1 /* route.c - Display routing table.
2 *
3 * Copyright 2012 Ranjan Kumar <ranjankumar.bth@gmail.com>
4 * Copyright 2013 Kyungwan Han <asura321@gmail.com>
5 *
6 * No Standard
7 *
8 USE_ROUTE(NEWTOY(route, "?neA:", TOYFLAG_BIN))
9 config ROUTE
10 bool "route"
11 default n
12 help
13 usage: route -neA inet{6} / [{add|del}]
14
15 Display/Edit kernel routing tables.
16
17 -n Don't resolve names
18 -e Display other/more information
19 -A inet{6} Select Address Family
20 */
21
22 #define FOR_route
23 #include "toys.h"
24 #include <net/route.h>
25 #include <sys/param.h>
26
27 GLOBALS(
28 char *family;
29 )
30
31 #define DEFAULT_PREFIXLEN 128
32 #define INVALID_ADDR 0xffffffffUL
33 #define IPV6_ADDR_LEN 40 //32 + 7 (':') + 1 ('\0')
34
35 #define TEST_ARGV(argv) if (!*argv) show_route_help()
36
37 struct _arglist {
38 char *arg;
39 int action;
40 };
41
42 static struct _arglist arglist1[] = {
43 { "add", 1 }, { "del", 2 },
44 { "delete", 2 }, { NULL, 0 }
45 };
46
47 static struct _arglist arglist2[] = {
48 { "-net", 1 }, { "-host", 2 },
49 { NULL, 0 }
50 };
51
52 // display help info and exit.
show_route_help(void)53 static void show_route_help(void)
54 {
55 toys.exithelp = 1;
56 error_exit("Invalid Argument");
57 }
58
59 // to get the host name from the given ip.
get_hostname(char * ipstr,struct sockaddr_in * sockin)60 static int get_hostname(char *ipstr, struct sockaddr_in *sockin)
61 {
62 struct hostent *host;
63
64 sockin->sin_family = AF_INET;
65 sockin->sin_port = 0;
66
67 if (!strcmp(ipstr, "default")) {
68 sockin->sin_addr.s_addr = INADDR_ANY;
69 return 1;
70 }
71
72 if (inet_aton(ipstr, &sockin->sin_addr)) return 0;
73 if (!(host = gethostbyname(ipstr))) return -1;
74 memcpy(&sockin->sin_addr, host->h_addr_list[0], sizeof(struct in_addr));
75 return 0;
76 }
77
78 // used to extract the address info from the given ip.
get_addrinfo(char * ip,struct sockaddr_in6 * sock_in6)79 static int get_addrinfo(char *ip, struct sockaddr_in6 *sock_in6)
80 {
81 struct addrinfo hints, *result;
82 int status = 0;
83
84 memset(&hints, 0, sizeof(struct addrinfo));
85 hints.ai_family = AF_INET6;
86 if ((status = getaddrinfo(ip, NULL, &hints, &result))) {
87 perror_msg("getaddrinfo: %s", gai_strerror(status));
88 return -1;
89 }
90 if (result) {
91 memcpy(sock_in6, result->ai_addr, sizeof(*sock_in6));
92 freeaddrinfo(result);
93 }
94 return 0;
95 }
96
97 //get the flag values for route command.
get_flag_value(char * str,int flags)98 static void get_flag_value(char *str, int flags)
99 {
100 int i = 0;
101 static unsigned flagarray[] = {
102 RTF_GATEWAY, RTF_HOST, RTF_REINSTATE, RTF_DYNAMIC,
103 RTF_MODIFIED, RTF_DEFAULT, RTF_ADDRCONF, RTF_CACHE
104 };
105
106 *str++ = 'U';
107 while ((*str = "GHRDMDAC"[i]))
108 if (flags & flagarray[i++]) ++str;
109 }
110
111 // extract inet4 route info from /proc/net/route file and display it.
display_routes(void)112 static void display_routes(void)
113 {
114 unsigned long dest, gate, mask;
115 int flags, ref, use, metric, mss, win, irtt, items;
116 char iface[64] = {0,}, flag_val[10]; //there are 9 flags "UGHRDMDAC" for route.
