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 source tree.
15  */
16 //config:config NETSTAT
17 //config:	bool "netstat (10 kb)"
18 //config:	default y
19 //config:	help
20 //config:	netstat prints information about the Linux networking subsystem.
21 //config:
22 //config:config FEATURE_NETSTAT_WIDE
23 //config:	bool "Enable wide output"
24 //config:	default y
25 //config:	depends on NETSTAT
26 //config:	help
27 //config:	Add support for wide columns. Useful when displaying IPv6 addresses
28 //config:	(-W option).
29 //config:
30 //config:config FEATURE_NETSTAT_PRG
31 //config:	bool "Enable PID/Program name output"
32 //config:	default y
33 //config:	depends on NETSTAT
34 //config:	help
35 //config:	Add support for -p flag to print out PID and program name.
36 //config:	+700 bytes of code.
37 
38 //applet:IF_NETSTAT(APPLET(netstat, BB_DIR_BIN, BB_SUID_DROP))
39 
40 //kbuild:lib-$(CONFIG_NETSTAT) += netstat.o
41 
42 #include "libbb.h"
43 #include "inet_common.h"
44 
45 //usage:#define netstat_trivial_usage
46 //usage:       "[-"IF_ROUTE("r")"al] [-tuwx] [-en"IF_FEATURE_NETSTAT_WIDE("W")IF_FEATURE_NETSTAT_PRG("p")"]"
47 //usage:#define netstat_full_usage "\n\n"
48 //usage:       "Display networking information\n"
49 //usage:	IF_ROUTE(
50 //usage:     "\n	-r	Routing table"
51 //usage:	)
52 //usage:     "\n	-a	All sockets"
53 //usage:     "\n	-l	Listening sockets"
54 //usage:     "\n		Else: connected sockets"
55 //usage:     "\n	-t	TCP sockets"
56 //usage:     "\n	-u	UDP sockets"
57 //usage:     "\n	-w	Raw sockets"
58 //usage:     "\n	-x	Unix sockets"
59 //usage:     "\n		Else: all socket types"
60 //usage:     "\n	-e	Other/more information"
61 //usage:     "\n	-n	Don't resolve names"
62 //usage:	IF_FEATURE_NETSTAT_WIDE(
63 //usage:     "\n	-W	Wide display"
64 //usage:	)
65 //usage:	IF_FEATURE_NETSTAT_PRG(
66 //usage:     "\n	-p	Show PID/program name for sockets"
67 //usage:	)
68 
69 #define NETSTAT_OPTS "laentuwx" \
70 	IF_ROUTE(               "r") \
71 	IF_FEATURE_NETSTAT_WIDE("W") \
72 	IF_FEATURE_NETSTAT_PRG( "p")
73 
74 enum {
75 	OPT_sock_listen = 1 << 0, // l
76 	OPT_sock_all    = 1 << 1, // a
77 	OPT_extended    = 1 << 2, // e
78 	OPT_noresolve   = 1 << 3, // n
79 	OPT_sock_tcp    = 1 << 4, // t
80 	OPT_sock_udp    = 1 << 5, // u
81 	OPT_sock_raw    = 1 << 6, // w
82 	OPT_sock_unix   = 1 << 7, // x
83 	OPTBIT_x        = 7,
84 	IF_ROUTE(               OPTBIT_ROUTE,)
85 	IF_FEATURE_NETSTAT_WIDE(OPTBIT_WIDE ,)
86 	IF_FEATURE_NETSTAT_PRG( OPTBIT_PRG  ,)
87 	OPT_route       = IF_ROUTE(               (1 << OPTBIT_ROUTE)) + 0, // r
88 	OPT_wide        = IF_FEATURE_NETSTAT_WIDE((1 << OPTBIT_WIDE )) + 0, // W
89 	OPT_prg         = IF_FEATURE_NETSTAT_PRG( (1 << OPTBIT_PRG  )) + 0, // p
90 };
91 
92 #define NETSTAT_CONNECTED 0x01
93 #define NETSTAT_LISTENING 0x02
94 #define NETSTAT_NUMERIC   0x04
95 /* Must match getopt32 option string */
