release/src/router/busybox/networking/netstat.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini netstat implementation(s) for busybox
   4  * based in part on the netstat implementation from net-tools.
   5  *
   6  * Copyright (C) 2002 by Bart Visscher <magick@linux-fan.com>
   7  *
   8  * 2002-04-20
   9  * IPV6 support added by Bart Visscher <magick@linux-fan.com>
  10  *
  11  * 2008-07-10
  12  * optional '-p' flag support ported from net-tools by G. Somlo <somlo@cmu.edu>
  13  *
  14  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  15  */
  16
  17 #include "libbb.h"
  18 #include "inet_common.h"
  19
  20 #define NETSTAT_OPTS "laentuwx" \
  21         USE_ROUTE(               "r") \
  22         USE_FEATURE_NETSTAT_WIDE("W") \
  23         USE_FEATURE_NETSTAT_PRG( "p")
  24
  25 enum {
  26         OPTBIT_KEEP_OLD = 7,
  27         USE_ROUTE(               OPTBIT_ROUTE,)
  28         USE_FEATURE_NETSTAT_WIDE(OPTBIT_WIDE ,)
  29         USE_FEATURE_NETSTAT_PRG( OPTBIT_PRG  ,)
  30         OPT_sock_listen = 1 << 0, // l
  31         OPT_sock_all    = 1 << 1, // a
  32         OPT_extended    = 1 << 2, // e
  33         OPT_noresolve   = 1 << 3, // n
  34         OPT_sock_tcp    = 1 << 4, // t
  35         OPT_sock_udp    = 1 << 5, // u
  36         OPT_sock_raw    = 1 << 6, // w
  37         OPT_sock_unix   = 1 << 7, // x
  38         OPT_route       = USE_ROUTE(               (1 << OPTBIT_ROUTE)) + 0, // r
  39         OPT_wide        = USE_FEATURE_NETSTAT_WIDE((1 << OPTBIT_WIDE )) + 0, // W
  40         OPT_prg         = USE_FEATURE_NETSTAT_PRG( (1 << OPTBIT_PRG  )) + 0, // p
  41 };
  42
  43 #define NETSTAT_CONNECTED 0x01
  44 #define NETSTAT_LISTENING 0x02
  45 #define NETSTAT_NUMERIC   0x04
  46 /* Must match getopt32 option string */
  47 #define NETSTAT_TCP       0x10
  48 #define NETSTAT_UDP       0x20
  49 #define NETSTAT_RAW       0x40
  50 #define NETSTAT_UNIX      0x80
  51 #define NETSTAT_ALLPROTO  (NETSTAT_TCP|NETSTAT_UDP|NETSTAT_RAW|NETSTAT_UNIX)
  52
  53
  54 enum {
  55         TCP_ESTABLISHED = 1,
  56         TCP_SYN_SENT,
  57         TCP_SYN_RECV,
  58         TCP_FIN_WAIT1,
  59         TCP_FIN_WAIT2,
  60         TCP_TIME_WAIT,
  61         TCP_CLOSE,
  62         TCP_CLOSE_WAIT,
  63         TCP_LAST_ACK,
  64         TCP_LISTEN,
  65         TCP_CLOSING, /* now a valid state */
  66 };
  67
  68 static const char *const tcp_state[] = {
  69         "",
  70         "ESTABLISHED",
  71         "SYN_SENT",
  72         "SYN_RECV",
  73         "FIN_WAIT1",
  74         "FIN_WAIT2",
  75         "TIME_WAIT",
  76         "CLOSE",
  77         "CLOSE_WAIT",
  78         "LAST_ACK",
  79         "LISTEN",
  80         "CLOSING"
  81 };
  82
  83 typedef enum {
  84         SS_FREE = 0,     /* not allocated                */
  85         SS_UNCONNECTED,  /* unconnected to any socket    */
  86         SS_CONNECTING,   /* in process of connecting     */
  87         SS_CONNECTED,    /* connected to socket          */
  88         SS_DISCONNECTING /* in process of disconnecting  */
  89 } socket_state;
  90
  91 #define SO_ACCEPTCON (1<<16)    /* performed a listen           */
  92 #define SO_WAITDATA  (1<<17)    /* wait data to read            */
  93 #define SO_NOSPACE   (1<<18)    /* no space to write            */
  94
  95 /* Standard printout size */
  96 #define PRINT_IP_MAX_SIZE           23
  97 #define PRINT_NET_CONN              "%s   %6ld %6ld %-23s %-23s %-12s"
  98 #define PRINT_NET_CONN_HEADER       "\nProto Recv-Q Send-Q %-23s %-23s State       "
  99
