->tcpi_snd_mss = tp->mss_cache;
info->tcpi_rcv_mss = tp->ack.rcv_mss;
info->tcpi_unacked = tp->packets_out;
info->tcpi_sacked = tp->sacked_out;
info->tcpi_lost = tp->lost_out;
info->tcpi_retrans = tp->retrans_out;
info->tcpi_fackets = tp->fackets_out;
info->tcpi_last_data_sent = ((now - tp->lsndtime)*1000)/HZ;
info->tcpi_last_ack_sent = 0;
info->tcpi_last_data_recv = ((now - tp->ack.lrcvtime)*1000)/HZ;
info->tcpi_last_ack_recv = ((now - tp->rcv_tstamp)*1000)/HZ;
info->tcpi_pmtu = tp->pmtu_cookie;
info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
info->tcpi_rtt = ((1000000*tp->srtt)/HZ)>>3;
info->tcpi_rttvar = ((1000000*tp->mdev)/HZ)>>2;
info->tcpi_snd_ssthresh = tp->snd_ssthresh;
info->tcpi_snd_cwnd = tp->snd_cwnd;
info->tcpi_advmss = tp->advmss;
info->tcpi_reordering = tp->reordering;
}
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
skb_trim(skb, b - skb->data);
return -1;
}
extern struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif);
#ifdef CONFIG_IPV6
extern struct sock *tcp_v6_lookup(struct in6_addr *saddr, u16 sport,
struct in6_addr *daddr, u16 dport,
int dif);
#endif
static int tcpdiag_get_exact(struct sk_buff *in_skb, struct nlmsghdr *nlh)
{
int err;
struct sock *sk;
struct tcpdiagreq *req = NLMSG_DATA(nlh);
struct sk_buff *rep;
if (req->tcpdiag_family == AF_INET) {
sk = tcp_v4_lookup(req->id.tcpdiag_dst[0], req->id.tcpdiag_dport,
req->id.tcpdiag_src[0], req->id.tcpdiag_sport,
req->id.tcpdiag_if);
}
#ifdef CONFIG_IPV6
else if (req->tcpdiag_family == AF_INET6) {
sk = tcp_v6_lookup((struct in6_addr*)req->id.tcpdiag_dst, req->id.tcpdiag_dport,
(struct in6_addr*)req->id.tcpdiag_src, req->id.tcpdiag_sport,
req->id.tcpdiag_if);
}
#endif
else {
return -EINVAL;
}
if (sk == NULL)
return -ENOENT;
err = -ESTALE;
if ((req->id.tcpdiag_cookie[0] != TCPDIAG_NOCOOKIE ||
req->id.tcpdiag_cookie[1] != TCPDIAG_NOCOOKIE) &&
sk != *((struct sock **)&req->id.tcpdiag_cookie[0]))
goto out;
err = -ENOMEM;
rep = alloc_skb(NLMSG_SPACE(sizeof(struct tcpdiagmsg)+
sizeof(struct tcpdiag_meminfo)+
sizeof(struct tcp_info)+64), GFP_KERNEL);
if (!rep)
goto out;
if (tcpdiag_fill(rep, sk, req->tcpdiag_ext,
NETLINK_CB(in_skb).pid,
nlh->nlmsg_seq) <= 0)
BUG();
err = netlink_unicast(tcpnl, rep, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
if (err > 0)
err = 0;
out:
if (sk) {
if (sk->state == TCP_TIME_WAIT)
tcp_tw_put((struct tcp_tw_bucket*)sk);
else
sock_put(sk);
}
return err;
}
int bitstring_match(u32 *a1, u32 *a2, int bits)
{
int words = bits >> 5;
bits &= 0x1f;
if (words) {
if (memcmp(a1, a2, words << 2))
return 0;
}
if (bits) {
__u32 w1, w2;
__u32 mask;
w1 = a1[words];
w2 = a2[words];
mask = htonl((0xffffffff) << (32 - bits));
if ((w1 ^ w2) & mask)
return 0;
}
return 1;
}
int tcpdiag_bc_run(char *bc, int len, struct sock *sk)
{
while (len > 0) {
int yes = 1;
struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc;
switch (op->code) {
case TCPDIAG_BC_NOP:
break;
case TCPDIAG_BC_JMP:
yes = 0;
break;
case TCPDIAG_BC_S_GE:
yes = (sk->num >= op[1].no);
break;
case TCPDIAG_BC_S_LE:
yes = (sk->num <= op[1].no);
break;
case TCPDIAG_BC_D_GE:
yes = (ntohs(sk->dport) >= op[1].no);
