1/* 2 * tcp_diag.c Module for monitoring TCP sockets. 3 * 4 * Version: $Id: tcp_diag.c,v 1.1.1.1 2008/10/15 03:27:33 james26_jang Exp $ 5 * 6 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14#include <linux/config.h> 15#include <linux/module.h> 16#include <linux/types.h> 17#include <linux/fcntl.h> 18#include <linux/random.h> 19#include <linux/cache.h> 20#include <linux/init.h> 21 22#include <net/icmp.h> 23#include <net/tcp.h> 24#include <net/ipv6.h> 25#include <net/inet_common.h> 26 27#include <linux/inet.h> 28#include <linux/stddef.h> 29 30#include <linux/tcp_diag.h> 31 32static struct sock *tcpnl; 33 34 35#define TCPDIAG_PUT(skb, attrtype, attrlen) \ 36({ int rtalen = RTA_LENGTH(attrlen); \ 37 struct rtattr *rta; \ 38 if (skb_tailroom(skb) < RTA_ALIGN(rtalen)) goto nlmsg_failure; \ 39 rta = (void*)__skb_put(skb, RTA_ALIGN(rtalen)); \ 40 rta->rta_type = attrtype; \ 41 rta->rta_len = rtalen; \ 42 RTA_DATA(rta); }) 43 44static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk, 45 int ext, u32 pid, u32 seq) 46{ 47 struct tcp_opt *tp = &sk->tp_pinfo.af_tcp; 48 struct tcpdiagmsg *r; 49 struct nlmsghdr *nlh; 50 struct tcp_info *info = NULL; 51 struct tcpdiag_meminfo *minfo = NULL; 52 unsigned char *b = skb->tail; 53 54 nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r)); 55 r = NLMSG_DATA(nlh); 56 if (sk->state != TCP_TIME_WAIT) { 57 if (ext & (1<<(TCPDIAG_MEMINFO-1))) 58 minfo = TCPDIAG_PUT(skb, TCPDIAG_MEMINFO, sizeof(*minfo)); 59 if (ext & (1<<(TCPDIAG_INFO-1))) 60 info = TCPDIAG_PUT(skb, TCPDIAG_INFO, sizeof(*info)); 61 } 62 r->tcpdiag_family = sk->family; 63 r->tcpdiag_state = sk->state; 64 r->tcpdiag_timer = 0; 65 r->tcpdiag_retrans = 0; 66 67 r->id.tcpdiag_sport = sk->sport; 68 r->id.tcpdiag_dport = sk->dport; 69 r->id.tcpdiag_src[0] = sk->rcv_saddr; 70 r->id.tcpdiag_dst[0] = sk->daddr; 71 r->id.tcpdiag_if = sk->bound_dev_if; 72 r->id.tcpdiag_cookie[0] = (u32)(unsigned long)sk; 73 r->id.tcpdiag_cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1); 74 75 if (r->tcpdiag_state == TCP_TIME_WAIT) { 76 struct tcp_tw_bucket *tw = (struct tcp_tw_bucket*)sk; 77 long tmo = tw->ttd - jiffies; 78 if (tmo < 0) 79 tmo = 0; 80 81 r->tcpdiag_state = tw->substate; 82 r->tcpdiag_timer = 3; 83 r->tcpdiag_expires = (tmo*1000+HZ-1)/HZ; 84 r->tcpdiag_rqueue = 0; 85 r->tcpdiag_wqueue = 0; 86 r->tcpdiag_uid = 0; 87 r->tcpdiag_inode = 0; 88#ifdef CONFIG_IPV6 89 if (r->tcpdiag_family == AF_INET6) { 90 memcpy(r->id.tcpdiag_src, &tw->v6_rcv_saddr, 16); 91 memcpy(r->id.tcpdiag_dst, &tw->v6_daddr, 16); 92 } 93#endif 94 nlh->nlmsg_len = skb->tail - b; 95 return skb->len; 96 } 97 98#ifdef CONFIG_IPV6 99 if (r->tcpdiag_family == AF_INET6) { 100 memcpy(r->id.tcpdiag_src, &sk->net_pinfo.af_inet6.rcv_saddr, 16); 101 memcpy(r->id.tcpdiag_dst, &sk->net_pinfo.af_inet6.daddr, 16); 102 } 103#endif 104 105#define EXPIRES_IN_MS(tmo) ((tmo-jiffies)*1000+HZ-1)/HZ 106 107 if (tp->pending == TCP_TIME_RETRANS) { 108 r->tcpdiag_timer = 1; 109 r->tcpdiag_retrans = tp->retransmits; 110 r->tcpdiag_expires = EXPIRES_IN_MS(tp->timeout); 111 } else if (tp->pending == TCP_TIME_PROBE0) { 112 r->tcpdiag_timer = 4; 113 r->tcpdiag_retrans = tp->probes_out; 114 