 100 /* When there are IPv6 connections the IPv6 addresses will be
 101  * truncated to none-recognition. The '-W' option makes the
 102  * address columns wide enough to accomodate for longest possible
 103  * IPv6 addresses, i.e. addresses of the form
 104  * xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:ddd.ddd.ddd.ddd
 105  */
 106 #define PRINT_IP_MAX_SIZE_WIDE      51  /* INET6_ADDRSTRLEN + 5 for the port number */
 107 #define PRINT_NET_CONN_WIDE         "%s   %6ld %6ld %-51s %-51s %-12s"
 108 #define PRINT_NET_CONN_HEADER_WIDE  "\nProto Recv-Q Send-Q %-51s %-51s State       "
 109
 110
 111 #define PROGNAME_WIDTH     20
 112 #define PROGNAME_WIDTH_STR "20"
 113 /* PROGNAME_WIDTH chars: 12345678901234567890 */
 114 #define PROGNAME_BANNER "PID/Program name    "
 115
 116 struct prg_node {
 117         struct prg_node *next;
 118         long inode;
 119         char name[PROGNAME_WIDTH];
 120 };
 121
 122 #define PRG_HASH_SIZE 211
 123
 124
 125 struct globals {
 126         const char *net_conn_line;
 127         smallint flags;
 128 #if ENABLE_FEATURE_NETSTAT_PRG
 129         smallint prg_cache_loaded;
 130         struct prg_node *prg_hash[PRG_HASH_SIZE];
 131 #endif
 132 };
 133 #define G (*ptr_to_globals)
 134 #define flags            (G.flags           )
 135 #define net_conn_line    (G.net_conn_line   )
 136 #define prg_hash         (G.prg_hash        )
 137 #define prg_cache_loaded (G.prg_cache_loaded)
 138 #define INIT_G() do { \
 139         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 140         flags = NETSTAT_CONNECTED | NETSTAT_ALLPROTO; \
 141         net_conn_line = PRINT_NET_CONN; \
 142 } while (0)
 143
 144
 145 #if ENABLE_FEATURE_NETSTAT_PRG
 146
 147 /* Deliberately truncating long to unsigned *int* */
 148 #define PRG_HASHIT(x) ((unsigned)(x) % PRG_HASH_SIZE)
 149
 150 #define print_progname_banner() do { \
 151         if (option_mask32 & OPT_prg) printf(PROGNAME_BANNER); \
 152 } while (0)
 153
 154 static void prg_cache_add(long inode, char *name)
 155 {
 156         unsigned hi = PRG_HASHIT(inode);
 157         struct prg_node **pnp, *pn;
 158
 159         prg_cache_loaded = 2;
 160         for (pnp = prg_hash + hi; (pn = *pnp) != NULL; pnp = &pn->next) {
 161                 if (pn->inode == inode) {
 162                         /* Some warning should be appropriate here
 163                            as we got multiple processes for one i-node */
 164                         return;
 165                 }
 166         }
 167         *pnp = xzalloc(sizeof(struct prg_node));
 168         pn = *pnp;
 169         pn->inode = inode;
 170         safe_strncpy(pn->name, name, PROGNAME_WIDTH);
 171 }
 172
 173 static const char *prg_cache_get(long inode)
 174 {
 175         unsigned hi = PRG_HASHIT(inode);
 176         struct prg_node *pn;
 177
 178         for (pn = prg_hash[hi]; pn; pn = pn->next)
 179                 if (pn->inode == inode)
 180                         return pn->name;
 181         return "-";
 182 }
 183
 184 #if ENABLE_FEATURE_CLEAN_UP
 185 static void prg_cache_clear(void)
 186 {
 187         struct prg_node **pnp, *pn;
 188
 189         for (pnp = prg_hash; pnp < prg_hash + PRG_HASH_SIZE; pnp++) {
 190                 while ((pn = *pnp) != NULL) {
 191                         *pnp = pn->next;
 192                         free(pn);
 193                 }
 194         }
 195 }
 196 #else
 197 #define prg_cache_clear() ((void)0)
 198 #endif
 199
 200 static long extract_socket_inode(const char *lname)
 201 {
 202         long inode = -1;
 203
 204         if (strncmp(lname, "socket:[", sizeof("socket:[")-1) == 0) {