117
118 FILE *fp = xfopen("/proc/net/route", "r");
119
120 xprintf("Kernel IP routing table\n"
121 "Destination Gateway Genmask Flags %s Iface\n",
122 (toys.optflags & FLAG_e)? " MSS Window irtt" : "Metric Ref Use");
123
124 if (fscanf(fp, "%*[^\n]\n") < 0) perror_exit("fscanf"); //skip 1st line
125 while ((items = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n", iface, &dest,
126 &gate, &flags, &ref, &use, &metric, &mask, &mss, &win, &irtt)) == 11) {
127
128 char *destip = toybuf, *gateip = toybuf+32, *maskip = toybuf+64; //ip string 16
129 memset(flag_val, 0, 10);
130
131 if (!(flags & RTF_UP)) continue; //skip down interfaces.
132
133 if (!dest && !(toys.optflags & FLAG_n)) strcpy( destip, "default");
134 else if (!inet_ntop(AF_INET, &dest, destip, 32)) perror_exit("inet");
135
136 if (!gate && !(toys.optflags & FLAG_n)) strcpy( gateip, "*");
137 else if (!inet_ntop(AF_INET, &gate, gateip, 32)) perror_exit("inet");
138
139 if (!inet_ntop(AF_INET, &mask, maskip, 32)) perror_exit("inet");
140
141 //Get flag Values
142 get_flag_value(flag_val, (flags & (RTF_GATEWAY|RTF_HOST|RTF_REINSTATE
143 |RTF_DYNAMIC|RTF_MODIFIED)));
144 if (flags & RTF_REJECT) flag_val[0] = '!';
145 xprintf("%-15.15s %-15.15s %-16s%-6s", destip, gateip, maskip, flag_val);
146 if (toys.optflags & FLAG_e) xprintf("%5d %-5d %6d %s\n", mss, win, irtt, iface);
147 else xprintf("%-6d %-2d %7d %s\n", metric, ref, use, iface);
148 }
149
150 if (items > 0 && feof(fp)) perror_exit("fscanf %d", items);
151 fclose(fp);
152 }
153
154
155 /*
156 * find the given parameter in list like add/del/net/host.
157 * and if match found return the appropriate action.
158 */
get_action(char *** argv,struct _arglist * list)159 static int get_action(char ***argv, struct _arglist *list)
160 {
161 struct _arglist *alist;
162
163 if (!**argv) return 0;
164 for (alist = list; alist->arg; alist++) { //find the given parameter in list
165 if (!strcmp(**argv, alist->arg)) {
166 *argv += 1;
167 return alist->action;
168 }
169 }
170 return 0;
171 }
172
173 /*
174 * get prefix len (if any) and remove the prefix from target ip.
175 * if no prefix then set netmask as default.
176 */
is_prefix(char ** tip,char ** netmask,struct rtentry * rt)177 static void is_prefix(char **tip, char **netmask, struct rtentry *rt)
178 {
179 char *prefix = strchr(*tip, '/');
180 if (prefix) {
181 unsigned long plen;
182 plen = atolx_range(prefix + 1, 0, 32);
183 //used to verify the netmask and route conflict.
184 (((struct sockaddr_in *)&((rt)->rt_genmask))->sin_addr.s_addr)
185 = htonl( ~(INVALID_ADDR >> plen));
186 *prefix = '\0';
187 rt->rt_genmask.sa_family = AF_INET;
188 } else *netmask = "default"; //default netmask.
189 }
190
191 /*
192 * used to get the params like: metric, netmask, gw, mss, window, irtt, dev and their values.
193 * additionally set the flag values for reject, mod, dyn and reinstate.
194 */
get_next_params(char ** argv,struct rtentry * rt,char ** netmask)195 static void get_next_params(char **argv, struct rtentry *rt, char **netmask)
196 {
197 while (*argv) {
198 //set the metric field in the routing table.
199 if (!strcmp(*argv, "metric")) {
200 argv++;
201 TEST_ARGV(argv);
202 rt->rt_metric = atolx_range(*argv, 0, ULONG_MAX) + 1;
203 argv++;
204 } else if (!strcmp(*argv, "netmask")) {
205 //when adding a network route, the netmask to be used.
206 struct sockaddr sock;
207 unsigned int addr_mask = (((struct sockaddr_in *)&((rt)->rt_genmask))->sin_addr.s_addr);
208 if (addr_mask) show_route_help();
209 argv++;
210 TEST_ARGV(argv);
211 *netmask = *argv;
212 if (get_hostname(*netmask, (struct sockaddr_in *) &sock) < 0)
213 perror_exit("resolving '%s'", *netmask);
214 rt->rt_genmask = sock;
215 argv++;
216 } else if (!strcmp(*argv, "gw")) {
217 //route packets via a gateway.
