1 /*
2 * route-linux.c
3 *
4 * Copyright (c) 2000 Dug Song <dugsong@monkey.org>
5 *
6 * $Id: route-linux.c 619 2006-01-15 07:33:29Z dugsong $
7 */
8
9 #include "config.h"
10
11 #include <sys/types.h>
12 #include <sys/ioctl.h>
13 #include <sys/socket.h>
14 #include <sys/uio.h>
15
16 #include <asm/types.h>
17 #include <net/if.h>
18 #include <netinet/in.h>
19 #include <linux/netlink.h>
20 #include <linux/rtnetlink.h>
21
22 #include <net/route.h>
23
24 #include <ctype.h>
25 #include <errno.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30
31 #include "dnet.h"
32
33 #define ADDR_ISHOST(a) (((a)->addr_type == ADDR_TYPE_IP && \
34 (a)->addr_bits == IP_ADDR_BITS) || \
35 ((a)->addr_type == ADDR_TYPE_IP6 && \
36 (a)->addr_bits == IP6_ADDR_BITS))
37
38 #define PROC_ROUTE_FILE "/proc/net/route"
39 #define PROC_IPV6_ROUTE_FILE "/proc/net/ipv6_route"
40
41 struct route_handle {
42 int fd;
43 int nlfd;
44 };
45
46 route_t *
route_open(void)47 route_open(void)
48 {
49 struct sockaddr_nl snl;
50 route_t *r;
51
52 if ((r = calloc(1, sizeof(*r))) != NULL) {
53 r->fd = r->nlfd = -1;
54
55 if ((r->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
56 return (route_close(r));
57
58 if ((r->nlfd = socket(AF_NETLINK, SOCK_RAW,
59 NETLINK_ROUTE)) < 0)
60 return (route_close(r));
61
62 memset(&snl, 0, sizeof(snl));
63 snl.nl_family = AF_NETLINK;
64
65 if (bind(r->nlfd, (struct sockaddr *)&snl, sizeof(snl)) < 0)
66 return (route_close(r));
67 }
68 return (r);
69 }
70
71 int
route_add(route_t * r,const struct route_entry * entry)72 route_add(route_t *r, const struct route_entry *entry)
73 {
74 struct rtentry rt;
75 struct addr dst;
76
77 memset(&rt, 0, sizeof(rt));
78 rt.rt_flags = RTF_UP | RTF_GATEWAY;
79
80 if (ADDR_ISHOST(&entry->route_dst)) {
81 rt.rt_flags |= RTF_HOST;
82 memcpy(&dst, &entry->route_dst, sizeof(dst));
83 } else
84 addr_net(&entry->route_dst, &dst);
85
86 if (addr_ntos(&dst, &rt.rt_dst) < 0 ||
87 addr_ntos(&entry->route_gw, &rt.rt_gateway) < 0 ||
88 addr_btos(entry->route_dst.addr_bits, &rt.rt_genmask) < 0)
89 return (-1);
90
91 return (ioctl(r->fd, SIOCADDRT, &rt));
92 }
93
94 int
route_delete(route_t * r,const struct route_entry * entry)95 route_delete(route_t *r, const struct route_entry *entry)
96 {
97 struct rtentry rt;
98 struct addr dst;
99
100 memset(&rt, 0, sizeof(rt));
101 rt.rt_flags = RTF_UP;
102
103 if (ADDR_ISHOST(&entry->route_dst)) {
104 rt.rt_flags |= RTF_HOST;
105 memcpy(&dst, &entry->route_dst, sizeof(dst));
106 } else
107 addr_net(&entry->route_dst, &dst);
108
109 if (addr_ntos(&dst, &rt.rt_dst) < 0 ||
110 addr_btos(entry->route_dst.addr_bits, &rt.rt_genmask) < 0)
