tcp_diag.c
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上传日期:2013-02-24
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文件大小:15k
- /*
- * 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} / %dn", 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.");
- }