96 #define NETSTAT_TCP       0x10
97 #define NETSTAT_UDP       0x20
98 #define NETSTAT_RAW       0x40
99 #define NETSTAT_UNIX      0x80
100 #define NETSTAT_ALLPROTO  (NETSTAT_TCP|NETSTAT_UDP|NETSTAT_RAW|NETSTAT_UNIX)
101 
102 
103 enum {
104 	TCP_ESTABLISHED = 1,
105 	TCP_SYN_SENT,
106 	TCP_SYN_RECV,
107 	TCP_FIN_WAIT1,
108 	TCP_FIN_WAIT2,
109 	TCP_TIME_WAIT,
110 	TCP_CLOSE,
111 	TCP_CLOSE_WAIT,
112 	TCP_LAST_ACK,
113 	TCP_LISTEN,
114 	TCP_CLOSING, /* now a valid state */
115 };
116 
117 static const char *const tcp_state[] ALIGN_PTR = {
118 	"",
119 	"ESTABLISHED",
120 	"SYN_SENT",
121 	"SYN_RECV",
122 	"FIN_WAIT1",
123 	"FIN_WAIT2",
124 	"TIME_WAIT",
125 	"CLOSE",
126 	"CLOSE_WAIT",
127 	"LAST_ACK",
128 	"LISTEN",
129 	"CLOSING"
130 };
131 
132 typedef enum {
133 	SS_FREE = 0,     /* not allocated                */
134 	SS_UNCONNECTED,  /* unconnected to any socket    */
135 	SS_CONNECTING,   /* in process of connecting     */
136 	SS_CONNECTED,    /* connected to socket          */
137 	SS_DISCONNECTING /* in process of disconnecting  */
138 } socket_state;
139 
140 #define SO_ACCEPTCON (1<<16)  /* performed a listen           */
141 #define SO_WAITDATA  (1<<17)  /* wait data to read            */
142 #define SO_NOSPACE   (1<<18)  /* no space to write            */
143 
144 #define ADDR_NORMAL_WIDTH        23
145 /* When there are IPv6 connections the IPv6 addresses will be
146  * truncated to none-recognition. The '-W' option makes the
147  * address columns wide enough to accommodate for longest possible
148  * IPv6 addresses, i.e. addresses of the form
149  * xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:ddd.ddd.ddd.ddd
150  */
151 #define ADDR_WIDE                51  /* INET6_ADDRSTRLEN + 5 for the port number */
152 #if ENABLE_FEATURE_NETSTAT_WIDE
153 # define FMT_NET_CONN_DATA       "%s   %6lu %6lu %-*s %-*s %-12s"
154 # define FMT_NET_CONN_HEADER     "\nProto Recv-Q Send-Q %-*s %-*s State       %s\n"
155 #else
156 # define FMT_NET_CONN_DATA       "%s   %6lu %6lu %-23s %-23s %-12s"
157 # define FMT_NET_CONN_HEADER     "\nProto Recv-Q Send-Q %-23s %-23s State       %s\n"
158 #endif
159 
160 #define PROGNAME_WIDTH     20
161 #define PROGNAME_WIDTH_STR "20"
162 /* PROGNAME_WIDTH chars: 12345678901234567890 */
163 #define PROGNAME_BANNER "PID/Program name    "
164 
165 struct prg_node {
166 	struct prg_node *next;
167 	long inode;
168 	char name[PROGNAME_WIDTH];
169 };
170 
171 #define PRG_HASH_SIZE 211
172 
173 struct globals {
174 	smalluint flags;
175 #if ENABLE_FEATURE_NETSTAT_PRG
176 	smallint prg_cache_loaded;
177 	struct prg_node *prg_hash[PRG_HASH_SIZE];
178 #endif
179 #if ENABLE_FEATURE_NETSTAT_PRG
180 	const char *progname_banner;
181 #endif
182 #if ENABLE_FEATURE_NETSTAT_WIDE
183 	unsigned addr_width;
184 #endif
185 };
186 #define G (*ptr_to_globals)
187 #define flags            (G.flags           )