111 return (-1);
112
113 return (ioctl(r->fd, SIOCDELRT, &rt));
114 }
115
116 int
route_get(route_t * r,struct route_entry * entry)117 route_get(route_t *r, struct route_entry *entry)
118 {
119 static int seq;
120 struct nlmsghdr *nmsg;
121 struct rtmsg *rmsg;
122 struct rtattr *rta;
123 struct sockaddr_nl snl;
124 struct iovec iov;
125 struct msghdr msg;
126 u_char buf[512];
127 int i, af, alen;
128
129 switch (entry->route_dst.addr_type) {
130 case ADDR_TYPE_IP:
131 af = AF_INET;
132 alen = IP_ADDR_LEN;
133 break;
134 case ADDR_TYPE_IP6:
135 af = AF_INET6;
136 alen = IP6_ADDR_LEN;
137 break;
138 default:
139 errno = EINVAL;
140 return (-1);
141 }
142 memset(buf, 0, sizeof(buf));
143
144 nmsg = (struct nlmsghdr *)buf;
145 nmsg->nlmsg_len = NLMSG_LENGTH(sizeof(*nmsg)) + RTA_LENGTH(alen);
146 nmsg->nlmsg_flags = NLM_F_REQUEST;
147 nmsg->nlmsg_type = RTM_GETROUTE;
148 nmsg->nlmsg_seq = ++seq;
149
150 rmsg = (struct rtmsg *)(nmsg + 1);
151 rmsg->rtm_family = af;
152 rmsg->rtm_dst_len = entry->route_dst.addr_bits;
153
154 rta = RTM_RTA(rmsg);
155 rta->rta_type = RTA_DST;
156 rta->rta_len = RTA_LENGTH(alen);
157
158 /* XXX - gross hack for default route */
159 if (af == AF_INET && entry->route_dst.addr_ip == IP_ADDR_ANY) {
160 i = htonl(0x60060606);
161 memcpy(RTA_DATA(rta), &i, alen);
162 } else
163 memcpy(RTA_DATA(rta), entry->route_dst.addr_data8, alen);
164
165 memset(&snl, 0, sizeof(snl));
166 snl.nl_family = AF_NETLINK;
167
168 iov.iov_base = nmsg;
169 iov.iov_len = nmsg->nlmsg_len;
170
171 memset(&msg, 0, sizeof(msg));
172 msg.msg_name = &snl;
173 msg.msg_namelen = sizeof(snl);
174 msg.msg_iov = &iov;
175 msg.msg_iovlen = 1;
176
177 if (sendmsg(r->nlfd, &msg, 0) < 0)
178 return (-1);
179
180 iov.iov_base = buf;
181 iov.iov_len = sizeof(buf);
182
183 if ((i = recvmsg(r->nlfd, &msg, 0)) <= 0)
184 return (-1);
185
186 if (nmsg->nlmsg_len < (int)sizeof(*nmsg) || nmsg->nlmsg_len > i ||
187 nmsg->nlmsg_seq != seq) {
188 errno = EINVAL;
189 return (-1);
190 }
191 if (nmsg->nlmsg_type == NLMSG_ERROR)
192 return (-1);
193
194 i -= NLMSG_LENGTH(sizeof(*nmsg));
195
196 entry->route_gw.addr_type = ADDR_TYPE_NONE;
197 entry->intf_name[0] = '\0';
198 for (rta = RTM_RTA(rmsg); RTA_OK(rta, i); rta = RTA_NEXT(rta, i)) {
199 if (rta->rta_type == RTA_GATEWAY) {
200 entry->route_gw.addr_type = entry->route_dst.addr_type;
201 memcpy(entry->route_gw.addr_data8, RTA_DATA(rta), alen);
202 entry->route_gw.addr_bits = alen * 8;
203 } else if (rta->rta_type == RTA_OIF) {
204 char ifbuf[IFNAMSIZ];
205 char *p;
206 int intf_index;
207
208 intf_index = *(int *) RTA_DATA(rta);
209 p = if_indextoname(intf_index, ifbuf);
