1 /* netstat.c - Display Linux networking subsystem.
2 *
3 * Copyright 2012 Ranjan Kumar <ranjankumar.bth@gmail.com>
4 * Copyright 2013 Kyungwan Han <asura321@gmail.com>
5 *
6 * Not in SUSv4.
7 *
8 USE_NETSTAT(NEWTOY(netstat, "pWrxwutneal", TOYFLAG_BIN))
9 config NETSTAT
10 bool "netstat"
11 default y
12 help
13 usage: netstat [-pWrxwutneal]
14
15 Display networking information. Default is netsat -tuwx
16
17 -r routing table
18 -a all sockets (not just connected)
19 -l listening server sockets
20 -t TCP sockets
21 -u UDP sockets
22 -w raw sockets
23 -x unix sockets
24 -e extended info
25 -n don't resolve names
26 -W wide display
27 -p PID/Program name of sockets
28 */
29
30 #define FOR_netstat
31 #include "toys.h"
32 #include <net/route.h>
33
34 GLOBALS(
35 struct num_cache *inodes;
36 int wpad;
37 );
38
39 // convert address into text format.
addr2str(int af,void * addr,unsigned port,char * buf,int len,char * proto)40 static void addr2str(int af, void *addr, unsigned port, char *buf, int len,
41 char *proto)
42 {
43 int pos, count;
44 struct servent *ser = 0;
45
46 // Convert to numeric address
47 if (!inet_ntop(af, addr, buf, 256)) {
48 *buf = 0;
49
50 return;
51 }
52 buf[len] = 0;
53 pos = strlen(buf);
54
55 // If there's no port number, it's a local :* binding, nothing to look up.
56 if (!port) {
57 if (len-pos<2) pos = len-2;
58 strcpy(buf+pos, ":*");
59
60 return;
61 }
62
63 if (!(toys.optflags & FLAG_n)) {
64 struct addrinfo hints, *result, *rp;
65 char cut[4];
66
67 memset(&hints, 0, sizeof(struct addrinfo));
68 hints.ai_family = af;
69
70 if (!getaddrinfo(buf, NULL, &hints, &result)) {
71 socklen_t sock_len = (af == AF_INET) ? sizeof(struct sockaddr_in)
72 : sizeof(struct sockaddr_in6);
73
74 // We assume that a failing getnameinfo dosn't stomp "buf" here.
75 for (rp = result; rp; rp = rp->ai_next)
76 if (!getnameinfo(rp->ai_addr, sock_len, buf, 256, 0, 0, 0)) break;
77 freeaddrinfo(result);
78 buf[len] = 0;
79 pos = strlen(buf);
80 }
81
82 // Doesn't understand proto "tcp6", so truncate
83 memcpy(cut, proto, 3);
84 cut[3] = 0;
85 ser = getservbyport(htons(port), cut);
86 }
87
88 // Append :service
89 count = snprintf(0, 0, ":%u", port);
90 if (ser) {
91 count = snprintf(0, 0, ":%s", ser->s_name);
92 // sheer paranoia
93 if (count>=len) {
94 count = len-1;
95 ser->s_name[count] = 0;
96 }
97 }
98 if (len-pos<count) pos = len-count;
99 if (ser) sprintf(buf+pos, ":%s", ser->s_name);
100 else sprintf(buf+pos, ":%u", port);
101 }
102
103 // Display info for tcp/udp/raw
show_ip(char * fname)104 static void show_ip(char *fname)
105 {
106 char *ss_state = "UNKNOWN", buf[12], *s, *label = strrchr(fname, '/')+1;
107 char *state_label[] = {"", "ESTABLISHED", "SYN_SENT", "SYN_RECV", "FIN_WAIT1",
108 "FIN_WAIT2", "TIME_WAIT", "CLOSE", "CLOSE_WAIT",
109 "LAST_ACK", "LISTEN", "CLOSING", "UNKNOWN"};
110 struct passwd *pw;
111 FILE *fp = fopen(fname, "r");
112
113 if (!fp) {
114 perror_msg("'%s'", fname);
115 return;
116 }
117
118 if(!fgets(toybuf, sizeof(toybuf), fp)) return; //skip header.
