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 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
12 */
13
14#include "libbb.h"
15#include "inet_common.h"
16
17enum {
18	OPT_extended = 0x4,
19	OPT_showroute = 0x100,
20	OPT_widedisplay = 0x200 * ENABLE_FEATURE_NETSTAT_WIDE,
21};
22# define NETSTAT_OPTS "laentuwxr"USE_FEATURE_NETSTAT_WIDE("W")
23
24#define NETSTAT_CONNECTED 0x01
25#define NETSTAT_LISTENING 0x02
26#define NETSTAT_NUMERIC   0x04
27/* Must match getopt32 option string */
28#define NETSTAT_TCP       0x10
29#define NETSTAT_UDP       0x20
30#define NETSTAT_RAW       0x40
31#define NETSTAT_UNIX      0x80
32#define NETSTAT_ALLPROTO  (NETSTAT_TCP|NETSTAT_UDP|NETSTAT_RAW|NETSTAT_UNIX)
33
34static smallint flags = NETSTAT_CONNECTED | NETSTAT_ALLPROTO;
35
36enum {
37	TCP_ESTABLISHED = 1,
38	TCP_SYN_SENT,
39	TCP_SYN_RECV,
40	TCP_FIN_WAIT1,
41	TCP_FIN_WAIT2,
42	TCP_TIME_WAIT,
43	TCP_CLOSE,
44	TCP_CLOSE_WAIT,
45	TCP_LAST_ACK,
46	TCP_LISTEN,
47	TCP_CLOSING /* now a valid state */
48};
49
50static const char *const tcp_state[] = {
51	"",
52	"ESTABLISHED",
53	"SYN_SENT",
54	"SYN_RECV",
55	"FIN_WAIT1",
56	"FIN_WAIT2",
57	"TIME_WAIT",
58	"CLOSE",
59	"CLOSE_WAIT",
60	"LAST_ACK",
61	"LISTEN",
62	"CLOSING"
63};
64
65typedef enum {
66	SS_FREE = 0,     /* not allocated                */
67	SS_UNCONNECTED,  /* unconnected to any socket    */
68	SS_CONNECTING,   /* in process of connecting     */
69	SS_CONNECTED,    /* connected to socket          */
70	SS_DISCONNECTING /* in process of disconnecting  */
71} socket_state;
72
73#define SO_ACCEPTCON (1<<16)	/* performed a listen           */
74#define SO_WAITDATA  (1<<17)	/* wait data to read            */
75#define SO_NOSPACE   (1<<18)	/* no space to write            */
76
77/* Standard printout size */
78#define PRINT_IP_MAX_SIZE           23
79#define PRINT_NET_CONN              "%s   %6ld %6ld %-23s %-23s %-12s\n"
80#define PRINT_NET_CONN_HEADER       "\nProto Recv-Q Send-Q %-23s %-23s State\n"
81
82#define PRINT_IP_MAX_SIZE_WIDE      51  /* INET6_ADDRSTRLEN + 5 for the port number */
83#define PRINT_NET_CONN_WIDE         "%s   %6ld %6ld %-51s %-51s %-12s\n"
84#define PRINT_NET_CONN_HEADER_WIDE  "\nProto Recv-Q Send-Q %-51s %-51s State\n"
85
86static const char *net_conn_line = PRINT_NET_CONN;
87
88
89#if ENABLE_FEATURE_IPV6
90static void build_ipv6_addr(char* local_addr, struct sockaddr_in6* localaddr)
91{
92	char addr6[INET6_ADDRSTRLEN];
93	struct in6_addr in6;
94
95	sscanf(local_addr, "%08X%08X%08X%08X",
96		   &in6.s6_addr32[0], &in6.s6_addr32[1],
97		   &in6.s6_addr32[2], &in6.s6_addr32[3]);
98	inet_ntop(AF_INET6, &in6, addr6, sizeof(addr6));
99	inet_pton(AF_INET6, addr6, (struct sockaddr *) &localaddr->sin6_addr);
100
101	localaddr->sin6_family = AF_INET6;
102}
103#endif
104
105#if ENABLE_FEATURE_IPV6
106static void build_ipv4_addr(char* local_addr, struct sockaddr_in6* localaddr)
107#else
108static void build_ipv4_addr(char* local_addr, struct sockaddr_in* localaddr)
109#endif
110{
111	sscanf(local_addr, "%X",
112		   &((struct sockaddr_in *) localaddr)->sin_addr.s_addr);
113	((struct sockaddr *) localaddr)->sa_family = AF_INET;
114}
115
116static const char *get_sname(int port, const char *proto, int numeric)
117{
118	if (!port)
119		return "*";