 205                 /* "socket:[12345]", extract the "12345" as inode */
 206                 inode = bb_strtol(lname + sizeof("socket:[")-1, (char**)&lname, 0);
 207                 if (*lname != ']')
 208                         inode = -1;
 209         } else if (strncmp(lname, "[0000]:", sizeof("[0000]:")-1) == 0) {
 210                 /* "[0000]:12345", extract the "12345" as inode */
 211                 inode = bb_strtol(lname + sizeof("[0000]:")-1, NULL, 0);
 212                 if (errno) /* not NUL terminated? */
 213                         inode = -1;
 214         }
 215
 216 #if 0 /* bb_strtol returns all-ones bit pattern on ERANGE anyway */
 217         if (errno == ERANGE)
 218                 inode = -1;
 219 #endif
 220         return inode;
 221 }
 222
 223 static int FAST_FUNC file_act(const char *fileName,
 224                 struct stat *statbuf UNUSED_PARAM,
 225                 void *userData,
 226                 int depth UNUSED_PARAM)
 227 {
 228         char *linkname;
 229         long inode;
 230
 231         linkname = xmalloc_readlink(fileName);
 232         if (linkname != NULL) {
 233                 inode = extract_socket_inode(linkname);
 234                 free(linkname);
 235                 if (inode >= 0)
 236                         prg_cache_add(inode, (char *)userData);
 237         }
 238         return TRUE;
 239 }
 240
 241 static int FAST_FUNC dir_act(const char *fileName,
 242                 struct stat *statbuf UNUSED_PARAM,
 243                 void *userData UNUSED_PARAM,
 244                 int depth)
 245 {
 246         const char *shortName;
 247         char *p, *q;
 248         char cmdline_buf[512];
 249         int i;
 250
 251         if (depth == 0) /* "/proc" itself */
 252                 return TRUE; /* continue looking one level below /proc */
 253
 254         shortName = fileName + sizeof("/proc/")-1; /* point after "/proc/" */
 255         if (!isdigit(shortName[0])) /* skip /proc entries whic aren't processes */
 256                 return SKIP;
 257
 258         p = concat_path_file(fileName, "cmdline"); /* "/proc/PID/cmdline" */
 259         i = open_read_close(p, cmdline_buf, sizeof(cmdline_buf) - 1);
 260         free(p);
 261         if (i < 0)
 262                 return FALSE;
 263         cmdline_buf[i] = '\0';
 264         q = concat_path_file(shortName, bb_basename(cmdline_buf)); /* "PID/argv0" */
 265
 266         /* go through all files in /proc/PID/fd */
 267         p = concat_path_file(fileName, "fd");
 268         i = recursive_action(p, ACTION_RECURSE | ACTION_QUIET,
 269                                 file_act, NULL, (void *)q, 0);
 270
 271         free(p);
 272         free(q);
 273
 274         if (!i)
 275                 return FALSE;   /* signal permissions error to caller */
 276
 277         return SKIP;            /* caller should not recurse further into this dir. */
 278 }
 279
 280 static void prg_cache_load(void)
 281 {
 282         int load_ok;
 283
 284         prg_cache_loaded = 1;
 285         load_ok = recursive_action("/proc", ACTION_RECURSE | ACTION_QUIET,
 286                                 NULL, dir_act, NULL, 0);
 287         if (load_ok)
 288                 return;
 289
 290         if (prg_cache_loaded == 1)
 291                 bb_error_msg("can't scan /proc - are you root?");
 292         else
 293                 bb_error_msg("showing only processes with your user ID");
 294 }
 295
 296 #else
 297
 298 #define prg_cache_clear()       ((void)0)
 299 #define print_progname_banner() ((void)0)