119
120 while (fgets(toybuf, sizeof(toybuf), fp)) {
121 char lip[256], rip[256];
122 union {
123 struct {unsigned u; unsigned char b[4];} i4;
124 struct {struct {unsigned a, b, c, d;} u; unsigned char b[16];} i6;
125 } laddr, raddr;
126 unsigned lport, rport, state, txq, rxq, num, uid, nitems;
127 unsigned long inode;
128
129 // Try ipv6, then try ipv4
130 nitems = sscanf(toybuf,
131 " %d: %8x%8x%8x%8x:%x %8x%8x%8x%8x:%x %x %x:%x %*X:%*X %*X %d %*d %ld",
132 &num, &laddr.i6.u.a, &laddr.i6.u.b, &laddr.i6.u.c,
133 &laddr.i6.u.d, &lport, &raddr.i6.u.a, &raddr.i6.u.b,
134 &raddr.i6.u.c, &raddr.i6.u.d, &rport, &state, &txq, &rxq,
135 &uid, &inode);
136
137 if (nitems!=16) {
138 nitems = sscanf(toybuf,
139 " %d: %x:%x %x:%x %x %x:%x %*X:%*X %*X %d %*d %ld",
140 &num, &laddr.i4.u, &lport, &raddr.i4.u, &rport, &state, &txq,
141 &rxq, &uid, &inode);
142
143 if (nitems!=10) continue;
144 nitems = AF_INET;
145 } else nitems = AF_INET6;
146
147 // Should we display this? (listening or all or TCP/UDP/RAW)
148 if (!((toys.optflags & FLAG_l) && (!rport && (state & 0xA)))
149 && !(toys.optflags & FLAG_a) && !(rport & (0x10 | 0x20 | 0x40)))
150 continue;
151
152 addr2str(nitems, &laddr, lport, lip, TT.wpad, label);
153 addr2str(nitems, &raddr, rport, rip, TT.wpad, label);
154
155 // Display data
156 s = label;
157 if (strstart(&s, "tcp")) {
158 int sz = ARRAY_LEN(state_label);
159 if (!state || state >= sz) state = sz-1;
160 ss_state = state_label[state];
161 } else if (strstart(&s, "udp")) {
162 if (state == 1) ss_state = state_label[state];
163 else if (state == 7) ss_state = "";
164 } else if (strstart(&s, "raw")) sprintf(ss_state = buf, "%u", state);
165
166 if (!(toys.optflags & FLAG_n) && (pw = bufgetpwuid(uid)))
167 snprintf(toybuf, sizeof(toybuf), "%s", pw->pw_name);
168 else snprintf(toybuf, sizeof(toybuf), "%d", uid);
169
170 printf("%-6s%6d%7d ", label, rxq, txq);
171 printf("%*.*s %*.*s ", -TT.wpad, TT.wpad, lip, -TT.wpad, TT.wpad, rip);
172 printf("%-11s", ss_state);
173 if ((toys.optflags & FLAG_e)) printf(" %-10s %-11ld", toybuf, inode);
174 if ((toys.optflags & FLAG_p)) {
175 struct num_cache *nc = get_num_cache(TT.inodes, inode);
176
177 printf(" %s", nc ? nc->data : "-");
178 }
179 xputc('\n');
180 }
181 fclose(fp);
182 }
183
show_unix_sockets(void)184 static void show_unix_sockets(void)
185 {
186 char *types[] = {"","STREAM","DGRAM","RAW","RDM","SEQPACKET","DCCP","PACKET"},
187 *states[] = {"","LISTENING","CONNECTING","CONNECTED","DISCONNECTING"},
188 *s, *ss;
189 unsigned long refcount, flags, type, state, inode;
190 FILE *fp = xfopen("/proc/net/unix", "r");
191
192 if(!fgets(toybuf, sizeof(toybuf), fp)) return; //skip header.
