| /* |
| * 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: |
| */ |