 300
 301 #endif //ENABLE_FEATURE_NETSTAT_PRG
 302
 303
 304 #if ENABLE_FEATURE_IPV6
 305 static void build_ipv6_addr(char* local_addr, struct sockaddr_in6* localaddr)
 306 {
 307         char addr6[INET6_ADDRSTRLEN];
 308         struct in6_addr in6;
 309
 310         sscanf(local_addr, "%08X%08X%08X%08X",
 311                    &in6.s6_addr32[0], &in6.s6_addr32[1],
 312                    &in6.s6_addr32[2], &in6.s6_addr32[3]);
 313         inet_ntop(AF_INET6, &in6, addr6, sizeof(addr6));
 314         inet_pton(AF_INET6, addr6, (struct sockaddr *) &localaddr->sin6_addr);
 315
 316         localaddr->sin6_family = AF_INET6;
 317 }
 318 #endif
 319
 320 #if ENABLE_FEATURE_IPV6
 321 static void build_ipv4_addr(char* local_addr, struct sockaddr_in6* localaddr)
 322 #else
 323 static void build_ipv4_addr(char* local_addr, struct sockaddr_in* localaddr)
 324 #endif
 325 {
 326         sscanf(local_addr, "%X",
 327                    &((struct sockaddr_in *) localaddr)->sin_addr.s_addr);
 328         ((struct sockaddr *) localaddr)->sa_family = AF_INET;
 329 }
 330
 331 static const char *get_sname(int port, const char *proto, int numeric)
 332 {
 333         if (!port)
 334                 return "*";
 335         if (!numeric) {
 336                 struct servent *se = getservbyport(port, proto);
 337                 if (se)
 338                         return se->s_name;
 339         }
 340         /* hummm, we may return static buffer here!! */
 341         return itoa(ntohs(port));
 342 }
 343
 344 static char *ip_port_str(struct sockaddr *addr, int port, const char *proto, int numeric)
 345 {
 346         char *host, *host_port;
 347
 348         /* Code which used "*" for INADDR_ANY is removed: it's ambiguous
 349          * in IPv6, while "0.0.0.0" is not. */
 350
 351         host = numeric ? xmalloc_sockaddr2dotted_noport(addr)
 352                        : xmalloc_sockaddr2host_noport(addr);
 353
 354         host_port = xasprintf("%s:%s", host, get_sname(htons(port), proto, numeric));
 355         free(host);
 356         return host_port;
 357 }
 358
 359 struct inet_params {
 360         int local_port, rem_port, state, uid;
 361 #if ENABLE_FEATURE_IPV6
 362         struct sockaddr_in6 localaddr, remaddr;
 363 #else
 364         struct sockaddr_in localaddr, remaddr;
 365 #endif
 366         unsigned long rxq, txq, inode;
 367 };
 368
 369 static int scan_inet_proc_line(struct inet_params *param, char *line)
 370 {
 371         int num;
 372         char local_addr[64], rem_addr[64];
 373
 374         num = sscanf(line,
 375                         "%*d: %64[0-9A-Fa-f]:%X "
 376                         "%64[0-9A-Fa-f]:%X %X "
 377                         "%lX:%lX %*X:%*X "
 378                         "%*X %d %*d %ld ",
 379                         local_addr, &param->local_port,
 380                         rem_addr, &param->rem_port, &param->state,
 381                         &param->txq, &param->rxq,
 382                         &param->uid, &param->inode);
 383         if (num < 9) {
 384                 return 1; /* error */
 385         }
 386
 387         if (strlen(local_addr) > 8) {
 388 #if ENABLE_FEATURE_IPV6
 389                 build_ipv6_addr(local_addr, &param->localaddr);
 390                 build_ipv6_addr(rem_addr, &param->remaddr);
 391 #endif
 392         } else {
 393                 build_ipv4_addr(local_addr, &param->localaddr);
 394                 build_ipv4_addr(rem_addr, &param->remaddr);
 395         }
 396         return 0;
 397 }
 398
 399 static void print_inet_line(struct inet_params *param,