210 if (p == NULL)
211 return (-1);
212 strlcpy(entry->intf_name, ifbuf, sizeof(entry->intf_name));
213 }
214 }
215 if (entry->route_gw.addr_type == ADDR_TYPE_NONE) {
216 errno = ESRCH;
217 return (-1);
218 }
219
220 return (0);
221 }
222
223 int
route_loop(route_t * r,route_handler callback,void * arg)224 route_loop(route_t *r, route_handler callback, void *arg)
225 {
226 FILE *fp;
227 struct route_entry entry;
228 char buf[BUFSIZ];
229 char ifbuf[16];
230 int ret = 0;
231
232 if ((fp = fopen(PROC_ROUTE_FILE, "r")) != NULL) {
233 int i, iflags, refcnt, use, metric, mss, win, irtt;
234 uint32_t mask;
235
236 while (fgets(buf, sizeof(buf), fp) != NULL) {
237 i = sscanf(buf, "%15s %X %X %X %d %d %d %X %d %d %d\n",
238 ifbuf, &entry.route_dst.addr_ip,
239 &entry.route_gw.addr_ip, &iflags, &refcnt, &use,
240 &metric, &mask, &mss, &win, &irtt);
241
242 if (i < 11 || !(iflags & RTF_UP))
243 continue;
244
245 strlcpy(entry.intf_name, ifbuf, sizeof(entry.intf_name));
246
247 entry.route_dst.addr_type = entry.route_gw.addr_type =
248 ADDR_TYPE_IP;
249
250 if (addr_mtob(&mask, IP_ADDR_LEN,
251 &entry.route_dst.addr_bits) < 0)
252 continue;
253
254 entry.route_gw.addr_bits = IP_ADDR_BITS;
255 entry.metric = metric;
256
257 if ((ret = callback(&entry, arg)) != 0)
258 break;
259 }
260 fclose(fp);
261 }
262 if (ret == 0 && (fp = fopen(PROC_IPV6_ROUTE_FILE, "r")) != NULL) {
263 char s[33], d[8][5], n[8][5];
264 int i, iflags, metric;
265 u_int slen, dlen;
266
267 while (fgets(buf, sizeof(buf), fp) != NULL) {
268 i = sscanf(buf, "%04s%04s%04s%04s%04s%04s%04s%04s %02x "
269 "%32s %02x %04s%04s%04s%04s%04s%04s%04s%04s "
270 "%x %*x %*x %x %15s",
271 d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
272 &dlen, s, &slen,
273 n[0], n[1], n[2], n[3], n[4], n[5], n[6], n[7],
274 &metric, &iflags, ifbuf);
275
276 if (i < 21 || !(iflags & RTF_UP))
277 continue;
278
279 strlcpy(entry.intf_name, ifbuf, sizeof(entry.intf_name));
280
281 snprintf(buf, sizeof(buf), "%s:%s:%s:%s:%s:%s:%s:%s/%d",
282 d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
283 dlen);
284 addr_aton(buf, &entry.route_dst);
285 snprintf(buf, sizeof(buf), "%s:%s:%s:%s:%s:%s:%s:%s/%d",
286 n[0], n[1], n[2], n[3], n[4], n[5], n[6], n[7],
287 IP6_ADDR_BITS);
288 addr_aton(buf, &entry.route_gw);
289 entry.metric = metric;
290
291 if ((ret = callback(&entry, arg)) != 0)
292 break;
293 }
294 fclose(fp);
295 }
296 return (ret);
297 }
298
299 route_t *
route_close(route_t * r)300 route_close(route_t *r)
301 {
302 if (r != NULL) {
303 if (r->fd >= 0)
304 close(r->fd);
305 if (r->nlfd >= 0)
306 close(r->nlfd);
307 free(r);
308 }
309 return (NULL);
310 }
311