120	if (!numeric) {
121		struct servent *se = getservbyport(port, proto);
122		if (se)
123			return se->s_name;
124	}
125	/* hummm, we may return static buffer here!! */
126	return itoa(ntohs(port));
127}
128
129static char *ip_port_str(struct sockaddr *addr, int port, const char *proto, int numeric)
130{
131	enum { salen = USE_FEATURE_IPV6(sizeof(struct sockaddr_in6)) SKIP_FEATURE_IPV6(sizeof(struct sockaddr_in)) };
132	char *host, *host_port;
133
134	/* Code which used "*" for INADDR_ANY is removed: it's ambiguous in IPv6,
135	 * while "0.0.0.0" is not. */
136
137	host = numeric ? xmalloc_sockaddr2dotted_noport(addr)
138	               : xmalloc_sockaddr2host_noport(addr);
139
140	host_port = xasprintf("%s:%s", host, get_sname(htons(port), proto, numeric));
141	free(host);
142	return host_port;
143}
144
145static void tcp_do_one(int lnr, const char *line)
146{
147	char local_addr[64], rem_addr[64];
148	char more[512];
149	int num, local_port, rem_port, d, state, timer_run, uid, timeout;
150#if ENABLE_FEATURE_IPV6
151	struct sockaddr_in6 localaddr, remaddr;
152#else
153	struct sockaddr_in localaddr, remaddr;
154#endif
155	unsigned long rxq, txq, time_len, retr, inode;
156
157	if (lnr == 0)
158		return;
159
160	more[0] = '\0';
161	num = sscanf(line,
162			"%d: %64[0-9A-Fa-f]:%X %64[0-9A-Fa-f]:%X %X %lX:%lX %X:%lX %lX %d %d %ld %512s\n",
163			&d, local_addr, &local_port,
164			rem_addr, &rem_port, &state,
165			&txq, &rxq, &timer_run, &time_len, &retr, &uid, &timeout, &inode, more);
166
167	if (strlen(local_addr) > 8) {
168#if ENABLE_FEATURE_IPV6
169		build_ipv6_addr(local_addr, &localaddr);
170		build_ipv6_addr(rem_addr, &remaddr);
171#endif
172	} else {
173		build_ipv4_addr(local_addr, &localaddr);
174		build_ipv4_addr(rem_addr, &remaddr);
175	}
176
177	if (num < 10) {
178		bb_error_msg("warning, got bogus tcp line");
179		return;
180	}
181
182	if ((rem_port && (flags & NETSTAT_CONNECTED))
183	 || (!rem_port && (flags & NETSTAT_LISTENING))
184	) {
185		char *l = ip_port_str(
186				(struct sockaddr *) &localaddr, local_port,
187				"tcp", flags & NETSTAT_NUMERIC);
188		char *r = ip_port_str(
189				(struct sockaddr *) &remaddr, rem_port,
190				"tcp", flags & NETSTAT_NUMERIC);
191		printf(net_conn_line,
192			"tcp", rxq, txq, l, r, tcp_state[state]);
193		free(l);
194		free(r);
195	}
196}
197
198static void udp_do_one(int lnr, const char *line)
199{
200	char local_addr[64], rem_addr[64];
201	const char *state_str;
202	char more[512];
203	int num, local_port, rem_port, d, state, timer_run, uid, timeout;
204#if ENABLE_FEATURE_IPV6
205	struct sockaddr_in6 localaddr, remaddr;
206#else
207	struct sockaddr_in localaddr, remaddr;
208#endif
209	unsigned long rxq, txq, time_len, retr, inode;
210
211	if (lnr == 0)
212		return;
213
214	more[0] = '\0';
215	num = sscanf(line,
216			"%d: %64[0-9A-Fa-f]:%X %64[0-9A-Fa-f]:%X %X %lX:%lX %X:%lX %lX %d %d %ld %512s\n",
217			&d, local_addr, &local_port,
218			rem_addr, &rem_port, &state,
219			&txq, &rxq, &timer_run, &time_len, &retr, &uid, &timeout, &inode, more);
220
221	if (strlen(local_addr) > 8) {
222#if ENABLE_FEATURE_IPV6
223		/* Demangle what the kernel gives us */
224		build_ipv6_addr(local_addr, &localaddr);
225		build_ipv6_addr(rem_addr, &remaddr);
226#endif