193
194 while (fgets(toybuf, sizeof(toybuf), fp)) {
195 unsigned offset = 0;
196
197 // count = 6 or 7 (first field ignored, sockets don't always have filenames)
198 if (6<sscanf(toybuf, "%*p: %lX %*X %lX %lX %lX %lu %n",
199 &refcount, &flags, &type, &state, &inode, &offset))
200 continue;
201
202 // Linux exports only SO_ACCEPTCON since 2.3.15pre3 in 1999, but let's
203 // filter in case they add more someday.
204 flags &= 1<<16;
205
206 // Only show unconnected listening sockets with -a
207 if (state==1 && flags && !(toys.optflags&FLAG_a)) continue;
208
209 if (type==10) type = 7; // move SOCK_PACKET into line
210 if (type>ARRAY_LEN(types)) type = 0;
211 if (state>ARRAY_LEN(states) || (state==1 && !flags)) state = 0;
212 sprintf(toybuf, "[ %s]", flags ? "ACC " : "");
213
214 printf("unix %-6ld %-11s %-10s %-13s %8lu ",
215 refcount, toybuf, types[type], states[state], inode);
216 if (toys.optflags & FLAG_p) {
217 struct num_cache *nc = get_num_cache(TT.inodes, inode);
218
219 printf("%-19.19s", nc ? nc->data : "-");
220 }
221
222 if (offset) {
223 if ((ss = strrchr(s = toybuf+offset, '\n'))) *ss = 0;
224 printf("%s", s);
225 }
226 xputc('\n');
227 }
228
229 fclose(fp);
230 }
231
scan_pids(struct dirtree * node)232 static int scan_pids(struct dirtree *node)
233 {
234 char *s = toybuf+256;
235 struct dirent *entry;
236 DIR *dp;
237 int pid, dirfd;
238
239 if (!node->parent) return DIRTREE_RECURSE;
240 if (!(pid = atol(node->name))) return 0;
241
242 sprintf(toybuf, "/proc/%d/cmdline", pid);
243 if (!(readfile(toybuf, toybuf, 256))) return 0;
244
245 sprintf(s, "%d/fd", pid);
246 if (-1==(dirfd = openat(dirtree_parentfd(node), s, O_RDONLY))) return 0;
247 if (!(dp = fdopendir(dirfd))) {
248 close(dirfd);
249
250 return 0;
251 }
252
253 while ((entry = readdir(dp))) {
254 s = toybuf+256;
255 if (!readlinkat0(dirfd, entry->d_name, s, sizeof(toybuf)-256)) continue;
256 // Can the "[0000]:" happen in a modern kernel?
257 if (strstart(&s, "socket:[") || strstart(&s, "[0000]:")) {
258 long long ll = atoll(s);
259
260 sprintf(s, "%d/%s", pid, getbasename(toybuf));
261 add_num_cache(&TT.inodes, ll, s, strlen(s)+1);
262 }
263 }
264 closedir(dp);
265
266 return 0;
267 }
268
269 /*
270 * extract inet4 route info from /proc/net/route file and display it.
271 */
display_routes(void)272 static void display_routes(void)
273 {
274 static const char flagchars[] = "GHRDMDAC";
275 static const unsigned flagarray[] = {
276 RTF_GATEWAY, RTF_HOST, RTF_REINSTATE, RTF_DYNAMIC, RTF_MODIFIED
277 };
278 unsigned long dest, gate, mask;
279 int flags, ref, use, metric, mss, win, irtt;
280 char *out = toybuf, *flag_val;
281 char iface[64]={0};
282 FILE *fp = xfopen("/proc/net/route", "r");
283
284 if(!fgets(toybuf, sizeof(toybuf), fp)) return; //skip header.
285
286 printf("Kernel IP routing table\n"
287 "Destination\tGateway \tGenmask \tFlags %s Iface\n",
288 !(toys.optflags&FLAG_e) ? " MSS Window irtt" : "Metric Ref Use");
289
290 while (fgets(toybuf, sizeof(toybuf), fp)) {
291 char *destip = 0, *gateip = 0, *maskip = 0;
292
293 if (11 != sscanf(toybuf, "%63s%lx%lx%X%d%d%d%lx%d%d%d", iface, &dest,
294 &gate, &flags, &ref, &use, &metric, &mask, &mss, &win, &irtt))
295 break;
296
297 // skip down interfaces.