188 #define prg_cache_loaded (G.prg_cache_loaded)
189 #define prg_hash         (G.prg_hash        )
190 #if ENABLE_FEATURE_NETSTAT_PRG
191 # define progname_banner (G.progname_banner )
192 #else
193 # define progname_banner ""
194 #endif
195 #define INIT_G() do { \
196 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
197 	flags = NETSTAT_CONNECTED | NETSTAT_ALLPROTO; \
198 } while (0)
199 
200 
201 #if ENABLE_FEATURE_NETSTAT_PRG
202 
203 /* Deliberately truncating long to unsigned *int* */
204 #define PRG_HASHIT(x) ((unsigned)(x) % PRG_HASH_SIZE)
205 
prg_cache_add(long inode,char * name)206 static void prg_cache_add(long inode, char *name)
207 {
208 	unsigned hi = PRG_HASHIT(inode);
209 	struct prg_node **pnp, *pn;
210 
211 	prg_cache_loaded = 2;
212 	for (pnp = prg_hash + hi; (pn = *pnp) != NULL; pnp = &pn->next) {
213 		if (pn->inode == inode) {
214 			/* Some warning should be appropriate here
215 			 * as we got multiple processes for one i-node */
216 			return;
217 		}
218 	}
219 	*pnp = xzalloc(sizeof(struct prg_node));
220 	pn = *pnp;
221 	pn->inode = inode;
222 	safe_strncpy(pn->name, name, PROGNAME_WIDTH);
223 }
224 
prg_cache_get(long inode)225 static const char *prg_cache_get(long inode)
226 {
227 	unsigned hi = PRG_HASHIT(inode);
228 	struct prg_node *pn;
229 
230 	for (pn = prg_hash[hi]; pn; pn = pn->next)
231 		if (pn->inode == inode)
232 			return pn->name;
233 	return "-";
234 }
235 
236 #if ENABLE_FEATURE_CLEAN_UP
prg_cache_clear(void)237 static void prg_cache_clear(void)
238 {
239 	struct prg_node **pnp, *pn;
240 
241 	for (pnp = prg_hash; pnp < prg_hash + PRG_HASH_SIZE; pnp++) {
242 		while ((pn = *pnp) != NULL) {
243 			*pnp = pn->next;
244 			free(pn);
245 		}
246 	}
247 }
248 #else
249 #define prg_cache_clear() ((void)0)
250 #endif
251 
extract_socket_inode(const char * lname)252 static long extract_socket_inode(const char *lname)
253 {
254 	long inode = -1;
255 
256 	if (is_prefixed_with(lname, "socket:[")) {
257 		/* "socket:[12345]", extract the "12345" as inode */
258 		inode = bb_strtoul(lname + sizeof("socket:[")-1, (char**)&lname, 0);
259 		if (*lname != ']')
260 			inode = -1;
261 	} else if (is_prefixed_with(lname, "[0000]:")) {
262 		/* "[0000]:12345", extract the "12345" as inode */
263 		inode = bb_strtoul(lname + sizeof("[0000]:")-1, NULL, 0);
264 		if (errno) /* not NUL terminated? */
265 			inode = -1;
266 	}
267 
268 #if 0 /* bb_strtol returns all-ones bit pattern on ERANGE anyway */
269 	if (errno == ERANGE)
270 		inode = -1;
271 #endif
272 	return inode;
273 }
274 
add_to_prg_cache_if_socket(struct recursive_state * state,const char * fileName,struct stat * statbuf UNUSED_PARAM)275 static int FAST_FUNC add_to_prg_cache_if_socket(struct recursive_state *state,
276 		const char *fileName,
277 		struct stat *statbuf UNUSED_PARAM)
278 {
279 	char *linkname;
280 	long inode;
281 
282 	linkname = xmalloc_readlink(fileName);
