/* * tcp_diag.c Module for monitoring TCP sockets. * * Version: $Id: tcp_diag.c,v 1.3 2002/02/01 22:01:04 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); }) /* Return information about state of tcp endpoint in API format. */ void tcp_get_info(struct sock *sk, struct tcp_info *info) { struct tcp_opt *tp = tcp_sk(sk); u32 now = tcp_time_stamp; memset(info, 0, sizeof(*info)); info->tcpi_state = sk->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; 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; } if (tp->ecn_flags&TCP_ECN_OK) info->tcpi_options |= TCPI_OPT_ECN; 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_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; info->tcpi_rcv_rtt = ((1000000*tp->rcv_rtt_est.rtt)/HZ)>>3; info->tcpi_rcv_space = tp->rcvq_space.space; } static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk, int ext, u32 pid, u32 seq) { struct inet_opt *inet = inet_sk(sk); struct tcp_opt *tp = tcp_sk(sk); struct tcpdiagmsg *r; struct nlmsghdr *nlh; struct tcp_info *info = NULL; struct tcpdiag_meminfo *minfo = NULL; struct tcpvegas_info *vinfo = NULL; unsigned char *b = skb->tail; nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r)); r = NLMSG_DATA(nlh); if (sk->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)); if (tcp_is_vegas(tp) && (ext & (1<<(TCPDIAG_VEGASINFO-1)))) vinfo = TCPDIAG_PUT(skb, TCPDIAG_VEGASINFO, sizeof(*vinfo)); } r->tcpdiag_family = sk->sk_family; r->tcpdiag_state = sk->sk_state; r->tcpdiag_timer = 0; r->tcpdiag_retrans = 0; r->id.tcpdiag_if = sk->sk_bound_dev_if; r->id.tcpdiag_cookie[0] = (u32)(unsigned long)sk; r->id.tcpdiag_cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1); if (r->tcpdiag_state == TCP_TIME_WAIT) { struct tcp_tw_bucket *tw = (struct tcp_tw_bucket*)sk; long tmo = tw->tw_ttd - jiffies; if (tmo < 0) tmo = 0; r->id.tcpdiag_sport = tw->tw_sport; r->id.tcpdiag_dport = tw->tw_dport; r->id.tcpdiag_src[0] = tw->tw_rcv_saddr; r->id.tcpdiag_dst[0] = tw->tw_daddr; r->tcpdiag_state = tw->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) { ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_src, &tw->tw_v6_rcv_saddr); ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_dst, &tw->tw_v6_daddr); } #endif nlh->nlmsg_len = skb->tail - b; return skb->len; } r->id.tcpdiag_sport = inet->sport; r->id.tcpdiag_dport = inet->dport; r->id.tcpdiag_src[0] = inet->rcv_saddr; r->id.tcpdiag_dst[0] = inet->daddr; #ifdef CONFIG_IPV6 if (r->tcpdiag_family == AF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_src, &np->rcv_saddr); ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_dst, &np->daddr); } #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->sk_timer)) { r->tcpdiag_timer = 2; r->tcpdiag_retrans = tp->probes_out; r->tcpdiag_expires = EXPIRES_IN_MS(sk->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->sk_rmem_alloc); minfo->tcpdiag_wmem = sk->sk_wmem_queued; minfo->tcpdiag_fmem = sk->sk_forward_alloc; minfo->tcpdiag_tmem = atomic_read(&sk->sk_wmem_alloc); } if (info) tcp_get_info(sk, info); if (vinfo) { vinfo->tcpv_enabled = tp->vegas.doing_vegas_now; vinfo->tcpv_rttcnt = tp->vegas.cntRTT; vinfo->tcpv_rtt = tp->vegas.baseRTT; vinfo->tcpv_minrtt = tp->vegas.minRTT; } 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, const 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) && ((u32)(unsigned long)sk != req->id.tcpdiag_cookie[0] || (u32)((((unsigned long)sk) >> 31) >> 1) != req->id.tcpdiag_cookie[1])) 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->sk_state == TCP_TIME_WAIT) tcp_tw_put((struct tcp_tw_bucket*)sk); else sock_put(sk); } return err; } static int bitstring_match(const u32 *a1, const 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; } static int tcpdiag_bc_run(const void *bc, int len, struct sock *sk) { while (len > 0) { int yes = 1; struct inet_opt *inet = inet_sk(sk); const struct tcpdiag_bc_op *op = bc; switch (op->code) { case TCPDIAG_BC_NOP: break; case TCPDIAG_BC_JMP: yes = 0; break; case TCPDIAG_BC_S_GE: yes = inet->num >= op[1].no; break; case TCPDIAG_BC_S_LE: yes = inet->num <= op[1].no; break; case TCPDIAG_BC_D_GE: yes = ntohs(inet->dport) >= op[1].no; break; case TCPDIAG_BC_D_LE: yes = ntohs(inet->dport) <= op[1].no; break; case TCPDIAG_BC_AUTO: yes = !(sk->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 ? inet->num : ntohs(inet->dport))) { yes = 0; break; } if (cond->prefix_len == 0) break; #ifdef CONFIG_IPV6 if (sk->sk_family == AF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); if (op->code == TCPDIAG_BC_S_COND) addr = (u32*)&np->rcv_saddr; else addr = (u32*)&np->daddr; } else #endif { if (op->code == TCPDIAG_BC_S_COND) addr = &inet->rcv_saddr; else addr = &inet->daddr; } if (bitstring_match(addr, cond->addr, cond->prefix_len)) break; if (sk->sk_family == AF_INET6 && cond->family == AF_INET) { if (addr[0] == 0 && addr[1] == 0 && addr[2] == 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); } static int valid_cc(const void *bc, int len, int cc) { while (len >= 0) { const struct tcpdiag_bc_op *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; } static int tcpdiag_bc_audit(const void *bytecode, int bytecode_len) { const unsigned 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; } static 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; struct hlist_node *node; if (i > s_i) s_num = 0; num = 0; sk_for_each(sk, node, &tcp_listening_hash[i]) { struct inet_opt *inet = inet_sk(sk); if (num < s_num) continue; if (!(r->tcpdiag_states&TCPF_LISTEN) || r->id.tcpdiag_dport) continue; if (r->id.tcpdiag_sport != inet->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; } ++num; } } 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; struct hlist_node *node; if (i > s_i) s_num = 0; read_lock_bh(&head->lock); num = 0; sk_for_each(sk, node, &head->chain) { struct inet_opt *inet = inet_sk(sk); if (num < s_num) continue; if (!(r->tcpdiag_states & (1 << sk->sk_state))) continue; if (r->id.tcpdiag_sport != inet->sport && r->id.tcpdiag_sport) continue; if (r->id.tcpdiag_dport != inet->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; } ++num; } if (r->tcpdiag_states&TCPF_TIME_WAIT) { sk_for_each(sk, node, &tcp_ehash[i + tcp_ehash_size].chain) { struct inet_opt *inet = inet_sk(sk); if (num < s_num) continue; if (!(r->tcpdiag_states & (1 << sk->sk_zapped))) continue; if (r->id.tcpdiag_sport != inet->sport && r->id.tcpdiag_sport) continue; if (r->id.tcpdiag_dport != inet->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; } ++num; } } 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; } static 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 || nlh->nlmsg_flags & NLM_F_ACK) netlink_ack(skb, nlh, err); } } static void tcpdiag_rcv(struct sock *sk, int len) { struct sk_buff *skb; while ((skb = skb_dequeue(&sk->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."); }