 400                 const char *state_str, const char *proto, int is_connected)
 401 {
 402         if ((is_connected && (flags & NETSTAT_CONNECTED))
 403          || (!is_connected && (flags & NETSTAT_LISTENING))
 404         ) {
 405                 char *l = ip_port_str(
 406                                 (struct sockaddr *) &param->localaddr, param->local_port,
 407                                 proto, flags & NETSTAT_NUMERIC);
 408                 char *r = ip_port_str(
 409                                 (struct sockaddr *) &param->remaddr, param->rem_port,
 410                                 proto, flags & NETSTAT_NUMERIC);
 411                 printf(net_conn_line,
 412                         proto, param->rxq, param->txq, l, r, state_str);
 413 #if ENABLE_FEATURE_NETSTAT_PRG
 414                 if (option_mask32 & OPT_prg)
 415                         printf("%."PROGNAME_WIDTH_STR"s", prg_cache_get(param->inode));
 416 #endif
 417                 bb_putchar('\n');
 418                 free(l);
 419                 free(r);
 420         }
 421 }
 422
 423 static int FAST_FUNC tcp_do_one(char *line)
 424 {
 425         struct inet_params param;
 426
 427         if (scan_inet_proc_line(&param, line))
 428                 return 1;
 429
 430         print_inet_line(&param, tcp_state[param.state], "tcp", param.rem_port);
 431         return 0;
 432 }
 433
 434 #if ENABLE_FEATURE_IPV6
 435 # define notnull(A) ( \
 436         ( (A.sin6_family == AF_INET6)                               \
 437           && (A.sin6_addr.s6_addr32[0] | A.sin6_addr.s6_addr32[1] | \
 438               A.sin6_addr.s6_addr32[2] | A.sin6_addr.s6_addr32[3])  \
 439         ) || (                                                      \
 440           (A.sin6_family == AF_INET)                                \
 441           && ((struct sockaddr_in*)&A)->sin_addr.s_addr             \
 442         )                                                           \
 443 )
 444 #else
 445 # define notnull(A) (A.sin_addr.s_addr)
 446 #endif
 447
 448 static int FAST_FUNC udp_do_one(char *line)
 449 {
 450         int have_remaddr;
 451         const char *state_str;
 452         struct inet_params param;
 453
 454         if (scan_inet_proc_line(&param, line))
 455                 return 1;
 456
 457         state_str = "UNKNOWN";
 458         switch (param.state) {
 459         case TCP_ESTABLISHED:
 460                 state_str = "ESTABLISHED";
 461                 break;
 462         case TCP_CLOSE:
 463                 state_str = "";
 464                 break;
 465         }
 466
 467         have_remaddr = notnull(param.remaddr);
 468         print_inet_line(&param, state_str, "udp", have_remaddr);
 469         return 0;
 470 }
 471
 472 static int FAST_FUNC raw_do_one(char *line)
 473 {
 474         int have_remaddr;
 475         struct inet_params param;
 476
 477         if (scan_inet_proc_line(&param, line))
 478                 return 1;
 479
 480         have_remaddr = notnull(param.remaddr);
 481         print_inet_line(&param, itoa(param.state), "raw", have_remaddr);
 482         return 0;
 483 }
 484
 485 static int FAST_FUNC unix_do_one(char *line)
 486 {
 487         unsigned long refcnt, proto, unix_flags;
 488         unsigned long inode;
 489         int type, state;
 490         int num, path_ofs;
 491         const char *ss_proto, *ss_state, *ss_type;
 492         char ss_flags[32];
 493
 494         /* 2.6.15 may report lines like "... @/tmp/fam-user-^@^@^@^@^@^@^@..."
 495          * Other users report long lines filled by NUL bytes.