218 if (!(rt->rt_flags & RTF_GATEWAY)) {
219 int ishost;
220 argv++;
221 TEST_ARGV(argv);
222 if ((ishost = get_hostname(*argv, (struct sockaddr_in *) &rt->rt_gateway)) == 0) {
223 rt->rt_flags |= RTF_GATEWAY;
224 argv++;
225 } else if (ishost < 0) perror_exit("resolving '%s'", *argv);
226 else perror_exit("gateway '%s' is a NETWORK", *argv);
227 } else show_route_help();
228 } else if (!strcmp(*argv, "mss")) {
229 //set the TCP Maximum Segment Size for connections over this route.
230 argv++;
231 TEST_ARGV(argv);
232 rt->rt_mss = atolx_range(*argv, 64, 32768); //MSS low and max
233 rt->rt_flags |= RTF_MSS;
234 argv++;
235 } else if (!strcmp(*argv, "window")) {
236 //set the TCP window size for connections over this route to W bytes.
237 argv++;
238 TEST_ARGV(argv);
239 rt->rt_window = atolx_range(*argv, 128, INT_MAX); //win low
240 rt->rt_flags |= RTF_WINDOW;
241 argv++;
242 } else if (!strcmp(*argv, "irtt")) {
243 long nclock_ticks = sysconf(_SC_CLK_TCK); //number of clock ticks per second.
244 argv++;
245 TEST_ARGV(argv);
246 nclock_ticks /= 100;
247 rt->rt_irtt = strtoul(*argv, NULL, 10);
248 if (nclock_ticks > 0) rt->rt_irtt *= nclock_ticks;
249 rt->rt_flags |= 0x0100; //RTF_IRTT
250 argv++;
251 } else if (!strcmp(*argv, "dev")) {
252 argv++;
253 TEST_ARGV(argv);
254 if ((!rt->rt_dev)) rt->rt_dev = *argv;
255 argv++;
256 } else if (!strcmp(*argv, "reject")) {
257 rt->rt_flags |= RTF_REJECT;
258 argv++;
259 } else if (!strcmp(*argv, "mod")) {
260 rt->rt_flags |= RTF_MODIFIED;
261 argv++;
262 } else if (!strcmp(*argv, "dyn")) {
263 rt->rt_flags |= RTF_DYNAMIC;
264 argv++;
265 } else if (!strcmp(*argv, "reinstate")) {
266 rt->rt_flags |= RTF_REINSTATE;
267 argv++;
268 } else show_route_help(); //No match found; exit form the application.
269 }//end of while loop.
270
271 if (!rt->rt_dev && (rt->rt_flags & RTF_REJECT)) rt->rt_dev = (char *)"lo";
272 }
273
274 // verify the netmask and conflict in netmask and route address.
verify_netmask(struct rtentry * rt,char * netmask)275 static void verify_netmask(struct rtentry *rt, char *netmask)
276 {
277 unsigned int addr_mask = (((struct sockaddr_in *)&((rt)->rt_genmask))->sin_addr.s_addr);
278 unsigned int router_addr = ~(unsigned int)(((struct sockaddr_in *)&((rt)->rt_dst))->sin_addr.s_addr);
279
280 if (addr_mask) {
281 addr_mask = ~ntohl(addr_mask);
282 if ((rt->rt_flags & RTF_HOST) && addr_mask != INVALID_ADDR)
283 perror_exit("conflicting netmask and host route");
284 if (addr_mask & (addr_mask + 1)) perror_exit("wrong netmask '%s'", netmask);
285 addr_mask = ((struct sockaddr_in *) &rt->rt_dst)->sin_addr.s_addr;
286 if (addr_mask & router_addr) perror_exit("conflicting netmask and route address");
287 }
288 }
289
290 // add/del a route.
setroute(char ** argv)291 static void setroute(char **argv)
292 {
293 struct rtentry rt;
294 char *netmask = NULL, *targetip;
295 int is_net_or_host = 0, sokfd, arg2_action;
296 int action = get_action(&argv, arglist1); //verify the arg for add/del.