283 	if (linkname != NULL) {
284 		inode = extract_socket_inode(linkname);
285 		free(linkname);
286 		if (inode >= 0) {
287 			char *pid_slash_progname = state->userData;
288 			prg_cache_add(inode, pid_slash_progname);
289 		}
290 	}
291 	return TRUE;
292 }
293 
dir_act(struct recursive_state * state,const char * fileName,struct stat * statbuf UNUSED_PARAM)294 static int FAST_FUNC dir_act(struct recursive_state *state,
295 		const char *fileName,
296 		struct stat *statbuf UNUSED_PARAM)
297 {
298 	const char *pid;
299 	char *pid_slash_progname;
300 	char proc_pid_fname[sizeof("/proc/%u/cmdline") + sizeof(long)*3];
301 	char cmdline_buf[512];
302 	int n, len;
303 
304 	if (state->depth == 0) /* "/proc" itself */
305 		return TRUE; /* continue looking one level below /proc */
306 
307 	pid = fileName + sizeof("/proc/")-1; /* point after "/proc/" */
308 	if (!isdigit(pid[0])) /* skip /proc entries which aren't processes */
309 		return SKIP;
310 
311 	len = snprintf(proc_pid_fname, sizeof(proc_pid_fname), "%s/cmdline", fileName);
312 	n = open_read_close(proc_pid_fname, cmdline_buf, sizeof(cmdline_buf) - 1);
313 	if (n < 0)
314 		return FALSE;
315 	cmdline_buf[n] = '\0';
316 
317 	/* go through all files in /proc/PID/fd and check whether they are sockets */
318 	strcpy(proc_pid_fname + len - (sizeof("cmdline")-1), "fd");
319 	pid_slash_progname = concat_path_file(pid, bb_basename(cmdline_buf)); /* "PID/argv0" */
320 	n = recursive_action(proc_pid_fname,
321 			ACTION_RECURSE | ACTION_QUIET,
322 			add_to_prg_cache_if_socket,
323 			NULL,
324 			(void *)pid_slash_progname
325 	);
326 	free(pid_slash_progname);
327 
328 	if (!n)
329 		return FALSE; /* signal permissions error to caller */
330 
331 	return SKIP; /* caller should not recurse further into this dir */
332 }
333 
prg_cache_load(void)334 static void prg_cache_load(void)
335 {
336 	int load_ok;
337 
338 	prg_cache_loaded = 1;
339 	load_ok = recursive_action("/proc", ACTION_RECURSE | ACTION_QUIET,
340 				NULL, dir_act, NULL);
341 	if (load_ok)
342 		return;
343 
344 	if (prg_cache_loaded == 1)
345 		bb_simple_error_msg("can't scan /proc - are you root?");
346 	else
347 		bb_simple_error_msg("showing only processes with your user ID");
348 }
349 
350 #else
351 
352 #define prg_cache_clear()       ((void)0)
353 
354 #endif //ENABLE_FEATURE_NETSTAT_PRG
355 
356 
357 #if ENABLE_FEATURE_IPV6
build_ipv6_addr(char * local_addr,struct sockaddr_in6 * localaddr)358 static void build_ipv6_addr(char* local_addr, struct sockaddr_in6* localaddr)
359 {
360 	char addr6[INET6_ADDRSTRLEN];
361 	struct in6_addr in6;
362 
363 	sscanf(local_addr, "%08X%08X%08X%08X",
364 		   &in6.s6_addr32[0], &in6.s6_addr32[1],
365 		   &in6.s6_addr32[2], &in6.s6_addr32[3]);
366 	inet_ntop(AF_INET6, &in6, addr6, sizeof(addr6));
367 	inet_pton(AF_INET6, addr6, &localaddr->sin6_addr);
368 
369 	localaddr->sin6_family = AF_INET6;