 496          * (those ^@ are NUL bytes too). We see them as empty lines. */
 497         if (!line[0])
 498                 return 0;
 499
 500         path_ofs = 0; /* paranoia */
 501         num = sscanf(line, "%*p: %lX %lX %lX %X %X %lu %n",
 502                         &refcnt, &proto, &unix_flags, &type, &state, &inode, &path_ofs);
 503         if (num < 6) {
 504                 return 1; /* error */
 505         }
 506         if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) != (NETSTAT_LISTENING|NETSTAT_CONNECTED)) {
 507                 if ((state == SS_UNCONNECTED) && (unix_flags & SO_ACCEPTCON)) {
 508                         if (!(flags & NETSTAT_LISTENING))
 509                                 return 0;
 510                 } else {
 511                         if (!(flags & NETSTAT_CONNECTED))
 512                                 return 0;
 513                 }
 514         }
 515
 516         switch (proto) {
 517                 case 0:
 518                         ss_proto = "unix";
 519                         break;
 520                 default:
 521                         ss_proto = "??";
 522         }
 523
 524         switch (type) {
 525                 case SOCK_STREAM:
 526                         ss_type = "STREAM";
 527                         break;
 528                 case SOCK_DGRAM:
 529                         ss_type = "DGRAM";
 530                         break;
 531                 case SOCK_RAW:
 532                         ss_type = "RAW";
 533                         break;
 534                 case SOCK_RDM:
 535                         ss_type = "RDM";
 536                         break;
 537                 case SOCK_SEQPACKET:
 538                         ss_type = "SEQPACKET";
 539                         break;
 540                 default:
 541                         ss_type = "UNKNOWN";
 542         }
 543
 544         switch (state) {
 545                 case SS_FREE:
 546                         ss_state = "FREE";
 547                         break;
 548                 case SS_UNCONNECTED:
 549                         /*
 550                          * Unconnected sockets may be listening
 551                          * for something.
 552                          */
 553                         if (unix_flags & SO_ACCEPTCON) {
 554                                 ss_state = "LISTENING";
 555                         } else {
 556                                 ss_state = "";
 557                         }
 558                         break;
 559                 case SS_CONNECTING:
 560                         ss_state = "CONNECTING";
 561                         break;
 562                 case SS_CONNECTED:
 563                         ss_state = "CONNECTED";
 564                         break;
 565                 case SS_DISCONNECTING:
 566                         ss_state = "DISCONNECTING";
 567                         break;
 568                 default:
 569                         ss_state = "UNKNOWN";
 570         }
 571
 572         strcpy(ss_flags, "[ ");
 573         if (unix_flags & SO_ACCEPTCON)
 574                 strcat(ss_flags, "ACC ");
 575         if (unix_flags & SO_WAITDATA)
 576                 strcat(ss_flags, "W ");
 577         if (unix_flags & SO_NOSPACE)
 578                 strcat(ss_flags, "N ");
 579         strcat(ss_flags, "]");
 580
 581         printf("%-5s %-6ld %-11s %-10s %-13s %6lu ",
 582                 ss_proto, refcnt, ss_flags, ss_type, ss_state, inode
 583                 );
 584
 585 #if ENABLE_FEATURE_NETSTAT_PRG
 586         if (option_mask32 & OPT_prg)
 587                 printf("%-"PROGNAME_WIDTH_STR"s", prg_cache_get(inode));
 588 #endif
 589
 590         /* TODO: currently we stop at first NUL byte. Is it a problem? */
 591         line += path_ofs;
 592         *strchrnul(line, '\n') = '\0';
 593         while (*line)
 594                 fputc_printable(*line++, stdout);
 595         bb_putchar('\n');
 596         return 0;
 597 }
 598
 599 static void do_info(const char *file, int FAST_FUNC (*proc)(char *))
 600 {
 601         int lnr;
 602         FILE *procinfo;
 603         char *buffer;
 604
 605         /* _stdin is just to save "r" param */
 606         procinfo = fopen_or_warn_stdin(file);
 607         if (procinfo == NULL) {