r->tcpdiag_expires = EXPIRES_IN_MS(tp->timeout); 115 } else if (timer_pending(&sk->timer)) { 116 r->tcpdiag_timer = 2; 117 r->tcpdiag_retrans = tp->probes_out; 118 r->tcpdiag_expires = EXPIRES_IN_MS(sk->timer.expires); 119 } else { 120 r->tcpdiag_timer = 0; 121 r->tcpdiag_expires = 0; 122 } 123#undef EXPIRES_IN_MS 124 125 r->tcpdiag_rqueue = tp->rcv_nxt - tp->copied_seq; 126 r->tcpdiag_wqueue = tp->write_seq - tp->snd_una; 127 r->tcpdiag_uid = sock_i_uid(sk); 128 r->tcpdiag_inode = sock_i_ino(sk); 129 130 if (minfo) { 131 minfo->tcpdiag_rmem = atomic_read(&sk->rmem_alloc); 132 minfo->tcpdiag_wmem = sk->wmem_queued; 133 minfo->tcpdiag_fmem = sk->forward_alloc; 134 minfo->tcpdiag_tmem = atomic_read(&sk->wmem_alloc); 135 } 136 137 if (info) { 138 u32 now = tcp_time_stamp; 139 140 info->tcpi_state = sk->state; 141 info->tcpi_ca_state = tp->ca_state; 142 info->tcpi_retransmits = tp->retransmits; 143 info->tcpi_probes = tp->probes_out; 144 info->tcpi_backoff = tp->backoff; 145 info->tcpi_options = 0; 146 if (tp->tstamp_ok) 147 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 148 if (tp->sack_ok) 149 info->tcpi_options |= TCPI_OPT_SACK; 150 if (tp->wscale_ok) { 151 info->tcpi_options |= TCPI_OPT_WSCALE; 152 info->tcpi_snd_wscale = tp->snd_wscale; 153 info->tcpi_rcv_wscale = tp->rcv_wscale; 154 } else { 155 info->tcpi_snd_wscale = 0; 156 info->tcpi_rcv_wscale = 0; 157 } 158#ifdef CONFIG_INET_ECN 159 if (tp->ecn_flags&TCP_ECN_OK) 160 info->tcpi_options |= TCPI_OPT_ECN; 161#endif 162 163 info->tcpi_rto = (1000000*tp->rto)/HZ; 164 info->tcpi_ato = (1000000*tp->ack.ato)/HZ; 165 info->tcpi_snd_mss = tp->mss_cache; 166 info->tcpi_rcv_mss = tp->ack.rcv_mss; 167 168 info->tcpi_unacked = tp->packets_out; 169 info->tcpi_sacked = tp->sacked_out; 170 info->tcpi_lost = tp->lost_out; 171 info->tcpi_retrans = tp->retrans_out; 172 info->tcpi_fackets = tp->fackets_out; 173 174 info->tcpi_last_data_sent = ((now - tp->lsndtime)*1000)/HZ; 175 info->tcpi_last_ack_sent = 0; 176 info->tcpi_last_data_recv = ((now - tp->ack.lrcvtime)*1000)/HZ; 177 info->tcpi_last_ack_recv = ((now - tp->rcv_tstamp)*1000)/HZ; 178 179 info->tcpi_pmtu = tp->pmtu_cookie; 180 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 181 info->tcpi_rtt = ((1000000*tp->srtt)/HZ)>>3; 182 info->tcpi_rttvar = ((1000000*tp->mdev)/HZ)>>2; 183 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 184 info->tcpi_snd_cwnd = tp->snd_cwnd; 185 info->tcpi_advmss = tp->advmss; 186 info->tcpi_reordering = tp->reordering; 187 } 188 189 nlh->nlmsg_len = skb->tail - b; 190 return skb->len; 191 192nlmsg_failure: 193 skb_trim(skb, b - skb->data); 194 return -1; 195} 196 197extern struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif); 198#ifdef CONFIG_IPV6 199extern struct sock *tcp_v6_lookup(struct in6_addr *saddr, u16 sport, 200 struct in6_addr *daddr, u16 dport, 201 int dif); 202#endif 203 204static int tcpdiag_get_exact(struct sk_buff *in_skb, struct nlmsghdr *nlh) 205{ 206 int err; 207 struct sock *sk; 208 struct tcpdiagreq *req = NLMSG_DATA(nlh); 209 struct sk_buff *rep; 210 211 if (req->tcpdiag_family == AF_INET) { 212 sk = tcp_v4_lookup(req->id.tcpdiag_dst[0], req->id.tcpdiag_dport, 213 