370 }
371 #endif
372 
build_ipv4_addr(char * local_addr,struct sockaddr_in * localaddr)373 static void build_ipv4_addr(char* local_addr, struct sockaddr_in* localaddr)
374 {
375 	sscanf(local_addr, "%X", &localaddr->sin_addr.s_addr);
376 	localaddr->sin_family = AF_INET;
377 }
378 
get_sname(int port,const char * proto,int numeric)379 static const char *get_sname(int port, const char *proto, int numeric)
380 {
381 	if (!port)
382 		return "*";
383 	if (!numeric) {
384 		struct servent *se = getservbyport(port, proto);
385 		if (se)
386 			return se->s_name;
387 	}
388 	/* hummm, we may return static buffer here!! */
389 	return itoa(ntohs(port));
390 }
391 
ip_port_str(struct sockaddr * addr,int port,const char * proto,int numeric)392 static char *ip_port_str(struct sockaddr *addr, int port, const char *proto, int numeric)
393 {
394 	char *host, *host_port;
395 
396 	/* Code which used "*" for INADDR_ANY is removed: it's ambiguous
397 	 * in IPv6, while "0.0.0.0" is not. */
398 
399 	host = NULL;
400 	if (!numeric)
401 		host = xmalloc_sockaddr2host_noport(addr);
402 	if (!host)
403 		host = xmalloc_sockaddr2dotted_noport(addr);
404 
405 	host_port = xasprintf("%s:%s", host, get_sname(htons(port), proto, numeric));
406 	free(host);
407 	return host_port;
408 }
409 
410 struct inet_params {
411 	int local_port, rem_port, state, uid;
412 	union {
413 		struct sockaddr     sa;
414 		struct sockaddr_in  sin;
415 #if ENABLE_FEATURE_IPV6
416 		struct sockaddr_in6 sin6;
417 #endif
418 	} localaddr, remaddr;
419 	unsigned long rxq, txq, inode;
420 };
421 
scan_inet_proc_line(struct inet_params * param,char * line)422 static int scan_inet_proc_line(struct inet_params *param, char *line)
423 {
424 	int num;
425 	/* IPv6 /proc files use 32-char hex representation
426 	 * of IPv6 address, followed by :PORT_IN_HEX
427 	 */
428 	char local_addr[33], rem_addr[33]; /* 32 + 1 for NUL */
429 
430 	num = sscanf(line,
431 			"%*d: %32[0-9A-Fa-f]:%X "
432 			"%32[0-9A-Fa-f]:%X %X "
433 			"%lX:%lX %*X:%*X "
434 			"%*X %d %*d %lu ",
435 			local_addr, &param->local_port,
436 			rem_addr, &param->rem_port, &param->state,
437 			&param->txq, &param->rxq,
438 			&param->uid, &param->inode);
439 	if (num < 9) {
440 		return 1; /* error */
441 	}
442 
443 	if (strlen(local_addr) > 8) {
444 #if ENABLE_FEATURE_IPV6
445 		build_ipv6_addr(local_addr, &param->localaddr.sin6);
446 		build_ipv6_addr(rem_addr, &param->remaddr.sin6);
447 #endif
448 	} else {
449 		build_ipv4_addr(local_addr, &param->localaddr.sin);
450 		build_ipv4_addr(rem_addr, &param->remaddr.sin);
451 	}
452 	return 0;
453 }
454 
print_inet_line(struct inet_params * param,const char * state_str,const char * proto,int is_connected)455 static void print_inet_line(struct inet_params *param,
456 		const char *state_str, const char *proto, int is_connected)
457 {
458 	if ((is_connected && (flags & NETSTAT_CONNECTED))