297
298 if (!action || !*argv) show_route_help();
299
300 arg2_action = get_action(&argv, arglist2); //verify the arg for -net or -host
301 if (!*argv) show_route_help();
302
303 memset(&rt, 0, sizeof(struct rtentry));
304 targetip = *argv++;
305
306 is_prefix((char **)&targetip, (char **)&netmask, &rt);
307 if ((is_net_or_host = get_hostname(targetip,
308 (struct sockaddr_in *) &rt.rt_dst)) < 0)
309 perror_exit("resolving '%s'", targetip);
310
311 if (arg2_action) is_net_or_host = arg2_action & 1;
312 rt.rt_flags = ((is_net_or_host) ? RTF_UP : (RTF_UP | RTF_HOST));
313
314 get_next_params(argv, &rt, (char **)&netmask);
315 verify_netmask(&rt, (char *)netmask);
316
317 if ((action == 1) && (rt.rt_flags & RTF_HOST))
318 (((struct sockaddr_in *)&((rt).rt_genmask))->sin_addr.s_addr) = INVALID_ADDR;
319
320 sokfd = xsocket(AF_INET, SOCK_DGRAM, 0);
321 if (action == 1) xioctl(sokfd, SIOCADDRT, &rt);
322 else xioctl(sokfd, SIOCDELRT, &rt);
323 xclose(sokfd);
324 }
325
326 /*
327 * get prefix len (if any) and remove the prefix from target ip.
328 * if no prefix then set default prefix len.
329 */
is_prefix_inet6(char ** tip,struct in6_rtmsg * rt)330 static void is_prefix_inet6(char **tip, struct in6_rtmsg *rt)
331 {
332 unsigned long plen;
333 char *prefix = strchr(*tip, '/');
334
335 if (prefix) {
336 *prefix = '\0';
337 plen = atolx_range(prefix + 1, 0, 128); //DEFAULT_PREFIXLEN);
338 } else plen = DEFAULT_PREFIXLEN;
339
340 rt->rtmsg_flags = (plen == DEFAULT_PREFIXLEN) ? (RTF_UP | RTF_HOST) : RTF_UP;
341 rt->rtmsg_dst_len = plen;
342 }
343
344 /*
345 * used to get the params like: metric, gw, dev and their values.
346 * additionally set the flag values for mod and dyn.
347 */
get_next_params_inet6(char ** argv,struct sockaddr_in6 * sock_in6,struct in6_rtmsg * rt,char ** dev_name)348 static void get_next_params_inet6(char **argv, struct sockaddr_in6 *sock_in6, struct in6_rtmsg *rt, char **dev_name)
349 {
350 while (*argv) {
351 if (!strcmp(*argv, "metric")) {
352 //set the metric field in the routing table.
353 argv++;
354 TEST_ARGV(argv);
355 rt->rtmsg_metric = atolx_range(*argv, 0, ULONG_MAX);
356 argv++;
357 } else if (!strcmp(*argv, "gw")) {
358 //route packets via a gateway.
359 if (!(rt->rtmsg_flags & RTF_GATEWAY)) {
360 argv++;
361 TEST_ARGV(argv);
362 if (!get_addrinfo(*argv, (struct sockaddr_in6 *) &sock_in6)) {
363 memcpy(&rt->rtmsg_gateway, sock_in6->sin6_addr.s6_addr, sizeof(struct in6_addr));
364 rt->rtmsg_flags |= RTF_GATEWAY;
365 argv++;
366 } else perror_exit("resolving '%s'", *argv);
367 } else show_route_help();
368 } else if (!strcmp(*argv, "dev")) {
369 argv++;
370 TEST_ARGV(argv);
371 if (!*dev_name) *dev_name = *argv;
372 argv++;
373 } else if (!strcmp(*argv, "mod")) {
374 rt->rtmsg_flags |= RTF_MODIFIED;
375 argv++;
376 } else if (!strcmp(*argv, "dyn")) {
377 rt->rtmsg_flags |= RTF_DYNAMIC;
378 argv++;
379 } else show_route_help();
380 }//end of while loop.
381 }
382
383 // add/del a route.
setroute_inet6(char ** argv)384 static void setroute_inet6(char **argv)
385 {
386 struct sockaddr_in6 sock_in6;
387 struct in6_rtmsg rt;
388 char *targetip;
389 int sockfd, action = get_action(&argv, arglist1);
390
391 if (!action || !*argv) show_route_help();
392 memset(&sock_in6, 0, sizeof(struct sockaddr_in6));
393 memset(&rt, 0, sizeof(struct in6_rtmsg));
394 targetip = *argv++;
395 if (*argv) {
396 unsigned long plen = 0;
397 char *dev_name = NULL;
398 if (!strcmp(targetip, "default")) {
399 rt.rtmsg_flags = RTF_UP;
400 rt.rtmsg_dst_len = plen;
401 } else {
402 is_prefix_inet6((char **)&targetip, &rt);
403 if (get_addrinfo(targetip, (struct sockaddr_in6 *) &sock_in6))
404 perror_exit("resolving '%s'", targetip);
405 }
406 rt.rtmsg_metric = 1; //default metric.