227	} else {
228		build_ipv4_addr(local_addr, &localaddr);
229		build_ipv4_addr(rem_addr, &remaddr);
230	}
231
232	if (num < 10) {
233		bb_error_msg("warning, got bogus udp line");
234		return;
235	}
236	switch (state) {
237		case TCP_ESTABLISHED:
238			state_str = "ESTABLISHED";
239			break;
240		case TCP_CLOSE:
241			state_str = "";
242			break;
243		default:
244			state_str = "UNKNOWN";
245			break;
246	}
247
248#if ENABLE_FEATURE_IPV6
249# define notnull(A) ( \
250	( (A.sin6_family == AF_INET6)                               \
251	  && (A.sin6_addr.s6_addr32[0] | A.sin6_addr.s6_addr32[1] | \
252	      A.sin6_addr.s6_addr32[2] | A.sin6_addr.s6_addr32[3])  \
253	) || (                                                      \
254	  (A.sin6_family == AF_INET)                                \
255	  && ((struct sockaddr_in*)&A)->sin_addr.s_addr             \
256	)                                                           \
257)
258#else
259# define notnull(A) (A.sin_addr.s_addr)
260#endif
261	{
262		int have_remaddr = notnull(remaddr);
263		if ((have_remaddr && (flags & NETSTAT_CONNECTED))
264		 || (!have_remaddr && (flags & NETSTAT_LISTENING))
265		) {
266			char *l = ip_port_str(
267				(struct sockaddr *) &localaddr, local_port,
268				"udp", flags & NETSTAT_NUMERIC);
269			char *r = ip_port_str(
270				(struct sockaddr *) &remaddr, rem_port,
271				"udp", flags & NETSTAT_NUMERIC);
272			printf(net_conn_line,
273				"udp", rxq, txq, l, r, state_str);
274			free(l);
275			free(r);
276		}
277	}
278}
279
280static void raw_do_one(int lnr, const char *line)
281{
282	char local_addr[64], rem_addr[64];
283	char more[512];
284	int num, local_port, rem_port, d, state, timer_run, uid, timeout;
285#if ENABLE_FEATURE_IPV6
286	struct sockaddr_in6 localaddr, remaddr;
287#else
288	struct sockaddr_in localaddr, remaddr;
289#endif
290	unsigned long rxq, txq, time_len, retr, inode;
291
292	if (lnr == 0)
293		return;
294
295	more[0] = '\0';
296	num = sscanf(line,
297			"%d: %64[0-9A-Fa-f]:%X %64[0-9A-Fa-f]:%X %X %lX:%lX %X:%lX %lX %d %d %ld %512s\n",
298			&d, local_addr, &local_port,
299			rem_addr, &rem_port, &state,
300			&txq, &rxq, &timer_run, &time_len, &retr, &uid, &timeout, &inode, more);
301
302	if (strlen(local_addr) > 8) {
303#if ENABLE_FEATURE_IPV6
304		build_ipv6_addr(local_addr, &localaddr);
305		build_ipv6_addr(rem_addr, &remaddr);
306#endif
307	} else {
308		build_ipv4_addr(local_addr, &localaddr);
309		build_ipv4_addr(rem_addr, &remaddr);
310	}
311
312	if (num < 10) {
313		bb_error_msg("warning, got bogus raw line");
314		return;
315	}
316
317	{
318		int have_remaddr = notnull(remaddr);
319		if ((have_remaddr && (flags & NETSTAT_CONNECTED))
320		 || (!have_remaddr && (flags & NETSTAT_LISTENING))
321		) {
322			char *l = ip_port_str(
323				(struct sockaddr *) &localaddr, local_port,
324				"raw", flags & NETSTAT_NUMERIC);
325			char *r = ip_port_str(
326				(struct sockaddr *) &remaddr, rem_port,
327				"raw", flags & NETSTAT_NUMERIC);
328			printf(net_conn_line,
329				"raw", rxq, txq, l, r, itoa(state));
330			free(l);
331			free(r);
332		}
333	}
334}
335
336static void unix_do_one(int nr, const char *line)
337{
338	static smallint has_inode = 0;
339
340	char path[PATH_MAX], ss_flags[32];