req->id.tcpdiag_src[0], req->id.tcpdiag_sport, 214 req->id.tcpdiag_if); 215 } 216#ifdef CONFIG_IPV6 217 else if (req->tcpdiag_family == AF_INET6) { 218 sk = tcp_v6_lookup((struct in6_addr*)req->id.tcpdiag_dst, req->id.tcpdiag_dport, 219 (struct in6_addr*)req->id.tcpdiag_src, req->id.tcpdiag_sport, 220 req->id.tcpdiag_if); 221 } 222#endif 223 else { 224 return -EINVAL; 225 } 226 227 if (sk == NULL) 228 return -ENOENT; 229 230 err = -ESTALE; 231 if ((req->id.tcpdiag_cookie[0] != TCPDIAG_NOCOOKIE || 232 req->id.tcpdiag_cookie[1] != TCPDIAG_NOCOOKIE) && 233 ((u32)(unsigned long)sk != req->id.tcpdiag_cookie[0] || 234 (u32)((((unsigned long)sk) >> 31) >> 1) != req->id.tcpdiag_cookie[1])) 235 goto out; 236 237 err = -ENOMEM; 238 rep = alloc_skb(NLMSG_SPACE(sizeof(struct tcpdiagmsg)+ 239 sizeof(struct tcpdiag_meminfo)+ 240 sizeof(struct tcp_info)+64), GFP_KERNEL); 241 if (!rep) 242 goto out; 243 244 if (tcpdiag_fill(rep, sk, req->tcpdiag_ext, 245 NETLINK_CB(in_skb).pid, 246 nlh->nlmsg_seq) <= 0) 247 BUG(); 248 249 err = netlink_unicast(tcpnl, rep, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); 250 if (err > 0) 251 err = 0; 252 253out: 254 if (sk) { 255 if (sk->state == TCP_TIME_WAIT) 256 tcp_tw_put((struct tcp_tw_bucket*)sk); 257 else 258 sock_put(sk); 259 } 260 return err; 261} 262 263int bitstring_match(u32 *a1, u32 *a2, int bits) 264{ 265 int words = bits >> 5; 266 267 bits &= 0x1f; 268 269 if (words) { 270 if (memcmp(a1, a2, words << 2)) 271 return 0; 272 } 273 if (bits) { 274 __u32 w1, w2; 275 __u32 mask; 276 277 w1 = a1[words]; 278 w2 = a2[words]; 279 280 mask = htonl((0xffffffff) << (32 - bits)); 281 282 if ((w1 ^ w2) & mask) 283 return 0; 284 } 285 286 return 1; 287} 288 289 290int tcpdiag_bc_run(char *bc, int len, struct sock *sk) 291{ 292 while (len > 0) { 293 int yes = 1; 294 struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc; 295 296 switch (op->code) { 297 case TCPDIAG_BC_NOP: 298 break; 299 case TCPDIAG_BC_JMP: 300 yes = 0; 301 break; 302 case TCPDIAG_BC_S_GE: 303 yes = (sk->num >= op[1].no); 304 break; 305 case TCPDIAG_BC_S_LE: 306 yes = (sk->num <= op[1].no); 307 break; 308 case TCPDIAG_BC_D_GE: 309 yes = (ntohs(sk->dport) >= op[1].no); 310 break; 311 case TCPDIAG_BC_D_LE: 312 yes = (ntohs(sk->dport) <= op[1].no); 313 break; 314 case TCPDIAG_BC_AUTO: 315 yes = !(sk->userlocks&SOCK_BINDPORT_LOCK); 316 break; 317 case TCPDIAG_BC_S_COND: 318 case TCPDIAG_BC_D_COND: 319 { 320 struct tcpdiag_hostcond *cond = (struct tcpdiag_hostcond*)(op+1); 321 u32 *addr; 322 323 if (cond->port != -1 && 324 cond->port != (op->code == TCPDIAG_BC_S_COND ? sk->num : ntohs(sk->dport))) { 325 yes = 0; 326 break; 327 } 328 329 if (cond->prefix_len == 0) 330 break; 331 332#ifdef CONFIG_IPV6 333 if (sk->family == AF_INET6) { 334 if (op->code == TCPDIAG_BC_S_COND) 335 addr = (u32*)&sk->net_pinfo.af_inet6.rcv_saddr; 336 else 337 addr = (u32*)&sk->net_pinfo.af_inet6.daddr; 338 } else 339#endif 340 { 341 if (op->code == TCPDIAG_BC_S_COND) 342 addr = &sk->rcv_saddr; 343 else 344 addr = &sk->daddr; 345 } 346 347 if (bitstring_match(addr, cond->addr, cond->prefix_len)) 348 break; 349 if (sk->family == AF_INET6 && cond->family == AF_INET) { 350 