459 	 || (!is_connected && (flags & NETSTAT_LISTENING))
460 	) {
461 		char *l = ip_port_str(
462 				&param->localaddr.sa, param->local_port,
463 				proto, flags & NETSTAT_NUMERIC);
464 		char *r = ip_port_str(
465 				&param->remaddr.sa, param->rem_port,
466 				proto, flags & NETSTAT_NUMERIC);
467 		printf(FMT_NET_CONN_DATA,
468 			proto, param->rxq, param->txq,
469 			IF_FEATURE_NETSTAT_WIDE(G.addr_width,) l,
470 			IF_FEATURE_NETSTAT_WIDE(G.addr_width,) r,
471 			state_str);
472 #if ENABLE_FEATURE_NETSTAT_PRG
473 		if (option_mask32 & OPT_prg)
474 			printf("%."PROGNAME_WIDTH_STR"s", prg_cache_get(param->inode));
475 #endif
476 		bb_putchar('\n');
477 		free(l);
478 		free(r);
479 	}
480 }
481 
tcp_do_one(char * line)482 static int FAST_FUNC tcp_do_one(char *line)
483 {
484 	struct inet_params param;
485 
486 	memset(&param, 0, sizeof(param));
487 	if (scan_inet_proc_line(&param, line))
488 		return 1;
489 
490 	print_inet_line(&param, tcp_state[param.state], "tcp", param.rem_port);
491 	return 0;
492 }
493 
494 #if ENABLE_FEATURE_IPV6
495 # define NOT_NULL_ADDR(A) ( \
496 	( (A.sa.sa_family == AF_INET6) \
497 	  && (A.sin6.sin6_addr.s6_addr32[0] | A.sin6.sin6_addr.s6_addr32[1] | \
498 	      A.sin6.sin6_addr.s6_addr32[2] | A.sin6.sin6_addr.s6_addr32[3])  \
499 	) || ( \
500 	  (A.sa.sa_family == AF_INET) \
501 	  && A.sin.sin_addr.s_addr != 0 \
502 	) \
503 )
504 #else
505 # define NOT_NULL_ADDR(A) (A.sin.sin_addr.s_addr)
506 #endif
507 
udp_do_one(char * line)508 static int FAST_FUNC udp_do_one(char *line)
509 {
510 	int have_remaddr;
511 	const char *state_str;
512 	struct inet_params param;
513 
514 	memset(&param, 0, sizeof(param)); /* otherwise we display garbage IPv6 scope_ids */
515 	if (scan_inet_proc_line(&param, line))
516 		return 1;
517 
518 	state_str = "UNKNOWN";
519 	switch (param.state) {
520 	case TCP_ESTABLISHED:
521 		state_str = "ESTABLISHED";
522 		break;
523 	case TCP_CLOSE:
524 		state_str = "";
525 		break;
526 	}
527 
528 	have_remaddr = NOT_NULL_ADDR(param.remaddr);
529 	print_inet_line(&param, state_str, "udp", have_remaddr);
530 	return 0;
531 }
532 
raw_do_one(char * line)533 static int FAST_FUNC raw_do_one(char *line)
534 {
535 	int have_remaddr;
536 	struct inet_params param;
537 
538 	if (scan_inet_proc_line(&param, line))
539 		return 1;
540 
541 	have_remaddr = NOT_NULL_ADDR(param.remaddr);
542 	print_inet_line(&param, itoa(param.state), "raw", have_remaddr);
543 	return 0;
544 }
545 
unix_do_one(char * line)546 static int FAST_FUNC unix_do_one(char *line)
547 {
548 	unsigned long refcnt, proto, unix_flags;
549 	unsigned long inode;
550 	int type, state;
551 	int num, path_ofs;
552 	const char *ss_proto, *ss_state, *ss_type;
553 	char ss_flags[32];
554 
555 	/* 2.6.15 may report lines like "... @/tmp/fam-user-^@^@^@^@^@^@^@..."
556 	 * Other users report long lines filled by NUL bytes.