341	const char *ss_proto, *ss_state, *ss_type;
342	int num, state, type, inode;
343	void *d;
344	unsigned long refcnt, proto, unix_flags;
345
346	if (nr == 0) {
347		if (strstr(line, "Inode"))
348			has_inode = 1;
349		return;
350	}
351	path[0] = '\0';
352	num = sscanf(line, "%p: %lX %lX %lX %X %X %d %s",
353			&d, &refcnt, &proto, &unix_flags, &type, &state, &inode, path);
354	if (num < 6) {
355		bb_error_msg("warning, got bogus unix line");
356		return;
357	}
358	if (!has_inode)
359		sprintf(path, "%d", inode);
360
361	if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) != (NETSTAT_LISTENING|NETSTAT_CONNECTED)) {
362		if ((state == SS_UNCONNECTED) && (unix_flags & SO_ACCEPTCON)) {
363			if (!(flags & NETSTAT_LISTENING))
364				return;
365		} else {
366			if (!(flags & NETSTAT_CONNECTED))
367				return;
368		}
369	}
370
371	switch (proto) {
372		case 0:
373			ss_proto = "unix";
374			break;
375		default:
376			ss_proto = "??";
377	}
378
379	switch (type) {
380		case SOCK_STREAM:
381			ss_type = "STREAM";
382			break;
383		case SOCK_DGRAM:
384			ss_type = "DGRAM";
385			break;
386		case SOCK_RAW:
387			ss_type = "RAW";
388			break;
389		case SOCK_RDM:
390			ss_type = "RDM";
391			break;
392		case SOCK_SEQPACKET:
393			ss_type = "SEQPACKET";
394			break;
395		default:
396			ss_type = "UNKNOWN";
397	}
398
399	switch (state) {
400		case SS_FREE:
401			ss_state = "FREE";
402			break;
403		case SS_UNCONNECTED:
404			/*
405			 * Unconnected sockets may be listening
406			 * for something.
407			 */
408			if (unix_flags & SO_ACCEPTCON) {
409				ss_state = "LISTENING";
410			} else {
411				ss_state = "";
412			}
413			break;
414		case SS_CONNECTING:
415			ss_state = "CONNECTING";
416			break;
417		case SS_CONNECTED:
418			ss_state = "CONNECTED";
419			break;
420		case SS_DISCONNECTING:
421			ss_state = "DISCONNECTING";
422			break;
423		default:
424			ss_state = "UNKNOWN";
425	}
426
427	strcpy(ss_flags, "[ ");
428	if (unix_flags & SO_ACCEPTCON)
429		strcat(ss_flags, "ACC ");
430	if (unix_flags & SO_WAITDATA)
431		strcat(ss_flags, "W ");
432	if (unix_flags & SO_NOSPACE)
433		strcat(ss_flags, "N ");
434	strcat(ss_flags, "]");
435
436	printf("%-5s %-6ld %-11s %-10s %-13s ",
437		   ss_proto, refcnt, ss_flags, ss_type, ss_state);
438	if (has_inode)
439		printf("%-6d ", inode);
440	else
441		printf("-      ");
442	puts(path);
443}
444
445#define _PATH_PROCNET_UDP "/proc/net/udp"
446#define _PATH_PROCNET_UDP6 "/proc/net/udp6"
447#define _PATH_PROCNET_TCP "/proc/net/tcp"
448#define _PATH_PROCNET_TCP6 "/proc/net/tcp6"
449#define _PATH_PROCNET_RAW "/proc/net/raw"
450#define _PATH_PROCNET_RAW6 "/proc/net/raw6"
451#define _PATH_PROCNET_UNIX "/proc/net/unix"
452
453static void do_info(const char *file, const char *name, void (*proc)(int, const char *))
454{
455	int lnr = 0;
456	FILE *procinfo;
457
458	procinfo = fopen(file, "r");
459	if (procinfo == NULL) {
460		if (errno != ENOENT) {
461			bb_perror_msg("%s", file);
462		} else {
463			bb_error_msg("no support for '%s' on this system", name);
464		}
465		return;
466	}
467	do {
468		char *buffer = xmalloc_fgets(procinfo);
469		if (buffer) {
470			(proc)(lnr++, buffer);
471			free(buffer);
472		}
473	} while (!feof(procinfo));
474	fclose(procinfo);
475}
476
477/*
478 * Our main function.