break;
case TCPDIAG_BC_D_LE:
yes = (ntohs(sk->dport) <= op[1].no);
break;
case TCPDIAG_BC_AUTO:
yes = !(sk->userlocks&SOCK_BINDPORT_LOCK);
break;
case TCPDIAG_BC_S_COND:
case TCPDIAG_BC_D_COND:
{
struct tcpdiag_hostcond *cond = (struct tcpdiag_hostcond*)(op+1);
u32 *addr;
if (cond->port != -1 &&
cond->port != (op->code == TCPDIAG_BC_S_COND ? sk->num : ntohs(sk->dport))) {
yes = 0;
break;
}
if (cond->prefix_len == 0)
break;
#ifdef CONFIG_IPV6
if (sk->family == AF_INET6) {
if (op->code == TCPDIAG_BC_S_COND)
addr = (u32*)&sk->net_pinfo.af_inet6.rcv_saddr;
else
addr = (u32*)&sk->net_pinfo.af_inet6.daddr;
} else
#endif
{
if (op->code == TCPDIAG_BC_S_COND)
addr = &sk->rcv_saddr;
else
addr = &sk->daddr;
}
if (bitstring_match(addr, cond->addr, cond->prefix_len))
break;
if (sk->family == AF_INET6 && cond->family == AF_INET) {
if (addr[0] == 0 && addr[1] == 0 &&
addr[2] == __constant_htonl(0xffff) &&
bitstring_match(addr+3, cond->addr, cond->prefix_len))
break;
}
yes = 0;
break;
}
}
if (yes) {
len -= op->yes;
bc += op->yes;
} else {
len -= op->no;
bc += op->no;
}
}
return (len == 0);
}
int valid_cc(char *bc, int len, int cc)
{
while (len >= 0) {
struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc;
if (cc > len)
return 0;
if (cc == len)
return 1;
if (op->yes < 4)
return 0;
len -= op->yes;
bc += op->yes;
}
return 0;
}
int tcpdiag_bc_audit(char *bytecode, int bytecode_len)
{
char *bc = bytecode;
int len = bytecode_len;
while (len > 0) {
struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc;
//printk("BC: %d %d %d {%d} / %d\n", op->code, op->yes, op->no, op[1].no, len);
switch (op->code) {
case TCPDIAG_BC_AUTO:
case TCPDIAG_BC_S_COND:
case TCPDIAG_BC_D_COND:
case TCPDIAG_BC_S_GE:
case TCPDIAG_BC_S_LE:
case TCPDIAG_BC_D_GE:
case TCPDIAG_BC_D_LE:
if (op->yes < 4 || op->yes > len+4)
return -EINVAL;
case TCPDIAG_BC_JMP:
if (op->no < 4 || op->no > len+4)
return -EINVAL;
if (op->no < len &&
!valid_cc(bytecode, bytecode_len, len-op->no))
return -EINVAL;
break;
case TCPDIAG_BC_NOP:
if (op->yes < 4 || op->yes > len+4)
return -EINVAL;
break;
default:
return -EINVAL;
}
bc += op->yes;
len -= op->yes;
}
return len == 0 ? 0 : -EINVAL;
}
int tcpdiag_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
int i, num;
int s_i, s_num;
struct tcpdiagreq *r = NLMSG_DATA(cb->nlh);
struct rtattr *bc = NULL;
if (cb->nlh->nlmsg_len > 4+NLMSG_SPACE(sizeof(struct tcpdiagreq)))
bc = (struct rtattr*)(r+1);
s_i = cb->args[1];
s_num = num = cb->args[2];
if (cb->args[0] == 0) {
if (!(r->tcpdiag_states&(TCPF_LISTEN|TCPF_SYN_RECV)))
goto skip_listen_ht;
tcp_listen_lock();
for (i = s_i; i < TCP_LHTABLE_SIZE; i++) {
struct sock *sk = tcp_listening_hash[i];
if (i > s_i)
s_num = 0;
for (sk = tcp_listening_hash[i], num = 0;
sk != NULL;
sk = sk->next, num++) {
if (num < s_num)
continue;
if (!(r->tcpdiag_states&TCPF_LISTEN) ||
r->id.tcpdiag_dport)
continue;
if (r->id.tcpdiag_sport != sk->sport && r->id.tcpdiag_sport)
continue;
if (bc && !tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), sk))
continue;
if (tcpdiag_fill(skb, sk, r->tcpdiag_ext,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq) <= 0) {