if (addr[0] == 0 && addr[1] == 0 && 351 addr[2] == htonl(0xffff) && 352 bitstring_match(addr+3, cond->addr, cond->prefix_len)) 353 break; 354 } 355 yes = 0; 356 break; 357 } 358 } 359 360 if (yes) { 361 len -= op->yes; 362 bc += op->yes; 363 } else { 364 len -= op->no; 365 bc += op->no; 366 } 367 } 368 return (len == 0); 369} 370 371int valid_cc(char *bc, int len, int cc) 372{ 373 while (len >= 0) { 374 struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc; 375 376 if (cc > len) 377 return 0; 378 if (cc == len) 379 return 1; 380 if (op->yes < 4) 381 return 0; 382 len -= op->yes; 383 bc += op->yes; 384 } 385 return 0; 386} 387 388int tcpdiag_bc_audit(char *bytecode, int bytecode_len) 389{ 390 char *bc = bytecode; 391 int len = bytecode_len; 392 393 while (len > 0) { 394 struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc; 395 396//printk("BC: %d %d %d {%d} / %d\n", op->code, op->yes, op->no, op[1].no, len); 397 switch (op->code) { 398 case TCPDIAG_BC_AUTO: 399 case TCPDIAG_BC_S_COND: 400 case TCPDIAG_BC_D_COND: 401 case TCPDIAG_BC_S_GE: 402 case TCPDIAG_BC_S_LE: 403 case TCPDIAG_BC_D_GE: 404 case TCPDIAG_BC_D_LE: 405 if (op->yes < 4 || op->yes > len+4) 406 return -EINVAL; 407 case TCPDIAG_BC_JMP: 408 if (op->no < 4 || op->no > len+4) 409 return -EINVAL; 410 if (op->no < len && 411 !valid_cc(bytecode, bytecode_len, len-op->no)) 412 return -EINVAL; 413 break; 414 case TCPDIAG_BC_NOP: 415 if (op->yes < 4 || op->yes > len+4) 416 return -EINVAL; 417 break; 418 default: 419 return -EINVAL; 420 } 421 bc += op->yes; 422 len -= op->yes; 423 } 424 return len == 0 ? 0 : -EINVAL; 425} 426 427 428int tcpdiag_dump(struct sk_buff *skb, struct netlink_callback *cb) 429{ 430 int i, num; 431 int s_i, s_num; 432 struct tcpdiagreq *r = NLMSG_DATA(cb->nlh); 433 struct rtattr *bc = NULL; 434 435 if (cb->nlh->nlmsg_len > 4+NLMSG_SPACE(sizeof(struct tcpdiagreq))) 436 bc = (struct rtattr*)(r+1); 437 438 s_i = cb->args[1]; 439 s_num = num = cb->args[2]; 440 441 if (cb->args[0] == 0) { 442 if (!(r->tcpdiag_states&(TCPF_LISTEN|TCPF_SYN_RECV))) 443 goto skip_listen_ht; 444 tcp_listen_lock(); 445 for (i = s_i; i < TCP_LHTABLE_SIZE; i++) { 446 struct sock *sk = tcp_listening_hash[i]; 447 448 if (i > s_i) 449 s_num = 0; 450 451 for (sk = tcp_listening_hash[i], num = 0; 452 sk != NULL; 453 sk = sk->next, num++) { 454 if (num < s_num) 455 continue; 456 if (!(r->tcpdiag_states&TCPF_LISTEN) || 457 r->id.tcpdiag_dport) 458 continue; 459 if (r->id.tcpdiag_sport != sk->sport && r->id.tcpdiag_sport) 460 continue; 461 if (bc && !tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), sk)) 462 continue; 463 if (tcpdiag_fill(skb, sk, r->tcpdiag_ext, 464 NETLINK_CB(cb->skb).pid, 465 cb->nlh->nlmsg_seq) <= 0) { 466 tcp_listen_unlock(); 467 goto done; 468 } 469 } 470 } 471 tcp_listen_unlock(); 472skip_listen_ht: 473 cb->args[0] = 1; 474 s_i = num = s_num = 0; 475 } 476 477 if (!(r->tcpdiag_states&~(TCPF_LISTEN|TCPF_SYN_RECV))) 478 return skb->len; 479 480 for (i = s_i; i < tcp_ehash_size; i++) { 481 struct tcp_ehash_bucket *head = &tcp_ehash[i]; 482 struct sock *sk; 483 484 if (i > s_i) 485 s_num = 0; 486 487 read_lock_bh(&head->lock); 488 489 for (sk = head->chain, num = 0; 490 sk != NULL; 491 sk = sk->next, num++) { 492 if (num < s_num) 493 continue; 494 if (!