479 */
480
481int netstat_main(int argc, char **argv);
482int netstat_main(int argc, char **argv)
483{
484	const char *net_conn_line_header = PRINT_NET_CONN_HEADER;
485	unsigned opt;
486#if ENABLE_FEATURE_IPV6
487	smallint inet = 1;
488	smallint inet6 = 1;
489#else
490	enum { inet = 1, inet6 = 0 };
491#endif
492
493	/* Option string must match NETSTAT_xxx constants */
494	opt = getopt32(argv, NETSTAT_OPTS);
495	if (opt & 0x1) { // -l
496		flags &= ~NETSTAT_CONNECTED;
497		flags |= NETSTAT_LISTENING;
498	}
499	if (opt & 0x2) flags |= NETSTAT_LISTENING | NETSTAT_CONNECTED; // -a
500	//if (opt & 0x4) // -e
501	if (opt & 0x8) flags |= NETSTAT_NUMERIC; // -n
502	//if (opt & 0x10) // -t: NETSTAT_TCP
503	//if (opt & 0x20) // -u: NETSTAT_UDP
504	//if (opt & 0x40) // -w: NETSTAT_RAW
505	//if (opt & 0x80) // -x: NETSTAT_UNIX
506	if (opt & OPT_showroute) { // -r
507#if ENABLE_ROUTE
508		bb_displayroutes(flags & NETSTAT_NUMERIC, !(opt & OPT_extended));
509		return 0;
510#else
511		bb_show_usage();
512#endif
513	}
514
515	if (opt & OPT_widedisplay) { // -W
516		net_conn_line = PRINT_NET_CONN_WIDE;
517		net_conn_line_header = PRINT_NET_CONN_HEADER_WIDE;
518	}
519
520	opt &= NETSTAT_ALLPROTO;
521	if (opt) {
522		flags &= ~NETSTAT_ALLPROTO;
523		flags |= opt;
524	}
525	if (flags & (NETSTAT_TCP|NETSTAT_UDP|NETSTAT_RAW)) {
526		printf("Active Internet connections ");
527
528		if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) == (NETSTAT_LISTENING|NETSTAT_CONNECTED))
529			printf("(servers and established)");
530		else if (flags & NETSTAT_LISTENING)
531			printf("(only servers)");
532		else
533			printf("(w/o servers)");
534		printf(net_conn_line_header, "Local Address", "Foreign Address");
535	}
536	if (inet && flags & NETSTAT_TCP)
537		do_info(_PATH_PROCNET_TCP, "AF INET (tcp)", tcp_do_one);
538#if ENABLE_FEATURE_IPV6
539	if (inet6 && flags & NETSTAT_TCP)
540		do_info(_PATH_PROCNET_TCP6, "AF INET6 (tcp)", tcp_do_one);
541#endif
542	if (inet && flags & NETSTAT_UDP)
543		do_info(_PATH_PROCNET_UDP, "AF INET (udp)", udp_do_one);
544#if ENABLE_FEATURE_IPV6
545	if (inet6 && flags & NETSTAT_UDP)
546		do_info(_PATH_PROCNET_UDP6, "AF INET6 (udp)", udp_do_one);
547#endif
548	if (inet && flags & NETSTAT_RAW)
549		do_info(_PATH_PROCNET_RAW, "AF INET (raw)", raw_do_one);
550#if ENABLE_FEATURE_IPV6
551	if (inet6 && flags & NETSTAT_RAW)
552		do_info(_PATH_PROCNET_RAW6, "AF INET6 (raw)", raw_do_one);
553#endif
554	if (flags & NETSTAT_UNIX) {
555		printf("Active UNIX domain sockets ");
556		if ((flags & (NETSTAT_LISTENING|NETSTAT_CONNECTED)) == (NETSTAT_LISTENING|NETSTAT_CONNECTED))
557			printf("(servers and established)");
558		else if (flags & NETSTAT_LISTENING)
559			printf("(only servers)");
560		else
561			printf("(w/o servers)");
562		printf("\nProto RefCnt Flags       Type       State         I-Node Path\n");
563		do_info(_PATH_PROCNET_UNIX, "AF UNIX", unix_do_one);
564	}
565	return 0;
566}
567