tcp_listen_unlock();
goto done;
}
}
}
tcp_listen_unlock();
skip_listen_ht:
cb->args[0] = 1;
s_i = num = s_num = 0;
}
if (!(r->tcpdiag_states&~(TCPF_LISTEN|TCPF_SYN_RECV)))
return skb->len;
for (i = s_i; i < tcp_ehash_size; i++) {
struct tcp_ehash_bucket *head = &tcp_ehash[i];
struct sock *sk;
if (i > s_i)
s_num = 0;
read_lock_bh(&head->lock);
for (sk = head->chain, num = 0;
sk != NULL;
sk = sk->next, num++) {
if (num < s_num)
continue;
if (!(r->tcpdiag_states&(1<<sk->state)))
continue;
if (r->id.tcpdiag_sport != sk->sport && r->id.tcpdiag_sport)
continue;
if (r->id.tcpdiag_dport != sk->dport && r->id.tcpdiag_dport)
continue;
if (bc && !tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), sk))
continue;
if (tcpdiag_fill(skb, sk, r->tcpdiag_ext,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq) <= 0) {
read_unlock_bh(&head->lock);
goto done;
}
}
if (r->tcpdiag_states&TCPF_TIME_WAIT) {
for (sk = tcp_ehash[i+tcp_ehash_size].chain;
sk != NULL;
sk = sk->next, num++) {
if (num < s_num)
continue;
if (!(r->tcpdiag_states&(1<<sk->zapped)))
continue;
if (r->id.tcpdiag_sport != sk->sport && r->id.tcpdiag_sport)
continue;
if (r->id.tcpdiag_dport != sk->dport && r->id.tcpdiag_dport)
continue;
if (bc && !tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), sk))
continue;
if (tcpdiag_fill(skb, sk, r->tcpdiag_ext,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq) <= 0) {
read_unlock_bh(&head->lock);
goto done;
}
}
}
read_unlock_bh(&head->lock);
}
done:
cb->args[1] = i;
cb->args[2] = num;
return skb->len;
}
static int tcpdiag_dump_done(struct netlink_callback *cb)
{
return 0;
}
static __inline__ int
tcpdiag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
return 0;
if (nlh->nlmsg_type != TCPDIAG_GETSOCK)
goto err_inval;
if (NLMSG_LENGTH(sizeof(struct tcpdiagreq)) > skb->len)
goto err_inval;
if (nlh->nlmsg_flags&NLM_F_DUMP) {
if (nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(struct tcpdiagreq))) {
struct rtattr *rta = (struct rtattr*)(NLMSG_DATA(nlh) + sizeof(struct tcpdiagreq));
if (rta->rta_type != TCPDIAG_REQ_BYTECODE ||
rta->rta_len < 8 ||
rta->rta_len > nlh->nlmsg_len - NLMSG_SPACE(sizeof(struct tcpdiagreq)))
goto err_inval;
if (tcpdiag_bc_audit(RTA_DATA(rta), RTA_PAYLOAD(rta)))
goto err_inval;
}
return netlink_dump_start(tcpnl, skb, nlh,
tcpdiag_dump,
tcpdiag_dump_done);
} else {
return tcpdiag_get_exact(skb, nlh);
}
err_inval:
return -EINVAL;
}
extern __inline__ void tcpdiag_rcv_skb(struct sk_buff *skb)
{
int err;
struct nlmsghdr * nlh;
if (skb->len >= NLMSG_SPACE(0)) {
nlh = (struct nlmsghdr *)skb->data;
if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
return;
err = tcpdiag_rcv_msg(skb, nlh);
if (err)
netlink_ack(skb, nlh, err);
}
}
static void tcpdiag_rcv(struct sock *sk, int len)
{
struct sk_buff *skb;
while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
tcpdiag_rcv_skb(skb);
kfree_skb(skb);
}
}
void __init tcpdiag_init(void)
{
tcpnl = netlink_kernel_create(NETLINK_TCPDIAG, tcpdiag_rcv);
if (tcpnl == NULL)
panic("tcpdiag_init: Cannot create netlink socket.");
}
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