 608                 return;
 609         }
 610         lnr = 0;
 611         /* Why xmalloc_fgets_str? because it doesn't stop on NULs */
 612         while ((buffer = xmalloc_fgets_str(procinfo, "\n")) != NULL) {
 613                 /* line 0 is skipped */
 614                 if (lnr && proc(buffer))
 615                         bb_error_msg("%s: bogus data on line %d", file, lnr + 1);
 616                 lnr++;
 617                 free(buffer);
 618         }
 619         fclose(procinfo);
 620 }
 621
 622 int netstat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 623 int netstat_main(int argc UNUSED_PARAM, char **argv)
 624 {
 625         const char *net_conn_line_header = PRINT_NET_CONN_HEADER;
 626         unsigned opt;
 627
 628         INIT_G();
 629
 630         /* Option string must match NETSTAT_xxx constants */
 631         opt = getopt32(argv, NETSTAT_OPTS);
 632         if (opt & 0x1) { // -l
 633                 flags &= ~NETSTAT_CONNECTED;
 634                 flags |= NETSTAT_LISTENING;
 635         }
 636         if (opt & 0x2) flags |= NETSTAT_LISTENING | NETSTAT_CONNECTED; // -a
 637         //if (opt & 0x4) // -e
 638         if (opt & 0x8) flags |= NETSTAT_NUMERIC; // -n
 639         //if (opt & 0x10) // -t: NETSTAT_TCP
 640         //if (opt & 0x20) // -u: NETSTAT_UDP
 641         //if (opt & 0x40) // -w: NETSTAT_RAW
 642         //if (opt & 0x80) // -x: NETSTAT_UNIX
 643         if (opt & OPT_route) { // -r
 644 #if ENABLE_ROUTE
 645                 bb_displayroutes(flags & NETSTAT_NUMERIC, !(opt & OPT_extended));
 646                 return 0;
 647 #else
 648                 bb_show_usage();
 649 #endif
 650         }
 651         if (opt & OPT_wide) { // -W
 652                 net_conn_line = PRINT_NET_CONN_WIDE;
 653                 net_conn_line_header = PRINT_NET_CONN_HEADER_WIDE;
 654         }
 655 #if ENABLE_FEATURE_NETSTAT_PRG
 656         if (opt & OPT_prg) { // -p
 657                 prg_cache_load();
 658         }
 659 #endif
 660
 661         opt &= NETSTAT_ALLPROTO;
 662         if (opt) {
 663                 flags &= ~NETSTAT_ALLPROTO;
 664                 flags |= opt;
 665         }
 666         if (flags & (NETSTAT_TCP|NETSTAT_UDP|NETSTAT_RAW)) {
 667                 printf("Active Internet connections "); /* xxx */
 668
 669                 if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) == (NETSTAT_LISTENING|NETSTAT_CONNECTED))
 670                         printf("(servers and established)");
 671                 else if (flags & NETSTAT_LISTENING)
 672                         printf("(only servers)");
 673                 else
 674                         printf("(w/o servers)");
 675                 printf(net_conn_line_header, "Local Address", "Foreign Address");
 676                 print_progname_banner();
 677                 bb_putchar('\n');
 678         }
 679         if (flags & NETSTAT_TCP) {
 680                 do_info("/proc/net/tcp", tcp_do_one);
 681 #if ENABLE_FEATURE_IPV6
 682                 do_info("/proc/net/tcp6", tcp_do_one);
 683 #endif
 684         }
 685         if (flags & NETSTAT_UDP) {
 686                 do_info("/proc/net/udp", udp_do_one);
 687 #if ENABLE_FEATURE_IPV6
 688                 do_info("/proc/net/udp6", udp_do_one);
 689 #endif
 690         }
 691         if (flags & NETSTAT_RAW) {
 692                 do_info("/proc/net/raw", raw_do_one);
 693 #if ENABLE_FEATURE_IPV6
 694                 do_info("/proc/net/raw6", raw_do_one);
 695 #endif
 696         }
 697         if (flags & NETSTAT_UNIX) {
 698                 printf("Active UNIX domain sockets ");
 699                 if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) == (NETSTAT_LISTENING|NETSTAT_CONNECTED))
 700                         printf("(servers and established)");
 701                 else if (flags & NETSTAT_LISTENING)
 702                         printf("(only servers)");
 703                 else
 704                         printf("(w/o servers)");
 705                 printf("\nProto RefCnt Flags       Type       State         I-Node ");
 706                 print_progname_banner();
 707                 printf("Path\n");
 708                 do_info("/proc/net/unix", unix_do_one);
 709         }
 710         prg_cache_clear();
 711         return 0;
 712 }