+/*
+ * tcp_diag.c Module for monitoring TCP sockets.
+ *
+ * Version: $
+ *
+ * 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 "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;
+
+ 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 {
+ 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);
+ }
+}
+
+static int __init tcpdiag_init(void)
+{
+ tcpnl = netlink_kernel_create(NETLINK_TCPDIAG, tcpdiag_rcv);
+ if (tcpnl == NULL)
+ return -EBUSY;
+ return 0;
+}
+
+static void __exit tcpdiag_exit(void)
+{
+ printk(KERN_INFO "Caution: unloading tcp_diag is not very well supported. Nothing to worry, but yet.\n");
+ if (tcpnl)
+ sock_release(tcpnl->socket);
+}
+
+module_init(tcpdiag_init);
+module_exit(tcpdiag_exit);
+
+/*
+ * Local variables:
+ * compile-command: "gcc -DMOPS -DMODULE -D__KERNEL__ -I../include -I/usr/src/linux/include -Wall -Wstrict-prototypes -O2 -c tcp_diag.c"
+ * End:
+ */
projects / mirror_iproute2.git / blobdiff