557 	 * (those ^@ are NUL bytes too). We see them as empty lines. */
558 	if (!line[0])
559 		return 0;
560 
561 	path_ofs = 0; /* paranoia */
562 	num = sscanf(line, "%*p: %lX %lX %lX %X %X %lu %n",
563 			&refcnt, &proto, &unix_flags, &type, &state, &inode, &path_ofs);
564 	if (num < 6) {
565 		return 1; /* error */
566 	}
567 	if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) != (NETSTAT_LISTENING|NETSTAT_CONNECTED)) {
568 		if ((state == SS_UNCONNECTED) && (unix_flags & SO_ACCEPTCON)) {
569 			if (!(flags & NETSTAT_LISTENING))
570 				return 0;
571 		} else {
572 			if (!(flags & NETSTAT_CONNECTED))
573 				return 0;
574 		}
575 	}
576 
577 	switch (proto) {
578 		case 0:
579 			ss_proto = "unix";
580 			break;
581 		default:
582 			ss_proto = "??";
583 	}
584 
585 	switch (type) {
586 		case SOCK_STREAM:
587 			ss_type = "STREAM";
588 			break;
589 		case SOCK_DGRAM:
590 			ss_type = "DGRAM";
591 			break;
592 		case SOCK_RAW:
593 			ss_type = "RAW";
594 			break;
595 		case SOCK_RDM:
596 			ss_type = "RDM";
597 			break;
598 		case SOCK_SEQPACKET:
599 			ss_type = "SEQPACKET";
600 			break;
601 		default:
602 			ss_type = "UNKNOWN";
603 	}
604 
605 	switch (state) {
606 		case SS_FREE:
607 			ss_state = "FREE";
608 			break;
609 		case SS_UNCONNECTED:
610 			/*
611 			 * Unconnected sockets may be listening
612 			 * for something.
613 			 */
614 			if (unix_flags & SO_ACCEPTCON) {
615 				ss_state = "LISTENING";
616 			} else {
617 				ss_state = "";
618 			}
619 			break;
620 		case SS_CONNECTING:
621 			ss_state = "CONNECTING";
622 			break;
623 		case SS_CONNECTED:
624 			ss_state = "CONNECTED";
625 			break;
626 		case SS_DISCONNECTING:
627 			ss_state = "DISCONNECTING";
628 			break;
629 		default:
630 			ss_state = "UNKNOWN";
631 	}
632 
633 	strcpy(ss_flags, "[ ");
634 	if (unix_flags & SO_ACCEPTCON)
635 		strcat(ss_flags, "ACC ");
636 	if (unix_flags & SO_WAITDATA)
637 		strcat(ss_flags, "W ");
638 	if (unix_flags & SO_NOSPACE)
639 		strcat(ss_flags, "N ");
640 	strcat(ss_flags, "]");
641 
642 	printf("%-5s %-6lu %-11s %-10s %-13s %6lu ",
643 		ss_proto, refcnt, ss_flags, ss_type, ss_state, inode
644 		);
645 
646 #if ENABLE_FEATURE_NETSTAT_PRG
647 	if (option_mask32 & OPT_prg)
648 		printf("%-"PROGNAME_WIDTH_STR"s", prg_cache_get(inode));
649 #endif
650 
651 	/* TODO: currently we stop at first NUL byte. Is it a problem? */
652 	line += path_ofs;
653 	chomp(line);
654 	while (*line)
655 		fputc_printable(*line++, stdout);
656 	bb_putchar('\n');
657 	return 0;
658 }
659 
do_info(const char * file,int FAST_FUNC (* proc)(char *))660 static void do_info(const char *file, int FAST_FUNC (*proc)(char *))
661 {
662 	int lnr;
663 	FILE *procinfo;
664 	char *buffer;
665 
666 	/* _stdin is just to save "r" param */
667 	procinfo = fopen_or_warn_stdin(file);
668 	if (procinfo == NULL) {
669 		return;
670 	}
671 	lnr = 0;
672 	/* Why xmalloc_fgets_str? because it doesn't stop on NULs */
673 	while ((buffer = xmalloc_fgets_str(procinfo, "\n")) != NULL) {
674 		/* line 0 is skipped */
675 		if (lnr && proc(buffer))
676 			bb_error_msg("%s: bogus data on line %d", file, lnr + 1);