298 if (!(flags & RTF_UP)) continue;
299
300 // TODO /proc/net/ipv6_route
301
302 if (dest) {
303 if (inet_ntop(AF_INET, &dest, out, 16)) destip = out;
304 } else destip = (toys.optflags&FLAG_n) ? "0.0.0.0" : "default";
305 out += 16;
306
307 if (gate) {
308 if (inet_ntop(AF_INET, &gate, out, 16)) gateip = out;
309 } else gateip = (toys.optflags&FLAG_n) ? "0.0.0.0" : "*";
310 out += 16;
311
312 // TODO /24
313 //For Mask
314 if (inet_ntop(AF_INET, &mask, out, 16)) maskip = out;
315 else maskip = "?";
316 out += 16;
317
318 //Get flag Values
319 flag_val = out;
320 *out++ = 'U';
321 for (dest = 0; dest < ARRAY_LEN(flagarray); dest++)
322 if (flags&flagarray[dest]) *out++ = flagchars[dest];
323 *out = 0;
324 if (flags & RTF_REJECT) *flag_val = '!';
325
326 printf("%-15.15s %-15.15s %-16s%-6s", destip, gateip, maskip, flag_val);
327 if (!(toys.optflags & FLAG_e))
328 printf("%5d %-5d %6d %s\n", mss, win, irtt, iface);
329 else printf("%-6d %-2d %7d %s\n", metric, ref, use, iface);
330 }
331
332 fclose(fp);
333 }
334
netstat_main(void)335 void netstat_main(void)
336 {
337 int tuwx = FLAG_t|FLAG_u|FLAG_w|FLAG_x;
338 char *type = "w/o";
339
340 TT.wpad = (toys.optflags&FLAG_W) ? 51 : 23;
341 if (!(toys.optflags&(FLAG_r|tuwx))) toys.optflags |= tuwx;
342 if (toys.optflags & FLAG_r) display_routes();
343 if (!(toys.optflags&tuwx)) return;
344
345 if (toys.optflags & FLAG_a) type = "established and";
346 else if (toys.optflags & FLAG_l) type = "only";
347
348 if (toys.optflags & FLAG_p) dirtree_read("/proc", scan_pids);
349
350 if (toys.optflags&(FLAG_t|FLAG_u|FLAG_w)) {
351 printf("Active %s (%s servers)\n", "Internet connections", type);
352 printf("Proto Recv-Q Send-Q %*s %*s State ", -TT.wpad, "Local Address",
353 -TT.wpad, "Foreign Address");
354 if (toys.optflags & FLAG_e) printf(" User Inode ");
355 if (toys.optflags & FLAG_p) printf(" PID/Program Name");
356 xputc('\n');
357
358 if (toys.optflags & FLAG_t) {
359 show_ip("/proc/net/tcp");
360 show_ip("/proc/net/tcp6");
361 }
362 if (toys.optflags & FLAG_u) {
363 show_ip("/proc/net/udp");
364 show_ip("/proc/net/udp6");
365 }
366 if (toys.optflags & FLAG_w) {
367 show_ip("/proc/net/raw");
368 show_ip("/proc/net/raw6");
369 }
370 }
371
372 if (toys.optflags & FLAG_x) {
373 printf("Active %s (%s servers)\n", "UNIX domain sockets", type);
374
375 printf("Proto RefCnt Flags\t Type\t State\t %s Path\n",
376 (toys.optflags&FLAG_p) ? "PID/Program Name" : "I-Node");
377 show_unix_sockets();
378 }
379
380 if ((toys.optflags & FLAG_p) && CFG_TOYBOX_FREE)
381 llist_traverse(TT.inodes, free);
382 toys.exitval = 0;
383 }
384