407 memcpy(&rt.rtmsg_dst, sock_in6.sin6_addr.s6_addr, sizeof(struct in6_addr));
408 get_next_params_inet6(argv, &sock_in6, &rt, (char **)&dev_name);
409
410 sockfd = xsocket(AF_INET6, SOCK_DGRAM, 0);
411 if (dev_name) {
412 char ifre_buf[sizeof(struct ifreq)] = {0,};
413 struct ifreq *ifre = (struct ifreq*)ifre_buf;
414 xstrncpy(ifre->ifr_name, dev_name, IFNAMSIZ);
415 xioctl(sockfd, SIOGIFINDEX, ifre);
416 rt.rtmsg_ifindex = ifre->ifr_ifindex;
417 }
418 if (action == 1) xioctl(sockfd, SIOCADDRT, &rt);
419 else xioctl(sockfd, SIOCDELRT, &rt);
420 xclose(sockfd);
421 } else show_route_help();
422 }
423
424 /*
425 * format the dest and src address in ipv6 format.
426 * e.g. 2002:6b6d:26c8:d:ea03:9aff:fe65:9d62
427 */
ipv6_addr_formating(char * ptr,char * addr)428 static void ipv6_addr_formating(char *ptr, char *addr)
429 {
430 int i = 0;
431 while (i <= IPV6_ADDR_LEN) {
432 if (!*ptr) {
433 if (i == IPV6_ADDR_LEN) {
434 addr[IPV6_ADDR_LEN - 1] = 0; //NULL terminating the ':' seperated address.
435 break;
436 }
437 error_exit("IPv6 ip format error");
438 }
439 addr[i++] = *ptr++;
440 if (!((i+1) % 5)) addr[i++] = ':'; //put ':' after 4th bit
441 }
442 }
443
display_routes6(void)444 static void display_routes6(void)
445 {
446 char iface[16] = {0,}, ipv6_dest_addr[41];
447 char ipv6_src_addr[41], flag_val[10], buf2[INET6_ADDRSTRLEN];
448 int prefixlen, metric, use, refcount, flag, items = 0;
449 unsigned char buf[sizeof(struct in6_addr)];
450
451 FILE *fp = xfopen("/proc/net/ipv6_route", "r");
452
453 xprintf("Kernel IPv6 routing table\n"
454 "%-43s%-40s Flags Metric Ref Use Iface\n", "Destination", "Next Hop");
455
456 while ((items = fscanf(fp, "%32s%x%*s%*x%32s%x%x%x%x%10s\n", ipv6_dest_addr+8,
457 &prefixlen, ipv6_src_addr+8, &metric, &use, &refcount, &flag,
458 iface)) == 8) {
459
460 memset(flag_val, 0, 10);
461
462 if (!(flag & RTF_UP)) continue; //skip down interfaces.
463
464 //ipv6_dest_addr+8: as the values are filled from the 8th location of the array.
465 ipv6_addr_formating(ipv6_dest_addr+8, ipv6_dest_addr);
466 ipv6_addr_formating(ipv6_src_addr+8, ipv6_src_addr);
467
468 get_flag_value(flag_val, (flag & (RTF_GATEWAY|RTF_HOST|RTF_DEFAULT|
469 RTF_ADDRCONF|RTF_CACHE)));
470 if (inet_pton(AF_INET6, ipv6_dest_addr, buf) <= 0) perror_exit("inet");
471 if (inet_ntop(AF_INET6, buf, buf2, INET6_ADDRSTRLEN)) {
472 sprintf(toybuf, "%s/%d", buf2, prefixlen);
473 }
474
475 if (inet_pton(AF_INET6, ipv6_src_addr, buf) <= 0) perror_exit("inet");
476 if (inet_ntop(AF_INET6, buf, buf2, INET6_ADDRSTRLEN)) {
477 xprintf("%-43s %-39s %-5s %-6d %-4d %5d %-8s\n",
478 toybuf, buf2, flag_val, metric, refcount, use, iface);
479 }
480 }
481 if ((items > 0) && feof(fp)) perror_exit("fscanf");
482
483 fclose(fp);
484 }
485
route_main(void)486 void route_main(void)
487 {
488 if (!(toys.optflags & FLAG_A)) TT.family = "inet";
489 if (!*toys.optargs) {
490 if (!strcmp(TT.family, "inet")) display_routes();
491 else if (!strcmp(TT.family, "inet6")) display_routes6();
492 else show_route_help();
493 return;
494 }//End of if statement.
495
496 if (!strcmp(TT.family, "inet6")) setroute_inet6(toys.optargs);
497 else setroute(toys.optargs);
498 }
499