677 		lnr++;
678 		free(buffer);
679 	}
680 	fclose(procinfo);
681 }
682 
683 int netstat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
netstat_main(int argc UNUSED_PARAM,char ** argv)684 int netstat_main(int argc UNUSED_PARAM, char **argv)
685 {
686 	unsigned opt;
687 
688 	INIT_G();
689 
690 	/* Option string must match NETSTAT_xxx constants */
691 	opt = getopt32(argv, NETSTAT_OPTS);
692 	if (opt & OPT_sock_listen) { // -l
693 		flags &= ~NETSTAT_CONNECTED;
694 		flags |= NETSTAT_LISTENING;
695 	}
696 	if (opt & OPT_sock_all) flags |= NETSTAT_LISTENING | NETSTAT_CONNECTED; // -a
697 	//if (opt & OPT_extended) // -e
698 	if (opt & OPT_noresolve) flags |= NETSTAT_NUMERIC; // -n
699 	//if (opt & OPT_sock_tcp) // -t: NETSTAT_TCP
700 	//if (opt & OPT_sock_udp) // -u: NETSTAT_UDP
701 	//if (opt & OPT_sock_raw) // -w: NETSTAT_RAW
702 	//if (opt & OPT_sock_unix) // -x: NETSTAT_UNIX
703 #if ENABLE_ROUTE
704 	if (opt & OPT_route) { // -r
705 		bb_displayroutes(flags & NETSTAT_NUMERIC, !(opt & OPT_extended));
706 		return 0;
707 	}
708 #endif
709 #if ENABLE_FEATURE_NETSTAT_WIDE
710 	G.addr_width = ADDR_NORMAL_WIDTH;
711 	if (opt & OPT_wide) { // -W
712 		G.addr_width = ADDR_WIDE;
713 	}
714 #endif
715 #if ENABLE_FEATURE_NETSTAT_PRG
716 	progname_banner = "";
717 	if (opt & OPT_prg) { // -p
718 		progname_banner = PROGNAME_BANNER;
719 		prg_cache_load();
720 	}
721 #endif
722 
723 	opt &= NETSTAT_ALLPROTO;
724 	if (opt) {
725 		flags &= ~NETSTAT_ALLPROTO;
726 		flags |= opt;
727 	}
728 	if (flags & (NETSTAT_TCP|NETSTAT_UDP|NETSTAT_RAW)) {
729 		printf("Active Internet connections "); /* xxx */
730 
731 		if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) == (NETSTAT_LISTENING|NETSTAT_CONNECTED))
732 			printf("(servers and established)");
733 		else if (flags & NETSTAT_LISTENING)
734 			printf("(only servers)");
735 		else
736 			printf("(w/o servers)");
737 		printf(FMT_NET_CONN_HEADER,
738 				IF_FEATURE_NETSTAT_WIDE(G.addr_width,) "Local Address",
739 				IF_FEATURE_NETSTAT_WIDE(G.addr_width,) "Foreign Address",
740 				progname_banner
741 		);
742 	}
743 	if (flags & NETSTAT_TCP) {
744 		do_info("/proc/net/tcp", tcp_do_one);
745 #if ENABLE_FEATURE_IPV6
746 		do_info("/proc/net/tcp6", tcp_do_one);
747 #endif
748 	}
749 	if (flags & NETSTAT_UDP) {
750 		do_info("/proc/net/udp", udp_do_one);
751 #if ENABLE_FEATURE_IPV6
752 		do_info("/proc/net/udp6", udp_do_one);
753 #endif
754 	}
755 	if (flags & NETSTAT_RAW) {
756 		do_info("/proc/net/raw", raw_do_one);
757 #if ENABLE_FEATURE_IPV6
758 		do_info("/proc/net/raw6", raw_do_one);
759 #endif
760 	}
761 	if (flags & NETSTAT_UNIX) {
762 		printf("Active UNIX domain sockets ");
763 		if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) == (NETSTAT_LISTENING|NETSTAT_CONNECTED))
764 			printf("(servers and established)");
765 		else if (flags & NETSTAT_LISTENING)
766 			printf("(only servers)");
767 		else
768 			printf("(w/o servers)");
769 		printf("\nProto RefCnt Flags       Type       State         I-Node %sPath\n", progname_banner);
770 		do_info("/proc/net/unix", unix_do_one);
771 	}
772 	prg_cache_clear();
773 	return 0;
774 }
775