(r->tcpdiag_states&(1<<sk->state))) 495 continue; 496 if (r->id.tcpdiag_sport != sk->sport && r->id.tcpdiag_sport) 497 continue; 498 if (r->id.tcpdiag_dport != sk->dport && r->id.tcpdiag_dport) 499 continue; 500 if (bc && !tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), sk)) 501 continue; 502 if (tcpdiag_fill(skb, sk, r->tcpdiag_ext, 503 NETLINK_CB(cb->skb).pid, 504 cb->nlh->nlmsg_seq) <= 0) { 505 read_unlock_bh(&head->lock); 506 goto done; 507 } 508 } 509 510 if (r->tcpdiag_states&TCPF_TIME_WAIT) { 511 for (sk = tcp_ehash[i+tcp_ehash_size].chain; 512 sk != NULL; 513 sk = sk->next, num++) { 514 if (num < s_num) 515 continue; 516 if (!(r->tcpdiag_states&(1<<sk->zapped))) 517 continue; 518 if (r->id.tcpdiag_sport != sk->sport && r->id.tcpdiag_sport) 519 continue; 520 if (r->id.tcpdiag_dport != sk->dport && r->id.tcpdiag_dport) 521 continue; 522 if (bc && !tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), sk)) 523 continue; 524 if (tcpdiag_fill(skb, sk, r->tcpdiag_ext, 525 NETLINK_CB(cb->skb).pid, 526 cb->nlh->nlmsg_seq) <= 0) { 527 read_unlock_bh(&head->lock); 528 goto done; 529 } 530 } 531 } 532 read_unlock_bh(&head->lock); 533 } 534 535done: 536 cb->args[1] = i; 537 cb->args[2] = num; 538 return skb->len; 539} 540 541static int tcpdiag_dump_done(struct netlink_callback *cb) 542{ 543 return 0; 544} 545 546 547static __inline__ int 548tcpdiag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 549{ 550 if (!(nlh->nlmsg_flags&NLM_F_REQUEST)) 551 return 0; 552 553 if (nlh->nlmsg_type != TCPDIAG_GETSOCK) 554 goto err_inval; 555 556 if (NLMSG_LENGTH(sizeof(struct tcpdiagreq)) > skb->len) 557 goto err_inval; 558 559 if (nlh->nlmsg_flags&NLM_F_DUMP) { 560 if (nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(struct tcpdiagreq))) { 561 struct rtattr *rta = (struct rtattr*)(NLMSG_DATA(nlh) + sizeof(struct tcpdiagreq)); 562 if (rta->rta_type != TCPDIAG_REQ_BYTECODE || 563 rta->rta_len < 8 || 564 rta->rta_len > nlh->nlmsg_len - NLMSG_SPACE(sizeof(struct tcpdiagreq))) 565 goto err_inval; 566 if (tcpdiag_bc_audit(RTA_DATA(rta), RTA_PAYLOAD(rta))) 567 goto err_inval; 568 } 569 return netlink_dump_start(tcpnl, skb, nlh, 570 tcpdiag_dump, 571 tcpdiag_dump_done); 572 } else { 573 return tcpdiag_get_exact(skb, nlh); 574 } 575 576err_inval: 577 return -EINVAL; 578} 579 580 581extern __inline__ void tcpdiag_rcv_skb(struct sk_buff *skb) 582{ 583 int err; 584 struct nlmsghdr * nlh; 585 586 if (skb->len >= NLMSG_SPACE(0)) { 587 nlh = (struct nlmsghdr *)skb->data; 588 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) 589 return; 590 err = tcpdiag_rcv_msg(skb, nlh); 591 if (err) 592 netlink_ack(skb, nlh, err); 593 } 594} 595 596static void tcpdiag_rcv(struct sock *sk, int len) 597{ 598 struct sk_buff *skb; 599 600 while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) { 601 tcpdiag_rcv_skb(skb); 602 kfree_skb(skb); 603 } 604} 605 606void __init tcpdiag_init(void) 607{ 608 tcpnl = netlink_kernel_create(NETLINK_TCPDIAG, tcpdiag_rcv); 609 if (tcpnl == NULL) 610 panic("tcpdiag_init: Cannot create netlink socket."); 611} 612